Wikipedia:Reference desk/Archives/Science/2007 March 11

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.

March 11

Acids...

Hello, please indulge me ^.^. We're doing acid-base equilibria in chemistry right now in my high school, grade 12. I was wondering:

1. Are there many inorganic solid acids? I.e does the fact that a sample of acid is a solid mean that it is most likely organic? I know of boric acid as a solid, but off the top of my head I don't know of many others, but then this would be because of my lack of knowledge not that there aren't any out there.

2. How many protons does it look like the acid that generated the following titration curve have? Obviously the big jump in the pH 8 range is considered an equivalence point, but does the little 'hump'/activity in the 2-4 range mean anything?

Titration Curve

74.102.89.241 02:51, 11 March 2007 (UTC)

Most acidic salts of diprotic acids are solid (e.g. NaHSO₄). What else could the hump be if not an equivalence point? Cacycle 04:39, 11 March 2007 (UTC)

Many acid anhydrides are solids; add water to reconstitute the original inorganic acid solution. (Note that the rehydration may generate a great deal of heat, and may involve the formation of unstable or highly reactive intermediate compounds.) TenOfAllTrades(talk) 04:50, 11 March 2007 (UTC)

Totally worthwhile question about hamster genetics

OK, I have heard that breeding two hamsters with white-furred bellies is doubleplusungood because there's a high chance the hamsterlings would be born without any eyes. Why is this? Specifically, how are the characteristics of having a white belly and not having any eyes connected? Vitriol 03:30, 11 March 2007 (UTC)

It may be an example of pleiotropy, where one gene affects more than one characteristic. A similar thing occurs in Manx cats, where if both parents contribute a copy of the tailless gene, the kitten will be spontaneously aborted. − Twas Now ( talk • contribs • e-mail ) 04:17, 11 March 2007 (UTC)

Yeah, but I was wondering why the gene influences such seemingly unrelated things. Vitriol 04:26, 11 March 2007 (UTC)

The things are only seemingly unrelated. Have a look at [1]. "Mating two hamsters that are Roan or White Bellied (both Whwh) gives litters in which 1/4 of the babies can be expected to be Eyeless Whites (WhWh). " "Wh" is the anophthalmic white gene, a "dominant spotting color mutation causing homozygotes to be deaf, blind, and white. An ultrastructural analysis of embryonic tissue reveals that Wh causes the retention of cilia by cells of opposing layers of the embryonic retina and by the lens fiber cells. Previous ultrastructural analyses indicate that Wh also causes the retention of cilia by secretory cells of the anterior lobe of adult pituitaries. We propose that the primary ultrastructural defects caused by Wh is the retention of cilia by embryonic cells. These retained cilia are hypothesized to interfere with normal cell-cell interactions and subsequent cell differentiation." [2] -Nunh-huh 06:21, 11 March 2007 (UTC)

Mutations in certain transcription factors can effect both eye development and pigmentation. The microphthalmia-associated transcription factor (Mitf), for example, is a key transcription factor that regulates melanocyte migration resulting in belly spots. Its is also a regulator of the pigmented retina. A mutated version of the gene can prevent this structure from fully differentiating, leading to malformation of the choroid fissure of the eye, resulting in the drainage of vitreous humor fluid. Without this fluid, the eye fails to enlarge, hence the name microphthalmia. Rockpocket 06:45, 11 March 2007 (UTC)

Of course even if the genes ARE unrelated, it is possible that they are just close together on the chromosomes and there could be genetic linkage. --Ocarina Cave Girl 23:03, 12 March 2007 (UTC)

No, there is only one gene being discussed, the "Wh" gene. - Nunh-huh 23:39, 12 March 2007 (UTC)

Oops, I apologize. I think I read that too fast and missed an important key fact... sorry! Ocarina Cave Girl 23:47, 12 March 2007 (UTC)

It's a good thought, just not relevant here :) - Nunh-huh 23:49, 12 March 2007 (UTC)

Does crying release endorphins?

So the other day, my friend told me that crying releases endorphins. I'm a big gully-bull and believed it. Then later I thought about it - endorphins are supposed to make you happy and are released when you laugh and things like that, but if you're crying there's a possibility you might be extremely sad. There's no mention of this on the article about tears and crying. If somebody could straighten this out, it would be much appreciated. Thanks for your time! NIRVANA2764 03:34, 11 March 2007 (UTC)

Have you never felt strangely comforted after a good cry? "Emotional" tears (rather than irritated eye tears) actually contain enkephalin and other hormones. It is also generally believed that crying stimulates the release of endorphins in the bloodstream and thus its evolutionary purpose is to reduce stress. Rockpocket 06:30, 11 March 2007 (UTC)

That's right. If you're extremely sad, to the point that you can't help crying, you won't be as sad afterwards as you were before. Whatever made you sad will still be there, and you may get that sad again some time down the track, but for now you'll feel a whole lot better. That's because you've expressed some of the feelings you had. And released endorphins. JackofOz 06:43, 11 March 2007 (UTC)

For a moment I thought you said you were a gull bully. I was about to warn you to watch your step, as the Gull Leader User:Kurt Shaped Box would not take kindly to your unwelcome attitude towards them... Now I realize that I mis-read and my comment is entirely irrelevant. Nimur 20:01, 11 March 2007 (UTC)

Medical marijuana question

I am a student preparing a presentation on medical marijuana and I have heard that it is grown in the U.S. Midwest (?), or in any case in different places than recreational marijuana, and that it is otherwise very different from the marijuana one acquires on the street. Are these claims true, and what sources prove it? Google has thus far been unhelpful. Thanks, anon. —The preceding unsigned comment was added by 162.84.156.63 (talk) 03:57, 11 March 2007 (UTC).

Penis Growth

Near the bottom of this website (Warning: contains pictures of penises), it claims that their penis enlargement pill can permanently increase penis size and uses a scientific-sounding explanation to back up their claim. This all sounds great and wonderful, but it also sounds like a miracle product, too good to be true. I'm wondering what on their page of special herbs makes this product work? Is this all bull? Just curious --71.98.20.104 05:52, 11 March 2007 (UTC)

Nope, it's all nonsense. I'm particularly amused by the 'What you can expect' section, which tells us:

"...Fifth/Sixth month you will notice an increase in penis size of up to 4 inches, plus a increase in Girth (Width) of 20%, plus all the benefits of the first month."

Anything that seems to good to be true almost always is. TenOfAllTrades(talk) 05:57, 11 March 2007 (UTC)

That's what I figured. Thanks for taking a look at it. --71.117.45.252 16:26, 11 March 2007 (UTC)

I dunno, those pills look pretty big. Depending on how many you can stuff in there, you might get some noticeable increases. --Tbeatty 04:08, 12 March 2007 (UTC)

Is the reference desk supposed to make me laugh so hard my students all look up from their exams? Jfarber 12:09, 12 March 2007 (UTC)

Only when the questions and answers border on the Galactically Inane :). --Tbeatty 04:11, 14 March 2007 (UTC)

indian scientists with events and photographs

indian scientists with events and photographs59.184.6.97 07:12, 11 March 2007 (UTC)

What is the question? − Twas Now ( talk • contribs • e-mail ) 07:16, 11 March 2007 (UTC)

Two answers. One, Category:Indian scientists; two, do your homework yourself. --Ouro (blah blah) 09:46, 11 March 2007 (UTC)

special relativity and vn=0.633c

From the special relativity we have, L= sqr{1-(v^2/c^2)} where c ,speed of light in vacuum Let`s presume that we have alarg number of an arbitrary frames,f1,f2,…..fn. Now, for the lengths transformation

Put r0= L1r1,

r0=L2r2, in such away that L2=(L1)^2

As amatter of fact the transformation of length ,time and mass is irrelevant here,what is important here is just the relation between L1&Ln

Now, put r0=Lnrn in away that , Ln=(L1)^n, That is, sqr{1-(vn^2/c^2)}= [sqr{1-(v1^2/c^2)}]^n

NOW , if we stablish the relation between n&v1 in this way, if n=100,{1-(v1^2/c^2)}=0.99 if n=1000,{1-(v1^2/c^2)}=0.999 if n=10000,{1-(v1^2/c^2)}=0.9999 and so on,one may get, vn=0.633c 80.255.40.168 12:23, 11 March 2007 (UTC)ARTHER

The answer is... um... Tuesday ? Nimur 20:04, 11 March 2007 (UTC)

Is there a question here? If not, you might consider adding it to the appropriate article, as long as you can cite it &c :) HS7 15:35, 12 March 2007 (UTC)

Uranium Enrichment by Laser Process

Source url : http://en.wikipedia.org/wiki/Enriched_uranium#Laser_processes

Query : Has any company developed, for acutal commercial use, a technology for the Enrichment of Uranium based on a Laser process (whether: AVLIS, MLIS or SILEX)?

--MyWikiName 14:57, 11 March 2007 (UTC)

The compnay is SILEX systems from Australia. For the latest public information see SILEX project update GB 01:54, 12 March 2007 (UTC)

I also thought that BNFL or URENCO had developed this process in the UK--88.110.12.93 04:30, 14 March 2007 (UTC)

Egg sizes

Are there any good sites out there that have experimental data comparing the size/weight of an egg to the size/weight of the bird as an adult? Thanks in advance. 71.240.57.211 19:12, 11 March 2007 (UTC)

The first thing I remembered was this 1972 paper about Egg Size vs. Profit, which I cited once a few years ago in a paper about a totally unrelated subject area. It's amazing how people never really check your work or citations. But anyway, North Carolina State University has a great Poultry Management web page, with boatloads of technical information about care and management. I can't find a specific "data" section, but this may be a starting location. This section includes technical information relevant to hatching-eggs. Nimur 20:10, 11 March 2007 (UTC)

Are you looking for intraspecific (within a given species) or interspecific (comparing various bird species) correlations? ---Sluzzelin talk 20:15, 11 March 2007 (UTC)

Intraspecific. 71.240.57.211 22:12, 11 March 2007 (UTC)

Kiwi birds have the largest egg in relation to their adult size. --Candy-Panda 01:25, 12 March 2007 (UTC)

A metric to use for measuring force.

22:30, 11 March 2007 (UTC)Sommerville We use a tensile tester to pull a sealed plastic blister from a .021pt.piece of cardboard.The width of the tear area is a quarter(.25in) and within that area the machine generates approx 800 readings in grams. The machine also gives use the average of the readings and a high or peak number of force that represents the initial rupture of the plastic blister from the card. WE are looking for the best metric that represents the strength of the sealed package. The product is a blister card. This is the product you see in a store that has a product enclosed in a preformed blister sealed to a cardboard card. Does the peak number actually represent the true strength of the sealed plastic blister to the card or is the average reading the best measurement to use? Thanks for your help.

                                   Jack

Pascals, or N/m²? --Wirbelwindヴィルヴェルヴィント (talk) 22:36, 11 March 2007 (UTC)

I'd use the peak, as the blister will not seperate completely if you don't reach that, but I'd also record the force at which the seal is broken in the first place. It really depends on what effect on the customer you are trying to predict. Greglocock 01:28, 14 March 2007 (UTC)