Science desk
< June 19	<< May \| June \| Jul >>	June 21 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

June 20

Homework Question

heat flows between 2 objects that are close to eachother if the objects have different what? —Preceding unsigned comment added by 66.66.198.72 (talk) 00:16, 20 June 2008 (UTC)[reply]

Please do your own homework.

Welcome to Wikipedia. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. -- kainaw ™ 00:30, 20 June 2008 (UTC)[reply]

Fellow refdeskers, this does appear to be homework. If I am giving too much information for a homework question, let me know. OP, see heat transfer. Ζρς ι'β' ^¡hábleme! 00:42, 20 June 2008 (UTC)[reply]

I think that we should link to articles for homework questions (as a matter of policy) even if it contains the answer in the first line. Zain Ebrahim (talk) 08:13, 20 June 2008 (UTC)[reply]

Agreed - if you know which article to link to. -- kainaw ™ 13:53, 20 June 2008 (UTC)[reply]

Temperature. One object has to be hotter than the other, and it will then transfer it's heat to the cooler object. This is called conduction. JessicaN10248 18:11, 20 June 2008 (UTC)[reply]

Thank you, but we try and avoid giving direct answers to questions that look like they are probably from someone's homework. People don't learn well by just being given the answer. --Tango (talk) 18:50, 20 June 2008 (UTC)[reply]

Sorry. Obviously it's not good to do someones entire homework, but I was just pointing them in the right direction. If nothing else they'll have learned what conduction is. JessicaN10248 19:10, 20 June 2008 (UTC)[reply]

That wasn't pointing them in the right direction, it was giving them the answer... --Tango (talk) 21:52, 20 June 2008 (UTC)[reply]

If you choose to be unhelpful in response to homework questions, that's your prerogative. But other people are free to chose to actually be helpful to questioners here, and you shouldn't suggest otherwise. If homework questions annoy you, just don't answer them. "Temperature" would have been a fine response, taken up a lot fewer persons' time, and a lot less space than having a silly discussion of whether or not the question is homework, and whether to divulge the answer or withhold it. - Nunh-huh 09:33, 22 June 2008 (UTC)[reply]

Although if they had clicked on the link from Zrs 12 they would have got the answer anyway, as well as further information. No harm done in this case, I think, since their homework will surely have been due in not long after they asked. (Given the question, it really does look like nothing so much as a fill-in-the-blanks paper) 79.66.22.23 (talk) 14:45, 22 June 2008 (UTC)[reply]

Retaining wall - construction

I'm looking for a website that shows me how to construct a retaining wall. I'd like to be able to learn how one functions and know the specific formulas used in the construction of a retaining wall. Kironide (talk) 05:31, 20 June 2008 (UTC)[reply]

As an encyclopedia, Wikipedia has an article Retaining wall. For how-to information it's best to search Google. Otherwise Wikibooks may have a textbook on constructing a retaining wall that you can search for here[1]. Cheers, Julia Rossi (talk) 08:28, 20 June 2008 (UTC)[reply]

Cells and Tissue

shanu 06:43, 20 June 2008 (UTC)Most of the plant tissue(like sclerenchyma tissue) are made up of 'cells' which contain no protoplasm and are completely dead. Is it correct to label them as a 'cell'? If they are not cells how can sclerenchyma be called a tissue( given that tissue is a group of 'cells' performing same function with common origin( correct me if I am wrong))?

I guess you've seen the section of the article Sclerenchyma here[2]. Afaik, there is living tissue and dead tissue, but it's all tissue. Julia Rossi (talk) 08:32, 20 June 2008 (UTC)[reply]

Friction down an incline

Can someone please check the reasoning of my answer to the question below:

Q: A body of mass 5kg slides from rest down a plane inclined at 30° to the horizontal. After sliding 12m down the plane it is found to have a final speed of 10m/s How much work is done to overcome the friction along the plane [textbook answer is 44 J]

A: Work done by gravity, Wg = Fx = mgsinφx = 294J

Energy lost due to friction, Ef = ΔKE = 1/2mv² - 1/2 mu² = 250J

Work to overcome friction = Wg - Ef = 44J

Did I use the formula Ef = ΔKE correctly? I mean, is the formula always true? I'm using the formula but I don't understand the physics behind it. ExitLeft (talk) 07:34, 20 June 2008 (UTC)[reply]

Your calculation is correct but your reasoning is a little off. ΔKE is not the energy lost to friction. It is the increase in the kinetic energy of the body due to falling down the ramp. The loss to friction is the difference between the work done by gravity (mgh) and the kinetic energy you actually ended up with (½mv²). If they were the same then there would have been no loss to friction. Energy lost to friction and work done to overcome friction are the same number. SpinningSpark 11:52, 20 June 2008 (UTC)[reply]

Ok. Thanks for your help!ExitLeft (talk) 06:27, 21 June 2008 (UTC)[reply]

Pubews

I have pubes growing out of my areolae and am male. Is this normal. Before 1901 C.E., did males have this?68.148.164.166 (talk) 18:28, 19 June 2008 (UTC)[reply]

See chest hair and yes. Dismas|^(talk) 18:41, 19 June 2008 (UTC)[reply]

Are you sure? Are there documented cases before 1910 of approximately 6.3 cm long pubes coming out of a male areola?68.148.164.166 (talk) 19:41, 19 June 2008 (UTC)[reply]

Pretty sure. Chest hair is very common, and it generally starts on or around the areola. I have no reason to believe it's a recent phenomenon. I'm sure plenty of men in history have been described as having hairy chests - portraits of them may not show it, though, in the same way they often don't show pubic hair, despite the fact that it was almost certainly there. --Tango (talk) 19:45, 19 June 2008 (UTC)[reply]

Also, my hair acts as an asymtote; it just drops off in length away from the areola, so is that normal?68.148.164.166 (talk) 08:03, 20 June 2008 (UTC)[reply]

1) STOP moving questions around on the desks. 2) NOBODY has "pubes" growing from anywhere except the pubic area. 3)Why the arbitrary cut-off date? --LarryMac | Talk 19:48, 19 June 2008 (UTC)[reply]

I'm not sure if my "pubic" hair is considered normal. Because before then, plastics were not invented.68.148.164.166 (talk) 08:03, 20 June 2008 (UTC)[reply]

There is no cut off date, he's asking if they had hair on areolae before 1901. I'm pretty sure this is a joke question, anyway. And also, i've NEVER heard of a 6.3cm hair coming from an areolae. Regards, CycloneNimrod ^talk?_contribs? 20:22, 19 June 2008 (UTC)[reply]

Some nasty person removed my explaination: I'm not sure which year plastics were invented, but that I'm just concerned that xenoestrogens can alter hair growth. That's why I provided 2 years.68.148.164.166 (talk) 08:09, 20 June 2008 (UTC)[reply]

Well, there is a cutoff of either 1901 or 1910 (both were used above) before which such hairs did not exist. Based on the message on my talk page, this is nearly a medical advice question anyway, so I won't be commenting further. Unless he starts to move questions around again, then it's clobberin' time. --LarryMac | Talk 20:41, 19 June 2008 (UTC)[reply]

Chest hair is often extremely curly, so when straightened out, 6.3cm doesn't sound strange to me. I agree this is becoming close to medical advice, so in response to the message on my talk page I did recommend seeing a doctor if he was concerned (I said it sounded normal to me, though). --Tango (talk) 21:03, 19 June 2008 (UTC)[reply]

As Tango has already said, chest hair has definitely existed prior to 1901 or whatever date you want to choose. For starters you'll find descriptions of people with hair chests in old books. I suspect you'll also find paintings and the like containing chest hair even if wasn't commonly potrayed for a variety of reasons in some cultures (the article mentions this briefly). Heck you may even find photos of people with chest hair. Besides that, the idea that people all over the world are going to suddenly develop chest hair because someone in Germany or whatever made plastics is silly so the cut off date is pointless. Also, if people didn't have chest hair, and it suddenly started developing throughout the world after the invention of plastic, you can bet people would have noticed. Whether there has been a change in the type, frequency of or length of chest hair since the invention of plastics no one can answer. And finally if you have concerns about your chest hair, you should see a doctor. Nil Einne (talk) 10:48, 20 June 2008 (UTC)[reply]

I think some of you people might have misunderstood. I think the OP meant rogue hairs that develop sometimes during puberty, such as ones coming out of the areolae. I had one like this, and there was a point where it was growing to almost full length every day, because I would cut it and it'd be back the next day. Then eventually puberty ended and it started slowing down, and then it finally stopped showing its head. It also looks like "pubes" because it's abnormally thick, thicker than typical chest hair. I'm pretty sure this is what the OP is referring to. As for if it's dangerous, from when I researched it on the internet before, it's not anything to be concerned about at all, but if you're worried, consult a physician, as we can't give medical advice. --Wirbelwindヴィルヴェルヴィント (talk) 15:45, 20 June 2008 (UTC)[reply]

Yes, your right, but I have more than one hair, and they come out of the areolae and they look like my pubes, not terminal hair. Hair around my areolae further from it is shorter, and close to the nipple is longer.68.148.164.166 (talk) 05:08, 27 June 2008 (UTC)[reply]

Sodium laureth sulfate

Sodium lauryl sulfate (SLS) is a foaming agent naturally derived from coconut and/or palm kernel oil.
— http://www.tomsofmaine.com/toms/ifs/sls.asp

Does sodium laureth sulfate have the same fate?68.148.164.166 (talk) 10:55, 18 June 2008 (UTC)[reply]

Does ammonium lauryl sulfate have the same fate?68.148.164.166 (talk) 11:02, 18 June 2008 (UTC)[reply]

Check the relevant articles at Sodium laureth sulfate and Ammonium lauryl sulfate --TomDæmon (talk) 11:36, 18 June 2008 (UTC)[reply]

Please don't tell someone to do something when you can't do it yourself.68.148.164.166 (talk) 08:06, 20 June 2008 (UTC)[reply]

Why can't you? After all, you're the one who wants to know... If your too lazy to do things for yourself, and rude when others offer you help, don't expect people to want to help you in the future. Nil Einne (talk) 09:28, 20 June 2008 (UTC) Sorry I may have been confused. Are you complaining that the articles don't really help answer your question? If so, then this is a legitimate complaint, although I would suggest you be more polite in the future to people who are trying to help. Nil Einne (talk) 09:37, 20 June 2008 (UTC)[reply]

I just wanted to point out that sodium lauryl sulfate and sodium laureth sulfate are different chemical compounds which tend to be readily confused (as may be the case here). Both are completely synthetic. But they can be produced from lauric acid, which is found in plant oils such as coconut and palm oils. I don't know if they actually are produced from naturally-derived oils, though. ChemNerd (talk) 16:43, 18 June 2008 (UTC)[reply]

The "naturally derived" term is misleading advertising. Of course all products we use are at some point derived from the natural environment such as from plants or from the earth, but in this case artificial production methods involving sulfuric acid are used. Graeme Bartlett (talk) 21:53, 18 June 2008 (UTC)[reply]

Of course it's even more misleading than that....the sulfuric acid could be collected from the run-off from mine tailings. Or acid rain. Now I assume the sulfuric acid used, even if a synthetic commercial product, was made using some other material found in nature. Lather, rinse, repeat backwards step by step. DMacks (talk) 22:24, 18 June 2008 (UTC)[reply]

IMHO, the problem is that 'naturally derived' is mostly a meaningless term. All products can be said to be naturally derived, perhaps unless you are producing them in a particle accelerator or fusion/fission reaction. The problem is of course, people assume something 'naturally derived' must be safe, which clearly isn't the case. The only case when naturally derived is perhaps meaningful is as a distinguisher when you are referring to flavours or other substances which occur in nature and are isolated without significantly changing them but can also be produced artificially. Nil Einne (talk) 09:44, 20 June 2008 (UTC)[reply]

Human Evolution

Evolution is an ongoing process. Thus humans should be evolving too. I want to know in what possible ways can humans evolve into in future?117.197.5.137 (talk) 10:33, 20 June 2008 (UTC)[reply]

There's Participant evolution, but for the more traditional biological angle, I can't find a thing in Wikipedia. I'm sure there are such predictions, though. Sorry. Try a Google search. --Allen (talk) 11:11, 20 June 2008 (UTC)[reply]

Modern medicine and welfare systems means there isn't all the much evolution. Evolution happens when genetic difference increases the number of offspring someone is likely to have, however these days how many children you have bares little relation to anything to do with your genes. Welfare means people that wouldn't otherwise be able to support themselves, or children, are able to anyway, and fertility treatments mean people that wouldn't otherwise be able to have children at all can anyway. In fact, I think there is a negative correlation between number of children and level of education (I don't have statistics, this is rather anecdotal), which is the opposite of what you would expect from natural selection. There are various other ways humanity can evolve, but conventional natural selection isn't going to do much (baring a major disaster - evolution generally goes much quicker if a population is facing extinction, see genetic drift for one reason). --Tango (talk) 11:53, 20 June 2008 (UTC)[reply]

Evolution is always ongoing, but it technically just means gene flow. If you mean, "major phenotypical changes on a noticeable level across the entire species", though, keep in mind that 1. even under highly selective circumstances, in which the difference between some individuals living, dying, and reproducing is extremely high, evolution is incredibly slow from a human point of view, and 2. humans have engineered their world so that our circumstances are, for the most part, not highly selective—that is, most people these days can make it to adulthood and reproduce and etc. without too much difficulty, even if they have bad eyesight or are overweight or are not very bright or what have you. Some have argued that this is a form of dysgenics but I don't see a lot of evidence that things have changed all that much for quite a long time and tend to think we are just going to see a regression toward the mean in the long run (that is, there will not be much change on average over the entire gene pool). But this is a point of dispute, and there is no rigorous way to know. We can't in any concrete way predict what will happen to the human species over the next, say, ten thousand years, especially since things like reproductive patterns are shaped not only by culture and society but more and more by the technologies we develop for them (without even considering things like reprogenetics, something as "simple" as the pill has changed those patterns dramatically from what they were a hundred years ago). But ANYWAY—if you just want to know "possible ways" that the human species could change over time, just look around you and imagine that any outlying individual you see could be indicative of the entire species. We have a lot of variables that could change, ranging from the very superficial (weight, height, eye color, etc.) to the more subtle (personality, intelligence). Probably not in the cards are things like multiple arms and extra fingers (which are likely to be non-beneficial mutations in most cases anyway, and are almost certainly to be selected against in almost all imaginable scenarios) or telepathic powers (or other things with no physical basis for existing). Boring, no? --98.217.8.46 (talk) 11:55, 20 June 2008 (UTC)[reply]

See Idiocracy for a not-unlikely scenario. :) --Sean 13:37, 20 June 2008 (UTC)[reply]

For a related idea see dysgenics--Fang 23 (talk) 19:07, 20 June 2008 (UTC)[reply]

See Man After Man: An Anthropology of the Future and the mbc article Human evolution at the crossroads for possible future human evolution scenarios.--Fang 23 (talk) 19:02, 20 June 2008 (UTC)[reply]

Also the Hard science fiction project Orion's Arm provides some interesting examples of posthuman species that may arise in the future from genetic engineering or other types of Participant evolution such as the Europans who are aquatic humans who dwell in the seas under the jovian moon Europa's ice.--Apollonius 1236 (talk) 19:42, 20 June 2008 (UTC)[reply]

Ok here's the problem. We aren't subjected to natural selection much anymore. We have modern technology protecting us from climate change, natural disasters, other animals, etc. Also there is a lot of gene flow which prevents speciation. You can live in America, and hop into a plane and travel to Japan in a day or so. The human populations of the world are no longer isolated, so there is a lot of mixing when people from different cultures mate. This inhibits speciation. And finally, and I think most importantly, we can evolve ourselves. With things like genetic engineering, or even the technological singularity, artificial evolution is far more likely to occur. Why depend on nature to evolve us, when we can evolve ourselves faster, and with desired results?

So unless a nuclear war occurs and blasts all of us back to the stone age, I don't think natural evolution will take precedence over artificial evolution. ScienceApe (talk) 18:13, 20 June 2008 (UTC)[reply]

Not voices in the head, but similar

Imagine that someone keeps repeating a frase or idea in his head over and over aware (but fully aware that it is not the Mary, the mother of Jesus). How do psychologies call this phenomenon? GoingOnTracks (talk) 11:18, 20 June 2008 (UTC)[reply]

You mean like having a song stuck in your head all day, or something more long term? Be warned, we can't give medical advice here, so you're going to get vague answers at best. --Tango (talk) 11:55, 20 June 2008 (UTC)[reply]

Yes, also like that. Some songs repeats on your head over and over. How do you call it? GoingOnTracks (talk) 12:01, 20 June 2008 (UTC)[reply]

Earworm? -- Ferkelparade π 12:41, 20 June 2008 (UTC)[reply]

Wow I never knew there was a name for that. WP is awesome 125.21.243.66 (talk) 14:22, 20 June 2008 (UTC)[reply]

Is this purposeful or something that just happens? There is an old book. If I remember correctly, it is Russian and the name translates to something like "The Pilgrim". Perhaps it is a fake book mentioned in another book - but that's not the point. In this book, a man attempt to pray at all times, so he purposely repeats the same prayer over and over until he is able to repeat it in his mind at all times. -- kainaw ™ 14:00, 20 June 2008 (UTC)[reply]

obsessive thoughts/intrusive thoughts? Or just a variant of earworm I suppose, if harmless. 79.66.20.219 (talk) 15:01, 20 June 2008 (UTC)[reply]

Oliver Sacks has a whole chapter on this in Musicophilia. He mentions the term earworm, and says it was coined in the 1980s (a translation of the German term Ohrwurm), but people have been describing it for a long long time. Sacks, liking the alternate term "brainworm", describes them as: "brainworms and allied phenomena -- the echoic or automatic or compulsive repetition of tones of words". Usually he will mention a "medical" Latin-type term for things if one exists (terms like, eg, aphasia, etc), but he doesn't for earworms. So perhaps there isn't a "scientific" name for it. His chapter on them explores, a little, the way they seem to work, and makes some vague comparisons to certain aspects of things like autism, Torrette's syndrome, and obsessive-compulsive disorder, but notes that unlike these things, virtually everyone experiences earworms from time to time. Pfly (talk) 00:39, 21 June 2008 (UTC)[reply]

As an anecdote, I used to get this all the time. I'd get fixated on a word and it would just keep popping up in my head repeatedly. Very frustrating. I recently started taking anxiety medication and have noticed that the earworms have ceased when I'm on the meds. They only pop up again in the late evenings/early mornings, when my dose has worn off. I do still get songs stuck in my head, but in a pleasant way rather than the irritant that the earworms are. (Got a Devils Haircut in my mind...) — The Hand That Feeds You:^Bite 13:25, 21 June 2008 (UTC)[reply]

Aerosol Can

The other day, I just kept pressing the button of an aerosol can used to store perfume, even after the perfume had finished, just to see what happens. To my surprise, a fair bit of some kind of gas came out, which was definitely not perfume (as it didn't smell) and just before it went completely empty, the bottle turned really cold, like it had just been brought out of the deep-freeze. Can anyone explain what happened? Aanusha Ghosh (talk) 16:58, 20 June 2008 (UTC)[reply]

It's the propellants. --Wirbelwindヴィルヴェルヴィント (talk) 17:06, 20 June 2008 (UTC)[reply]

The gas was the propellant, used to propel the perfume out of the can. The perfume, or whatever, generally runs out before the propellant in my experience, so you get propellant on its own at the end. The reason it got really cold is because the pressurised gas expanded. When gas expands, it cools, see Charles's law. I can't see why it would happen right at the end, it should have got gradually colder as you used it up. It would have got really cold because you used it all up at once, normally it has time to warm up inbetween uses, so the temperature change it minimal. You can see the same affect if you look at gas canisters used for a gas heater, or BBQ or something - they often develop frost on the outside as they are used. --Tango (talk) 17:07, 20 June 2008 (UTC)[reply]

I imagine it took the can a minute to cool down after the gas inside cooled, so you would expect a slight delay between starting to spray and feeling the can cool down. StuRat (talk) 17:19, 20 June 2008 (UTC)[reply]

A thin metal can won't take long to cool down, but yes, there would be a slight delay. That still doesn't explain why there was a sudden change in temperature, it should have been a delayed gradual change. --Tango (talk) 18:17, 20 June 2008 (UTC)[reply]

Perhaps a propellant/perfume mixture was coming out for most of the expulsion, and then a shot of pure-propellant at the end comes out very fast due to its lower viscosity, explaining the last-minute freeze. --Sean 19:32, 20 June 2008 (UTC)[reply]

By the way, you should be careful about spraying a lot of gas out of an aerosol can like that. Once upon a time the propellant was typically freon, but this is no longer preferred due to the ozone layer depletion problem, and the gases now used are often flammable. (Of course, aerosols are also a fire hazard when used in the normal way, if the product is flammable.) --Anonymous, 01:37 UTC, June 21, 2008.

But of course this can be a distinct feature, if for example there's a deadly snake in the bathroom of your hut [3]. —Steve Summit (talk) 06:17, 21 June 2008 (UTC)[reply]

For a more godly example, see also the elevator scene in The Blues Brothers. --Anon, 21:47 UTC, June 21, 2008 AD.

Asperger Syndrome in Females

This question has been removed as it may be a request for medical advice. Wikipedia does not give medical advice because there is no guarantee that our advice would be accurate or relate to you and your symptoms. We simply cannot be an alternative to visiting the appropriate health professional, so we implore you to try them instead. If this is not a request for medical advice, please explain what you meant to ask, either here or at the talk page discussion (if a link was provided). Regards, CycloneNimrod ^talk?_contribs? 18:38, 20 June 2008 (UTC)[reply]

My 25 year old cousin has Asperger yet she seems normal (normal meaning she doesn't appear to have Aspergers). Maybe just slightly a little too shy and sometimes she fumbles her words when she speaks. She has a lot of trouble explaining to people that she has this condition because they simply don't believe her. She was diagnosed a long time ago with this. How could this be? --Anthonygiroux (talk) 18:31, 20 June 2008 (UTC)[reply]

I've restored the question, as I see no sign of a request for medical advice here. As for Asperger's Syndrome, I suggest you read up on it by following that link. StuRat (talk) 21:00, 20 June 2008 (UTC)[reply]

I understand the question in a way if there is Asperger in females. As the article states that cause of Asperger is not fully understood and no specific gene has yet been identified, it is not limited to male, so a female dignosed with Asperger is possible.--Stone (talk) 21:43, 20 June 2008 (UTC)[reply]

I moved the discussion to Wikipedia talk:Reference desk#Medical question discussion. Zain Ebrahim (talk) 22:44, 20 June 2008 (UTC)[reply]

(Responding because in my opinion question is asking for information, not for advice) Asperger syndrome can definitely occur in females, although it is more common in males. If you or your cousin want to know more about the process of diagnosis, we have an article on diagnosis of Asperger syndrome. It is important to realise that Aspeger syndrome is not a disability - it is a set of behavioural traits and cognitive preferences that are an advantage in some situations but may also be a disadvantage in others. Indeed, some people with Asperger syndrome refer to it as a "gift". Think of it like being taller than average - good for reaching things on high shelves; not so good for driving a small car. I see no reason why your cousin should need to "explain" to people that she has Asperger syndrome unless it is relevant in a specific situation - you don't need to tell everyone that you hate garlic, only someone who is about to cook a meal for you. For more information on Asperger syndrome there is the Wrong Planet online community, and books by Elisabeth Hughes and Luke Jackson. Gandalf61 (talk) 13:02, 21 June 2008 (UTC)[reply]

A more straightforward explanation could be that your cousin was misdiagnosed. You mention that she was diagnosed 'a long time ago' and in my personal and professional experience a significant number of people with neurological or neurogenic disorders were misdiagnosed a long time ago. This issue brings to my mind a long time problem with people who make miraculous recoveries against all medical prognostication. "The doctors said he'd never walk again" and when the patient takes up his bed and walks do we admire with awe the spirit and courage of the patient or should we treat with deep scepticism the ability of the doctors to make an accurate forecast about the outcome. Richard Avery (talk) 14:27, 21 June 2008 (UTC)[reply]

Im confused about all the responses. None of them answered my question. I'm either accused of being a fifth grader trying to get my homework completed by someone else (I'm a 35 year old man) or causing some terrible harm by asking for "medical advise". I guess I will need to do my own research on the net regarding Aspergers in females. I guess my question was, in general, the difference in how Aspergers is manifested in females versus males. The article in Wikipedia does not state any distinction. --Anthonygiroux (talk) 13:27, 23 June 2008 (UTC)[reply]

My apologies for the chaos that has resulted from your question. It was not supposed to be an inconvenience but more of a precautionary measure. In any case, we can certainly tell you about how Asperger's manifests in women and men. To the best of my knowledge, there is no specific difference in the manifestation of Asperger's syndrome in either sex. — CycloneNimrod ^talk?_contribs? 16:54, 23 June 2008 (UTC)[reply]

One reason why you may not have gotten what you were looking for is that your question was quite vague. You said a whole lot of stuff and then you asked "How could this be?" and I totally misinterpreted what you really were looking for which is differences in manifestations. I thought that you were asking whether the usual symptoms of Asperger syndrome were necessarily applicable to Asperger syndrome in females. Zain Ebrahim (talk) 09:46, 24 June 2008 (UTC)[reply]

Suggestion: In the future, ask the OP to clarify the question before censoring/deleting question. It seems that it is quite common that the WIKI Editors squabble over the question then start censoring or deleting questions instead of simply asking the OP whether the question is legit. --Anthonygiroux (talk) 19:32, 24 June 2008 (UTC)[reply]

Lab coats

Correct me if I'm wrong, but I'm pretty sure scientists don't drive to work wearing lab coats, so they must put on lab coats after they get to work. So my question is, at research facilities,

(A) is there a single big closet filled with lab coats of various sizes, and when a scientist arrives at work he or she just picks one out of the closet OR

(B) do scientists each have their own lab coats which they keep in their office, and they put it on when they get to work?

If (B), then what happens if you're a scientist visiting for a single day a research facility you don't work at, so you don't have an office with your own lab coat in it? Is there a closet of lab coats for visiting scientists?

Also, someone should add the answers to these questions to the lab coat article.

—Lowellian (reply) 19:29, 20 June 2008 (UTC)[reply]

Unless you have your own lab coat, I'd imagine the research facility would have several lab coats on a rack for each department that needed them. The scientists would simply pick any one they wanted, and return them at the end of the day, and presumably a cleaner would come along now and then to clean them. Thats how it is in every lab I've been in. But if your dealing with hazardous materials such as nuclear wast the lab coats would be worn only once before being destroyed, so they would probably have a large supply in a store room somewhere. JessicaN10248 19:37, 20 June 2008 (UTC)[reply]

In the labs I've been in, each of us had our own lab coat. Not that they had our names or anything on them, but they came in different sizes, and each had their own unique set of smudges, stains, burns, contaminants, etc. that identified them to their "owners". Occasionally I would wear mine home, but usually kept it on a rack at work.

When I visited another facility, I don't remember wearing a coat. That's because I was visiting for the purpose of observing, not for doing things that might get my clothing dirty. ~Amatulić (talk) 19:43, 20 June 2008 (UTC)[reply]

In the hospital here, all people have their own lab coat with name and position on it. I never wear mine. It has been hanging on the back of my door since I received it. Visitors don't wear lab coats unless they are here for a length of time. Then, the department they are attached to can opt to give them a lab coat. -- kainaw ™ 20:02, 20 June 2008 (UTC)[reply]

It depends on the lab. In the institute where I work, I wear a lab coat only when I'm doing something messy or when I'm working with bugs (microbes, not insects...). When I want a clean coat, I drop the old one in the laundry bag and pick up a fresh one from the supply room. Used coats aren't shared—you don't know what the last guy spilled on the coat, now do you? The lab coat never leaves the lab, since you don't want to transfer toxic chemicals, caustic solvents, or infectious materials from the lab out to your office, the lunchroom, or to the WC. (There's an old joke—Q: How do you identify a chemist? A: He always washes his hands before he goes to the washroom.) Different laboratories will have different policies depending on the nature of (and risks associated with) their work, government regulations, and local attitudes toward health and safety. TenOfAllTrades(talk) 22:13, 20 June 2008 (UTC)[reply]

Where I used to work you got given a lab coat when you first arrived. Members of one lab each dyed their lab-coats a different colour to ensure they always got their own one back from the laundry. Currently where I work, there is no personal ownership of lab coats: instead we have a lab-coat laundry that one can collect a coat from or drop of off at will. Rockpocket 00:50, 21 June 2008 (UTC)[reply]

In my lab (biosafety level 2, working with infectious human viral pathogens) the technicians each have multiple coats. Some coats are for a specific room, to avoid cross-contamination from room to room. Transient visitors are not allowed to work in the lab, except to service equipment. Longer-term visitors who work in the lab are provided with coats to use.Scray (talk) 04:01, 21 June 2008 (UTC)[reply]

Two experiences of my own:

R&D section of a medium size food products company - Everyone had a couple lab coats with their names that were left at work and cleaned by a laundry service. I think lab coat use was mandatory. The work here tended to be messy.
Government ag research agency. Lab coat use totally optional and most don't use. Cloth lab coats actually not allowed, for some safetly/liability related reason. Disposable lab coats available in the stock room.

Anything in this discussion we can fold into the article? ike9898 (talk) 14:05, 21 June 2008 (UTC)[reply]

Where I used to work as a tech everyone had a film tag pinned to their own lab coat. The pockets would have their own spatula for measuring chemicals also. So definately individual usage of coats.Polypipe Wrangler (talk) 23:55, 22 June 2008 (UTC)[reply]

Rainbow frequency

Hi. Over the past 4 weeks or so, I've seen four rainbows. That's one per week! What does this indicate about the precipitation patterns over this period? 3 of the rainbows were complete, 2 were especially bright, 2 were low to the ground, all occured between 6 and 8 pm EDT (Southern Ontario), 2 had a secondary bow visible, 2 occured when it was raining in sunlight, 2 occured after "missed" thunderstorms, 3 were photographed, and all occured in spring. Is this particularly unusual? Are there statistics for the average number of rainbow days in S. Ontario? Thanks. ~A H 1^(TCU) 22:10, 20 June 2008 (UTC)[reply]

I expect they all occurred while it was raining in sunlight, since that's how rainbows work. It may not have been raining exactly where you were, but it must have been raining nearby. Since rainbows occur when it's raining and sunny at the same time, they generally happen in light showers, which are quite common in spring - see April showers. --Tango (talk) 22:41, 20 June 2008 (UTC)[reply]

How do we not have an article on April showers? What is Wikipedia coming to... --Tango (talk) 22:42, 20 June 2008 (UTC)[reply]

Ironically, WP has April Showers (song) and April's Shower (film). Zain Ebrahim (talk) 23:43, 20 June 2008 (UTC)[reply]

I'm a mergist, but I'm also a big fan of properly annotated disambig articles as well. Tango and Zain, you've inspired me to create April showers. --arkuat (talk) 05:37, 23 June 2008 (UTC)[reply]

Hi. I just saw another rainbow yesterday, ~8pm. It seems that the later it is in the day, the higher and farther south the rainbow. I think I know what the precipitation pattern is now: for the past two weeks or so, there have often been showers and thunderstorms one day after the next, and on all of those days there was some sunshine, and there have been thunderstorms in the reigon for the past 3 weekends (18 thunderstorm days already this year compared to 22 for the whole year last year, just yesterday tornadoes and funnel clouds were reported, one funnel cloud was even sighted in Toronto). Thanks. ~A H 1^(TCU) 22:02, 24 June 2008 (UTC)[reply]

Color of birds' eggs

What factors are relevant to the color of a bird's eggs? Does the color in the eggshells come from the bird's diet, the same pigment used for its feathers, or something else? Also, how do egg colors evolve and what advantage do various colors and patterns serve? For instance, the robin's blue eggs seem like they'd be easily spotted by predators. 69.106.4.120 (talk) 22:22, 20 June 2008 (UTC)[reply]

Don't know about pigments, evolutionary advantage, etc. (the eggshell article is a little sparse), but one thing I have heard (confirmed by Egg_(food)#Shell) about chicken eggs is that the color of the eggshells matches the color of the hen's ear (that is, the skin around the hole which leads to the eardrum). White ear = white egg. Brown ear = brown egg. Blue-Green ear = blue-green egg. I don't know if this holds for other birds, though. -- 128.104.112.147 (talk) 23:35, 20 June 2008 (UTC)[reply]

There are probably lots of factors involved in driving egg colour (see [4] for a review). There are a range of pigments known to colour eggs, these include biliverdin in blue eggs and complex porphyrin polymers in brown and black speckled eggs. Its been questioned why birds use these pigments, and not the more ubiquitous melanin, to pigment their eggs. A clue might lie in the fact that biliverdin and other porphyrins do not absorb infrared light (which is a large proportion of solar energy), thus they may help the eggs from over heating. A remarkable study (Gosler, A.G., Higham, J. P. & Reynolds, S. J. (2005), Why are birds' eggs speckled?, Ecology Letters) demonstrates that the speckled parts are thicker than the unspeckled part of the egg, suggesting one of the purposes of the pigment may be to provide structural support. Rockpocket 00:45, 21 June 2008 (UTC)[reply]

I'd say the color usually has one of two primary purposes:

1) Camouflage. This would apply to birds which must leave the eggs alone to find food. They would want them to be the same color as the nest or cover in which they are left.

2) Ease of location. For birds which take turns watching the eggs, so they are never left alone, it would make sense to make them easy to spot so the birds can easily keep track of them. Thus, they would want a color that sticks out versus the surroundings. StuRat (talk) 05:22, 21 June 2008 (UTC)[reply]

Sturat, wouldn't the second cancel out the first? They ain't Easter eggs. ;) Julia Rossi (talk) 10:17, 21 June 2008 (UTC)[reply]

One of two Stanstaple (talk) 12:31, 21 June 2008 (UTC)[reply]

Mmm. It's that I can't figure the second one being significant. I'd guess for birds (though who can know) it's not a case of "my god, I've mislaid the eggs!", but that camo and temperature control would be primary. Wouldn't birds find their own eggs by other factors than markings, by say, having information about the whole nest print, sun angles and geography? Julia Rossi (talk) 12:44, 21 June 2008 (UTC)[reply]

When birds trade positions sitting on eggs, they frequently knock them about a bit. It's critical that they find any that rolled away quickly, to keep them warm. Obvious colors may make them able to notice the eggs which rolled away more quickly. StuRat (talk) 16:02, 21 June 2008 (UTC)[reply]

Also, some birds don't even seem to use color cues when identifying their eggs-- there have been cases of chickens willingly incubating objects like lightbulbs because they had the same overall shape as eggs. (But they will throw out an egg that's unlike the others in the nest, even if it's really theirs.) 69.106.4.120 (talk) 14:20, 21 June 2008 (UTC)[reply]

Chickens aren't exactly the most intelligent birds, are they ? StuRat (talk) 16:02, 21 June 2008 (UTC)[reply]

Maybe what we're seeing here is a cue from shape, however vague, rather than colour? Julia Rossi (talk) 02:48, 22 June 2008 (UTC)[reply]

Right. Whereas a more intelligent bird (which is to say, just about any bird) would use a range of visual and nonvisual clues to determine what is and what isn't an egg. StuRat (talk) 15:16, 22 June 2008 (UTC)[reply]

Incidentally, we have a problem that needs the attention of several editors. Egg (biology) exists side by side with Ovum, and they ought to be merged. In the process of the merger, we ought to do some splitting and also produce a more detailed article specific to the shelled eggs of land animals who lay them, which would address evolutionary pressures that result in various birds' eggs being coloured the way they are. We also probably need an independent article on Human ovum to contain much of the stuff that is currently at the Ovum article (such as the categorization). Right now, Egg (biology) looks like a feeble attempt at being an article about bird eggs, which also discusses eggs in general, and Ovum looks like a feeble attempt at being an article about human ova, which also discusses eggs in general. I can't do better than this editing them all by myself, but we can do better than this. At least two current redirects will have to be developed into new articles. I'm not casting aspersions on the efforts of any of the past editors of these two articles, but a namespace problem has developed in the meantime, that needs to be fixed, and that will take some work. --arkuat (talk) 05:19, 23 June 2008 (UTC)[reply]

Of course, we don't just want articles on bird eggs and human ova, but also on reptile eggs, amphibian eggs, insect eggs, mammilian ova, etc. StuRat (talk) 11:37, 23 June 2008 (UTC)[reply]

I entirely agree with you, but the sort of coordinated merge/split that would help Egg and Ovum, merged with the content they have in common, and split with the non-common content that is currently there, would be an excellent start. And just that little bit is certainly more work than I can do alone. (I've been busy cleaning up binary fission!) --arkuat (talk) 07:42, 24 June 2008 (UTC)[reply]

In response to StuRat's egg/intelligence speculation, "just about any bird" has to sit on eggs that are swapped such as having a cuckoo replace their eggs with the nester's. Recognition/differentiation might not be a factor here either. Why do I get a cartoon in my mind like, Henry! sit on that round thing! – No, no, Corinne, ovoid thing, ovoid! Don't be an egg-head Henry, what are you, a passerine? Julia Rossi (talk) 09:03, 23 June 2008 (UTC)[reply]

Hawk-headed Parrot - undeserving of bad reputation?

If you keep psittacines, or associate with people who do, you'll probably eventually hear the horror stories about the fearsome Hawk-headed Parrot, supposedly the ultimate 'expert-level' companion parrot. This bird's 'difficulty' is nothing to do with price, size, noise, eating habits or its rarity, mind. Rather, it is a supposedly 'difficult' bird because of its extreme aggression, unpredictable temperament and sly, cunning malice.

Yes, it will apparently kill any other bird housed with it once it tires of the company - even its own mates and/or offspring, will break human fingers for fun and will feign playfulness or use human language in order to attract humans within striking range - then lunge for the eyes, lips, nose and ears, with intent to cause serious damage. Or at least that's what they'd have you believe (sounds like a bit of an exaggeration to me). "An abused pitbull with a brain" is one description I've heard for this bird.

So, does anyone here have any *real* experience with Hawk-heads? I'm slightly curious to know how they got such a bad rep. I've never actually seen one in real life... --Kurt Shaped Box (talk) 22:59, 20 June 2008 (UTC)[reply]

Hi Kurt, do you have the right bird? I googled them and there's nothing except "affectionate", "likes to be held close", great pet and the like. When I searched "vicious hawk-headed etc" not much more except that one was anxious, agitated and in need of treatment. "Kamikaze" gets this[5]. Maybe the problem arises with the owners. For 1200 to 1800 bucks though, I'll never find out. Julia Rossi (talk) 10:03, 21 June 2008 (UTC)[reply]

I can't remember the exact search terms I used now, but I did come up with a few horror stories (the one you linked above was one that stuck in my mind, as it confirmed something I had previously been told, WRT the birds maliciously luring humans). Most of the things I've heard have been from fellow parrot fanciers in person, none of whom actually own Hawk-heads. I subscribed to Cage and Aviary Birds Magazine a few years ago and I remember there being a few writeups and write-ins mentioning that one always had to be careful around Hawk-heads, due to their Jekyll/Hyde nature. Whether this is another case of people just repeating stories that they've heard, I don't know.

Do you know much about Rosellas? I've heard that they can be quite 'difficult' too. --Kurt Shaped Box (talk) 23:40, 21 June 2008 (UTC)[reply]

Not Rosellas personally, but a nasty Masked Lovebird (little though it was, it destroyed any bird put with it), a vicious eastern Sulphur-crested Cockatoo and a Rainbow lorikeet. It had a lot to do with jealousy, their keepers indulging them and allowing them to dominate. All had bad tempers. The sulphur one would bite its keeper while speaking sweetly. Even though they start off young and cute, the more smart and aggressive parrots are vigorous, demanding pets even if hand-raised. So for me, it looks like behaviour problems on the one hand, being bored in captivity, and maybe keepers bragging about having power pets... you know how bad news catches on. Julia Rossi (talk) 02:43, 22 June 2008 (UTC)[reply]

The thing about parrots of all kinds is that it can be quite difficult to determine if you're annoying/scaring them. There are cues, but they are sometimes very subtle - a slight tensing of the body, or a nervy look in the eyes. It doesn't take long for a bird to go from 'cuddly pet wanting to be played with' to 'full-on fight-or-flight' mode (and bloody fingers) if the owner doesn't *immediately* pick up on this and back off. It varies from species to species and bird to bird - but for the most part, their wild instincts are closer to the surface than they are in other pet animals. I have also come to the conclusion that some parrots just like to mess with humans for fun - my friend's Scarlet Macaw being a case in point. She doesn't usually have a problem with strangers in her master's home - unless they act nervously around her. Then she'll lunge, chase and dive-bomb them until they run around screaming - then she'll get all hyper and happy. I'm sure that she does it just to see their expressions change.

Have you ever owned a parrot that has ended up training you to behave correctly around it? I have. :) --Kurt Shaped Box (talk) 23:30, 22 June 2008 (UTC)[reply]

Wikipedia:Reference desk/Archives/Science/2008 June 20

Contents