Wikipedia:Reference desk/Archives/Science/2012 December 23

= December 23 =

Columbia River Dams
If the Columbia River Dams had not been built what would be the effect on the last 80 years economy? Did the Columbia River Dams have any long term effect on the financial and political strength of United States?

Guy Swanson. Spokane. — Preceding unsigned comment added by 67.185.227.135 (talk) 02:19, 23 December 2012 (UTC)


 * They certainly had a major effect, but evaluating what things would be like without them is a difficult task, because the money not spent on them might have gone to some other major project which would have been just as beneficial (see opportunity cost). StuRat (talk) 06:47, 23 December 2012 (UTC)


 * The area would have been deprived of hydropower and would have had to resort to power from fossil fuels and nuclear fuel. But the Native Americans would have been able to continue fishing at Celilo Falls. ←Baseball Bugs What's up, Doc? carrots→ 07:31, 24 December 2012 (UTC)

Scientific racism and pseudo science?
I came across this video on YouTube, link, and it basically involved two YouTubers ranting about whether race exists or not.

The point I have a question about starts at 12:12 and ends at 14:53 where the YouTuber in question, fringeelements, was trying to refute the claim that Eurasians have more in common with Africans than Africans do with each other which cited this paper as evidence for this claim. He contended that this study only analyzes SNPs and not entire genomes, and then cited this paper as evidence that the possibility that individuals of one self identified race are more genetically similar to individuals of another self identified race than they are to individuals of the same self identified race are virtually zero. He then goes on to point out that the opponent he was arguing against invoked Lewontin's Fallacy.

I'm not entirely sure if what he's saying is true or not. Are there any problems with his argument? Is it true that Eurasians are more genetically similar to Africans than Africans are to each other? Malamockq (talk) 04:07, 23 December 2012 (UTC)


 * What's an African? HiLo48 (talk) 04:36, 23 December 2012 (UTC)
 * LOL, African people. Bonkers The Clown  (Nonsensical Babble) 04:45, 23 December 2012 (UTC)


 * "Similarity" is vague and undefined. The evidence points to all extra-African human populations having evolved from one subbranch of humanity, with all the other branches being African.  (This is a simplification, but clear enough.)  You'll get a lot of ideological squealing over this, as the Lewontin Fallacy article shows.  The out of Africa theory article addresses the main points. μηδείς (talk) 04:49, 23 December 2012 (UTC)


 * Races aren't black and white (no pun intended), a race is defined by a continuous spectrum of genetic profiles with arbitrary boundries. For instance, a person of equatorial-eastern African descent would be expected to be tall, dark skin colour, and a particular skull shape, hence facial features; However, a short person with that descent can not be excluded. The point I'm trying to make is that a race is not discrete, it is an heuristic term used to describe a common combination of genetic ranges, and very often containg large overlaps. Plasmic Physics (talk) 05:19, 23 December 2012 (UTC)
 * You could say that. Or you could say people are all one species, and interbreed. μηδείς (talk) 07:54, 23 December 2012 (UTC)


 * They aren't mutually exclusive. There's no logic-reason why you can't say both. Plasmic Physics (talk) 10:17, 23 December 2012 (UTC)


 * You have to realize also that the differences amongst different people in Africa are greater than those in the rest of the world put together so lumping all Africans together is really rather silly. Saying "Eurasians have more in common with Africans than Africans do with each other" has rather a lot of things wrong with it. You could say for instance instead that Eurasians have more in common with one group of people in Nigeria than that group does with the two other main groups in Nigeria. Dmcq (talk) 00:52, 24 December 2012 (UTC)

oranamental conifer
Which one of the below is an ornamental conifer? pinus cedrus araucaria cycas sequoia — Preceding unsigned comment added by 117.201.244.229 (talk) 05:30, 23 December 2012 (UTC)


 * See the following:


 * pinus
 * cedrus
 * araucaria
 * cycas
 * sequoioideae
 * StuRat (talk) 06:42, 23 December 2012 (UTC)

Do your own homework. Whoop whoop pull up Bitching Betty 15:08, 23 December 2012 (UTC)

Why is the charge of quarks exactly proportional to the charge of electron?
For example, why is charge of up quark exactly equal to two thirds of the charge of an electron and down quark one third? How is it made to be like that? Or are the charges not properties of the quarks themselves but a result of interactions between those quarks?--Inspector (talk) 07:26, 23 December 2012 (UTC)
 * If we accept the numbers of up and down that combine to make a proton and a neutron and that those combinations have charges or +1 and 0 respectively, it's basic algebra to determine the charges of up and down themselves. The charge is an actual intrinsic property of the quarks themselves. We have plenty of articles with titles such as quark, up quark, etc. that have details of the history of their discovery and individual properties. DMacks (talk) 08:04, 23 December 2012 (UTC)
 * I have looked at the articles and the question isn't answered. Quarks have the charges they do. Electrons have the charges they do. But there is no explanation given as to whether this elegant ratio derives from some deeper principle of quantum mechanics, or if that's simply what's measured and there is no apparent need for it to be that way. Someguy1221 (talk) 08:06, 23 December 2012 (UTC)
 * If it were not so, then uncharged atoms could not exist, and chemistry would be very different, but that isn't an explanation. There must be something more fundamental about the nature of charge that we have not yet discovered (or is not yet explained in Wikipedia articles).    D b f i r s   08:20, 23 December 2012 (UTC)

The charges of leptons and quarks are determined by underlying symmetries of the standard model. In particular, they lead to the following Gell-Mann–Nishijima like formula for the electrical charge of quarks (q) and leptons (l):


 * $$Q_{q,l}=\frac{Y_{W(q,l)}}{2}+I_{W3}$$

where the third component of the weak isospin is $$I_{W3}=\pm 1/2$$, the weak hypechrage of leptons (electron and neutrino) is (by definition) $$Y_{W(l)}=-1$$, so that electron has an electrical charge of $$-1$$ and neutrino of $$0$$. The sum of electrical charges of leptons is therefore $$S_l=-1+0=-1$$. For quarks the same sum is $$S_q=3Y_{W(q)}$$, taking into account that quarks come in three colors.

Another important consideration is cancellation of the chiral anomaly, which requires that $$S_q+S_l=0$$. The result is that $$Y_{W(q)}=1/3$$. The final result is that quarks have electrical charges of $$-1/3$$ and $$2/3$$. Ruslik_ Zero 12:49, 23 December 2012 (UTC)
 * A propos of nothing, for some reason I find your typo hyperchrage to be very appealing. If I were ever to get into some MMORPG, I think I might use that as my avatar name. --Trovatore (talk) 21:57, 23 December 2012 (UTC)
 * It's not a typo, we even have an article on weak hypercharge. Nonetheless, it is appealing and would make a cool screen name.Phoenixia1177 (talk) 17:32, 25 December 2012 (UTC)
 * It is probably better to think of electric charge as a kind of twist in space rooted at the electron or quark rather than as a property of the particles themselves. As a geometric property of space it is quantised and it doesn't matter what you do to the quark or electron itself - it remains the same even if you speed up an electron near the speed of light for instance. Dmcq (talk) 10:45, 24 December 2012 (UTC)

Instinct and sex positions
Suppose a young human male and female want to copulate, but they have absolutely no information how to do it (no experience, no porn, no friends stories, no Discovery channel etc). Which sex position they choose instinctively?

I don't need an advise, lol. It's about biological vs cultural in human beings. --Ewigekrieg (talk) 09:15, 23 December 2012 (UTC)


 * I'd say something face-to-face, based on sociological norms. That being said, that's my 2012 American sociology talking.  DRosenbach  ( Talk 20:08, 23 December 2012 (UTC)


 * Is there any way of knowing? Would all such couples instinctively go for the same position?  If they'd watched dogs and other animals, it'd probably be something other than the missionary position.   --   Jack of Oz   [Talk]  22:20, 23 December 2012 (UTC)


 * I figured that no information [on] how to do it (no experience...no Discovery channel, etc.) would exclude the sort of thing include.  DRosenbach  ( Talk 23:02, 23 December 2012 (UTC)


 * If they've had no exposure of any kind to sexuality, why would it even occur to them? ←Baseball Bugs What's up, Doc? carrots→ 23:22, 23 December 2012 (UTC)
 * You're under the influence of Western religion's oppressive view of sexuality as something shameful that spoils "innocent" minds, and that must be hidden away at all costs to prevent the spread of happiness. Bacteria know how to have sex. Domestic dogs that have never seen other dogs know how to have sex. Solitary animals like the tiger don't travel in packs and rarely interact with members of their own species, yet they have no problem having sex. Do you suppose all these organisms got their information from Discovery Channel?
 * EDIT: Scray pointed out that I never directly answered the question of "why would it even occur to them?" I meant to suggest that the human sex drive is instinctive.  As other editors pointed out, sex is fundamental to the species' survival.  It is also extremely old--sexual reproduction evolved 3 billion years ago, which is about a million times longer than the entirety of human history.  I don't know the mechanism by which a human's hormones cause him/her to have sex, but I'm saying that such a mechanism is deeply ingrained in every animal that reproduces sexually, because reproduction is literally the only goal that evolution can be said to have.

--140.180.249.194 (talk) 01:10, 24 December 2012 (UTC)
 * Of course it would occur. Wow, what is this delightful person in front of me? I want to get closer. I want to hug. Still need more closeness. What a nice recess for my growing erection. I will take off my loincloth if it's too uncapacious to comfortably allow this. (as appropriate): I will take off my penis gourd because I feel so little of you there and so much everywhere else. (inevitably: I want to see you naked. Wow this must be even intimater. Let's try it. If you don't call intracrural a position.) Sagittarian Milky Way (talk) 00:40, 24 December 2012 (UTC)


 * I'm guessing they would figure it out. Sex is as built-in a function as we have, after perhaps breast feeding and fear of falling.  Besides, the shapes are pretty self-explanatory to any curious mind.
 * My totally unreferenced guess as to the original question: Standing, face-to-face.  --Trovatore (talk) 23:31, 23 December 2012 (UTC)


 * See this article. The bonobo, one of the closest human relatives, uses a variety of sex positions. The most common is doggy style, followed by missionary position. Bonobos also engage in tongue-kissing and oral sex. Just in case you still think human sexual instincts are learned from Discovery Channel, bonobos also engage in clitoris rubbing (amongst females), scrotum rubbing, penis fencing, masturbation, and mutual masturbation between an older male and a younger male. --140.180.249.194 (talk) 01:10, 24 December 2012 (UTC)
 * I really have no idea what this debate is, but I am happy that you are entering the level of bonobo awareness that results in pedantically preaching to everyone your knowledge of bonobo practices to the point of defeating your own points. The reason why you—and others—are aware of bonobo's behavior is exactly because of the world of the media educating you on exactly one theory on bonobo behavior. If you do some more research, you would realize that bonobo's are not some magical sex monkeys & folks are not as convinced about their behavior as you seem to imply. --SpyMagician (talk) 01:14, 24 December 2012 (UTC)
 * I am answering the OP's question by assuming that humans and bonobos have the same "natural" sex positions. Considering that bonobos are a close human relative, and that everyone else has been guessing without any references whatsoever, I think that's a pretty good response.  If you want to link to a specific reference supporting your claims, please do so, because the bonobo article supports almost every single one of my claims.  --140.180.249.194 (talk) 03:29, 24 December 2012 (UTC)


 * How many people here had to be taught how to masturbate? μηδείς (talk) 21:02, 25 December 2012 (UTC)
 * No and a someone up there was telling something about discovery channel hahaha
 * man... REALLY!?
 * I guess it would be just like all the other mammals, it’s true that I’m influenced by… “Discovery channel” but at least is the first position that come to my mind

Have a question about Avogero's law.. Can anybody solve it?
Avogedro's law says that every gas's gram molecular mass has 6.02X10^23 atoms and its volume is 22.4 litter; its also applicable for solids and liquids. But as we know 1litter water/steam=1kg/1000g water/steam... So how can 18g(gram molecular mass of water) water/steam be 22.4 litter??? — Preceding unsigned comment added by Rishader (talk • contribs) 11:17, 23 December 2012 (UTC)


 * Who said that it is also applicable for solids and liquids? ~22.4 is also only correct for an ideal gas. Plasmic Physics (talk) 12:13, 23 December 2012 (UTC)


 * One gram of a gas (or any other substance) does not contain 6.02 x 1023 atoms, but approximately that number of (protons + neutrons). The weight of 6.02 x 1023 water molecules is (6.02 x 1023 u/g) x 18 u = +/- 18 g, because the weight of one water molecule is about 18 u. Avogadro's law, which implies that 6.02 x 1023 molecules occupy 22.4 liters is only applicable to gasses. However, Avogadro constant can be used in converting weight units of any substance, gasses, liquids and solids alike. - Lindert (talk) 13:40, 23 December 2012 (UTC)
 * Thanks everyone. Lindert properly solved my problem. Thanks to u specially.. I wasn't clear about the Avogadro Number uses. I mixed up with the Law — Preceding unsigned comment added by Rishader (talk • contribs) 16:11, 23 December 2012 (UTC)

I don't understand anything said above, but one Mole of a molecular substance contains 6.02X10^23 molecules of it, whether they be O2 or NH3. One can figure out their weight in grams by summing the molecular weights times the number of each atom in the formula. This is rather simple chemistry. And the name is Avogardo Avogadro, BTW.μηδείς (talk) 21:20, 23 December 2012 (UTC)


 * You're maybe thinking of the Italian judge (advocato) or the fruit (avocado). This one is Avogadro.  --   Jack of Oz   [Talk]  21:30, 23 December 2012 (UTC)
 * Just by the way, Italian for "lawyer" is avvocato, with the double v and no d. And avocado is a vegetable. --Trovatore (talk) 21:50, 23 December 2012 (UTC)
 * I was continuing the time honoured tradition of making deliberate errors while correcting others for their making of deliberate errors while correcting others .... And I see you're also getting into the swing of things with your vegetable claim, contrary to what our article says.  Who's next? :)  --   Jack of Oz   [Talk]  22:16, 23 December 2012 (UTC)
 * Our article is wrong. Well, it's right, from a botanical point of view, which I suppose is what it's getting at.  But from a culinary point of view it's flat wrong to call avocado a fruit, as it is neither sweet nor sour. --Trovatore (talk) 23:04, 23 December 2012 (UTC)
 * "Knowledge is knowing a tomato is a fruit. Wisdom is knowing you don't put tomatoes in a fruit salad." -Unknown.  The same sentiment works for avocados.  And cucumbers.  And squash.  And chili peppers.  And... -- Jayron  32  23:43, 23 December 2012 (UTC)
 * The correct solution is to realize that the culinary usage of the word fruit is distinct from the botanical sense, and culinarily, none of those things is fruit. In fact, they are all completely unambiguously non-fruit.  Rhubarb, on the other hand, is a culinary fruit but not a botanical one. --Trovatore (talk) 00:01, 24 December 2012 (UTC)
 * So, what you're saying is this: There's more than one valid way of classifying edible things, and according to one of those ways, the avocado is a fruit.  I chose that way.  I never disputed that there are other ways.  I just don't get what you're going on about.  Must be the silly season.  --   Jack of Oz   [Talk]  00:19, 24 December 2012 (UTC)
 * Hehe, was just a misfortunate unspeling, as you can see from the redlink. μηδείς (talk) 21:32, 23 December 2012 (UTC)
 * Worth an, perhaps? Tevildo (talk) 21:34, 23 December 2012 (UTC)


 * Please Note! Whoop whoop has sneakily made the Avogardo redlink into a blue one.  μηδείς (talk) 21:01, 25 December 2012 (UTC)
 * Just to make it clear:
 * In simple terms, Avogadro's law states that all gases occupy same volume.
 * Also note that one gram-molecular weight of any gas/compound would contain one mole (6.02 x 1023 number) of molecules.
 * ···V ani s che nu「m/Talk」 22:01, 25 December 2012 (UTC)

boltzmann brain
Are we humans considered as Boltzmann brain?203.112.82.129 (talk) 15:29, 23 December 2012 (UTC)
 * We are definitely a product of biological evolution. So, we are not a Boltzmann brain. --Ewigekrieg (talk) 15:46, 23 December 2012 (UTC)


 * It depends on how you look at it. On a macro scale, the brain is highly structured, with well defined functional areas and communication channels.  Clearly that's an evolved situation.  However, at a micro level, much of the brain appears to be randomly connected, and the detail nueronal wiring is not inherited.  No two brains are identically wired, even in newborn indetical twins. Further, computer simulations of randomly connected large numbers of "nuerons" shows that quite realistic looking brain waves, that show a vigorous response to sudden stimuli and then gradually settle down to a well defined rhythm, just like the real brain does, generally appear in ramdonmly connected nets.  However, the processing power of randomly connected nets in such computer simulations is often very resource inefficient, at least as far as simulations I have done go.  One would expect natural selection to eliminate anything that is wasteful.
 * Our brains are, as far as nueronal interconnection goes, partly nature and partly nuture. Many nuerons start out randonly connected, but as we learn, skills increase by selectively dropping connections (and even entire nuerons) and adding others.  Does something that satrts out randomly connected, and ends up after years of use efficiently structured mean that it is no longer a Boltzman network?
 * It seems to me though, that looking at the brain as a Boltzman structure is not terribly useful.
 * Wickwack 120.145.48.199 (talk) 13:56, 24 December 2012 (UTC)
 * I think you don't understand the Boltzmann brain argument, the whole point of which is that our brains are not Boltzmann brains. More precisely, the argument is that some cosmological scenarios predict that more intelligent life should arise through random fluctuation than through evolution (because there's so much vacuum for quantum fluctuations to happen in), and those scenarios should be ruled out on that basis. -- BenRG (talk) 17:18, 24 December 2012 (UTC)
 * The Wiki article on Boltzman Brains begins with the sentence A Boltzmann brain is a hypothesized self-aware entity which arises due to random fluctuations out of a state of chaos - which can be interpreted as function arising out of chaos - just as the human brain appears to work at the micro level - and does not at all show that show that something arising out of a random beginning should be ruled out. Perhaps the article should be rewritten if it does not give the view that you have presented.  But I think not, for the reasons I gave earlier.  If the Boltzman Brain paradox is due to not acepting that intelligence can come from random noise, then that is like religion - it is an aspect of faith that our brains are not Boltzman brains. Wickwack 60.230.194.179 (talk) 03:00, 25 December 2012 (UTC)
 * Hi guys. Wickwack, no, nonacceptance of the hypothesis is not like religion. Without sufficiently valid physics in place its a spherical cow, thus I'm skeptical that Boltzman brains are even possible, let alone likely. -Modocc (talk) 04:58, 25 December 2012 (UTC)


 * Yes, the article should be improved, like most of the physics-related articles on Wikipedia, which are surprisingly bad in general. There's nothing wrong with talking about the role of chaos in the human brain, but "Boltzmann brain" has a specific meaning and it's not that. See here for more information. -- BenRG (talk) 19:07, 26 December 2012 (UTC)

Bromeliad species? Prognosis?
I usually get my sister an Amaryllis for Christmas, but this year I bought a bromeliad that is of this species. Can anyone identify it? Are the plants semelparous? The one I got her is about a cubic foot in spread (including root mass) and has three spikes on two shoots. Should she just enjoy watching it bloom as it dies, or can she cut off the blooms and expect further growth and future blooming? Thanks. μηδείς (talk) 21:13, 23 December 2012 (UTC)
 * This plant looks like a vriesia which has a number of varieties. yours looks like 'Drako' or Miranda'. After flowering they usually throw offshoots which provide the next generation of flowers. These can be left on the parent plant or repotted to make another plant. Richard Avery (talk) 07:57, 24 December 2012 (UTC)
 * Actually, from your link, I am sure it is Bromeliad Vriesea Charlotte - Tawi. Happy to learn this plant will live long if taken care of.  Maybe I will keep it for myself, since my sister kills everything else. μηδείς (talk) 20:59, 25 December 2012 (UTC)