Wikipedia:Reference desk/Archives/Science/2008 March 4

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March 4

What was the goal of the Wright Brothers?

The wright brothers created a heavier-than-air air craft, but did they have a goal behind it? Did they imagine a world in where aircraft would be a form of transportation? Thanks. —Preceding unsigned comment added by Legolas52 (talk • contribs) 00:45, 4 March 2008 (UTC)

See Wright brothers. They were not the first to get a heavier-than-air craft to fly. They were focused on creating a steering system to make fixed-wing flight manageable. They succeeded. At the time, many people thought the future would be full of people flying around in small aircraft. Even in the 50's and 60's, it was imagined that personal airplanes were just a few years away. So, assuming that the Wright brothers didn't imagine a world full of airplanes would be very unconvincing. -- kainaw™ 02:55, 4 March 2008 (UTC)

It's pretty amusing how many countries consider one of their own to be the inventor of true flight, simply by adjusting the lever on what constitutes true flight. Once in casual conversation a Brazilian mentioned to me that Alberto Santos-Dumont invented the airplane with as much surety as most Americans say the Wright brothers did so.  :) --Sean 13:09, 4 March 2008 (UTC)

Yes, and New Zealand always trots out Richard Pearse. First flying machine makes interesting reading. Deciding who was "first" and determining it by control, or power, or distance is missing the point. The fact is no one person invented the aeroplane; there was a lot of parallel development late 19th/early 20th C, all of which, in small ways or large, contributed to the development of the modern aeroplane. As to why: well, everyone since Icarus has wanted to fly. Gwinva (talk) 20:22, 4 March 2008 (UTC)

Correct me if I'm wrong, but I believe nature was the inventor of true flight. We took a hell of a long time to catch up!206.252.74.48 (talk) 15:50, 4 March 2008 (UTC)

I flew just fine when I was a small fruit bat. In fact, I often bragged about my ability to zip from place to place in near complete darkness. Then there was that whole evolution thing and it's been downhill ever since. -- kainaw™ 04:04, 5 March 2008 (UTC)

No, things started going downhill after gravity was invented. 206.252.74.48 (talk) 21:50, 5 March 2008 (UTC)

I've always thought that at least part of the Wright Brothers' goal was to make a better income with airplanes than with bicycles. Pfly (talk) 08:10, 6 March 2008 (UTC)

Glow-in-the-dark cats

Where on Wikipedia may I read an article about South Korean glow-in-the-dark cats?--The Fat Man Who Never Came Back (talk) 01:17, 4 March 2008 (UTC)

I would like to see pictures as well.--The Fat Man Who Never Came Back (talk) 01:18, 4 March 2008 (UTC)

It's not on Wikipedia, but I found an article and pictures. [1] Someguy1221 (talk) 01:21, 4 March 2008 (UTC)

Thanks to you!!!!!!!!--The Fat Man Who Never Came Back (talk) 01:44, 4 March 2008 (UTC)

You probably want to look into bacterial transformation (BT), green fluorescent protein (GFP). -- MacAddct  1984 ^{(talk • contribs)} 02:01, 4 March 2008 (UTC)

How about glow-in-the-dark pigs? [2] Sandman30s (talk) 14:35, 4 March 2008 (UTC)

The death of Betelgeuse

I am a fan and ardent reader of Wikipedia, especially the science pages. My question is: why is it so controvertial to discuss the imminent demise of Betelgeuse and what that means for humanity in the Wikipedia article?

Firstly, it is a celebrity star. It is one of the largest stars in the known universe; if it replaced Sol in our solar system, it would reach out almost to Jupiter. This red supergiant is very close, only a few hundred light years away, and it is the very shoulder of Orion: a star that surely each and every one of us can thank for untold choices made by our ancestors in its bright contenance.

Secondly, it is dying. Yes, it's only a few tens of millions year old but it's burning up very large atoms at the moment and there is no doubt that this utterly massive star is at its utter breaking point.

Thirdly, there is an extremely high probability that it will undergo a type II supernova. Perhaps it already has. It's possible, and not all that improbable, that tomorrow night the sky will be a canvas to the most spectacular (and anticipated!) supernova we've ever known. The sky will have a new full moon. The brightness will last for months and maybe even a few years, being visible even in broad daylight.

Orion will lose a shoulder, and a new moon will be born.

This isn't mysticism. It's not astrology. It's likelihood. Surely part of the point of Science is to inspire new generations by presenting facts that captivate. I understand turning down entries to articles that are outlandish though technically possible. But there are an undeniably strong contingent of articles out there that point to the supernova of Betelgeuse and what that implies for the landscape of the sky each and every one of us look upon. Sappysap (talk) 02:02, 4 March 2008 (UTC)

Quick answer - Wikipedia is not a crystal ball and Wikipedia is not a repository for original research. And for good measure, don't use weasel words.

Slightly longer answer - information in Wikipedia has to be verifiable with citations to reliable sources. Even in articles on mathematical subjects (at least the ones that have been labelled good or even featured, like 0.999...) use only information that can be referenced, even in the case of proofs which follow from known axioms. So if Betelgeuse is going to go supernova in the next million years, find a reference for it! If "some scientists say" something, say who. If something "may" happen, put a couple of citations next to it - one that says why it might happen, and one that says why it might not. And, as much as possible, make sure that those references are ones that have some degree of reliability - Physics Review is good, New Scientist is ok, a letter to the Washington Post is out of the question. Confusing Manifestation(Say hi!) 02:17, 4 March 2008 (UTC)

Fantastic use of buzzwords. Hands down, grats for that. But I don't think you have any grasp of the science of supernovae. I'm quite sure you did not research a single lick into why this particular star is unstable. When you want to present yourself as an authority, at least have the audacity of fact to support you. Sappysap (talk) 02:27, 4 March 2008 (UTC)

You asked a question about Wikipedia, Confusing Manifestation explained the issues within Wikipedia. You did not ask anything about the star, only about why things work like they do in Wikipedia. Confusing Manifestation did not attempt or pretend to present themself as an authority on supernovae, or say anything about the science of them. I suggest you reread what was written, perhaps apologise for jumping on someone trying to help you (rather than simply pointing you to the Help Desk where questions about Wikipedia are more properly addresses) and hopefully see that the answer to your question ("why is it so controvertial to discuss the imminent demise of Betelgeuse and what that means for humanity in the Wikipedia article?") has been thoroughly provided. Skittle (talk) 02:40, 4 March 2008 (UTC)

And, to add one more note to Confusing Manifestation's answer: Wikipedia is not a message board. Articles are not a good place to discuss anything. They are for referenced and encyclopedic content. If you want to discuss a possible supernova, go do a supernova message board. I'm sure there are hundreds of possible ones to choose from. -- kainaw™ 02:50, 4 March 2008 (UTC)

Thanks guys. I just needed the publicity. I'm sure the article will be looked at and revised. Just glad this post is still hereSappysap (talk) 02:53, 4 March 2008 (UTC)

I must say that this is a very unusual way of having an article improved. It sure gave me a good laugh. --Bowlhover 03:36, 4 March 2008 (UTC) —Preceding unsigned comment added by Bowlhover (talk • contribs)

Hey, the whole purpose of the reference desk is to improve the quality of the articles, although we treat the purpose as to answer questions! Graeme Bartlett (talk) 05:53, 4 March 2008 (UTC)

I doubt such an event can outclass the Great Collapsing Hrung Disaster of Gal./Sid./Year 03758. 206.252.74.48 (talk) 16:23, 4 March 2008 (UTC)

What is a Hrung, and why should it choose to collapse there, particularly? --Trovatore (talk) 01:29, 5 March 2008 (UTC)

I'm afraid I can't explain that one. Ix talk 15:47, 6 March 2008 (UTC)

Photosynthesis question

I'm doing a sheet of 5 photosynthesis-related problems and I think I've gotten all of them except for 1, which has me totally stumped: "The photosynthetic rate of aquatic plants in a test tube can be determined by collecting and measuring the amount of oxygen that gases out of the water. If bicarbonate, the source of CO₂ for aquatic plants, is added to the water, the rate of oxygen evolution increases. If CO₂ is fixed by the Calvin cycle but oxygen is evolved by the light reactions, how can an increase in CO₂ supply increase the rate of oxygen evolution?" If anyone could point me in the right direction, I'd greatly appreciate it. Thanks, anon. —Preceding unsigned comment added by 70.18.18.201 (talk) 04:33, 4 March 2008 (UTC)

You need to consider the ratio of NADPH/NADP⁺. How does it affect the rate of photolysis? How does the concentration of carbon dioxide affect the ratio? David D. (Talk) 05:12, 4 March 2008 (UTC)

Be mindful in the future that the reference desk is not an appropriate place to seek answers to obvious homework questions. Wisdom89 _{(T / ^C)} 05:16, 4 March 2008 (UTC)

I find homework questions perfectly acceptable on the reference desk. The top of this reference desk has a guideline stating:

"Do your own homework. The reference desk will not give you answers for your homework, although we will try to help you out if there is a specific part of your homework you do not understand. Make an effort to show that you have tried solving it first."

User:70.18.18.201 has not asked for answers and he showed that he tried solving the photosynthesis problem himself, so I see no problem with him asking for help here. --Bowlhover 05:41, 4 March 2008 (UTC)

Not only is there no problem with the question, there is no problem with the answer either. David D has not done the homework for the questioner, but provided him/her with hints and links to help him do it himself, as per guidelines. SpinningSpark 07:09, 4 March 2008 (UTC)

Don't totally misunderstand me. I wasn't admonishing anyone for providing the answer or asking the question. I was just alerting the user to the fact that such questions could be construed as such, and that editors at the reference desk will abstain from answering questions of that nature - in case he/she wasn't aware. It was more of just be careful in the future kind of thing. Wisdom89 _{(T / ^C)} 00:30, 5 March 2008 (UTC)

It's not particularly helpful to indulge in hypothetical philosophical discussions about reference desk procedure with questioners. Best just to get out of the way and let the question be answered, if you don't care to answer it yourself. "Do your own homework" is a means of "biting the newbie" that has been too often tolerated here. - Nunh-huh 02:49, 5 March 2008 (UTC)

Equivalent of menstruation, but in men

Is there such a thing? Do men have cyclical hormonal changes?Mr.K. (talk) 12:10, 4 March 2008 (UTC)

No, there is no monthly cycle in men. Yes, men have cyclical hormonal changes, but they are diurnal, with testosterone levels slightly higher in the morning. But it's a daily cycle, and there's no cycle in men that's longer than a day. As men age, their testosterone levels become lower, but again, that's not a cyclical change, but one due to senescence. - Nunh-huh 12:24, 4 March 2008 (UTC)

Closest I can think of is accidental bloodletting, aka 'accidentally' cutting your finger while chopping vegetables, accidentally falling of your bike and scraping up your knees and elbows, accidentally getting clipped in the face with a hockey stick. Vranak (talk) 21:30, 4 March 2008 (UTC)

Depends on what you mean by equivalent. A nocturnal emission is somewhat equivalent- the body is casting off leftover stuff it wanted to use for reproduction. Friday (talk) 21:33, 4 March 2008 (UTC)

That's not very eqivalent. That only happens if you are aroused while sleeping. Dreaming about having sex, or thinking about having sex. That sort of thing. 64.236.121.129 (talk) 15:33, 5 March 2008 (UTC)

The OP is asking about hormonal cycles, not regular bleeding. Mr K, Chronobiology and Circadian rhythm might interest you.

The OP is asking about the equivalent of menstruation in men. Vranak (talk) 01:04, 5 March 2008 (UTC)

A couple decades ago, I made a non-scientific empirical observation that the severity of acne in a male teenager varies on an approximate monthly basis. It's suggestive of a monthly hormone cycle, but I haven't seen anything written about the phenomenon (if it has been verified to exist). =Axlq 01:40, 10 March 2008 (UTC)

The Human Ship of Theseus thing...

You hear all the time people saying that the cells of your body get completely replaced every 7-10 years or so, questioning the identity over time of human beings by invoking the Ship of Theseus paradox. My question is this: that's just plain BS, isn't it? I mean, sure, some cells do get replaced all the time (skin cells, most obviously), but the cells that play a role in determining who you are, what your identity is, that's your brain-cells, and they don't get replaced, right? I've always been taught that when you hit puberty, you have as many brain cells as you're ever going to have. So doesn't that pretty much blow that little brain tickler clear out of the water (not the general paradox, but as applied to human beings)? 83.250.207.187 (talk) 13:26, 4 March 2008 (UTC)

brain cells might/can regenerate - see brain cell, also why assume they don't?87.102.44.156 (talk) 14:51, 4 March 2008 (UTC)

Some cells are rarely replaced, neurons being an excellent example of one such cell type. However, even in those cells, many of the molecules that compose it are regularly replaced or recycled. For example, the plasma membrane in many cells, again including neurons. The short answer is this: nope, no BS here. – ClockworkSoul 19:44, 4 March 2008 (UTC)

If every cell is replaced by its exact duplicate then the sum of its parts (you) will be exactly the same. Environmental and dietary factors will move you towards, away from, or equidistant to good health. Vranak (talk) 21:23, 4 March 2008 (UTC)

Identity is a complex topic, so to say that it depends entirely on a tangible, precise group of cells or molecules (or to imply that changing the cells changes the identity) makes many profound assumptions. Philosophy of mind may provide some insight. Nimur (talk) 07:03, 5 March 2008 (UTC)

Insects in vegetables?

Hi. I am asking this on behalf of a friend who is a vegetarian. I've heard in various places that the Food and Drug Administration (and in Canada too) allows a maximum number of insect body parts in certain vegetables. Can I get some stats on how many insect body parts are allowed in certain vegetables? I also heard that ant eggs are allowed in peanut butter. In fact, one time I discovered some tiny yellow-brown insects in (homemade) soup (cooked). Now, some people may think it's gross, but it is just extra protein, but for strict vegetarians this may be a problem. Can you give me some stats for Canada, and is there an article on this? They shouldn't spray the vegetables with pesticides to get rid of the bugs, because that might make us sick (which is why I always wash my fruit [except bananas]). Does organic vegetables have more or less maximum insects, or is the limit identical? Please provide some statistics for Canada and which vegetables and other food froducts are most likely to contain insect body parts. Thanks. ~AH1^(TCU) 18:42, 4 March 2008 (UTC)

Its name completely escapes me, but there is a wax secreted from an insect that is used to replace the natural wax coating of apples. It often contains parts from the insect itself. 206.252.74.48 (talk) 19:38, 4 March 2008 (UTC)

Beeswax is often used for coating fruits & veggies. --Sean 20:00, 4 March 2008 (UTC)

While that is true, I'm thinking of another wax created by an insect. The fact that I can't recall its name is really bugging me (no pun intended, seriously). 206.252.74.48 (talk) 20:08, 4 March 2008 (UTC)

Google led me to here http://www.geocities.com/perfectapple/apple_wax.html so check out shellac.87.102.44.156 (talk) 21:22, 4 March 2008 (UTC)

Yep, that's the one! Thank you. 206.252.74.48 (talk) 13:33, 5 March 2008 (UTC)

http://www.cals.ncsu.edu/course/ent425/text18/food.html for canada recommend contacting the canadian equivalent of the 'ministry of food and agriculture'87.102.44.156 (talk) 19:43, 4 March 2008 (UTC)

To get you started, the maximum permissible quantities of insect (and other) bits in foods are specified by the FDA as food Defect Action Levels (DALs). The FDA DAL Handbook is online here: [3]. Canada's rules are probably somewhere on the Canadian Food Inspection Agency website: [4]. TenOfAllTrades(talk) 19:58, 4 March 2008 (UTC)

There are also standards for grain crops foreign matter (mostly stones and insects) that permit them at low levels as it is not practical to perfectly sort them.Polypipe Wrangler (talk) 22:15, 4 March 2008 (UTC)

I suppose it is probably not worthing saying that trying to eat a vegetarian diet without accidentally digesting insects at some level is going to be impossible. Insects are everywhere and they eat everything and it's a fact of life that some of them are going to get sucked up into the food processing apparatus every once in awhile even if you are doing it by hand! Personally I think there are more pressing moral and ethical issues in the world than whether or not you eat a few ants, assuming the objection is moral/ethical (as they pose no real nutritional benefit/deficit). --98.217.18.109 (talk) 14:10, 5 March 2008 (UTC)

• There is now an article on FDA's publication about food contaminants: The Food Defect Action Levels. — Reinyday, 01:36, 14 March 2009 (UTC)

quantity required of trypticase soy agar to test water for fecal coliform

Hi. How much trypticase soy agar is required to test water sample for fecal coliform?Sarah Orlowski (talk) 18:49, 4 March 2008 (UTC)

Thanks, Sarah Orlowski

I'm not sure how anyone could possibly answer the question as put; the quantity of medium you need would depend on the number of samples you're going to test, and on the lab protocol you're using for the testing (I also wonder why you're using trypticase soy agar vs MacConkey medium - unless you're making your own selective medium, in which case again quantity depends on the recipe you're using. - Nunh-huh 02:44, 5 March 2008 (UTC)

BBC Bird Question

In every early morning quiet scene in a British costume dramas, they'll show the protagonist looking pensively over the landscape for whatever reason. Then 4 times of 5, they'll throw in a soundbite of some English bird with a very shriekish call. It's supposed to set the ambiance or something. For instance, you hear it in the beginning of Part 4 of the 1995 version of Pride and Prejudice as Darcy looks over the moors. What is that bird?160.10.98.106 (talk) 19:57, 4 March 2008 (UTC)

Looking in my Collins Bird Guide and having listened to P&P a little, I think you might be hearing the goshawk. Most hawk screams are perfect for punctuating the wildness of an outdoor scene. According to Collins, there aren't many species of raptor in Derbyshire, only the goshawk, the sparrowhawk, the hen harrier, and Montagu's harrier. --Milkbreath (talk) 20:50, 4 March 2008 (UTC)

In the U.S., we use a Red-tailed Hawk scream as the avian version of the Wilhelm scream. -- Coneslayer (talk) 20:54, 4 March 2008 (UTC)