Science	Mathematics	Computing/IT	Humanities
Language	Entertainment	Miscellaneous	Archives

How to ask a question

Search first. It's quicker, because you can find the answer in our online encyclopedia instead of waiting for a volunteer to respond. Search Wikipedia using the searchbox. A web search could help too. Common questions about Wikipedia itself, such as how to cite Wikipedia and who owns Wikipedia, are answered in Wikipedia:FAQ.

Sign your question. Type ~~~~ at its end.
Be specific. Explain your question in detail if necessary, addressing exactly what you'd like answered. For information that changes from country to country (or from state to state), such as legal, fiscal or institutional matters, please specify the jurisdiction you're interested in.
Include both a title and a question. The title (top box) should specify the topic of your question. The complete details should be in the bottom box.

Do your own homework. If you need help with a specific part or concept of your homework, feel free to ask, but please don't post entire homework questions and expect us to give you the answers.

Be patient. Questions are answered by other users, and a user who can answer may not be reading the page immediately. A complete answer to your question may be developed over a period of up to seven days.

Do not include your e-mail address. Questions aren't normally answered by e-mail. Be aware that the content on Wikipedia is extensively copied to many websites; making your e-mail address public here may make it very public throughout the Internet.
Edit your question for more discussion. Click the [edit] link on right side of its header line. Please do not start multiple sections about the same topic.
Archived questions If you cannot find your question on the reference desks, please see the Archives.
Unanswered questions If you find that your question has been archived before being answered, you may copy your question from the Archives into a new section on the reference desk.
Do not request medical or legal advice.
Ask a doctor or lawyer instead.

After reading the above, you may
ask a new question by clicking here.
Your question will be added at the bottom of the page.

How to answer a question

Be thorough. Please provide as much of the answer as you are able to.
Be concise, not terse. Please write in a clear and easily understood manner. Keep your answer within the scope of the question as stated.

Link to articles which may have further information relevant to the question.
Be polite to users, especially ones new to Wikipedia. A little fun is fine, but don't be rude.
The reference desk is not a soapbox. Please avoid debating about politics, religion, or other sensitive issues.

January 26

Breed and race...?

Other than one being applied to dogs and the other being applied to humans what is the difference in the terms? -- Barringa 10:24, 26 January 2007 (UTC)[reply]

According to our breed article, a breed is a domesticated subspecies or infrasubspecies of an animal. By contrast, according to race, different races of humans are typically populations differentiated by some attributes (e.g. skin color) and not others (e.g. height) and are not identified as subspecies in the biological sense by scientists; it is disputed whether there is a substantial genetic basis for the common racial divisions or whether they are simply a social construct. See breed and race for more information. -- SCZenz 10:54, 26 January 2007 (UTC)[reply]

In other languages, such as French, there is a less strong distinction. I remember once being taking a back when an elderly French woman asked me what race of dog I had. --Cody.Pope 15:57, 26 January 2007 (UTC)[reply]

Landrace is often used for traditional crop varieties. But a breed isn't necessarily a subspecies - different breeds of dog or cat are certainly not subspecies. Guettarda 16:18, 26 January 2007 (UTC)[reply]

One simple difference is that dog breeds were created - and maintained - by strict inbreeding. This is how members of the same breed are so alike. Human races, while certainly inbred at some point due to evolutionary bottle necks, are rarely maintained in that way. Infact, human races are becoming more outbred with every generation. This is why members of the same race can look so different to each other (with perhaps some defining features, such as skin tone, in common). So, to stretch an analogy, these days almost all humans would be considered mongrel in dog-breeding terms. We simply divide ourselves into somewhat arbitrary groups ("races") based on certain artifactual characteristics, be it geo-political, cultural or physical. There probably are what we might consider relatively "pure-bred" humans in remote parts of the world. But even those are not inbred to anywhere near the same level as animal breeds. For humans races to be truly equivalent to animal breeds, we would need to go adopt techniques from the Master race philosophy, involving racial segregation and eugenics. That is generally not seen as a favourable course of events in human history. Rockpocket 23:20, 26 January 2007 (UTC)[reply]

What about in cases which some religious groups represent where inbreeding is a natural consequence resulting from the virtual exclusion of "outsiders." -- 71.100.10.48 04:11, 27 January 2007 (UTC)[reply]

There are certain groups that are more inbred (and I don't mean that in a pejorative manner) than others for religious, geographical or cultural reasons. Endogamy is common in Ashkenazi Jews and the Yazidi, for example. Although the level of consanguinity is high in some of these populations, it still doesn't match the level of inbreeding required to create a breed or strain of domesticated animal. To create true breeds, one needs to backcross or intercross through many generations. Its difficult to get good data on dogs, but we could use lab mice as an example. The guidelines for generating inbred mouse strains, first published in 1952, state:

"A strain shall be regarded as inbred when it has been mated brother-times-sister (hereafter called btimess) for twenty or more consecutive generations (F20), and can be traced to a single ancestral breeding pair in the 20th or a subsequent generation. Parent-times-offspring matings may be substituted for btimess matings provided that, in the case of consecutive parent-times-offspring matings, the mating in each case is to the younger of the two parents. Exceptionally, other breeding systems may be used, provided that the inbreeding coefficient achieved is at least equal to that at F20 (0.99)." [1]

Even in the most inbred human groups, its rare for people to reproduce with anyone more closely related than a first cousins (there are very good evolutionary reasons for this). Parent/offspring and brother/sister breeding is almost universally taboo and thus is rare. For humans to be as inbred as mouse strains we would need subsequent brothers and sisters pairs to reproduce through 20 generations.

Dog breeds are not quite so genetically inbred as mice strains - especially not these days. Rather than strict backcrossing, dog breeding uses phenotype selectivity in mating (which is a kind of proxy for kin mating). When dog breeds were created they were done so for a purpose in mind. If you wanted to breed a lapdog, you would specifically select the characteristics you want (small, timid) and mate the animal that had these characteristics, with another animal that had these characteristics (often a relative). Similar selections would be made over multiple generations, thus enriching for these characteristics. Humans obviously select mates, but we do not all select for the same criteria (i.e. we are not all turned on by the same thing) and we are also less attracted to those that are most similar to us (see Major histocompatibility complex for a possible mechanism for this). So even in populations that are highly inbred, there is a natural propensity for humans to "outbreed" as much as possible. This is because inbreeding reduces genetic diversity and, inevitably, leads to reduced fitness (which is why mongrels tend to live longer than purebred dogs). Hopefully, then, you can why even the most inbred human "races" are nowhere near as genetically and physically homogeneous as breeds of dog. Rockpocket 05:22, 27 January 2007 (UTC)[reply]

So then from what you are saying, in tems of longevity, Racial purity as a concept or direction may not necessarily be that good for the human race, using the consequences for pure bred canines as an example? -- Barringa 13:45, 27 January 2007 (UTC)[reply]

See heterosis/hybrid vigour. -- 我♥中國 19:41, 27 January 2007 (UTC)[reply]

I think that is a fair assumption. Obviously we can't do the controlled long term experiments to prove it in humans explicitly. But the observations we make from naturally inbred human populations, and what we know from animal models (and plant models) seems to support that. For example, there increased levels of certain genetic diseases (including cystic fibrosis) in certain Pakistani and Ashkenazi Jew communities due to the cultural propensity for consanguinous marriages (see Ashkenazi Jews#Population genetics). See also our article on the founder effect, which results from breeding from a restricted gene pool (with similar genetic consequences to inbreeding). Rockpocket 22:08, 27 January 2007 (UTC)[reply]

See also Clinic for Special Children which treats effects in the Amish population. Rmhermen 01:54, 31 January 2007 (UTC)[reply]

Help me identify this insect

In the past days a few of these critters have been found in my house flying around. I'm located on the North Shore of Sydney. Any help would be greatly appreciated as I've been dying to find out what they are! http://img224.imageshack.us/img224/7646/img1855rs6.jpg http://img262.imageshack.us/img262/327/img1857um2.jpg JSIN 14:04, 26 January 2007 (UTC)[reply]

Those same insects swarm in Vancouver, Canada during the summer. I've always wondered what they were, besides a darned nuisance, that is. Anchoress 15:23, 26 January 2007 (UTC)[reply]

That, I think, is a lacewing. I found a useful Aussie bug identification site. --jpgordon^∇∆∇∆ 15:48, 26 January 2007 (UTC) --jpgordon^∇∆∇∆ 15:47, 26 January 2007 (UTC)[reply]

Thanks a lot. JSIN 08:15, 27 January 2007 (UTC)[reply]

Classification by genome...?

Are living organisms yet classified by their genomes and if so or if not how would such a classification scheme work? -- 71.100.10.48 14:24, 26 January 2007 (UTC)[reply]

That's a big question. Some systems of classification depend solely on genomic information, others incorporate other information or depend on genetics only indirectly. For further reading, I'd suggest starting with our articles on taxonomy, alpha taxonomy, cladistics, molecular systematics, molecular phylogeny, and phylogenetic tree. TenOfAllTrades(talk) 15:26, 26 January 2007 (UTC)[reply]

Under molecular phylogeny I found DNA barcoding which looks like the most practical scheme so far. -- 71.100.10.48 15:54, 26 January 2007 (UTC)[reply]

Some organisms are only known because some of their genes have been isolated. Techniques such as PCR and shotgun sequencing can identify new organisms that have never before been recognized and they can be classified based on gene sequence information. Some microbes are very hard to grow in the lab and are minor species in the wild, making genomic methods the best way to learn about them. --JWSchmidt 01:41, 27 January 2007 (UTC)[reply]

what is the concept

can you tell me the concept behind how a paper plane flies and aslo what are the advantages of the plane mention in www.zurqui.com over the simple plane .and the advantages or dis advantages of each over the other212.72.2.182 15:05, 26 January 2007 (UTC)[reply]

The upward force is called "lift", see Lift (force) for details. Friday (talk) 15:47, 26 January 2007 (UTC)[reply]

Most paper planes use flat wings and are weighted or designed so as to provide a slight upward tilt to the wing while flying. When you throw the plane, you are forcing a wedge through the air, literally pushing the air below the wing down, which provides "lift" from the bottom. In contrast, most airplanes use [airfoil] shaped wings, which lower the pressure of the air above the wings, thus "lifting" the wing from above via suction. Droud 05:28, 27 January 2007 (UTC)[reply]

please can you give me more details62.231.249.115 13:27, 27 January 2007 (UTC)[reply]

running and human body structure

What is the current research connecting running and the development of the human skeletal structure?

I recall reading something about it being highly efficient: the leg is structured in such a way that taking a step down stores a large proportion of the energy that would otherwise be directed into the ground, which can then be released on the way up. Vranak

I thought it wasn't efficient compared to many animals? --Wirbelwindヴィルヴェルヴィント (talk) 22:22, 26 January 2007 (UTC)[reply]

I can't figure out how the leg could store energy, is that really what you meant, Vranak? As to the specific question, scholar.google.com turned up some promising results, including this. Friday (talk) 22:29, 26 January 2007 (UTC)[reply]

Can't find any backing info on Wikipedia; have a look at Biped#humans for some hypotheses on why the human skeletal structure may have evolved to accomodate upright running. Vranak

Memory Systems

I'm aware of only a few effective, flexible memory techniques:

Association Systems

Associating visually via bizarre images
Associating verbally via bizarre sentences
Recoding nonphysical things as objects, followed by one of the above

Method of Loci/Memory Palace
Mnemonics

First-letter reminders

Acronyms
Nonsense or near-nonsense sentences (Please Excuse My Dear Aunt Sally, etc)

Verse
Endless Repetition
If content meaningful, finding logic and pattern
Writing it down

All of these, however, were discovered a long time ago. Has anything been worked out more recently that builds on or can replace them? Black Carrot 19:15, 26 January 2007 (UTC)[reply]

Well, there are stranger associations, like smells that trigger seemingly unrelated memories. Any of the senses can do this. When the memory is traumatic, such a trigger can cause a panic attack. StuRat 20:19, 26 January 2007 (UTC)[reply]

See Mnemonic which in turn provides links to a number of articles. The method of loci gave rise to a system used by memory performers, which is to have a well learned set of concrete memmory hooks in an ordered list. As a quick example, to remember 10 things, and be able to recite them first to last, last to first, every other one, etc, the rhyme "1 is a bun, 2 is a shoe, 3 is a tree, 4 is a door, 5 is a hive, 6 is sticks, 7 is heaven, 8 is a gate, 9 is a lion, 10 is a hen" is easily learned. Then you can make a vivid action association between each of 10 persons, object, appointments, grocery items or whatever with the hook for that place. If you have a 10 item shopping list for the grocery store, and item number 2 is cheese, then picture a shoe full of cheese, a shoe made of cheese, or some vivid image, the more action oriented or bizarre the better. An ordered list of 10 is good, but it is almost as easy to do a 26 memory hook list, where A is ape, B is bus, on through Z is Zebra, and remembering 26 items in order is fairly impressive. Professional performers will have a 500 hook list. For memorization, repetition is pretty ineffective, since the mind is conservative and slow to learn new material. It is essential to force the production of the material, by attempting to recite it, so that the gaps are evident.Overlearning is essential to recall under pressure. Spaced practice is needed for long term retention, because somehow overnight the short-term memories become more durable. See "The Memory Book: The Classic Guide to Improving Your Memory at Work, at School, and at Play" (Paperback) by Harry Lorayne, Jerry Lucas (1996) available at Amazon.com and amaze your friends, remember phone numbers, lock combinations, and passwords. But there are still people who are apparently born with amazing natural mnemonic ability. A friend told of a professor who was such a mneonist where he went to college. The prof had a class most freshmen took. He asked each on day 1 to state their name, their high school, and the nickname of the athletic team. He did not see him again until he was a senior, when he encountered the prof on the quad, and the prof greeted him by name and asked him "How are the Bulldogs doing this year ?" (That being the name of his schools football team). Edison 22:47, 26 January 2007 (UTC)[reply]

I've already read all the Wikipedia articles I can find on the subject, and I've had The Memory Book since I was a kid. Good book. Most of the stuff you describe falls squarely into the Association System category, which was developed to its current peak decades ago. Do you know of any new discoveries? Black Carrot 18:52, 27 January 2007 (UTC)[reply]

A techophile has devised a great memory aid: He records everything he sees, hears, or says with glasses mounted camera and microphone and a high capacity storage device, then uses artificial intelligence to index it.(Sorry, forgot his name). Another new discovery in memory is an Autistic savant named Daniel Tammet who was featured on 60 Minutes yesterday. He can store and retrieve 22,514 digits of pi and do amazing calculations and storage and retrieval feats. He is articulate and can describe the visual waysynesthesia by which he does it. He was also able to learn good Iceandicin one week, as an experiment, He has written a book called "Born On A Blue Day: Inside the Extraordinary Mind of an Autistic Savant." Perhaps you might derive some insights in memory from his writings or the language cources he offers. Edison 22:27, 29 January 2007 (UTC)[reply]

Now that's something I've never heard of. I'll see if I can get hold of his book. Thank you very much. If anybody else has ideas, the question's still open. Black Carrot 04:23, 30 January 2007 (UTC)[reply]

Oxidation state

What is the average oxidation number ) of Cr in (NH₄)₂Cr₂O₇? 72.140.201.32 22:57, 26 January 2007 (UTC)[reply]

What is the typical charge on NH₄? How about ionic oxygen? Given that the total charge on the molecule is zero, do the arithmetic to figure out what the charge on chromium has to be to balance the others. DMacks 23:00, 26 January 2007 (UTC)[reply]

The compound is called ammonium dichromate - the article on chromate will give you the answer.83.100.132.60 23:30, 26 January 2007 (UTC)[reply]

Thank you both for your help. 72.140.201.32 23:53, 26 January 2007 (UTC)[reply]

Beta emitter capacitor(?) power and voltage...?

-- 71.100.10.48 23:41, 26 January 2007 (UTC)[reply]

Atomic Battery? Droud 05:44, 27 January 2007 (UTC)[reply]

Is this homework? --Cody.Pope 07:22, 27 January 2007 (UTC)[reply]

No. She just said that when I'm smart enought to answer this question then I can be the teacher. 71.100.10.48 12:46, 27 January 2007 (UTC)[reply]

Well, it isn't a capacitor, in the first place. But the problem is rather easy. I assume that the large size is so that you don't have to worry about solid angle considerations, and thus can just assume an infinite anode size. In that case (we are talking about Beta-'s, not Beta+'s, right?), it is a rather simple problem, but you have to make assumptions about the sources. I would suggest assuming that the source has a single beta- decay of energy E and an activity A. The only thing I'm not sure about is what happens at the air-anode junction, especially for electrons at a high angle of incidence. --Philosophus ^T 20:02, 27 January 2007 (UTC)[reply]

The "air" gap could be a vacumn but unless a Supercapacitor material would support it then it could not likely be made into a practical device. I think the distance between the plates can be optimized too. 71.100.10.48 22:56, 27 January 2007 (UTC)[reply]

January 27

Gas laws

Why does the temoerature of a fixed mass of gas increase if the pressure is increased?

The total kinetic energy of the gas stays the same, so by decreasing the volume of the gas you are concentrating the energy, resulting in a temperature increase. Droud 05:41, 27 January 2007 (UTC)[reply]

Sorry to disagree with Droud, but I think this explanation is incorrect. If you decrease the volume of a container of gas while keeping its total kinetic energy the same (by allowing it to exchange heat with its surroundings) then the average kinetic energy per molecule is unchanged, so the temperature of the gas is unchanged (the "concentration" of the energy in a smaller volume is irrelevant to temperature). However, the pressure of the gas increases because the molecules are colliding with the walls of the container more frequently, as they are confined to a smaller volume. See the calculations in kinetic theory of gases. If, on the other hand, you decrease the volume of the container while preventing the gas from exchanging heat with its surroundings, then you increase its total kinetic energy because of the work you are doing to move the walls of the container against the gas pressure, so the temperature and pressure of the gas both increase - see adiabatic process. Gandalf61 09:49, 27 January 2007 (UTC)[reply]

At fixed volume and number of particles, the higher the temperature, the faster the particles move and collide with the walls, the higher the pressure exerted. In fact, the pressure is proportional to the absolute temperature. See Gay-Lussac's law. --Spoon! 05:50, 27 January 2007 (UTC)[reply]

Correct. Temperature is a function of the average kinetic energy of a gas. Increasing the temperature increases their speed so that they smash into the walls of their container more violently. --Soulscanner 01:40, 28 January 2007 (UTC)[reply]

Reporter Gene vs Selection Gene - Accepted distinction?

In a journal article I'm reading, a distinction is made between a "reporter gene", lacZ, used to produce a measurable indicator of gene expression and a "selection gene", HIS3, used to allow survival of only the cells that express the gene sufficiently. Until I read this, I had made no distinction, and would have referred to the HIS3 gene as a reporter gene. I'm asking, is such a distinction generally accepted? I've checked out the reporter gene article which implies no distinction but I'd like to be reassured. --Seans Potato Business 04:59, 27 January 2007 (UTC)[reply]

I guess one could argue the HIS3 "reports" its expression by the survival of the expressing cell. However, its not a very good "reporter" in that sense as its report lacks the information regarding the number of cells that doesn't express it (because they will be dead), and it also reports only a threshold of expression (alive or dead). In contrast, LacZ provides reports on both expressing an non-expressing cells, and can provide limited information on of the levels of expression. In contrast, LacZ could be considered a selection marker, but it doesn't do the selection itself (unlike HIS3), it only reports what needs to be selected. Therefore I would argue that there is a accepted distinction between the two, which this article makes clearer that I have. Rockpocket 05:37, 27 January 2007 (UTC)[reply]

In terms of the 'correctness' of the terminology, one can choose to make a distinction between a 'selection gene' and a 'reporter gene', or not. Selection genes can be described as a subset of reporter genes, but it is sometimes useful to treat them as distinct classes. This can be particularly handy when describing multiple transfections, where some have the purpose of selecting a specific population while others are used to report on gene expression levels through some sort of assay. TenOfAllTrades(talk) 05:46, 27 January 2007 (UTC)[reply]

The terms "reporter" and "selector" refer to how the genes are used. You could use LacZ as a selector, i.e. keep splitting cells until you only have blue ones. Generally, don't worry about the "proper" definition as long as you can understand what is being said.

Mikmd 20:41, 29 January 2007 (UTC)[reply]

Food Processing

If brown rice is better for you, why do companies go through all that processing trouble to make an inferior product (polished, white rice)? --Seans Potato Business 05:20, 27 January 2007 (UTC)[reply]

"White rice is the name given to milled rice which has had its husk, bran, and germ removed. This is done largely to prevent spoilage and to extend the storage life of the grain...." TenOfAllTrades(talk) 05:39, 27 January 2007 (UTC)[reply]

It shortens cooking time too, and increases the reliability of the finished product by reducing variability of cooking time and water requirement. Anchoress 05:42, 27 January 2007 (UTC)[reply]

Brown rice doesn't work for weddings. Droud 05:45, 27 January 2007 (UTC)[reply]

Our article on white rice says this:

While most of the nutrition is preserved by the milling process, many have relatively recently come to advocate brown rice or wild rice as a healthier alternative since the bran contains significant dietary fiber and the germ contains many vitamins and minerals (see whole grain). This is in contrast to the traditional view of brown rice, where it was associated with poverty and famine

If white rice was traditionally the choice pick for the upper classes, I'd have to assume it was for a good reason. It could be easier to digest, it could taste better, it could be a purer form of carbohydrate, though this is pure speculation. Vranak

The law of supply and demand: "Since the Atkins craze has subsided... one of the most common changes is eating brown rice instead of white, which has traditionally been the rice of choice in the United States." [2] Rockpocket 05:49, 27 January 2007 (UTC)[reply]

I'd wager the reason white rice is the preferred choice is elitism. Due to the extra milling involved, it's more labour intensive, and thus more expensive to produce. The richer households thus serve and eat white rice to show that they can afford it. Others then try to copy their "betters." Similar things happened in Europe with white flour and whole wheat flour. -- 18:10, 27 January 2007 (UTC)

That is correct! The upper-class in Japan pre-WWII ate only white rice and experienced a certain vitamin deficiency much more often than the rural class. X [Mαc Δαvιs] (How's my driving?) ❖ 20:39, 27 January 2007 (UTC)[reply]

I see. Well, thanks for the info! I've found that brown rice in a small box is only three eurocent more expensive per kilo than white rice in a big bag. I don't think I'll bother with the white stuff anymore. --Seans Potato Business 20:17, 28 January 2007 (UTC)[reply]

Rice: Cooking Time

The company that supplied my rice advises a cooking duration of 10 minutes. I've been extending that time to upto 30 or so minutes, having been exposed to the concept of fluffier, better rice. I think I've also noticed however, that after about three or four hours, I'm very much hungry again. Has extended boiling made the rice pass through the stomach stage of digestion more quickly? The rice article claims that 'rice porridge' is easier to digest. --Seans Potato Business 05:47, 27 January 2007 (UTC)[reply]

I don't know that easier to digest necessarily equals hungrier sooner, hunger doesn't elaborate but it says it is to do with glycogen in the liver, I certinally know i can eat some things that make me less hungry for longer without necessarily having to eat a lot of it. Before I gave it up I could eat a crap load of McDonalds and still be hungry two hours later, never thought that means it is easy to digest.. Vespine 02:56, 29 January 2007 (UTC)[reply]

Journal Article Collaboration

A journal article I have lists the contributors and their institutions. There are a few from Finland, one from the Netherlands, one from Autralia and one from the US. A large distance between contributors to a scientific paper is not an uncommon observation for me and I'm just wondering how it works. Do some of them travel to a common location and stay their for a while? Do some do some of the work and send their product to the next researcher so they can do their bit? How much does a person have to do to get their name included in the list of authors? What exactly goes on? --Seans Potato Business 06:16, 27 January 2007 (UTC)[reply]

Collaboration can be a complicated task: often the amount of contact depends on the nature of the science being practiced. For example, a bunch of particle physicists might meet at Fermi Lab or CERN for a particular experiment. However, sometimes the interaction is more tenuous, where a statistician, a physicist, and a chemist interact via only email for an entire paper. The only requirement to be listed on a paper is to sign a waiver that says "I have contributed a significant amount to the scientific process of this study". --Cody.Pope 07:19, 27 January 2007 (UTC)[reply]

Labs on different sides of the world may work on different aspects of a problem, communicating my email and telephone and occasionally sending material between them. I share authorship on some papers with individuals I have never met in person. One lab in Australia was working on bioinformatics analyses, another in Puerto Rico was collecting clinical data from patients and my lab, in Scotland, was using an animal model of the same disease. In the end the principle investigators collated the data and wrote the paper. The individuals listed on the paper all contributed either intellectually (by thinking up the experiments) or practically (by doing the experiments). Rockpocket 08:06, 27 January 2007 (UTC)[reply]

Sometimes the collaborators listed have actually very little impact on the published work, but control some resource that was invaluable. For example, a scientist I know is commonly a listed author solely because his lab developed a knockout mouse that is used by the experimenters of other groups around the globe; he's listed as an author, but did none of the experiments in the paper... -- Scientizzle 20:18, 27 January 2007 (UTC)[reply]

In the event that one of those experiments turns out to be a sham, are all the people listed as authors held responsible? I don't suppose there are many result-faking scientists: I only know of that Korean stem-cell guy. Just wondering... --Seans Potato Business 20:22, 28 January 2007 (UTC)[reply]

You can read our article on scientific misconduct for more about that. The bottom line is that there are result-faking scientists, but they are in a tiny minority. Co-authors do hold some responsibility if one of them are shown to have committed misconduct. Investigations will follow into exactly who knew what and when. However, there is obviously a level of trust involved when working with distant collaborators. As with most things it is rarely black and white. There is usually a grey area between co-authors being completely unaware of fraud, and being guilty of not being rigorous enough in questioning the results of their co-authors. You can understand how that happens, especially when the co-worker is well respected and providing amazing results that you want to believe ((such as in the Hwang Woo-suk case). See what happened to Gerald Schatten, for example. Rockpocket 21:14, 28 January 2007 (UTC)[reply]

In the field I am working in, theoretical physics, collaboration over distance is not such a big deal and quite common. As we mainly work with pencil and paper or with computer calculation, this stuff is easily to share via e-mail.The most common thing to happen is that a couple of people meet on a conference, have a stimulating discussion during the coffee break which results in a good idea, and then they decide to try to work out the details back home. There is even conferences with only few formal talks, mainly aimed at providing time for such informal discussions. Also, scientists move quite a lot, especially post-docs typically only get eployed for one, two or three years and then move on to another city. This is annoying but provides them with a network of contacts the world over. To keep up these contacts, e-mail and phone helps to continue to work together. Physicists like to stand together in front of black-boards and scribble calculations onto it. As this is difficult to do by phone, some collegues of mine like to point their webcam to the blackboard in their office, their collegue somewhere else does the same, and then they discuss using Skype. Simon A. 10:09, 28 January 2007 (UTC)[reply]

Thanks for the insight! --Seans Potato Business 20:22, 28 January 2007 (UTC)[reply]

transformers?

if the output voltage is coming out to be a lot less than that suggested by the turns ratio, what could be the possible reason?

59.180.32.227 07:40, 27 January 2007 (UTC)[reply]

Measure the primary voltage when the transformer is attached. Is the ratio still off? --Tbeatty 08:10, 27 January 2007 (UTC)[reply]

The most likely reason is that you're drawing more current (more power) than the transformer can supply. Is it getting hot? Does the undervoltage condition persist when you disconnect the load? —Steve Summit (talk) 13:30, 27 January 2007 (UTC)[reply]

Both of Summit's questions are good ones. My experience years ago was that small transformers for electronic devices were designed to supply the stated voltage (say 120v ac stepped down to 12 v ac when they are loaded to the stated power level. If the hypothetical transformer says it supplies 5 amps at 12 volts, then when if supplied with 120 volts and loaded to 5 amps it would supply 12 volts. If it were connected to 120 v ac and there were no load, such a transformer might have more than 12 volts output. It seemed that the manufacturer of such a transformer adjusted the turns ratio to give a slightly high no-load voltage so as to ensure rated voltage at rated current. A transformer has an impedance, consisting of the losses in the core and the resistance of the windings. I don't know offhand what that is for such small consumer transformers, but if it were 5%, then at full rated load the output voltage would drop 5 %. With utility transformers, there is no such correction. They might be designed to step down 7200 volts phase to ground in a nominal 12 kv (actually 12470) volt 3 phase system, to 240 volts center tapped to provide 120-240 volts to the customer. With no load, and 7200 volts on the primary winding, it would have a turns ratio of 7200/240 or 30:1, and the no load voltage would be 240. Again, at full load (say 50KVA) the output voltage would drop by the percent impedance. There are usually primary taps which can be selected to provide higher voltage under load, at the cost of higher no-load voltage. Or maybe your transformer is defective or overloaded. A shorted turn would cause excess current, low voltage and might cause it to burn up. This could be detected by measuring the current to the transformer when it has no load, and comparing it to another similar good transformer. A turn to turn short would cause it to draw much more exciting current when it had no load. Edison 17:14, 27 January 2007 (UTC)[reply]

This is pretty obvious, but there could be an immense amount of resistance. Rya Min 05:56, 28 January 2007 (UTC)[reply]

As others have suggested, maybe some of the input power is being converted to heat. One possible mechanism is eddy currents. Cardamon 09:38, 28 January 2007 (UTC)[reply]

podletknov gravity experiments

I have read an article recently about a scientist who claims that he has stopped a portion of gravity and invented a beam that can act like super gravity and put immense pressures on objects. does anyone know about this subject and can answer me some questions on it. Firstly with the gravity beam gun, is he getting the effects that he describes [immense pressures] and claiming it is gravity and the scientific community says it cant be that, or is he not getting anything and just claiming that he is and they are saying that he cannot be getting what he is getting? secondly is there any possibliltythat these experiments could be real effects, though not caused my manipulation of gravity [ immense pressure by em force or somthing]? thanks
curious bystander — Preceding unsigned comment added by 80.41.53.197 (talk • contribs) 12:48, 27 January 2007 (UTC)[reply]

It certainly reeks of pseudoscience (or perhaps more accurately pathological science). Our article on Eugene Podkletnov has quite a bit of information. —Steve Summit (talk) 13:26, 27 January 2007 (UTC)[reply]

Chemistry

Anyone, pls help me with this question. I have been stuck with it for a long time. Thanks a million.

A household cleaner contains ammonia.A 25.37g sample of the cleaner is dissolved in water and made up to 250cm^3. A 25.0cm^3 portion of this solution requires 37.30cm^3 of 0.360M sulphuric acid for neutralization. What is the percentage by mass of ammonia in the cleaner? Ans: 18%

THANK YOU SO MUCH.

It may help if you start by working backwards.

Write out the equation for the reaction between aqueous ammonia and sulfuric acid. How many moles of each are involved?
Given 37.30 cm³ (37.30 mL) of 0.360 M (0.360 mol/L) sulfuric acid, how many moles of sulfuric acid are present, and how many moles of ammonia were required for the neutralization?
What mass of ammonia is this, then, in your 25.0 mL?

Hopefully this should put you on the right track. TenOfAllTrades(talk) 15:05, 27 January 2007 (UTC)[reply]

State of the Universe prior to the Big bang...?

If the state of the Universe prior to the Big bang was at a temperature below that of Superconductivity regardless of the small amount of space it occupied and then gained enough temperature to loose Superconductivity or acquired some other parameter that would amount to the same thing then could this be the trigger for the Big Bang? 71.100.10.48 15:18, 27 January 2007 (UTC)[reply]

Hmmm... as I understand it, it is generally accepted that "prior" to the Big Bang there was nothing, since even time was created at that point. --Taraborn 15:25, 27 January 2007 (UTC)[reply]

Time isn't a real substance, so it can't be created, and it can't be absent in the first place, despite what you may have learned from TNG. Vranak

Stephen_Hawking would disagree with Vranak and agree with Taraborn--inks ^T 21:17, 27 January 2007 (UTC)[reply]

Well I've heard about all sorts of exotic particles being created in CERN and so on, but has any team of scientists created something they've called 'time'? If so, what were its properties? Vranak

To realy understand this, you'd need a course in Tensor Calculus. The point is that the amount of energy present at the big bang was so high that time and space become meaningless (i.e. impossible to quantify) --Soulscanner 01:45, 28 January 2007 (UTC)[reply]

I guess. There must be a vast divide between philosophical interpretations of 'time', and 'time' as understood in a Tensor Calculus course. So much so that the only similarity between the two is phonetical. Vranak

I've heard it put, rather neatly, that asking what was before the big bang is like asking what is north of the North Pole. Of course, it also depends on which astrophysicist you ask. Maelin (Talk | Contribs) 05:26, 29 January 2007 (UTC)[reply]

Not even "space". —LestatdeLioncour t 16:30, 27 January 2007 (UTC)[reply]

This is rather silly guys :) Of course there was spacetime and a universe (otherwise where did it come from hmm?). The Big Bang was a moment in time where spacetime and the universe just started getting bigger all of a sudden, and really fast. ~~Temperature is a measure of kinetic energy. Conservation of energy. Same overall temperature. Q.E.D.~~ Also note that not all materials have the ability of superconduction. (strikethrough, I wasn't thinking) X [Mαc Δαvιs] (How's my driving?) ❖ 20:33, 27 January 2007 (UTC)[reply]

We have a pretty good handle on what the universe was like from the first fraction of a second after the big bang. But if you go early enough, and approach the moment of the big bang, we don't really have any idea. There are ideas like eternal inflation and cosmological natural selection that make our universe's big bang only one of many, or the Big Bounce which says there was another universe right before ours. -- SCZenz 21:35, 27 January 2007 (UTC)[reply]

But you have to admit the possibility of other forms of energy suspension in light of the fact of a suspended magnetic field at near absolute zero... 71.100.10.48 23:05, 27 January 2007 (UTC)[reply]

Since energy is proportional to mass, at 0K there is no energy and therefore no mass:) Below this there would be negative energy and negative mass:) If the universe was at absolute zero at the exact time of the big bang, there would have been equal amouts of matter and antimatter, which was entirely replaced by matter as the universe started to heat up (heat travels at a finite speed, so this would take some time):) However I am not the universe, so I could easily be wrong:(Hidden secret 7 11:17, 28 January 2007 (UTC)[reply]

So mass and energy decrease as the temperature goes lower... interesting. 71.100.10.48 05:17, 29 January 2007 (UTC)[reply]

Please be more careful in your speculation. The word "energy" in particular is highly overloaded (rest energy, free energy, internal energy, etc.), and while such a thing as negative temperature exists, it is not at all how you suggest. Further, antimatter does not have negative mass or negative energy as you imply it does if it "balanced" the normal matter. Moreover, while absolute zero is not practically achievable, there is nothing wrong with a system at 0K with non-zero mass; energy that is not available for interchange does not count when considering temperature. (Note that a charged car battery need not be any warmer than the same battery discharged.) --Tardis 21:33, 29 January 2007 (UTC)[reply]

The biggest problem with this question is that it runs the fine line between physics and philosophy. A scientific answer is probably best described as, "there is nothing before the big bang." A philosophical approach can go on in more detail. Things like "time" and "before" start to lose scientific precision in this case. I would sum it up as, "The big bang is not a single event, but it's the entire process of the early universe's expansion." In this case, there isn't something "before" the bang. It's just the ongoing process of early coalescing of our reality out of ... something that is less intelligible. Forces and matter and energy sort of form up into a sensible, "normal" form. Prior to that, "something" exists, but it's difficult and/or impossible to describe, from a scientific standpoint. Nimur 22:44, 30 January 2007 (UTC)[reply]

what should we do to free our planet from terrorism a short note

If you're interested, this discussion is excellent to read, which cites Universal patterns underlying ongoing wars and terrorism and The Mathematical Structure of Terrorism. Foreign Affairs [3] would be excellent for this subject to research, and the Council on Foreign Relations [4] has a few great things as well! "Here Is the Way to Counter Palestinian Terrorism," and "The Challenge of Terrorism." X [Mαc Δαvιs] (How's my driving?) ❖ 20:24, 27 January 2007 (UTC)[reply]

My other planet is made of meat

This barely qualifies as a science question, but what would happen if we got a quantity of dogs the same mass as the Earth and set them orbiting the Sun at the same speed and distance as the Earth? I assume that it would be crushed into a sphere under its own gravity... would the blood and the air that was in the dogs' lungs be forced to the surface? Would the centre get hot? Would it stratify into bones, hair, flesh etc, and how long would it take for these things to become unrecognisable, or would that be so rapid as to be neglegible? Would the substances react with each other under the pressure into something like rocks? Would the bacteria survive and evolve? What would it be like after 4.57 billion years? Are these questions answerable? Vitriol 16:31, 27 January 2007 (UTC)[reply]

We would be able to get lots of oil from it, if we left it long enough:) It would become a sphere, as it's gravity would be the same as the earths:) Bacteria nearer the surface would be likely to survive as some bacteria can live in almost any conditions:(Hidden secret 7 20:55, 27 January 2007 (UTC)[reply]

Where would we get that many dogs from, or that many of any animal, as they wouldn't all fit on the sufrace of the earth:) And I doubt people would like you doing that, there would be a lot of protests &c:]Hidden secret 7 20:57, 27 January 2007 (UTC)[reply]

Exactly... if the dogs are the same mass of the earth, does that mean that we tranformed the Earth into a quantity of dogs? Or did we create the dogs out of interstellar dust and so on? At any rate the one thing that springs to mind is that this planet would be a disgusting mess for a very long time. Vranak

Maybe God used dog cadavers to do it? X [Mαc Δαvιs] (How's my driving?) ❖ 21:04, 27 January 2007 (UTC)[reply]

The dog world would be a flea heaven...Mikmd

I'm no chemist or geologist or dog scientist but I think what would happen is the dogs would coalesce into one huge ball and under the immense gravity the individual elements of the dogs would migrate toward either the surface or the core depending on their densities. Since a dog is primarily carbon, oxygen, hydrogen, nitrogen with only some trace elements, the new planet would essentially be a huge ball of carbon with a tiny metallic core, with an atmosphere of nitrogen, oxygen and hydrogen (therefore also dihydrogen monoxide, an extremely toxic substance). It might also have a diamond core, but I don't know if the pressure near the core would be enough for the carbon to become diamond... hmm, I can just envision that a million years into the future the universe's source of diamonds would be... dog planets. There would probably be no advanced life on that planet, just a huge blob of coal... or diamond. Not sure about bacteria, but some photosynthetic bacteria might survive. -- 我♥中國 21:15, 27 January 2007 (UTC)[reply]

Damn! I want to do this experiment now!! X [Mαc Δαvιs] (How's my driving?) ❖ 21:33, 27 January 2007 (UTC)[reply]

Diamond is a metastable state of carbon that requires an unusual combination of high pressure and low temperature to form. It isn't clear exactly how or why they form in the Earth's crust. Either way, I don't think these disgusting dog planets would be a particularly abundant source of diamond :) --bmk

Damn that dihydrogen monoxide! Chickenflicker---♣ 22:09, 27 January 2007 (UTC)[reply]

It is the most dangerous of the monoxides... DHMO --66.195.232.121 15:25, 29 January 2007 (UTC)[reply]

This thread is reminding me irresistably of dogs in meat. (See also the denouement here.) —Steve Summit (talk) 21:56, 27 January 2007 (UTC)[reply]

I like this question, an opportunity to speculate wildly! To start with the dogs are a lot less dense than the earth even if you pack them in quite tightly (densities <1000 and 5500 kg/m^3. The dogs will collapse to a sphere. This will be a sphere that is larger than the earth but still quite a lot smaller than whatever shape they were in to start with so a fair amount of energy will be released heating up the new planet a bit (the exact amount could be calculated if you know how densely packed your dogs were to start with). No dogs should survive the fall (or the crushing) which will be very messy! I assume that plenty of bacteria will survive and so on the surface initially they will have all the air in the dogs' lungs and a ready supply of dead organic matter to live off so you will get plenty of mouldly dogs. Deeper down the air should all get squeezed out of the dogs and gradually make its way upwards. I think it would take a long time for all the air to make its way out though, so presumably you would get great vents of dog breath coming out of the surface as the planet gradually settled down. Also:

The dog world will not end up with much of an iron core due to the lack of metals in dogs (or are they all wearing chains?) and so will not develop a magnetic field.
Dog world won't rotate unless your initial dog mass was spinning so you'll probably get 1 very hot side and 1 colder side.
Dogs are not made of particularly radioactive stuff so I think that dog earth will not heat itself very much but there will probably be a lot of carbon dioxide going around in the atmosphere after a while so there may be a decent greenhouse effect, probably enough to kill off all the bacteria
The escape velocity of dog world will be lower than that of Earth but not that much lower so it should hang on to some atmosphere but certainly not all of the air that was in the dogs' lungs to begin with.
There's a lot of water in dogs so potentially there could be very large oceans covering the entire planet to quite a depth
I'm sure that there woud be massive amounts of oil in a few million years time. JMiall 23:35, 27 January 2007 (UTC)[reply]

Now wouldn't escape velocity_dogworld be the same since the force of gravity is the same? X [Mαc Δαvιs] (How's my driving?) ❖ 00:24, 28 January 2007 (UTC)[reply]

If we assume that dogworld is less dense than earth but the same mass then the escape velocity at the surface will be less. JMiall 01:11, 28 January 2007 (UTC)[reply]

Sort of related: would it be economically and efficiently feasible to, say, launch animal remains onto high-pressure planets? Would said animal remains actually turn into oil, as HS7 claimed? --Wooty Woot? contribs 01:33, 28 January 2007 (UTC)[reply]

Dude, if we're able to dump dead animals on hostile planets and retrieve them again, I doubt we'd be using oil. Vitriol 04:28, 28 January 2007 (UTC)[reply]

No, it would decrease the biomass. --V. Szabolcs 11:02, 28 January 2007 (UTC)[reply]

The dogs wouldn't go mouldy unless there was already mould living on them, and some bacteria can survive temperatures of hundreds of degrees, and could evolve into more complex creatures over a long period of time:) Then we could make another planet out of these creatures, and so on..:]Hidden secret 7 11:23, 28 January 2007 (UTC)[reply]

Acid Into Water

I've always been told that you should pour acid into water, not water into acid. Why is that? I've heard acid can burst into flames if you pour water into it, but someone else I know said that's stupid. Black Carrot 18:56, 27 January 2007 (UTC)[reply]

You pour acid into water instead of anything into a container full of acid so the acid doesn't splash on you if you aren't careful in pouring, which can always happen. Safety, always. X [Mαc Δαvιs] (How's my driving?) ❖ 20:29, 27 January 2007 (UTC)[reply]

No, it's more specific (and more interesting) than that. When you dilute a strong acid, you actually set up an exothermic and potentially vigorous reaction. If you have a lot of water and a little acid, there's not so much heat liberated, and a lot of water to absorb the heat. But if you have a lot of acid and a little water, the amount of heat released can actually be sufficient to boil some of the water, spitting droplets of acid out of the beaker you're doing it in, or liberating fine mists of acid which you can then inhale. "Acid to water, is what you otter." See our Sulfuric acid article (especially the Reaction with water and Laboratory hazards sections) for more explanations. —Steve Summit (talk) 21:21, 27 January 2007 (UTC)[reply]

Ah, thank you. Interesting! X [Mαc Δαvιs] (How's my driving?) ❖ 21:32, 27 January 2007 (UTC)[reply]

Diluting conc sulphiric acid down to make 1M solution - even pouring acid into water creates enough heat to warm you hands by placing them on the outside o the flask. And even then you can get some spitting if you pour the acid in too quickly you can get some hissing and spitting until the acid mixes with the water. Hence safety goggles, gloves and a fume cupboard. Theresa Knott | Taste the Korn 00:37, 28 January 2007 (UTC)[reply]

Otter?? "Acid to Water is what you Utter" is what I thought it was. But "Add Acid To Water" AATW/ Alphabetical. therefore, easy to remember.--Tbeatty 06:30, 28 January 2007 (UTC)[reply]

"Otter" is how I always heard it, although I concede that the phrase as I spelt it yields all of zero Google hits. You get one hit for "acid to water is what you oughta", although this works for me only with a Boston accent, i.e. "Acid to watah is what you oughta". And then there are the contrapositives: "Water to acid is not too placid" or even "Water to acid if your life's too placid". —Steve Summit (talk) 14:06, 28 January 2007 (UTC)[reply]

Another factor is the different densities of the two liquids, which tend not to mix immediately. Adding water to the acid lets it sit on top and get extremely hot. It soon boils, spits and carries some of the acid back out again. I've tried it, and it's not for the faint-hearted (or those without appropriate knowledge or safety apparatus). --G N Frykman 08:45, 28 January 2007 (UTC)[reply]

Dielectric Saturation

I'd like to know more about Dielectric Saturation as applied to electrical capacitance. Neither the Capacitor nor Capacitance article on Wiki cover this eccentricity. Specifically the rate and conditions under which dielectric breakdown of an insulator occurs. From what little I can gather, Dielectric Saturation occurs in so called High-K dielectric materials when subjected to high voltages. In theory the dielectric material in a capacitor has a calculable maximum voltage to which it can be subjected without current jumping through it. From what I've read however this value is actually a moving target since the actual dielectric constant of the material drops as the voltage it is subjected to rises. This term Dielectric Saturation was used in a discussion of capacitors which use Barium-Titanate powder as the dielectric. Thank-you for your help. | Jason 74.100.176.85 20:51, 27 January 2007 (UTC)[reply]

Enzymes and surrounding environment

Enzymes are rather sensitive to their surrounding environment. I understand this has some sort of affect on the survival of living organisms, but I'm not sure what. Thanks. --Fbv65edel / ☑t / ☛c || 22:28, 27 January 2007 (UTC)[reply]

Enzymes are important for the functioning of living things in that they allow chemical reactions to occur much much faster than they otherwise would. If an enzyme is in a particularly hot or acidic environment, for example, it may "unfurl" and become useless. Check out Enzyme. BenC7 01:28, 28 January 2007 (UTC)[reply]

From my limited knowledge enzymes are specific to the environment they are used in, i.e. Pepsin in the stomach will denature and become useless unless the stomach environment is around PH2, while Amylase in the saliva prefers a PH of around 5.5-7. Reaction rates vary according to PH and temperature. RHB ^{Talk - Edits} 01:48, 28 January 2007 (UTC)[reply]

Medical news

Where are your favorite places to get medical news, both in physical and online form? I'm looking for academic stuff, or at least a link to the university news website or something like Eurekalert X [Mαc Δαvιs] (How's my driving?) ❖ 23:09, 27 January 2007 (UTC)[reply]

Google News with keywords works for me. 71.100.10.48 01:33, 28 January 2007 (UTC)[reply]

For infectious disease news I like CIDRAP. --Joelmills 05:10, 28 January 2007 (UTC)[reply]

January 28

Another rice question

I've been trying to find this out for a while, and now seems like the perfect time to ask. Certain types of rice come with the instruction to 'rinse carefully until the water runs clear'. I always do it, and as I'm standing there washing the stupid stuff over and over and over, I wonder exactly what am I rinsing away that's sooo important to get rid of? Is it pesticide? Dirt? Powdered mouse poop? Did the farmer spit in the rice paddy a lot? Or is it just excess starch that would make the rice sticky? Anchoress 03:59, 28 January 2007 (UTC)[reply]

Rinsing rice several times can help remove stickiness, and also helps the rice to cook better. Rya Min 05:48, 28 January 2007 (UTC)[reply]

I remember eating someone's unwashed rice once and it didn't taste very good, but maybe that was their cooker. --Wirbelwindヴィルヴェルヴィント (talk) 05:57, 28 January 2007 (UTC)[reply]

Our rice article says that “The white rice may then be buffed with glucose or talc powder (often called polished rice, though this term may also refer to white rice in general).” I guess I’ll keep washing the rice. S.dedalus 07:55, 28 January 2007 (UTC)[reply]

But what about other types of rice? Anchoress 07:56, 28 January 2007 (UTC)[reply]

Here are two links mentioning all of the above, plus having different opinions regarding the loss of added vitamins and minerals caused by washing: Faunton's Fine Cooking (talc, maybe starch, no significant loss of added vitamins through washing), food network (mainly starch, mentions loss of added minerals and vitamins, separation of grains in case of basmati rice). Sage V Foods mentions bran and other contaminants that get removed through the process of rinsing but also claims there is a significant loss of vitamins, they say it's a trade-off between nutrition and gourmet quality. I admit I never questioned this and thought I was removing remainders of the hull (and maybe starch) when mindlessly washing not only rice, but other grains too. ---Sluzzelin 11:26, 28 January 2007 (UTC)[reply]

The labelling should really say 'rinse until practically clear'; it's a terribly laborious task otherwise, with rapidly diminishing returns after the second or third rinsing. Vranak

Yeah I know. I shiver at the amount of water I use; it takes me about 8 rinses with fresh water to get it that clean. Tastes really good tho. Anchoress 05:50, 29 January 2007 (UTC)[reply]

Thanks to all for the answers. Anchoress 05:50, 29 January 2007 (UTC)[reply]

Oxygen concentration

~moved from the Entertainment desk~

if using two oxygen concentrators with one on 5liters per min and the other on 5 liters per min what oxygen concentration would you get?

Sounds like a homework question to me. --Zach 04:00, 28 January 2007 (UTC)[reply]

It doesn't make very much sense either. A litre is a measurement of volume, not of concentration, and without knowing the size of the container or the pressure of the oxygen or anything, what are we supposed to do? -- Consumed Crustacean (talk) 05:59, 28 January 2007 (UTC)[reply]

Who makes Wankel Engines?

I am interested in, from an investor's perspective, wankel engines and other rotary engines. However, for the life of me, I cannot find a publicly traded company that builds them. Only mazda comes up in searches, are they big on this? Thank you. ChowderInopa 04:40, 28 January 2007 (UTC)[reply]

Mazda have done a lot of work with Wankel engines since the '60s, most prominently the Renesis engine in the RX-8 and before that the RX-7. Another company which was once heavily involved with Wankel cycles was the German firm NSU Motorenwerke AG in the 1960s-1970s, but they were bought out by Volkswagen, largely because the early engines were unreliable and they got thoroughly shafted by warranty costs. See the relevant articles for more info. I believe (and the article says) that Mazda is the only company currently building Wankel engines. --YFB ¿ 05:09, 28 January 2007 (UTC)[reply]

Don't forget the hobbyist market, pioneered by (and still made today by) the Japanese company OS in the 70s. The large (automotive scale) rotary engine is also used by a variety of prominent companies in racing applications, Google is your friend!--66.195.232.121 15:11, 29 January 2007 (UTC)[reply]

Seizure / sleep paralysis / lucid dreaming / extreme long-windedness

This is not a request for medical advice, and I would appreciate if no one posted advice. I'm not going to do anything about this; it's been more than 5 years. I probably do not need to go into all this detail, but I'm bored, so what the hell.

When I was younger I hit a short period where I was mildly interested in odd occult and paranormal things. This was fairly brief, but an interest in lucid dreaming lingered. I was 13 around this time. Having read the lucid dreaming websites (many of which are "out there"), I got a lot of weird information about "out of body experiences", which I dismissed but still read. Bored over the summer, I decided to begin doing the whole dream journaling thing, recording every dream I could recall upon waking up.

One fine sunny day I awoke, decided it wasn't worth getting up, and went back to sleep. Almost immediately (perceptually) I found myself in a dream. I realized I was dreaming after a short time, and decided to check my watch as a "dream test" - the websites indicated that it should appear garbled while in a dream. Before I could manage to do so I found myself in another dream, in which I was in my own room, though with slight differences that I only realized after the fact. Being a lazy young adolescent, I decided to fall asleep again, despite already being in a dream.

This is where it actually gets weird. After closing my eyes in this dream, everything went pitch black. The letters "HBO" suddenly appeared in the blackness, in an intense white, and I felt quite startled. This reminded me of "OOBE" for no reason; OOBE being an acronym for "out of body experience" that I had read on the mentioned lucid dreaming websites. Thinking that in turn caused me to wake up, though for real this time.

I didn't simply wake up though. I began to shake uncontrollably, as well as hearing a slight "humming" noise as one hears when their head shakes or their jaw is overly tensed (err). This was not fun. It ended after maybe a minute, but scared the hell out of me.

This thing is strange though. I have never before, nor since suffered from seizures, nor any neurological disorder. The shaking is also something which I may have come to expect due to it being described quite vividly on those crazy websites as a precursor to out of body experiences.

So, after all of that crap, I finally come to the question(s): Is it likely that it was merely a coincidence that I had this happen to me after having read about something exactly like it, and having developed my interest in lucid dreaming, or did I actually manage to self-induce a seizure? Is there any scientific work on self-induced seizures? Was it even a seizure? Are there any reported connections between, perhaps, sleep paralysis and convulsions? What happened? Am I making a crazy fool of myself? Have I posted this before? Is this far too verbose? -- Consumed Crustacean (talk) 05:41, 28 January 2007 (UTC)[reply]

Interestingly enough, I read a book that talked about astral catalepsy (no article about it, though), and it sounds like something similar to that phenomenon. Google it for some interesting info. Titoxd^(?!?) 08:51, 28 January 2007 (UTC)[reply]

That just sounds like a paranormal explanation for sleep paralysis, though semi-voluntarily induced. This is exactly the type of thing I read about while trying to read up on lucid dreaming, which is why I think my expectations to have such an experience may have helped shape it (as in the placebo effect). Again, because of my own experience and the numerous reports, I'm just wondering if there has been any scientific research into this. Considering the connotations, I've got a feeling that's a negative. -- Consumed Crustacean (talk) 18:23, 29 January 2007 (UTC)[reply]

I noticed something similar a little while ago:) Everything seemed to be somehow connected to something I was interested in, things in books would remeind me of it, I had dreams about it &c:( Maybe you want this to happen so much you are persuading yourself you are seeing it:) The stuff that happens in our dreams doesn't actually happen at all, unlike in books and films where someone has already decided what you will see:)Hidden secret 7 12:25, 28 January 2007 (UTC)[reply]

I have had an experience very similar to yours, though not after a lucid dream (I have only had once when I was quite young). I saw the word GOD in intense yellow letters spelled before a dark background (though in my dream the dark background looked a lot like my bedroom window). I woke up paralyzed (see sleep paralysis) and remained so for about a minute. As far as I know, sleep paralysis is not normally accompanied by convulsions, the strange thing with my sleep paralysis (which happens often) is that I always experience convuslions in one single muscle (eyelid, foot, ...) while being otherwise completely paralyzed. The convulsions are both voluntary and involuntary at once: I seem to be straining to get any muscle into action and somehow that muscle seems to respond, although I do not intend it to convluse. As for the word I saw, I think that what I really saw wasn't the word GOD, but I interpreted it that way (I thought I was dying then). It's very likely I saw/interpreted this word because of my then-obssession with theological issues (possibly similar to your obssession with OOBE?). I only woke up because I felt the enormity of what I saw was too much and it felt like my heart had somehow exploded (again, I thought I was dying), not merely "thinking about it". I hope this wasn't too confusing. —LestatdeLioncour t 14:16, 28 January 2007 (UTC)[reply]

That sounds eerily similar. -- Consumed Crustacean (talk) 18:23, 29 January 2007 (UTC)[reply]

Is it likely that it was merely a coincidence that I had this happen to me after having read about something exactly like it?

In my experience, we tend to become interested in things that are relevant to our current stage of intellectual development. Once we 'pass through' a stage, our interest wanes.

As for the unpleasant episode itself, all I can say is that our minds and bodies can and will do all sorts of unsettling things in order to 'sort itself out'. The best analogy I can think of is defragmenting a hard-drive. All sorts of disparate data passes through a computer's CPU as it cleans up a hard drive. If a CPU had consciousness, it might get all bugged-out from the garbled data passing through its core. But it is purely an artifact of how data is stored; there's no higher meaning.

Also, from the aforementioned article: "[Defragmentation] is a memory intensive operation [...]", i.e. it's best to do it when your computer isn't doing anything else. So if the analogy holds true, this is why we can only afford to have these wierd experiences when we're at rest. Vranak

That's like one of the theories of dreaming. Considering that I expected it to happen though, that explanation doesn't do it for me. I'm leaning towards it being something like the subject-expectancy effect or placebo effect. -- Consumed Crustacean (talk) 18:23, 29 January 2007 (UTC)[reply]

Stuff on my toungue

What is the white stuff on the back of my tongue that I have to brush off when I brush my teeth? Imaninjapirate^{talk to me} 06:15, 28 January 2007 (UTC)[reply]

Plaque. See tongue scraper, albeit a small article. --Wirbelwindヴィルヴェルヴィント (talk) 06:31, 28 January 2007 (UTC)[reply]

Antimatter

What would have to be the diameter of a particle accelerator that could produce a gram of antimatter in a year? Using todays technologies.67.125.157.144 06:43, 28 January 2007 (UTC)[reply]

Our article on antimatter says: The biggest limiting factor in the production of antimatter is the availability of antiprotons. Recent data released by CERN states that when fully operational their facilities are capable of producing 107 antiprotons per second. Assuming an optimal conversion of antiprotons to antihydrogen, it would take two billion years to produce 1 gram of antihydrogen. This data comes from this FAQ on antimatter from CERN . I think a larger particle accelerator would not necessarily make more antiprotons, it would just make faster antiprotons, which is exactly what you don't want - you want to produce slow antiprotons which are easier to contain with electromagnetic fields. But the biggest problem in antimatter production is how to contain the antimatter and stop it interatcing with ordinary matter and destroying itself. Charged particles like antiprotons and positrons can be contained with electromagnetic fields (see Penning trap, for example), but you can't keep large numbers of the same particle together because they strongly repel one another. If you let them combine into, say, antihydrogen then you have a neutral atom which is even more difficult to contain. Gandalf61 12:50, 28 January 2007 (UTC)[reply]

Antihydrogen is easy to contain. You just need an anti-matter tank! anonymous6494 12:51, 29 January 2007 (UTC)[reply]

History of Pause Button

can anyone please help in finding the history of invention of Pause button/key?

The earliest use of the pause button that I can recall is on reel-to-reel audio tape players/recorders in the 1960s, like this one. It was used to temporarily halt the tape when recording - using the stop button would have created a noticeable break in the reording. Certainly the pause button/key was a standard feature on cassette decks such as this one, where it is the smaller key to the right of the stop key. Gandalf61 09:58, 28 January 2007 (UTC)[reply]

I think one could argue that turntables, especially the professional turntables used for radio broadcasting contain an even earlier implementation of the same feature. You could "cue up" a record to the exact starting point of a song and then there were two methods of rapidly starting it at the exactly correct moment. One was mechanical, much like a "pause" key. The other was to hold the record from spinning while the turntable continued to turn underneath it. When you released the record, it almost instantly accelerated to full speed. But the mechanical method wasn't much slower, and it left your hands free to do other things while the record remained "paused".

Atlant 01:06, 29 January 2007 (UTC)[reply]

The recording device and the reproducer could be lifted off the recording via a lever in the Edison cylinder phonograph in the 19th century. That is a Pause control. Did you mean when was it first labelled as a pause control? That must have come later. Some tape recorders had a pause control ion the 1950's. Before that as on wire recorders, one just pressed stop, the play or record. Some devices did not distinguish that from pause. Pause allowed a tape or cassette recorder to begin recording almosfaster than pressing record from the off position. Edison 05:34, 29 January 2007 (UTC)[reply]

Firing a gun in space

If you were to fire a gun in space (ignoring whether or not it's actually possible to fire a gun in space) would you be propelled backwards at the same speed as the bullet? Battle Ape 10:18, 28 January 2007 (UTC)[reply]

Not at the same speed. While the force applied to both objects is the same, the mass is not. If you're twice as heavy as the bullet, you'll only go half as fast as the bullet. -- Ec5618 10:29, 28 January 2007 (UTC)[reply]

To elabortate, your speed would equal the speed of the bullet multiplied by the ratio of the bullet's mass to your mass. (See linear momentum) —LestatdeLioncour t 11:22, 28 January 2007 (UTC)[reply]

(after edit conflict) Twice?

According to 5.56 × 45 mm NATO the standard NATO round weighs 4-5 g, an adult male about 75000 g. So you'd have to fire 15000-18750 bullets before you would have the same speed as the bullet. - Dammit 11:29, 28 January 2007 (UTC)[reply]

You could fire most modern guns, just obviously not old flintlock guns! Mathmo ^Talk 23:54, 28 January 2007 (UTC)[reply]

This talk started me thinking off about firing underwater, and I've just by chance came across this interesting weapon. [5] Is a bit off at a tanget, but still somewhat related and interesting.... Mathmo ^Talk 15:22, 29 January 2007 (UTC)[reply]

Yes, most bullets will fire in space or even under water, because the cartridge contains the propellant and oxidant necessary for the reaction. The reason why a lot of guns fail underwater is because of mechanical reasons not chemical ones, eg, the water can't get out of the way fast enough. I actually think it would take fewer bullets then your total mass, think about the explosion it self, it would also impart some energy, i.e. if you fired a blank, it would act like a tiny little rocket for a split second, the expanding gas would also act on you because the gun barrel is acting like a nozzle, the effect is probably small but I doubt negligible when you are talking about firing 15000 times. Vespine 02:42, 29 January 2007 (UTC)[reply]

But I thought mass and weight didn't matter in zero gravity, since both yourself and the bullet technically weigh nothing while you're up there? Battle Ape 12:44, 29 January 2007 (UTC)[reply]

mass is not the same as weight (the intro to weight explains this adequately). — Lomn 16:04, 29 January 2007 (UTC)[reply]

Blackpowder contains an oxygen-supplying compound so even flintlocks should work in space. A gun has been fired in space before. The Russian Salyut 3 space station used its aircraft cannon to target a satellite. They were uncertain how bad the resulting vibrations would be on the space station and fired the gun by remote after the cosmonauts left. Rmhermen 01:17, 31 January 2007 (UTC)[reply]

Handheld GPS and Map Datum

Hello,

I recently bought an entry level handheld GPS receiver (The Magellan eXplorist 100). I live in Canberra, Australia (this will become important later). I am planning a hike using 1:25000 topographic maps provided by the NSW Department of Lands, based on the GDA94 datum. However, my GPS only supports AUS66, AUS84 and WGS84, as well as many other useless datums (IRAN, ADIND, etc.). It does support a USER setting, but I must enter in the following information:

Delta A (meters)
Delta F (X 10,000)
Delta X (meters)
Delta Y (meters)
Delta Z (meters)

I have no idea what numbers to put in, does anybody know? I have found these details of the GDA94:

Equatorial Radius (semi-major axis): 6378137.0000 m
Flattening: 1/298.257223563
Polar Radius (semi-minor axis): 6356752.3142 m
Eccentricity: 0.00669437999013

Also, would it be okay just to use WGS84?

Thankyou in advance,

--Alexs letterbox 11:43, 28 January 2007 (UTC)[reply]

WGS84 and GDA94 are practically the same. The algorythm is almost identical with a small change in the flattening term. You will not notice a difference on your map at that scale. All GPS receivers get coordinates in WGS84 and transform them to the chosen datum. The difference is about 200m as far as I can tell but this will vary depending on location.

See this.

and for a transform from X to DGA94 see this. --Tbeatty 04:52, 29 January 2007 (UTC)[reply]

Comment

Looking in the archives it seems jan 18 to jan 28 has dissapeared...87.102.33.144 12:10, 28 January 2007 (UTC)[reply]

They were manually archived by hand. --Parker007 12:27, 28 January 2007 (UTC)[reply]

Unfortunately they are not appearing here http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/January_2007

87.102.33.144 12:43, 28 January 2007 (UTC)[reply]

Done up to Jan 25th. Skittle 18:33, 28 January 2007 (UTC)[reply]

Gallium

From gallium

Gallium also attacks most other metals by diffusing into their metal lattice — another reason why it is important to keep gallium away from metal containers such as steel or aluminum

Exactly how corrosive is gallium and at what temperature - I've added a ^{[citation needed]} to this part of the gallium article. See Talk:Gallium#diffusion

Can anyone give figures for the rate of this diffusion at different temperatures.

Surely no one is suggesting that this occurs at around room temperature?87.102.33.144 12:24, 28 January 2007 (UTC)[reply]

I put in a citation! This looks most likely that the diffusion takes palce at room temperature.--Stone 22:58, 28 January 2007 (UTC)[reply]

electrolytes

i am drinking a bottled water product called smartwater is there any danger in using this on a daily basis? can one ingest too many electrolytes? --Kmessick 12:24, 28 January 2007 (UTC)k[reply]

How can we possibly answer this? You've given us virtually no info, and even if you did you are basically asking medical advice.What does it say on the bottle? Do whatever it says there, however people have managed to live on tap water up until now perfectly healthily. Why waste money on a bottled product? Theresa Knott | Taste the Korn 13:36, 28 January 2007 (UTC)[reply]

A facile answer is that if it tastes good, and you gulp it down, it's probably good for you, and if it tastes wierd, and you only take little sips, you're probably wasting your money. The relationship between taste and nutritional value is not random, haphazard, or arbitrary. No citations on this however.

Another facile answer is that if you have to ask, the answer to both your questions is probably yes.

^{As this response makes no attempt to establish evidence, it may be summarily removed.} Vranak

Vranak, Coca-cola tastes pretty good, so that means the sugar is good for my weight, the phosphoric acid for my bones, and the caffeine for my nerves and blood pressure? See how circumstance-dependent and worthless that guideline is? alteripse 17:27, 28 January 2007 (UTC)[reply]

Well, when do you usually drink Coca-cola? All that high-glucose corn syrup can't be good in the long term, but it may help kickstart digestion after a particularly heavy meal. What you drink will depend on what you eat, as in wine matching. Vranak

Note that what is marketed as electrolytes is often just disolved salt (for example, sports drinks). Assuming the electrolytes in smartwater is just salt, is drinking extra salt on a daily basis bad? It'd depend on your diet. As a side note, I remember watching a program on Gatorade where their "scientists" were doing all these research and using all these fancy words, when it basically came out to... We wanted to find how salty to make our water. --Wirbelwindヴィルヴェルヴィント (talk) 18:17, 28 January 2007 (UTC)[reply]

(Addendum) I found the site Glaceau, which claims to contain no impurities, while adding electrolytes in the form of magnesium, potassium, and calcium, without the use of salt. Sounds excessive to me, but now the limit is digesting more magnesium, potassium, and calcium instead of sodium. Personally, I think it's just way too expensive. --Wirbelwindヴィルヴェルヴィント (talk) 18:25, 28 January 2007 (UTC)[reply]

Antagonism vs Inhibition (with lots of ADDICTIVE DRUGS)

On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as bupropion and vanoxerine, have mild stimulant effects and little abuse potential, and can be used to treat stimulant addiction. ^{[citation needed]}

Olanzapine's antipsychotic activity is mediated primarily by antagonism at dopamine receptors.

Scientifically speaking, is there any differece between Antagonism and Inhibition? Please provide references to back up your answer.

I would appreciate the answers provided. Thnx. --Parker007 12:37, 28 January 2007 (UTC)[reply]

I'd suggest that the usage choice is a language one, (I can't call a difference between the two)

Medical dictionary (is this a good source?) has the two lumped together for the same definition see http://www.wrongdiagnosis.com/medical/inhibitor_antagonist.htm 87.102.33.144 12:53, 28 January 2007 (UTC)[reply]

The real difference is actually in other usage - an antagonist 'works against' eg pairs of muscles that pull on either side of the bone, an inhibitor prevents the action itself. I'm not sure that in biochemical usage the distinction is made (of perhaps even known).87.102.33.144 12:56, 28 January 2007 (UTC)[reply]

Also http://www.thefreedictionary.com/antagonist defines antagonism in a biochemical sense as "Biochemistry A chemical substance that interferes with the physiological action of another, especially by combining with and blocking its nerve receptor" eg as an inhibitor.

So in biochemistry they seem to have the same meaning - though if more becomes known about the mode of action of a given substance perhaps in the future a distinction will be made.

Comment on proper usage...

For instance a compound that causes dopamine uptake is antagonistic to a compound that causes dopamine release - but does not inhibit.

Whereas a compound that binds to a site causing dopamine release (not activating it) can be called an dopamine release inhibitor. (But may also be decribed as antagonistic to a compound causing dopamine release by the nature of it's inhibitory action). Hope that helps.87.102.33.144 13:04, 28 January 2007 (UTC)[reply]

Actually, antagonism and inhibition are two distinct concepts in most biomedical contexts. Antagonism usually refers to interference with the action of a substance, or sometimes to the production of an effect that opposes that of another substance. An example of a steroid antagonist is spironolactone, which reduces mineralocorticoid effects and androgen effects. Inhibition usually refers to interference with production of a substance. An example of an inhibitor of steroid production is metopirone. alteripse 17:22, 28 January 2007 (UTC)[reply]

I see that competitive anatagonist, noncompetitive antagonist & uncompetitive antagonist need articles...I'll have to work on that. -- Scientizzle 03:14, 29 January 2007 (UTC)[reply]

For maybe a litle semantic clarity of the difference between antagonism and inhibition...Inhibition is the prevention of some event and antagonism is one biochemical pathway through which one might cause inhibition. Enzymes or biological receptors, for example, can be inhibited by several means (phosphorylation state, missing co-factors, pH, etc.), including antagonism. An antagonist may inhibit by one of several methods (see below), but chiefly it interrupts the the otherwise natural activity of the enzyme/receptor in the local state. -- Scientizzle 00:22, 30 January 2007 (UTC)[reply]

Thanks alot :) --Parker007 07:07, 30 January 2007 (UTC)[reply]

copper iron

Are there any uses for copper iron alloys? could any of these alloys be describe as stainless eg resistant to rust.

Does anyone know the appearance of, or have pictures of these alloys.

Thanks.87.102.33.144 12:48, 28 January 2007 (UTC)[reply]

Search Wikipedia, there's plenty of info. Here's an example for you. http://en.wikipedia.org/wiki/Special:Search?search=copper+iron+alloy&go=Go . Cheers, Dr_Dima

Properties_and_uses_of_metals --Parker007 22:07, 28 January 2007 (UTC)[reply]

Seriously both of those answers are useless.87.102.2.226 10:05, 29 January 2007 (UTC)[reply]

Cunife is the closest I can find to a copper-iron alloy. Any help? Oh, and you might like to reword your reaction up there. While it's frustrating when people don't provide answers that meet your needs, a polite response can ensure they keep trying and answer next time :-) Perhaps something along the lines of "That's not really what I'm looking for." "Those links don't contain the information I'm looking for." or similar. Oh, and if you do change your reaction to something along these line, you can remove this bit from my reply :-D Skittle 19:02, 29 January 2007 (UTC)[reply]

Thanks for your response - though the very short article wasn't useful.

As for my response - I think it sums up the answers perfectly - a little impolite perhaps - but so are non-answers - obviously I have the ability to search for 'copper iron' and did. I was looking for some intelligence - not useless directions on how to begin a search. Maybe you could explain how "Properties_and_uses_of_metals "" is anywhere even slightly close to an answer - it isn't - it would be better if people unable to give a reply didn't try. Sorry to be so grumpy but this happens a lot.87.102.13.207 15:08, 30 January 2007 (UTC)[reply]

For an answer to your first question, see copper.org which came from a simple and obvious Google search of copper+iron+alloy (see, we can be testy too and I "liked" your obscene remark on the Misc Desk):

Copper-infiltrated iron parts are particularly suitable for applications requiring good resistance to shock loading and good fatigue strength accompanied by resistance to wear.

That alloy was created using powder metallurgy. BTW, I do agree with you that there is no reason to post a non-answer. I just wonder if you are making a WP:POINT as you say it has happened to you a lot. --Justanother 15:44, 30 January 2007 (UTC)[reply]

Thanks87.102.13.207 16:32, 30 January 2007 (UTC)[reply]

You are welcome. --Justanother 16:35, 30 January 2007 (UTC)[reply]

kinematics

Please help me solve this problem:

Water drips from the nozzle of a shower onto the floor 200cms below.The drops fall at regular (equal)intervals of time,the first drop striking the floor at the instant the fourth drop begins to fall.Find the locations of second and third drops when the first strikes the floor. —The preceding unsigned comment was added by 59.93.70.85 (talk) 14:43, 28 January 2007 (UTC).[reply]

Do your own homework. Where are you getting stuck? –EdC 15:16, 28 January 2007 (UTC)[reply]

Consider the water droplet starts at v, d and t = 0 and a constant acceleration of 9.8m/s per second is applied to it then work out what the t is at d = 0.2m. Then simply solve the exuation for 1/4 t, 1/2 t and 3/4 t. Vespine 21:41, 28 January 2007 (UTC)[reply]

I think those times should be 1/3 t and 2/3 t - see fencepost error. Gandalf61 15:00, 29 January 2007 (UTC)[reply]

Indeed. Anyone trying to do this sort of problem (eg, the questioner) could avoid such an error by drawing a diagram. Specifically, they could draw a diagram of the situation described (with 4 drops: one at the top, one at the bottom and two in between), then follow Vespine's advice with the necessary corrections. Skittle 18:57, 29 January 2007 (UTC)[reply]

genetic parentage

i had read in an article that molecular markers are used in genetic parentage.can u help me understand it? —The preceding unsigned comment was added by 59.95.203.167 (talk) 16:15, 28 January 2007 (UTC).[reply]

Boltzmann distribution

I'm confused by the pages relating to the boltzmann distribution. Can someone clarify what the assumptions are in the model that is used as a basis for the distribution. (I thought it was that each energy state is equally likely and each distinct energy state is counted once?)87.102.44.44 12:41, 21 January 2007 (UTC)[reply]

The Boltzmann distribution applies to a classical system that consists of a number of particles that are in a canonical ensemble. That means that temperature T is fixed and well defined, the volume V is fixed, and the number of particles N is fixed. There are additional necessary conditions: 1. each state must have occupation probability much smaller than unity; 2. The interaction between particles must be relatively weak and/or short-ranged. The second condition is the most problematic, as it formulates differently for different systems. What system do you have in mind? Dr_Dima

1. Say there are 3 particles, is the total energy of those particles fixed at a given temperature?87.102.32.146 18:54, 28 January 2007 (UTC)[reply]

2. And if so is each distribution of energy amongst the particles considered equally likely (excluding degeneracy) or is the situation more complex?87.102.32.146 19:06, 28 January 2007 (UTC)[reply]

(assuming question 1 and 2 are answer yes) If I have understood this correctly then for total energy 5, with 3 particles with equally spaced energy levels (singly degenerate) there are 21 possible states, with state (5,0,0) occuring 3 times, (4,1,0) occuring 6 times, (3,2,0) occuring 6 times, (3,1,1) occuring 3 times and (2,1,2) occuring 3 times. Where (3,2,0) means one particle has energy 3, another energy 2, and another has energy 0.

Is this the type of counting situation used in the boltzmann distribution (albeit simplified?)87.102.32.146 19:24, 28 January 2007 (UTC)[reply]

A few remarks (without bothering to answer the question fully): The OP assumes that all "energy states" are populated with the same probability. This may hide a misunderstanding. The so-called ergodic principle, which is the underlying assumption, states that any microstate has the same probability. A microstate is, in the classical case, a point in phase space, i.e. one complete specification for position and momentum for each particle. Now, many microstates have the same energy, but not every possible energy value is associated with the same number of microstates. Hence, some energy values are more probable than others, and so, the Boltzmann formula

p(E)dE=\exp(-E/kT)dE

gives the probability density that the system has energy E, which is proportional to the volume in phase space (number of microstates) with this energy. Note also a possible confusion of terminology: The Maxwell-Boltzmann distribution deals with classical systems in thermal equilibrium at a temperatur T. The Boltzmann factor

\exp(-E/kT)

, however, appears as well in the derivation of the quantum-mechanical analoga, the Bose-Einstein statistics and the Fermi-Dirac statistics. Simon A. 20:16, 28 January 2007 (UTC)[reply]

What fucking use is that - you've just stated that 'the boltzmann distribution' is the answer without any explanation.87.102.2.226 10:03, 29 January 2007 (UTC)[reply]

Power draw on US Home electical supply

Someone asked me why Americans always use stove-top kettles, and not the far more convenient electrical kettles. My answer was that it is likley that US power couldn't draw the amperage required for them. A 2000W kettle (as we use here) would draw 18A at 120V which is more that our standard outlets are rated for.

Is this the sensible reason? Or is it just tradition with the kettles. How do they use other high wattage devices in the US then, like vacuum cleaners (the one we have is rated at 2500W)? Things like electrical ovens have there own circuit (and perhaps use 3 phase 240V in the US?), but I'm talking about the stuff you plug into the wall. 86.133.205.209 17:11, 28 January 2007 (UTC)[reply]

It's true that in the U.S., there's a limit to what you can plug into the wall. Outlet circuits are normally fused at 20 amps, but there's an expectation that no one appliance will draw more than 15 amps, or 1800 watts. In practice, most high-wattage appliances (e.g. hair dryers) top at out 1200 or 1500 watts.

(An appliance that actually needs 20 amps at 120V, such as a medium-sized air conditioner, uses a slightly different style of plug, that only fits into a dedicated 20A outlet.)

You're correct that appliances that need more power than that, such as electric stoves and ovens, electric water heaters, electric clothes dryers, and whole-house air conditioners, normally run on 240V (and often using dedicated circuits of 30, 40, or even 50 amps). But in normal residential usage this is still single-phase. Three-phase power is typically available only in commercial and industrial zones.

With all of that said, it's also the case that "far more convenient" is to some extent in the eye of the beholder. Me, I don't boil much water, but I'd rather use a pot on the stove than a fussy special-purpose appliance. YMMV. (In other words, yes, a lot of this is just tradition.)

And there are electric hotpots in the U.S., but they're not 2000 watts like yours are. (And is your vacuum cleaner really 2500W? My goodness! How do you keep from sucking up the carpets and floorboards? :-) ) —Steve Summit (talk) 17:33, 28 January 2007 (UTC)[reply]

I suppose in the real world, not _that_ many house hold appliances do need more than 1500W. Yes, our vacuum cleaner rates at 2500W, but I'm a 'bigger number better shopper', and the majority rate around 1200W I think.

Of course we constantly boil water for our 50 cups of tea a day :) When I say more convenient, it's usually faster (our big wok burner on the stove is 3kW, but I think most hobs are only 1.5kW), and more so you can use it where you don't have a cooker, like in the office. (How does that work then?) I suppose if the latter is needed a lower wattage kettle is fine, just slower.

These super high wattage sockets. Are they common, i.e. one in each room?

Well, no. A 40 or 50 amp stove outlet is common in the kitchen if the house is to have an electric rather than a gas stove. A 30 or 40 amp dryer outlet is common in the laundry area if the house is to have an electric dryer. Most other high-current appliances (whole-house air conditioners, heat pumps, electric water heaters, some electric stoves) are permanently wired, with no plug at all.

20 amp (as opposed to 15 amp) outlets are becoming more common in commercial construction, but they're still rare in residential. You can see what they look like in the diagram at http://www.quail.com/nema.cfm. A standard 15 amp outlet ("receptacle") is a NEMA 5-15R. The standard plug for an appliance that draws no more than 15 amps is a 5-15P. The special 20 amp outlet I spoke of is a 5-20R. Notice that one of the slots is T-shaped. The plug on an appliance that draws 20 amps (such as a medium-sized air conditioner) will be a 5-20P. Notice that one prong is horizontal. Notice also that a 15-amp plug (the conventional one with both prongs vertical) will plug into either kind of outlet. See also NEMA connector. —Steve Summit (talk) 21:50, 28 January 2007 (UTC)[reply]

We have separate circuits for cookers that are 30/50A, but normal sockets are fused at 13A (or at least the plugs on the appliance are never higher than this, most sockets on the wall I don't /think/ have fuses). But things like free standing air conditioners (or more likely 3 bar heaters :) ), can be plugged anywhere.

I'm trying to work out if I should pity the US and their substandard electrical system full of inconveniences ;). 86.133.205.209 18:29, 28 January 2007 (UTC)[reply]

Electric kettles are used in England because they drink tea much more freuqently than the U.S. and it is simply faster. They are certainly available in the U.S. and I have two myself. European electric power is more expensive than U.S. power and my experience is that the U.S. power to homes (especially to new construction) has more capacity than European counterparts.

Typical U.S. homes have a 200 Amp meter service (200A at 240V). 120V is available at standard wall sockets. 240V, 30A is used for the Electric water heater tank (Europe is going tankless, probably more efficient). 240, 30A is for the electric clothes dryer. 240V, 50A for the oven/stovetop. 240/50 for the Air Conditioner. Kitchens have 120v/20A circuits for small appliances. Living areas have 120V/15A circuits for general lighting and small appliances such as TVs and radios. --Tbeatty 19:57, 28 January 2007 (UTC)[reply]

Maybe the main reason is for tea, but I don't drink that much tea and I'd find it very inconvenient not to have an electric kettle, at work and in the kitchen. Apart from normal tea and herbal tea, you use it for hot chocolate, instant coffee and cafetiere coffee. You can use it for noodles (whether Pot Noodles or plain noodles). You can use it whenever hot water is needed, like to get water to boiling point before cooking rice, pasta or vegetables in it (much faster that way), or if you need to melt chocolate, or clean something, or get a spoon hot before trying to spoon golden syrup or treacle. Do Americans not do any of these things? Skittle 21:12, 28 January 2007 (UTC)[reply]

Just looking at kettles, the current ones all seem to be 3000+W these days(/me puts new kettle on shopping list). But here is a question: Why can you not just have standard 120V@30A. Would it require thicker wiring, thicker than 240V@15A (i.e. what would be in the non cooker circuits in UK houses)? 86.133.205.209 00:20, 29 January 2007 (UTC)[reply]

Yes, the loss from electrical wirings grows exponentially with current, P=I²R, and thus if you double the current your wires need to dissipate 4 times more heat from the losses, or be a lot thikcer. --antilived^{T | C | G} 04:59, 29 January 2007 (UTC)[reply]

s/exponentially/quadratically/ :) -- mattb @ 2007-01-29T05:15Z

As to that last question, the current that determines the thickness you need for the actual wire while the voltage determines the thickness you need for the insulation. In practice all modern wiring in North America is rated for at least 250 V, but yes, a 30 A circuit would need thicker wiring than a regular 15 A one. There is no strong reason why 30 A couldn't be provided at 120 V on one circuit -- there's even a standard plug design for that specification -- it just isn't one that's ordinarily used. Note that North American homes typically have 240 V power in the form of two opposite phases of 120 V, so it's easy to provide 240 V for high-power appliances, as described above.

Above, Steve Summit says that in the US, "outlet circuits are normally fused at 20 amps, but there's an expectation that no one appliance will draw more than 15 amps." Canada follows US electrical standards in most respects, but none of the places I've lived in Canada has had more than 15 A fusing for ordinary outlets. My guess is that 15 A is an older standard in the US (for ordinary 120 V circuits) and that there are still a lot of 15 A circuits in some places.

Oh, and I have an electric kettle. They're common here. It's so old that the sticker that probably had rating on it has come off, but I expect it draws about 1000-1200 W. Let's see, say 600 ml for the teapot, heated from 5° to 100°C, that's 57 cal or about 240 J. If all the heat went into the water, 1200 W would do it in 200 seconds, or 3.3+ minutes; that sounds about right. No doubt if many people had experience with high-wattage British kettles they'd find it unreasonable, but we don't.

--Anonymous, January 29, 2007, edited 05:12 (UTC).

Mr. Anonymous means 57 capital Calories (kcal) and 240 kJ, but the 3.3 minute figure is correct.

Also, with respect to insulation thickness (in North Americal, at least) conventional building wire is rated at 600V. Above 600V, you not only need to use special wire, but completely different sections of the NEC apply.

The situation with current, voltage, and power is quite interesting. Everything else being equal, the higher the current the thicker (and heavier and more expensive) the wires need to be. Everything else being equal, the higher the voltage, the more power you can carry without increasing the current and without having to use heavier wires. That's why cross-country transmission lines use such high voltages (hundreds of thousands of volts). But, alas, as with so many other aspects of nature, everything else is not equal, after all. We can't further reduce the I²R losses of transmission lines by making the voltages even higher, because at extremely high voltages (above 750,000 volts or so) you lose even more energy due to corona discharge; basically the electricity starts leaking out into the air, sort of like low-grade lightning. —Steve Summit (talk) 02:53, 31 January 2007 (UTC)[reply]

yeah really, i couldnt live without a kettle, if fact i dont know anyone (in the UK) who does. i suppose americans have coffee machines typically and drink less tea than we do, so for the other stuff maybe they just put up with waiting.. (maybe its a case of them not knowing any better, i mean, only 10% have passports..) but seriously, all that manly chat about electric voltages kind of washed over me, in a yes or no answer, is the lack of kettles in America becuase of the energy supply? 87.194.21.177 18:30, 29 January 2007 (UTC)[reply]

I think the conclusion is that yes, they can't have the super-fast kettles that we have in the UK. Theoretically stove-top kettles are therefore faster, but the main reason they use them is simply tradition. Back 10 years, I don't think electric kettles were quite so good, they were slower and not fancy flat bottomed (but we still used them), back 30 years I think stove-type whistle kettles were actually quite common in the UK.

Another point, good hobs are not that common. How about all those bed-sits with exceptionally crappy two-coil electric hobs? Stove-top kettles are only good if you have a massive 3kW burner on the hob.

Perhaps the reason we use electric kettles now is because we are used to having kettles _everywhere_. In the office, in a porta-cabin on a building site, I have one in my bedroom. Americans probably have coffee machines in these environments. (And to be honest I drink more tea than coffee and would love a coffee machine in the office so I don't have to drink nasty instant) 86.145.143.21 00:16, 31 January 2007 (UTC)[reply]

Yes, the reason we don't have electric kettles is that we don't drink tea. Remember we chucked it all in the harbor. (Actually per capita yearly tea consumption in Britian is 2.5 kg compared to 0.3 kg in the U.S. and remember we drink a lot of our iced.[6]) Besides stovetop kettles work plenty well - when you are done frying your chicken you slide the pan onto a cool burner so the grease doesn't get baked on so badly. Then you slide the kettle onto the hot burner so the children don't burn their fingers - and it humidifies the room as well. I hear you can boil water for hot chocolate in one as well - if it is winter. (While some hotels provide coffee makers in rooms, I wonder how many people have them in their own bedrooms?) Rmhermen 01:04, 31 January 2007 (UTC)[reply]

morning breath

hey, what is it that makes your mouth feel horrible after you've slept? (even, it seems if you nod off for 5 minutes). i'm sure there's an article on it but sadly i dont know the big grown-up name.. thanks. —The preceding unsigned comment was added by 87.194.21.177 (talk) 17:16, 28 January 2007 (UTC). oops, forgot to sign,87.194.21.177 17:17, 28 January 2007 (UTC)[reply]

Halitosis? --Wirbelwindヴィルヴェルヴィント (talk) 18:10, 28 January 2007 (UTC)[reply]

Yup, that is the "big grown-up name" you are looking for. Morning breath is even a redirect to Halitosis. Mathmo ^Talk 00:01, 29 January 2007 (UTC)[reply]

The article list possible causes as dryness, stress, hunger (ketosis), eating certain foods such as garlic and onions, smoking, or poor oral hygiene. I'd add one more: cheese, though it's a delayed effect. Vranak

Somebody has asked this before, last year. The verdict was actually just dryness. [Mαc Δαvιs] X (How's my driving?) ❖ 18:50, 28 January 2007 (UTC)[reply]

No one has accused bacteria! I accuse bacteria! − Twas Now ( talk • contribs • e-mail ) 05:12, 29 January 2007 (UTC)[reply]

But why is it dry:?

Spaghetti Bridge

Anyone have any ideas on building a spaghetti bridge without compromising weight? —The preceding unsigned comment was added by 66.82.9.49 (talk) 18:13, 28 January 2007 (UTC).[reply]

This question was asked last week. The most interesting answer is to create a suspended bridge by using thick spaghetti tubes for the vertical poles and boiled (soft) spaghetti for the cables. --Kainaw ^(talk) 18:46, 28 January 2007 (UTC)[reply]

Avoid soft spaghetti. It will be heavier because of the water content, and it has virtually no tensile strength. I've never done this myself, but I would have thought a truss bridge design would be the way to go.--Shantavira 19:52, 28 January 2007 (UTC)[reply]

The intention was to let the spaghetti dry out again once formed into the proper parabolic shape of the evenly-loaded support cables.

Atlant 01:18, 29 January 2007 (UTC)[reply]

I'm not sure what's meant by "compromising weight", but: the most interesting way to answer the question is to think about the material properties of spaghetti versus the material properties of building materials in general, and versus the necessary material properties for various types of bridges.

Some materials are great in compression: stone, wood, concrete, steel.
Some materials are great in tension: rope, wood, steel.
Some materials are lousy in compression: rope, steel cables, cooked spaghetti.
Some materials are lousy in tension: stone, concrete.
Some materials are lousy in both modes: sand.

(From the above you can see that a few materials are good in both modes: wood and steel.)

Sometimes a structural element must act, in effect, in both tension and compression at the same time. The most obvious example is a beam, which while carrying a load ends up in compression along its top edge and in tension along the bottom. Wood and steel can obviously be used to make beams, but other materials must be used in combination (the canonical examples being reinforced and prestressed concrete). I might call this third mode of stress flexion, but I'm not sure if that's the official term.

Now, to bridges. One of the oldest types of constructed bridge, I suspect, is the stone bridge, where everything acts in compression. Most other bridge types involve some elements which are in compression and some elements which are in tension. Our bridge article talks about the various types, and in the Bridge structural and evolutionary taxonomy section, talks specifically about the various materials and stresses I've mentioned.

Finally, think about spaghetti. It's okay in tension. It might be okay in straight compression, if you could keep it straight, but a single strand is very likely to bow out if you pushed it from both ends. Many individual strands bundled together somehow (if the contest rules allow it) would make a decent post, i.e. would act pretty well in compression. A single strand is obviously terrible in flexion. Several strands glued together along their entire length (again, if the rules allow it) might be okay in flexion.

So, thinking about all these things, take a look at various bridge designs and try to figure out what their requirements are, in terms of building materials that work well in compression, and in tension, and in flexion. Think about which design could be most readily realized using (and capitalizing on the strengths of) spaghetti. Or perhaps you can think of a brand new design uniquely suited to the particular strengths of spaghetti!

But of course, this is not just a theoretical exercise. It will also be necessary to do plenty of experimentation. Don't just ask on the net how to do it, or listen to me blathering from my armchair about how you might do it -- go out and get a bunch of spaghetti, and some glue and thread and whatever else the contest rules allow, and try building some bridges, and put some weights on them, and see if they break. When (not if!) they break, examine how they broke: which parts broke, and what stresses those parts were subjected to that they couldn't handle. Redesign your next bridge differently, either with more material in the spot that broke, or using a different design that doesn't subject your building material to that particular stress. (And, most importantly, do stress your early designs to failure! Don't spend so much time building them that you come to think of them as works of art, that you can't bear to break. To learn where their weak points are, you're going to have to break them. You won't learn anything if you don't.)

—Steve Summit (talk) 20:55, 28 January 2007 (UTC)[reply]

Oh, and here's another angle. If those words "compromising weight" have to do with a requirement to minimize the mass of the bridge while maximizing the load it can carry, then you have an additional, optimization task. Not only must you strengthen the parts of the bridge that break under load, you must also seriously consider weakening those portions that don't break under load -- because they're stronger than they need to be, and hence contributing dead weight to the body of the bridge without increasing its carrying capacity.

Rumor has it that Henry Ford was especially partial to this technique, hounding his engineers to scrimp on the materials in all the parts of his cars that weren't breaking, since they were "wasting" materials and hence increasing the manufacturing cost (and hence decreasing profits).

I also heard a story about the builders of military aircraft in Britain during WWII. Whenever a plane limped home after barely surviving damage done by an opposing fighter or by antiaircraft fire, the builders would reflexively strengthen the parts that had broken. But this was faulty logic -- though those parts had broken, the plane had managed to limp home safely. What the builders should have been doing (so the argument goes) was strengthening all the parts of the plane that weren't broken in planes that limped home, since those were presumably the parts that, if they broke, caused a plane to crash and never come home... —Steve Summit (talk) 01:48, 31 January 2007 (UTC)[reply]

Cf. The Deacon's Masterpiece.

Ooohh, definitely! I like this version, with pictures. —scs

Incidentally, by "stone bridge" above, Steve means a stone arch bridge. A clapper bridge, of course, would have the upper surface in tension. --Anonymous, January 31, 2007, 02:34 (UTC).

CuSO4.5h20

In a lab, we were asked to grind some crystals of CuS0₄.5H₂O into a powder, heat it over a Bunsen Burner in Cone B, and then add water after a minute or so. The crystals changed color from blue to white and then to teal. When water was added, it bubbled up and rose up in the test tube. Is heating CuS0₄.5H₂O a physical or a chemical change? How can you support it? And also, what exactly happens in that reaction? Thanks so much, Katie. —The preceding unsigned comment was added by 75.4.65.143 (talk) 18:19, 28 January 2007 (UTC).[reply]

I haven't done this lab in school...I'm in high school, grade 12, but the colour change you observed changing to white most likely was removing the water of hydration, i.e. making anhydrous cupric sulfate from the pentahydrate. Maybe the second part was rehydrating it? 74.102.89.241 00:38, 29 January 2007 (UTC)[reply]

This is the very first chemistry experiment I did at school so I remember it quite well. I believe the above post is an accurate represemtation of whats going on-- although I dont remenber the CuSO4 going teal. OTOH, you could always ask your chemistry teacher if this is not homework.--Light current 08:57, 30 January 2007 (UTC)[reply]

well perhaps it was not the first expt I did. But anyway I still have my schoolbook detailing the expt. THe expt was to find the percentage of water of crystallisation in hydrated copper suplfate .

The substace was weighed before heating. Then heat was gently applied (must have been a bunsen burner) until the poweder became white. It was reweighed. The substance was heated some more until the final two weights were equal. THis showed that all the water had been driven off. My experiment showed that the percentage of water in CuSo4. 5H2O was 36.3%. I believe the correct theoretical value is 36%. But dont take my word for it IANAC 8-)--Light current 12:12, 30 January 2007 (UTC)[reply]

volcano age

how old is the kilauea volcano in hawaii —The preceding unsigned comment was added by 141.152.246.102 (talk • contribs).

Check the infobox of Kilauea. --Wirbelwindヴィルヴェルヴィント (talk) 19:48, 28 January 2007 (UTC)[reply]

Mitochondria Reproduction

If mitochondria reproduce independently of the cell, what controls their reproduction? Why do they not reproduce wildly and clog up the cell?

I understand that a lot of their former DNA has been transferred to the nucleus; does this do the job? If so, how does the nucleus establish a reproduction rate, and how does it differentiate between the mitochondria to be reproduced (e.g. between those whose DNA has mutated in a bad way and those which still function adequately)?

Philip Day —The preceding unsigned comment was added by Madphilday (talk • contribs) 19:35, 28 January 2007 (UTC).[reply]

According to the article, mitochondria within a cell reproduce when the cell needs more energy, but then are destroyed or quit working when the cell doesn't need so much. It doesn't mention the specific mechanism though. Vitriol 21:53, 28 January 2007 (UTC)[reply]

Quantum mechanics

Your article is all on physics, it omits biological psychology and the quantum mechanics of the brain, I also looked under biological psychology and I did not find it. Im taking a biological psychology class and I was looking for extra information and I am disappointed I could not find it at your site. —The preceding unsigned comment was added by MarkJam (talk • contribs) 21:33, 28 January 2007 (UTC).[reply]

You didn't read it well enough. See the quantum mind link on the "See also" section. — Kieff | Talk 21:57, 28 January 2007 (UTC)[reply]

It probably should be pointed out that quantum mechanics is, in fact, a physical theory. The biological application is a lot more speculative and less widely accepted. QM has given us an understanding of things like semiconductor devices and lasing and a way to describe three of the fundamental forces of nature in terms of particle interactions. In other words QM is well supported by experimental results. As yet, the quantum mind theories are little more than conjecture (in fact, I don't think they even make any concrete predictions that could be measured, so their status as "theory" is also questionable). -- mattb @ 2007-01-28T22:28Z

If your looking for "Free Will" in quantum mechanics, your looking in the wrong place. --Tbeatty 08:46, 29 January 2007 (UTC)[reply]

No. of chromosomes in Neanderthals?

I know that it is not a well researched topic. But it'd be great if anyone could give me an idea about the number of chromosomes in the genome of Neanderthals? Thanks.nids (♂) 22:19, 28 January 2007 (UTC)[reply]

Neanderthals are now widely believed to have bred with homo sapiens, therefore they must have had a corresponding number of chromosomes, 46. Vespine 00:42, 29 January 2007 (UTC)[reply]

Widely believed? I thought this was merely a theory. Do you have some references? Clarityfiend 03:03, 29 January 2007 (UTC)[reply]

Isn't it truer to say that, if Neanderthals bred with homo sapiens then they must have had 46 chromosomes and therefore must have been human beings and therefore the distinction between Neanderthals and homo sapiens breaks down; or, if they didn't have 46 chromosomes then they were not humans and could never have bred with homo sapiens? JackofOz 03:09, 29 January 2007 (UTC)[reply]

Recent genetic work (e.g. the work of Krings [7], Bryan Sykes, and others) strongly argues that the humans and Neanderthals did not interbreed. Samples of mitochondrial DNA from well preserved Neanderthal fossils are too distinct from modern humans for the gene pools to have been mixing. Given that the two populations almost certainly had opportunities to interact, a lack of interbreeding would likely indicate that they were genetically incompatible, and one plausible (but by no means certain) explanation for that would be that Neanderthals had a different number of chromosomes from modern homo sapiens. Notably, homo sapiens have 46 chromosomes, while living great apes have 48, and that transition could have occurred after the Neanderthal population split from the pre-homo sapien line. Dragons flight 05:42, 29 January 2007 (UTC)[reply]

No it isn't, number of chromosomes isn't a unique species identifier, a domestic cat and a domestic pig has 38, doesn't mean they are the same species, nor that they can interbreed. But animals that DO interbreed do need to have the same number of chromosomes. Neanderthals had 46 chromosomes but that doesn't mean they were the same as humans, but they were probably close, it doesn't 'prove' that they bred. And I think recently it went beyond being just a theory, there was evidence found that Neanderthals could have actually just been bred into the population, not died out due to homo sapiens as previously thought. I'll try to find the sources. Vespine 05:15, 29 January 2007 (UTC)[reply]

We can have both the scenarios. i.e. Neanderthals had 48 chromosomes and they interbred with humans to produce Hybrids (they would be mostly sterile though). Also, Neanderthals may be having 46 chromosomes but still unable to interbreed with Humans. So, even if they interbred with humans, this does not prove that they had 46 chromosomes. But have you read somewhere that Neanderthals had 46 chromosomes. I am not asking for a source, just confirming if you had read that in a reliable source.nids (♂) 10:30, 29 January 2007 (UTC)[reply]

Skull suggests human-Neanderthal link. Anchoress 05:55, 29 January 2007 (UTC)[reply]

This skull, by itself, suggests nothing. For all we know, he could have been just a sterile hybrid.nids (♂) 10:11, 29 January 2007 (UTC)[reply]

Just another note. It is not required that species that breed have the same number of chromosomes (see Donkey, Horse, Mule). If the homo sapien population exploded and interacted with Neanderthals, cross breeding (and the subsequent sterile offpsring) would have wiped Neanderthals off the planet quickly and with no genetic trace. Imagine 10,000 horses and 100 donkeys. Females are almost constantly pregnant and the large majority of female donkeys would be carrying sterile offspring. Homo Sapien/Neanderthal offspring wouldn't be sterile for the same reason as mules but they may be for other reasons. (This is my own pet theory, no pun intended :) ). --Tbeatty 06:25, 29 January 2007 (UTC)[reply]

The Cell paper from Svante Pääbo's group that was linked to, studied mitochondrial DNA. Humans are but a medium in which mitochondria propagate themselves. The fact that Neanderthal mtDNA is not found in contemporary populations, only shows that there is no unbroken maternal line between contemporary humans and neanderthals. If the carriers of particular mitochondrion variants had even the slightest disadvantage compared to others, they would be less likely to have children, and those mitochondria would die out. This does not mean that the people that carried these mitochondria have no ancestors today, only that there is no unbroken chain of maternal ancestors. Consider also, that the fitness of mitochondria reasonably might depend on climate, since they are the cells' "power plants". And the neanderthals lived in a climate that was very different from today's. Therefore, to me it proves absolutely nothing that neanderthal mitochondria are extinct. I also disagree with the statement made in the Cell paper, that the observation that the time of divergence between neanderthal mitochondria and modern human mitochondria, being much longer ago than than the estimated divergence time of modern human mitochondria, argues against interbreeding. The fact that all contemporary human mitochondria stem from the mitochondria that lived in a woman some 200,000 years ago only proves that mitochondria are subjected to evolutionary pressure. Studies of the Major histocompatibility complex of primates, show that humans, chimps, orangutans and gorillas share many polymorphisms, particularly in the class II region. This argues strongly against very narrow bottlenecks in the size of the human (and ape) populations, and also shows that speciation is not an event that happens in a single individual, but in large groups which, while diverging, gradually lose the ability to interbreed. Jan Klein wrote a very interesting review on this way back in 1987 (Origin of major histocompatibility complex polymorphism: the trans-species hypothesis. Hum Immunol. 1987 Jul;19(3):155-62.). Note, incidentally, that this also shows that a difference in the number of chromosomes cannot be an absolute obstacle to interbreeding. --NorwegianBlue^talk 20:22, 29 January 2007 (UTC)[reply]

NITRIC OXIDE AND THE IMMUNE SYSTEM

Could someone please give me a detaile d explanation of the role of nitric oxide in the human and mammalian immune system? —The preceding unsigned comment was added by Wizzybone (talk • contribs) 22:47, 28 January 2007 (UTC).[reply]

January 29

Human "Radio Wave" Transmitter

For at 20 years (maybe even more) I have been able to effect street lights or the gas in them somehow to make them go out when I walk under them. This particular type gas (whatever it is in these bulbs) apparently is sensitive to radio waves. I can not effect ALL street lights, but perhaps 10% of them. The ones that go out I can then go back later (after it eventually comes back on in 5 minutes to 5 hours) and I can make this same bulb go out again. At my apartment complex where I live they have outside lights (of apparently the same type inner gas) that I also effect about 10% of them. It is so predictable that I have been able to video record the event many times (proving it is not happenstance). Also it proves that it is not mechanical in any way (i.e. loose or intermittent connection). Also street lights do not have "On / Off" switches, so there is not a person turning it off when I walk under it (many times no person within 1000 feet). I have many eye witnesses (i.e. apartment complex maintenance people, apartment complex managers, friends, relatives, and complete strangers). Many times when the bulb is out I walk under them and the bulb pops back on when apparently my "human radio waves" are with range (about 20 feet +/- 10 feet). Is these such phenomena as "human radio waves" or a "human radio transmitter" or something like this known in science? --Doug ^talk 00:37, 29 January 2007 (UTC)[reply]

Sure, it's called black body radiation, though the EM radiation you should be emitting ought to be at a slightly shorter wavelength... -- mattb @ 2007-01-29T00:45Z

You do understand that high-intensity discharge lamps "cycle" at the end of their lives, going on and off on a, say, five minute cycle. You might also want to check Magical objects in Harry Potter for the "put-outer".

Atlant 01:26, 29 January 2007 (UTC)[reply]

As it happens, we do have an article about that! It's at Street light interference. (Yes, sometimes it seems Wikipedia has an article about everything.) --cesarb 02:16, 29 January 2007 (UTC)[reply]

Wow! Thanks for that! I always figured that this was just another hint that Jesus hates me. There's a light that does this outside the security gate to my workplace. I didn't realize people actually did some research into it. Dismas|^(talk) 05:51, 29 January 2007 (UTC)[reply]

I've had a similar experience, and always figured that there was some sort of sensor on the lights that turned them off if it saw any reflected light, and that my car or clothing or whatever reflected just enough light, in those circumstances where my presence seemed to turn them off, to trip the sensor. I suppose I do walk past an awful lot of street lamps on a daily basis, some are bound to turn off, and of course I wouldn't notice those that didn't. ^tucker/_rekcut 12:48, 29 January 2007 (UTC)[reply]

The sensors, at least the ones I've taken apart, wouldn't be affected by your passing by for at least two reasons: One, they include substantial time delays for both turn-on and turn-off; they don't change their minds quickly. Two: If properly installed, they tend to be arranged to look towards the northern sky rather than down at you walking by.

Atlant 13:42, 29 January 2007 (UTC)[reply]

i agree with Atlant (again?) that the sensors I had experience of for cotrolling street lighting were mounted on top of the lamp housing looking at the sky. Its difficult to see these sensors from the ground.

I did not however know about this discharge lamps cycling. Is that a design feature or are you taking us for a (bike) ride 8-)--Light current 12:34, 30 January 2007 (UTC)[reply]

:-). But "cycling" is a well-known phenomenon in the life cycle of HID lamps. It's a natural result of the Work function of the cathodes rising as the emissive material is blasted off of them over the life of the lamps, combined with the way the voltage across the arc tube rises as temperature (and so, pressure) rise in the arc tube as the lamp heats up.

Atlant 12:59, 30 January 2007 (UTC)[reply]

Hmmm IDKT. You learn something new every day. THanks for illuminating the process! 8-)--Light current 13:02, 30 January 2007 (UTC)[reply]

I cant see anything in the article about end of life cycling. Maybe someone could add it?--Light current 14:31, 30 January 2007 (UTC)[reply]

I wrote text for Street light interference yesterday; I'll go swipe it into the HID articles.

Atlant 16:56, 30 January 2007 (UTC)[reply]

(Done, although the various cut-n-pastes may have some redundant Wikilinks.

Atlant 17:38, 30 January 2007 (UTC))[reply]

You all have given me excellent answers. Appreciate it very much. I figured that probably I was not unique on this phenomena so was looking for others where this happens. The Wikipedia article Street light interference has touched on the subject pretty close. Now I can call myself either a "SLIer" or a "Puter-Outer". For the "skeptics" I will respond:

Not the "Pauli effect" or "Synchronicity", closer to that of a "Put-Outer". Somehow I am sending out a type of "radio signal" that has a frequency that interfers with the gases igniting within the bulb itself. Also I am not effecting the electrical ballast or associated electronics. It is definitely the igniting of the gases that produces the light.
Recorded it several times on video. To prove that I am the one "sending out a signal" I have had several other people go under the same Street Light and nothing happens; however when I go under it, then "Out" goes the bulb. Or if the bulb is already out, then I turn the bulb back "On" igniting the gases withing the bulb to ignite with a type of a microwave signal.
I have watched the Street Light from a distance with several other witnesses and nothing happens to the bulb for hours. However the minute I go under it, "Out" it goes (video recorded). If it was something mechanical (i.e. light at the end of its life cycle) then it would happen with no person coming close to it - however nothing happens to it on its own.
Many times, once I put "Out" the Street Light, it never comes back on until the electrical power is turned off the following morning at daybreak. Then the Street Light works normally again the next day for hours on end, until I walk under it. If it was of a mechnical or electronic nature then the bulb would re-ignite on its own, however it does not (most times). When other people I send out to go under this same Street Light, nothing happens. Tested this several times to prove it is beyond just a "happenstance" event. It is definitely a type of "radio signal" or "micro-wave signal" or of this nature. It is some sort of electrical signal sent out from the brain interfering with the gases igniting as they were designed to do to produce the light. Also I have figured it is not something I can control; nor is it good or bad. It is just a phenomena that happens, apparently to only a few people worldwide.

Apparently it looks like it is less than 1-in-a-million this happens to. I didn't even know what this was called or that it had an official name ("SLI"), however I knew for a fact it does exist. Is there others out there this happens to also? I would like to hear from others; maybe we can pinpoint its exact source, which is probably a type of a microwave "radio signal".
For the "skeptics": never read Harry Potter, never went to any of the movies. I am an old retiree interested in articles on Francesco Petrarch. --Doug ^talk 14:57, 30 January 2007 (UTC)[reply]

It seems out of the realm of science to answer your question... As alluded to earlier, the chance that you're emitting any significant microwave EM radiation is pretty infintesimal.. -- mattb @ 2007-01-30T15:05Z

It is definitely a science question. Just because the "skeptics" didn't have it happen to them or video record the event themselves, doesn't mean it doesn't exist. Video recording the event takes away "happenstance". This phenomena definitely exist, as others already responded to and know. So, bottomline: Is there others out there this happens to also? I would like to hear from others; maybe we can pinpoint its exact source. Thanks "SLIers" for responding. We will figure out what it really is (scientifically).--Doug ^talk 15:28, 30 January 2007 (UTC)[reply]
Since I started this article, I would like to add some additional information to this article of Street Light Interference after doing additional research recently on the internet. I believe this would relate to primary source and proving this phenomena exists instead of it being a mere coincidence. I have video recorded this on many occassions and it was definitely repeatable. I have several eye witnesses at the time of the video recording the event taking place. One was an apartment maintenance manager to a very large apartment complex. I could get him to sign a statement that he was an eye witness to the event. He held the camera when he took this video when I went under the bulb and make it go out (several times). He had several people adjacent next to him at the time. They are all eye witnesses. Would this then be considered a primary source that this information could be entered into the article Street light interference? Would this be sufficient proof (at least for a start)? What additional proof would be needed to show this phenomena is real?--Doug ^talk 19:53, 30 January 2007 (UTC)[reply]

See Wikipedia:Reliable sources, in particular the part about primary sources. --cesarb 23:52, 30 January 2007 (UTC)[reply]

Suicide question

I've been thinking about suicide a lot lately, and I was wondering if you shoot yourself in the head with a gun (whether it be to the side of the head or in the mouth), do you die in pain because of the incredibly loud gunshot blast? I would assume a gunshot at that close range (literally a few inches from your ear) would be well above 200 decibels and the threshold of pain is 120. I think about 300 is instantly deafening. So would you hear the gunshot a second before you die, thus causing you immense pain in your last second of life? Thanks. NIRVANA2764 01:26, 29 January 2007 (UTC)[reply]

I thought bullets travel faster than the speed of sound anyway. And besides, it would take awhile for the pain to register since 1) Your body would be in shock 2) You'd be dead --⁪froth^T 01:35, 29 January 2007 (UTC)[reply]

Typically bullets travel around the speed of sound. That's beside the point, if you've been 'thinking about suicide' even if you haven't been thinking of actually doing it, please be careful because thinking about it is actually a warning sign, it's on those lists of 'things to look out for'. I've been there too and it sometimes seems too hard to overcome on your own, no matter where you live if you have access to the internet you no doubt have access to suicide support services, it's not something to take lightly, you only get one chance. Vespine 02:32, 29 January 2007 (UTC)[reply]

It takes a long time for signals to travel from the ear to the brain. By the time that happens, you'd always be dead. What I don't understand, though, is why you don't want to endure only a very short-lived pain if you truly want to suicide. If even that small pain matters, then your life is probably not horrible enough for something like suicide to be warranted. --Bowlhover 04:35, 29 January 2007 (UTC)[reply]

People who commit suicide also don't think about the impact that it has on the people around them. Families and friends see a life that has been wasted, and have immense trouble coming to grips with the fact that someone they care about decided to kill themselves. Suicide is not a solution. Problems are only temporary, and suicide is permanent. It cannot be undone. BenC7 01:43, 30 January 2007 (UTC)[reply]

Not to defend the OP (i obviously don't know anything about him; he certainly might be crazy as a loon), but that is a bull-shit arguement. No-one is obligated to keep families and friends feeling warm and fuzzy, especially not if it involves suffering for them. This is the same arguement relatives sometimes use when they disapprove of a person's life-style -- e.g., Don't marry that man, can't you see it's killing your mother? How can you be so selfish? or How can you be gay? This will crush your father. Can't you think of anybody but yourself?

Certainly suicide is a pretty serious issue that often (but not always) has its roots in some mental illness, and this is a factor to consider, but the last thing a person in such a position should have to worry about is somebody guilt-tripping them about wanting to end their suffering. ~ lav-chan @ 23:11, 30 January 2007 (UTC)[reply]

Wrist Pain

I don't think it's carpal tunnel (wrong side). I'm getting it by typing in a very weird position, with my laptop on about a 45 degree angle up against my knees. On the upper side of my right wrist-to-forearm which is (currently) typing not only at this incline but at another 45 or so degree angle into the keyboard (so my arm is laying from the corner of the keyboard plane to the center), I'm getting what may or may not just be muscle tiredness from typing in this weird position. The muscle that's tired is the one on the upper-front forearm that stiffens (ie flexes) when you cock your hand back to be nearly perpendicular to your forearm. It's tired close to the wrist. I know you aren't supposed to give medical advice, but does anybody think this is something to worry about? If I keep typing like this, will the muscle get used to it so I can continue, or will I get an injury? Thanks, Sashafklein 03:47, 29 January 2007 (UTC)[reply]

If it was me, I'd stop. A 45 degree angle is a lot for the wrist to keep bending at while typing and operating. Try sitting cross-legged so the laptop will be flatter, so sit at a coffee table. But this is not medical advice, just advice. --Wirbelwindヴィルヴェルヴィント (talk) 03:55, 29 January 2007 (UTC)[reply]

^{The following could be considered medical advice and may be removed summarily.}

If you want to cripple yourself, keep typing as you have been. If the muscles 'get used to it', they will basically be seizing up, and you may lose flexibility, range of motion, and sensitivity. If you absolutely must keep typing, change your typing arrangement whenever you begin to feel discomfort. Vranak

So nobody thinks there's any chance that it's just a rarely used muscle group in need of some exercise? It doesn't feel acutely painful or anything, just sort of like doing a weird weightlift you've never tried before and tireing out immediately. Sashafklein 04:46, 29 January 2007 (UTC)[reply]

Nobody is going to be able to say that, because this is a medical question, and suggesting to you that a pain you have developed is nothing to worry about would be extremely irresponsible. All we can say is "see a doctor", and I really mean that. If you keep working on, for example, a repetitive strain injury, you could make it much worse and give yourself problems for life. Go and see someone who's qualified to tell you what's wrong and what to do. Skittle 22:34, 29 January 2007 (UTC)[reply]

Symptoms of Insomnia -- Burning Eyes

Hi,

I was wondering why your eyes burn after not getting enough sleep? I also am curious if there is a way to counteract this effect?

Thanks,

Best Username Ever 06:25, 29 January 2007 (UTC)[reply]

Counteract? Sleep. Problem solved. -- mattb @ 2007-01-29T06:27Z

Thank you so much! I've tried eye drops but those are a hassle and don't work very well. Anyone know why it happens?--Best Username Ever 06:33, 29 January 2007 (UTC)[reply]

There's an eye massage that I use that works fairly well for me. With two fingers on each hand, massage in circular motions (approx 10 circles counterclockwise and 10 circles clockwise) 4 areas: Roughly the center of the eye-lids when you close your eyes, where you can feel the bottom part of your eye socket under your eye, the area between your eyes at the top of your nose (bridge? forgot what it's called), and about an inch forward of your temples. Do it fairly gently. I learned it from my sister who learned it from her teacher, many years ago, and I still use it when my eyes are sore because it seems to work. Also note that this is not medical advice, and it's what I personally do. --Wirbelwindヴィルヴェルヴィント (talk) 06:46, 29 January 2007 (UTC)[reply]

Thanks!--Best Username Ever 11:43, 29 January 2007 (UTC)[reply]

Your eyes are dry. You blink less frequently when you get sleepy in an attempt to make your eyes dry, to make your eyes close to alleviate the problem. (that's what I read on the desk last year) I take care of this by... squirting out more water. I don't know how to explain that one! [Mαc Δαvιs] X (How's my driving?) ❖ 18:55, 29 January 2007 (UTC)[reply]

I think burning eyes is a symptom of your eyes being on fire..... Sorry, couldn't help it! Vespine 21:40, 29 January 2007 (UTC)[reply]

Power Grid Failure Solution

We know that throught the nearly full loaded grid, if one line were to overload , it would trip thereby causing the entire grid to trip causing a blackout. Instead Why NOT place additional circuit breakers at every distribution point, so in case that node is causing the overload, only that node distribution point would trip saving that particular grid and then avioding the blackout?Somewhat similar analogy to the domestic Fuses in our house.

Your supposition is false. Power grids are WAY more complicated than just cascaded loads and cascade failure is designed out meaning it takes multiple failures of the system to induce a cascade failure. Tbeatty 08:43, 29 January 2007 (UTC)[reply]

But even if it were true, reflected energy from an instantaneous open is a problem just as big (or bigger) than cascade failure. Imagine a power plant that generates 3,000 MegaWatts and delivers it 1000 miles. It takes time to go 1000 miles. If suddenly the load is no longer there, that energy is reflected back to the generator. This is animpedance mismatch and can destroy the generator. Tbeatty 08:43, 29 January 2007 (UTC)[reply]

The whole picture is indeed a bit complex. Quick summary (will vary depending on where you live): the power network has three or four voltage levels: distribution voltage (e.g. 400 kV), high voltage (e.g. 100 kV), medium voltage (e.g. 20 kV) and low voltage (e.g. 0.4 kV which gives 230 V in a two phase wall socket). The line that comes out of a generating plant is HV (the generator is really more like MV, but there's a transformer.) HV gets converted down to MV in a distribution substation. The substation has a big transformer or two with e.g. 10-20 feeders (outgoing MV lines). The feeders are guarded by microprosessor-driven relays. The relays automatically trip if there is an MV short circuit or similar fault specific to that feeder. The relays can also be remote controlled. If the frequency in the whole network starts to drop (i.e. there is a general overload), a centralized computer will start reducing load by tripping MV feeder relays. Each MV feeder trip will black out a couple of city blocks or a handful of residential streets. This happens automatically and takes a few seconds, until an acceptable frequency is restored. It can also be done to a pre-engineered plan, resulting in rolling blackouts. As the article on power outage mentions, complications may arise in this process. Weregerbil 12:56, 29 January 2007 (UTC)[reply]

Another problem is defining exactly what we mean by an "overload". Because of the diversity factor, you won't find that (to radically simplify things) the generator has a 100 amp circuit breaker and there are five loads with 20 amp circuit breakers. Instead, because power system designers know that the likelihood of every customer having everything switched on all at once is essentialy nil, there may be 20 loads with 20 amp circuit breakers. The downside is that on a hot summer day or a cold winter day, the generator can be overloaded even while every individual 20 amp branch is running well under its limit.

This is why the entire grid can go down even though no individual distribution circuit has faulted. That's why adding more breakers won't solve the problem.

Atlant 13:37, 29 January 2007 (UTC)[reply]

What may be slightly surprising at first is that overload (of the non-short-circuit kind) is not detected by looking at amperage or voltage, but frequency. When there is too much load, the generators at the power station won't have enough input energy (water, steam, etc) to turn them fast enough. Generator turns slower = frequency drops. This is bad because then different generators are trying to feed electricity into the same wires at different frequencies and different phases. So in high quality networks (discounting developing countries etc) the frequency tolerance is pretty strict. If frequency drops, first power stations will try to increase input energy; e.g. open another dam hatch to let in more water. If that fails to fix the frequency, load reduction and other measures can start. Weregerbil 15:00, 29 January 2007 (UTC)[reply]

The frequency drops when the load is greater than the connected generators can supply. Witin limits the governors on the generators open or close steam valves or the equivalent on diesels to regulate the frequency within a narrow range, until they have adjusted as far as they can go. Frequency drop beyond a certain limit causes relays to automatically drop preselected loads (ones with no critical load such as the water pumping plant or a hospital) untili the load matches the generating capability. Then, once a generator is brought back on line or a tie line is reclosed to another utility, the load can be restored. If the whole system goes down, it can take many hours to restart the system, since most generators have to trip off line when the connected grid goes dead, and cannot restart without large amounts of auxiliary power from the grid to operate pumps etc. As for line relays, the relays are usually set to trip for fault current, which is usually much more than it takes to overload the line and cause it to fail from overheating. Such overloads should sound an alarm at the control center, and the operator should take action, such as closing a bus tie or correcting an abnormal switching configuration due to an oops error (OOPS, WE PUT THE TOWN ON A 1 LINE FEED WHEN IT TAKES 3 LINES TO SUPPLY IT.) Some utilities have "transformer overload relays" which do trip a transformer when it is so overloaded as to exceed its short term emeregency rating, because transformers can take months to replace, much longer than burned down conductors. Unlike in, say, radio transmission lines, the impedance of the generator is usually way less than the system impedance, which means the voltage is easier to keep constant as the load varies. There are lightning arrestors or similar overvoltage surge protection which would probably reduce the high voltage spikes from switching transients. Therefore, I would not expect a switching transient from an opened line to destroy a generator. The transient would also be intercepted by the impedance of the generating unit transformer. But stability considerations might well require the generator to trip offline if a large portion of the load were suddenly dropped by a system disconnection. Large utility generators trip offline a lot, since they would rather have a false trip than buy a replacement generator. The original questioner's observation that a trip of one line can cause a cascading blackout has held true numerous times since the U.S. Northeast Blackout of 1965. A lot of thought has gone into system relaying, improved operator training and improved system monitoring and displays. A good system does contingency analysis 245 hours a day, to see if the loss of, say, any generator and any line, or any transformer and any line, would start a cascading blackout. They can arrange for more purchased power, or tell interruptible rate customers to shut down or go on generators to reduce the hazard. If the cascade starts, they must initiate rolling blackouts and voltage reduction to keep the system alive until the overload is corrected. A bad utility system has poorly trained operators and does not give them the big picture of where the overloads are and what has tripped, so each individual utility has only a limited view of the expanding problem, This can allow a failure of 1 or 2 lines to snowball into outages in 2 countries. Automatic relays are best, because then no operator is too afraid of losing his job to do his duty without calling some executive at home to get permission, as happened in the 1965 New York blackout. It is an exhilarating experience to see a system control room in action on a new peak load day, with operators sweating to see if they will make it through the peak load, without knowing how high the peak will be, and ready to initiate the dreaded relief measures if necessary. It has been described as being like a guy with a hotrod car going 100 miles an hour and wondering if it can go 110. Edison 21:43, 29 January 2007 (UTC)[reply]

renewable energy sources and non-renewable energy sources

what are the differences between renewable energy sources and non-renewable energy sources? —The preceding unsigned comment was added by 61.246.87.56 (talk) 06:57, 29 January 2007 (UTC).[reply]

You should check out the links I've added to your question...all shall be answered! -- Scientizzle 07:12, 29 January 2007 (UTC)[reply]

Dopamine reuptake inhibitor (Want References) (still not clarified, eh)

Q1. I am looking for references to back up this paragraph:

In general, the abuse potential of DAR inhibitors depends on how they affect the pattern of dopamine release and reuptake. Compounds that inhibit reuptake and also induce release of dopamine, such as methamphetamine or phenmetrazine, or compounds that inhibit reuptake but have no effect on release, such as cocaine or methylphenidate, tend to be addictive drugs with potential for abuse in humans. ^{[citation needed]} On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as bupropion and vanoxerine, have mild stimulant effects and little abuse potential, and can be used to treat stimulant addiction. ^{[citation needed]}

I would appreciate the references provided. Thank you. --Parker007 07:10, 29 January 2007 (UTC)[reply]

this mentions the addictive properties, in relation to preventative treatments; this mentions addiction's reuptake patterns in general, and then in relation to methadone and some othe B-drug that I forgot the name of. All provided by this Goog search. V-Man737 07:10, 30 January 2007 (UTC)[reply]

Please explain how the above references are actually related to: "On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as bupropion have mild stimulant effects and little abuse potential." I would much appreciate a reply. Thanks. --Parker007 07:30, 30 January 2007 (UTC)[reply]

Oh - now I see the first article doesn't mention Bupropion specifically... hrmph. Perhaps the sentence in the article should be changed to match the source, rather than whoring up a source to fit an exact claim? I'm sorry for the scanty help, it's past my bedtime... V-Man737 07:44, 30 January 2007 (UTC)[reply]

Name of multi-step action

When you set up objects to affect each other in consecutive motions to result in one ultimate action, what is the name of the action? (i.e. To get toothpaste on my toothbrush, I might set up a 16 step operation that starts with dropping a ball on a lever.) Is there a name for this? —The preceding unsigned comment was added by 64.19.108.85 (talk) 07:12, 29 January 2007 (UTC).[reply]

Domino effect? --Wirbelwindヴィルヴェルヴィント (talk) 07:25, 29 January 2007 (UTC)[reply]

Algorithm, perhaps, is what you are looking for... --Proficient 07:51, 29 January 2007 (UTC)[reply]

Err, this sounds like you want a Rube Goldberg machine. —The preceding unsigned comment was added by 149.135.104.21 (talk) 09:08, 29 January 2007 (UTC).[reply]

Or Heath Robinson contraption. Skittle 17:38, 29 January 2007 (UTC)[reply]

Also see Decomposition (computer science) (although the concept is far more generic to all engineering disciplines than just computer science).

Atlant 13:39, 29 January 2007 (UTC)[reply]

Thank you for your help. Rube Goldberg machine is what I was trying to remember.

Mistake in The Blind Watchmaker?

There is a part The Blind Watchmaker where Dawkins analyzes the doppler effect wrt echolocation/sonar in bats:

It is relative motion that matters, and as far as the Doppler Effect is concerned it doesn't matter whether we consider the sound source to be moving past the ear, or the ear moving past the sound source. If two trains pass in opposite directions, each travelling at 125 m.p.h., a passenger in one train will hear the whistle of the other train swoop down through a particularly dramatic. Doppler Shift, since the relative velocity is 250 m.p.h.

Isn't the statement that only relative motion matters in sonar a mistake? I seem to recall that the calculations for the doppler shift with sound waves include the speed of the observer and the speed of the source as distinct entities (rather than just subtracting them for the relative speed). From my reading of Wikipedia's article on doppler effect, it seems that this is because the two speeds are judged with respect to a stationary medium, air. On the other hand relative motion is in fact the only thing that matters if you consider radar, which has no medium.

Is this passage in fact mistaken, or is it my reasoning that's flawed? --JianLi 08:58, 29 January 2007 (UTC)[reply]

The relative motion includes both speeds of the observer and sound emiiter -so both are right - 87.102.2.226 09:59, 29 January 2007 (UTC)[reply]

Our article is confusing. I think it is written to include the case of a strong wind! Other sources make it very clear: The Doppler effect is the apparent change in the frequency of a wave motion when there is relative motion between the source of the waves and the observer. So, Dawkins is right, and our article has been written for philosophers! --Zeizmic 14:03, 29 January 2007 (UTC)[reply]

For waves that travel in a medium (e.g., sound; not light, as you said) there are in fact two shifts (although they need not be non-zero): the waves in the medium away from the source have a different frequency than the source's frequency if the source is moving with respect to the medium, and the observed waves differ from that in the medium if the observer is moving with respect to it. These two effects are distinct, and have different equations, even; you will in fact get a Doppler shift even between two objects moving at the same velocity through the medium, so long as they are far enough apart that they do not force the intervening medium to adopt their velocity. As a special, singular case, consider two jets moving at the speed of sound along the same course: though they have no relative motion, the front one can never hear the back one because the waves can never catch up (corresponding, with some abuse of the mathematics, to 0 frequency). The point there about motion at the speed of sound negating all sound from the rear (as in directly behind) applies regardless of the speed of the source, of course, so Dawkin's analysis is fundamentally incorrect. That said, for velocities that are small relative to the wave velocity, they will approximately add as he suggests; note, however, that

250{\text{mph}}\not \ll c_{\text{sound}}

at normal conditions. --Tardis 17:57, 29 January 2007 (UTC)[reply]

Thanks, that makes sense. --JianLi 01:36, 30 January 2007 (UTC)[reply]

Water and Ice

How much does water expand by when it freezes? —The preceding unsigned comment was added by 193.120.72.83 (talk) 12:53, 29 January 2007 (UTC).[reply]

Ice#characteristics "Ice has a density of 0.917 g/cm³ at 0 °C, whereas water has a density of 0.9998 g/cm³ at the same temperature"

Volume =mass/density therefore volume change = mass x(1/0.917 - 1/0.9998) = mass x 0.0903 (4decimal places)

I cubic centimeter of water at 0 C weighs 1/0.9998 g

So the volume change for 1 cubic centimeter = 1/0.9998 x(1/0.917 - 1/0.9998) = 0.0903

Thats an increase of 9%.87.102.4.142 13:35, 29 January 2007 (UTC)[reply]

Fourier transform on random signals

Consider a chord of three notes. The resulting signal in time will be the sum of these wave functions, and therefor a periodical function. If I have understood well, performing a fourier transform on this function results in a new function that is zero everywhere except at the three frequenties of the notes, right? Now consider a random signal (eg a phone call). Is it useful here to fourier transform that signal, for it is not periodical? If so, how? Thanks for any help--Gnorkel 14:11, 29 January 2007 (UTC)[reply]

Sure it's useful.. "Real" signals are seldom composed of a couple of simple pure frequencies that lend themselves to the easy continuous Fourier transform. See DFT and FFT. -- mattb @ 2007-01-29T15:16Z

The reason the transform can still be very useful is that a signal can often be much-more-compactly represented in the frequency domain rather than in the time domain. This is easy to see: I'll hum a note for you. In the time domain, you need a long sequence of samples with the samples continuing for as long as I hum. But take the Fourier transform of my humming and you've basically got it captured and that one sample represents my humming for as long as you care to go on.

It's not quite that simple, of course, but the Fourier transform is the basis for many of the audio compression algorithms out there today. I believe you'll find that that's the case for DAT, MP3, and AAC encoding among others.

Essentially, we take "time slices" (say, 100 ms) out of the waveform and perform the transform on those slices.

Atlant 17:24, 29 January 2007 (UTC)[reply]

What you mean by "random" here is really "posessing dominant frequencies which change over time", yes? That's what characterizes, say, music. Then what you want is the Short-time Fourier transform or some variant thereof. Does that help? --Tardis 17:27, 29 January 2007 (UTC)[reply]

If you want to be pedantic, sure, but a lot of the DSP texts I've seen refer to "random signals" in the treatment of the DFT... It's a pretty physically accurate description. -- mattb @ 2007-01-29T20:17Z

Thanks for helping me out. The concepts of time slices an stft were what I was searching for. --Gnorkel 17:50, 29 January 2007 (UTC)[reply]

Time slices slowly and silently its bread for breakfast. -- DLL ^{.. T} 19:18, 29 January 2007 (UTC)[reply]

postgraduate studies

what are the functions of the postgraduate medical institute? —The preceding unsigned comment was added by 204.16.125.203 (talk) 15:38, 29 January 2007 (UTC).[reply]

Well if it isn't obvious, to offer postgraduate education in the field of medicine. There is a little more to it then that but it varies, if you google postgraduate medical istitute you can read the different things they do. Vespine 21:16, 29 January 2007 (UTC)[reply]

Ringing in the ears

My ears ring all the time. Usually, most other sounds drown it out, but if I concentrate, I can hear it. Or at night or in a very quiet place, I can hear it really well. What causes it, is there a fix, and what is the long-term effects? Thanks Civil Engineer III 17:26, 29 January 2007 (UTC)[reply]

While I would say it sounds a lot like tinnitus, it's very possible it could be something else. I would recommend you ask a real-life doctor about it, as he would be far more able to answer this question safely. Also, he's more likely to be able to do something about it! Skittle 17:31, 29 January 2007 (UTC)[reply]

It is tinnitus; that's just a general term that refers to hearing noise when no external sound source exists. It can be caused by a multitude of different things though. We most definitely can not figure out the cause for you, nor the long-term implications, nor possible treatments. -- Consumed Crustacean (talk) 18:32, 29 January 2007 (UTC)[reply]

We can only refer you to your doctor. Tinnitus contains some general information on the subject, and says it can have a variety of causes and a variety of possible treatments or remediation methods. A white noise generator such as the "Sleep Sound" [8] consisting of a fan in a plastic box, can mask sounds such as tinnitus, traffic noise, or someone's snoring while you're sleeping. But definitely see a doctor if it is a medical question. Edison 22:01, 29 January 2007 (UTC)[reply]

Get some real dope hear! [9]--Light current 14:38, 30 January 2007 (UTC)[reply]

Out of band emission regulations in the United States

I am looking for out of band emission limits for intentional radiators in various frequency bands for in the US. I work for a company that is doing research into UWB transmission techniques and we have become aware of a company which seems to be doing UWB in areas (centered in the 900MHz unlicensed band but covering other bands)other than those set aside for UWB (3.1-10GHz). This company is a larg(ish) start-up and is traded on the london "AIM" market thus they are probably not just "flying under the radar". Also they claim to have received FCC "approval". Anyway I am wondering how this works and what the power limitations are for other bands thna the 900MHz band (i.e 2.4GHz and licensed band such as those used for cellular communications).

Note: I called the FCC and was directed to an area of there web. This was helpful but since there were thousands of pages of information it was a little to much to wade through...I am looking for someplace where it is neatly summarized.

THANKS!Duncan St. Ives 19:41, 29 January 2007 (UTC)[reply]

You've seen our articles at Unintentional radiator, Intentional radiator, Incidental radiator, and Product certification, right?

Atlant 19:36, 29 January 2007 (UTC)[reply]

Yeah but I need specific numbers... In power or some reletive measure (such as percentage or DB down from the carrier). Also I forgot to sign my earlier post :)Duncan St. Ives 19:41, 29 January 2007 (UTC)[reply]

NITRIC OXIDE AND IMMUNITY

What is the role of nitric oxide in the immune system?Wizzybone 18:30, 29 January 2007 (UTC)[reply]

See Nitric_oxide#Biological_functions! [Mαc Δαvιs] X (How's my driving?) ❖ 18:44, 29 January 2007 (UTC)[reply]

Sex

How long does an average man take to orgasm? what about average woman? what about for masturbation, are these times different? — Preceding unsigned comment added by 209.53.180.18 (talk • contribs)

Premature ejaculation is an interesting read, and it may raise questions to whether or not premature ejaculation is something normal, due to the definitions posed. "How long" greatly depends on the circumstances; I'm sure somebody else can give a better answer. [Mαc Δαvιs] X (How's my driving?) ❖ 23:20, 29 January 2007 (UTC)[reply]

Condoms

Is there any harm in wearing it tight enough to supress semen excretion? would that comprimise pleasure? would it even still be possible for the man to orgasm? — Preceding unsigned comment added by 209.53.180.18 (talk • contribs)

IF you'd actually achieve the feat of putting a condom on tight enough to supress semen excretion in this manner, yes, that would be quite harmful I'd suppose. --Ouro 21:17, 29 January 2007 (UTC)[reply]

I believe that most condoms have a pocket for semen in front, as in Image:Condom_unrolled.jpg. Thus it doesn't seem anatomically possible to wear it tight enough to do what you describe. -- SCZenz 21:21, 29 January 2007 (UTC)[reply]

The old joke is, a man asks an advice columnist 3 questions: 1)How can I keep from getting the girl pregnant and also prevent STDs? 2) How can I ensure that I don't orgasm too quickly? 3)How can I make my member seem larger? And the answers were 1) Wear a condom. 2) Wear 2 condoms. 3) Wear 3 condoms. Of course this is only presented as lame humor, and you should get all condom advice from a doctor or condom expert. Edison 22:07, 29 January 2007 (UTC)[reply]

A chemestry major once told me that wearing two increases the chance of malfunction cause it rips. Well, didn't tell -me-, specifically. --Wirbelwindヴィルヴェルヴィント (talk) 23:01, 29 January 2007 (UTC)[reply]

Last time I was at the condom page it had instructions on proper technique for putting one on. As I remember, it recommended pinching the end so there is a small bit of space at the tip (if it doesn't come with one). Also, retrograde ejaculation in males can be harmful and painful. It would still be possible for the man to orgasm, that doesn't even take ejaculation. [Mαc Δαvιs] X (How's my driving?) ❖ 23:25, 29 January 2007 (UTC)[reply]

I also doubt the validity of the assumption that you can wear a condom tight enough to supress semen at all. If the condom is pulled back so tight that there is no "air pocket", the semen excretes down the side of the penis, which is why you're supposed to make sure that there's some air in the first place. I find it hard to believe that you could maneuver on a condom tight enough to supress exretion on the sides, while fitting snug enough to remove the air pocket. You'd probably risk serious damage to your penis. freshofftheufo ΓΛĿЌ 01:39, 30 January 2007 (UTC)[reply]

Animal mating

Do animals rape one another? — Preceding unsigned comment added by 209.53.180.18 (talk • contribs)

Male orcas have been observed appearing to 'gang up' on lone females and copulate with them. I read that item a while ago, don't know if the observations have been repeated, refuted or analysed since I first encountered the info. But in a broader sense, the concept of 'rape' is dependent upon the wishes of the 'victim', and there are arguably few species of animals that have sufficient social, intellectual and emotional complexity (combined with the ability to resist hormonal urges) to be able to object to sexual activity. Anchoress 21:39, 29 January 2007 (UTC)[reply]

I watched a documentary on koalas (on the Discovery Channel, I think) where a male jumped onto a female in a tree, began copulating with her. There were screeches, but it wasn't clear which of the two was making the sounds, and eventually—perhaps after he had finished—she got him off and aggressively chased him away. − Twas Now ( talk • contribs • e-mail ) 22:41, 29 January 2007 (UTC)[reply]

In Richard Wrangham and Dale Peterson's book Demonic Males, they recount a few instances of rape in primates, specifically orangutans. Mature male orangutans develop very striking features, including large size and prominent cheek pouches. Females invariably choose to mate with these mature, dominant males. But some adolescent, undeveloped males have been observed forcing sex on unwilling females. The book even recounts an instance in which an orangutan in a wildlife preserve raped a (human) female employee. TheSPY 00:54, 30 January 2007 (UTC)[reply]

Shaving

why does shaving make hair grow thicker and stronger? also, how does hair "know" when to stop growing? for example, i shaved my eyebrows off once, and as expected, they grew back steadily until 6 or 7mm then stopped growing. why? why doesnt head hair and beard "know" when to stop?

To the first question, I'm not sure that it does. Shaving a) makes the regrowth blunt at the tip, which can make it seem stiffer; b) sometimes makes the regrowth lie differently, at a more obtuse angle to the skin; and c) makes the hair feel stiffer while it's shorter. Anchoress 21:35, 29 January 2007 (UTC)[reply]

Hair typically grows for a while and then falls out. If the average time until falling out is enough time to produce 6 or 7 millimeters of hair, that's how much you get; the hair never actually stops growing. --Tardis 21:52, 29 January 2007 (UTC)[reply]

The notion that shaving can cause hair to grow in faster seems like a meltdown of logic to me, whether or not it's true. I mean, what is the objectionable thing here, the rate of growth, or the hair itself? Vranak

I was under the impression that hair growing faster was an urban legend. Splintercellguy 05:39, 30 January 2007 (UTC)[reply]

Yup. http://www.snopes.com/oldwives/hairgrow.asp --Shantavira 09:20, 30 January 2007 (UTC)[reply]

Lk to hairy site. [10]

There's been a long history of study in this field. The general consensus is that shaving doesn't make hair grow back thicker or tougher, however it may seem that way. (The cut tip of the hair is blunter than an uncut tip; short, bristly hairs seem more rigid than longer strands.)

There's significantly more dispute over the effect on growth rate. Published studies on this question go back more than a century; if your university library has an online subscription to the American Journal of Physiology, you can start with Raymond J. Seymour, "THE EFFECT OF CUTTING UPON THE RATE OF HAIR GROWTH", Am J Physiol (1926) 78:281-6. Seymour found that beard hair growth was fastest in the 12 hours immediately after cutting, and later slowed.

On the other hand, Lynfield and Macwilliams report that shaving has no effect on leg hair growth rate in "SHAVING AND HAIR GROWTH" (1970) Journal of Investigative Dermatology 55:170-172.

Those of you trying to conceal your age will be disappointed by W. Nagl's report "Different growth rates of pigmented and white hair in the beard: differentiation vs. proliferation?" Brit J Dermat (1995) 132(1):94-97, which found that white beard hairs grow nearly three times as fast as pigmented hairs.

I saw a fairly recent result that suggested the stimulatory effect of shaving was short-lived, and was followed by a period of quiescence in which growth rate slowed; this meant that over a day or two following a shave, the average rate of hair growth was comparable to that observed in an unshaven control. Unfortunately, I can't find the reference, so if anyone can help out it would be appreciated. TenOfAllTrades(talk) 15:21, 30 January 2007 (UTC)[reply]

(1) As mentioned, it doesn't make it grow thicker or stronger. It only appears thicker. (2) Hair grows in three stages. The length and frequency of these stages depend on the area of the body the hair is growing in. In the case of eye brows, i've heard that these hairs go through their cycle relatively quickly (i don't remember the exact number, i think it's like one or two weeks). At the end of this cycle, the hair stops growing, and eventually it is displaced by a new hair, which goes through the same cycle all over again. This keeps the hair at a relatively constant length. ~ lav-chan @ 22:58, 30 January 2007 (UTC)[reply]

Dependance on humans

Wikipedia articles state that cats and dogs are carnivores. What about small dogs like poodles, and some domestic cats.. they look too small and helpless to hunt. if abondoned in the wild, would they be able to feed themselves? are all or at least any of the common breeds of domestic dogs and cats evolved into dependence on humans? —The preceding unsigned comment was added by 209.53.180.18 (talk) 21:15, 29 January 2007 (UTC).[reply]

I'm no expert, but I'd be inclined to believe that thanks to domestication and selective breeding, certain breeds of dogs and cats are indeed now quite useless at survival and would be quite unlikely, in the wild, to survive more than a couple of generations before being wiped out. We've been creating breeds that would surely be ill-equipped for life outside of human care. Maelin (Talk | Contribs) 23:37, 29 January 2007 (UTC)[reply]

Cats certainly can go feral if released into the wild, they can feed on birds and rodents, they obviously have more of a wild streak then dogs like poodles, I would guess dogs like pugs would indeed probably not survive very long in the wild, but then again, so would probably most humans that grew up in a city if released into the wiild. Dogs were, by the way, the very first animal to be domesticated, the domestication article is very interesting. Vespine 00:55, 30 January 2007 (UTC)[reply]

The article's reference to "carnivore" was to their diet, rather than their behavior. It's talking about the types of things their teeth and digestive systems are designed to eat. "Carnivore" doesn't necessarily mean "hunter." And I haven't checked the article recently, but it should probably state that domestic dogs are omnivores, not strict carnivores. Most domestic animals (and many plants) end up dependent on humans. If we "freed" domestic chickens, even a poodle would be able to dispatch them pretty easily. If we "freed" corn, it would die in a generation or so, because it's not really capable of breeding in its domestic form. TheSPY 01:00, 30 January 2007 (UTC)[reply]

Tree shrews are the smallest mammals, but the most ferocious. They will attack and kill a mouse weighing twice as much as they. So a little predator needs only find a smaller prey. "So naturalists observe, the flea hath little fleas upon his back to bite'em. And little fleas hath lesser fleas, and so proceeds, ad infinitem." Edison 05:56, 30 January 2007 (UTC)[reply]

Pet breeds

are all breeds of pet dogs subspecies of the same species? what about for domestic cats?

The answer to both questions is yes. --NorwegianBlue^talk 22:26, 29 January 2007 (UTC)[reply]

Actually, all dogs are the same subspecies. Some recent discussion of this has occurred here and here − Twas Now ( talk • contribs • e-mail ) 22:30, 29 January 2007 (UTC)[reply]

Yeast

What is the one thing that yeast can do that no other living organism can. Deniselemons 21:39, 29 January 2007 (UTC)[reply]

Is this a riddle? Is the answer 'turn water into wine'? Anchoress 21:41, 29 January 2007 (UTC)[reply]

Make more yeast? --Tardis 21:49, 29 January 2007 (UTC)[reply]

Be yeast. − Twas Now ( talk • contribs • e-mail ) 22:33, 29 January 2007 (UTC)[reply]

Well, according to the Bible, Jesus turned water into wine, and I don't think he was yeast. --Wirbelwindヴィルヴェルヴィント (talk) 22:58, 29 January 2007 (UTC)[reply]

And the Yeast shall be the Foist. --Justanother 15:33, 30 January 2007 (UTC)[reply]

Perhaps Jesus was yeast. Who are we to say? − Twas Now ( talk • contribs • e-mail ) 23:47, 29 January 2007 (UTC)[reply]

Yeast does float on water... DMacks 23:55, 29 January 2007 (UTC)[reply]

So do some people ;) A ecis^Brievenbus 00:05, 30 January 2007 (UTC)[reply]

I feel I should point out that yeast cannot turn water into wine. Theresa Knott | Taste the Korn 00:37, 30 January 2007 (UTC)[reply]

A valid point! − Twas Now ( talk • contribs • e-mail ) 04:28, 30 January 2007 (UTC)[reply]

Tom Pryce/Jansen Van Vuuren collision

hey folks, i have a doubt about the tom pryce fatal crash: i dont know how much a f1 racing car weighed at 1977 but i think that jansen, who was crossing the track at 2km p/h weighed 68 kgs, and he was hit by the car at 350 km p/h, please i wanna know how much the impact weighed, thanks.--201.9.73.29 21:50, 29 January 2007 (UTC)[reply]

I'm sorry, but your question about Tom Pryce doesn't make sense as written. Could you perhaps explain what your doubt is about the crash, rather than asking for a specific quantity (collisions don't have mass), and maybe somebody could help. --Robert Merkel 23:07, 29 January 2007 (UTC)[reply]

He was asking about Tom Pryce. I don't know what the weight is without knowing the acceleration. However, here are some calculations for momentum (in SI units), assuming Pryce was moving at 5.0 km/h (2km/h is very slow):

Momentum_{Pryce walking} = 68kg × 5.0 km/h × 1000 m/km × 1h/3600s = 94.44444444 kg m/s

Momentum_Car = 605kg × 350 km/h × 1000 m/km × 1h/3600s = 58,819.44444 kg m/s

|Momentum_Sum| = √ (Momentum_{Pryce walking}² + Momentum_Car²) = 58,819.52027 kg m/s

Angle = tan(94.44444444 ÷ 58,819.44444) = 0.091998025°

I hope these are correct (and helpful), it's been a while since I've done trig. − Twas Now ( talk • contribs • e-mail ) 23:33, 29 January 2007 (UTC)[reply]

Actually was Jansen Van Vuuren(who was a safety marshal) who was walking the track, and Pyrce was the guy piloting the f1 car, being hit by 58 tons is really scary, but this helped, thanks.--201.9.11.148 00:30, 30 January 2007 (UTC)[reply]

If by "what the impact weighed", you mean the force imparted, then the impulse imparted to Vuuren, assuming that he was crossing the track perpendicular to the direction of the car (hence his velocity in that direction was 0), would have been ~58,819 kg m/s (or Ns). The collision would have taken place in a fraction of a second, so he would have experienced a force of well over 59,819 Newtons, equivalent to almost 6 tonnes of force. Laïka 14:54, 30 January 2007 (UTC)[reply]

Craters on Mars

According to the planetary nomenclature, small craters on Mars are named after towns on Earth with a population of less than 100,000. But how come there's also a crater called Amsterdam? A ecis^Brievenbus 22:22, 29 January 2007 (UTC)[reply]

See Amsterdam. :-) --NorwegianBlue^talk 22:28, 29 January 2007 (UTC)[reply]

Thanks for the quick answer. I could have guessed... I've corrected the list of craters on Mars. A ecis^Brievenbus 22:51, 29 January 2007 (UTC)[reply]

Sorry, it was a joke, and I realise now that it was not a very good one. --NorwegianBlue^talk 23:51, 29 January 2007 (UTC)[reply]

I am much more inclined to believe it is Amsterdam (city), New York (not to be confused with Amsterdam (town), New York). The town in Saskatchewan has less than 25 people! − Twas Now ( talk • contribs • e-mail ) 22:59, 29 January 2007 (UTC)[reply]

And I've made the appropriate change at List of craters on Mars. There must be a database out there with which we can verify this. − Twas Now ( talk • contribs • e-mail ) 23:02, 29 January 2007 (UTC)[reply]

According the USGS, it was named after the Dutch port city (i.e. the capital) in 1979 [11]. A ecis^Brievenbus 23:19, 29 January 2007 (UTC)[reply]

Same according to NASA's list of craters. Most of NASA's staff are men, they are from Mars and should know. (I made one appropriate change at List of craters on Mars, but maybe the less-than-100,000 bit needs to be removed or the exception(s) need to be named. ---Sluzzelin 23:26, 29 January 2007 (UTC)[reply]

Perhaps (I'm just speculating here) those craters were named after the cities before the criterion of less-than-100,000 was established. That, or we've missed/omitted a criterion. Because there are quite a few exceptions to this rule: Amsterdam, Bordeaux, Bremerhaven, Bristol, Cadiz, Cairns, Canberra, Charleston, Innsbruck, Johannesburg, Kaliningrad, ... A ecis^Brievenbus 23:55, 29 January 2007 (UTC)[reply]

Drugs that increase semen volume

We've heard of all the ones that decrease sperm production, what about increase semen volume? [Mαc Δαvιs] X (How's my driving?) ❖ 23:18, 29 January 2007 (UTC)[reply]

Check out Spermatogenesis#Influencing_factors − Twas Now ( talk • contribs • e-mail ) 23:35, 29 January 2007 (UTC)[reply]

January 30

DNA degradation

Hi

I'm trying to find out whether nuclear DNA or mitochondrial DNA degrades faster after death. I'm talking about forensic/fossil kind of situations. Does anyone have any tips/references/ideas?

Thanks for your help!

Aaadddaaammm 01:53, 30 January 2007 (UTC)[reply]

I think if you were after a reliable answer you'd have to spend a few hours hunting down papers on PubMed--inks ^T 02:18, 30 January 2007 (UTC)[reply]

For a number of reasons, the mitochondrial DNA is more likely to degrade faster. The nucleoplasm is large, neutral, and contained within a double membrane, which is for the most part shrouded in layers of endoplasmic reticulum. The mitochondrial DNA, however, is in close proximity to stuff in more reactive oxidative states. Also, there is a lot of DNA in the nucleus, and a good deal of it in heterochromatin, wrapped up with histones and the like, which make it less reactive. The mitochondrial DNA is tiny and not as well protected. ^tucker/_rekcut 02:25, 30 January 2007 (UTC)[reply]

I'm not sure which degrades faster, however in forensic/fossil situations, mitochondrial DNA is more easily used for population level analysis, since there are more copies of it per cell than nuclear DNA. --Cody.Pope 09:27, 30 January 2007 (UTC)[reply]

I think tucker's explanation is correct when it comes to the speed. Cody makes a good point, though. If there is more copies of mitochondrial DNA, there may be a question of which material is fully degraded first. - Mgm|^(talk) 10:06, 30 January 2007 (UTC)[reply]

Reduced Fat cheese melting point

I've noticed that reduced fat cheese melts much differently than normal cheese. A slice doesn't really melt, but rather it turns into leathery wrinkled chewy "cheese jerky" (especially when microwaved). The ingredients are virtually identical to normal cheese: Milk, rennet, salt. What's going on? --72.202.150.92 05:57, 30 January 2007 (UTC)[reply]

Fats tend to add the property of fluidity (for example, cholesterol in the cell membrane). With reduced fat, presumably there is less fluidity. Hopefully someone will come after me and give some biochemical details… − Twas Now ( talk • contribs • e-mail ) 06:21, 30 January 2007 (UTC)[reply]

Nuts

what nuts have embryos? — Preceding unsigned comment added by 58.168.42.153 (talk • contribs)

No nuts have embryos. Please see the nut (fruit) and embryo article if this is a serious question. [Mαc Δαvιs] X (How's my driving?) ❖ 07:15, 30 January 2007 (UTC)[reply]

Gallnuts are not true nuts, but they do contain larvae.--Shantavira 09:31, 30 January 2007 (UTC)[reply]

I don't understand Mac Davis's response in the context of the question. It seems to me that the Nut (fruit) article essentially claims that all true nuts contain embryos. Or am I misunderstanding the lede to that article?

Atlant 12:54, 30 January 2007 (UTC)[reply]

Yeah, Doesn't a nut contain a embryonic plant? ike9898 17:07, 30 January 2007 (UTC)[reply]

THank you for correcting me, I answered incorrectly, and will remember my error. All nuts are seeds and therefore have embryos. How early in development can we say a seed contains an embryo? [Mαc Δαvιs] X (How's my driving?) ❖ 19:39, 30 January 2007 (UTC)[reply]

A nut is a seed, but not all seeds are nuts (from nut (fruit)).
A seed plant embryo is part of a seed, consisting of precursor tissues for the leaves, stem (see hypocotyl), and root (see radicle), as well as one or more cotyledons (from embryo).

− Twas Now ( talk • contribs • e-mail ) 19:46, 30 January 2007 (UTC)[reply]

Protein synthesis

describe the process of protein synthesis in animal cell. — Preceding unsigned comment added by 212.88.98.165 (talk • contribs)

It would be more likely for someone to answer, if you made an effort to compose a question, and not just quickly copy-paste something from your homework. You can find a lot of information in our article Protein biosynthesis, and if something remains unclear, you can still return here and ask more specific questions. --V. Szabolcs 09:31, 30 January 2007 (UTC)[reply]

You probably wouldn't have been asked this question if it wasn't in your textbook. I suggest you read that. - Mgm|^(talk) 10:03, 30 January 2007 (UTC)[reply]

The doctors say my friend suffers from electric discharge

Hello people from this fantastic site. First of all let me tell you that I have solved a lot of problems reading different articles on this site and want to thank you for all the information and time put in here.

I wanted to discuss something for which I cannot find an answer.

The doctors say my friend suffers from electric discharge. Let me explain what he feels often. All of a sudden he feels very tired, he cannot stand on his feet and his heart beats faster. His pressure usually goes very high and later it comes back to normal. Sometimes it even goes low and then back to normal.

Sometime back his potassium level had gone down and also suffered from diarrhoea for a long time.

Let me explain his work habits. He has very stressful days and he is on the computer for long hours, has 8 monitors and 2 CPU's which are on, almost 18 hours a day. While he goes out to work the computers are left on and he also sleeps in the same room. He eats too very very fast and just swallows the food.

I think I have given enough explaination. I was wondering if there is any connection with his lifestyle or if you'll you understand where his problem lies. Please do help me. Thanks in advance and hope to receive a reply. user: StellamirettoStellamiretto 09:39, 30 January 2007 (UTC)[reply]

Just a note: While someone may be able to explain electric discharge in some detail, we can't offer medical advice. − Twas Now ( talk • contribs • e-mail ) 10:29, 30 January 2007 (UTC)[reply]

Maybe your friend needs a thorough checkup and some lifesytle advice from a doctor/--Light current 11:55, 30 January 2007 (UTC)[reply]

I would encourage you, if your interest is to find out more about your friend's condition, to find out the medical name for his illness. Electric discharge is not a term that has any real pathological meaning to an allopathic (or, I suspect, osteopathic) doctor, as far as I know. This term may have resulted from an analogy or translation error. You may find information browsing the following, but don't jump to any conclusions: hypokalemia, cushing's syndrome, panic disorder, ozone. ^tucker/_rekcut 15:52, 30 January 2007 (UTC)[reply]

How many computers is irrelevant to his medical condition. How quickly he eats, also, probably doesn't have to do with it. [Mαc Δαvιs] X (How's my driving?) ❖ 18:59, 30 January 2007 (UTC)[reply]

You don't think that since he "just swallows the food" he will digest it poorly or get as much nutrients from it? − Twas Now ( talk • contribs • e-mail ) 19:50, 30 January 2007 (UTC)[reply]

Does your friend take any Antidepressants eg. Prozac, or Benzodiazepines eg. Valium, or does any illegal drugs? The reason I am asking this is because there is scientific evidence that these type of drugs increase or decrease the neuronal firings, which is involved throuhout the body. I mean this neuronal firings occur in the brain, but also expands via the spinal chord throughout the body. You might also be interested in the articles: Movement Disorders, Epillepsy and other neuroscience articles. Interesting question nonetheless, I will give you that. --Parker007 04:47, 31 January 2007 (UTC)[reply]

test for pesticides

can the lassaignes test be used for the detection of nitrogeneous pesticides in fruits? wont the nitrogen already present in fruits give a positive test, even if it has not been subjected to nitrogenous pesticides?

59.180.122.192 09:55, 30 January 2007 (UTC)[reply]

Scientific pronunciation dictionary

Where can I find an online dictionary for the pronunciation of the latin words used in taxonomy? Meanings too would be helpful. —LestatdeLioncour t 13:13, 30 January 2007 (UTC)[reply]

I did a Google search for "latin pronunciation" and found a number of sites. This one looked specific to your needs. As for meanings I imagine any Latin dictionary will be reasonably useful. --140.247.249.189 18:18, 30 January 2007 (UTC)[reply]

Pesky Air Bubbles

Is there an easy way to prevent air bubbles when placing a coverslip on a microscope slide. I have tried numerous techniques, none with satisfactory results. I tried tilting the coverslip, but this causes a "Tidal wave" effect since my samples usually aren't fixed to the slide. I tried slowly lowering the coverslip, but I can't seem to lower it slowly enough to prevent the bubbles. Does anyone know a better way? Mikmd

Do you have too much liquid on the slide? Particularly with low-viscosity solutions (stuff that's mostly water, rather than a glycerol-based mountant) there is a definite tendency for sample and mountant to get pushed out to the edge of the coverslip. (Your tidal wave effect.)

Depending on your application, you might try using less liquid, soaking off some of the excess liquid with a Kimwipe, using a larger coverslip, just putting up with the bubbles, or – if all else fails, and this is by far the most difficult option – experiment with changing your mountant.

Are the bubbles actually causing a specific problem for your application, or are they just not 'pretty'? TenOfAllTrades(talk) 15:28, 30 January 2007 (UTC)[reply]

Double bump... I need to type faster) :It sounds like you are using to much liquid. For a wet mount, there should be very little water, perhaps somewhere between 50 and 100µl. Putting the slide down on the edge, so that the water sticks to one side, and then slowly decreasing the angle between the cover slip and the slide with prevent air bubbles from forming. There will be just enough water to form a layer between the slip and the slide, so a "tidal wave" is not an issue. ^tucker/_rekcut 15:31, 30 January 2007 (UTC)[reply]

One of the best tricks I found was placing the coverslip on the slide on an angle. Then slowly place the coverslip on the slide.

_\  -->  the backslash is your coverslip, de underscore your slide.

This causes what you call the tidal wave effect but only when you do it too quickly. You shouldn't push untill the coverslip is flat on the slide. You generally want to push from the side you don't want your samples to flow to. Last trick is not to oversaturate the slide with your mounting medium (less is more!).

When I was doing slides with braintissue (not fixed to the slide) we used a sticky gunk called histomount. Now I don't know what your mounting medium is so I'm not sure if this trick will work for you.PvT 15:36, 30 January 2007 (UTC)[reply]

I was told to hold a piece of paper close to the slide, which should then absorb whatever liquid you are using, making it flow past the sample:) Something like that:( Pushing down on the top of the slide might also help, but it could damage whatever you are studying:(Hidden secret 7 16:07, 30 January 2007 (UTC)[reply]

If you have a "vacuum pickup" (that may not be the generic term), it makes it much easier to handle the coverslip, allowing any of several techniques to work better.

Atlant 16:40, 30 January 2007 (UTC)[reply]

Hot melt glue...?

Is all hot melt glue made out of the same material and if so or not where can I find the Material Safety Data Sheet? 71.100.10.48 16:10, 30 January 2007 (UTC)[reply]

The article Hot glue talks about a "common" material for the glue. If you want specifics though, you'd want to read the packaging on the specific glue- different kinds may be made of different stuff. Friday (talk) 16:14, 30 January 2007 (UTC)[reply]

The packaging just says: Non-toxic Conforms to ASTM D-4236-88. 71.100.10.48 16:47, 30 January 2007 (UTC)[reply]

Loss of efficiency...?

What kind of efficiency loss would be the result of using DC generators to provide power with battery, capacitor, Superconductor magnetic storage, etc. devices to maintain the necessary voltage and inverters to provide a steady frequency within a specified voltage range to maintain frequency quality on the grid? -- Barringa 16:26, 30 January 2007 (UTC)[reply]

You'd probably still use an alternator (AC generator) fed into a rectifier. Alternators are mechanically simpler than DC generators and usually have better overall efficiency. The key, as you've probably realized, is the storage medium; it must be cheap, have reasonable energy density, and have good energy recover efficiency. Power utilities have experimented with batteries, compressed air, and pumped-storage hydroelectricity among others, with superconductivity remaining on the horizon.

Atlant 16:45, 30 January 2007 (UTC)[reply]

AC allows easy stepup to high voltage, perhaps 345 kv or 765 kv to send the power long distances, where it can be stepped down succesively to 138 kv to go from substation to substation, then 34 kv or 12 kv to go along distribution lines. While DC can also be sent long distances at 500kv or higher, per High-voltage direct current and [12] and is useful for tieing together different power grids which are not synchronized, it would be difficult to insulate Electrical generator windings to that voltage. To get enough turns of conductor in to the generator stator and rotor for it to work efficiently, the insulation level is usually less than 20,000 volts. Then a generating unit transformer steps it up to the higher transmission voltage. It would be a challenge to connect enough cells in series to have say even a 20,000 volt battery much less a 500,000 volt battery, because of the large clearances required by high voltage. In a downtown area of a large city, or an industrial park where constant AC voltage without momentary interruptions is needed for computer operation or growing semiconductor crystals, there would be great merit in having onsite energy storage in the form or batteries, superconductive magnetic storage, flywheel motor generator, or any other form of storage which acts as an uninterruptible power system on a large scale. That way if the utility line tripped and reclosed due to lightning, the customer or downtown would not see a flicker. It would be very expensive per megawatt hour of energy capability and per megawatt of power capability to provide such storage. Downtowns of New York, Chicago and other cities have had starting in the 1930's low voltage AC network grids, where perhaps 20 different 12kv lines go through transformers with the low voltage secondaries interconnected. Since the primaries come from several different substation fed by several transmission lines, the secondary 120/208 volt grid may go many years without even a momentary interruption, much less a Power outage. When it goes dead, there are usually numerous burned up low voltage cables, making for a long restoration time as in the 2006 Queens blackout. These grids were replacements for DC grids from the beginnings of utility power, in which a power plant (which needed to be within about 1.5 miles of the load) sent in DC which was stored in giant batteries. The load could be maintained with DC power during short interruptions of the line or short shutdowns of the generator, and could store power off peak, to increase the power available for the peak load period. Today labs and large data processing centers are the places which pay the premium to have "polished power" provided by systems such as you describe. More commonly, a business will have 2 or more 12 kv or 34 kv lines supplying it, and when one goes dead, an automatic throwover device opens the feed from the dead line and closes the other one, after a selected delay of perhaps 5 to 30 seconds, which can seem like an eternity. Typically the Uninterruptible power supply is small and is located near the personal computer or network server or phone system, since most of the load can be spared for a few seconds (vacuum cleaners, air conditioners, lights, etc,) except for a few battery powered emergency lights. Hospitals go the route of having generators (perhaps 10 MW diesels) which come online in 5 seconds or so for operating rooms and critical care units. Edison 17:16, 30 January 2007 (UTC)[reply]

poker millionaires??

Is it really possible to become a millionaire playing poker (or at least make a good living) or is this a bit of a myth in that gamblers tend to ignore massive losses incurred and remember their spectacular wins. Is it possible to learn a good strategy to constantly win or use a supercomputer etc for no limit texas hold 'em in the same way that you can card count in blackjack?

Yes, it is possible to become a millionaire playing poker; it is not easy, and there are very few players who accomplish this. (The top prizes for some major tournaments like the World Series of Poker and the Professional Poker Tour can reach more than a million dollars; bear in mind that the buy-in for competitors in these tournaments can be many thousands of dollars per player.)

No, you can't play 'by computer' to win at games like Texas Hold'Em. Unlike blackjack, poker depends very heavily on the behaviour of other players. I have heard it said that there are three stages to learning to play poker. The first is learning to play your own cards: understanding the value of your hands, how betting and blinds work, etc. The second is learning to play your opponents' cards: figuring out from the community cards on the table and your opponents' bets what hands they are likely to hold. The final step – and the one perhaps most important to professionals – is learning how to play your opponents. The cards can become nearly irrelevant if you can successfully manipulate other players' expectations and perceptions through clever betting. It's this last step that is difficult to 'teach' to a computer. TenOfAllTrades(talk) 17:07, 30 January 2007 (UTC)[reply]

There is no theoretical barrier to teaching a computer to react to and manipulate other players. A variety of poker playing computer programs already exist that can consistently beat the average player, but because they tend to be predictable in the long run, good players are still able to detect and exploit patterns that give them an advantage. It is a very complex task, but I don't think there is any reason a computer program couldn't be written to consistently make money on online poker. Dragons flight 17:29, 30 January 2007 (UTC)[reply]

Newton's cat

I once heard Isaac Newton invented the cat door/cat flap/kitty door. Can anyone confirm that?

Certainly plenty of websites [13] confirm this, although I can't find any truely definitive sources. If he did invent the door, it was more likely originally intended for his dog, Diamond, who famously set fire to all his work. Laïka 17:40, 30 January 2007 (UTC)[reply]

Every one has heard that version of the story which compromises the rather apocryphal little dog 'Diamond'; while it is supposed to exhibit so beautiful a trait of the imperturbability of his master. Humphrey tells us that he 'kept neither dog nor cat in his chamber.' Powell, Baden (1856). "Sir Isaac Newton". Edinburgh Review. 103: 499–534.

He kept neither Dog nor Cat in his Chamber... Keynes Ms. 135

—eric 18:38, 30 January 2007 (UTC)[reply]

Looking through his doorway we might have seen a small study...a desk littered with papers and lighted by a sputtering candle; a little dog with a diamond shaped mark near his tail, disporting himself in dangerous promimity to both candle and papers... Heyl, Paul R. (1928). "Newton as an Experimental Philosopher". Sir Isaac Newton, 1727-1927: A Bicentenary Evaluation of His Work. pp. p. 105. {{cite book}}: |pages= has extra text (help)

—eric 19:06, 30 January 2007 (UTC)[reply]

Sous-vide

Here's a "PERFECT STEAK RECIPE" that:

uses sous-vide to cook the inside of a steak in a warm water bath
then brown the steak's outside in a skillet to give the meat a brownish coat (see Maillard reaction).

Can I make a lot of individually wrapped boiled steaks, freeze them for storage. And then defrost them with a microwave oven for browning each time I want to have a steak? Is it safe? I guess an ordinary refrigerator may not achieve required flash freezing. You may need to use a large refridgerator with a large container of salty water to freeze the meat very quickly. The possibility of botulinum poisoning cannot be ignored. -- Toytoy 18:34, 30 January 2007 (UTC)[reply]

It states in the sous-vide article that there is a risk of poisoning by botulinum toxin, one of the most deadly toxins in the world. − Twas Now ( talk • contribs • e-mail ) 19:56, 30 January 2007 (UTC)[reply]

Boiled steak?? Come on, everyone knows perfect steak is done rare ;). The sous-vide article describes a process that I would not describe as boiling. Personaly I don't think there is a high risk of botulinum if you boil a steak and then re fry it at a later date, otherwise no one would ever eat left overs. I suppose the important thing is that when you fry it you have to make sure it is heated well all the way through, so probably wait until it is well defrosted before doing it and don't just sear the outsides. Vespine 22:02, 30 January 2007 (UTC)[reply]

It's not refrigeration that creates the risk of botulism, it is the boiling in an airtight plastic bag. Clostridium botulinum, the bacteria which causes botulism, thrives in low-oxygen environments (such as would be found in an airtight container). − Twas Now ( talk • contribs • e-mail ) 03:31, 31 January 2007 (UTC)[reply]

Magnetic materials

Hello! Could someone tell me a few applications for magnetic materials?--Anonymous

I'll give you one - loudspeakers - how and why can be found in magnet under the section magnet#Common uses for magnets and electromagnets - ignore the electromagetic uses - and not suprisingly the major use for magnetic materials is as magnets!87.102.13.207 20:18, 30 January 2007 (UTC)[reply]

Depleted Uranium Disposal

Does anyone have an idea of the best way to dispose of depleted uranium(without putting it into weapons)? DebateKid 20:01, 30 January 2007 (UTC)[reply]

Well it isn't an extremely dangerous material. It has extremely low radioactivity and is more dangerous as a heavy metal (and potentially a source of radon -- you wouldn't want to build a house over a mound of it, I imagine) than it is as a radioactive element (though this depends on the form you are talking about disposing -- if you are talking about hexafluoride gas, that has its own difficulties from a chemical point of view). In any case, this page has a nice discussions of the precautions usually taken. If you treat it as any old Low Level Waste material, that means that you probably want to bury it in the ground for some long length of time. Because the amount of radioactivity is low, the length of time it will be radioactive will be quite long, though even if it escaped for some reason it would only have a small long-term statistical effect on any surrounding populations. --24.147.86.187 22:39, 30 January 2007 (UTC)[reply]

Why would you want to dispose of it? is it not a useful material? DU I imagine it could be used for many of the things that lead is used for.--Light current 22:49, 30 January 2007 (UTC)[reply]

Indeed. For example, the first Boeing 747 had several hundred pounds of it formed into the engine nacelles, because the designers discovered at the very last minute that they needed a concentrated bit of mass just there to damp out certain wing vibrations. —Steve Summit (talk) 01:54, 31 January 2007 (UTC)[reply]

What would the slogan be? Just like lead...but radioactive. Mmmmm. :) --18.214.1.125 01:29, 31 January 2007 (UTC)[reply]

Uranium 238 appears to be less radioactive than certain isotopes of lead. U238 half life is 4.5 billion years. Thats longer than the age of the ~~universe~~ earth! 8~)--Light current 01:35, 31 January 2007 (UTC)[reply]

so basically, I think you could eat it with negligible damage from a radiological point of view.--Light current 02:28, 31 January 2007 (UTC)[reply]

Someone's going to kick off over that comment. I just know it. :) --Kurt Shaped Box 02:30, 31 January 2007 (UTC)[reply]

They can argue with this then! [14]--Light current 02:34, 31 January 2007 (UTC)[reply]

Appendicitis and diet

Is there any relationship?--Light current 22:47, 30 January 2007 (UTC)[reply]

My nan used to tell me never to eat tomato seeds as they could get stuck in my appendix and cause appendicitis. I don't know if that's true or not (to be honest, it's something I haven't thought about for a long time) - but come to mention it, does anyone know? --Kurt Shaped Box 22:51, 30 January 2007 (UTC)[reply]

Seeds and nut fragments can indeed become stuck in outpouchings of the colon and intestines (called diverticuli) and cause inflammation and possibly infection. The appendix, though, has a pretty wide mouth, so it is probably less likely for anything to get stuck in there for too long. From what I've read, the biggest predictor of appendicitis is posture during bowel movements. In societies where one squats to defecate, appendicitis is rare, because the pressure of the right thigh against the abdomen may squeeze out the contents of the appendix. However, since the appendix has variable placement, this is only a predictor. ^tucker/_rekcut 23:04, 30 January 2007 (UTC)[reply]

How about toothbrush bristles and chewing gum? I was warned about those as a kid too... :) --Kurt Shaped Box 01:15, 31 January 2007 (UTC)[reply]

I'm pretty sure they are old wives tales, my mum used to tell me if you ate apple seeds a tree might grow in your stomach... WHY??? I have no idea, but I can't wait to fck with my kids heads by telling them crazy crap! when I have some:).. Vespine 03:07, 31 January 2007 (UTC)[reply]

Actually, it was a serious Q 8-|--Light current 03:11, 31 January 2007 (UTC)[reply]

Despite popular belief, you will just pass the chewing gum out "the other end", rather than it doing any damage to your internal organs. People believe chewing gum may have this effect becasue it is sticky & could potentially adhere to your intestinal walls, but in all reality, your stomach acids & functions would easily break down the make up of chewing gum. However, I myself would not swallow it... :) As for toothbrush bristles, it is possible for them to enter through opeinings inside you. However, this is very very very rare & would take a miracle for it to do any real damage. Swallowing stuff like this runs the same risk (or a smaller risk) as if you ate some other small object, such as a marble or key - it passes through your body without harm... Hope that helps a little bit..? Spawn Man 04:03, 31 January 2007 (UTC)[reply]

Ethnomedical treatment for Persimmon

In the persimmon article, it says that persimmons are used to treat constipation, but persimmons are astringent, so they should be used to treat diarrhea. Can anyone tell me if persimmons are used to treat constipation or diarrhea? bibliomaniac 1 5 23:40, 30 January 2007 (UTC)[reply]

Wrist damage

Just wondered if too muck jackin can damage your wrist!

No - penis usually breaks first.87.102.2.51 00:43, 31 January 2007 (UTC)[reply]

Though this sobering tale should give you cause to consider moderation

Moderation mate is CRITICAL

Maybe you haven't wanked yourself as much as I have.
If you wank 5 or more times a day , everyday, for at least 5 years, you will know what i'm talking about.
You can get serious repetitive strain injuries on both wrist, AND testicle disorders, AND cock shaft problems from excessive friction, AND bacterial infections from not being able to wash your hands before you NEED a wank. if you wank as much as I do, you can get seriously addicted, to the point where you cannot walk if you do not spill your juice. AND your wrists are fucked and you cant walk, (like ive been), you are totally FUCKED
Crack one off once or twice a day and you should be on the safe side of injuring yourself.

from http://www.steadyhealth.com/Masterbation_t63170.html 87.102.2.51 00:54, 31 January 2007 (UTC)[reply]

Hmmm... Artificial vagina to the rescue, I guess. If lots of exercise, a few fist fights, enlisting in the army and imagining the Queen in a bikini don't do the trick. Anchoress 03:04, 31 January 2007 (UTC)[reply]

Highest Temperature Possible?

Hello. I was reading an article on the temperature of 0*K, or absolute zero. I was thinking, if the lowest possible temperature is achieved when the atoms of the material stop moving completely, then wouldn't the highest temperature possible be achieved when the atoms are moving at (or close to) the speed of light? I mean, when an atom is moving at the speed of light, it can't move faster, so it can't raise in temperature, can it?65.28.13.120 00:54, 31 January 2007 (UTC)65.28.13.120Wild Irishman[reply]

According to the theories E=mc²#Background - the energy keeps increasing as the speed approaches the 'speed of light' - but a thing would have infinite energy at the speed of light - so there is no upper bound to the amount of energy a moving thing can have - effectively the mass is supposed to increase as the speed increases (see section 'relativistic mass' in a sub section of the section linked above- and things with more mass have more kinetic energy at a given speed.

So if an atom was at the speed of light it would have infinite energy..87.102.2.51 01:01, 31 January 2007 (UTC)[reply]

Space combat with lasers...

Would I be right in thinking that ship-to-ship combat in space with lasers would be an incredibly brief affair? For all intents and purposes, a laser is an instant hit weapon - so, whichever ship managed to lock on to the other with a 360-degree rotation-capable, turret-mounted, computer-controlled laser first and concentrate the beam onto the same spot on the hull for a few seconds would emerge victorious, right? None of this dogfighting-in-space stuff like you see in the movies. I know that if combat in space became a regular thing, the design of ships would evolve to reflect this (thick armour plating, separately pressurised compartments, mirrored hulls, clouds of chaff launched to defract the laser, etc.) - but that would pretty much be the gist of it, right? Two ships firing at each other constantly, hitting 100% of the time, each hoping that the other one decompresses or is disabled first? --Kurt Shaped Box 01:46, 31 January 2007 (UTC)[reply]

Much easier than making a viable space-based laser would be coating objects to reflect large amounts of the energy. Extremely powerful lasers are often in the infrared range like hydrogen or deuterium fluoride lasers which is reflected quite well by copper, gold, or germanium (common mirror materials in CO2 lasers, which operate in the far-infrared). Lasers have tons of problems. It would be extremely difficult to focus enough energy onto a small enough spot at great distances, or be able to track very quickly and accurately. Hardened missiles might be a viable weapon, assuming we have space wars anytime soon. You're probably right thought, what this would be like if it worked well would probably be pretty dull, which is why Star Wars, Star Trek, et. al. spice it up with cool-looking weapons. Atropos235 02:11, 31 January 2007 (UTC)[reply]

HEY! Maybe that's why those UFOs in old 'saucer' movies spin? So that an enemy targeting the ship with a laser can't hit "the same spot" for any amount of time, because "the same spot" is rotating around the craft.. It's a laser weapon countermeasure! Hmmm, that's interesting!:) Vespine 03:03, 31 January 2007 (UTC)[reply]

Even if the technology did exist to aim huge amounts of energy accurately over large distances, there's going to be a range in which it causes damage, and aiming at any target outside that range cause progressively less and less damage relative to the distance. In the middle there's a range where it causes a little damage (uncomfortably hot/minor radiation damage), and since there's no reason to believe that ships are going to be popping into existance a few meters away and you're not suicidal so you're not going to rush in when you don't have to, that's the range where most of the action would probably have out, making incredibly slow and boring fighting sequences. freshofftheufo ΓΛĿЌ 04:59, 31 January 2007 (UTC)[reply]

Kittens

I got 2 2-month old kittens from my freind. they havent been spayed, neutered, and didnt get any shots yets. they both look the exact same. i cant realy tell them appart. she said one of them is male and the other is female. i checked them both out all around and niether of them seems to have a dick. how do i know which one is which?

hahaha! A kitten with a dick! I'm nearly 30 and I still find that funny.. I guess some people never grow up... Anyway, really, in public, you should refer to it as a penis:).... As for the answer, google kitten sex and I'm sure you'll find the answer, if you ignore all the kitten porn sites first:), I'm sure it's easier to explain with pictures then with words.. As for the kittens not having a visible penis, that's right, cat's penises are retractable, so you can't really tell just by the dick. haha. sorry, *cough*. hmmVespine 02:57, 31 January 2007 (UTC)[reply]

Sleep

I'm a highschooler with a packed academic schedule and a hell of a lot of homework that usually keeps me up to, say, 2 or 3 in the morning every night. I wake up fairly exhausted at 6:30, but I tend to do just fine at school. When I get home at fourish in the afternoon, I've gotten in the habit of taking a one or two hour nap because if I don't, I tend to get bleary eyed and can't focus when reading anything, so I just waste time reading the same paragraph a hundred times. After a week of this, I'll usually catch up some on sleep over the weekend. The question, however is one prompted by my dad's getting angry at me for this "bad cycle." He says I should make an effort to stop napping so I can instead go to sleep two or so hours earlier and get the same amount of sleep but on a normal schedule. Apart from the fact that I probably wont go to sleep earlier at all (even on the nights with light homework, I get a second wind of sorts at around ten or eleven and am not tired until at least 1:30 in the morning), is this really so much better of an idea? I feel that if I take an early afternoon nap, I'll be alert for the rest of the night (which is the case), whereas the extra sleep I'd get during the night would still probably leave me bleary eyed in the afternoon because it's still only 6 or so hours of sleep. It also seems to me that my dad's argument is similar to someone saying that three meals a day are more healthy than 5 simply because that's the "normal" cycle of eating. Is my dad's "normal" sleeping cycle of one 6 hour night actually any better for me than a four hour night and a two hour nap? Thanks, Sashafklein 04:01, 31 January 2007 (UTC)[reply]

As far as I know, it's contested. You'll hear people say things like "Leonardo Da Vinci napped 12 times a day", though that's (probably) not (quite) true. First of all, realize that shifting your 2-3 hour nap into the evening all of a sudden will not immediately show positive results. The most important thing is to keep a regular schedule, and changing your regular schedule will make it difficult to sleep well, at least until you become accustomed to the "new" schedule. Trying to "catch up" also isn't a good idea, because your body doesn't respond to weekly patterns of sleep, and you're basically assuring that your brain will have to shift schedules twice every week. I have horrible sleeping problems too, but I attribute most of them to the fact that I'm not strict enough about my sleeping patterns. freshofftheufo ΓΛĿЌ 04:39, 31 January 2007 (UTC)[reply]

The only reason I believe that you have a need to sleep after school is because you are introverted thus your energy is drained in any social settings.