Wikipedia:Reference desk/Science

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February 27

roms, where do i find them

where would i find a good site to download roms for gameboy advanced or other emulators?

99.99% of console roms breach copyright laws. Stay away from them! If you are looking for good, free, downloadable games, try Home of the Underdogs, or make your way over to indie gaming and follow the links from there. --Sam Pointon 04:16, 27 February 2006 (UTC)

Romhustler. Nuff said.

Why is China all in one time zone?

Anyone know the answer? Is it political?

Is the border between China and Tajikistan the only political border you can cross and gain/lose 3 hours (like you just flew from New York to LA)?

-Quasipalm 04:32, 27 February 2006 (UTC)

China does border Afganistan for a bit less than 100km, so crossing that border means a 3.5hr time change. — TheKMan^talk 05:05, 27 February 2006 (UTC)

Interesting topic. I dunno the historic reason, but I suppose that they all follow the Beijing time, hallmark of a centralised controlling government. An incidental question is why does United States have different timezones. For one thing, it's quite confusing when connecting flights. --Vsion 07:29, 27 February 2006 (UTC)

Time zones are a strange bag of physics and politics. Ideally, each time zone should be exactly 15° wide to compensate for longitude (and even then, your watch could still be off by half an hour compared to local solar time, but this is judged acceptable). Of course, national borders and politics twist this, all the way to aberrations like China, which spans enough longitude for three-and-a-bit timezones but only has one - so, at the eastern end of China, the sun rises a full three hours earlier than at the western end, even though the clocks in both places show the same time. Vsion, if the US was only one timezone, it would be even worse - assuming it was centered somewhere in the midwest, noon would be at 10am in New York and at 3pm in Hawaii, which would be very silly. Europe is another example of politics prevailing over physics - save the British Isles and Portugal, all of Europe west of about 25°E is in one time zone, when it spans more than 30° of longitude. If done 'properly', France, Spain and the Benelux should be at GMT+0, together with the UK, Ireland and Portugal. See our article on time zone, it's rather good. — QuantumEleven | (talk) 08:59, 27 February 2006 (UTC)

The half-hour zones are even weirder. In the case of Iran it makes some sense because a 'solar zone' border runs straight through the country. But India is bang in the middle of the +5 hour zone, yet they're at +5,30 hours. And the Central Australian zone is weirder still. It looks designed to be coincide with the +9 hour zone, yet it's at 9,5 hours. DirkvdM 12:10, 27 February 2006 (UTC)

That's a good point - could any Aussies on the Ref Desk (yes, JackofOz, that means you :)) enlighten us as to why in the world your central time zone is at UTC+9.5? It seems very random. — QuantumEleven | (talk) 13:47, 27 February 2006 (UTC)

I've searched in vain for info about the reason it was done that way. Originally the local mean time of Adelaide was used (138E35). On 1 February 1895, the time zone was based on 135E00, and on 1 May 1899 it changed to 142E30, and it's stayed there ever since despite at least 3 attempts (1986, 1994, 2000) to change it. I can only assume it had something to do with the population of the state being concentrated in the eastern half. Or maybe it was a metaphor for South Australia's forward looking vision of the world (eg. South Australia had the first Parliament in the world to allow women to be elected as members). JackofOz 09:32, 28 February 2006 (UTC)

You may consult Time zones of China for more information in depth. In fact, zh:中國時區 (Time zones of China) was on Chinese Wikipedia's DYK section last week. -- Toytoy 14:16, 27 February 2006 (UTC)

Time zone changes can be confusing, and daylight savings too. Each time anyone proposes any changes in the UK, people appear out of the woodwork to complain about the loss of daylight at one end of the day or the other. Perhaps the Chinese are smart enough to realise that changing the clocks doesn't actually affect how much daylight there is, and (shock) adjust outdoor work to match. Notinasnaid 14:21, 27 February 2006 (UTC)

I think this is a nice idea. You can travel from Singapore to Shanghai to Hong Kong to Taipei to Manila to Perth without adjusting your watch. It's lazy man's heaven! However, you still suffer from mild jet lag because you can't cheat the sun. You can't cheat Skype either. ... Well, latest Skype can display a user's local time so you know if it's proper to call. ...

Taiwan had observed day light saving time several times in history (1945-1961, 1974-1975, 1980; start and end dates varied). People hated it. The government had to call it off. Some Chinese cities, Macau and Hong Kong had observed day light saving time too. -- Toytoy 14:49, 27 February 2006 (UTC)

I'm also wondering why can't we all follow the Beijing-style system, everyone fixed the time at say the UTC, but start work at different time depending on local sunrise: Singapore start work at 0000hr, UK at 0800hr, california at 1600hr, etc.. I wake up at 11am everyday anyway, no problem. Wouldn't this system be better and less confusing? Daylight saving is another archaic thing, but I shouldn't complain, the worse victims are the diary cattles: for one particular day each year, the cows are forced to wake up one hour earlier than usual for milking, totally confused and irritable. Then half a year later, they have to hold the milk in their systems for one more excruciating hour; thanks to this human-invented daylight saving scheme. --Vsion 15:16, 27 February 2006 (UTC)

It's worth noting that cows don't read clocks; their schedules only change if the farmers in question don't adjust to the time change to compensate. — Lomn Talk 18:27, 27 February 2006 (UTC)

You may want to see Image:ROC-TimeZones.png. This picture shows the time zones of China from 1912 to 1945 (Taiwan was under Japanese occupation then but was also GMT+8; but Hong Kong was GMT+9 during the 1942-1945 Japanese occupation). The GMT+8 provinces (pink area) consistutes more than 80% of China's population and an even larger pie of economics (the rest of China are mostly mountains and deserts). I think it is quite reasonable for China to adopt a single time zone policy because it helps people to do business. -- Toytoy 15:28, 27 February 2006 (UTC)

I totally agree with Vsion.It is ridiculous to change the clocks time.It is more easy to follow the UTC everywhere with particular schedule for each palce.amrahs 15:40, 27 February 2006 (UTC)

Does anyone remember Swatch Internet Time? Thought not. —Blotwell 10:37, 1 March 2006 (UTC)

Personally, I think it's a good idea to adopt the time zone after your nearby economic partners. It's an even better idea that we all adopt GMT or UTC whatever you call it. I sent a package from Taipei to Washington D.C. last week, the DHL tracking system is really doing a bad job by displaying only local time. My package travelled from Taiwan (GMT+8) to California (GMT-8) to Ohio (GMT-5) to Maryland (GMT-5). It could be even more complex if it's summer in the USA. I hate daylight saving time. -- Toytoy 15:48, 27 February 2006 (UTC)

Yeah, that's what Singapore did when Malaysia switched the whole country to UTC+8 (previously both Peninsular Malaysia and Singapore had been under UTC+7, but to accomodate East Malaysia which is in UTC+8, the whole country set its clocks an hour ahead, forcing Singapore to follow suit). Johnleemk | Talk 16:06, 27 February 2006 (UTC)

There is also a tendency for time zones to be slanted towards longer evenings and shorter mornings. Central European Time is the equivalent of solar time in Berlin, but is used in many areas to the West: Galicia (Spain) is two and a half hours ahead of local solar time in summer. Physchim62 (talk) 04:35, 28 February 2006 (UTC)

In The United States, in the State of Indiana, the dividing line between Central Time zone and Eastern Standard Time zone runs in between the east bound and west bound traffic of Interstate 64.

Comment:

The half-hour zones are even weirder. In the case of Iran it makes some sense because a 'solar zone' border runs straight through
the country. But India is bang in the middle of the +5 hour zone, yet they're at +5,30 hours. And the Central Australian zone is
weirder still. It looks designed to be coincide with the +9 hour zone, yet it's at 9,5 hours. DirkvdM 12:10, 27
February 2006 (UTC)

I believe the IST is based on the meridian (82° 30' E ) which is roughly halfway between India's two extremes, so it's a perfectly logical choice. Note that Historically, Indians were using Ujjain (75° 47' E) as the reference prime meridian (in place of Greenwich), and astrologers still use the same. deeptrivia (talk) 04:24, 2 March 2006 (UTC)

Erosion and Weathering

Why don't the continents disappear as they are continually worn down by weathering and erosion?

There are several processes involved. A major one is this - the Earth's surface rocks basically float on the molten rock underneath. The surface is heavy - not heavy enough to sink, but heavy enough to sink into the molten layer to some extent (much like an iceberg floats on the surface of the ocean, with most of its contents below the surface. As the land is eroded, it floats up a little more, since it now weights a little less. Another major process is the land-building which comes from the movement of the earth's plates. In some parts of the world, one plate is passing under another, and this causes the land to rise. In other places (Iceland, for instance), volcanic activity is building the land up., Elsewhere, notably the Himalayas and Alps, plates are colliding, and buckling where the collision occurs (look at the shape of the mountains in southern Asia - they were caused by the collision of India into the Asian mainland. So yes, erosion wears the rocks down, but there are enough other activities going on which are building them up again. Grutness...wha? 06:09, 27 February 2006 (UTC)

Another (quite minor) contribution is from dust and occasionally visible meteors from space. StuRat 06:51, 27 February 2006 (UTC)

Plate tectonics --Zeizmic 13:12, 27 February 2006 (UTC)

• They are disappearing, but erosion is a slow process, so it takes time for an entire content to disappear. - Mgm|^(talk) 09:04, 28 February 2006 (UTC)

I disagree, they are in equilibrium, with the processes listed above building them up at the same rate erosion wears them down. StuRat 05:51, 1 March 2006 (UTC)

Puberty

After a teenager develops puberty, hair appears in areas of the body such as around the penis or vagina, below the armpits, and on the face. But why? I mean, what is the purpose of all this hair appearing in different parts of the body?

No one knows. People guess. Trap smell? WAS 4.250 01:24, 28 February 2006 (UTC)

It's compliated. Basically, it's neotony. The adult form of our species, being descended from ape-like creatures, is supposed to have hair all over its body. Hair doesn't develop until after birth, however. But as a result of hundreds of thousands of years of evolution-driven neotony, human young tend to look juvenile longer (e.g, live later without hair in areas adults have it). Raul654 06:57, 27 February 2006 (UTC)

Humans grow hair while still in the womb. Neotony is part of why we have hair that looks small/thin/short compared to the other apes (the numbers of hairs in humans are the same as in the other apes, ours are just small/thin/short). Sexual choice (people prefering to mate with less hairly other humans) is a prime guess for why this is so. WAS 4.250 01:24, 28 February 2006 (UTC)

Agreeing with Raul, I would just like to add that in the future, mankind may lose the need for hair, and evolution will possibly get rid of it.

The Ronin00:36, 28 February 2006 (UTC)

Is that why I'm balding? That's comforting... --Vsion 00:41, 28 February 2006 (UTC)

This is purely science fiction. A more fact based look into the future would note the increase in human ability to look any way they want; technological evolution replacing genetic evolution. WAS 4.250 01:24, 28 February 2006 (UTC)

As a matter of fact, there is already a magical gizmo that allows us to change this aspect of ourselves at will. Black Carrot 01:44, 28 February 2006 (UTC)

WAS 4.250 is in teh ball park, but not exactly right. Natural selection for humans has virtually ceased. How many people die of natural causes before hitting puberty? A vanishingly small number compared to the past.

My uncorrected vision is (roughly) 20/800 -- basically blind. if I lived 50,000 years ago, I wouldn't have survived very long (you can't hunt if you can't see). However, with LASIK, I can live a normal, happy life. This is NOT "technological evolution" - any child I have will also get my genes for severe nearsightedness. So it's not "evolution" of any kind, as the frequency of allelles does not change (which is the definition of evolution).

However, while natural selection has almost ceased, there is another driving force - social selection. Social selection has always been present, but as natural selection became less important, social selection became more important. Think about it this way - if someone is (for example) genetically smelly, no one is gonna want to marry him and have kids with him. Thus, he is weeded out. Social characteristics have become far more important with technology. Raul654 01:38, 28 February 2006 (UTC)

Technological evolution is not any kind of biological evolution. Biologists don't have a copyright on the english language word "evolution". Look it up in a dictionary or even in wikipedia (pay attention to the first thing you read, it directs you to a disambig page where other articles using the word "evolution" with other meanings are described and linked to. WAS 4.250 17:58, 28 February 2006 (UTC)

Text and Image copyright confusion

The following was posted at Wikipedia:Clueless newbies:

What a great place. I just created an account. Did quite a bit of reading, but don't understand in simple terms if my problem is solved here.

I'm creating my first web site in XHTML and am writing a family photojournal as my learning tool. It has tons of photos that I prefer to protect with copyright on the web site. We may SOMEDAY (no time soon) use the site commercially to sell bonsais and arts & crafts products.

(1) Does not our copyright exlamation at the bottom of the site protect the images even though there are no tags? Do PhotoShop watermarks carry any weight?

(2) Is it possible to use articles verbatim about bonsai from Wikipedia and create a copyright that explains that the use of text is GNU-free-licensed, but the graphics, indeed, remain copyrighted solely to us on our web site if we follow the example page that references GNU and Wikipedia? Thanks for the help.

--InMyWords

— QuantumEleven | (talk) 09:44, 27 February 2006 (UTC)

(1) Yes, and technically they would be protected even if you didn't specifically say so on your site (though it is always best to make it clear). Whether or not people on the internet will respect those copyrights is a different matter. Photoshop watermarks or otherwise marking the copyright on the image itself might help protect against that, if you're worried.

(2) Read Wikipedia:Copyrights for a detailed response. — Asbestos | Talk (RFC) 21:30, 27 February 2006 (UTC)

Yes. Our interpretation is that images can be licensed (or not) separately from GFDL text; in other words, "mere aggregation". Superm401 - Talk 03:36, 28 February 2006 (UTC)

X-Ray and Dental Problems

Another question from Wikipedia:Clueless newbies:

Ten year back I was working some electricity work during my working one copper wire inserted in my gum, I immediate went to the doctor and told him the entire thing doctor diagnose but did not take x-ray and told there is nothing, Time to time I went to the different doctor and told them the entire story doctor did not believe me and said if there is wire in your gum there must be some swelling and infection in the gum but there was nothing, but there is a continuously feeling that wire is in my gum

Recently one month back I went to doctor and he took two X-Ray but he did not find any thing in my gum he operate my gum and saw through high resolution Camera but result was zero, but to day as on date 27/2/2006 my tongue feeling that wire get loose and displaced Doctor say nothing is their every thing is all right it is all physiological but I feel that wire is in my gum

Pl. Answer the following

1) Can a metal wire dissolved automatically after this long period 2) If metal wire is exact behind the teeth it can be seen through X-Ray 3) In what condition Metal wire does not show image through X-Ray

Pl. suggest me the right direction and right test

— QuantumEleven | (talk) 09:49, 27 February 2006 (UTC)

I once had a really terrible dentist, who caught a nerve while giving me an injection of novocaine prior to dental work, and to this day I can still occasionally feel swelling around the area, that almost feels like there's still a needle in my gum, however I'm quite sure I'd notice if there was actually a hypodermic needle sticking out of my face, so I'm fairly certian there's another explanation, maybe extremely trivial nerve damage, or just swelling along the tissue split by the needle, I know something similar happens after certian surgeries, where scar tissue forms along the inside of a incision, and after it heals there's a slight clump of dense tissue around where the openning used to be, resulting in one being able to "feel" someting that isn't there anymore, I know there's a better word for this--64.12.116.74 21:46, 27 February 2006 (UTC)

And if it helps anyone figure out what the hell I'm talking about, I know it's a big problem after most heart surgeries in which the patient develops an arrhythmia as a result of irregular fiberous growth near the incision, but for some reason I just can't remember what this is called,

but presumably you could experiance the same thing if your skin or some other tissue were pierced by a long, thin, irregular piece of metal, and then rehealed along that line, leaving a long, thin, fiberous cyst in it's place--64.12.116.74 21:54, 27 February 2006 (UTC)

1-A copper wire could conceivably dissolve completely over 10 years; copper is not chemically inert, and would corrode and be absorbed. Whether it would be completely absorbed would depend on the gauge of the wire.

2-Depending on the metal composition and the thickness of the wire, it may or may not be visible behind a tooth on x-ray.

3-A metal wire would not be visible on x-ray if its composition and thickness caused it to have the same radio-opacity as the environment in which it is situated. It would also not be visible if it was behind or in front of a more radio-opaque object, such as a metallic filling or denture prosthesis.

Although it is possible that you do have an embedded wire in your gum, it is unlikely that it would fully embed itself; copper is ductile, and it is reasonable to assume that it would not break off within the wound, and that at least part of it would protrude and be visible. In any event, your dentist is correct-- an embedded wire would most likely provoke a foreign body reaction, with pain, swelling, redness, or overt infection. Absence of these obvious signs would argue that your doctors are correct. Whether your perception of a wire is psychological is something else-- you could be experiencing a paresthesia from local afferent nerve injury or other neurological pathology. If your dentist is unable to determine the basis for your complaint, you might consider a consultation with your physician or a neurologist.--Mark Bornfeld DDS 15:55, 27 February 2006 (UTC)

Forget what you think it is. Forget the past. Focus solely on what it feels like now and if it is a problem, what exactly do you want. Tell a doctor (regular or dentist - your choice) what you feel and why that's a problem without talking about the past. (If how it feels is not a problem, you don't have a problem.) Let the doctor deal with the why and so forth. Assume there is no wire inyour gums. Maybe its nerve damage. Maybe its a super-sentitivity in your brain to nerve signals from a part of your gums. I had tooth pices migrate out of my gums, after a wisdom tooth extraction. Any piece of foreign matter in your gums would have migrated out after 5 years (I think). WAS 4.250 01:41, 28 February 2006 (UTC)

anti-virus backups on different file systems

Suppose I'd have a computer with both Linux and msWindowsXP installed. These can both use fat. But Linux without special tools (which I will therefore not install) cannot alter anything on ntfs partitions (XP's native fs) and WinXP can not access Linux partitions at all (hell, it doesn't even acknowledge their existence). So if I'd have all my files on a fat partition for normal use (where they can both access it) and regularly make backups on both an ntfs and a native Linux partition (reiser, ext, or whatever). Would my backups then be safe from viral attacks? Assuming a virus is specific to one OS (which is always the case, right?) then it won't be able to alter anything on the non-native file system, right? Or are they accessible, just not in a consumer-friendly way? DirkvdM 11:44, 27 February 2006 (UTC)

Viruses can always write to the physical hard disk, or "PHYSICALDRIVE" as it is called on MS Windows. I forgot its name but I remember reading about a virus which overwrote random 65KB portions at a raw level to the HDD. This tended to destroy filesystems and, if it got the right place, partitions. So your data on any type of partition isn't completely safe. Mind you, most Windows virus writers are relatively ignorant, so they're only likely to try do anything to the XP NTFS partitions. By the way, are you sure you don't want to install linux-ntfs? It's a good tool. -- Daverocks (talk) 12:31, 27 February 2006 (UTC)

I haven't tried either myself (I need to get around to backing up my system and reinstalling XP so that searching for files doesn't crash explorer first...) but Captive NTFS looks good as well (external links in the article). Thryduulf 14:11, 27 February 2006 (UTC)

Ah, so it's a matter of at which level the virus (or whatever) operates. So I do get some protection, but only against the ones that only work at the level of the OS (provided I don't install something like linux-ntfs or Captive ntfs) and not against the ones that bypass that and work at the most basic level. How many are there of each type and which tend to be the most dangerous ones? By the way, the scheme would also protect backups against my own stupidity, as long as I don't work at too elementary a level (which is usually the case). DirkvdM 12:39, 28 February 2006 (UTC)

You seem really worked up about viruses :) I don't know about others, but I've only ever had about 5 infected files ever walk into my computers, and they've all been zapped by my antivirus... enochlau (talk) 15:11, 28 February 2006 (UTC)

A warning: we all think we're 1337 Windows geeks and that with two firewalls and an up-to-date virus scanner and a bit of common sense we're immune to virus infection. I learnt the hard way a few days ago when I assumed AVG would take care of this virus that appeared on my hard drive. One almost-wiped-out Windows installation later (which I could only fix by installing a second copy of Windows and using that to clean the first one) and I learnt never to take my geekiness for granted. Sum0 21:01, 28 February 2006 (UTC)

And that was just an OS, which you can re-install. The loss of essential data would be a much bigger pain, to put it mildly. This is indeed one of those things that hardly ever go wrong so we're lulled into a sense of security. But when it goes wrong it can go wrong big time. Same with car accidents (30 million dead and counting). I'm sure my computer is infested woth all sorts of malware and is a time bomb that might never go off. But then ....

But there's still my question how many (malicious) viruses and such there are that this scheme would not protect against. DirkvdM 09:03, 1 March 2006 (UTC)

Obviously, it's impossible to give a number of viruses that you are not protected against. I can say that your data is not fully protected as viruses do exist which write physically to the hard drive. Despite this, it would be difficult to get one of these viruses if you have the right protection. Sum0's experience shows us that we are never fully protected even though we think we are, but you should be fine. -- Daverocks (talk) 11:52, 1 March 2006 (UTC)

Those crystallization hand warmer thingies

Our article explains quite well how they work, but can anybody tell me when and where they were invented? I'm just curious... -- Ferkelparade π 14:41, 27 February 2006 (UTC)

I had no hope on finding the inventor, but got this really interesting link [[1]] --Zeizmic 17:47, 27 February 2006 (UTC)

Low Density Solids

Is water the only common molecule that becomes less dense as a solid than it is as a liquid? I'm not interested in freaky lab-produced molecules. --Kainaw ^(talk) 15:28, 27 February 2006 (UTC)

No, it's not. See Water#Density of water and ice for a few other substances that are less dense in their solid form than in their liquid form. Acetic acid, the substance that gives vinegar its awful smell and sour taste, is one example. The (non-artificial) elements silicon, antimony, bismuth, and gallium, are also examples. --Bowlhover 23:43, 27 February 2006 (UTC)

Water's maximum density is at about 4C. Lower than that, it becomes less dense as a liquid. This is important for us up in Canada, because lakes completely 'turn over' as it gets cold (and warm again). There is no common fluid that does this. --Zeizmic 16:30, 27 February 2006 (UTC)

Hair

Hi, I'd like to ask about sthg 1-Whats the function of the hair on our bodies? 2-y is it thicker in some places? 3-If it is usefull, y do we remove it?

Thanks Yasmeen

I just read the article on Hair. It has everything anybody needs to know. :) --Zeizmic 17:32, 27 February 2006 (UTC)

Kinetic energy in relativity

Is it correct to say that: kinetic energy = (mv^2)/(2*sqrt(1-(v/c)^2))

Re-arranged: 1/2 γm v^2

That is, using the formula for mass being: mass = γm where m is the rest mass

and substituting it into the formula kinetic energy = 1/2 m v ^2

This gives: 1\2 γm v^2

or: (mv^2)/(2*sqrt(1-(v/c)^2))

I have checked the articles on special relativity and kinetic energy and can't find what i'm looking for.

If this is not true, WHY NOT?

It isn't true. Generally speaking, you can't just insert a factor of gamma in front of the mass in a Newtonian formula and get a relativistic formula. Sometimes you need a factor of gamma^3, or gamma^-1, and it can be hard to tell which. Sometimes you need something more complex altogether.

As for your specific formula, 1/2 γm v^2, try comparing it to a known formula for the kinetic energy, (γ - 1)m c^2. With a little algebra, you'll find that the two are equal only if v = 0. Melchoir 08:40, 28 February 2006 (UTC)

The formula isn't true because of the way Newton's formula for kinetic energy, KE=(1/2)mv^2, was derived. Kinetic energy is basically the work needed to accelerate a mass up to a certain speed. If a constant force is applied to an object, causing the object to accelerate at a, the object will reach a final speed of v=at after time t. The average speed of the object during acceleration is 1/2 v (where v is the final speed), which means the object traveled a distance of 1/2*v*t during acceleration. Work is equal to force multiplied by distance, so W=F*(1/2)*vt. Since F=ma, W=ma*(1/2)*vt. Acceleration (a) is measured in d/t^2, but d/t^2 times t is d/t. Substituding d/t for a and getting rid of t, we get W=m(d/t)*1/2*v, but d/t is the average speed and can be replaced by v. That is how we get the final equation: W=(1/2)*m*v*v = (1/2)*m*v^2

As you can see, the equation (1/2)*m*v^2 assumes that, if a constant force is applied to an object, the object will accelerate at exactly the same rate for as long as the force is applied. This assumption cannot be fulfilled. According to the theory of relativity, it will become harder and harder to accelerate an object as its velocity approaches the speed of light. For example, more force is needed to accelerate an object from 299 792 400 m/s to 299 792 450 m/s in one second, than from 10 m/s to 60 m/s in one second. --Bowlhover 17:17, 28 February 2006 (UTC)

Water Droplet formation

Why does a water droplet when suspended in freespace form a perfect sphere before losing its shape on coming into contact with a surface? Bob Pollard18:53, 27 February 2006 (UTC)

Surface tension makes it energetically beneficial to minimize the surface area. Less area means less energy, and a sphere has the smallest area-to-volume ratio. On coming into contact with a surface, what happens depends on the surface. If the surface is hydrophilic (water-attracting), then the attraction of the surface will cause the water to disperse, because it'll have even lower energy on the surface, even if it means higher area. If the surface is hydrophobic (water-repelling) then the drop won't disperse, and you'll be left with a bead of water resting on the surface. --BluePlatypus 19:25, 27 February 2006 (UTC)

A bead of non-spherical water, to be sure.  freshgavinΓΛĿЌ  11:36, 2 March 2006 (UTC)

Thank you for the explanation.

Losing neurons due to a weak hit

There's a belief (likely a myth) that if you hit somebody in the head he loses a number of neurons, no matter how strong the hit was, even if it almost didn't hurt the "victim". Is that true?

This is not true. Your brain is protected by a thick skull and is suspended in Cerebrospinal fluid, both of which act as protection for your brain in the case of mild hits — even those hard enough to raise a bruise or a bump on your head. Harder hits, however, which might cause loss of consciousness or concussion, can indeed damage neurons. This damage may or may not be permanent. See also our article head injury for more information. — Asbestos | Talk (RFC) 21:17, 27 February 2006 (UTC)

Thank you very much ;)

For what its worth, adults lose some thousands (figures quoted on the web run as high as a hundred thousand, and I can't be bothered to find something more reliable and precise) of neurons each and every day. It's natural cell death; there's little you can do about it, and there's really little need to worry about it.

Very mild traumas may push a few neurons 'over the edge', but they get lost in the noise. Still, it's generally better to avoid getting hit altogether. TenOfAllTrades(talk) 01:43, 28 February 2006 (UTC)

Wiki GUI in PHP?

I'd like to make a wiki-like web page where users could add text and click on words to do things like add links. Would PHP be the best language to do this in? What would you recommend? Thanks!

I just did this for our water polo club, but I can't figure out what to do with this new baby. Basically, your hosting site (ours is myhosting.com) gives you a Linux account. They tell you how to load up MediaWiki (which is what runs Wikipedia). It's all php, etc. --Zeizmic 22:15, 27 February 2006 (UTC)

Thanks, but I don't want to use media wiki. I'd like to try to create a gui-based system, where users clicked on words to add media or links. Do you think PHP would be good for this?

PHP isn't a client-side language. For what you're talking about, JavaScript is what you want on the client side; there is more freedom on the server side. PHP would work, but so would Ruby + Rails, or Python + a decent framework, or practically any language/framework combo. --Sam Pointon 00:40, 28 February 2006 (UTC)

Mediawiki is written in PHP, but it uses a MySQL database to store things. You could feasably write something similar to this in PHP. The downside of PHP is that it's a server side language so everything needs to essentially have a 'submit' button (or a link that does the same thing). — Ilyanep (Talk) 23:23, 4 March 2006 (UTC)

conscious sleep

Our article notes that "sleep is the regular state of natural rest observed in all mammals, birds and fish. Sleep is not actually 'unconsciousness,' but rather, it is a natural state of rest characterized by a reduction in voluntary body movement and decreased awareness of the surroundings. Therefore, since consciousness is literally the awareness of the surroundings, being asleep is just an altered state of consciousness, as opposed to being unconscious."

Over the past few weeks I've experienced a few episodes of wakeful, conscious sleep. They seem to be 30-45 minutes in duration. I'm aware of my body sleeping and can observe my breathing, heartbeat, and other bodily sensations, including very minute twitches, as well as the myoclonic jerks I've experienced since the time of the first conscious sleep experience. I'm bipolar, and for the past few months have been experiencing the high side. The week during which the sleep experience and the myoclus began was very stimulating (a cruise) and my own perception of the highest point of my current mania is a few days before the sleep experience began.

The experience is definitely not associated with drowsiness. Nor is it at all like lying awake.

I'm receiving treatment from a psychiatrist (long-term) and a neurologist (since the jerks began). But I wonder: what is this conscious sleep? How is it related to the sleep cycle? Could it be a part of stage 1? Have you ever heard of a similar case? --Halcatalyst 23:20, 27 February 2006 (UTC)

Look at our articles on lucid dreaming and sleep paralysis, if you haven't already. Is that what you're looking for? — Asbestos | Talk (RFC) 23:24, 27 February 2006 (UTC)

That article on sleep paralysis is fascinating, and seems to fit the description. I'm semi-bipolar (unipolar with cycles), and I just get along with lucid dreams, and intense thought dreams when I was more uncontrolled. --Zeizmic 23:32, 27 February 2006 (UTC)

• Thanks for the references. I've known of lucid dreaming for some time; it's not that. There's nothing dreamlike about the state -- the sense I have is that I'm just there observing. The observation persists through waking, and then I behave as I would during normal wakeup, except that I'm aware of what's going on instead of coming out of unconsciousness. On one occasion, my wife said I appeared to be in deep sleep when she woke me up. Other times, I've awakened on my own. I don't think it's sleep paralysis; it's not at all like what's described there, although "I" do have the sense that my body has to do the waking up, not "me." That doesn't bother "me"; in fact, it makes me feel very happy and relaxed. I can perceive, or I can think about anything I like. Occasionally I've noticed my eyes flicking open, and if there's any light I can see something. But it's not something willed. Another observation: I remember many of my dreams. They're definitely dreams. Lately, they seem to consist of sequences of frustration and are not particularly related to my waking life. --Halcatalyst 00:18, 28 February 2006 (UTC)

Write down details. And try to get a witness to verify stuff. Misremembering and self deception are big problems in dealing with conciousness. When I have lucid dreaming, thinking too much wakes me up, making me think that's not what you are experiencing. Do experiments to get data, and write it down. you might have some special gifts and be able to provide insight into human conciousness during sleep states. Be aware that conciousness is mostly about laying down memory tracks in the brain where they can be recovered later. WAS 4.250 01:52, 28 February 2006 (UTC)

Thanks to all who responded. --Halcatalyst 14:40, 1 March 2006 (UTC)

Teen Pregnancy

A few weeks ago, Stephen Colbert (the Colbert Report) reported an interesting story that I haven't been able to find direct reference to anywhere. According to him, teen pregnancy rates are decreasing, and it's because teens are starting to go for oral sex instead of actual intercourse. Is any part of that true? Black Carrot 02:04, 28 February 2006 (UTC)

"A major analysis by the Alan Guttermacher Institute attributes about a fourth in the decline to delayed intercourse but three-quarters to improved contraceptive use among sexually experienced teenagers." (Harmful to Minors, 112) Raul654 03:46, 28 February 2006 (UTC)

There has been a drastic increase in oral sexually transmitted diseases among teenage girls because of this.

Only amonst the girls...? --Username132 20:05, 3 March 2006 (UTC)

A few years back, I saw an article that said certain European countries were promoting oral sex over intercourse instead of the normal abstinence bit. It was on sxxxy.org, I believe. Skomae 04:16, 4 March 2006 (UTC)

February 28

I want Wikipedia e-mail addres please , then I send my article to you .

Please see Wikipedia:Articles for creation. Superm401 - Talk 03:56, 28 February 2006 (UTC)

I expect Help:Starting a new page would be a more useful link. — Asbestos | Talk (RFC) 23:15, 28 February 2006 (UTC)

Ant Farm

Hi. Just wondering a few things concerning an ant farm I am constructing:

1. Can ants stand to live in perpetual darkness? My farm will likely be in a locker.
2. The only entrance to the farm is a hole I drilled in the top. I am thinking about cutting a long strip of sponge to plug the hole and reach down to the dirt floor. Will a suitable amount of fresh air come through the sponge? Will the ants be able to extract water from the wet sponge or will over-saturating it be necessary (where water drips onto the dirt)?
3. I recieved a small packet of "ant food". It looks like little bits of green stuff, bird seed and misc. stuff. Will any and all types of human food suffice when I run out of "ant food"?

Thank you. Ross Uber - Talk - Contributions - 04:16, 28 February 2006 (UTC)

You are planning to turn your school locker into an ant farm? Cool. But how will you watch them burrow and do ant stuff? And they are likely to generate some social opprobrium on your behalf if they go foraging, don't you think? alteripse 04:29, 28 February 2006 (UTC)

Actually, I bought two wooden picture frames, took out the backs and glass, put in unbreakable clear plastic and wood-glued them together. Then I drilled a hole in the top. I got a picture frame mount and some nails. It worked out nicely. I have made it impossible for them to escape the farm. Ross Uber - Talk - Contributions - 04:51, 28 February 2006 (UTC)

1 probably. they live underground. 2. Not sure. 3. They seem to love sugar in my ant farm/kitchen. GangofOne 05:05, 28 February 2006 (UTC)

I see a disaster in the works here. The ants will climb to the top of the sponge, chew through it, and escape. When people put their jackets on they will be full of ants and you will go home black and blue that day. I suggest you buy a proper ant farm from a pet store, they are cheap enough and will be built such that no ants can escape. I don't think total darkness is good for them, either. StuRat 10:57, 28 February 2006 (UTC)

Just keep them out of my kitchen, that's all I care about. JackofOz 11:26, 28 February 2006 (UTC)

I see a genious at work here. But if you tell too many people at school you'll get shut down before the ants escape. Even one person maybe too many. If you're careful you can keep the ants contained by making sure they can't escape even if it some how tips over. Don't let your locker get stinky. Rubber bands are great in so many ways. A small strip of screening will ensure they have enough air IF your drill hole is large enough. But make sure the screen is very securely attached. God bless duct tape. Have a good look at the commercial ant farms at a store. They've been designed with these kind of questions in mind. My ants died because they didn't get enough water, even though I tried to keep the dirt wet. You might try jamming a medicine dropper with water through another drill hole; but that might present a high escape risk. They love fruit, and it has lots of water, but I don't know if they will need more water than that. They will also eat most other human foods. Remember, ants don't live very long anyway; you'll just need to get more. I don't know if they can live permanently in the dark. I hope you will tell us the end of the story and what you find out. --Leah

This should be in an Archie comic! --Zeizmic 12:46, 28 February 2006 (UTC)

Need to verify an answer on a TMSCA test

• Yes, you should always verify your answer before handing in your test. - Mgm|^(talk) 09:08, 28 February 2006 (UTC)

Map of Ice Thickness at Last Glacial Maximum

Hello, I need a topo map of the ice depth above what is now the UK (or European or even global map if available) during the Last Glacial Maximum 20,000 years ago. Thanks, - Halidecyphon 10:25, 28 February 2006 (UTC)

Try 20th Millenium BC topographical ice depth charts

Global Warming

Dear all,

Are there any actual evidences of human causing or enhancing Global Warming?

If not, what are the natural causes? Can it be prevented?

Thanks!

The article on global warming does a pretty good job at answering some of your questions. Have you had a look at it? Dismas|^(talk) 11:42, 28 February 2006 (UTC)

Chemical Reactions and the Atom

Dear all,

As you see, in Chemistry lessons, what they teach you are just equations. Can anyone tell me, microscopically speaking, what is actually happening to a reaction? For example, a neutralization reaction, what is actually happening to the HCl and the NaOH? Are the bonds broken and "re-bonded" together? Where do they get this energy?

Secondly, why does electrons revolve around the nucleus? I mean, if you put a negatively-charged metal beside a positively-charged (with the distance of 0 - 5 cm), I mean, the negatively-charged metal won't just go revolving around the positively-charged metal, so why is that?

Thanks for all the time! - Just love science

The Na and OH in NaOH aren't really bonded to each other, just electrostatically attracted to each other. In water the two separate, since both are attracted to the polar water molecules almost as strongly as to each other.

The H and Cl in HCl are covalently bonded, but the bond breaks when the HCl dissolves in water. This happens more or less for the same reason: both halves of the HCl molecule are so strongly attracted to the nearby water molecules that they get easily pulled apart.

In any case, in aqueous solution both NaOH and HCl do not exist as whole molecules, but as ions (Na⁺ and OH^-, or H⁺ and Cl^-, respectively). When you mix the two solutions, the OH^- and H⁺ ions combine to form H₂O, leaving you with water containing Na⁺ and Cl^- ions.

If you evaporate the water, the Na⁺ and Cl^- ions will stay behind. Being oppositely charged, they will be attracted to each other (just like the Na⁺ and OH^- in NaOH) and will stick together to form NaCl. —Ilmari Karonen (talk) 13:23, 28 February 2006 (UTC)

For the second question, hm...how to best answer this? See quantum mechanics. I have to run, but hopefully some more Wikipedians will come and elaborate. --HappyCamper 14:35, 28 February 2006 (UTC)

I think the revolution of electrons around the nucleus of an atom is similar to that of a satelite (e.g. the moon) around a planet (e.g. the earth). At a certain speed of revolution, the satelite (moon/electron) is able to constantly fall towards a specific point, which is what causes it to go around and around.

Your charged metal idea would work if you took it far into space where there is "no gravity" and moved one of the objects at just the right speed. See Orbit - this is about planetary orbit, which is what I learned in Physics but I think it's applicable in this situation too. It's just the graviational forces in the case of planets are electrostatic forces in the case of electrons. The article might be a bit heavy for you though (it's a bit heavy for me anyways).

Ask your physics teacher if they can explain electron oribtals to you --Username132 16:22, 28 February 2006 (UTC)

Chemistry lessons don't teach what is actually happening in a chemical reaction because that is physics, the behavior of electrons ("psychology of electrons"). Electrons do not revolve around the nucleus. An "electron orbital" is a word meaning a 3-d shape describing the electrons probability of interacting due to its wave nature (its position is not in one point spot, like a wave washing up on the beach is not in one point spot). WAS 4.250 18:51, 28 February 2006 (UTC)

Chemistry does teach that, once you get past the level of high-school chemistry education. --BluePlatypus 08:23, 1 March 2006 (UTC)

isotopes

I want to know about some important applications of isotopes cobalt-60, iodine-131, sodium-24 and uranium-235. Thank you.

Well, I searched for the term "cobalt-60" and found a page for it at, cobalt-60. You might want to try searching for the others as well. Hint: It will narrow down how many you need to look for more info on. Dismas|^(talk) 13:25, 28 February 2006 (UTC)

Can cows read clocks?

In the question about Chinese time zones lomn put forth the proposition that cows can not read clocks. I dare challenge this. Of course, it there is no clock in the stable (which will usually be the case) they can't, but what if there were? Say, one with just one big clear hour hand? Surely they'd figure out that the hand moves over time (they've got little else to do). And then they'd figure out that it's near the bottom around daybreak. And then they might figure out that the milking starts at a certain position of the hand. In the case of daylight savings, the hand could be slowed down or speeded up over a period of, say, a week, giving them the feeling nothing much has changed. Pavlov's dogs reacted to a bell. Why couldn't cows react to a clock? DirkvdM 13:41, 28 February 2006 (UTC)

First of all, of all the things in the barn that move on a day to day basis, why would a cow even know to look at a clock. Secondly, animals just seem to know what time it is. I'm not saying that a cow is smarter than any of my dogs although my dogs are able to tell me within 5 minutes +/- when their dinner time is. So why would a cow need a clock? Dismas|^(talk) 13:51, 28 February 2006 (UTC)

Ah, but that's their biological clock. Suppose you erased all other indications of time (particularly sunlight) would the cows then start to use the clock and could you make them believe that over their biological clock and thus manipulate them? Of course artificial light would do that too, but that would be too obvious. I'm just curious if one could teach cows to read the clock. Most people would agree that they can't but I'm sure they can, so that would be an interresting experiment. Of course that would be easier with, say, rabbits, but cows start lactating at a certain time of day. Or do other (small) animals do that too? I suppose they do. DirkvdM 20:17, 28 February 2006 (UTC)

You may not consider this relevant to the original question but your comment of "cows start lactating at a certain time of day" set off bells and whistles in my head. Cows don't care what time it is. The idea that cows can only get milked at dawn or some other set time is wrong. A great number of dairy farms, in the U.S. at least, milk their cows twice a day. It is because of the production of milk by the cow throughout the day and the size of their udder that it's essentially required that the cow get milked at least every 12 hours. Otherwise the cow starts to become uncomfortable with the heavy weight of all the milk in its udder. Afterall, in the wild a calf would be drinking from this supply throughout the day and not letting it get too full.

There are also a number of farmers that milk their cows three times a day. There are advantages to this but most farmers simply don't have the man-power to be in the barn three times a day milking while other things on the farm need to be done as well.

And as far as the times at which the cows are milked, while it's true that many farmers will milk their herd near daybreak, it's not a biological necessity. I know of a few farmers who milk their cows starting between 1 and 3 a.m. They do this because that schedule happens to just work for them.

Then there are the robotic farms. Some farms have robots that open a gate to let cows in one at a time, milk them, then release them back into the herd. The cows go in when they feel like it and the RFID tag around their neck lets the robot know which cow is in the machine. A laser guided milker attaches to the teats and milks the cow. While this is taking place the cow is fed a little grain to keep it busy. So at these farms, the cows and not the farmer establish their own schedules of when they get milked. And again, it's not always at dawn. (On a sidenote, I don't see an article right off the bat about robotic milkers... I may just write one)

So, anyway, that's probably more than you wanted to know or maybe you already knew some of that and I just took the comment you made the wrong way. But it at least adds a bit of info to the experiment of teaching a cow to read a clock. Dismas|^(talk) 01:43, 1 March 2006 (UTC)

Ding Ding! This wins the silliest thing of the week award! Collect your Suitly Emphazi medal at the door. --Zeizmic 22:37, 28 February 2006 (UTC)

I have covered this in multiple research papers on AI. It is a minor topic in my studies, but I think it is a very important one. When asked if computers will ever have true intelligence, I reply that we must teach them to understand time first. So, going back to the question here... I continually pester animal experts about an animal's concept of time. What actions do they perform that show they recognize a past, present, and future? Can those actions be explained without a requirement to understand past, present, and future? For the most part, animals show no comprehension of anything but the present. They know cause and effect, but they don't understand something like "I'll give you some food tomorrow if you work extra hard today." It has to be rather immediate cause and effect.

There are some things that show some understanding of a future. Squirrels bury nuts in the fall to prepare for the winter. So, they must understand that the winter is coming, right? I easily found many studies on squirrels and their nuts. It is a biological thing. One study went so far as to determine the chemical released in their body that made the brain have a sudden OCD thing about hoarding nuts. Then, I spent a long time begging for info on apes. They are similar to us, so they must understand time. Even the ones who learn sign language show no understanding of anything but the present. You can't tell them you will give them something tomorrow because they don't understand it.

So, cows are rather low on the IQ scale. If some attention getting event happened at a certain time every day, they would learn that the event happens at that time every day. However, a moving hour hand is not very attention getting. So, it is very doubtful that they would ever relate a position of the hand to an event.

An anecdote on animal behavior and time. A study used a bird in a box. Every 5 minutes, the bird would get food. So, the bird should learn to wait 5 minutes and the food will come out. After a few days, the lid was taken off the box and the bird was watched. It would turn three times to the left. Bounce twice. Turn four times to the right. Bounce three times. Back up. Step forward. And then chirp. After doing this pattern slowly over a 5 minute period, food came out. Then, the bird did it all again exactly as before. The bird didn't learn time. It learned that it had to do this funky series of movements to force the food to appear. --Kainaw ^(talk) 01:30, 1 March 2006 (UTC)

I didn't say cows would understand the concept of time the way we do (!), just that it could use a device we use and thus understand that. Make it a small animal (mice are popular for that reason) and make the clock really simple and big and the only thing they get to see. Wouldn't it be cool to be able to say you taught an animal to read the clock?

Btw, in your comment I taste something that I often encounter, namely that the intelligence of an animal should be measured by human means. Like we're the summum of anything to do with intelligence and other animals can only hope to achieve our level. A favourite experiment of mine was when a pigeon was given food when it pressed the right button. First it was presented with two paintings with different types of painting styles and it had to pick the expressionist painting (or whatever). At the same time a class of university students were presented with the same problem. Both the pigeon and the students got this one. Then came a series of paired graphs, one going up and one down. The students got this, the pigeon didn't. Ah yes, of course, pigeons don't get such an abstract thing. Then came another series of graphs. Which the pigeon got. But the students didn't. The difference was simply the surface below the graph. Also an abstract thing, but still the pigeon beat the humans. (Actually, the pigeons reacted to how much red (or whatever) was visible in the images, but still pigeons beat humans in a human test. How would we do in a pigeon test? And who would then have to devise that? Can we ever know?)

Tricky follow-up question. Are there humans who can't read clocks? (IQ 50 perhaps?) DirkvdM 09:29, 1 March 2006 (UTC)

Unfortunately, behaviour like nut burrying does not proove a concept of the future. I bite my nails, but I don't do it out of an understanding that if I don't, in the future they will get so long that I will poke my eye out - nut burrying is an instinctive (or perhaps learned) behavior that tells us nothing about the animal's ideas about time. We could, of course, train a cow to respond to a clock being at a certain time, as long as it could distinguish the two stimuli (clock a and clockb).

google mail

I would like to know how gmail manages to increase the memory space every day. How is that posible. Any information provided will be appreciated.

While not "every day" our article on Gmail states the following:

On 1 April 2005, exactly one year after the initial release, Gmail increased the mailbox size to 2 GB (advertising it as 2GB plus) and introduced some other new features, including formatted editing (giving users the option of sending messages in HTML or plain text). As of February 2006, the mailbox size is 2.63 GB, and is increasing continuously at a rate of approximately 10 MB per month.

My guess as to how it's possible would be money. They see a need to stay ahead of Yahoo and others so they keep throwing money into newer and bigger servers. Dismas|^(talk) 14:35, 28 February 2006 (UTC)

A more direct analogy would be network providers selling service like 5/1 mbit when there's no way the total pool of subscribers has access to that if they all tried at the same time. It's called oversubscribing or overselling and its a very common practice as part of 'Economy of Scale'. On this network comparison, it dates back to the days of dialup where there were typically 10 users to every 1 modem (or maybe 8:1 or lower if you had a real good service). Sure, there would be a huge problem if every single user wanted on, but they rarely did. It probably existed in some form for the better part of written history, as your banking example shows, it is a tenet of our capital economy. I couldn't find any relevant articles on this, which I am suprised at since it's a very common and (imho) interesting subject.
Back on to the subject, what would happen if everyone tried to fill their inboxes. I think that one of two things would happen, google would rescind their offer of 2+GB and say 'oops sorry you only get 75MB' which they are entitled to do, its a FREE service after all. The other option is that the clever lads they are, they figure out what everyone is up to and come up with a way to aggregate the data (for ex. if you tried to fill it by sending huge attachment mails around, they would simply soft link the email so that 100000 copies in different inboxes only cost 1 worth of disk space). As far as your lawsuit goes, good luck with it, hopefully you get all your subscription fees back!

I have a feeling that the actual amount of available memory would be less - not all mailboxes use up their allotted memory - they just need to provide a service which gives the illusion that the particular amount of space posted is available. As long as they can do this, it is not necessary to actually have that amount of memory available. Think of it this way as an analogy: banks do not have enough money available for every one of their customers to spontaneously take out their money. However, as long as they can provide the money every time it's requested, there's no problem with that. --HappyCamper 14:42, 28 February 2006 (UTC)

Thats a really interesting thought. What would happen if everyone tried to use all their memory. Could we sue google for it? I would like a gmail account, but its still in beta. Does anyone know when it starts properly, and will anyone invite me?--Bjwebb (talk) 15:48, 28 February 2006 (UTC)

Sure, I have 100 invites. Ask on my talk page. And I think you're right, we could sue Google if that was the case. Even more interesting is if everyone decided to get their money in cash at the same time. The system would collapse! ☢ Ҡi∊ff⌇↯ 18:16, 28 February 2006 (UTC)

And so it did. What resulted was the great depression. DirkvdM 20:20, 28 February 2006 (UTC)

Good idea. Do you want me to send you the Wikimedia database dumps? ;) --Optichan 17:16, 1 March 2006 (UTC)

Well, just me wouldn't be enough. Why not send them to every single G-mail user :)--Bjwebb (talk) 17:23, 1 March 2006 (UTC)

No, you could not (successfully) sue Google. The TOS states that "Google may, in its sole discretion, modify or revise these terms and conditions and policies at any time, and you agree to be bound by such modifications or revisions." Superm401 - Talk 04:02, 6 March 2006 (UTC)

A good way to insulate aluminium

Hi, I have gotten my A-level coursework today for physics, and I need to find the specific heat capacity of aluminium. The problem is that I need a suitable material to insulate it from the air, otherwise I will end up supplying more energy to the metal than the true value. What is a suitable way of insulating an aluminium cylnder from the air? It needs to be something available in a secondary school science lab. Thanks. --Krackpipe 18:19, 28 February 2006 (UTC)

Yeah, you made it up to A levels! (Whatever that means.). Having got this far, it is good to learn how to research. There's some stuff in this encyclopedia, but for real A-level pros, there's Google. I put in 'determine specific heat' and this is the very first hit [[2]] It's for copper, but a little bit of paint could change it to an aluminum colour. --Zeizmic 18:38, 28 February 2006 (UTC)

Like you said, for people without A levels there is Wikipedia, which can tell you just what an A level is. Apparently there may also be something like a B level. But a C level only seems to exist with a hyphen. No D levels, sorry. DirkvdM 20:27, 28 February 2006 (UTC)

Nope, but there are O levels, which are related to A-levels. --BluePlatypus 06:40, 1 March 2006 (UTC)

There WERE O levels. They were replaced a long time ago with something called GCSEs...

Thanks, this page is useful, and I will do some more digging around on google--Krackpipe 19:19, 28 February 2006 (UTC)

If going to a home supply superstore (Home Depot, Lowe's) and buying pipe insulation is not an option, and assuming you don't want to pilfer the insulation around the hot water pipes in your lab, you might be able to cobble together a few styrofoam hot drink cups for this purpose...--Mark Bornfeld DDS 18:40, 28 February 2006 (UTC)

Thank you, I was considering using the stuff that goes around the pipes in my loft, I guess that is what I will end up using for the investigation. --Krackpipe 19:19, 28 February 2006 (UTC)

If you steal the pipe insulation in your loft, the best thing to do is to take it from the cold-water pipe right above your bed. --Zeizmic 22:30, 28 February 2006 (UTC)

Personally, I wouldn't worry too much about insulating it from the air. I don't think you're expected to set any records for precision. Just note it as a source of error, and you could perhaps do an estimate of the effect of not insulating from the air. Even in a vacuum you'll be losing energy by radiative heat. --BluePlatypus 06:43, 1 March 2006 (UTC)

The idea of everyone using up their gmail space might seem plausible, i saw something but just a glance on the web about using ur gmail for storing files and stuff. I think if 60-70% of the subscribers find that tool very handy in a couple of mmonths we might be able to see what google really were doin.

March 1

Plants and their production of oxygen

I was wondering if it was possible for future moon colonization for the colony's oxygen supply to be totally relient on plants? Could the colonists provide the plants with their carbon dioxide while the plants supplied them with oxygen?

Yes, so long as the whole thing is in air tight containers. The Earth's moon can not be teraformed because its gravity is too low to maintain an atmosphere. WAS 4.250 02:04, 1 March 2006 (UTC)

Closed ecological system --Zeizmic 00:30, 1 March 2006 (UTC)

In order for a planet/moon to have an atmosphere it has to generate enough gravity to hold the gases to the surface of the planet. Our moon has a very thin atmosphere because of its relatively small mass. There is also the question of sustaining the plants. At the very minimum, plants need water, sugar, and carbon dioxide to live. If the moon cannot provide this, in the right quanities, then plants cannot survive. In actuallity, what you want to do is put plants on the moon to generate oxygen. Though it sounds like a good idea, if it were possible, the moon would be as green as our planet. It would have already gone through this process, which is an interesting read. --Chris 01:03, 1 March 2006 (UTC)

I have another question the moon may not have the gravitational pull strong enough for this process but does Mars? If the temperture could be raised then could plants be grown on the surface, of course this would require the discovery of a water source, but could it be done? The carbon dioxide is already there.

I think there's already a lot of water (frozen) on Mars. The problem comes in "raising the temperature". I don't think it would be possible to live on Mars in the same way we use Earth because the amount of energy required would be difficult to generate so far from the Sun. Not to mention the lower intensity of natural light required for photosynthesis. Unless there are high quantities of quality radioactive materials available, forget it. --Username132 01:37, 1 March 2006 (UTC)

Mars can be teraformed by crashing into it a large object that has a lot of frozen water. Objects like this are plentiful. There are a lot of interesting details involved, but Mars is do-able, Earth's moon isn't. You do realize we are talking huge amounts of time, right? WAS 4.250 02:04, 1 March 2006 (UTC)

If the caps were melted would the amount of carbon dioxide released be enough to raise the temperture any? Also if the caps were melted then water would be released.

It's difficult to tell, since to this day we still don't know just how much CO₂ there is in the martian polar caps. Modelling planetwide climate change is something we can't even do well on our own planet, let alone on a planet we have never been to.

Aside: we have a pretty good article on terraforming. — QuantumEleven | (talk) 11:20, 1 March 2006 (UTC)

Degree symbols on Computers

Anybody know why there is not a key for a "degree symbol" on computer keyboards? I frquently have need of one and I'm sure many other people do too.

If you need to use the degree symbol "°" regularly, you may be able to configure your word processing program to assign the degree symbol to a keyboard shortcut. --Robert Merkel 03:41, 1 March 2006 (UTC)

I've got it in my GNOME Character Palette. —Keenan Pepper 04:52, 1 March 2006 (UTC)

There's two things here: 1) computer keyboards evolved from Typewriter keyboards. There was no need for a degree sign with typewriters, because you could simply manually move the platen half a row down and type "o" (in otherwords, put a lower case O in superscript), which is all that was needed given the rudimentary font capabilities of typewriters. 2) most computers use a simple key combination to get a degree symbol. I can't recall offhand what it is with PCs, but with Macs "option-shift-8" gives you "°" in most editing and word-processing programs. Grutness...wha? 05:56, 1 March 2006 (UTC)

If you are using an Apple Computer, just press option and K. K for Kelvin.

There is no degree symbol on a standard US QWERTY keyboard. The (IMO much improved, but very rare) US-International layout has the ° accessible by SHIFT-ALTGR-: . The German QWERTZ and French AZERTY layouts also have a ° key (either SHIFT-) or SHIFT-^ ). See keyboard layout - the standard US keyboard is one of the least functional of them all, and useless for languages which use diacritic marks, or for inputting all but the most common of symbols.

(first answer written which doesn't even answer the question!) If you're using a French keyboard (probably not, but just in case :)), the ° is on a key just to the right of 0 (press shift + that key). If not, you can get it by using it's ASCII key combination, press and hold down ALT, type 0176 on your numerical keypad, and release ALT. (you can use this method to type pretty much any character, find out the different codes by using the Character Map utility, usually in your start menu under Accessories -> System Tools). — QuantumEleven | (talk) 08:36, 1 March 2006 (UTC)

Planet spinning

Can someone tell me why every thing in the Universe spins? Do all stars, planets etc. spin in the same direction? I can understand that a baseball spins because of the friction between the ball and the throwers hand but I'm not sure this would explain why a star spins. Thanks WSC

Something started them spinning a long time ago, and they can't stop because angular momentum is conserved. It would be amazing if the angular momentum randomly happened to be exactly zero. —Keenan Pepper 04:49, 1 March 2006 (UTC)

More specifically, something started them moving a while ago. Then all kinds of gravity happened. Venus and some other orbiting bodies, mainly comets, have retrograde rotations. -LambaJan 07:44, 1 March 2006 (UTC)

Take a simple analogy - water flowing down a drain. In theory, the water could flow straight down the drain without any sort of spin (all that about the draining water spinning the other way in the southern hemisphere is rubbish). But in practice it almost never does, because any slight imbalance (a bit more water on one side, the bowl not being perfectly symmetrical...) will cause the draining water to start spinning.

With stars and other objects it works in a similar way - they are formed when clouds of gas and dusk contract under their own gravity. In theory, the cloud could be perfectly uniform in every direction, and contract perfectly symmetrically. In practice, that's never the case, any small variation will cause the resulting object to start spinning, and in space, as there's no friction, something which starts spinning won't stop.

Because of this, no, not all stars and planets spin the same way, far from it! Their axis and velocity of spin is dependent on how they were formed, and so can be every which way. We have a decent article on axial tilt if you're interested. — QuantumEleven | (talk) 08:27, 1 March 2006 (UTC)

Consider a good-sized chunk of plasticine hanging from a string attached to the ceiling. This is going to be our model of a planet being formed. Assume that it starts out stationary. If you give the lump a little kick–say, by throwing another little chunk of plasticine at it–our lump will start moving. If you hit it dead center, the lump moves sideways: no rotation. If you're even a little bit off center, there will be some movement sideways and some rotation. If you just graze the edge of the lump with a tangential hit, you'll get essentially pure rotation.

When any astronomical body forms, billions of little particles smack into it, and very few strike dead center. It's also very unlikely that the off-center impacts will cancel out perfectly. Consequently, everything spins.

Gravity makes it worse. Like the classic example of a figure skater pulling in her arms, as stars and planets pack their material more densely they spin faster. (Conservation of angular momentum.) TenOfAllTrades(talk) 16:51, 1 March 2006 (UTC)

It may be that the off-centre hits will not cancel each other out perfectly, but with a large number of relatively small hits they will effectively. And they will in time be small because the surviving celestial bodies will be much much bigger than the stuff that hits them. The amount of energy needed to make a planet spin at the speed at which they do would require either a lot of small ones going off-centre on the same side, which would be statistically impossible or a big one, which would either destroy it or knock it so far out of orbit that it will get destroyed in some other way (or flung out into deep space).

I have thought about this too and haven't come up with an answer. It makes me think a bit about the question where structure in the Universe comes from. It can not have formed without already being present before the Big Bang. But we can't explain structure there, so we simply have to accept its existence. Jus like matter and time 'just are' and structure 'just is', maybe rotation is something that simply is. Asking about its origin would be like asking why there is matter.

Now that sounds like a lame answer, so let me try a different one. Maybe it's a matter of starting conditions. Maybe the very first momentum caused by chance will amplify. Chaos theory would probably come in here because we've got am instable system the outcome of which is determined by minute variations in the starting conditions. And I've got a feeling relativity might come in here too, with the initial rotation determining how attracted matter will approach it, but that's no more than a hunch.

I wonder. If one would add up all the rotations in the Universe, would they cancel each other out? DirkvdM 09:08, 2 March 2006 (UTC)

False Embryo Sketchings?

I've heard some Christians and creationists say that Ernst Haeckel's drawings of embryoes, which he claimed to be scientific evidence for evolution, are fake or flawed.Is that true?Bowei 06:50, 1 March 2006 (UTC)

That can be dismissed without addressing the main question. It's a straw man argument, since a drawing isn't scientific evidence of anything, ever. (at least in the context of biology/medicine) --BluePlatypus 07:38, 1 March 2006 (UTC)

Yes, Haeckel's sketches are flawed—he gets a bit fanciful with his third row of sketches in the figure at right. Haeckel's Theory of Recapitulation stated that the development of an embryo would follow the evolutionary development of a species. (Often this is condensed down to the catchy slogan 'Ontogeny recapitulates phylogeny'.)

While Haeckel's theory fails in the strictest sense and his drawings sometimes strayed into wishful thinking, it does provide a useful rule of thumb. In the human embryo, features that evolved early (a backbone, for instance) are formed early in embryogenesis, whereas features that evolved recently (the cerebrum) form last. In whales (which evolved from land mammals) the embryo grows and then loses hair during the course of its development.

Certainly if Haeckel's sketches were the only evidence in support of evolution, they would be poor proof indeed. However, there is a wealth of other evidence that supports evolutionary theory quite well; an error made by a zoologist in 1866 doesn't render the theory any less reliable. TenOfAllTrades(talk) 16:33, 1 March 2006 (UTC)

Of course, they are flawed in many ways. Embryos aren't two dimensional, to begin with. deeptrivia (talk) 04:12, 2 March 2006 (UTC)

porn site

Can anyone give me the best porn site in the world?

What are your criteria? JackofOz 12:21, 1 March 2006 (UTC)

Because there is no reputable ranking site, I don't think you can say. It all boils down to personal preference. For example, you might like http://mary-kateandashley.com or http://www.hairybearmen.com. Proto||type 14:09, 1 March 2006 (UTC)

As of a couple of years ago Usenet literally contained more FREE porn of EVERY category (including illegal) than you could view in a lifetime. I haven't been there in years, so I don't know its current status. WAS 4.250 18:12, 1 March 2006 (UTC)

Our article onit says in one place it currently has a daily volume of "2.00 TB" and in another place says " Commonly omitted from such a newsfeed are foreign-language newsgroups and the alt.binaries hierarchy which largely carries software and erotica and, in the 21st century, accounts for over 99 percent of the article data." So does 2 TB of free porn a day qualify as "best"? WAS 4.250 18:22, 1 March 2006 (UTC)

Sure, but only if you can tell me correctly what the best book ever written and the best movie ever made were (and have *everybody* agree on it). --Robert Merkel 00:25, 2 March 2006 (UTC)

There is only one book that stands out from all others and that is The Bible. There is no moving picture that stands out above all others so the "best" movie that everyone can agree is the "best" is yet to be made. That's not exactly what you asked, but that's what's available in terms of books and movies. What's available in reality-land is fresh bread with cheese and tomato and sausage topping (pizza) with wine (or beer), and an opposite-sex friend (ask around, find a real life babe, beats anything on the internet); or as someone once put it a loaf of bread, a jug of wine, and thou. WAS 4.250 03:11, 2 March 2006 (UTC)

To be fair, the question was the best site, not the best porn, it's more like asking what is the best library than what is the best book. I think it's fair to say that the site containing the largest amount and largest range would be most likely to be agreed on by the most people as the best site. Your milage may vary.

No no no no no! You're saying that 'best' is defined by quantity. That should be quality. Wikipedia is the best site on the Internet because it's structured (and free). The Internet is a huge collection of info, but what was lacking was an easy way to get the right information. Search engines were one solution, but you still usually have to wade through a lot of stuff you're not interrested in. Even though Wikipedia doesn't quite come near the quantity of what these search engines can access (the whole Internet) it is already an equal competitor (I already often search on Wikipedia before I Google a term). When Wikipedia encompasses all information of some importance (a decade from now?) search engines will be out the window. So the best porn site would have all sorts of types of porn, but it would stand out by making it easy to find what you are looking for. And it would be free. That probably doesn't exist yet. So maybe we should start this? Wikiporn anyone? Of course we'd need to have images under gpl, so we'd have to make them ourselves. I suggest you start asking pretty girls (and guys) in your neighbourhood if they'd want to have their photos taken. All in the name of the open source movement of course. It's for a good cause. :) DirkvdM 09:28, 2 March 2006 (UTC)

It's been suggested already. :) I even proposed the "This page is currently softcore. You can help Wikiporn by hardcoring it" template. ;) ☢ Ҡi∊ff⌇↯ 15:12, 2 March 2006 (UTC)

So the best porn site would have all sorts of types of porn, but it would stand out by making it easy to find what you are looking for. And it would be free. That probably doesn't exist yet. Obviously you haven't bothered to look at either usenet nor any of the myriad ways of accessing it. Usenet is free, volumous, contains high quality by any standards mixed in with high quality by every standard (meaning whatever you want is in there somewhere), AND it is divided up into categories as precise as "alt.binaries.pictures.olsen-twins" (see [3]). To search and sort more thoroughly, you have to find an accessing method (tool, site, provider) that suits your desires/needs whatever that may be. Just cause you don't check something out doesn't mean it doesn't exist. Ever hear about the economist who said there is no such thing as a quarter on the ground because someone would have picked it up according to economic theory? By any standard except trying to get you to pay money for what you can get elsewhere for free, usenet is the best. Usenet has been for a decade well known as the best web porn site period. On slashdot it's been compared to trying to get a drink of water from a firehose. Porn sites flood the place with free pics trying to get customers to come to their specialized sites. Enthusiasts share entire collections with one another. It's also spam city. examples of tame usenet from[4]:

1. alt.binaries.videos.tv.shaggable-babes (sources, sample of binaries)
2. alt.binaries.multimedia.japanese (sources, FAQ, sample of binaries)
3. finet.binaries.keskustelu (sources, sample of binaries)
4. alt.binaries.pictures.autos (sources, sample of binaries)
5. alt.binaries.pictures.hannigan (sources, sample of binaries)
6. alt.binaries.pictures.ba (sources, sample of binaries)
7. alt.binaries.pictures.rail (sources, FAQ, sample of binaries)
8. alt.multimedia.mpeg (sources)
9. alt.binaries.e-book.flood (sources, sample of binaries)
10. alt.binaries.pictures.child.starlets (sources, sample of binaries)
11. alt.binaries.pictures.kid (sources)
12. alt.binaries.pictures.suntan (sources, sample of binaries)
13. alt.binaries.webstars (sources)
14. alt.binaries.pictures.chelda (sources)
15. alt.binaries.slack (sources, sample of binaries)
16. alt.binaries.pictures.woodworking (sources, sample of binaries)
17. alt.binaries.pictures.animated.gifs (sources, sample of binaries)
18. alt.binaries.sheet-music (sources, sample of binaries)
19. alt.binaries.pictures.anime (sources, FAQ, sample of binaries)
20. alt.binaries.cracks (sources, sample of binaries)
21. alt.binaries.e-book.fantasy (sources, sample of binaries)WAS 4.250 10:32, 2 March 2006 (UTC)

Examples of untame usenet from [5]: alt.binaries.pictures.erotica.boys alt.binaries.pictures.erotica.breasts

   Pictures of mammalian protruberances

...pictures.erotica.breasts.large ...pictures.erotica.breasts.natural ...pictures.erotica.breasts.saggy ...pictures.erotica.breasts.small

   More than a handful is too much

alt.binaries.pictures.erotica.british

   A binaries group devoted to British glamour girls

alt.binaries.pictures.erotica.brunette

   Erotic pictures of brunettes

...erotica.brunettes-short-hair.reposts

   Reposts of erotic photos of brunettes with short hair (on their head!), corrected

...pictures.erotica.bulgarians.female

   Erotic pictures of women of fractional or full Bulgarian ancestry or close enough

...pictures.erotica.buttnuggets alt.binaries.pictures.erotica.butts

   Erotic butts come into view

alt.binaries.pictures.erotica.cancel alt.binaries.pictures.erotica.cartoons WAS 4.250 10:57, 2 March 2006 (UTC)

energy change

what is the energy change in a pendulum?

Just take the energy change outside the pendulum and subtract! Seriously, check out pendulum, and work it from there.  freshgavinΓΛĿЌ  13:48, 1 March 2006 (UTC)

Where does the EM energy go when the Poynting vector is zero?

I hope you've guessed that I'm talking about an electromagnetic wave. According to the electromagnetic wave equation, the phase difference between the E and B fields is zero, so the Poynting vector, which is their cross-product, is a cos-squared function of time. This means that the energy in a wavefront oscillates between zero and some value. Where does nature put the energy while the Poynting vector is zero, so that it can magically produce it a quarter-cycle later? I'm not trying to be controversial: I just want to know how I have misunderstood the equations. This stems from a question that someone asked me on my Talk page about why the E and M components in the light-wave.png image are in-phase. --Heron 14:53, 1 March 2006 (UTC)

It means that the energy of the EM wave is zero at that particular point of the wave - however, the wave must have some spatial extent in the longitudinal direction, and the E & H fields are not zero as you move away from the crossing point. So the answer is, the energy is stored in other parts of the wave, and as it propogates, the zero-energy points move along with the rest of it. If you integrate the energy for the whole wave-packet, you'll see that it is conserved as you expect.

Note that this isn't just a mathematical fiction - if you create an EM standing wave, you get no effect from the wave at the nodes (since there is no E or H field there), which can cause unwanted effects in lasers. --Bob Mellish 16:27, 1 March 2006 (UTC)

Thanks Bob, that makes sense. --Heron 18:50, 1 March 2006 (UTC)

telephone usage

Excluding mobiles which country has the most telphones per head of population? 15:48, 1 March 2006 (UTC)~

You will want an anomoly - extremely small population with high telephone usage. My best guess would be Palau. They have 6,600 wired telephones and 20,000 people. That is 30% of the population with a wired telephone (assuming 1 phone per person and not one person with 6,000 phones). So, look at the micro-nations and look for high telephone use and low population. The Vatican may be a good one. --Kainaw ^(talk) 16:08, 1 March 2006 (UTC)

Thank you :) much appreciated 19:23, 1 March 2006 (UTC)~

I'd be willing to bet it's the Vatican City - population about 900, but employing a couple of thousand non-resident workers, and in the heart of Western Europe. I can't see them having less than the 300 phones needed to beat Palau's 30%. Grutness...wha? 01:20, 2 March 2006 (UTC)

The Netherlands had 8 million connections in 1995 (if that figure includes mobiles it won't be too many). In 1997 that was 8,8 million (different source). Mobiles will have slowed the increase of wired connections, but if we assume 10 million now, on a population of 16 million that would be 60%. That said, the Netherlands is said to be the most 'connected' country in the world in different respects (highest Internet usage, for one). The main causes for that are probably high GDP combined with socialism (everyone gets to share in the wealth) and a high population density (there is no 'outback' in the Netherlands). Scandinavian countries have the former but not the latter (except maybe Denmark). But indeed smaller countries may score better. Maybe Luxemburg, Hong Kong or Singapore? DirkvdM 09:42, 2 March 2006 (UTC)

Well it's for a radio quiz & it's been going for 8 days now & it's not Vatican City because someone tried that last night - before I got chance to ring in. Belgium, Liechtenstein, France, Guernsey, Jersey, Hong Kong, Singapore, Norway, Sweden, England, Luxemburg, Malta, Republic of Ireland, Spain, Andorra, Afghanistan, New Zealand, Australia, US, Canada, Vatican City, Falkland Islands, Taiwan, Holland, Japan & Korea are the answers given so far. It's just driving me nuts now! Tonight I'm hoping to get on there & try Palua which was Kainaw's guess. Failing that it's back to banging the head on the desk! Will keep eveyone informed 82.46.54.254

If it is a radio contest, the answer they want is most likely wrong. They read obscure news articles that they don't understand, grab a fact that uses words they don't understand, and then turn it into a questions loosely based on the fact. Your best bet is searching Google News for articles about telephone usage as that is where the question came from. --Kainaw ^(talk) 14:30, 2 March 2006 (UTC)

Searched Google News... A recent new article claims Monaco has the most telephones per capita (199.4%). --Kainaw ^(talk) 01:20, 3 March 2006 (UTC)

Thanks Kainaw you've been ever so helpful. I'm new to all this so I do appreciate it :) Only worked out yesterday how to get a user name rather than a number!Devononlyknows

Have you tried using the CIA The World Factbook? However, it doesn't seem to have per capital figure, and you may have to divide the list of number of telephones with population. The Monaco's figure given above seems difficult to beat. Interestingly, the Pitcairn Islands has only one telephone, i wonder if they complain about long-distance charges. --Vsion 09:13, 3 March 2006 (UTC)

I will check that link now thank you Vsion. I wonder if the Pitcairn Islanders do complain about phone charges! Must be a pain in the neck if they need an engineer because the phone isn't working!Devononlyknows

Why haven't I ever even SEEN a B Battery?

I've seen and used AAA, AA, A, C, D, 9V, and other sizes of batteries, but why haven't I even seen a "B" battery? Why aren't they made? --Shultz III 18:12, 1 March 2006 (UTC)

Hmm... it appears that they are made: [6] [7]. Put the second one appears to be "hand-made". ^KILO-_LIMA 18:26, 1 March 2006 (UTC)

You just weren't looking in the right place. --LarryMac 18:32, 1 March 2006 (UTC)

Obviously, however, C battery (vacuum tubes) is not the same as the consumer C battery originally referenced, so I wouldn't call B battery (vacuum tubes) "the right place". Duracell only lists yours above as "common" (though I've also seen AAAA), so Bs certainly appear to be long gone. I'll keep poking around. — Lomn Talk 19:00, 1 March 2006 (UTC)

Well, I did show him a B battery, even if it came from the wrong family. There is amazingly little to be found on the web about the consumer style. The ANSI standard (referenced below) is C18.1, but NEMA wants $79 to see it. --LarryMac 19:49, 1 March 2006 (UTC)

Here's a quick note on A and B being part of the 1920s ANSI standard for battery sizes (noting simply that those extant today are the ones that caught on commercially) and a chart of standard battery sizes (A is included, but B appears not to be). — Lomn Talk 19:06, 1 March 2006 (UTC)

A related question - is it just my imagination, or did Britain used to have the same betteries but with completely different names? ISTR U-11 batteries as a young kid. Grutness...wha? 01:21, 2 March 2006 (UTC)

They did used to. I can't remember the names either though. I remember figuring out what the equivalents were. 67.40.249.122 03:11, 2 March 2006 (UTC)

The codes are of the form LR06 = AAA, LR6 = AA, LR20 = D, 6LF22 = 9V, etc., and are still printed on batteries here in the UK. Ojw 20:16, 3 March 2006 (UTC)

Not the codes I'm thinking of - these were definitely U-number, as in U-11, U-5 (I think) and U-22. Grutness...wha? 00:04, 4 March 2006 (UTC)

Good quote from Dan's data on the AAAA cells - "no matter whether you're at the bottom of a five-mile cave system, performing extra-vehicular activity on the International Space Station, or lost in the middle of the Gobi Desert, you at least know you're no further away from a place that sells AAAA cells than you'd be if you were standing in your local shopping centre.". Ojw 20:22, 3 March 2006 (UTC)

I added them as A battery (vacuum tubes), B battery (vacuum tubes), and C battery (vacuum tubes) specifically to avoid confusion with the modern A battery and C battery as the letters used in the vacuum tube batteries refered to usage not specific sizes/packages (all three came in many different sizes/packages). The modern A and C cells are battery sizes/packages. -- RTC 23:46, 4 March 2006 (UTC)

websites

What is the estimation of current number of WWW. sites?

By www site, do you mean a unique site or a domain name. Many sites have multiple names all pointing to the same site. Also, some sites have many subsites (like aol.com and all the user pages under the aol.com domain). So, using "site" is very vague. But, an estimate can be made. Assume 5% of the computers in the world are web servers hosting a web site. If you think that is low, then consider that some web servers host multiple sites. If you think that is high, then use a different percentage. Now, take into account that there are currently around 4 billion IP Addresses in use - meaning there are around 4 billions computers connected to the Internet. Many are printers, switches, and the like. But, we only consider 5% of them to be web servers. So, 5% of 4 billion is... 200 million. That may sound high, but I think it is rather low. Google claims to have indexed well over 9 billion pages. They don't even touch all the "Hi. I learned to make my own webpage!" pages. So, either a lot more of the computers on the Internet are web servers or the web servers are hosting a lot more than one site on average. --Kainaw ^(talk) 01:38, 2 March 2006 (UTC)

The February 2006 Netcraft survey received responses from 76 184 000 sites, so there are at least 76 million websites out there. --Bowlhover 13:33, 2 March 2006 (UTC)

DRUG HAIR TEST

WHAT WILL CAUSE HAIR TO TEST POSITIVE FOR COCAINE, IF A PERSON NEVER USED DRUGS BEFORE.

Little bit of trivia, the mass spectrometers they use for those tests are so sensitive that if you've used cocaine any time in the last 6 months you'll test positive, so if you've haven't done anything recently it doesn't mean that it's a false positive, just a very sensitive spectrometer--205.188.116.74 22:15, 1 March 2006 (UTC)

Please stop yelling. Turn off your caps lock. The logic of your dillemma there is obviously flawwed. If a person has never used drugs, then the person should pass the test, assuming the test was done correctly. Is there a specific person involved? Is it yourself? Did this actually happen or is it a theoretical question? More information is needed. In the mean time, you can take a look at our article on hair drug testing. It might help you out. --Chris 20:07, 1 March 2006 (UTC)

• In a test, the Mythbusters showed consumption of poppy seeds could cause you to test positive for opiates, but for such things to show up in a hair test, that would require massive amounts of the stuff. - Mgm|^(talk) 20:47, 1 March 2006 (UTC)

Few tests are so good that they have NO false positives - what is the accuracy of this test?

• Actually, there are no false positives, it's the same machine they use to sequence proteins, and is more than capable of telling the difference between cocaine and coca flavored shampoo, LOL--152.163.100.74 05:17, 2 March 2006 (UTC)
  • I don't see how, given that coca-flavored shampoo would actually contain cocaine. --Trovatore 05:20, 2 March 2006 (UTC)

It occurs to me that if you were to use an herbal shampoo containing coca leaf, it could mess you up this way. I've never heard of any such shampoo, but you never know. --Trovatore 03:20, 2 March 2006 (UTC)

The short answer is, it depends. If you have been in the presence of other individuals using cocaine (smoking large amounts of crack, in particular), then it is possible for some cocaine to become attached to your hair. Hair testing protocols call for fairly extensive washing of the hair sample to remove drug that may have been absorbed from the air, but there are studies which suggest that this process may not be 100% effective. Dark-haired individuals may be particularly vulnerable, as there is evidence to suggest that melanin (a pigment in dark hair) can effectively bind cocaine. Modern hair-testing labs should be testing the hair for both cocaine and for its metabolites: compounds like benzoylecgonine. The presence of such compounds is usually taken to be indicative that the drug was ingested, since they are produced as the body processes the drug. (If a lab cuts corners or offers cheap tests, they may not be testing for metabolites.) There is also an off chance that someone screwed up sample handling or labelling somewhere along the line; if someone else's hair was tested in place of yours, then you're going to get incorrect results. I am operating under the assumption that the lab is using a GC/MS (gas chromatography/mass spectrometry) system to run these tests. Such equipment–used properly–is pretty much the gold standard. Other testing protocols may be more prone to false positives. TenOfAllTrades(talk) 05:45, 2 March 2006 (UTC)

I am actually pretty sure I saw in Scientific American that it is possible to detect certain drug usage, and how much a person has been using after they've had enough time to grow their hair out. I don't remember any details, maybe it was crack they talked about. -- Mac Davis ☢ ญƛ. 10:18, 2 March 2006 (UTC)

You might get a positive result if the lab is sloppy. If they have cocaine around, the dust can contaminate the room so that test samples could pick up cocaine from air or surfaces. The FBI whistleblowers made just that claim about the FBI labs. They had a lot of cocaine around. I have read that money counted out near drugs will pick up particles of drug. As that money gets passed around, it rubs off on other money in the money drawer. Thus I read that a large percentage of money has detectable drug residue, and could be confiscated under USA forfeiture laws, if the police decide to test YOUR money. GangofOne 08:12, 3 March 2006 (UTC)

Why is Schrondinger's Equation The Way It Is?

This question might be asking something that isn't very answerable by anyone, or at least answerable without recourse to talking about 11 dimensions and Hilbert Spaces, but why is Schrodinger's Equation what it is? I'm in Intro QM at Uni, and was talking to a friend, trying to describe what wave functions are. I was explaining the infinite-square well potential, and she asked why it was that the stationary states were all sinusoidal. The answer, of course, is that time-independent equation becomes a differential equation for a simple harmonic oscillator in the infinite-square well case, and the rest is boundary conditions. But she wanted to know why the time-independent eq. (and by extension the general eq.) worked out to a harmonic oscillator. I had no answer, was wondering if one existed. A simpler question might be, how did Schrodinger come up with the equation in the first place? It hardly seems as intuitive as f=ma and the like.

• A particle in an infinite square potential well wouldn't be a harmonic oscillator, you're confusing two entirely different models, so I'm not sure quite what you're asking, and certianly the number of dimensions is irrelevant, if you're asking why is the Schrondinger Equation sinusoidal then the answer is simple, the linear, or in your case angular momentum can be defined as the sum of two exponential functions (in 1 space), representing momentum in both the positive and negative directions, euler allows us to summarize this as a harmonic function, and as far as where the expoential terms come from, you simply apply your Ĥamiltonian over your wavefunction, which gives you a second order differential equation, which in turn gives you your exponential term, it's not only more intuitive than F=ma, it's more accurate as well, although if you replaced your a term for an expression involving an expression of momentum, and your m term for your reduced mass, you could probably construct some sort of rudimentary Fx operator ;)--205.188.116.74 22:03, 1 March 2006 (UTC)

• Are you asking why the Schrödinger equation is the way it is, or are you asking why the solutions to it are the way they are? The former is physics, the latter is a purely mathematical issue. As for the former, you can't really go by how Schrödinger derived it, because his way was rather ad-hoc. A ground-up approach from basic postulates is given in, for instance, the first three chapters of Landau & Lifschitz book on QM. It's not string theory, but it's not introductory-level stuff either. --BluePlatypus 04:03, 2 March 2006 (UTC)

• This is – approx – how Schrödinger came by his equation (or how we've been told he did): It was at the time that people had quite agreed that particles are waves, and someone asked Schrödinger: "Now, we have waves, shouldn't we have wave equations?" So Schrödinger went searching. In time before QM, fysicians had constructed Lagrangian and Hamiltonian formalisms (you may know them, though you may not) and there's a formula, saying: energy = kinetic energy + potential energy (though it's stated in a slightly more different way, so as to be so general it can be applied to cases that have nothing to do with energy at all; the "real" formula is in fact: H = pq۟ + V). Now he needed waves, and these go like sin(kx - ωt) or cos(kx - ωt). If you derive them with respect to x, you get k (≈impulse) in front of them, and if you derive them to t, you get ω (≈energy). So you add some constants where needed and you get an equation that certainly looks pretty smart and cool, and it even works. Greetings. David 15:28, 2 March 2006 (UTC)

Scientific Journals - where does the money go?

$20 to download a single article from some journal publishers seems a bit steep (especially for a student). Why do they have to charge so much? Are some of the publishing executives struggling to pay for their second homes? Some day us scientists will raise our conical flasks and petri dishes and revolt! --Username132 16:09, 28 February 2006 (UTC)

It depends on the journal. Some are published by professional societies; in those cases the money ges back into the cost of production of the journals (which are usually subsidised by members dues). In the case of journals that are published by publishers like Elsevier and others - it's all about profit. You charge a library $1000 for a subscription to a journal, charge authors page charges and get peer reviewers to work for free. Guettarda 16:22, 28 February 2006 (UTC)

Do you know how the peer review process works? If peer review is free, would it be possible to set up a free/cheap/donation-based online journal? --Username132 20:24, 28 February 2006 (UTC)

The money certainly isn't paid to the editors: I once applied for a job at a journal produced by a commercial publisher (not a scientific society), but the salary they offered was almost exactly half what I was earning as a university researcher! Physchim62 (talk) 20:33, 28 February 2006 (UTC)

Is an editor the same as a peer-reviewer? If not, how do they differ? --Username132 23:46, 28 February 2006 (UTC)

An editor will edit the content for the journal (spell-check, grammar check, introduce incorrect grammar when they simply don't understand the scientific wording...). A peer-reviewer reads and rates submissions. For example, I primarily work in research on hypertension. When we submit articles to journals, the editor most likely knows nothing about hypertension. So, they send it to peers who know a lot about it. Then, they read it and tell the journal if the article is worth publishing. If you are very lucky, you get the article back with suggestions. You fix it up and resubmit it. Sometimes it can be something rather silly. We had to resubmit one because we used "underpriveleged" to mean "lacking in access to healthcare". In this particular journal, "underpriveleged" is a reserved synonym for "African-American". We changed it to "deprived" and everyone was happy. --Kainaw ^(talk) 01:36, 1 March 2006 (UTC)

Thanks for the insight. What do peer-reviewers get for their work? Free journal access?

Gratitude --pom 00:11, 2 March 2006 (UTC)

Depends on ethics. Some peer reviewers get into it just to steal ideas. Others are really trying to help. --Kainaw ^(talk) 01:55, 2 March 2006 (UTC)

You would be better stealing ideas from reviewing grants not papers. Most people (99%) review papers because others have done it for their own papers. David D. (Talk) 08:34, 3 March 2006 (UTC)

---

Most universities have subscriptions to most journals, including the online versions. If you're a university student, you can inquire with your library for what journal subscriptions they have and how to access them. At my university, merely by being on a university machine (or logging in through a proxy server), I can get free copies of articles from any journals I've ever looked for. I don't know if that helps you or not, but it might be something to check into. -- SCZenz 23:51, 28 February 2006 (UTC)

Yeah we have subscriptions to the most relevant ones. Occasionaly though, I find an article I'd like but can't access. I know people writing some dissertatations are even less well served by the available subscriptions. My main concern is how I keep up between leaving university and getting a research position. --Username132 08:41, 1 March 2006 (UTC)

---

The scientific journal business has made a large number of scientists rather unhappy; see open access (which is not the most neutral of articles, but anyway) for an alternative approach. --Robert Merkel 22:17, 28 February 2006 (UTC)

Thanks, this is great! I'm actually a representative for my university course to our university library. Is there any way our university library can do more to support open access? I'd like to make the most of my position for the remaining couple of months that I still have it.

Also is research funded by a corporation such GlaxoSmithKline more likely to be published in a traditional journal? When they're close to something, they stop publishing at all so they can patent it first, don't they?

Supposing I had really good eye-site and looked through a GSK window as I passed by and saw the notes jotted by some scientist and then ran to the internet and published "the cure" for HIV before it had been patented... apart from being on GSKs hitlist, would I have comitted a crime, and would people be allowed to use the information published? --Username132 22:56, 28 February 2006 (UTC)

Patenting depends on where you are. If memory serves me, in Europe, you can publish after the application has been sent in, in the US you have to wait for the patent to be approved. And assuming you weren't trespassing, then no, you haven't done anything illegal. This is all kind of moot though, because in reality Pharma companies patent stuff at a very early stage (pretty much as soon as the idea presents itself), far before the years of development and clinical testing (from candidate to approved drug is a process that takes over a decade). So even if you managed to get hold of a not-yet-patented idea, you wouldn't have the resources to turn it into a drug. And even if you did, less than 1 in 1000 candidates make it through all the way to an approved drug. --BluePlatypus 08:20, 1 March 2006 (UTC)

What can an individual library do to help support open access? --Username132 08:29, 3 March 2006 (UTC)

Kinetic Energy and Einstein's Theory of Special Relativity

Firstly, can someone please verify that the equation for kinetic energy, taking into account Einstein's Theory of Special Relativity is: $K_{e}=mc^{2}\left({\frac {1}{\sqrt {1-{\frac {v^{2}}{c^{2}}}}}}-1\right)$

Secondly, can someone explain how we get that equation from $E={\frac {mc^{2}}{\sqrt {1-{\frac {v^{2}}{c^{2}}}}}}$ I think I get it now, although it would still be handy if someone could explain it just in case...

Thirdly, can someone please tell me of a computer program/language that will enable me to perform calculations with this with absolute accuracy. All the software I have at the moment doesn't seem to be able to cope with numbers such 299792458 squared (which isn't surprising I suppose). P.S. I think I'll stick to the Key Stage 3 stuff I'm supposed to be doing... 80.229.152.246 21:29, 1 March 2006 (UTC)

Once you subtract the rest energy $mc^{2}$ from the total energy $\gamma mc^{2}$, you get the energy of motion $(\gamma -1)mc^{2}$.

As for your software, have you looked for a scientific mode? The speed of light should not be stored as an exact integer, but as a floating point value, which usually has a lot more range. —Keenan Pepper 21:41, 1 March 2006 (UTC)

Thanks for the answer Keenan. As for the software, it doesn't have a scientific mode, although I think I will try it with something else I have found. Thanks. 80.229.152.246 17:30, 2 March 2006 (UTC)

Drug Hair Test

What causes hair to test positive for cocaine, if one never used it.

You asked that question already. Scroll up a bit. Optichan 22:03, 1 March 2006 (UTC)

Ever get really tweaked on some coke, ask a question, and then, just a few minutes later, forget if you asked it or not already? --Kainaw ^(talk) 01:11, 2 March 2006 (UTC)

And then the darn test results come in, and you forgot you even took it... --Zeizmic 13:34, 2 March 2006 (UTC)

Drug store?

Why is a drug store called a drug store instead of a medicine store? (Aidan Age 8)

I don't know, but my guess is that the word "drug" has less syllables than "medicine". --HappyCamper 23:16, 1 March 2006 (UTC)

Hi Aidan. The meaning of words changes over time. When the phrase "drug stores" was invented the word "drugs" was a word that people associated with relief from pain and other good things so it was a good name for a type of store. Today "medicine" means something that you won't go to jail for and make you better; while "drugs" means things people say are bad for you. The words mean the same thing, but the connotation is different. You are trained to feel one way about one word and you are trained to feel a different way about the other word even though the two words mean the same thing. WAS 4.250 23:34, 1 March 2006 (UTC)

When a police officer ask "Are you on medication", such as [8], he is refering to general substance abuse including non-medicinal drug, isn't it? --Vsion 15:05, 2 March 2006 (UTC)

There is a store near me, owned by a person of Middle Eastern descent, whose English leaves quite a bit to be desired. The name of the store ? "The Drug and Party Fair". LOL StuRat 23:55, 1 March 2006 (UTC)

Out on a limb here, but the Dutch word for 'drug store' is 'drogist', which refers to the word 'drogen', which means 'to dry'. And indeed most medicines have in the past been dried plants. Considering the overlap between the Dutch and English languages there is a good chance the English word has a similar origin. And indeed over time the usage has changed when the word is used by itself, but (possibly) retained its original meaning in the term 'drug store'. DirkvdM 09:56, 2 March 2006 (UTC)

The OED says drug-store is originally U.S. The archaic English word druggist has the same meaning as drogist in Dutch, and is also usually traced back to a root meaning 'dry'. --Heron 20:56, 2 March 2006 (UTC)

Note that, at least in American English, "drug" still retains the meaning of "pharmaceutical", as well as "recreational substance". (For that matter, the line between the two is not always entirely clear.) --Trovatore 03:30, 3 March 2006 (UTC)

Well, the definition of the line between the two is in general quite simple; whether it's legal or not. Which, of course, is an upside down way of reasoning; "It is illegal, therefore any use must be recreational". But some drugs are used both pharmaceutically (legally) and recreationally (illegally), such as opium (laudanum) in the past and marihuana (which is literally a dried plant) recently. Interrestingly, heroin was originally devised as a wonder drug against opium addiction (so as a medicinal drug). Now, such a wonder drug is methadon. I wonder how long it will take until that becomes a 'street drug' like heroin. DirkvdM 08:51, 3 March 2006 (UTC)

March 2

Is it true that the earth wobbles while it spins?

Yes. --Kainaw ^(talk) 01:12, 2 March 2006 (UTC)

How much does it wobble? And at what frequency? --HappyCamper 01:13, 2 March 2006 (UTC)

Well, he didn't ask that. Anyway, according to axial tilt, "The Earth's axial tilt varies between 21.5° and 24.5° with a 41,000 year periodicity". --Kainaw ^(talk) 01:41, 2 March 2006 (UTC)

Oh, I didn't know that was what it was called. Thank you :-) --HappyCamper 01:55, 2 March 2006 (UTC)

The actual wobble is called a precession, the kind of motion you get if you deliver a sideways prod to a spinning top. --BluePlatypus 03:50, 2 March 2006 (UTC)

To be clear, there are two overlapping 'wobbles' at work. The axial tilt changes on a 41,000 year cycle, and the axis precesses on a 26,000 year cycle.

The geophysicist Milutin Milanković looked at the combined effect of these wobbles (as well as a number of other factors) on Earth's climate. He proposed that there would by cyclical variations in climate (resulting in periodic ice ages and the like) on a roughly 100,000 year time scale; these are called Milankovitch cycles. TenOfAllTrades(talk) 05:24, 2 March 2006 (UTC)

I also found something interesting while searching for this. There's another (much) smaller wobble called the Chandler wobble, which has a period of only 435 days. Interesting read; you learn something new every day. EWS23 | (Leave me a message!) 05:35, 2 March 2006 (UTC)

iTunes and storage

I have MUCH more music than I want to store on my G4 Powerbook. I have some of it on the PB, and a lot, lot more on an external drive that is accessable when the PB is 'docked' on my desk, but not on the road. I want to have a way to easily choose which music stays and which goes, much as I can with my iPod. Anything?

Well, it looks like you've actually got three hard drives: the Powerbook's drive, the external drive and the iPod. So how about you store all the music on the external drive, but manage it using iTunes (make sure iTunes on the PB isn't copying the files to the local drive). Set up a playlist in iTunes of the songs you want to take on the road which you can easily alter. Sync the iPod to that playlist only, and then when you go on the road, plug the iPod into the Powerbook and play the music straight off the iPod through the Powerbook speakers. --Canley 05:02, 2 March 2006 (UTC)

Good idea - thanks. The problem is the iPod is tiny, and the PB has a pretty large drive. I'd really like to have a boat load on the PB. Any other ideas?

I don't understand why you wouldn't just put all the music on the Powerbook. If its too much, just choose what songs go. -- Mac Davis ☢ ญƛ. 10:07, 2 March 2006 (UTC)

The reason that I don't put it all on the PB is that the harddrive is too small for the whole collection. What I am looking for is a way to easily manage what songs go on it, and what stays at home. I want to be able to change what is on the PB and what is not on a fairly regular basis.

1. . iPod - 1 gig. Good for jogging, and other small outings.
2. . PB - 80 gig. About 20 gig I am willing to use for music. Good for trips out of town.
3. . External drive - 300 gig. All my music, about 100 gig filled.

So I want to keep everything on the external. I want to put pretty much a random and changing selection on the iPod. I can do this already. I want to put pretty much a random and changing (but bigger) selection on the PB. I can't figure out how to do that.

Nature red in tooth and claw

What exactly does the phrase "Nature red in tooth and claw" (from Tennyson's "In Memoriam") mean, particularly as used in evolutionary biology? Dawkins makes a reference in it in The Selfish Gene [9], though he doesn't explain it. --JianLi 04:10, 2 March 2006 (UTC)

It is a reminder that animals eat each other without mercy. It is the reality to which "the lion shall lie down with the lamb" is the imaginary antithesis. alteripse 04:15, 2 March 2006 (UTC)

Earthquakes

Is it true that earthquakes often occur after a heavy rain during a hot day? --ct

If you find out, why don't you clean up the article earthquake weather? --Trovatore 06:11, 2 March 2006 (UTC)

I can assure you there is absolutely no scientific basis behind that. Geothermal mantle currents have nothing to do with how sunny it is or how wet it is. -- Mac Davis ☢ ญƛ. 10:09, 2 March 2006 (UTC)

That would be a handy indication of wheather or not an earthquake is coming. (Ok, that was lame even by my standards). DirkvdM 10:08, 2 March 2006 (UTC)

The phoney concept of 'earthquake weather' was reinforced by Mark Twain. Here is a hilarious quote. [[10]] --Zeizmic 13:29, 2 March 2006 (UTC)

Perhaps you meant that avalanches or landslides often occur after hot days or heavy rains. --Leah

Perhaps this is part of where the misconception comes from, as I imagine earthquakes can cause landslides and avalanches as well. EWS23 | (Leave me a message!) 01:46, 3 March 2006 (UTC)

Chewing gum versus bubblegum

What exactly is it about bubblegum that allows you to blow larger bubbles than is possible with the same amount of regular chewing gum? Is there some chemical that facilitates bubble blowing? —Keenan Pepper 06:00, 2 March 2006 (UTC)

More gum base (so it holds together better), and softer gum (so it's easier to blow bubbles). It's softened by adding glycerine or vegetable oil. --BluePlatypus 06:28, 2 March 2006 (UTC)

Now that that is answered, if you wish to kick the habit of chewing gum, you might go to a gum producing area. I followed chiclero tracks in Guatemala and saw how the gum is handled. I never touched a chewing gum since (then again I hardly ever did before, so there was no cold turkey :) . DirkvdM 10:15, 2 March 2006 (UTC)

I thought nowadays it's all made of petroleum products. —Keenan Pepper 14:58, 2 March 2006 (UTC)

So you're chewing oil. Which is rotten plant material. You know, that stinking black fluid that drips from a garbage bag if you leave it out too long. That sounds a lot tastier. :) DirkvdM 08:59, 3 March 2006 (UTC)

I thought oil came from dead dinosaurs. User:Zoe|^(talk) 16:44, 3 March 2006 (UTC)

If you're going to get squeemish about where your food ultimately comes from, you're in big trouble. For great justice. 19:22, 3 March 2006 (UTC)

cure for wet bed

(question moved from Wikipedia:Newcomers help page)

clothes line?

clothes dryer?

• What is the person's age? potty training, bladder control. - Mgm|^(talk) 09:10, 2 March 2006 (UTC)

Someone makes a diaper with an attached alarm that goes off when it gets wet. This is used to train a person to wake up when they have a full bladder. --Kainaw ^(talk) 16:47, 2 March 2006 (UTC)

Or, at least, moments after having a full bladder. :) kmccoy (talk) 03:27, 3 March 2006 (UTC)

old or used systems

how to use old or used computers as a firewall

What computers? How old? —The preceding unsigned comment was added by 67.40.249.122 (talk • contribs) .

• You can't use computers as a firewall. A firewall a piece of software. - Mgm|^(talk) 09:11, 2 March 2006 (UTC)

A firewall can be software or hardware. You can use an old computer as a demilitarized zone, but I'm not sure if that's what you want to do.--Commander Keane 09:48, 2 March 2006 (UTC)

Maybe the user was trying to turn the old computer into a router, presumably with a firewall software running on it. — QuantumEleven | (talk) 11:23, 2 March 2006 (UTC)

If you have enough old computers, you could weld them together and make a pretty good firewall. It would probably take a good two hours to burn through a wall of old computers. --Kainaw ^(talk) 16:48, 2 March 2006 (UTC)

Read this for clues. WAS 4.250 11:07, 2 March 2006 (UTC)

if you perform the test for starch and the iodine remains yellow, what does this indicate?

• It becomes blue if there's starch. So what do you think you proved if there's no reaction? - Mgm|^(talk) 09:12, 2 March 2006 (UTC)

That the raison bread wasn't pregnant!  freshgavinΓΛĿЌ  11:15, 2 March 2006 (UTC)

• Simple, that the is no starch present in whatever you tested. If you would like to test for other substances, there's a whole category of tests you can use to find different things Obli (Talk)^? 16:23, 2 March 2006 (UTC)

Bacteria in our ears!!

I have heard that listening to music with headphones for over an hour multiplies the bacteria present in our ears.is this true?? thanks 59.92.36.216 10:03, 2 March 2006 (UTC)sciencefreak!!59.92.36.216 10:03, 2 March 2006 (UTC)

I think so, it increases the humidity and temperature slightly in our ears. But theoretically, every second bacteria are multiplying, or you could look at it like at all times there are bacteria in your ear being born and dying. Don't worry, the bacteria aren't the bad kind either. They won't make you sick. As gross as bacteria's connotation might seem, don't worry about it when you pump up Green Day on your headphones. -- Mac Davis ☢ ญƛ. 10:16, 2 March 2006 (UTC)

What music do they prefer then? Wet warm music? DirkvdM 10:18, 2 March 2006 (UTC)

I've no idea, but I bet if you did a study on it you'd have a good shot for an Ig Nobel prize. —Ilmari Karonen (talk) 10:39, 2 March 2006 (UTC)

If you're wearing your earbuds for too long I could see a potential risk of it, they'll improve the conditions for bactera substantially (less light, moist, dark, not to mention dirty - earbuds are never washed). Obli (Talk)^? 16:13, 2 March 2006 (UTC)

I read somewhere that bacteria are multiplied in there 700 times! Something to do with anaerobic environments being a major breeding ground. However, your feet are subjected to anaerobic environments for far longer, usually daily, so it multiplies who knows how many times more! I apply Germ-X to my feet at the end of the day to take care of the bacterial build-up. And speaking of ears and bacterial growth, I feel compelled to apply it right now. --Shultz III 00:16, 3 March 2006 (UTC)

You could also regularly ventilate your feet (and then swap socks) like I do. My feet used to give off a horrible stink. This, plus no more soap, solved the problem. A solution by using less is always preferable to one that uses more, I'd say. DirkvdM 09:03, 3 March 2006 (UTC)

Ventilate feet often, fresh clean dry socks at LEAST twice a day, let shoes air out for at least 24 hours between uses (IE at least two pairs of shoes, alternated), and using rubbing alcohol on your feet are all good methods to deal with the fungal problems caused by enclosing feet. WAS 4.250 12:21, 3 March 2006 (UTC)

See obsessive compulsive... --Username132 20:00, 3 March 2006 (UTC)

And which would be that? It often refers to excessive use of soap and it's precisely the fact that I stopped using soap that was probably a major part of my 'cure'. DirkvdM 13:21, 4 March 2006 (UTC)

Head-on auto crash.

If two autos of equal weight, and each going 50 miles an hour, crash head on, will the impact be 100 miles an hour or just 50 miles an hour? Thank you. Paul Weiss

Assuming both cars are travelling forward, and the earth isn't spinning at a crazy rate, then yes. Err... I mean 100 miles per hour. It's a 2-dimensional collision so you simply subtract the vectors: $50mph-(-50mph)=50mph+50mph=100mph$.  freshgavinΓΛĿЌ  11:17, 2 March 2006 (UTC)

If you're standing on the road watching the crash, you'll see both autos travelling at 50 mph but in opposite directions. If you're sitting in either auto, you'll see the other as approaching at 100 mph. --Bowlhover 16:57, 2 March 2006 (UTC)

The question is what you mean by "will the impact by 100 miles an hour". If you imagine an extremely solid wall of heavy steel or something that you could crash a car into without damaging the wall, then the 50+50 mph collision will damage the cars in the same way that a 50 mph collision into this wall would be, because all of the kinetic energy goes into damaging the cars, and colliding with an identical car will stop a car in the same way that the very solid wall would.

On the other hand, if you imagine the damage from crashing the car into a stationary car of the same kind, then the 50+50 mph collision would be like a crash at 71 mph into a stationary car. Here 71 is 50 times the square root of 2, and that arises because the energy will be distributed equally between the two cars and energy varies as the square of speed.

For some calculations involving collisions you want to consider momentum rather than kinetic energy, but energy is the right measure when you're thinking about the amount of damage.

--Anonymous, 00:57 UTC, March 3, 2006.

Nope, I agree with your first para about the wall, but the 50+50 mph collision is like a crash at 100mph into a stationary car. Yes, the 100mph system has twice the total energy, but only half of that energy goes into destroying the cars. The other half is left as kinetic energy after the collision as the two cars, smashed together, are still trundling along the road at 50mph by conservation of momentum. —Blotwell 05:50, 4 March 2006 (UTC)

Argh dammit. I should have realized that. Sorry. --Anon, 19:30 UTC, March 5.

Cocaine

A friend of mine claims that rubbing cocaine on one's penis before intercourse makes the sex more pleasurable for the woman, but this doesn't sound right. Is it true?

Cocaine, when applied topically, acts as an anesthetic and intense vasoconstrictor. I'd say it has the opposite effect... — TheKMan^talk 13:21, 2 March 2006 (UTC)

Rub it on your hair, and you fail the drug test. --Zeizmic 13:36, 2 March 2006 (UTC)

"Because of the extensive processing it undergoes during preparation and its highly addictive nature, cocaine is generally treated as a hard drug, with severe penalties for possession and trafficking." [11]

"After the US helped the Colombian military dismantle the Medellín and Cali cocaine cartels in the '90s, the guerrillas moved in and took over much of the drug trade. By the late '90s, rebels controlled more than a third of the country and had the financial clout to intensify the [civil] war and protect their newfound position as narcotraffickers. It's an extremely lucrative business. The coke habit in the US alone was worth $35 billion in 2000 - about $10 billion more than Microsoft brought in that year." [12]

Sorry, I couldn't help it. -LambaJan 20:39, 2 March 2006 (UTC)

I guess an anasthetic, applied to the male, is likely to reduce his stimulation, so things go on longer than the regulation three minutes. This in turn may appeal to the female, if her tastes run that way. Notinasnaid 21:11, 2 March 2006 (UTC)

I doubt she would appreciate the effect the cocaine would have on her bits =P. — TheKMan^talk 21:55, 2 March 2006 (UTC)

Try powdered ginger mixed with honey. She will never look at another man. (Never use chilli powder!) --Anon.

Usenet

The concept of "Usenet" has confused me (and yes, I read the article). Is it basically just a huge group of "bins" (like alt.binaries.videos, etc) and people post any message or file they want into the suitable "bin", and when you read it with a client it shows everything posted in that "bin" with the most recent first? - unsigned

Usenet is essentially a newsgroup or forum, however you want to look at it. Its a resource whereby messages very similar to emails are sent into the system and then processed and stored in order, and someone with a reader can come along and read all the stored messages in order. Many people have adapted it for use with files, but its essentially the same strategy as sending files attached to emails. The only thing to remember is that someone has to host those groups, and many places only host the non-space-hogging kind since server disk space isnt exactly cheap. -unsigned

So what's the deal with the readers? I mean, google groups doesn't let you download files AFAIK, or look very far back. Is there some free way to look at and download usenet files and look atp osts from way back (like months ago?) - unsigned

Since its a service that is rather resource-intensive, its access is often subscriber based. Most ISPs will run some form of USEnet relay for their customers, although this is going by the wayside as it's use has shifted from the legitimate, to grey filesharing and piracy. — Preceding unsigned comment added by 66.195.232.121 (talk • contribs) 15:44, 2 March 2006 (UTC)

Google doesn't carry binaries groups, but it does archive old posts (pretty much for ever - the oldest usenet post in Google's archive is from 1981.) Binaries groups are not generally achived and are not carried by as many servers as text groups. -- AJR | Talk 16:50, 2 March 2006 (UTC)

Go here and try out a temporary free reader called Agent. It's highly recommended. Permanent free versions of Agent exist if you look hard enough. To connect the usenet reader to the usenet, ask your ISP for the net address to type into the reader. Its generally not an additional ISP charge so far as I know. (mine isn't - EarthLink) WAS 4.250 16:53, 2 March 2006 (UTC)

First a terminology correction: the original poster referred to "bins", and those are the newsgroups. Each newsgroup is a forum. Usenet is all of the newsgroups taken collectively. Some newsgroups are intended for messages in text form (that was the original idea, back when most of Usenet was carried on 300 or 1200 baud telephone connections); others are intended for binaries, which are encoded in text form. Most newsgroups are "unmoderated" and anyone can post anything, just as they can here; others have a moderator who screens all postings, or variations on this.

The original poster referred to seeing messages "newest first". The order that you see articles in depends on what newsreader (software ) you use. Historically, the original presentation was oldest first; then came oldest first but grouped by subject line; then came threading, which allows people to read a sequence of followups in a sensible tree-traversal order. Good newsreaders allow you a lot of control over what they see and how they see it, and they keep track of what you've already read, which is essential when you're reading oldest-first. Frankly, it's a much more congenial presentation of messages than the massive concatenation of everything into a single web page that we see in Wikipedia talk pages like this.

If you read newsgroups via Google Groups, then in effect you're using Google's newsreader running on their site (which you access via your web browser), where it accesses the postings locally. This contrasts with the traditional newsreader, which runs on your machine (so you can run whichever one you want to install) and accesses the postings you choose from a remote news server. Historically there was a third approach: all postings in all newsgroups you might want to read were stored on your machine, and your newsreader accessed them as local files. ("Your machine" in that case would likely be a big corporate or institutional one, rather than a personal computer. Postings would stay online for a few days or weeks, depending on disk capacity.) --Anonymous, 01:15 UTC, March 3, 2006.

Gagging, vomiting daily through stress

My girlfriend has recently started teaching at a public school. Over the first couple months the stress was extremely intense and she thought she was going to quit. Recently, the stress has dies down somewhat, but she is still experiencing stomach problems: each morning she dry heaves or vomits, and can't keep any food down until about lunch.

Obviously the problem is mainly psychological, and ought to go away once the stress starts becoming managable. However, is there anything she can take to help the symptoms? Would antacid tablets help? Any other over-the-counter stomach medicine? What is the physical response that is turning stress into an upset stomach?

Thanks in advance.

She should probably consult her physician to be sure that there isn't something physically wrong. If necessary, her doctor can also refer her to an appropriate specialist for help in managing her response to stress.

Whether physical or psychological at its root, cranking out gobs of stomach acid and vomiting every morning isn't a good thing, and warrants medical attention. Depending on the precise cause, antacid tablets (calcium carbonate, e.g. TUMS) may provide some relief. More potent blockers of acid production are also available over the counter (ranitidine, sold under the brand name Zantac in North America). TenOfAllTrades(talk) 15:51, 2 March 2006 (UTC)

This sounds like extreme anxiety. Get the doctor to refer to a specialist. I just read about a drug for extreme stage fright. I just get along with common meds, for my anxiety. --Zeizmic 18:00, 2 March 2006 (UTC)

She needs to go to the doctor (is she pregnant?), but I have noticed ginger and ginger ale help me with nausea. -Ravedave 06:22, 3 March 2006 (UTC)

great pyramids

It is claimed that even with todays technology the great pyramids could not be built -is this true?

Since most people agree that they were build even without today's technology, I think one could say with great certainty that they could be built with today's technology. See our Great Pyramid of Giza and Egyptian pyramid construction techniques articles for information on how they were built. — Asbestos | Talk (RFC) 20:20, 2 March 2006 (UTC)

Of course, it is impossible, with today's technology, to stack rocks. That is why all those buildings and monuments that look like stacked marble, stone, or steel girders are just illusions. It is a four-inch model that appears big based on your frame of reference. In fact, I think Manhattan is only about three feet wide. --Kainaw ^(talk) 20:25, 2 March 2006 (UTC)

Actually most buildings that look like large stacked rock slabs are actually illusions, usally they're brick or concrete, and the stone is just a thin outer facade. But that's because it's cheaper of course, not because we can't stack rocks. --BluePlatypus 13:04, 3 March 2006 (UTC)

We couldn't build it the way they did, with today's technology. Just the life insurance on 10,000 expendable slaves would break the bank. --Zeizmic 22:25, 2 March 2006 (UTC)

Whoever is claiming this is trying to prove something; from the way the assertion is worded I suspect that the intent is to demonstrate that extraterrestrials did it. It is of course nonsense; when one considers what can be built with modern construction technology, one realizes that reproducing the Great Pyramid would not be impossible. (Whether anyone today would want to build it is a different question.) —Charles P._(Mirv) 23:47, 2 March 2006 (UTC)

Sure, it could be done. Just need a nice large quarry, the right machinery, a large dedicated workforce, and plenty of cash and time. And would anyone want to do it? Unlikely, when instead you could make a neat looking hollow one made of glass and put a casino inside. — TheKMan^talk 03:17, 3 March 2006 (UTC)

Asbestos, you basically say that if something could be done in the past of course we can do it too. You seem to assume that all new knowledge is simply added to the old knowledge. But it can also replace it. A simple example is survival skills of hunters/gatherers as they learn western ways and stop hunting and gathering. Or knowledge of old western trades that has been lost because the need has disappeared. Or take cement. The Romans knew about it. Almost 2000 years later it was re-invented. It is quite possible that a technique was used to build the pyramids that we don't need because we have different solutions. Sure, we could build something similar, but with our technology it would be different in many ways. To make an exacts copy would probably be prohibitively expensive, because we would have to first invent the techniques or adapt ours to get the desired effect. Sorry I said this a bit messy, but the thought behind it is not less valid for it. :) DirkvdM 10:38, 3 March 2006 (UTC)

Another good example of this is Damascus steel (or more specifically Wootz steel.) Reports of weapons made using the technique date back to 30AD, but up until 1980, noone could reproduce the effect. GeeJo _{(t) (c)} • 11:06, 3 March 2006 (UTC)

We don't know how to make Greek fire, either. User:Zoe|^(talk) 16:47, 3 March 2006 (UTC)

Right - there are two things going on here 1) whether it would be possible, in the abstract, to build a replica of the pyramids, and 2) whether it would be possible in terms of mobilizing the money, time, manpower and other resources to do it. I think we need to clarify which question we're asking. For great justice. 17:56, 3 March 2006 (UTC)

Well the answer to 1) is yes. And the answer to 2) is yes as well. Most modern nations have greater economic and human resources than ancient Egypt. Not that it would be needed, we'd no doubt be able to do it with less (human and economic) expense. The main obstacle is political will. Not many countries today would allow their leaders to spend a large part of their national GDP on building a tomb for themselves. Not that it'd be a large part for most countries, but it's still money most people would rather see erecting schools or something useful. --BluePlatypus 18:08, 3 March 2006 (UTC)

Yes. That's what I meant. For great justice. 19:20, 3 March 2006 (UTC)

March 3

Dual core CPU questions

I have an athlon 64 4400 (dual core). I use windows xp.

1) Is there some kind of update that I should get for windows to optimize it for using a dual core cpu? If so, what exact update(s) should I get and where?

2) I've noticed that when running certain games, it goes extremely fast (not at all playable). Is this because I have a dual core?

3) I've also noticed that when playing music and movies and such in windows media player it periodically skips (it sounds similar to how it is when cds skip in old portable cd players) Is this because I have a dual core?

4) Is there some program out there that can make my dual core cpu temporarily run on only one core? Flea110 01:16, 3 March 2006 (UTC)

I don't know all of the answers to your questions, but (1) according to AMD, Windows XP has dual core support; you shouldn't need to do anything special. If you go into Task Manager and look at your CPU usage, you'll see two CPU graphs. (2) It depends on what sort of games you're playing. If they're old DOS games, they were probably designed to run on machines orders of magnitude slower. Look into using something like DOSBox, if that's the case. I don't know about (3), but (4) according to some dude on HardOCP forums, you can disable one core if you add an option with the /onecpu option in boot.ini. If your skippy-media problems go away, then they were probably due to the use of two cores. grendel|khan 15:33, 3 March 2006 (UTC)

Re your skippy music and games, can you try the same media on a different machine? A different media player? Try to isolate the conditions under which it happens and give some more information. For great justice. 18:14, 3 March 2006 (UTC)

Re (4), yes, there is (and probably are) programs that support what you are looking for. A slight variation of what you're describing is called CPU Affinity - locking a process to a particular CPU, after so many associations you can achieve dedication of one CPU (core) to a single process. You would have to lock processes to a particular CPU one at a time and eventually you could achieve this dedicated situation such that only 1 process had affinity to 1 cpu, all others to the other (or any number of other cpus). The only program that I know of is called TaskInfo, if my memory serves. I think this feature was available in 'TaskInfo 2000' and may still be in the latest version. You could only confirm that this was occuring by monitoring Windows Taskmanager once you had assigned all of the running processes. Even then it may be challenging to really know for certain. 151.199.150.176 16:35, 4 March 2006 (UTC)

astronomy

In an elliptical orbit,what happens to the distance between the planet and the sun?

As compared to? When what happens? Your question is a bit unclear. --Obli (Talk)^? 11:18, 3 March 2006 (UTC)

I think the questioner means how it changes over the course of one orbital period. But since it sounds suspiciously like homework (apols if I am just being hyper-cynical), I'm just going to point 'em at Planetary orbit. --Bth 11:29, 3 March 2006 (UTC)

Cells

Why are cells usually small? Ana

The cytoskeleton of a cell is an important, complex, and dynamic cell component made up of microfilaments. It acts to organize and maintain the cell's shape; anchors organelles in place; helps during endocytosis, the uptake of external materials by a cell; and moves parts of the cell in processes of growth and motility. Diffusion does not limit cell size. According to Biology Cell biology Introduction Cell Size which shows cell sizes range from "150-250 nm small bacteria such as Mycoplasma" to "1 mm Diameter of the squid giant nerve cell" the limits to cell size are due to "Prokaryotes - Limited by efficient metabolism Animal Cells (Eukaryotic) - Limited by Surface Area to Volume ratio Plant Cells (Eukaryotic) - Have large sizes due to large central vacuole which is responsible for their growth". Cells have lenghs of meters in some cases, like nerve cells. Multicellualr organisms have out-evolved single cell organisms in the the competive space defined by "large size" because modular structures are a better design. Even things humans build tend to be modular due to the various superiorities of modular over unitary. WAS 4.250 12:57, 3 March 2006 (UTC)

Diffusion is slow. A large spherical cell would not be able to use diffusion to get small molecules into all parts of the cell. Look up Fick's Law of diffusion for more details on the math. David D. (Talk) 08:38, 3 March 2006 (UTC)

I wanted to say "Define small. Compared to what?" But are you now saying that they couldn't be any bigger because diffusion places a limit? In that case, I'd change the question to "Why are cells so big?" If being smaller makes diffusion easier and still they are as big as that permits, then they must have a reason for being so big. DirkvdM 10:44, 3 March 2006 (UTC)

I'd like to rephrase the question to "why aren't cells much larger than they are?"

It's a question of surface area, David D. touched the subject by talking about diffusion. Osmosis (diffusion through a plasma membrane) is not instant, and only a certain amount of osmosis can take place at a give point at the plasma membrane, therefore the area of the plasma membrane limits the volume of the cell, usually to something really small by our standards. Think of the membrane as transport routes in and out of a city, a cell the size of your fist would then be like New York city, with one dirt road connecting it, it just won't work. This problem is remedied in some cells, such as the inner lining of the small intestine by the use of Microvilli.

I hope I answered your questions, you are welcome to drop me a note on my talk page if you need further clarification. --Obli (Talk)^? 11:10, 3 March 2006 (UTC)

ova are often pretty big. Gdr 21:57, 3 March 2006 (UTC)

URGENT! - AutoText in MS Word

Hey I was using MS Word and would like to insert automatic pagenumber, and that never seems to work. I used "Insert", then "AutoText", "Headers and Footers", and selected "-PAGE-", and the only thing that appeared on the screen is "-1-", and never continued (on the second page, there is no "-2-"). How can that be accomplished?

Also, I accidentally deleted the "-PAGE-" AutoText, how can I restore it? I added one in AutoText Settings "-PAGE-", and when I insert it, it is firstly cannot be found in the headers and footers category, and also, turns out to be "-PAGE-" instead of the expected "-1-". Very urgent! Thanks!

Just Love Science

• Can't you just use "Insert", then "Page numbers" to insert page numbers? - Mgm|^(talk) 10:32, 3 March 2006 (UTC)

I've just had a play with my copy of Word and I think you need to make sure you're in the Header/Footer view. (View->Header and Footer) before you do the insert. The "Header/Footer" section under the Autotext menu is just a collection of things that are useful in headers and footers, it doesn't automatically put it into the footer -- when I followed your description of what you'd done I just got a "-1-" at the location of the cursor. It's only when the cursor is in the footer that it'll propagate properly. HTH. HAND. --Bth 11:18, 3 March 2006 (UTC)

As to recreating the deleted autotext entry, you need Fields. Ctrl-F9 will bring up a pair of grey-background curly braces {}. Type "PAGE" in between them and you'll have a page number variable. Select it (and any stuff you want to put round it) and save it as a new bit of autotext (Insert->Autotext->New) and you'll have something that should do the job. It won't work quite as neatly as the original -- you may have to switch to print preview or a different view before it kicks in. See site for more detail than you might want. --Bth 13:08, 3 March 2006 (UTC)

It's possible that you have set it so that the first page has a "different" header and footer than the other pages. This setting should be in document properties or page setup. Skomae 04:14, 4 March 2006 (UTC)

Sharp weapons vs. blunt weapons

Regarding wounds in pre-modern times, I have two conflicting sources. One tells me that sharp weapons are more lethal because while a broken bone could be set, a cut from a sword might lead to infection, which was a major headache before people learnt to disinfect things. The other source says that broken bones from blunt weapons are more dangerous, because they were difficult at best to treat. Which is correct? 219.93.29.135 11:51, 3 March 2006 (UTC)

Both statements seem to be correct. A sharp sword will penetrate further and cause more damage to internal organs. A big blunt rock will break more bones. Either can be lethal, depending where they strike and with how much force. --Shantavira 12:28, 3 March 2006 (UTC)

It depends on the exact nature of the weaponery, the defensive gear, the soldier training, and the battle tactics used. Polybius in The Rise of the Roman Empire recounts a battle between Romans with pointy blades fighting against Gauls/Celts who were armed with sharp edges but non-pointy blades and the Roman tactic was to fight so closely packed that the Gauls couldn't swing their weapons, while the Romans were able to thrust theirs. Romans won. WAS 4.250 13:10, 3 March 2006 (UTC)

"The Romans are thought to have shown uncommon skill in this battle; the Tribunes instructing the troops how they were to conduct themselves both collectively and individually. They had learned from former engagements that Gallic tribes were always most formidable at the first onslaught, before their courage was at all damped by a check; and that the swords with which they were furnished, as I have mentioned before, could only give one downward cut with any effect, but that after this the edges got so turned and the blade so bent, that unless they had time to straighten them with their foot against the ground, they could not deliver a second blow. The Tribunes accordingly gave out the spears of the Triarii, who are the last of the three ranks, to the first ranks, or Hastati: and ordering the men to use their swords only, after their spears were done with, they charged the Celts full in front. When the Celts had rendered their swords useless by the first blows delivered on the spears, the Romans close with them, and rendered them quite helpless, by preventing them from raising their hands to strike with their swords, which is their peculiar and only stroke, because their blade has no point. The Romans, on the contrary, having excellent points to their swords, used them not to cut but to thrust: and by thus repeatedly hitting the breasts and faces of the enemy, they eventually killed the greater number of them. And this was due to the foresight of the Tribunes: for the Consul Flaminius is thought to have made a strategic mistake in his arrangements for this battle. By drawing up his men along the very brink of the river, he rendered impossible a manœuvre characteristic of Roman tactics, because he left the lines no room for their deliberate retrograde movements; for if, in the course of the battle, the men had been forced ever so little from their ground, they would have been obliged by this blunder of their leader to throw themselves into the river. However, the valour of the soldiers secured them a brilliant victory, as I have said, and they returned to Rome with abundance of booty of every kind, and of trophies stripped from the enemy." [13] WAS 4.250 13:23, 3 March 2006 (UTC)

Hmm... more complicated than I originally imagined :) Thanks for all your informative replies. 219.93.29.135 05:47, 4 March 2006 (UTC)

if science is about growing and learning

then my is the MSM so opposed to people who offer new and better theories? Isn't it true that so called "scineces" are much more of a dogma than anything else, yes, some things may be true, but isn't most sceince usually looked back on as stupid after the fact? Whose to say what's a valid scientific theory and what isn't? Isn't the fact that mainstream scinece won't even investigate certian things because they're so steeped in secularist ideolgies, a sign that scinece is, for lack of a better word "broken"?--Name2354325` 14:17, 3 March 2006 (UTC)

Science is not about growing and learning, it is about performing experiments and doing things that produce results (going to the moon, blowing up cities, fighting H5N1, finding oil in the ground, etc). Science is not a dogma of any kind, it's just "whatever works". Most science is usually looked back on as what worked then, but now we have other additional things that work. "A valid scientific theory" is what works (produces results). Mainstream science investigates everything; it is not broken. Science even has developed to the point that we know what works about theories about what works! The scientific method is all about that. WAS 4.250 14:36, 3 March 2006 (UTC)

The "mainstream media" (MSM) on the other hand includes whatever media outlets are in harmony with the prevailing direction of influence in the culture at large. In the United States, usage of these terms often depends on the connotations the speaker wants to invoke. The term "corporate media" is often used by leftist media critics to imply that the mainstream media is itself composed of large multinational corporations, and promotes those interests (see e.g., Fairness and Accuracy in Reporting; Noam Chomsky's "propaganda model"). This is countered by right-wingers with the term "MSM", the acronym implying that the majority of mass media sources are dominated by leftist powers which are furthering their own agenda (see Conspiracy theory, Media bias in the United States). WAS 4.250 15:20, 3 March 2006 (UTC)

I completely agree with the question. I believe that everything science tells is fact - all we see and feel - is just a persistent imagination of a large purple goat. We are in a goat's dream. Some have talked to the goat and called it God. That bothers him and terrible things happen. So, it is our job to be quiet and let the goat sleep soundly. However, no matter how often I send this to all the mainstream media outlets, they never call me in for an interview. They are just secularist mouthpieces for the science fools. --Kainaw ^(talk) 15:26, 3 March 2006 (UTC)

Who's opposed to "new and better theories"? The media loves new theories; they don't even have to be better! Claim to invent a perpetual motion machine, hold a press conference, and you'll get written up everywhere. You'll even get written up on slashdot, even though they ought to know better.

Science, on the other hand, does tend to insist that new theories actually be better. That may end up looking like dogma, and sometimes there is a certain amount of dogma, but mostly, what's operating is that science demands things like proof and reproducability, and those take time. —Steve Summit (talk) 18:21, 3 March 2006 (UTC)

It should also be noted that historically it has been difficult for new scientific theories to be immediately accepted (for example, ask Galileo). This has improved in recent years a bit, since scientists are less focused on religion and more focused on proving the facts and reproducibility, but it still often takes new theories a relatively long time to gain acceptance, as old theories are so ingrained into our heads as truth. This isn't necessarily a bad thing, as it keeps us from believing every hoax that comes along, but I can see how it would be frustrating to individuals who don't always subscribe to mainstream theories. EWS23 | (Leave me a message!) 19:11, 3 March 2006 (UTC)

They've hit the high points, so I won't repeat them; how the 'media' is an unreliable way to judge science; how science is only as dogmatic as necessary to prevent hoaxes and mistakes; the fact that most things (electricity, the chemistry that created plastic, sperm) will never be looked back on as stupid; the fact that science's judge is the harsh realities of the natural world; the fact that science investigates more things than you will ever hear of or imagine, and investigates them well... no, I'd like to respond to the message itself. If you ever come back to see the answers to your question, I'd like to ask you a few things, for my own edification:

• Is your post as indignant as it sounds? Because it sounds like a pet theory of yours (probably religious, based on the references to dogma and secularism) is getting what it deserves, and you're pissed off.
• Were you just talking, or were you hoping to learn, or were you hoping we'd see the light?
• Do you have any idea what secular and ideology mean? Do you know what buzzword means?
• What specific things are you thinking of when you talk about stupid past theories? I ask because it's always fun to hear about a new one. Phlogiston is a classic in that area.
• Similarly, what specific things are you thinking of when you talk about things science won't investigate? The paranormal? The existence of Jesus? The existence of Jesus's evil twin brother, Billy? The existence of Juan and Cindy? Black Carrot 00:39, 4 March 2006 (UTC)

Good questions. I wonder if we'll get any answers, any more than any of the previous N times questions like this have been asked on the various Reference Desks. —Steve Summit (talk) 15:03, 4 March 2006 (UTC)

• There are many texts about whether science is inherently dogmatic or not, whether it is conservative or daring, etc. etc. There's no easy answer to it -- scientists will always claim that they are not dogmatic (unless they feel "outside" the mainstream), while historians, sociologists, and philosophers go back and forth over it depending who you are reading. A good starter into thinking about these sorts of things is Thomas Kuhn's The Structure of Scientific Revolutions. If you are feeling very daring you can try tracking down Pierre Bourdieu's "The Specificity of the Scientific Field and the Social Conditions of the Progress of Reason", which I find to be a bit more to-the-point that Kuhn (and discusses Kuhn quite a bit). There's a copy of it, I think, in The Science Studies Reader, ed. Mario Biagioli. You could also check out Paul Feyerabend's work, which by its titles you can judge is a bit more radical: Against Method and Farewell to Reason. --Fastfission 23:24, 5 March 2006 (UTC)

Sound in water

When we put our hands inside water and clap we don't hear the sound. Why is this so?

Because you didn't clap hard enough for the anything to vibrate. Hit the side of the pool with a rock and vibrations will be created that you can hear even underwater. Sound is your perception of vibration that gets to your ears. WAS 4.250 14:43, 3 March 2006 (UTC)

Because sound waves, at least those in the range audible to human beings, tend to propagate in air, as opposed to water--152.163.100.74 14:29, 3 March 2006 (UTC)

No, audible sound waves can propagate through water just as well. As WAS 4.250 said, you'd have to clap much harder in water to make an audible sound, because the water is more dense so it's harder to push out of the way. Also, the inside of your ear is filled with air, so the difference in density between the two fluids makes a kind of filter, muffling the sounds. —Keenan Pepper 14:53, 3 March 2006 (UTC)

Oh, oh, we are getting silly here. Sound waves are perfectly happy in water, the dolphins carry out excellent conversations about silly humans. But you can't get anything to 'clap' underwater because of the viscosity of the thin film of water. --Zeizmic 16:03, 3 March 2006 (UTC)

Scuba divers have developed a number of ways of using sound to communicate under water too - the most common is to band on the air tank with something metal, which produces a sound that travels well (although it is more difficult to locate direction underwater using sound, I don't really know why). More complex systems use pitch shift devices, or wireless radio comms to circumvent difficulties of propogation in water. For great justice. 19:29, 3 March 2006 (UTC)

Sound does travel really well underwater, and it turns out that's why it's so hard to localize. One way we localize sounds is by (unconsciously) measuring the difference in arrival times between one ear and the other. But since sound travels faster in water, the differences become too quick for our land-evolved brains to measure. —Steve Summit (talk) 20:31, 3 March 2006 (UTC)

There's a type of lobster or something similar that catches its prey by snapping a claw so fast that it produces a shockwave that stuns (or even kills?) the prey. I don't know if this is audible, but it should be. Because of the viscosity of water clapping hands are slowed down too much. The claws cut through the water more easily. I suspect there will be a cavity in the claw where the water is compressed and then jets out. If this is fast enough it should qualify as sound. (So this is a very Zen creature that can clap with one hand (well, claw).) I'm not sure here, but I suppose most sound is a vibration but it can also be one single shockwave, as with clapping hands.

A related question: can one snap one's fingers under water? Probably not. DirkvdM 13:42, 4 March 2006 (UTC)

Actually, yes, you can. A good 'finger snapper' can produce a light sound underwater. Try holding your hand out in front of you and then next to your ear while snapping. Then do it out of water. The volume is greater out of water right next to your ear, and in water it's muffled in both instances and the volume doesn't change much. A good example of the characteristics of sound waves traveling through water vs. air. 151.199.150.176 16:48, 4 March 2006 (UTC)

midwinter

It's very cold in Birmingham. Why is it that the coldest and hottest weather usually occurs a good two months after the winter and summer solstices, at least in the UK? I'd expect there to be some time lag with the earth/sea having to heat up and cool down, but two months seems a lot. Is this the norm in other parts of the world? --Shantavira 14:32, 3 March 2006 (UTC)

Yep, this is normal. Where I'm from (Texas) the hottest month is typically August, a good 2 months after the summer solstice. As you suspected this is due to time lag, often referred to as seasonal lag (a page I should probably do some work on). According to this page, the typical lag is about one month for continental areas and about two months for areas near large bodies of water (such as Birmingham and Texas). EWS23 | (Leave me a message!) 19:23, 3 March 2006 (UTC)

In North America people are taught that the winter solstice is the "official first day of winter" and the spring equinox is the "official last day of winter"; some people in Britain also use this terminology (although of course the solstice is also called "midwinter's day" there). The fact that people generally don't see anything wrong with this terminology shows that people find it natural for temperature changes to lag by something like a month and a half behind the changes in the amount of daylight.

Remember that during the period near the solstices, the amount of daylight isn't changing very fast. At latitude 45°N, from December 1 to December 21 the reduction in daylight is only about 16 minutes out of 9 hours, and similarly on the other side of the solstice. The continued short days (and the low-angle sunlight that goes along with them) keep the temperature dropping. Of course if the days remained like that permanently then an equilibrium would be reached, but it does take a while.

--Anonymous, 02:38 UTC, March 4, 2006.

What is Einsteins Theory of Relativity?

What is Einsteins Theory of Relativity and how do you use it?

See Special relativity and General relativity. —Keenan Pepper 14:47, 3 March 2006 (UTC)

What is a black hole?

What is a black hole (space) and how does it work?

See Black hole. —Keenan Pepper 14:48, 3 March 2006 (UTC)

What is the difference between black hole and wormhole in space?

What is the difference between a black hole and a wormhole in space?

For one thing, black holes are probably real and wormholes are still only theoretical (at best). For another, if you get sucked into a black hole you'll just get streched out and then crushed into a point. See Spaghettification. —Keenan Pepper 14:55, 3 March 2006 (UTC)

A black hole is like a huge vacuum cleaner sucking up everything. A wormhole is like a cool subway tunnel between two locations. --Kainaw ^(talk) 14:59, 3 March 2006 (UTC)

A wormhole connects two parts of the universe, sort of a shortcut. One way this might exist is as a combination of a black hole and a white hole. See Wormhole#Schwarzschild_wormholes. DirkvdM 13:51, 4 March 2006 (UTC)

transmission

hi i would like to know 1.why cant we run a vehicle in 2nd or higher gear shifts directly.

2.problems in using diesel in petrol engine and vice virsa

You can start in second and possibly third if you give it enough gas. Gears are used to optimize the horsepower of the engine. As for diesel and petrol (we call it just "gas" in the U.S.), they burn at different rates. Engines are very particular about timing. Put diesel in a non-diesel engine and it will start, but it will make a knocking sound and you won't get much power out of it. I've never put gas in a diesel engine. I figure it is like a 2-stroke. It will start and then die quickly. --Kainaw ^(talk) 14:57, 3 March 2006 (UTC)

I had a friend, who's daughter put in diesel unaware. Naturally it went nuts and took it to a mechanic who couldn't figure out what was wrong, and they spent a fortune. I think they even replaced the engine. Finally took it to a second mechanic who had a sniff of the gas tank and immediately knew what happened. --Zeizmic 15:38, 3 March 2006 (UTC)

Diesel engines and gas engines work in very different manners. Gas/petrol uses a spark and a relatively flammable fuel while diesel use an less flammable fuel (almost non-flammable) and high compression with a glow plug to ignite the fuel. One will certainly not work in the other - diesel may gum up a gas engine and gas may burn up a diesel. See aslo the "Differences in fuel dispensers" in the Filling station article. Rmhermen 17:09, 3 March 2006 (UTC)

The problem is octane, diesel is much much lower in octane, and much more 'energetic' per volume than typical gasoline (this is my second hand understanding, i am not a chemical engineer). In a normal gasoline engine, diesel fuel will knock due to compression, and the engine will produce very little power and may even become damaged if the operator persists in trying to run it. As for the story about someone doing it on accident, it takes an INCREDIBLY thick-skulled person to do this. Why? The pumps are different, a (larger) diesel nozzle will not fit into the fill hole on a standard gasoline vehicle, which is usually enough of an indication to the operator that something isn't right, since trying to fill it will result in it spilling everywhere.

The pumps here (South Carolina) and back home (Missouri) are the same size for gas and deisel. So, it is very easy to put deisel in a normal engine. The larger pump was for leaded gasoline back when unleaded gasoline was introduced. --Kainaw ^(talk) 19:14, 3 March 2006 (UTC)

All the ones i've seen in OH are sized this way, it's a small difference but it's enough to stop someone from doing something stupid, I know this first hand after watching my friend try it. I just figured this was standard practice as all major brands seem to do it.

Not literally lower in octane (although probably) - Octane rating is a measurement system for gasoline; for diesel, it is rated by the cetane rating. Rmhermen 00:49, 4 March 2006 (UTC)

In the US there are petrols with an octane level under 90% (as low as 86% even, I believe). I once put a bit of that in an almost empty tank. The car started making very scary clonking noises, so I quickly filled the tank up with a high quality petrol. Why do such petrols exist in the US? Are there engines that can run well on it? Or is it meant for old cars that are just months away from the scrap heap? DirkvdM 13:59, 4 March 2006 (UTC)

Octane is not measured in percent - and it doesn't measure the amount of octane either. Most cars work fine on 86 octane, although 87-88 is the most common in the U.S. - but note that this same fuel is labeled as 91 octane in Europe due to a difference in measurement definitions. This may be part of what you are noticing. Rmhermen 15:58, 4 March 2006 (UTC)

Ah, that's something I had been wondering about for 10 years now. Given that the octane ratings in Europe are usually in the high nineties, 86 sounded ridiculously low. Could we get all our units standardised please (before another Mars lander crashes)? DirkvdM 10:29, 5 March 2006 (UTC)

engine

1. what is the significance of inclination of engine in bikes?

On an inline motor, or a V?

Uh... See V engine, straight engine and inline engine? ☢ Ҡi∊ff⌇↯ 18:05, 3 March 2006 (UTC)

Motorcycles are typically designed to have the lowest possible center of gravity, especially those used for sport riding and racing. This is to allow the bike to turn quicker with less lean angle. To accomplish this, the motor is typically inclined as much as possible, to bring it lower to the ground given that the motor/transmission assembly are the heaviest things on the bike, and by inclining the motor and keeping the transmission in the same spot the overall center of gravity will become lower. --66.195.232.121 19:37, 3 March 2006 (UTC)

brakes

why front brakes are stronger than rear in bikes

The same reason they are on cars. When stopping, the force causes the suspension to compress, because the force vector expressed as the relationship between gravity and acceleration causes the realized weight to shift forward. This means much more downward force is on the front tire. For the exact same reason, bikes and cars (preferrably) power themselves via the rear wheel, the forces involved make it the most ideal wheel for the task.

Erm, re rear wheel drive, it's a little more complicated than that for cars... For great justice. 19:33, 3 March 2006 (UTC)

We have pretty good articles on front wheel drive and rear wheel drive. — QuantumEleven | (talk) 12:37, 6 March 2006 (UTC)

Is this monkey a Drill?

Is this monkey a Drill? I think it is, but I'm not quite certain; I didn't mark down the sign at the zoo at the time. grendel|khan 15:22, 3 March 2006 (UTC)

I doubt it, the facial features suggests it's a prettier monkey than the Drill (lack of mane, no bald forehead) --Obli (Talk)^? 16:54, 3 March 2006 (UTC)

Maybe Allen's swamp monkey? I think you took the image at Chicago's Lincoln Park Zoo. Here is a list of [mammals] they have. You can google for images of each species. Rmhermen 17:01, 3 March 2006 (UTC)

Our image in the swamp monkey article doesn't look much like the one on this page though. Rmhermen 17:04, 3 March 2006 (UTC)

Thanks for the link; that helps tremendously. It looks a bit like a De Brazza's Monkey, I think, but the white beard isn't nearly as pronounced, and it doesn't have the weird brow ridge. Maybe an Allen's Swamp Monkey? That looks pretty similar. grendel|khan 21:38, 3 March 2006 (UTC)

No monkeying around here, THIS IS NOT A DRILL! (sorry, couldn't resist that one.) DirkvdM 14:04, 4 March 2006 (UTC)

Right click on words in web textbox

I'd like to make a website which includes a textbox that users can write in. When the users rightclick on any word in the text box, I want the usual right-click pop-up menu to be replaced by one that allows them to, say, make the text bold or add a link. Is this possible? I know a little JavaScript. Thanks in advance!

Text box that doesn't look like a text box

How would I be able to make a text box that doesn't look like your standard text box? For instance, I could have a thin line around it, instead of the "indented" look of most text boxes (like this one), or maybe have curved corners. Also, could the font be changed, so it's not courier? Thanks in advance (again)!

Take a look at cascading style sheets. --Kainaw ^(talk) 19:10, 3 March 2006 (UTC)

Li-Ion Batteries (specifically for iPod)

Hey. I have a few questions about iPod battery life. I have a 5G iPod (which I got 2 days ago).

1. Is it better to keep the iPod on the charger all the time when not using it, or to take it off when it's charged (even though i'm not using it atm)?
2. Apple reccomends not charging inside a case, however my case has little holes around the corners that allow the iPod to breathe. Also, it's been on the charger and in the case for at least 12 hours and is still cool to the touch on the outside. On the other hand, the case is made of leather. I am paranoid of leaving it out of its case though because i have a REALLY dusty house. What should I do?

— Ilyanep (Talk) 18:41, 3 March 2006 (UTC)

iPod batteries last an optimal amount of time if they maintain a 40% charge. So take it off once its charged. And yeah, I know you are paranoid (I was too) but it is better to charge without the case. They do warm during charging, and its best if the heat can dissapate. pschemp | talk 00:54, 4 March 2006 (UTC)

Oh i almost forgot, a great resource is iLounge [14]. They've tested and dissassembled all the iPods and you can find answers to most iPod questions there. Hope this helps! pschemp | talk 01:02, 4 March 2006 (UTC)

But I can't stand taking it out :P It gets completely covered in dust within 10 seconds :( Oh well. Thanks for the website — Ilyanep (Talk) 01:34, 4 March 2006 (UTC)

Can viruses invade a host and creat a zombie?

Yes. HHV Latency Associated Transcript. WAS 4.250 20:50, 3 March 2006 (UTC)

Viruses invade a host by attaching to a cell and injecting DNA or RND into the cell. This DNA/RND info tells the cell to stop making the product it was and to start making protein coat and viral genetic info. This however will eventually kill the host.

But what would happed if a virus attached to a cell and injected DNA or RND into the cell which did not coda for making protein coat and viral genetic info, instead, made the cell duplicate its self with the new DNA/RND being replicated too. Eventually (7 years or so) the entire body would be a cross breed of the virus and a human… a Zombie! Many problems of reality must be over come such as the inability of the Brain cells to divide … yet this may be untrue as brain tumours exist.

My question is could this be a reality and has anything like it ever been reported?

Um, so you're asking what would happen if a tiny fraction of a viral genome were replicated by the cell and unintentionally incorporated into the host genome?? See Junk DNA for ref, about 60% or so of the human genome doesn't code for anything at all, just tiny bits of viral DNA that replicate themselves, and resplice over and over again, and ultimatly don't code for anything, non-coding DNA, over a few million years these tend to pile up, and it's kind of neat, because if you examine the genomes of several distantly related species, you can find paterns of non-coding DNA vs coding DNA, and you can see where they diverged, but no, no zombies--64.12.116.74 20:23, 3 March 2006 (UTC)

Ok, I just read the articles on Junk DNA and non-coding DNA, and it's prompted me to ask a sub-question:

Why is it that...

...all the science related articles on wikipedia contain creationist counter arguments against whatever the article is about?--64.12.116.74 20:48, 3 March 2006 (UTC)

It actually would happen much faster, occuring in 3-4 hours or so. See Shaun of the Dead for more information. --Sam Pointon United FC 18:47, 3 March 2006 (UTC)

No, a virus could not cause a person to become a zombie. Because viruses are so small, they can contain very little genetic information and code only for a few different proteins. There is no way for them to control a person's movements or do anything like you see on TV. I virus especially, cannot re-animate someone who is already dead.

Making cells divide (for which they must be alive to begin with) does not create zombies. If they divide frequently enough, out of control, it creates a cancer.

Furthermore, only certain cells can replicate to form other cells and there is not ONE cell in you body that can replicate and form any differrent type of cell. Some cells, [[stem cells], can be induced to form many different types of cell, but not ANY type of cell. This of course means that you have many different types of stem cell in your body.

Also, you mean RNA, not RND... --Username132 19:42, 3 March 2006 (UTC)

Not true, if I was a virus, I'd want to do some serious Research and Development before turning anyone into a zombie!--64.12.116.74 20:23, 3 March 2006 (UTC)

Hahaha. Kudos. — Ilyanep (Talk) 20:46, 3 March 2006 (UTC)

As mentioned above, it is likely that every cell in your body has bits of DNA from various viruses, and you will pass this amalgam of genetic material on to your children. In fact, it has even been theorized (but not widely accepted by any means) that the eukaryotic cell nucleus arose through incorporation of a DNA virus (a la the endosymbiotic theory). Under most circumstances, neurons cannot divide. Tumors in the brain are due to unrestrained growth of the “helper” cells such as astrocytes or glial cells, not neurons. — Knowledge Seeker দ 02:00, 4 March 2006 (UTC)

Long-term Effects of Medication for Attention-Deficit (Stimulants)

I have searched and come across very little about what science knows about the longe-range effects of stimulant medications used to treat Attention Deficit Disorder, such as Adderall and Ritalin. Is it fair to thus compare the changes amphetamine (which Adderall is, I believe) and cocaine create in the brain to such medications? The studies I read were linked to in the Wiki ADHD article; yet they were only two and themselves admitted further research is necessary. Are such long-term studies being done? - C

Probably. I might be able to hook you up if you can be more specific about what studies you're after (how about; "Review of ritalin (methylphenidate) medication use in children, in British Columbia, Canada"?). What level of study are you at? I've got access to a lot of journal articles, but you have to be well versed in the area to understand them. What year were the studies that you read conducted? --Username132 19:53, 3 March 2006 (UTC)

Anything relating to evidence for/against/concerning permanent changes in the brain as a result of amphetamine or methylphenidate, as prescribed for Attention Deficit. I have no medical training to speak of. The studies were both from 2005, one June, the other November. I confess only a vague awareness of what they are discussing. They can be found here and here. - C

occuring in 3-4 hours or so? What ?

occuring in 3-4 hours or so? What ?

Come again? --Obli (Talk)^? 18:59, 3 March 2006 (UTC)

In 3-4 hours from now, I'll be ending my workday, headed out to run some errands, maybe stop for a beer. --LarryMac 19:05, 3 March 2006 (UTC)

Hopefully in 3-4 hours I'll be done with homework. — Ilyanep (Talk) 19:13, 3 March 2006 (UTC)

I think this is referring to the virus/zombie question above. — Ilyanep (Talk) 19:26, 3 March 2006 (UTC)

Doesn't this refer to the zombie virus question above? For great justice. 19:34, 3 March 2006 (UTC)

Gues what? I think this refers to the zombie virus question above. DirkvdM 14:19, 4 March 2006 (UTC)

Are you sure it refers to the zombie virus question above? Kilo-Lima ^{Vous pouvez parler} 14:43, 5 March 2006 (UTC)

Phlegm

As one who has been coughing for about a week now, and is just now starting to feel better, what component of phlegm makes it green? User:Zoe|^(talk) 19:57, 3 March 2006 (UTC)

I could have gone all day without reading that... --Username132 20:17, 3 March 2006 (UTC)

I know that green phlegm is a sign of bacterial infection, but I couldn't tell you precisely why--might be that the bacterial mass itself is green. grendel|khan 21:53, 3 March 2006 (UTC)

Yes, but what pigment is responsible? It couldn't be chlorophyll, could it? —Keenan Pepper 23:06, 3 March 2006 (UTC)

Thanks, Keenan, that was really what I was trying to ask. Is there any copper involved? User:Zoe|^(talk) 23:32, 3 March 2006 (UTC)

I doubt there would be copper, but I'm no biologist or doctor. I think of Cu²⁺ ions, which are blue. I suppose it would look green if some copper compounds were somehow mixed in with some yellow pigments in the phlegm, but I really have no idea. --HappyCamper 13:31, 4 March 2006 (UTC)

Iron, not copper. Myeloperoxidase is the culprit, which has a ferric (Fe(II)) heme iron, which makes it green. --BluePlatypus 13:54, 4 March 2006 (UTC)

<phew> Thank God it is iron! --HappyCamper 13:56, 4 March 2006 (UTC)

Wow. Thanks! I'd really been wondering about that. Color me impressed. And green. grendel|khan 14:49, 4 March 2006 (UTC)

Awesome! Thanks, Blue. User:Zoe|^(talk) 19:43, 4 March 2006 (UTC)

Titanium dioxide as a sunscreen in cosmetics

I know that titanium dioxide is a sunscreen and is currently used as such in products. I make my own lip balm and recently some people who like to use my product asked if I could make it with sunscreen properties. I have titanium doixed in powder form, but as stated in its fact sheet, it is insoluable. How do go about using titanium dioxed in my lip balm so that it will act as a sunscreen without the product feeling gritty? Thanks for your help. Debbie Bliss

In suntan creams it is a suspenion of tiny particles, not a solution. You need to grind the powder more finely if it feels gritty. For great justice. 22:18, 3 March 2006 (UTC)

Titanium dioxide is in sunscreens because of how immensely white it is, in fact either zinc or titanium di/oxide is the whitest thing known to man. Black as you probably know is hotter to wear on a sunny day than a bright color, because light is absorbed into black, whereas white reflects most of the light. Long and medium wave ultraviolet rays from the sun are what cause sunburn, more of these are reflected off with the addition of zinc or titanium di/oxide You're not going to be able to add the titanium in, unless you can make it finer than a dust, the kind of dust you see in the light floating around in the air. -- Mac Davis] ☢ ญƛ. 04:31, 6 March 2006 (UTC)

March 4

Maple program

How does one factor polynomials in Maple?

Have you tried using factor(whatever)? expand() and factor() should do what you need. grendel|khan 01:45, 4 March 2006 (UTC)

Moved from my user talk page. grendel|khan 14:55, 4 March 2006 (UTC)

Thanks, but how do I factor equations in the form ax+bx+c. It doesn't work out well in Maple.

You mean $ax^{2}+bx+c$? Like quadratic equations? You should be able to enter, for instance, factor(x^2-5*x+6) and have it return to you $(x-2)(x-3)$. I've never actually used Maple; I Googled up an instructional page about it, which might be of more help to you. grendel|khan 14:55, 4 March 2006 (UTC)

Detecting the "days-without-a-shower" smell

In a club meeting one night, when we were all asked to tell the club some of our greatest pet peeves, one of the leaders of the club said that hers was the "days-without-a-shower" smell, and that she could detect the difference between the "after-a-heavy-workout" smell, and the "days-without-a-shower" smell. (Apparently, a lot of smelly people she's encountered tried the "after-a-heavy-workout" excuse if their days-without-a-shower smell was brought to their attention.) Can most (if not all) girls detect a difference between the after-a-heavy-exercise smell and the days-without-a-shower smell, or can only some?

I read in a Maxim magazine a long time ago that a female's sense of smell is 100x (yes, one-hundred times) more sensitive than a male's. I do have my doubts, however. How much more sensitive is the female sense of smell really? Also, how much sooner can a female detect a negative odor than a male?

What hints would typical college girls give, directly or indirectly, that she's detecting this kind of smell from you? (Or otherwise in each other's vicinity, if not you?) I know that in Elementary, Middle, and sometimes High School, people were more direct about what odors they sensed. In college, we're more polite and tactful, so oftentimes hints are given so subtly we may not even decipher them when we need to.

Finally, when a guy who hasn't had a shower in a few days decides to apply deodorant more thoroughly (beyond the armpits; onto the torso, back, legs, arms, et al.) and spray himself some cologne, can it successfully "camouflage" the bad smell or can one still sense the odor "underneath" the deodorant and cologne? --Shultz III 00:39, 4 March 2006 (UTC)

From personal experience, I've had the days-without-a-shower smell mistaken for the just-worked-out smell. Do you live on Arrakis? All this seems a bit much work to avoid washing. (Though I shouldn't really throw stones here.) The method I preferred for the thirty second scrub at work was to take a paper towel in the work restroom, wet it, throw some soap on it, scrub under the armpits and down the shorts. Worked quite well, much better than throwing on a ton of cheap cologne, which, trust me, even guys can detect. As for the women's sense of smell being better than men's, that sounds way fishy to me. If that were true, wine tasters and perfume testers would all be women, because their performance would be so superior to men's that they'd take over the trade. Which they haven't. grendel|khan 01:35, 4 March 2006 (UTC)

I guess this heightened sense of smell only applies to some women, based on what you say about wine and perfume testing. --Shultz III 01:58, 4 March 2006 (UTC)

According to http://news.bbc.co.uk/1/hi/health/1796447.stm, "A US study showed women of reproductive age are far better at identifying odours than men after repeated exposure to the source of the smell". Females were able to improve their sensitivity to the smell of benzaldehyde after smelling it multiple times, while males did not improve. This means that there is no significant difference in the sensitivity of males and females to smell, if the test subjects are only allowed to smell something for an instant.

There was no significant gender differences in people older than 45 years. There was also no significant difference in "young" boys/girls. (I think "young" means younger than the reproductive age, i.e. before puberty begins.)

Nobody can detect a bad smell "underneath" deodorant, if the deodorant is 100% effective. A person smells bad after a few days without a shower because of bacteria, and if a deodorant can kill all the bacteria, the smell will disappear. Cologne (Eau de Cologne?) is just a perfume, and perfumes do nothing but provide a pleasant smell, so it is possible to smell bad odour underneath cologne.

Finally, for the question "Can most (if not all) girls detect a difference between the after-a-heavy-exercise smell and the days-without-a-shower smell, or can only some?" Obviously some people are more sensitive to smell than others. Those with anosmia cannot smell anything. My guess is that if most girls you know can detect a difference between a specific after-a-heavy-exercise smell and a specific days-without-a-shower smell, than most girls can detect that difference. --Bowlhover 02:17, 4 March 2006 (UTC)

What material is best to make something leap over 20m?

What sort of material will work best for designing an A4 sized object to leap (or jump) over 20m from the ground? The object must not expel gas/liquid, and not require any other external devise to make it leap. Another thing is that all energy must come from the person supplying the force for the leap. Thank you for your help.

Designing? Or making? A4 is a two-dimensional size, so how tall can it be?
Slumgum 01:48, 4 March 2006 (UTC)

I am not completely sure that this is the best material for this application, but the Titanium-Nickel alloy used in braces is exceptionally springy and generally only retains shapes that it is formed in when heated. Skomae 04:30, 4 March 2006 (UTC)

How about a big rubber band? GangofOne 04:58, 4 March 2006 (UTC)

Making an A4 sized object with a height limit of say 1m. Are springs and rubber bands the only materials possible? Thanks.

Affectedness

I was reading the Klinefelter's Syndrome article and noticed that one of the symptoms mentioned was "affectedness." I'm no doctor, but I'm pretty sure that "affectedness" is not a medical condition. Does anyone know more about this? --JianLi 01:04, 4 March 2006 (UTC)

I think it's just "creative" writing. What they mean by "signs of affectedness"(!) is "symptom". JackofOz 01:41, 4 March 2006 (UTC)

Oh, I see. --JianLi 02:47, 4 March 2006 (UTC)

Microphone Query

My microphone will make a low hum when recording unless I blow loudly into it. The hum is recorded as unchanging. Why does this happen? What can I do? Thanks. M@$+@ Ju ~ ♠ 01:42, 4 March 2006 (UTC)

Are you near a fluorescent tube? Does the hum get louder or quieter if you move it closer or further from a piece of equipment? If someone is running a microwave or a fluorescent light (among other things), it can emit radio interference that the mic will pick up. grendel|khan 01:49, 4 March 2006 (UTC)

Nah, it goes away only if I blow loudly into it, like overloading then it resets. M@$+@ Ju ~ ♠ 03:48, 4 March 2006 (UTC)

Type of thermoplastic polyurethane fro making soles/shoes

The soles of the shoes are made of thermoplastic polyurethane or NON thermoplastic polyurethane.

The P... article tells us that there are different kinds ; some foams can be moulded.

Thermoplastic means "mouldable with the action of heat". If a substance is not thermoplastic, its use is quite different : varnishes are layered rather than moulded. Moulding leaves sometimes marks and allows to design textures that you would not want to draw mechanically. Also, my shoes' soles are leather. Can you decide by yourself now ? --DLL 21:49, 4 March 2006 (UTC)

mysql password

I've just installed mysql on my computer, and following some online post-installation configuration instructions, I guess I accidentally set the password to something I don't know. Can you tell me how to recover it? -lethe ^{talk +} 05:47, 4 March 2006 (UTC)

I found some instructions, which tells you to start mysql with an initfile containing instructions to change the passowrd. However, it didn't work, I got the error

ERROR: 1133  Can't find any matching row in the user table

So I guess I need to also tell the init file to add a user named root? How do I do that? -lethe ^{talk +} 06:26, 4 March 2006 (UTC)

OK, so I've started mysql with

/usr/local/mysql/bin/mysqld_safe --init-file=~/mysqlpass

and the file contains this:

use mysql;
INSERT INTO user (host, user, password, select_priv, insert_priv, update_ priv) VALUES ('localhost', 'root',
PASSWORD('somepassword'), 'Y', 'Y', 'Y');
FLUSH PRIVILEGES;

which I believe should create a root user with a specified password. Nevertheless, when I try to connect using

/usr/local/mysql/bin/mysql -u root -p

I get the delightfully uninformative error:

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

So I guess what I really need to know is: is there a way I can see which accounts are defined without being able to connect? -lethe ^{talk +} 07:13, 4 March 2006 (UTC)

OK, well I figured it out. If you read the file data/mysql/user.MYD, it's a binary file, but you can still see some text in there with all the crud, and I saw the names of all the accounts. So now I can connect and should be able to fix. -lethe ^{talk +} 07:21, 4 March 2006 (UTC)

When you first install MySQL, root has no password. You start it without using any password option so you can set a password for root. --Kainaw ^(talk) 01:22, 5 March 2006 (UTC)

That's true. But maybe other stuff also happens. -lethe ^{talk +} 15:03, 5 March 2006 (UTC)

Shortcut keys

I use Windows XP. I know that I can type Alt+0147, for instance, to type a left double quotation mark (“). Is there any way I can assign a keyboard shortcut to type characters like this (and for instance, different dashes)? I'd like to be able to do this in all programs, not just Microsoft Word. I know there are some programs available to download that let you create complex macros, but is there any way within Windows XP to do this? Or alternately, does anyone have a suggestion for a simple, light program that I can use to accomplish this? I'd rather not have a memory hog running all the time, if possible. Thanks for any assistance! — Knowledge Seeker দ 06:22, 4 March 2006 (UTC)

I need help for my science assignment.

I'm doing my assignment on ALLOYS. I just want to know who invented the idea. PLease answer as soon as possible or maybe you can give me some advice about where to look it up. Thank you guys.

I'm really desperate.

Gemmy

For general information, alloy is a good place to start. However, as for the first creation of alloys, this page seems like a good jumping-off point. It doesn't say who or what civilization started alloys, but it says that bronze was the first intentional alloy created by man. It also mentions brass which, according to our article on it, has been known to man since prehistoric times, so there seems to be slightly conflicting reports on this. I really don't know much about the topic, but hopefully this gets the ball rolling, or hopefully someone more knowledgable will come along to help. EWS23 | (Leave me a message!) 07:14, 4 March 2006 (UTC)

I suppose it largely depends on your definition of "prehistoric" whether that's conflicting information. After all, the discovery of the alloy bronze is the reason for the age known as the "Bronze Age" Prior to that Iron was the principal metal in use (hence "Iron Age"). Bronze Age culture is often (perhaps questionably) described as prehistoric, simply because so little of its history was preserved. As far as the initial question is concerned, although the first alloys may be difficult to track down the original creators of, some later innovators of processes for creating alloys are far easier to trace (one of the most famous is Henry Bessemer, who revolutionised the production of steel). Actually, the article on steel might give you several pointers, since that is still one of the most widely used alloys and historically has been around for a long time. Grutness...wha? 13:26, 4 March 2006 (UTC)

Asking who invented alloys is like asking who invented salt water. It predates life itself. WAS 4.250 16:02, 4 March 2006 (UTC)

True? Do alloys occur in nature with no human involvement? JackofOz 07:53, 5 March 2006 (UTC)

Depends on your definition; 16 Psyche if apparently one enormous lump of iron, nickel, and probably a collection of various platinum group metals. But it gets into whether you assert that by definition an alloy must be artificial. --Robert Merkel 09:20, 5 March 2006 (UTC)

There exist very few metals (and they're all the very unreactive ones) in the Earth's crust which exist as the metals themselves, rather than as compounds, or ores. But there is no reason, I suppose, why two such metals, eg silver and gold, could not alloy themselves "with no human involvement".G N Frykman 09:19, 5 March 2006 (UTC)

bending

Light waves bend when they move from one medium to other. So does sound or radio waves ben when they move from one medium to other?why?

Yes, they do. --HappyCamper 08:23, 4 March 2006 (UTC)

As do water waves as they go from one depth to another. It's because they change thier speed. Theresa Knott | Taste the Korn 08:41, 4 March 2006 (UTC)

You might find our article on refraction interesting. --HappyCamper 08:43, 4 March 2006 (UTC)

Also, light waves and radio waves are both forms of electromagnetic radiation. Light waves are electromagnetic waves with a wavelength range of 400 nm to 700 nm, whilst radio waves are electromagnetic waves with a wavelength of 1mm to 100 000km. So they behave in the same way. - Akamad 13:35, 4 March 2006 (UTC)

Sound waves refract by changing their speed. Electromagnetic waves can't do this, since their speed is fixed at the value c. So they change their wavelength.G N Frykman 09:22, 5 March 2006 (UTC)

Genes

Is it possible for genes to overlap one another? --HappyCamper 08:46, 4 March 2006 (UTC)

It is called "alternate open reading frame".Google for details, we lack an article on it. H5N1 has one one these. Our article on that states: "PB1 codes for the PB1 protein and the PB1-F2 protein.* The PB1 protein is a critical component of the viral polymerase.* The PB1-F2 protein is encoded by an alternative open reading frame of the PB1 RNA segment and "interacts with 2 components of the mitochondrial permeability transition pore complex, ANT3 and VDCA1, [sensitizing] cells to apoptosis. [...] PB1-F2 likely contributes to viral pathogenicity and might have an important role in determining the severity of pandemic influenza."[22] This was discovered by Chen et. al. and reported in Nature[23]." WAS 4.250 15:46, 4 March 2006 (UTC)

In a way, yes. See Alternative splicing. Basically if several proteins share parts of their amino-acid sequence, that part can be encoded in a single exon and both proteins can be created by the same gene as splice variants. --BluePlatypus 09:47, 4 March 2006 (UTC)

In that way yes, but not in the sense that you can imagine two meaningful encyclopedia articles that overlap, with the last page of one constituting the first page of the next-- for exactly the reasons the metaphor implies: starts and stops of genes are defined by special signals, and it is hard to imagine an instance where it would be useful to have the tail of one protein constitute the tail of another in reversed attachment. alteripse 12:55, 4 March 2006 (UTC)

Oh, I see. How about in smaller examples, like plasmids? Are there examples where the overlapping is much more significant? --HappyCamper 13:26, 4 March 2006 (UTC)

Language question about anencephaly

It's a question about norms of english language: how may the notion "anencephalic person" be expressed by a single word? In russian it's "anacephal" -- a person born without brains. Does anything similar exist in English? Thank you. ellol 10:03, 4 March 2006 (UTC)

I suppose if it had to be shortened to one word, you'd use anencephalic, in the same way that diabetic can be used as a noun. Though strictly speaking a person with the condition is only missing the forebrain, not the whole brain.GeeJo _{(t) (c)} • 10:17, 4 March 2006 (UTC)

Thank you, GeeJo! ellol 12:04, 4 March 2006 (UTC)

Many doctors avoid using a disease adjective as a noun, especially in formal or public speech. Person with diabetes is preferred over diabetic. One never wants to forget that a person is not a disease. This distinction was introduced publicly in the 1970s in an era of PC speech that often degraded accuracy and enshrined ignorance, and much of it (fortunately) has not survived, but this distinction is both functional and accurate, as well as sensitive. The people who use the term diabetic as a noun most freely are people with diabetes. Anencephaly and anencephalic is a special case, however, as you may be aware, because there has long been debate about the personhood of a body born without a brain. Anencephalic is sometimes used as a noun in a medical context. alteripse 12:50, 4 March 2006 (UTC)

Thank you. It's interesting. Actually, i wondered why does the word that must exist seem to be non-existing. The concept of political correctness is not common here. ellol 17:46, 4 March 2006 (UTC)

Is it likely that AA will become Persons With Alcoholism Anonymous? JackofOz 07:50, 5 March 2006 (UTC)

water potential

hello, I'm doing biology coursework on osmosis in potato tissue and there is one criteria i'm slightly confused on how to achieve. I have to say why is it better to use water potential instead of molarity.can you help? thank you

There is a hint in the article water potential which you might find useful. Also, check out molarity (and possibly molality). Note how the former takes something very important into account... --HappyCamper 14:21, 4 March 2006 (UTC)

ssh -X and ssh -Y

What is the difference between the -X and -Y options for ssh? I've read the man pages over and over, and I still don't understand what it means. Thanks for your help! --HappyCamper 14:49, 4 March 2006 (UTC)

Judging by this mailing list message, it's to do with whether or not you trust the applications running using X forwarding (ie what permissions they have on your machine you're SSHing from). -X runs them as untrusted, which can cause some things to break. -Y runs them as trusted. But you shouldn't notice any difference if you're not using an application sensitive to whether or not it's trusted. --Bth 15:20, 4 March 2006 (UTC)

Plugged Ears feeling after running in cold weather

Why do my ears feel like they're all plugged up during and after I go running/jogging in the cold weather (see your breath kind of cold)? It seems I have to 'pop' my ears after each breath once I go indoors. It's horrible if I have a stuffy nose. 151.199.150.176 17:04, 4 March 2006 (UTC)

If your Eustachian tubes get plugged up with a bit of mucous, the pressure on the inside of your eardrum will be higher than that outside. Your hearing will be distorted, and 'popping' your ears will clear it. TenOfAllTrades(talk) 21:47, 4 March 2006 (UTC)

Its possible that you have an Ear Infection. I have had it on multiple occasions and its symptoms include plugging on the ears and that popping of the ears is the ears trying to adjust the the pressure changes within your ear to the outisde pressure but somehting is blocking it making it more noticeable. Ear infection is caused by fluid entering the Eusachan tube in the ear and bacteria getting in there and infecting it. See a physician for more of an explanation. This is usually remided with common medicines. I hope this helps. :-) 5aret 00:55, 5 March 2006 (UTC)

Perhaps I just have overproductive mucous membranes in the area of my eustachian tubes since it occurs everytime I exercise in the cold and feel quite healthy. Thanks for the info. But is there a reason why these membranes would produce mucous while Im exercising and not when Im just sitting around out in the cold? 70.106.18.50 16:38, 5 March 2006 (UTC)

OpenID

Does OpenID provide a way to link different identities? For example, let's say I have a Livejournal OpenID and a DeadJournal (or experimental MediaWiki) OpenID. Is there any way I can tell the servers that these are one and the same person? — Ilyanep (Talk) 19:48, 4 March 2006 (UTC)

If you have full control over one of the URLs you can delegate it to the other URL, but if it's LiveJournal or MediaWiki, then no. Ashibaka tock 06:09, 5 March 2006 (UTC)

You'll probably have do decide which one you prefer more and just stick with that one. Use your favorite OpenID to log into sites that support it. Why did you create more than one OpenID anyway? --Optichan 19:48, 6 March 2006 (UTC)

Java loading code

Does anyone know how I could make a program that reads in java code from a text file and executes it. I think I can do it by reading in a class, using the "load"[15] command and doing somthing similar to the code on this [16] page. I'm lost though. Could someone give me an overview of what has to be done? I know I'll have to cast the class after reading it... but how do I get it in the first place? Is this even possible. BrokenSegue 22:11, 4 March 2006 (UTC)

By "java code" I'm assuming you mean "compiled bytecode stored in a .class" file (and not "java sourcecode"). The easy way is to make sure the class file is in the classpath, and then invoke Class.forName (an example is here). If it isn't, you have to create your own classloader (i.e a class that extends ClassLoader), which is what that example you quote does. The important line is the call to defineClass (which is in ClassLoader) which takes a byte array (containing the same stuff as a .class file) and loads it. That will give you a java.lang.Class object. Now, if memory serves, you can't just cast that to something (like an interface) and just go using it (unless they've added some clever stuff to do that after I stopped doing so much java). Instead you have to call the Class object's newInstance method. Note that if your constructor (for that class) has arguments, you'll have to use java.lang.reflect to build the arglist for newInstance (discussed here). One last thing (it's obvious, probably): your compiled class has to implement an interface which your hosting code knows about (and was compiled with) so that you can have something meaningful to cast the result of newinstance to. Here is a rather basic AppletClassLoader (the Sun one is rather more complete) which uses a classloader that comes with the system (NetworkClassLoader). Don't worry if this all seems rather excessive - this is probably the hardest, yet most infomative, part of Java. Once you get this you'll understand how security really works, how reflection works, and how stuff like JINI and Javabeans work. -- Finlay McWalter | Talk 22:37, 4 March 2006 (UTC)

Thanks man. BrokenSegue 12:50, 5 March 2006 (UTC)

mac OS finder windows

Since this seems to have become the computing reference desk....

I'm running Mac OS 10.4.4. I like to apple-tab between applications. But something very frustrating happens with the Finder. When I apple-tab to the finder, it doesn't bring the last finder window I was working with to the front. The focus seems to go there, because I can apparently navigate directory structures with the arrow keys, but the window itself doesn't come to the front, so I usually can't see what's going on. I have to either somehow find it with the mouse, or apple-tilde until the right window shows up. Extremely annoying. I don't think it behaved like this on older OSes. Does anyone know how to fix this? Thanks... Dmharvey 22:18, 4 March 2006 (UTC)

Not really a fix, but I tend to use Exposé (F9 or F10) to pick the Finder window I want. Sum0 22:52, 4 March 2006 (UTC)

I think it's always been for computing. Its description is "To ask questions about science, medicine, computing, and technology". — Knowledge Seeker দ 23:29, 4 March 2006 (UTC)

I think it might be worthwhile to split off into a Reference desk/Technology. — Ilyanep (Talk) 23:30, 4 March 2006 (UTC)

I don't think you can get what you want, you're going to need to use the exposé feature, F9 or F10.

Apple-backtick cycles between windows in the same application, e.g. between different finder windows. Ojw 12:21, 5 March 2006 (UTC)

(Oops, when I said apple-tilde I meant apple-backtick.) Well, it's very strange, after behaving like this for several months, as soon as I ask a question on the reference desk, the problem goes away. Now it does what it's supposed to do. I don't think I changed any settings. Very mysterious. Thanks guys! (I guess!) Dmharvey 12:31, 5 March 2006 (UTC)

Science fiction weapon

I had an idea for a fancy futuristic weapon: Ordinary rifled barrel, magnetic/magnetised bullet. Behind the bullet is a powerful (as powerful as necessary/possible) electromagnet with an opposite charge to the bullet. When the electromagnet switches on, the bullet is repelled straight out of the gun at a high speed. So, sort of like a coilgun but with no coil. Plausible, or fatally flawed? Thanks y'all. Sum0 23:04, 4 March 2006 (UTC)

Doesn't sound very likely to me. By the way you don't really mean "charge"; no one has been able to prove experimentally the existence of magnetic charge, though there is theoretical work about how it would behave if it did exist. If it did exist, you wouldn't want opposite magnetic charge, but rather the same (opposites attract, like charges repel). So what you're really talking about is a magnetic dipole. Dipole forces fall off very quickly with distance. My guess is you'd be lucky to get the bullet to go ten feet. --Trovatore 23:16, 4 March 2006 (UTC)

Oh yeah, I meant same charge. Also, I must have not explained it very well: the idea isn't for the magnetic force to keep "pushing" the bullet as it goes along, but to accelerate it very quickly to a high speed before it leaves the magnetic field. Would that work, or does physics get in the way? Thanks for the replies, anyhow. Sum0 23:32, 4 March 2006 (UTC)

It'd make a nice pistol-like weapon. But what real advantage would it have? — Ilyanep (Talk) 23:26, 4 March 2006 (UTC)

I think the magnet-at-the-back design is just wrong. Why don't you want the coil along the barrel? I haven't worked the numbers or anything, but my intuition is you'll get a much higher muzzle velocity with the latter design. --Trovatore 23:36, 4 March 2006 (UTC)

This is called a rail gun. It isn't science fiction. Working models have been made. The problem is that the power supply is about the size of a VW Bug - so it isn't very portable. --Kainaw ^(talk) 01:18, 5 March 2006 (UTC)

Some fellow pupils made one of these (under supervision) when I was at school in Oxford in the 1970s. They used the properties of the 3-phase supply to induce huge eddy currents in a metal bolt and to shoot it out of a tube. When it was first tried out, it was just as well that sand-bags had been placed at both ends of the tube, because the connections had been made the wrong way round, and the bolt shot out backwards with huge force... Do not try this at home, is the motto!G N Frykman 09:31, 5 March 2006 (UTC)

One problem is that the bullet will want to turn around, which will cause a lot of friction and make it come out of the barrel at a slight angle. Btw, I came up with the rail gun principle as a kid and asked the physics teacher about it and he hadn't a clue what I meant. Only later did I find out that some trains use this principle. Someone else stole my idea again. :( DirkvdM 10:38, 5 March 2006 (UTC)

The most successful one I've seen (Texas A&M) used a little caddy to carry the bullet down the rails. It was a little bullet-sized bucket with two wings that rode along the rails. This meant that the bullet could be uncharged - instead the wings of the caddy were charged. Then, you can set it up so they try to turn into each other - cancelling out that problem. The new problem is that the wings will easily weld themselves to the rails due to the high amount of electricity travelling through the system. When that happens, you get big sparks and a very expensive paper weight. --Kainaw ^(talk) 17:58, 5 March 2006 (UTC)

But from what I can tell, this isn't a railgun. There are no rails, for a start, and it's just one magnet behind the bullet. Sum0 20:37, 5 March 2006 (UTC)

Sounds very much like a Gauss gun, but with only a single electromagnet. BTW, you can make a handheld gaussian gun with 5 (magnetic) ball bearings and some similiarly sized neodymium magnets. Connect 4 bearings and the magnets in series, then let the fifth bearing roll towards the exposed magnets. The impact velocity is transferred to the farthest bearing, which by not being in as strong a magnetic field, is propelled away at high velocity. It's more of a toy, since neodymium magnets are too brittle for large-scale versions. PS - I credit MechWarrior 2 for introducing the topic to me - the Gauss Cannon rocked faces. Tzarius 07:54, 6 March 2006 (UTC)

March 5

Thermostat 7 to 5 wire

I have a 7-wire thermostat. I went through every thermostat at Lowes and Home Depot. The most connections any have is 5. I tried to use one by connecting the 5 matching colors and leaving the two odd colors (Cyan and Orange) disconnected. The heater runs non-stop. I've been searching and searching on the Internet for information, but I can't find anything about how to connect a 7-wire system to a 5-wire thermostat. Are there any AC experts here? --Kainaw ^(talk) 00:47, 5 March 2006 (UTC)

Well, I'm not an expert, but I have here the instruction sheet for the Lux TX 1500 thermostat I installed in my house a couple of weeks ago, and it accepts up to 7 wires. (I can't imagine what they're all for; my heating system has only two.) —Steve Summit (talk) 04:35, 5 March 2006 (UTC)

Stopped by an AC supply shop today. They were closed (Sunday), but some guys were there putting in extra hours. It turns out that my "7-wire" is technically called a "C-wire". It is considered commercial, not residential, so I had to get a commercial thermostat. The only ones they carry are from Rite-Temp, which are cheap, but function. They showed me why it is was impossible to use a C-wire heat pump with a 5-wire thermostat. The relay for the fan and heater gets voltage on one side, but not the other. So, no matter what the thermostat says, it always thinks it is supposed to be running the heat. --Kainaw ^(talk) 17:54, 5 March 2006 (UTC)

some compound

I mixt (chlorine) bleach with (household) ammonia and put a 1989 canadian 1 cent into it. 2 days later, the mixture is blue. i'm wondering what it's chemical formula is and why it turned blue. --152.163.100.74 04:01, 5 March 2006 (UTC)

Gah! Please, don't try this again, and nobody try this at home. Mixing chlorine bleach and aqueous ammonia will result in the formation of chloramine, a highly toxic compound that is being used in many cities as a substitute for chlorine in water purification. Nasty stuff. TenOfAllTrades(talk) 04:26, 5 March 2006 (UTC)

Did you actually do it or is it just a nicely phrased homework question? deeptrivia (talk) 04:41, 5 March 2006 (UTC)

I'm kind of hoping that a homework question wouldn't encourage a student to do something so blindingly dumb, actually. There's a reason why household bleach and ammonia bottles both have dire warnings on their labels not to mix the two of them together. *grumbles* What are they teaching kids in school these days? *grumbles*

To answer your question, Canadian pennies before 1997 were almost (98%) pure copper. Taking stock of what's present in your beaker, you have copper, sodium hypochlorite (from the bleach) and ammonia (from the ammonia). Now just do some research and find out which combination of those is vividly blue. TenOfAllTrades(talk) 04:57, 5 March 2006 (UTC)

According to a very old book I read, old coins can be cleaned by putting them in ammonia, which will leave the coin clean and the liquid blue. Given the age of the book, I'd assume they presumed most coins are made from copper, which would suggest that ammonia was the only ingredient doing the cleaning in the experiment you described. --Aramգուտանգ 20:23, 5 March 2006 (UTC)

As mentioned above on this page (in some discussion about phlegm) $\mathrm {Cu} ^{2+}$ ions are blue. So if you can get some copper to ionize, for instance by putting it in an acid, you'll end up with a blue solution. I think. My memory of high school chemistry is poor. moink 23:40, 5 March 2006 (UTC)

Okay! Thanks. It's not homework, I was just bored so i wanted to see what would happen if i mixt stuff that it says i shouldn't mix. I really dont care what the compound is called anymore, i just wanted to know why it's blue. PS: I realize it would produce poisonous gas, so i first poured some bleach into a plastic cola bottle and then pushed in a water balloon filled with ammonia, and then popped the balloon while it was inside. Now...is there anyway i can make the mixture blow up, or fizzle or some cool reaction by adding more household chemicals? --152.163.100.74

Look, just mixing random stuff together is just dumb alchemy. Go find a book on chemistry experiments you can do at home and try some of the stuff in that. Some of it can involve explosions, fizzing, and so on, you may actually learn some interesting stuff in the process, and you run a far lesser chance of killing or injuring yourself and your family in the process. --Robert Merkel 03:39, 6 March 2006 (UTC)

Incidentally, the blue may well be the complex "cuprammonium" ion, which is a deeper blue than copper. Hyperman 42 00:29, 6 March 2006 (UTC)

Australia's First Triple Transplant

I'm requesting information on the details of Jason Grey's transplant, which was Australia's first triple transplant (heart, lung and liver).

I would specifically like to know the date that the 14 hour operation was done on.

(I have tried using Google, but am not getting much luck.)

Thanks for the help.

05:40, 5 March 2006 (UTC)

I'm not having much luck with Google either. I can't get an exact date, but I've narrowed it down to the last week of July or the first week of August 2003. According to [17] Jason's surgery was performed sometime during the week prior to August 8. This is confirmed by [18] [19], which gives Jason's post-op condition as of August 5. --David Iberri (talk) 16:28, 5 March 2006 (UTC)

viruses

i bought some software from e bay about 3 month ago and ive looked at it a few times with no trouble. today i done a avg test on my pc and this software had a virus in it. the virus was

           Trojan horse psw. Banker. wzp
ive looked up a few types of virus but could not find this one

is it very dangerous for my pc and files or not --Titanicful 08:56, 5 March 2006 (UTC)

• What software did you buy? Some anti virus programs label stuff as trojan by accident, but you can't be too careful. I would look up the trojan's name on symantec's website www.symantec.com and download a patch to get rid of it. - Mgm|^(talk) 14:01, 5 March 2006 (UTC)

What antivirus software are you using?

The question says AVG.
Slumgum 20:18, 5 March 2006 (UTC)

Oh you're quite right... Are you sure the virus defs are up to date?

Is it possible to change a Yahoo username?

Is it possible to change a Yahoo username? —Masatran 12:28, 5 March 2006 (UTC)

• Did you try asking it at Yahoo first? They are the people who are supposed to know this. - Mgm|^(talk) 14:02, 5 March 2006 (UTC)

No. But, you can just create a new Yahoo account and stop using the old one. --Kainaw ^(talk) 15:05, 5 March 2006 (UTC)

Undeletion

Can anyone recommend good free software to recover files from my old NTFS hard drive? I'm running Windows XP. The freeware I've found has found and recovered some of the deleted files I need, but not all. A shareware program I've found (called WinUndelete [20]) detects the remaining files and tells me they're in "good" condition, but the shareware version won't actually recover them. Seahen 14:12, 5 March 2006 (UTC)

What is the freeware you have used already?

There isn't a lot of free data-recovery software, but Directory Snoop is a shareware program that you can try for free. It can recover files instead of just telling you they're in good condition. I used it back in May/June 2005, but unfortunately it couldn't help me out.

Good luck! --Bowlhover 20:59, 5 March 2006 (UTC)

Food allergy?

I've noticed repeatedly and quite predictably that these two situations will cause 1 episode of diarrhea for me (almost without fail) within 30 minutes after finishing: 1) having large quantities (1/4 teaspoon) of nutmeg in 1 8-12 oz cappuccino, 2) an Italian dinner from a respectable American-Italian restaraunt (e.g. The Olive Garden, Romano's Macaroni Grill). Obviously, I know what the cure is, but i was wondering if anyone knows why this happens? Is this a food allergy? Male, I have an unusually high metabolism, have weighed 150 lbs for more than the last 5 years, and am generally healthy. 70.106.18.50 17:04, 5 March 2006 (UTC)

Nutmeg is a common cure for diarrhea, not a cause of it. Also, a person with a high metabolism usually has a very low weight as a high metabolism requires more calories to maintain muscle and fat than a normal metabolism. 150-180 pounds is an average weight for a normal male. In our modern obese time, 200-250 is considered normal, but that is normally obese, not normal. So, if you are maintaining 150 pounds without trouble, you probably have a normal metabolism. --Kainaw ^(talk) 17:50, 5 March 2006 (UTC)

Bloody hell, over 100 kg normal? For someone 2,5 m tall maybe. DirkvdM 07:11, 6 March 2006 (UTC)

Interesting point about my metabolism - you're probably right. 71.241.8.77 05:14, 6 March 2006 (UTC)

When I and my friends were, how you say, "experimenting" with nutmeg, we had problems with nausea, but not diarrhea. —Keenan Pepper 17:59, 5 March 2006 (UTC)

I once 'experimented' with nutmeg, but remembered incorrectly and put a tablespoon of cinnamon in my mouth. Which instantly sucked my mouth dry and made it almost impossible to spit it out. That cured me from any desire for further experimentation. :) DirkvdM 07:16, 6 March 2006 (UTC)

Could it be coffee? That does it for me in large enough quantities.

Nutmeg is extremely poisonous if inject instantaneously! Kilo-Lima ^{Vous pouvez parler} 16:31, 6 March 2006 (UTC)

Don't know about the nutmeg, but you may have lactose intolerance. - Taxman ^Talk 19:41, 6 March 2006 (UTC)

Why do objects appear smaller with distance?

Why do objects appear smaller as the distance between the object and the eye increases? Consider a square object that is smaller than the eye lens and is lined up perfectly with the center of the lens some distance away. Now the parallel rays of photons/lightwaves coming from the top edge and the bottom edge of the object will hit the eye lens at exactly the same spot no matter how far the object is. So why should the object appear smaller with distance? I once brought this up with my physics teacher back when I was still in high school and he wasn't able to give a satisfactory explanation, and suggested that the post-processing of the optical signal in the brain is what makes the object appear smaller, referring to the Moon illusion as an example. Is that explanation valid? Thanks, this has been bothering me for ages. --Aramգուտանգ 20:37, 5 March 2006 (UTC)

Objects do not appear smaller because of the "post-processing of the optical signal in the brain". If you measure the Sun's angular diameter at 1 AU, and measure it again at 50 million kilometres, you'll find that it is much larger at 50 million kilometres than at 1 AU. But if you measure the Moon's angular diameter when it's high in the sky, and measure it again just before it sets, you'll notice that the angular diameter doesn't change.

Let's say you have an object that's bigger than your eyes. As you move farther away from the object, light rays from the top and bottom of the object will gradually become more parallel. If you measure the angle they form when they intersect (at your eyes), you'll get the angular distance between the top and bottom of the object. The angular distance is what determines how big or small an object appears to be, and as the light rays become more parallel to each other, the angular distance will shrink. This is why objects appear smaller when you move farther away from them--it's not because of an optical illusion like the Moon illusion is. --Bowlhover 21:23, 5 March 2006 (UTC)

Well said, Bowlhover. Objects subtend a smaller angle on your visual sphere the farther away they are. —Keenan Pepper 21:36, 5 March 2006 (UTC)

To address your specific query about parallel rays, you're right that those will not change as the object moves away; however, they are not the only relevant ones (otherwise, you wouldn't be able to see anything larger than the diameter of your lenses. Image:Lens3.png gives an illustration of what's involved in focusing a point of the image. One could imagine moving the object father back. The top ray would remain the same, as it is parallel to the axis of the lens, as you have noted. But the slope of the middle one would decrease and it is easy to see that it would now intersect the top ray further to the left of the original intersection; calculations will show that the other rays will do the same. Of course, the new image is also more ot the left of the original and wouldn't be focused on the retina, but even as the lens adjusted the new image would still be smaller. If you'd like to go through the specific calculations, let me know. Post-processing is not involved in the phenomenon as you have described it. — Knowledge Seeker দ 21:55, 5 March 2006 (UTC)

Ah, thanks a lot Knowlegde Seeker, the Image:Lens3.png diagram really got the point through. I'm surprised at the incompetency of my old teacher now, I recall he wasn't able to explain why mass increases with velocity in general relativity either, but that's not a question that bothers me a lot. Oh and thanks to Bowlhover too, although I was really looking for an exlanation that would go into ray bending in the eye lens. --Aramգուտանգ 05:16, 6 March 2006 (UTC)

Vinyl Cancer

Now that they have whimped out in using the killer plasticizers in Polyvinyl chloride, something very bizarre has happened. I have a vinyl insulated cover on my hot-tub (I use it all year up in Canada). It's santized with Bromine. The last couple of months, the underside started bubbling in the middle, and quickly spread. I finally had to rip it off today. It was as hard and as brittle as original PVC. Has anybody seen this happening. Is this a new thing? Many thanks. --Zeizmic 21:37, 5 March 2006 (UTC)

It *sounds* like the plasticizer which is used to keep the plastic flexible has simply left the polymer. How old is it? --HappyCamper 05:16, 6 March 2006 (UTC)

Sounds like it could be water causing seperation of layers, which is something that could happen if the thing is made from a laminate. --BluePlatypus 09:51, 6 March 2006 (UTC)

Only about 2 years old. It was a funny vinyl, without the usual cloth backing. It happened so fast, and now the bottom is tissue paper. I just ripped it out, and there's another type of plastic underneath. Maybe that was the original backing. --Zeizmic 12:54, 6 March 2006 (UTC)

How much do we cost?

If we were to deconstruct our body to elementary segments, and then convert the cost of each quantity to monetary units, how much would we cost? Now, we all know we are priceless, but...just for the sake of this question.

It all depends on what you mean by "elementary segments". If that means atoms, we're almost worthless. —Keenan Pepper 22:43, 5 March 2006 (UTC)

Here's our percentage makeup of the elements, I guess you'll have to do the maths and some stoichiometry from there, find a chemicals supplier and see how much they charge for the elements, I didn't manage to find any such supplier, though. --Obli (Talk)^? 22:56, 5 March 2006 (UTC)

If we were to deconstruct a canon DSLR camera EOS 1Ds mark II body to elementary segments, and then convert the cost of each quantity to monetary units, how much would the canon DSLR camera cost? Now, we all know Canon Camera are expensive, but...just for the sake of this question.

You see the problem. A canon camera cost more than the sum of its parts. A human being cost more than the sum of the chemical components. What about the cost of the skills in a human being if that human is a olympic gold medalist? Ohanian 03:14, 6 March 2006 (UTC)

It would be interesting to try to make a breakdown of how much value is added at each level of complexity. The raw elements are worth some small amount of money; the molecules are worth a different, higher amount, the living cells even more, and so on. —Keenan Pepper 03:29, 6 March 2006 (UTC)

But value depends on supply, which means the means of production, which vary greatly. Producing 1 gram of a single protein in pure form is a *lot* more expensive than producing 1 gram of cultivatable cells. Producing 1 gram of copies of a single DNA is rather cheap, thanks to PCR. The cost of synthesizing organic substances varies enormously depending on what precursors you need, and what reactions yuo can use. And so on. --BluePlatypus 19:32, 6 March 2006 (UTC)

histogram equalization stretch

when modifying a satellite image, in what situation should the histogram equalization stretch be used, should it be used to enhance a rare feature on an image?

Try it and see if it works for you. GangofOne 02:36, 6 March 2006 (UTC)

What does 'histogram equalisation stretch' mean? Is that some preset for a program? If so, which one and could you describe it's function? I suppose it means reducing the overall contrast. What effect this has on a specific feature depends on that feature. You should increase the contrast between the important parts of the image (and thus 'stretch' the rest?). In Photoshop or the Gimp, play around with 'curves' (don't know what that's called in other programs). DirkvdM 07:33, 6 March 2006 (UTC)

Christmas lights fiasco

I did something stupid the other day: I used a string of Christmas lights as an extension cord for a vaccum cleaner. (Don't ask why. Yes, it was stupid. Yes, I probably could have guessed what would happen.) The lights of course went off and won't come back on, and electricity no longer seems to pass through the cord at all. What's the probable extent of the damage -- is it a light or two that blew needs to be replaced, or is the whole string dead? --Fastfission 23:16, 5 March 2006 (UTC)

Do you happen to know if the lights are strung in series or in parallel? When were they made approximately (and in what country)? moink 23:22, 5 March 2006 (UTC)

From looking at User:Fastfission/About me, you're in the US and youngish. So unless you inherited these from your parents when they were young, they're most likely in parallel. If none of them are working, replacing one won't cause the rest to work. I don't know what's wrong with them. moink 23:29, 5 March 2006 (UTC)

If I am not mistaken, most strings of Christmas lights produced for use in the US in the recent past have a fuse within the plug. (see the fourth major paragraph here); check to see if there seems to be a latch or cover of some kind in the plug. And yeah, don't try that again! --LarryMac 23:40, 5 March 2006 (UTC)

I had a recent set of those tiny lights, and the cord broke. No problem, I thought, I would just solder it together. Well, they are soooo cheap that there is no wire! It just looks like thread wound into string! I think it must be silvered string, or somehow they get it to conduct the little bit that is necessary. This stuff cannot be rejoined, and if you put a bolt through it, I'm sure you get a lot of burnt string! Puts new meaning to a 'string of lights'. --Zeizmic 02:27, 6 March 2006 (UTC)

The tiny lights are actually in series, but if one goes out the whole string doesn't go out because the blown light is designed to short itself. These are low voltage blubs, the voltage of the mains is divided among the either string. The wire is small, you probably burnout the wire somewhere due to too much current. But maybe the bulbs can be used as replacements on your next string. GangofOne 02:41, 6 March 2006 (UTC)

March 6

March 6? But can you be more specific in your question? For great justice. 05:24, 6 March 2006 (UTC)

You made my day! I think it was referring to the actual date of questions to be asked :) --Ali K 05:29, 6 March 2006 (UTC)

Hey, if you go up a bit, there's another header saying 'March 5' and a bit further up there's a 'March 4'. And so on. Maybe these are not questions at all. Now what might they be for? DirkvdM 07:37, 6 March 2006 (UTC)

It's the Wikipedia fitness regime. Yesterday we were supposed to march five miles and today it's six. --Bth 08:15, 6 March 2006 (UTC)

Actually, I think it's a typo. Today we are supposed to answer questions at Mach 6. - EWS23 | (Leave me a message!) 16:58, 6 March 2006 (UTC)

• To whoever forgets: Remember Wikipedia uses UTC time and may switch to the next day, when you're still a few hours behind. - Mgm|^(talk) 09:32, 6 March 2006 (UTC)

Thanks - it was actually just a silly joke, but the Mach comment made me wonder - if Mach is the ratio of the speed of a thing to the speed of sound in the same medium, what happens as a plane gets higher into the atmosphere and eventually into the vacuum of space, where the speed of sound is, presumably, zero, because there is nothing for it to transmit through in that medium? For great justice. 19:21, 6 March 2006 (UTC)

Pang tree?

Please see Pang (color). What is a pang tree? User:Zoe|^(talk) 18:19, 6 March 2006 (UTC)

Hmm, good question. That article has only been edited by one person, who hasn't edited anything else.. --BluePlatypus 19:26, 6 March 2006 (UTC)

[21]

I'm not altogether convinced that there is such a thing... For great justice. 19:28, 6 March 2006 (UTC)

rotational equilibrium

Is "rotational equilibrium with constant angular velocity" dynamic rotational equilibrium?, analogous to the dynamic equilibrium with constant linear velocity

Dripping Faucets

This has been bugging be for quite some time now. Turn on your faucet so that it produces a continuous stream of water. Then slowly nudge it closed until the stream is as thin as it can be without turning into drops. Now place your finger under the stream and move it up towards the faucet. As your finger approaches it, the stream turns into drops. But — and this is the weird part — the faucet stays dripping even after you remove your finger. You would think that it would go back to being a continuous stream, considering that the conditions are exactly the same as before and you have not adjusted the faucet. Does anyone know why this happens? --BrainInAVat 20:35, 6 March 2006 (UTC)

It's to do with surface tension on the water stream. The surface tension on the stream keeps it as a stream. When you interupt it, it colapses, causing a drip to form - the surface tension on the drip 'sucks' more water into it, causing it to fall, etc. You could coax it back into a stream if you were careful. For great justice. 20:47, 6 March 2006 (UTC)

Wow, that was fast :-). So do you mean each drop causes another drop to form? --209.6.213.142 21:00, 6 March 2006 (UTC)