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Headphones

I have been thinking about what kind of headphones I want. I want the best pair of headphones I can get for under $200. I want low impedance, I want durability, I want comfort, I want terrific sound quality. Right now I have my eye on some Sony MDR-7506'ers after dying over them a month ago. I will be listening to rock, and classical, and I will use these headphones a lot. Thanks, — [Mac Davis] (talk)

• I like Etymotic, but you're probably looking more for over-the-head models. Are you looking for noise cancelling, or will these be for home use? I've tried some Bose headphones, and the sound and noise-cancelling is phenomenal. This pair is in your price range. Deltabeignet 20:58, 13 August 2006 (UTC)

I would recommend looking where DJ equipment is found, for three reasons. A) DJs demand high volume and noise reduction, sturdiness of build, sound quality, and techno-modern appearance, and that's more variables than your average listener, or even headphone afficianado usually requires. B) There is a significant DJ community which supports a variety of high-quality brands. C) DJs generally don't have money to waste on gimmick products, so headphones marketed for DJs probably aren't as expensive as they would be if they were built with others in mind.  freshofftheufoΓΛĿЌ  11:37, 14 August 2006 (UTC)

Bigger and blacker is better

Do black men statistically have larger penes, or is it just made up? — [Mac Davis] (talk)

Have you looked at Human_penis_size#Race_and_penis_size?-gadfium 01:16, 13 August 2006 (UTC)

I once heard that the English complain more about condoms being too small. Then again, such things may be caused by either the size of the penis or the size of the brain. DirkvdM 12:02, 13 August 2006 (UTC)

Or condom companies knowing that a customer with an inflated ego is more likely to keep buying the ones that make him feel that he's "Extra Large". Confusing Manifestation 10:07, 14 August 2006 (UTC)

Libido

What hormones govern one's libido? Are each gender's totally different? — [Mac Davis] (talk)

It's mainly testosterone, in both sexes. Anchoress 01:14, 13 August 2006 (UTC)

gender and fetal development

I've just read a review (The Globe and Mail - August 12, 2006) af a new book (The Female Brain by Louann Brizendine. In the review, this statement is made: "In the beginning, actually, we are all the same: the fetal brain is female". I believe that this statement is incorrect even though I have seen it repeated often in many different sources, I'd like to know the correct answer. From conception, as I understand it, all the cells of female brains contain two Y chromosomes and all the cells of male brains contain one X and one Y chromosome? Therefore, from the moment of conception, a male brain would be male and a female brain would be female wouldn't it? When speaking of fetal development, however, perhaps it is true that in the early stages of development, male and female brains do not appear much different until testosterone (as is stated in the review) influences that development. Please give me the straight information about this or direct me to a source which will do so. Thanks.

That's probably a feminist talking. The brain really isn't "female" or "male," its just a developing brain. Woman is not the ultimate gender. — [Mac Davis] (talk)

See our sex differentiation article. The statement "the fetal brain is female" is misleading and inaccurate. It is a garbled version of pre-gene expression understanding of differentiation. The old version goes roughly like this:

• The fetal mammalian brain is undifferentiated. If exposed to testosterone from testes it becomes masculinized. Those brains not exposed to testosterone continue to develop without testosterone effect and become feminine. In a sense, there was no known difference between a brain destined to be female and a brain destined to be male before the testes start making testosterone at about the 7th week of gestation. In the late 1970s feminists made much of this, and this is the lineage of the statement you quote. However, it is certainly misleading, if not downright false, to claim that an undifferentiated 6 week fetal brain is the same as a female brain.

More recent molecular genetic research makes the statement even more ridiculously wrong, as it has now been shown that male and female brains express a number of gene activities differently even before testosterone levels rise enough to cause the differentiation described above. I would not believe anything else this author writes about biology. alteripse 02:02, 13 August 2006 (UTC)

And a point of clarification for our original questioner. You wrote, "all the cells of female brains contain two Y chromosomes", but you meant "all the cells of female brains contain two X chromosomes." (at least for humans!) - Nunh-huh 02:05, 13 August 2006 (UTC)

can this happen

can a star ever hit the earth?

No. Every star except the sun is too far away. Things like comets or meteorites can hit the earth and destroy all life forever though. Hyenaste ^(tell) 02:17, 13 August 2006 (UTC)

Ever? Take a look at this website about galactic collisions and Interacting galaxy. --JWSchmidt 02:43, 13 August 2006 (UTC)

Yes it could happen, but the chances are so small you would do a lot better to worry if your seat belt is fastened (but then again, that's true of almost every other risk, too). StuRat 03:21, 13 August 2006 (UTC)

Actually, if you want to be technical, a star can never hit the earth. The gravity of the star would pull the earth towards it, not the other way around. Emmett5 03:41, 13 August 2006 (UTC)

Unless it was a dwarf star. Hyenaste ^(tell) 03:48, 13 August 2006 (UTC)

Actually, if you want to be technical, it doesn't matter who pulls who, the Earth and the star would be hitting each other. Besides, the Earth was here first.

Where is "here"? In a universe with unknown boundaries filled with moving objects we have no fixed points of reference by which identify any one point, so identities such as "here" are completely arbitrary. Location in the cosmological context is entirely relative, so all one can really say is that two bodies — the Earth and Star X — are moving towards one another. – ClockworkSoul 07:33, 13 August 2006 (UTC)

Is this an Earth first argument?

I dont think any stars (or galaxies) are close enough to collide with the earth before it is absorbed when the sun entres the red giant stage. So no is the answer. Philc _T^E_C^I 10:29, 13 August 2006 (UTC)

You mean the ones we know of? The moment the Sun turn red giant is about 5 billion years away. Suppose a rogue star would travel at one millionth the speed of light (1000 km/h). It could then be 5 thousand lightyears away and still get here in time. At that distance it would have to be fairly sizeable for us to see it. So yes, it seems possible. DirkvdM 12:27, 13 August 2006 (UTC)

So that's the answer. When the Sun turns red giant, it will hit the Earth, but only very slowly. --Heron 12:50, 13 August 2006 (UTC)

The Sun will not absorb the Earth. So yes, it's possible that a star can hit the Earth. But the distance to even the nearest stars (besides the Sun) are huge, compared to the size of the stars, so it's extremely unlikely. --72.136.70.187 18:24, 13 August 2006 (UTC)

Sorry, my browser logged me out. --Bowlhover 18:26, 13 August 2006 (UTC)

Oh, thanks for that link, Bowlhover. I didn't realise that the Earth had an escape plan. --Heron 20:42, 13 August 2006 (UTC)

I've always liked the idea that you could sort of 'ride' a small body out of the solar system after the sun collapses, might be the only way a human being is ever going to get anywhere near another solar system, of course human beings will be lucky to last another thousand years, let alone 3.5 billion years, not to mention in about 3 billion years the Andromeda Galaxy is going to be knocking at our doorstep, and will probably wreak havoc on a galatic scale, spark massive changes in predicted orbits and so on, might give a small planetesimal on the outer edge of our solar system a chance to 'surf' the waves of gravitation right out into deep space. Of course within a few million years of the collision, the massive shifts in gravitation would begin to spark rapid star formation and collapse, and waves of radiation would probably fill the resultant galaxy, and I imagine whatever super massive black holes happened to be sitting in the center of such a galaxy would go into their active phase and start chewing up everything in sight, which gives our cold dark planetesimal another escape route. Since the outer arms of that galaxy would probably fragment and be blown off into even deeper space, and what's left of our galaxy would light up like a Quasar. And that's probably about 5 billion years right there, and there goes the neighborhood. Of course, the current Human population is about 6.534 billion, so chances are the Earth will dump us like a bad habit long before any of that stuff happens. So it really doesn't matter, but it's fun to think about.--71.247.125.144 16:40, 15 August 2006 (UTC)

If we really want to be remembered as a species, probably our best bet is to stick some recognizable feat of human civilization on as many Oort cloud objects as we can get to, maybe some sort of transmitter, or radioisotope, something to attract attention, while at the same time something that would be instantly recognized as not a natural phenomena. That way if it ever wandered into a stray galaxy some 80 or 90 billion years from now, someone might actually see it, of course that only works if by some fluke some debris from our galactic fender bender actually reaches another galaxy before the eventual heat death of the universe--71.247.125.144 16:40, 15 August 2006 (UTC)

Longest run on sentance, ever oooOooOoh--71.247.125.144 16:40, 15 August 2006 (UTC)

4G networking and application

Would someone plz tell me about the networking techniques involved in 4G mobile communication?

This question may be more appropriately posed at the Computing/IT Reference desk. --Lambiam^Talk 02:53, 13 August 2006 (UTC)

Animals with weird names

Are there any animals with weird names other than Proceratium_google, Goldenpalace.com_monkey, and Pachygnatha_zappa? Thanks! :) -Ravedave 05:57, 13 August 2006 (UTC)

Meh. It's gonna be a long list. But just cuz I don't have a date tonite, I think Homo erectus is a strange name, as are woodpecker, titmouse, and booby. Anchoress 06:00, 13 August 2006 (UTC)

axolotl - Nunh-huh 06:03, 13 August 2006 (UTC)

how about: [[1]] Adambrowne666 09:29, 13 August 2006 (UTC)

Also: atlascopcosaurus - I like your examples, though, Ravedave, I'd never heard of them Adambrowne666 09:33, 13 August 2006 (UTC)

Penis worm appeals to my inner teenager, as do bustards. I also like my boobies blue-footed. Henry^Flower 09:52, 13 August 2006 (UTC)

GoldenPalace.com Monkey: yikes, sponsored naming of a species? "This animal was brought to you by a casino?" What's next? Could you put your baby's name up for auction? Luckily my day is saved by the fact that the article speaks of 'pairs of titties' and even 'male titties'. :) DirkvdM 12:41, 13 August 2006 (UTC)

Would you care for some blue tits with your spotted dick ? (OK, that last one is more of a food, but I couldn't resist.) StuRat 08:52, 14 August 2006 (UTC)

• Just imagine what happens if they ever change their domain name--71.247.125.144 14:44, 13 August 2006 (UTC)

Does this count as weird: Stephen Nash's Titi Callicebus stephennashi? I remember reading an article about species that had been given weird names just for the humorous effect, which had quite a few examples. --Lambiam^Talk 17:39, 13 August 2006 (UTC)

Dracorex hogwartsia was named by children recently. Rmhermen 18:43, 13 August 2006 (UTC)

I think this must be the articlre mentioned above: http://www.nytimes.com/2005/02/20/weekinreview/20foun.html?ex=1266642000&en=072f74ff6a4493dd&ei=5088&partner=rssnyt I found it while googling for a mention I saw once of species names ending in tomii, dickii, and harrii, though it's not the article I was thinking of, it seems relevant. Malcolm Farmer 19:37, 13 August 2006 (UTC)

Supersaurus always struck me as funny. --Ginkgo100 ^{talk · contribs · e@} 22:10, 13 August 2006 (UTC)

Timber rattler= "Crotalus horridus horridus." Sounds like he made a bad impression on some naturalist. There is an extinct snake species named "Montypythonoides riversleighensis."Edison 17:42, 15 August 2006 (UTC)

For some reason, Scrotum humanum never really caught on. Still, as mentioned above, there are the everlasting favorites of elementary school biology, the tits and the boobies. —Ilmari Karonen (talk) 18:40, 15 August 2006 (UTC)

Anyone up for a crappie meal ? StuRat 19:37, 15 August 2006 (UTC)

I don't know why, but Felis cattus domesticus has always seems funny to me. Like they've just taken normal words and added "us"s. Aaadddaaammm 09:51, 16 August 2006 (UTC)

the doctors round mirrors

what are those round mirrors that were attached to a headband which doctors wore used for and do they have a name?

They were used for indirect laryngoscopy (before direct laryngoscopy became commonplace). Indirect laryngoscopy involved the use of a small laryngeal mirror (not unlike modern dental mirrors) that was inserted into the throat, in combination with the head mirror you speak of (used to illuminate the smaller mirror). If they had a name more specific than "head mirror", I don't know it. - - Nunh-huh 06:40, 13 August 2006 (UTC)

Just to make it a little more clear - the little mirrors that you normally see perched on their heads in pictures, when used, are swung around to cover their eye - there is a little hole in the center to see through. A light source was placed pointing at the mirror which reflected the light forward wherever they were looking (such as the mouth). Although some ENT doctors still use them, they have largely been supplanted by headlamps which perform the same purpose. InvictaHOG 00:04, 14 August 2006 (UTC)

Physics

Hello all. I'm studying for a test tomorrow, and this particular question has me stumped- i have bad notes, and the text book is even worse.

A box of mass 20 kg is dragged along a rough horizontal floor by means of a rope held at the angle of 30 degrees with the horizontal. The force of friction between the box and the floor is 50N. Uf the force exerted along the rope is 350 N, what is the net horizontal force on the box? What is the accelreation on the box?

I would like to know what formual to use, and what adjustments i would need to make. Thanks in advance.Cuban Cigar 08:53, 13 August 2006 (UTC)

• First you have to know how to how to break down the diagonal force into two forces: one would be vertical, and the other would be horizontal.
  • You can do it by trigonometry. You know one angle and the length of the diagonal of a right-angle triangle. You can calculate the horizontal using cos(30°)*350.
  • You can do it by using Pythagoras's theorem.
  • If you know that the height of an equilateral triangle is approximately (1.732/2) times the length of one of its sides, you can use that instead. An equilateral triangle has angles of 60°, so imagine one that's been cut in half. (The square root of 3 is approx. 1.732.)
• Next you have to know that two forces that act on the same object, but in opposite directions, cancel each other out. (Assuming the object doesn't spin or anything.) If the forces are in opposite directions but they don't equal each other, subtract the weaker force from the stronger force. That's the strength of the net force. The net force will be in the direction of the stronger force.
• Next you have to know that a Newton is a measure of force, which is mass (in kilograms) multiplied with acceleration (in metres per second squared).

Good luck. --Kjoonlee 09:47, 13 August 2006 (UTC)

I know some of this, but what really stumps me is the force between the object and the ground is 50N.

The friction (50 N) will counter the horizontal pull by its size of 50 N. So you should subtract it from cos(30°)*350. The results of that will be the net horizontal force acting on the box. :) --Kjoonlee 09:56, 13 August 2006 (UTC)

Well, to be honest, I *think* that's correct, but I'm not sure about the effects of friction. Will 50 N of friction really result in 50 N of horizontal force in resistance to the pull? Maybe I should read Friction. --Kjoonlee 10:02, 13 August 2006 (UTC)

Yes it will, because that's just what it means. The force of friction is by definition the force you have to overcome while dragging the object. If you exert a larger force, the object will accelerate. --Lambiam^Talk 17:50, 13 August 2006 (UTC)

50N will just be subtracted from the net force, it gives me the right answer. Thanks to everyone who helped.

How many atoms are there in a cell?

Aproximately... Thanks.

Please suitly emphazi, a human cell, an animal cell, a plant cell, a brain cell, a sex cell..... Benbread 11:06, 13 August 2006 (UTC)

A cellular tissue is composed mainly of water. Water molar mass is 18.02g/mol, which means that single molecula of water weights ${\frac {18.02g/mol}{6.02*10^{23}moleculae/mole}}=3*10^{-26}kg/molecula$.

"Typical cell mass 1 nanogram...", therefore signle cell has ${\frac {1*10^{-9}kg/cell}{3*10^{-26}kg/molecula}}=3.34*10^{16}moleculae/cell$.

Water molecula is composed of three atoms, so single cell has about $10^{17}$ atoms. Michagal 11:13, 13 August 2006 (UTC)

Thats more atoms in a cell than miles to the nearest star (not the sun) and back 250 times, and the same number as 20% of the grains of sand on the earth, or The worlds population multiplied by 2 million if random QI facts help you comprehend the magnitude of that number. Philc _T^E_C^I 11:23, 13 August 2006 (UTC)

What's with the "moleculae"? I've never heard that term before. Aaadddaaammm 09:54, 16 August 2006 (UTC)

Spaced out link

In answer to a question above, I made a link to a Dutch Wikipedia article, with a description that started with 'In', but the 'In' disappeared. Here's the format: [url|In ... bla bla]. This effect disappeared when I added a space, thus: [url| In ... bla bla]. Here are the real links (see source):

het donker zijn alle katjes grauw

In het donker zijn alle katjes grauw

Any idea what caused that? DirkvdM 11:52, 13 August 2006 (UTC)

wikisyntax? You don't put pipes (|) in external links, the link is separated from the description with a space (that's unambiguous since spaces do not appear in urls, they are rendered as '%20'). dab (ᛏ) 12:06, 13 August 2006 (UTC)

In an exolink you should not use a pipe but a space to separate the url from the text rendered:

In het donker zijn alle katjes grauw

(When you hover on your first link, you'll see that "|In" is taken to be part of the url.) Alternatively, use a wikilink like this:

In het donker zijn alle katjes grauw

--Lambiam^Talk 17:15, 13 August 2006 (UTC)

Silly me, I knew that. DirkvdM 10:16, 14 August 2006 (UTC)

Caffeine in breast milk

How long does it take for caffeine to enter breast milk after ingestion and/or how could one test for its possible impact in a breastfeeding baby? Is it possible a mother having one cup of tea could affect her baby soon after? We've googled this, but get contradictory answers. Thanks in advance. Adambrowne666 12:07, 13 August 2006 (UTC)

The half life of caffeine in humans is around 5-7 hours, but this is extended in pregnant women (18-20 hours), women on contraceptives (13 hours) and newborn babies (30 hours). caffeine is completely absorbed form the stomach within 45 minutes, and is widely distributed, which means is likely to be in breast milk. the test for caffeine in a newborn would be pretty drastic, i imagine a blood test or similar, but a test of the breast milk would be easier. i recommend reading caffeine, and talking to a doctor. Xcomradex 12:31, 13 August 2006 (UTC)

I would suggest that the mother gives up caffiene altogether (I would suggest this for most people) since like a lot of other drugs, the body becomes tolerant/dependant after a while and you receive no additional benefits from further drug use other than to achieve the same level arousal that a normal person has from day to day who does not use caffeine. --130.161.182.91 14:07, 13 August 2006 (UTC)

Why does the word 'addicted' change to tolerant/dependant when we're talking about legal drugs? DirkvdM 10:19, 14 August 2006 (UTC)

On the other hand, caffeine is used as a respiratory stimulant for newborn infants with apnea. The amount passed in breast milk is trivial and harmless. alteripse 18:21, 13 August 2006 (UTC)

Thank you! :blows kisses to alteripse:. Anchoress 20:02, 13 August 2006 (UTC)

It makes me feel all fuzzy inside when people read and/or quote text that I wrote. Thanks for making my hour! – ClockworkSoul 05:01, 14 August 2006 (UTC)

Thanks, all Adambrowne666 00:25, 15 August 2006 (UTC)

Anecdote re: speed of transfer from mother's digestive tract to her bloodstream to breast milk: a new mom went out to dinner at a restaurant and ate food containing a lot of ginger, garlic, and onion. Within an hour, she started to breast feed the baby, who was always a good feeder, but who screamed in outrage at the taste of the milk. Then tried to nurse again, baby screamed again. It was ok by the next day, but the mom kept apologizing to the baby all night. Or maybe the milk was still garlicky the next day but the baby had acquired the taste.Edison 17:56, 15 August 2006 (UTC)

Scientific Journal Access Through Wikipedia?

Is it possible for Wikipedia to subsribe to scientific journals (particularly review ones - since these aren't "original research") as an institution so that its member could improve it better? --130.161.182.91 14:03, 13 August 2006 (UTC)

• I doubt it, Journal Access is usually on the expensive side, and this is, for the most part, a non-for-profit site.. also usually Journal Access is usually authorized by either IP or passcode, since wikipedia can't provide an IP to it's users, and since a password would never remain private, I'm just not sure how it could be made to work. Besides, I have Journal Access through my university, and I assume I'm not the only one who does--71.247.125.144 14:41, 13 August 2006 (UTC)

I'm not sure how the access could be licensed to be distributed to editors, either. Would be nice though. --Ginkgo100 ^{talk · contribs · e@} 22:16, 13 August 2006 (UTC)

Note that WP:NOR only applies to people attempting to publish their own original research on Wikipedia. It's perfectly fine to cite original research that's already been published in a journal. Citing OR is good, including it is bad. —Keenan Pepper 00:55, 14 August 2006 (UTC)

If you are not already aware, there are many free full-text journals and collections of research papers avaiable on the web. A random selection of some of my collection of links about this:

http://citeseer.ist.psu.edu/

http://www.doaj.org/

http://cogprints.org/perl/search/simple

http://www.citebase.org/search

http://ideas.repec.org/search.html

http://www.publist.com/

My favourite site is Citeseer, which deals with a wide range of things. I do not know if there is a wikipedia list about free journals, but their ought to be. 81.104.12.50 21:00, 15 August 2006 (UTC)

Diesel

What products form after diesel has been burnt?

Combustion of hydrocarbons always yields carbon dioxide and water. Additives and incomplete combustion result in other products as well. Isopropyl 14:48, 13 August 2006 (UTC)

carbon dioxide, water, incomplete combustion (anything except a bright blue flame with no smoke) also leaves carbon and carbon monoxide. Philc _T^E_C^I 15:24, 13 August 2006 (UTC)

Assuming you are asking about the differences in combustion products versus gasoline engines, classic diesels engines produced a fair amount of soot, although modern diesels burn much more cleanly than their predecessors. StuRat 08:42, 14 August 2006 (UTC)

Common name for Gordionus violaceus

Does anyone know what is the common name for Gordionus violaceus?

I can't find a name for it, but if it helps, it Gordiona seem to be parasitic worms, and here is callasified as a horse hair worms. Philc _T^E_C^I 18:14, 13 August 2006 (UTC)

I doubt the species has a common name. We have an article on Nematomorpha. --Lambiam^Talk 20:36, 13 August 2006 (UTC)

Assuming that violaceus refers to the colour, you could try calling it the "Violet horse hair worm". --Lambiam^Talk 20:43, 13 August 2006 (UTC)

kineto baric force and biefeld brown question

I have heard of something called a kineto-baric force that can move things useing electric fields and produce pressure. apparently its similar to electrokinetics except it needs no conductor and can only push things i think. I dont understand physics so could someone explain it to me in simple terms. Also does anyone know if this is mainstream accepted as i can find no skeptical or sites disproving it. It doesnt seem like anti-gravity stuff though, just another method of electro-propulsion. here are the links

http://science.radioelectronics.biz/electrokinetics/electrokineticPropulsion.html

http://www.rexresearch.com/zinsser/zinsser.htm

http://jnaudin.free.fr/lifters/files/ElectrograviticsElectrokineticsValone.pdf this has a mention of its relation to electrokinetics

There is a section on this website http://www.seaspower.com/Movingbeyond-LaViolette.htm "Kineto-baric Field Propulsion. German scientist Rudolph Zinsser discovered that sawtooth electromagnetic waves could be made to push distant objects. He produced a radio tube circuit that transmitted 45 megahertz radio waves having a sharp rise and gradual fall. His experiments demonstrated that these waves could exert impulses of up to 104 to 105 dyne seconds, which is equivalent to the application of about 1 to 3 ounces of force for a period of one second. He found that this force could be generated with an amazingly low input power, the output-force–to–input-power ratio surpassing that of conventional propulsion methods by several powers of ten. His projections imply a thrust of 1350 pounds force per kilowatt."

Secondly could the biefeld brown effect move non conductive substances like plastic or stone if a means to cause the ion wind, or thrust could be produced on its surface?

Thank you for your time Robin research

"Kineto-baric force" seems to be a term unknown to physics (just did a tiny search), but this sounds rather like a more recent claim by Eugene Podkletnov. Be this as it may, if you read the talk pages at Wikipedia:WikiProject Physics-Wikipedia:WikiProject Pseudoscience you'll see that there has been quite a bit of unflattering discussion of several of the other topics discussed at some of the websites you cited. At least three of the four websites you mention can probably be safely regarded as "fringe-science"/cranky websites, as I would think should be fairly obvious:

1. rexresearch.com says that it promotes "suppressed/dormant/emerging science, inventions, technologies, experiments", which is a pretty good hint that stuff discussed there may not be mainstream :-/
2. seaspower.com says that "Space Energy Access Systems, Inc. (SEAS) is in the process of identifying and testing new technologies that claim to be over unity"; see perpetual motion machine for the meaning of "over-unity"; I hardly need add that proposals which would violate of the laws of thermodynamics are highly unlikely to belong to the canon of generally accepted mainstream science;
3. Paul LaViolette, the fellow mentioned in the page you cited, is a "UFO researcher"; Etheric stargate says that it promotes "Zodiac cryptogram and books and scientific discoveries of Paul LaViolette on interstellar communication, cosmology, mythology, ether physics," and Starburst Foundation claims "the closing of the last ice age our ancient ancestors endured one of the most lethal global catastrophes to have occurred in the course of human history."
4. jnaudin.free.fr says "Dear new explorers and experimenters, You are WELCOME in the JLN Labs web site dedicated to the search of Free-Energy solutions..."; note that "free-energy" as in "low to no-cost energy", especially alleged extraction of vacuum energy to do useful work, belongs to the "over-unity" fringe and is certainly far from the mainstream; note that this website has also promoted MEG, another putative over-unity device.

See also

1. Biefeld-Brown_effect-Reactionless drive-Lifter (ionic propulsion device)-John Hutchison-Teleforce-Free energy suppression (a conspiracy theory) and their talk pages (among others)
2. List of pseudoscientific theories#Physics
3. Crank dot (not often updated, but gives some idea of the amount of stuff which is "out there")

Summing up: it would be a serious mistake to assume that just because you can't find comments on weird topic X at a mainstream website like The National Academies (formerly the National Academy of Science), that X must be mainstream science! I would hope this commonsense principle would be obvious, but took the trouble to reply since it seems that it might not be.---CH 23:54, 14 August 2006 (UTC)

Why wet things are dark

Hi, why are they? Whenever I wet a napkin with a "clear" liquid - water - it darkens. Why on earth? Thanks! -- 88.91.136.190 18:09, 13 August 2006 (UTC)

Because water makes the lights go out, you silly. — [Mac Davis] (talk)

Assuming you have a flashlight or something ;-), probably because water refracts light, changing the frequency of reflected light? Anchoress 20:04, 13 August 2006 (UTC)

Read The Straight Dope's answer, then come back here if you need a second opinion. --Heron 20:24, 13 August 2006 (UTC)

I would like to know the Ph.D. thesis version. — [Mac Davis] (talk)

Here is a second opinion already: more light goes through (as you can see when you look through the wet cloth to a light source – the wet spots appear lighter), and therefore less is reflected. And that is because the light bounces less (not more). Third opinions, anyone? --Lambiam^Talk 20:30, 13 August 2006 (UTC)

The same thing is true of things that are wet while being opaque (e.g. wet paint), so I don't think it has anything to do with refraction. I always assumed that the chemical properties (or I guess colloidal properties) of the molecules of water that interact with the other material are less transparent to light, and thus appear darker.  freshofftheufoΓΛĿЌ  03:13, 14 August 2006 (UTC)

This was asked before, but those answers don't satisfy me. My explanation was that dry cloth scatters the reflected light because of all the tiny hairs on it. Those will get flattened (stick to the cloth) when wet, so the reflection is more directional. most of the time you will not look at the cloth in exactly that angle, so it appears darker. But I tested this and I didn't find the brighter reflection that should be there at the right angle, so I didn't dare give that answer. I'm being a little bolder this time. DirkvdM 11:30, 14 August 2006 (UTC)

This may be a stretch, but it's not completely off the wall. A lot of the color in textiles come from chemical dyes, which are subject to oxidation and reduction. Perhaps the presence of water induces a reduction reaction, dulling the dyes. Thus, when you get your cloth or paper wet, it becomes darker. This reaction is reversible, though... detergent operates by releasing an oxidizing agent to re-oxidize the dyes, hence so much commercial advertisement for "brighter colors" after washing. Nimur 16:43, 14 August 2006 (UTC)

Thanks for many, yet few answers. I do urge you to take into account the darkening of wet wood, so the thesises regarding dye can be ignored, or so I think. There was one answer here that appealed to me, the "first second" opinion. To my limited knowledge, one more easily sunburns when bathing. The question is just if that is caused from being wet, plus the limited depth of one's skin under water - or simply from the light bouncing off the water, and striking the body which is so very close. Now, whatever way one looks at this, LIGHT IS LOST. It may be absorbed by the wettened material at a greater rate than before... I really don't know the answer to this. Can Oxford be contacted? 88.91.136.190 18:07, 14 August 2006 (UTC)

Is sunburn increased when you are just wet? Or is it when you are in the water, thus getting a double-dose of UV as it gets reflected off the surfaces around you (similar to snow blindness)?  freshofftheufoΓΛĿЌ  18:46, 14 August 2006 (UTC)

I suspect that being wet makes you feel cool and thus stay in the sun longer. If dry, you would get hot and go indoors before getting sunburned. StuRat 20:48, 14 August 2006 (UTC)

Being wet doesn't make you sunburn faster. Being on or near water does, however.Anchoress 21:14, 14 August 2006 (UTC)

It's an interesting question. Also, why does a white bird feather go grey when you dip it in clear acohol? It has to do with the index of refraction of the materials that the light travels through, as well as on the arrangement of the molecules in the material, which can alter reflected or transmitted light according to the differing interfaces and the distances between them. Reflection depends on differences in index of refraction. When you change the air/material interface to a water/material interface then the difference in refractive indices decreases, so there is less scattered reflection of light. Structural colour (as opposed to pigment) effects will also alter as the diffraction of light changes, so that phenomena such as colour caused by constructive interference will change. On top of that, the light reflected from the molecules in the material has to pass throught a water/air interface back to your eye, which reflects some of it back into the material. In the end, yes, more light "stays inside" and less comes back at you, and the light that does return will have a different "wave composition" from when the material is wet. You can observe some of these physical effects if you change the "wetting agent" from say water to alcohol to colourless oil. To add to the above, pigments may change their light absorption properties when they "get wet". --Seejyb 21:40, 14 August 2006 (UTC)

The reason that you sunburn quicker in the water is because of the compression of light caused by the waves. You know when you see that moving pattern of sunlight on the bottom of a pool, where the waves compress/rarefact the light because of the shifting angles of incidence on the surface? These magnifications intensify UV and Infared light also, burning you faster. As for the paper towel, i think that in THAT case the color change is mostly due to the tiny fibers being flattened. --Classic1977 09:43, 6 September 2006

Questions about "self surgery".

Since our article is a bit devoid of the information I seek: What, exactly, are some useful methods for self surgery? Like, how to fix your own dislocated shoulder, or how to extract a foreign object from your abdomen, or how to treat an infection in the wilderness.

Actually, does Wikipedia have like...A WikiSurvival project or something similar, for questions much like this? --Abnerian 22:35, 13 August 2006 (UTC)

Any instructions that could make it easier for people to do something as blatantly hazardous as performing surgery on themselves would probably be a legal liability. But you might try googling 'wikisurvival' or something, it might exist elsewhere. And I'm sure there are lots of sites that feature survival first aid etc.Anchoress 22:38, 13 August 2006 (UTC)

One should be able to treat dislocation (medicine) without resort to surgery, but, as our article states: Such manipulation should not be attempted without sufficient training, as it is possible to greatly increase the severity of the injury through improper attempts at care. For a shoulder you will need extra training because you can't perform this in the usual way on yourself anyway. For surgery, it helps to have some insight into human anatomy. This is also true for self-surgery. Further useful stuff is some surgical instruments, including needles for sewing up afterwards (don't forget the surgical yarn), ways of sterilizing them, materials for making the neighbourhood of the incision antiseptic, materials for handling and stopping the flow of blood, and for bandaging. Roughly speaking, there are no methods that are specifically useful for self-surgery; the best methods are the same ones used for surgery in general, except that the patient must remain conscious, or else the surgeon too passes out. --Lambiam^Talk 23:37, 13 August 2006 (UTC)

For dislocation, you really need somebody else to do it for you while you scream in pain. — [Mac Davis] (talk)

Not for Jack Bauer. --mboverload@ 02:49, 14 August 2006 (UTC)

I once saw someone in a movie set his dislocated shoulder by wedging his arm between branches and then throwing his body away from that. Might work in principle, and if you're alone in a survival situation it might be worth a try because you'd be useless with a dislocated shoulder. The SAS survival handbook doesn't tell. It just says to put your foot in the patient's armpit and pull. I don't see anyone doing that to themselves. Then again, autofellatio seems to be possible, so who knows. :) DirkvdM 11:43, 14 August 2006 (UTC)

Oh, and my mother once dislocated her little toe, causing it to point sideways. The way she told this, she 'simply pushed it back'. DirkvdM 11:46, 14 August 2006 (UTC)

How to relax my over-exercised muscles without drinking alcohol?

I have ethical objections to alcohol as I've known three or four drinkers who have ruined theirs and other peoples lives because of it. Also its bad for your physical and mental health. However after taking a lot of exercise over the past few days my muscles are very tense and ache slightly. Is there anything else that I could eat or drink that would relax them please? I am not into massage. Thanks.

Maybe smoke something? It is normal, by the way, if your muscles feel tense after much exercise; it does not necessarily mean they are actually not relaxed. For some people a hot bath helps, although others report it aggrevates the condition. The best remedy is a couple of good nights of sleep. --Lambiam^Talk 23:42, 13 August 2006 (UTC)

Just rest. Sleep is probably the best, (and cheapest!). P.S.:(did I read "taking exercise" right? Do we need to have Exercise (drug)?) — [Mac Davis] (talk)

The expression 'to take exercise' is a turn of phrase common in the UK. Anchoress 00:31, 14 August 2006 (UTC)

Though I'd buy it if they sold it!  freshofftheufoΓΛĿЌ  03:01, 14 August 2006 (UTC)

Its like taking tea and scones albeit with a bit more sweat involved. Rockpocket 06:11, 14 August 2006 (UTC)

That may depend on the tea and scones. DirkvdM 11:59, 14 August 2006 (UTC)

Thanks for the alcohol-education. We didn't know that it can develop into a bad habit. But you finally got around to an actual question, so I'll give an answer to that. Meditation. What I do is lie down on bed and put a folded towel in my back (not too thick) and neck (getting that right takes practise because the sensation changes as you relax more). Then, first I tense up the muscles in my toes. Next, I very gradually let the tension move up to my ankles, legs, body, neck, and then down to my fingers, where I let it 'flow out of my body' (it actually feels like that). Then I focus on relaxing the muscles in my toes (this is a bit harder, but somehow the preparatory tensing helps) and then up again, through my body and out through my fingers. This whole process takes a minute or two. After that, my muscles are very relaxed and I can start meditating. Provided the towel in my neck doesn't feel wrong, as a result of which I have to rearrange it, which ruins the effect. The more experience you get with this, the better the effect will be. Same for the meditation itself. But that makes too much sense to point out. :) DirkvdM 11:56, 14 August 2006 (UTC)

Have you tried ibuprofen or naproxen?Tuckerekcut 21:03, 14 August 2006 (UTC)

You are most likely asking about delayed onset muscle soreness (DOMS). Incidence and severity reduced by a gradually increasing exercise regime, and by eating after exercise. Also by NSAIDs. Opioid analgesics reduce the soreness only for as long as they would work for any injury. Local rubs like methyl salicylate reduce the discomfort by couter-irritation, but recovery is not hastened. The natural course of DOMS is not reduced by massage, stretching, homeopathy, local heat or cold, or electrical stimulation. --Seejyb 22:03, 14 August 2006 (UTC)

Well answered, Seejyb. BenC7 02:15, 17 August 2006 (UTC)

Drink at least 20 oz of water after exercise; eat after exercise, especially protein, salt, and carbohydrates. Eat something like pasta with a chunks of steak on top, seasoned with salt. Use ice or a cold pack directly onto the sore muscles, followed by the high heat of a steamy shower. If you are not taking a multivitamin daily, start taking one. Do not rely on creams or expensive store bought products, this works just fine if you follow the above directions. I take Kyokushin Karate and have encountered many a sore muscle and tried many 'remidies'...the simpliest things always work, believe me. --69.138.61.168 03:51, 15 August 2006 (UTC)

Straight after exercise jump into icy water, it helps with the recovery process. Einstein's shadow 11:47, 17 August 2006 (UTC) (Copied from below by 68.100.203.44 05:45, 19 August 2006 (UTC).)