Wikipedia:Reference desk/Archives/Science/2009 July 5

Science desk
< July 4	<< Jun | July | Aug >>	July 6 >

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.

July 5

Vacuum energy

How can I tap into it? —Preceding unsigned comment added by 79.75.115.133 (talk) 00:07, 5 July 2009 (UTC)

You can't. According to the vacuum energy article, at least, “consensus among particle physicists is that ... vacuum energy cannot be harnessed to do usable work”. Getting “free energy” would violate the law of conservation of energy, which has never been violated in any experiment. Red Act (talk) 01:12, 5 July 2009 (UTC)

Apparently nobody's told the U.S. Patent Office, since it's granted a patent. Clarityfiend (talk) 04:50, 5 July 2009 (UTC)

USPTO has granted a bunch of perpetual-motion-machine patents...just one of many pieces of evidence why existence of a patent for something doesn't prove that the something actually works as claimed and that the patent approval process does not include scientific review. DMacks (talk) 05:38, 5 July 2009 (UTC)

Right. In particular, the "inventors" who were granted the patent linked to do not actually have their device functioning as a net source of energy.[1] It’s all just a pipe dream. Red Act (talk) 06:08, 5 July 2009 (UTC)

So you can buy a patent on something that could work, saving the cost and effort of actually engineering the device to actually work. When later someone else, unaware of the patent, finds out how to do things and really builds that machine the first one can claim all the benefits and enforce license payments by law? 95.112.189.234 (talk) 12:03, 5 July 2009 (UTC)

One who holds a patent can claim anything but only Law can enforce. Cuddlyable3 (talk) 12:37, 5 July 2009 (UTC)

Yes, that would be patent law in this case. 95.112.189.234 (talk) 13:39, 5 July 2009 (UTC)

There's some requirement about a patent being "reduced to practice" in order to have a strong claim of originality (and be a valid patent)...you can't patent an idea, but only specific items or processes of it (though they are often be described in vague or general terms). Here's a decent article I found:[2]. On the other hand, Patent trolls do things at least close to what you propose. DMacks (talk) 14:34, 5 July 2009 (UTC)

Regarding the above mentioned patent the article you linked is just some good intention. 95.112.189.234 (talk) 15:43, 5 July 2009 (UTC)

The whole Claims section describes the specifics of what is being patented. That appears to be the intended implementation (facts of the process or device) of this ZPE system, not the idea of ZPE extraction in general. DMacks (talk) 16:42, 5 July 2009 (UTC)

With what "reduce to practice"? Either it did really work and science is wrong or there is some flaw in the patenting process. 95.112.189.234 (talk) 17:12, 5 July 2009 (UTC)

Doesn't mean it actually does what it says it does, just that it's built the way it says it's built. But going back to the heart of the matter in this, "there is some flaw in the patenting process" is a position supported by numerous legal experts (and also why patents are considered self-published rather than reliable proof of anything other than the facts of the device for WP:RS). DMacks (talk) 17:40, 5 July 2009 (UTC)

So it just building up a legal insecurity for those doing similar work, if they can be sued for doing that work? Patents regarded as being self-published is one thing, but evoking government authority to protect "self-published" things against other people is another thing. Thus owing a government-granted patent at least means that no one doing work on that subject can be sure not to get suede and sentenced. 95.112.189.234 (talk) 18:31, 5 July 2009 (UTC)

Maybe they should start by getting smarter patent examiners... Clarityfiend (talk) 18:41, 5 July 2009 (UTC)

I don't think he would get a chance nowadays 95.112.189.234 (talk) 19:23, 5 July 2009 (UTC)

I don't agree with patents "just" doing that, but otherwise yes, companies have huge legal research departments that make sure any work they might want to patent does not fall victim to prior art of existing patents. They might urge adjusting the company's product or process to "novel enough" to avoid being covered by them, they would certainly use careful wording in new patents to make things look clearly novel vs existing work (whether they actually are or not is often a court issue) and/or by trying to invalidate prior patents as too vague or over-reaching. See also Submarine patent, another trap for the unwary. DMacks (talk) 19:33, 5 July 2009 (UTC)

So you agree that current patent laws incite companies to spend lots of money to "huge legal research departments" to find the proper "careful wording in new patents to make things look clearly novel" instead of using that money on proper original research and development. 95.112.189.234 (talk) 20:02, 5 July 2009 (UTC)

I have to correct me: I should have said "current patent practice" instead of "current patent laws", but for a researcher that boild down to all the same. 95.112.189.234 (talk) 20:06, 5 July 2009 (UTC)

Don't put words in my mouth or make it seem like you're winning a debate that isn't happening by forcing me into a corner that doesn't exist. I'm not (and I refuse to) take a position here on what's happening, I'm merely stating the current situation. I didn't say "instead of". But if companies don't carefully protect their interests and aren't careful to make their products distinguishable from competitors and/or protectable from them, you can bet some other company will take advantage of it (read "find a way to get their customers") because there's clear benefit to doing that. DMacks (talk) 02:25, 6 July 2009 (UTC)

Aqua Regia

Who knows, why aqua regia is 1:3 mixture of nitric and hydrochlorous acid? Not 1:1, 1:10 or in other proportion?Renaldas Kanarskas (talk) 00:51, 5 July 2009 (UTC)

Well, that ratio is a "rule of thumb" and not an exact requirement. That ratio tends to yield best results for dissolving noble metals (like gold). Take a look at Aqua_Regia#Chemistry for the chemical equilibrium equations. To some extent, any answer will boil down to "because that is the ratio which best dissolves gold, as verified by experiment" - but you can get more specific about the detailed physics and ionic chemistry to explain this statement further. Nimur (talk) 01:34, 5 July 2009 (UTC)

Aqua Regia was discovered by Abu Musa Jabir ibn Hayyan (known in Europe as Geber) some time before 815 AD, or about 900 years before the rise of the modern atomic theory of chemistry. After first inventing both hydrocloric acid and nitric acid, he then determined the best ratio experimentally. -Arch dude (talk) 11:35, 5 July 2009 (UTC)

The actual molar ratio between Cl- and NO3- is ~2:1 , this fits ok with the ratio required for dissolving gold which is between 4:3 and 4:1 depending on the extent to which NO2 produced produces more HNO3, I've also heard it said that the ratio is a good one for producing NOCl see Aqua_Regia#Decomposition_of_aqua_regia - which is a particularily active reagent - it's suggested that the ratio is the one which dissolves gold most rapidly.

Sauroposeidon

I was reading the artical on the Sauroposeidon and it says that this sauropod is known from four vertebrea. How it is possible to extrapolate an entire animal (length, weight, etc.) from so little data? —Preceding unsigned comment added by 216.154.19.192 (talk) 04:35, 5 July 2009 (UTC)

Part of it follows the rule of "quacks like a duck, looks like a duck ..." There is a lot more to it, though. Bones grow in response to the stress that they are subjected to in addition to the basic plan laid out in the animals DNA. So the size of a bone will tell you something of the size of the animal. From the shape of the bone you can deduce where in a body it would have been, based on similar bones in other animals. The article states that the ribs were still attached. Our article doesn't say, but in dinosaurs (and some reptiles today) all vertebrae had ribs attached. From the size of those you could also deduce the size of the neck. Blood vessles, nerve channels and tendons leave holes and grooves in bone. From those you can sometimes guess how muscles were attached and thus what an animal looked like and how it moved, based on what is known of similar features in modern animals. There are also bones of related animals where more complete skeletons have been preserved. 71.236.26.74 (talk) 06:14, 5 July 2009 (UTC)

It boils down to scale: you take a similar sample from an animal you know more about and try to apply the same ratio to get a better understanding of the unknown animal. This works much better in theory than in practise, but it does provide a place to start. In some ways, it's like inferring an unknown person's height when all you have is his shoe size: grossly simplistic, but it may provide useful clues for later. Matt Deres (talk) 16:36, 7 July 2009 (UTC)

TRYING TO FIND AN ARTICLE ON HOW COME DOES IT SNOW

CAN ANYONE HELP ME —Preceding unsigned comment added by 98.113.231.179 (talk) 07:05, 5 July 2009 (UTC)

There is a lot of information about snow in the article titled "Snow". I see several paragraphs about how snowflakes form and fall. DMacks (talk) 07:17, 5 July 2009 (UTC)

capslock Ivtv (talk) 02:06, 10 July 2009 (UTC)

Intergovernmental Panel on Climate Change trends

It seems that every time the IPCC comes out with a report they say their previous forecast had underestimated some effect or their model has improved and the effects will be worse. And now I read on the front of New Scientist "It's worse than we thought" about the latest forecasts on sea level rises compared to the 2007 report. Is there any aspect in any of their reports where a later report has said an effect will probably not be as bad as they said previously? Dmcq (talk) 10:01, 5 July 2009 (UTC)

I don't think that's a correct observation. As far as I can tell, the IPCC position has been fairly stable. The level of detail and the confidence have increased over time (and with that negative consequences can be predicted more exactly), but the basic predictions have not shifted a lot. The 1990 report estimated 3 degrees of temperature increase during the 21st century, the 2007 report has a number of scenarios that still cluster around the same value. Sea level rise from 2001 to 2007 is similar, too (in fact, the nominal 2007 range is lower, but explicitly excludes non-linear changes in polar ice caps). --Stephan Schulz (talk) 10:24, 5 July 2009 (UTC)

I agree with Stephan Schulz - the predictions have been, very roughly speaking, stable, and I believe there are examples where the prdition has been less significant that in the prior report. It is temping to put together a chart of of the key predictions, but I fear this may run into problems. A small problem is that in some cases the central estimate has gone down, but the range has gone up. A larger problem is that they have modified the way they present some of the values, so there's not precisely an apples to apples comparison. While adjustments for these issues are possible, they constitute research, so they must be done outside WP. Additionally, the reference to the New Scientist statement implicitly accepts its validity - I don't believe everyone or even a consensus is on board with that conclusion.--SPhilbrickT 13:25, 5 July 2009 (UTC)

Sorry yes, reading it better you're right. It is surprisingly consistent despite the improvements in measurements and models. Perhaps I just read too many scare stories that keep pointing out that it could be far worse and quoting the highest figures. And the range of values has got wider instead of narrower because they've put in a number of different scenarios. Dmcq (talk) 16:08, 5 July 2009 (UTC)

Resolved

 – Dmcq (talk) 16:08, 5 July 2009 (UTC)

Cheese oxidises or loses water when exposed to air at 4 degrees celcius?

When cheese goes hard in the fridge, is it because of reduced water content or oxidisation or both? ----Seans Potato Business 13:09, 5 July 2009 (UTC)

If the cheese is left open it will dry out - a hard cheese can't oxidise in the middle, there might be some oxidisation at the surface - but I don't know what process this is.83.100.250.79 (talk) 13:25, 5 July 2009 (UTC)

Cheese may oxidize some, but bacterial and yeast action will also work on exposed cheese; if the right mix of cultures are present, you will get a very tasty cheese indeed. These cultures will tend to soften, rather than harden, the cheese. The hard rind is mostly due to drying out. --Jayron32.talk.contribs 17:44, 5 July 2009 (UTC)

If you leave your cheese in the fridge unwrapped, it will dry out. End of story. If you put it in the fridge, you have to wrap it in plastic. If you live in a climate where you can leave it in a cool dark cellar, you can wrap it in cheesecloth and it will be a happy cheese for a considerable time. Looie496 (talk) 01:58, 6 July 2009 (UTC)

You can also baste the outside with salt water. It will then grow a rind that you can use in cooking or throw out. 71.236.26.74 (talk) 03:42, 6 July 2009 (UTC)

If it is placed in a sealed plastic bag in the refrigerator at 40 degrees Fahrenheit, it should not dry out as you describe, but it may eventually get green mold. If vacuum sealed it may last longer. Edison (talk) 02:20, 7 July 2009 (UTC)

biology red blood cells

When red blood cells are placed in pure water it bursts,this is due to the absence of which structure.

Your textbook probably has the answer. If not, try reading "Cell (biology)", focussing on the "Anatomy of cells" section. Axl ¤ [Talk] 13:54, 5 July 2009 (UTC)

Since Axl didn't say it, one of our policies is not to answer your homework questions for you. What Axl did - pointing you to how to find the answer - is all we do. Vimescarrot (talk) 14:44, 5 July 2009 (UTC)

Also, the original poster forgot to close his NOWIKI tag. Nimur (talk) 19:57, 5 July 2009 (UTC)

Pain in buttocks and legs

• 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).

I have removed this question because it explicitly requested diagnosis. (discussion link). Nimur (talk) 19:52, 5 July 2009 (UTC)

Ecological Term

What is the term used for a still pool adjacent to a moving current? (specifically a river)

I believe there is a word for it and I'm trying to remember it and it's driving me crazy.

Alfonse Stompanato (talk) 20:41, 5 July 2009 (UTC)

Just a question, as I am ignorant of this subject matter -- is the still pool connected the moving current of the river? Bus stop (talk) 21:06, 5 July 2009 (UTC)

Here is a "Glossary of River Ecology Terms". Bus stop (talk) 21:10, 5 July 2009 (UTC)

Could be a "backwater," according to the above glossary. Bus stop (talk) 21:17, 5 July 2009 (UTC)

An "oxbow" would also fit that definition. It is said to be: "An abandoned meander in a river or stream, caused by cutoff. Used to describe the "U" shaped bend in the river or the land within such a bend of a river." Bus stop (talk) 21:37, 5 July 2009 (UTC)

Sounds like the OP is describing an Eddy (fluid dynamics). -Atmoz (talk) 21:41, 5 July 2009 (UTC)

This glossary is a good find. Seems like "backwater" is the term closest to what I'm looking for—but "backwater", it appears, can be used to refer to something quite vast. I'm looking for a word that can be used figuratively to refer to something off to the side (of the movement and activity of a like substance). I vaguely remember reading or watching something that mentioned still pools connected to a moving body of water—and that they were ecologically important to some species. For example, if you wanted to spear yourself a fish, you might want to find one of these. But it's possible that there isn't a short term for this. —Preceding unsigned comment added by Alfonse Stompanato (talk • contribs) 23:10, 5 July 2009 (UTC)

The people I've canoed with call it an eddy. Looie496 (talk) 01:47, 6 July 2009 (UTC)

What's called "oxbow" in US is called Billabong in Australia. - KoolerStill (talk) 06:29, 9 July 2009 (UTC)

lard

can you store lard at room temp? —Preceding unsigned comment added by 74.65.3.30 (talk) 21:52, 5 July 2009 (UTC)

Well, Lard suggests that most lard should not melt below temperatures of 30^oC (85 or so degrees Fahrenheit). However, lard, like all animal products, will probably spoil if stored for extended periods at room temperature, so storing in a refrigerator is recommended. Intelligentsium 22:05, 5 July 2009 (UTC)

Google books search [3] gives old references suggesting temperatures for long term storage of lard anywhere from 31 to 60 degrees Fahrenheit. Certainly people have stored lard for a time at room temperature, but long term storage seems to require lower temperatures. [4] suggests that antiooxidants can delay lard becoming rancid. [5] Says lard's shelf life is "not particularly long."[6] say that supermarket lard will be usable for one yuear if refrigerated. Lard makes superior pie crusts and biscuits, but the saturated fats are not that healthful. Edison (talk) 22:19, 5 July 2009 (UTC)

Perhaps - if you could kill every last bacterium and mold spore in the stuff (eg by pasteurization or irradiation) - then you could either can, bottle or vacuum seal it and keep it for a very long time. Whether it would spoil for other reasons (internal chemical reactions, etc) is tough to estimate. But other meat products can be canned (think Spam) and kept pretty much indefinitely at room temperature - those military ration packs are vacuum-sealed and last almost indefinitely - even at quite high temperaturess. I think lard should survive similar treatment. SteveBaker (talk) 23:30, 5 July 2009 (UTC)

Lard is essentially all saturated fat; as such it is probably atleast as shelf-stable as say vegetable shortening, that is if you aren't going to leave it already opened in your pantry for months at a time, you probably don't need to refrigerate it. It may be animal derived; but its no more a "meat" product than "vegetable oil" is a vegetable. --Jayron32.talk.contribs 23:57, 5 July 2009 (UTC)

OR: We used to store lard in a pot. every couple of days it was boiled in a pot of water and then put in the "larder" (sic.) after the pot no longer felt hot. When the lard had solidified on top of the water it was removed, the water was thrown out and the lard was kept till the next round or until it was used in cooking. This procedure was done as part of the usual cooking routine. So if the stove was run on firewood or coal there was no need for starting it for a separate run. I think there is an old saying out there about having "a pot of lard on the fire". 71.236.26.74 (talk) 03:39, 6 July 2009 (UTC)

WP:OR Living elderly cooks who used lard to make delectable baked goods say they stored it in the refrigerator. I have seen it turn brown and rancid at room temp in a cabinet. If you make biscuits, piecrust, cookies and such with it every day you could use it up before it turned rancid. Edison (talk) 02:18, 7 July 2009 (UTC)

Bony lumps

My mind is teasing me; I cannot remember the term for this. There is an inherited condition where there are additional deposits of bone in the mouth cavity. They may be present as bumps in front of the teeth (i.e. within the gum), ridges on the palate, or even processes within the mandible. The condition is not usually a source of trouble; they're just extra bone. I'm drawing a complete blank and my look through our various dental and anatomical articles isn't helping me. I am not, by the way, think of something like tonsilloliths, but of actual additions to the normal bones. Matt Deres (talk) 23:48, 5 July 2009 (UTC)

See torus mandibularis, torus palatinus, and exostosis. Red Act (talk) 01:00, 6 July 2009 (UTC)

That's it! Thanks. Matt Deres (talk) 10:31, 6 July 2009 (UTC)