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 mean, a broken bone will hurt, but what if you get a clean straight shot, only perforating the flesh? Could that be the same case like getting a needle stick by an able med professional, without pain? Wikiweek (talk) 00:06, 2 October 2011 (UTC)[reply]
No, because a bullet produces a relatively large permanent cavity and therefore destroys large amounts of tissue, releasing lots of chemicals which stimulate the pain receptors in your arm. A needle is much narrower, produces a much smaller permanent cavity, and produces much lower amounts of chemicals, which translates into much less pain. Also with a needle, much of the small amounts of chemicals that are produced are reabsorbed by non-nervous cells, and never get a chance to stimulate pain receptors. Whoop whoop pull upBitching Betty | Averted crashes00:20, 2 October 2011 (UTC)[reply]
Getting shot is a combination of multiple types of pain. There is the puncture of the skin, which is a sharp pain. If a bone is hit, there is damage not only the bone, but also to the joints around the bone. Then, just to piss you off, there is a sever burning if the bullet remains near the skin. For an anecdote... I've been shot 3 times. All three times, it hurt a hell of a lot. I've had countless shots and donated blood multiple times each year. I don't flinch when a needle is put in my arm. -- kainaw™01:58, 2 October 2011 (UTC)[reply]
You mean, you were shot three times one bullet or at one occasions three bullets? In the former case you seem to have a pretty bad luck (or good luck of being alive, depending on how you see it). Wikiweek (talk) 02:05, 2 October 2011 (UTC)[reply]
I don't think that's correct but correct me if I'm wrong here. My understanding is that the sympathetic nervous system would be activated in response to a stressful event. If that event was something like getting shot, epinephrine and norepinephrine would be released in a sympathetic response while the endocrine system would release endorphins. So while epinephrine would be pumping through you after getting shot, it would actually be the endorphins killing the pain. I can't think of a receptor site for epinephrine to kill pain, though I could maybe think of ways in which it might stimulate certain neuronal activity to ignore pain signals, but that's a bit of a stretch in my understanding. NoformationTalk23:23, 6 October 2011 (UTC)[reply]
Photon-tachyon interactions
A photon travels directly towards a tachyon moving directly towards it (the photon). They collide. Since the tachyon travels faster than the photon and the photon therefore cannot bounce off it and travel forwards away from the tachyon (because the tachyon will be continuously overtaking it), is the photon destroyed, does it pass through the tachyon, or does it swerve to avoid the tachyon? Whoop whoop pull upBitching Betty | Averted crashes00:14, 2 October 2011 (UTC)[reply]
Tachyons are purely theoretical. There is no way of knowing how they would interact with other particles. There is a flaw in your logic though. If tachyons behave anything like any other particle one would assume that if it contacted another particle it would be deflected as well. Thus both particles would end up traveling in different directions, avoiding the problem. --Daniel01:00, 2 October 2011 (UTC)[reply]
Good point... maybe. Tachyons lose energy as they speed up so it might depend on speed of the tachyon. From what I understand by reading the article is that to if one calculates a tachyon interacting with a normal particle you end up with imaginary numbers which have no meaning in our universe. --Daniel01:13, 2 October 2011 (UTC)[reply]
I can't see any particular reason why a tachyon would have more momentum that a photon. It's moving faster, but that's not the same thing. In fact, I'm not sure their momenta are even comparable. In some formulations, a tachyon has imaginary mass. Doesn't that mean it would also have imaginary momentum? It doesn't make sense to ask whether a real number or an imaginary number is larger. Even if you are right and the momentum is greater for the tachyon, that doesn't mean it would "overpower" the photon. Typically, they would both be deflected, just the photon would be deflected more. --Tango (talk) 11:55, 2 October 2011 (UTC)[reply]
But it might well get derailed and go off to the side (if it weren't for the rails, it almost certainly would go off to the side). That's what we mean by "deflect". The collision isn't going to be perfectly head-on, so the particles will each be deflected to opposite sides. If it were a perfect head-on collision, then I think you would just end up with the photon following the tachyon as though the tachyon had gone straight through it. There isn't a problem there before photons don't actually bounce, they are absorbed and then re-emitted. There is nothing to stop the photon being on the other side when it gets re-emitted. (That is all based on some wild guesses about how tachyons behave that come from extrapolating our existing theories to particles that they don't really make sense for, so it should be taken with a very large sack of salt.) --Tango (talk) 17:07, 2 October 2011 (UTC)[reply]
A tachyon that couples to the electromagnetic field would emit Cherenkov radiation as it moves through vacuum. The recent OPERA results suggesting that neutrinos move faster than light can be ruled out because of this effect, see here.Count Iblis (talk) 01:14, 2 October 2011 (UTC)[reply]
I don't understand that paper at all. They seem to assume that the neutrinos are straight-up QFT tachyons with E² = p² + m² and m² < 0. But I haven't seen anyone suggest that as an explanation for the OPERA data. QFT tachyons aren't superluminal. The proposed explanations I've seen are quantum gravitational, and I don't think this QFT argument would apply to them, not that I know anything about quantum gravity. -- BenRG (talk) 05:15, 2 October 2011 (UTC)[reply]
To find the answer for any specific atom, go to the periodic table, find the atomic weight of an element, and then do the following calculation: Atomic weight/(6.02X10^23). So for instance for hydrogen you would do 1.008/(6.02X10^23). NoformationTalk23:31, 6 October 2011 (UTC)[reply]
Bacteriophages as antibiotics?
Would bacteriophages be useful as a practical replacement of chemical antibiotics? Because they produce more of themselves whenever they kill bacteria (and become inactive and are flushed out of the system when all the bacteria are dead), while chemicals require repeated treatments to eliminate the infection, it seems that they'd be much more efficient. --70.250.214.149 (talk) 01:25, 2 October 2011 (UTC)[reply]
See the article Bacteriophage therapy. It appears that bacteriophages can indeed be used to treat infectious diseases, but only if the exact strain of the disease-causing bacteria involved is known with certainty. For this reason, it would probably be ineffective against infections that involve a rapidly mutating bacterial strain, or several strains at the same time (as is often the case, e.g. with tuberculosis). 67.169.177.176 (talk) 01:35, 2 October 2011 (UTC)[reply]
Given enough hits at the exact same point, even the strongest bulletproof glass can eventually be breached. It all depends on how strong is the glass, and how many hits it takes at the same point. 67.169.177.176 (talk) 01:50, 2 October 2011 (UTC)[reply]
And for the record, there is nothing illegal about owning or holding an AK-47 in many jurisdictions around the world. In the US for example, they are legal in many areas provided they do not have full auto capability. Googlemeister (talk) 14:11, 3 October 2011 (UTC)[reply]
Global warming and future
What will the effects, as can be scientifically predicted from present climate scenario, of global warming to human civilization in 2100 and later? Will islands like Mauritius and coastal areas like Sunderbans sink? --DinoXYZ (talk) 05:56, 2 October 2011 (UTC)[reply]
Yes. Hence why representatives of the most low-lying island nations were pretty much disgusted at the failure to produce a resolution in the 2009 United Nations Climate Change Conference.
Wind instruments do not have all their notes perfectly in tune with corresponding notes on the piano. There is a chart published indicating the discrepancies with respect to alto and tenor saxophones. It would interesting to have similar charts for, at least the B flat trumpet and the slide trombone. — Preceding unsigned comment added by 82.44.58.70 (talk) 09:01, 2 October 2011 (UTC)[reply]
I'll ask it then. Does anyone have a link to a chart for various instruments indicating the discrepancies between their notes and those of a piano? I know[original research?] that there are many secondary-adjustments sax and clarinet players use, various combinations of keys and tone holes distant from the main ones used for the standard fingering, so would also be useful to know how much this counteracts the discrepancy. Trumpets have a tuning slide that can be kicked in or out while playing to fix certain notes. And a trombonist could just slide a little in or out and match any arbitrary frequency exactly, no? DMacks (talk) 16:16, 2 October 2011 (UTC)[reply]
Comment: "perfectly tuned" is a bit of pseudoscience. Though musicians will adamantly insist that there is such a thing as a true "perfect pitch" - and then furthermore attest that certain humans are "endowed" with a flawless capability to discern exact pitches - anybody with an engineering background will scoff at the idea.
Musical instruments have timbre - they are not monotonal - which means that their frequency spectrum is very complicated. A peak frequency exists (the root note), but it always (always) has a bandwidth. It is physically impossible to construct a real, non-theoretical instrument (including electronic synthesizers) that deliver a pure monotone sine wave. (To do so would require a musical instrument that never started or stopped playing - to have zero bandwidth tone, i.e. "exactly one specific frequency," the extent of the signal must propagate to ±∞ time. Nimur (talk) 18:45, 3 October 2011 (UTC)[reply]
Inflation-Adjusted Cost of Electricity?
Is there a way to calculate (or find) the Inflation-Adjusted Cost of Electricity in the US or EU for the past 50 years or so? On a similar note, is there a way to find the inflation-adjusted cost of lighting? --CGPGrey (talk) 10:31, 2 October 2011 (UTC)[reply]
By which methods and how accurate can we predict the properties of an unknown isotope?
I'm just a bit curious about some sites that claimed like "In case no experimental data is available, trends in the systematics of neighboring nuclides have been used, whenever possible, to derive estimated values"--Inspector (talk) 11:19, 2 October 2011 (UTC)[reply]
That kind of guessing is one of the main strengths of the arrangement of the Periodic Table. We've come a long way from Mendelejev and his Eka-aluminum, but the system still pretty much works the same. Take neighboring elements and extrapolate, mainly. I cannot tell you which Algorithms are used in the creation of such data, sadly, but the system in general is pretty sound. I cannot comment of the reliability of any such specific data though. --Abracus (talk) 15:25, 2 October 2011 (UTC)[reply]
I depends on the properties you are trying to predict. Look for example at figure 2 here. One can see that while properties across the periodical table are not exactly continuous or obvious, there are trends, so that if you knew some "goalposts", you could try to work backwards to extrapolate the remaining parts. There are other forms of regularity that can be extrapolated ahead of time — e.g. magic numbers. This doesn't mean that these things are understood greatly — there are often surprises (imagine trying to extrapolate the phase diagram of Plutonium only knowing Uranium and Curium, in the aforementioned figure 2) but you can often get a pretty good idea of what the possible and/or likely cases are (in the case of the U and Cm, you'd know that something weird was going to be happening there, because you've got two radically different phase diagrams — Pu, as it turns out, is something of a juncture point in the higher actinides, making it metallurgically quite interesting). Depending on the properties you are investigating, there are probably more or less reliable ways of deducing from other nuclides. --Mr.98 (talk) 17:07, 2 October 2011 (UTC)[reply]
Nuclear half lives fall into the domain of nuclear physics (or "nuclear chemistry"); so the periodic table (which really is a taxonomy of electron behaviors) is sort of inapplicable. To study half-life quantitatively, you need to use a lot of nuclear physics theory, but most of the time, the simple theories can't accurately predict nuclear stability. Loads of experimental correction factors are used, based on known, measured properties. Consider reading: about isotopic stability. Nimur (talk) 18:52, 3 October 2011 (UTC)[reply]
future binary solar system?
Given the enormous gravity of Jupiter and the available hydrogen/deuterium in space, how much larger would Jupiter have to be, or how much time would it take, for Jupiter to reach sufficient mass to trigger internal fusion reaction and become a sun/star? Has anybody ever figured this out?, or is this just a stupid question?190.149.154.16 (talk) 12:43, 2 October 2011 (UTC)[reply]
It's a perfectly sensible question and has been extensively studied. The article Brown Dwarf should get you started, and will have further relevant links. {The poster formerly known as 87.81.230.195} [[Special:Contributions/90.197.66.7Insert non-formatted text here0|90.197.66.70]] (talk) 12:56, 2 October 2011 (UTC)[reply]
Definitely not time, mass yes. Time has no effect on whether fusion initiates or not. There is a net loss of mass from Jupiter not a net gain, so unless its mass is artificially increased significantly, it will not happen. Plasmic Physics (talk) 12:57, 2 October 2011 (UTC)[reply]
Thanks guys. But I'm a little confused about the(Jupiter's mass loss) statement because atmospheric escape indicates that Jupiter's great distance from the sun, It's enormouse magnetic sheild, and large mass/gravity would minimize or eliminate mass loss, even though it doesn't mention jupiter specifically. Now since an enormouse amount of space hydrogen must be attracted by Jupiter's gravity it seems that the mass must be increasing. Please help.190.56.17.233 (talk) 16:00, 2 October 2011 (UTC)[reply]
The mass Jupiter is losing is probably very small, but it isn't attracting much either. The inter-planetary medium, especially out as far as Jupiter, is extremely thin. I think Jupiter gains more mass from meteors than the inter-planetary medium, but it will never get anywhere near enough to become a star. It would need to become about 80 times as massive as it is now. There isn't enough matter in the entire the solar system (excluding the Sun) to do that. --Tango (talk) 17:15, 2 October 2011 (UTC)[reply]
A good point Medeis. I tried several titles but could not find anything indicating Jupiter mass loss. Bearing in mind the enormous gravitational influence of Jupiter, It's clear that it's influence cannot be limited to the space volume within the solar system, and must also effect a large volume of interstelar space, and even though those atoms of hydrogen are widely seperated there must be a lot of matter available to Jupiter. Anybody have anything on that?190.56.17.233 (talk) 18:39, 2 October 2011 (UTC)[reply]
P.S. It has been asertained that Jupiter is giving off more heat energy than it gets from the sun, but that's not the same as loosing mass. Or is it?190.56.17.233 (talk) 18:48, 2 October 2011 (UTC)[reply]
It was in last my talk that human can change the Jupiter to be a star. Although its effect and brightness will be very poor and only it will appear in day and create shadow. No more energy and week light than moon.
If we send any space craft to explode Metis (one of Jupiter moons) to fall on Jupiter then its mass will increase to be a star. --Akbarmohammadzade (talk) 05:06, 4 October 2011 (UTC)
The mechanism of this event is carrying Metis to Roche limit --Akbarmohammadzade (talk) 05:15, 4 October 2011 (UTC)[reply]
Recently we are studying on solar system planets moons and Kuiper and asteroid belt, our work shows a bit mass increasing of jovian planets, after acceptance of such calculations I can say it here. --Akbarmohammadzade (talk) 05:51, 4 October 2011 (UTC)[reply]
No, Metis is a very small moon, and so will not be of sufficient mass to initiate fusion in Jupiter to turn it into a star. The gas giants may be gaing mass, but it will never be nearly 80 times as large as it is now. 190.56.17.233: Remember the energy-mass equivalce. Plasmic Physics (talk) 06:18, 4 October 2011 (UTC)[reply]
Would the antimatter even make it from the event horizon to the singularity? I thought anything added to a black hole after it forms stays suspended in the infinitely extended spacetime. Or is that just from the antimatter's frame of reference? 69.171.160.9 (talk) 19:33, 2 October 2011 (UTC)[reply]
In the frame of reference of the object falling into the black hole, it reaches the singularity within finite time. It is in the frame of reference of an object far away from the black hole that objects falling in seem to become frozen just above the event horizon. --Tango (talk) 22:44, 2 October 2011 (UTC)[reply]
I try to explain. So, we have a bath full of water. We open the plug and create a whirlpool ("black hole"). Now we make really big wave ("gravitation wave"), and the whirlpool collapsed. Can we repeat this with real black hole? -Ewigekrieg (talk) 14:12, 2 October 2011 (UTC)[reply]
Anti-matter and gravitational waves both have positive energy and will only make the BH bigger. Note that the singularity is not made of matter. It is a space-time singularity. Think of it as a part of the structure of space-time itself, not as an object located somewhere in space-time. Dauto (talk) 14:18, 2 October 2011 (UTC)[reply]
A white hole is just another name for a black hole. read the article you linked (specially the 3rd paragraph) for an explanation. Dauto (talk) 15:10, 2 October 2011 (UTC)[reply]
What are the chemical equations of some exothermic reactions that take place in the bodies of some warm-blooded animals? Please use common sense and understand that I am aware that lots of exothermic and endothermic reactions take place in the bodies of both warm-blooded and cold-blooded animals, but by my question I of course am only interested in reactions that are significant enough to be ones relevant in heat output to be one of the reactions that cause the animal to be considered by humans as warm-blooded (and again, yes, I am aware that the term has fallen into disuse; humor me). Peter Michner (talk) 13:42, 2 October 2011 (UTC)[reply]
This explains it pretty well. For shivering thermogenesis, it's basically the waste energy released during ATP hydrolysis. In non-shivering thermogenesis, it's the disruption of oxidative phosphorylation (creation of ATP) by UCP-1 which enables the mitochondria to "waste" substrate, generating heat instead of storing them in ATP as it normally would.
I'm sure there are more detailed breakdowns of the reactions mentioned in the linked articles or somewhere else, but you'd probably be better off looking for them yourself. My brain shuts down when I see diagrams of metabolic reactions, I disliked biochem :P -- Obsidi♠nSoul15:41, 2 October 2011 (UTC)[reply]
Newton's laws of motion
Isn't Newton's first law of motion simply a special case of his second law of motion, where f=0? And would massless particles still be affected by the first law, because they have no mass and therefore no force is needed to produce any given acceleration (because , therefore , so any value of a satisfies the equation)? Whoop whoop pull upBitching Betty | Averted crashes14:21, 2 October 2011 (UTC)[reply]
Yes, the first law is just a special case of the second.
I like to think of the "first law" as the definition of inertia, rather than as an equation. The second law is the definition of force in Newtonian physics; and the third law is the formal statement of Newtonian kinematics.
When you compare the "Three Law" statement of Newtonian physics to alternative formulations of classical physics, (i.e., the principle of least action), you see that these three items are explicit. For example, inertia does exist conceptually, when we study Lagrangian physics; but it's not defined so succinctly.
When viewed this way, the shortcomings of Newtonian physics become blatantly obvious: for example, force is defined in terms of mass and acceleration, but mass is never defined. (Nor is acceleration, for that matter!) Newton assumed mass was an innate property of the universe! And he didn't consider wacky spatial geometries where acceleration is poorly defined. Extending the Newtonian definitions to account for these properties leads to general relativity. Nimur (talk) 19:03, 3 October 2011 (UTC)[reply]
Infinite Regress and General Relativity
It is often asserted in arguments related to the existence of God that an infinite regress of events is not possible. This to me seems to just be a bare assertion, but I would like a more specific demonstration that an infinite regress is at least theoretically possible to use as a clincher in such arguments. Has someone ever mathematically proved that an infinite regress does not violate General Relativity? Rabuve (talk) 15:00, 2 October 2011 (UTC)[reply]
In classical theories an infinite regress (in a finite amount of time) is possible. This has been shown rigorously for classical mechanics, and I think in General Relativity there is a similar result. Count Iblis (talk) 15:18, 2 October 2011 (UTC)[reply]
I'm not asking why the universe exists; I'm asking if there is a proof that having an infinitely long string of events casually linked doesn't violate General Relativity. Rabuve (talk) 20:08, 3 October 2011 (UTC)[reply]
So I bought some cinnamon rolls, and I ate one. Then the next day, I see inside the box a whole bunch of flying insects. I was so disgusted, I have no idea how they got in there because the box was closed and in a plastic bag that was wrapped tight. Anyway I got rid of the bugs (They were quite small so I think they were gnats), and considered throwing out the rest. But they tasted really good, and I decided that they were probably harmless so I ate the rest. Now I'm a bit worried (hypochondria?), is there any possibility that they have any parasites in them or diseases? Could they have layed their eggs in the cinnamon rolls? ScienceApe (talk) 15:15, 2 October 2011 (UTC)[reply]
We cannot give medical advice here as a general rule. If you are worried about parasites, please ask an appropriately qualified medical professional. --Abracus (talk) 15:27, 2 October 2011 (UTC)[reply]
Yeah I didn't think this was a medical question lol. If you want, just ignore my little backstory and tell me if there's any danger to consuming gnats or food that gnats were crawling around on. ScienceApe (talk) 15:47, 2 October 2011 (UTC)[reply]
With this sort of question, the problem is that if we tell you not to bother to seek medical advice and then you get sick, we are partly to blame. So if you are in any doubt it's best you call NHS Direct or the equivalent in your country.--Shantavira|feed me16:03, 2 October 2011 (UTC)[reply]
Good point, you reminded me of this article where it says (halfway through) that frozen broccoli is filled with bugs. As the FDA article says there can be more than one aphid/thrip/mite per 2 grams of broccoli. Considering that these are similar to gnats (they feed mostly on plants) it would seem unlikely you'll come to any harm. As the link above shows, you could in fact be a pioneer of entomophagy in the west! (Obviously if you do feel ill go see a doctor). SmartSE (talk) 20:39, 2 October 2011 (UTC)[reply]
Insects do not spontaineously generate parasites or other disease causing microbes. They simply convey them from one animal to another. so if those insects do not feed on animals/humans and just like to eat sugar,then that just makes them sweeter.190.56.17.233 (talk) 16:27, 2 October 2011 (UTC)[reply]
Well our article suggest that it is not that highly toxic. I suppose if you ate a meal of cockroaches, and they had all fed on Oleander seeds, then you might be at risk. Dbfirs07:38, 3 October 2011 (UTC)[reply]
The Alcubierre drive is not permitted by the laws of physics and violates causality. When you can violate causality you can do anything, including, I suppose, destroying black holes by preventing their original formation. However, I think that the Alcubierre drive, as usually defined, has no mass, so just tossing one haphazardly into a black hole wouldn't grow or shrink the hole. -- BenRG (talk) 18:23, 2 October 2011 (UTC)[reply]
So I was wondering why I had never heard of that drive before, and now I see why. It's a useless piece of non-sense. Dauto (talk) 19:18, 2 October 2011 (UTC)[reply]
As BenRG says, the drive can't actually exist (at least, not without some pretty serious changes to our understanding of physics). That means it's meaningless to try and describe how it would work, except as a mathematical exercise. Black holes certainly can be perturbed, in as much as the event horizon won't always be spherical (collisions between black holes are a good example of this), but that won't destroy the black hole. --Tango (talk) 22:50, 2 October 2011 (UTC)[reply]
The principle of general covariance implies that the event horizon of a black hole is not fundamentally different from any other place in the universe. An Alcubierre drive would pass through it just like any other region of spacetime. But because it exceeds the speed of light, the usual rule that "what happens inside the event horizon stays inside the event horizon" doesn't necessarily apply any more. Maybe it could shrink the hole by transporting out infalling matter before it hits the singularity. Regardless, the Alcubierre drive requires exotic matter with a negative mass density, and if you've got that you could simply drop some of it into the hole to shrink it, no warp drive required. -- BenRG (talk) 04:29, 3 October 2011 (UTC)[reply]
It would depend significantly on what part of your body is hit each time, as well as the calibre and type of bullet and the medical care available (and how near it is). There is no way you can come up with a single number. You could theoretically come up with the number of people who have been shot three times and see what percentage of them survived but I doubt those statistics are easy to come by (and whatever statistics you have are likely to be somewhat flawed anyway, e.g. if you go by hospital visits some people aren't going to go to hospital unless it is severe), and the number it self is fairly meaningless. Nil Einne (talk) 16:47, 2 October 2011 (UTC)[reply]
I realised I forgot to mention how deeply the bullet penetrates will also often have an effect, which will depend on the first 2 I mentioned but also things like the type of gun and distance it was fired from. BTW just to emphasise 'part of the body hit' isn't a simple thing. Obviously a shot which actually penetrates he heart is likely to be fatal and the brain isn't good either but it seems likely you have a greater chance of surviving some shots to the body then a shot whick knicks the Femoral artery. Incidentally I found this very mildly related article [1]Nil Einne (talk) 18:24, 2 October 2011 (UTC)[reply]
As Nil Einne states, two of them were small caliber and didn't even break the bone they hit. I grew up playing in woods where hunters were always shooting at anything that moved. The third was a larger caliber, but it was a ricochet into my shoulder. So, it was travelling relatively slow. I know that getting shot isn't common - most people aren't raised around guns - but I don't find this notable. I was raised in an area full of hunters and then I served in the U.S. Marines (they have a few guns too). Now, I work in a hospital, so I have more concerns about infections than guns. -- kainaw™17:17, 2 October 2011 (UTC)[reply]
Well, as I asked whether being shot hurts, I didn't mean such cases: 2x hitting a bone, 1x ricocheting bullet, and therefore not straight. I thought about a clean high energy straight shot, maybe just hitting your waste fat (only skin and fat), getting in and out. Wikiweek (talk) 19:43, 2 October 2011 (UTC)[reply]
I see somene mentioned 50cent. Iremember once in the 1990's reading in a science magazine (or science section of a periodical) that on average there is a 50% chance of death per bullet wound over the general population. Paradoxically, that doesn't mean your chances of survivng one bullet wound is 50%. μηδείς (talk) 17:20, 2 October 2011 (UTC)[reply]
This guy survived being "executed" by a firing squad who shot him 9 times including being shot straight in the head - there is a pic here! If you search for "El Fusilado" you'll also find a song telling his story by Chumbawamba(much better than a song I can be fairly sure 50 cent will have made about him being shot). SmartSE (talk) 20:53, 2 October 2011 (UTC)[reply]
I watched an episode of Mayday (TV series), and noticed that the airplanes on the Air Traffic Controller's radar display were moving "live", very smoothly. However, there was also the familiar slowly rotating green strike going across the display, indicating the antenna orientation; the motion of the dots just was in no way related to the rotation of the radar. Sometimes the dots even changed direction between the sweeps. Is this how the (modern) radars actually work, or is it just an artist's misconception? I've seen it in numerous other episodes of Mayday, too, and it really sticks out. Thanks! ›mysid (☎✎) 18:55, 2 October 2011 (UTC)[reply]
What you see on a radar is called a "track" (well, you see many tracks). Radars rarely work alone. The controlling computers gather information from other radars also. So, you have information even when your radar isn't sweeping an area. Further, the controlling computers predict what will happen between sweeps and show that. When an aircraft behaves in an abnormal manner, it will jump. In reality, it didn't jump. It is just that the computer predicted it would be in one place, but it showed up in another. That isn't as easy as it seems. What if an aircraft dropped chaff to make it look like it is somewhere it isn't? What if it was two aircraft all along and they were real close to one another and then they suddenly separate? All in all, the person at the radar station is seeing the best guess of the computer, not real radar information. -- kainaw™19:09, 2 October 2011 (UTC)[reply]
Thanks for the info! But what role does the green strike play, then? It was only shown for one radar. (And does this system have a name? Our article on radar tracker doesn't mention one where the dots are moving smoothly) ›mysid (☎✎) 19:25, 2 October 2011 (UTC)[reply]
Civilian trackers definitely are not required to display the antenna swipe, at least in Europe. Moreover, in all but the most basic installations, multi-radar tracking is the norm, so there is no single swipe. There are two possible sources for the "stripe". First, if it really was rotating, it may just have been artistic license - they asked a prop man to provide a display, and he programmed a fake. If, on the other hand, the stripe went up (or down), it may just have been interference between the radar screen and the movie camera. --Stephan Schulz (talk) 21:17, 2 October 2011 (UTC)[reply]
The green sweep display is just from one radar system of which there are usually several available, and the display is there with controls so that the sweep region can be adjusted or controlled in an emergency. The smooth operational display system displays are multilateration from all the radars that aren't under manual control for the Short Term Conflict Alert, transponders, and communications systems. 69.171.160.45 (talk) 03:35, 3 October 2011 (UTC)[reply]
At a non-military control tower, they are mostly looking for the aircraft transponder to tell them where they are, not so much actually bouncing radar beams off of the aircraft. However, they could very well keep that radar system operating in case some doctor is flying his Cessna around without a transponder so mostly the sweep radar is a secondary system. Googlemeister (talk) 13:54, 3 October 2011 (UTC)[reply]
Aircraft transponders actively providing position information is ADS-B, a technology that is currently being phased in, but which is not yet supported by all airframes, and rarely used exclusively. Secondary Surveillance Radar uses transponder replies, but still computes the position from the antenna azimuth (i.e. direction ;-) and the signal run time, just as a classical primary radar. The difference is that it take the known latency of the transponder into account (and, of course, the fact that the transponder provides identity and barometric altitude, or, if it is a modern Mode-S transponder queried by a Mode-S Radar, everything from the stock of coffee in the pantry (separated into decaf and regular) to the frequency and duration of the pilot's rest room visits). --Stephan Schulz (talk) 17:55, 3 October 2011 (UTC)[reply]
can't be done because of the uncertainty principle. An electron is not a tiny little ball that can be confined and will have a track. It is a wave that fills the available space without a clearly defined track. Dauto (talk) 20:13, 2 October 2011 (UTC)[reply]
Not possible. Put an electron in a box. Now make that box smaller over time. The smaller you make the box, the more kinetic energy must be transferred to the electron. In the limit that the box contracts to a single point, the kinetic energy of the electron becomes infinite. It is not possible, even in principle, to make a trap that can completely confine an electron to a single point in space. Unlike classical physics, quantum mechanics teaches that a confined electron must have non-zero kinetic energy at all times. Dragons flight (talk) 21:24, 2 October 2011 (UTC)[reply]
See quantum tunneling, I'm sure some users here might take issue with this, but for layman's purposes, imagine the electron can teleport through physical walls. So it's impossible to confine in a physical space. At most you can alter its probability cloud with electric fields. ScienceApe (talk) 23:22, 2 October 2011 (UTC)[reply]
You can actually measure (and observe) the exact moment when everything classical goes out the window and quantum rules. When you say, "an electron is a particle. it has diameter and mass", you're using a classical language. That can be very effective in some contexts. But when you start talking about sizes of a certain scale, then you have to switch to a fully quantum vocabulary and reasoning. And that means uncertainty. There is a lot of interesting work on physics at that boundary between the classical and the quantum — it turns out to be pretty important in nanoscale engineering. See Mesoscopic physics. Your idea of the box is a classic way to think about it. At a macroscale, you can talk about an electron being "inside" a box, sure. But as you start to shrink it, when you hit the mesoscale, suddenly that language starts to get really problematic, and stops being correct at all. --Mr.98 (talk) 00:23, 3 October 2011 (UTC)[reply]
That's certainly right, but not the most common case. I was thinking more about concrete office buildings or normal brick and mortar houses. Wikiweek (talk) 21:26, 2 October 2011 (UTC)[reply]
For tax purposes, the US convention (since 2010) is to assume that most new construction will have a 50 year useful life. Obviously some buildings continue to be used well beyond that, while others are replaced after much less than 50 years, but 50 years is probably a decent rough estimate. Dragons flight (talk) 21:39, 2 October 2011 (UTC)[reply]
So, what about all those pre-war Manhattan buildings? Are they worthless? I suppose that for tax purposes you needed a rule to amortize it. The lawmakers chose 50 years, but could have chosen more or less years. Quest09 (talk) 22:11, 2 October 2011 (UTC)[reply]
The White House? It's barely 200 years old... I know Americans think that is old, but it's really not. America doesn't have old buildings. I live in London. You can't walk for 10 minutes here without tripping over buildings far more than 200 years old. --Tango (talk) 23:00, 2 October 2011 (UTC)[reply]
There is some distinction that should be made between the 'remains standing' lifetime, the 'still usable' lifetime, and the 'roughly the same, functionally, as new construction' lifetime. While it is certainly the case that buildings 200 years old remain in service, many have limitations which would not be acceptable (or even legal) in new construction. Older buildings (or sometimes just their shells, or even their street-facing facades) are often retained and retrofitted at great cost and inconvenience for the purposes of 'historical preservation' and so forth. I don't dispute that older buildings can have value as works of art and can form an essential part of a street or city's character and be worth retaining on that basis—but by the purely practical measure of cost, it would make more sense to demolish them and replace them with new construction.
Any building older than two or three decades faced much more limited requirements for accessibility by disabled persons. Doorways (and even hallways, if one looks at construction more than a hundred years old, especially in very densely-packed cities) aren't wide enough to admit wheelchairs. Ramps and elevators may be absent or extraordinarily inconvenient. Methods used for heating two hundred years ago were very different from those used today. Retrofitting modern heating, air conditioning, ventilation, elevators, fire containment, fire suppression, electrical supply, lighting, computer networking, handicapped accessibility, and plumbing isn't trivial; building occupants are often forced to make an unpleasant choice between astronomical cost and tolerating inconveniences, discomforts, and hazards—and even if they do spring for the upgrade, it can mean that the building is partly or wholly unusable for months or years of construction anyway. TenOfAllTrades(talk) 11:36, 3 October 2011 (UTC)[reply]
If wood-and-masonry buildings can last hundreds of years, I see no reason why steel and concrete buildings wouldn't last longer. So, the answer is very very long, specially if you maintain the building properly and avoid things like water damage. Quest09 (talk) 23:07, 2 October 2011 (UTC)[reply]
Indeed. If they are well-maintained, they can last pretty much forever. Such buildings are often demolished when they still have plenty of life left in them in order to be replaced by new buildings. That's far more common that them getting too old (unless they've been abandoned for some time). --Tango (talk) 00:46, 3 October 2011 (UTC)[reply]
European castles made of solid blocks of stone will start decaying in a few decades if unmaintained. The roofs are the weakest part since they are made of more fragile materials. Then the rainwater will flood places that were intended to remain dry. Internal rooms will no longer be protected from very low temperatures, so that water will start freezing inside the cracks of the stone, cracking them even more. Certain stones will crack way sooner than others, if left unrepaired they will damage surrounding stones. Damaged pillars will fall on other stones, cracking them, sometimes adding weight in places not designed for it. Stones in the middle of a wall will debilitate stones above it and will eventually cause the falling of whole wall sections. Usually, the cracks among stones are covered with masonry stuff, which gets destroyed in a couple of decades. If the cracks are kept well covered, stone walls may last millenia. Some stone buildings in Egypt were covered in sand and forgotten, and have been preserved magnificently for 4000 years or so. Now they are been eroded slowly by wind/ice and might last a few centuries if unmaintained. Summary: good frequent maintenance works because it prevents damage to buildings before it happens. Bad unfrequent might repair the most damaged parts but it will not prevent damage to parts that are still in good shape. --Enric Naval (talk) 14:18, 3 October 2011 (UTC)[reply]
Any well-constructed building that receives conscientious maintenance should remain standing indefinitely, absent an environmental disaster. That said, the economic life, as calculated by the span between major renovations, can be quite short. For retail buildings, built on the cheap with inexpensive HVAC and roof systems, 15 years is fairly standard. For higher-quality commercial buildings, 30 years may pass before the structure is obsolescent. For public buildings such as schools it may be 40 or 50 years. Bear in mind that most low-slope roofing must be replaced every 15 to 25 years no matter what, and even very durable roof systems rarely go more than 50 years without significant work. Building code requirements or building standards for accessibility, life safety, earthquake or storm resistance, or for energy efficiency may render a building non-competitive in the marketplace or perceived as unsatisfactory. For specialized buildings (again, such as schools) changes in usage requirements may make the building unsatisfactory in a shorter period of time. Technology may affect usage (i.e., air conditioning and artificial lighting may remove requirements for airshafts, or may result in their adaptation for other uses). Few buildings go for more than 50 years without some kind of more-than-routine maintenance. Acroterion(talk)14:28, 3 October 2011 (UTC)[reply]
A couple of cents:
just because you know some pretty old buildings (+100, +200 or even +300 years) it doesn't mean that buildings on average last that long: you simply don't know how many didn't make it up to our time.
A life span of 50 for tax purposes doesn't mean the building will probably last 50 years or that it will be worthless in 50 years. It means buildings lose on average 2% value each year, which sounds perfectly normal for me. If you keep repairing that per-war loft, that Quest09 mentions above, it can get even more valuable. For an apartment worth $200,000, you'll have to set aside $4,000/year on average. Just remember that a new HVAC, a new roof, new plumbing, a new elevator, and many other things; all cost some thousand dollar. As the building gets older the costs get higher.
Just on the matter of the White House, other than the outer shell, it is only about 60 years old. See White_House#The_Truman_reconstruction. It's the old problem of the Ship of Theseus paradox; sure, there has been a structure known as The White House for 200 years, but it is constantly renovated and updated (and occasionally almost completely rebuilt from scratch), so what you see now is not, except for some cosmetic bits here and there, really all that old. The same is likely true for many really old buildings.--Jayron3218:54, 3 October 2011 (UTC)[reply]
The White House was burned by our British friends in the war of 1812 and rebuilt about 1820. American sometimes read [2], [3], [4] that it was "white" only because it had to be painted after the burning to hide the soot stains, but in fact it was painted white from the beginning,because of the porousness of the exterior stone, and there was little left to paint after the burning. All that remained of the original building was the foundation and a portion of the south wall. By about 1900 the interior was in danger of collapse and was extensively rebuild. The roof and its support structure was replaced in the 1920s because it was collapsing. By 1948 Truman found it necessary to completely gut it, preserving only the walls and the 1920's roof, and replaced the interior with steel and concrete construction. In each incarnation before the Truman rebuilding, it was ready for condemnation and demolition every several decades, had it not become a national symbol. In the late 1800's its survival as a presidential palace was in doubt, not for structural reasons, but because it was judged obsolete and old fashioned, and there was serious consideration of building a "modern" presidential palace on another site in DC, and converting the building to offices. Edison (talk) 19:51, 3 October 2011 (UTC)[reply]
Angle of repose
Does the angle of repose depend on gravity or not ? I thought the consensus was that it doesn't.
..yes but the changes in the shear stress and normal stress due to gravity cancel eachother out so the coefficient of friction just depends on the angle for a given material or so the story goes... Sean.hoyland - talk05:50, 3 October 2011 (UTC)[reply]
N-terminal signal sequences in Archaea
I am analysing a protein sequence from from the Archaeon Thermotoga maritima...
Looks suspiciously like a His-tag, used for protein purification. The protein is an alcohol dehydrogenase, the histidines don't appear to be part of the protein. Hzh (talk) 00:31, 3 October 2011 (UTC)[reply]
Yup, on checking, pretty sure it is a His-tag, i.e. something artificial added to make protein purification easier. The sequence MGSDKIHHHHHH appears to be called Thio6His6 tag. Hzh (talk) 00:57, 3 October 2011 (UTC)[reply]
Definitely an added tag. The record for T. maritima aldehyde dehydrogenase here shows the sequence starting with MMGLK...—which would be right after the His tag. (When in doubt, BLAST it....) TenOfAllTrades(talk) 01:31, 3 October 2011 (UTC)[reply]
Big Bang theoreticians have made the claim that 80% or so of gravitating matter in the universe must be some unknown kind of non-byronic matter that is as yet undetected and barely interacts with normal matter (or itself). This claim is apparently needed for agreement with Big Bang nuclear synthesis calculations.
I am looking for any firm confirmation that dark matter cannot be large quantities of cold dark H2, the most common molecule in the universe. I understand that at least someone believes that the FUSE satellite data has proved that no large amounts of H2 exist to account for the gravitating mass. However I have been unable so far to deduce such a claim from science reports from the FUSE project that I have seen.
Can anyone enlighten me on this subject?
Moreover in 1999 large amounts of neutral H2 were detected in the edge-on galaxy NGC 891. The reports suggested that enough was found to account for the missing dark matter. Does anyone know if this claim was refuted?
Finally around 1998 through about 2002 several articles appeared discussing Extreme Scattering Events which have been attributed to a large population of extraordinarily small and dense H2 clouds in our galaxy. Has any further progress been made in this research since? Will the Planck mission data be able to shed some light on the existence of such gas clouds?
Hydrogen and all other atoms and molecules have characteristic absorption and emission spectra including in the < 10 Kelvin blackbody emission region which would be evident if there were massive unmapped clouds of cold dust or gas. There are no such clouds because dark matter is primordial, intermediate mass black holes.[5] We know this because any massive but non-baryonic or weakly-interacting matter would have fallen into black holes billions of years ago.[6] Professor Paul Frampton has been saying this for decades,[7](free at [8]) but the hundreds of astrophysicists who search for WIMPs and axions refuse to listen, because even though there has never been a shred of empirical evidence for such exotic particles (they are merely the hypothetical postulations of supersymmetry, which is not doing so well at the Large Hadron Collider at the moment) there was until very recently no way that anyone had thought of to detect intermediate mass black holes[9][10] so you couldn't get a grant to look for them. Science meets economics and economics wins, sadly. Our Dark matter article is pathetically equivocal on this topic because it's been heavily edited by astrophysicists in favor of their own continued funding, and you can't blame them, really. However, this is not to say that there aren't large unmapped clouds of interstellar hydrogen emitting in the < 10 Kelvin blackbody range; there most certainly are, and they are being detected all the time by, e.g., the Spitzer telescope, but they are orders of magnitude less massive than dark matter. Do you have links for the NGC 891 and scattering observations? 69.171.160.45 (talk) 06:49, 3 October 2011 (UTC)[reply]
I've always thought that "dark matter" (and "dark enery") is simply the "here be dragons" of modern astrophysics. Just a convenient label for "everything we can't specifically identify (yet)", thus it could basically be anything (that isn't "glowing" and thus broadcasting it's identity). Roger (talk) 07:52, 3 October 2011 (UTC)[reply]
An event rate modulation which has been unconfirmed since 1986, and 69 detection events from unexplained sources which are therefore theorized as WIMPs? I'm glad you're not picking my investment portfolio. On the other hand, two intermediate mass black holes have been confirmed for years now. Is there anyone supporting WIMPs who isn't in the community depending on grants for looking for them? NASA doesn't. 69.171.160.119 (talk) 20:37, 3 October 2011 (UTC)[reply]
Another shower of PoV from 69.171.160.119. The 69 events have no other known explanation while the Black holes might not be primordial. Dauto (talk) 22:46, 3 October 2011 (UTC)[reply]
Oh, By the way, the DAMA/LIBRA experiment has collected data as recently as 2009 published in 2010 showing modulation beyond 8.9 sigma confidence limit. Dauto (talk) 23:10, 3 October 2011 (UTC)[reply]
Is there a link for that? I seem to remember that wide binary star measurements are consistent with black holes but not WIMPs. Does anyone remember where that was discussed? 67.21.131.22 (talk) 23:53, 3 October 2011 (UTC)[reply]
The wide binary orbits were once said to be inconsistent with black holes but that has been overturned by [11](free at [12]) but this is not strictly evidence for black holes at present. 69.171.160.201 (talk) 19:48, 4 October 2011 (UTC)[reply]
Any idea if it's made it through peer review? Or how they deal with DM particle accretion in ordinary stellar mass or supermassive black holes? 69.171.160.201 (talk) 19:48, 4 October 2011 (UTC)[reply]
The peer reviewed reference is Eur. Phys. J. C (2010) 67: 39-49. Any claims to constraints coming from possible Black holes are not their concern since it is not related to their experiment. Dauto (talk) 20:06, 4 October 2011 (UTC)[reply]
That just your opinion, not a fact. The observed modulation is quite solid, the explanation given in the paper is reasonable, and I haven't seen any alternate explanation being proposed. Dauto (talk) 20:31, 4 October 2011 (UTC)[reply]
One more thing. The NASA page linked above is talking about micro black holes not intermediate black holes. Micro black holes are just another variety of WIMPs. Dauto (talk) 14:26, 4 October 2011 (UTC)[reply]
Yes, they are. In fact their interactions is even weaker. They only interact through gravity. You need a large mas in order for gravity to become strong and those micro holes have sub-grams masses. Dauto (talk) 20:06, 4 October 2011 (UTC)[reply]
Thanks for everyone's response. I was actually asking more specifically about the search for molecular hydrogen and how much has been found. Here is a link to the 1999 paper about H2 in NCG 891
Here is a link to one of the papers about Extreme Scattering Events probably due to dense H2 clouds: arXiv:astro-ph/9802111v2.
It would appear that very cold clouds of nearly pure H2 would be difficult to detect, so perhaps it still is an unknown, but I'm not sure. Maybe not as exciting as primordial black holes and WIMPs but seems to me scientist should be looking for horses as well as zebras.
The remark about POV is valid but it seems to be the case in this field that not enough is yet known to have a solid scientific theory that can be agreed upon and solidly supported by evidence. After all we don't even know what 95% of the Universe is made of. Carl Hitchon (talk) 00:11, 4 October 2011 (UTC)[reply]
Again, hydrogen or any other gas or dust would emit blackbody radiation, and while that would not be detectable from the surface of the Earth because of atmospheric absorption and heat interference, the several cryostatic infrared space telescopes which have been operational since 1999 have not found any evidence of the necessary masses of interstellar media to explain more than a tiny fraction of dark matter. 69.171.160.201 (talk) 20:06, 4 October 2011 (UTC)[reply]
Actually, this is only true if you assume that the ISM (or H2 gas as DM for that purpose) is actually dense enough to form a Maxwell-Boltzmannn style velocity distribution, which -while only being indirectly related to a Plack Black Body- is required to show this kind of radiation. However, the ISM is mostly regarded as being "too transparent" or in other words, not dense enough to have photon creation by collision on a global scale. This is also the reason why we can observe the rather "bright" 21cm hyperfine structure transition line of Neutral Hydrogen, which would otherwise drown in the pure thermal radiation of HI, considering it being created by a highly forbidden, low probability event.
Can you site a reference indicating that it would radiate as a black body? I thought awestonomers always looked for specific emission and absorption lines to detect the stuff. I've heard the claim that's it's been ruled out, however there do seem to some instances of detection (mentioned above) that could be large amounts. Carl Hitchon (talk) 18:02, 5 October 2011 (UTC)[reply]
A recent proposal is that much hydrogen may be hidden from view in the form of Hydrogen ion clusters, although these too would have an absorption spectrum. Solid hydrogen snow is possible if the vapour pressure is lower than the gas density. However there is a problem with primordial nucleosynthesis if the density of baryonic matter is too great, it does not end up producing elements in the ratio that we see now. Graeme Bartlett (talk) 10:02, 4 October 2011 (UTC)[reply]
The Extreme Scattering Events I referred to are thought to be caused by relatively small (<1AU) H2 gas clouds that are quite dense (10^3 or so times the usual ISM). Yes, I'm well aware of the conflict with the BBN theory and that's apparently why we are looking for harder for zebras than horses (so to speak). Thanks for the references. Carl Hitchon (talk) 18:02, 5 October 2011 (UTC)[reply]
Are there physical or biological lower limits on the size of mammals? In particular, would it be possible for a cat or dog to evolve to an insect-like or microscopic size (full grown), while retaining its basic cat/dog body shape and characteristics? 69.111.16.7 (talk) 03:48, 3 October 2011 (UTC)[reply]
Most mammals (and most birds) are endothermichomeotherms (traditionally, but inaccurately - "warm-blooded"). The smaller the size, the harder it is to maintain acceptable body temperatures for their metabolisms to occur normally. The smallest homeothermic vertebrates (e.g. shrews and hummingbirds), as a consequence have very high metabolic rates. They have to keep eating all the time and require so much oxygen that their heartbeat rates are astonishing (600 to 1320 bpm for the masked shrew).
The other limit, is of course, morphological. This affects poikilotherms and ectothermic homeotherms ("cold-blooded" animals) as well as endothermic homeotherms. A microscopic dog or cat would not have enough space (or cells even) to possess the organ systems necessary to keep functioning. Unless of course, it devolves drastically and manages to find a way to remain alive even after jettisoning most of its organs. Examples of miniaturization achieved by basically giving up the necessities of having to remain alive include anglerfish males which can only survive by becoming embedded parasites of the much larger females (they are basically nothing more than living testes). The males of the fairyfly Dicopomorpha echmepterygis, the smallest insects, also do not have eyes and have no means to feed themselves as adults - they only live to fertilize the females immediately after emerging as adults, then die. Even down to the mm range, there are already constraints as to what can be fitted into a body. In the smallest vertebrate adults, fish of the genus Paedocypris, the skulls have become cartilaginous and roofless, leaving their brains exposed. In the tiny Thorius salamanders, the eyes and the brain have a larger "smallest operational sizes" than other elements of the skull and thus now take up much of the space.
And lastly, smaller sizes means different niches. They have to adapt to different ways of acquiring food, different methods of locomotion, etc. And that means necessarily changing body shape. So no, a microscopic vertebrate is impossible. -- Obsidi♠nSoul06:53, 3 October 2011 (UTC)[reply]
"Or"? Most currently-used English Bibles are pretty clear about it being seven pairs (or seven and their mates) in Genesis 7:2. Direct translation of the Hebrew agrees ("you shall take seven seven man and woman of him") So WP:V wins again. DMacks (talk) 12:00, 3 October 2011 (UTC)[reply]
Maybe the scribe stuttered? Oh well... at least we got a rainbow out of it. Antediluvian Earth must have been completely monochromatic.-- Obsidi♠nSoul12:25, 3 October 2011 (UTC)[reply]
Are shrews smaller than marmosets, or are these just young? I guess they are young, since Shrew says, "several are very small, notably the Etruscan Shrew (Suncus etruscus) which at about 3.5 cm and 2 grams is the smallest living terrestrial mammal." Terrestrial? Is there a tiny dolphin or something? 69.171.160.45 (talk) 07:56, 3 October 2011 (UTC)[reply]
The larger marmosets in those pictures are (assuming the hand is of an average adult human) at least 10cm long excluding their tails, and by comparison even the smaller younger ones are considerably larger than a typical adult shrew. {The poster formerly known as 87.81.230.195} 90.197.66.215 (talk) 08:33, 3 October 2011 (UTC)[reply]
I think that might actually be an Imperial hand, although in the current context its difference from the Metric hand is not great enough to be significant. {The poster formerly known as 87.81.230.195} 90.197.66.215 (talk) 18:10, 3 October 2011 (UTC)[reply]
I have only found this message a day later! How you find who edited an article is by looking at the history. A talk link will be listed against the editor. Graeme Bartlett (talk) 09:51, 4 October 2011 (UTC)[reply]
Losing weight
In terms of attempting to lose weight ... why do they say that when you have more muscle, it helps you to burn more fat? What exactly is the relationship between the two? What are the basics of the underlying concepts involved? What is the basic physiology or biology involved with that concept? Thanks! (Joseph A. Spadaro (talk) 15:27, 3 October 2011 (UTC))[reply]
Perhaps it's very simple and just means that when you have more muscle you can exercise more strenuously and for longer. And when you exercise you burn calories. Itsmejudith (talk) 16:14, 3 October 2011 (UTC)[reply]
I don't believe that's right Judith. More muscle increases the Basal metabolic rate which makes you burn more energy along the day. The energy that you lose through exercise it not very high (despite popular believe that exercise can make you thin). That's why you always have to combine exercise ((muscle building and aerobic) with a diet to lose weight. Trustinchaos (talk) 16:20, 3 October 2011 (UTC)[reply]
You lose 100-150 kcal for every mile you walk or run. That translates into 20-30 miles per lb of fat. Most people in reasonable condition could walk/run 3-4 miles a day, which is around 500 kcal. Many people might find it easier to just eat 500kcal less, but doing both is how to lose weight the fastest obviously. Googlemeister (talk) 16:25, 3 October 2011 (UTC)[reply]
That implies losing about 3-4 pounds/month, which is not much, but only if you indeed walk 3-4 miles every day, which is more than most people do. Provided that you don't eat more (or more energetic food/drinks), it could work for losing a little bit of weight, but it's highly improbable. Wikiweek (talk) 22:04, 3 October 2011 (UTC)[reply]
Most doctors don't recommend people try to lose more then 1-2 lbs per week in normal circumstances. And if losing weight was easy, there wouldn't be a multi-billion dollar industry for it. Googlemeister (talk) 13:29, 4 October 2011 (UTC)[reply]
That's double of what I said, but you are right, losing weight is not as easy as it sounds, specially not gaining it again can be a tough thing. Wikiweek (talk) 20:59, 4 October 2011 (UTC)[reply]
Just keeping tissue alive (even if you're not moving about or visibly 'exercising') burns a certain number of calories (as noted by others, see basal metabolic rate). This page suggests a burn rate of 7-10 calories per day for every pound of muscle tissue, versus approximately 2-3 calories per day per pound of body fat. So keeping a pound of muscle alive for a year burns about 3000 calories—the amount of energy, coincidentally, stored in a pound of fat.
Of course, you're likely to burn far more calories than that in the activities used to build and maintain that pound of muscle than you ever will relying on its contribution to your basal metabolic rate. (If you start with a pound of muscle and don't use it for a year, it won't still be there at the end of the year, and your body will have used up the material in that muscle (catabolism) as a source of energy.) TenOfAllTrades(talk) 16:53, 3 October 2011 (UTC)[reply]
One reason for that would of course be that no one in the U.S. has been daft enough to eat potato fruits in the last 50 years... =) JIP | Talk18:49, 5 October 2011 (UTC)[reply]
Petroleum value and chemical uses
I was very surprised to read a statement in Nature News, "Eighty-five percent of the volume of a barrel of oil is used to make fuel, but the chemicals that come from the remaining 15% account for 85% of the barrel's monetary value." I'm skeptical... is there truth to this?[13]
For example, if a barrel of oil cost $100, and this is true, then with petroleum at $100, 55*0.85 = 47 gallons of petroleum destined for fuel should cost $15 - the base cost of the fuel, before refining, should be about $0.33.
More to the point, if this claim were true, then if the technologies discussed in the article, such as biotech isoprene for tires, come to fruition, the base cost of the fuel should be increased. This is because the chemical part of the oil becomes less and less valuable due to competition, whereas the expense of producing it doesn't decrease. (If capitalism even applies to the oil market, which I'm also a bit skeptical about). If that 47 gallons has to produce most of the $100 cost of the petroleum, the base price of the fuel rises $1.66 per gallon to around $2.00.
I suspect what they really mean is that, after the chemicals are worked on, adding value, they become more valuable than bulk fuel, not that those fractions of the oil are more valuable to start? Wnt (talk) 19:21, 3 October 2011 (UTC)[reply]
At face value it sounds very fishy to me too. Another possible reading that I could imagine is if "value" were understood as "profit" for refiners. I could easily believe that there isn't much profit margin in gasoline for refiners, and that the profit margins on the less common refined products might be much higher. Dragons flight (talk) 20:00, 3 October 2011 (UTC)[reply]
Some of the longer chain hydrocarbons in petroleum are used to synthesize ridiculously expensive pharmaceuticals, and less expensive pesticides which are still often much more valuable than fuel by weight. 69.171.160.201 (talk) 20:16, 4 October 2011 (UTC)[reply]
Mean swell wavelength in the open ocean
What is the mean wavelength of swells in the open ocean? E.g. if I placed a large number buoys in the open ocean at random and collected wave data for several years, then looked at just the wavelengths, and averaged them, what length would I get? Standard deviation would be great too! :) — Preceding unsigned comment added by 131.107.0.115 (talk) 20:25, 3 October 2011 (UTC)[reply]
The wavelength depends on the speed of the waves and the speed becomes roughly equal to the speed of the wind.[14]Wind wave says
using the notation in the article. For deep water
so λ is approximately (0.8c)2 where λ is in metres and c in m/s. Swell tends to continue in this way even after the wind has stopped (all this in Wind wave). I expect you were hoping the weather wouldn't come into things! Thincat (talk) 23:11, 3 October 2011 (UTC)[reply]
Thanks for this. I understand that wavelength is a function of wave period and speed; I guess what I'm really asking is what is the actual value? — Preceding unsigned comment added by 131.107.0.95 (talk) 00:01, 4 October 2011 (UTC)[reply]
There is no actual value for the average wave length. Waves come in ripples and tsunamis, so the mean you'd want is completely dependent on the accuracy of the buoys used. An extremely precise buoy might come up with millimeters. A very nice read about waves (how they work, how they're measured, and a lot more) is in Oceanography and Seamanship by William G. Van Dorn. Joepnl (talk) 01:04, 4 October 2011 (UTC)[reply]
Thanks Joepnl, I hadn't considered that a buoy could register a 1 mm change in water height as a wave (which I suppose it is; it sounds like now we're getting in to defining what a wave is) or that a buoy would be unable to differentiate the peak of one wave from that over another passing at a different speed. — Preceding unsigned comment added by 131.107.0.94 (talk) 01:13, 4 October 2011 (UTC)[reply]
The buoys can differentiate between different waves coming from different directions at different speeds. One cool thing I learned from the book I mentioned is that Fourier transformations are used to calculate where all the waves came from. Joepnl (talk) 01:29, 4 October 2011 (UTC)[reply]
Awesome! I'm disappointed that I'm not getting a quick answer to what I thought was a simple problem, but I am beyond stoked to find out that something I thought was simple (because I wasn't really thinking about it) opens the door to what looks like a super interesting subject. I can't wait to dig into this book.
Waves are just a small part of it but it seems that every (non-scientific) article about waves refers to this quite old (and pretty expensive) book which is about seamanship, really. Waves are really interesting. I thought an object on a wave was just going up and down. But the water needs to go somewhere. So here are some more fun facts: a floating object on a wave moves in circles, the circles go on below the surface, and they go on way further down than you'd expect. I think that smart kids learning about where canon balls should land after being shot at X degrees at speed Y should also be learning how waves work. Btw, thank you for making me look up the word "stoked", I'm learning here as well :) Joepnl (talk) 00:33, 5 October 2011 (UTC)[reply]
My cat pees on a power socket. Why? How can I stop it?
He's done it three times now! After each incident I've removed the power socket (known as a power point where I am in Australia) and left the wires there (with the live ends suitably covered with insulating tape) while I unstressed myself, cleaned everything up, and figured out how to stop it happening again.
Most recently, some badly stained carpet was completely removed, and the timber flooring and wall panelling thoroughly washed and sealed with two layers of a quality timber finish. The cat stopped showing any interest in the area. The power socket was finally replaced two days ago after a couple of months. First, the cat peed on the floor close by, then peed on the power socket itself, shorting out the power for the house, again!
Why? Any cat psychologists in the house?
How do I stop it? Sensible repellent suggestions welcome, but please don't recommend citronella. That repels me as well. HiLo48 (talk) 20:47, 3 October 2011 (UTC)[reply]
There are passive infrared sensor devices that emit ultrasonic sound and spray gasses or liquids or whatever concoction you enjoy. Some cats are deterred by whatever puts them on alert to possible danger. Even a wind blown CD outdoors will keep them searching for the places they feel safe. --DeeperQA (talk) 23:49, 3 October 2011 (UTC)[reply]
The approach is twofold: make the area he's peeing in less attractive, and make the area you want him to pee in (presumably the litter box) more attractive. So, you want to make sure that he likes the litter you're using (no scent might be better than scented), that you change it often, that the box is in a quiet, safe, and convenient place. He may prefer one with a "privacy" lid, or may prefer an open-topped type. To make the socket area less appealing, you want to be sure that previous urine mistakes are thoroughly cleaned up (may need enzyme-type products to do so). Purportedly, some cats don't like walking on aluminum foil, so spreading it out on the floor might also make the area less appealing. - Nunh-huh00:24, 4 October 2011 (UTC)[reply]
Perhaps put his bedding, such as a nest bed, there or nearby, because if he is still a healthy cat he should be keeping his den area clean and not marking it... or perhaps a small bowl of dry food down on a mat in the area for him to graze, because you wouldn't think he would want to ruin his appetite. I can't say for sure if those ideas would work though, and, in any case, since this is also a question of safety; yours, your home and the cats from both electric shock and fire due to the high current from an electrical short, you should block his access to the outlet. Thus, I'd put some plastic and a throw rug over the area to protect the floor and a bookcase or chest against the wall so that there is absolutely no chance of a repeat episode. --Modocc (talk) 04:54, 4 October 2011 (UTC)[reply]
Thanks guys. There's some creative ideas there. The food bowl idea could work. I'm aware of the safety issues. We do have what's called a safety switch here in Australia which automatically and very quickly turns off the current when it detects high leakage. I still think the dumb cat is rapidly working through his nine lives though. I'll put the idea of something blocking access into my subconscious to see if it can come up with something appropriate for the location. HiLo48 (talk) 05:37, 4 October 2011 (UTC)[reply]
Here in the UK we have Feliway pheromone diffusers, which you plug into the socket and which emits a "happy cat" odour. I wonder if putting one of these in the socket would confuse the cat enough to send him away happy? --TammyMoet (talk) 07:32, 4 October 2011 (UTC)[reply]
Wow, that looks highly relevant. The vet has said before that this cat is very susceptible to stress. (There is actually very little stress in its life. It's just crazy.) And your web link even took me to the company's local counterpart in Australia. Thanks. HiLo48 (talk) 21:44, 4 October 2011 (UTC)[reply]
It seems very difficult to apply a subjective ethical determination like "evil" to a power meter with any real meaning or significance. Issues of data protection certainly exist, but I'm not sure what you're wanting beyond that. — Lomn22:18, 3 October 2011 (UTC)[reply]
They're certainly not popular. Your question is very topical in my neighbourhood. Our local major spreadsheet newspaper (not the more popular Murdoch tabloid) has just published this article with the headline "Smart meters given a fail". HiLo48 (talk) 22:19, 3 October 2011 (UTC)[reply]
It depends what you use your electricity for. High electricity use seems to be a common way that hydroponic marijuana growing is detected around my part of the world. (Not suggesting that our OP is an indoor gardener.) HiLo48 (talk) 22:27, 3 October 2011 (UTC)[reply]
Yes, they could know when I am at home/at the office, and therefore call me offering some junk product or service. And a hacker could break into the system and know exactly when I am at home and more or less what I am doing - they could discover how many appliances I have. A potential employer could discover that I rarely stand up early, but come home late at night many days during the week. The question is not how they could use my private data, the question is that they are my private data. Wikiweek (talk) 22:41, 3 October 2011 (UTC)[reply]
Given the meters are individually hackable and regulatable, yes, their mandatory installation is yet another statist evil.μηδείς (talk) 22:31, 3 October 2011 (UTC)[reply]
Not for the first time, you win this weeks most stupid answer competition. Congratulations. That there are risks associated with access to banking facilities from the internet has no bearing whatsoever on the question of whether or not smart meters are evil. So. Did you have a point to make or were you just a bit pissed off that your previous stupid comment had been proven to be, err, stupid? --Tagishsimon(talk)00:00, 5 October 2011 (UTC)[reply]
In NZ there is no regulation or legal requirement for power companies to install smart meters. (Most major power companies here are state owned enterprises which in NZ means they operate more or less as private companies albeit with the government as share holder.) Howevering probably figuring it will be cheaper in the long run, they're doing it anyway but not bothering to make sure their meters have support a home area network to provide any info to the consumer or are compatible with each other [15][16][17][18][19]. If you want those you'll usually have to install a device yourself whicn connects to the power line since there doesn't seem to be any easy way to get it from the smart meters. Without your seperate power meter you paid for directly, any info on usage needs to come from the power company (if they want to provide it) and at best tends have a day granularity [20][21]. Some installers have even admitted said there is basically no real benefit to the consumer for the smart meters that are being installed, it's all to the power company. Of course if you don't want an ordinary smart meter, a prepaid one is an easy option, just don't pay your bill on time once [22]Nil Einne (talk) 23:57, 3 October 2011 (UTC)[reply]
(edit conflict)As an anthropologist I can say that the idea of evil varies greatly from culture to culture and doesn't really have a concrete definition; it's also a matter of opinion. If you define evil from a US perspective though, evil would mean Communist. As I don't like electric metres given that they are depressing (that's money they're measuring); then I, as an American, must define it as most likely Communist and therefore evil. Question answered. As for a serious answer, it's hard from them to really pin down the make and model of appliances you are using. Even if a hacker did care enough to look at your smart meter thingy, it wouldn't tell him the type of computer you use, the OS, programs, passwords, or any other thing of remote interest to him (or her). I don't think that your employer would access your meter without your permission either.... Sir William Matthew Flinders Petrie | Say Shalom! 6 Tishrei 5772 00:06, 4 October 2011 (UTC)[reply]
Technically a potential employer could demand to see your meter info before they offer you a job, or make it a part of your contract you need to give them access when employed. You could reject such a condition, but if you're fairly low-skilled with a lot of people competing for the same job you may have limited choice if you want to make a living. Now, why they would want to do this, I'm not sure, unless you live alone the fact there's high power usage late in to the night won't necessarily tell them you sleep late, nor will a sudden drop at say 9pm tell them you sleep early (perhaps someone else does and you don't bother with lights when using your computer). Also in evil statist countries, it may be illegal for employers to make such demands and even if it isn't it may become so if they start doing it. Nil Einne (talk) 13:27, 5 October 2011 (UTC)[reply]
It's worth considering whether one's electricity usage counts as private information that ought to be concealed. I'm not sure it does. Does one really generally expect that such information is kept confidentially? The meters usually are accessible from the street, their numbers displayed. The power company gives you no assurance that your usage is considered private information. The possibility of misuse seems ridiculously low, even with the idea that "hackers" are somehow getting all of the data at once. The potential threats to any individual seem nil — your named threats are that you are afraid of some so far totally ridiculous schemes by which telemarketers or employers, none of which sound very plausible to me, and all of such ills could be cured through separate policy (if employer actually did start discriminating on the basis of electrical meters, the easier option is to just ban that sort of discrimination). Anyway it all seems rather silly to me. I don't see any "evil". I'm not sure I see anything that actually even ought to legitimately harm or irritate the consumer, other than the apparent fact that they may not work correctly or may be expensive. (Which I consider a separate question from the privacy issue. Smart meters may not be a good idea, but I don't see how privacy has anything to do with that. There are far bigger fish to fry in the privacy arena.) --Mr.98 (talk) 01:02, 4 October 2011 (UTC)[reply]
I'm not sure it does not count as private information. BTW, it doesn't matter if people expect that it will be kept confidential and it doesn't matter if you expect it to be misused or not. If it's your private information no company should be using it for purposes other than agreed upon. And it doesn't matter if I cannot imagine any real harm that could be done. Wikiweek (talk) 13:13, 4 October 2011 (UTC)[reply]
You keep stating that you think it is private information, yet you offer up no criteria for deciding what you should be private and what should not. My analysis is based in the concept of privacy in US law; what are you offering up as yours? --Mr.98 (talk) 23:14, 4 October 2011 (UTC)[reply]
Information on the energy leaving their network and entering your house would seem to be as much their information as it is yours. Of course, you always have the freedom not to buy electricity from the power company. Dragons flight (talk) 23:56, 4 October 2011 (UTC)[reply]
To answer questions above, note that tools are not evil but foolishly installing tools open to abuse by hackers and the police state is a bad thing and when mandated by the government (you know, the ones who put you in jail, seize your property, and shoot you if you resist) it is evil. And Mr. Petrie, what it the world are you talking about saying evil in the US is defined as Communism? Evil is simply willful harm of any sort. Malice or (reckless disregard) which violates another. That's not a difficult definition. Doesn't require, but does include Marxist dictatorships. μηδείς (talk) 01:17, 4 October 2011 (UTC)[reply]
Ah, that is a joke I use sometimes, making fun of my country's tendency to refer to certain things as Socialist or Communist (though I am a socialist myself and have no real dislike of the communist idea itself, just the results of its practice thus far). Willful harm as defined by our values, but in anthropology, you learn to grey the hell out of everything you consider as many things we view are viewed very differently in other cultures. And I'm afraid that Prof. Petrie is no longer with us. Sir William Matthew Flinders Petrie | Say Shalom! 6 Tishrei 5772 01:27, 4 October 2011 (UTC)[reply]
The problem here seems to be that once a "technical upgrade" is envisioned, there seems to be no discretion in deciding what features to add. You could make a smart meter that tots up the electrical usage during each hour of the day and can be interrogated for a monthly report for billing purposes, to encourage conservation - yet not give it the ability to shut down the home's access to current, nor give it any real-time monitoring ability so that someone can try to figure out exactly what kind of grow light is being used in the house, nor allow it to spy on RF signals leaking down the line from a computer monitor nor receive sound recordings from bugs concealed in the house. (I'm not sure they do every last one of those things, though nowadays, one expects it until proven otherwise - and is usually right) Wnt (talk) 03:29, 4 October 2011 (UTC)[reply]
Puh-leeze. These thing are not that smart. And the fallout from violating various wiretapping laws (yes, there are laws about this sort of thing!) would be huge and prohibitive. These things almost surely just measure the electrical output and send it home when they ask for it. If there's no reason to suspect otherwise, it's ridiculous to assume they have all sorts of nefarious capabilities that are well outside their technical specifications. --Mr.98 (talk) 23:14, 4 October 2011 (UTC)[reply]
Not that I agree with Wnt but I disagree with your idea the only thing they can do is to measure the output. Some do in fact have the ability to do remote disconnects (meaning the power company can send a signal to your meter to cut off your power completely) and some do have a home area network meaning they could cut the power to certain devices when receiving a signal from the power company, but only if the device supports it. This is mention in our article on smart meters. However these features aren't hidden, in fact the HAN feature is generally an advertised one (remote disconnects perhaps less so but I see no sign it's usually hidden). The rest of the stuff is largely nonsense. (Well the real time monitoring of power usage is obviously real, any ability to figure out what devices you are using and when would depend entirely on their remote computer systems. I do agree they're unlikely to be able to figure out that much.) Of course, cutting off the power to certain devices isn't new, we've had it in NZ for hot water heaters for years and see Load management. Nil Einne (talk) 13:18, 5 October 2011 (UTC)[reply]
If you are going to insist it is private, you should give some argument as to why. So far the argument has been based on the potential of misuse. This would be a valid reason, if the potential was really there. I'm not sure it is, more than a lot of other information that is not considered private. I still don't understand what hackers are supposed to be doing with this information, or what the police state is supposed to be doing with it, or whatever. This seems like a lot of to-do about nothing. I wonder if you put as much thought into your choice of ISP or phone carriers, who almost surely are doing things that you would definite as violations of privacy or police state-ish. --Mr.98 (talk) 23:14, 4 October 2011 (UTC)[reply]
A smart meter could tell the police right away if I am at home. A normal meter gets read only once in a while, and only if I allow it. You seem to believe that it doesn't matter, since the police just persecute criminals. However, keep in mind that some people around the globe want (yes, that's true) to have a weak police force, which cannot control the whole of the population. It's certainly not a sensitive private data issue (like race, health, sexual preferences), but I still believe citizens have a right not to be the object of surveillance. Regarding the ISP or phone company, the problem is even more acute. Wikiweek (talk) 12:14, 5 October 2011 (UTC)[reply]
Personal information in general is information that can be tied to you. So, 1,80 m is not personal, but Wikiweek: 1,80 m is. But, not all personal information is worth protecting. Applied to the case of energy consumption, 50kw/h for client number x is not private, but 50kw/h for wikiweek is. There are ways of anonymizing information and still being able to process it to provide a service, which is perfectly legit.
A second point: just knowing how much energy you are consuming does not give much clues about what you are doing. Modern devices are as smart as the smart meters: they stop and start autonomously. Refrigerators do that since ages, a computer downloading a file will also change it's consumption of energy without user's input, you cell-phone will stop charging after the battery is full.
Third: the easier way to track you down is through your cell-phone. This would be, if hacked illegally or tapped by the police, one of the best sources of private information from you too, together with your computer. However, most people rarely care about the security of their computer, and even less about the cell-phone. They equally join unknown wifi nets, choose weak passwords and do much more things that are potential insecure. Some evil private data gathered have much better sources to hack than a smart meter. Quest09 (talk) 14:49, 5 October 2011 (UTC)[reply]
And don't forget about NFC. Makes stealing someone's money much easier. "Oh my, he's stolen my e-wallet! Well, I'll just use my cellphone to call the bank and... wait, that was my e-wallet". Even having a BB won't help you with that. Sir William Matthew Flinders Petrie | Say Shalom! 7 Tishrei 5772 19:12, 5 October 2011 (UTC)[reply]
In response to Mr98's question above, police have been using electrical profiles of houses to look for grow lights (i.e. for marijuana) for decades - I think they were doing it even in the 70s in some crude way.
But beyond this, there's a separate risk that emerges when collective data becomes too available, that goes beyond the risk to one individual. If the electric company knows when one person turns on his air conditioning, there is little they can do with that. But if they know they know when every single person turns it on, then they might decide to charge a higher rate for turning it on during peak times, for example. Now such programs in real life are generally voluntary and perceived as a discount good for the environment; nonetheless, it would be possible for the information to be used in a way customers wouldn't like. Wnt (talk) 19:40, 5 October 2011 (UTC)[reply]
Well, they are collaborating in an unjust campaign to deny basic civil liberties for the sole and deliberate purpose of enriching and expanding the Zeta and Sinaloa cartels. Wnt (talk) 03:21, 6 October 2011 (UTC)[reply]
You know, peaking power really does cost the power company more to produce than baseload power. For large industrial and commercial users, charging more for power during peak times has actually been pretty standard in many jurisdictions for quite a while. That kind of detailed, time-resolved monitoring had been expensive though so it wasn't economical to apply at a residential level, but the wide distribution of smart meters is changing that. I wouldn't be surprised to see the actual costs of peak power passed on to all consumers in the not-too-distant future. Dragons flight (talk) 20:17, 5 October 2011 (UTC)[reply]
Indeed, charging more or less under market conditions wouldn't be much different than what happens with other services and products. Quest09 (talk) 20:22, 5 October 2011 (UTC)[reply]
Oh, it's all perfectly good logic, and yet, it's a reason why customers might legitimately object to the meters. Maybe they don't want to think about when they're using electricity. There are other industries where intelligence and flexibility create huge disadvantages - for example, consider how preferable it is in a city to use a train rather than a bus for public transit. It's not really that the train is all that much faster - the point is, it's locked to a track and there's no way to move it. You can't have one schedule for weekdays, one for Saturdays, one for Sundays, one for holidays and Labor Day, all with different routes here and there (as is literally the case for the Madison, Wisconsin bus system). Another example would be the supermarket's quaint simplicity of ordinary cash and fixed prices versus the glitzy game of shopper cards, credit cards, "cash back", etc., all played out in daily bottlenecks at the card reader. Stupidity can be liberating ... it has a hidden sensibility to it. Wnt (talk) 03:19, 6 October 2011 (UTC)[reply]
No one is likely to force you to think about when you use electricity. If you don't want to think that's your choice, you'll just potentially have to pay higher prices then if you thought a little about it. Note that long term, depending precisely on how people react and how the companies choose to adjust their rates, those who choose not to think about it could still end up paying less then if that info had not been available. Similarly I don't know where you live but in most countries you can still use cash, no one is forcing you to use anything else. On a personal level, I find credit cards and debit cards much simpler then cash a lot of the time. No need to look for change or anything like that and although this does depend on your financial system and bank set up, often no need to worry about whether you have enough money (without carrying a lot of cash around). Your comment on buses vs trains isn't that accurate either. It depends significantly where you live.Nil Einne (talk) 06:49, 6 October 2011 (UTC)[reply]
I'm not really disagreeing with you much - I'm not actually an activist against smart meters. I just wanted to point out that opposition to them can be rational, and hope that a vigorous discussion about such issues will help to ensure a better outcome. From your "depending precisely..." statement it sounds like you actually agree with me that the meters could be problematic for some people. Wnt (talk) 13:55, 6 October 2011 (UTC)[reply]
No, I'm simply saying if they actually cause people to significantly modify their behaviour, by their own choice, then this could lead to a significant reduction in the peak demand which could lead to a lower price for everyone. On the other hand, if most people, again by their own choice, don't adjust their behaviour then it may not. In such a case, the majority may end up paying a slightly higher price, with some (those who do adjust their behavior) paying less. However it doesn't automatically follow these people will feel hard done by. They may recognise that it was their choice not to adjust their behaviour. Nil Einne (talk) 15:26, 6 October 2011 (UTC)[reply]
I just had a can of Manischewitz Chicken Noodle Soup and I noticed afterward that there's 20g of protein per serving for a total of 40g in all. Here is the nutritional fact label [23] So, why does this wee can of soup have more protein than a bottle of that Super Protein Odwalla stuff? Is it the egg noodles? Sir William Matthew Flinders Petrie | Say Shalom! 6 Tishrei 5772 00:19, 4 October 2011 (UTC)[reply]
Could be from the grain the noodle is made from. Wheat has a lot of protein. Chicken breast also has a lot of protein. Other than that can't think of anything. --DeeperQA (talk) 00:51, 4 October 2011 (UTC)[reply]
So, another question. First the context. After consuming an omelette composed of ten large eggs, I was told by my ima that I need to have egg white omelettes from now on or I'll have a heart attack, etc. I looked at Wiki's article about them and saw that 4/5 of the egg's protein is contained in the egg whites, but it says nothing of the vitamins (unless I missed something). So my question is, what is the usual vitamin content of egg whites in a large egg? I'd like to know before I consider switching to egg white omelettes. Sir William Matthew Flinders Petrie | Say Shalom! 6 Tishrei 5772 00:27, 4 October 2011 (UTC)[reply]
Little vitamins. Many sites on the Internet provide the exact breakdown. (Nutitiondata) I purchased 50 lbs of egg white to support the protein requirements of my diet and depend upon vitamin supplements for vitamins. However I have returned to whole fresh eggs since the egg yoke has many vitamins and I take a Lecithin concentrate (400mg) 3 times a day plus a prescription medication to keep the cholesterol under control. --DeeperQA (talk) 00:43, 4 October 2011 (UTC)[reply]
Ima? You do realize unless your under medical advice to cut out yolks entirely you could cut down to one whole egg and a few eggwhites on top? It'll taste better too. Ten eggs'd kill anybody. There's the case of that guy on death row got a reprieve and died from the final meal of two whole chickens and a five lb bucket of peaches he'd eaten. μηδείς (talk) 00:55, 4 October 2011 (UTC)[reply]
Ima is the rapport of every Israeli child (though usually said as imaaaaaaaaaaaaaaaaaaa!!!!!!) Yeah I was thinking about that. It would be half and half though as I use one of those pans with the weird egg guy on it and it only fits two eggs at a time (and cooks them in a manner similar to pita bread with an air pocket in the center). Last doctor's check I had just had two slices of cheese pizza and so the doctor thought it best to wait on a cholesterol test (though a few years back I had had a cholesterol issue of levels which sounded like they would be fatal from the Wiki article). Come to think of it, the perscription slip for one is lying right there on the end table since 22 August. Meh, if I didn't eat it, my dad wouldn't have he was concerned that it had sort of missed the spatula if you get my meaning (though I roasted any germs off). I probably won't eat one that big again though, but man was it good (with a lot of parsley in it). Well the inmate sounds like an idiot for eating that many peaches, and I have a desire to lol, but at the same time... not a bad way to die, really. Sir William Matthew Flinders Petrie | Say Shalom! 6 Tishrei 5772
Isn't it true though that the cholesterol in your blood is not terribly related to the cholesterol content of the food you eat since the cholesterol in your blood is stuff that you yourself produced from fat? Googlemeister (talk) 13:19, 4 October 2011 (UTC)[reply]
It is quite true afaik my good sir, but try telling that to a Jewish mother. From what I have read, your body will either excrete excess food cholesterol or produce the missing on its own; the bad evil heart clogging cholesterol comes from saturated fats, or, more specifically, the content of delicious Hagen Dasz Ice Cream sundaes and beef ribs. :( Sir William Matthew Flinders Petrie | Say Shalom! 7 Tishrei 5772 01:10, 5 October 2011 (UTC)[reply]
Our nearby Whole Foods was selling ostrich eggs at one point, but I didn't like eggs at the time. Now that I do, they've stopped selling ostrich eggs! How do those taste compared to chicken omelettes (not that my spicing can't fix anything)? Sir William Matthew Flinders Petrie | Say Shalom! 7 Tishrei 5772 01:10, 5 October 2011 (UTC)[reply]
Unless maybe you are in South Africa or something I would think an ostrich egg would have to be way more expensive then the number of chicken eggs it would take to make a similar sized dish. Googlemeister (talk) 13:14, 5 October 2011 (UTC)[reply]
Hi,
every time that someone makes a buzzcut, you can see its scalp.
Well my question is why on the the top of the head you see the skin, and on the other places you can't, another question is which parameter is related to this subject. — Preceding unsigned comment added by 77.126.59.28 (talk) 00:35, 4 October 2011 (UTC)[reply]
It depends on the angle of vision, the type of cut caesar haircut, fade haircut and the fact that hair does not all lie flat, with hair on the top of the scalp of people with straight hair usually curling outward from a hair whorl or cowlick. Ask a friend to let you examine his hair next time he gets such a cut. Run your fingers across the top of his head, then around the ears and up the back of his neck and see how it feels. μηδείς (talk) 01:44, 4 October 2011 (UTC)[reply]
Though I suffer from both acrophobia and a sincere fear of flying, during a flight the one thing that does not bother me is the height we're at. It's great to be able to land and recognize individual trees because it means we're about to have an end to this quest. But this is when we're still at a 1000 feet. Being on a balcony at 200 feet scares me. The 1000 feet in a plane is something I seem to take for granted, the 200 feet is actually quite high and obviously I could easily fall over this rather low fence, strange that nobody else seems to acknowledge in what horrible situation we are, I hate this evil architect who probably never walked here himself and probably lives in a bungalow, etc.
My theory is that the big difference is that in the case of flying there is no building or rock I need to trust not to fall apart. My evolutionary brain obviously doesn't understand that falling from a hot air balloon is just as deadly as falling from a big building because my genes never had to deal with flying to survive. My genes also never had a problem with heights when walking up a 200 ft hill. In my experience, acrophobia does not really imply a fear of height itself but a fear of the consequences of a failing construction which are obviously higher at 100ft than at 10ft. I see no mention of that in Acrophobia and I would like some insight in my own phobias :) Joepnl (talk) 00:40, 4 October 2011 (UTC)[reply]
I don't know from phobias, but I share your seeming dichotomy about flying vs. balconies, except that I don't have any fear of flying at all. I feel "safe" in an airplane because it's totally enclosed. (I could be wrong, but if I'm wrong, I'll only be wrong once.) Being anywhere near a situation where I could either fall off a high place or where a structure such as a balcony railing could give way, has the effect of making sure I keep well away from the edge. And the photo of Phillippe Petit tightrope walking between the World Trade Center towers still gives me sweaty palms. However, keep in mind you could be killed falling from the second story of a building. The only difference in falling a hundred stories is that you have time to think about it on the way down. ←Baseball BugsWhat's up, Doc?carrots→ 06:22, 4 October 2011 (UTC)[reply]
I can't quite understand what you mean by 'my genes...' As I understand it as a sufferer and an ex-therapist who has treated people for other kinds of phobias, the fear is an acquired behavioural problem and has less to do with genes. The anxiety associated with acrophobia can be overcome with help and permanently suppressed. The anxious ideas and emotions felt within an active phobia are always present and always irrational, 'I might throw myself off this parapet', 'If I go any further I will have a heart attack', 'this building could collapse at any moment'. This irrationality is the heart of the beast and once you have been able to overcome the apparent 'truth' of these silly ideas then the phobia will be overcome. Your theory about the plane not collapsing does not hold for many people who fear its mechanical failure/pilot being suicidal/terrorist attack/bird strike etc. etc. Getting a phobia fixed is not difficult, it requires some steely determination as you challenge to destruction those irrational ideas of what might happen. I am not advising you to do anything, that is up to you.Caesar's Daddy (talk) 07:34, 4 October 2011 (UTC)[reply]
By "my genes" I mean that I think that down below there is a rational reason to be afraid of heights. People who are afraid of heights probably live longer than people who really like heights. That's where the genes come in. Being scared too much is acquired as you say. When I was 9 I didn't have it. (But when I was 2, I also didn't have a problem eating poo for which I have acquired a phobia, too). My theory about planes not collapsing is only meant for heights. I experience exactly the things you describe when it comes to flying, but the very odd thing about it is that the height absolutely doesn't bother me. Being "phobia-prone" that's the thing that amazes me. Btw, I do fly when it's necessary, it's just not a nice experience. Tall buildings are easy to avoid. Being afraid of spiders would be more inconvenient. Joepnl (talk) 00:02, 5 October 2011 (UTC)[reply]
I'm curious about this too. It's odd. Tiny planes, large planes, hot air balloons are fine but standing on the edge of cliffs, tall buildings (and I've lived/stayed in many), the decks of large boats, being in tall trees are all scary for me. Being connected to the ground seems to makes a big difference. It's patently irrational because I can rationally compare the consequences (fell off a cliff=wasn't too bad vs botched hot air ballon landing=fractured a rib, hurt like hell) and it hasn't changed my instinctive response at all. Sean.hoyland - talk07:33, 4 October 2011 (UTC)[reply]
Aren't phobias, strictly speaking, irrational fears? I don't know about you but I think that the fear of falling off a 100 ft cliff to be perfectly rational. It would be irrational if one were to fear a cliff which was only 4 feet tall. Googlemeister (talk) 13:14, 4 October 2011 (UTC)[reply]
Yes, I guess a phobia is by definition irrational but it's odd how some responses are pretty resistant to evidence and experience e.g. people only have to put their hand in a fire once to not do it again and they aren't left with an irrational response everytime they see a fire whereas most phobias are hard to dislodge. I guess it would be rational to fear heights etc if it made someone more careful in those situations but oddly it often seems to have the opposite effect and increases the likelihood of someone doing the wrong thing. Phobias rarely seem to be useful either. I've never met anyone, anywhere, with a mosquito phobia for instance (which you might expect to be quite a useful thing to have evolved) or an irrational fear of pointy things but put a harmless snake in front of many people or put them on a perfectly safe ledge up in the air and everything goes wrong. Bizarre. Sean.hoyland - talk15:39, 4 October 2011 (UTC)[reply]
Evidence and experience are both not hardwired in a brain. From personal experience "doing the wrong thing" is not what you do. People with acrophobia trying to jump over the fence sounds like a urban legend to me. I do have a mosquito phobia and so do you. If a mosquito touches you, you're not going to think "in this area it won't carry malaria so I'll just let it feed on my blood". You smash it the moment you see it landing. That's pretty close to a phobia to me, except that because everyone has the same phobia it's not called one. The fear of pointy things may not be observed a lot, but pointy things are usually not that lethal. To differentiate between harmless snakes and the ones that kill you is quite a job whereas just running away when you see any snake is easy. That's perfectly rational, like not eating any mushrooms because some of them might kill you and it's not worth it to find out which. Washing your hands is a wise thing to do, washing them 200 times a day is not. I think a fear of heights is perfectly rational too, till a certain level. Being afraid that the structure you walk on might fail is wise, but rationality is gone when one, like me, is afraid the Eiffel Tower could collapse because you feel movement.
Anyway, my own acrophobia nor fear of flying was a reason to start this topic. My job does not involve meeting people at 300 ft and I'm perfectly happy driving to France for a holiday. I'm just wondering if the psychologists have been looking at the right thing. A skyscraper at 300ft is scary, a hill at 300 ft is not. It's not the height itself, it's the building. Joepnl (talk) 23:42, 4 October 2011 (UTC)[reply]
"because everyone has the same phobia it's not called one" is a good point. I'm curious whether someone has measured the error rates, completion times etc for people walking along something like a 20cm wide, 5m long straight path at various heights to see whether the error rate is flat, increases or decreases with height. Nevertheless, attachment to the ground does seem to play some kind of role for many people. Being on a balcony in a tall building seems to feel different from being in a hot air balloon. Maybe the brain can't deal with not being attached to the ground and it just treats it like being in deep water for lack of a better hardwired model. Sean.hoyland - talk06:10, 5 October 2011 (UTC)[reply]
I am working to put together a simple list of “Open Questions in Science”, as topics for speakers at a Science Club to which I belong. They would be ones of some interest to professionals and the general educated public, and cover all fields. To give you an idea, here are ones I have nominated already:
1. What is dark matter, and does it really exist?
2. What is dark energy, and does it really exist?
3. How did Neanderthals become extinct, and are we really related to them?
4. Did an asteroid impact really wipe out the dinosaurs?
5. How did our Moon come to be? (this one has recently been regarded as settled).
6. Is time travel theoretically possible?
7. How do new species emerge from the old species to which they belonged?
8. Could we engineer our bodies to become immortal?
9. Why do we see no evidence of extraterrestrial life?
10. Is the general form of our Solar System common or rare?
11. Are quantum computers really possible?
12. Is faster than light travel possible, or is it forever prohibited?
That is more like a pop-culture list than what I would expect from scientists in their fields. 3,4,5,and 7 have consensus answers. Six, 8 and 12 are perennial fantasies, although immortality in some form is theoretically possible with enough time and resources to develop and apply the methods. Eleven is an engineering program. The answers to 9 and 10 need more data, but look at Fomalhaut b for recent evidence of Borg activity.
Some better questions might be:
A Is the replicating molecule or the lipid-membrane first model of life's origin correct.
B Are all human languages descended from a common source, and can it or its daughters be partially reconstructed?
C Why is gravitic mass apparently equal to inertial mass?
D Are the physical constants arbitrary, or mathematically necessitated from self-evident principles?
Is our system of nucleic acids one of only a few possibilities for life during evolution, or are there many ways just as good or better for life to use to store its genetic information during its early evolution?
Do alien ecosystems develop the species concept like Earth did? If they evolve species, do they resemble those on Earth? Do they develop plants and animals? Trees have evolved many times here - did similar-looking autotrophs evolve elsewhere? Is bilateral symmetry inevitable? Do quadrupeds, segmented organisms with many legs, bipeds, birds, snakes evolve on other worlds?
How did the laws of logic, mathematics, and physics come to exist? Why is mathematics so detailed? Could another cosmos have different values for pi and e, different arithmetic, different theorems in predicate logic?
Both a person and a video of a person appear to talk, experience stimuli, think and feel. But the video playback is believed incapable of sensation. If you develop the computing system playing the video sufficiently, is there some level of complexity in the computer algorithms controlling the video that can make it so that it becomes capable of feeling? If not, if any arbitrarily complex computer program is never capable of "real" consciousness, what distinguishes brain matter from the computing system in this regard?
The biggest open, obvious, super-important question that I can think of — one that we as of yet have still only groping ideas of even how to approach — is What is consciousness? How does it emerge? How does it work? To me there are few problems of such severe importance as the hard problem of consciousness, and yet after centuries of research, we still have only glimpses as to the answer. --Mr.98 (talk) 23:15, 4 October 2011 (UTC)[reply]
From the realm of meteorology, "Why/How do tornadoes form?" is a pretty big one that is yet unsolved. See Tornado#Ongoing research. If that question could be definitively answered, it would be much easier to forecast where and when tornadoes would hit, possibly eventually leading to the development of Warn on Forecast for tornadoes. Ks0stm(T•C•G•E)23:33, 4 October 2011 (UTC)[reply]
OP myles325a back live. Thanks all, for a great list, it's more than a beginning. I have one, philosophical AND scientific of my own.
PROB: Are all causative agents ultimately reducible to fundamental physics, or can laws governing reality somehow emerge at higher levels and possess a structure which is not defined by laws at a lower level? This is one of those problems, like the possibility of extra terrestrial life, in which either a yea or nay answer is equally astounding. If all phenomena are reducible to quantum physics, then the Weimar Republic is explicable in those terms, and a better understanding of particle physics will make for a better understanding of the history of that Republic. If it is not, then that means that laws can emerge as higher levels come into being. But how can such a thing operate?
I think Wnt's point, above, on AI, is spot on. Consciousness may very well be an emergent property of complexity (and it would be hard to imagine a conscious matchbox) but if complexity is NECESSARY, is it also SUFFICIENT? That is the rub. For I can imagine very complex machines which might not be conscious, say one that controls air traffic all around the world. Myles325a (talk) 01:05, 5 October 2011 (UTC)[reply]
Maximum weight per unit surface area that water can support
Small objects can float on the surface of water due to finite surface tension. Suppose one makes a platform of a few square meters consisting of billions of nanotubes a few nanometers apart as the support. Would such a platform support a few million kg/m^2 as one would expect from the total length times the surface tension, or wouldn't this work? Count Iblis (talk) 04:24, 4 October 2011 (UTC)[reply]
No, it would not work. You got your nanotube surface density calculation wrong. All you would accomplish, is to trap a film of air underneath the platform, but it will still sink. Plasmic Physics (talk) 04:41, 4 October 2011 (UTC)[reply]
It could work, but there are some serious changes that needs to be made, and it is highly impractical with current technology. I'll go into it a bit later. Plasmic Physics (talk) 04:53, 4 October 2011 (UTC)[reply]
Essentially, surface tension keeps a single nanotube afloat, if a sufficiently large weight is applied to a nanotube, it will sink. A cluster of nanotubes is kept afloat by having a lower density than water, provided by a thin film of air trapped between nanotubes closer than the critical radius by surface tension. The more air can be trapped the lower the density, this can be accomplished by altering the length of the nanotubes, or by using multiple layers nanotube clusters. Frankly, it's chheper to glue layers of aerogel to your platform. Plasmic Physics (talk) 05:58, 4 October 2011 (UTC)[reply]
... and, of course, "a few million kg/m^2" is completely unrealistic. Nanotubes, however clever they are, cannot overcome Archimedes' principle, so you would need to displace "a few million kg" of water to provide the buoyancy. Surface tension only modifies buoyancy by moving the displaced water further away from the object. It doesn't provide a force independent of buoyancy. Dbfirs07:41, 4 October 2011 (UTC)[reply]
But surface tension can provide a force in the absence of gravity, showing that the two mechanisms are indeed independent. Robinh (talk) 18:41, 4 October 2011 (UTC)[reply]
Yes, I wasn't suggesting that surface tension is not an independent force, just that its role under gravity can only be to modify the distance to which a fluid is displaced. It is a force between molecules, so has no net large-scale effect. Archimedes' principle rules buoyancy. I suppose that surface tension can also provide a "downwards buoyancy force" by lifting a liquid upwards against gravity. I agree fully with the analysis by Plasmic Physics above, except that I would add that the buoyancy of the nanotube is provided ultimately by the weight of water it displaces. The surface tension acts only as an intermediary force, upwards on the nanotube and downwards on the displaced water. Dbfirs07:28, 5 October 2011 (UTC)[reply]
In solution, copper (II) ions form more stable bonds with water, likely due to the greater charge density (2+ vs. 1+ over essentially the same volume), thus forming stronger bonds with the Solvation shell. Copper (I) ions tend to disproportionate in water, as the difference in energy between the solvation of copper (II) and copper (I) ions is greater than the energy needed to transfer an electron between two copper (I) ions to cause the disproportionation to occur. At least, that's the opinion here: [25]. This page: [26] has a discussion of Copper (I) chemistry and how to avoid disproportionation. This page here looks at the disporpotionation of copper (I) from an electrochemical/thermodynamic point of view. The disproportionation reaction has a positive Eo value, which means that it is thermodynamically spontaneous. It is apparent that the existance of the radical is not the predominant factor in determining the stability of a species in this case. (And in other cases as well. The ground state of O2 is Triplet oxygen, which is a diradical.) --Jayron3213:13, 4 October 2011 (UTC)[reply]
Copper (II) is more stable than copper (I) in nearly all conditions, given a long enough time frame nearly all copper (I) compounds will eventually (and in solution, usually rather quickly) disproportionate; this can be of a long enough time frame to create metastable copper (I) compounds which remain long enough to be useful for long times, however thermodynamically the disporportionation of copper (I) into copper (II) and neutral copper is always spontaneous. The Jahn–Teller effect doesn't deal with the overall stability of these ions, it is pretty much unrelated to the OP's question. That effect deals with the shapes and symmetries of coordination complexes of some metal ligands; it applies to copper (II) because of the radical nature of copper (II) prevents complexes of copper (II) from assuming certain types of symmetry. That has nothing to do with the overall stability of copper (II) vis a vis copper (I) which is an unrelated problem. --Jayron3213:33, 4 October 2011 (UTC)[reply]
TenOfAllTrades:By more stable, I mean at a lower ground state. I understand that diradicals are more stable than monoradicals, but not why this monoradical is more stable than the nonradical. It is to me like someone saying that Ga•4+ is more stable than Ga3+, we all know it's not, but that's point. My logic tells me that it should be energetically unfavourable to remove a second electron from Cu+, but it is not. (proven by experiment) Plasmic Physics (talk) 23:07, 4 October 2011 (UTC)[reply]
I think, Plasmic, the mistake you are making here is assuming that a single variable (paired vs. unpaired electrons) is the sole variable when determining the relative "stability" of two species. It is true that, in many situations, radicals are often less stable than those situations where there are no unpaired electrons; but not always (the example of dioxygen is important to consider here) and can't be handwaved with "but it's a diradical". If the only consideration were the presense of unpaired electrons, dioxygen would have all of its electrons paired. There are obviously other factors at play which can make radicals more stable than non-radical analogues. Arguing that copper (I), a nonradical, should be more stable than copper (II), a radical, ignores an important bit of evidence called "reality". If your assumptions don't match reality, then it isn't reality which is incorrect. --Jayron3200:12, 5 October 2011 (UTC)[reply]
I don't really have an answer yet, having a positive Eo value is consequencial rather than casual. The disproportionation of Cu+ is consequencial of its relative instability compared to the products. What is at the root of it all? Plasmic Physics (talk) 22:05, 5 October 2011 (UTC)[reply]
Actually I had taken this photo in Malaysia, and the size is like a thumb's size(you can also compare it with the structure of the moss). Thanks for the information.--Inspector (talk) 08:46, 5 October 2011 (UTC)[reply]
Ah, then it's very likely to be C. sulcipes :) There are several pictures of them also from Malaysia on the internet. I have requested a rename of the file.-- Obsidi♠nSoul11:25, 5 October 2011 (UTC)[reply]
firing a blank
The old story goes that when someone is executed by a firing squad, one of the rifles contains a blank and the rest contains live rounds. Supposedly this is done so that each firer will have some doubt whether he fired a bullet killing the condemned. However, since the gun is not actually sending a projectile out, but only the firing gasses, I would think that he would know he did not fire a bullet because the gun would not recoil nearly as much. I myself have never fired a blank round, but is my supposition correct here? Googlemeister (talk) 13:37, 4 October 2011 (UTC)[reply]
It depends on the type of blank and the rifle used. For example, you cannot fire a blank from an M-16. The gas will escape and it will not push the bolt back. So, the M-16 requires a blank firing adapter to trap the gas in the barrel. It would be very obvious if you had a BFA on your rifle. But, the recoil would be similar because the recoil you feel is used to push the bolt back and, if the recoil of the blank+BFA is capable of pushing the bolt back, you feel it. Ignoring semi-auto gas-powered rifles like the M-16, consider gunpowder rounds in a standard rifle. If you have a round with just gunpowder, it doesn't kick very hard at all. If you use a wax round, you get a reasonable kick compared to a live round. It depends heavily on how intact the wax is as it escapes the rifle barrel. So, by using good wax, you can create a dummy round that won't kill anyone at a distance, but will kick reasonably well. There are also paper rounds - often used in movies.The paper burns up in the air, but still allows for a reasonable kick. My experience is that the paper rounds don't kick as hard as the wax rounds. So, if I was trying to fake a real round, I'd use wax. -- kainaw™13:59, 4 October 2011 (UTC)[reply]
I can say both from personal experience and from my knowledge of physics that a weapon with a BFA (blank fire adapter) will not have anywhere near the same recoil as a when you fire a live round. The recoil you will feel comes from the conservation of momentum, and for a given weapon it depends on the weight and forward velocity of the bullet and the gases as they leave the muzzle (or BFA as the case may be). Blank rounds for military use often have a plastic bullet that's much lighter than a live one. The plastic bullet disintegrates in the BFA and leaves the weapon with a pretty low forward velocity. The lower weight and velocity makes for a weaker recoil. Yes, the BFA traps the powder gases for a short while so there's a force that acts on the bolt and pushes it back, but there's also a forward force acting on the BFA from the bullet and gases hitting it and those forces nearly cancel each other out.Sjö (talk) 17:57, 4 October 2011 (UTC)[reply]
None of the blanks I used in my M-16 had bullets of any kind. They were regular rounds with the bullet removed and the case crimped shut. There are obviously many kinds of blanks with very different results. -- kainaw™18:15, 4 October 2011 (UTC)[reply]
I've never fired an M-16 with a BFA so I guess it's possible that the recoil for that weapon is roughly the same with or without the BFA.Sjö (talk) 18:30, 4 October 2011 (UTC)[reply]
Although there have been very few firing squads since the introduction of automatic or self-loading rifles - at least in countries civilized enough to worry about the guilty conciences of the participants. The last person shot in this way by the British Army seems to have been a German spy called Josef Jakobs who was shot in 1941 in the moat of the Tower of London, presumably with standard Lee Enfield bolt-action rifles. Alansplodge (talk) 23:22, 5 October 2011 (UTC)[reply]
Gary Gilmore was executed by firing squad in 1977, and according to a source in the article [30] one of the rifles was loaded with a blank. I'd also like to point out that you can easily fire a single blank round in a self-loading weapon, but it won't reload due to the weaker recoil and gas pressure.Sjö (talk) 10:32, 6 October 2011 (UTC)[reply]
Of course, but if the point is to camouflage the fact you fired a blank, the firearm would need to behave as normal, which would mean the self loading would need to take place. Googlemeister (talk) 13:31, 6 October 2011 (UTC)[reply]
Strength of glass vs aluminium
Imagine I was building an oceangoing vessel (I'm not, this is purely hypothetical, but it helps to make the question less abstract). I would like to make the windows in my imaginary wheelhouse proof against being broken in a very severe storm. The damage they need to resist could come either from the pure weight of water, or potentially a point impact from items on deck being thrown against the windows. It's not really possible to model those forces, so instead I set my hypothetical design requirement to be that the windows mustn't be any weaker than the metal structure of the wheelhouse itself. The wheelhouse is made of aluminium, whatever grade is commonly used for such purposes. As a finger in the air, let's say it's made of 10mm plate. Each window is perhaps 2 feet by 2 feet.
The glass can be toughened, laminated, whatever technology is available, but it does need to behave like "real" glass, eg not scratch like plastic windows. Since it is to be fitted to an imaginary vessel, cost is not really a concern, but the suspension of disbelief probably doesn't extend to really exotic materials costing hundreds of thousands.
Is it feasible to have a window that is as strong as the wheelhouse in this way? What material would it be made of, and how thick would it have to be?
Energy absorbed by brittle (red) and ductile (blue) materials before breaking You can certainly increase the strength of glass by laminating or tempering it, but I'm going to venture a guess that achieving equivalent strength of the structure (by the way, most oceangoing ships are made of steel, not aluminum) is probably not feasible without a very, very thick pane of glass. The reason is the difference in the Resilience of glass and metals (i.e. the amount of energy that can be absorbed before breaking)--glass is very brittle, while metals are more ductile, so metal can absorb much more energy before breaking. This is commonly cited as one of the reasons the Titanic sank-- the steel that composed the hull was much more brittle than it should have been, which was exacerbated by sailing in the cold waters of the North Atlantic. Mildly MadTC16:38, 4 October 2011 (UTC)[reply]
According to our article on AlON, your 2'x2' window pane could be made at a cost of around $5-10k each. I don't know if strictly speaking it is a strong as aluminum, but it seems like it is very good at impact resistance. Googlemeister (talk) 18:31, 4 October 2011 (UTC)[reply]
I'd go with coated polycarbonate, to get both polycarbonate's impact resistance and the coating's scratch resistance. There's a reason why it's used for things like airplane canopies and bulletproof glass. --Carnildo (talk) 01:07, 5 October 2011 (UTC)[reply]
Thanks for your answers - must admit I'd hoped someone might find some specific figures from a manufacturer or engineering databook :-). I'll look at the general references though.
For what it's worth, aluminium upperworks are not uncommon on smaller vessels even when the hull is steel - helps keep the centre of gravity a bit lower. --Pete — Preceding unsigned comment added by 93.97.184.230 (talk) 20:54, 5 October 2011 (UTC)[reply]
What makes a material tough from a molecular point of view?
On one hand, you have ceramic which is hard, but brittle. On the other hand you have metal which is ductile, but not as hard as ceramic. Is it possible to model on a computer, an arrangement of atoms and say, "yeah this would give it characteristics of both"? ScienceApe (talk) 21:13, 4 October 2011 (UTC)[reply]
To some extent, the ability to resist impact is diametrically opposed to hardness. However, there are materials, such as metals, which are a good compromise between hardness and the flexibility needed to absorb energy from impacts without fracture. Also, a denser material is able to absorb more force, hence the use of materials like depleted uranium for armor. Another approach to get "the best of both worlds" is composite materials, such as in a Kevlarbulletproof vest. StuRat (talk) 02:18, 5 October 2011 (UTC)[reply]
Young's modulus in metals and fully bound solids like diamond and salts is notoriously difficult to simulate from Schroedinger wave equations because it's heavily dependent on resonances between many if not most of the substance's outer electrons. And the other quantity you ask about, resilience, depends on it. You can have slightly better luck with composites but in general they are much weaker and more brittle, and when they aren't, as in carbon fiber composites, you run in to the same problem. 69.171.160.19 (talk) 04:10, 5 October 2011 (UTC)[reply]
Irish winters
What were the causes of the cold winters that hit Ireland and other countries in europe to get a cold winter of during 2009-10 and 2010-2011 is this likely happen again this year at the same severity or much worse. --86.45.141.20 (talk) 21:15, 4 October 2011 (UTC)[reply]
No. See Winter of 2010–2011 in Great Britain and Ireland; "During the latter part of November, northern blocking established over Greenland which resulted in the Jet Stream moving south, allowing cold air to flow in from the east." The Winter of 2009–2010 in Europe: "Globally, atypical weather patterns brought cold, moist air from the north. Weather systems were undergoing cyclogenesis from North American storms moving across the Atlantic Ocean to the west, and saw many parts of Europe experiencing heavy snowfall and record-low temperatures."Alansplodge (talk) 23:04, 5 October 2011 (UTC)[reply]
What's the maximum distance an electron can be from the nucleus before the value of the probability distribution is 0? Or is it always positive (though very small)? --99.119.63.240 (talk) 21:32, 4 October 2011 (UTC)[reply]
An electron will have positive probability almost everywhere including at arbitrarily large distances (though the probability decreases exponentially towards zero with distance). Dragons flight (talk) 21:36, 4 October 2011 (UTC)[reply]
Sort of. Except that would assume that you could identify an electron at a single location which you cannot. Saying (in a quantum sense) that the probability of finding an electron at any given distance from the nucleus is nonzero is not the same thing as finding a discrete ball of negative change just hanging out at a point in space at that distance. The electron would have to actually, you know, exist as a discrete ball which stays still at that point. Also, as electrons are nondistinguishible, detecting an electron with an actual detector gives you no information as to the actual specific atom that is the source of that electron. So, you actually can't extend the probability distribution given by the wavefunction into a real chance of finding a specific electron (such as say, the ground state electron of a specific atom of hydrogen) at a specific distance from the nucleus. There's just no way to do that, in an empirical sense. --Jayron3202:57, 5 October 2011 (UTC)[reply]
Yes, one can observe this indirectly. If you put an atom in a constant electric field, then it has a finite ionization probability, no matter how weak the electric field is. The physical reason for this is that there is enough energy to ionize the atom if the electron moves a large enough distance. But this does mean that even in the ground state, the electron can be arbitrarily far removed from the nucleus. If the wavefunction were such that an electron is always less than some distance d from the nucleus, the ionization probability would become zero already below some nozero electric field strength. Count Iblis (talk) 23:40, 4 October 2011 (UTC)[reply]
Previously in 2008 on the Ref Desk or in the article Atom we discussed an experiment in which an atom was isolated, and energy was pumped into it until the electron was at a ridiculous distance from the nucleus, like a millimeter. The phenomenon was derided as being merely was something like a "Rydberg atom" without clarifying how it was not a "true atom." The archives of the article are not responding, so I cannot cite the relevant revisions other than [31].Edison (talk) 05:04, 5 October 2011 (UTC)[reply]
We do have an article about the Rydberg atom (cool (sorry:) bit of physics!). The comment appears to have been removed from Atom with this talk-page discussion. I disagree with that, now that there are multiple papers (heck, a whole cited article about the phenomenon)...not for WP editors to judge whether it's "a real atom" if that's what WP:RS call it. Can certainly improve the wording to be more WP:V correct numerically, etc. DMacks (talk) 18:04, 5 October 2011 (UTC)[reply]
Wardens
My question for the community to investigate is, "Do wardens execute criminals?" I have attempted to respond accurately to this science question, but I CANNOT DO IT! Can someone in the community PLEASE help me? — Preceding unsigned comment added by 24.0.70.91 (talk) 22:53, 4 October 2011 (UTC)[reply]
The warden gives the final order for the execution to proceed (indicating, among other things, that there's been no reprieve). To that extent, he/she is a participant in the execution: even though someone else sets up the IVs and pushes the button, the warden is the one who, in the end, says "push it". -Nunh-huh01:52, 5 October 2011 (UTC)[reply]
Yes. The OP seems to be using warden in its sense of any prison guard while the answerers seem to be using the (apparently mainly American) definition meaning only the boss of the prison. Certainly in most cases a prison employee is the executioner. Rmhermen (talk) 14:08, 5 October 2011 (UTC)[reply]
Yes, I was confused over the meaning of the term used in the question. In the UK, a prison officer is a warder not a warden. Dbfirs20:58, 5 October 2011 (UTC)[reply]
Whether you call him a warder or a warden, if he's executing anyone in the UK, I'd say he's improvising rather dangerously. - Nunh-huh05:03, 6 October 2011 (UTC)[reply]
Clinton Duffy was the Warden for 12 years at San Quenton prison, and suoervised the execution of 90 people. In the US, it has been common to establish continuous communication with the state Attorney General and Governor to make sure there is no impediment such as a stay from a judge or a pardon or stay from a Governor. The Warden would arrange for an executioner and for the means of execution (gallows, firing squad, electric chair, gas chamber, lethal injection). He decides on the exact time of execution. He would arrange for a physician to pronounce the prisoner dead. He would ascertain that there was a valid execution order. He would arrange for a Priest or spiritual adviser if the condemned prisoner requests one. He would arrange for witnesses (friends or family of the condemned, victims' family, citizens and press). [33], [34], [35]. Edison (talk) 22:52, 5 October 2011 (UTC)[reply]
October 5
Why are impact craters on Moon all circular?
This came up at a Science Meet where an exponent of non-Standard Model of the Universe (to wit: Electric Universe) declared that these formations were volcanic in origin, and were not impact craters. He cited in evidence that if they were impact craters, then many would be like skid marks, from asteroids which came in obliquely. There were other criticisms of the asteroid theory, but they were quite technical. Otoh, the objection to craters in that they are all too circular and neat caused me to raise my monobrow like a big hairy boomerang. What do you think? Myles325a (talk) 01:14, 5 October 2011 (UTC)[reply]
The energy released at the point of impact converts to heat, causing debris to expand in all directions from that point. There will also be a few skid mark craters that are elliptical in shape due to glancing blows. Did you read Impact crater? Graeme Bartlett (talk) 01:41, 5 October 2011 (UTC)[reply]
I believe the maria are ancient lava flows, so volcanism did occur early on. Here's an example that looks like a skipping meteor blow to me, in the lower left corner: [36]. Also, if the meteor skips enough, it may make a shallow impact over a wide area rather than a single deep crater. That type of shallow crater is likely to be obscured more quickly by volcanism, dust, and later meteor impacts. StuRat (talk) 01:50, 5 October 2011 (UTC)[reply]
Reaching back into the inventory of everything I ever read, some fictional work about space exploration asserted that if you spread a layer of flour on a countertop, then throw little round dense objects (lead shot? peas?) at it vertically or at any conceivable angle, every crater is observed to be circular. Intuitively, I would have expected a vertical drop to produce a circle, but a 45 degree angle to produce an ellipse. Edison (talk) 04:53, 5 October 2011 (UTC)[reply]
There are young craters with asymmetric ray systems such as Proclus (crater) suggesting an oblique impact. I don't understand how the person who is suggesting a volcanic origin proposes to explain the extensive shock deformations you can see in lunar samples. Sean.hoyland - talk05:49, 5 October 2011 (UTC)[reply]
Apparently the answer is most, but not all are circular. Please see Impact crater#Crater formation, "Since craters are caused by explosions, they are nearly always circular – only very low-angle impacts cause significantly elliptical craters." Ref. Melosh, H.J., 1989, Impact cratering: A geologic process. New York, Oxford University Press, 245 p.' The same section of the article also has a video of "a laboratory simulation of an impact event and crater formation" (apologies to Graeme Bartlett, who I now see has referred you to the same article.) • Here is an Australian Broadcasting Corporation (ABC) webpage on the question, Are impact craters always circular? - 220.101talk\Contribs08:44, 5 October 2011 (UTC),[reply]
If I were to have a sheet of say, aluminum that was a 2-inch square and 1 atom thick, would I be able to see it by looking at it from the "square" side? If so, would it look any different from the kind of aluminum foil that comes on a roll? (other than the fact that it appears much thinner) Assume that variables that could damage the foil (oxidation, corrosion, wind, etc.) are nonexistent. Hmmwhatsthisdo (talk) 06:34, 5 October 2011 (UTC)[reply]
It would be completely transparent at optical wavelengths (except for a few sharp faint frequency harmonic bands that you would be completely unable to discern.) The atomic radius of aluminum, 1.4 angstroms, is less than 1/2,500th the wavelength of visible light. Also it would spontaneously disintegrate due to unavoidable Brownian motion of the air, which isn't wind. 69.171.160.19 (talk) 07:03, 5 October 2011 (UTC)[reply]
It spontaneously disintegrates in a vacuum too, just as fast, due to inherent mechanical strain of the vibration of room temperature heat. There is essentially no cohesion of metals an atom thick. They might as well be molten as far as they act. 69.171.160.19 (talk) 07:28, 5 October 2011 (UTC)[reply]
I've made a <5 nm (50 angstroms) bismuth nanofilm in the lab before. It's very translucent, and has infinite resistance (whereas a 20 nm nanofilm conducts a decent amount of electricity -- a small piece would have had a resistance of about 500-1000 ohms). elle vécut heureuseà jamais (be free) 05:08, 6 October 2011 (UTC)[reply]
Height Increase
I have heard that height of a human being can be increased artificially by a painful surgery. Is it possible? Please give the name of it. — Preceding unsigned comment added by 119.235.51.130 (talk) 14:16, 5 October 2011 (UTC)[reply]
The phylogeny of the flowering plants, as of APG III (2009).
It's not just catnip really. Those (unranked) 'ranks' above the ordinal level in plants are clades, which do not actually have taxonomic ranks. This is because all plant articles in Wikipedia follow the modern APG III system of the Angiosperm Phylogeny Group. This system is more accurate than the old Linnean system because it uses molecular genetic data for grouping plants. Remember that the Linnean system was established before the discovery of evolution and the DNA. So they were traditionally and inaccurately grouped simply by morphological and biochemical characteristics.
For example, flowering plants (angiosperms) were once grouped into two classes - Monocotyledons and Dicotyledons based on the number of cotyledons. Obviously this is a rather unreliable way to classify plants. APG discovered that though monocots are monophyletic (that is, they are all descendants of a common ancestor), dicots are not. Though most dicots are monophyletic (now grouped into the clade Eudicots - 'true dicots'), not all of them descended from a common ancestor. Magnoliids, for example, exhibit two cotyledons and have been traditionally classified under dicots, but they actually diverged earlier than eudicots (see phylogenetic tree on the right). Some genera, like Amborella, are also basal (arising earlier than other clades) and thus can not be classified under any of the traditional orders (as of APG III, the single species of the genus has been classified under their own order, separate from the rest). Others are simply not well understood like members of the family Sabiaceae, etc.-- Obsidi♠nSoul04:07, 6 October 2011 (UTC)[reply]
I have not tried to do that. I have run a 3 phase motor on 2 phase power. That is not very uncommon. When the only power available is 1 phase power, a static 1 phase to 3 phase power converter will produce 3 phase power to get a 3 phase motor started. Then, the static converter will drop to 2 phase power to continue running the motor (yes, this can damage 3 phase motors not designed for 2 phase power). I don't see how a single phase will keep it rotating under any load. Unlike a single phase motor, a three phase motor doesn't have a capacitor to rotate the incoming power and create a second phase (technically, single-phase motors convert the power to 2 phase power internally and are really 2 phase motors). It is possible that some very fancy three phase motors are internally six-phase motors (using the same technology as a single phase motor). Then, I'd be certain that if you got it started, you can keep it spinning on a single phase of power. -- kainaw™13:19, 6 October 2011 (UTC)[reply]
homology / analogy of env viral coat proteins, across mammals and Drosophila
I'm designing the beginnings of a selective intercellular transport protocol, and I'd like to take advantage of some of the interesting properties exhibited by HIV env (perhaps make a pseudotype). I note that Drosophila has some endogeneous retroviruses, such as gypsy which too, codes for an "env-like" protein. However, when I actually do a BLAST search between gypsy env and HIV env, the alignment is quite poor, on both a protein level (for gypsy open reading frame 3, which codes for env, and HIV gp120 / gp160 etc.) and a nucleotide level -- often the query coverage is less than 20%. How possible is that HIV env and gypsy env would just keep a few conserved domains and rapidly mutate all the non-critical domains, and that BLAST scores aren't useful for detecting homology between retroviruses of distant species?
Other than the receptors, are there significant differences in the mechanisms of HIV-1 env and gypsy env? Could I use HIV env in Drosophila? This is because the required receptors on the target cell required for gypsy env to induce efficient infections remain poorly-characterised, unlike the receptors/coreceptors required for HIV env. elle vécut heureuseà jamais (be free) 05:05, 6 October 2011 (UTC)[reply]
Eating "unpleasant" foods
There are many foods that people eat routinely that are in some sense "unpleasant", such as spicy, sour, and bitter foods. Many of these contain chemical irritants that "burn" your mouth or otherwise might discourage some people from eating them, and yet many of us (myself included) enjoy eating them frequently. Presumably such qualities originally evolved to discourage animals from eating these plants, though now they are paradoxically the reason that we intentionally cultivate many foods for consumption.
Now, what I am really wondering about is whether the irritants in "unpleasant" foods have an impact beyond the mouth and immediate process of eating them. For example, does eating such foods also tend to irritate the stomach or bowel in a way that can make people more prone to digestive problems such as stomach aches, heart burns, diarrhea, etc? I know people who have given such an explanation for not eating spicy food, but I'm not sure if there is good empirical evidence for this or not. Dragons flight (talk) 07:56, 6 October 2011 (UTC)[reply]
Eating certain spicy foods, irritates the digestive tract. Normally, this is not a problem however, regular consumption of such foods can result in ulceration which may lead to further complications. In fact, it has been proven that daily consumption of curries usually causes the stomach lining to thin considerably. Plasmic Physics (talk) 09:55, 6 October 2011 (UTC)[reply]
Centipedes
Specifically, Scutigera coleoptrata, or the "house centipede". They look like a little mustache running along. Creepy critters. But supposedly they feed on other, creepier critters. One thing is unclear or unstated in the article: Do they pose any threat to humans? That is, do they bite? Or are they harmless? Does anyone here know? Thank you! ←Baseball BugsWhat's up, Doc?carrots→ 09:39, 6 October 2011 (UTC)[reply]
I know that the earth's tilted axis is the primary reason that we have seasons, but how much of an effect does the varying day length have? --CGPGrey (talk) 10:07, 6 October 2011 (UTC)[reply]
That might be a bit more detail than an encyclopedia would get into. OR, it might just be that no one has researched it and added it. Obviously, the length of the day has a qualitative effect on both atmospheric and oceanic temperatures. An exact percentage might be hard to come by, as it's liable to vary from season to season, due to factors such as el nino, la nina, and any number of other things. ←Baseball BugsWhat's up, Doc?carrots→ 10:32, 6 October 2011 (UTC)[reply]
Part of the problem is that it would essentially be a 3-dimensional table: One dimension would be the average daily temperature. Another would be the number of hours and minutes of sunlight per day. The third dimension would be the latitude. Obviously, a lot of info, and probably beyond the scope of a wikipedia article. Have you tried googling this subject? ←Baseball BugsWhat's up, Doc?carrots→ 10:38, 6 October 2011 (UTC)[reply]
The inclination of the Earth's axis relative to the Earth's orbital plane causes the cyclic variation in the duration of daylight and solar heating, and this variation causes the seasons. Therefore it is reasonable to say that the seasons are due entirely (100%) to inclination of the Earth's axis. Dolphin(t)10:54, 6 October 2011 (UTC)[reply]
But that's not the whole story, otherwise the coldest day of the year would be the Winter Solstice and the hottest day would be the Summer Solstice (or the opposite in the southern hemisphere). But thanks to seasonal lag, the coldest day of the year is liable to be in early February, and the hottest day in early August, by which time the days are longer than the winter solstice and shorter than the summer solstice, respectively. And besides, the OP apparently wants numbers rather than qualitative observations. ←Baseball BugsWhat's up, Doc?carrots→ 11:00, 6 October 2011 (UTC)[reply]
I agree that the seasonal extreme temperatures don't occur on the solstices, but that doesn't detract from the fact that the Earth's seasonal variations are due 100% to the inclination of the Earth's axis relative to its orbital plane. All other observations, such as seasonal variation in duration of solar radiation and seasonal variation in ocean temperatures, are consequences of the Earth's inclination, not independent causes of seasonal variation. Dolphin(t)11:12, 6 October 2011 (UTC)[reply]
OK. So the simple answer to the OP's question is, indeed, 100 percent. One way to look at it is to look at the extremes. The poles never get warm, but they are not as cold in their respective summertimes when they get 24-hour sunlight, vs. wintertimes when they get none. And at the equator, it's pretty much the same all year around, apart from daily variations due to weather changes. ←Baseball BugsWhat's up, Doc?carrots→ 11:16, 6 October 2011 (UTC)[reply]
oxidation no. in halogens
my teacher said that oxidation no. of Halogens like fluorine and iodine in their peracids is +7 not -1 like HClO4 but i want to know the other peracids which i must calculate the oxidation no. of their halogens by +7 not -1 — Preceding unsigned comment added by Mido22 (talk • contribs) 13:00, 6 October 2011 (UTC)[reply]
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