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= June 19 =
== ArrowrootFlour==
= December 24 =
== Unknown species of insect ==
I have ground arrowroot and I have flour - in what ratio do I mix these to make 'arrowroot flour'? --[[User:Username132|Username132]] ([[User talk:Username132|talk]]) 02:32, 19 June 2006 (UTC)
Am I correct in inferring that [[File:Anomala orientalis on window screen.jpg|150px]] this guy is an [[oriental beetle]]? I was off-put by the green head at first, but the antennae seem to match. '''[[User:JayCubby|<span style="background:#0a0e33;color:white;padding:2px;">Jay</span>]][[User talk:JayCubby|<span style="background:#1a237e;color:white;padding:2px;">Cubby</span>]]''' 03:00, 24 December 2024 (UTC)
:Um, I think "arrowroot flour" simply means flour made from arrowroot, not arrowroot mixed with wheat or whatever. So I'd say 100:0. Depends what you want to use it for, though. —[[User:Keenan Pepper|Keenan Pepper]] 03:08, 19 June 2006 (UTC)
:Keep in mind that what is sold in the store as "arrowroot flour" is often not real [[arrowroot]] (see note in that article). [[User:128.197.81.181|128.197.81.181]] 18:41, 19 June 2006 (UTC)
== Is the Wikipedia being censored by the academic guild? ==
:<s>It looks like one of the invasive [[Japanese beetle]]s that happens to like my blackberries in the summer.</s> [[User:Modocc|Modocc]] ([[User talk:Modocc|talk]]) 13:11, 24 December 2024 (UTC)
This may seem like a rare problem but I have noticed that some scientific and technical articles are being edited to '''''prevent''''' other users from obtaining a complete and full comprehension of a topic in the same manner as a member of a trade or artisan guild might try to hide techniques or methods or understanding of what the topic actually involves. Such articles are only permitted to have a highly technical version or explanation of the process being presented in the same manner as a tradesman or artisan might withhold simple explanations from a patron for the sole purpose of mystifying the topic and keeping the patron from knowing “too much.” What is the Wikipedia policy on such behavior where simple and accurate explanations are continuously deleted from an article on the false pretense that the article is not about the example although the example fully clarifies the topic? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 04:36, 19 June 2006 (UTC)
:Examples?
::Yes, I'd like to see an example too. Of course there's a lot of information difficult for "outsiders" to understand in the 'pedia, but generally it's because of the persons lack of concern for readers with a very low level of understanding. Nothing of what I have seen suggests censorship. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 04:59, 19 June 2006 (UTC)
::I would say not necessarily a Japanese beetle, but almost certainly one of the other [[Scarabaeidae|Scarab]] beetles, though with 35,000 species that doesn't help a lot. Looking at the infobox illustration in that article, 16. & 17., "[[Anisoplia segetum]]" looks very similar, but evidently we either don't have an article or (if our [[Anisoplia]] article is a complete list) it's been renamed. {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.1.223.204|94.1.223.204]] ([[User talk:94.1.223.204|talk]]) 14:18, 24 December 2024 (UTC)
:::I would hope not but then suppose all sysops were also members of the telecom brotherhood or union and certain accurate but simplified technical disclosures were routinely deleted? Would this not make you a bit suspicous? As for examples. Put the [[Half-life]] article on your watch list and see over a period of time what conclusion you might reach. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 05:23, 19 June 2006 (UTC)
:::Yes, it's not the Japanese beetle for this beetle appears to lack its white-dotted fringe although its condition is deteriorated. Its shape is also more or less more slender; and not as round. [[User:Modocc|Modocc]] ([[User talk:Modocc|talk]]) 15:02, 24 December 2024 (UTC)
::::I'd say sometimes the medical articles are written in unnecessarily technical language. But I think this is just health professionals failing to consider their audience when writing here rather than a deliberate attempt to obscure. See [http://www.jargon.net/jargonfile/h/HanlonsRazor.html Hanlon's Razor]. There's also the fact that writing both accessibly and accurately about technical is a very difficult skill.
:Perhaps it is the [[shining leaf chafer]] [[Strigoderma pimalis]]. Shown [https://bugguide.net/node/view/224249 here]. [[User:Modocc|Modocc]] ([[User talk:Modocc|talk]]) 16:09, 24 December 2024 (UTC)
:::::I understand the difficulty for any individual to step far enough away from the field of expertise to see it clearly form a layman's pov but that is why we participate in the Wikipedia in the first place. My concern is that when such experts guard an article with such jealously that any user who is able to bridge the gap between the experts and the layman is prevented from adding simple but accurate explanations. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 06:30, 19 June 2006 (UTC)
::That looks like easily the best match I've seen so far, and likely correct. {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.1.223.204|94.1.223.204]] ([[User talk:94.1.223.204|talk]]) 17:09, 24 December 2024 (UTC)
= December 25 =
::::I do think there's scope for stronger attention to be paid to [[Wikipedia:Explain jargon]].--[[User:Robert Merkel|Robert Merkel]] 05:31, 19 June 2006 (UTC)
== Mass of oscillating neutrino ==
:::::In this regard you must unfortunately include mathematical symbols and representations which more often than not require examples of computer code and data in order that the '''''jargon''''' be explained. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 06:33, 19 June 2006 (UTC)
From the [[Mass in special relativity|conservation of energy and momentum]] it follows that a particle that is not subject to external forces must have constancy of mass.
::::Perhaps we don't want to sit around and watch the [[half-life]] article—did you choose this article as a pun? Why don't you find an example of an edit that removed factually accurate information that made the article harder to understand? My guess would be that incorrect analogies are removed from articles by people who have a definite understanding of the material and that you are simply paranoid. Also, just because a statement is understandable doesn't mean it is true. —[[User:BradleyEE|Bradley]] 23:16, 19 June 2006 (UTC)
If I am right, this means that the mass of the neutrino cannot change during the [[neutrino oscillation]], although its flavoring may. Is this written down somewhere? Thank you. [[User:Hevesli|Hevesli]] ([[User talk:Hevesli|talk]]) 19:24, 25 December 2024 (UTC)
:To have coordinated censorship you'd need coordination among academics in the first place. Which generally does not exist. But as a form of systemic bias, I think it is true that sometimes certain lesser-known topics get monopolized by those who know a lot about them but are not good at explaining it. The better known a topic is, the less likely this can last for long. But there are some articles which reflect a total lack of consideration for the layman (even something as non-technical and narrative-based as our biography of [[Franz Boas]], which is about 3X too long, suffers from this). --[[User:Fastfission|Fastfission]] 13:54, 19 June 2006 (UTC)
:Any (flavored) neutrino that is really observed is a superposition of two or three mass eigenstates. This is actually the cause of [[neutrino oscillations]]. So, the answer to your question is complicated. [[User:Ruslik0|Ruslik]]_[[User Talk:Ruslik0|<span style="color:red">Zero</span>]] 19:40, 25 December 2024 (UTC)
:Important note: particle physicists today generally only ever use "mass" to mean "[[invariant mass]]" and never anything else: [https://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/more-on-mass/the-two-definitions-of-mass-and-why-i-use-only-one/]. Like the term says, invariant mass is well, invariant, it never changes ever, no matter what "external forces" may or may not be involved. Being proper particle-icans and following the standard practice in the field, then, the three neutrino masses are constant values. ..."Wait, three?" Yeah sure, turns out [[neutrino flavor|neutrinos come in three "flavors" but each flavor is a mixture of the three possible mass "states"]]. As mentioned, due to Quantum Weirdness we aren't able to get these different states "alone by themselves" to measure each by itself, so we only know the differences of the squares of the masses. Yeah welcome to quantum mechanics.
:[[Richard Feynman]]: "Quantum mechanics describes nature as absurd from the point of view of common sense. And yet it fully agrees with experiment. So I hope you can accept nature as She is {{snd}} absurd." --[[User:Slowking Man|Slowking Man]] ([[User talk:Slowking Man|talk]]) 06:06, 26 December 2024 (UTC)
::The equation <math>E^2 = (p c)^2 + \left(m_0 c^2\right)^2</math> uses invariant mass {{math|''m''<sub>0</sub>}} which is constant if {{math|''E''}} and {{math|''p''}} are constant. The traveling neutrino has a varying mass mixture of different flavors with different masses. If a mixture of different masses changes, you would expect the resulting mass to change with it. But somehow this does not happen as the neutrino mass mixture changes. These mixture changes cannot be any changes. The changes must be such that the resulting mass of the traveling neutrino remains constant. My question is whether this is described somewhere. [[User:Hevesli|Hevesli]] ([[User talk:Hevesli|talk]]) 11:16, 26 December 2024 (UTC)
:::I freely confess I'm uncertain exactly what's being "asked for" or "gotten at" here. Have you looked at the [[neutrino oscillation]] article? From it: {{tpq|That is, the three neutrino states that interact with the charged leptons in [[weak interaction]]s are each a different [[superposition]] of the three (propagating) neutrino states of definite mass. Neutrinos are emitted and absorbed in weak processes in flavor [[eigenstate]]s[a] '''but travel as mass eigenstates.'''[18]}}
:::What is it that we're "doing" with the [[energy–momentum relation]] here? For the neutrino, we don't have a single value of "mass" to plug in for <math>m_0</math>, because we can't "see" the individual mass eigenstates, only some [[linear combination]] of them. What you want for describing neutrino interactions is [[quantum field theory]], which is special relativity + QM. (Remember, relativity is a "classical" theory, which presumes everything always has single well-defined values of everything. Which isn't true in quantum-world.) --[[User:Slowking Man|Slowking Man]] ([[User talk:Slowking Man|talk]]) 18:41, 26 December 2024 (UTC)
::::Not all potential evolutions of a linear combination of unequal values produce constant results. Constancy can only be guaranteed by a constraint on the evolutions. Does the fact that this constraint is satisfied in the case of neutrino oscillation follow from the [[mathematical formulation of the Standard Model]], or does this formulation allow evolutions of the mass mixture for which the combination is not constant? If the unequal values are unknown, I have no idea of how such a constraint might be formulated. I think the OP is asking whether this constraint is described somewhere. --[[User talk:Lambiam#top|Lambiam]] 00:51, 27 December 2024 (UTC)
::::::I think that in many cases, the technical jargon is used because it saves time--it describes something specific in a way that is easily recognized by people in the field, while using a minimum amount of language. The challenge for Wikipedia, or any widely-used reference source, is how satisfy both "expert" users as well as the public at large. Experts don't want to plod through simplified explanations of what they already know; novices don't want to be frustrated by language they don't understand.
= December 27 =
::::::Going back to your question, I believe that there's a policy or guideline or something about how Wikipedia editors should not act as if they "own" a given article. Wikipedia is about reaching [[Wikipedia:Consensus|consensus]] and allowing many people to do their bit towards improving an article. --[[User:Tachikoma|Tachikoma]] 14:06, 19 June 2006 (UTC)
== Low-intensity exercise ==
:::::::The problem with reaching consensus is that there is a small group of committed academics who jealously guards some articles, immediately removing any attempt to make them accessible to the general public (which, while far more numerous, lacks the same level of commitment and is thus easily scared off by such actions). The only way I was able to find around this problem was to create a separate article for laymen. For example, the article [[Boolean algebra]] suffered from this problem, so I created the simplified version as [[Boolean logic]], and added dabs at the top of each, pointing to the other. [[User:StuRat|StuRat]] 17:11, 19 June 2006 (UTC)
If you exercise at a low intensity for an extended period of time, does the [[runner's high]] still occur if you do it for long enough? Or does it only occur above a certain threshold intensity of exercise? [[Special:Contributions/2601:646:8082:BA0:CDFF:17F5:371:402F|2601:646:8082:BA0:CDFF:17F5:371:402F]] ([[User talk:2601:646:8082:BA0:CDFF:17F5:371:402F|talk]]) 20:13, 27 December 2024 (UTC)
::::::::Yes this possible solution occurred to me as well so I did the same thing and avoided even the temptation of putting a link to the new article in the existing article's "See also" section. Perhaps this way the new article will not be found and deleted before it has gained a few edits from other users who can help fight those who are unsympathetic with the needs of the layman and sometimes experts alike The real scare is that the person standing guard over the article I am concerned about has a false concept of the subject matter. Perhaps it is just as well that a new article be created to give everyone an opportunity to know the truth about the topic. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 19:43, 19 June 2006 (UTC)
:Hows about you try it and report back? :) ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 21:31, 27 December 2024 (UTC)
::I wanted to try it just today, but I had to exchange the under-desk [[elliptical trainer]] I got for Christmas for a different model with more inclined treadles because with the one I got, my knees would hit the desk at the top of every cycle. Anyway, I was hoping someone else tried it first (preferably as part of a formal scientific study) so I would know if I could control whether I got a runner's high from exercise or not? [[Special:Contributions/2601:646:8082:BA0:9052:E6AF:23C7:7CAF|2601:646:8082:BA0:9052:E6AF:23C7:7CAF]] ([[User talk:2601:646:8082:BA0:9052:E6AF:23C7:7CAF|talk]]) 03:09, 28 December 2024 (UTC)
Also, sorry for adding to my own question, but here's a related one: is it known whether the length of a person's [[dopamine receptor D4]] (which is inversely correlated with its sensitivity) influences whether said person gets a runner's high from exercise (and especially from low-intensity exercise)? [[Special:Contributions/2601:646:8082:BA0:9052:E6AF:23C7:7CAF|2601:646:8082:BA0:9052:E6AF:23C7:7CAF]] ([[User talk:2601:646:8082:BA0:9052:E6AF:23C7:7CAF|talk]]) 03:14, 28 December 2024 (UTC)
== [[fastidious organism]] vs [[auxotroph]] ==
:<small>←dragging discussion back a few indents←</small>
:Please, please, ''please'' don't just create your own [[Wikipedia:Content forking|fork of an article]] and try to hide it away somewhere. For one thing, it's very inefficient. Editors may contribute to one branch or the other, allowing both versions to be incomplete. For another, it's frustrating to our readers—they've only got a 50/50 shot of hitting the 'right' article. Finally, it's an ultimately futile effort. Eventually someone will notice the duplication and merge the two articles anyway.
:There are several strategies for dealing with an article that you believe is overly technical.
:*Add the {{tl|technical}} template to the article. This flags the article as needing some added detail and description for accessibility, and adds the article to the [[:Category:Wikipedia articles that are too technical]] category.
:*Open a discussion on the article's talk page, and invite participation from the article's regular editor(s).
:*If an article contains many technical subtopics, it may be appropriate to rewrite it in [[Wikipedia:summary style|summary style]]. (Create a main article with short, accessible descriptions of each subtopic, and link appropriately to technical subarticles.)
:*Seek comment from other editors using a [[WP:RFC|request for comment]]. We can't help to resolve your dispute if you don't even tell us what article you're talking about.
:*Finally – and most importantly – [[WP:AGF|assume good faith]] on the part of your fellow editors. Accusing other editors of censorship, or of deliberately concealing information on behalf of some mysterious guild, tends to taint the working relationship a bit. Communication through text alone can be difficult and ambiguous. Other editors might interpret your attempts to make the article more accessible as sloppy or imprecise and be unaware of their own [[WP:OWN|article ownership issues]]. They might feel attacked by your implications that they are censoring material or trying to hide information.
:So do we at least get a hint about what article(s) you're talking about? We can't help you fix things if you won't tell us what the problem is. :D [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 00:09, 20 June 2006 (UTC)
::See [[Talk:Half-life]] starting June 12 and the recently created [[Half-life computation]] which has been sent to AFD [[Wikipedia:Articles for deletion/Half-life computation]]. Just a ''hint'' :-) [[User:Vsmith|Vsmith]] 02:50, 20 June 2006 (UTC)
== First patented form of life... ==
Hi! The following question is a product of my 'momentary inattentiveness' in class(please don't avoid answering for punishing me).
What is the first ''''patented form of life''''? I'm quite sure, I heard the name of a scientist- Ananda Mohan Chakrabarty, in this connection(though I doubt its authenticity).
How far '''Super Bug''' is related to this? Thanks,--[[User:Pupunwiki|Pupunwiki]] 07:51, 19 June 2006 (UTC)
hi!
The first "patented form of life" was invented by the scientist CHAKRABARTY which are nothing but the OIL EATING BACTERIA....
Oil Eating Bacteria are chiefly used to clear oil spills in the process of BIOREMEDIATION
In the year 1980 Chakrabarty discovered a bacteria[SUPERBUG] that could digest crude oil.
SUPER BUG is said to be a strain of bacteria that is resistant to all antibiotics.
It is also said to be a strain that is accidentally imported into florida from the Middle East then spread to California where it is a very serious pest feeding on almost all vegetable crops and poinsettias
eg;- Bemisia tabaci, poinsettia strain
some oil eating bacteria are also resistant to antibiotics...in this way super bugs are related to oil eating bacteria
The oil eating bacteria Pseudomonas species is one such example for a super bug[resistant to antibiotics]
--hima 10:27, 19 June 2006 (UTC)
Thanks a lot, Hima, for clearing my doubts.
--[[User:Pupunwiki|Pupunwiki]] 10:41, 19 June 2006 (UTC)
::Well, the [[Diamond v. Chakrabarty]] resulted in the first patent for genetically modified life. But the [[Plant Patent Act]] of 1930 allows for the patenting of asexually produced cultivars, which are also "life", technically speaking. --[[User:Fastfission|Fastfission]] 13:47, 19 June 2006 (UTC)
== Ridiculous Information from Wikipedia. ==
well, i was surfing the "war portal" on wikipedia recently. One of the articles had this link : "http://uncyclopedia.org/wiki/Palestine", under its "external links" section. And i was shocked to visit the link and the contents. And i think that site itself is open for editing, but the content still is shocking. And they have not even deleted it. Can someone help?
:Uncyclopedia is in no way affiliated with Wikipedia, the site looks similar beacause they use the same software (and because they are a conscious parody site of Wikipedia). We have no influence on the content of articles on uncyclopedia, if you think their Palestine article is crossing the line of good taste, it's best to take your concerns there. Now, whether or not an external link to an uncyclopedia article is appropriate for a Wikipedia article is another matter...where did you find the link? -- [[User:Ferkelparade|Ferkelparade]] [[User_talk:Ferkelparade|π]] 10:04, 19 June 2006 (UTC)
::Thank god they don't have a reference desk. Yet. Where is this link? Wikipedia articles shouldn't link to [[Unencyclopedia]] (unless they're discussing a topic such as [[parody]]). --[[User:Shantavira|Shantavira]] 12:22, 19 June 2006 (UTC)
I read somewhere (maybe in the uncyclopedia) that it was purchased by Wikimedia. Since you can't edit articles who writes them? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 13:59, 19 June 2006 (UTC)
:Uncyclopedia uses MediaWiki software, like Wikipedia. They are not "owned" by the same people. You can edit articles there, just like here - anyone can. What the above poster meant is that the editors here are not responsible for content there, as the majority of users do not overlap between the two sites. -[[User:Goldom|Goldom]] [[User_talk:Goldom|‽‽‽]] [[Special:Contributions/Goldom|⁂]] 14:32, 19 June 2006 (UTC)
::It's a great outlet when you feel like posting nonsense, though! (As long as you keep it funny.) [[User:Melchoir|Melchoir]] 19:27, 19 June 2006 (UTC)
::Well you can edit some things but not the majority of things in line with the idea of a contra-wiki. If you could edit everyting then it might actually serve the role of a parody where Wikipedia users could vent steam but as is its more like a spoof than a parody. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 19:33, 19 June 2006 (UTC)
"The [[complex square]] of the wavefunction, <math>|\psi|^2\,</math>, is interpreted as the [[probability density]] associated with the particle's position"
I was thinking in terms of an electron though I imagine the specific case is unimportant - my question is - Is there any reasoning or justification behind this relationship, (it seems to be a theorectical assumption used in a model) - and additionally, who originally came up with this idea and are they still alive and sufficiently sentient to be asked how/why they came up with this relationship?[[User:HappyVR|HappyVR]] 14:19, 19 June 2006 (UTC)
:(disclaimer: not a physicist) Could you maybe clarify the question? Are you asking why is the complex square not simply a part of the wavefunction so that it evaluates directly to a probability? If so, this is far from a perfect answer, but it is one perspective: consider [[variance]] and [[standard deviation]] from statistics. Mathematically, variance is the simpler value, in a sense, but its units aren't the same as the original data, they are the square of those units, so the standard deviation is often used, which is simply the square root of the variance, and thus in the same units as the data. Now I'm not saying that's the real answer to your question, I'm just saying sometimes the mathematically easy quantity and the intuitively simple quantity are not the same. A better answer might be that photons/electrons/etc act like complex numbers in a sense (i.e. they follow the same rules when looked at in the right light) and it works out that once you have the complex "amplitude" for an event worked out you can square it and find the actual probability for that event. But perhaps I've only restated your question and added nothing... [[User:128.197.81.181|128.197.81.181]] 18:56, 19 June 2006 (UTC)
:Well - I'll try to clarify(using electrons) - within the theory, the wavefunction is a property of (an electron), physical properties can be calculated using functions operating on the wavefunction. (A bit like we could have a function describing my velocity at a given time and you could use that function to calculate how far I've gone etc). In this case the probabilty density (thats how likely it is for an electron to be found in a given region - a bit like gas density) is calculated using the complex square of the wave function - thus if the wavefunction is complex eg a+ib the propability density is (a+ib)(a-ib). I was wondering why this function - what reason - why not (for instance) the magnitude of the complex number, or indeed any other function? Whats the reason or reasoning behind it?[[User:HappyVR|HappyVR]] 09:14, 20 June 2006 (UTC)
:As [[Probability amplitude]] says, this interpretation is due to [[Max Born]] who is long dead; he eventually got a Nobel for it though. [[User:Melchoir|Melchoir]] 19:24, 19 June 2006 (UTC)
::Thanks for that 'melchoir', god bless Max Born.[[User:HappyVR|HappyVR]] 08:35, 20 June 2006 (UTC)
:I wouldn't say it is a "theoretical assumption." It is experimentally verified. ([[User:Cj67|Cj67]] 22:18, 19 June 2006 (UTC))
::?
I have one answer now (Max Born developed this), however maybe a physicist could explain (maybe they have read Borns papers) why this relationship was chosen - is it just for simplicity - I can't see any reason why this relationship has to be right (eg units) - as possible alternatives I could suggest (using a+ib to represent a complex number) the magnitdue sqrt (a^2+b^2) or the square of the magnitude (aa+bb) as two of many possibilities as alternatives to the complex square (aa-bb) being the right answer. Can anyone explain any reason to believe that the complex square should be used as a measure of the probability density.[[User:HappyVR|HappyVR]] 08:35, 20 June 2006 (UTC)
:Wavefunctions are a mathematical construction. They provide a convenient mechanism for describing the relationships which ultimately give rise to quantum mechanical observables, but they need not have any tangible meaning themselves and are never directly measured. In fact, you don't need wavefunctions to describe quantum mechanics. [[Matrix mechanics]] and [[mathematical formulation of quantum mechanics]] describe a number of alternative mathematical formulations that give rise to the same observables and hence must be equally valid descriptions of quantum mechanics. However, for many practical applications, wavefunctions are the easiest approach. In this sense, asking why should <math>|\psi|^2 = |a+bi|^2 = (a+bi)*(a-bi) = a*a+b*b</math> (note, not aa-bb, as you suggest) be a probability density isn't really a sensible question. If it wasn't a probability density then it wouldn't be useful and we would be using some other formalism. However, asking what it means that this relationship holds for the intrepretation of quantum mechanics is an interesting question. In the simplistic way of thinking about things, it means that every particle describable by quantum mechanics can be equated to a wave that has not only an amplitude but also an orientation in space (e.g. a direction in the complex plane) and that determining the interactions between waves depends on considering these oreintations, but ultimately after considering any interactions it is the magnitude, the resulting a*a+b*b, that gives rise to the observable states. [[User:Dragons flight|Dragons flight]] 09:13, 20 June 2006 (UTC)
::oops - yes bit of a bodge up by me with the 'complex square' - however what I was asking was basically what about sqrt(aa+bb) - (in a simple sense eg addition of vectors this seems to make more sense.[[User:HappyVR|HappyVR]] 10:35, 20 June 2006 (UTC)
::Or to put it much simpler - is there someway of showing that using (for instance) |sqrt(aa+bb)| as probability density is wrong?[[User:HappyVR|HappyVR]]
:::I think Bohm's ''Quantum Theory'' has something along these lines. - [[User:Mako098765|mak]]''[[User_talk:Mako098765|o]]'' 08:04, 24 June 2006 (UTC)
::::The page [[Bohm interpretation]] doesn't seem to give an answer?[[User:HappyVR|HappyVR]] 14:13, 24 June 2006 (UTC)
== Appropriate Waste Disposal ==
I have an old computer that I failed to fix. I've salvaged some components but I don't know if the motherboard works properly. It used to run on a 112 W PSU and has no AGP slots (just three PCI and some weird stubby slot). Should I just chuck the mobo and processor in the electrical waste at the tip? Should I keep the processor or PSU? What should I do with the case? Can't it be melted and used in something? There aren't enough provisions for people who want to be environmentally friendly... --[[User:Username132|Username132]] ([[User talk:Username132|talk]]) 14:27, 19 June 2006 (UTC)
:You can reuse the case. As for the rest, have you considered an art project? [[User:HighInBC|HighInBC]] 14:32, 19 June 2006 (UTC)
:You are correct that computer parts may contain nasty stuff that you don't want ending up in landfill. The best bet is to contant your local recycling company and ask if they have a place to take it. (If your city picks up recycling, ask them, or if not, just another local company). Places like Office Depot often take in things like used-up rechargable batteries for recycling, but I doubt they'd have room to take whole MBs. -[[User:Goldom|Goldom]] [[User_talk:Goldom|‽‽‽]] [[Special:Contributions/Goldom|⁂]] 14:36, 19 June 2006 (UTC)
:The plastic case is probably just that plastic plus some filler - maybe you could put that in any plastic recycling bin you can find. The processor is mostly inert - might contain some gold though but not much - the case will be ceramic or a resin. As far as I know its the glass fibre and the resins gluing it together and the lead used in soldering on the motherboard that are supposed to contain the nasties - no idea what you are supposed to do with this though - burning it is the way to release the chemicals enviromentalist don't like. The PSU contains sufficient scrap metal to be worth at least 50p to a scrap metal merchant - that's most of what I can say to help. (Art project is good idea - maybe you could use the processor as a coaster for small tots of rum)[[User:HappyVR|HappyVR]] 14:38, 19 June 2006 (UTC)
:I'm pretty sure you could find a homeless guy that could find some way to use your junk. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 00:27, 20 June 2006 (UTC)
::Why wait for a homeless person? I bet one of your friends would like a hunk of junk. I sort of would, but I'd like it to be in slightly better condition. --[[User:M1ss1ontomars2k4|M1ss1ontom]]<font color="green">[[User:M1ss1ontomars2k4/Esperanza|a]]</font>[[User:M1ss1ontomars2k4|rs2k4]] <sup>([[User talk:M1ss1ontomars2k4|T]] | [[Special:Contributions/M1ss1ontomars2k4|C]] | [[Special:Emailuser/M1ss1ontomars2k4|@]])</sup> 04:55, 20 June 2006 (UTC)
== Can medium format (120) film be developed by my local pharmacy? ==
Is it likely that the neighborhood drugstore would be equipped to develop 120 film? [[User:Javguerre|Javguerre]] 15:28, 19 June 2006 (UTC)
:No. It is likely that your local drugstore sends ''all'' film to a processing service. It is probably easiest if you just call or visit the drugstore to ask; however you might be better served by searching for a nearby camera store (not a chain like Ritz or its siblings) and asking them for advice. --[[User:LarryMac|LarryMac]] 16:11, 19 June 2006 (UTC)
::Right.......and you think getting stuff to an external service and back would allow a 1 hour turnaround? that would be some pretty impressive logistics. [[User:Plugwash|Plugwash]] 01:00, 20 June 2006 (UTC)
:::Where did anybody ask for 1 hour turnaround? I should have added that many stores do now have the self-contained machines that allow processing of 35MM C-41 process film on premises, but 120 is a whole different animal. --[[User:LarryMac|LarryMac]] 01:03, 20 June 2006 (UTC)
== The Moon ==
From what points on the Earth does the moon apear largest?
Thanks, Lucy Hallam
:The [[Moon]] would be closest to an [[Earth]]-bound observer on [[Mount Everest]], but that's only a 9 km difference versus a [[sea-level]] observer. By comparison, the Moon's orbit causes it to vary in distance from the Earth by 40,000 km. So actual size from earth doesn't appreciably vary no matter where you are.
:However, there is a well-known [[Moon illusion]] where the Moon ''appears'' largest near the horizon, though it's simply a trick of the brain's interpretation of the image, not the actual size of the Moon itself. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 16:05, 19 June 2006 (UTC)
::To be pedantic, you'd be better going up [[Chimborazo (volcano)]] than Mount Everest - it's peak is two kilmetres further from the centre of the earth than Everest's. [[User:Dmn|Dmn]] '''[[Special:Contributions/Dmn|€]]''' [[User talk:Dmn|Դմն]] 21:35, 19 June 2006 (UTC)
:::To add to that, you should wait until perigee occurs near Chimborazo. You could be waiting for a very long time. --[[User:M1ss1ontomars2k4|M1ss1ontom]]<font color="green">[[User:M1ss1ontomars2k4/Esperanza|a]]</font>[[User:M1ss1ontomars2k4|rs2k4]] <sup>([[User talk:M1ss1ontomars2k4|T]] | [[Special:Contributions/M1ss1ontomars2k4|C]] | [[Special:Emailuser/M1ss1ontomars2k4|@]])</sup> 04:52, 20 June 2006 (UTC)
::Oh yeah. Back to the moon illusion. Due to geometry, shouldn't the moon's actual angular diameter be greatest at the zenith rather than the horizon? --[[User:M1ss1ontomars2k4|M1ss1ontom]]<font color="green">[[User:M1ss1ontomars2k4/Esperanza|a]]</font>[[User:M1ss1ontomars2k4|rs2k4]] <sup>([[User talk:M1ss1ontomars2k4|T]] | [[Special:Contributions/M1ss1ontomars2k4|C]] | [[Special:Emailuser/M1ss1ontomars2k4|@]])</sup> 04:54, 20 June 2006 (UTC)
::Yes. [[Moon illusion]] says "The true angular diameter of the Moon is about 1.5% smaller when it is near the horizon than when it is high in the sky, because it is further away by up to one Earth radius." -- [[User:Wikicheng|Wikicheng]] 05:58, 20 June 2006 (UTC)
Thanks for answering that for me, much appreciated! Lucy
== Fish question ==
What is the name of this fish? It lives deep in the ocean where there is no light. It has an extendor over its eyes that has a bulbuous attachment that glows. It was used in Disney's movie Nemo.
:Maybe today you are in luck since this came up on another talk page I was reading - is it [[Black seadevil]] - it sounds v. similar. -- [[User:HappyVR|HappyVR]] 17:12, 19 June 2006 (UTC)
:and [[Anglerfish]] -- [[User:HappyVR|HappyVR]] 17:13, 19 June 2006 (UTC)
:It was the angler fish. — [[Image:Flag_of_the_United_States.svg|17px]] <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]]
== How much did Apollo 11 cost? ==
Good afternoon,
Does anyone know how much the first manned mission to land on the moon, Apollo 11, cost?
:: ''The data show that over the entire lifetime of the the space shuttle program the cost has been $145 billion, and about $112 billion since the program became operational.''
:: ''Furthermore, the average cost per flight has been about $1.3 billion over the life of the program and about $750 million over its most recent five years of operations.''
: Now I think sending people to the moon is cheap. -- [[User:Toytoy|Toytoy]] 01:06, 20 June 2006 (UTC)
::Not to get OT, but take into consideration the expanded capability of the STS, in crew capacity, flight duration, and payload. Not to say that $1.3B to gas up a ship and send it around the earth seems cheap, but...
::: I seem to recall a long discussion of costs at [[Space Shuttle]]. There's a lot of ways to define costs -
* Average Cost ("How much did the total program spend; then divide by number of missions...")
* Incremental Cost ("How much extra money does it cost to send one more launch, ''after the program infrastructure exists''")
* Opportunity Cost ("How much could we have earned if we spent money elsewhere...")
:::... etc. There's no easy way to assign an exact dollar value to spaceflight. [[User:Nimur|Nimur]] 17:29, 22 June 2006 (UTC)
== Edibility of ''[[Cucumis melo]]'' leaves ==
Many cucurbits have edible leaves, but I have not been able to satisfy myself about ''Cucumis melo''. I was surprised at how little information I could find for such a well-studied plant. [http://www.geocities.com/bionaturalza/cucumis.htm BioNatural claims] that the [[Pedi]] and the [[Sukuma]] people eat the leaves as a "potherb and relish", but the mention is off-hand and undetailed, and the company sells herbal extracts, so they may have a profit motive in giving this information. [http://www.ipgri.cgiar.org/publications/HTMLPublications/500/ch15.htm An agricultural researcher in Uganda lists] the leaf among the plant's edible parts, but again no detail is given. ''Cucumis melo'' is ''not'' on [http://www.leafforlife.org/PAGES/ALSPECS.HTM Leaf for Life's very long list of plant species that have reportedly been eaten by people]. [http://www.pfaf.org/database/plants.php?Cucumis+melo Plants for a future reports] that "the sprouting seed produces a toxic substance in its embryo", but not what the toxic substance is, where in the plant it is distributed, nor how long it persists as the plant grows.
I have added ''Cucumis melo'' to the [[list of plants with edible leaves]], but have not eaten the leaves of the melon vines in my garden. Any further information would be appreciated. Thank you. [[User:Leafeater|Leafeater]] 17:53, 19 June 2006 (UTC)
:This is a tough one. All I have to contribute is that Francois Couplan's very comprehensive ''The Encyclopedia of Edible Plants of North America'' does ''not'' mention the leaf as one of the edible parts of ''Cucumis melo'', and he generally doesn't miss much. — [[User:Pekinensis|Pekinensis]] 20:42, 23 June 2006 (UTC)
== EMP nullification ==
What is the name of the device that nullifies the effect of an electromagnetic pulse on electronic devices? It resembles a cage made of wire. I tried a number of searches under different topics and come up empty. It's driving me crazy. <small>—The preceding [[Wikipedia:Sign your posts on talk pages|unsigned]] comment was added by [[User:72.54.24.94|72.54.24.94]] ([[User talk:72.54.24.94|talk]] • [[Special:Contributions/72.54.24.94|contribs]]) 19:39, 19 June 2006 UTC.</small>
:I'll put you out of your misery. See [[Faraday cage]]. --[[User:GraemeL|GraemeL]] [[User_talk:GraemeL|<sup>(talk)</sup>]] 18:43, 19 June 2006 (UTC)
Thanks much. Now I can sleep at night.
== JPG image problem ==
I have a group of jpg images which were scanned into the computer under Windows 98 using an HP Scanjet IIcx flatbed scanner. The images seem to be okay except that their widths have been compressed to about 1/3 of the left side of the page with the remainder of the page being solid black. I have never seen this before. Does anyone know what caused this and more importantly how to restore the width of the image without loss of information? Thanks. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 19:04, 19 June 2006 (UTC)
:I guess one question that has to be asked is what did you do with them? Were they copied to a diskette or CD and were they fine when you first scanned them? I've have some problems with scanners before where no matter how many times I scan the same image, it always scans half the image wrong, and I usually assume it to be a scanner problem. If you've used storage media on the images though it might be a different problem, and there are jpeg rebuilders that may be able to fix them. Oh, and for the record, the blank area of the image is usually called the "canvas". [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 00:20, 20 June 2006 (UTC)
::Right the programs I have to view and edit call the whole area the canvas but I can't find the one at the moment that actually allows the image on the canvas to be streched by default rather than moved across the canvas. This is the one I had planned to use to restore the images but I am curious as to the cause. The images were fine after scanning and were only transferred from a FAT32 drive to a NTFS drive over a local Ethernet and have been there ever since. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 08:58, 20 June 2006 (UTC)
:::Ah, I see what you're getting at now. Any program like Photoshop lets you fiddle with the canvas and size settings, but as you know that's not going to leave you with the same detail as the original 1:1 images. It's not likely that the full quality image is still preserved in the file unless they've been somehow vectorized. Sorry, I can't think of why they would suddenly be compressed like that, since they obviously haven't been simply corrupted. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 10:21, 20 June 2006 (UTC)
By looking in the subdirectory (I was only looking at the results of a search for jpg files)the reason for the problem may now be revealed although I still do not understand what caused the problems. The image name ends with ....tif.jpg so it looks like they were tif images that got saved as jpg images but that still does not indicate how they were distorted in this manner. After removing the jpg extension the thumbnail image does not change and there is no effect on the edit views of the image as if the extension has been ignored and file type determined by some other means. Anyway I suspect some kind of accidental conversion due to file name change and now possibly even a virus. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 15:22, 20 June 2006 (UTC)
== Orbit/gravity/weightlessness ==
I have a question relating to gravity/orbits, etc. Do you know who I can direct it to?
I understand that objects/people in orbit around the earth only appear
weightless due to the fact that they are in freefall, and since the spacecraft
and everything/everyone aboard are all falling at the same rate of speed
around the earth (in orbit), they appear to be weightless.
My question is this:
When the astronauts travelled to the moon, they also experienced
weightlessness. Since they left earth orbit on the journey to the moon, and were not in freefall, why were they weightless en route?
Jake Whalen
:You should probably check out our article on [[weightlessness]], particularly the discussion on pressure gradients. As a layman, though, here's my attempt:
:Weightless freefall isn't dependent on "falling" ''per se'' but rather on you and your reference frame (that is, the spacecraft) not resisting gravitational forces, whether or not those forces will eventually cause you to collide with the relevant astronomical body. When you consider "falling" as instead being "coasting without support", weightlessness between the Earth and Moon makes a good bit more sense (to me, at least).
:Also, it's a good idea not to post your phone number on the internet. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 20:02, 19 June 2006 (UTC)
:: Please note that [[weightlessness]] is experienced only when the spacecraft engines are shut-off (free-fall). Any time the engines are on, they exert a force on the craft and its content, and the reaction, e.g., the force exerted by the astronaut on his seat, is the equivalent of a residual weight. --[[User:Michel M Verstraete|Michel M Verstraete]] 00:04, 20 June 2006 (UTC)
: Adding to Michel's answer: When the engines are turned off, even if the spacecraft is travelling away from earth, it is still 'free fall' because the only force acting on it is the gravity. So you can say that you will experience weightlessness the moment the engines are turned off, whether the spacecraft is moving away or orbiting earth -- [[User:Wikicheng|Wikicheng]] 06:21, 20 June 2006 (UTC)
:When you throw a ball it is in ''freefall'' from the instant it leaves your hand, even though for half of its trajectory it is "falling" upwards. Tiny astronauts inside the ball would experience "weightlessness" - right up until the point when the ball hits the ground and they are squashed by the deceleration. The [[Vomit Comet]] does the same thing, only on a bigger scale (and without the hard landing). [[User:Gandalf61|Gandalf61]] 10:36, 20 June 2006 (UTC)
The original poster asked a very good question, and it is fundamental to understand it. Everyone's answer was very well written so I can't add much, but one thing : when I was a child they explained me : you are far away from earth, gravity becomes weak.
Well that is simply untrue, in the [[International Space Station]] (or [[Mir]]) gravity was 9.5 m/s^2 , compared to 9.81 m/s^2 here on earth, I doubt a human would really feel that difference.
The correct answer is simple : you experience weightlessness when you and your ship have exactly the same forces that work on them.
[[User:Evilbu|Evilbu]] 11:07, 20 June 2006 (UTC)
:Just to clarify - it is true that far from the earth the force of gravity due to the earth does become weak; it obeys an inverse square law. Around the distance of the moon, acceleration due to the earth's gravity is less than 0.01 m/s^2. When the astronauts left orbit, they did experience some acceleration due to the ship's rockets, but it was probably pretty small, and once they got far enough out, Earth's gravity became negligible. They were never completely "weightless", but nearly so. --[[User:Bmk|Bmk]] 17:36, 20 June 2006 (UTC)
There seems to be a confusion here. When an object is orbiting earth, it is again a case of free fall (only that while moving tangentially, the object falls just enough distance, to keep it at the same distance from the earth). As Mir is orbiting earth, the astronauts in Mir experience zero gravity and not 9.5 m/s^2 -- [[User:Wikicheng|Wikicheng]] 08:12, 26 June 2006 (UTC)
== Symptoms of long-term oxygen deprivation ==
What are some possible symptoms of shallow breathing, or mild long-term oxygen deprivation? For instance, someone contracts sleep apnea in conjunction with asthma and allergies, causing generalized shallow breathing and low oxygen intake.
:Look under "Symptoms" in the article [[Sleep apnea]]. Googling for the term also gives results. --[[User:Seejyb|Seejyb]] 01:39, 20 June 2006 (UTC)
You are actually asking about five sometimes associated, but distinct and independently diagnosable, conditions. Chronic effects, as opposed to acute effects, vary by severity from minimal to marked. At their worst, these conditions can cause some fairly serious effects over time, depending on age and co-morbidities.
# [[asthma]]: This is usually episodic rather than continual. It usually does not cause hypoxia except in extreme exacerbations. Although it can coincidentally occur in someone with sleep apnea, it is a completely independent condition.
# respiratory [[allergy|allergies]]: The most common of these are simply a stuffy, runny nose, not affecting oxygen level. The most severe kind of respiratory allergy (as distinct from much rarer hypersensitivity reactions) is typically allergen-triggered asthma.
# chronic [[hypoventilation]]: This can occur from a variety of conditions ranging from genetic defects of breathing drive to congenital brain syndromes to [[COPD]] to severe [[obesity]], but not usually from asthma. It typically causes fatigue. In a severe form it can cause chronic hypoxia, and long-term strain on heart leading to [[cor pulmonale]] and even death.
# [[sleep apnea]]: This is most commonly due to upper airway obstruction due to obesity but can have other causes as well. It can cause transient hypoxia during sleep. It can cause daytime fatigue, headache, difficulty concentrating and remembering. There is mounting evidence that obstructive sleep apnea can contribute to the development of [[insulin resistance]] and [[type 2 diabetes]].
# [[chronic hypoxia]]: Chronic hypoxia has many causes ranging from COPD to chronic restrictive lung disease to chronic airway obstruction to [[cystic fibrosis]] to [[cyanotic congenital heart disease]]. Chronic hypoxia can cause a variety of long-term problems ranging from poor growth in children to fatigue and neurocognitive impairment in adults. In severe cases it can lead to cardiac hypertrophy and [[congestive heart failure]]. [[User:Alteripse|alteripse]] 02:17, 20 June 2006 (UTC)
::Cigarettes, anyone ? --[[User:Harvestman|DLL]] 20:52, 20 June 2006 (UTC)
Since a object on the equator is spinning faster then one on the pole, shouldn't there be a difference in weight between them? [[User:Wizrdwarts|Wizrdwarts]]<small> ([[User_talk:Wizrdwarts|T]]|[[Special:Contributions/Wizrdwarts|C]]|[[Special:Emailuser/Wizrdwarts|E]])</small> 21:19, 19 June 2006 (UTC)
:Yep, and there is. See [[Gravity (Earth)]] and [[Apparent weight]]. [[User:Moink|moink]] 21:28, 19 June 2006 (UTC)
::Thanks for the quick answer! And according to the timestamp on your post, you replied one minute before I even asked! Do you know how much the actual difference would be? [[User:Wizrdwarts|Wizrdwarts]]<small> ([[User_talk:Wizrdwarts|T]]|[[Special:Contributions/Wizrdwarts|C]]|[[Special:Emailuser/Wizrdwarts|E]])</small> 21:37, 19 June 2006 (UTC)
:::According to [[Gravity (Earth)]], 0.5% (also, Moink's timestamp is 9 minutes after yours). — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 22:12, 19 June 2006 (UTC)
::::Must've gotten less than enough sleep today. I misread the "2" as a "1". Thanks! [[User:Wizrdwarts|Wizrdwarts]]<small> ([[User_talk:Wizrdwarts|T]]|[[Special:Contributions/Wizrdwarts|C]]|[[Special:Emailuser/Wizrdwarts|E]])</small> 22:46, 19 June 2006 (UTC)
== Why is AC current prefered over DC? ==
I've read about the subject, but I have never found a conclusive answer. There must be a major reason, otherwise we would still have both systems. Which reason is that? [[User:Afonso Silva|Afonso Silva]] 21:20, 19 June 2006 (UTC)
:DC power supplies require a power station to be built every fifty miles or so, which becomes very impractical outside large cities. As a result, AC current is used; see the [[War of Currents]] article. [[User:Andromeda321|Andromeda321]] 21:34, 19 June 2006 (UTC)
::Eh, what? There's no problem with transmitting DC over long distances; for long runs [[high-voltage direct current]] (HVDC) is actually more efficient than AC. (It has a number of other advantages in certain situations, as well.) AC's major advantage is that its voltage can be easily stepped up and down with a simple [[transformer]], making it possible to transmit current over long distances.
::DC transformers are much more complicated and costly than their AC counterparts, rendering them poorly-suited for ubiquitous power grid use. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 22:23, 19 June 2006 (UTC)
:::There is really no such thing as a "DC transformer." AC voltage can be stepped up and down with two coils of wire and an optional lump of iron (called a transformer). DC voltages are stepped up and down with relatively complex switches and switching circuits referred to as DC-DC converters or through other more involved or less efficient means (e.g., motor-generator hookups). —[[User:BradleyEE|Bradley]] 22:59, 19 June 2006 (UTC)
Thanks! I was trying to find an article in Wikipedia about it. The name is strange. [[User:Afonso Silva|Afonso Silva]] 22:19, 19 June 2006 (UTC)
Yeah, DC transformer is a weird thing, as DC keeps the magnetic field constant. Is that it? At least, it is what I learned. The magnetic flux must change in order to induce a current. [[User:Afonso Silva|Afonso Silva]] 23:13, 19 June 2006 (UTC)
:Correct. As stated above, to change DC voltage levels you need converters such as the [[flyback converter]].
:As also mentioned above, there are some cases where DC transmission is used over long distances, with much lower losses, one factor that helps it is the fact that AC currents only "run through" thin layer of the conductor increasing resistance, compared to DC current that flows through the whole section of the conductor. <font color="#207912">[[User:VdSV9|<b>VdSV9</b>]]</font>•<font size="4px">[[User talk:VdSV9|♫]]</font> 01:20, 20 June 2006 (UTC)
: I think it also has to do with safety purposes. I personally had the "oppurtunity" to get electrocuted by AC and DC voltages, and I found that the AC voltage actually pushes your body away so you have a chance of pulling away your hand or the part that is in contact with the circuit. But try pulling your hand from a 220 V DC (thats the common voltage in India) voltage. I think the death rate would be a lot higher if we had used DC voltage. ;-) [[User:Jayant412|Jayant,]][[WP:EA|<font color="green">17 Years,</font>]][[User_talk:Jayant412|<font color="red"> India</font>]] • [[Special:Contributions/Jayant412|contribs]] 11:55, 20 June 2006 (UTC)
::Whatever you prefer, it's not been the same since [[Bon Scott]] died. --[[User:Dweller|Dweller]] 11:59, 20 June 2006 (UTC)
AC offers numerous advantages over DC such as:
* Voltages can easily and cheaply (compared to DC) be stepped up or down using transformers for diferent transmission and distribution needs
* Using 3-phase supply allows different voltage levels to be obtained (phase-phase, phase-ground) from the same set of transmission lines
* Using 3-phase supply, loads on each phase can be balanced in order to reduce or eliminate the need for a conductor to provide the return path to earth. This means less "conductor per kilometer per megawatt", reducing costs. (This is offset by the phenomenon mentioned above about DC current flowing through the whole conductor whereas AC flows only through a thin surface layer). p.s. where is the wikipedia article on the [[skin depth effect]]?
* Protection systems in AC circuits are simpler i.e. cheaper because the current passes through a zero every cycle, which can help to extinguish e.g. a short-circuit arc
Disadvantages of AC include:
* Line [[inductance]] and [[capacitance]] to ground may be significant, especially over long distances, causing losses over and above normal [[electrical resistance|resistive]] losses
* [[Power factor]] becomes one of the main considerations to system stability and power flow. In particular, attention has to be paid to active and [[reactive power]]
* It's just a lot more difficult to understand intuitively than DC. You've got all sorts of messy things such as series and shunt capacitors used for various purposes such as voltage boosting, improved power transmission etc.
In conclusion, the reason most systems are AC is because AC is cheaper. As for the electric shock comment, I simply don't think it is correct. An electric current through your body (AC or DC) causes your muscles to contract involuntarily. When someone touches an exposed electric circuit with their hand, muscle contraction prevents them from letting go, which is why when working on an electrical system, workers will (obviously after making sure everything is earthed!) often touch the device/conductor with the BACK of their hand to test for dangerous induced voltages (muscle contraction would then cause their hand to spasm AWAY from the metal). [[User:Zunaid|Zunaid]] 12:29, 20 June 2006 (UTC)
::I think your second point on the advantages of AC – different voltages – isn't valid, as that can be done with DC as well. – [[User:b_jonas|b_jonas]] 11:01, 23 June 2006 (UTC)
:Zunaid gave a great complete answer on the subject. But actually, as for the electric shock, it's much worse in DC, just think of a continuous 220V shock as compared to an intermitent shock. For one thing, the power dissipated by one's body will decrease to 70,7% of the DC, value, not to mention a the reactance of the human body that increases impedance.
:This is not the reason "why AC is preferred over DC", I'm just clarifying this electric shock issue. <font color="#207912">[[User:VdSV9|<b>VdSV9</b>]]</font>•<font size="4px">[[User talk:VdSV9|♫]]</font> 15:47, 20 June 2006 (UTC)
::That's not true. X volts of AC dissipates exactly the same power as X volts of DC in a given resistance, by definition, because AC voltages in this context are specified in [[RMS]]. Furthermore, the peak value of X volts AC is 1.41 X volts, so you would get a 41% worse shock, intermittently, from X volts AC than from X volts DC. The current due to capacitive reactance is negligible, only a few microamps (240 V * 2π * 50 Hz * 100 pF). Inductive reactance would make the current smaller. --[[User:Heron|Heron]] 21:22, 20 June 2006 (UTC)
Hmmm... right, it slipped my mind. Still, from all I know, the intermitent nature of AC makes the shock less damaging. And resistance and reactance are variable from person to person anyway. -- <font color="#207912">[[User:VdSV9|<b>VdSV9</b>]]</font>•<font size="4px">[[User talk:VdSV9|♫]]</font> 18:04, 21 June 2006 (UTC)
:[http://www.allaboutcircuits.com/vol_1/chpt_3/2.html allaboutcircuits.com] mentions particular hazards of both AC and DC. In summary:
:*Tetanus (muscle spasm): DC worse, because you can't let go
:*Ventricular fibrillation: AC worse, because it interferes with [[pacemaker]]
:*Burns: no difference, if exposure time and voltage are equal (for reason given above)
:There's no clear winner, which is probably why the dispute won't die. --[[User:Heron|Heron]] 20:57, 21 June 2006 (UTC)
= June 20 =
== Currency ==
Is the serial number of US currency machine readable yet? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 03:35, 20 June 2006 (UTC)
:Is there any reason to suspect that the serial numbers are not readable by [[optical character recognition]]? I think the answer is obvious.
::Should be. I saw a bit on the History Channel tonight noting the Fed having automated systems to detect [[superbill]]s mixed in with legit [[$100 bill]]s. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 04:49, 20 June 2006 (UTC)
:::Actually I am thinking more in terms of a device anyone might carry in their pocket similar to a battery powered credit card reader. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 08:00, 20 June 2006 (UTC)
::::Well, the technology certainly exists. You'd basically be doing OCR on a specific location with a roll-through scanner, and that can be done. I don't know that anybody has actually created a product, though. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 17:22, 20 June 2006 (UTC)
:::I don't believe such a machine would be effective in detecting forged notes. There are simple (and cheap) devices that help in that, the most common example being this ultraviolet light thing which shows small coloured strands in the note (I don't know if that applies to US currency). Compared to the other security features like this, the hologram, the metallic stripe in which you can read the minute text and the sign that fits perfectly if you hold it towards light, the watermark, etc, I believe the serial number wouldn't be too difficult to forge. Also, as new banknotes get printed all the time, to decide if the note is valid, the data in device would have to be updated frequently or have a continuous link to some central server. (Also, if you wanted a machine-readable serial number, it would probably better to use some kind of bar code.) – [[User:b_jonas|b_jonas]] 10:55, 23 June 2006 (UTC)
==Stupid question==
In what way is it justifiable to allow stupid people to vote, hold positions of power, etc.? By this I mean ''logically'', as it's obvious that nearly every country's constitution gives them this right, and it is in every way illegal to exclude them of this right. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 04:15, 20 June 2006 (UTC)
:Um... who decides who's "stupid"? —[[User:Keenan Pepper|Keenan Pepper]] 04:30, 20 June 2006 (UTC)
::Well that wasn't the question. In fact, I deliberately avoided that question. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 04:36, 20 June 2006 (UTC)
:::Assuming that "stupid" means they are not able to hold a position of power in a responsible manner, I don't believe they would be voted into that position. Appointed, perhaps. As for voting, I don't see why "stupid" people shouldn't be allowed to vote, unless they do not understand what a vote is or what the voting process means. --[[User:M1ss1ontomars2k4|M1ss1ontom]]<font color="green">[[User:M1ss1ontomars2k4/Esperanza|a]]</font>[[User:M1ss1ontomars2k4|rs2k4]] <sup>([[User talk:M1ss1ontomars2k4|T]] | [[Special:Contributions/M1ss1ontomars2k4|C]] | [[Special:Emailuser/M1ss1ontomars2k4|@]])</sup> 04:48, 20 June 2006 (UTC)
:Of course, "who is stupid" ''is'' the core question, avoided or not. Find an objective unambiguous means of defining "stupid" and you've then got a position to argue from (analagous to how many US states deny the right to vote to convicted criminals). Otherwise you've just got a regime masquerading as democracy. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 04:52, 20 June 2006 (UTC)
:Intelligence is hardly the only criterion that makes somebody suitable for a leadership position. To take a simple example, the senior staff at [[Long Term Capital Management]] were extremely smart people. Didn't stop them losing an enormous pile of money through overconfidence in their own abilities. However, I think I'd expect my elected representatives to have a certain level of intelligence and intellectual curiosity. --[[User:Robert Merkel|Robert Merkel]] 05:09, 20 June 2006 (UTC)
:: People are not stupid; they are loyal to their politicians.
:: People are not gullible; they are ...
:: In a model two-party democracy, both parties offer capable and wise candidates. Even a moron can vote.
:: In the real world screwball democracy, ...
:: Anyway, democracy abhores disfranchising voters. Some countries allow criminals to be disfranchised. Some others are even afraid to do so. Making mistakes now is not the end of the world. There will be future generations to pay for our mistakes. This is democracy. -- [[User:Toytoy|Toytoy]] 07:19, 20 June 2006 (UTC)
:Stupid people are idiots. The word idiot is derived from the greek ''idiotes'' meaning a private individual who doesn't participate in politics or public life. Given that in the UK almost half the people don't bother to vote, with similar figures in most other democracies, it is the case that stupid people don't vote (we can tell they're stupid because they don't vote). If they're not going to vote anyway it isn't really necessary (& could be counter productive) to actually legally prevent them from voting. [[User:AllanHainey|AllanHainey]] 08:09, 20 June 2006 (UTC)
Many smart people do not vote anyway. Why you ask? They know that elected officials are the go-betweens. Go-betweens are the people who represent the bureaucracy to the public and the public to the bureaucracy. For this reason the stupidity or lack thereof among elected officials is virtually nullified. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 08:08, 20 June 2006 (UTC)
:The other reason why smart people don't vote is that they can not decide which stupid one to vote for. - [[User:Wikicheng|Wikicheng]] 08:33, 20 June 2006 (UTC)
::Depending on who you think are the stupid people, they are possibly the most likely type of people to vote.
::Let me try something else: If I set the definition of stupid as a "person who has a low ability to make correct, logical decisions ''independently'' in a variety of situations" does that work better? I'm curious about M1ss1ontom's opinion. And as for Lomn's comment, I believe most certainly that it ''is'' possible to argue without a position on "stupid", just like you can argue about the existance of God whether you believe or not. You just have to allow some assumptions. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 09:58, 20 June 2006 (UTC)
:::It's not whether you ''believe'' or not -- I believe some people are stupid -- but whether you can create any meaningful basis for discussion. To use your example, most discussions as to whether God exists understand that they're discussing an omnipotent supernatural being, not just some lame superhero like Aquaman. A useful discussion about God is impractical if one of the parties is instead arguing the existence of his dog.
:::Therefore, without some standard, all you're asking the ref desk is whether or not we think it's a good idea for you to dictate who votes, and the core point is that when an arbitrary standard is sued to select voters, the actual power lies only with the people who set the standard. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 14:23, 20 June 2006 (UTC)
:::As an additional note, "stupid" is a particularly vague term. It's possible to debate political vagaries (say, is it right to tax the rich more than the poor) so long as at least an objective comparison is understood -- a rich person makes more money than a poor one, in tax terms -- even if the precise boundaries aren't defined (how much income constitutes "rich"). However, what's the measuring stick for "stupid" vs "smart"? — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 14:27, 20 June 2006 (UTC)
:Well, I don't know about ''stupid'' people, but if you want to exclude particular groups from democracy based on character traits, how about ''selfish'', or ''lazy'', or ''greedy'', or ''racist'', or ''not policitally correct''? Would you rather your representative was stupid or greedy? Stupid or racist? Where does it stop? The particular problem with excluding people from democracy in large numbers is that they are likely to be upset; if you exclude enough you have the potential for unrest or revolution. The general problem in all these cases is making a definition, because in practical terms you couldn't propose a real action or estimate effects until you make a definition of the term. [[User:Notinasnaid|Notinasnaid]] 12:53, 20 June 2006 (UTC)
::The thing is, I never suggested that they shouldn't be allowed. I was actually asking why they ''should'' be. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 16:53, 20 June 2006 (UTC)
:::Do you see how that's a [[loaded question]] suggesting that they shouldn't be, though? Anyway, to try to answer the original question: stupid people should be able to vote because no one has presented a coherent objective case as to why they shouldn't, and modern [[liberal democracy|liberal democracies]] generally agree that [[elective rights]] are restricted primarily by age and citizenship. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 17:24, 20 June 2006 (UTC)
::::Women decided to prove they were no more idiots in the beginning of the last century. Before, only rich and educated people did vote - as in [[Athens]].
::::Each time politicians allowed some groups to vote, thet did so because they hoped they would gain more votes than the other party. What if pets and IA machines were allowed to help us choosing ? --[[User:Harvestman|DLL]] 20:49, 20 June 2006 (UTC)
:::::I suspect you're talking about the USA. [[women's suffrage|Women have had the vote]] continuously since 1893 in New Zealand and 1894 in South Australia. [[User:JackofOz|JackofOz]] 09:25, 22 June 2006 (UTC)
In case you're interested, the kind of government you propose, where intelligence forms a primary criterion for voting/governence, is called a [[geniocracy]]. [[User:GeeJo|<span style="padding : 0px 1px 1px 1px; border : 1px solid #809EF5; cursor: wait; background: #FFFFFF ; color: #99B3FF">GeeJo</span>]] <sup>[[User talk:GeeJo|(t)]]</sup>⁄<sub>[[Special:Contributions/GeeJo|(c)]]</sub> <small>• 23:00, 20 June 2006 (UTC)</small>
:At elections, everyone hears from the television how many people have voted and more importantly, how many had the right to vote. Thus, if stupid people weren't allowed to vote, it would get out very soon that there are so many stupid pepole in the country or state. I believe this would have a bad impact on people's mood, especially if they started to compare figures from all the regions. People would be discriminated just because they come from a region where fewer people can vote. – [[User:b_jonas|b_jonas]] 10:48, 23 June 2006 (UTC)
===Do you suffer from short-term memory loss? - I don't remember ==
Hi, I've looked at [[Short term memory]], [[working memory]] & [[amnesia]] but I can't find what I'm looking for. Does anyone know if there is a condition which renders someone unable, or makes it harder to, remember regular or irregularly recurring events once they've happened once. For example something that would make it harder for someone to remember to renew a monthly bus season ticket after she had bought the ticket the first time; or which made it harder to remember to pay regular council tax bills?
I realise that there may not be a name for this other than "forgetfullness" or "disorganised" but if there is a specific condition or conditions which could have this effect could you please let me know.
Thanks [[User:AllanHainey|AllanHainey]] 07:55, 20 June 2006 (UTC)
:I guess we would have to know the rest of the person's story. Many different things, from [[anterograde amnesia]] to [[dementia]]/[[delirium]] to [[depression]] can all cause the symptoms you describe. The key is to know what else is going on and what the rest of the brain is capable of doing! [[User:InvictaHOG|InvictaHOG]] 10:45, 20 June 2006 (UTC)
:I hope this doesn't come over as flippant, but it just sounds like a perfectly normal pattern. At least in my experience. The first time you have to pay that bill, it will pray on my mind until it is done. After that, it's impossible for me to hold in my head that it needs doing over and over. What you need is not a better memory, but better organisation. It's hard, and I'm bad at it, but a key thing is not to have lots of places to check: just one master list of things to do. Then you only have to remember to check the list once a week, and have the discipline to both check and act. [[User:Notinasnaid|Notinasnaid]] 10:53, 20 June 2006 (UTC)
::What was the question ? --[[User:Harvestman|DLL]] 20:50, 20 June 2006 (UTC)
== Medicine ==
What does the "C" stand for in vitamin C?
:Apparently nothing. I thought it might be [[citrus]] but it appears to have been used because it's the letter after [[B]] (or possibly because it simply wasn't taken yet). [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 10:05, 20 June 2006 (UTC)
*Like many things in science, I think this was just convenient naming. A, B, C, D.... - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 12:50, 20 June 2006 (UTC)
:What about Vitamin K? Why was it named so? (Assuming that vitamin K actually exists, I am not too good in biology) [[User:Jayant412|Jayant,]][[WP:EA|<font color="green">17 Years,</font>]][[User_talk:Jayant412|<font color="red"> India</font>]] • [[Special:Contributions/Jayant412|contribs]] 13:09, 20 June 2006 (UTC)
::K = koagulation. The [http://www.madsci.org/posts/archives/feb99/918153014.Me.r.html MadSci Network] has answered this. –[[User:Mysid|Mysid]]<sup><font color="#ffa500">[[User talk:Mysid|(t)]]</font></sup> 13:12, 20 June 2006 (UTC)
:: It is named because it was derived from and added features to B. C++ added classes, templates, etc, by Bjerne Stroupguard. (Object oriented, etc). There's no "D" derived from "C", though, to whoever said thait.
:: He was talking about vitamins not Object oriented programming languages.;-) [[User:Jayant412|Jayant,]][[WP:EA|<font color="green">17 Years,</font>]][[User_talk:Jayant412|<font color="red"> India</font>]] • [[Special:Contributions/Jayant412|contribs]] 20:23, 20 June 2006 (UTC)
:::Maybe some emoticons are just to be supposed in most part of these pages ;-). --[[User:Harvestman|DLL]] 20:42, 20 June 2006 (UTC)
:I wonder why nobody pointed to [[vitamin]]. This has some info -- [[User:Wikicheng|Wikicheng]] 09:35, 21 June 2006 (UTC)
::Vitamin S makes you sick, and Vitamin H makes you grow horns on the top of your head. -- [[User:Chuq|Chuq]] 03:11, 26 June 2006 (UTC)
== electricity in sea water ==
Hi,
Hi,
Its simple but i have this in mind for long time..
In rainy season,in road side some transformer may get burst and the wires get fallen in rain water,so the people who are all walking in settled rain water get shocked.
My question is like the same thing, if some transformer or current giving thing get fallen in sea water,what about the flow of current in the water?Is the whole water get current?If people swim in sea hat happende to them?
*They get electrocuted if they touch conducting material or are swimming closely to the source of the shock. But the farther away they are the less likely they are to get a shock because the available current would either spread or go through to the ground. The first would spread it over such a large area it's no longer dangerous, the second would mean it's gone in seconds. - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 12:48, 20 June 2006 (UTC)
*It's an issue even when an [[electric power transmission]] cable is torn and falls to the ground. Ground is also a conductor, so the current spreads from the cable in all directions. If you happen to be near you are advised not to make long steps (so that the potential between your feet is not too high) or even to jump on one foot. [[User:Conscious|Conscious]] 04:38, 21 June 2006 (UTC)
==Another quantum mechanics question==
Using the wavefunction derived on [[Hydrogen-like atom]] can anyone point me to a page that shows or describes how to calculate (using a quantum mechanical method) the energy of (or energy difference between) quantum states. I was thinking for simplicity of taking the energy when the quantum number (n) tends to infinity as being 'zero' as this seems to approximate totally separate electron and proton. Does this energy correspond to using a semi classical method of using the wavefunction to give propabilty density and using that probabilty density function combined with coloumb potential integrated over all space to give the 'average energy' of a wave-like electron?[[User:HappyVR|HappyVR]] 11:46, 20 June 2006 (UTC)
:The purely quantum method is to solve the Schrodinger equation '''''H'''Ψ = E·Ψ'', where the resulting [[eigenvalue]]s ''E'' are the energy levels of each orbital. For some reason, we have the solutions for ''Ψ'' but not for ''E'' in the [[hydrogen-like atom]] article. Instead, the solution for ''E'' is in [[hydrogen atom]]. Hope that helps, anyway. (And yes, as you can see, as ''n'' goes to infinity, you get to zero potential energy.) To be honest, I haven't tried integrating the probability-weighted potential...I suspect that it ought to give you the right total potential energy, and I'd be concerned if it didn't. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 15:15, 20 June 2006 (UTC)
:If you know the wave function, energy is just HΨ/Ψ, indeed (and it's constant if you have the right wavefunction). For your second question, [[quasiclassical approximation]] is applicable when n >> 1. (Either I don't know the correct English term or we should have an article on this.) [[User:Conscious|Conscious]] 04:34, 21 June 2006 (UTC)
== Cutting animals in half? ==
Could someone be kind enough to satisfy my curiosity and post a list of animals which can be cut into two (or more) pieces and survive, with each piece growing into a separate creature? Cheers. --[[User:Kurt Shaped Box|Kurt Shaped Box]] 11:54, 20 June 2006 (UTC)
:Are you planning to cut animals in half? That said, the [[planarian]] would work nicely. --[[User:Zemyla|Zemyla]]<sup>[[User talk:Zemyla|t]]</sup> 12:39, 20 June 2006 (UTC)
*The story that earthworms can regenerate in such a way they form two worms afterwards is an [[urban legend]] as [http://www.newton.dep.anl.gov/askasci/zoo00/zoo00690.htm this link] and various others show. Given the fact such animals would require duplicate organs, I actually doubt any animals can do this. The living part of some animals can regenerate limbs and/or tails, but the cut-off part will never grow into a full animal itself. - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 12:44, 20 June 2006 (UTC)
[[Colony (biology)|Colonial animal]]s such as [[sponge]]s and [[coral]]s. [[User talk:Gdr|Gdr]] 12:53, 20 June 2006 (UTC)
:... and a species of [[starfish]] called [http://www.saltcorner.com/sections/zoo/inverts/echinoderms/starfish/Llaevigata.htm ''Linckia laevigata''] can grow a new individual from a single severed arm. [[User:Gandalf61|Gandalf61]] 12:56, 20 June 2006 (UTC)
:(edit conflict) What about [[starfish]]? I heard that if you chop off one of their arms, it'll becoming a new starfish. But it could just be an urban myth. [[User:Jayant412|Jayant,]][[WP:EA|<font color="green">17 Years,</font>]][[User_talk:Jayant412|<font color="red"> India</font>]] • [[Special:Contributions/Jayant412|contribs]] 13:02, 20 June 2006 (UTC)
::It is true. The starfish has an extraordinary ability to regererate. But for a chopped-off arm to grow a complete new starfish, the arm must be of sufficient size – and, as I've heard, the arm should include at least part of the central disc, too. –[[User:Mysid|Mysid]]<sup><font color="#ffa500">[[User talk:Mysid|(t)]]</font></sup> 13:10, 20 June 2006 (UTC)
:::Then if people can give examples of animals that can regenerate, there must be a full list. --[[User:Proficient|Proficient]] 22:01, 20 June 2006 (UTC)
I do know that there are certain lizards, that if you grab them by the tail, as a last resort, they'll simply let their tail detach, and grow a new one later. However that's not to say that the tail itself will grow a new lizard! [[User:Loomis51|Loomis]] 22:24, 25 June 2006 (UTC)
== how does biology affects our life? ==
how does biology affects our life?
:Without it we wouldn't be alive. Perhaps you should read [[biology]] and come back with specific questions that you need help with. [[User:Dismas|Dismas]]|[[User talk:Dismas|<sup>(talk)</sup>]] 13:35, 20 June 2006 (UTC)
::Do your own homework, kid. :-) -[[User:Quasipalm|Quasipalm]] 16:01, 20 June 2006 (UTC)
== Jumping from a height? ==
Is it possible for a human to fall from a height of about 1-5 stories without injury reliably? I'm getting tired of taking the stairs... --[[User:Zemyla|Zemyla]]<sup>[[User talk:Zemyla|t]]</sup> 13:57, 20 June 2006 (UTC)
:That's quite a range... I would think it has a lot to do with the physical condition of the person as well as what they are landing on. Concrete would be much harder than grass, sand, or gravel. I used to jump from a height of about 12-15 feet when I was a kid to escape being beat up by the bigger kids on the playground (they'd chase me to the top of a slide, I'd jump, that would give me a few seconds to get away) but I doubt I could do it very often now without straining something. [[User:Dismas|Dismas]]|[[User talk:Dismas|<sup>(talk)</sup>]] 14:13, 20 June 2006 (UTC)
And the ground was designed to be fallen upon. Most buildings have wood or concrete floors covered with linoleum or carpeting and falling on them would be very different from falling on loose sand, rubber, or gravel. [[User:Emmett5|Emmett5]] 16:24, 20 June 2006 (UTC)
*It happened. I even heard about a parachutist that survived a fall when his chute didn't open. But don't count on it being in any way reliable when it comes to not getting injured. - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 18:08, 20 June 2006 (UTC)
:So I'd say it depends mostly on the material. The height and state of the person are also very important. I would not risk trying it though. --[[User:Proficient|Proficient]] 22:04, 20 June 2006 (UTC)
If you use the same setup as stuntmen do, and jump into a giant airbag, then yes, you can jump from that height and survive. It is important to land back first, however, to distribute the force evenly. [[User:StuRat|StuRat]] 00:02, 21 June 2006 (UTC)
:The biggest danger in jumping from such heights is broken bones, twisted ankles, that sort of thing. One storey is definitely doable, although I wouldn't recommend it on a regular basis. Two storeys, you run a high risk of broken bones - soft, even ground helps some but not much (although, if you have to jump in an emergency, you probably ''will'' survive). Three and above, you run a high risk of death. This is all assuming that you're landing on 'ordinary' materials - a huge airbag (as StuRat said) is a very good surface to land on, even from great heights, but you need to land correctly. You can dive into water from 10-12m without much danger, but make sure you land feet first and ensure the water is deep enough! — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 09:09, 21 June 2006 (UTC)
==== Falling in an elevator ====
Can we infer then, from [[User:StuRat|StuRat]]s reply, that the best thing to do if being trapped in an elevator which starts falling from the fifth floor, would be to lie down on your back? --[[User:62.16.189.71|62.16.189.71]] 06:02, 21 June 2006 (UTC)
:Not sure about that... but it does suggestion I've wondered about for a while. Say you're trapped in something like an elevator and you can tell exactly when it will hit the ground. ''A split second before it hits, you jump up in the air.'' Assuming that the elevator survives intact, are you more likely to be uninjured than if you'd just stood in the elevator or braced yourself for impact? [[User:Grutness|Grutness]]...''<small><font color="#008822">[[User_talk:Grutness|wha?]]</font></small>'' 06:19, 21 June 2006 (UTC)
::No - this is a myth (see the book ''Worst Cast Scenario''). The upward speed you can create by jumping isn't anywhere near enough to compensate for the speed of the falling elevator. Your best bet to survive in a falling elevator is to try and distribute the force as much as possible by lying on your back or on your stomach, trying not to damage your vital organs. Even then, it's dicey. — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 09:30, 21 June 2006 (UTC)
:Guys, you have forgotten [[weightlessness]] in a falling elevator. The moment the elevator starts falling, you'll lose your footing and you will be floating in the air, falling along with the elevator. You will not be able to anything (turn / jump up etc), except to wait till the elevator hits the bottom. This is, not considering the shock and panic at that moment -- [[User:Wikicheng|Wikicheng]] 10:16, 21 June 2006 (UTC)
:::I dont understand. You wouldnt be going that fast, so why would you die?
::This is one of many of the questions discussed in the (frankly hilarious) book, "Why Girls Can't Throw: And Other Questions You Always Wanted Answered" by Mitchell Symons (ISBN: 0060835184 for the hardback) which is an excellent "toilet-reading" book. Symons comes to similar conclusions to those above, but argues (reasonably convincingly) that your best chances of survival lie in having travelled in a lift where you have fellow passengers who are (preferably) fat. --[[User:Dweller|Dweller]] 10:21, 21 June 2006 (UTC)
:::If we assume the elevator isn't quite in free fall due to resistance from the walls of the elevator shaft, then you would have a choice of what to do. While lying on your back is best to reduce the risk of any injury in a mild impact, that's not the case in the elevator. Since you are certain to suffer major injuries, the goal is to just stay alive. I would suggest that standing upright, with the knees slightly bent, would be best. This would allow the legs to fold and then fracture on impact, hopefully protecting the vital organs in the abdomen and head from fatal forces. [[User:StuRat|StuRat]] 12:32, 21 June 2006 (UTC)
::::Although, if you were nearly weightless, you could attempt to gather your body into a tight ball spinning at high-speed, and when you landed you would roll around distributing the shock of the fall to all parts of your body. It'd be funny to watch on the CCD after it all ended too. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 16:24, 21 June 2006 (UTC)
: Actually, your best chance is to pinch yourself and wake up, because I don't think an elevator has ever fallen, at least not in the last 100 years. If you look down an elevator shaft, you'll see they have massive cables up the wazoo - way overkill, thankfully. (correct me if I'm wrong about elevators never crashing - i didn't actually research that)--[[User:Bmk|Bmk]] 21:25, 21 June 2006 (UTC)
::Elevators still fall, but due to emergency brakes, nowadays they are usually stopped (relatively) gently before they hit the bottom. But not always. A Google News search on ''elevator fall'' turned up [http://www.mlive.com/news/jacitpat/index.ssf?/base/news-17/115090597510110.xml&coll=3 this article] from today. And here are two [http://www.theaustralian.news.com.au/common/story_page/0,5744,19473195%255E25658,00.html recent] [http://www.unian.net/eng/news/news-156010.html articles] about elevator falls where the emergency brakes stopped the car before it hit bottom. [[User:Chuck Carroll|Chuck]] 21:48, 21 June 2006 (UTC)
Wikicheng, because of friction between the elevator and the tracks you would still have...god some physicist is going to stab me in the face for putting it this way..."some gravity". --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 02:38, 22 June 2006 (UTC)
Yes. Agreed :-) -- [[User:Wikicheng|Wikicheng]] 08:16, 26 June 2006 (UTC)
== Hairyness and evolution ==
Male and female primates are both very hairy.
What is the evolutionary reason for female humans being so hairless? What is the evolutionary reason for both sexes sprouting armpit hair, but not knee hair?
Hairy [[User:Dweller|Dweller]] 14:10, 20 June 2006 (UTC)
:Here is something to consider:
::* [http://www.economist.com/science/displayStory.cfm?story_id=2281888 The bare truth - Why are humans nearly hairless? And why do some wish to become more so?]
::''For many decades, the most popular explanation of hairlessness was that humans lost their hair to keep cool. Too much hair made humans—very active apes—hot, like elephants. Elephants evolved huge floppy ears to radiate heat back into their surroundings. But when hominids moved out of the forests and into the savannah, the same task could be carried out by the entire body, thanks to hominids' upright posture (which exposed less skin to the sun) and their lack of hair.''
::''Mark Pagel, at the University of Reading, and Sir Walter Bodmer, at the John Radcliffe Hospital in Oxford, have a new idea. They believe that parasites are the key to human hairlessness. Humans, they say, lost their hair in order to reduce the burden of parasites such as fleas and ticks, some of which would have transmitted disease. Early humans probably lived close together in hunter-gatherer groups, in which the rate of parasite transmission was high. Hairless skin was easier to keep clean. Cultural adaptations, such as the use of fire, shelter and clothing, allowed humans to become furless.''
::-[[User:Quasipalm|Quasipalm]] 16:04, 20 June 2006 (UTC)
:::Really interesting, but to be harsh, it actually doesn't answer either of the questions I posed. a) why are women less hairy and b) why do we have armpit hair? --16:08, 20 June 2006 (UTC)
::::The fact that women are less hairy is probably a [[secondary sex characteristic]], and armpit and pubic hair are believed to have remained for reasons of friction and pheromones. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 16:49, 20 June 2006 (UTC)
:Nice. So women are hairless to appear different. Difficult to imagine an evolutionary mechanism for that though. Hairy 'pits reduce friction? Again, I think it would be difficult to demonstrate a survival advantage there. But as a non-scientist, my understanding of evolution is probably as childish as my sense of humour. --[[User:Dweller|Dweller]] 17:49, 20 June 2006 (UTC)
::For the former, many species have different appearances for genders. For the latter, reducing chafing and irritation would seem a clear (albeit minor) survival advantage. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 18:12, 20 June 2006 (UTC)
:::[[The Naked Ape]]: A Zoologist's Study of the Human Animal (ISBN 0385334303) by [[Desmond Morris]]. Read this, it's fun and sometimes more fun. --[[User:Harvestman|DLL]] 20:39, 20 June 2006 (UTC)
::::Just my 2 cents. Human Females have a layer of fat just under the skin which males normally do not have. This provides a measure of insulation against the cold which means less body hair is needed to keep warm.
:::::Men have fat under their skin, too, although perhaps less than women. When I cut my arm on a piece of glass, I saw the little yellow fat globules myself. [[User:StuRat|StuRat]] 23:58, 20 June 2006 (UTC)
Very cool answers. Thank you. Still unconvinced, but enjoying the banter. Also, thanks for proving that scientists can answer questions in plain English. Just wish your cousins on the Mathematics page were able to do so. (Mind you, I brought it on myself) --[[User:Dweller|Dweller]] 21:19, 20 June 2006 (UTC)
:Secondary sex characteristics don't only emerge as ways to differenciate the sexes. One of the only logical explanations why human breasts are so much larger than those of other mammals is that they evolved as an attractive trait. This makes sense because a healthier female (with better access to food) would more likely be able to sustain large breasts and it would be extremely easy for a male to recognize that. You could as well theorize that it is easier for hairless females to show off their health than patchy hairy ones, though that doesn't explain why other animals don't evolve in the same way. It's probably a much more complex combination of factors. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 05:22, 21 June 2006 (UTC)
*The "science" is breast augmentation, hair removal, et cetera.[[User:Patchouli|Patchouli]] 05:36, 23 June 2006 (UTC)
Not sure how much this is really backed up by science, but supposedly humans lost hair after the domestication of fire. With an external means of keeping warm at night, hair wasn't necessary and, since hair hosted parasites, became a liability. Hair remained where sweat glands doubled as scent glands and the head, which had more stringent requirements for protection from cold or sun. However, that doesn't explain beards or male pattern baldness... [[User:Peter Grey|Peter Grey]] 05:55, 21 June 2006 (UTC)
:I have heard something similar, stating that hair disappeared after HS started wearing clothing, probably around the same time that they started using fire, and possibly for the same reasons. Facial hair could be a secondary sex characteristic too, or some similar visual feature. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 16:19, 21 June 2006 (UTC)
:Women do have as much hair as men, it's just much finer. The coarseness of body hair has to do with the timing of introduction and the dosage of male hormones. Read up on [[Polycystic ovary syndrome]], [[Anabolic_steroids#Female-specific_side_effects|anabolic steroids]], [[Hirsutism]], and [[Sex hormones]]. A theory for the existence of underarm and groin hair is to trap body scent indicators, for the purpose of reproduction and scent recognition of relatives. Try reading up on [[Underarm hair]] and [[Pubic hair]].--[[User:Anchoress|Anchoress]] 20:45, 21 June 2006 (UTC)
[Link causing problems in IE removed] [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 06:47, 25 June 2006 (UTC)
== Circumcision ==
I just read the [[circumcision]] article, but couldn't find any information on how the "string" that runs on the back of the penis is "dealt with". Isn't the "string" some kind of "tube" for urin and semen? How does one avoid not cutting it off when doing a circumcision? [[User:Jack Daw|Jack Daw]] 14:46, 20 June 2006 (UTC)
:I think you're talking about the [[frenulum]]; it's a band of tissue that runs along the bottom of the foreskin...? It is not involved in the passage of urine or semen; all of that happens in the [[urethra]]. the frenulum is frequently trimmed or removed during circumcision without ill effect—it only contains some small blood vessels which heal rapidly. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 15:18, 20 June 2006 (UTC)
:It's harmless to cut off. --[[User:Proficient|Proficient]] 22:05, 20 June 2006 (UTC)
::Though I wouldn't recommend trying this out for yourself... [[User:GeeJo|<span style="padding : 0px 1px 1px 1px; border : 1px solid #809EF5; cursor: wait; background: #FFFFFF ; color: #99B3FF">GeeJo</span>]] <sup>[[User talk:GeeJo|(t)]]</sup>⁄<sub>[[Special:Contributions/GeeJo|(c)]]</sub> <small>• 23:10, 20 June 2006 (UTC)</small>
:I wonder whether the word "harmless" is appropriate for this procedure. I think that it is more correct to say that the dissection of the frenulum is a normal part of cicumcision, which typically does not produce immediate or long-term physical harm.[[User:Tuckerekcut|Tuckerekcut]] 23:44, 20 June 2006 (UTC)
:Nota bene: There is a small but noisy contingent of people who have very strong opinions about circumcision, either pro or con. Be careful about circumcision info you find on the web. A lot of it is provided by such people, so stick to very reputable sources. --[[User:Antifamilymang|George]] 04:16, 21 June 2006 (UTC)
::Interesting comment, George. Are you saying that someone with a very strong opinion one way or the other, about this or any other subject, is ''ipso facto'' out of contention as "very reputable"? Does your own post above count as a "strong opinion", and does that make your proferred advice not very reputable? [[User:JackofOz|JackofOz]] 09:12, 22 June 2006 (UTC)
== Texas Instruments subfamily abbreviations ==
Hi all. I'm trying to figure out what some Texas Instruments IC subfamily abbreviations stand for. For example, I know that LS stands for "Low power Schottky". I want to know what other abbreviations stand for, such as NE, SA and SE (specifically for the [http://focus.ti.com/lit/ds/symlink/ne555.pdf 555 timer]). Thanks! ~[[User:Mdd4696 |MDD]][[User talk:Mdd4696 |46]][[Special:Contributions/Mdd4696 |96]] 16:19, 20 June 2006 (UTC)
:Actually, I believe the NE, SA and SE abbreviations belong to Fairchild Semiconductor... but I still have no idea what they mean! Perhaps they're just random.... ~[[User:Mdd4696 |MDD]][[User talk:Mdd4696 |46]][[Special:Contributions/Mdd4696 |96]] 18:50, 20 June 2006 (UTC)
::Signetics, according to [[555 timer IC]]. Data sheets like [http://eu.st.com/stonline/books/ascii/docs/2182.htm this STM one] say that those three prefixes refer to different temperature grades. I can't find out why those particular letters were chosen, though. --[[User:Heron|Heron]] 20:13, 20 June 2006 (UTC)
== Ethanol ==
Do you have any information on how to make ethanol from paper
Thank you Richard--[[User:203.109.165.249|203.109.165.249]] 22:44, 20 June 2006 (UTC)
:The most efficient route would be to add [[cellulase]], typically from [[symbiotic]] [[bacteria]] from [[ruminant]]s, which'd break the [[cellulose]] to [[glucose]]. From there, add [[yeast]] in [[anaerobic]] conditions to produce [[ethanol]] [[User:GeeJo|<span style="padding : 0px 1px 1px 1px; border : 1px solid #809EF5; cursor: wait; background: #FFFFFF ; color: #99B3FF">GeeJo</span>]] <sup>[[User talk:GeeJo|(t)]]</sup>⁄<sub>[[Special:Contributions/GeeJo|(c)]]</sub> <small>• 23:18, 20 June 2006 (UTC)</small>
== Microsoft Outlook Problem ==
When I type the word ''products'' in an Outlook e-mail message, ''pr'' appears on the first line and ''oducts'' jumps to the second line. How can I fix this?[[User:Patchouli|Patchouli]] 23:26, 20 June 2006 (UTC)
:It ''could be'' an autocorrect problem. Try clicking the 'undo' button right after. If that fixes it (shows products correctly), someone's played a joke on you and added an autororrect to Word, which you can correct in word.--[[User:Anchoress|Anchoress]] 23:29, 20 June 2006 (UTC)
*I sent the e-mail. Now when I look at the e-mail in the '''Sent Items''' folder, the word ''products'' is not disconnected and appears whole.
: '''Use AutoCorrect when Word isn't the e-mail editor''' check box is currently selected. Should I deselect it?[[User:Patchouli|Patchouli]] 23:55, 20 June 2006 (UTC)
::Well if the email looks fine now, it probably wasn't an autocorrect problem. Sometimes, either because of refresh problems, font size/paragraph alignment etc, words will appear to break across lines. Of paramount importance is whether or not it ever was apparant that the text was broken across lines in your unsent message? Did you check? Because if it was, you'll have to wait until it happens again and investigate further. If it wasn't, then it's just a failure of WYSIWYG and can be ignored. As for the Autocorrect, don't change anything unless or until you know for sure it's a problem.--[[User:Anchoress|Anchoress]] 12:48, 21 June 2006 (UTC)
*Thanks.[[User:Patchouli|Patchouli]] 23:53, 21 June 2006 (UTC)
= June 21 =
== Bismuth Tellurium Transistors used in water heating/cooling ==
I just recently heard about a device using bismuth telluride transistors that has the potential to boil/freeze water in seconds from the power of two flashlight batteries. I read this randomly in an old version of the CRC handbook of Chemistry and Physics. I, personally, really enjoy building things, and I would like to add this to my wanted collection, but I do not know where to begin, let alone have the schematic for such a device. I want to ask how should I build this device, and where can I gather the proper information regarding the potential power outputs and details of this machine?
:Sounds like [[Thermoelectric cooling]]. [[User:DMacks|DMacks]] 01:00, 21 June 2006 (UTC)
::I don't believe there is sufficient energy in two flashlight batteries to boil or freeze any significant amount of water, even if we could release all of it instantaneously. Perhaps if you could use mains power... but you'd probably blow a fuse. Thermoelectric cooling is neat, but it isn't magic. ~[[User:Mdd4696 |MDD]][[User talk:Mdd4696 |46]][[Special:Contributions/Mdd4696 |96]] 03:39, 21 June 2006 (UTC)
----
:Ha! Something I know a lot about! I entered this into the [[Junior Science and Humanities Symposium]] through the US DOD. This is called a [[Peltier junction]], and I believe that page redirects into [[thermoelectricity]] (last time I was there). They are really fun! I blew mine out with more than five amperes (oh crap). What I had done was run so much current through, I either melted the bismuth-tellurium (I don't know it's melting point) or I had melted the sodder leads which flowed into the Peltier-Seebeck junction. As a note, "Peltier junctions" are used in cooling applications, and "Seebeck junctions" are used in heating. Although the heat is just "moved" using the thermoelectric effect, usually Peltier junctions are used, because there is always an opulence of heat. Peltier junctions are usually used in microprocessor cooling applications when hackers modify their processors to run at dangerously high speeds. As for the heating and freezing, in my experience with commecrially-made ones, you need at least two-three amperes before water vapor starts to directly freeze out of the air.
::'''Construction/Parts''': Ceramic plates are on each side of the sandwitch of bismuth-tellurium to create a smooth flat surface area, a freakin lot of the bismuth-tellurium alloy curved sandwitches are bent around between the ceramic (read the links already above to get this).
::'''Building''' is tough! Unless you've been doing this kind of thing for decades you won't be able to. You have to have at least 20 P-N-P junctions right next to each other for it to work, and a pretty high density (I think mine was something like ~200/in<sup>2</sup>. All I remember is that you'll need a fume hood and some great smelting skills and lots of bismuth and tellurium. I tried to
::'''Buying''' is your best bet. You can buy a great one off of eBay for ''reeeally'' cheap. I think mine was between forty and sixty dollars. The junction density is prime and the bismuth-tellurium structures are industrial-made. Google it correctly and there are some awesome mods people do with Peltier junctions. My favorites involve the portable mini-, single-can- beer cooler.
What kind of plastic do they use in plastic surgery?-<font size=2 title="THIS IS MY SIGNATURE, USE IT TO FIND OUT MORE ABOUT ME"><font color=orange>'''[[User:Beeyti|Bee]]'''</font>('''<b><font size=1 title="CLICK ON THIS IF YOU WANT TO LEAVE ME A MESSAGE ON MY TALK PAGE"><span class="plainlinks">[http://en.wikipedia.org/enwiki/w/index.php?title=User_talk:Beeyti&action=edit§ion=new y]</span></font></b>''')<font color=orange></font><sup>'''<font size=4 title="THIS IS MY TALK PAGE, CLICK ON THIS IF YOU WANT TO SEE MY TALK PAGE">[[User_talk:Beeyti|T]]</font>[[User_talk:Beeyti|i]]'''</sup></font> 01:17, 21 June 2006 (UTC)
: Sometimes when plastics is hurt; you send it to a hospital. If a man hits your car's plastic bumper; you must send it to a hospital to perform immediate surgery. -- [[User:Toytoy|Toytoy]] 01:33, 21 June 2006 (UTC)
:[[Plastic surgery]] has nothing to do with [[plastic]] materials. The word ''plastic'' comes from the Greek ''πλασσειν'', meaning "form", "mould", or "shape". Originally only flexible materials were called ''plastic'', but now the word is commonly applied to all synthetic polymers, even rigid ones. Plastic surgery is surgery in which the flesh is molded into a different shape. —[[User:Keenan Pepper|Keenan Pepper]] 01:46, 21 June 2006 (UTC)
::Usually squished or pulled into a different shape. — [[Image:Flag_of_the_United_States.svg|17px]] <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]]
:It would depend on the plastic individual's health insurance. I'm sure they'd do their best to match the original plastic. [[User:Peter Grey|Peter Grey]] 06:09, 21 June 2006 (UTC)
::[[Silicone]]. (--[[User:Shantavira|Shantavira]] 06:44, 21 June 2006 (UTC))
:::When a family member injured her hand slicing an avocado, we were told by the plastic surgeon that operated on her that the most common reason why people in London require plastic surgery is because of accidents to the hand while cutting fruit and veg. Avocados are particularly troublesome because of the combination of the softness of the fruit and the hardness and slipperiness of the stone. "Avocado cuts" are the number 1 cause for "middle class" families, apparently. Plastic surgery using silicone/plastic on people's chests (or wherever on their bodies) is apparently off-the-scale less common than routine repairs to skin injuries etc. --[[User:Dweller|Dweller]] 10:13, 21 June 2006 (UTC)
Plastics are used in surgical implants, both temporary and permanent, but this is, as noted above, unrelated to the use of the term "plastic surgery". Plastics may be used in plastic surgery, as in other surgical fields. Other materials, like titanium, may also be used in any form of surgery. [[User:StuRat|StuRat]] 13:18, 21 June 2006 (UTC)
== Color and black body radiation ==
What is "color" molecularly? Are there any certain rules that say certian combination of particles create certain colors? How about the black body case? How does black body radiation work in this case molecularly?
*colors depend on the frequency and color of the futons emitted by the black body--<small>—The preceding [[Wikipedia:Sign your posts on talk pages|comment]] was added by [[User:Beeyti|Beeyti]] ([[User talk:Beeyti|talk]] • [[Special:Contributions/Beeyti|contribs]]) {{{2|}}}.</small> 01:58, 21 June 2006 (UTC)
:I'm sorry, but what on earth do [[futon]]s have to do with it? Colour is determined by the frequency of EM radiation emitted by the source. On the receiver's end, colour can be determined by the cells reacting to the radiation. See [[trichromatic color vision|trichromatic vision]] for details. [[User:GeeJo|<span style="padding : 0px 1px 1px 1px; border : 1px solid #809EF5; cursor: wait; background: #FFFFFF ; color: #99B3FF">GeeJo</span>]] <sup>[[User talk:GeeJo|(t)]]</sup>⁄<sub>[[Special:Contributions/GeeJo|(c)]]</sub> <small>• 02:31, 21 June 2006 (UTC)</small>
:Yes, there are rules that determine the colors of substances given their chemical compositions, but they are very complex. See [[crystal field theory]] which explains why blood is red and grass is green. Black body radiation has nothing to do with color at room temperature, because black bodies at room temperature are, well, black. —[[User:Keenan Pepper|Keenan Pepper]] 02:41, 21 June 2006 (UTC)
::However black body radiation ''does'' change the frequency and color of emissions from a body. — [[Image:Flag_of_the_United_States.svg|17px]] <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]]
:::Yeah, sorry. I obviously left that part out (unconciously), becuase you had just said that. Add a "at very high temperatures" to that. :) — [[Image:Flag_of_the_United_States.svg|17px]] <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 22:17, 21 June 2006 (UTC)
::::Many of the relevant articles really need some additional explanation for non-scientists, but to sketch it out, you have [[Electron|electrons]] that are flying around very quickly around the [[Atom|atoms]] make up matter. These electrons are flying around so quickly that it's often better to describe their [[Electron configuration|location]] as being within a cloud where any given electron is more or less likely to be at any one time.
::::The shape and size of these clouds varies according to the [[Molecule|molecule]](s) involved. Said another way, when you have two or more atoms in a molecular bond, their electron clouds combine and interact in ever more complex ways.
::::A side-effect of these electron clouds is that they will absorb or repel different wavelengths of light; basically different colors of light. And so the combination of the color of the incoming light, combined with the electrons in these clouds leads to what we perceive as the color of an object.
::::I've tried to make it understandable and avoid jargon, but certain terms really are needed for a discussion like this. Also, this is really not my field, so hopefully someone better versed in [[Quantum chemistry|quantum chemistry]] will chime in.--[[User:Tachikoma|Tachikoma]] 16:20, 22 June 2006 (UTC)
== Cockroaches ==
I've heard that after we spray a cockroach with a pesticide, the cockroache transfers its DNA that is resistant to that kind of pesticide to its offspring, am I right? If I am, how do they do it, i mean, shouldn't they be dead by then? How do they change their DNA?
:The only way that resistance can be propagated in a population of cockroaches is by the following sequence of events:
# The presence in a population of cockroaches of various degrees of heritable vulnerability and resistance to pesticide, followed by
# the killing off of the susceptible ones by spraying of the pesticide, followed by
# successful reproduction of the surviving resistant cockroaches, followed by
# now a much higher proportion of resistant cockroaches in the local population.
You have been hearing nonsense from the ignorant. Animals and plants do not consciously select the genes or change the genes they pass to their offspring. As long as you have a population with a variety of genes, and the presence of pressures that reduce the reproductive success of some of the gene types, the genetic make-up of the population will change. This is how evolution works. Why are there so many people out there who think they understand mutation and evolution and spread this kind of nonsense when they wouldn't dream of claiming knowledge of cell biology? [[User:Alteripse|alteripse]] 03:36, 21 June 2006 (UTC)
Thanks a lot!
== Diluting sulfuric acid ==
How can you work out how hot a solution will become when diluting sulfuric acid? Eg. 98% -> 20%, how much energy will be given off?
Thanks very much
[[User:210.246.0.84|210.246.0.84]] 04:32, 21 June 2006 (UTC)
*Any type of chemical process involves the transfer of energy. Any chemical has a certain amount of energy stored in its molecule. Dissolving sulfuric acid would release the energy. All you need to figure out is how much energy you need to heat the resulting solution 1 degree, then see how many degrees you can heat it with the energy you got. - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 07:46, 21 June 2006 (UTC)
*There is no simple way to calculate this, it is one of the technical points which you learn doing practical chemistry. When I demonstrate the dilution of sulfuric acid to my students, I prepare a solution which is roughly 50%: this easily gets to excess of 80 °C. I then get the students to carefully touch the flask, which demonstrates why conc. sulfuric acid is so dangerous... [[User:Physchim62|Physchim62]] [[User talk:Physchim62|(talk)]] 08:21, 21 June 2006 (UTC)
== Train Vs Fly ==
Someone told me this riddle once but never left me with the answer. Perhaps someone here can help.
A fly is flying along a railway track at, say, 5 kph. He is hit by a locomotive travelling at 100 kph in the opposite direction. The fly quickly decelerates from 5 kph and, considering he is now squashed to the train, travels at 100 kph in the opposite direction to what he was initialy flying.
Re: the deceleration- he would have decelerated very (very) quickly from 5 kph in order to travel at 100 kph in the opp direction (5,4,3,2,1,0,1,2,3,4...100 all of which would have happened in the blink of an eye).
But for the briefest moment his speed would have been zero (the moment between travelling forward and traveliing along with the train). Now if he is not moving, and he is attached to the front of the train, surely this means the train isn't moving (if only for the briefest of moments)
Of course I know a fly can't stop a train so what is the explanation?
Sorry if I made this more complicated than it should be!
:A variation on [[Zeno's Paradox]]. Speed ([[velocity]], technically) is distance per unit time. If you're considering, not ''the briefest moment'', but ''zero'' elapsed time, then you would be "stopped" only in the sense of considering a zero displacement, no different from if the fly wasn't there at all. Unless you wanted someone to explain motion on the scale of [[Planck time]] (that would really be cool!) [[User:Peter Grey|Peter Grey]] 06:06, 21 June 2006 (UTC)
::This riddle has a corollary. What was the last thing to go through the fly's head?--[[User:Shantavira|Shantavira]] 06:48, 21 June 2006 (UTC)
:::His ass. [[User:Johntex|'''Johntex''']]\<sup>[[User_talk:Johntex|talk]]</sup> 08:28, 21 June 2006 (UTC)
:I don't think it's really a variation of Zeno's paradox; even over a finite length of time the fly will have a velocity of close to zero. The key is that implicit in the questioner's reasoning is that the the fly (and train) are point-like or rigid structures. They're not, of course. One could track the center of mass of the fly and it certainly would slow, come to a stop, then speed up in the other direction, and yes, if you neglect the effects of wind/air, this will occur after the fly has come in contact with the train. However (not to be gruesome), after the head has come in contact with the train, it will begin to be squashed towards the body. At the instant the center of mass of the fly is stationary, the back part of the fly is still moving towards the train, while the train is continuing forward squashing the head of the fly. If the fly were a point-like particle, it would bounce off the front of the change, instantaneously changing velocities. It would never have a velocity of zero; the derivative of its position at that instant would be undefined. Of course, all of this assumes classical mechanics; in reality (well, in quantum mechanics), position, velocity, and time become hazy if you probe them too deeply. — [[User:Knowledge Seeker|Knowledge Seeker]] [[User talk:Knowledge Seeker|দ]] 08:22, 21 June 2006 (UTC)
:A fly can't stop a train, but a train can stop a fly - where's the paradox? [[User:Physchim62|Physchim62]] [[User talk:Physchim62|(talk)]] 08:24, 21 June 2006 (UTC)
:Perhaps harder to explain, but surely the same paradox; what about a cricket ball being hit by a cricket bat. Does the cricket ball (shall we say, does the ''centre of gravity of the cricket ball'') ever have a velocity of zero? Is it only during the brief instant where both bat and ball are compressing at their mutual surface, and compressing at a rate that compensates for the combined velocity (over 100 mph?) [[User:Notinasnaid|Notinasnaid]] 09:48, 21 June 2006 (UTC)
::We're making a mountain out of a molehill here, the answer is pretty simple: when a fly hits a train, there will be a moment when the fly is at rest. Since at that moment, the fly is in contact with the train (ie is being squashed by it), the surface it's in contact with will also be at rest. If the train were a completely solid, undeformable object, that would mean the fly would stop the train (even if only for an instant). What happens in reality is the material the fly impacts (eg the windshield) deforms on impact, and ''it'' will be momentarily at rest. Of course, it will spring back almost immediately, and oscillate a few times, which is where the sound you hear on impact comes from: the windshield vibrating.
::So, the fly doesn't stop the train, but it does stop the windshield. The same goes for the cricket ball - if we treat both objects as being deformable (which they are), then the ''contact surface'' between the two will be momentarily at rest on impact. However, almost immediately, both the ball and bat will be compressed by a certain amount, and since the bat is ''much'' more massive than the ball, the bulk of its mass will continue moving forward without stopping. — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 12:09, 21 June 2006 (UTC)
::::'''QuantumEleven makes excellent points''' except for one minor (insignificant?) detail! The bat is not much more massive than the ball. The reason it continues forward is because an external force is being supplied to the bat. The bat and ball are of similar masses such that the momentum is matched (similar to [[Impedance matching]] in electric circuits - maximum power is transferred only if the masses are closely matched. Otherwise, great explanations. [[User:Nimur|Nimur]] 18:30, 23 June 2006 (UTC)
:::::Er, the fly never stops anything, not even necessarily the first layer of atoms on the windshield's surface. The velocity of the fly-as-point-particle corresponds to the average velocity of the fly, which is 0 when the fly's butt and head are moving in opposite directions (i.e., the fly is squishing). At no time is it necessary for the windshield (which is only touching the head, not the [[center of gravity]]) to be stationary. You could argue that the head itself must have 0 velocity at some point; then we refine it to "the windshield is only touching the ''front'' of the fly's head". Then you say that even that must stop at some point, and eventually we're arguing about individual atoms on the surface of the fly. As those are too small to be "in contact" with anything, the argument that any part of the train must have the same speed as them breaks down. (Also, remember that all velocities are relative; all of this is in a frame where the fly and train were moving in opposite directions before impact and the train's velocity wasn't negligible.) --[[User:Tardis|Tardis]] 00:40, 24 June 2006 (UTC)
:::I've seen photos taken with high-speed lens/film that show different kinds of balls deforming. Tennis balls, being so squashy, are naturally a great subject for this type of shot. A cricket ball feels extremely hard, but its leather surface and (frankly rather odd) innards will nonetheless compress. --[[User:Dweller|Dweller]] 12:14, 21 June 2006 (UTC)
*None of the tennis ball pix I could find on Google were much good, but here's a nice one of a rubber ball deforming [http://www.mellner.com/Objects/Drello/highspeed/ball5.jpg]
:Also, on the impact, the windshield of the train will undergo some deformity (it will bend back a bit) and then (after some oscillations) come to its normal position. There will be the instant when the train is moving forward but the windshield (with the fly squashed against it) is moving backward. This combination (of WS+fly) can attain zero velocity. It all becomes too messy (to calculate and also physically) because the fly gets squashed -- [[User:Wikicheng|Wikicheng]] 13:43, 21 June 2006 (UTC)
::Please see my above post in this same section: the windshield need not move backward except relative to the rest of the train (as it must deform to apply force to the fly), and that movement can be entirely insignificant compared to the train's velocity (which can be anything, since we can fling the fly at a train instead of ramming the fly with the train). --[[User:Tardis|Tardis]] 00:40, 24 June 2006 (UTC)
== Mobile phones radiation ==
Hello. Is there any article or websaite about the radiation that is generated from different types of mobile phones? If possible, I would like to see a website that contains all brands and models of mobile phones. Thank you! --[[User:Alexignatiou|Alexignatiou]] 06:23, 21 June 2006
:[http://www.arpansa.gov.au/mph1.htm].... u can get som information here....--hima 09:19, 21 June 2006 (UTC)
:First, you might be interested in our article about [[mobile phone radiation and health]].
:Secondly, if this worries you, have you considered buying and using a handsfree kit?
:Thirdly, here's [http://asia.cnet.com/reviews/mobilephones/0,39050603,39002664,00.htm such a site], using published data from the manufacturers. I found this in about 10 seconds by using [[Google]] to search for the words [http://www.google.com.au/search?hl=en&q=mobile+phone+radiation+comparison&btnG=Google+Search&meta= mobile phone radiation comparison]. Try searching first, it's quicker. --[[User:Robert Merkel|Robert Merkel]] 09:13, 21 June 2006 (UTC)
I did search, however I didn't find what I was looking for. And it's not something that worries me, I don't use mobile phones a lot, just because I always hear stuff... '''Thanks, anyway''' --[[User:Alexignatiou|Alexignatiou]] 13:04, 21 June 2006 (UTC)
What is the ''safety'' factor of a handsfree kit? Instead of putting radiation near my brain, I should but it near my balls? That makes no sense. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 15:52, 21 June 2006 (UTC)
:Answering seriously, and to say something that has not been said without jumping into the links: Cell phones do not release the kind of radiation that you may at first think they do. They release electromagnetic radiation, but it won't give you cancer. The United States government I recall as having spent some hundreds of millions or a few billion dollars on clearning up this panic in the United States about powerlines. The scare has also existed with microwave ovens. — [[Image:Flag_of_the_United_States.svg|17px]] <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 22:23, 21 June 2006 (UTC)
== Aircraft Safety ==
I have seen destructive videos of an blade coming loose in a turbine fan of the air intake of a jet engine.Instead,Why cant they make a composite fan and then surround all its blades with a ring,so that even if one blade brakes the plane can still land safely?Guess it would be stronger and lastlonger.
:A composite fan is difficult to do at present because composites are not strong enough to widthstand the forces in a compressor fan. As for the 'ring', that's already done - all jet engines have reinforcement in the cowling around their compressor and turbine blades, so that if a blade should detach when the engine is spinning (this is called a ''blade-off''), the engine will contain the blade and prevent it from damaging the rest of the aircraft. As a matter of fact, it's a requirement for the engine to be allowed to fly, it must contain the damage should a blade detach.
:This used to be a bit of a problem with propeller aircraft - without any cowling, there would be nothing stopping a detached blade from zooming away at high speed and hitting something. Nowadays, this happens very rarely, but on some propeller aircraft (eg the [[ATR]] aircraft) you can still see the reinforcement of the fuselage wall near the propeller. — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 09:00, 21 June 2006 (UTC)
::I read a story, either in the National Geographic or New Scientist about the design and construction of the A380. It discussed this requirement somewhat. IIRC, it was quite a scary time for them (as it would be for any aircraft design team) when they tested it... [[User:Nil Einne|Nil Einne]] 14:36, 21 June 2006 (UTC)
:::I saw a test when they where making the big airbus thing that they had to build a complte engine and then destrucivlty test this it by blowing a propller of when the engine was at full power, which is slightly expensive as the engine was said to be worth its weight in gold --[[User:Colsmeghead|Colsmeghead]] 21:54, 21 June 2006 (UTC)
Just a note: Those fans have a completely insane amount of kinetic energy. You'd need QUITE a ring. I remember awhile ago I saw a program about how a turboprop pretty much fucked the whole backside of a plane with shrapnel. I think it may have been a military plane...I don't remember if they died or not... --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 02:29, 22 June 2006 (UTC)
:Yup, that's why those rings are made of some very strong stuff :) If you think the fans in turbofans are bad, the blades in turboprops are much worse: they spin at about the same speed, but each blade is considerably heavier (there are fewer of them). If a turboprop blade were to detach at full speed, it would likely go straight through the fuselage and maybe even out the other side... hence the need for, to put a name on it, armour :) (note that modern propeller designs mean that there are ''very'' few blade detachs, so no need to get worried about flying on turboprops!) — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 06:30, 22 June 2006 (UTC)
I did not mean a stationary ring on the body of the engine cover,but a ring attached to all the ends of the blades(Something like the rim of a cycle wheel with spokes) that rotates along with the blades
== Electromagnetic Question ==
If an inductor were charged,but its terminals were placed far apart so that it would not short when open.Would the wave become am Electro Magnetic Wave?
Also,If light were to enter a drop of water,we know it would choose the shortest path as soon as it enters the light drop(refraction).But what if the shape of the drop had changed as the light is still in between the drop?GUESS it would again choose the path of shortest distace.BUT observing this change,is it possible to predict the future shape of the drop,or is it that shape is the cause,direction is the effect?
:I don't understand your first question, but as for the second... you seem to be referring to [[Fermat's principle]]. The thing is, light rays don't have any foresight or predictive power. As a ray of light travels, it bends due to changes in the local refractive index, but it doesn't know about what lies ahead. Mathematically speaking, the extremum in Fermat's principle is a local extremum, not a global extremum. [[User:Melchoir|Melchoir]] 19:23, 21 June 2006 (UTC)
:: Re your first question, an inductor doesn't really get charged. What happens instead is that you store energy in the magnetic field. You may be thinking of a capacitor. But anyway you seem to be describing a steady-state situation. To have a wave you need to have some kind of oscillation. The question is rather confusing; could you describe in more detail what you mean? [[User:Arbitrary username|Arbitrary username]] 20:22, 21 June 2006 (UTC)
== Better Solar Panels ==
Is it possible to make the sunlight induce a charge by virtue of its EMW nature rather than just cause photonic emmision and build better solar panels?
: Your question is a bit confusing - perhaps you should read [[photovoltaic cell]].--[[User:Bmk|Bmk]] 21:38, 21 June 2006 (UTC)
:The question does not make any sense. I am unfamiliar with EMW natures. If my mind is just not being sharp, that's ok, but I suggest you stay away from that kind of "scientific" material. — [[Image:Flag_of_the_United_States.svg|17px]] <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 22:25, 21 June 2006 (UTC)
The swift answer is no (or at least unlikely). The frequency of the electromagnetic waves in sunlight (where most of the energy comes from) is way beyond the potential (unbound) electron oscillation frequency in most materials. Quite simply, the electrons can't move quickly enough, and if they can, no harnessable current is produced (unlike radio wave EM induction). --[[User:Eh-Steve|Eh-Steve]] 08:16, 22 June 2006 (UTC)
== Sunglasses ==
Is there a method to test the uv blocking effectiveness of sun glasses at home?
:I found this at Netwon/ANL's [http://www.newton.dep.anl.gov/askasci/eng99/eng99272.htm Ask a Scientist] and modified it (in [square brackets]) to fit into this situation:
::''A way of testing the [UV] transparency is to place the [sunglasses] between the UV light source and a piece of high quality white paper. The paper will fluoresce a bright blue if there is no [filter] present. If the bright blue disappears when you put the [sunglasses] in between, the [glasses are] absorbing the UV light.''
:I doubt that's a very accurate method to test the filter's effectiveness, but at least it can be done at home. –[[User:Mysid|Mysid]]<sup><font color="#ffa500">[[User talk:Mysid|(t)]]</font></sup> 09:37, 21 June 2006 (UTC)
:As far as I know, glass absorbs UV rays (that is why [[Fluorescent lamp]]s are safe, even though they have UV rays inside them). So the sunglasses made of glass is the simplest UV protection. Am I wrong on this? -- [[User:Wikicheng|Wikicheng]] 13:53, 21 June 2006 (UTC)
:Not all glass absorbs UV, otherwise how do you expect a [[Black light]] to work? The key in fluorescent bulbs is the white powder they coat the glass with, it causes the UV to (wait for it...) *Fluoresce* into white(ish) light. If you have a true UV source, what better test is there for a UV blocker than trying to stop the UV from hitting a surface and fluorescing? It's pretty obvious when it works.
::The article [[Ultraviolet]] says ''Ordinary glass is partially transparent to UVA but is opaque to shorter wavelengths''. It also says ''the range of UV wavelengths is often subdivided into UVA (380–315 nm), also called Long Wave or "blacklight"; UVB (315–280 nm), also called Medium Wave; and UVC (< 280 nm), also called Short Wave or "germicidal" ''. This means that ordinary glass blocks most of the UV (except the longer blacklight). The article also mentions ''Tungsten-halogen lamps have bulbs made of quartz, not of ordinary glass. Tungsten-halogen lamps that are not filtered by an additional layer of ordinary glass are a common, useful, and possibly dangerous, source of UVB light.'' But the surprise is ''Ordinary eyeglasses give some protection, and most plastic lenses give more protection than glass lenses'' -- [[User:Wikicheng|Wikicheng]] 15:04, 21 June 2006 (UTC)
But where would i get the uv light source from?
: Also, let's make clear that '''opaque''' and '''transparent''' aren't yes-no answers - there are degrees of opacity (e.g., blocks 95% of all UV rays... etc). As for a UV light source, you could use a Black Light (available in a lot of stores, esp. novelty stores, but maybe even stores such as a WalMart). You might also try a halogen lamp; they usually have a (removable) glass cover to block UV rays. Be careful as both the intense heat and the UV rays of a halogen lamp may be harmful if you are continuously exposed to either. [[User:Nimur|Nimur]] 18:43, 23 June 2006 (UTC)
== Osmosis in potatoes ==
Dear all I need to conduct an experiment on Osmosis in potatoes, and for that I need to write a scientific background and an extension. I know the scientific background of Osmosis, but as an extension, does the surface of potatoe affect Osmosis and if so, how could one carry out an experiment on such phenomenon? This is NOT a homework question but an extension task to my write-up
*Have you read [[Osmosis]]? The surface is probably the semi-permeable membrane between the water and the surface cells. - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 11:40, 21 June 2006 (UTC)
Does surface area of the potato affect the Osmosis?
:Absolutely. I would, in general, expect the osmosis rate to be proportional to the surface area, until the potato chunks are "soaked thru". If you have some substance you can submerge potatoes into, allow osmosis, and then detect the quantity absorbed by the potatoes, then you can design an experiment. Submerge a whole potato in a given quantity of the substance, then submerge a chopped up potato in the same quantity for the same length of time. I suggest peeling both potatoes first to avoid any effect of differing osmosis rates thru the peel than thru the rest of the potato. A simple, but less accurate, test would be to put the potatoes in iodine, then mash them and look at the color. The chopped up potatoes will presumably have much more color than the whole potato. The timing is critical, however; if you soak them too long both will be fully soaked with iodine, and show the same color. [[User:StuRat|StuRat]] 12:56, 21 June 2006 (UTC)
== Processor Architecture ==
If I'm installing Linux on a machine with two processor boards, should I look for a distribution designed for a 64-bit processor architecture? --[[User:Username132|Username132]] ([[User talk:Username132|talk]]) 10:06, 21 June 2006 (UTC)
:No, unless you know the processors are indeed 64-bit. Instead, look for the abbreviation [[Symmetric multiprocessing|SMP]] (symmetric multiprocessing), which refers to the use of multiple CPUs. –[[User:Mysid|Mysid]]<sup><font color="#ffa500">[[User talk:Mysid|(t)]]</font></sup> 11:11, 21 June 2006 (UTC)
:You need a linux kernel compiled specifically for SMP machines (otherwise only one CPU will be actually used). Some linux distributions already have one, but when it doesn't, you have to compile one yourself. You may also have to do turn on a special option if the machine has more than 1 gigabyte of RAM. – [[User:b_jonas|b_jonas]] 10:22, 23 June 2006 (UTC)
== I forget where I buried my threads... ==
I post lots of things on lots of different forums. It would be nice to be able to use one single program to track all my threads and keep me informed of replies. I sometimes forget to check up on a thread or even where I posted it. --[[User:Username132|Username132]] ([[User talk:Username132|talk]]) 11:32, 21 June 2006 (UTC)
:[[Help:Watching pages]] may help. --[[User:Hydnjo|hydnjo]] [[User talk:Hydnjo|talk]] 12:06, 21 June 2006 (UTC)
::I'm assuming it's for the whole net, not just WP. First, consider using either your favourites or adding links to your browser toolbar (AFAIK you can do this with most). Most BBS software has a feature where it will show the most recent 50 or so posts by a user, so rather than creating a link to every single active thread on the net, you can just create a link to your author pages on BBSs you post to.--[[User:Anchoress|Anchoress]] 12:44, 21 June 2006 (UTC)
* I agree with Username132. How difficult would it be to modify the MediaWiki software to provide RSS feeds or email notification of replies to all wiki discussions? --[[User:JWSchmidt|JWSchmidt]] 01:58, 22 June 2006 (UTC)
::I think it would be failry difficult, more trouble than it would worth. As this is a wiki, MediaWiki doesn't know about threads. People edit the text of pages, not add reply to "threads". If you want to be able to follow threads, you'll have to use a software more like a message-board.
::Also, someone has mentioned watching pages. In addittion to that, the "my contributions" link can also help. – [[User:b_jonas|b_jonas]] 10:28, 23 June 2006 (UTC)
::: Well, MediaWiki does allow for sending email when a page on one's watchlist is edited, but imagine the amount of email that would ensue... it was turned off for performance and spamming reasons in Wikimedia wikis. [[User:Titoxd|Tito]][[Wikipedia:Esperanza|<span style="color:#008000;">xd</span>]]<sup>([[User talk:Titoxd|?!?]])</sup> 05:21, 24 June 2006 (UTC)
== THREE CLASIIFICATIONS OF TECHNOLOGY ==
What are three classifications of technology and meanings of each classification.
#Homework questions blatantly copied directly from the book or worksheet.
#Homework questions poorly disguised as legitimate ref desk questions.
#Homework questions well disguised as legitimate ref desk questions.
[[User:StuRat|StuRat]] 13:07, 21 June 2006 (UTC)
:Broken, impractical and obsolete --[[User:Dweller|Dweller]] 13:15, 21 June 2006 (UTC)
::Stone age, space age, garbage ? [[User:Gandalf61|Gandalf61]] 14:00, 21 June 2006 (UTC)
:::Too much, too little, and wrong kind?--[[User:Inkypaws|inks]][[User talk:Inkypaws|<sup>T</sup>]] 21:18, 21 June 2006 (UTC)
::::One, two and three? --[[User:ColourBurst|ColourBurst]] 04:56, 22 June 2006 (UTC)
:Out of date, soon to be out of date, not yet created and thus doesn't yet have the opportunity to be out of date. --[[User:Fastfission|Fastfission]] 18:17, 21 June 2006 (UTC)
::That's the winner! --[[User:Dweller|Dweller]] 11:26, 22 June 2006 (UTC)
:The question absolutely needs context, because there are no actual "three classifications of technology." Just those described in the book. Is this high school level? --<tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 00:10, 22 June 2006 (UTC)
:Cheap, good, and fast? – [[User:b_jonas|b_jonas]] 09:46, 23 June 2006 (UTC)
::Most of the technology I buy doesn't fit any of those descriptions. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 15:32, 24 June 2006 (UTC)
== Lowering cholesterol levels through exercise ==
How is cholesterol levels lowered through exercise? What's the process? [[User:Jack Daw|Jack Daw]] 13:23, 21 June 2006 (UTC)
:While perhaps not completely answering your question, the [[cholesterol]] (especially the regulation section) and the [[hypercholesterolemia]] articles should help. [[User:Nil Einne|Nil Einne]] 14:52, 21 June 2006 (UTC)
::Yeah the latter says that exercise is one way to lower cholesterol levels, but it doesn't say how it works. Thanks though. [[User:Jack Daw|Jack Daw]] 20:00, 21 June 2006 (UTC)
If I were to hazard a guess, i would say that the increased cellular turnover induced by excersize would help lower cholesterol through cell formation. Also, changes in steroid production may factor in (although, as i remember, cortisol production decreases with improved excersize habits). This segmaent, taken from the [[HDL]] article, may also shed some light on the subject:
:In the stress response, serum amyloid A, which is one of the acute phase proteins and an apolipoprotein, is under the stimulation of cytokines (IL-1, IL-6) and cortisol produced in the liver and carried to the damaged tissue incorporated into HDL particles. At the inflammation site, it attracts and activates leukocytes. In chronic inflammations, its deposition in the tissues manifests itself as amyloidosis.
Sorry I can't be more specific.[[User:Tuckerekcut|Tuckerekcut]] 21:40, 21 June 2006 (UTC)
:That's specific enough, thanks! :D [[User:Jack Daw|Jack Daw]] 23:18, 21 June 2006 (UTC)
==[[Paleocollapse]]==
I did another article! But did I finally kick my refdesk addiction? --[[User:Zeizmic|Zeizmic]] 14:17, 21 June 2006 (UTC)
:I've done you a favor and rephrased your comment into an acceptable question, as you seemed to have forgotten to ask one! [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 15:33, 21 June 2006 (UTC)
:[[User:Zeizmic|Zeizmic]], could you rephrase your question? I have no idea what you're asking.--[[User:Yanwen|Yanwen]] 18:55, 21 June 2006 (UTC)
== Shortest & longest day ==
According to the [[Solstice]] page, the June solstice was on the 21st at 12:26 UTC. According to my local paper in NZ, tomorrow (well today now for me), June 22th is the shortest day. The solstice was at 0:26 on June 22nd here (since we're +12) so I guess this is why the shortest day is the 22nd. Am I right that the longest day in Malaysia, UTC+8 would have been June 21st since the solstice would have been at 20:26 (on the 21st)? Or is it more complex then that? N.B. I appreciate the difference is very small, especially so in a equitorial country such as Malaysia. [[User:Nil Einne|Nil Einne]] 14:44, 21 June 2006 (UTC)
:Wouldn't an equatorial country have two longest days each year. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 15:13, 21 June 2006 (UTC)
::I believe you're mistaken. The summer solstice is still the summer solstice (depending on which hemisphere the country or area is in) and the winter solstice is still the winter solstice. Of course, there is no real climatical seasonal differences in an equatorial country. For example, in Malaysia, the June solstice is the summer solstice. If you happen to be on the equator, there is no longest day or shortest day I believe since there is no variation between daylength. [[User:Nil Einne|Nil Einne]] 15:47, 21 June 2006 (UTC)
::BTW, incase you haven't realised, I was using equatorial country in the loose sense (as it is frequently used) to mean the same thing as tropical country. Of course, even a country that is on the equator, would still have summer and winter solstices, except on the equator itself of course. [[User:Nil Einne|Nil Einne]] 16:17, 21 June 2006 (UTC)
:::THats what I mean, on the equator itslef, the country would have two longest days, due to the leaning of the earth. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 16:20, 21 June 2006 (UTC)
::::As I discussed above, unless I'm mistaken when you're on the equator there is no longest or shortest day. Each day is the same. As you move away from the equator, south or north this is no longer true (technically). It's been a long time since I took any physics but I would assume that even a metre away from the equator, there is still technically a longest day and a shortest day even if the difference is in microseconds. The longest day is still on or about the summer solstice and the shortest day is still on or about the winter solstice.
::::BTW, of course a country that has a part on the equator would also have parts in both the south and northern hemisphere. Therefore it would have a longest day in the southern hemisphere which is the shortest day in the northern hemispehere and vice versa. In this sense it would have two longest days, perhaps this is what you meant. But in a specific area, it's still either the longest day or shortest day (or just the solstice on the equator). [[User:Nil Einne|Nil Einne]] 16:32, 21 June 2006 (UTC)
:::::I disagree. The day is longest at the equator when the Sun appears to go directly overhead, which happens twice a year, at the vernal and autumnal equinox. However, I don't think there is nearly as much variation in the length of a day at the equator as there is in temperate zones (and, of course, the huge variation in day lengths at the poles). [[User:StuRat|StuRat]] 16:41, 21 June 2006 (UTC)
:::::Exactly my point, due to the tilt of the earths axis, as the year passes the sun will be directly over head first one hemisphere then the other, crossing the equator twice. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 16:48, 21 June 2006 (UTC)
::::::I've been trying to do this in my head, but I have a severe headache. So, on the equator, the solstice is the longest day (regardless of which solstice it is). The equinoxes are the shortest days (one shorter than the other), right? At what degree latitude do they change so that the equinoxesa are equal length days and one solstice is longest and one is shortest? What about that latitude right in the middle? --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 17:50, 21 June 2006 (UTC)
::::::See [[Tropic of Cancer]] and [[Tropic of Capricorn]] for more information on which latitudes are the northmost and southmost of the sun's overhead travel. See [[Equator]] for that latitude right in the middle. Also, something handy for day length calculation is [http://aa.usno.navy.mil/data/docs/RS_OneYear.html This navy site] which will compute the sunrise/sunset times for any place on the globe. Pick a spot between the To'Cancer and To'Capricorn and see the effect on day length compared to any spot outside that.
::(re-indenting for clarity) I've likewise been hurting my head with mental math, but a tropical location will still conform to the usual longest-day / shortest-day relation to the solstices. However, at the equator, the day/night cycle is precisely divided at the solstice, just as it is at the equinox. Since the length of day at the equator is a sine function with the same period as that at every other latitude, the only function that puts a 12 hour day at 0 rad and pi/2 rad is one with no magnitude; that is, the length of day at the equator doesn't vary. Sidenote: due to how the length of day is measured (any point of sun over horizon, not midpoint), the day is always longer than 12 hours. See also the graph linked from [[solstice]] at [http://herbert.wikispaces.com/Length+of+day?token=8660d4563127717cd90822d4a82a026c this site] — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 18:34, 21 June 2006 (UTC)
:::Thanks for that, it's as I expected. I checked out the [[solstice]] article but not really the links. I also missed [[length of day]] which is equally useful. This appears to have settle the above issue, as I expected in a tropical location it's still the normal situation. Precisely on the equator, there is no variation in daylength. As you move away, there is variation but obviously e.g. a second away would have such a small difference to be meaningless. Having lived in Malaysia (KL, 3 degrees, 8 min), I know the difference is small but is not completely insignificant, about 30 minutes between longest and shortest. Of course, you do hardly notice it compared to e.g. you do here in Auckland (let alone somewhere like London).
:::However I'm still a bit uncertain about my original question namely how do you work out which is the longest day from the summer solstice (or the shortest day from the winter solstice). After more thinking, I'm guessing I was wrong above but it doesn't matter in most circumstances. You can't say for sure the day of the summer solstice would be the longest day since it will depend on factors such as your timezone in comparison to your actual longitude. In most case it will be but my guess here is that is actually depends which day length period is closer to the time when the summer (or winter) solstice occured.
:::So for example, in Malaysia since the summer solstice occured at June 21st 2026 (local time), the longest day would have clearly been June 21st since the June 21st sunset (about 1900) is far closer to the solstice then the June 22n sunrise (about 0700).
:::In New Zealand (or Auckland), it's a little more complex. The winter solstice occured at June 22nd 0026 as mentioned above. The sunset time on the 21st (according to a calendar I have for 2006) was at 1712 while sunrise for 22nd is at 0734. The sunrise on 22nd is closer (7h8m) then the previous sunrise (7h14m) so the 22nd is the shortest day but if the solstice was at 0001 for example clearly it would have been different.
:::Of course, it's probably easier just to work it out mathematically and in any case, given we're talking about a sine graph here, the difference between day length of the longest (or shortest) day and the day just before and just after are minute (even more so when the difference in daylength is so small as in Malaysia) but it's interestingly nevertheless.
:::[[User:Nil Einne|Nil Einne]] 08:00, 22 June 2006 (UTC)
::::Here is a site with sunrise and sunset data for [[Quito]], [[Ecuador]], which is close to the equator: [http://www.timeanddate.com/worldclock/astronomy.html?n=190&obj=sun&month=5&year=2006&day=1]. The length of each day is about 12 hours and 7 minutes, with earliest sunrise and sunsets around November 3 and May 13 and latest around July 26 and Feb 12. [[User:StuRat|StuRat]] 03:16, 24 June 2006 (UTC)
== Larva ==
We had recently found a small spot on our dining room ceiling. It contained Alot of little (probably 1-2 millimeters long) of black worm looking things. They had been there for a few weeks. There were almost hundreds of them. I have searched and searched, but have no luck finding any pictures or anything on them. I don't know if we need to spray our house our what? and for what? I have a baby on the way and would like to find out ASAP, please please help! Thanks, <-- email removed--> [[User:207.69.138.6|207.69.138.6]] 16:58, 21 June 2006 (UTC)--
:Well, it's not good, whatever it is. Get an infestation control person round asap. You could be risking the integrity of the structure of your house in the long term if this gets out of control. [[User:Trollderella|Trollderella]] 22:02, 21 June 2006 (UTC)
::Ehm, irony doesn't travel well over the Internet. At least, I hope this was irony. :) [[User:DirkvdM|DirkvdM]] 08:05, 23 June 2006 (UTC)
== Java SDK ==
What is a recommended Java SDK for developing Java programs? I have the JS2E Runtime Enviorment 5.0 Update 6 installed. Is there any traditional SDK I can get similar to how the VM is the one and only? --[[User:Russoc4|Chris]] 17:39, 21 June 2006 (UTC)
:There are only two Java SDK's to my knowledge. There is the official one from Sun (with multiple versions from 2.x to 5.x). Then, there is the Gnu version that is commonly distributed with Fedora Linux. Of the two, the official one would be best. I suggest using a lower version for compatability (like 4.x) and a higher one for the latest features. You appear to be asking which IDE is best used for developing Java programs. That is a completely different question. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 17:47, 21 June 2006 (UTC)
::Okay, maybe that is what I'm asking. I got my terms confused. Any answers? what is this thing called Net Beans? I programmed in Java before using [[jGRASP]], but I never had to install the necessary components by myself. This is why I'm asking. --[[User:Russoc4|Chris]] 19:13, 21 June 2006 (UTC)
:::NetBeans are a collection of objects that you can use in your programs. Sun has an IDE that makes NetBeans easy to use (the NetBeans IDE). Also, the free Eclipse IDE (from IBM if I remember correctly) allows you to easily choose NetBeans (as well as many other object repositories) for code usage. If you only want to use your objects (and the default set of Java objects), than any IDE is fine. Both NetBeans IDE and Eclipse allow you to compile and run with a single button click and both have on-the-fly popups to "help" you. I put that in quotes because I hate it when boxes pop up while I'm trying to work. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 19:23, 21 June 2006 (UTC)
: There are probably hundreds of SDK's, actually - there is the '''OFFICIAL SUN JAVA SDK''' [http://java.sun.com/j2se/1.5.0/download.jsp] as well as many other corporations or open-source groups who have created their own versions of the compiler (for various reasons ranging from business/license restrictions; running on unusual/obscure hardware; removing or adding features for performance, security, or connectivity; etc etc etc). Further, there are also multiple '''types''' of java: Standard Edition, Micro Edition, and Enterprise Edition. SE is the "standard" java you probably want. EE is for large corporate networks who have ''intense'' networking, security, and reliability needs. ME is designed for deployment on small devices such as PDAs, Cell Phones and VCRs, or [[embedded system]]s. Your best bet is the one linked above. Good luck, [[User:Nimur|Nimur]] 18:52, 23 June 2006 (UTC)
== Propane.... ==
Hi, are you ok? I hope so...
I don't know much about this, so I need your help.
I would like to know if propane lights up, does it create a expansive wave?
Could that be posible if a place's air is full of propane and it lights up?
Please... I need that info...
If you don't understand something please answer me.
Thank you.
:You appear to be asking if propane can explode. Yes. It can. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 18:26, 21 June 2006 (UTC)
:also, this may be obvious, but "there's no one here" -- I don't know who you were addressing, but the reference desk is empty. Volunteers edit answers on to the questions.
::I'm have a tab open with this most of the day. -- <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 00:13, 22 June 2006 (UTC)
What I find more interesting is: why does the propane flame in the bbq always make a loud 'wump' when you turn off the burners? There must be some air collapse, but I always thought this would be just a slow fade. --[[User:Zeizmic|Zeizmic]] 19:33, 21 June 2006 (UTC)
:Wow, that's a great question. There's so many things in life that we never think about. I think it was only a few years ago that they actually found out why coffee stains are light in the middle and have very dark edges =D --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 02:24, 22 June 2006 (UTC)
: Quite simple actually. Once the fuel supply is cut off, there is a higher Oxygen : Fuel ratio, so the fuel "bangs" rather than burns. This is why a room full of oxygen and propane will explode, not just burn (provided the O<sub>2</sub> is well mixed and there is enough of it) .--[[User:Eh-Steve|Eh-Steve]] 08:24, 22 June 2006 (UTC)
What i mean is this....
Imagine this scenario: A place like a sears store. It's air is full of propane due to an escape. So someting lights it up. I know that the flames are going to wrap everything up and everything is gonna burn. But the "explosion" if there is in this case, may produce a expansive wave enoughly strong to blow out all the windows of the store? Or the propane light up doesn't create a expansive wave?
No, it will create a shockwave given the right fuel-oxygen mixture, otherwise it will simply burn. Thats how [[thermobaric]] explosions work. --[[User:Eh-Steve|Eh-Steve]] 05:14, 23 June 2006 (UTC)
== how phenolphthalein was invented/discovered? ==
how phenolphthalein was invented/discovered?
:Search for [[Adolf von Baeyer]]'s experiments - especially those done in the 1870s. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 19:40, 21 June 2006 (UTC)
== Death ==
Unstable radioactive isotopes subject to Beta decay ''which are not replenished'' say within a container will eventually die out in the same manner as living organisms will die out on an island which are likewise not replenished and fail to reproduce.
Is this statement true or false?
<small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 20:17, 21 June 2006 (UTC)
:To be more succint: probability suggests that all atoms of a radioactive isotope will eventually decay, provided they're not being replenished. However, something being ''true'' isn't a justification for "winning" an edit war, as (among other things) the relevance of the fact to the article must be considered. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 20:38, 21 June 2006 (UTC)
::<small>See latter portions of [http://en.wikipedia.org/enwiki/w/index.php?title=Talk:Half-life&oldid=59863960 Talk:Half-life] for the rationale for my "however" comment — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]]</small>
:::In that case you should have no problem answering this question rather than skirting. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 21:22, 21 June 2006 (UTC)
::::I feel that I did answer the question, I just found the analogy to living organisms cumbersome (as, apparently, did Melchior) as it seemed to be unrelated to your primary question. If I have misinterpreted, please amend my response to that of Melchior's: atoms do not decay like people.
::::To be blunt, though, this looks like an attempt to drag a content dispute away from the relevant talk page and/or dispute resolution mechanisms (might I suggest [[WP:3O]]?). Therefore, I tried to gently insert a suggestion along those lines. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 21:33, 21 June 2006 (UTC)
:::::Bottom line here is revealing the truth. You need to answer "yes" or "no" to the question rather than to defer to someone else. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 21:53, 21 June 2006 (UTC)
::::::Please remain [[WP:CIVIL|civil]]. Melchior and I are both attempting to answer a rather vague question as best we can. As I've noted, your question, as posed, is vague enough that a "yes" or "no" isn't really sufficient. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 22:27, 21 June 2006 (UTC)
:False. The fundamental principle behind the statistics of radioactive decay is that an individual atom's probability to decay is independent of its age. This is not true of the deaths of living beings! Even if the half-life of a non-reproducing human population is 50 years, within 200 years literally all of them will be dead. But for a population of radioactive isotopes with a half-life of 50 years, after 200 years 1/16 of them will have survived. [[User:Melchoir|Melchoir]] 20:59, 21 June 2006 (UTC)
::Do you mind showing a table of values which with the fraction or percent of isotopes for each year over the span of the 200 years? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 21:17, 21 June 2006 (UTC)
:::Each year? I'll do it for five bucks, no less. [[User:Melchoir|Melchoir]] 21:22, 21 June 2006 (UTC)
::::Don't do it for me. Do it for other users. I submitted my evidence for free. Please provide the same courtesy for them. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 21:25, 21 June 2006 (UTC)
:::::I get the feeling that there isn't a huge audience for a 200-row table of values whose only purpose is to verify that 2^4=16. [[User:Melchoir|Melchoir]] 21:28, 21 June 2006 (UTC)
::::::::Okay using your own criteria (above) of percentage remaining p=1/(2^(200/50)) consider this:
::::::::We want to know the percentage remaining after 200 years of any amount of anything that has a half life of 50 years.
::::::::We therefore apply the formula p=1/(2^(number of years/half-life)) or p=1/(2^(200/50)) or 1/16 or .0625 or 6.25%.
::::::::So it appears that since there is a percentage of 6.25% of the item left after 200 years that it does not matter what the item is or how much of the item there was to start off with. This is where your concept fails. For instance suppose that we start with only 10 items. How much will we have left after 200 years. That’s easy. we just multply .0625 times 10 and we get .625. Thus we have .635 items left after 200 years of the original 10 we started with. But what if the items are not divisible? What if there is not such a thing as .625 of the items we have and that any amount of the item that is less than '''''one''''' simply does not exist? Hummm... Since we can not divide an atom into parts by the method of Beta decay then sorry but even though we might have 6.25% of the original amount of the items left that percent is meaningless because 1.) we started with only ten items and 2.) each item is a complete and indivisible unit rather than a continuous value. If you apply half-life computation to the real world then you must take these facts into account. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 03:15, 22 June 2006 (UTC)
:::::::::See below. [[User:Melchoir|Melchoir]] 03:50, 22 June 2006 (UTC)
::::::I see. Then you refuse to back up your claim with data. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 21:56, 21 June 2006 (UTC)
:::::::Maybe take a look at the table at the beginning of the [[half-life]] article. For a half-life of 50 years, after 4 half-lives (200 years), 1/16 = 6.25% of the particles will remain. [[User:128.197.81.181|128.197.81.181]] 22:39, 21 June 2006 (UTC)
:::::::Amending previous answer: After further research (i.e. the discussion on the [[half-life]] talk page), I now believe user IMHO's question is simply this: Like a non-reproducing population of humans, after a sufficient amount of time will a specific amount of a substance with a given half-life disappear completely? User IMHO's request for a table is particularly confusing given that (s)he generated exactly the requested table in an article that is up for deletion. Nevertheless, the answer seems to be that as a non-reproducing human population would not necessarily be described as exponential decay, the two processes are not the same, even though both processes may eventually end when all elements of the original collection (humans or, e.g., C-14 atoms) have decayed (barring unlikely quantum effects of a human coming back to life or an N-14 turning into a C-14). [[User:128.197.81.181|128.197.81.181]] 23:16, 21 June 2006 (UTC)
:The answer is false, and quite obviously so. If a non-reproducing human population decayed the same way unstable particles do, a human population of initial size <math>N</math> would, in a period 3 times the median human life span, reduce to <math>N/8</math>. Now I don't know what a good estimate for the median human life span is, but 70 years should not be too far off. The probability than a random person will still be alive after 210 years is not 12.5%, it is (for all we know) 0%!--[[User:72.78.101.61|72.78.101.61]] 02:30, 22 June 2006 (UTC)
''(rewrap reply to 03:15, 22 June 2006)'' If you start with 10 items with a half-life of 50 years, then after 200 years, there is approximately a 52.4% chance that all 10 decay, 35.0% that 1 is left, 10.5% that 2 are left, 1.9% that 3 are left, 0.2% that 4 are left, and the rest are insignificant. Now compute .350 + 2*10.5 + 3*.019 + 4*.002 and tell me what you get. [[User:Melchoir|Melchoir]] 03:40, 22 June 2006 (UTC)
You must first provide the basis for your statements. I can say that 1 = 0 but if I do I think whoever I say it to might be entitled to the courtesy of my telling them why and showing them step by step my reasoning. Otherwise they have every right to reject what I am saying and interact with me no more. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 03:57, 22 June 2006 (UTC)
:I'll tell you how I got 35.0% if you tell me the result of the computation I asked for. [[User:Melchoir|Melchoir]] 04:01, 22 June 2006 (UTC)
::I don't care how you got it and I am not interested in solving puzzles or playing games. Please find someone else to play games with. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 04:07, 22 June 2006 (UTC)
:::Rather ironic, from someone who seems to have quite a grasp of mathematics. Here you go, though:
:::First, Melchoir has an error ("2*10.5" should be "2*.105"). After that, though, it's just summed probability. The average number of atoms remaining is equal to P(0)*0 + P(1)*1 + ... P(n)*n, where in this case n=10.
:::The probability P(x) is [http://www.mathwords.com/c/combination_formula.htm C(n,x)]. Sum all those terms and you get 0.625 atoms remaining, on average, in your example. As I noted way back in the first response, though, this is ''probability'', not reality. The number of atoms must, of course, be integral, and is most likely 0 or 1 (an 82.5% chance, if my math is correct).
:::Does that clarify things? — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 04:13, 22 June 2006 (UTC)
:::Then stop acting as if you knew what you're talking about. [[User:Melchoir|Melchoir]] 04:10, 22 June 2006 (UTC)
:::He's not playing games; he's trying to explain to you why not all of the particles will necessarily have decayed even after the expectation value generated by the half-life calculation falls below 1.
:::Given a half-life of 50 years and an elapsed time of 200 years, we have a total of 4 half-lives elapsed. The probability of a given particle undergoing radioactive decay during any fifty-year period is 0.5, by definition. The probability of a particle surviving ''four'' such consecutive periods is therefore (0.5)<sup>4</sup>, or 0.0625 (6.25%); the probability of one particle decaying is therefore 1-0.0625, or 0.9375. The probability that all ten particles will decay is therefore 0.9375<sup>10</sup>, or 0.5244 (52.44%): the value Melchior gives above. Similar calculations give the remaining figures (it's an example of a [[binomial distribution]]). There's even a small probability (about 10<sup>-12</sup>) that ''none'' of the atoms will have decayed. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 04:22, 22 June 2006 (UTC)
At this point in the discussion the issue seems to be one of certainty versus probability. In fact I think we agree that they are opposites. When one is uncertain one turns to probability for a reasonable answer but when one is certain one would be foolish to turn to probability for the answer. I am certain that isotopes which undergo radioactive or Beta decay as individuals and therefore as a population are not immortal unless you have an infinite supply. Thus if you have a closed container of Carbon-14 which can not be penetrated by cosmic radiation or influenced in any way such that Nitrogen-14 within the container will be converted to Carbon-14 that the Carbon-14 contained within the container will eventually perish, die, drop dead, cease to exist, go kapoof, say bye bye, bite da bullet, kick the bucket, fall off the cliff, go kaplunk, join King Neptune, ride the ferry, antagonize da horn, get whacked, meet it's maker, build a pyramid, get blue screened, sweet repose, see the henchmen, walk the plank, push up the lillies, etc. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 12:16, 22 June 2006 (UTC)
----
:You still appear to misunderstand the vital role probability plays in [[radioactive decay]] (in fact, it's solely and entirely driven by probability). While it is exceedingly likely that radioactive decay eventually consumes all non-replenlished atoms, that cannot be said with mathematical or scientific certainty. Aside from that minor quibble of vocabulary, I think we've now resolved your original question. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 13:02, 22 June 2006 (UTC)
:How about this thought experiment: Assume that radioactive decay is random (as it appears to be) and that each atom's decay is independent of each other atom (as it appears to be). The universe is very large and there will be a *lot* of Carbon-14 (for example)—enough Carbon-14 to last a *very* long time. If we take 15 atoms of this large amount of Carbon-14 in the universe and put the in an inpenetrable container (no gamma rays, etc.) what will happen? The answer is that we cannot say for certain. Even though we know that Carbon-14 is unstable we cannot predict (with certainty) when or if these 15 atoms will ever decay. We might have, by chance, picked the few atoms that basically out-last the universe. We will find (at the least) that our small number of atoms on the whole of human experience appear to never decay--that they last forever. '''This is the problem with your desired example.''' You ([[User:Pce3@ij.net|IMHO]]) are applying your intuition to a random process and humans, generally, have poor intuition when it comes to randomness—it appears to not be in our genes. —[[User:BradleyEE|Bradley]] 17:45, 22 June 2006 (UTC)
:The question asked if isotope atoms ''die out in the same manner'' as living things and that's clearly false. Even as a metaphor the comparison is weak. [[User:Peter Grey|Peter Grey]] 22:29, 22 June 2006 (UTC)
:I think they won't die out. The lifetime of atoms of a radioactive material have an exponential distribution which will cause that you need lots of time for many atoms together to all die out. This is quite unlike living organisms, which age with time and die more easily as they're older. Radioactive atoms don't get older. – [[User:b_jonas|b_jonas]] 09:24, 23 June 2006 (UTC)
== DVD decoder? ==
Having installed a DVD optical drive and Windows XP Media Center 2005 Edition on a new computer, I am unable to play content-protected DVD's (although unprotected DVD's can be painlessly played). Windows Media Center, Windows Media Player as well as other DVD software show various error dialogs, complaining about problems with the decoder. My guess is that the problem may be resolved by purchasing either of the following products: [http://www.sonic.com/products/Consumer/CinePlayer/Decoder/quicklook.aspx CinePlayer DVD Decoder Pack] or [http://www.nvidia.com/object/dvd_decoder_1.00.67.html NVIDIA DVD Decoder]. I am right? Is it worth a try? --[[User:Andreas Rejbrand|Andreas Rejbrand]] 20:45, 21 June 2006 (UTC)
:It might be that your DVD drive is set to the wrong region. Do the messages give any hint of this? See if you can check the region. Many DVD drives allow you to change the region up to five times; after that (a hardware limit) you are stuck in the last region you chose. [[User:Notinasnaid|Notinasnaid]] 21:11, 21 June 2006 (UTC)
::Thanks for your respons, but, actually, I've already checked that, and it is valid. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 21:20, 21 June 2006 (UTC)
:::The software you've listed may fix the problem. I notice that the NVIDIA one has a 30-day trial, might I suggest you see if that fixes the problem before you spend money? — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 21:24, 21 June 2006 (UTC)
::::Seems very wise indeed. Thanks! --[[User:Andreas Rejbrand|Andreas Rejbrand]] 21:31, 21 June 2006 (UTC)
:You might try using [[VLC]], which is usually not picky about playing things. If that works, you can rule out issues with your drive, and probably won't want to continue to mess with Windows Media Player. [[User:Trollderella|Trollderella]] 21:59, 21 June 2006 (UTC)
::Thanks for your answer. (Actually, however, I think Windows Media Player and particularly Windows Media Center are great software.) --[[User:Andreas Rejbrand|Andreas Rejbrand]] 22:05, 21 June 2006 (UTC)
:::Regardless, the advantage with VLC is that you do not have to worry about codecs issues and the like. This will help to establish a base line to work out what the problem is. If your drive or the disc is broken, then it's no use fooling around with other issues [[User:Nil Einne|Nil Einne]] 08:13, 22 June 2006 (UTC)
:De gustibus non est disputandem. Did you get it working? [[User:Trollderella|Trollderella]] 22:18, 21 June 2006 (UTC)
::It works in VLC, but that does not completely solve my problem. I want it to work in WMC. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 10:34, 22 June 2006 (UTC)
:::WMC does not have its own DVD decoders. You are required to get third party codecs for it. I know Dell computers come with Cyberlink PowerDVD preinstalled, but I decided to uninstall it and as much preinstalled software as I could, and then eventually reformatted. [http://www.microsoft.com/windows/windowsmedia/mp10/getmore/plugins.aspx#DVDDecoder This] is the official WMC DVD decoder page, but they cost money. This is why I use VLC religiously. --[[User:Russoc4|Chris]] 15:23, 22 June 2006 (UTC)
::::I see. Well, at least they aren't excessively expensive. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 15:47, 22 June 2006 (UTC)
== Metal Plate in Head Questions ==
1. First of all, if someone is shot in the head and miraculously survives, is a metal plate inserted into the skull the normal procedure to repair the damage?
more importantly,
2. Let us assume hypothetically that a person has been shot in the head by a 10mm bullet, and survives. Let say it 'grazed' his head and pulled some of his skull off, but left his brain competely intact. Would a doctor use a metal plate in this instance to repair the missing skull fragment(s)? How would he go about inserting it? How long would it take for the wound(s) to completely heal and for the plate to be completely integrated into his skull?
and finally,
3. If a man with a metal plate in his skull was shot directly, at a 90 degree angle of impact from the tip of a 9mm full metal jacketed bullet, in the same spot as the plate is inserted in his skull, would the metal plate protect him from the bullet? What would the effects be on the man? Would he be knocked unconscious, or not? Would the bullet ricoshet? If the plate does protect him from a 9mm bullet, what is the maximum full metal jacketed caliber that the plate would protect him from (.357, .44, etc.)?
Thanks, [[User:69.138.62.148|69.138.62.148]] 22:10, 21 June 2006 (UTC)
:None of these questions are easy to answer, since traumatic head wounds are very unpredictable. The effect, recovery and treatment depend greatly on the specifics of the injury. The balistic properties of metal plates in the context of head injury are likewise not easy to predict. I assume that you are researching a novel, since I don't want to contemplate the other possibilities. Go for it - it's certainly not impossible that a man with a plate in his head could be saved by a freak balistic trajectory. [[User:Trollderella|Trollderella]] 22:17, 21 June 2006 (UTC)
To answer:
1) Yes, if the original skull fragments are unworkable.
2) It depends entirely upon the injury. Titanium plates are custom made to fit the skull (also full oseointegration occurs), and some insight can be given here [http://www.science.ulster.ac.uk/health/titanium_plates.html at this link]. i.e. the plates are screwed into existing bone (pictures of the screws [http://cmpicsu.utt.ro/zat/Tascau_Iovan.pdf here])
3) Bullet deflection will only occur at grazing incidences with such thin metal plates. At 90 degrees, the titanium plate probably won't even stop a .22 round. However, it is possible for a 9mm para at a high incidence (i.e grazing) to be deflected. This has been demonstrated with the guy who shot his friend's XBOX with a 9mm parabellum and it wasn't even scratched. As for higher calibres (including FMJ), it's even less likely, and for a .357 magnum to be stopped by this is just silliness.
Reply if you want further details. --[[User:Eh-Steve|Eh-Steve]] 08:43, 22 June 2006 (UTC)
:As for being shot directly by a 9mm full metal jacket, a thick metal plate (you are talking inches, not millimeters) will absorb the strike, denting inward. However, to push against the bullet coming in, it also has to push against the skull where it is attached - likely crushing it on one side. So, assuming the plate is thick enough to keep the bullet from punching a hole right through it, the likely end-scenario would be that the weak side of the skull would cave in, causing the plate to fold inward (into the brain) and the smashed bullet fragments would go into the brain as well. I would expect more damage to the brain than having a 9mm hole punched through it. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 14:18, 22 June 2006 (UTC)
::Thank you to all for responding so throughly. In response to Trollderella's comments, I am indeed researching a novel, not planning an assassination or some such violent foolishness. From what I have read in the responses and through other research, it seems unlikely that a metal plate inserted in the skull via the normal medical procedures would protect a person from bullets flying at his or her head. However, seeing that I am writing a fiction novel, I may be able to exaggerate the strength of these plates, and a person's ability to stay conscious from trauma to the brain. Hopefully I will not have to exaggerate these factors to the point of rediculousness or, even worse, to the point that it breaks the readers suspension of disbelief. Thanks again to all. [[User:69.138.62.148|69.138.62.148]] 21:45, 22 June 2006 (UTC)
:::Well, speaking of novels, some novel of [[Rejtő Jenő]] features a men who was protected from a gunshot to his heart by a metal plate he's placed there deliberately because he knew the antagonist would always aim there. – [[User:b_jonas|b_jonas]] 09:17, 23 June 2006 (UTC)
== 'Good' cholestrol ==
I want more of it. I read the article, which told me what it is, but not how to get more of it. What should I be eating more of? Thanks! [[User:Trollderella|Trollderella]] 22:14, 21 June 2006 (UTC)
:Eat more: vegetables, fish, nuts, high glycemic index carbs, and monosaturated fats. Eat less: polyunsturated fats, hydrogenated fats, junk food. Consider taking omega fatty acid supplements (fish oil, evening primrose oil, seabuckthorn oil) and lecithin.--[[User:Anchoress|Anchoress]] 22:24, 21 June 2006 (UTC)
::Have polyun'''sturat'''ed fats had multiple comments by me removed from them ? :-) [[User:StuRat|StuRat]] 03:23, 24 June 2006 (UTC)
Thank you very much - it might be good to add these to the articles on LDL and HDL. [[User:Trollderella|Trollderella]] 22:26, 21 June 2006 (UTC)
:Garden of Eatin' chips and [[Lance, Inc|Lance]] crackers have good fats in them. —[[User:Keenan Pepper|Keenan Pepper]] 00:56, 22 June 2006 (UTC)
::What about Steakhouse of Eatin'? — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 01:38, 22 June 2006 (UTC)
:I had a very low HDL (less than 10). I increased it through excercise and drastically increasing fish in my diet. By fish, I don't mean shrimp, crab, oysters... I mean things like salmon, whitefish, and bass. After a year of using the stairs (I work on the 12th floor) and having fish a minimum of 3 days a week, my HDL is now 22. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 18:29, 22 June 2006 (UTC)
::Becareful with too much fish though. They retain lots more toxins than the water they live in retains. Mercury is one of the things you'll hear about today, though I don't know how much truth there are behind this. --[[User:Russoc4|Russoc4]] 21:02, 22 June 2006 (UTC)
= June 22 =
== Bomb detection ==
What methods/devices does the military currently use to detect explosive devices? For that matter, what are most explosive devices (for instance those made by insurgents in Iraq) made of? How could they be detected? Is anyone developing an all-purpose IED detector? This has puzzled me, since it seems like a high-priority question for a budget-rich military, and not obviously infeasable. Some kind of radar or sonar device for scanning the road ahead? Thanks, --[[User:Bmk|Bmk]] 00:26, 22 June 2006 (UTC)
:My (limited) understanding about explosives detection is that you do it by chemical analysis of one form or another, either by having a bomb-sniffing machine of some sort or a bomb-sniffing animal of some sort (i.e. a trained dog). According to the "detection" section of our article on IED's ([[Improvised_explosive_device#Detecting_and_disarming_an_IED]]) attempts have been made at remote universal IED detectors but have not yet been successful despite a lot of funding going into it. --[[User:Fastfission|Fastfission]] 00:55, 22 June 2006 (UTC)
:Living on a military base, I've seen a lot of cool stuff. The best they could do is a chemical sensor that senses certain chemicals commonly found in IEDs. But that would take a stationary explosive, that has a self detonation, instead of one where the bombmaster can detonate when he chooses. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 01:37, 22 June 2006 (UTC)
I wonder if some kind of sonar-imaging with some computer-aided pattern recognition would do the trick. Thanks for the replies. --[[User:Bmk|Bmk]] 01:46, 22 June 2006 (UTC)
:There are many people around the working on this, the problem is that there is no way to tell exactly what explosive someone will use. While you can look for traces of common chemicals used in bomb making (that is what they are doing in airports when they 'swab' your baggage), you need to get close enough to take a dust sample, which, on a battlefield isn't going to help you much. For a simpler case, look at some of the methods and equipment used in mine detection - there is not 100% reliable way to detect mines still. A major issue with IEDs is that you have to be able to detect them before you get within the effective blast radius for the information to help you. It's a difficult problem indeed. I doubt sonar would help, because it's not very accurate, and you don't know in advance what shape the explosive is. [[User:Trollderella|Trollderella]] 02:11, 22 June 2006 (UTC)
:It woiuldn't work fast enough. I think you are talking mainly about rockets and such? That's the problem. Projectiles move way too fast for detectors, even with today's best technology. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 02:31, 22 June 2006 (UTC)
:: No, I was thinking of buried or concealed explosives, like those used to attack convoys along roads. --[[User:Bmk|Bmk]] 12:13, 22 June 2006 (UTC)
:::The difficulty in spotting IEDs with a ''visual'' method (like sonar) is that by definition they are improvised and probably non-standard in shape (though I suppose if you could x-ray something you would have an idea of its internal structure and texture and perhaps do something with that...). Using a ''chemical'' method improves on that a bit since there are a limited number of materials they are made from. It'd be ''really'' awesome if you could combine the two -- if you were able to "see" certain chemical concentrations in a visual way ("Gosh, an awful lot of ammonium nitrate over in that area..."). But I am not a scientist. :-) --[[User:Fastfission|Fastfission]] 16:55, 22 June 2006 (UTC)
A different, but related topic you may also be interested in missile or airborne threat detection. The standard techniques for detection of such threats include radar (bouncing a radio wave off of the reflective metal); infrared detection of heat (hot gases from a jet or rocket engine); or optical surveillance. Often, several tracking systems are combined to maximize detection of the threat. Finally, automated systems attempt to follow and destroy the target. Such areas are actively researched and advancements are continuously made. [[User:Nimur|Nimur]] 19:04, 23 June 2006 (UTC)
== Need help in physics ==
If this is house that has vents
And there are also vents at the soffits then what is the difference in pressure if the wind 65mph comes from the side of the house. Say wind comes form North to South then what is the difference in pressure between North and South part of the house. Plus how can I figure out the difference in pressure between attic and exterior.
Hope you will be able to help me. Kind regards.
Thank you
You can write to me directly at <small>address removed to prevent spam</small>
Your help is greatly appreciated.
: What the heck are "the soffits"? --[[User:Bmk|Bmk]] 01:44, 22 June 2006 (UTC)
::[[Soffit]]. --[[User:LarryMac|LarryMac]] 17:58, 22 June 2006 (UTC)
:Oh my god, why do you have 65mph winds? Are you just meaning "hurricane speed winds?" I can't imagine you regularly experiencing them. As for your question, there is no way to tell without measuring because it would be tough for you to convey to use the schematics of your vent system and erm... soffits. The pressure will be greater on the north side of the house than the south. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 01:49, 22 June 2006 (UTC)
:HA! I KNEW this would come in handy some day! *gets out his pocketbook because he he's had 3 Palms and they all sucked*
::'''Force = 0.004 x (The area of the wall) x (Windspeed)<sup>2</sup>
:That's F=0.004Av<sup>2</sup> --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 02:18, 22 June 2006 (UTC)
::Nice formula, but I was thinking he ment air pressure. Now that I read it again, you may be right. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 02:35, 22 June 2006 (UTC)
:If you simply the problem a bit, ignoring compressibility (reasonable at these windspeeds) and sofftis (which I have no idea what they are) it boils down to [[stagnation pressure]], which is <math>\frac{1}{2} \rho V^2</math>, where <math>\rho</math> is the air density and <math>V</math> is the wind speed (in metric units, please!). The result will be in [[pascal]]s. So the pressure on the upwind side of the house will be the ambient pressure (current atmospheric pressure) plus the stagnation term I just quoted, and the pressure on the downwind side will be the ambient pressure - thus, the pressure difference is the stagnation term. The difference in pressure between the attic and the outside will be the same. — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 06:20, 22 June 2006 (UTC)
::As to what soffits are, there is a good reference source on the web for all kinds of things. Here is a link to its entry on soffits: [http://en.wikipedia.org/wiki/Soffit]. --[[User:Lambiam|Lambiam]][[User talk:Lambiam|<small><sup>Talk</sup></small>]] 09:15, 22 June 2006 (UTC)
== Leg length ==
Once in a while one leg will feel longer than the other. The effect will pass in a few hours, but what could be the cause? - [[User:RoyBoy|Roy]][[User talk:RoyBoy|'''Boy''']] <sup>[[User:RoyBoy/The 800 Club|800]]</sup> 01:53, 22 June 2006 (UTC)
:Some kind of pinched nerve is my guess. Like it says at the top of the page, asking a real doctor - your doctor - is 10000x better than here =D --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 02:13, 22 June 2006 (UTC)
::Then again, some of us are doctors. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 02:36, 22 June 2006 (UTC)
:::Was that an implication that you were a doctor, at 14? [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 13:26, 22 June 2006 (UTC)
:I heard that one of legs is ''actually'' shorter than the other (I think it is the right leg that is shorter). That is supposed to be the reason why the guys lost is desert go in big circles, even if they think they are walking along a straight line. I am not sure about this, though -- [[User:Wikicheng|Wikicheng]] 04:00, 22 June 2006 (UTC)
::One leg is almost always shorter/longer than the other. Usually the difference is quite small, and it can change from day to day as the soft tissue in the joints is stretched or compressed. Differences can also arise due to differences in the lengths of the major bones of the leg; in those cases corrective [[orthotics]] or even surgery may be required for a normal gait and to stave off posture-related problems down the road. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 10:52, 22 June 2006 (UTC)
How long should a man's legs be? Long enough to reach the ground.
:: Long enough to reach his torso.
:Whose legs are you feeling? --[[User:Dweller|Dweller]] 13:30, 22 June 2006 (UTC)
== Biological Evolution versus Intelligent Design ==
A recent revival of the anti-evolutionary "argument from design" holds that biochemical pathways are too complex to have evolved, because all intermediate steps in a given pathway must be present to produce the final product. Critique this argument. How could you use the existing diversity of metabolic pathways that produce the same or similar products to support your case?[[User:Patchouli|Patchouli]] 02:17, 22 June 2006 (UTC)
:Similar to the "How do different animals have different number of chromosomes"? There might not be an answer, but good luck. I'm a believer in Evolution but it does have some problems because we still know quite little about biological systems. In fact, I think they just had to revise how they thought some part of a cell worked a few months ago. --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 02:20, 22 June 2006 (UTC)
:Is this a homework assignment?--[[User:72.78.101.61|72.78.101.61]] 02:49, 22 June 2006 (UTC)
*Yes.[[User:Patchouli|Patchouli]] 03:24, 22 June 2006 (UTC)
::Congrats on the honesty. --[[User:Dweller|Dweller]] 11:43, 22 June 2006 (UTC)
The fact that we do not know everything about biological systems does not mean "evolution has problems". Almost everything we know about the workings and inheritance of biological systems we have learned since 1860. Every major new discovery since Darwin has supported or is compatible with the basic concepts of evolution. You cannot name a single important new aspect of understanding of animal physiology, cell biology, or genetics that is incompatible or contradicts it. It is the single most useful concept about biology introduced in the last 2 centuries. [[User:Alteripse|alteripse]] 03:40, 22 June 2006 (UTC)
:The [[Talk.Origins Archive]] [http://www.talkorigins.org website] has a huge collection of standard creationist claims and refutations thereof...might be worth a visit. [[User:DMacks|DMacks]] 04:07, 22 June 2006 (UTC)
:You are correct Alteripse...I'm not sure what I was trying to get at. Hm. --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 07:19, 22 June 2006 (UTC)
: Second reading the [[TalkOrigins Archive]]. Two points to start you off:
:* A particular pathway might not produce the same endproduct if a component is removed - but perhaps the resulting product is nearly as good at the task - or is useful for something else entirely.
:* The creationist argument assumes that the only way for evolution to operate is to add components to a pathway - but there are other ways for mutations to occur: joining existing pathways, stitching pathways together, altering steps; in particular, removing steps from longer pathways.
: [[User:EdC|EdC]] 11:06, 22 June 2006 (UTC)
::That should read "One creationist argument is to assume...". There's no shortage of creation arguments and no shortage of refutations. And vice versa for evolution. That's what makes is ''so much fun''. All you need to remember is that both are correctly called "theories". Could be that neither is right, thought about that yet? <grins> --[[User:Dweller|Dweller]] 11:43, 22 June 2006 (UTC)
:::Creationism isn't a "theory" – certainly not in the scientific sense – as it is not falsifiable. It's arguments against the legitimate theory of evolution almost always amount to pointing to the next gap in scientific understanding, and saying "Oh yeah? I bet you can't explain ''this''! Therefore, there must be a Creator (ahem...Intelligent Designer...)." When an explanation is forthcoming, creationists can just point to the next gap in understanding. See [[God of the gaps]]. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 11:55, 22 June 2006 (UTC)
::::Not sure what you mean by "legitimate". Do you mean there's one evolution theory that's correct and many others that are wrong, or do you (as I suspect) mean that evolution is Truth? As I understand it, you want to have your cake and eat it. You want to decry creationism because it cannot be disproved and you want to knock creationist attempts to disprove evolution! Let's face it. It's an argument neither side will win. Probably because neither is true and really the world was made by [[Slartibartfast]]. --[[User:Dweller|Dweller]] 12:12, 22 June 2006 (UTC)
:::::"Legitimate" probably being an actual "theory" in the scientific sense. Note the context is as a counterpoint to creationism ''not'' being a "scientific theory". An oft-seen creationist ploy is to say "see? even scientists themselves admit that evolution is just a 'theory', so our competing theory is just as valid", forgetting (to be generous about their motives) that the scientific meaning of "theory" is different than the common-language word. [[User:DMacks|DMacks]] 15:30, 22 June 2006 (UTC)
::::::Why are you so sure that creationism could never be disproved? --[[User:Dweller|Dweller]] 16:29, 22 June 2006 (UTC)
:::::::Because it generally doesn't allow for testable questions. (See our article on [[falsifiability]] to understand the specific relevance of this to the definition of a "theory") Many individual statements of Creationists can be disproved, of course, but as a whole when you have a system predicated upon an omnipotent agent then you can explain away anything. --[[User:Fastfission|Fastfission]] 16:50, 22 June 2006 (UTC)
:(moving back here, cos I'm not a right-winger)
:You couldn't explain away Slartibartfast's home movies?
:It's a pointless argument anyway. It doesn't matter how good either sides proofs are... the creation lobby will never concede that evolution is truth and the upholders of evolution will never concede that the world was created by a mysterious omnipotent being. With or without a long, white beard.
:If creationists ever came up with a "winning" argument, science would be just as slippery as you aver creationists are... I doubt you'd see blokes in white coats rushing out to their nearest church/synagogue/mosque/long pole in the middle of the desert. The scientists would at best acknowledge that evolution was a flawed theory and they'd then sit back and wait until someone came up with a better one, while continuing to insist that creation isn't even a theory. --[[User:Dweller|Dweller]] 18:42, 22 June 2006 (UTC)
::Not quite. The ends of scientists and creationists are markedly different. Science is looking for understanding and predictability. If god or UFOs or the [[Flying Spaghetti Monster]] appeared and explained that they were soley responsible for every species on Earth and all of our evidence for Evolutionary Theory was fabricated, scientists would think that was great and they'd want to understand how the "designer" did such an amazing thing. We would take the new evidence (which would have to be extraordinary) and try to figure out every little detail of its operation. Creationists do not have that end. They just don't want there to be thoughts and ideas that contradict the word of their god as presented to them in form of the bible.
::Additionally, it's really not quite that funny—in the United States, at least. It's really more along the lines of shocking and horrifying. Here we have ignorance versus reason and in the minds of the masses the winner is not clear. What will the creationists see as the next threat to their way of life? —[[User:BradleyEE|Bradley]] 19:11, 22 June 2006 (UTC)
:''biochemical pathways are too complex to have evolved'' is an assertion with a precise mathematical requirement. Without the math proving that it's "too complex" and identifying '''all''' conceivable intermediate steps, the argument is a merely a failure of the human imagination without scientific merit. But hey, if the creationists ''could'' prove it, then we'd have to say they might be on to something... [[User:Peter Grey|Peter Grey]] 22:39, 22 June 2006 (UTC)
: It's possible that you might want [[argument from poor design]], an opposite (somewhat) observation for the opposite conclusion. —[[User:AySz88|AySz88]][[Special:Contributions/AySz88|\]][[User talk:AySz88|<font color="#F96">^</font><font color="#F63">-</font><font color="#F30">^</font>]] 04:34, 23 June 2006 (UTC)
== Equation out of the Middle East ==
I: Since at least the year 1300, no human out of the Middle East has ever contributed a mathematical equation or formula.
Joe: You are wrong; this can't be. You are offending the intelligence of Middle Easterners.
I: This is the bitter truth. I never said there are no mathematicians or scientists who understand every equation or formula that has been discovered. I just say that there is not been an ''original'' contribution since at least 1300. To prove me wrong, I ask that you name a specific person with the specific equation that he came up with like the [[Schrodinger equation]].
Joe: I am at a loss.
: I wish to verify with more knowledgeable people whether I am correct. I appreciate any response in advance.[[User:Patchouli|Patchouli]] 02:25, 22 June 2006 (UTC)
:May be right, since around then they have not contributed much to world society. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 02:37, 22 June 2006 (UTC)
:Hmm, let's see... the Turkish mathematician [[Cahit Arf]] has some things named after him. Does that count? —[[User:Keenan Pepper|Keenan Pepper]] 02:41, 22 June 2006 (UTC)
::I couldn't find a specific <u>equation</u>. I don't want principles. In addition, Turkey is generally considered European according to the [[Middle East]] article.[[User:Patchouli|Patchouli]] 03:18, 22 June 2006 (UTC)
:[[Mergelyan's theorem]] is named after Armenian mathematician [[Sergey Mergelyan]]. —[[User:Keenan Pepper|Keenan Pepper]] 02:45, 22 June 2006 (UTC)
:And don't forget Israeli cryptographer [[Adi Shamir]], the ''S'' in ''[[RSA]]''. —[[User:Keenan Pepper|Keenan Pepper]] 02:49, 22 June 2006 (UTC)
:Do half-Middle Easterners count? [[Michael Atiyah]] is half Lebanese. --[[User:ColourBurst|ColourBurst]] 04:52, 22 June 2006 (UTC)
::I personally believe Michael Atiyah is one of the greatest living mathematicians; nevertheless he was neither born in Lebanon nor received any substantial schooling in the Middle East.[[User:Patchouli|Patchouli]] 05:20, 22 June 2006 (UTC)
:::I have a little trouble with this. The original statement was "no human out of the Middle East...", not "no human born and trained in the Middle East...". One implies something about the people; the other implies something about their circumstances. --[[User:ColourBurst|ColourBurst]] 07:16, 22 June 2006 (UTC)
::::In the vein of literalnesss, a person born in Great Britain has not sprung ''out of'' the Middle East. One could even argue that [[Martin Van Buren]] was Dutch, Steve Jobs is [[Syrian]], and so on.[[User:Patchouli|Patchouli]] 08:11, 22 June 2006 (UTC)
*I am interested in the Middle East composed of Arabs, Persians, and Afghans. Definitely not someone from a former USSR state; while Israel is in the Middle East, I should have said excluding Israel.[[User:Patchouli|Patchouli]] 03:18, 22 June 2006 (UTC)
:Until now, I've assumed good faith but since Israel IS in the Middle East, your question is undermined. Are you asking about anyone born in a '''Muslim''' country and if you are, why not say so? Sadly, you've given me evidence to subdue my good faith assumption and suspect your motives. --[[User:Dweller|Dweller]] 11:52, 22 June 2006 (UTC)
*Yes; a Muslim country in the Middle East — since I do not fear betting that no one born and educated in Indonesia, Nigeria, Sudan, et cetera ever came up with an equation. I made the mistake in good faith because I should have said a Muslim country in the Middle East. Therefore, I apologize for this error. I thought maybe there is an obscure equation that ''I'' know nothing about and I have no motives to belittle any nation. I basically wanted to extract a fact since I am not infallible and don't know every equation.[[User:Patchouli|Patchouli]] 02:11, 23 June 2006 (UTC)
*:''No'' equation is going to be fairly hard to verify, but Mac Davis is correct above: there's a marked shift from possibly the most advanced civilization mathematically around 1000 CE to a near-complete lack of scholarly interest by 1300 or 1400 CE. I would expect that blanket statements ''today'' are incorrect, though, as (even if the culture in the Middle East isn't yet shifting) students from the region are increasingly studying at European and American (and other) institutions where good mathematical work is being produced. I would expect that such work also continues in regional institutions, and that it has to some degree or other all along.
*:Quick summary: the absolute is almost certainly false. The general case (the decline of Middle Eastern contributions to mathematics) is almost certainly true. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 04:33, 22 June 2006 (UTC)
*I already know about [[Mahmoud Hessaby]], for instance, yet over the past few weeks my sporadic research on him did not unearth a single equation.[[User:Patchouli|Patchouli]] 05:20, 22 June 2006 (UTC)
::[[Ahmed H. Zewail]] Egyptian, Nobel Chemistry. [[Abdus Salam]], Pakistani , is that close enough? Nobel, physics, ElectroWeak theory --[[User:GangofOne|GangofOne]] 06:37, 22 June 2006 (UTC)
*I didn't know who Ahmed Zewail was; this anwer is on target especially since Egypt is always classified as a Middle Eastern nation.[[User:Patchouli|Patchouli]] 07:24, 22 June 2006 (UTC)
*I thank everyone for its responses notwithstanding my further request that if there is a specific equation discovered by a Middle Eastern individual that you provide a link for it or paste it hereon.[[User:Patchouli|Patchouli]] 07:32, 22 June 2006 (UTC)
:A non-Israeli Middle Eastern, you request (above). What about a Jew born in, say, Iraq? Or a Christian born in, say, Oman? --[[User:Dweller|Dweller]] 16:33, 22 June 2006 (UTC)
*Fundamentalism & mathmatical advances don't exactly go hand-in-hand. [[User:Mayor Westfall|Mayor Westfall]] 12:25, 22 June 2006 (UTC)
**It is worth differentiating between authoritarianism and fundamentalism in the case of the Middle East. Much of the Middle East is under some form of authoritarianism which is not rooted in religious fundamentalism (i.e. Syria). --[[User:Fastfission|Fastfission]] 16:46, 22 June 2006 (UTC)
::<font style="color:green">Many pioneers who came up with equations were born and raised in the authoritarian regime of the Soviet Union.</font>[[User:Patchouli|Patchouli]] 06:06, 23 June 2006 (UTC)
***Well it was the collapse of [[early Islamic philosophy]] at the hands of opposition from key scholar/theologians like [[Al-Ghazali]] that triggered a return to theological fundementalism and the abandonment of scientific thought circa early 12th century AD. Just as a form of [[Christian fundamentalism]] might be said to have ushered in the [[dark ages]] in Europe, fundementalism played a key role is impeding the progress of science and mathematics in the Islamic world as well. [[User:Dragons flight|Dragons flight]] 21:45, 22 June 2006 (UTC)
*Even [[Khwarizmi|Al-Khwarizmi]] in 800s CE did not contribute an equation that I can find. I have concluded that he simply rehashed Diophantine's ''[[Arithmetica]]'' in Arabic.[[User:Patchouli|Patchouli]] 00:33, 23 June 2006 (UTC)
** I think he contributed a technique (or several) for solving equations. You should remember that equations are not a particularly important output product of math research. If anything, theorems would be what you'd want to look for. Someone like [[Galois]] who is very important, contributed the fact that there's no equation of a certain form, and so if he happened to be middle-eastern you wouldn't ve counted him either, I take it? --[[User:Ornil|Ornil]] 03:55, 23 June 2006 (UTC)
:No; I wouldn't count Galois notwithstanding his enormous accomplishment. As I stated first, I am simply interested in a ''meaningful'' equation with a principle - like a theorem - tied to it like the [[Photoelectric effect#Explanation|Einstein photoelectric equation]] or the [[Compton wavelength|Compton wavelength equation]]. This is what I am searching for.[[User:Patchouli|Patchouli]] 04:37, 23 June 2006 (UTC)
Is there any relevance to this question? Or is it just a very contrived way to point out that the heyday of mathematics in the Islamic world is a thing of the past? Formulating it as a question suggests sincerity. Similar question then. How does Russian scientific literature fare since the fall of the Soviet Union? It used to constitute 1/3 of the world's scientific literature. But I don't know what it's like now. So a legit question? Or am I trying to make a point, whithout actually making it, so that that can not be held against me? (sneaky, sneaky) [[User:DirkvdM|DirkvdM]] 08:16, 23 June 2006 (UTC)
*Not necessarily since I learned who Cahit Arf and Ahmed Zewail are as a result of this conversation. I will close this discussion because it is becoming very lengthy without achieving any intellectual purpose.[[User:Patchouli|Patchouli]] 10:19, 23 June 2006 (UTC)
::Oi! I'll decide when this discussion is over! Ok, it's over now. :) [[User:DirkvdM|DirkvdM]] 17:56, 23 June 2006 (UTC) No, it isn't .... [[User:DirkvdM|DirkvdM]] 06:08, 24 June 2006 (UTC)
The biggest problem is that you're mistaking two claims:
#No equations were developed in the Middle East
#No Western educational system teaches about Middle Eastern mathematical developments.
I have heard from reputable research historians who specialize in the [[History of Mathematics]] that an entire career can be made simply by learning [[Arabic]] and proceeding to translate literally thousands of archived documents which are essentially un-studied by Western historians. The biggest problem is that concurrent developments in the Middle East during the 12th through 19th centuries went largely untranslated because of the animosity and xenophobic divide between Arab and European cultures. To claim that no mathematicians (or equations) came from that region is a ''very'' strong argument based solely on the premise that ''we do not know of them.'' [[User:Nimur|Nimur]] 19:21, 23 June 2006 (UTC)
:Of course, something similar goes for Russian scientific literature, and I forgot to mention that. Chinese literature too, and that's 1/5 of the world's population. Now China has always stuck to its own affairs, so it's not that likely they will translate it themselves (who for?). And with the way thingsa are going in Russia, it doesn't seem likely it will happen there either. But many Arabic countries have plenty money, so they can afford to hire people. But then I suppose that is what you are saying. I'm unemployed and good at languages. Thanks for the tip! Where do I apply? :) [[User:DirkvdM|DirkvdM]] 06:08, 24 June 2006 (UTC)
The original question is an obvious (and obnoxious) troll, but I can't pass up the opportunity to mention that some of the most remarkable theorems in modern mathematics come from [[Saharon Shelah]], who was born in [[Jerusalem]] and whose extraordinary contributions have been widely [http://www.math.rutgers.edu/docs/shelah.html recognized]. See also this archive [http://shelah.logic.at/ Shelah's papers]. The question specified "formulas", but I am guessing that he doesn't know enough about modern mathematics to know that he probably meant "theorems". But in a sense too technical to explain here, Shelah's work is related to [[combinatorics]], a subject well known for its beautiful formulae.
There are many, many other examples. To mention just one which comes to mind, one of my former professors was born in [[Turkey]], and he is a leader in his field. I am sure that if I bent my mind to the task, I could come up with other examples. ---[[User:Hillman|CH]] 08:57, 26 June 2006 (UTC)
Of course, five seconds after I sent that I remembered that [[Branko Grünbaum]] (who was on my thesis committee) was also born in [[Israel]]. Grünbaum has enjoyed a long and very distinguished career in convex geometry and allied subjects. Much of his work has involved hard classification theorems in geometry, but his well known book on convex polytopes contains plenty of nice combinatorial formulae. Even nonmathematical readers might know his book with Shephard on tilings. ---[[User:Hillman|CH]] 09:03, 26 June 2006 (UTC)
:Yeah, but the poster specifically excluded Israelis from this, thus excluding Shelah and Grünbaum. --[[User:Dweller|Dweller]] 09:25, 26 June 2006 (UTC)
== Most effecient device ==
What is the most effecient device for converting electricity to light? I heard that they use LEDs in some torches which give light of brightness comparable to the incandescent bulbs. Are the LEDs most efficient? -- [[User:Wikicheng|Wikicheng]] 04:13, 22 June 2006 (UTC)
:I don't want to commit to ''most'' efficient, but [[LED]]s are more efficient than [[incandescent bulb]]s. LEDs also have an advantage in being practically unbreakable. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 04:18, 22 June 2006 (UTC)
The nuclear bomb. (In addition to electricity, a minimal amount of mass is also converted to light. There is also considerable heat by-product.) Hope this helps.
:But like you said, a minimal amount of mass is also converted to light, so they would be terribly inneficient. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 10:36, 22 June 2006 (UTC)
I don't know how efficient they are, but [[arc_lamp|arc lamp]]s are fucking bright. That article also has a nice table at the end, which is a template I'll insert here:
{{ArtificialLightSources}}
You might want to look through those. You should also consider the fact that it probably matters to you what frequencies energy is concentrated in (for example, reflective biker gear I heard is brighter because it takes many ambient frequencies and redirects the energy into one bright [say, orangey] wavelength, obviously not reflecting more energy than it absorbs however seeming much brighter). In theory, of course, any electricity you're not producing heat with is 100% converted to "light" but is this enough to tell you how efficient it is at the part of the spectrum you're interested in producing light at?
I was looking at a device which can probably used in a hand torch (flashlight). I can not include a nuclear bomb in this. Moreover, I an trying to convert electricity and not mass to light. Anything close to white light is welcome -- [[User:Wikicheng|Wikicheng]] 11:38, 22 June 2006 (UTC)
:Could you fit some glow worms in your hand torch? --[[User:Dweller|Dweller]] 11:55, 22 June 2006 (UTC)
Not a bad idea though! :-) -- [[User:Wikicheng|Wikicheng]] 12:56, 22 June 2006 (UTC)
:Apparently [[Organic light-emitting diode]]s can be made almost 100% electricity-to-light, but very much "in development". Otherwise low pressure sodium [[Electric light]]s are the most efficient, but the light is pure yellow - no other colours - and the tube is large. For torch size the white torch LEDs are reasonably cheap, but seem to be less efficient than flourescent lamps (40 lm/W vs 50 lm/W). I haven't seen a standard torch-size flourescent source that gives bright enough light though, they all use pretty long tubes. So LEDs seem the best for smaller torches, fluorescent tubes for larger battery powered area lighting. A 2 or 3-cell (1.5V cells) torch can be converted to LED by buying an LED and fitting it in the reflector without any other conversion (not a bright light though). --[[User:Seejyb|Seejyb]] 22:58, 22 June 2006 (UTC)
::Well, that very much depends on the [[Surefire|brand]] of light. :) Some of the tactical flashlights have LED conversion kits that are still very bright flashlights. :) [[User:Kmccoy|kmccoy]] [[User_talk:Kmccoy|(talk)]] 10:32, 23 June 2006 (UTC)
== Amount of water in dew ==
In a cubic meter of air with a humidity of 70% how many liters of water would they be in it? and what is the formula for calculation?
Regards, Albert W Howard
:Well, since 70% means a relative humidity, it's going to depend on the temperature. A cubic meter of air can hold more liters of water if it's warmer. There's some information at [[Humidity]], but probably not all that you need. [[User:Melchoir|Melchoir]] 04:25, 22 June 2006 (UTC)
I googled "how much water can a cubic meter hold" and one of the results is [http://www.everything2.com/index.pl?node=relative%20humidity this everything2 write-up] (remember everything2? Ah, the days before wikipedia...):
Air temp, Water content of
deg C saturated air,
gram/cubic meter
-------- ----------------
-10 2.1
0 4.8
10 9.4
18 15.4
20 17.3
30 30.4
40 51.2
50 83.0
.....
90 423.5
so as you can see, you need to know the temperature. Read the writeup I linked, it's very interesting. Unfortunately, I don't know if "70% humidity" or saturation is just 70% of the gram weight of the water, since it's conceivable that another scale (logarithmic or something, or volume, or...) is used. This is what [[relative_humidity]] says: "Relative humidity is the ratio of the amount of water vapor in air to the maximum amount of water vapor that could be in the air if the vapor were at its saturation conditions." I wish it would explicitly state that this is the same as grams of liquid water, or volume of liquid water, or mols of h2o or whatever. Anyway, I think it's safe to just multiply the gram/cubic meter by 70% to get 70% relative humidity, after deciding what temperature you want it at. Be sure to convert to liters of water / cubic meter, since that's what you asked for!
[[User:82.131.191.135|82.131.191.135]] 10:29, 22 June 2006 (UTC)
==Meaning of "MMgy"==
Please expand MMgy; apparently it is a unit of measure of liquid fuel.
:From Google, it appears to mean "million gallons per year". [[User:Melchoir|Melchoir]] 05:34, 22 June 2006 (UTC)
:Update: I've created [[Million gallons per year]] and [[MGY]], with appropriate redirects. [[User:Melchoir|Melchoir]] 05:52, 22 June 2006 (UTC)
:...and if someone knows which kind of [[gallon]] is implied, that would help. [[User:Melchoir|Melchoir]] 05:57, 22 June 2006 (UTC)
== Binoculars ==
How can I measure or calculate the magnification factor of my binoculars?--[[User:Shantavira|Shantavira]] 07:11, 22 June 2006 (UTC)
It's going to be an even multiple, so maybe if you taped a piece of paper vertically to the wall opposite of you, after drawing a small rectangle at 1/10th size (for example, if your sheet of paper is 8.5 by 11 inches you could draw a 0.85 by 0.11 inch rectangle) in the same orientation, then you could look at the rectangle from one eye and the whole sheet of paper from the other eye and see if the apparent size is the same. Repeat with different ratios until you get the same apparent size. (It should be easy to judge, since if you do it right, the images come to different eyes but from the same plane and so they should line up nicely.) Try it and let us know.
:Thanks. Yes, using both eyes makes a lot of sense. I hadn't thought of that. Rather than experiment with different sized rectangles I could use a whole line of sheets of paper as a scale, but in that case I might as well use the slats of my garden fence as a scale to compare with the magnified width of one slat. I have another pair of binoculars of known magnification, so I will try it using those first.--[[User:Shantavira|Shantavira]] 12:00, 22 June 2006 (UTC)
::Yes it works. The paper rectangle idea turned out to be the simplest solution after all. --[[User:Shantavira|Shantavira]] 07:37, 23 June 2006 (UTC)
== Environmental Question ==
Can you tell me about destructive distillation of wood?With Pictures
please.--[[User:Saksham Sharma|Saksham Sharma]] 11:03, 22 June 2006 (UTC)
:This is an experiment that we do with our Year 8 classes (12-year-olds). The pupils heat some wood chips in the bottom of a test tube, and light the flammable gases which emerge at the mouth of the tube. Soon the flame dies down, and what is left inside the tube are fragments of charcoal and some brown tar. I believe that the flammable gas given off at the start is mainly methanol.[[User:G N Frykman|G N Frykman]] 21:09, 22 June 2006 (UTC)
== The Ultimate Speed Limit ==
I've heard that the Special Theory of Relativity's Ultimate Speed Limit applies not only to matter and material objects but to influences,disturbances,forces, and signals,etc ''of any sort''.
I don't understand.I know that special relativity says that all matter and objects undergo changes as they move or travel and that they change back into their original state when they stop moving or stand still.I know that one of these changes is an increase in mass and that the mass of objects become infinitely large when they approach the speed of light.But that doesn't explain how things that are not material objects can't travel faster than light.
So how come things that are NOT matter can't travel faster than light?I mean, how ''can'' it and how ''does'' it apply to ''anything'', not just matter and substances?
:One way to look at it would be that if a signal could move faster than light, it would violate [[causality]]. Suppose you have two events, at different times and places: A) a person sends a signal, and B) the signal, arriving at its destination, causes a phone to ring.
:Now, suppose you have some observers witnessing these two events. They're not all at the same place; some are moving at different, near-light speeds and in different directions. Because one's velocity affects time, according to special relativity, different observers will disagree about how much time elapsed between A and B. To one observer, there might be two seconds between A and B, while another observer might measure five seconds between A and B. However, as long as the signal traveled at the speed of light or slower, all observers will agree that B happened after A.
:If the signal traveled faster than the speed of light, however, the math works out such that to some observers, it would appear that B happened before A! And it's not so much that B ''appears'' to happen before A; since observations in all reference frames are equally valid, B ''does'' occur before A for that observer. The effect would happen before its cause! [[User:Chuck Carroll|Chuck]] 11:59, 22 June 2006 (UTC)
::And this is the reason we have [[call waiting]] [[User:Mayor Westfall|Mayor Westfall]] 12:18, 22 June 2006 (UTC)
:The problem is that the non-matter things that carry forces, disturbances, influences, etc. are all either light or its cousins. Light, radio waves, x-rays, ''et al.'' are all [[photon]]s with different energies—by definition they travel at the speed of light. Photons are actually responsible for all electromagnetic effects; all electric and magnetic fields are the result of photons being passed back and forth between objects, explaining why those influences can't travel faster than light—they ''are'' light.
:Gravity is believed to be mediated by the exchange of particles called [[graviton]]s: massless particles that are like photons, but carry the gravitational force between bodies instead of the electromagnetic. The two other fundamental forces (the [[strong force|strong]] and [[weak force|weak nuclear forces]]) are similarly mediated by the exchange of particles. (There's funny stuff about the weak force and [[W and Z bosons|its associated particles]] that I don't want to go into; it doesn't affect the validity of this explanation, however.)
:So we've got the 'stuff' of the universe that's made up of particles with mass that are limited (by relativity theory) to speeds less than the speed of light, and we've got the massless bits that mediate forces (interactions) which travel at the speed of light. All of the fundamental forces are associated with particles, so there isn't any way to generate an influence without using those particle intermediaries—all of which are limited by the ultimate speed limit. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 14:04, 22 June 2006 (UTC)
:See [[faster than light]], especially section "Apparent FTL". [[User:Conscious|Conscious]] 18:36, 22 June 2006 (UTC)
:This might not quite be revelant to the question asked, but if you were "travelling" at the speed of light, consider the Lorentz contraction of the rest of the universe - everything would be at zero distance. Then faster-than-light would mean you would have to start thinking about how to go zero distance in less than zero time. [[User:Peter Grey|Peter Grey]] 22:53, 22 June 2006 (UTC)
But I was asking about how can and does it, I mean such a rule like that, apply to ''anything'' and ''everything'', not just matter.Couldn't there be some kind of massless force-mediating particle, or some other unknown and undiscovered influence, which the changes associated with special relativity, and therefore the ultimate spped limit, doesn't apply to and occur in?
:You can never conclusively know something ''undiscovered'' isn't there, but they haven't found any signs of one yet i.e. no known phenomena where an undiscovered [[tachyon|faster than light effect]] is the best explanation. [[User:Peter Grey|Peter Grey]] 04:14, 23 June 2006 (UTC)
==Food==
It seems like everything we eat is something that is made from a living soruce--e.g. animal/plant. Can anyone think of an example where this is not true? Also, why is this?
[[User:Mayor Westfall|Mayor Westfall]] 12:30, 22 June 2006 (UTC)
yeah, [[salt]] is the exception. I guess you could trace it back to the fact that humans don't do photosynthesis. (or, needless to say, organic atomic power).
:The simple answer to your question is that the source of energy for animal metabolism is the energy released by breaking down energy-rich molecules such as glucose in [[cellular respiration]], and some plant or animal has to create these energy-rich molecules (a.k.a. ''food'') in the first place. [[User:Gandalf61|Gandalf61]] 12:45, 22 June 2006 (UTC)
:Some argue that petroleum is not from a living source(see [[abiogenic petroleum origin]]), though many believe it is from a living source. Many foods are made with petroleum. [[User:HighInBC|HighInBC]] 12:53, 22 June 2006 (UTC)
::What foods are made from petroleum?! -[[User:Quasipalm|Quasipalm]] 14:41, 22 June 2006 (UTC)
:[[Pub grub]]. --[[User:Dweller|Dweller]] 12:55, 22 June 2006 (UTC)
:I wouldn't recommend it myself, but in [[Ancient Rome]], [[Lead|lead]] salts were used as sweeteners. I have also read that in some countries, pregnant women eat clay as a supplement to their diet.--[[User:Tachikoma|Tachikoma]] 16:56, 22 June 2006 (UTC)
:What about something like Diet Coke? Both artificial flavors and sweeteners, but I'm not sure from what constituents these are produced from—could be peroleum distillates for all I know. —[[User:BradleyEE|Bradley]] 17:49, 22 June 2006 (UTC)
:Another bit of trivia: [[gold leaf]] is apparently non-toxic and can be eaten. I believe it was popular in the bad old days of Thatcher / Reagan. --[[User:TheGoldMiner|The Gold Miner]] 18:08, 22 June 2006 (UTC)
:: Yes, E175 in Europe, see [[E number]]. You'll find a fair few inorganic substances on that list. [[User:Arbitrary username|Arbitrary username]] 18:49, 22 June 2006 (UTC)
:::But everything that was named is not nutritious. [[User:Conscious|Conscious]] 20:39, 22 June 2006 (UTC)
:Apparently there are bacteria that live in caves that no organic matter (or sunlight) reaches, which eat rock. Don't know about the metabolism details, though. [[User:DirkvdM|DirkvdM]] 08:57, 23 June 2006 (UTC)
::Perhaps you are thinking of ''SLiME''? ('''S'''ubserface '''Li'''thotrophic '''M'''icrobial '''E'''cosystem)[[User:Tuckerekcut|Tuckerekcut]] 16:54, 23 June 2006 (UTC)
:::No, that's not it, but it reminds me of a different bacteria, fittingly named [[snottite]]. They corrode rock with their acidic drip, but don't eat rock. However, they eat sulphur, so it's still an answer to the question. [[User:DirkvdM|DirkvdM]] 18:07, 23 June 2006 (UTC)
::::Well, if you're opening this up to non-humans, think of the [[Ecosystem|ecosystems]] that have developed around undersea [[hydrothermal vents]]. These vents are also known as [[Black smoker|black smokers]], and a variety of [[archaea]] and [[extremophile]] bacteria survive either from the dissolved chemicals in the magma-heated water itself, or even the faint glow that emanates from the black smoker.--[[User:Tachikoma|Tachikoma]] 03:43, 24 June 2006 (UTC)
: [[Water]] is not from a living source. It might contain living organisms or formerly living organisms, but it's not alive.
::"not from a living source" ... I've done the math once and given the total volume of animals through time, I concluded that all water on Earth has at one point been piss. [[User:DirkvdM|DirkvdM]] 06:12, 24 June 2006 (UTC)
== Define "temperature equilibration" ==
Can someone please point me to a clear and concise definition of "temperature equilibration?"
And specifically, does it occur when, say, a connecting door between two spaces--one warmer than the other--is opened, and the air allowed to flow between the two spaces?
Thank you.
--[[User:129.71.112.32|129.71.112.32]] 13:55, 22 June 2006 (UTC)
: Temperature equilibrium is achieved between two bodies when their temperatures are the same, or equivalently, when both bodies' temperatures are no longer changing --[[User:198.125.178.207|198.125.178.207]] 14:03, 22 June 2006 (UTC)
I think you did not realize that the poster said "temperature equili'''bration'''". Look at [http://www.google.com/search?q=temperature+equilibration the first few hits] and see if the poster had the right definition. (Also, could pressure-temperature equilibrium of a gas figure in the definition?) [[User:82.131.189.199|82.131.189.199]] 14:09, 22 June 2006 (UTC).
== Buffalo Coin Value ==
On the [[Main Page]] there is a link to the article about the new [[American_Buffalo_(Coin)|Buffalo coin]]. It is a solid gold coin worth $50, but it is an ounce of gold. How can an ounce of gold be worth $50? Wouldn't it be easy to melt it down and sell it for pure gold? --[[User:Russoc4|Chris]] 15:18, 22 June 2006 (UTC)
:The face value of the coin and its selling price are different things. The external links in the article mention the US Mint will sell the coin at price of gold + small premium; at today's price that would be in the USD 600 range. Later the "street price" will be what collectors are prepared to pay each other for the coin. [[User:84.231.33.34|84.231.33.34]] 16:07, 22 June 2006 (UTC)
:At $1.13 dollars per gram of gold, this thing weighs 31g, so you would lose money by melting them and selling the gold. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 16:53, 22 June 2006 (UTC)
::I don't see how thats possible. Mostly because gold is currently USD18.72[http://www.goldprice.org/gold-price-per-gram.html] per gram or USD582.30[http://www.goldprice.org/gold-price.html] per troy ounce (which is 31g). --[[User:Russoc4|Russoc4]] 17:51, 22 June 2006 (UTC)
:::My bad, I rephrase, at $582 per 31g, this thing weghs 31g and costs $800, so good luck on making a profit, you'll need it. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 23:55, 22 June 2006 (UTC)
:Currently, the article mentions that its face value is $50, but it's issue price is $800. That means you have to pay $800 to get one [[American Buffalo (Coin)|American Buffalo]] coin from the U.S. mint. The $50 is not what you pay to get one from the mint; it's what the coin "counts as" if you use it as a coin. If you wanted to buy a $250 stereo, and for some strange reason you wanted to pay the store in American Buffalo coins, you'd need 5 coins. (This would be stupid, of course, since the market value is going to be at least the value of the actual gold in the coin, currently $582.30. But you theoretically could.) It's a bit confusing because with ordinary coins, the two numbers are the same--it costs $0.25 to get a quarter, and a quarter counts as $0.25 when you spend it. But those two numbers are not the same for all coins. [[User:Chuck Carroll|Chuck]] 20:20, 22 June 2006 (UTC)
::If you tried that at [[Best Buy]], they'd probably [http://fox.phoenix.az.us/2005/03/30/best-buy-has-man-arrested-for-using-2-bills/ have you arrested]. --[[User:LarryMac|LarryMac]] 20:33, 22 June 2006 (UTC)
:::Thank you for explaining, Chuck, and thank you for making me laugh Larry :) --[[User:Russoc4|Russoc4]] 20:54, 22 June 2006 (UTC)
:::God that links funny, especially ''“It’s a sign that we’re all a little nervous in the post-9/11 world,”'', what was he going to do with his smeared two dollar bill, give a policeman a paper cut!? I'm pretty sure a piece of paper has considerably less impact than a 777. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 00:04, 23 June 2006 (UTC)
== Why does insulin stimulate glycolysis ==
I just read that insulin stimulates glycolysis - essentially the breakdown of glucose into energy. Why is this? It seems to me that this goes against the "normal" anabolic effects of insulin. Or is this simply what occurs in cell metabolism after glucose has been pushed into cells by the insulin? I'm confused. Anyone? [[User:Jack Daw|Jack Daw]] 16:36, 22 June 2006 (UTC)
Insulin is reponsible of making energy ot of glucose found it the body. This is why you inject it to yourself if you have that specific illness (do not know the exact english name of it). Please consult the Book : Human Anthology for more specific answers. The brakdown of Glucose to Co2 happens in the cells, by ensims, so this has nothing to do with insulin, except that it is needed for it to happen. Ensims NADP and NADPH (if I remember correctly, couse I have learned it more than 8 years ago and have not used this knowlage since then) are responsoble of turning sugar into energy wich your body uses.--Mike
Let's try another explanation. In healthy people [[insulin]] rises when there is plenty of [[glucose]] around, like when you are digesting a high-[[carbohydrate]] meal. Insulin serves as a signal for many types of cells, stimulating some processes and inhibiting others. In general the processes stimulated by insulin are those that consume and store excess glucose, while the processes that are inhibited are those (in the [[liver]]) that produce glucose and release it into the blood. [[Glycolysis]] is an example of a process that consumes glucose, transforming it into energy and into substrates for storage or further synthesis. The opposite of glycolysis is the process of glucose production, [[gluconeogenesis]], which is inhibited by insulin. [[User:Alteripse|alteripse]] 00:11, 23 June 2006 (UTC)
::Firstly the effect of insulin on the rate of glycolysis (specifically [[phosphofructokinase]](PFK) activity, PFK being the rate limiting step of glycolysis ) is independent of the effect on Glucose uptake by cells that insulin has. While insulin stimulates the breakdown of Glucose (Glycolysis) it does not stimulate the [[Citric acid cycle|Krebs Cycle]], this leaves the breakdown products of [[Glucose]] - in the form of [[acetyl-CoA]], an intermediate which can then go on to be used in the synthesis of [[lipids]], so if as [[User:Alteripse|alteripse]] suggested you view the actions of insulin as being to promote processes which consume glucose then you can see that all the effects of insulin are in fact pulling in the same direction.
== Data Flow Diagram ==
Question number1:
What is the dataflow diagram to prepare a library management software?
:Please post all of your homework questions at the same time so we only have to respond once with '''DYOH'''. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 17:34, 22 June 2006 (UTC)
== jvc video tape ==
←→§hello, could someone please help with my question.Iam trying to find out when JVC first launched its SX E-30 video tape many thanks –—…°≈±−×÷Alan Fry--[[User:80.41.71.23|80.41.71.23]] 17:58, 22 June 2006 (UTC)
:You could start by asking JVC, rather than us? --[[User:Dweller|Dweller]] 18:27, 22 June 2006 (UTC)
== US Experimental High Speed Recon Crafts ==
I have been given the VERIFIED information, that a US military Recon Fighter Called "Aurora" exists. It has a speed of around 8 MACHS and uses RAMJET engines. I would like to ask if you have any information on this plane developped by france and sold to the US for use (france is currenly updating it as AURORA-II, with estimated speeds of around 10-12 MACHs. Please be warned, that this information was very hard to acquire and took me a couple contacts to get.
What I found otu, is that it probably has a triangle shape and all engines are housed on under the wing.
I am also missing the technical study aircraft of the russians (made by Mig)wich had a stealthy design and was capable of lifting weapons in it's two bays, each holding an A-bomb or 2 Aphid Heat seeking missiles. Both programs were considered Black, so no public informations were published.
Your answer can be posted to (blanked for privacy), due to the fact, that my other email addresses are probably being monitored.
Yours sincerely: (blanked for privacy).
:Have you considered seeing what has already been written by people here at [[Aurora aircraft]]? --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 19:25, 22 June 2006 (UTC)
::As it says at the top of the page, Wikipedia content is distributed widely on the internet, and putting your e-mail address here makes it very public. If you are concerned about your e-mail addresses being known, posting them on Wikipedia was probably not the best move.--[[User:Tachikoma|Tachikoma]] 19:37, 22 June 2006 (UTC)
== Browsing v Downloading ==
Forgive my ignorance of all things IT, but quite simply, is there a difference between Browsing and Downloading, or are they one and the same thing? Answers in non-techy speak please.
:If you want to be anal, to browse something, you must download it first. Even if you are using remote browsing (ie: Remote Desktop), you have to download the image of what you are browsing locally. But, in common terms, browsing means you are just looking. Downloading means you are saving a copy for future use. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 19:28, 22 June 2006 (UTC)
Thanks Kainaw, that's most helpful - but I will pass on the anal methinks.
:Even some politicians don't seem to know this. In Dutch politics, there was a proposal to make the downloading of information that could be used for terrorist purposes illegal. The problem is, if you follow a link to a page that holds such info, you've already downloaded it. So you have to download the info before you can tell it's something 'illegal' (unless it's marked as such). [[User:DirkvdM|DirkvdM]] 09:04, 23 June 2006 (UTC)
::OK DirkvdM, to pursue your point: if a Dutchman innocently clicks on any link, and another webpage opens on his screen (whether legal or illegal), has he in fact '''downloaded''' it such that it will always be retrievable from his hard drive, even though he did not save it as per Kainaw's earlier explanation?
:::That depends on the web browser. 99.999999999% of the time, the answer is 'yes'. The page is stored in a "temporary" location on the harddrive and can be viewed later directly from the drive. I quoted "temporary" because web browsers tend to keep the files for a very long time. I've worked on people's computers that have "temporary" files that are over a month old. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 16:31, 23 June 2006 (UTC)
::OK and thanks. But what does our innocent but now worried Dutchman do after he has innocently clicked on the link and finds himself reading a notice from the Dutch Government that he has broken the law by doing so. Can he eliminate all evidence of his "crime", or does he destroy his hard drive, before they come knocking on his door to arrest him for his so called illegal activities?
:::All popular browsers have a way to delete temporary files. It is different for every browser. Usually, it is in settings or tools or something similar. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 16:55, 23 June 2006 (UTC)
::Thanks again. I was getting really worried about our poor Dutchman. I can now relax and let him concentrate on watching his national team win in their game next week against Portugal.
:::Thanks for rooting for us, but our innocent Dutchman is still not out of trouble. Deleting a file just makes the disk space available for future use. Unless the data is actually overwritten by other data, the info will still be there. You won't find it through normal ways, but there are ways to retrieve it. [[User:DirkvdM|DirkvdM]] 18:15, 23 June 2006 (UTC)
::Oh Dear. So he's back to destroying his hard drive then, before he can settle down to enjoy the match? And the lesson for the rest of humanity is to buy a crystal ball so that you can predict what is beyond the weblink you are about to click to ensure it doesn't contain anything illegal?
:::Actually, the trick is to avoid actions that would put you under suspicion to begin with. Is there one single example of a person who was investigated and arrested for visiting a website and doing '''absolutely nothing else''' that was illegal? There was a case shortly after 9/11 of a man (Nichols - forget his first name) who was arrested (and plead guilty) on something like 111 counts of child pornography. Nutjobs claimed he was arrested for looking at naked women that he didn't realize were underage. The truth: He was turned in by his mother for sexual assault of a little girl (6 or 7 years old - I don't remember). Police went to his house to investigate and found file cabinets full of photos of children, indexed by the sex act they were performing. After arresting him, it was discovered that the Feds were investigating him for online trade of child pornography. How this became a case of "an innocent guy who was abused by the system" completely escapes me. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 23:48, 23 June 2006 (UTC)
::::Well, the thing is that that is exactly what was proposed in the Netherlands, to make the mere download illegal. The whole world is going apeshit and I'm surprised to find the Netherlands so much at the forefront of it (then again we've got the most right-wing coalition in ages at the moment). Innocent children in jail, people burned alive in a make-shift prison and mass extradition of immigrants (except when it's a [[Ayaan Hirsi Ali|party member]] of course). [[User:DirkvdM|DirkvdM]] 06:27, 24 June 2006 (UTC)
::::There's the case of the guy who was [http://www.boingboing.net/2005/01/27/jailed_for_using_a_n.html arrested for using a uncommon web browser]. --[[User:CesarB|cesarb]] 17:23, 24 June 2006 (UTC)
:::::Funny thing about those stories... The [http://news.bbc.co.uk/1/hi/england/london/4195339.stm BBC News article] makes no mention of the guy making a donation or using Lynx. However, [http://www.boingboing.net/2005/01/27/jailed_for_using_a_n.html some anonymous guy with a blog] says that he has emails from the guy and we are to trust that he has the truth and everything else is a lie. I never trust anyone who claims to have heard the "truth" from some guy who knows some guy who heard about something from an email someone sent that came from some guy who worked someplace that contracted with someone who knew something... --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 18:22, 24 June 2006 (UTC)
::::::[http://news.zdnet.co.uk/0,39020330,39226548,00.htm This report] on ZDNet seems more authoritative, with specific information about the trial. It implies that the guy didn't do what he was accused of doing, but the judge found him guilty anyway because he looked a bit shifty. --[[User:Heron|Heron]] 21:21, 24 June 2006 (UTC)
:::::::Yes, that is a much better article. It makes a lot more sense. From the defendents own statement, he donated money and thought it may be a scam, so he "tested" the security of the site in a manner that was illegal. In my opinion, that does not fall under the umbrella of "being found guilty for just visiting a website." --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 23:26, 24 June 2006 (UTC)
:: Now see what all this conflicting comment has done to our poor Dutchman. He took his eye off the ball whilst worrying that he was going to be arrested for innocently accessing a website he wasn't supposed to, and in so doing, he forgot to support his team and that loss allowed Portugal to go through to the quarter finals.
Just to start this one over again - in Australia, many ISPs give you a certain download limit, so you may get an ADSL plan with a 200Mb, 10Gb, or 40Gb limit per month. It isn't such a problem with the larger limits, but many with a 200Mb limit may think that "they haven't downloaded anything - i just check my email and look at web pages" without realising that the email and web browsing does count towards their download limit. I got this a lot when working at an ISP helpdesk (in the dial-up days). -- [[User:Chuq|Chuq]] 04:02, 26 June 2006 (UTC)
== Untitled Windows XP Install Issue ==
-Added heading to this question [[User:Benbread|-Benbread]] 21:32, 22 June 2006 (UTC)
hi im trying to install a copy of wondows xp on ly laptop, but the instalation prosess ceeps going round in a loop, as it formats the hard drive then it copies files ot it, then it reebots and then so on in that sequence and i dont knwo what to do
there is nothign in the instructions to help me. and i dont understand y it is doing this.
(ps there is no former operating systm on the laptop as that was some hoe wiped form the hard drive and the recovery disks for some reason dont work)
what should i do to install XP?
:When the computer reboots do you press the key it prompts you to press, and if so don't. I always found that to be a stupid thing that seemed to confuse a lot of people. [[User:Benbread|-Benbread]] 21:56, 22 June 2006 (UTC)
== Teaching myself anatomy ==
I want to teach myself anatomy, to a doctor's level, profound knowledge. Would you recommend me any sources or good books? Thanks.
*Start [http://www.bartleby.com/107/ here]. Memorize every page. There will be a test. --[[User:Jpgordon|jpgordon]][[User talk:Jpgordon|∇∆∇∆]] 22:39, 22 June 2006 (UTC)
***Well, you did say "to a doctor's level"... -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 07:57, 23 June 2006 (UTC)
*I'll echo Jpgordon's comment and say that ''[[Gray's Anatomy]]'' is the unquestioned gold standard for anatomical reference texts. From the standpoint of actually ''learning'' the anatomy, you could try visiting your local medical school's bookstore and pick up some anatomical colouring books. (Forcing yourself to identify and colour every bit of the anatomy is one of many pedagogical tactics to aid memory.) Practice always helps—for every part of your body that you can see and reach, try to identify all the visible or tacticle bones, muscles, tendons, blood vessels, etc. It's even more fun if you can find a friend who will let you play doctor. :D [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 23:00, 22 June 2006 (UTC)
*'''Video!''' [http://www.torrentspy.com/search.asp?h=&query=anatomy+for+beginners&submit.x=0&submit.y=0 Anatomy for Beginners]. Before you read anything, it's best to have a visual understanding of what's inside the body. It's utterly fascinating. --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 23:04, 22 June 2006 (UTC)
I would recommend the '''Anatomy Coloring book''' very strongly (ISBN 0805350861), the Physiology Coloring Book is great too.[[User:Tuckerekcut|Tuckerekcut]] 01:21, 23 June 2006 (UTC)
You could try vivisection on yourself. Several mirrors and loads of sedatives are recommended for this method. [[User:DirkvdM|DirkvdM]] 18:18, 23 June 2006 (UTC)
Thank you very much for the very informative and humorous comments ;)
== human diagram - showings measurements of age groups ==
Been searching 2 days for a really basic, HUMAN BODY DIAGRAM - showing measurements of body divisions. (as, theigh portion of leg.)
Measurements divided into 3 major age groups, (child, teen, & adult)-
Thanks,
Boswell --[[User:Boswell6|Boswell6]] 23:15, 22 June 2006 (UTC)
Is this what you wanted? [http://www.healthandwelfare.idaho.gov/_Rainbow/Documents/medical/pediatric%20burns.pdf] [[User:Alteripse|alteripse]] 23:54, 22 June 2006 (UTC)
= June 23 =
== Name of a Phobia? ==
Someone I know is scared of wrists. Not that she constantly fears them or anything, she just doesn't like looking at them. She'll be fine as soon as she stops looking at a wrist so it's not like it really affects her in a huge way. However, everytime you show her a wrist, she'll cover her face with her arms and whimper. She wears short sleeved shirts quite often and says she avoids looking at her own wrists completely as well. Is this even a phobia and if it is, is there a name for it? --[[User:71.235.83.132|71.235.83.132]]
:According to our article [[Greek and Latin roots]], carp- is either Latin or Greek for wrist. It's probably Latin. In that case it wouldn't work because the suffix -phobia is Greek. In any case, carpophobia would most likely work because there are a lot of phobias that mix Greek and Latin roots. I don't know for sure though. [[User:Schyler|schyler]] 01:52, 23 June 2006 (UTC)
please see or write the article [[wrist_cutting|wrist cutting]]. [[User:82.131.184.195|82.131.184.195]] 01:52, 23 June 2006 (UTC)
:On [http://www.unusualphobias.com/wrists.html this page] there are messages from a number of people who fear wrists. (May not display entirely in Firefox; IE is ok.) -[[User:R. S. Shaw|R. S. Shaw]] 06:42, 23 June 2006 (UTC)
:Every person's phobia doesn't have to have some silly Greco-Latin name. What your friend is experiencing is a [[specific phobia]], and what it happens to be attached to is probably not that significant.--[[User:Pharos|Pharos]] 07:11, 23 June 2006 (UTC)
== percolated coffee ==
Why does percolated coffee loose its aroma and flavor after the first cycle of percolation? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 01:55, 23 June 2006 (UTC)
:I believe that a lot of the flavor in coffee comes from certain volatile oils that are released when you heat the coffee. Since the percolation process is in effect cooking the coffee over and over, more and more of those oils evaporate into the air instead of remaining in the liquid.--[[User:Tachikoma|Tachikoma]] 05:05, 23 June 2006 (UTC)
:I thought the oils broke down during percolation, but it may be that they evaporate. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 21:16, 23 June 2006 (UTC)
Why doesn't this happen when roasting? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 23:32, 23 June 2006 (UTC)
:The oils might break down too, I forget--this was from a book on coffee I read a long time ago. In any case, I don't recommend percolation as a way to make coffee.
:I assume that only whole beans would be roasted, so maybe the exterior of the bean is impermeable enough to keep the flavor in, at least for a while.--[[User:Tachikoma|Tachikoma]] 23:41, 23 June 2006 (UTC)
== mesh-ups ==
What is a mesh-up?
I am asking in the context of the related term called "Mashing". The term mash-up is borrowed from the world of music, where it refers to the unauthorised combination of the vocal from one song with the musical backing of another, usually from a completely different genre. Web mash-ups do the same sort of thing, combining websites to produce useful hybrid sites and illustrating the internet's underlying philosophy: that open standards allow and promote unexpected forms of innovation.
Apparently, this is actually a manifestation of MESHING, of finding bridge points between disparate pieces to make a new "sense" of something. In fact, this might be a very early community indicator, as mash/meshes point out areas of shared interest.
NOTE: there is also another meaning of "mesh-up" in the computer world of 3-D imaging. It is the term that describes the creation of 3-D shapes which are "meshed-up" into an interactive plane. This is not to be confused in our context!
So I am not sure that this is accurate and cant find information other than perhaps a book on the subject called: "Web 2.0: Web Services Mesh-up" by Alexander Peter.
Can you clarify this subject area?
== breaking down .rar file into little parts ==
I've often seen this done (especially on torrents) but never been able to find out how to do it myself. Say I have a .rar file 2 GB large and want it to be broken into little files of 10 MB each. What programs can do it? -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 08:00, 23 June 2006 (UTC)
:If you have [[WinRAR]] installed then, unpack the RAR rile, now right-click on the file or directory you want to split and select the Add to archive... option, a dialogue box will pop up and the quickest way to split the file is edit the option in the bottom right corner that indicated "Split to volumes, bytes". Since you want 10MB files then fill in 10000000. You may also want to play around with the archiving options (specifically create solid archive, put authenticity verification, and put recovery record).--[[User:69.171.123.148|69.171.123.148]] 08:31, 23 June 2006 (UTC)
::Actually, 10MB would be 104857600 (bytes). [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 13:27, 24 June 2006 (UTC)
:::Not necessarily. See [[binary prefix]] for the details. --[[User:CesarB|cesarb]] 17:13, 24 June 2006 (UTC)
::::Since nobody uses "mebibytes" in normal conversation ''yet'', it's safe to assume that we're all talking about plain old 1999 megabytes here. Regardless, 10000000 is still wrong. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 06:58, 25 June 2006 (UTC)
== Memory ==
Does a full hard-drive weigh more than an empty hard drive?
: Careful reading of the [[hard disk]] article would suggest not. '''[[User:Rockpocket|<font color="green">Rockpock</font>]]<font color="black">e</font>[[User_talk:Rockpocket|<font color="green">t</font>]]''' 08:17, 23 June 2006 (UTC)
:No, a "full" harddrive merely has all of its mini-magnets rearranged by the write head into patterns recognisable by the read head. AFAIK. -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 08:19, 23 June 2006 (UTC)
:However, if you save your word documents in smaller fonts and increase the font size only when you open them, that might save some weight. – [[User:b_jonas|b_jonas]] 08:55, 23 June 2006 (UTC)
::: I don't think this is true, because hard drives don't contain paper. They're already miniature sized representations. Is [[User:b_jonas|b_jonas]] just trying to mislead you?
::I really must remember not to read the reference desk while drinking coffee. There's a high risk of drowning. [[User:Grutness|Grutness]]...''<small><font color="#008822">[[User_talk:Grutness|wha?]]</font></small>'' 09:32, 23 June 2006 (UTC)
:Certainly not, writing to a hard drive just rearranges existing magnetized particles, it doesn't add any mass (where would it come from?) [[User:EAi|EAi]] 10:12, 23 June 2006 (UTC)
:It depends on how you define "full" and "empty". First, if you mean full or empty relating to meaningful information, then there is no mass difference since the orientation of a dipole does not affect the atomic mass of its composing particles. (Or does it? I'll have to doublecheck this assumption.) Second, say that by empty you mean demagnetized (that is, the same material exactly but not magnetized or magnetizable) vs a full (that is, a magnetized one), then the masses have to be different, because some of the electrons will occupy different atomic orbits (different energy levels), thus will have very slightly different mass.--[[User:JLdesAlpins|JLdesAlpins]] 14:49, 23 June 2006 (UTC)
I was just thinking about whether a charged capacitor weighs more (on an electron mass scale), but I don't think so, since more electrons on one plate means less on the other. I wonder if any electronic (computer) component experiences a change of mass. --[[User:Zeizmic|Zeizmic]] 12:18, 23 June 2006 (UTC)
::Would a USB flash disk, with all the tunneling of electrons? I haven't looked at the article to see a detailed description, so this is just a guess. --[[User:80.229.152.246|80.229.152.246]] 15:58, 23 June 2006 (UTC)
:::Guessing, a ''new'' one would weight less, although even if it was wiped and empty, if it was used, it still has the electrons in it all set to whatever 0 or 1 positions your wiping software did. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 21:18, 23 June 2006 (UTC)
:A charged capacitor has an [[electric field]] between its plates; this field has energy and therefore mass. The energy in a capacitor is <math>CV^2/2</math>; typical values for a computer-type application are <math>C=1\mu F</math> and <math>V=5V</math>, giving <math>E=1.25\times 10^{-5} J=1.53\times 10^8 m_e c^2</math>. So the energy stored in a capacitor can easily have mass equal to that of millions of electrons. But remember that the capacitor will have many more electrons than that: a gram of iron contains <math>2.80\times 10^{23}</math> electrons! --[[User:Tardis|Tardis]] 02:13, 24 June 2006 (UTC)
::Given that a computer is a modelisation of our own thinking processes : When we learn something, whe should gain weight. --[[User:Harvestman|DLL]] 10:12, 24 June 2006 (UTC)
:::That explains why the really nerdy students at university get so fat ... [[User:ConMan|Confusing Manifestation]] 03:56, 25 June 2006 (UTC)
== Why don't ships sink? ==
Paddling a canoe the weigh of the paddler is spread over a large area. Given the weigh of a large ship, for example aircraft carrier of oil tanker, and the small area in the water, why doesn't it sink?
Einstein's Shadow
--[[User:Einstein's shadow|Einstein's shadow]] 10:03, 23 June 2006 (UTC)
: Due to [[Buoyancy]]. The water surrounding a boat exerts a force on it. The angled sides of the boat channel this force upwards, i.e. pushing the boat out of the water. As soon as the entire boat is under water, an equal force is exerted on all sides (i.e. there's water on top of it) and the boat sinks (well, actually the force is marginally higher at the bottom due to the fact that the pressure of a liquid increases as the depth increases, but gravity outweighs this). [[User:EAi|EAi]] 10:11, 23 June 2006 (UTC)
:From what I remember of buoyancy, the shape of the boat isn't really relevant to whether it sinks or floats, is it? Buoyancy helps you decide whether things float, and how high in the water they would be, but really it's as simple as this: things that are heavier than water (like stones) sink; things that are lighter than water (like wood) float. Big ships have a lot of metal, but they also have a lot of air inside, and it is this that makes them, overall, lighter than the water. ("Lighter than water" is shorthand for "having a lower density than water"). Of course, if a ship is badly designed so that water can get in and replace the air, it will probably sink. To return to terms in the original question: the ''area'' is not important, but the ''volume'' is critical. [[User:Notinasnaid|Notinasnaid]] 10:52, 23 June 2006 (UTC)
::Shape sure does make a difference - if a boat capsizes, the air will leak out (to be replaced with water), and the boat will sink. If the ship were hermetically sealed, the shape would not make a difference as the average buoyancy would be unchanging, but in the real world (other than a submarine) that's not how it works. [[User:Raul654|Raul654]] 11:54, 23 June 2006 (UTC)
:I think we're just agreeing with each other, but let's try to be clear: the shape itself doesn't dictate whether an object floats, but of course if the shape is badly thought out the boat may capsize, and if the boat is badly designed a capsized boat will leak, so it will replace air by water and it will sink. However, I don't think it makes any difference to buoyancy whether the area below the water is slope edged or square box or anything else, except in as much as this shifts the centre of gravity and affects how much can be above the waterline and remain stable; and some shapes are better for moving through water (which isn't the issue). [[User:Notinasnaid|Notinasnaid]] 12:01, 23 June 2006 (UTC)
:::You may have a look at the wiki article - [[waterline]]...
[[User:Pupunwiki|Pupunwiki]] 12:08, 23 June 2006 (UTC)
:: Shape will determine ''how'' it floats - what level the water rises to, and which direction points up.... [[User:Nimur|Nimur]] 19:46, 23 June 2006 (UTC)
:Because a ship weighs less than the water it displaces? Obviously! remeber a cubic metre of water weighs a tonne, its not light stuff. And with all that air on board, its bound to be lighter. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 21:35, 23 June 2006 (UTC)
Thanks for answering my question........so is it yes? or no?
:er.. the intial question isn't a yes/no question. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 01:33, 24 June 2006 (UTC)
== A QUESTION ABOUT C PROGRAMMING. ==
Hello, I was recently reading a book "Structured C Programming" by some author. In it he has mentioned one code which i am not able to understand. It goes as follows :
printf("%d %8.2f %d %hn",i,x,j,&count);
He says that : " If you need to verify the number of input or output characters, you can do so by specifying the n code. This code requires a matching variable address into which scanf or printf places the count of the characters input or output. If the code is prefaced with an h, the matching variable must be short; if it is l, the variable must be long. Since the operation places the results in the variable, its address must be used in the parameter list. In the following example, "count" is a short integer that is to receive the number of characters written".
And then he mentions the forthmentioned code.
My question is that what is the variable count doing? And if I want to see the value of this variable "count", how should I get it printed, because I tried the usual way : printf("%d",count), but it didnt work ! Then I tried to print it using the "%hn" specifier as mentioned by the author, but it also didnt work !
So some help is needed. Thank You.
Perhaps a programming website would be more suitable for such a question? Theres many of them. See [http://www.cplusplus.com/ref/cstdio/printf.html] for documentation on printf. This code:
short count = 0;
int i = 1, x = 2, j = 3;
printf ( "%d %8.2f %d %hn", i, x, j, &count );
Would store the value '3' in count as three values: i, x and j have been outputted so far. I've never used or seen this functionality and can't see much reason to.
%hn means: output the number of variables written so far to the '''short''' specified. The ''h'' indicates that the argument is a ''short'', not (as assumed by default) a ''long''. Hence, the variable ''count'' in the example above is defined as ''short''. Read that linked documentation for more info.
[[User:EAi|EAi]] 11:01, 23 June 2006 (UTC)
:'''printf("%d",count)''' should be fine, provided count has a suitable type. For instance if you've used '''int count'''. If count is another type (like long or double) you need to use a suitable, different, format string. Indeed you should spend some time looking at the specification of printf strings, though it can be pretty confusing; if you are just starting out, maybe stick to some recipes for the types you use, and come back to learn format strings later. (Even as a C programmer for over 10 years, I still have to go back to check the rules for printf sometimes). [[User:Notinasnaid|Notinasnaid]] 11:53, 23 June 2006 (UTC)
::Well, its going to be a short, not an int as its %hn :) [[User:EAi|EAi]] 12:01, 23 June 2006 (UTC)
== Human genetic variation by continent ==
Not too long ago, I was confronted with the following multiple choice question in an exam (freely translated):
The human population of which continent shows the highest degree of genetic variation?
# Europe
# Africa
# North America
# Asia
# South America
Now, the correct answer according to them is Africa. I answered it right by feeling, but I still thought it can't really be true. I mean, even with the "out of Africa" hypothesis, which would mean that modern humans in Africa had the most time to evolve etc., there are people of African origin in all parts of the world. So my natural feeling was that Northern America, with its most recent, but most mixed population should have the highest degree of genetic variation.
Is Africa the correct answer? Would Africa only be the correct answer if the question would be: "The '''native/original''' human population ..."? Is the question just plain dumb and not clearly answerable? Thanks, -- [[meta:User:Totti|Totti]] [[meta:User talk:Totti|(talk)]] 11:37, 23 June 2006 (UTC)
: Have a read of [http://human-nature.com/ep/reviews/ep03255262.html this article] (about a quarter of the way down it mentions this specifically). It doesn't make it seem as cut-and-dry as the question suggests. You could also see table 2 on page 3 of [http://jorde-lab.genetics.utah.edu/elibrary/Jorde_2000a.pdf this document] - it gets pretty technical, but you could probably find some help there. [http://www.actionbioscience.org/evolution/johanson.html This article] is also very accessible and could be interesting to you. [[User:EAi|EAi]] 11:48, 23 June 2006 (UTC)
:: Thank you, although not ''really'' answering my question (which I expected), those links were very useful. -- [[meta:User:Totti|Totti]] [[meta:User talk:Totti|(talk)]] 14:10, 23 June 2006 (UTC)
:The answer is correct based on all of the population genetics research of the last 4 decades. The question requires a relatively sophisticated understanding of human population genetics. As you mention, most people would assume that the population of North America has the greatest diversity, which might be true if the question were posed as "which continent shows the greatest degree of diversity of geographical location of 3 century ancestors?" The gene polymorphisms responsible for the most obvious outward differences of human skin and face shapes are fewer and less ancient and fundamental than a variety of other less visible polymorphisms present in the African population. Nearly all of the populations of the other continents share many of these genes with one subset of the African population. I assume this was a higher-level exam? [[User:Alteripse|alteripse]] 13:08, 23 June 2006 (UTC)
:: Yeah, I do have advanced understanding of population genetics, and I knew about most of that (visible vs. hidden polymorphisms), but I just thought the question itself was biased, because as I said, due to migration, I'm pretty sure no one can clearly say what ''continent'' has, at the given time being now, the highest amount of genetic diversity. Of course I both agree and would naturally assume (and also it's undoubted because of research), that the ''original'' population of Africa would match this criteria. Or do you mean that despite migration, Africa still has a larger gene pool (e.g. more Africans would have to emmigrate to reduce Africa's gene pool or expand other continent's gene pools enough)? It's a question from my finals (second semester, medicine, [[Medical University of Vienna]]), and in my opinion a bad one. -- [[meta:User:Totti|Totti]] [[meta:User talk:Totti|(talk)]] 14:10, 23 June 2006 (UTC)
:::I don't know from genetics. But the blacks in blacks in Africa that descend from slaves are of the [[Bantu]] variety. But in Africa there are also [[nilotic]] people in the East, who are a completely different 'race' (insofar as there are human races), more closely realted to [[semite]]s, I believe (actually, they look like whites, except that their skin is black. And there are also [[pygmy|pygmees]] in the centre and [[bushmen]] in the south. And especially these last two groups you won't likely find elsewhere. But 'races' from other parts of the Earth ''are'' found in Africa, namely whites and Asians. No Indians, though, I suppose (American Indians, I mean). But I suppose the nilotic people, pygmees and bushmen tip the balance. [[User:DirkvdM|DirkvdM]] 18:44, 23 June 2006 (UTC)
The answer is correct, and is consistent with the [[recent single-origin hypothesis|Out-of-Africa]] theory of human migration. Non-Africans are genetically more related to each other than they are to Africans because they are all descended from a small group of humans that migrated out of Africa. - [[User:Cybergoth|Cybergoth]] 22:14, 23 June 2006 (UTC)
:If one person from "one end of the human gene" born in Africa moved to South America, and a person from the "opposite end of the human gene" born in Africa moved to South America too, wouldn't the contrast between only those two people qualify SA as the continent with the highest amount of genetic variation? Or would that only count as genetic range? I find it difficult to accept such a simple answer to the multiple choice question. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 12:21, 24 June 2006 (UTC)
::The exam question is not very detailed and probably makes a few assumptions. I assume that it refers to the native population of these continents (excluding recent migration?). In your example of individual Africans moving to South America, yes, it would increase the genetic range and the variation slightly. Because of the large number of native South Americans, the population would still be more genetically homogenous than the African population. - [[User:Cybergoth|Cybergoth]] 16:02, 24 June 2006 (UTC)
== Dream ==
Sometimes I dream I stumble and fall and during that I shudder in bed. Is it because of the fall of the muscular tone? --[[User:Brandmeister|Brand]] [[User talk:Brandmeister|'''<font color="Black">спойт</font>''']] 12:11, 23 June 2006 (UTC)
:Since you are interested, this is a great opportunity to look up sleep and dreaming in this encyclopedia. You will find that when you dream, the brain turns off its ability to control muscles. However, this is not perfect, and some 'leakage' occurs. If you watch a dog dream, you can see that their 'switch' is not that good. --[[User:Zeizmic|Zeizmic]] 12:24, 23 June 2006 (UTC)
::And lets not even start about sleepwalkers...
:You have possibley fallen victom to the [[Hypnic jerk]], which more interestingly happens to teenagers at night than say, adults, or younger kids. Otherwise, its just a [[Myoclonic twitch]]. If you actually made it to the full dreaming stage, and drempt you fell, and woke up because of your unconcious body moving around, that came from (I forget) some kind of falling-from-the-tree-impulse, because we used to sleep in trees. If we started falling, the impulse would make us immediatley wake up and already have our limbs moving out to try and grab a branch or at least break our fall with a lmib instead of a head. The only times I wake up from deep sleep this way are when I am actually falling off the side of the bed. It is amazing to me that I can wake up and pull myself back up ''before'' I hit the ground. Guess its working!! — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 21:23, 23 June 2006 (UTC)
:::[[Odysseus]] build his bed in an old olive tree and his house around. His [[Penelope|wife]] recognizes him when he hints at that. --[[User:Harvestman|DLL]] 10:07, 24 June 2006 (UTC)
== Referrence ==
Can you exolain me and give refference to me on destructive distillation of wood?With pictures.--[[User:Saksham Sharma|Saksham Sharma]] 12:58, 23 June 2006 (UTC)
:You already asked this question and it was answered: [[Wikipedia:Reference desk/Science#Environmental Question]]. — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 13:16, 23 June 2006 (UTC)
== ocean currents ==
Please tell me about ocean currents in full detail.Please give me the referrence also.--[[User:Saksham Sharma|Saksham Sharma]] 13:05, 23 June 2006 (UTC)
:There is a very nice little box on the left side of your screen, labelled "search". Type in "ocean current". Hit "Go". It will take you to our article on [[ocean current]]s, where you should find anything you need to know. The article even has some external links for further information if you need more. — [[User:QuantumEleven|Quantum]]<i>[[User_talk:QuantumEleven|Eleven]]</i> 13:08, 23 June 2006 (UTC)
:Also note that just saying "please" at the beginning of every question doesn't necessarily make them polite. The requests have to be reasonable ''and'' you have to say please for the question to sound polite. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 12:14, 24 June 2006 (UTC)
== Glycol-modified PET ==
I'm looking for the chemical structure of a plastic, but all my web searches have been fruitless. The plastic in question is PETG (Glycol-modified PET). Wikipedia has a nice article on PET, but not PETG. Can sombody help me figure out where the glycol modifications are on this molecule? Many thanks. - M
:I was having lots of fun looking up 'petg' and 'chemical structure petg' on Google, but then I discovered that this was a standard university homework assignment. --[[User:Zeizmic|Zeizmic]] 17:13, 23 June 2006 (UTC)
:: Not, not homework: my lab is growing endothelial cells on PETG disks, and we want to modify the plastic so as to be more hydrophilic. I was hoping somebody would know exactly how glycol-modified PET is glycol-modified so that we can figure out whether it's worth it. - M
[[Image:PET.png|thumb|right|200px|Chemical structure of polyethylene terephthalate]]
PET is poly(ethylene terephthalate) while PETG is poly(ethylene terephthalate) glycol. The only difference between the two is that PET has a hydrogen at one end and a hydroxyl at the other, while PETG is a [[glycol]], with two terminal hydroxyls. – [[User:ClockworkSoul|Clockwork]][[User_talk:ClockworkSoul|<b>Soul</b>]] 19:06, 23 June 2006 (UTC)
{{-}}
== IAU and the naming of satellites ==
Inspired by the recent naming of Nix and Hydra (moons of Pluto), I have a couple of questions about the formalities of satellite-naming:
# When the IAU officially accepts a name for a satellite, what form does the official announcement take? Is it always in an IAU Circular?
# Does the IAU have several official languages in which it makes such announcements, like the UN? Or are the announcements only made in English?
Thanks, [[User:Cam|Cam]] 14:57, 23 June 2006 (UTC)
*After some reading, I'll attempt to answer my own questions:
# The body that names natural satellites is the IAU's Working Group for Planetary System Nomenclature (WGPSN). When the WGPSN comes up with a name for a satellite, the decision is usually (''but perhaps not always''?) announced in an IAU Circular.
# As near as I can tell, the WGPSN does all its work in English and the IAU Circulars are only published in English. It seems that spelling is important, for example the name of Jupiter XXXV is Orthosie, not Orthosia; Pluto II is Nix, not Nyx, despite the fact that these goddesses can be referred to by all these spellings in English. How this works out for other languages that can't make these distinctions in their writing systems is not clear to me. Any thoughts?
*[[User:Cam|Cam]] 19:47, 25 June 2006 (UTC)
== [[entomogamy]] ==
I've been translating [[Clematis vitalba]] from the French article, and there is a word "entomogame", which it appears means something like "transferring seeds by the wind". I guessed the English translation would be [[entomogamy]] or something similar. Does Wikipedia have an article on this, or something the same? I assume we would anyway. --[[User:Brandnewuser|Brandnewuser]] 15:44, 23 June 2006 (UTC)
:No, not by the winds, by insects. See the related word [[entomology]]. The ''-gamy'' bit relates to reproduction (i.e. here pollination), see the related word [[gamete]]. [[User:Arbitrary username|Arbitrary username]] 16:31, 23 June 2006 (UTC)
::It turns out that [[entomophily]] is the actual term. But entomogamy seems to be listed elsewhere, so I'll create a redirect. [[User:Arbitrary username|Arbitrary username]] 16:33, 23 June 2006 (UTC)
:::Good work. How about the phrase "méso à eutrophiles", which was listed under the "habitats" section? --[[User:Brandnewuser|Brandnewuser]] 23:23, 23 June 2006 (UTC)
::::Méso is greek for middle - medium habitat I'd guess. eutrophile indicates a living form that loves good food : like some water plants where there's plenty of [[nitrates]] dissolved. --[[User:Harvestman|DLL]] 10:02, 24 June 2006 (UTC)
== Sugar Granule Size - Does It Really Matter? ==
If it's going to get disolved in water, what possible difference does it make, whether I use caster sugar or icing sugar? Why not just granulated sugar? When it's dissolved, it's just sugar water, no matter what size the granules were to begin with? http://www.supercook.co.uk/inspiration/recipe-ideas/details/12011 --[[User:Username132|Username132]] ([[User talk:Username132|talk]]) 17:21, 23 June 2006 (UTC)
:Dissolving is a reaction that occurs on the surface. The smaller the sugar granules the more surface for a given amount of sugar (assuming the sugar is the same thing except for granule size obviously), so the faster it will dissolve. [[User:DMacks|DMacks]] 17:41, 23 June 2006 (UTC)
::Yeah, so it takes five minutes longer - big deal - at the end of it, you're left with the same solution, right? --[[User:Username132|Username132]] ([[User talk:Username132|talk]]) 18:08, 23 June 2006 (UTC)
:::Perhaps a given volume of caster sugar is slightly more dense than the same volume of granulated sugar, thus you'd get a sweeter syrup using the former. Given the recipe you linked, you probably won't care after consuming one or two of those jellies. --[[User:LarryMac|LarryMac]] 18:18, 23 June 2006 (UTC)
:If you're disolving it in water, you're right. The reason for the variety is that the texture of the granuals and their speed of entering solution matter for some cooking. [[User:Trollderella|Trollderella]] 18:21, 23 June 2006 (UTC)
:According to the [[sugar]] article, in powder sugar, "The manufacturer may add a small amount of anti-caking agent to prevent clumping". [[User:DirkvdM|DirkvdM]] 18:53, 23 June 2006 (UTC)
:Also keep in mind that the actual shape and size of sugar is sometimes used. For example, when making cookies you start by creaming butter by adding sugar and mixing it so that the sugar crystals basically slice up the butter and introduce small pockets of air. Using a finer sugar would create smaller pockets of air and so the resulting texture would be different. There may also be times when you want to form a sort of colloid of sugar and fat, in which case the size of the sugar particles would affect the texture of the mixture (e.g. in frosting/icing). [[User:128.197.81.181|128.197.81.181]] 21:41, 23 June 2006 (UTC)
:When dealing with ingredients such as sugar and salt, it's important to use the same grade as the recipe calls for if the recipe amounts are volumetric (as they almost always are). Finer particles will result in adding too much of the substance and coarser ones in adding too little. Flour is so variable in density that I've seen recipes that specify a weight of flour rather than a volume. [[User:128.197.81.181|128.197.81.181]]'s comments are also important if the sugar is not to be dissolved. --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 21:59, 23 June 2006 (UTC)
== photosynthesis and cellular respiration ==
Okay i have two questions that are tied in with each other.
1a. How would the composition of earth's atmosphere change if green plants and other autotrophs disappeared?
1b. How would animal life be affected by this atmospheric change?
Any help with these questions would really be appreciated. I've looked all over and can't find answers. I don't remember anything like this being in the book, and i homeschool so there is no teacher for me to ask.
Hopless Biology Student
: Your best bet is to research [[photosynthesis]], [[autotrophism]], and [[atmosphere]] - I think you'll see quickly that green plants contribute to the various gas cycles, release and absorb [[Oxygen]] and [[Carbon Dioxide]], participate in the [[Carbon cycle]], [[Nitrogen cycle]], and probably absorb considerable [[solar radiation]] that would otherwise become [[heat]]. I imagine your questions should be answered in essay form, so you might want to do some thorough reading in your textbook as well. [[User:Nimur|Nimur]] 19:54, 23 June 2006 (UTC)
:C'mon man, read the textbook first next time!! You may not be able to copy a sentance verbetium, but you will learn the answer rather than relying on us to tell you. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' [[User talk:Mac Davis|ญƛ.]] 21:43, 23 June 2006 (UTC)
Thank you for letting me know what to look up... i kinda get it all now... thanks :)
== Macbook Pro // Bootcamp ==
Okay, I want to get a [[Macbook Pro]] for my next school year. But I also want to have [[Windows]] on there.
My question is this: [[Boot Camp]] is currently in beta, but it'll be official when OS X 10.5 comes out in late November I believe. However, I will need to have a laptop before August. Is it likely that Apple will release Bootcamp Final for all the saps who bought a new computer for the new school year with 10.4? — [[User:Ilyanep|<span style="font-variant:Small-caps;color:black;">Ilyan</span>]][[User:Ilyanep/Esperanza|<span style="font-variant:Small-caps;color:green;">e</span>]][[User:Ilyanep|<span style="font-variant:Small-caps;color:black;">p</span>]][[User talk:Ilyanep| <span style="font-variant:Small-caps;color:#808080;">(Talk)</span>]] 20:04, 23 June 2006 (UTC)
:Well, no one can tell you that without resorting to tea leaves or tarot cards. But even as beta, Boot Camp seems quite well-behaved and problem-free. So I wouldn't wait for Bootcamp Final, as it will mostly be a name change. But if beta vs final is important, and even if not, I would consider using Parallels [[Desktop for Mac]] virtualization software [http://www.macnn.com/articles/06/06/15/parallels.desktop.for.mac/] instead of Boot Camp, as you can run MacOS & Windows simultaneously (Windows running in a window in the Mac OS), and cut and paste between them, rather than rebooting and running only one at a time as Boot Camp requires. [http://www.eweek.com/article2/0,1895,1977152,00.asp] - [[User:Nunh-huh|Nunh-huh]] 20:26, 23 June 2006 (UTC)
::But I probably want to have full performance for gaming. Also, the difference between beta and final may be pretty big considering what Apple tends to do. On the other hand, the way it works now is probably enough for me. — [[User:Ilyanep|<span style="font-variant:Small-caps;color:black;">Ilyan</span>]][[User:Ilyanep/Esperanza|<span style="font-variant:Small-caps;color:green;">e</span>]][[User:Ilyanep|<span style="font-variant:Small-caps;color:black;">p</span>]][[User talk:Ilyanep| <span style="font-variant:Small-caps;color:#808080;">(Talk)</span>]] 20:47, 23 June 2006 (UTC)
:::How good ''is'' Bootcamp? I thought that Windows would be noticeably slower. I predict OS X 10.5 to come out later this year (oh, you said that), and it will have Bootcamp bundled in a final release. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 21:14, 23 June 2006 (UTC)
::::I hear that a Mac running Boot Camp and Windows XP is almost as good and even better than some high-end PCs running Windows XP. — [[User:Ilyanep|<span style="font-variant:Small-caps;color:black;">Ilyan</span>]][[User:Ilyanep/Esperanza|<span style="font-variant:Small-caps;color:green;">e</span>]][[User:Ilyanep|<span style="font-variant:Small-caps;color:black;">p</span>]][[User talk:Ilyanep| <span style="font-variant:Small-caps;color:#808080;">(Talk)</span>]] 22:33, 23 June 2006 (UTC)
::There are ways to just install both, and choose as it boots which you run. Though I cant remeber how, thoguh some clever guy programmed the choice to a tilt swith, so it booted linux one way up, and woindows the other. I'm sure a similar thing can be done with OSX and windows. though a tilt swith would be innapropriate in a laptop! [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 21:24, 23 June 2006 (UTC)
== Types of melting ==
i was tolt that there are two types of melting, one is called a '''"pasteous melting"''' and the other one is '''"frank melting"''', physics consider some objects like parafin and glass as liquids and when heat is added to them, they melt not like the water ice cubes, they do it slowly and they call it pasteous melting.
I have found this right here -> [http://72.14.207.104/search?q=cache:GD5wJNDce6oJ:www.prmsp.org/cncat/jump.php%3F644+%22fusion+pastosa%22&hl=es&gl=pe&ct=clnk&cd=4 in spanish] on page one, but i am still confused on the meaning of both types of melting. What a '''"pasteous melting"''' and '''"frank melting"''' are ?--[[User:HappyApple|HappyApple]] 22:07, 23 June 2006 (UTC)
:I'm not familiar with those terms, but some materials, like water ice, melt all at one temperature, while others, like glass, slowly transition from an apparent solid to a thick liquid to a thin liquid as the temp increases. [[User:StuRat|StuRat]] 03:45, 24 June 2006 (UTC)
:I'm not that familar with those terms either but I think you've almost answer the questions yourself- pasteous melting is melting of a solid that does not have a definate [[melting point]] - so it goes through a semi solid stage. Whereas 'frank melting' refers to a solid that does have a distinct melting point - this would melt directly into a liquid - with no intermediate 'gooey' or 'pastey' phase.[[User:HappyVR|HappyVR]] 13:53, 24 June 2006 (UTC)
It may be of note that nothing really has a definite melting '''point''', but rather a melting '''range'''. This range may vary in size, from a few hundredths of a degree in very pure substances, to many degrees in less pure solids. This range is often created by imperfections in the crystalline structure of some solids (though not all solids are crystalline), but can also be effected by impurities (even impurities caused by putting a pure substance in contact with air). I would venture to say that the difference in melting behavior of wax and ice is due less to some different "type" of melting, and more to the thermal masses of the substances, and the relative liquidity of the newly melted products.[[User:Tuckerekcut|Tuckerekcut]] 17:52, 25 June 2006 (UTC)
== Optical propreties of the human eye ==
If you had to compare the human eye to a camera lens and sensor, how would you describe the ISO range, aperture range and focal length? --[[User:Jcmaco|Jcmaco]] 22:26, 23 June 2006 (UTC)
:[[F-number]] says "the f-number of the human eye varies from about f/8.3 in a very brightly lit place to about f/2.1 in the dark". The eye doesn't really have a focal length, because it's the shape of the lens that changes, not the distance from the lens to the retina. I have good eyes and I can focus from infinity to about 15 cm. —[[User:Keenan Pepper|Keenan Pepper]] 22:49, 23 June 2006 (UTC)
:ISO corresponds to adaptation to light intensity (such as night vision) and aperture is determined by the iris. The focal length is indeed fixed. I suppose this is possible because the retina is essentially part of the brain and therefore able to interpret the 'blurry image'. Though I'm not sure how that would work. [[User:DirkvdM|DirkvdM]] 06:37, 24 June 2006 (UTC)
::Huh? The lens of the eye changes shape to change its [[focal length]] so it can focus on objects at different distances even though the lens-retina distance is the same. It's called [[accommodation (eye)|accommodation]]. This is the opposite of a camera, in which the lens stays the same shape, with the same focal length, but the lens-film distance changes. The retina and brain don't do any [[deconvolution]], if that's what you're thinking... —[[User:Keenan Pepper|Keenan Pepper]] 17:30, 24 June 2006 (UTC)
:::Oops! Of course the focal length of the lens changes. What I meant was that the distance between the lens and the retina remains the same, unlike with a camera. And then I took an odd turn. Sorry. [[User:DirkvdM|DirkvdM]] 18:12, 24 June 2006 (UTC)
== steriliziing an Ace bandage ==
I wish to know whether there is a way to sterilize an [[Ace bandage]] <nowiki>[redlink, needs writing]</nowiki> without ruining it. I have an Ace bandage that has possibly [[MRSA]]-infected bodily fluids on it.—[[User:msh210|msh210]]<span class="Unicode">℠</span> 22:54, 23 June 2006 (UTC)
:I see [[Sterilization (microbiology)#Chemical sterilization]], which has some information, but I need a household-available sterilizing agent, and need to know that it won't ruin the Ace bandage. Any help would therefore be appreciated.—[[User:msh210|msh210]]<span class="Unicode">℠</span> 23:09, 23 June 2006 (UTC)
Why not just get a new Ace bandage and dispose of the infected one? What makes this particular one so important? [[User:Mattman723|<font color="#000000">M@$+</font>]][[WP:EA|<font color="green">@</font>]] [[User:Mattman723|<font color="#000000">Ju</font>]] ~ [[User_talk:Mattman723|<font color="#000000">♠</font>]] 00:36, 24 June 2006 (UTC)
:Can an Ace bandage survive high temperatures? Baking it at 350F for a few hours should kill anything. Alternatively, if you've got a pressure cooker, you could try using it as an [[autoclave]]. --[[User:67.185.172.158|67.185.172.158]] 04:55, 24 June 2006 (UTC)
'''Get rid of it'''. There is a reason why most medical equipment these days is disposable. It's cheaper and much safer just to get another one. Can you explain why you wish to keep an infected and soiled bandage? --[[User:Mboverload|mboverload]][[Special:Emailuser/Mboverload|<font color="red">@</font>]] 13:48, 24 June 2006 (UTC)
:Maybe it has sentimental value. ;-) --[[User:Fastfission|Fastfission]] 17:30, 24 June 2006 (UTC)
Thanks, Mattman723, mboverload, everyone else. I didn't know what Ace bandages cost, although [http://groups.google.com/group/sci.med/browse_frm/thread/927bc74eb5bf7b1e someone on Usenet has now told me that they're cheap], and, from growing up, I remember their being reused (not when bloodstained, though). So, yes, I'll chuck it. It? Them. I get one bloodstained daily. That leads me to my next question, which is whether my discharges are still [[MRSA]]-infected, now that I've been on [[Vancomycin|vanc]] this long — but that's a question for my doctor, not for here. Thakns again, folks, for your responses.—[[User:msh210|msh210]]<span class="Unicode">℠</span> 08:15, 25 June 2006 (UTC)
:Be careful disposing of such contaminated bandages. You don't want someone (such as a sanitation worker) to come into contact with it. In fact, you should probably ask your doctor about disposal. --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 18:55, 25 June 2006 (UTC)
::...or better still, put it in a ziplok bag or some other airtight container and bring it to your doctor's office for disposal by the hazardous waste protocols there. [[MRSA]] contaminated stuff is <u>'''not'''</u> something you want to be casual about - leave it for the experts to deal with. --[[User:Hydnjo|hydnjo]] [[User talk:Hydnjo|talk]] 19:10, 25 June 2006 (UTC)
== Solquid ==
What is the technical/formal term for a substance that is neither solid nor liquid, but somewhere in-between? [[Yogurt]] is the best example I can think of at the moment, or perhaps a thick [[milkshake]]. --[[User:71.98.5.11|71.98.5.11]] 23:11, 23 June 2006 (UTC)
:Custard is a [[Non-Newtonian fluid]] meaning its viscousity changes with strain, so with enough pressure applied, it can become solid. I think. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 23:18, 23 June 2006 (UTC)
::It's either one or the other. However, you may be thinking of a suspension of solid particles in a liquid, which is known as a [[colloid]]. --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 00:35, 24 June 2006 (UTC)
:Yeah, this question was recently asked by [[User:Keenan_Pepper]] like last month. — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 03:12, 24 June 2006 (UTC)
::My question was specifically about [[Frosty|Frosties]], in response to the "soquid" commercials. I think we concluded they were [[colloid]]s, right? —[[User:Keenan Pepper|Keenan Pepper]] 04:05, 24 June 2006 (UTC)
How about a plain old [[gel]] ? [[User:StuRat|StuRat]] 03:34, 24 June 2006 (UTC)
Amorphous solids, like glass, also have characteristics of liquids (such as flowing over time), and are sometimes called "supercooled fluids". [[User:StuRat|StuRat]] 03:40, 24 June 2006 (UTC)
There are classifications for everything... try this: [[Suspension (chemistry)]]. I think that's where yogurt would fall. --[[User:Bmk|Bmk]] 03:51, 24 June 2006 (UTC)
:Frostys - it's a [[mixture]] - probably contains ice (solid) (very small ice particles) and a liquid (sugary water) plus probaly emulsifiers or thickening agents - it's not a phase of matter - but a mixture of solid and liquid. (a bit like very fine sand in honey maybe)[[User:HappyVR|HappyVR]] 14:00, 24 June 2006 (UTC)
Hmmm... how about an [[emulsion]]? - [[User:Cybergoth|Cybergoth]] 16:12, 24 June 2006 (UTC)
:Colloid. --[[User:Proficient|Proficient]] 17:37, 24 June 2006 (UTC)
::I guess emulsions and gels are types of [[colloid|colloids]]. - [[User:Cybergoth|Cybergoth]] 17:18, 25 June 2006 (UTC)
== [[Yellow Water-lily]] ==
Does the word [[hydrochore]] or something that may look similar mean anything, maybe meaning something like "disperses seeds through water", in the dissemination of plants, specifically the [[Yellow Water-lily]]?
:Sure, a ''hydrochore'' or a ''hydrochoric'' plant undergoes ''hydrochory'', the dispersal of seeds by water. They're all legitimate English words. Maybe someone should start an article at [[Hydrochory]]. —[[User:Keenan Pepper|Keenan Pepper]] 04:15, 24 June 2006 (UTC)
:They all come from the Greek ''ὕδωρ'', "water", and ''χωρειν'', "spread". —[[User:Keenan Pepper|Keenan Pepper]] 04:24, 24 June 2006 (UTC)
= June 24 =
== Help Me Identify This Butterfly ==
On my [[User:Mattman723/photos|photographs page]], I have added a picture of a butterfly that I took this morning. The picture was taken in New York City, and I'm interested in what it is. Thanks to anyone who can help! [[User:Mattman723|<font color="#000000">M@$+</font>]][[WP:EA|<font color="green">@</font>]] [[User:Mattman723|<font color="#000000">Ju</font>]] ~ [[User_talk:Mattman723|<font color="#000000">♠</font>]] 00:54, 24 June 2006 (UTC)
:That's a black swallowtail, resting on a purple coneflower (echinacea)--[[User:Markitos76|Mark Bornfeld DDS]] 03:03, 24 June 2006 (UTC)
::Awesome! Thanks alot for your help :) [[User:Mattman723|<font color="#000000">M@$+</font>]][[WP:EA|<font color="green">@</font>]] [[User:Mattman723|<font color="#000000">Ju</font>]] ~ [[User_talk:Mattman723|<font color="#000000">♠</font>]] 03:26, 24 June 2006 (UTC)
== Ice cubes ==
Why do my ice cubes come out of their trays crushed sometimes and whole other times? --[[User:24.209.166.131|24.209.166.131]] 03:47, 24 June 2006 (UTC)
:When water frees, it expands. This can result in ruptures in the cube, and can even cause a spike to form in the center. If the freezing happens from the bottom up, however, the water level will just rise and a nice cube will be formed. How the ice tray cubes are placed in the freezer, and how close they are to the cooling elements and other items, may affect the direction in which the cubes freeze. [[User:StuRat|StuRat]] 03:52, 24 June 2006 (UTC)
Depends a lot on from where the cold source is coming from. --[[User:Proficient|Proficient]] 17:40, 24 June 2006 (UTC)
== Neuroprosthetics or Neuro cybernetics ==
I have checked both pages on Neuroprosthetics and Neuro cybernetics, but am I still not sure of the following.
I want a career in Neurology, but am not sure of the exact one. I want to be able to study making machines work with human and animal brains, and other parts of the central nervous system, such as virtual reality or machines that "alter" the mind in order to create a false reality. I have narrowed it down to either Neuroprosthetics or Neuro cybernetics, but I still can't figure out which one best fits that description. Can somebody please tell me which title, Neuroprosthetics, Neuro cybernetics, or something else best fits that description? Thank you.
Sincerely,
--[[User:Dac011893|Dac011893]] 03:54, 24 June 2006 (UTC)
:I would think the neuro-cybernetics would be closer to what you want. This might include things like the new process for implanting electrodes into the brain so blind people can "see" using a video camera. [[User:StuRat|StuRat]] 04:10, 24 June 2006 (UTC)
Okay. Thank you. --[[User:Dac011893|Dac011893]]
:I'm not sure if this helps, but where I work (Boston University), the department in which work that is most similar to what you're asking about takes place is called Biomedical Engineering (BME). I'm specifically thinking of John White's work on the dynamic clamp, which allows one to interface a computer with real neurons, such that the computer basically simulates extra neurons and machines provide the input/output between the real and simulated neurons. I'm know there are labs that do work more similar to what you're asking, but I don't know of them personally so I can't really say much about them. Nevertheless, you may want to at least look at [[biomedical engineering]] to get other ideas. [[User:128.197.81.181|128.197.81.181]] 15:51, 24 June 2006 (UTC)
Thank you. I clicked on the link and it stated that "It has been suggested that Neuro cybernetics be merged into this article or section," so I would assume that they are similar fields and probably include work from one another, and possibly are the same thing at their cores. Thanks again. --[[User:Dac011893|Dac011893]]
== Magnetic fields ==
I know that a moving electric current creates a magnetic field, but why?
:Gooood question. I think the answer has something to do with [[tensor]]s, something about how the electric and magnetic fields are really parts of one complex [[tensor field]]. I think it also has to do with [[special relativity]], because if you're moving along with the charge then in your reference frame it's at rest, so there's no magnetic field, but if you're moving relative to it, then spacetime is all shifted so there is a magnetic field. Someone more advanced in physics than I should probably handle this one... —[[User:Keenan Pepper|Keenan Pepper]] 04:35, 24 June 2006 (UTC)
:Anyone?? —[[User:Keenan Pepper|Keenan Pepper]] 17:21, 24 June 2006 (UTC)
:I can't wait for a suitable answer ;) —[[User:GTubio|GTubio]] 21:57, 24 June 2006 (UTC)
:::Thats almost completely correct [[User:Keenan Pepper|Keenan Pepper]], and it's explained (slightly) in [[Maxwell's equations]] and [[Magnetic field]]. Using vector calculus, you can split up the electric field of the current into a stationary electric field, and a stationary magnetic field. That's just a mathematical way of demonstrating the fact that they are part of a rank-2 tensor.
:::To quote... "''In relativity, the equations [[Formulation of Maxwell's equations in special relativity |are written]] in an even more compact, "manifestly [[covariant]]" form, in terms of the rank-2 antisymmetric field-strength 4-[[tensor]] that unifies the electric and magnetic fields into a single object.''" --[[User:Eh-Steve|Eh-Steve]] 13:40, 26 June 2006 (UTC)
Thanks for actually taking your time and explaining it to me but can you explain it in layman's terms? Thanks!
How about this: if we remove all the metal and positive ions from an electric circuit and just leave the flowing electrons, those electrons will produce an immense electrostatic field or "e-field," ...but because they are moving, the e-field will be distorted in an odd way. The distortion vanishes if you walk along at the same speed as these electrons (since after all, motion is relative, so when you follow the electrons, from your viewpoint they're not moving.) OK, now put the positive metal ions back into the wires. The positives cancel out the negatives; the huge e-field is gone, but the motion-distorted part of the field is still there. (To get rid of the odd distortion, the positives and negatives would both have to flow along together, and in that case the electric current in the wire would be zero.) We call this residual e-field distortion by the name "magnetic field." However, there's another effect too: if you walk along at the same speed as the electrons in the wire, the distortion doesn't go away ...since from your point of view the positive metal ions are now moving backwards, and they produce an electric current and a similar type of distortion. --[[User:Wjbeaty|Wjbeaty]] 03:45, 26 June 2006 (UTC)
== Solid eggs ==
What's the freezing point of a chicken egg? Is there anything else that could cause an egg to solidify in a refrigerator? --[[User:67.185.172.158|67.185.172.158]] 04:46, 24 June 2006 (UTC)\
:The shell seems to thin and would appear to easily break if frozen. --[[User:Proficient|Proficient]] 17:53, 24 June 2006 (UTC)
:The freezing point of what kind of egg? Hard-boiled? Scrambled? Raw? A chicken egg? Crocodile, ostrich? — <tt>[[User:Mac_Davis/Esperanza|<font color="green">'''The'''</font>]]</tt> '''[[User:Mac Davis|<span style="font-family:Times;color:navy;cursor:crosshair;"><em><font color=#006600>Mac Davis</font></em></span>]]]''' ⌇☢ [[User talk:Mac Davis|ญƛ.]] 18:46, 24 June 2006 (UTC)
::Supposedly-raw chicken eggs. I've got a dozen eggs in my refrigerator that pass the "hard-boiled" test, despite never having been cooked. Cracking one open (with great difficulty) revealed a mostly-solid, translucent yellow mass. --[[User:67.185.172.158|67.185.172.158]] 06:05, 25 June 2006 (UTC)
:::Different stuff in your eggs would have different freezing points. -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 00:22, 26 June 2006 (UTC)
== Part 15 of the FCC rules. ==
Why is it so important that FCC rules require electrical devices to '''accept''' interference that may cause undesired interference? I'm a science teacher and when one of my students asked me this question, I had no clue. I've searched a bit, but the only explanations I have found pertain to '''causing''' inteference.
Here's the standard language found on many consumer electronics:
''This device complies with [[Part 15 (FCC rules)|Part 15 of the FCC rules]]. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that may cause undesired operation.'' [[User:User101010|User101010]] 05:14, 24 June 2006 (UTC)
:Isn't this a linguistic thing? Doesn't "must accept" here mean "must be able to deal with"?
:By the way, are you as generous to your pupils or do you only give yourself all tens? :) [[User:DirkvdM|DirkvdM]] 06:50, 24 June 2006 (UTC)
::I don't give grades. I just assign whatever grade the student earns. Tens are rare from me, mainly because I grade everything on a 100 point scale. ;-) [[User:User101010|User101010]] 00:53, 25 June 2006 (UTC)
::I don't think that's a "linguistic thing". There are many clearer ways of stating it if "must be able to deal with" is what the phrase is supposed to mean. The language of the certification makes you wonder what '''''not''''' accepting interference may mean, since, apparently, having "undesired operation" is still within the meaning of "accepting any interference received".
:::It looks to me as if the Rules ([http://www.fcc.gov/oet/info/rules/part15/part15-2-16-06.pdf PDF here, by the way]) are badly worded. The statement that User101010 correctly quoted is from Section 15.19 (Labelling requirements), and it doesn't make sense. However, if you look at Section 15.5 (General conditions of operation), it says something similar, except that it is the "operator" who must not cause harmful interference and must accept interference from other sources. I think that someone has clumsily cut and pasted 15.5 into 15.19, changed the implied "operator" to "device", and not noticed that the result is gibberish. This may be because the Rules were originally aimed at radio operators who knew what they were doing, but have been hastily adapted to the modern world in which every gadget is suddenly a source and sink of RFI.
:::I think the FCC confused themselves by their over-use of the passive voice, so that they forgot who the subject of the sentence was. So, in conclusion, the statement should have said, "You, the owner, must operate this device so that it does not cause harmful interference. If it does, then it's your fault for switching it on, not ours for designing it badly. If it picks up interference from other devices, even if that causes undesired operation, then that's your problem too." --[[User:Heron|Heron]] 16:18, 24 June 2006 (UTC)
::::Good wording. --[[User:Proficient|Proficient]] 17:55, 24 June 2006 (UTC)
A quick clarification... you can find this statement on the bottom of many consumer electronics such as CD players, radios, electronic games, etc. That is why I (and my student) are asking. [[User:User101010|User101010]] 00:53, 25 June 2006 (UTC)
:You sound as if you don't consider your question to have been answered yet. Let me try again. The FCC allows manufacturers to sell products that both produce and suffer from interference, as long as the manufacturers put this standard disclaimer on their products. The disclaimer tells the user that it is his responsibility if the device causes interference, and that he or she must "accept" any problems caused by interference affecting his device. That way, he or she can't sue the FCC for failing to enforce the radio regulations. The manufacturer is also happy because it absolves him from responsibility for what the product might do. Presumably there are limits to what you can get away with under a disclaimer, but that's another matter. Have we answered your question yet? --[[User:Heron|Heron]] 17:15, 25 June 2006 (UTC)
::That does help, thanks! ;-) [[User:User101010|User101010]] 21:01, 25 June 2006 (UTC)
== Has anyone ever disproven this idea? ==
Is it possible that all identical isotopes have the same life span and were simply created at random times and therefore appear to have random life spans? Has anyone ever disproven that what many consider to be entirely random decay occurs instead at exactly the same interval from the moment the isotope was created? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 08:34, 24 June 2006 (UTC)
:If your theory would be correct, I am quite sure that someone would have ''proven'' it already. Thus, most likely, it is not correct. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 08:55, 24 June 2006 (UTC)
::Perhaps this explains why we find outselves living in a world in which only certain prized individuals are allowed to invent anything or at least to receive the credit. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small>
:::Credit is more complicated than just coming up with it first, but in any case all he is saying is "If it were that simple, then someone else would have already figured it out by now." It's not a rigorous way to disprove something but as a rough heuristic it often works. --[[User:Fastfission|Fastfission]] 17:29, 24 June 2006 (UTC)
:Routine [[neutron activation]] work rules out your idea. [[User:Dragons flight|Dragons flight]] 09:34, 24 June 2006 (UTC)
::Please explain how [[neutron activation]] would rule out a uniform interval between isotope creation and termination except by interuption of the interval. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 10:11, 24 June 2006 (UTC)
:::Simple, I create a sample of radioisotopes over say a day of irradiation, and then watch them decay with a characteristic half life over weeks, months, or years afterwards. By tracking characteristic [[gamma ray]]s I can tell which isotope is decaying and control for contamination. If your idea was correct they should all decay at once, not exponentially distributed over a long period. [[User:Dragons flight|Dragons flight]] 15:59, 24 June 2006 (UTC)
::::So you are essentually citing a similar process as when I "irradiate" a luminus dial and watch its intensity of emission decline exponentially. Is that correct? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 16:09, 24 June 2006 (UTC)
:::::There are aspects of the process which are similar. (Assuming you're talking about a [[phosphorescence|phosphorescent]] watch dial, and not one of the old [[tritium]]-based ones.) Exposure of the dial to light excites molecules of a phosphorescent chemical. Most of them will (virtually) immediately decay back to their ground state, releasing a [[fluorescence]] photon and storing no energy. A few will undergo [[intersystem crossing]] while in their excited state, and get trapped in a quantum state where the decay back to ground is [[forbidden transition|forbidden]] under quantum mechanics. (The longer you illuminate the dial, the more molecules will end up trapped in this excited state.) In practice this just makes those excited states very long-lived (a long half-life), resulting in a slow trickle of light as they return to ground state. The math is the same as for radioactive decay, in terms of modelling the process. Note, of course, that the physical processes are very different. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 16:52, 24 June 2006 (UTC)
:Nuclear waste takes tens of thousands of years to decay, if your theory were correct it would have taken tens of thousands of years to make, and it didn't. Thats an obvious example, but more obviously, all substances start to decay immediately, meaning some atoms have decayed in fractons of a second, which would mean that some process would have to bee continually making atoms to decay, if they decayed after one second, and the half life was longer. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 10:05, 24 June 2006 (UTC)
::You have misunderstood the question. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 10:12, 24 June 2006 (UTC)
:::Please don't delete my posts, if they are legitimate you have no right too. If your so sure I don't know what you're on about, try making the question less ambiguous. I'm pretty sure I do understand the question, you are asking how can it be proven halflives are random, and not just that the isotopes were created and differing times. If not please explain what you mean. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 17:24, 24 June 2006 (UTC)
:::My point is if you are right '''explain this'''. Nuclear waste is created, over a period of '''ten years''', when it leaves the reactor it has already begun decaying, and takes '''50,000''' years to decay to an acceptable level. THEREFORE: the interval between the creation and decay of the atoms that were decaying when it left the reactor is '''maximum ten years''' and the interval between when it left the reactor and when it had decayed to an acceptable level is '''minimum 50,000 years'''. IN DEDUCTION: 10 year period of creation --> minimum 50,000 year period of decay.
: No. [[Radionuclides]] produced for use in [[nuclear medicine]] (e.g. [[positron emission tomography]]) decay according to their accepted half-lives, not all at once. [[User:EdC|EdC]] 13:46, 24 June 2006 (UTC)
::Can you name the experiment in which [[Radionuclides]] were produced where 1.) only a single isotope was produced (i.e,. no impurities are included), and 2.) there is a record of the exact moment each individual atom was created and later the moment of each atom's decay? <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 14:44, 24 June 2006 (UTC)
:::No, and I don't need to. Radionuclides produced in a cyclotron are created at constant rate over a short period of time. If your idea was correct the decay curve would be hat-shaped; it's not, it's exponential. Although, you might look for papers on the production of the [[transuranide]]s and the calculation of their half-lives; some of those were produced in single-figure amounts. [[User:EdC|EdC]] 23:19, 24 June 2006 (UTC)
:Isotopes (I'm assuming you mean atomic nuclei) are composed of smaller particles, so it's not clear how you would define the time when they are "created". [[User:Peter Grey|Peter Grey]] 13:58, 24 June 2006 (UTC)
::Yes it is. When the protons and neutrons were created is immaterial. They are proposing that each atomic nucleus will decay after the same time interval as every other atomic nuclei of the same isotope. This is incorrect, however, since we can create nuclei in a lab at a specific time and watch how long they take to decay, and have determined that this period is not constant for each isotope. [[User:StuRat|StuRat]] 14:12, 24 June 2006 (UTC)
::With that definition, there's nothing random about the creation time. Half-life decay has pretty simple math, and you could argue the conjecture was disproved as soon as they figured out the behaviour of radioactivity (over 100 years ago). [[User:Peter Grey|Peter Grey]] 02:44, 25 June 2006 (UTC)
:Here's a snippet from usenet that I found on the subject: "Spontaneous radioactive decay is governed by second order perturbation theory which produces a Lorentzian energy spectrum whose Fourier transform to the time domain is a simple exponential, which results in a constant per unit time probability for a decay transition.
:"A constant per unit time probability is the essence of a true random process, namely the decay for any given nucleus can happen any time with equal probability. The Lorentzian line shape has been directly observed experimentally in the Mossbauer Effect and so has the exponential in time. That puts the theory on solid experimental ground." source: [http://groups.google.com/group/sci.physics.particle/browse_thread/thread/60533358e717e038/b41ad80ddbb5c3eb?lnk=st&q=beta+decay+deterministic&rnum=9&hl=en#b41ad80ddbb5c3eb]
:The poster provided no references, but I'm sure you can look up the appropriate terms and come across suitable experiments that have been done. [[User:128.197.81.181|128.197.81.181]] 16:06, 24 June 2006 (UTC)
Here's some evidence that radionuclides do not have a single decay-time: Nearly all of the heavy elements in our solar system, including the radioactive ones, were probably produced in a short cataclysmic supernova. Therefore by the idea posed one would expect them all to catastrophically decay at one, probably vaporizing large parts of the earth. Instead we experience the phenomenon of radioactivity, which is the slow, steady, random decay of heavy elements. That is, they were pretty much all created at once, so they would pretty much all decay at once.--[[User:Bmk|Bmk]] 04:15, 26 June 2006 (UTC)
== technology ==
i have heard that a student from electronics/electrical engineering can specialize in computer science laterbut not vice versa. how far is this true?
:Well electronics could be a good foundation for computer science - however if you just have learnt programming from a computer course that won't be much use for electronic engineering - you'd have to learn a lot of new stuff.[[User:HappyVR|HappyVR]] 13:53, 24 June 2006 (UTC)
::In most countries, engineering is a regulated discipline, as it is a profession (see [[ABET]] and [http://www.ccpe.ca/e/ccpe_boards_2.cfm CCPE] for examples in North America) and therefore subject to restrictions on cirriculum and so forth. This includes a minimum amount of credits for science and math courses. While usually a CS student can get the required amount of math credits for an engineering degree, CS cirriculums usually don't include enough science to meet the requirements, unless the cirriculum is specifically designed to cover the requirements (eg CS/EE, Computer Engineering and Software Engineering programs). Unless a person takes one of the previous courses, or takes a ton of science courses then wade through a lot of bureaucracy, it's probably very hard for them to switch from CS into engineering without retaking a lot of courses. For an electrical engineering student to specialize in computer science, it usually involves taking some extra computer science courses as their electives, as the restrictions for a CS major, minor, or option are lighter. --[[User:ColourBurst|ColourBurst]] 05:56, 25 June 2006 (UTC)
== Cure for a phobia ==
Interested in the question above about that irrational fear towards wrists, I was wondering... Are there general cures for phobias? What is, generally speaking, the "method" they follow? Thanks.
:[[Shock treatment]] has been used to cure fears, though that article is relatively irrelavent to how I mean the term. It is where patients are exposed to excessive amounts of whatever they fear, eg, taking someone with vertigo sky-diving, or hydrophobia deep sea diving. Not sure how you apply this to wrists though. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 14:18, 24 June 2006 (UTC)
:Desensitization treatment involves slowly increasing the exposure level so the subject has time to become accustomed to the stimulus. This is quite similar to the method used for allergies, although here it is a mental tolerance which is built up to the stimulus, not a physical one. [[User:StuRat|StuRat]] 14:57, 24 June 2006 (UTC)
:Those two are pretty much the main two forms of treatment. Shock treatment is sometimes prefered as there is very little scope for backing out, but desensitization treatment is less harsh, and generally preffered due to it's less extreme dosage, I think. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 17:16, 24 June 2006 (UTC)
:Gather your friends and wave your wrists in front of the patient. --[[User:Proficient|Proficient]] 17:57, 24 June 2006 (UTC)
::No, an amateur doing this could just make things worse. If you have a debilitatiing phobia, please go to a professional psychiatrist for treatment.--[[User:Pharos|Pharos]] 18:37, 24 June 2006 (UTC)
:::I saw [[Paul McKenna]] do some work on similar cases, he worked by quickly socially conditioning the patient to assiciate things they severly dislike with bad habits, so I guess a similar thing can be done the other way. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 22:09, 24 June 2006 (UTC)
== Seagulls ==
Which is your favourite breed of [[seagull]]? I like the [[great black-backed gull]] the best. It's like having an [[albatross]] in your garden. Big, beautiful bird. --[[User:84.66.114.107|84.66.114.107]] 11:52, 24 June 2006 (UTC)
:How do you judge the goodness of seagulls? I can't say I've ever had a good experience with a seagull before, people from 'round my parts tend to think of them as pests rather than magestic birds. Personally, I prefer the seagulls I saw in Toronto to the ones in Tokyo, but that's only because they look less menacing to me up close. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 11:58, 24 June 2006 (UTC)
::With or without gravy ? Actually, my favorite seagull is [[Jonathan Livingston Seagull|Jonathan Livingston]]. [[User:StuRat|StuRat]] 14:50, 24 June 2006 (UTC)
::Sure, they're noisy, vicious and quarrelsome birds but I think they look handsome, strong, majestic and noble when at rest. They have something of the eagle about them. The babies are really sweet too. --[[User:84.66.114.107|84.66.114.107]] 16:38, 24 June 2006 (UTC)
:::There tends to be a lot of questions asked here about seagulls. ;o --[[User:Proficient|Proficient]] 17:59, 24 June 2006 (UTC)
:::::Squawk!! You caught us. Wikipedia is a mind control program run by we seagull overlords.--[[User:Bmk|Bmk]] 04:17, 26 June 2006 (UTC)
==Glasses==
Can aesthetic glasses (no corrective lenses) cause eye strain? I've just started wearing glasses (though I've never needed them) and I'm wondering if this pain is just from the weight of the glasses on my nose or from staring into the (<strike>flat</strike>parallel) lenses. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 11:58, 24 June 2006 (UTC)
:It's kinda weird wearing glasses for aesthetic reasons.
:First of all you say 'flat' lenses - are they actually flat (like a desktop) - I'm guessing not but if they are that will have an optical effect - if you wearing glasses just for aesthetic reasons you should make sure that the 'glass' in the lenses has no effect on your vision (roughly speaking they lenses should be equal thickness and spherical) - suggest you consult an optician for advice.
:Secondly - yes as someone who wears glasses - they can be painful - like new shoes - until you get used to them - or if they are a bad pair - always painful. Hope that helps.[[User:HappyVR|HappyVR]] 13:53, 24 June 2006 (UTC)
::Many people wear glasses for aesthetic reasons, take [[Drew Carey]] for example. By "flat", I meant that there was no index on the lenses, e.g. no optical effect that you can't see looking through a pane of clear plastic. Is the pain you get from wearing new glasses from the frames or is it a muscle pain in your eyes? [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 14:18, 24 June 2006 (UTC)
:::Ha ha! Drew Carey referred to his glasses as "contraceptive glasses". - [[User:Cybergoth|Cybergoth]] 16:04, 24 June 2006 (UTC)
:It could be pain from the frames - that's common - the constant pressure on you nose and ears can give rise to pain. If their is no index in the lens you still could get pain in the eyes from having your field of view framed by the frame of the glasses (that could cause a headache) - also if your eyes keep focussing on the frame or reflections in the lens this can cause eye strain too (focusing too close) - causing pain. It could be either - and probably a combination of both - again if you are getting pain from wearing glasses (not just a one off headache) then you should see an 'eye doctor' at least to check that there is nothing wrong with the glasses.[[User:HappyVR|HappyVR]] 14:29, 24 June 2006 (UTC)
:Also even with lenses with no optical effect - if the lenses are not fitted correctly over the center of the eye then they will have a slight effect - which could cause a headache if worn for a long period of time. Different people have different distances between the eyes - if the centre of the lenses are not the same distance apart as the centres of the pupils the 'no index' lenses will act to a small extent - distorting your vision?[[User:HappyVR|HappyVR]] 14:58, 24 June 2006 (UTC)
== Application Error ==
Quite often, but not always, when I close my newly installed Internet Explorer 7 Beta window, I get the error message below.
[[image:Application Error.png]]
If you are familiar with this problem, then I ask that you suggest a solution. <br> My operating system is Windows XP Media Center Edition.[[User:Patchouli|Patchouli]] 12:49, 24 June 2006 (UTC)
:if you don't want your browser to crash, I suppose you shouldn't use a [[Development_stage#Beta|Beta]] version. In fact, you probably shouldn't use IE at all in that case and try an alternative such as [[Firefox]]. [[User:Dbachmann|dab]] <small>[[User_talk:Dbachmann|('''ᛏ''')]]</small> 14:02, 24 June 2006 (UTC)
:I am also using IE 7 beta 2, and it has “crashed” sometimes during shutdown. My best idea is to wait until the stable version of IE 7 is released. This is a [[beta]], and is “allowed” not to be “perfect”. Mainly, however, I am quite found of Internet Explorer. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 14:30, 24 June 2006 (UTC)
::IF you're using Media Center Edition, it's hopeless, it's going to keep doing that forever on to infinitie, I've seen the exact same thing happen over and over again on computers with nothing in common other than Media Center--[[User:64.12.116.74|64.12.116.74]] 16:54, 24 June 2006 (UTC)
::Just downgrade from beta. --[[User:Proficient|Proficient]] 18:00, 24 June 2006 (UTC)
*After clicking okay, I see another small window, which I add hereon.
[[image:Error 217.JPG|thumb|right|This image is too big.]].[[User:Patchouli|Patchouli]] 01:53, 25 June 2006 (UTC)
*I don't know how to crop the image (I pasted it in the Paint program before uploading it).[[User:Patchouli|Patchouli]] 01:55, 25 June 2006 (UTC)
::Googling "CiceroUIWndFrame" (which is clearly the handle which is crashing it) reveals that there are articles describing how to fix it. (such as [http://www.attention-to-details.com/newslog/391-remove-cicerouiwndframe-to-avoid-crashes.asp this one], which says it is part of the Speech and Handwriting Recognition software in Microsoft XP and is probably not used by most people). --[[User:Fastfission|Fastfission]] 02:52, 25 June 2006 (UTC)
:::In MS Paint, you can drag the edge of the image (where the white canvas becomes grey) to make the image smaller. You can also use the [[lasso tool]] to move the image to the top-right of the canvas. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 06:52, 25 June 2006 (UTC)
*I moved the image to one corner of the white canvas and made the canvas smaller by dragging the opposite corner inward.[[User:Patchouli|Patchouli]] 13:48, 25 June 2006 (UTC)
::::The best way to take a picture of only one (1) window, is to hold the mouse over its title bar and press Alt+PrtScn. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 10:03, 25 June 2006 (UTC)
:::::If you have done so, and just want to save the window screenshot as an image file no larger than the window, you can resize the MS Paint canvas to a size even ''smaller'' than the window, and then paste. MS Paint will then (at your permission) resize the canvas so it will perfectly fit the window. --[[User:Andreas Rejbrand|Andreas Rejbrand]] 10:07, 25 June 2006 (UTC)
:::Perhaps, to be very clear, we should explain why the answer has been "don't run beta software". I note that the original questioner seems to have ignored this answer, and kept on with the original expectation that there will be solution. So I hope this helps... not everyone knows what a "beta" is. I think some people think it is a way of saying "better". "Beta" software is software that is not ready. Not finished. Not of final quality. It is there for you to try, to find problems and report them. By reporting the problems, you help improve the quality of the final product. So using beta software can be interesting, and can benefit future users of the product. You should never be surprised if it crashes, and you can't expect to find a solution, but it is helpful to report crashes to the maker of the software. You should also always have an alternative plan, what to do if the beta software isn't any use to you. [[User:Notinasnaid|Notinasnaid]] 10:28, 25 June 2006 (UTC)
*Thank you.[[User:Patchouli|Patchouli]] 13:48, 25 June 2006 (UTC)
==remove coating==
Can anyone give a simple household method for removing a lacquer (note not a glaze) from a ceramic?[[User:HappyVR|HappyVR]] 14:00, 24 June 2006 (UTC)
:Abrade it with steel wool or sandpaper ? [[User:StuRat|StuRat]] 14:43, 24 June 2006 (UTC)
::Thanks but that isn't really an option - too many crevices for one reason - was really looking for a non-abrasive method (wet method?)[[User:HappyVR|HappyVR]] 14:58, 24 June 2006 (UTC)
:Lacquer thinner? Maybe alcohol plus boiling water? --[[User:Proficient|Proficient]] 18:02, 24 June 2006 (UTC)
::I've tried boiling water, hot water with detergent, paint and varnish remover, petrol and white spirit. Not sure than Lacquer thinner will be any different. Can't really get any alcohol into boiling water - it just keeps boiling off..[[User:HappyVR|HappyVR]] 20:30, 24 June 2006 (UTC)
[[Gamma butyrolactone]] should do it... You can buy it as a superglue remover/debonder. Paint it on, and rub it off with a cloth covered in white spirit. --[[User:Eh-Steve|Eh-Steve]] 03:14, 25 June 2006 (UTC)
:Doesn't seem to work.[[User:HappyVR|HappyVR]] 14:14, 25 June 2006 (UTC)
:You tried Gamma butyrolactone and it didn't work? It should remove an acrylic lacquer within a few mins... In that case, it might help if you knew what the lacquer was. --[[User:Eh-Steve|Eh-Steve]] 13:46, 26 June 2006 (UTC)
== PC's Parellel Port Programming in C++ ==
I have made a project of controlling a simple hardware by interfacing it with the 25pin D type connector(parellel port).It has 8 LED which i connected it parellely with the 8 bit data comming out from Data Register of the port but i want to run it sequencially or as desired by us or randomly sequence.the programme i used is as under.
#include<stdio.h>
#include<dos.h>
void main(void)
{outp(0x3BC,128);
delay(100);
outp(0x3BC,64);
delay(100);
return 0;
}
but the problem in it is that the delay command is not viewed or the sequence of first 128 and then 64 is not fllowed n it goes directly to 64.but it is not waiting for 128 and then go for 64.i saw the same by using sleep(n) command it also did not worked.do help me.
:Are you sure your delay function is in seconds? Most delay/sleep functions are in milliseconds. Rare ones are in microseconds. I believe the unix sleep function is in seconds. 100 milliseconds isn't very long to wait (1/10th of a second). --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 18:33, 24 June 2006 (UTC)
==Bios problems?==
For some reason my computer seems to have started waiting for about 30 seconds doing apparently nothing when I reboot it. Well a screen saying "Compac V3.07" comes up, then it appears to just sit there. Eventually grub loads and then either XP or ubuntu boots up perfectly normally. This same thing happens if I have a floppy or DVD in the drive - do nothing for ages then boot from the floppy or DVD.
To get into the bios I have to hit f1 (I used to have to be quick but now I have plenty of time) instead going straight to the bios setup it again waits ages.
I have another problem which may or may not be related. Neither operating system properly sees my usb hard drive anymore. XP makes a ding dong noise when i switch it on and off so something is going on but no icon appears on the desktop and I can't see it in "my computer". in linux no icon appears on the desktop anymore.
I've had a quick look at the bios and i cant see anything glaringly obvious but I'm not an expert and don't know what to look for. Does anyone have any ideas? BTW I have recently gone from ubuntu "breezy badger" to "Dapper Drake" (but i can't see how that could affect anything that happens before the operating sytem boots) and i do occasionaly let young children play on my computer (but not recently) [[User:Theresa knott|Theresa Knott]] | [[User talk:Theresa knott|Taste the Korn]] 17:07, 24 June 2006 (UTC)
:Well, if both OS's are affected it's bound to be a hardware problem. Have you tried booting without the usb drive connected? A wild guess is that the computer sees it, tries to connect, can't somehow, tries a few more times and then gives up after half a minute and boots. Does the drive show in the BIOS? [[User:DirkvdM|DirkvdM]] 18:30, 24 June 2006 (UTC)
::Could your BIOS have been set to allow booting from a network? If so, it would probably be waiting a bit to see if some server would like to deliver it some instructions. Or if it is set to allow boot from CD, it might be waiting till the drive says "hey, there's nothing here, just move along!" --[[User:LarryMac|LarryMac]] 21:32, 24 June 2006 (UTC)
:Maybe a clean install will help. Or try to get a flash BIOS update so that your problems may be solved. Contact the manufacturer of your motherboard. --[[User:Proficient|Proficient]] 22:04, 24 June 2006 (UTC)
Thanks for the replies. I've just tried removing the external hard drive and doing that solved the delay problem. Does that mean there is something physically wrong with the drive? I only got it 6 months ago. [[User:86.7.146.177|86.7.146.177]] 23:18, 24 June 2006 (UTC)
:Could be. Try plugging the hard drive into another computer. --[[User:Carnildo|Carnildo]] 05:39, 25 June 2006 (UTC)
== Levorotary sugars? ==
Do L-form sugars cause sweet tastes? Are they metabolized by the body? Because if they are sweet and not processed, why are they not used more often as artificial sweeteners? --[[User:Zemyla|Zemyla]]<sup>[[User talk:Zemyla|t]]</sup> 18:08, 24 June 2006 (UTC)
:They don't taste sweet. The receptors on your tongue are chiral, so the wrong enantiomer doesn't fit into them. See [[Sweetness]] or google ''glucophore''. —[[User:Keenan Pepper|Keenan Pepper]] 18:14, 24 June 2006 (UTC)
:A few minor asides. First, not all <small>L</small>- [[enantiomer]]s are levorotatory. The <small>D</small>- and <small>L</small>- notation are based on the geometric configuration of the molecule rather than directly on their optical activity. See [[Optical isomerism#By configuration: D- and L-]].
:The (+) and (-) notation, in contrast, ''are'' directly related to dextro- and levo- rotation, and are sometimes specified as ''d-'' or ''l-'' isomers, leading to no end of notational confusion. To take an example, <small>D</small>-fructose is actually levorotatory, and equivalent to ''l''-fructose or (-)-fructose—and it's definitely sweet.
:Surprisingly, the relative sweetness of <small>D</small>- versus <small>L</small>- isomers is difficult to predict. There's a chap by the name of [[Gilbert Levin]] who started looking at <small>L</small>- isomers as artificial sweeteners back in the 1980s (late 70s, even?); he started a company called [[Spherix]] [http://www.spherix.com/] that does this type of research. Levin found that people couldn't tell the difference between <small>D</small>- and <small>L</small>-glucose in taste tests. Unfortunately, producing large quantities of these <small>L</small>- isomers proved too costly for use in food products.
:Levin's story does have a happy ending, in that he discovered that <small>D</small>-[[tagatose]] actually tasted as sweet as sugar but with only a third of the calories; he also developed a process to generate tagatose inexpensively from [[lactose]] and sold it to [[Arla Foods]]. To my knowledge there are no tagatose-containing food products on the market yet. [[User:TenOfAllTrades|TenOfAllTrades]]([[User_talk:TenOfAllTrades|talk]]) 18:56, 24 June 2006 (UTC)
== Info Needed about Arrow International ==
Could someone give intimate information regarding Arrow International Medical company?
I believe they are based out of Reading Pennsylvania and understand that they make catheters and balloon pumps, but more info would be appreciated.
:Have you checked [http://http://www.arrowintl.com/ their website]? --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 00:37, 25 June 2006 (UTC)
== Hand swelling ==
Hi. I'm 19 year old and sometimes when I go out at night (and drink, though not heavily I lose some reflexes) I quite often feel swelling in my hands. This only happens recently, about one year ago I didn't have any problem. Any ideas? Thanks. {{unsigned|85.50.40.204}}
:My suggestion would be to try abstaining from the consumption of alcoholic beverages, to determine whether alcohol is causing this problem. Consumption of beverage alcohol can cause numerous health problems -- see [[Alcohol_consumption_and_health]] and [[Effects_of_alcohol_on_the_body]] -- so it could easily be causing the symptoms that you are experiencing. If this doesn't help, you might want to consult with a physician. Good luck. [[User:John254|John254]] 21:09, 24 June 2006 (UTC)
:It happens also to me sometimes, when I am a bit dehydrated, which I think alcohol exacerbates. ([[User:Cj67|Cj67]] 21:44, 24 June 2006 (UTC))
:If you determine alcohol as the problem, then it's quite possible that dehydration is the reason for your swelling hands, as Cj67 says. Many people also experience swelling of the face when drinking even small amounts of alcohol. Drink lots of water in between drinks (to replace the fluids you've lost going to the toilet) and that might help. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 06:06, 25 June 2006 (UTC)
::Well, that depends on what is most convenient. Whenever I've had a bit too much too drink I make sure to drink at least a litre of water before I go to bed to prevent a hangover. Works great (up to a point). [[User:DirkvdM|DirkvdM]] 07:06, 25 June 2006 (UTC)
== While on the subject of gulls again... ==
Anyone know why humans don't keep them as pets? Thnking about it, a gull would be very low maintenance, both in terms of food and care - and if raised from the egg, they can become very tame. --[[User:Kurt Shaped Box|Kurt Shaped Box]] 21:20, 24 June 2006 (UTC)
:For a start, gull droppings are one of the most evil substances known to man, and gulls need a large area to fly around. If not given regular access to the sea, they'd also probably start to behave crazily and attack people; gulls can get very violent. <font style="color:#BBBB00">'''s'''murrayinch</font>[[WP:EA|<font style="color:green">'''''e'''''</font>]]<font style="color:#BBBB00">ster<sup>([[User:Smurrayinchester|User]]), ([[User talk:Smurrayinchester|Talk]])</sup></font> 21:45, 24 June 2006 (UTC)
::I once raised a baby gull. She was incredibly sweet, if a bit feisty at times. I had her living in my garden for six months once she was old enough to fly - she didn't want to leave. Can't say that the droppings were ever a problem - I just hosed them away every couple of days. I wouldn't advise keeping one in the house but I could recommend gulls to anyone - much less hassle than an outdoor rabbit (no piss for one thing). --[[User:Kurt Shaped Box|Kurt Shaped Box]] 21:59, 24 June 2006 (UTC)
:::I've got this huge aviary with gulls, swans, koots, grebes, ducks, shags and what have you. All I need to do is look out the window. I live at an Amsterdam canal. :) [[User:DirkvdM|DirkvdM]] 07:13, 25 June 2006 (UTC)
= June 25 =
== Insomnia side-effects ==
1. A few days ago I stopped drinking coffee and find that I am now unable to sleep for more than a few hours each night, and some nights I am unable to sleep at all. There is no associated anxiety or muscular tension. I feel physically fatigued, but can't seem to lose consciousness. When I used to drink coffee regularly, I slept at least six hours every night, though I often couldn't get to sleep until very late. Is this not the opposite of what should happen? I thought quitting coffee would leave me more tired.
2. Another question I've long asked myself... After a night without sleep, why does one's face tend to become oily? How does sleep prevent facial greasiness? And why does the face not produce such copious grease all day, but rather only when one ought to be sleeping? Why don't we wake up greasy?
Thanks! [[User:Bhumiya|Bhumiya]] ([[User talk:Bhumiya|said]]/[[Special:Contributions/Bhumiya|done]]) 00:31, 25 June 2006 (UTC)
:I cannot fully answer your questions, but I can provide some ideas. 1. Caffeine is a noncompetitive adenosine antagonist (if memory serves). Put roughly: adenosine is what makes you tired; caffeine decreases the effect of adenosine on neurons, and so one effect is to make you less tired. For this reason, one expects that a result of caffeine withdrawal would be fatigue. As someone who is not familiar with caffeine withdrawal on an academic level, your symptoms sort of surprise me, but sleep difficulties do often result when habitual medication or drug use changes, so even if I can't describe the exact process, it isn't really *that* surprising that you'd suffer from sleep disturbances. In any rate, the effect should go away fairly soon, I would imagine (but I am not a doctor!). 2. I know of no real reason, except that, if you sleep like I do, in the process of tossing and turning one's face will tend to contact one's pillowcase, which would have the effect of sort of dabbing your face clean over the course of the night. By not sleeping you just let the oil build up. Hope that helps... [[User:65.96.221.107|65.96.221.107]] 01:04, 25 June 2006 (UTC)
:*Speaking as a coffee drinker, I'll just say this, start drinking coffee again, quiting just isn't worth it '''(:'''[[User:205.188.116.74|205.188.116.74]] 05:46, 25 June 2006 (UTC)
:[[Caffeine]] notes that one effect of withdrawal is anxiety, and anxiety can definitely inhibit sleep. Caffeine withdrawal can be nasty, as I learned when I gave it up for Lent and experienced many of those symptoms. Fortunately it is over relatively quickly (no more than a week for me; one to five days according to the article). --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 19:24, 25 June 2006 (UTC)
== Lightening in my eye ==
Remember how when you were a little kid you would always go around the house testing every 9 volt battery you could lay your tongue on? Well, I got very good at this, in fact, I could test the 1.5v AAA and AA batteries by pressing one terminal to the inside of my cheeck and the other terminal to my tounge. Well, one night I took the small, cylindrical 10v lithium battery out of my garage door opener and I 'tested' it using the same method. BAM! on the same side of my mouth which I tested it on, I saw huge streaks of lightening with that eye. It was pretty cool, so cool infact, I had my bro try it. About 2 hours later, both of our eyes ached. That was the one and only time I tried this. Tell me, what is causing my eye to see the lightening?
*I'm confused, your garage door has a remote that needs a '''ten volt lithium ion battery'''? what?--[[User:205.188.116.74|205.188.116.74]] 05:44, 25 June 2006 (UTC)
::http://en.wikipedia.org/wiki/Lithium_ion_battery It's commonplace for electronics. --[[User:Proficient|Proficient]] 06:11, 25 June 2006 (UTC)
:::Lithium Ion Batteries ''are'' common place for electronics, but 10 volt baterries for a remote? less so, I'd think--[[User:205.188.116.74|205.188.116.74]] 07:30, 25 June 2006 (UTC)
:Are you experiencing pain/dizziness when you see the lightning? --[[User:Proficient|Proficient]] 06:11, 25 June 2006 (UTC)
:Presumably your are depolarising the [[retina]]l cells or [[optic nerve]] on that side. One assumes that the discharge can cause uncoordinated contraction of the [[ocular muscles]], which may cause the eye ache. An [[EEG]] and [[EMG]] may give a scientific answer, if you have a friendly neuro lab owner who is prepared to help you. --[[User:Seejyb|Seejyb]] 07:33, 25 June 2006 (UTC)
:Li-ion batteries have a lot of charge in them, maybe the lightening was there, and it was arcing. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 12:04, 25 June 2006 (UTC)
== How closely are [[seagull]]s and [[fulmar]]s related? ==
Anyone know? I was told by someone today that a [[fulmar]] is not a seagull and is really a different species. I didn't believe him, so I looked up fulmars on Wikipedia. Is that article right?
If this is true, why does a fulmar look, sound, move and act like a seagull?
:You would too if you saw how much booty seagulls get. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 06:00, 25 June 2006 (UTC)
::They are a different order of bird. The have similarities because they fill similar niches. The birds of [[Australia]] are interesting to study in this respect. Their so-called robins and wrens, for example, resemble European robins and wrens, but they are completely unrelated. They fill equivalent niches by a process called [[convergent evolution]].--[[User:Shantavira|Shantavira]] 08:40, 25 June 2006 (UTC)
== Hissing soft drink ==
When I start to unscrew the cap of a bottle of soft drink and then stop (i.e., partially undo the cap), air hisses out, then the hissing subsides. If I loosen the cap a little more, the same thing happens again. Why does the air not all hiss out the first time? [[User:220.253.90.98|220.253.90.98]] 01:57, 25 June 2006 (UTC)BenC
:The cap continues to resist airflow for lower pressures. With the cap partially off, an equilibrium is reached at a level between the original pressure and the atmosphere, corresponding to the pressure difference that the partially unscrewed cap can resist. [[User:Peter Grey|Peter Grey]] 02:40, 25 June 2006 (UTC)
::Nice prose. --[[User:Proficient|Proficient]] 06:12, 25 June 2006 (UTC)
== History of AIDS epidemc in Dallas, Texas ==
When was the first case of AIDS reported in Dallas County, Texas?
When did the first person die of AIDS in Dallas, Texas, and who was
the first person to die of AIDS in Dallas, Texas?
How many people have died of AIDS in Dallas County as of Jan. 1, 2006?
:[http://www.house.gov/list/speech/tx30_johnson/morenews/HIVAIDSEpidemicinDallasFortWorthArea.html This] is the best I could come out with. Though, it is three years out of date, but it should provide enough information about you questions. <font color="#007FFF">[[User:Kilo-Lima|Iola]]</font>'''[[User:Kilo-Lima/Esperanza|<font color="#50C878">k</font>]]'''<font color="#007FFF">[[User:Kilo-Lima|ana]]</font>|<sup><font color="orange">[[User talk:Kilo-Lima|(talk)]]</font></sup> 14:46, 25 June 2006 (UTC)
:The [http://www.dshs.state.tx.us/ Texas Department of State Health Services] may be able to help you. --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 19:31, 25 June 2006 (UTC)
== Spider identification ==
I found this spider crawling across a book I was reading ([[:Image:Unknown spider 1.JPG]]), and despite a lot of internet searching, I can not ID it. It kind of looks like a [[brown recluse spider]], but without the violin shape on its back. The body was about 7 or 8 mm long. I live in the Chicago suburbs. I haven't seen any web. --[[User:Joelmills|Joelmills]] 02:38, 25 June 2006 (UTC)
:It looks to me like a [[yellow sac spider]]: [http://www.extension.umn.edu/projects/yardandgarden/EntWeb/galleries/house/house-other-sacspider.html][http://www.insectimages.org/browse/detail.cfm?imgnum=1252104]. [http://www.uky.edu/Ag/CritterFiles/casefile/spiders/brownspider/brownspider.htm#whatis This page] even says that they "resembles the brown recluse except that it is lighter in color and has no fiddle-shaped marking." --[[User:Fastfission|Fastfission]] 03:00, 25 June 2006 (UTC)
Thanks, that's definitely it. It looks just like the one on [http://ohioline.osu.edu/hyg-fact/2000/2060A.html this page]. Glad it didn't bite me when I was trying to get it to pose. --[[User:Joelmills|Joelmills]] 03:18, 25 June 2006 (UTC)
:It is quite normal if you did not find the beast on the internet, as it was in a book (today I'm busy putting emoticons :). --[[User:Harvestman|DLL]] 18:32, 25 June 2006 (UTC)
== Officially Respected IQ Test ==
I have seen hundreds of different IQ tests; some require knowledge of historical facts plus basic knowledge of mathematics such as understanding permutations, combinations, and geometry.
Is there an official IQ test produced by an organization that is respected worldwide such as the [[United Nations University]] or [[Institute for Advanced Study]]?
I personally have come to the conclusion that this IQ matter is a hoax and basically a popular entertainment. Can someone give some guidance?[[User:Patchouli|Patchouli]] 06:52, 25 June 2006 (UTC)
Straight out of Harvard to the rescue: Perkins, David 1995, Outsmarting IQ, The Free Press, New York.
--[[User:124.168.65.71|124.168.65.71]] 07:05, 25 June 2006 (UTC)
You can pay for a psychologist to give you a proper one. Thats about theonly legitimate way I know of. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 12:00, 25 June 2006 (UTC)
:The article [[IQ]] has some interesting insights, which suggests the "intelligence" part can be overplayed. ''"These tests measure a person's ability to conduct a number of tasks to which most people raised in that society will be exposed, and so measure a person's ability to absorb and repeat mechanical intellectual tasks."''. This essentially is self-defining IQ as the ability to do well in IQ tests. Testing isn't about individual analysis; rather, it's a way to avoid dealing with individuals. The really useful thing about IQ tests is that it arranges people into an order, and on that basis quick decisions can be made without knowing the people. Some might argue that IQ tests simply measure what is easy to measure, rather than what is important, but that could be said of every test, and every measurement method in social science. See also [[IQ test controversy]]. [[User:Notinasnaid|Notinasnaid]] 12:21, 25 June 2006 (UTC)
*I have often heard that "Intelligent Quotient scores are distributed normally with mean 100 and standard deviation 15." Thus, to obtain this famous IQ test that I don't know where to find and have never seen, do I need to pay a psychologist?[[User:Patchouli|Patchouli]] 13:59, 25 June 2006 (UTC)
:I wouldn't trust any of the abundant free "IQ tests" on the Internet. There is no reason to believe any of them are standardized. When psychologists develop IQ tests, they take the distribution of scores (which for a good test is a normal distribution, a type of bell curve described by an equation) and "standardize" it. In other words, they make the mean raw score correspond to an IQ score of 100 and make all the others scores correspond to where they would fall on a normal distribution of standard deviation 15. See [[standard score]] for more information. So yes, if you want a standardized IQ test, talk to a psychologist. --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 19:40, 25 June 2006 (UTC)
*I just took one test that I was looking for at the [[International High IQ Society]]. I have become very confident that this IQ business is pure entertainment and fun. It is not like the Graduate Record Examination in Mathematics which I would never pass.
[[image:IQMe.JPG|center|400px]][[User:Patchouli|Patchouli]] 14:38, 25 June 2006 (UTC)
:::I've had similar experiences. I've taken online "IQ Tests" and generally scored no lower than 130, and as high as 165. I'm not saying this to brag, rather the opposite, these online "IQ Tests" seem to be more of a scam than the real thing, as they often encourage you to purchase a more detailed analysis of your score.
:::So what I've done is "tested" the tests themselves. Try it. Answer "C" to every question and see what score it gives you. A true IQ test should rate you as a moron with an IQ of no more than 50. If you get that, you'll be surer that you're dealing with a more legit test. However, if answering "C" to every question gives you an IQ of something like 110, you know you're dealing with a scam IQ test. [[User:Loomis51|Loomis]] 23:09, 25 June 2006 (UTC)
::::In my experience, the only accurate IQ test I ever took was for Mensa. Since they take IQ very seriously, it isn't a marketing scam with them. However, the best test I've ever taken for aptitude was the U.S. military [[ASVAB]]. It is free if you are under 35 and eligible to enlist. Of course, the recruiters will hound you for months afterward. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 23:38, 25 June 2006 (UTC)
*If I wanted to get in the U.S. military as a [[second lieutenant]], would I have to take the ASVAB or a different test? I ask this because [[Patrick Tillman]] became a [[corporal]] whereas General [[Michael Hayden]] was granted the commission of a 2nd lieutenant at the commencement of service. Did they get different scores? [[User:Patchouli|Patchouli]] 02:31, 26 June 2006 (UTC)
** My guess is [[ASVAB]] is only for enlisted personnel, not officers. Hayden got a comission effectively because he had a college degree and went to a ROTC. I think basically a college degree is what separates a future officer from a soldier. --[[User:Ornil|Ornil]] 05:42, 26 June 2006 (UTC)
*Patrick Tillman had a bachelor's degree in marketing.[[User:Patchouli|Patchouli]] 06:03, 26 June 2006 (UTC)
::In the current U.S. military, a college degree (Bachelors or higher) is required to join as an officer. However, a person with a degree can enlist as an enlisted person (which Tillman did). Also, there is a warrant officer program that can allow an enlisted person to become an officer without a college degree - but every warrant officer I've met was working on a degree. As to why a person would opt to go enlisted when they could be an officer... it is a matter of choice. Some people feel that an officer who never was enlisted can never be as effective as one who knows what it is like to be enlisted. I served in the Marines and I remember a discussion that the Commandant of the Marine Corps is almost always an officer who began as an enlisted Marine. All in all, a college degree doesn't make a person in the military an officer. Also, the ASVAB score has nothing to do with becoming an officer. It is used to weed out idiots (if you can't pass the ASVAB, you are a danger to yourself and everyone around you) and help decide what job will be the best use of your potential. It is not the only test. I scored high on all sections of the ASVAB which led to two more tests in boot camp. One was computers/electronics and the other was languages. I failed the language test miserably, but did great on the computer/electronic test. So, I was sent off to computer/electronic school. I've always wished I was better at languages. I'd love to be able to communicate with anyone anywhere in the world. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 14:33, 26 June 2006 (UTC)
*There are many people who don't have any schooling but have considerable education. Is there any way for a person with no degree to either take a test and somehow demonstrate that he can become an officer?[[User:Patchouli|Patchouli]] 15:04, 26 June 2006 (UTC)
== brazilian essential oils ==
Where can I find an overview of typical brazilian plants/flowers which can be used in essential oils?
Thanks,
with kindly regards
:I have no clue, but [[:Category:Flora of Brazil]] and [[:Category:Essential oils]] might somehow help...? [[User:Melchoir|Melchoir]] 07:59, 25 June 2006 (UTC)
== Rate of diffusion ==
How do you calculate the rate of diffusion? I found 3 or 4 versions on calculating the rate of diffusion but which one is correct? (Does the surface of the solute affect osmosis? Yes it does right?). Many thanks. {{unsigned|219.78.198.201}}
:According to Graham's law of diffusion (and effusion, but we don't care about that,) the rate of diffusion is inversely proportional to the square root of the density of the gas. -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 00:17, 26 June 2006 (UTC)
::Note that this, as with all gas laws, only work for [[ideal gas]]es... bummer. -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 00:17, 26 June 2006 (UTC)
:: I always wondered why it was square root. One would think in a three dimensional environment it would be cubic. Thought that square root would only come into play during [[fundamental force]]s, ie. when describing the strength of forces in inverse proportion to distance, but not diffusion. [[User:Natalinasmpf|Elle <small><sub><font color="#CC9920">vécut heureuse</font></sub></small> <small><font color="blue"><sup>à jamais</sup></font></small>]] ([[User talk:Natalinasmpf|Be eudaimonic!]]) 04:02, 26 June 2006 (UTC)
How do I calculate the rate of diffusion of distilled water through a semi-pearmeable membrane (potato cylinders)?
== Man made lakes ==
How are man made lakes made? Where do they get the water from and how are the ones that are connected to the ocean created? {{unsigned|66.75.254.45}}
:I'm from the Netherlands, where we do the opposite, so I shouldn't be an expert on this. :) The first thing that springs to mind is lakes created by hydro-electric dams. Sort of like beaver-made lakes, just bigger. :) [[User:DirkvdM|DirkvdM]] 08:54, 25 June 2006 (UTC)
:As far as I know the vast majority of artificial lakes are [[reservoir]]s created by [[dam]]ming rivers. They are only 'connected to the ocean' in that the rivers on which they sit eventually reach the sea. [[User:Henry Flower|Henry]][[User talk:Henry Flower|<sup>Flower</sup>]] 08:57, 25 June 2006 (UTC)
::For connection to the ocean, see [[Zuiderzee Works]]. --[[User:Shantavira|Shantavira]] 12:17, 25 June 2006 (UTC)
:::To be complete, there are also man destroyed lakes or inner seas. See [[irrigation]] and the like.--[[User:Harvestman|DLL]] 18:28, 25 June 2006 (UTC)
An interesting article for you to check out would be the one about the [[Salton Sea]]. Basically, though, all that's necessary is to find an area with a relatively low elevation, dig a trench from that area to the nearest large body of water at a higher elevation, and then let gravity do the rest. [[User:Loomis51|Loomis]] 22:53, 25 June 2006 (UTC)
*A lake created in a dry river bed, [[Tempe Town Lake]]: "using inflatable rubber barriers in the riverbed to confine water within its boundaries". --[[User:JWSchmidt|JWSchmidt]] 01:27, 26 June 2006 (UTC)
== Aircraft safety ==
I have seen destructive videos of an blade coming loose in a turbine fan of the air intake of a jet engine.Instead,Why cant they make a composite fan and then surround all its blades with a ring,so that even if one blade brakes the plane can still land safely?Guess it would be stronger and lastlonger.
I did not mean a stationary ring on the body of the engine cover,but a ring attached to all the ends of the blades(Something like the rim of a cycle wheel with spokes) that rotates along with the blades
:Please see [[#Aircraft Safety]] for the previous discussion on this point. [[User:Notinasnaid|Notinasnaid]] 11:28, 25 June 2006 (UTC)
:Well the blades can't get out anyway. I suppose its because it would make incredibly difficult to replace fractured or otherwise damaged blades, possibly to the extenet that a new turbine would have to be installed, whereas at the moment individual blades can easily be replaced, and the engine housing is strong enough to contain the blades anyway, so really, all I can see from it are added costs, and no real benfits. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 11:59, 25 June 2006 (UTC)
== major revisions complete ==
The [[Half-life computation]] article has undergone substantial revision which has hopefully addressed everyone's concerns. If you have any further comments after looking at the article again, please list the items you do not like, make whatever comment you have and please be specific and allow time for further revision. If there is any reason I can not comply with your wishes then I will let you know the reason why. <small> ...[[User:Pce3@ij.net|IMHO]] ([[User talk:Pce3@ij.net|Talk]])</small> 12:21, 25 June 2006 (UTC)
:Why is there so much quibbling about Half-Life? Is it something to do with how many questions about Seagulls are asked on the reference desk?
::Remember that the half life of seagulls depends on the various isotopes. --[[User:Harvestman|DLL]] 18:25, 25 June 2006 (UTC)
== Alternative to internal combustion engine ==
I have seen on slashdot and other places on the interweb references to some alternative to or different type of internal combustion engine with massive energy savings which Ford/GM bought the patent to but refused to develop. I had always written it off as a conspiracy theory and ignored it, but i recently heard a respectable scientist refer to it on the radio the other day, so that got me interested. Unfortunately i haven't been able to find any info on it. Anyone know anything? [[User:The bellman|The bellman]] 15:14, 25 June 2006 (UTC)
:The entire purpose of the patent system is to make new discoveries ''public'' while giving inventors a period of time with a monopoly on the invention so that they can make money off of it. If there was a patent for the super engine or carburetor, then you should be able to find it at the [http://www.uspto.gov/ United States Patent and Trademark Office] web page. So, in other words, a patent is unlikely. Without a patent, legal protection of the idea is difficult. It's unlikely that such an invention exists. —[[User:209.98.224.158|209.98.224.158]] 21:46, 25 June 2006 (UTC)
::There are no magic solutions to radically improve the efficiency of internal combustion engines. Things like direct injection give incremental improvements, but that's all. About the only plausible "radical" improvement I've seen is BMW's experimentation with a [[combined cycle]] engine - see [http://www.autoblog.com/2005/12/09/bmw-turbosteamer-gets-hot-and-goes/]. To do much better, you have to start doing things like going to [[fuel cell]]s as a direct replacement. --[[User:Robert Merkel|Robert Merkel]] 01:33, 26 June 2006 (UTC)
:::Combustion engines only have an efficiency of under 50% [http://ecen.com/content/eee7/motoref.htm], so I'd say there's so much room for improvement that you can't dismiss the idea so easily.
:::About the patent thing, maybe it wasn't a patent but some other [[Intellectual property]] thingy. Many years ago I saw a demonstration on tv of a much lighter and more efficient wheel (yes, someone re-invented the wheel) the rights to which were sold to a car tyre company and they ended with the remark that therefore it was likely that we would never hear from it again because the wheel was too cheap and would therefore not make the manufacturer as much money. And indeed I have never heard of it since. So this sort of thing ''does'' seem to happen. The wheel existed of a ribbon-shaped 'tyre' that was attached to the axis with strings in stead of rigid spokes. The result was that the ribbon flattened at the bottom, giving it much more grip than a traditional tyre. [[User:DirkvdM|DirkvdM]] 13:32, 26 June 2006 (UTC)
::::Just offhand about the {tire|tyre} thing, I'd expect that a tire with significantly more road contact area would also have significantly more drag, leading to reduced fuel efficiency (more or less the same as running on tires well below their recommended pressures). So patents may certainly disappear from the market, but it doesn't have to be because of cover-ups.
::::For the original question, though, it's generally agreed that the problem with replacing internal combustion engines isn't that the technology doesn't exist or isn't known (there are plenty of options) but that few of them are as-yet economical. It's entirely plausible that car manufacturers are sitting on technologies that can't yet be sold for profit. — [[User:Lomn|Lomn]] | [[User talk:Lomn|Talk]] 14:18, 26 June 2006 (UTC)
== 5th state of matter? ==
Is there a fifth state of matter what this site:
http://www.5th-state-of-matter.info/home.html
claims?
If so why doesn't it exist in wikipedia. I trust Wikipedia for the moment that there are only 4 states of matter. Please reply if you can
:Don't put your email address here, automated bots crawl the web, steal them and send them spam. If you absolutely '''have''' to, put them like this: us ern ame <AT> w eb <DOT> c om for username@web.com (with apologies to the actual holder of that address). Wikipedia does not have this information because, from what I can see, the man appears to be a crank (not to put to fine a point on it). I'm sure that other Wikipedians can clarify. That said, if you read our article on [[states of matter]] you would realise that there can be many more than 3 if you choose to define them in certain ways. [[User:Dbmag9|D]]<small>[[User:Dbmag9/Esperanza|'''<font color="green">a</font>''']][[User:Dbmag9|niel]]</small> ([[User_talk:Dbmag9|‽]]) 15:57, 25 June 2006 (UTC)
::Dbmag9 is right. If anywhere, it belongs at [[Electric universe (concept)]]. [[User:Melchoir|Melchoir]] 15:59, 25 June 2006 (UTC)
:Horay, I'm right about something! [[User:Dbmag9|D]]<small>[[User:Dbmag9/Esperanza|'''<font color="green">a</font>''']][[User:Dbmag9|niel]]</small> ([[User_talk:Dbmag9|‽]]) 17:29, 25 June 2006 (UTC)
:Traditionally, plasma is classified as the fourth state, so perhaps a quark-gluon plasma is the 5th state. Eh. --[[User:Bmk|Bmk]] 04:27, 26 June 2006 (UTC)
::[[Bose-Einstein condensate]] is often referred to as the fifth form of matter. Looking at the [[Template:Phase of matter|link template]] at the bottom of that article suggests a lot of other candidates, though. [[User:Grutness|Grutness]]...''<small><font color="#008822">[[User_talk:Grutness|wha?]]</font></small>'' 06:49, 26 June 2006 (UTC)
== Clinical depression ==
Hi!
I was reading your article on clinical depression on wikipedia.org/wiki/clinical_depression.
You refer under the section 'hypomania' to two specific doctors studies.
The first is Hagop Akiskal, M.D. The second is Giovanni Cassano, who is busy with the 'spectrum project'.
I would like to get full copies of their studies on 'hypomania'.
Can you help me with this information, please??
Kind regards
Julie
:You can try to locate their journal articles on [[Medline]] yourself. Alternatively, you could contact them directly and ask for reprints of their studies/articles. See [http://unimap.unipi.it/cercapersone/dettaglio.php?ri=4160&template=dettaglio.tpl this website] for Giovanni Cassano and [http://blink.ucsd.edu/Blink/Libraries/cgi/1,1318,1652,00.html?cgiURL=http%3A%2F%2Fwww%2Dact%2Eucsd%2Eedu%2Fcgi%2Dbin%2Fphone%2Fss%2Fphone%2Epl&dir=faculty%2Fstaff&entry=akiskal&entry_fands=akiskal&entry_blink= here] for Dr. Akiskal. - [[User:Cybergoth|Cybergoth]] 17:34, 25 June 2006 (UTC)
== Stinging and Biting pests ==
It seems like every time I allow myself to doze off on my hammock or in my yard, I am soon startled back into wakefulness by an ant bite or some such thing. I may have been moving in my sleep, but probably not very much, and cant imagine that I represented much of a threat to any insect colonies nearby. So why do these insects sting/bite me? Do fire ants and hornets merely cruise around stinging and biting rocks and blades of grass, until they happen upon me? Or do they somehow know that I will react? (By my softness? Plants can be soft. My heat? The sun warms many things. My movement? The wind blows the grasss and the trees too...). This question is specifically applicable to fire ants, which seem to want to bite me even when I sit on my granite bench in the garden and hold perfectly still.[[User:Tuckerekcut|Tuckerekcut]] 14:27, 24 June 2006 (UTC)
I posted this a few days ago but someone deleted it, that wasn't very nice. (And can someone get rid of the box? I don't know how to...)[[User:Tuckerekcut|Tuckerekcut]] 18:02, 25 June 2006 (UTC)
: The box appears when you insert an initial space in front of the first word of the paragraph; I've removed it now. —[[User:AySz88|AySz88]][[Special:Contributions/AySz88|\]][[User talk:AySz88|<font color="#FF9966">^</font><font color="#FF6633">-</font><font color="#FF3300">^</font>]] 18:06, 25 June 2006 (UTC)
::Thank You. [[User:Tuckerekcut|Tuckerekcut]] 18:19, 25 June 2006 (UTC)
:::Insects allow the USA to earn billions each year : they pollinate plants, but they also bite and digest dead things. So doing their job, they just taste you in case of. --[[User:Harvestman|DLL]] 18:22, 25 June 2006 (UTC)
::::Unfortunately, it is the nature of [[fire ant]]s to bite you because they smell you and perceive you as a threat. You will either need to find somewhere else to sit, or move them on. According to the article, you need to get yourself a few [[ant-decapitating fly|ant-decapitating flies]]. --[[User:Shantavira|Shantavira]] 18:27, 25 June 2006 (UTC)
:::::How do those ant-decapitating flies get the ants to stay still long enough to lay an egg on its head? The fly must be massive compared to the ant... surely it would notice?!?!? --[[User:Dweller|Dweller]] 09:38, 26 June 2006 (UTC)
So it is primarily through chemoreception that biting insects choose their targets, I guess I should have suspected that. Does that mean that the ants will bite the granite bench I sat on (for this example, we will suppose that I sat on it nude) soon after I stand up? My chemical smell would remain on the surface for a while... However, I should point out that, say, hornets, will sting animals digging into their nests, but usually not animals lounging far away, both should smell just about the same. And to extrapolate this example further, will the hornets sting the digging animal with the same ferocity that they would sting a mechanical shovel? What if that shovel was soft? or warm? [[User:Tuckerekcut|Tuckerekcut]] 22:09, 25 June 2006 (UTC)
== Rehydrating drinks ==
do carbonated beverages and soft drinks rehydrate you?
Gatorade has a fair bit of salt in it. Does gatorade rehydrate you?
I've heard ocean water has a fair bit of salt in it. Does ocean water rehydrate you?
Thanks
~Peter
:You can get water from anything less salty than [[urine]]. Soft drinks and gatorade are less salty that urine, but seawater is more salty, so the more you drink the more water you have to waste to get rid of the salt. —[[User:Keenan Pepper|Keenan Pepper]] 19:13, 25 June 2006 (UTC)
::That statement can be misleading, as Urine varies in salt concentration in accordance with your water intake. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 19:34, 25 June 2006 (UTC)
:The best drinks for [[rehydration]] are sports drinks such as Gatorade. Water is also good for mild dehydration, although it does not replenish salts lost through sweating or urination and an excess can cause [[water toxicity]]. Drinking [[sea water]] is worse than drinking nothing for rehydration, as it has a salt concentration of about 3.5% (far less than that of [[blood]]). Sweetened soft drinks are better than nothing for rehydration, but are not the most effective because they both lack salts and contain sugar, which is [[hygroscopy|hygroscopic]]. Also, many soft drinks are caffeinated, and [[caffeine]] is a [[diuretic]], increasing urination and therefore interfering with rehydration. [[Alcoholic beverage]]s are also diuretic and should be avoided when dehydrated. --[[User:Ginkgo100|Ginkgo100]] <sup>[[User talk:Ginkgo100|''talk'']] · [[Special:Contributions/Ginkgo100|''contribs'']]</sup> 19:55, 25 June 2006 (UTC)
:That is quite interesting. --[[User:Proficient|Proficient]] 20:23, 25 June 2006 (UTC)
Ocean water does not rehydrate you. It has way too much salt and will harm you, not help you in case of dire thirst.[[User:User101010|User101010]] 21:46, 25 June 2006 (UTC)
Dehydration can result from problems controlling not just the volume of water in the body (hypovolemic dehydration) but also the concentration of soluble chemicals (osmotic dehydration). Gatorade is made to replenish the body of both water (for liquid volume) and salts (for osmotic regulation) to replace liquids lost through sweating, and as such it is a good choice for rehydration when you are dehydrated due to fluid loss (sweating, diabetes insipidus, diarrhea, and I suppose bleeding, if the only chioice is to drink something). however, if you are already getting enough salt from other parts of your diet, then it is better to drink plain water. For other drinks, remember that diuretics will cause you too lose more water than salt, which may lead to an undesireable osmotic situation, so avoid alcohol and caffiene when you are dehydrated. The actual carbonation in soft drinks is of little nutritional significance, most of it fizzes out and the remaining carbonic acid won't really effect hydration. However, as Ginkgo points out above, the sugar constituent of soft drinks is hygroscopic (that means that water molecules tend to gather around the molecules of sugar, making them less biologically available). Because of this, and the fact that sugar, by weight is far less "concentrated" in an osmolar sense (the molecules are big, and they don't ionize like salts), sugary drinks are not nearly as good as salty drinks at controlling osmotic dehydration. As for saltwater, don't ever drink it. Saltwater is just a tiny bit saltier than your body's natural fluids, so even if your stomach is full of saltwater, your cells will actually give up water to dilute it, even if it means dehydrating themselves. Body fluids have a salt concentration of about 0.9g of table salt per liter of water, anything more concentrated will be able to replace water volume, but will not be able to restore osmotic balance. This all sounds a little complicated, but if you do a little searching, you may find it is deviously simple, I recommend looking at the following articles if you find yourself confused: [[osmosis]], [[renal system]], [[hypernatremia]], [[hyponatremia]], [[hypovolemia]], [[thirst]]. [[User:Tuckerekcut|Tuckerekcut]] 22:49, 25 June 2006 (UTC)
What is the difference between an auxotroph and a fastidious organism? It seems to me the second one would have more requirements than the first one, but the limit between the two definitions is rather unclear to me.
:I thought that not only salt, but sugar also increased the osmotic value of a solution and since soft drinks are so full of sugar, they also cause dehydration. [[User:DirkvdM|DirkvdM]] 14:21, 26 June 2006 (UTC)
Thank you [[Special:Contributions/212.195.231.13|212.195.231.13]] ([[User talk:212.195.231.13|talk]]) 23:17, 27 December 2024 (UTC)
::Any solute in water will increase its osmolarity, the reason that "sugar" is less effective than "salt" is twofold. First, Sugar molecules are much more massive and voluminous than salt molecules (sugars being, at the smallest, C6H12O6 (about 180g/mole), with table salt (NaCl) around 58g/mole) therefore one gram of sugar has far fewer molecules than one gram of salt, and in osmosis, the only thing that matters is how many individual molecules or ions are floating around. Second, sugar remains a single molecule when dissolved in water, so one mole of dry sugar yields one mole of molecules in solution (1 molar = 1 osmolar). Salt, on the other hand, ionises in water, and thus one mole of salt yields two moles of ions in solution (1 molar = 2 osmolar). (Also, simple sugars are hygroscopic, which means that they readily absorb water. This is mentioned above, but it only effects bioavailability, not osmolarity). The upshot of all of this is that a gram of salt is roughly six times more osmotically active than a gram of sugar. Sugar does effect osmolarity, but not nearly as much as salt. Assuming "normal" dehydration (hypovolemia with hypernatremia), something like D5W (water with 5% dextrose sugar w/v) would be a more effective rehydrator than gatorade.[[User:Tuckerekcut|Tuckerekcut]] 15:59, 26 June 2006 (UTC)
:I'm not 100% sure, but it seems to me that an auxotroph is a specific type of a fastidious organism. [[Special:Contributions/2601:646:8082:BA0:9052:E6AF:23C7:7CAF|2601:646:8082:BA0:9052:E6AF:23C7:7CAF]] ([[User talk:2601:646:8082:BA0:9052:E6AF:23C7:7CAF|talk]]) 03:02, 28 December 2024 (UTC)
:Symbiosis aside, it would seem that most auxotrophs would be fastidious organisms, but there could be many more fastidious organisms that aren't auxotrophs. Auxotrophs specifically can't produce organic compounds on their own. There are a LOT of organisms that rely on the availability of non-organic nutrients, such as specific elements/minerals. For instance, vertebrates require access to calcium. Calcium is an element; our inability to produce it does not make us auxotrophs.
:But perhaps symbiosis would allow an organism to be an auxotroph without being a fastidious organism? For instance, mammals tend to have bacteria in our guts that can digest nutrients that our bodies can't on their own. Perhaps some of those bacteria also assemble certain nutrients that our bodies can't? -- [[User:Avocado|Avocado]] ([[User talk:Avocado|talk]]) 14:27, 28 December 2024 (UTC)
= December 28 =
== Engineering Software ==
== Paper with wrong enantiomer in a figure ==
I am looking for an software which could do the beam deflection. Please send me some name. If threre are any open source software please send me the name. <small>—The preceding [[Wikipedia:Sign your posts on talk pages|unsigned]] comment was added by [[User:208.110.17.154|208.110.17.154]] ([[User talk:208.110.17.154|talk]] • [[Special:Contributions/208.110.17.154|contribs]]) {{{2|}}}.</small>
In the following reference:
:{{cite journal |last1=Quack |first1=Martin |last2=Seyfang |first2=Georg |last3=Wichmann |first3=Gunther |title=Perspectives on parity violation in chiral molecules: theory, spectroscopic experiment and biomolecular homochirality |journal=Chemical Science |date=2022 |volume=13 |issue=36 |pages=10598–10643 |doi=10.1039/d2sc01323a |pmid=36320700}}
it is stated in the caption of Fig. 8 that ''S''–[[bromochlorofluoromethane]] is predicted to be lower in energy due to [[parity violation]], but in the figure the wrong enantiomer is shown on this side. Which enantiomer is more stable, according to the original sources for this data? –[[User:LaundryPizza03|<b style="color:#77b">Laundry</b><b style="color:#fb0">Pizza</b><b style="color:#b00">03</b>]] ([[User talk:LaundryPizza03|<span style="color:#0d0">d</span>]][[Special:Contribs/LaundryPizza03|<span style="color:#0bf">c̄</span>]]) 08:18, 28 December 2024 (UTC)
== Where can I find data on the circulation and citation rates of these journals? ==
Hello everyone, To write an article about a scientist, you need to know, where can I find data on circulation and citation rates of journals from [https://pubmed.ncbi.nlm.nih.gov/?term=%22Trump%20D%22%5BAuthor%5D this list]? [[User:Vyacheslav84|Vyacheslav84]] ([[User talk:Vyacheslav84|talk]]) 09:58, 28 December 2024 (UTC)
== So-called “Hydrogen water” ==
:What kind of "beam deflection"? Your question needs more context. —[[User:Keenan Pepper|Keenan Pepper]] 19:17, 25 June 2006 (UTC)
I saw an ad promoting a device which presumable splits water into
:Electron or wood? —[[User:209.98.224.158|209.98.224.158]] 21:54, 25 June 2006 (UTC)
hydrogen and oxygen and infuses water with extra hydrogen, to
a claimed surplus of perhaps 5 ppm, which doesn’t seem like much. I found a review article which looked at several dozen related studies that found benefits:https://pmc.ncbi.nlm.nih.gov/articles/PMC10816294/ .
I’ve noticed that carbon dioxide or chlorine (chloramine?) dissolved in water work their way out pretty easily, so I wonder if dissolved hydrogen could similarly exit hydrogen enriched water and be burped or farted out, rather than entering the blood stream and having health benefits. is it more than the latest snake oil? [[User:Edison|Edison]] ([[User talk:Edison|talk]]) 23:01, 28 December 2024 (UTC)
::Maybe the person who asked the question was looking for ray tracing software.--[[User:72.78.101.61|72.78.101.61]] 04:14, 26 June 2006 (UTC)
:Yes, the dissolved hydrogen will exit the water just as quickly (even faster, because of its low [[molecular mass]] and complete lack of [[polarity]] or capability for [[ionic dissociation]]), and even if it does enter the bloodstream, it will likewise get back out in short order before it can actually do anything (which, BTW, is why [[deep-sea diver]]s use it in their breathing mixes -- because it gets out of the bloodstream so much faster and therefore doesn't [[Decompression sickness|build up and form bubbles like nitrogen does]]) -- so, I don't think it will do much! [[Special:Contributions/2601:646:8082:BA0:209E:CE95:DB32:DD64|2601:646:8082:BA0:209E:CE95:DB32:DD64]] ([[User talk:2601:646:8082:BA0:209E:CE95:DB32:DD64|talk]]) 01:50, 29 December 2024 (UTC)
:::Have you [[google:beam deflection software|googled]]? –[[User:Mysid|Mysid]]<sup><font color="#ffa500">[[User talk:Mysid|(t)]]</font></sup> 07:44, 26 June 2006 (UTC)
::It's conceivable it might take out the chloramine, I guess. I don't think there's very much of it, but it tastes awful, which is why I add a tiny bit of vitamin C when I drink tap water. It seems to take very little. Of course it's hard to tell whether it's just being masked by the taste of the vitamin C. --[[User:Trovatore|Trovatore]] ([[User talk:Trovatore|talk]]) 02:12, 29 December 2024 (UTC)
:If you just want to split water into hydrogen and oxygen all you need is [[Electrolysis|a battery and two bits of wire]]. You don't say where you saw this ad but if it was on a socia media site forget it. [[User:Shantavira|Shantavira]]|[[User talk:Shantavira|<sup>feed me</sup>]] 11:47, 29 December 2024 (UTC)
::If this so-called hydrogen water was emitting hydrogen bubbles, would it be possible to set it afire? ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 14:03, 1 January 2025 (UTC)
:We once had an article on this topic, but see [[Wikipedia:Articles for deletion/Hydrogen water]]. [[User:Graeme Bartlett|Graeme Bartlett]] ([[User talk:Graeme Bartlett|talk]]) 22:27, 1 January 2025 (UTC)
::I don't know if it is rubbish or not but a quick look on the web indicates to me it is notable enough for Wikipedia. I didn't see anything indicating it definitely did anything useful so such an article should definitely have caveats. I haven't seen any expression of a potential worry either so it isn't like we'd be saying bleach is a good medicine for covid. [[User:NadVolum|NadVolum]] ([[User talk:NadVolum|talk]]) 23:07, 1 January 2025 (UTC)
:''[[International Journal of Molecular Sciences]]'' does not sound of exceptionally high quality. [[User:DMacks|DMacks]] ([[User talk:DMacks|talk]]) 01:05, 2 January 2025 (UTC)
== Condoms==
= December 29 =
== Potential energy vs. kinetic energy. Why not also "[[potential velocity]]" vs. "[[kinetic velocity]]"? E.g. in the following case: ==
How many times can I reuse a condom before I have to replace it?
In a [[harmonic oscillator]], reaching the highest point involves - both a minimal kinetic energy - along with a maximal potential energy, whereas reaching the lowest point involves - both a maximal kinetic energy - along with a minimal potential energy. Thus the mechanical energy becomes the sum of kinetic energy + potential energy, and ''is a conserved quantity''.
:Well, once. Unless your somewhat disgusting. [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 19:38, 25 June 2006 (UTC)
So I wonder if it's reasonable to define also "potential velocity" vs. "kinetic velocity", and claim that in a harmonic oscillator, reaching the highest point involves - both a ''minimal'' "kinetic velocity" (i.e. involves what we usually call ''a rest'') - along with a ''maximal'' "potential velocity", whereas reaching the lowest point involves - both a ''maximal'' "kinetic velocity" (i.e. involves what we usually call ''the actual velocity'') - along with a ''minimal'' "potential velocity". Thus we can also define "mechanical velocity" as the sum of "kinetic velocity" + "potential velocity", and ''claim that the mechanical velocity is a conserved quantity'' - at least as far as a harmonic oscillator is concerned.
::Unless you're also disgusting, Philc, I assume you've been caught by a [[tautology]] and you really mean "none". --[[User:Dweller|Dweller]] 09:32, 26 June 2006 (UTC)
Reasonable?
:They're usually disposable. --[[User:Proficient|Proficient]] 20:24, 25 June 2006 (UTC)
Note that I could also ask an analogous question - as to the concept of "potential momentum", but this term is already used in the theory of [[hidden momentum]] for another meaning, so for the time being I'm focusing on velocity.
:Never use a [[condom]] more than once. Always use a new condom for each separate act. Once the condom is removed, the bodily fluids can go anywhere, so an old condom can easily transfer bodily fluids. If you're lucky enough to get seconds, then use a second condom. One condom is far cheaper than the costs of a pregnancy and/or medical care for an STD. According the wikipedia article on [[condoms]], the typical effectiveness of condoms is only 85%. If you re-use it, that number will drop even further. [[User:User101010|User101010]] 21:16, 25 June 2006 (UTC)
[[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 12:26, 29 December 2024 (UTC)
::You are assuming the questioner is referring to a disposable condom. Older condoms, commonly made from the intestines of goats, pigs, and the like, are not disposable and intended to be used indefinately. While it is highly unlikely that anyone would be using such a condom in modern times, I feel that a reference desk answer should be complete. So, I wanted to note on this special sort of condom. --[[User:Kainaw|Kainaw]] <small><sup>[[User_talk:Kainaw|(talk)]]</sup></small> 23:09, 25 June 2006 (UTC)
: 'kinetic velocity' is just 'velocity'. 'potential velocity' has no meaning. [[User:Andy Dingley|Andy Dingley]] ([[User talk:Andy Dingley|talk]]) 13:56, 29 December 2024 (UTC)
Oh, if you are talking about the steel condom [http://wycked.com/steel-condom-p-643.html] I believe you can use it forever. Just place it in the dishwasher after use! --[[User:Zeizmic|Zeizmic]] 01:11, 26 June 2006 (UTC)
::Per my suggestion, the ratio between distance and time is not called "velocity" but rather "kinetic velocity".
::Further, per my suggestion, if you don't indicate whether the "velocity" you're talking about is a "kinetic velocity" or a "potential velocity" or a "mechanical velocity", the very concept of "velocity" alone has no meaning!
::On the other hand, "potential velocity" is defined as the difference between the "mechanical velocity" and the "kinetic velocity"! Just as, this is the case if we replace "velocity" by "energy". For more details, see the example above, about the harmonic oscillator. [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 15:14, 29 December 2024 (UTC)
:::You could define the ''potential velocity'' of a body at a particular height as the velocity it would hit the ground at if dropped from that height. But the sum of the potential and kinetic velocities would not be conserved; rather <math>v_{\mathrm{tot}} = \sqrt{v_{p}^{2} + v_{k}^{2}}</math> would be constant. [[User:Catslash|catslash]] ([[User talk:Catslash|talk]]) 18:54, 29 December 2024 (UTC)
::::Thank you. [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 20:07, 29 December 2024 (UTC)
::: 'Potential velocity' has no meaning. You seem to be arguing that in a system where energy is conserved, but is transforming between kinetic and potential energy, (You might also want to compare this to [[conservation of momentum]].) then you can express that instead through a new conservation law based on velocity. But this doesn't work. There's no relation between velocity and potential energy.
::: In a harmonic oscillator, the potential energy is typically coming from some central restoring force with a relationship to ''position'', nothing at all to do with velocity. Where some axiomatic external rule (such as [[Hooke's Law]] applying, because the system is a mass on a spring) ''happens'' to relate the position and velocity through a suitable relation, then the system will then ([[Necessity and sufficiency|and only then]]) behave as a harmonic oscillator. But a different system (swap the spring for a [[dashpot]]) doesn't have this, thus won't oscillate. [[User:Andy Dingley|Andy Dingley]] ([[User talk:Andy Dingley|talk]]) 00:00, 30 December 2024 (UTC)
::::Let me quote a sentence from my original post: {{tq|Thus we can also...claim that the mechanical velocity is a conserved quantity - '''at least as far as a harmonic oscillator is concerned'''.}}
::::What's wrong in this quotation? [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 07:52, 30 December 2024 (UTC)
:::::It is true, not only for harmonic oscillators, provided that you define {{math|1='''v'''<sub>pot</sub> = − '''v'''<sub>kin</sub>}}. --[[User talk:Lambiam#top|Lambiam]] 09:07, 30 December 2024 (UTC)
::::* You have defined some arbitrary values for new 'velocities', where their ''only'' definition is that they then demonstrate some new conservation law. Which is really the conservation of energy, but you're refusing to use that term for some reason.
::::: As Catslash pointed out, the conserved quantity here is proportional to the square of velocity, so your conservation equation has to include that. It's simply wrong that any linear function of velocity would be conserved here. Not merely we can't prove that, but we can prove (the sum of the squares diverges from the sum) that it's actually contradicted. For any definition of 'another velocity' which is a linear function of velocity.
::::: Lambiam's definition isn't a conservation law, it's merely a [[mathematical identity]]. The sum of any value and its [[additive inverse]] is always [[additive identity|zero]]. [[User:Andy Dingley|Andy Dingley]] ([[User talk:Andy Dingley|talk]]) 14:04, 30 December 2024 (UTC)
::::::{{small|It is a law of conservation of ''sanity''. Lacking a definition of potential energy, other than by having been informed that kinetic energy + potential energy is a conserved quantity, there is not much better we can do.}} --[[User talk:Lambiam#top|Lambiam]] 11:20, 31 December 2024 (UTC)
::::::: We have a perfectly viable definition of potential energy. For a pendulum it's based on the change in height of the pendulum bob against gravity. For some other oscillators it would involve the work done against a spring. [[User:Andy Dingley|Andy Dingley]] ([[User talk:Andy Dingley|talk]]) 16:33, 31 December 2024 (UTC)
::::::::Oops, I mistyped. I meant to write:
:::::::::"{{small|Lacking a definition of potential velocity, other than by having been informed that kinetic velocity + potential velocity is a conserved quantity, there is not much better we can do.}}"
:::::::: --[[User talk:Lambiam#top|Lambiam]] 23:32, 31 December 2024 (UTC)
= December 30 =
:::What the hell!? A steel condomn!? Well, I suppose I could get one if I wanted my parter to experince a softer sensation. [[User:Mayor Westfall|Mayor Westfall]] 05:20, 26 June 2006 (UTC)
== Saltiness comparison ==
::::It was certainly possible to buy reusable condoms in the 1970s. They came with cleaning instructions, talc, and a "re-rolling machine". Useful for kids on a budget who were only - er - practising on their own.--[[User:Shantavira|Shantavira]] 06:27, 26 June 2006 (UTC)
Is there some test one might easily perform in a home [[test kitchen]] to compare the [[saltiness]] (due to the concentration of [[Na+|Na<sup>+</sup>]] [[cation]]s) of two liquid preparations, without involving biological [[taste bud]]s? --[[User talk:Lambiam#top|Lambiam]] 09:22, 30 December 2024 (UTC)
:::::About being on a budget. I buy my condoms at less than 20 euro per gross. That's just over 10 cents per condom. Condom prices are hugely inflated, just like funerals - who is going to complain about the price at such moments? [[User:DirkvdM|DirkvdM]] 14:28, 26 June 2006 (UTC)
:Put two equally sized drops, one of each liquid, on a warm surface, wait for them to evaporate, and compare how much salt residue each leaves? Not very precise or measurable, but significant differences should be noticeable. {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.1.223.204|94.1.223.204]] ([[User talk:94.1.223.204|talk]]) 10:21, 30 December 2024 (UTC)
== Reading faces, liver lines etc. ==
::The principle is sound, but the residue from one drop won't be measurable using kitchen equipment -- better to put equal amounts of each liquid in two warm pans (use enough liquid to cover the bottom of each pan with a thin layer), wait for them to evaporate and then weigh the residue! Or, if you're not afraid of doing some [[algebra]], you could also try an indirect method -- bring both liquids to a boil, measure the temperature of both, and then use the formula for [[boiling point elevation]] to calculate the saltiness of each! [[Special:Contributions/2601:646:8082:BA0:BD1B:60D8:96CA:C5B0|2601:646:8082:BA0:BD1B:60D8:96CA:C5B0]] ([[User talk:2601:646:8082:BA0:BD1B:60D8:96CA:C5B0|talk]]) 18:22, 30 December 2024 (UTC)
Somewhere in my study of macrobiotics a few years back, I heard about a book (chinese medicine) that told how you could read peoples faces. One that I remember is "liver lines" 2 vertical lines on the middle of the forhead. The other I remember........the lips had something to do with the bowels. Can anyone enlighten me on this subject, or refer me to a book about it?
:::Presumably the ''liquid preparations'' are not simple saline solutions, but contain other solutes - or else one could simply use a hydrometer. It is unlikely that Lambian is afraid of doing some algebra. [[User:Catslash|catslash]] ([[User talk:Catslash|talk]]) 18:57, 30 December 2024 (UTC)
Thank you very much
:<s>Assuming the liquid preparations are water-based and don't contain alcohols and/or detergents one can measure their rates of dispersion. Simply add a drop of food dye to each liquid and then time how rapidly droplets of each liquid disperse in distilled water. Materials needed: food dye, eye dropper, distilled water, small clear containers and a timer.</s> [[User:Modocc|Modocc]] ([[User talk:Modocc|talk]]) 21:09, 30 December 2024 (UTC)
Marie Wasilik
:::The [[colligative properties]] of a solution will indicate its molarity, but not identify the solute. ''Liquid preparations'' that might be found in a kitchen are likely to contain both salt and sugar. Electrical conductivity is a property that will be greatly affected by the salt but not the sugar (this does not help in distinguishing Na<sup>+</sup> from K<sup>+</sup> ions though). [[User:Catslash|catslash]] ([[User talk:Catslash|talk]]) 22:23, 30 December 2024 (UTC)
:You're looking for the [[meridian (TCM)]] network in traditional Chinese medicine. [http://www.traditionalmedicine.net.au/images/meridian.gif This] picture shows the most important meridians. -- '''[[User talk:Miborovsky|<font color="#FF0000">Миборовский</font>]]''' 00:11, 26 June 2006 (UTC)
::::That's what I'm thinking too -- use an [[ohmmeter]] to measure the [[electrical conductivity]] of the preparation, and compare to that of solutions with known NaCl concentration (using a [[calibration curve]]-type method). [[Special:Contributions/73.162.165.162|73.162.165.162]] ([[User talk:73.162.165.162|talk]]) 20:18, 31 December 2024 (UTC)
= June 26 =
:Quantitative urine test-strips for sodium seem to be available. They're probably covering the concentration range of tens to hundreds millimolar. [[User:DMacks|DMacks]] ([[User talk:DMacks|talk]]) 00:58, 2 January 2025 (UTC)
::Thanks, test strips seem more practical in the kitchen setting than an ohmmeter (why not call it a "[[mho]]meter"?), for which I'd need to devise a way (or so I think) to keep the terminals apart at a steady distance. Test strips require a colour comparison, but I expect that a significant difference in salinity will result in a perceptible colour difference when one strip is placed across the other. Only experiment can tell whether this expectation will come true. Salinity is usually measured in g/L; for kitchen preparations a ballpark figure is 1 g/L. If I'm not mistaken this corresponds to {{nowrap|1=(1 g/L) / (58.443 g/mol) ≈}} {{nowrap|1=0.017 M = 17 [[Millimolar|mM]].}} I also see offers for salinity test strips, 0–1000 ppm, for "Science Education". --[[User talk:Lambiam#top|Lambiam]] 11:40, 2 January 2025 (UTC)
:::Test strips surely come with a printed color-chart. But if all you are trying to do is determine which is more salty, then that's even easier than quantifying each separately. Caveat for what you might find for sale: some "salinity" tests are based on the chloride not the sodium, so a complex matrix that has components other than NaCl could fool it. [[User:DMacks|DMacks]] ([[User talk:DMacks|talk]]) 18:44, 2 January 2025 (UTC)
== The (uncommon?) terms "relativistic length", and "relativistic time". ==
==Evolutionary question==
1. In Wikipedia, the page [[relativistic length contraction]] is automatically redirected to our article [[length contraction]], ''which actually doesn't mention the term "relativistic length" at all''. '''I wonder if there is an accepted term for the concept of relativistic length'''.
Why do lines have mains? What is their function, and why did they evolve? [[User:Mayor Westfall|Mayor Westfall]] 05:22, 26 June 2006 (UTC)
2. A similar qusestion arises, at to the concept of relativistic time: The page [[relativistic time dilation]], is automatically redirected to our article [[time dilation]], which prefers the abbreviated term "time dilation" (59 times) to the term "relativistic time dilation" (8 times only), and ''nowhere'' mentions the term "relativistic time" alone (i.e. without the third word "dilation") - although it does mention the term "proper time" for the shortest time. Further, this article doesn't even mention the term "dilated time" either. It does mention, though, another term: [[coordinate time]], but regardless of time dilation in ''Special'' relativity. '''To sum up, I wonder what's the accepted term used for the dilated time (mainly is Special relativity): Is it "coordinate time"? "Relativistic time"?'''
:Is this a question about [[lion]]s and their manes?--[[User:Shantavira|Shantavira]] 06:29, 26 June 2006 (UTC)
[[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 09:32, 30 December 2024 (UTC)
::No, electricity, surely. Electricity lines carry mains current. If they didn't, the TV wouldn't work. Older lines carried trains, but it was difficult getting them into the TV. [[User:Grutness|Grutness]]...''<small><font color="#008822">[[User_talk:Grutness|wha?]]</font></small>'' 06:47, 26 June 2006 (UTC)
:::Yes what is the purpose of a lion's mane? [[User:Mayor Westfall|Mayor Westfall]] 05:22, 26 June 2006 (UTC)
::::I'd guess that it's a [[secondary sex characteristic]]. [[User:GeeJo|<span style="padding : 0px 1px 1px 1px; border : 1px solid #809EF5; cursor: wait; background: #FFFFFF ; color: #99B3FF">GeeJo</span>]] <sup>[[User talk:GeeJo|(t)]]</sup>⁄<sub>[[Special:Contributions/GeeJo|(c)]]</sub> <small>• 15:14, 26 June 2006 (UTC)</small>
:Are you reading these things as "contraction of relativistic length" etc.? It is "relativistic contraction of length" and "relativistic dilation of time". --[[User:Wrongfilter|Wrongfilter]] ([[User talk:Wrongfilter|talk]]) 09:37, 30 December 2024 (UTC)
== Does facial structure change during puberty? ==
::When I wrote: {{tq|The page [[relativistic time dilation]] is automatically redirected to our article [[time dilation]] which...nowhere mentions the term "relativistic time" alone (i.e. without the third word "dilation")}}, I had already guessed that the term "dilation of relativistic time" (i.e, with the word "dilation" preceding the words "relativistic time") existed nowhere (at least in Wikipedia), and that this redirected page actually meant "relativistic dilation of time". The same is true for the redirected page "relativistic length contraction": I had already gussed it didn't mean "contraction of relativistic length", because (as I had already written): {{tq|the article [[length contraction]]...doesn't mention the term "relativistic length" at all}}.
::Anyway, I'm still waiting for an answer to my original question: Are there accepted terms for the concepts, of relativistic length - as opposed to [[proper length]], and of relativistic time - as opposed to [[proper time]]? [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 10:12, 30 December 2024 (UTC)
:::A term that will be understood in the context of relativistic length contraction is ''relative length'' – that is, length relative to an observer.<sup>[https://books.google.com/books?id=gV6kgxrZjL8C&pg=PA174&dq=%22relative+length%22&hl=en][https://books.google.com/books?id=z925BQAAQBAJ&pg=PA20&dq=%22relative+length%22&hl=en][https://books.google.com/books?id=B5HYBAAAQBAJ&pg=PA195&dq=%22relative+length%22&hl=en]</sup> --[[User talk:Lambiam#top|Lambiam]] 10:55, 31 December 2024 (UTC)
::::Thank you. The middle source uses the term "comparative length", rather than "relative length". I couldn't open the third source. [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 08:04, 1 January 2025 (UTC)
:::::The text under the graph labelled '''Comparative length''' on page 20 of the middle source reads:
::::::Graph of the relative length of a stationary rod on earth, as observed from the reference frame of a traveling rod of 100cm proper length.
:::::A similar use of "relative length" can be seen on the preceding page. --[[User talk:Lambiam#top|Lambiam]] 10:23, 2 January 2025 (UTC)
== What did Juan Maldacena say after "Geometry of" in this video? ==
A friend asked an excellent question...So good, I had no clue what the answer is:
I was watching this video [[Brian Greene]] and [[Juan Maldacena]] as they explore a wealth of developments connecting black holes, string theory etc, [[Juan Maldacena]] said something right after "'''Geometry of'''" Here is the spot: https://www.youtube.com/live/yNNXia9IrZs?si=G7S90UT4C8Bb-OnG&t=4484 What is that? [[User:HarryOrange|HarryOrange]] ([[User talk:HarryOrange|talk]]) 20:46, 30 December 2024 (UTC)
"Can/will a person's face change structure during puberty? I mean, I know the rest of the body does, but no one's ever mentioned what happens to the structure of a person's face."
:[[Schwarzschild solution]]. --[[User:Wrongfilter|Wrongfilter]] ([[User talk:Wrongfilter|talk]]) 21:05, 30 December 2024 (UTC)
::Thank you, its the [[Juan Maldacena]]'s accent which made me post here. [[User:HarryOrange|HarryOrange]] ([[User talk:HarryOrange|talk]]) 21:18, 30 December 2024 (UTC)
= December 31 =
Now, nobody else I know could answer either. So I submit it here, in hopes someone can answer. -[[User:Penta|Penta]] 05:25, 26 June 2006 (UTC)
:The bones certainly grow, along with the rest of the body. I can't say whether there is a noticeable change in the shape of the face though. [[User:Freshgavin|<font size="-2" color="white" style="background:blue"> freshofftheufo</font>]][[User_talk:Freshgavin|<font size="-2" color="blue">ΓΛĿЌ </font>]] 05:40, 26 June 2006 (UTC)
::Yes, the [[hormone]]s (namely [[testosterone]] and [[estrogen]]s) do affect the shape of the face during puberty. A boy's jaw broadens and a "ridge" of bone may develop above the eyes, to name a few. The male jaw also gets an overall more chiselled shape. A girl's face gets somewhat more rounded due to fat being distributed under the skin. –[[User:Mysid|Mysid]]<sup><font color="#ffa500">[[User talk:Mysid|(t)]]</font></sup> 07:34, 26 June 2006 (UTC)
:Actually, I think the male face continues changing long past puberty, till about the age of thirty.--[[User:Pharos|Pharos]] 07:38, 26 June 2006 (UTC)
Here is a nice article. [http://www.bbc.co.uk/science/humanbody/mind/articles/emotions/faceperception2.shtml] Besides violence, the high-test. face (movie star) is also associated with chasing anything in a skirt before and after marriage. --[[User:Zeizmic|Zeizmic]] 11:46, 26 June 2006 (UTC)
== Brightest spot of a discharge tube ==
== Mars Meteorites ==
[[File:Neon discharge tube.jpg|thumb|Neon is brighter in the middle.]]
How to meteorites that come from places like Mars and the Moon get 'dislodged' from these bodies, sent into space, so that they have a change of colliding with Earth? --[[User:Silex|Silex]] 09:02, 26 June 2006 (UTC)
[[File:Xenon discharge tube.jpg|thumb|Xenon is brighter at the edges.]]
:Have you seen our article on [[Mars meteorite]]s? They originate when a substantial body (a larger meteorite) hits Mars or the Moon, which sends rocks flying. Sometimes the rocks fly fast enough to escape the planet/moon's gravity and enter solar orbit. This is much more likely to occur on the moon and Mars than it is for Earth, because they have much lower escape velocities.-[[User talk:gadfium|gadfium]] 09:16, 26 June 2006 (UTC)
What causes the discharge tubes to have their brightest spots at different positions? [[User:Nucleus hydro elemon|Nucleus hydro elemon]] ([[User talk:Nucleus hydro elemon|talk]]) 13:12, 31 December 2024 (UTC)
::Thanks a lot! I'd had a look on the [[meteorites]] page, but not the one you pointed too! Thanks. --[[User:Silex|Silex]] 11:08, 26 June 2006 (UTC)
: See also the pictures at [[Gas-filled tube #Gases in use]]. --[[User:CiaPan|CiaPan]] ([[User talk:CiaPan|talk]]) 13:26, 31 December 2024 (UTC)
== Fire ==
= January 1 =
How hot is fire? What temperature is a flame?
== Two unit questions ==
Please provide answers in degrees, celsius, where possible. :) Thanks.
*That would depend on the situation. A flame's temperature is determined by the fuel that's being burnt, the surrounding temperature (is there any cooling?) and the amount of oxygen present. For example, you can't burn ice with a regular flame match or gas flame, but on [[Braniac]] they use an explosive that's so hot, it can make ice explode. - [[User:MacGyverMagic|Mgm]]|[[User talk:MacGyverMagic|<sup>(talk)</sup>]] 10:54, 26 June 2006 (UTC)
*See [[Fire#Typical temperatures of fires and flames]]. [[User:Conscious|Conscious]] 11:57, 26 June 2006 (UTC)
#Is there any metric unit whose ratio is not power of 10, and is divisible by 3? Is there any common use for things like "{{frac|2|3}} km", "{{frac|5|12}} kg", "{{frac|3|1|6}} m"?
== Fermi's Hypothesis ==
#Is a one-tenth of nautical mile (185.2 m) used in English-speaking countries? Is there a name for it?
--[[User:40bus|40bus]] ([[User talk:40bus|talk]]) 10:41, 1 January 2025 (UTC)
:1 not that I know of (engineer who has worked with SI for 50 years)
I read the hypothesis and people's views to it. I'd like to raise a point and ask some questions:
:2 not that I know of (yacht's navigator for many years on and off)
:[[User:Greglocock|Greglocock]] ([[User talk:Greglocock|talk]]) 11:35, 1 January 2025 (UTC)
::In Finland, ''kaapelinmitta'' is 185.2 m. Is there an English equivalent? --[[User:40bus|40bus]] ([[User talk:40bus|talk]]) 18:11, 1 January 2025 (UTC)
:::[[Cable length]]. --[[User:Wrongfilter|Wrongfilter]] ([[User talk:Wrongfilter|talk]]) 18:26, 1 January 2025 (UTC)
::::Good article. I was wrong [[User:Greglocock|Greglocock]] ([[User talk:Greglocock|talk]]) 22:26, 1 January 2025 (UTC)
1. What happens if aliens don't think like us? Or they don't see things as we do? What if they do not have the concept of communication, nor do they see the universe like we do? Always remember - everything we perceive to dictated by our senses.
:::The answer can be found by looking up ''[[wikt:kaapelinmitta|kaapelinmitta]]'' on Wiktionary. --[[User talk:Lambiam#top|Lambiam]] 00:14, 2 January 2025 (UTC)
== What is more physiological (for a right-hander) left-hand drive or right-hand drive? ==
2. If aliens do use radio communication technologies, what is the effective range of it?
Has anyone determined whether it is better for a right-hander to have the left hand on the steering wheel and the right hand on the gear shift stick, or the other way round? Are there other tests of whether left-hand drive or right-hand drive is physiologically better (for a right-hander at least)? [[Special:Contributions/178.51.7.23|178.51.7.23]] ([[User talk:178.51.7.23|talk]]) 12:03, 1 January 2025 (UTC)
3. What is the definition of an intelligent lifeform? Surely it can't be something based on us humans, can it?
:<small>Supplementary question: I've only driven right-hand-drive vehicles (being in the UK) where the light stalk is on the left of the steering column and the wiper & washer controls are (usually) on the right. On a l-h-drive vehicle, is this usually the same, or reversed? {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.6.84.253|94.6.84.253]] ([[User talk:94.6.84.253|talk]]) 12:12, 2 January 2025 (UTC)</small>
:This is more a discussion topic than a question. However, as far as point 1 goes, SETI researchers make the working assumption that they exist in the same universe as we do and are subject to the same physical laws. Furthermore, it seems a fair assumption that an intelligent species, by definition, would have some ability to communicate, even if their communication methods between each other are different to our own. They may well also see the universe differently, but the electromagnetic spectrum is the same for them as it is for us, and radio (and visible light) are two parts of the spectrum which are relatively well-suited for interstellar communication.
::<small>Modern cars are designed for mass production in RH- and LH-drive versions with a minimum difference of parts. Steering columns with attached controls are therefore unchanged between versions. [[User:Philvoids|Philvoids]] ([[User talk:Philvoids|talk]]) 12:29, 2 January 2025 (UTC)
:::In the UK nowadays, are cars still mostly manual transmission, or has automatic become the norm? ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 12:38, 2 January 2025 (UTC)
::::In the UK, sales of new automatics have just recently overtaken manuals - so probably still more manuals than automatics on the road. [[User:Catslash|catslash]] ([[User talk:Catslash|talk]]) 14:37, 2 January 2025 (UTC)</small>
:::::<small>This may be tied to the rise of EVs, since they have automatic transmissions by default. {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.6.84.253|94.6.84.253]] ([[User talk:94.6.84.253|talk]]) 05:29, 3 January 2025 (UTC)</small>
:::In Australia, we drive on the left, and the indicator and wiper stalks are the opposite way to the UK. Having moved back from the UK after 30 years, it took me a while to stop indicating with wipers. [[User:TrogWoolley|TrogWoolley]] ([[User talk:TrogWoolley|talk]]) 05:08, 3 January 2025 (UTC)
::::This depends more on where the car came from I think. For European or American cars it tends to be in the UK direction. For Asian cars or I guess those odd Australian made cars which are out there, it tends to be in the other. See e.g. [//www.reddit.com/r/cars/comments/7kmxpu/people_with_right_hand_drive_cars_what_side_is/]. The UK being a bigger market I think most manufacturers have come to follow the new UK norm for cars they intend to sell there [//www.honestjohn.co.uk/forum/post/index.htm?t=44927] [//www.reddit.com/r/BYD/comments/1b93pwc/uk_byd_seal_now_has_indicators_on_left_side/] [//www.reddit.com/r/drivingUK/comments/1hh96lg/indicators_on_the_right/] [//www.ozbargain.com.au/node/379783] although I suspect to some extent it's still true in the sense that I think most Asian car brands, at least assemble their cars in the EU or maybe the UK if they're destined for the UK (made a lot of sense pre-Brexit) [//www.smmt.co.uk/2017/10/japan-uk-auto-trade-strong-ever-third-british-car-buyers-choose-japanese-brands/]. It sounds like the new UK norm is fairly recent perhaps arising in the 1980s-1990s after European manufacturers stopped bothering changing that part of the production for the reasons mentioned by Philvoids. As mentioned in one of the Reddit threads, the UK direction does make it difficult to adjust indicators while changing gear which seems a disadvantage which is fairly ironic considering the the UK has much more of a preference for manuals than many other RHD places with the other direction. [[User:Nil Einne|Nil Einne]] ([[User talk:Nil Einne|talk]]) 04:31, 6 January 2025 (UTC)
:::::<small><p>For further clarity, AFAICT, LHD vehicles generally have their indicators on the left and wipers on the right. As mentioned, assuming the gear stick is in the middle which AFAIK it is for most cars by now, this seems the better positioning especially on manual cars since you're much more likely to want to need to indicate while changing gear than you are going to want to adjust your wipers even in the rainy UK. The UK being LHT/RHD especially with their own manufactured cars tended to have the indicators on the right and wipers on the left in the more distant past so again the positions that made most sense. </p><p>While I don't have a source for this going by the history and comments, it sounds to me like what happened is European manufacturers who were primarily making LHD vehicles, with the UK and Ireland their main RHD markets but still small compared to the LHD market stopped bothering changing positions for RHD vehicles as a cost saving measure. So they began to put wipers on the right and indicators on the left even in their RHD vehicles no matter the disadvantage. I'm not so sure what the American manufacturers did or when and likewise the British but I think they were a fairly small part of the market by then and potentially even for them LHD was still a big part of their target market. </p><p>Meanwhile Asian manufacturers however still put their indicators on the right and wipers on the left in RHD vehicles, noting that Japan itself is LHT/RHD. I suspect Japanese manufacturers suspected, correctly, that it well worth the cost of making something else once they began to enter the LHD markets like the US, to help gain acceptance. And so they put the indicators on the left and wipers on the right for LHD vehicles even if they did the opposite in their own home market and continued forever more. Noting that the predominance of RHT/LHD means even for Japanese manufacturers it's generally likely to be their main target by now anyway. </p><p>Later I assume South Korea manufacturers and even later Chinese felt it worth any added cost to increase acceptance of their vehicles in LHT/RHD markets in Asia and Australia+NZ competing against Japanese vehicles which were like this. And this has largely continued even if it means they need to make two different versions of the steering column or whatever. It sounds like the European and American brands didn't bother but they were primarily luxury vehicles in such markets so it didn't matter so much. </p><p>This lead to an interesting case for the UK. For the Asian manufacturer, probably many of them were still making stuff which would allow them to keep putting the indicators on the right and wipers on the left for RHD vehicles as they were doing for other RHD markets mostly Asian. And even if they were assembling them in the EU, I suspect the added cost of needing to ship and keep the different components etc and any difference it made to the assembly line wasn't a big deal. </p><p>So some of did what they were doing for the Asian markets for vehicles destined for UK. If they weren't assembling in the EU, it made even more sense since this was likely what their existing RHD assembly line was doing. But overtime the UK basically adopted the opposite direction as the norm no matter the disadvantages to the extent consumers and vehicle enthusiast magazines etc were complaining about the "wrong" positions. So even Asian manufacturers ended up changing to the opposite for vehicles destined to the UK to keep them happy. So the arguably better position was abandoned even in cases where it wasn't much of a cost saving measure or might have been even adding costs. </p><p>[[User:Nil Einne|Nil Einne]] ([[User talk:Nil Einne|talk]]) 05:43, 6 January 2025 (UTC)</p></small>
::I've driven different (automatic) left-hand-drive vehicles with the light stalk on each side, but left side has been more common. Perhaps because the right hand is more likely to be busy with the gear shift? (Even in the US, where automatic has been heavily dominant since before I learned to drive.) -- [[User:Avocado|Avocado]] ([[User talk:Avocado|talk]]) 17:32, 2 January 2025 (UTC)
:It's better for a right-hander to have both hands on the steering wheel regardless of where the gear lever is. See [https://www.gov.uk/guidance/the-highway-code/using-the-road-159-to-203 Rule 160]. I suspect the same goes for a left-hander. [[User:Bazza_7|Bazza <span style="color:grey">7</span>]] ([[User_talk:Bazza_7|talk]]) 14:39, 2 January 2025 (UTC)
::I suppose that the question is whether right-handers have an easier time operating the gear stick when changing gears in manual-transmission cars designed for left-hand traffic, with the steering wheel on the right (like in the UK) or right-hand traffic, with the steering wheel on the left (like in most of continental Europe). Obviously, drivers will use their hand at the side where the gear stick is, so if it is in the middle and the driver, behind the wheel, sits in the right front seat, they'll use their left hand, regardless of their handedness. But this may be more awkward for a rightie. Or not.
::--[[User talk:Lambiam#top|Lambiam]] 16:30, 2 January 2025 (UTC)
:::In my personal experience (more than 10 years driving on each side of the road, in all four combinations of car handedness and road handedness) the question which hand to use for shifting gears is fairly insignificant. Switching from one type of car to the other is a bit awkward though. —[[User:Kusma|Kusma]] ([[User talk:Kusma|talk]]) 18:33, 2 January 2025 (UTC)
::::My first car, a [[Rootes Arrow|Hillman Minx]], had the gearstick on the left and the handbreak on the right, which was a bit of a juggle in traffic. [[User:Alansplodge|Alansplodge]] ([[User talk:Alansplodge|talk]]) 19:13, 3 January 2025 (UTC)
== Distinguishing a picture of a sunset from the picture of a sunrise? ==
:As far as the "range" of radio communication, that depends on the power of the signal and the sensitivity of the receiver. With current technology and a reasonably modest investment in antennas, it's possible to have point-to-point communications [http://www.setileague.org/articles/oseti.htm across the galaxy]. A working assumption of SETI is that technological civilizations with interstellar communications capabilities are likely to be more advanced than us, seeing we have had such capabilities for only a few decades.
Is there a way (if you don't know which way is west and which way is east in a particular location) to distinguish a picture of a sunset from the picture of a sunrise? [[Special:Contributions/178.51.7.23|178.51.7.23]] ([[User talk:178.51.7.23|talk]]) 12:08, 1 January 2025 (UTC)
:As to what an "intelligent" lifeform is, we don't have a good definition of what "intelligence" in the context of humans and computers is. I suspect the answer might be "we'll know it when we see it". --[[User:Robert Merkel|Robert Merkel]] 12:06, 26 June 2006 (UTC)
:Generally, no, but there are a few tricks that sometimes work. In dry sunny weather, there's more dust in the air at sunset (due to thermals) than at sunrise, making the sky around the sun redder at sunset. But in moist weather, mist has the same effect at sunrise. If the picture is good enough to see [[sunspots]], comparing the distribution of sunspots to the known distribution of that day (this is routinely monitored) tells you where the North Pole of the sun is. At sunset, the North Pole points somewhat to the right; at sunrise, to the left. If you see any [[cumulus]] or [[cumulonimbus]] clouds in the picture, it was a sunset, as such clouds form during the day and disappear around sunset, but absence of such clouds doesn't mean the picture was taken at sunrise. A very large cumulonimbus may survive the night. [[Cirrus aviaticus]] clouds are often very large, expanding into [[cirrostratus]], in the evening, but are much smaller at dawn as there's more air traffic during the day than at night, making the upper troposphere more moist towards the end of the day. Cirrostratus also contributes to red sunsets and (to lesser extend, as there's only natural cirrostratus) red sunrises. [[Dew]], [[rime ice|rime]], flowers and flocks of birds may also give an indication. And of course human activity: the beach is busier at sunset than at sunrise. [[User:PiusImpavidus|PiusImpavidus]] ([[User talk:PiusImpavidus|talk]]) 13:41, 1 January 2025 (UTC)
:If an alien intelligence has a completely different means of communication, then SETI is wasting its time. I believe the SETI people have considered that risk, and decided to take the chance. [[User:Peter Grey|Peter Grey]] 15:23, 26 June 2006 (UTC)
::Supposing the photograph has high enough resolution to show [[Sunspot]]s it can be helpful to know that the pattern of spots at sunrise is reversed left-right at sunset. [[User:Philvoids|Philvoids]] ([[User talk:Philvoids|talk]]) 13:21, 3 January 2025 (UTC)
:::At the equinox, the disk of the Sun with its pattern of sunspots appears to rotate clockwise from sunrise to sunset by 180 degrees minus twice your latitude (taking north positive). At my place, that's 75 degrees. Other times of the year it's less; at the start and end of polar day and polar night, there's no rotation. Sunset and sunrise merge then.
:::And I forgot to mention: cirrostratus clouds will turn red just after sunset or just before sunrise. At the exact moment of sunrise or sunset, they appear pretty white. [[User:PiusImpavidus|PiusImpavidus]] ([[User talk:PiusImpavidus|talk]]) 17:06, 3 January 2025 (UTC)
::::I differ: the same rotation is involved everywhere on Earth. If you stand on tiptoe at a N. or S. pole to take a picture of the Sun it is you who must pirouette 15 degrees per hour to keep facing the Sun. The Earth rotates you at this rate at all non-polar locations. If you stand within the arctic or antarctic circles, for parts of the year the 24-hour night or 24-hour daylight seem to prevent photographs of sunrise or sunset. However the terms "sunrise" and "sunset" can then be interpreted as times that are related to particular timezones which are generally assigned by longitude. In photographing the 24-hour Sun the equatorial rise and set times for your own longitude are significant elevation maxima worth mentioning even though the minimum elevation remains above the horizon. I maintain that the sunspot pattern observed from any location on Earth rotates 360 degrees per 24 hours and that "night", the darkness from sunset to sunrise, is when the Earth's bulk interrupts one's view of the rotation but not the rotation itself which is continuous.
:::::Taking the Earth as reference frame, the Sun rotates around the Earth's spin axis. The observer rotates around his own vertical axis. The better both axes are aligned, the smaller the wobble of the Sun. In the northern hemisphere, it rotates clockwise from about 6 till 18 by 180 degrees minus twice your latitude and counterclockwise at night, in the southern hemisphere it's the opposite. Try a planetarium program if you want to see it. [[Stellarium (software)|Stellarium]] shows some sunspots, does things right and is free and open source. [[User:PiusImpavidus|PiusImpavidus]] ([[User talk:PiusImpavidus|talk]]) 10:27, 5 January 2025 (UTC)
:::::[[File:axial_tilt_vs_tropical_and_polar_circles.svg|thumb|center|420px|Relationship between Earth's axial tilt (ε) to the tropical and polar circles]]We deprecate the obselete [[Geocentric model]] and suggest Wikipedia references that are free and just one click away (no extra planetarium software needed). The axes of rotation of the Sun and Earth have never in millions of years aligned: the [[Ecliptic]] is the orbital plane of Earth around the Sun and Earth currently has an [[Axial tilt]] of about 23.44° without "wobbling" enough from this to concern us here. [[User:Philvoids|Philvoids]] ([[User talk:Philvoids|talk]]) 14:56, 5 January 2025 (UTC)
::::::This isn't my field but sunspots aside, if you know the location and date, I assume the appearance of other astronomical objects like the moon or rarely another star probably Venus, in the photograph should be enough to work out if it's a sunset or sunrise. That said, to some extent by taking into account other details gathered from elsewhere's I wonder if we're going beyond the question. I mean even if you don't personally know which is east or west at the time, if you can see other stuff and you know the location or the stuff you can see is distinctive enough it can be worked out, you can also work out if it's sunset or sunrise just by working out if it's east or west that way. [[User:Nil Einne|Nil Einne]] ([[User talk:Nil Einne|talk]]) 03:54, 6 January 2025 (UTC)
:::::In my experience (Southern England) they tend to be pinker at dawn and oranger(!) at dusk. {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.6.84.253|94.6.84.253]] ([[User talk:94.6.84.253|talk]]) 03:23, 4 January 2025 (UTC)
::::::Pink clouds must result from blending of reddish clouds with the blue sky behind. There's actually more air between the observer and the clouds than behind the clouds, but for that nearby air the sun is below the horizon. [[User:PiusImpavidus|PiusImpavidus]] ([[User talk:PiusImpavidus|talk]]) 10:27, 5 January 2025 (UTC)
::::The questioner asks for interpretation of a single picture. It is beside the point that more would be revealed by a picture sequence such as of changing cloud colours. [[User:Philvoids|Philvoids]] ([[User talk:Philvoids|talk]]) 12:41, 4 January 2025 (UTC)
:Recalling Leonard Maltin's comment about the ''Green Berets'' movie, which was filmed in the American state of Georgia: "Don't miss the closing scene, where the sun sets in the east!" ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 22:37, 5 January 2025 (UTC)
::Which you can only tell if you know which way is east in the image. Maltin, or his writer, appears to have assumed that Vietnam has a seacoast only on the east, which is wrong. --[[Special:Contributions/142.112.149.206|142.112.149.206]] ([[User talk:142.112.149.206|talk]]) 03:46, 6 January 2025 (UTC)
:::Georgia has only an eastern seacoast. ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 10:31, 6 January 2025 (UTC)
::::<small>[[Georgia (country)|Black seas matter!]] [[User:Philvoids|Philvoids]] ([[User talk:Philvoids|talk]]) 14:18, 6 January 2025 (UTC)</small>
::::So what. Bugs? The claim is about the setting, not the filming location. --[[Special:Contributions/142.112.149.206|142.112.149.206]] ([[User talk:142.112.149.206|talk]]) 07:30, 7 January 2025 (UTC)
:::::But as it was filmed in (The US State of) Georgia, it must actually show a sunrise, regardless of what the story line says – how do you know that wasn't what Maltin actually meant? {The poster formerly known as 87.81.230.195} [[Special:Contributions/94.6.84.253|94.6.84.253]] ([[User talk:94.6.84.253|talk]]) 10:35, 7 January 2025 (UTC)
::::::I assume (not having seen the film) that, <u>in the story line</u> of ''[[The Green Berets (film)|The Green Berets]]'' , the closing scene takes place in the late afternoon, which means it shows a sunset. The plot section of our article on the film places the closing scene at or near [[Da Nang]], which is on the east coast of Vietnam. This means that Maltin did not make an unwarranted assumption; he was just seeking an excuse to bash the film. --[[User talk:Lambiam#top|Lambiam]] 13:55, 7 January 2025 (UTC)
= January 6 =
==How the hell!?==
== Does the energy belonging to an electromagnetic field, also belong (or is considered to belong) to the space carrying that field? ==
[[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 18:41, 6 January 2025 (UTC)
:I cant get it to show the video. how do you see it? [[User:Philc_0780|<font color="Green">Philc</font>]] <sub>[[User talk:Philc_0780|T]]</sub><sup>[[User:Philc 0780/Esperanza|E]]</sup><sub>[[Special:contributions/Philc_0780|C]]</sub><sup>[[User:Philc_0780/Improve me|I]]</sup> 13:47, 26 June 2006 (UTC)
::It works fine for me clicking on the link beneath the video frame. It appears to show a magician in a park getting two people to pull on a third person, who's lying down. The person then splits apart, and her torso chases after people. Quite scary, and the snopes article claims there is no digital trickery. Personally, I'mn not sure if I'd want the trick explained. [[User:199|199]] [[User talk:199|<small>(talk)</small>]] 14:27, 26 June 2006 (UTC)
::It can also be seeen [http://youtube.com/watch?v=r0BukAy_dko here]. [[User:199|199]] [[User talk:199|<small>(talk)</small>]] 14:34, 26 June 2006 (UTC)
Reading the explanation, and just looking at the still, you can see certain geometrical oddities. Since this trick has been regularly done from the beginning of time, it is obvious that mrrpfl gaaggg (help I'm being attacked by rabbits coming out of hats!) --[[User:Zeizmic|Zeizmic]] 15:04, 26 June 2006 (UTC)
:It would be unusual to express the situation in such terms. Since the notion of energy "belonging to" some entity is not itself a physical concept – any practical approach to energy bookkeeping that satisfies the law of conservation of energy will do – this cannot be said to be wrong. It is, however, (IMO) not helpful. Does an apple belong to the space it occupies? Or does that space belong to the apple? --[[User talk:Lambiam#top|Lambiam]] 23:37, 6 January 2025 (UTC)
== Tired eyes ==
::First, I let you replace the notion of energy "belonging to" some entity, by the notion of energy "attributed to" some entity, or by the notion of energy "carried by" some entity, and the like. In other words, I'm only asking about the abstract relation (no matter what words we use to express it), between the energy and the ''space'' carrying the electromagnetic field, rather than about the specific term "belong to".
::Second, I'm only asking about ''what the common usage is'', rather than about whether such a usage is wrong or helpful.
::The question is actually as follows: Since it's ''accepted'' to attribute energy to an electromagnetic field, is it also ''accepted'' to attribute energy to the ''space'' carrying that field?
::So, is your first sentence a negative answer, also to my question when put in the clearer way I've just put it? [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 03:28, 7 January 2025 (UTC)
:::The answer remains the same. It would be a highly unusual use of language to "attribute" electromagnetic energy to a volume of space, in quite the same way as it would be strange to "attribute" the mass of an apple to the space the apple occupies. But as long as an author can define what they mean by this (and that meaning is consistent with the laws of physics), it is not wrong. --[[User talk:Lambiam#top|Lambiam]] 13:21, 7 January 2025 (UTC)
::::An electromagnetic field that we may [[Wave–particle duality|(even tenuously)]] conceive to have the form of a massless photon has, like the aforementioned apple (a biological mass) its own unique history, that being a finite path in [[Spacetime]]. I reject apparent effort to give spacetime any kind of identity capable of owning, or even anticipating owning or remembering having owned anything at all. Concepts of owning[[Ownership|<sup>1</sup>]][[Ownership (psychology)|<sup>2</sup>]], attributing[[Attribution (psychology)|<sup>3</sup>]] or whatever synonymous wordplay one chooses all assume identification that can never be attached to the spacial <i>location</i> of an em field. The energy of the photon is fully accounted for, usually as heat at its destination, when it is absorbed and no lasting trace remains anywhere. I am less patient than Lambian in my reaction to this OP who under guise of interest in surveying "what is commonly accepted" returns in pursuit of debate by patronisingly "allowing" us to reword his question in abstract "words that don't matter" to make it purportedly clearer and worth responders' time. [[User:Philvoids|Philvoids]] ([[User talk:Philvoids|talk]]) 14:55, 7 January 2025 (UTC)
::::Thank you Lambiam for your full answer. I always appreciate your replies, as well as your assuming good faith, always. [[User:HOTmag|HOTmag]] ([[User talk:HOTmag|talk]]) 15:08, 7 January 2025 (UTC)
= January 7 =
Why do my eyes feel so heavy and ache so much when I haven't slept enough the night before? What could help ease the achyness? Thanks, [[User:199|199]] [[User talk:199|<small>(talk)</small>]] 14:21, 26 June 2006 (UTC)
:Read the [[sleep]] article while lying in bed. --[[User:Zeizmic|Zeizmic]] 15:06, 26 June 2006 (UTC)
::Wait, was that chiding me for not having read the article, or a suggestion for my second question? The article doesn't seem to have anything in it that answers why eyes feel sore when we are tired, and I didn't suggest I'm an insomniac, so I'm confused as to the point of that answer. [[User:199|199]] [[User talk:199|<small>(talk)</small>]] 15:30, 26 June 2006 (UTC)
The heaviness and aching you feel in your eyes is pobably due to a few things. First, the muscles around your eyes are not particularly strong, and they tire easily; thus as your body begins, at the end of the day, to tire, the weak eye muscles feel the most tired. The achyness is probably a byproduct of that exhaustion, but may also be due to dryness. People tend to blink less at night, and this can lead to dry eyes. You may find relief through rehydration (you can probably figure out how to do that yourself, I don't want to give medical advise over the internet), and a cold compress (they sell gel masks you can put in the refrigerator for just this). As always, if you think that you suffer from these things more than other people, or if you find that your symptoms get worse, call your doctor.[[User:Tuckerekcut|Tuckerekcut]] 16:11, 26 June 2006 (UTC)
:Thanks Tuckerekcut, for that explanation! Why are our eyes dryer at night? Aren't our eyelids closed, and aren't our eye's moving due to REM sleep? I don't know how I'd manage blinking while I'm asleep... Anyway, that's for those leads. [[User:199|199]] [[User talk:199|<small>(talk)</small>]] 16:26, 26 June 2006 (UTC)
Latest revision as of 15:08, 7 January 2025
Welcome to the science section of the Wikipedia reference desk.
The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.
I would say not necessarily a Japanese beetle, but almost certainly one of the other Scarab beetles, though with 35,000 species that doesn't help a lot. Looking at the infobox illustration in that article, 16. & 17., "Anisoplia segetum" looks very similar, but evidently we either don't have an article or (if our Anisoplia article is a complete list) it's been renamed. {The poster formerly known as 87.81.230.195} 94.1.223.204 (talk) 14:18, 24 December 2024 (UTC)[reply]
Yes, it's not the Japanese beetle for this beetle appears to lack its white-dotted fringe although its condition is deteriorated. Its shape is also more or less more slender; and not as round. Modocc (talk) 15:02, 24 December 2024 (UTC)[reply]
Important note: particle physicists today generally only ever use "mass" to mean "invariant mass" and never anything else: [1]. Like the term says, invariant mass is well, invariant, it never changes ever, no matter what "external forces" may or may not be involved. Being proper particle-icans and following the standard practice in the field, then, the three neutrino masses are constant values. ..."Wait, three?" Yeah sure, turns out neutrinos come in three "flavors" but each flavor is a mixture of the three possible mass "states". As mentioned, due to Quantum Weirdness we aren't able to get these different states "alone by themselves" to measure each by itself, so we only know the differences of the squares of the masses. Yeah welcome to quantum mechanics.
The equation uses invariant mass m0 which is constant if E and p are constant. The traveling neutrino has a varying mass mixture of different flavors with different masses. If a mixture of different masses changes, you would expect the resulting mass to change with it. But somehow this does not happen as the neutrino mass mixture changes. These mixture changes cannot be any changes. The changes must be such that the resulting mass of the traveling neutrino remains constant. My question is whether this is described somewhere. Hevesli (talk) 11:16, 26 December 2024 (UTC)[reply]
I freely confess I'm uncertain exactly what's being "asked for" or "gotten at" here. Have you looked at the neutrino oscillation article? From it: That is, the three neutrino states that interact with the charged leptons in weak interactions are each a different superposition of the three (propagating) neutrino states of definite mass. Neutrinos are emitted and absorbed in weak processes in flavor eigenstates[a] but travel as mass eigenstates.[18]
What is it that we're "doing" with the energy–momentum relation here? For the neutrino, we don't have a single value of "mass" to plug in for , because we can't "see" the individual mass eigenstates, only some linear combination of them. What you want for describing neutrino interactions is quantum field theory, which is special relativity + QM. (Remember, relativity is a "classical" theory, which presumes everything always has single well-defined values of everything. Which isn't true in quantum-world.) --Slowking Man (talk) 18:41, 26 December 2024 (UTC)[reply]
Not all potential evolutions of a linear combination of unequal values produce constant results. Constancy can only be guaranteed by a constraint on the evolutions. Does the fact that this constraint is satisfied in the case of neutrino oscillation follow from the mathematical formulation of the Standard Model, or does this formulation allow evolutions of the mass mixture for which the combination is not constant? If the unequal values are unknown, I have no idea of how such a constraint might be formulated. I think the OP is asking whether this constraint is described somewhere. --Lambiam00:51, 27 December 2024 (UTC)[reply]
I wanted to try it just today, but I had to exchange the under-desk elliptical trainer I got for Christmas for a different model with more inclined treadles because with the one I got, my knees would hit the desk at the top of every cycle. Anyway, I was hoping someone else tried it first (preferably as part of a formal scientific study) so I would know if I could control whether I got a runner's high from exercise or not? 2601:646:8082:BA0:9052:E6AF:23C7:7CAF (talk) 03:09, 28 December 2024 (UTC)[reply]
Also, sorry for adding to my own question, but here's a related one: is it known whether the length of a person's dopamine receptor D4 (which is inversely correlated with its sensitivity) influences whether said person gets a runner's high from exercise (and especially from low-intensity exercise)? 2601:646:8082:BA0:9052:E6AF:23C7:7CAF (talk) 03:14, 28 December 2024 (UTC)[reply]
What is the difference between an auxotroph and a fastidious organism? It seems to me the second one would have more requirements than the first one, but the limit between the two definitions is rather unclear to me.
Symbiosis aside, it would seem that most auxotrophs would be fastidious organisms, but there could be many more fastidious organisms that aren't auxotrophs. Auxotrophs specifically can't produce organic compounds on their own. There are a LOT of organisms that rely on the availability of non-organic nutrients, such as specific elements/minerals. For instance, vertebrates require access to calcium. Calcium is an element; our inability to produce it does not make us auxotrophs.
But perhaps symbiosis would allow an organism to be an auxotroph without being a fastidious organism? For instance, mammals tend to have bacteria in our guts that can digest nutrients that our bodies can't on their own. Perhaps some of those bacteria also assemble certain nutrients that our bodies can't? -- Avocado (talk) 14:27, 28 December 2024 (UTC)[reply]
I saw an ad promoting a device which presumable splits water into
hydrogen and oxygen and infuses water with extra hydrogen, to
a claimed surplus of perhaps 5 ppm, which doesn’t seem like much. I found a review article which looked at several dozen related studies that found benefits:https://pmc.ncbi.nlm.nih.gov/articles/PMC10816294/ .
I’ve noticed that carbon dioxide or chlorine (chloramine?) dissolved in water work their way out pretty easily, so I wonder if dissolved hydrogen could similarly exit hydrogen enriched water and be burped or farted out, rather than entering the blood stream and having health benefits. is it more than the latest snake oil? Edison (talk) 23:01, 28 December 2024 (UTC)[reply]
It's conceivable it might take out the chloramine, I guess. I don't think there's very much of it, but it tastes awful, which is why I add a tiny bit of vitamin C when I drink tap water. It seems to take very little. Of course it's hard to tell whether it's just being masked by the taste of the vitamin C. --Trovatore (talk) 02:12, 29 December 2024 (UTC)[reply]
I don't know if it is rubbish or not but a quick look on the web indicates to me it is notable enough for Wikipedia. I didn't see anything indicating it definitely did anything useful so such an article should definitely have caveats. I haven't seen any expression of a potential worry either so it isn't like we'd be saying bleach is a good medicine for covid. NadVolum (talk) 23:07, 1 January 2025 (UTC)[reply]
In a harmonic oscillator, reaching the highest point involves - both a minimal kinetic energy - along with a maximal potential energy, whereas reaching the lowest point involves - both a maximal kinetic energy - along with a minimal potential energy. Thus the mechanical energy becomes the sum of kinetic energy + potential energy, and is a conserved quantity.
So I wonder if it's reasonable to define also "potential velocity" vs. "kinetic velocity", and claim that in a harmonic oscillator, reaching the highest point involves - both a minimal "kinetic velocity" (i.e. involves what we usually call a rest) - along with a maximal "potential velocity", whereas reaching the lowest point involves - both a maximal "kinetic velocity" (i.e. involves what we usually call the actual velocity) - along with a minimal "potential velocity". Thus we can also define "mechanical velocity" as the sum of "kinetic velocity" + "potential velocity", and claim that the mechanical velocity is a conserved quantity - at least as far as a harmonic oscillator is concerned.
Reasonable?
Note that I could also ask an analogous question - as to the concept of "potential momentum", but this term is already used in the theory of hidden momentum for another meaning, so for the time being I'm focusing on velocity.
Per my suggestion, the ratio between distance and time is not called "velocity" but rather "kinetic velocity".
Further, per my suggestion, if you don't indicate whether the "velocity" you're talking about is a "kinetic velocity" or a "potential velocity" or a "mechanical velocity", the very concept of "velocity" alone has no meaning!
On the other hand, "potential velocity" is defined as the difference between the "mechanical velocity" and the "kinetic velocity"! Just as, this is the case if we replace "velocity" by "energy". For more details, see the example above, about the harmonic oscillator. HOTmag (talk) 15:14, 29 December 2024 (UTC)[reply]
You could define the potential velocity of a body at a particular height as the velocity it would hit the ground at if dropped from that height. But the sum of the potential and kinetic velocities would not be conserved; rather would be constant. catslash (talk) 18:54, 29 December 2024 (UTC)[reply]
'Potential velocity' has no meaning. You seem to be arguing that in a system where energy is conserved, but is transforming between kinetic and potential energy, (You might also want to compare this to conservation of momentum.) then you can express that instead through a new conservation law based on velocity. But this doesn't work. There's no relation between velocity and potential energy.
In a harmonic oscillator, the potential energy is typically coming from some central restoring force with a relationship to position, nothing at all to do with velocity. Where some axiomatic external rule (such as Hooke's Law applying, because the system is a mass on a spring) happens to relate the position and velocity through a suitable relation, then the system will then (and only then) behave as a harmonic oscillator. But a different system (swap the spring for a dashpot) doesn't have this, thus won't oscillate. Andy Dingley (talk) 00:00, 30 December 2024 (UTC)[reply]
Let me quote a sentence from my original post: Thus we can also...claim that the mechanical velocity is a conserved quantity - at least as far as a harmonic oscillator is concerned.
You have defined some arbitrary values for new 'velocities', where their only definition is that they then demonstrate some new conservation law. Which is really the conservation of energy, but you're refusing to use that term for some reason.
As Catslash pointed out, the conserved quantity here is proportional to the square of velocity, so your conservation equation has to include that. It's simply wrong that any linear function of velocity would be conserved here. Not merely we can't prove that, but we can prove (the sum of the squares diverges from the sum) that it's actually contradicted. For any definition of 'another velocity' which is a linear function of velocity.
It is a law of conservation of sanity. Lacking a definition of potential energy, other than by having been informed that kinetic energy + potential energy is a conserved quantity, there is not much better we can do. --Lambiam11:20, 31 December 2024 (UTC)[reply]
We have a perfectly viable definition of potential energy. For a pendulum it's based on the change in height of the pendulum bob against gravity. For some other oscillators it would involve the work done against a spring. Andy Dingley (talk) 16:33, 31 December 2024 (UTC)[reply]
Oops, I mistyped. I meant to write:
"Lacking a definition of potential velocity, other than by having been informed that kinetic velocity + potential velocity is a conserved quantity, there is not much better we can do."
Put two equally sized drops, one of each liquid, on a warm surface, wait for them to evaporate, and compare how much salt residue each leaves? Not very precise or measurable, but significant differences should be noticeable. {The poster formerly known as 87.81.230.195} 94.1.223.204 (talk) 10:21, 30 December 2024 (UTC)[reply]
The principle is sound, but the residue from one drop won't be measurable using kitchen equipment -- better to put equal amounts of each liquid in two warm pans (use enough liquid to cover the bottom of each pan with a thin layer), wait for them to evaporate and then weigh the residue! Or, if you're not afraid of doing some algebra, you could also try an indirect method -- bring both liquids to a boil, measure the temperature of both, and then use the formula for boiling point elevation to calculate the saltiness of each! 2601:646:8082:BA0:BD1B:60D8:96CA:C5B0 (talk) 18:22, 30 December 2024 (UTC)[reply]
Presumably the liquid preparations are not simple saline solutions, but contain other solutes - or else one could simply use a hydrometer. It is unlikely that Lambian is afraid of doing some algebra. catslash (talk) 18:57, 30 December 2024 (UTC)[reply]
Assuming the liquid preparations are water-based and don't contain alcohols and/or detergents one can measure their rates of dispersion. Simply add a drop of food dye to each liquid and then time how rapidly droplets of each liquid disperse in distilled water. Materials needed: food dye, eye dropper, distilled water, small clear containers and a timer.Modocc (talk) 21:09, 30 December 2024 (UTC)[reply]
The colligative properties of a solution will indicate its molarity, but not identify the solute. Liquid preparations that might be found in a kitchen are likely to contain both salt and sugar. Electrical conductivity is a property that will be greatly affected by the salt but not the sugar (this does not help in distinguishing Na+ from K+ ions though). catslash (talk) 22:23, 30 December 2024 (UTC)[reply]
Quantitative urine test-strips for sodium seem to be available. They're probably covering the concentration range of tens to hundreds millimolar. DMacks (talk) 00:58, 2 January 2025 (UTC)[reply]
Thanks, test strips seem more practical in the kitchen setting than an ohmmeter (why not call it a "mhometer"?), for which I'd need to devise a way (or so I think) to keep the terminals apart at a steady distance. Test strips require a colour comparison, but I expect that a significant difference in salinity will result in a perceptible colour difference when one strip is placed across the other. Only experiment can tell whether this expectation will come true. Salinity is usually measured in g/L; for kitchen preparations a ballpark figure is 1 g/L. If I'm not mistaken this corresponds to (1 g/L) / (58.443 g/mol) ≈0.017 M = 17 mM. I also see offers for salinity test strips, 0–1000 ppm, for "Science Education". --Lambiam11:40, 2 January 2025 (UTC)[reply]
Test strips surely come with a printed color-chart. But if all you are trying to do is determine which is more salty, then that's even easier than quantifying each separately. Caveat for what you might find for sale: some "salinity" tests are based on the chloride not the sodium, so a complex matrix that has components other than NaCl could fool it. DMacks (talk) 18:44, 2 January 2025 (UTC)[reply]
The (uncommon?) terms "relativistic length", and "relativistic time".
1. In Wikipedia, the page relativistic length contraction is automatically redirected to our article length contraction, which actually doesn't mention the term "relativistic length" at all. I wonder if there is an accepted term for the concept of relativistic length.
2. A similar qusestion arises, at to the concept of relativistic time: The page relativistic time dilation, is automatically redirected to our article time dilation, which prefers the abbreviated term "time dilation" (59 times) to the term "relativistic time dilation" (8 times only), and nowhere mentions the term "relativistic time" alone (i.e. without the third word "dilation") - although it does mention the term "proper time" for the shortest time. Further, this article doesn't even mention the term "dilated time" either. It does mention, though, another term: coordinate time, but regardless of time dilation in Special relativity. To sum up, I wonder what's the accepted term used for the dilated time (mainly is Special relativity): Is it "coordinate time"? "Relativistic time"?
Are you reading these things as "contraction of relativistic length" etc.? It is "relativistic contraction of length" and "relativistic dilation of time". --Wrongfilter (talk) 09:37, 30 December 2024 (UTC)[reply]
When I wrote: The page relativistic time dilation is automatically redirected to our article time dilation which...nowhere mentions the term "relativistic time" alone (i.e. without the third word "dilation"), I had already guessed that the term "dilation of relativistic time" (i.e, with the word "dilation" preceding the words "relativistic time") existed nowhere (at least in Wikipedia), and that this redirected page actually meant "relativistic dilation of time". The same is true for the redirected page "relativistic length contraction": I had already gussed it didn't mean "contraction of relativistic length", because (as I had already written): the article length contraction...doesn't mention the term "relativistic length" at all.
Thank you. The middle source uses the term "comparative length", rather than "relative length". I couldn't open the third source. HOTmag (talk) 08:04, 1 January 2025 (UTC)[reply]
The text under the graph labelled Comparative length on page 20 of the middle source reads:
Graph of the relative length of a stationary rod on earth, as observed from the reference frame of a traveling rod of 100cm proper length.
Is there any metric unit whose ratio is not power of 10, and is divisible by 3? Is there any common use for things like "2⁄3 km", "5⁄12 kg", "3+1⁄6 m"?
Is a one-tenth of nautical mile (185.2 m) used in English-speaking countries? Is there a name for it?
Has anyone determined whether it is better for a right-hander to have the left hand on the steering wheel and the right hand on the gear shift stick, or the other way round? Are there other tests of whether left-hand drive or right-hand drive is physiologically better (for a right-hander at least)? 178.51.7.23 (talk) 12:03, 1 January 2025 (UTC)[reply]
Supplementary question: I've only driven right-hand-drive vehicles (being in the UK) where the light stalk is on the left of the steering column and the wiper & washer controls are (usually) on the right. On a l-h-drive vehicle, is this usually the same, or reversed? {The poster formerly known as 87.81.230.195} 94.6.84.253 (talk) 12:12, 2 January 2025 (UTC)[reply]
Modern cars are designed for mass production in RH- and LH-drive versions with a minimum difference of parts. Steering columns with attached controls are therefore unchanged between versions. Philvoids (talk) 12:29, 2 January 2025 (UTC)[reply]
In the UK, sales of new automatics have just recently overtaken manuals - so probably still more manuals than automatics on the road. catslash (talk) 14:37, 2 January 2025 (UTC)[reply]
In Australia, we drive on the left, and the indicator and wiper stalks are the opposite way to the UK. Having moved back from the UK after 30 years, it took me a while to stop indicating with wipers. TrogWoolley (talk) 05:08, 3 January 2025 (UTC)[reply]
This depends more on where the car came from I think. For European or American cars it tends to be in the UK direction. For Asian cars or I guess those odd Australian made cars which are out there, it tends to be in the other. See e.g. [5]. The UK being a bigger market I think most manufacturers have come to follow the new UK norm for cars they intend to sell there [6][7][8][9] although I suspect to some extent it's still true in the sense that I think most Asian car brands, at least assemble their cars in the EU or maybe the UK if they're destined for the UK (made a lot of sense pre-Brexit) [10]. It sounds like the new UK norm is fairly recent perhaps arising in the 1980s-1990s after European manufacturers stopped bothering changing that part of the production for the reasons mentioned by Philvoids. As mentioned in one of the Reddit threads, the UK direction does make it difficult to adjust indicators while changing gear which seems a disadvantage which is fairly ironic considering the the UK has much more of a preference for manuals than many other RHD places with the other direction. Nil Einne (talk) 04:31, 6 January 2025 (UTC)[reply]
For further clarity, AFAICT, LHD vehicles generally have their indicators on the left and wipers on the right. As mentioned, assuming the gear stick is in the middle which AFAIK it is for most cars by now, this seems the better positioning especially on manual cars since you're much more likely to want to need to indicate while changing gear than you are going to want to adjust your wipers even in the rainy UK. The UK being LHT/RHD especially with their own manufactured cars tended to have the indicators on the right and wipers on the left in the more distant past so again the positions that made most sense.
While I don't have a source for this going by the history and comments, it sounds to me like what happened is European manufacturers who were primarily making LHD vehicles, with the UK and Ireland their main RHD markets but still small compared to the LHD market stopped bothering changing positions for RHD vehicles as a cost saving measure. So they began to put wipers on the right and indicators on the left even in their RHD vehicles no matter the disadvantage. I'm not so sure what the American manufacturers did or when and likewise the British but I think they were a fairly small part of the market by then and potentially even for them LHD was still a big part of their target market.
Meanwhile Asian manufacturers however still put their indicators on the right and wipers on the left in RHD vehicles, noting that Japan itself is LHT/RHD. I suspect Japanese manufacturers suspected, correctly, that it well worth the cost of making something else once they began to enter the LHD markets like the US, to help gain acceptance. And so they put the indicators on the left and wipers on the right for LHD vehicles even if they did the opposite in their own home market and continued forever more. Noting that the predominance of RHT/LHD means even for Japanese manufacturers it's generally likely to be their main target by now anyway.
Later I assume South Korea manufacturers and even later Chinese felt it worth any added cost to increase acceptance of their vehicles in LHT/RHD markets in Asia and Australia+NZ competing against Japanese vehicles which were like this. And this has largely continued even if it means they need to make two different versions of the steering column or whatever. It sounds like the European and American brands didn't bother but they were primarily luxury vehicles in such markets so it didn't matter so much.
This lead to an interesting case for the UK. For the Asian manufacturer, probably many of them were still making stuff which would allow them to keep putting the indicators on the right and wipers on the left for RHD vehicles as they were doing for other RHD markets mostly Asian. And even if they were assembling them in the EU, I suspect the added cost of needing to ship and keep the different components etc and any difference it made to the assembly line wasn't a big deal.
So some of did what they were doing for the Asian markets for vehicles destined for UK. If they weren't assembling in the EU, it made even more sense since this was likely what their existing RHD assembly line was doing. But overtime the UK basically adopted the opposite direction as the norm no matter the disadvantages to the extent consumers and vehicle enthusiast magazines etc were complaining about the "wrong" positions. So even Asian manufacturers ended up changing to the opposite for vehicles destined to the UK to keep them happy. So the arguably better position was abandoned even in cases where it wasn't much of a cost saving measure or might have been even adding costs.
I've driven different (automatic) left-hand-drive vehicles with the light stalk on each side, but left side has been more common. Perhaps because the right hand is more likely to be busy with the gear shift? (Even in the US, where automatic has been heavily dominant since before I learned to drive.) -- Avocado (talk) 17:32, 2 January 2025 (UTC)[reply]
It's better for a right-hander to have both hands on the steering wheel regardless of where the gear lever is. See Rule 160. I suspect the same goes for a left-hander. Bazza 7 (talk) 14:39, 2 January 2025 (UTC)[reply]
I suppose that the question is whether right-handers have an easier time operating the gear stick when changing gears in manual-transmission cars designed for left-hand traffic, with the steering wheel on the right (like in the UK) or right-hand traffic, with the steering wheel on the left (like in most of continental Europe). Obviously, drivers will use their hand at the side where the gear stick is, so if it is in the middle and the driver, behind the wheel, sits in the right front seat, they'll use their left hand, regardless of their handedness. But this may be more awkward for a rightie. Or not.
In my personal experience (more than 10 years driving on each side of the road, in all four combinations of car handedness and road handedness) the question which hand to use for shifting gears is fairly insignificant. Switching from one type of car to the other is a bit awkward though. —Kusma (talk) 18:33, 2 January 2025 (UTC)[reply]
Is there a way (if you don't know which way is west and which way is east in a particular location) to distinguish a picture of a sunset from the picture of a sunrise? 178.51.7.23 (talk) 12:08, 1 January 2025 (UTC)[reply]
Generally, no, but there are a few tricks that sometimes work. In dry sunny weather, there's more dust in the air at sunset (due to thermals) than at sunrise, making the sky around the sun redder at sunset. But in moist weather, mist has the same effect at sunrise. If the picture is good enough to see sunspots, comparing the distribution of sunspots to the known distribution of that day (this is routinely monitored) tells you where the North Pole of the sun is. At sunset, the North Pole points somewhat to the right; at sunrise, to the left. If you see any cumulus or cumulonimbus clouds in the picture, it was a sunset, as such clouds form during the day and disappear around sunset, but absence of such clouds doesn't mean the picture was taken at sunrise. A very large cumulonimbus may survive the night. Cirrus aviaticus clouds are often very large, expanding into cirrostratus, in the evening, but are much smaller at dawn as there's more air traffic during the day than at night, making the upper troposphere more moist towards the end of the day. Cirrostratus also contributes to red sunsets and (to lesser extend, as there's only natural cirrostratus) red sunrises. Dew, rime, flowers and flocks of birds may also give an indication. And of course human activity: the beach is busier at sunset than at sunrise. PiusImpavidus (talk) 13:41, 1 January 2025 (UTC)[reply]
Supposing the photograph has high enough resolution to show Sunspots it can be helpful to know that the pattern of spots at sunrise is reversed left-right at sunset. Philvoids (talk) 13:21, 3 January 2025 (UTC)[reply]
At the equinox, the disk of the Sun with its pattern of sunspots appears to rotate clockwise from sunrise to sunset by 180 degrees minus twice your latitude (taking north positive). At my place, that's 75 degrees. Other times of the year it's less; at the start and end of polar day and polar night, there's no rotation. Sunset and sunrise merge then.
And I forgot to mention: cirrostratus clouds will turn red just after sunset or just before sunrise. At the exact moment of sunrise or sunset, they appear pretty white. PiusImpavidus (talk) 17:06, 3 January 2025 (UTC)[reply]
I differ: the same rotation is involved everywhere on Earth. If you stand on tiptoe at a N. or S. pole to take a picture of the Sun it is you who must pirouette 15 degrees per hour to keep facing the Sun. The Earth rotates you at this rate at all non-polar locations. If you stand within the arctic or antarctic circles, for parts of the year the 24-hour night or 24-hour daylight seem to prevent photographs of sunrise or sunset. However the terms "sunrise" and "sunset" can then be interpreted as times that are related to particular timezones which are generally assigned by longitude. In photographing the 24-hour Sun the equatorial rise and set times for your own longitude are significant elevation maxima worth mentioning even though the minimum elevation remains above the horizon. I maintain that the sunspot pattern observed from any location on Earth rotates 360 degrees per 24 hours and that "night", the darkness from sunset to sunrise, is when the Earth's bulk interrupts one's view of the rotation but not the rotation itself which is continuous.
Taking the Earth as reference frame, the Sun rotates around the Earth's spin axis. The observer rotates around his own vertical axis. The better both axes are aligned, the smaller the wobble of the Sun. In the northern hemisphere, it rotates clockwise from about 6 till 18 by 180 degrees minus twice your latitude and counterclockwise at night, in the southern hemisphere it's the opposite. Try a planetarium program if you want to see it. Stellarium shows some sunspots, does things right and is free and open source. PiusImpavidus (talk) 10:27, 5 January 2025 (UTC)[reply]
Relationship between Earth's axial tilt (ε) to the tropical and polar circlesWe deprecate the obselete Geocentric model and suggest Wikipedia references that are free and just one click away (no extra planetarium software needed). The axes of rotation of the Sun and Earth have never in millions of years aligned: the Ecliptic is the orbital plane of Earth around the Sun and Earth currently has an Axial tilt of about 23.44° without "wobbling" enough from this to concern us here. Philvoids (talk) 14:56, 5 January 2025 (UTC)[reply]
This isn't my field but sunspots aside, if you know the location and date, I assume the appearance of other astronomical objects like the moon or rarely another star probably Venus, in the photograph should be enough to work out if it's a sunset or sunrise. That said, to some extent by taking into account other details gathered from elsewhere's I wonder if we're going beyond the question. I mean even if you don't personally know which is east or west at the time, if you can see other stuff and you know the location or the stuff you can see is distinctive enough it can be worked out, you can also work out if it's sunset or sunrise just by working out if it's east or west that way. Nil Einne (talk) 03:54, 6 January 2025 (UTC)[reply]
In my experience (Southern England) they tend to be pinker at dawn and oranger(!) at dusk. {The poster formerly known as 87.81.230.195} 94.6.84.253 (talk) 03:23, 4 January 2025 (UTC)[reply]
Pink clouds must result from blending of reddish clouds with the blue sky behind. There's actually more air between the observer and the clouds than behind the clouds, but for that nearby air the sun is below the horizon. PiusImpavidus (talk) 10:27, 5 January 2025 (UTC)[reply]
The questioner asks for interpretation of a single picture. It is beside the point that more would be revealed by a picture sequence such as of changing cloud colours. Philvoids (talk) 12:41, 4 January 2025 (UTC)[reply]
Which you can only tell if you know which way is east in the image. Maltin, or his writer, appears to have assumed that Vietnam has a seacoast only on the east, which is wrong. --142.112.149.206 (talk) 03:46, 6 January 2025 (UTC)[reply]
But as it was filmed in (The US State of) Georgia, it must actually show a sunrise, regardless of what the story line says – how do you know that wasn't what Maltin actually meant? {The poster formerly known as 87.81.230.195} 94.6.84.253 (talk) 10:35, 7 January 2025 (UTC)[reply]
I assume (not having seen the film) that, in the story line of The Green Berets , the closing scene takes place in the late afternoon, which means it shows a sunset. The plot section of our article on the film places the closing scene at or near Da Nang, which is on the east coast of Vietnam. This means that Maltin did not make an unwarranted assumption; he was just seeking an excuse to bash the film. --Lambiam13:55, 7 January 2025 (UTC)[reply]
It would be unusual to express the situation in such terms. Since the notion of energy "belonging to" some entity is not itself a physical concept – any practical approach to energy bookkeeping that satisfies the law of conservation of energy will do – this cannot be said to be wrong. It is, however, (IMO) not helpful. Does an apple belong to the space it occupies? Or does that space belong to the apple? --Lambiam23:37, 6 January 2025 (UTC)[reply]
First, I let you replace the notion of energy "belonging to" some entity, by the notion of energy "attributed to" some entity, or by the notion of energy "carried by" some entity, and the like. In other words, I'm only asking about the abstract relation (no matter what words we use to express it), between the energy and the space carrying the electromagnetic field, rather than about the specific term "belong to".
Second, I'm only asking about what the common usage is, rather than about whether such a usage is wrong or helpful.
The question is actually as follows: Since it's accepted to attribute energy to an electromagnetic field, is it also accepted to attribute energy to the space carrying that field?
The answer remains the same. It would be a highly unusual use of language to "attribute" electromagnetic energy to a volume of space, in quite the same way as it would be strange to "attribute" the mass of an apple to the space the apple occupies. But as long as an author can define what they mean by this (and that meaning is consistent with the laws of physics), it is not wrong. --Lambiam13:21, 7 January 2025 (UTC)[reply]
An electromagnetic field that we may (even tenuously) conceive to have the form of a massless photon has, like the aforementioned apple (a biological mass) its own unique history, that being a finite path in Spacetime. I reject apparent effort to give spacetime any kind of identity capable of owning, or even anticipating owning or remembering having owned anything at all. Concepts of owning12, attributing3 or whatever synonymous wordplay one chooses all assume identification that can never be attached to the spacial location of an em field. The energy of the photon is fully accounted for, usually as heat at its destination, when it is absorbed and no lasting trace remains anywhere. I am less patient than Lambian in my reaction to this OP who under guise of interest in surveying "what is commonly accepted" returns in pursuit of debate by patronisingly "allowing" us to reword his question in abstract "words that don't matter" to make it purportedly clearer and worth responders' time. Philvoids (talk) 14:55, 7 January 2025 (UTC)[reply]
this guy is an oriental beetle? I was off-put by the green head at first, but the antennae seem to match. JayCubby 03:00, 24 December 2024 (UTC)
