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February 1

Project

For our project at Uni, we have been asked to pick an animal to make extinct and argue our case. It has to be a vertibrate and not man. I dont want to pick panda cos it is too obvious and it doesnt really do any harm, does it? It should be preferrably something that does harm to the environment or nature or something. I thought beaver or something. Do you agree? Any further suggestions and why?

Beavers have a huge impact on ecosystems, providing wetlands for many other species to use, so removing them would probably have many repercussions. From a purely pragmatic and uninformed point of view, I would argue for the extinction of a species that is critically endangered or extinct in the wild, as I would imagine this would have the lowest impact on the planet's eco-system as a whole. Flipping the assignment on its head, you could go the satirical route and argue for the extinction of a species that would cause as large of an impact/disaster as possible, in effect showing that everything plays their part. Atropos235 01:20, 1 February 2007 (UTC)

The ranchers in the American West are after timber wolf (a.k.a. gray wolf) again; they want to see it extinct in their area again. American suburbians everywhere think the coyotes should all die.

Atlant 01:21, 1 February 2007 (UTC)

Nah! I go for the Roadrunner!--Light current 01:33, 1 February 2007 (UTC)

The safest thing to pick is a parasite. Not to sound utterly heartless, but humans are by far the most damaging parasite. But then, I like history and culture and being alive enough that I wouldn't want to wish the end of all humanity. This is a tough call for anyone to make. Think about the environmental impact removing a single animal would do. 67.174.211.89 06:00, 1 February 2007 (UTC)

I'd pick an introduced species, like the cane toad, and argue that it's value in it's native ecosystem is trumped by it's impact on it's introduced ecosystem. --Cody.Pope 06:54, 1 February 2007 (UTC)

What about the dreaded mosquito? | AndonicO ^{Talk · Sign Here} 11:39, 1 February 2007 (UTC)

Unfortunately, our questioner is limited to vertebrates. Otherwise, the mosquito is the obvious choice.

Atlant 13:10, 1 February 2007 (UTC)

You can really pick anything you want. It doesn't even matter. Species are rising, falling, gaining, being pushed back, bottlenecking, exploding, all the time everyday. It is simply the way of nature to kill off species. It may not be nice, but that's just how it is. That is normal, and it is change. It is absurd to try and do something with the intention of changing nothing, because the environment will change on its own, it doesn't matter what part of the environment changes it (may it be a particular species), because each species is part of nature. Since we are being so inherently anthropocentric, you can say humans have helped some species, and humans have destroyed some species, directly or indirectly. We can relate alien species invasion since it is the opposite of entirely removing a species. Both on the same continent and at the same time Bos taurus was being bred in vast quantities, while Bison bison was being hunted to near-extinction. Cattle are aliens too, and are among the most destructive friends we tend. The grazing and trampling of livestock threaten more than three and a half times as many native plant species globally as are threatened by nondomesticated aliens. Livestock threaten almost as many native animal species as alien predators do. Pueraria montana is an Asian plant despised in the southeastern states for aggressive growth. American gardeners of the late 1800s loved its fragrant blossoms, and in the 1920s it was promoted as Bos torus chow, and in the 30s widely planted by the Soil Conservation Service for erosion control. The Department of Agriculture declared it a weed in 1972. Similar in history, Taraxacum officinale, or "common dandelion" was introduced to North America from Eurasia for its medicinal and culinary properties. Even if you don't agree with me, you perhaps should mention it to bring something new to the table. [Mαc Δαvιs] X (How's my driving?) ❖ 12:24, 1 February 2007 (UTC)

Vertebrate eh? I'd pick the Panda. Think about all the resources, time & money that have been squandered to protect or preserve a species that has become so specialized that even without our intervention, was likely to become extinct in the very near future. Are there even enough Panda's left to sustain a genetically diverse viable population? Now if those same resources had been applied to a species not quite so cute and cuddley perhaps the passenger pigeon, great auk, or any now extinct species you can name might still be with us. This then brings into question the entire reason why we choose to protect some species while ignoring others? If the Panda was an ugly mollusc that crawled up your leg and bit you on the ass, would we be so willing to protect it? Extinction is a natural process. It is not that extinction occurs that should concern us rather, the acclerated rate of extinction that we as a species seem to be responsible for. Canis sylvaticus

How about the Water moccasin or Copperhead snake?, or maybe the Rattlesnake? Your study could look at whether nonvenomous species could step up to replace their pest control benefits without harming humans. In other words, would we be overrun by rats and mice without the venomous snakes, or could the less harmful species take care of the pests. These species do harm humans and their pets and livestock, and the water moccasin and copperhead snakes make the enjoyment of the outdoors difficult in the southern US in the summer, as the rattlesnake does in the west. I acknowledge that many people love all animals, and that they are all pretty to look at, unless you have just stepped over a log and they have sunk their fangs into your leg. (edited to add: Here I refer to the snakes, not the animal lovers as biters). Keep the panda. They do not bite humans as often, and are not known to be venomous. Edison 16:38, 1 February 2007 (UTC)

Human deaths from venomous snake bites in the USA (those species in particular are US snakes, yes?) are so uncommon today as to be statistically negligible. You get far more deaths from dog bites per year, more deaths related to riding the bus. --140.247.248.95 17:33, 1 February 2007 (UTC)

Country people in the southern U.S. avoid wooded or grassy areas, or creekbanks in the southern US in weather above freezing because of the presence of copperheads. They are numerous and aggressive, and like to live near human habitation, and move into outbuildings or onto farm equipment. I have had several close calls. Besides deaths, they cause painful injuries with lengthy recuperation. No one claimed that poisonous snakes are leading cause of deaths, and more people obviously ride buses that step on copperheads. Dogs are domesticated pets and offer the benefit of companionship or guarding as a tradeoff for the chances of biting soemone. Copperheads make poor pets, but if it were known that they lived in a building, people would, I guess, pretty much stay out. Edison 21:43, 1 February 2007 (UTC)

I'm just pointing out that you'd have to indicate that the number of lives you'd be saving would be in the dozens, whereas the likely ecological damage would be quite high. In terms of cost/benefit the panda is an easy one in comparison to the venomous snakes of the US, which cost very little (in terms of human costs and resources) to live with. The panda's non-venomous quality does not really give it an edge over the snakes in a strictly utilitarian model. --24.147.86.187 00:22, 2 February 2007 (UTC)

I'm sure if you made your presentation on a list of animals you initially thought you might like to make extinct, then talked about what made you reconsider, and concluded the whole exericse to be abhorrent, you would not receive an autofail. That's what I'd do. Vranak

---

I would pick the goat or the Norway Rat. Goats devastate ecosystems, and rats have a huge impact on humans. The one you pick will depend on your perspective. -Arch dude 02:39, 2 February 2007 (UTC)

If you want to be a smartass you could go for the Madagascar Pochard. The rationale being that everyone thought it was extinct 15 years ago anyway, and the world kept turning. Then a few of them were spotted last year. However, they are clearly critically endangered and - one could argue - removing the few remaining would have a negligible environmental impact. The opposing argument is that the Madagascar flora and fauna is rich in genetic diversity. Rockpocket 06:21, 2 February 2007 (UTC)

Excellent idea! Frilled shark, Megamouth, coelacanth, and Lazarus taxon. [Mαc Δαvιs] X (How's my driving?) ❖ 18:03, 2 February 2007 (UTC)

And the Tazmanian wolf

purifying water and sourdough

I have recently heard that the brewing industry use to use sourdough (from bread) to purify water. I wondered if there was anyone who could validate this. Also, how does it work? Thanks Valerie

Sourdough bread is bread that is leavened with sourdough starter, a symbiotic colony of yeast and bacteria (lactobacilli). The closest to "purifing" water might be the microorganisms living in the starter form somewhat hostile conditions to "squeeze out" other potential micro-invaders.That process is fairly slow and complex compared to filtering water through activated charcoal or distillation, and you'd end up with a bunch of floury water. I'm not a big beer aficionado, but using some sourdough starter in a ferment might impart some of the same acidic, complex flavors you can get in sourdough bread. Atropos235 02:44, 1 February 2007 (UTC)

Is it at all possible that this is a garbled version of the idea that alcoholic drinks were once drunk in great quantity because they were less likely to poison you than the water? That was mostly (if not entirely) due to the boiling involved in the production of alcoholic drinks. Skittle 15:36, 1 February 2007 (UTC)

Petroleum Oil

I am doing a science fair project for my 8th grade class. My question that i want to ask you is this: What is oil's real purpose in the Earth? Does is it act like some sort of insultaor or anything else? I mean, everthing on this Earth is here for a purpose. I am stuck and do not know what to do. I found one website that asked the same question to but did not have any information that I needed. Template:Please Help Me 4.129.87.148 00:57, 1 February 2007 (UTC)

Oil wasn't intentionally placed into the Earth for any sort of reason, but it is just the result of dead biomatter being compressed and heated under millions of years of sediment. Man's persistant exploration of the world lead to the discovery of petroleum and its seemingly millions of uses over the ages, from lighting up ancient homes to sending people to the moon. It can easily seem like everything in the world has a purpose because we are the ultimate tool-users and we can find a purpose for just about anything. Atropos235 01:36, 1 February 2007 (UTC)

For all we can tell, purpose is not inherently present on anything. There's no purpose for the existence and presence of oil, or even life, on Earth. It exists because that's how chemistry and physics work. Things also tend to naturally find their most stable state throughout time, so the feeling of deliberation and purpose arises naturally everywhere, since everything ends up fitting together so well. That being said, oil has no purpose, we just happen to find it very, very useful for many different things. — Kieff | Talk 01:44, 1 February 2007 (UTC)

The scientific way to phrase it is that purpose is not scientifically testable in experiment and therefore not relevant in a scientific sense. However, to absolutely claim there is no purpose is making a leap that science cannot explain so claiming there is no purpose or deliberation goes beyond the scientific method. --OpusPenguin 03:17, 1 February 2007 (UTC)

I personally believe "everything having a purpose" to be rubbish. As Richard Dawkins said, "We see the world through purpose-colored spectacles," because our nature is to see objects of having potential uses to us, we assume if we can't use it, it has a use to some other organism. [Mαc Δαvιs] X (How's my driving?) ❖ 12:17, 1 February 2007 (UTC)

See Teleology for a discussion of the old notion that someone (God?) placed everything herre for a purpose. This view might say that if I am hiking and have to make a pitstop in the woods, that my excrement is there for the purpose of nourishing a bush which will grow into a tree and provide shelter for some future weary travellor. A less teleological and more naturalistic view might be that "excrement happens." Edison 16:44, 1 February 2007 (UTC)

If you were to put any purpose to oil, surely it would be to warm up the Earth, not that there's anything wrong with that. Vranak

You are in 8th grade. Teleology is usually considered to be way too heavy for your age: Plato thought that one should not be concerned with Philosophy until age 40. Science fair: you are probably in time trouble: you don't need generalities, you need an answer, NOW. Here is what we are trying to tell you in simple terms:

• forget "purpose." That is way too complicated. It is philosophy, not science.
• Try to rephrase your hypothesis into something more scientific and less philosophical.

If you can reply with your current hypothesis, We can probably critique it for you and suggest a better hypothesis. I just got home from judging a high-school Science Fair, so I am sympathetic. -Arch dude 02:33, 2 February 2007 (UTC)

What did Plato know? Him and his ilk never understood inertia nor evolution nor planetary harmonics. Nonetheless, the above statements correctly emphasize that purpose is not testable and has no place in science. We can study much about petroleum - how it forms, what it is made of, what we can make out of it... but none of this implies a purpose. However, I think the original question was asking whether there petroleum performs a geological function - such as "insulating. "Petroleum reserves do not really insulate very much; but they contain lots of dissolved gases (notably, helium, sometimes hydrogen, and very often methane or other natural gas.They also serve as boundaries between rock layers (though this is probably an effect due to their formation). Nimur 08:05, 2 February 2007 (UTC)

Since no one actually gave the simple answer to your questions, I will: The purpose of the oil is for people to burn it for fuel. Do you think it needs some other reason to be there? Ariel. 13:11, 4 February 2007 (UTC)

Database for lab experiments

Hello, I am currently working on my PhD in the biopharmaceutical field. I am doing a number of lab experiments and I am looking for a way to store information about the experiments and the outcomes in a database.

Typical data about an experiment would be: Title, notes, Dates (when run, when analysed), material used, method used (i.e. word files), raw data (i.e. sampling points), secondary data (i.e. halflifes), graphs.

I have attempted to come up with an MSAccess solution, it works more or less but it has its bugs and entering data can be somewhat time consuming.

I was wondering if anyone knows a flexible tool to handle this kind of task. (I think there should be, since the core of what I need it to do is probably needed by uncountable other people working in similar areas. I haven't really found anything practical so far though).

Thanks, Lukas 04:32, 1 February 2007 (UTC)

Honestly, I'd use a spreadsheet if you don't have any prior experience with RDBMSes. Spreadsheet software is very flexible and useful for sufficiently small amounts of data. Most of the data I need to process goes directly from my notebooks into a spreadsheet program. -- mattb @ 2007-02-01T05:50Z

I don't think you could include all of the data he wants in just that. However it sounds to me like it is a flat database anyway, so you don't necessarily need it to be relational. Have you tried something like FileMaker Pro? It is like MS Access but much simpler on the whole. It doesn't let you do as complicated or customized things with the data but it doesn't sound like you are using Access to its full capabilities anyway. Access is probably the most "flexible" thing you are going to find, but being able to use that capability well requires a lot of time and experience with it. If you wanted to post the nature of the bugs to the computing desk, I am betting we can iron out some of them (I say this as someone who has wrestled with Access for eight years or so at this point). --24.147.86.187 12:49, 1 February 2007 (UTC)

Well, he didn't specify how much data he is working with...If we're talking single data sets with a million rows, then a spreadsheet will be insufficient. A few thousand rows is reasonable, though. -- mattb @ 2007-02-01T15:08Z

I'm not talking about total records. Look at the types of data he describes -- Word files, lengthy descriptions, etc. It is not easy to do that in a spreadsheet program, at least not any I have seen. The lines get very long and hard to read, use, and edit. --140.247.248.95 17:27, 1 February 2007 (UTC)

Need to share the data among workers ? Why not try a hosted DB solution like www.teamdesk.net at 7 $ / month / user. I found it easy to customize. Pcarbonn 16:03, 1 February 2007 (UTC)

Be very careful when using spreadsheets to store experiment results. See for instance The December 1 DWIM effect (reported on RISKS Digest 24.19; some comments on 24.20 and 24.21). Some other spreadsheet horror stories can be found at the European Spreadsheet Risks Interest Group site. --cesarb 18:57, 1 February 2007 (UTC)

Thanks for the replies so far. Especially thanks for the warning on excel, I've encountered some bugs in it myself before. Excel/spreadsheed is not a viable option for me. The reason to use the database is, as correctly pointed out, not that I have thousands of records, but that I have descriptive text data, files, etc. I do not need to share the data (and I don't see that happening within this project). I want to be able to easily enter data into a form and retrieve data matching certain characteristics (this is what I have attempted in my test database (msaccess2002). One thing it should take over is the task to think of where I should save which files and make it easy for me to find them again. I'm still looking for a product or an msaccess template which is designed for this or a similar purpose (there are should be tons of other people out there with similar requirements as me....). Lukas 01:47, 2 February 2007 (UTC)

Having a look at the teamdesk thing, too. Thanks Lukas 01:51, 2 February 2007 (UTC)

Many computer science types make a hefty profit handling other people's databases, because to even this day it gets messy and application-specific. Though numerous utilities exist (MySQL, MS Access, etc) which supposedly make managing data "simple(r)", I don't know of any that make the solution "user-friendly" to an inexperienced operator. It may be worth paying a fee to an outside service provider, or hire an undergraduate CS intern, if you are unable to develop a complete solution on your own. Nimur 08:11, 2 February 2007 (UTC)

Squid Brains and CNS?

Hello all!

I was talking to a friend recently who said that he couldn't understand how it worked, not being scientifically oriented, but that while in Japan he had been told that the liquid he was eating was squid brain, and that it was a liquid. This puzzled us both, as I, too, have not studied marine biology in great depth. Any idea if a) the brain really is liquid, and b) if so, how does the nervous system of a squid work? I know they are invertebrates, but that's about it. The Squid article doesn't seem to reap much information. 67.174.211.89 05:57, 1 February 2007 (UTC)

And hello to you too. Your brain is about 60% water, and can be liquified in a blender and is considered a gastronomic delicacy on R'tyrovkv in the Betegeuse system (lucky for us they are so far away). The unique thing about squid neurons from a neurophysiologist's point of view is that the individual axons are unusually large and were heavily used in the 1960s-80s to study depolarization and potential propagation. They work basically the same way your neurons work. alteripse 10:45, 1 February 2007 (UTC)

Some more info is at Squid giant axon. --David Iberri (talk) 18:04, 1 February 2007 (UTC)

On the brain into a liquid tangent, ancient Egyptians removed the brains in their mummification process by sticking a flexible tube up their nose and jiggling it several times to turn it into a mush, which was easily extracted from the cadaver from the nostril. bibliomaniac15 01:45, 2 February 2007 (UTC)

The brains of squids, like all other invertebrates, lack a myelin sheath. Not sure if this would affect the taste or texture of the brain from a culinary perspective however. Mikmd 17:55, 5 February 2007 (UTC)

After reading the myelin article, and the references, it seems that squids may have some form of myelin after all. However, it seems to have evolved independently from vertebrate myelin. Mikmd 18:05, 5 February 2007 (UTC)

I'd never heard of a "squid brain paste" food here in Japan so I looked it up, and the only thing I can find close is shiokara. It IS a liquid of sorts, but as far as I know there is no variety that is purely made of squid brains (though the brains are most certainly included with the rest of the pureed, fermented squid).  freshofftheufoΓΛĿЌ  05:18, 2 February 2007 (UTC)

Top 10 Engineering Projects With The Most Human Fatalities?

Hello wikipedians,

My brother in law and I were discussing the top 10 human engineering projects with the most fatalities. So far we have come up with the Death Railway (116,000 deaths of workers) and the Panama_Canal (27,500 deaths of workers).

What other engineering projects would be in the top 10?

Incomplete or unfinished projects are fine.

We are more interested in projects that have fairly specific numbers. For example, we know that lots of people died making the pyramids of Egypt but for obvious reasons we will never really know even approximate figures.

Thanks in advance, Kategorian 11:21, 1 February 2007 (UTC)

Interesting question. I suppose one would have to look at the oldest major engineering works, such as dams and canals. Searching Wikipedia for "workers died" suggests that 120,000 people died during construction of the Suez Canal, and 80,000 during the building of "the British railtrack" in Egypt.--Shantavira 11:55, 1 February 2007 (UTC)

Chinese urban myth claims that thousands upon thousands of people died while building the Great Wall. There are songs and stories that claim human meat and bone was used for the mortar. However, those horror stories have very little evidence to back them up. --Kainaw ^(talk) 12:52, 1 February 2007 (UTC)

You might also look into massive modern works produced in socialist countries in the 1940s and 1950s. I don't know whether many workers died in the construction of the dam on the Dnieper river, for example, or Magnetogorsk, but I would be surprised if they were bloodless, having been constructed with Gulag labor. --24.147.86.187 12:59, 1 February 2007 (UTC)

The Trans-Siberian railroad has to be a candidate. Clarityfiend 15:56, 1 February 2007 (UTC)

The production of military goods for the German army in WW2 should count as an engineering project, and very many imprisoned workers died in it, including death camp inmates and persons from occupied countries. China's Great Leap Forward was an engineering program to make China into a leading industrial country. It took a great many lives: villagers were told to make steel in little backyard furnaces by burning their doors and furniture and all trees as fuel, and all they managed was to convert their plows and pots into lumps of molten iron. The harvests were neglected, and in a pretense that agricultural yields had increased, the actual small harvests wer seized for export. The death toll is stated in the article as 14 to 43 million excess deaths. Edison 17:12, 1 February 2007 (UTC)

Among single construction projects in modern times, the White Sea-Baltic Canal has to rank pretty high.--Rallette 17:55, 1 February 2007 (UTC)

Cigarette lighters

why cigarrette lighter cant be lit by smouldering cigarette? —The preceding unsigned comment was added by 221.134.57.69 (talk • contribs). (Arun singh Bagh)

Basicalliy it seems that smouldering cigarrete is not hot enought to rase the gas temp above the critical temerature. See flash point for some info on this.--Light current 16:44, 1 February 2007 (UTC)

There was an episode of MythBusters where they featured a popular Hollywood myth, that dropping a lit (smoldering) cigarette into a pool of gasoline could ignite it. They were never able to make it happen, but deemed it plausible because the temperature of the cigarette was hotter than the flash point of gas so it "could" happen. I've also heard of anecdotes of people putting out cigarettes in jet fuel (similar to kerosene or diesel). Atropos235 18:25, 1 February 2007 (UTC)

Yep - the lighter hydrocarbons are always easier to light - lighter gas is propane or butane, the flash point increases with molecular mass. And yes kerosene and diesel are difficult to light, especially diesel - you ever need a wick or otherwise it helps if you heat it in a frying pan first until it starts smoldering - then it lights easily..

Plus a straight cigarette contains significant amounts of nitrate to get sudden flashes of high temperature as the tobacco impregnated with the nitrate burns - these are like little sparks and help ignite things. A 'roll your own' cigarette doesn't have this nitrate and burns much colder and is less likely to ignite a lighter flame - in general they don't..87.102.77.95 19:30, 1 February 2007 (UTC)

Sodium vapour lamps

why sodium vapour lamps are used for street lights? —The preceding unsigned comment was added by 221.134.57.69 (talk • contribs). (Arun singh Bagh)

The most amount of light for the least amount of electricity. See Sodium vapor lamp.

Atlant 16:14, 1 February 2007 (UTC)

High efficacy?--Light current 16:37, 1 February 2007 (UTC)

From a desire to make everything look yellowish with monochromatic 590 nm illumination, to make the skies over cities look orange, or to save electricity. Edison 17:15, 1 February 2007 (UTC)

its gotta be efficacy. If someone invented a higher efficacy green light, our night skies would turn green.--Light current 18:33, 1 February 2007 (UTC)

One consideration is that low-pressure sodium-vapor lamps are good for astronomers, because their light pollution can easily be filtered out (that's because they're so nearly monochromatic; you just have to block that one single line). In my opinion they're also less ugly than high-pressure sodium-vapor lamps (those are the pink ones). --Trovatore 18:37, 1 February 2007 (UTC)

It's what we already have, and would cost too much to replace all of them:)Hidden secret 7 19:40, 1 February 2007 (UTC)

Xenon arc lamp

New lamps can vary greatly. I've seen several recently which look to be high-intensity fluorescent lights (sort of like the Compact_fluorescent_light_bulb soft-glow lightbulbs. And of course xenon arc lamps are used, especially on high traffic highways.

Sorry, no. A variation on xenon arc lamps may be in your car's headlamps, but they're not used for overhead lighting on highways (because sodium vapo[u]r lighting is so much more efficacious).

Atlant 14:10, 2 February 2007 (UTC)

Chlorophyll efficiency

Is there some reason why the green part of the visible spectrum is not absorbed by chlorophyll and associated pigments? Why is chlorophyll able to absorb only red and blue light? Would a more efficient system absorb all visible light? — Preceding unsigned comment added by 220.236.73.126 (talk • contribs)

I'm not sure, but at a guess I would say that plants just doesn't need to. They get sufficient energy from the wavelengths that they do absorb. Also, if plants were absorbing all wavelengths in the visible spectrum, they would probably overheat. (And who wants a world full of black plants anyway?) BenC7 07:14, 2 February 2007 (UTC)

I think the best way to explain this is that "nature" didn't just engineer the optimum system. It evolved this way, probably based on prior chemical reactions. I'm not entirely sure how the chemical reaction operates, but it very likely cannot use any arbitrary energy, requiring specific frequencies to serve as activation energy for chemical changes. Nimur 08:22, 2 February 2007 (UTC)

• Chlorophyll is green. The reason we can observe that is because it doesn't get absorbed. If it did, it wouldn't be green anymore. - Mgm|^(talk) 11:09, 2 February 2007 (UTC)

Don't some plants already have black leaves

Body Changes

I am not sure how to phrase this correctly nor have the proper terminology, but my question is:Is it possible that your genetic makeup can change throughout your life. When I was a child, I remember having very straight hair and I longed for curly hair. However, in my early 20's, my hair became very thick and curly. Now, I am in my mid 30's and my hair changing it's structure again. It is becoming straighter. Any ideas?

It is not possible for your genetic makeup to change (aside from random DNA mutation that would likely only result in damaged or cancerous individual cell populations). There are many reasons why your hair might be changing structure, including age, changes in diet, or moving to a different climate. It's not at the DNA level. -- Scientizzle 16:28, 1 February 2007 (UTC)

This is probably common knowledge to anyone who has taken high school biology, but I couldn't locate anything in our article on DNA that says as much. Vranak

It is hard to believe that the dramatic changes of my hair structure was from what I ate or where I lived.Please understand that I had pin straight hair (similar to Asian hair) when I was 8 but by the time I was 21, it was very thick and curly...

Though I've never heard of what you describe specifically, hair does respond in a variety of way to the levels of certain hormones that increase during puberty/maturation and fall off during middle age.See Hair#Growth.Dragons flight 17:46, 1 February 2007 (UTC)

It isn't just puberty, my hair has been getting darker from light blond to a very dark brown at least since I was born:)Hidden secret 7 19:44, 1 February 2007 (UTC)

It's very common for light hair to get darker through childhood - lots of kids are born with blond hair but don't keep it - blond kids are usually born with very white hair. I don't know if this means you will go platinum in later years or not. It's common in the animal world for juveniles to have a different colouration to adults.87.102.77.95 19:56, 1 February 2007 (UTC)

As for your hair changing from curly to straight again - don't know.87.102.77.95 19:58, 1 February 2007 (UTC)

I always thought it was strange that my hair behaved this way.Someone mentioned that our skin(?) completely changes every 7 years and maybe so with hair texture.Maybe I am not human!

I don't think I am either:)Hidden secret 7 20:50, 1 February 2007 (UTC)

There is one important exception to the rule that your DNA doesn't change during life, which applies to cells of the immune system, i.e. B lymphocytes and T lymphocytes. During maturation, the DNA coding for these cells' receptors is rearranged, see VDJ recombination. The changed DNA is inherited by daughter cells. The rearrangement occurs in a random fashion, and because various fragments are involved, each of which comes in a large number of variants, combinatorics ensures that the number of different receptors is formidable. In addition, there are enzymes that insert non-coded nucleotides at the points where the DNA is spliced. The potential number of antigen receptors is enormous. Lymphocytes which encounter antigens that happen to match their receptors, are selected in a Darwinian manner. This is the basis of immunization - somatic DNA recombination is the reason why we are able to make antibodies against such an enormous number of pathogens. The fact that the receptors aren't "hard-coded" makes this a very flexible system, which can adapt to new threats. To my knowledge, it is the only known example of somatic DNA recombination in vertebrates. --NorwegianBlue ^talk 20:56, 1 February 2007 (UTC)

Only known example, except of course somatic mutations that lead to cancer. --NorwegianBlue ^talk 21:03, 1 February 2007 (UTC)

In your comment NorwegianBlue,"The rearrangement occurs in a random fashion, and because various fragments are involved, each of which comes in a large number of variants, combinatorics assures that the number of combinations is formidable", are you saying as our DNA changes during maturation for immunizations against pathogens, this possibly can affect hair texture, iris color, etc?I also know of an African-American person who also experienced the same issue as well...

No. This process only applies to the genes coding for the T cell receptor and the B cell receptor (immunoglobulin), and "maturation" refers to the maturation of the individual cell. --NorwegianBlue ^talk 21:03, 1 February 2007 (UTC)

Think of your hair changes similar to how your body changes when you go through puberty. When you hit puberty, you grow facial hair, get bigger & stronger & grow an adam's apple etc. This is not your DNA changing, but instead hormones & internal changes stirred by chemicals. Your body can change drastically without warning. Keep in mind however, that indeed DNA can affect whether we do have curly or straight hair, but changing between the two isn't unheard of either. Many children may have curly or straight hair in childhood & then have the opposite later in life. When babies are born, they may have a different eye colour to later on in life & so on & so on. Your DNA does not change unless you're one of the X men. Hope this explains it easily... Spawn Man 21:45, 1 February 2007 (UTC)

And if you're interested in whats going on on the molecular, level, you might want to read the article regulation of gene expression. --NorwegianBlue ^talk 08:45, 2 February 2007 (UTC)

I also experience this. When I was little, I had curly, thick blonde hair. Later my hair became really straight and black, and now my hair is this dark brown, but it's really curly and somewhat thick. All this happened in 16 years of my existence. I have a question, if it's not possible for your genes to change, where does evolution happen? Surely your genes have to change. ► Adriaan90 ( Talk ♥ Contribs ) ♪♫ 13:30, 5 February 2007 (UTC)

There are in fact mutations and genetic recombinations, and even DNA repair, but there are no deliberate, routine, permanent changes to DNA made by any organism. (The result would be very hard to do safely, after all.) Evolution is a result of the accumulated random changes to DNA inherited by offspring. See, however, the current field of genetics research dealing with promoters and company, which do not modify DNA but have much the same effect by dynamically affecting how it is used. --Tardis 19:15, 5 February 2007 (UTC)

If you tied a rope around the moon and let the other end hang down onto the surface of the earth...

1)When the moon moved, would the rope drag across the surface of the earth, and if so how fast? 2)And if not, would it go out into space and trail behind the moon or what would it do? The gravity field of the earth and the moon are significantly less than the amount of empty space in between the earth and the moon. 3)If the answer to the first question is no, could you hold onto the rope as it pulled you up into the sky? 4)How much weight would it take to keep the rope vertical to the earth? 5)Would that amount of weight cause the moon to stop moving and come crashing down onto the earth?

This will be a big help for one of the questions on my thirty-problem physics project, thanks! Xhin 16:47, 1 February 2007 (UTC)

(numbered the questions to make responses easier). During a single night, the earth's rotation makes the moon appear to move across the sky. Per Moon the Moon makes one complete orbit about the Earth every 27.3 days. The nearest point to the moon on the earth's surface makes a revolution every day, with adjustment for the moons 27.3 day cycle. What does that suggest about the rope staying at one point? Per Earth the planet's mean circumference is 40,041.47 km, and its sidereal rotation period is 0.997 258 d (23.934 h). Earth's rotation velocity at the equator is 465.11 m/s or 1040 miles per hour, which has to be adjusted plus or minus for the moon's travel around the earth.The question implies that the rope starts on the earth's surface. The statement "The gravity field of the earth and the moon are significantly less than the amount of empty space in between the earth and the moon." makes a meaningless comparison between gravity and space. How can gravity be less THAN space. Did the question originally say IN space? I suggest the hypothetical rope would have to be extremely strong and perhaps fireproof. I suggest that no amount of weight could keep it absolutely vertical to the earth, but the deflection from passage through the atmosphere would be a difficult calculation depending on air resistance, which would depend on the diameter and surface of the rope, and more complex because it would change with altitude. Edison 17:31, 1 February 2007 (UTC)

The question would be interesting if rephrased for a sitution where both bodies are tidally locked with respect to each other (eg. Pluto and Charon). What stresses would be suffered by a space elevator linking these two bodies? Carcharoth 18:01, 1 February 2007 (UTC)

You should note the difference between the apogee and perigee of the moon's orbit.—eric 18:12, 1 February 2007 (UTC)

Well I've come up with a simple answer to your question. All the roads in New Zealand, lined back to back, would make it 3 quarters of the way to the moon. Now all you have to do is measure all the roads in New Zealand & then do the math. ;) Spawn Man 21:49, 1 February 2007 (UTC). P.S. The rope might catch on a rock & send the moon crashing down in the Atlantic, so be sure you use duel fibre twine... ;)

To question 1, I think yes. The rope would be close to vertical most of the way, but once it hits the Earth's atmosphere, the atmospheric drag will push it forward (since the Earth rotates faster than the moon orbits), so it will be slanted at an angle near the surface of the Earth. To question 4 (if I understand what you mean), that is impossible, because the atmospheric drag pushes the rope forwards, and if were vertical, there would be no force to oppose it going the other way. --Spoon! 23:55, 1 February 2007 (UTC)

Why Don't They Send Hubble's Twin in Orbit?

When they constructed the Hubble telescope two decades ago, all key components were manufactured in pairs (in case one breaks down, the redundant component is available right away). Now that the one currently in operation is approaching its end of life--and that another shuttle repair mission will cost a fortune--why don't they just put all the spare parts together and launch the thing up there? The twin may not be the latest technology, but it sure could be a cheaper way to get a new telescope in orbit, serving science for the next two decades.--JLdesAlpins 17:23, 1 February 2007 (UTC)

Is there evidence they made a second mirror? At the time of its making, there was an article about how expensive it was, and that it was the best mirror ever built. Later it turned out they had totally botched the fabrication and testing and the thing had to have corrective lenses added. Have some of the spares been used on the repair missions? An unanswered question is how similar the general optics of spy satellites are to those of Hubble. They are supposed to have amazing resolution, but would lack some of the aiming ability and some of the special astronomical optics. Edison 17:38, 1 February 2007 (UTC)

One of the largest differences between an earth-observing satellite and the Hubble is the amount of light collection area and maybe to a lesser extent the ability to keep attitude very precisely.Images like the Hubble Deep Field require an extremely long exposure time, even with the Hubble's large mirror.Images like [1] also show what vistas large amounts of light gathering area can give you.Like spy satellites, you or I can easily see things on Earth because they're illuminated so well, could never see anything like that with our pair of 1x 1-cm refractors. Atropos235 18:03, 1 February 2007 (UTC)

See Hubble Space Telescope#Optical Telescope Assembly (OTA) for information about the second mirror. --cesarb 18:30, 1 February 2007 (UTC)

Hubble was designed to be orbited in the carbo bay of the space shuttle.Given that you'd have to launch a shuttle either way, it is unlikely that there would be much cost savings.Dragons flight 17:42, 1 February 2007 (UTC)

Lets not forget the cost to acctually form the second hubble. putting the spare parts together will still require extreamly skilled scientest to put it together and many months to do it right Maverick423 17:51, 1 February 2007 (UTC)

And lets not forget, the spare parts were there in case something goes wrong, so imagine something went wrong while assembling the spare parts, they'd have no redundancy.Vespine 21:32, 1 February 2007 (UTC)

Hubble's "dubble"? Clarityfiend 01:20, 2 February 2007 (UTC)

OK, suppose that everything on Hubble was duplicated - Hubble has been serviced a couple of times since launch - might some of those duplicate "spares" have been used up in servicing it? Richard B 01:31, 2 February 2007 (UTC)

I think it's probably an engineering exaggeration to say "everything" was doubled; furthermore, the likelihood that all parts are carefully cataloged, stored in one warehouse, with blueprints and assembly instructions is virtually zero.Significant engineering effort would be needed; and even the original engineers probably don't even remember all of the design properties.It is probably easier and cheaper to start from scratch.After all, the most expensive part of spaceflight systems is very rarely the actual components costs. Nimur 08:29, 2 February 2007 (UTC)

Narcotics

Is there any type of narcotic drugs that include iodine atoms in the molecule? TERdON 18:07, 1 February 2007 (UTC)

The simple answer is yes - but they are not common. Iodine (and also other halogens chlorine, bromine and fluorine) is sometimes incorporated into the basic drug structure - one of the main reasons this is done is that the resultant compound is easier to absorb through the gut walls as it is more 'fatty'.

(also Iodinated and brominated 'ecstacy' derivatives are found often enough to be called common, I'm not sure that amphetamines are classed as narcotics though.)

I don't have enough knowledge to say if there are any drugs of this type in common use.87.102.77.95 19:23, 1 February 2007 (UTC)

In Sweden, no doubt amphetamine is illegal, I suppose the same holds true of its derivates. Thanks for the answer! :) TERdON 20:18, 1 February 2007 (UTC)

I don't think amphetamine is a narcotic (narcotics are derivatives of opium), but perhaps you meant psychoactive drug? − Twas Now ( talk • contribs • e-mail ) 22:13, 1 February 2007 (UTC)

I didn't mean they were narcotics by the scientific definition, but by the Swedish legal definition, which includes all kinds of addictive drugs that aren't, technically, narcotics. TERdON 22:18, 1 February 2007 (UTC)

Yes, "crack," but it's not in the narcotic.Instead it's part of the precursors, see Iodine in Methamphetamine production.As part of the "war on drugs," some states in the USA require that iodine suppliers record and retain customer information on anyone buying iodine. --Wjbeaty 20:42, 1 February 2007 (UTC)

Source

Is their there enough kinetic energy in a human body to move an object?— Preceding unsigned comment added by 71.201.233.107 (talk • contribs)

People move things every day - I'm not sure what else you could be asking? please explain..87.102.77.95 19:15, 1 February 2007 (UTC)

Do you know what kinetic energy is?It's the energy of a mass in motion.One way to tell that an object in motion has kinetic energy is to watch what happens when the object hits another object: in a collision, one moving object can impart kinetic energy to the collided-with object, causing the collided-with object to move as well.Does this answer your question? --Steve Summit (talk) 19:19, 1 February 2007 (UTC)

are you trying to talk about telekinetic energy? which is more of a phycic power then anything. Maverick423 21:09, 1 February 2007 (UTC)

See Psychokinesis. I would have to answer "No, there is not enough psychokinetic/telekinetic energy in a human body to move anything." But I have an open mind and would be ready to be proven wrong. There are many ways to fake it or to think it is observed in poorly controlled experiments. Edison 21:30, 1 February 2007 (UTC)

There's often just enough to move money from a believer's wallet/purse to the claimant's. Spooky! Clarityfiend 21:53, 1 February 2007 (UTC)

It might just be that things that can be moved like this are too small to see:)Hidden secret 7 20:47, 3 February 2007 (UTC)

To move an object with the kinetic energy of a human, you would need to have the human collide with the object.Imagine body-slamming a box.Then, your kinetic energy would (partially) transfer and the box would jolt forward.Perhaps you mean potential energy which may be stored in the muscles in chemical form (adenosine triphosphate)?This can be converted into kinetic energy, (probably also generating thermal energy and other forms...) allowing the muscle to move an object. Nimur 08:32, 2 February 2007 (UTC)

Hah.I'm now having hilarious visions of ragdoll-physics style "human collisions" to test the inelasticity of collisions.Efficient transfer of kinetic energy from the human to the object is almost as much fun as inefficient transfer. Nimur 08:34, 2 February 2007 (UTC)

High density polyethylene

Hello, does anyone know of a supplier for blocks of high density polyethylene.I'm looking for a small cube of the stuff that I can mill down a little bit.

Try McMaster-Carr. anonymous6494 20:55, 1 February 2007 (UTC)

Isnt polyethylene always the same density? --Light current 01:36, 2 February 2007 (UTC)

No. See HDPE vs LDPE. DMacks 02:46, 2 February 2007 (UTC)

Water on Mars

is there really water in Mars?–––Thanks

There is no doubt about the presence of water on Mars. A more intriguing question is whether or not there is liquid water on Mars, and recent evidence has been pointing towards a positive answer. — Kieff | Talk 00:29, 2 February 2007 (UTC)

Lava and Magma

Which is thinner, magma or lava?

same stuff I thought!--Light current 01:32, 2 February 2007 (UTC)

Well according to Chloe Talbot from The Simpsons, magma is the word for lava when it's underground. Which would mean that lava would be more viscous, but magma would be denser. Anchoress 01:42, 2 February 2007 (UTC)

No no Yes. Lava is magma when its under ground.When its erupted its lava. Pumice--Light current 02:28, 2 February 2007 (UTC)

That's what Anchoress said. =) Chickenflicker---♣ 04:33, 2 February 2007 (UTC)

Quire rite sorry. It was the Simpsons who put me off.8-)--Light current 11:45, 2 February 2007 (UTC)

If it had to be one or the other, it would be lava; but not by much, I would imagine. As the molten rock comes closer to the surface it experiences less pressure and presumably expands, making it less dense or "thinner". I'm not sure, however, the degree to which it would expand, or if that would be significant to appropriately label it "thinner". BenC7 07:22, 2 February 2007 (UTC)

If lava can be approximated as an uncompressable fluid, the pressure change would have little effect on the density.One thing that does significantly affect density is silica content.Hawaiian volcano lava is quite different from, say, Mount Saint Helens (which has more silica, is more dense, and thus exploded violently!)Hawaiian lava flows gracefully with much less exploding. Nimur 08:37, 2 February 2007 (UTC)

(comment) doesn't the explosiveness of magma relate to the amount of dissolved gas in it (eg water) - that is released when the pressure vessel that is the inner volcano is opened..(or does silica rich magma have greater ability to hold gases???)87.102.4.6 11:55, 2 February 2007 (UTC)

I too would expect lava to be thinner thicker (less more viscous) than magma since it is cooler. I don't know how pressure affects viscosity. Reading both articles it explains that the viscosity depends on the composition - so there may not be a definative answer.87.102.4.6 10:33, 2 February 2007 (UTC)

Both lava and magma is made of all types of substances, and are all different temperatures. [Mαc Δαvιs] X (How's my driving?) ❖ 18:09, 2 February 2007 (UTC)

I would have expected lava to be more viscous as it is cooler, since this would mean less kinetic energy for each molecule, and therefore less energy to move them apart:)Hidden secret 7 20:50, 3 February 2007 (UTC)

Unlike gases, there is no "ideal law" for fluids, let alone an accurate one. Non-ideal effects will dominate what factors determine density. Nimur 01:08, 4 February 2007 (UTC)

February 2

Appendectomy and oxygen

Is it normal for a person who has undergone an appendectomy (burst appendix) to be on post operative oxygen?--Light current 01:31, 2 February 2007 (UTC)

THis would be for a person abot 70 years old.--Light current 11:46, 2 February 2007 (UTC)

I was about 5 when it happened, but I remember them putting tubes down my nose, so I wouldn't think it'd be somewhat normal. It is a potentially fatal thing. --Wirbelwindヴィルヴェルヴィント (talk) 03:59, 2 February 2007 (UTC)

For any procedure involving general anesthesia, and intubation, one can expect to wake up with an oxygen mask on, especially at an advanced age. High oxygen will help a patient overcome the trauma of the surgery, and more important it will help that patient clear infections from the perforation and the surgical insult. ^tucker/_rekcut 12:11, 2 February 2007 (UTC)

Ah thank you. Just the ans I wanted!--Light current 12:12, 2 February 2007 (UTC)

Best position to land

When falling from high up (for example, a fifth storey), what would be the safest position to land when hitting solid ground? --Codell ^{[ Talk]} 02:39, 2 February 2007 (UTC)

[2] [3] -- Consumed Crustacean (talk) 02:43, 2 February 2007 (UTC)

Dunno if it was ever proven, but I'd always heard if you can somehow pull off a rolling landing, you could possibly survive (height depending of course). Cyraan 02:51, 2 February 2007 (UTC)

Thank you, Consumed Crustacean. This answers my question.--Codell ^{[ Talk]} 03:47, 2 February 2007 (UTC)

as far above the ground as possible

How to draw: trans-3,5-dibromocyclodecyne?

This is the only problem I can't do for my alkyne nomenclature homework. I submitted the structure, but the program keeps telling me to show the trans configuration of the Br Atoms.But I'm pretty sure I put the Br atoms where they're supposed to be.I'm also sure that I have the cyclodecyne structure right, so it must be something else I'm missing.I tried all combinations of where the Br are located respective of one another.Because it's trans, I'm guessing that one of the Br atom is inside the ring, and the other on the outside.I tried that, but it wasn't correct.Any ideas?Thanks in advance 128.163.214.199 03:06, 2 February 2007 (UTC)

By saying "inside" and "outside", you're thinking about the ring and everything attached to it as being flat. Ain't so...visit your textbook chapter about alkanes or orbital hybridisation to see why things attached to the ring are often described as "above" and/or "below" the plane of the ring, never inside/outside the ring. DMacks 03:14, 2 February 2007 (UTC)

from trans "A similar phenomenon is seen in cyclic compounds (in which the atoms form a closed ring), where substituents can be on the same "face" of the ring (cis) or opposite faces (trans.)" - so agree with above - it's above or below the plane of the ring.87.102.4.6 11:06, 2 February 2007 (UTC)

Geometric isomerism has more details, and a diagram for the cycohexane case.87.102.4.6 11:07, 2 February 2007 (UTC)

3,5-dibromocyclodecyne is chiral at both the 3 and 5 positions, usually a trans structure refers to atoms on opposite sides of a thing (atom, double bond) - it sounds like you need to know the most stable conformation of the molecule and put the bromines on opposite sides. In actuality the name you've got doesn't seem to be a useful description of the molecule - I'd expect something like R,R 3,5-dibromocyclodecyne, R,S 3,5-dibromocyclodecyne, S,R 3,5-dibromocyclodecyne, S,S 3,5-dibromocyclodecyne.87.102.4.6 10:31, 2 February 2007 (UTC)

Thanks a lot, everyone. I misinterpreted the diagram in the book; somehow I didn't look at the type of bond (up/down). Now I understand the concept better.128.163.224.201 18:08, 3 February 2007 (UTC)

Time for Escape!!!

How long would it take to accelerate human passengers in a craft to about eight miles per second, and lets say they are traveling at a constant 3g?67.127.96.131 03:39, 2 February 2007 (UTC)

Sorry, but we don't answer homework questions! But to help you out: have a look at the acceleration article, you'll notice the following equation:

$\mathbf {\bar {a}} ={\mathbf {v} -\mathbf {u} \over t}$

Using that, you can find the time required. All the best. - Akamad 03:48, 2 February 2007 (UTC)

Oh man thank you someone finally gives me an equation and thank you but this is not homework I am just very curious about these things.67.127.96.131 05:19, 2 February 2007 (UTC)

Yes, I am similarly curious about how long it will take a train leaving Philadelphia traveling at 180 km/h to reach a train that has left New Jersey traveling at 200 km/h. But of course, not for my homework! − Twas Now ( talk • contribs • e-mail ) 06:50, 2 February 2007 (UTC)

Several of the times when I've tried it, Amtrak or New Jersey Transit has had equipment failures. Where does that go in the equation?

Atlant 14:04, 2 February 2007 (UTC)

We surely don't want to confuse the questioner, but this equation might be helpful as well.

$x(t)=x_{0}+vt+1/2at^{2}$

$v(t)=v_{0}+at=dx(t)/dt$

Nimur 08:42, 2 February 2007 (UTC)

Awesome eqautions but once again it's not homework and believe it or not I haven't ever had a physics class. Someone just please tell me how to plug in the numbers.

What you want to do is solve the equation (the equation I gave you, the first equation that Nimur gave is for finding displacement, and the second equation is the same as the one I wrote down) for t (the time variable). Here is a link on how to solve equations if you need help: http://www.sosmath.com/algebra/solve/solve0/solve0.html. You already know the final velocity (8 miles/second) and the acceleration (3g). From your question, you can assume the initial velocity to be zero. So all the variables are known. But make sure all your units are the same (for example, you'll have to change the 3g to miles/second/second, have a look at this article: Earth's gravity for what the "g" means. Hope that helps. - Akamad 11:17, 3 February 2007 (UTC)

Okay, I'll assume good faith and give the answer. The simplest form of the relevant equation is just v = at: speed (assuming you start from 0) is acceleration times time. So t = v/a: time is speed divided by acceleration. g is 9.8 m/s², so the acceleration 3g is 29.4 m/s². 8 miles is 12,875 meters, so 8 mi/s = 12875 m/s. So the answer is 12875/29.4 = 438 s (see, dividing the units of m/s² by m/s gives seconds) or 7.3 minutes. I've rounded the numbers along the way since I assume the 8 mi/s was not intended to be an exact number. --Anonymous, February 3, 2007, 22:02 (UTC).

Okay thank you because I did attempt to do the eqaution given to me by Akamad and I ended up with 8.76 hours! The reason why I asked this I wanted to know if the speed could be acheived without killing the passengers. Now the next problem to face is making it through the atmosphere without burning up or the craft loosing velocity. Anyways everyone thank you again.

Note that real-life space launches achieve orbital velocity of about 5 miles/second without killing the passengers. Achieving 1.6 times the speed could be done by accelerating 1.6 times as long. (In practice the acceleration is not constant, so it's a bit more complicated than that, but that'll do for a rough idea.) --Anon, Feb. 4, 05:05 (UTC).

Light

Greetings,

I have done small studies an have a theory. Light has mass and weight. It must, because a black hole pulls in light. I don't understand the technical jargon. Please let me know if it has mass. (In layman's terms)

Fare thee Well, AlexanderTG 05:58, 2 February 2007 (UTC)

What is your theory? This sounds like the wave–particle duality of light. − Twas Now ( talk • contribs • e-mail ) 06:52, 2 February 2007 (UTC)

General Relativity is exactly the technical jargon which explains how gravity can "pull" something (like light), even if it has no mass.Some people try to explain this by saying that the gravity bends space and time.It is very well established that light has no mass, and many experiments and equations exist to back this up. Nimur 08:44, 2 February 2007 (UTC)

You might also consider General Relativity at the Simplified Wikipedia if you are having difficulty with technical jargon. Nimur 08:46, 2 February 2007 (UTC)

Also, what do you mean by mass? Mass in general relativity is very complicated and may not be well defined at all. --Spoon! 09:25, 2 February 2007 (UTC)

Short answer - light is made up of photons; photons do not have rest mass, but they do have relativistic mass, because they have momentum. This article answers the question "If light has no mass how can it be deflected by the gravity of a star?". Gandalf61 14:12, 2 February 2007 (UTC)

They say gravity bends space, but the experiment they do to show this where the balls roll toward each other only works because of the earths gravity below it:( Is this because they can't find any real way to show what is happening, and are hoping we don't notice, or am I missing something important here:(Hidden secret 7 20:54, 3 February 2007 (UTC)

You didn't miss anything - the bending thing is bogus. The reason light is attracted to black holes is that is has mass, just like any other particle. True it doesn't have rest mass, but that doesn't make the mass any less real. There is no need to invent bending of space or anything like that. Ariel. 13:19, 4 February 2007 (UTC)

donut constellation

There seem to be models for ethernet structures described as a donut constellation. The descriptions of the structure are too technical for me to understand. I have heard the term donut constellation used to described the way energy revolves in some physical structures as well. The philosphers Deleuze and Guattari describe social maps and organizations that evolve rhizomatically along a number of axi and levels. As a result many creative and visual thinkers use this structure as an exploratory model. I think the donut constellation whereby energy is constantly revolving on a number of planes around a vacant middle maybe used to as an alternative model for describing the way chunks of the creative thought process evolves. I would like to read more about this type of structure. I think there is a more accurate word, that those versed in physics would use to describe it.

The word is torus, the surface is represented by a quartic equation in three dimensional space. As for a doughnut shaped ethernet this would be a ring shaped data bus with various data items branching off it.87.102.4.6 10:24, 2 February 2007 (UTC)

Antagonism vs Inhibition | Enzymes & Neurotransmiters

• On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as Wellbutrin and vanoxerine, have mild stimulant effects and little abuse potential, and can be used to treat stimulant addiction.

• Zyprexa's antipsychotic activity is mediated primarily by antagonism at dopamine receptors.

Scientifically speaking, is there any differece between Antagonism and Inhibition? Please provide references to back up your answer.

I would appreciate the answers provided. Thnx. --Parker007 12:37, 28 January 2007 (UTC)

I'd suggest that the usage choice is a language one, (I can't call a difference between the two). Medical dictionary (is this a good source?) has the two lumped together for the same definition see http://www.wrongdiagnosis.com/medical/inhibitor_antagonist.htm

The real difference is actually in other usage - an antagonist 'works against' eg pairs of muscles that pull on either side of the bone, an inhibitor prevents the action itself. I'm not sure that in biochemical usage the distinction is made (of perhaps even known).

Also http://www.thefreedictionary.com/antagonist defines antagonism in a biochemical sense as "Biochemistry A chemical substance that interferes with the physiological action of another, especially by combining with and blocking its nerve receptor" eg as an inhibitor.

So in biochemistry they seem to have the same meaning - though if more becomes known about the mode of action of a given substance perhaps in the future a distinction will be made.

Comment on proper usage...

For instance a compound that causes dopamine uptake is antagonistic to a compound that causes dopamine release - but does not inhibit.

Whereas a compound that binds to a site causing dopamine release (not activating it) can be called an dopamine release inhibitor. (But may also be decribed as antagonistic to a compound causing dopamine release by the nature of it's inhibitory action). Hope that helps.87.102.33.144 13:04, 28 January 2007 (UTC)

Actually, antagonism and inhibition are two distinct concepts in most biomedical contexts. Antagonism usually refers to interference with the action of a substance, or sometimes to the production of an effect that opposes that of another substance. An example of a steroid antagonist is spironolactone, which reduces mineralocorticoid effects and androgen effects. Inhibition usually refers to interference with production of a substance. An example of an inhibitor of steroid production is metopirone. alteripse 17:22, 28 January 2007 (UTC)

I see that competitive anatagonist, noncompetitive antagonist & uncompetitive antagonist need articles...I'll have to work on that.

For maybe a litle semantic clarity of the difference between antagonism and inhibition...Inhibition is the prevention of some event and antagonism is one biochemical pathway through which one might cause inhibition. Enzymes or biological receptors, for example, can be inhibited by several means (phosphorylation state, missing co-factors, pH, etc.), including antagonism. An antagonist may inhibit by one of several methods (see below), but chiefly it interrupts the the otherwise natural activity of the enzyme/receptor in the local state. Types of enzyme inhibition | Competitive inhibition | Uncompetitive inhibition | Non-competitive inhibition | Suicide inhibition | Mixed inhibition | -- Scientizzle 00:22, 30 January 2007 (UTC)

I am inclined to agree with User:Alteripse & User:Scientizzle, otherwise I wouldn't have asked the question, because I already read the dictionary before asking the question. --Parker007 05:52, 2 February 2007 (UTC)

Wow, so biochemists can just make up new definitions of words can they! If 'you' used the words in correct context of their english meaning maybe you wouldn't have this problem???87.102.4.6 10:38, 2 February 2007 (UTC)

I'd just like to point out that we do have articles on Receptor antagonist and agonist, as well as the featured atricle Enzyme inhibitor, which also was linked to above. It might be better to expand on those, and add some redirects, rather than create new articles. --NorwegianBlue ^talk 09:24, 2 February 2007 (UTC)

Yeah...I know. I was considering how best to go about either combining receptor dynamics into the enzyme inhibition articles or making new, separate articles. Receptors and enzymes are very unrelated in terms of activity, and are separate targets for drug interactions (through which most antagonism occurs), but the molecular methods and pharmacological models of inhibition are largely similar...I'll figure it out... -- Scientizzle 16:14, 2 February 2007 (UTC)

How do enzymes have anything to do with neurotransmitters? --Parker007 09:41, 2 February 2007 (UTC)

Enzymes are to substrates as receptors (eg, neurotransmitter receptors) are to ligands (eg, neurotransmitters). --David Iberri (talk) 01:19, 3 February 2007 (UTC)

That makes no sense; So what does enzymes do to neurotransmitters? --Parker007 00:10, 4 February 2007 (UTC)

What David Iberri is trying to say is that the interaction between enzyme-substrate is analagous to receptor-ligand. The kinetics are often very similar. -- Scientizzle 07:31, 4 February 2007 (UTC)

Bending of light.

Why does a light ray bend when there is mass in vicinity of it's line of journey? Considerable bending has been observed when the amount of mass is large.Does bending occur even when amount of mass is small?Is there any relation between gravity and electromagnetism?Well, something fishy is going on.I think unification of gravity and electromagnetism is not far.(Ecclesiasticalparanoid) —The preceding unsigned comment was added by 210.212.215.141 (talk) 10:13, 2 February 2007 (UTC).

• Light is an odd thing. It can behave both like a wave and like particles. Since particles have mass, they are affected by the gravitational pull of a mass in its vicinity. Light probably bends too when the mass is small, the effect is just smaller. 'Small' is a relative term in that case. Usually we're talking planet-sized masses in discussions like this. - Mgm|^(talk) 10:59, 2 February 2007 (UTC)

At the moment there is no known way to unify gravity and electromagnetism into one force though it is presumably the goal of a Theory Of Everything. Many people have sought such a connection, including Albert Einstein (see Unified field theory), and failed. Whether it is far away or not probably depends on whether you think they are going the right direction with string theory or not. --24.147.86.187 13:33, 2 February 2007 (UTC)

Unless I'm mistaken, classical electromagnetism and modern gravitational theory (general relativity) have already been shown to be consistant.My answer to your last question contained a link to Kaluza-Klein theory, which shows that Maxwell's equations (the basis of classical electromagnetics) can be derived from principles in general relativity.In other words, KK theory more or less united modern gravitation theory and classical electromagnetics back in the 1920s.

Also note that it isn't just light that exhibits wave-particle duality, but all matter at sufficient scales.However, pertaining to the question you originally posed, I'm not sure if it's totally appropriate to embark on a discussion of quantum mechanical effects (which is where you would consider wave-particle duality).In general, QM and GR haven't been reconciled, so I don't know if it's appropriate to talk about wave-particle duality in the same breath as gravitational (spacetime) effects on light.Look at Maxwell's equations in curved spacetime and General relativity.Perhaps a physicist can fill in some of the gaps I've omitted in my explanation...I'm definitely not a GR person, and I can only do fairly basic QM.

P.S. - The photon is massless (at rest). -- mattb @ 2007-02-02T13:42Z

I believe the current understanding is that the light really doesn't bend. It travels straight in spacetime and it is spacetime itself that is distorted by the presence of the mass. The analogy usually used for us non-physicists is to imagine spacetime as a rubber sheet and the massive objects as heavy objects pressing down into that rubber sheet. The depressions thereby formed are analagous to the bends in spacetime.

Atlant 14:07, 2 February 2007 (UTC)

Light also distorts space-time depending only on it's frequency. The fundamental understanding of Einstein's theories is that Energy and Mass are equivalent. --Tbeatty 07:09, 3 February 2007 (UTC)

If i remember correctly Lightning consist of Plasma, which is a super hot gas; gas has mass. in anyway if your talking about lightning i can see why it would bend, however if you were talking about regular light, light accelrates Ions or electrons or something (someone here should know) in anyways these ions or electrons also have a mass (although its not much its still there) that would explain how a high gravity mass can alter light in such ways. Maverick423 15:07, 2 February 2007 (UTC)

Nobody said anything about lightning as far as I can tell.Please don't take this the wrong way, but given your second sentence I would suggest reading some of the linked articles.The article on light itself provides a pretty good overview. -- mattb @ 2007-02-02T15:13Z

Meh sorry and thanks for the corrections its been a while since i read or studied about light so i can get my info confused at time =( Maverick423 15:32, 2 February 2007 (UTC)

No need to apologize.I'm by no means an expert on modern physics, and I've probably said some things that aren't totally accurate.Just take a moment sometime to read that article on light. -- mattb @ 2007-02-02T15:40Z

Statistics/Normal Distribution

(repost of a question previously posted on another reference desk and previously moved to the math desk. Te Q and A have been moved there as well. Please do not doublepost.)Edison 16:17, 2 February 2007 (UTC)

Another poision question

Hi there again its me! im sure you know me from my old question from radiation =P anyways here i go again. my curiosity has gotten Intrested in the cyinade (think thats how its spelled). Cyinade Poisioning yes it says its fast and kills rapidly, but exactly how does it do it? What does a person feel (yes i am intrested in stuff like this as you can see) when they get cyinade poison? does the skin melt does the person feel immense pain or is it just a drink and fall dead with no feelings of the poison coursing through your body?? what about the range of cyinade? how far can it reach if a cup of it was spilled on the floor and how fast does it evaproate? there are lots of questions about this i want awnsered but well i dont know if people sugar coat it when they talk about it or what but please guys DONT sugar coat it i am intrested in the raw effects of it. thanks Maverick423 15:24, 2 February 2007 (UTC)

Ok try not to get carried away - the skin does not melt.

Cyanide poisons (in one way I know of) by complexing to metal ions such as the iron in haemoglobin - (it may be poisonous in other ways) - this is similar to carbon monoxide poisoning - effectively you aspyhyxiate due to lack off oxygen.

The 'cyanide capsule' is often sodium cyanide solution.

Hydrogen cyanide is a gas and also poisonous.

In the case of swallowing cyanide choking and spluttering occurs - followed by loss of conciousness - the death. There is not much pain - but the choking and spluttering is unpleasant but not that bad.. People poisoned by cyanide can be saved - the longer they are out the less chance they have of surviving.

Sodium cyanide and potassium cyanide are solids - as solutions they may produce a small amount of hydrogen cyanide - adding an acid to a cyanide salt will produce the hydrogen cyanide gas - this is capable of spreading - I don't know how fast though.

Interestingly hydrogen cyanide will burn.

The cynanide links above all give more info on mode of action and lethal doses etc. Suggest you read them..87.102.4.6 15:49, 2 February 2007 (UTC)

Alright great info man thanks much! so then what they say about cyanide being a quick and painless death is a lie? i kinda figured there was something about that line. well anymore information is greatly appreciated as for me i got some stuff to look at thanks again! Maverick423 15:57, 2 February 2007 (UTC)

I'm afraid much of the above is incorrect. Cyanide does not act on hemoglobin, but on cytochrome oxidase, as a metabolic poison. Cytochrome oxidase is an important electron carrier in the electron transport chain. It is a necessary component of mitochondrial respiration, and without it the mitochondria are not able to induce a proton gradient for their ATPase. Cyanide binds to cytochrome oxidase and renders it useless. Also, death from cyanide poisoning would probably not be very painful; first, it only takes about a minute to become unconscious with a reasonable dose, and second, reduced ATP would not be likely to initiate nociception in the appropriate nerves until long after a victim was unconscious (if at all). Usually the "choking and spluttering" described above does not happen while the patient is conscious. A time course might look like this: cyanide is introduced to bloodstream, cyanide enters central nervous system and renders the (high ATP consuming) neurons unable to function, unconsciousness occurs, cyanide in heart renders Ca++ uptake/sarcomere resetting impossible via reduced ATP, cardiac arrest occurs, rest of cells in body die either from cyanide exposure/ATP paucity or anoxia resultant from cardiac arrest. ^tucker/_rekcut 22:52, 2 February 2007 (UTC)

thanks much for the corrections and thanks much IP dude for telling me about the corrections on my talk page =). I will ask another question about the information on the bottom in a bit because by this time many people dont read this far up. Maverick423 22:44, 5 February 2007 (UTC)

body temperature

How do you raise your body temperature? —The preceding unsigned comment was added by Andiman56 (talk • contribs) 15:26, 2 February 2007 (UTC).

Ahh good one well there are many ways to do this. one such way is exercising. the other is involenttary shivering in the cold. Maverick423 15:33, 2 February 2007 (UTC)

Give it better fuel. Vranak

Put more layers of clothing on. Eating spicy food feels like it does too, but I don't know if it does. A hot drink and hot food. Lower your exposed surface area by huddling as tightly as you can. Skittle 17:25, 2 February 2007 (UTC)

Spicy foods actually help lower body temperature. Thats one of the reasons why they are consumed in warmer climates. --Russoc4 04:18, 3 February 2007 (UTC)

Indeed. You eat spicy foods, which causes you to sweat, which leads to puuuuuuure coolness! − Twas Now ( talk • contribs • e-mail ) 09:00, 3 February 2007 (UTC)

Increase the speed of your metabolism, so you produce heat faster from your food:)Hidden secret 7 20:56, 3 February 2007 (UTC)

Feeling Gassy

Are there foods that I can eat during the day (at work) that causes the LEAST gas?I seems that no matter what I eat, I end up feeling uncomforatable all day or until I relieve myself...

As you know, we can't give medical advice. But I think it's safe to mention that any carbonated beverages (such as soda) will free their carbon dioxide gas inside of you and it's got to go somewhere.

Atlant 16:19, 2 February 2007 (UTC)

This shouldn't be a request for medical advise.If you would like for me to rephrase it, what type of foods would cause the least amount of gas produced in the stomach for humans?I am assuming that vegatables like broccoli is one of the culprits, but what other types of foods?

Peppermint tea can help settle the gastrointestinal system.Vranak

Flatulence#Causes may be of some help -- WikiCheng | Talk 10:56, 3 February 2007 (UTC)

I heard ginger is good for seyyling the gutts

Muscle Cramps

I infrequently get cramps in various muscles.Most often in my calves.However, I have found that I can make myself get these cramps very easily by holding my calves or bicepts in a flexed position.My question is what do these cramps do to the muscles in which they occur?Is it like lifting weights at all, or is it somehow detrimental?Thank You. —The preceding unsigned comment was added by 66.99.100.66 (talk • contribs).

How does your leg feel afterwards – better or worse? Vranak

I don't have an answer to your question, but FYI a common cause of calf spasms is calcium deficiency. Anchoress 17:16, 2 February 2007 (UTC)

CD28 gif 3d rotating structure

I really enjoyed the rotating 3d image of CD28 on your CD28 page.My question is simply that I would like to know if I could use your .gif format software (code) to portray the 3d structure of another protein molecule for which I have the .pdb file (3d coordinates)on my website?Can you please help me with how to do this if it is indeed legal?Thanks again for another terrific Wikipedia page, as always!

Don Kaiser <Rm email to reduce spam>

• If you click on the image, you will find yourself on a page that indicates who created it...ask him how he did it. I've used the free Jmol program to make 3D molecular models from PDB files. I think it can export animated gif images, but not sure. DMacks 20:48, 2 February 2007 (UTC)

Plantiferitus

Plantiferitus... what is this word? It is a very painful foot condition and I can't remember it. [Mαc Δαvιs] X (How's my driving?) ❖ 18:18, 2 February 2007 (UTC)

Have you tried at "foot.com" http://www.foot.com/info/info_cond.html Plantar fasciitis. ?83.100.183.48 18:30, 2 February 2007 (UTC)

abnormal oozing of blood from skin,teeth etc

recently came accross a person suffering from peculiar problem of loosing blood from skin,has already supplemented 3 bottles of blood in last 2 year.Seems condition is detoriaoting day by day.Blood report are about to come in few days.Pls advice. —The preceding unsigned comment was added by 59.93.247.53 (talk • contribs).

Have them see a doctor. Considering that a blood report is being performed, it seems this if being taken care of. We can not provide medical advice. -- Consumed Crustacean (talk) 18:55, 2 February 2007 (UTC)

Think this person your talking about might have Hemophilia. im not sure but u might wanna check it out and compare. Maverick423 20:30, 2 February 2007 (UTC)

Are you the patient, a friend of the patient, the nurse, or what? Your IP suggests Australia. Don't they have an established health system there which could diagnose and treat the problem? Edison 03:40, 3 February 2007 (UTC)

hovercrafts

Is it possible that in the next 20-30 years, we would have hovercrafts as a normal mode of transportation replacing automobiles?

I think it's unlikely since hovercrafts expend (quite a lot of) energy just to keep themselves of the ground - so I'd suggest that they are intrinsically less efficient. Plus they are not as easy to steer as cars especially in a high wind - they definately wouldn't be good on motorways - unless they had big bumpers like dodgems. Given that it seems important to increase fuel efficiency I think the answer is definately most unlikely.83.100.183.48 20:18, 2 February 2007 (UTC)

i dont know about hover cars however i do know that this car has been in prototype testing for quite some time and is already being considered for mass production soon! check out the Moller Skycar Maverick423 20:36, 2 February 2007 (UTC)

That's what they told us 10 years ago about that Skycar... Face it, it's not going to happen. — Kieff | Talk 21:42, 2 February 2007 (UTC)

Aw kieff come on its possable sooner now then later. after all they are getting the permission from that agency that says its ok to fly them. since the car is also in production and has actually flown, the chances of it comming out soon is great. Moller said his car was going to come out by 2008 and then mass produced by 2012. people have already bought the car itself and are going to recive it soon. also in Iran they are also making a flying car that is going to be used in rescue and police related instances. http://www.cnn.com/2007/TECH/01/31/israel.flying.car.ap/index.html http://www.moller.com/purc.htm

Maverick423 21:55, 2 February 2007 (UTC)

Flying cars - are you mad - I can just imagine coming home oneday and finding one sticking out of my roof.. Hopefully never83.100.183.48 22:14, 2 February 2007 (UTC)

dont ya worry the flying car has full safety features including backup engines, full car parchute, GPS locater, Automatic GPS Driver. simply enter the place you want to go and sit back and read a book the car will do the rest itself! Read Mollers Website to find out more on the car itself. Crashes will be reduced massively! Maverick423 22:50, 2 February 2007 (UTC)

The thing has barely hovered so far, and this project has been going on as far as I can remember. I can't see something like that becoming mainstream and affordable in the near future. — Kieff | Talk 01:34, 3 February 2007 (UTC)

Ah but the smaller version of the car has already flown across the country in previous test. its smaller (1 passenger) and ligheter and has more power (10 Engines 5 main 5 back up) instead of the 8 (4 main 4 back up). it goes faster and uses less fule since it is lighter. i think the problem with the 4 passenger one is that it only has 8 engines and uses more fule its less how can i say it? well i guess cost effectiveness is less for that one. think the smaller version has already been proven to go 64 miles per gallon then the bigger version (which only hovers) at 20 miles per gallon. tell ya what ill get back to you with this one i just need to make sure k. Maverick423 20:05, 3 February 2007 (UTC)

ahh sorry here it is it appears that the smaller version has this http://www.moller.com/m150.htm ( i took out the list that i placed cause it was bigger then i thought so i just linked it for ya ((should of done that to begin with))) well those are the specifications on that 1 passenger one so the engines are acctually 2X2 enginesMaverick423 20:22, 3 February 2007 (UTC)

I really don't expect a project like this will ever get off the ground:@Hidden secret 7 21:00, 3 February 2007 (UTC)

Acctually from what i heard the plane and the car were both being considered for use in public travel. the only problem was that planes were more expensive to buy then cars used more fule and needed a flat surface to take off. that is what made the car as the primary mode of transportaion. if these issues were assest from the begining we would be saying traveling on the ground is impossable or primitive. Maverick423 15:26, 5 February 2007 (UTC)

Do Snails Have Eyelids?

I was wondering if snails have eyelids.

Thanks!

It seems not - but the eyes are on muscular stalks and can be retracted - in fact snails don't have very good eyes apparently - relying more on touch and taste - the entire body is a bit like one big tongue.

See this website http://www.applesnail.net/content/anatomy/senses.php for more info on one type of snails eyes - a bit of the way down there's an diagram/image showing just how bad their eyesight is - it's probably not worth them having eyelids anyway.83.100.183.48 20:38, 2 February 2007 (UTC)

Deep Fat Frying

Does deep fat frying potato chips (including the skins) reduce the nutritional value? I don't care about the fat that's added (I only eat them on occasion) but rather the nutrients that may be leached out or otherwise rendered useless. --Seans Potato Business 20:45, 2 February 2007 (UTC)

Some vitamins, Vitamin C for example (and including other water-soluble vitamins if I'm not mistaken), are sensitive to high cooking temperatures. Although this section seems to contradict what I said (but note the fact tag), so maybe my belief is in error. Anchoress 21:09, 2 February 2007 (UTC)

Flash frying (don't know if we have an article) preserves many sensitive compounds due to the short time the stuff in the the pan - plus I don't think water solubilty has a lot to do with it - that would be boiling - it's all a matter of degree - it's usually air (oxygen) that degrades vit C - so a minute at 200C probably won't make much difference - though obviously prolonger frying will degrade all the nutrients.83.100.183.48 21:23, 2 February 2007 (UTC)

As a rule I'd say no - with modern preparation methods the degredation is very small - the time on the shelves way have a bigger role - though if the food package is airtight/block out light this shouldn't be a problem either - In general the nutritional value is increased by frying - by virtue of the increase in calorific value due to the fat; this doesn't apply if you are supposed to be on a diet obviously..83.100.183.48 21:27, 2 February 2007 (UTC)

Need help at Big Bang

There are some edits there today that I don't agree. Can we have some physicists over at Big Bang? Thanks. Xiner (talk, email) 20:52, 2 February 2007 (UTC)

Christ - good luck - as the big bang is speculative (or not if you're a big bang scientist) - this entire topic is open to original research and speculation. For instance this difference http://en.wikipedia.org/w/index.php?title=Big_Bang&diff=105174931&oldid=105171230 replaces expands on something that is already purely speculative - what is one to do?83.100.183.48 21:02, 2 February 2007 (UTC)

However if the edits get too much for you, you can always fall back on our good old friend - use {{fact}} - I'd suggest removing debateable parts to the talk page - stating your reasons for the removal and suggesting that adequate citations are provided before it's readdition.83.100.183.48 21:06, 2 February 2007 (UTC)

Plus there are so many variants on this theory in terms of explanation and outcome that you've got a real minefield..83.100.183.48 21:10, 2 February 2007 (UTC)

Could you say which edits were problematic?83.100.183.48 21:10, 2 February 2007 (UTC)

Actually, the one you pointed out is the one I'm having most trouble living with. I don't mind speculations, but this guy is putting things down as fact, with no way to check its veracity. He's editing a lot of articles too. Xiner (talk, email) 21:20, 2 February 2007 (UTC)

I'd suggest the method of removing and asking for citations - that's the way here I've learnt - even if the guy's right... Mention that the information must be verifyable - see Wikipedia:Verifiability "The threshold for inclusion in Wikipedia is verifiability, not truth" that's official policy.

It looks like they are adding fairly respectable explanations-I wouldn't expect it to be difficult to find citations for them - but I doubt that those explanations are the only subsets of the theories out there..I'm sure there are many other ones - The article might need a rewrite to cover the various possibilities and explanations thereof - with a non-contentious introduction.

I'd say the second paragraph about the 'origin from nothing' either has or should have it's own article - the info is relevant - but I'm not sure how much in the context of the article being called 'big bang' - it would be worth pointing out that the two theories are consistent in this respect - but I don't think in the main body of the article - maybe in a 'comparison with other cosmological theories' section. If the two were inconsistent that would be worth noting too.83.100.183.48 21:48, 2 February 2007 (UTC)

I see. I'll see what I can do. Thanks a lot for the advice. Xiner (talk, email) 22:04, 2 February 2007 (UTC)

By the way I do it like this (on the talk page):

..Removal of .... ..

I removed this text "the x is y because of z" because I'm unsure/think it's wrong/think it's exaggerated/think it's in the wrong place...

Could somebody please provide a reference for this infomation before re-adding it.

or

This is not relevant to the section it's in and should be in a new/existing section - I will/could you create such a section..

or

Shouldn't this be in a separate article - named '....' -

I wouldn't recommend just removing stuff without pasting it to the talk page - that can be annoying/seem aggressive.. (unless of course it is obviously vandalism - not the case here).

If you copy debated stuff to the talk page then they can discuss it there or they haven't got a leg to stand on - separates the reasonable from the unreasonable people. Also (from experience) if someone makes grammatical changes - don't revert - make little edits (taking into account their addition) until the article is satisfactory to all of you - that works too (though it can be very time consuming) -

I don't envy you...probably one of the worst articles to have on your watchlist, jesus, and george bush being slightly worse.83.100.183.48 22:10, 2 February 2007 (UTC)

Stick bomb.

I was reading the article stick bomb and a quick google search on it didn't really tell on how to construct one. Is there a website that shows how, that perhaps I missed? --Proficient 21:34, 2 February 2007 (UTC)

I agree that there should be the basic popsicle stick bomb I made as a kid. Somebody will have to whip up the 3D software and make a model! (Perhaps me, one day). --Zeizmic 22:10, 2 February 2007 (UTC)

Is that article a copy-vio, or is it just really weirdly written? I can't see any of it on Google, but Google isn't the world. I've never heard of stick bombs before, so I can't really do more than remove references to an 'Author'. Anyone here able to improve it? Skittle 22:43, 2 February 2007 (UTC)

Me neither, and I'm guessing that's not their running name then. The current article is an obvious self-promotion by that Tim guy, so if you guys think this stuff is notable enough for an article, rename, rewrite and get us some sources. — Kieff | Talk 01:30, 3 February 2007 (UTC)

This video has instructions for the type I used to make as a kid: http://www.youtube.com/watch?v=KyzsDmkYnJY 75.138.84.159 00:58, 3 February 2007 (UTC)

Point drag coefficient

Does anyone know the definition of the point drag coefficient? What I know is as follows...

$C_{D}=\int _{-\infty }^{+\infty }{{C_{D}}'\,d({\frac {z}{c}})}$

where $C_{D}$ is the drag coefficient of the aerofoil, and c is the chord length. ${C_{D}}'$ is apparently the point drag coefficient. Can anyone tell me the definition of ${C_{D}}'$? I have the ${C_{p}}$ distribution over the aerofoil, which I presume is needed. Thanks! Readro 22:56, 2 February 2007 (UTC)

The point drag coefficient ${C_{D}}'$ (or section drag $C_{d}$, as I learned it) is the coefficient of drag for a 2-D cross section, with chord length replacing wetted area to nondimensionalize the drag per section span. It seems what you have is the definition, that is if you split the wing into infinitely small cross sections, each cross section will have a section drag coefficient. Integrating all of these over the wing span gives the total drag coefficient $C_{D}$. anonymous6494 00:30, 3 February 2007 (UTC)

February 3

Abs and Resting Time

How often can you work out your abs without them needing rest? I've heard that you can work out the abs nearly every day, whereas the other muscles need rest. Why the difference? Also, how much resting time is needed for abs? PitchBlack 03:45, 3 February 2007 (UTC)

Do sit ups until it hurts? --Russoc4 04:17, 3 February 2007 (UTC)

I didn't find any real sources, but google results did say to treat your abs like any other muscle and excercize them about 3 times a week. On a related note, 6 Week Abs has 7 myths about abs. I'm curious now too, because when I used to work out (yea, yea, I got lazy), I could lift barely more than I weigh with my upper body, but I can use ab machines at max weight and not have them hurt afterwards while my arms did. --Wirbelwindヴィルヴェルヴィント (talk) 06:19, 3 February 2007 (UTC)

I have never had sore abs when I would exercise them 5-6 times a week, whereas my arms and legs needed a day to rest afterwards. − Twas Now ( talk • contribs • e-mail ) 23:50, 3 February 2007 (UTC)

A plant that is also a pathogen

I recently added to the article protothecosis that Prototheca was the only known pathogen that is also a plant. I got this from the Journal of Clinical Microbiology. Is it true, or am I forgetting some other plant that causes an infectious disease? --Joelmills 04:19, 3 February 2007 (UTC)

Wow, that's pretty cool. [Mαc Δαvιs] X (How's my driving?) ❖ 05:26, 3 February 2007 (UTC)

Hello Joelmills, this is very nice, but when you're not sure, why not asking before updating ? Now it's only because fungus are not sorted along with plants that your first case [meaning of prototheca] is an 'only plant' candidate. -- DLL ^{.. T} 10:57, 3 February 2007 (UTC)

I was sure when I added it, having the reference to back me up and a precursory google search not showing any contradiction. But then I thought that it was a pretty big claim to make, so I better ask here, where I know that there are a lot of knowledgable people. Protothecosis hasn't attracted many edits in the months it's been in existence, so I figured a few hours of waiting to doublecheck something was OK. --Joelmills 19:37, 3 February 2007 (UTC)

Wireless control

HI friends,I have undertaken a project "Multi-axis wireless control for Robots".In it's details,all I have to do is to control the robot using my transmitter pad.I have planed to use 5 to 6 keypads to control different axis.Then at the receiving end,using some RF module,the data is decoded and it will be used to control the relay using a microcontroller and ULN driver.Which will then be interfaced to PLC for robotic arm movement....For this entry level,I have stuck somewhere in choosing the exact means of communication.At first someone stated to go for IR,later someone suggested RF and now few others state to pick bluetooth for industrial standard...Now I have decided to ask to you guys in this forum so that I can get a good solution for this..For IR based TX and RX,I have seen many circuits practically used,but I still can't get one for multiple device control...For Rf based TX and RX,I tried MAXIM-1472(TX) and 1473(RX)...All pin connections and other spec seems pretty nice but I'm not able to get any practical circuits for it's contruction.I also tried Cypress wireless solution.But the practical construction seems almost impossible...Should I have to only buy modules?.Isn't there any other solution?..Guys can anyone get me some more detailed view in designing using such SOCs please?..I don't know what type of data format that should be used for this chip.No proper details in Maxim Website...I tried...Please someone help me out...And about bluetooth project,I have simply no idea...I thank you all in advance for you consideration..Looking up for the suggestions........ —The preceding unsigned comment was added by 59.96.23.95 (talk • contribs).

I'm slightly confused about what you're asking. When you mean practical circuit, you mean you can't do it because the traces of the MAX1472 and 1473 are too small, or you don't have a schematic? IIRC, one of those is TSSOP and have a pin clearance of like 0.2 mm or something tiny. There are adaptors available for them, I believe, which cost around $10 a piece. But even then, they're surface mount. I'm not sure what your level is, etc, so it's hard to tell if I can even provide you an answer when you ask for a more detailed view in designing. The datasheet usually has that kind of info, and the 1472/1473 uses SPI I believe. If the problem is that you're making prototypes, you should look for DIP packages for chips to construct them easily. Somehow, I doubt I helped any, so do tell if anything applies, and if not, what info you need (design software, RF packages, comparison of RF / Bluetooth / IR, etc). --Wirbelwindヴィルヴェルヴィント (talk) 08:54, 3 February 2007 (UTC)

How does window gel work?

My kids have window gel toy stickers (hearts, snow flakes, and so on) that stick to non-porous surfaces like windows, mirrors, and metal. They don't stick to fingers. From my research all I've been able to determine is that window gel toys are primarily manufactured in China and South America, mostly Brazil.

What is window gel made of? How is it made? How does it work? Does it leave a film behind? —The preceding unsigned comment was added by Dstinchf (talk • contribs).

They appear to be static cling vinyl. See also Colorforms. --Wirbelwindヴィルヴェルヴィント (talk) 17:50, 3 February 2007 (UTC)

Unknown Bird

Found browsing flickr : "IF anyone know the bird's name please write clicking the comments link. " http://www.flickr.com/photos/subirbose/167852801/. Seems the guy's photos are from the Himalaya and surroundings. Thanks for your help and more : which method do you use and recommand to find the name of a [living creature] from its photo or sketch ? -- DLL ^{.. T} 10:50, 3 February 2007 (UTC)

To find a species, you want to use an Identification key. There are plenty around; you'd need to find one for the class Aves (birds) to find the identity of this bird. Laïka 13:18, 3 February 2007 (UTC)

Skin aging

I was trying to find some information on the process of the aging of the skin, and I guess both physical aging in general and the (human) skin are not as well covered, unfortunately, as some other biology-related topics on WP. I am particularly interested in how the dermis ages vs. the epidermis - it is my intuitive understanding that while the epidermis' aging concerns wrinkles and other skin imperfections more, it is the dermis' aging that is responsible for the sagging of the skin and the fact that our cheeks and neck don't look south youthful anymore :(

I was inspired to research Wiki for that by reading about this company's product: [4]. Even if their product actually works, it is my understanding that it affects epidermis only (even if it's "all five layers of the skin" as the company claims, I understand it is epidermis), so the product wouldn't prevent the skin from sagging anyway. OTOH, Wikipedia says stretch marks form in the dermis, and the company advertises using a "testimonial" from a customer saying her stretch marks have "faded" after using the product.

OK, what I would like to learn is how the skin actually ages and how, theoretically and practically, it can be prevented/alleviated, and what is the state of research into it - not to mention it would be nice to be able to find out the same about other tissues... I guess it is not a "question" one could answer overnight at the reference desk, I am rather counting on drawing the attention of editors who are into biology/medicine to that topic. It wouldn't hurt, though, if somebody could provide a quickie lowdown on the topic here :D

Thanks a lot to any merciful soul who would take interest in that request. PrinceGloria 11:17, 3 February 2007 (UTC)

Energy saving Light bulbs?

I'd like to know just how much energy it takes to make an energy saving light bulb compared to the older glass filament type. It is widley known that the energy saving kind will use less energy to generate light of a similar intensity as a filament type and will last around ten times longer. But what about the enery of production? Hesaurus 12:37, 3 February 2007 (UTC)

See Talk:Compact fluorescent lamp#Energy used to manufacture CFLs Rmhermen 01:38, 4 February 2007 (UTC)

Genetic Variation in and between Populations

I have heard many times, normally when discussing race and whether it exists, sentences like (and this is a real example from the reference desk) "there is more genetic variation among Africans than there is between Europeans and Africans". What does this mean? That a randomly selected African will have more in common with a randomly selected European than another African? Because that sounds hard to believe. Or that the standard deviation in the African population is larger than the differences between an average European and African? 85.1.5.207 13:37, 3 February 2007 (UTC)

It means that there is more genetic variation within an African population than within a European population, measured by things like the number of minor varieties of genes (called polymorphisms). The most economical explanation is that several African "peoples" (i.e., populations, like Bantu, Khoisan, etc) partly separated from each other far longer ago than did the various European "peoples" (like Nordic, Mediterranean, Basque, etc). It does not mean that a random African is likely to share more gene polymorphisms with a random European than with another African. alteripse 14:22, 3 February 2007 (UTC)

Thanks, although the statement made seems to suggest that there is more variation within Africans, than between Africans and Europeans. Are people who make this statement misunderstanding the claim, or is this a different claim? It is normally made in the context of proving how similar humans are, so we shouldn't be racist. Maybe it should be that we shouldn't lump all blacks together as one, which we don't do to white Europeans.85.1.5.207 14:45, 3 February 2007 (UTC)

Which "statement made"? A number of research studies have shown more genetic variation among the large population of people whose ancestors lived in Africa a couple of centuries ago than among those whose ancestors lived in Europe a couple of centuries ago. I do not know how to say it any more plainly. This statement itself is neither racist nor anti-racist. All of us recognize gradations of physical difference more easily among those who are most similar to the people among whom we grew up. This is the origin of the "all ___ look alike to me" kind of statement-- it reflects a nugget of truth about human perceptions and recognitions of other people, but it is an entirely relative fact, as the same assertion can be made by a member of the "other" population. Or should I have simply stopped at the first sentence? alteripse 23:34, 3 February 2007 (UTC)

It means that two randomly selected Africans have less in common with each other than the average African has with the average European. − Twas Now ( talk • contribs • e-mail ) 23:43, 3 February 2007 (UTC)

The above statement is true, however: there is more genetic variation among Africans than among any other group (Asians, Native Americans, Europeans, Australian Aborigines). This is, in very simle terms, because they have been there the longest. − Twas Now ( talk • contribs • e-mail ) 23:45, 3 February 2007 (UTC)

Thanks to both of you. Alterprise, the statement I was referring to was the quote in my original post, but thanks for your info. The stuff I mentioned on racism was simply to try and clarify the difference between your explanantion and how I interpreted the original quote. Obviously facts cannot be racist or not, they are simply facts. Also thanks Twas Now for your answer, that would have been my guess but the statement seemed open to interpretation. (Same user - different IP!)137.138.46.155 08:05, 5 February 2007 (UTC)

Sex in evolution

How can evolution explain how species evolved sexes? The primitive life forms didn't have sexes, so when did it all start? Did it have to evolve in one generation of a species? Or what? My biology teacher said that no-one really has an answer for this. Also, if natural selection or whatever found it necessary for two sexes to exist, will we be able to evolve a third or fourth sex? Please take this seriously, I'm not trying to attack evolution or anything, I'm just really interested in this. ► Adriaan90 ( Talk ♥ Contribs ) ♪♫ 14:33, 3 February 2007 (UTC)

Well, no one has a definite answer to this, though there is a lot of speculation going back even before Darwin's work. You might check out our article on evolution of sex for quite a lot of discussion of it. Once you've evolved sexual reproduction of this sort, the specialization of the different sexes to different functions, appearances, etc. is, I think, a comparatively easy thing to understand. --24.147.86.187 14:45, 3 February 2007 (UTC)

Sex#Animal species shows that there are several animals with more than two sexes. − Twas Now ( talk • contribs • e-mail ) 23:41, 3 February 2007 (UTC)

Yeast is a "primitive life form," and it has a sexual form of reproduction, too. In fact, bacterial conjugation is kind of like sex. -- Scientizzle 01:26, 4 February 2007 (UTC)

Land fill solution or not...?

After watching the movie Soylent green and reading the article on Digestion I was wondering if it would be possible (and practical) to process solid waste both mechanically and chemically in a similar fashion as digestion or using the steps in Quantitative analysis or Qualitative analysis to produce a resource for useful byproducts such as plastics or for other purposes such as eliminations of Toxins or Pathogens? 71.100.10.48 15:23, 3 February 2007 (UTC)

Yes, indeed - I assume you mean household waste..

There are methods similar to digestion for treating household waste, see Waste_management#Waste_management_techniques subsection Composting and anaerobic digestion, also for sorting the waste see subsection Mechanical biological treatment - just as food is broken down in the gut by enzymes (an sometimes bacteria) - in the treatment of biodegestible household waste bacteria and enzymes break down some waste producing 'soup' that may be suitable for fertilizer, and possibly gas (methane). Any organic matter might be suitable for this - includes waste food obviously, but also wood, paper, some plastics, non synthetic clothes - it all depends on how good the bacteria are..

As for a similar process to the steps in Quantitative analysis or Qualitative analysis - I assume you mean as in chemical analysis, and again the answer is a resounding yes.

See subsection Pyrolysis & gasification in Waste_management#Waste_management_techniques - in this case waste is heated to a very high temp (eg much greater than 200 degrees C - maybe much greater than 1000C depending on method), but air (oxygen) is excluded so it doesn't burn - this causes all organic matter including synthetic plastics to break down (see also cracking (chemistry)) - the process typically yields a great mixture of products - that can be separated by distillation. It's comparable to the process where chemicals used to be obtained by heating coal (eg Karrick process or similar).

We have excellent articles on this see pyrolisis and gasification - both are great routes to synthetic 'diesel' and other petroleum replacement products - it's a form of recylcing of organic matter.87.102.9.55 16:20, 3 February 2007 (UTC)

If you want to read more I can suggest

Gasification#Gasification_process_examples and all the article pyrolysis - similar to chemical analytic methods.

For methods similar to digestion see Anaerobic digestion

If you look at the page on waste_management you may find other useful links.87.102.9.55 16:26, 3 February 2007 (UTC)

As for getting rid of toxins and pathogens - there is some infomation in the articles - the answer seems to be yes in some cases - specifically biological toxins.87.102.9.55 16:31, 3 February 2007 (UTC)

This is not a joke and is not me trying to be sarcastic

This is not a joke so please answer seriously. Is it possible to kill someone by throwing (using their arms) an almond or a soybean at high enough velocity or by hitting a vulnerable part of the head. If you have heard any anecdotes of this please respond. Thanks. Again, this is not a joke, as ridiculous as it may sound. 63.135.8.94 15:42, 3 February 2007 (UTC)

No. A human arm can't give those objects enough kinetic energy to do any lethal damage on their own. But, I guess the person could choke and die of asphyxiation if it happened to go down their throats... — Kieff | Talk 15:46, 3 February 2007 (UTC)

Even if the KE of the almond cannot exceed whatever amount of joules, is it not entirely impossible that it may hit a certain area of the head, such as a vein or artery or a nerve and cause death or serious injury? Thanks again for your previous reply63.135.8.94 15:54, 3 February 2007 (UTC)

Sure it is possible, but then any small, light object could also be considered lethal in these conditions. — Kieff | Talk 16:15, 3 February 2007 (UTC)

Even with the assistance of a sling or slingshot, you need a projectile of at least 50 grammes to do any damage - many times heavier than an almond or soybean. The part of the body most vulnerable to injury by a small hand-thrown projectile is probably the eye. But I really don't see how it could be lethal (apart from the choking danger that Kieff mentioned). Gandalf61 16:29, 3 February 2007 (UTC)

There are no parts of the head and neck that vulnerable to a small hand-thrown projectile in a healthy person If you want to make the person unusual, or if you want to add some more conditions, you can concoct all kinds of semi-plausible scenarios. The person has heart disease, gets angry, and dies of a heart attack. The person is standing on the edge of a crowded train platform as the train is approaching, and the thrown object startles him and causes him to fall in front of the train. The person is so depressed that this one additional unexpected expression of contempt and anger from a previous friend causes him to decide life is too painful. And so forth... alteripse 16:35, 3 February 2007 (UTC)

It would be very, very difficult to kill (or even injure) someone with an almond or soybean. (Apart from Alteripse's "cooked" solutions, that is.) Theoretically, you can give even a lightweight projectile a lethal amount of momentum by shooting it fast enough. In practice, however, there are two crippling difficulties: (1) neither an almond nor a soybean is particularly aerodynamic -- they'd lose velocity rapidly between your gun and the target; and (2) neither an almond nor a soybean is particularly rigid, so it would be nearly impossible to accelerate them up to the stupefyingly high necessary velocity without disintegrating them. —Steve Summit (talk) 18:35, 3 February 2007 (UTC)

If you think we don't take silly things seriously, check out Wikipedia:Reference desk/Archives/Science/2007 January 26 & 27#My other planet is made of meat. In high school, a guy I knew had a pencil thrown at him that lodged into his temple, and just stuck there. He was OK, and I think he didn't even notice until someone pointed it out. − Twas Now ( talk • contribs • e-mail ) 23:39, 3 February 2007 (UTC)

I saw someone's eyeglasses broken by a thrown pingpong ball. An almond should have an easier time breaking the glass lens, and the broken glass could penetrate the eyeball leading to lethal infections. (Sure it's funny, until someone looses an eye) Edison 00:02, 4 February 2007 (UTC)

Total Cholesteral Reduction

I am a 61 year old male. My TC was measured twice at a six month interval. It was 234 each time. The doctor reccommended exercise and diet to reduce the TC. I've engaged in 20 minutes per day of aerobic exercize and reduced my intake of cholesterol to less than 100 mg/day. I've also increased my intake of soluable fiber to more than 4 gm/day. I've followed a diet aimed at weight reduction and have lost 14 lbs in the last 33 days putting me at 192 lbs. What level of reduction in TC can I reasonably expect to achieve following this regimen? From a minimum to maximum?Brucearugg 17:56, 3 February 2007 (UTC)

Because your cholesterol levels are going to be based on the interplay of a number of factors – environmental ones related to the changes you've made in your behaviour as well as luck-of-the-draw genetics – and because you've made so many (healthy!) changes to your lifestyle, any answer we give you here would be no better than a wild guess.

Moreover, total blood cholesterol is only one indicator of health. More important are the levels (absolute and relative) of HDL (so-called "good cholesterol") versus LDL ("bad cholesterol").

In any case, you're best off just asking your doctor or cardiologist what changes or benefits are likely to accrue from the specific changes you've made to your own, unique lifestyle. TenOfAllTrades(talk) 18:22, 3 February 2007 (UTC)

I don't know the answer to your question, but let me just say: kudos on the positive changes you've made! Keep with it! —Steve Summit (talk) 18:29, 3 February 2007 (UTC)

Do rats have spleens?

?

Don't you ? We're all mammals, ain't us ? -- DLL ^{.. T} 18:52, 3 February 2007 (UTC)

I read that rats don't have bladders, so there might be other differences too. --84.69.30.24 19:26, 3 February 2007 (UTC)

Rats have bladders. Chickenflicker---♣ 19:28, 3 February 2007 (UTC)

There's a diagram and a discussion of rat dissection here: [5]. Rats do indeed have bladders, as well: [6]. TenOfAllTrades(talk) 19:31, 3 February 2007 (UTC)

Sorry. I've clearly been misinformed. It was an article in the newspaper about ratcatching where it was stated by a ratcatching expert that rats do not have bladders and hence constantly dribble piss behind them wherever they go to mark a trail for other rats to follow. --84.69.30.24 19:36, 3 February 2007 (UTC)

Rats don't have gallbladders. Maybe that is the source of confusion. --Joelmills 19:39, 3 February 2007 (UTC)

....and ratcatchers have a wicked sense of humour. (At least, they're usually portrayed that way.)--Shantavira 09:12, 4 February 2007 (UTC)

Question about pets and domestication

What's the difference between a tame pet and a domesticated pet? This comes up a lot on the birdkeeper forums and people actually have big arguments about it. Why would a cat be considered a 'domestic' pet while a cockatoo (for example) would be referred to by avian science people as a 'tame' pet? Is a budgie 'tame' or 'domesticated'? --84.69.30.24 19:25, 3 February 2007 (UTC)

If you take a look at the article on domestication, it says that budgies are considered domesticated. "These species or varieties are bred and raised under human control for many generations and are substantially altered as a group in appearance or behaviour." As for cockatoos, the same article would probably put them in the category of "raised commercially" or "semidomesticated" rather than fully domesticated. Chickenflicker---♣ 19:47, 3 February 2007 (UTC)

How should you heat up an embryo?

I have a curiosity about how can embryos be defrosted from the fridge prior to being implanted to avoid that the water present expands thus damaging it. Can you heat it rapidly without burning the specimen?20:09, 3 February 2007 (UTC)

I'd just let it warm up slowly, or in luke warm water - I think your question/my question should be "how can an embryo be frozen without causing frost damage from the ice crystals that will inevitably form" - the same goes for sperm.213.249.232.136 20:12, 3 February 2007 (UTC)

Our article on cryopreservation gives a good overview of the challenges associated with freezing (and thawing) viable tissue and cells. Cryoprotectants are chemicals which are added to cells at the time they are frozen; these chemicals typically discourage the formation of ice crystals which would otherwise puncture and kill cells.

Thawing most frozen tissue or cells is actually a very straightforward process. There are two key goals in thawing. First, one wants to warm the tissue fairly rapidly through the temperature range where ice crystals are most likely to form; this runs from roughly -50°C to -15°C, give or take. Second, you want to wash off or dilute out the cryoprotectant. (Prolonged exposure to cryoprotectants will kill a warm cell.)

Accomplishing these goals is generally straightforward. Frozen specimens are normally in glass or plastic tubes or vials. They can be warmed rapidly by immersion in a body-temperature (37°C) water bath; this thawed solution can then be diluted to reduce the concentration of cryoprotected to below toxic levels. For thawing small volumes, rapid warming and dilution can be accomplished by directly adding warm liquid to the frozen-solid sample. TenOfAllTrades(talk) 21:27, 3 February 2007 (UTC)

DMSO is commonly used for cryopreservation of cell lines...but I'm not sure if it's used for embryos... -- Scientizzle 07:28, 4 February 2007 (UTC)

Scarlet Fever

I am doing a report in science on an infectious diseases caused by bacteria. I picked scarlet fever. Please tell me all that you can!!!!!!!!!22:44, 3 February 2007 (UTC)

Have a look at scarlet fever and Streptococcus pyogenes, the latter being the species of bacteria that causes the disease. --David Iberri (talk) 22:46, 3 February 2007 (UTC)

Is FM radio lossless? If not, what bitrate is it at?

Hello, my question is concerning the audio quality of FM radio. Does the transmission of the sound through the air bring the quality down? Do radio stations load up lossy files on their playlists, like 128 kb/s mp3 files? Basically, what bitrate would be comparable to the quality of FM radio on the receiving end/through my stereo? Thanks! NIRVANA2764 23:11, 3 February 2007 (UTC)

Its complicated to say, as it will depend upon the audio codec imployed, in the UK DAB broadcasts at 160 kb/s IIRC, via a form of MP2 encoding, with the speech only networks at a lower 128 kb/s and Radio 3 (classical music) at 192 kb/s. It is suggested that 192 kpbs is needed to give high quality audio broadcasts.

For more info checkout the Digital Audio Broadcasting page, more specificaly this section.

There are other issues of course - often audio will sound different between a CD, radio and television broadcast, and if you are used to a particular version of a song then even though the other is at a higher rate of transmission it may still sound worse! --Neo 23:31, 3 February 2007 (UTC)

Er... Traditional FM radio uses a purely analog modulation method (ignoring some of the sub band extensions). You can't talk about it in terms of "bit rate" (as you could with digital modulation schemes like PSK and OFDM). Your usage of "lossless" seems to be in the sense of digital audio compression methods, which is simply irrelevant here. The article on frequency modulation proper provides some insights on maximum bandwidth, drift, SNR, etc. -- mattb @ 2007-02-04T03:30Z

FM Radio has a Signal to Noise ratio and is not digital. 1 bit corresponds to roughly 6 db (6 db is double signal level, 1 bit in base 2 is double). Original CD quality is 16 bits which corresponds to about 96db of S/N. Bit rate corresponds to the frequency range. IIRC, CD's are about 24KHz of range which for Nyquist is 48 KHz. So a CD plays 16 bits at 48 KHz => 768 kb/s. You can trade frequency or S/N to reduce this number and compression does it smarter than just the baseline cut.

FM as implemented has a frequency range to 15 kHz (30 KHz Nyquist) and I believe the noise floor give about 60dB of dynamic range (~10 bits). Note that this is best case in FM and in practice is worse than this. That's 30*10 or 300 Kbps for Nyquist sampling to Digitally recreate the best possible fidelity of FM analog. --Tbeatty 07:02, 4 February 2007 (UTC)

A fair point - but FM is analogue - therefor the resolution (eg CD resolution is 16bit) could be considered infinite..(not quite true)

Resolution, whether it's digital or analog, is expressed as signal-to-noise ratio. Quantization error (the error between "infinite" analog and discrete digital) can be expressed as noise. In fact, moving the quantization error out of the baseband frequency is how 1-bit, oversampling works. It is entirely accurate to compare digital resolutions with S/N and analog with S/N. There is no additional resolution because of the continuous nature of the analog signal. That portion of continuity that distinguishes iteself from the digital portion is unrealizable signal that is lost in the noise. Analog FM is not infinite resolution because there is a finite noise floor that limits it. Currently that noise floor is 60 dB and that is an equivalent noise floor to 10 bits. You have to think in the frequency domain (for both anaolog and digital) to understand the mathematics that proves this. Fourier Transforms and the Discrete Fourier Transform/Fast Fourier Transform is the mathematics required for the analogue and digital respectively. --Tbeatty 19:22, 4 February 2007 (UTC)

FM quality depends critically on reception conditions as it is an analogue signal - in general a good signal strength of FM radio would produce audio quality comparable to analogue records or cd's - but not quite as good - better than cassette tape though.

The weaker the signal the poorer the sound so yes - transmission affects quality.

I'd guess that FM radio stations don't usually transmit MP3 files - most likely they use CD's or another digital source such as DAT. However audio level compression is common on FM - resulting in a percieved loss of quality.

I wondered if you were thinking about DAB - digital radio - apparently a FM gives a comparable quality of sound as 192kbit/s digital radio as a best case - in reality it's probably a lot less.87.102.7.169 10:23, 4 February 2007 (UTC)

Cold fusion? real?

How come wikipedia's article on Cold Fusion is written from the POV that Cold Fusion is real? Isn't it odd for an article to be writtin from such an obscure perspective?--71.249.19.4 23:43, 3 February 2007 (UTC)

Could you quote an example of this alleged bias? I looked it over just now and it seems fine, but of course I could have missed something. Anyway, the reference desk is not for questions about Wikipedia. Next time bring it up on the talk page. —Keenan Pepper 00:39, 4 February 2007 (UTC)

Actually, the Reference Desk can be for questions about Wikipedia. One of the Reference Desk's primary purposes is to help the project, and one way it does this is by assisting editors in their research. (There's a fine example just below.) —Steve Summit (talk) 01:05, 4 February 2007 (UTC)

IMO, it does seem to be a bit biased towards cold fusion, but nothing blatant enough for a non-expert to object to. It would take someone really knowledgeable in the field to do that. Clarityfiend 03:16, 4 February 2007 (UTC)

The original cold fusion claims reportedly lacked the emission of neutrons sufficient for the energy claimed. As I recall, the energy production was chalked up to normal electrochemical processes and inadequate process control. Reading this article, I get more of an impression of there being fusion than the earlier analyses implied. I believe there have ben recent reputable claims of cold fusion, but in processes which could never be energy sources, but still useful as neutron sources. Any nuclear engineers out there? Edison 05:14, 4 February 2007 (UTC)

I too agree that there is no noticable bias - to a non expert - and in terms of the info. in the article. It is possible that information/papers against cold fusion occuring are underepresented and evidence for is over represented... But in terms of the writing style I can see no bias.

87.102.35.119 12:57, 4 February 2007 (UTC)

The perceived "bias" may be that the article does not come out and say "Cold fusion is wrong! R O N G wrong! Fleischmann and Pons were charlatans and frauds! It was all a hoax!" But of course, that would be just as badly POV, in the other direction. —Steve Summit (talk) 13:40, 4 February 2007 (UTC)

Now, now. Cool down; don't go nuclear on us. Clarityfiend 17:19, 4 February 2007 (UTC)

February 4

Water as a yellow solid?

I left the lid on a pot of boiling water and came back thirty or so minutes later. Aside from my being an idiot, here's what I found: the lid had a thin layer of yellow power over in, and little balls of yellow powdery substance had formed in the pot. There was an intense smell, and the pot was hot enough to vaporize the hot water I poured on it on contact. Should I contact poison control? Is the pot safe to use again? And most importantly, what the heck just happened? --162.83.149.125 18:46, 4 February 2007 (UTC)

What's the material the pot is made of, and what do you usually use the pot for? — Kieff | Talk 20:29, 4 February 2007 (UTC)

It sounds like sulfur, but sulfur isn't water soluble. On the other hand, if it's water from the tap, there maybe lots of sulfur within the water (because it comes from the ground). Boiling water is one of extracting elements and compound within it.

I would call poison control, just to be on the safe side.--Honeymane_{Heghlu meH QaQ jajvam} 20:40, 4 February 2007 (UTC)

Same here call poison control to check it out If it is toxic and was tap water then you need to bring it to the attention to the city you live in . but before you do that check your pipes (if you are using metal pipes then its probably rust) Maverick423 23:26, 4 February 2007 (UTC)

You didn't happen to take a picture of the pot and these yellow balls, did you? —Steve Summit (talk) 23:41, 4 February 2007 (UTC)

It sounds like gunge to me (it don't think the wikipedia article does the word justice) - it could be vaporised organic matter from the bottom of the sauce pan that condensed on the lid. The yellow stuff is not water! GB 23:57, 4 February 2007 (UTC)

Dopamine reuptake inhibitor| Antidepressants | NEED REFERENCES

Q1. I am looking for references to back up this paragraph:

In general, the abuse potential of DAR inhibitors depends on how they affect the pattern of dopamine release and reuptake. Compounds that inhibit reuptake and also induce release of dopamine, such as methamphetamine or phenmetrazine, or compounds that inhibit reuptake but have no effect on release, such as cocaine or methylphenidate, tend to be addictive drugs with potential for abuse in humans. On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as Wellbutrin and vanoxerine, have mild stimulant effects and little abuse potential, and can be used to treat stimulant addiction.

I would appreciate the references provided. Thank you. --Parker007 07:10, 29 January 2007 (UTC)

http://www.drugabuse.gov/NIDA_Notes/NNVol12N3/Compounds.html mentions the addictive properties, in relation to preventative treatments; http://www.medscape.com/viewarticle/418525 mentions addiction's reuptake patterns in general, and then in relation to methadone and some othe B-drug that I forgot the name of. All provided by this Goog search. V-Man737 07:10, 30 January 2007 (UTC)

Please explain how the above references are actually related to: "On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as bupropion have mild stimulant effects and little abuse potential." I would much appreciate a reply. Thanks. --Parker007 07:30, 30 January 2007 (UTC)

Oh - now I see the first article doesn't mention Bupropion specifically... hrmph. Perhaps the sentence in the article should be changed to match the source, rather than whoring up a source to fit an exact claim? I'm sorry for the scanty help, it's past my bedtime... V-Man737 07:44, 30 January 2007 (UTC)

• On the other hand, compounds that inhibit reuptake but also inhibit release of dopamine, such as Wellbutrin and vanoxerine, have mild stimulant effects and little abuse potential, and can be used to treat stimulant addiction.
• I believe the above statement, I just want a reference. Please? --Parker007 00:05, 4 February 2007 (UTC)

Please say which part of the statement you want a reference for.87.102.7.169 10:57, 4 February 2007 (UTC)

Its "but also inhibit release of dopamine" --Parker007 02:05, 5 February 2007 (UTC)

Searching for 'zyban' another name for bupropion - gives many references saying that it can be used to treat nicotine addition.

Searching for 'vanoxerine addiction' turns up numerous references saying that it may be useful for cocaine addiction eg http://dmd.aspetjournals.org/cgi/content/full/29/9/1216 (note this says it is a dopamine reuptake inhibitor..I haven't done a full search for the best example.

Is this what you wanted references for or did you want a reference that says specifically that they inhibit dopamine release? If so see below.87.102.7.169 10:47, 4 February 2007 (UTC)

((Also the statement 'have little abuse potential' could be construed as weasel words when the articles on Bupropion clearly state that they have been abused by some patients.. Why not just re-write to match the facts.))87.102.7.169 11:10, 4 February 2007 (UTC)

From what I can find it seems that Vanoxerine inhibits other drug induced dopamine release - eg it inhibits the action of dopamine release by another drug - so that's subtly different. here http://www.mdma.net/dopamine/vanoxerine.html a 60% reduction in the dopamine release under the conditions described if I've read correctly.

Here's a reference that states that bupropion decreases spontaneous dopamine release http://www.cocaine.org/dopamine/efflux.html 87.102.7.169 11:22, 4 February 2007 (UTC)

Thank you very much friend; (I am looking for reference that states Wellbutrin/bupropion inihibits the release of dopamine; as there is already a reference in the article bupropion regarding it inhibits reuptake of dopamine.) from the last reference I got this:

“ Release of dopamine via the human transporter

by Eshleman AJ, Henningsen RA, Neve KA, Janowsky A., Research Service, Veterans Affairs Medical Center, Portland, Oregon. Mol Pharmacol 1994 Feb;45(2):312-68

ABSTRACT A human dopamine transporter cDNA was cloned and transfected into COS-7 cells, a cell line that lacks vesicular storage and release mechanisms. Cells expressing the dopamine transporter acquired the capacity to take up and release dopamine via the transporter. Ionic conditions that stimulate inside-out transport in vivo, such as depolarizing concentrations of K+ or low concentrations of extracellular Na+, were found to stimulate Ca(2+)-independent release of [3H]dopamine from transfected COS-7 cells. Dopamine re-uptake inhibitors had one of three effects on transporter-mediated efflux. Some drugs, in addition to inhibiting re-uptake, inhibited spontaneous release of dopamine. Drugs in this class included mazindol, GBR-12935, bupropion, nomifensine, and benztropine. All of the drugs with the potential for abuse by humans either enhanced release (methamphetamine, amphetamine, and ethanol) or had no effect on release (phencyclidine, cocaine, and WIN 35,428). The ability to define classes of uptake blockers based on their effects on human transporter-mediated dopamine efflux may lead to the identification of structural features of the transporter that differentiate abused from nonabused drugs.

”

--Parker007 02:16, 5 February 2007 (UTC)

Wikipedia:Reliable_sources --Parker007 11:58, 5 February 2007 (UTC)

On the subject of cockatoos...

I've never owned a cockatoo myself but having spoken to cockatoo owners in real life and online, I have been told that peculiarly amongst pet birds, tame cockatoos (particularly Umbrella Cockatoos and Moluccan Cockatoos) actively enjoy being picked up and cuddled and will continuously pester their owners to be held like babies (screeching and screeching until they get their own way - and they can be *loud*). Now, as someone with experience keeping parrots, I know that the birds generally *hate* being picked up, especially if their wings are restrained. Anyone know what the deal is with cockatoos? More than one owner has reported to me that these birds behave like this 'out of the box', with little in the way of training required, like it comes completely naturally to them to enjoy being held by a potential predator. I find it a bit odd. --Kurt Shaped Box 00:24, 4 February 2007 (UTC)

Not a cockatoo, but our sun conure loves being cuddled, climbing inside clothing, and the like.

Atlant 13:39, 4 February 2007 (UTC)

I can't answer the "why", but my sister Suzy had a cockatoo (looked exactly like our picture), and I can confirm all of the above. Coral would spend as much time on my sister's shoulder as possible, even in the shower, lifting first one wing and then the other as my sister turned so that the bird could wash under both. Coral was also deeply sexist, vastly preferring the company of women, and hissing whenever I or Suzy's husband or any other man got near.

The arrival of first Suzy's husband, then their dog, then their first child -- all put deeper and deeper strains on Coral's emotions. It got so bad that on the day when I was at their house babysitting the first child while Suzy was at the hospital delivering her second, Coral walked into the room and started nuzzling up against my leg; that's how desperate the bird was for affection in what she seemed to see as her abandonment by Suzy. Eventually she had to give Coral away, to a bird farm where Coral found another cockatoo to fall in love with instead of a human, and was much happier after that.

I'll have to ask Suzy if she can give any insight into why cockatoos are like this. —Steve Summit (talk) 14:33, 4 February 2007 (UTC)

Speed of Light

What is the speed of light, and how can we tell? It goes too fast to just use a speed gun on. 71.219.43.14 01:32, 4 February 2007 (UTC)

THe speed of light is approximately 300 000 km/s or 186 000 miles/s. Have a look at the speed of light article for more information. The article also gives a description of how these numbers were reached. The method used is to reflect a beam of light off an object and time how long it takes. This site also gives a quick explanation. - Akamad 01:44, 4 February 2007 (UTC)

The speed of light is different in different media. What is often colloquially referred to as "the speed of light" is actually the speed of light in a perfect vacuum. -- mattb @ 2007-02-04T03:21Z

Quite right, but the speed of light in air is practically the same. It's slower than speed of light in vacuum by only about 100 km/s or 60 miles/s, wihch is less than the roundoff error in the approximate numbers quoted above.

Not incidentally that a "speed gun", mentioned by the original poster, is a device that's only possible because we know what the speed of light is. (Well, it uses radio waves, but the speed is the same.) --Anonymous, February 4, 05:02 (UTC).

And that brings up another way to measure speed. Permittivity can be measured from capacitance and the relationship to the speed of light is known, therefore, two paths (one free space, the other through a dielectric) could be set up and the difference in arrival times measured. This will reduce measurement error as it is common to both measurements. Just a guess. --Tbeatty 08:30, 4 February 2007 (UTC)

The sun

How old is the sun? Nucleocosmochronology has a different answer than sun. Also how does Nucleocosmochronology tell the age? The article is vague. 71.219.43.14 02:01, 4 February 2007 (UTC)

Huh? Both articles say the Sun is 4.57 billion years old, give or take. Clarityfiend 05:13, 4 February 2007 (UTC)

Phylogenetic tree

Hi! Would anyone know where i could find a phylogenetic tree of life, containing all groups, made in a nice and clear way, and up-to-date? It's to print and use as a poster. It can be in a book, article, website,... The best would be if it could have little drawings for species examples, derived characteristics, and maybe other features like that. Thanks!! —The preceding unsigned comment was added by 84.55.198.228 (talk) 02:39, 4 February 2007 (UTC).

Try the tree of life project. --JWSchmidt 23:31, 4 February 2007 (UTC)

Look at Phylogenetic_tree, but the images here are more useful as a page in a book rather than having the amount of detail presented on a poster. GB 23:50, 4 February 2007 (UTC)

Given issues with copyright from other sources it might be a good idea to construct your own..87.102.8.103 12:40, 5 February 2007 (UTC)

Methadone and Anestesia?

Is it safe to be a methadone patient (receiving methadone on a daily basis) and undergo surgery with a general anesthesia such as Propofol? I'm not asking for any kind of advice, diagnosis, nor would I have surgery while being on any kind of drug without first discussing it with my Doctor. I just would like to know if there are any problems or interactions with general anesthesia that is most commonly used and methadone. I'm sure there are tons of medications used, but there must be one that is commonly used such as Halothane or Propofol. Thanks

Sniggity 05:54, 4 February 2007 (UTC)

I think you are asking a question that could pretty much only be answered by a qualified anesthetist, I don't know if there are any that read this board. I'm sure methadone patients have undergone surgery but as to how safe or which anesthetic is used, I have no idea. Vespine 10:58, 4 February 2007 (UTC)

Fin Dimensions

Greetings... For a rated average power of 3 KW and frequency range of DC to 3.0 GHZ, what fin dimensions would I require in my heat sink??? As the coolant I would use Silicone oil, capacity of 1 Gallon Load resistor would be of 10-12 inches and Diameter would be 12-15 mm. All this is for building a RF Load as a part of engineering curriculum. —The preceding unsigned comment was added by 203.187.198.42 (talk) 06:45, 4 February 2007 (UTC).

Sounds like homework. But for starters, don't you need to know the temperature requirement of the load resistor or temp limit of the oil or other components? --Tbeatty 07:08, 4 February 2007 (UTC)

We absolutely need to know the max allowable temperature of the oil and the resistor, and also the ambient temperature (how hot of a room will it be in) and whether there is air circulating or not. Also, do you want it to be able to run continuously, 24/7, or will it have , say, a 50 % duty cycle, or be rated for 10 minutes of operation. As a refinement, will it be in the sun or in the shade, and if in the sun, what color will it be. As a thought experiment, I compare it to a distribution transformer with say a 4% loss at full load. Your 3 KW heat dissipation would then require about the same radiator as a 60 kilowatt transformer, which is HUGE compared to a 1 gallon paint can. Another comparison: [7] says an electric range burner uses about 800 watts, fso your device would need enough radiationg surface to siddissipate the heat of almost 4 range burners. 3000 amps is 12.5 amps at 240 volts, so you have a very large amount of heat to dissipate. I would go with a cooling fan. Your device wilkl heat up like two 4 slice toasters per the site listed. To avoid overheating you will need a large area of copper or aluminum fins connected to the can in such a way heat is efficiently transferred (soldered? Or tight fit with the special grease they use on top of PC chips to connet them to the heatsink.? (Someone who took a course in thermal engineering, should the radiator fins be painted black? And there will still be a tendency for the oil to overheat and expand, if you only have convection inside the can, so the top of the resistor might get excessively hot. Could you install a thermometer or thermocouple or an oil temp thermometer? Edison 23:23, 4 February 2007 (UTC)

Firstly, I must apologize. I will operating at 600 Watts average and not 3KW which I errenously mentioned. Secondly, Thanks for responding. The max. allowable temp. of the oil is 250 degree Celsius and the resistor of about 200 degree celsius. NO, it wouldn't run 24/7 and ambient temp. would be 30-40 degrees depending on the climate.

Names for bioluminescence in the ocean

Are there any common (non scientific) names for bioluminescence in the ocean? (Note that Milky Sea is thought to be caused by bacteria, not by bioluminescencing plankton.) Thanks for your help. S.dedalus 06:47, 4 February 2007 (UTC)

There is in Norwegian, Danish, German, and possibly also Turkish. My Norwegian-to-English dictionary has no entry for the word. Google translate translates Meeresleuchten (German) to "Sea lights", but that is simply a literal translation, I have no idea whether it's actually used. According to the German wikipedia, these "sea lights" play a key role in this children's novel, so if anyone's got a copy, they might check how it has been translated. --NorwegianBlue ^talk 15:42, 4 February 2007 (UTC)

Wormholes in 3d space

Wormholes are commonly represented in images explaining them as 2d holes or tunnels, however, because space is 3d, and not 2d, I am having difficulty visualizing. How are things like wormholes represented in 3d, rather then the 2d represention. (like the warping of space time due to a massive object like the sun is shown as a ball on a plane).--Honeymane_{Heghlu meH QaQ jajvam} 08:15, 4 February 2007 (UTC)

Notice how it takes 3-D to "visualize" the bending of 2-D space. So it will take at least 4-D to visualize the bending of 3-D space. Can you visualize in 4-D? --Spoon! 10:45, 4 February 2007 (UTC)

The reason that it is difficult to visualise could be that a worm hole is impossible in 'conventional' 3D euclidean space - (I'd imagine that you visualise things in 3D euclidean space - I do anyway). I could say it's difficult to imagine because they don't exist...87.102.35.119 13:18, 4 February 2007 (UTC)

developement of SPRING stl?

<email removed> —The preceding unsigned comment was added by 12.72.54.244 (talk) 12:52, 4 February 2007 (UTC).

Please try to write a coherent question.. Did you mean 'can I have more info on the development of spring steel? (if so you may wish to look at the crucible steel and puddling process Please clarify?87.102.35.119 12:59, 4 February 2007 (UTC)

ARUUN SINGH

what are the benefits of swallowing human semen? —The preceding unsigned comment was added by 221.134.58.58 (talk) 14:16, 4 February 2007 (UTC).

The Master has already addressed one aspect of this question; see here. —Steve Summit (talk) 14:50, 4 February 2007 (UTC)

Less messy than any other method of oral evacuation? Rockpocket 07:48, 5 February 2007 (UTC)

And of course the possibility of gratitude if the donor is of the mind that any other method is some kind of insult.

Bird identification and image request

Hi, does anyone recognize this bird? Could a better image that's more suitable for printing be made? (It wouldn't have to be the same species, but I wonder if finding a bird with all the features would be easy.) Thank you. :) --Kjoonlee 14:57, 4 February 2007 (UTC)

Is it the dreaded caption bird, who skewers would-be predators with sharp words, like a verbal porcupine? Clarityfiend 19:07, 4 February 2007 (UTC)

I too would like to point out it's the green diagram bird (birdus diagrammaticus) - seriously it looks a lot like a finch, or tit - a passerine. I doubt it would be difficult to find and alternative - as long as the species has wing bars your in luck.87.102.8.103 11:17, 5 February 2007 (UTC)

Yes, it's almost certainly a composite made up for the purpose of labelling. See insect for a really weird composite insect!--Shantavira 19:43, 4 February 2007 (UTC)

Heh. :) The original uploader has responded to my inquiry.

Hi, this image was meant to describe the most important characteristics to the anatomy of a common (passerine) bird, and not to represent an actual species. However, this fantasy bird was loosely based on the anatomy of the chaffinch (although the colors do not match). I do not have a higher resolution version of this image, nor do I have an unlabeled version. Sorry. :-(

So I guess that's enough info to get someone to come up with a better image.. :) --Kjoonlee 15:06, 5 February 2007 (UTC)

history of nitroglycerine as a medicine for heart pain

Hello- I am writing a historical novel set in the 1880's. One of my characters has heart pain (angina), and takes nitroglycerine for it. Is this appropriate for the times? I know that it had been discovered, and was being used as an explosive, but when did it start being used as a medicine? Thank you for your help.

Sincerely,  Irene Wolf 16:50, 4 February 2007 (UTC)

I am not sure myself, but I think the article, Glyceryl trinitrate (pharmacology) may have what you are looking for. - Dozenist talk 16:55, 4 February 2007 (UTC)

William Osler mentions it in his 1892 Principles and Practice of Medicine as an alternative treatment to amyl nitrite, which either he preferred or was the standard treatment of the time. The wording might be interpreted that nitroglycerin was relatively new and not universally considered standard. alteripse 17:11, 4 February 2007 (UTC)

You're in luck. According to [8], it was first used for angina in 1879. Clarityfiend 17:56, 4 February 2007 (UTC)

Off on a slight tangent but the topic reminded me of this Darwin Award story... --Kurt Shaped Box 18:58, 4 February 2007 (UTC)

That raises another question. Who thought this up? Let's treat heart pains with...a dangerous explosive. An ancestor of Dr. Kevorkian? Monty Python? Clarityfiend 20:12, 4 February 2007 (UTC)

A short history of nitroglycerine and nitric oxide in pharmacology and physiology. --JWSchmidt 23:17, 4 February 2007 (UTC)

Dioxygen leak?

Is it true that a major dioxygen leak could have drastic effects on local plant and animal life? Is it true that leaks of this type have occured all over the country leaving very high dioxygen levels in the atmosphere? Isn't this hazardous?

See dioxygen. See also dihydrogen monoxide. TenOfAllTrades(talk) 19:59, 4 February 2007 (UTC)

It's definitely a fire hazard. And I've heard that everyone who breathes it, expires. Clarityfiend 20:13, 4 February 2007 (UTC)

Dioxygen is a good oxidizer, and therefore can be very dangerous in the presence of a fuel and ignition source. -- mattb @ 2007-02-04T20:35Z

But it is nothing compared to dioxin which comes from PCB. Edison 23:01, 4 February 2007 (UTC)

Well that's true, even literally! No one lives forever!

Funnily enough, our atmosphere is 20% dioxygen! —LestatdeLioncourt 14:46, 5 February 2007 (UTC)

mmmm mmm smell that beautiful dioxygen! i dont know man but for some reason i think you need to double check your sources lol you might find the extra info useful that is if you havent done so already. Maverick423 16:02, 5 February 2007 (UTC)

Dioxygen is just oxygen —The preceding unsigned comment was added by 88.109.41.162 (talk • contribs).

No, dioxygen is O₂. There is a difference between a molecule and an element, even if we are being silly and pedantic about it. -- mattb @ 2007-02-06T06:39Z

Free radical bromination of ethane

I already looked at the articles related to this subject, (free radical halogenation, and ethane) but I'm not sure I understand the initiation, propagation, and termination mechanisms behind it. Is there a visual examination for the free radical bromination of ethane that anyone knows of?

free radical halogenation has the answers - could you be more specific as to what you don't understand/want explaining.

Also I don't understand what you mean by 'visual examination' - do you mean a page with images to explain the process, or a way visually of telling if the process is occuring or something else?87.102.8.103 11:21, 5 February 2007 (UTC)

Can't afford the real thing, so I make doo with sham poo

When my shampoo runs low, I leave the bottle turned over, so the last dregs accumulate at the cap. But I've noticed that it seems to eat the plastic in the cap (the color runs into the shampoo). What causes it? Is this harmful? Clarityfiend 20:20, 4 February 2007 (UTC)

Wow, what are you putting in your shampoo?! [Mαc Δαvιs] X (How's my driving?) ❖ 14:30, 5 February 2007 (UTC)

i think your using bleach as shampoo... nah just kidding its that thing that helps clean your hair thats causing that. its not harmful (unless swallowed ((or left on your hair for a long time))). Maverick423 16:04, 5 February 2007 (UTC)

Lots of the chemicals in shampoo disolve other chemicals, so it could be one of these causing this:(

Some of these chamicals also disolve the proteins that hair is made from, so it probably isn't a good idea to wash with it at all:(

It's a nationally-marketed brand, not some weird generic glop. Oh well, I suppose the company may be saving money by using a cheaper, less durable plastic for the top. Clarityfiend 22:03, 5 February 2007 (UTC)

jaw injury

What is the likelihood that a serious injury to the upper jaw, would subsequently cause a person to be reported as a chronic drunk? Consider the effect upon motility of the tongue, and the distinct possibility of affecting the inner structures involving balance. — Preceding unsigned comment added by 71.104.2.173 (talk • contribs) 20:50, 4 February 2007 (UTC)

What is the likelihood? ?? Is that a serious question? What kind of answer do you want? The likely hood is unlikely? or, maybe a one in ten? Or do you want to discuss the various conditions? If it is dark and the observer is himself drunk then the likelihood is higher then if the subject is in an operating theatre being examined by physicians. Serious injury seems to imply some sort of pain and breakage if not bleeding, those are going to be hard to mistake for drunkenness. I work with a guy who has sclerosis and he was refused entry into a bar once because the bouncer thought he was drunk, no kidding.. So I guess it's not impossible. Vespine 21:30, 4 February 2007 (UTC)

Given that someone with a recent serious jaw injury would be either - bleeding or screaming in pain - I'd say it's unlikely. They'd probably also be pointing to their jaw as well and be saying something like 'I've got a serious jaw injury - please help me..' - whereas a chronic drunk would stink of beer, smell of urine and probably be singing 'auld lang syne'...87.102.8.103 11:25, 5 February 2007 (UTC)

It is phrased like a homework question. I feel sorry for the student-- if actually provided as cited, it is a question so poorly phrased that we are all guessing at the real intended question. My guess is that the teacher is asking, "An injury to what part of the vocal apparatus would produce speech that would sound like drunken slurring to most people." The answer is a stroke or an injury to the brain would be the best mimic, because most of us can readily tell the difference between defects of central speech processing and defects of articulation. If the answer is to be restricted to the area of the upper jaw, it would be an injury to efferent motor nerves controlling tongue, mouth and palate. Good luck to the student. alteripse 14:14, 5 February 2007 (UTC)

Damage to the inner ear, which is very possible in an upper jaw punch, could cause damage to the semicircular canals, which measure the orientation of the head. Damage to the canals causes loss of balance and difficulty walking, just like alcohol. Laïka 21:25, 5 February 2007 (UTC)

Well I suppose whatever had injured the upper jaw might also have caused other problems, like concussion. People with head injuries can be mistaken for being drunk, as occasionally happens in police stations and hospitals on Friday nights in town centres... Skittle 23:17, 5 February 2007 (UTC)

Fermi Problems

When I get fermi problems, do I have to use my "own basic knowledge and experience" or am I allowed to look stuff up? I don't know how much cheese France consumes every year/day/month! How do I guess that? --JDitto 23:18, 4 February 2007 (UTC)

One of the purposes of a Fermi problem is to get an idea of scale and the approximate magnitude of the answer, it is not intended to be that accurate. I don't know how many people live in France off-hand, but I might guess 20 million based on size relative to some US states and given Europe has a higher population density. The average person eats maybe a half-pound of cheese a week. 20 million people * 0.5 pounds cheese week/person = 10 million pounds per week, or roughly 1 million pounds a day, which is undoubtedly totally wrong, but I have some confidence that it isn't under 100 thousand per day, or over 10 million. On actually looking at the France article, my estimate is off by three times, but the magnitude of my estimate didn't change significantly. Atropos235 03:02, 5 February 2007 (UTC)

Have you read our article on Fermi problems? As that article explains, you typically work with just a bunch of guesses. Certainly you can't look up the final answer -- if you could, it wouldn't be a Fermi problem -- and for the intermediate numbers leading up to the answer, most are either educated guesses, or "basic knowledge and experience". (In the "number of piano tuners in Chicago" example in the Fermi problem article, the only quantity you could easily look up is the number of people in Chicago; all the rest of the numbers are pulled out of the air.) The point of the exercise is usually to come up with a quick estimate, without doing any research, and perhaps at the same time to discover which potential avenues of research might be used to obtain a more accurate (non-guessed) answer later. —Steve Summit (talk) 02:50, 5 February 2007 (UTC)

[P.S. It occurs to me in light of recent debate that the Fermi problem approach -- pulling a bunch of numbers out of the air, and combining them with some basic knowledge and educated guesses -- is precisely what Wikipedia's verifiability policy suggests we shouldn't be doing in answering questions on the Reference Desk... :-)]

I just need to know what I'm allowed to look up. I know I'm not allowed to look up the answers, so I want to stay away from reading the article itself right now. Thank you so far, though.--JDitto 05:37, 5 February 2007 (UTC)

Wait -- you're not allowed to read the articles on cheese or France, or you're not allowed to read the article on Fermi problem??

I'd say the short answer is, no: for a proper Fermi solution you shouldn't look anything up. Background knowledge, armchair speculation, and erudite pontification only. —Steve Summit (talk) 12:37, 5 February 2007 (UTC)

Fermi problems are problems where you are not able to calculate the answer, given the proper information. You are allowed to look up whatever you want, but at the end you will have to estimate a plausible answer anyway. Mr.K. (talk) 18:26, 5 February 2007 (UTC)

I would say that a fermi problem should only include information known to you or easy to find and integral to the problem. so for the france one it seems fine to look up the pop of france. its a matter of effort and time not deliberate limitation of knowledge. Beckboyanch 02:44, 7 February 2007 (UTC)

Okay, this is what I got for the "France eating the Moon", looking up as many non-internet sources as possible:

• Earth's Mass: 5.9 X 10²⁴ kg
• Children's Astronomy Book: Earth is 50X bigger than the Moon.
• Therefore: (5.9 X 10²⁴) / 50 = 1.18 X 10²³ kg

• MAYO Food Guide Pyramid says that 2-3 servings of milk group everyday.
• Each serving = 1 1/2 oz. of natural cheese
• 1 oz = 28.35 g
• Therefore: 2.5 X 28.35 = 70.875 g cheese eaten by a person per day, .0070875 kg

• France's population found in Encarta Encyclopedia: 58,609,285
• That's approximately 59 X 10⁶ people

• So the rate of consumption is: 59 X 10⁶ people X .0070875 kg = 418 163 kg consumed per day.

• In the arithmetic series equation, I'd have to solve for n.
• $a_{n}=a_{1}+(n-1)d$ would become $n=(an-a1)/d+1$.
• Then it would be $n=(1.18X10^{23}kg-418163)/418163+1$
• So it would take France 2.82 X 10¹⁷ days to eat the moon.

What do you think?--JDitto 07:04, 6 February 2007 (UTC)

Planet Rotations

Why do all of the planets (and many other stellar objects) have somewhat parallel orbits around the sun? Why aren't there things orbiting the sun that are more perpendicular to the orbit of the planets? Imaninjapirate^{talk to me} 00:55, 5 February 2007 (UTC)

The prevailing theory (Planet#Formation) has the planets forming from a nebula condensing into a thin disk rotating around the proto Sun. There are things orbiting outside this narrow plane, but they're just not big things. Clarityfiend 01:06, 5 February 2007 (UTC)

When matter starts to gather up, it tends to flatten in the shape of a disc, what we call protoplanetary disc (see article for a good explanation of why this happens.) This is how solar systems form. Most of the big objects in our solar systems were formed this way, that's why they all tend to have roughly the same orbital plane and move at the same direction. Smaller objects, however, are easily disturbed and have less-stable, irregular orbits. That's why smaller moons and asteroids have highly inclined orbits and all that. — Kieff | Talk 01:19, 5 February 2007 (UTC)

The flattening of a nebula into a protoplanetary disc is simply a case of the conservation of angular momentum. It is exactly the same reason why an ice skater spins faster when they pull their arms in closer to themselves. Carcharoth 02:01, 5 February 2007 (UTC)

Correlation of events...?

Where can I find the correlation between eating a big meal followed by a heart attack? 71.100.10.48 02:41, 5 February 2007 (UTC)

This study found that:

Of the 158 patients who reported eating an unusually heavy meal during the 26 hours before their attack, 25 of them had the meal in the two hours right before the attack. Only 6 patients had their big meal in the corresponding two-hour period the previous day. By comparing the two time-slots-24 hours apart-the study controlled for the possibility that time of day, and not the meal itself, was the trigger. The remaining patients in the group of 158 had their heavy meal at various other times in the 26 hours before the heart attack, but no other time-slot emerged as significant.

Rockpocket 07:41, 5 February 2007 (UTC)

Unknown disease

Anyone know of a disease nicknamed drop(s)? --The Dark Side 02:52, 5 February 2007 (UTC)

Dropsy? —Steve Summit (talk) 02:55, 5 February 2007 (UTC)

Reversed West and East on the Moon?

Hi - I read somewhere years ago that West and East are reversed on the Earth's Moon as a result of astronomers projecting our own West and East onto it - but now I can't find references to that idea anywhere - am I looking in the wrong places, or am I totally mistaken?

Thanks Adambrowne666 03:16, 5 February 2007 (UTC)

Having a look at these two images: Western Hemisphere and Moon surface. It seems like they are not reversed. - Akamad 05:20, 5 February 2007 (UTC)

That's what I keep finding too - I've got such a strong impression of this notion, but can't find evidence of it - I wonder if it has always been the way it is now - is it possible early astronomers mapped it that way, and it has been switched since? Adambrowne666 10:49, 5 February 2007 (UTC)

It's an intersting point you make - it depends on how you define east and west - for instance does the sun always rise in the east? Is east defined by the rotation of the body? The earth and moon are separate bodies so it's difficult to say what is east on the moon??87.102.8.103 11:29, 5 February 2007 (UTC)

It is either based on the rotation of the body, or the Earth as a reference. [Mαc Δαvιs] X (How's my driving?) ❖ 14:31, 5 February 2007 (UTC)

It might have something to do with the fact that astronomical telescopes invert the image. Since reverting the image will degrade it, astronomers have gotten used the inverted images, to the point that even their drawings are inverted. This would mean that "west" is on the right. Perhaps this is what the questioner has in mind. (But before you take this to the bank, this is remembered from when I was an astronomy buff, about 35 years ago. Maybe 'scopes have changed in the meantime). Bunthorne 06:40, 6 February 2007 (UTC)

Why would reverting the image degrade it? Surely a digitally stored image could be spatially inverted in a lossless fashion. I suppose you couldn't do it with an analogue form like a photograph, as you'd have to produce a new photograph from it, which would be a copy of a copy. Maelin (Talk | Contribs) 04:09, 7 February 2007 (UTC)

only eating vitamins

What would happen if I stop eating conventional food and only eat vitamins? Would I die? What if I also eat sugar? Thank you. Renaud Miclette Lamarche

From nutrition: "There are six main classes of nutrients that the body needs: carbohydrates, proteins, fats, vitamins, minerals, and water. It is important to consume these six nutrients on a daily basis to build and maintain healthy bodily function." If you take vitamins, that'd cover vitamins.

And from Sugar#Health_concerns, "The panel [at WHO] stated that the total of free sugars (all monosaccharides and disaccharides added to foods by manufacturers, cooks or consumers, plus sugars naturally present in honey, syrups and fruit juices) should not account for more than 10% of the energy-intake of a healthy diet, while carbohydrates in total should represent between 55% and 75% of the energy-intake."

So the short answer is, no. --Wirbelwindヴィルヴェルヴィント (talk) 04:02, 5 February 2007 (UTC)

YOu need some dietary fiber too. --Shantavira 08:15, 5 February 2007 (UTC)

Vitamins are part of the group called micronutrients (along with minerals), which are needed in doses of milligrams or micrograms. Vitamins are needed for the body to be able to do properly some of its functions. Macronutrients, that is lipids, carbohydrates and proteins are the bulk of our needs (doses in the order of magnitude of grams), and they provide energy. If you only ate vitamins you would be lacking almost all the daily energy intake and would become weaker and weaker in a very short time span (maybe less than 3 weeks) and with die of hunger. --Taraborn 10:10, 5 February 2007 (UTC)

You don't actually need polysaccharides, fat or protein for energy, but proteins are useful for other things instead

mitosis and meiosis

do you have any draws of meiosis and mitosis?

Meiosis and Mitosis? Splintercellguy 03:43, 5 February 2007 (UTC)

Gummy Bear Rocket

I’m having a contest with my buddies to see who can make a device that can fling/shoot/launch a gummy bear the farthest, anything goes. I seem to remember a demonstration that rocketed a bear after it (the bear) was heated. Ring any bells? Thanks --Willworkforicecream 04:55, 5 February 2007 (UTC)

You might want to see our article on Sabots. With such a device (and perhaps a railgun), I'd imagine you could impart nearly unlimited velocity to your Gummy (former) bear.

Atlant 12:48, 5 February 2007 (UTC)

I would think that in order to have a contest, the bear would have to be a projectile in its natural state, and impact with full gumminess. Otherwise, you could just pour a melted gummy into a hollow-nose bullet, and fire away! --Zeizmic 13:12, 5 February 2007 (UTC)

If anything really goes, how about sending the gummy bear by air mail to someone living on the other side of the earth? It will have flown most of the way. Or figure out some other way to get the gummy bear on an airplane.

To beat even that, you'll need a friend who works at NASA and owes you a big favor. Unfortunately, you missed your best chance by just over a year. —Ilmari Karonen (talk) 13:09, 5 February 2007 (UTC)

Today they told me that "anything goes" means anything mechanical goes, so chemical, magnetic, etc. isn't allowed any more. Wusses, they were just scared of my coilgun idea. --Willworkforicecream 19:06, 5 February 2007 (UTC)

You could build your own scale model of an aeroplane, and stick it to that

Well, if you aren't allowed any chemical or magnetic you can't use anything with an engine, I'm thinking: "What did people use to fling things far before engines and explosives and stuff?". I'd be investigating trebuchet and catapault. Vespine 21:50, 5 February 2007 (UTC)

You could try a stomp rocket or a water rocket. Theresa Knott | Taste the Korn 21:57, 5 February 2007 (UTC)

Hmm a red link! See here Theresa Knott | Taste the Korn 21:59, 5 February 2007 (UTC)

And I've turned it blue. If anyone wants to help edit our brand new stomp rocket article please feel free. Theresa Knott | Taste the Korn 22:33, 5 February 2007 (UTC)

Thanks for the ideas. I think that I'll go with a trebuchet because they're awesome. I'll blow everyone out of the water by putting the bear inside of a bouncy ball that will bounce and roll to gain extra distance. --Willworkforicecream 18:51, 6 February 2007 (UTC)

That might be an excellent idea, if the terrain downrange is such that the ball will bounce nicely on it. If the terrain was, say, loose sand, I'd suggest a (mostly) solid iron/steel ball instead: maximizing the density of the projectile minimizes the effects of atmospheric drag. In any case, you may want to experiment with balls of various sizes and materials. Denser is still better, but elasticity will count a lot too if you go for the bounce. The optimal size of the ball (for a given material) will depend on how powerful your launcher is: too big and the initial velocity will be low, too small and you'll lose speed to drag; a back-of-the-envelope calculation of the optimal mass would be a nice physics exercise, but in practice an empirical approach will probably work just as well if not better. I'd expect a fairly large superball might do well, if you can get the gummy bear inside it without ruining its bounce. —Ilmari Karonen (talk) 20:13, 6 February 2007 (UTC)

a weed pest called Wolsia or Wollsia

This pest is growing in our dam and we cannot find a way to get rid of it - the plant has been identified by the Department of Natural resourses Queensland but they have no knowledge of how to kill it Gwen Kelly

I can't find any info on those two names, I don't think you have spelt it right. If you can't find the correct name, would you be able to upload a photo here? Thanks. --liquidGhoul 12:46, 5 February 2007 (UTC)

woollsia in Ericaceae  ?87.102.8.103 18:02, 5 February 2007 (UTC)

Most pest plants aren't easy to kill - that's why they become pests - you need to find out how it can regenerate - for instance some plants can survive fire / chopping down - because they have a rhizome - the plant regenerates from the rhizome - is this is the case one way to proceed is to keep chopping it down - eventually the store of energy in the rhizome will be used up and the plant die.

You could try using a strong weedkiller - killing everything - don't forget to salt the ground as well.

An alternative is to add an even more invasive species that out grows it.

Or if you are lucky a pest that kills the plant can be found.

It's difficult to beat nature though.87.102.8.103 18:15, 5 February 2007 (UTC)

You're evil. – b_jonas 20:45, 6 February 2007 (UTC)

Han and Hong classification of inverted nipples

This classification is used by plastic surgeons to classify the three main types of inverted nipples. The Han and Hong classification is often cited in journals. I would like to know when this classification first came into effect, the first time it was published and where and also who owns the copyright to this classification. Thank you. Dharani.

Look at the last journal article in which you saw it cited-- it likely contains the reference that answers your question. alteripse 14:05, 5 February 2007 (UTC)

Hyperbolic cooling

Do the huge "hyperbolic cooling towers" seen in power stations actually utilize a section from the perfect shape of hyperboloid? If so, how close to the shape is it? And how does this system improve water cooling efficency?Wbchilds 10:15, 5 February 2007 (UTC)

I can't answer your first two questions. But the reason for the shape is one of structural integrity see Cooling_towers#Cooling_Towers_of_Nuclear_Reactors The shape is chosen for it's stabilty not to improve cooling efficiency. (Not sure if that was your question)87.102.8.103 11:36, 5 February 2007 (UTC)

Projectile Motion

I'm currently doing a prac write up for year 12 Physics. At the moment I've hit some what of a road block. I'll try to describe the problem. A projectile is fired from a table (same height as the table) at a 45° angle, the projectile lands on the ground 2.54m away. The table is 0.75m high. The speed of the projectile is unknown, the time of flight is unknown. Is it possible to work out how far away from the origin the projectile is when it comes in line with the table. Heres a diagram I drew in MS Paint to help illustrate the problem:

The green question marks indicate the value I would like to know. Oh yeah, I almost forgot, Ignore air resistance.

P.S. If anyone works this out could they please tell me how because I would also like to do this with my measurements of other angles/distances.

P.P.S. This isn't really counted as "answering my homework" because we aren't required to put this info in our prac report, I simply want to enhance it.

Yes you can. First, if you were given the initial velocity, angle (which is known), and the time after firing, can you calculate where (x,y position) the projectile is? If so, you have a known (x,y) position of the projectile at some point (the position where it hits the floor, relative the the firing position). From that you should be able to solve for the initial velocity and time after firing (2 equations with 2 unknowns). With the initial velocity and angle, you should easily be able to solve your problem. --Spoon! 12:09, 5 February 2007 (UTC)

(edit conflict) Well, ignoring air resistance, the trajectory is a parabola, which, in general, is described by the function $y(x)=ax^{2}+bx+c$, with the first derivative $y'(x)=2ax+b$. Setting the origin to the starting point on the table, we have $c=0$, and the starting angle tells us that $y'(0)=b=1$. The remaining condition is that $y(2.54)=a(2.54)^{2}+2.54=-0.75$, which can be rearranged to give $a=-(0.75+2.54)/(2.54)^{2}=-0.51$ (approximately). Solving for $y(x)=-0.51x^{2}+1x=0$ the usual way, we get $x=1/0.51=1.96$ (again approximately). Depending on how pedantic your teacher is about significant figures, you may need to round that up to $2.0$ meters (since the table height was technically given only to two significant digits), though in practice I'd consider the three-digit figure a more useful answer. Ps. If you do use these answers in your report, remember to be nice and credit the reference desk. —Ilmari Karonen (talk) 12:36, 5 February 2007 (UTC)

science in transportation

information of what science contribute in transportation. — Preceding unsigned comment added by 210.186.3.142 (talk • contribs) 14:37, 5 February 2007 (UTC)

I guess you mean "information from which sciences contributes to transportation (technology)." - if so the answer includes engineering primarily, computer science in modern computer controlled systems, mathematics - various models not related to engineering eg queueing theory, chemical engineering and metallurgy contribute to materials used in construction of transportaton devices, social sciences may also help in the design of public transportation systems, geography and geology relate to the way the transport network is built, meteorology is important easpecially in sea and air travel, in fact most of the common practical sciences contribute in some way.87.102.8.103 15:29, 5 February 2007 (UTC)

To measure distances on earth

I woud like to know how i can measure shortest way from a place to an other, for exsamble from boston to london.Any solution for this.

hp

If you know the latitude and longitude of the two places, and you assume the earth is spherical it's quite simple.

First calculate the angle between the two places, using the latitude and longitude (relative to the centre of the earth. If you don't know how to do this please ask about it.

Then multiply the angle(in degrees) by 2πR/360 - ie Anglex2πR/360 this is the length of an arc(geometry) which subtends an angle of A - that is the distance 'as the crow flys' - R is the radius of the earth.

If you want the absolutely shortest distance from A to B (ie though the earth's crust in a straight line the distance is 2Rsin(πA/360) 87.102.8.103 16:30, 5 February 2007 (UTC)

See the articles Great circle and Great-circle distance. The second article describes a method which uses a sphere to approximate the shape of the earth, and the article claims a maximum error of about 0.5%. The problem of finding a geodesic on an oblate spheroid is much more complex and cannot by solved analytically.

For calculating the shortest distance between two points along a straight line running beneath the surface, convert the latitude and longitude of the two points to earth centered, earth fixed coordinates:[9].—eric 16:59, 5 February 2007 (UTC)

isn't the cross section of the earth elliptical, meaning the difference from the equator streight up is proportional to the distance from a line between the poles outward

Is denatured alcohol 100% volatile as a solvent?

If I were to extract some essential oils from lavendar using denatured alcohol, would it completely evaporate (like acetone or high grade ethanol)?

typically no. If it's surgical spirit no - it leaves an oil behind. If it's purple 'meths' no it leaves a purple residue.

You should be able to get denatured alcohol that does not leave a residue (I assume to avoid having to pay tax) if you seek it out specifically - that could be ethanol with only methanol in. Find a supplier (chemical or similar - and tell them what you want)

Alternatively you could distil some other denatured alcohol to get a residue free liquid (obviously this is a potential hazard and may even require a license to do..) and the distillate may carry over some impurities.

Or it's possible to use alternatives such as propanol.87.102.8.103 17:22, 5 February 2007 (UTC)

Pissing too often

i recently switched from sitting down when i piss to standing up. all of a sudden, it seems like i need to take a leak too often. could it be because sitting down empties my bladder better or is this a sign i could have a serious male medical condition.. i dono prostate colorectal something like that? do i need to see the doctor? i dono why im asking all these questions.. shouldn't i just switch back to sitting and see if the problems stops?

There are lots of different causes of needing to piss more often - including mild infections, over injestion of diuretics (eg coffee), psychological reasons and more serious problems and diseases. As I/We can't see you and check your general health or ask about what other factors may be an issue it's really impossible to give you an good answer.

If it's a problem eg you can control your bladder (wet yourself), or are pissing many times more often than you should you should see a doctor - definately.

However if the difference in the amount of pissing you are doing is trivial - Could it be because it's easier to piss standing up that's why you go more often?

I'd recommend you go and see a doctor - and ask them about it. They usually give you a look over anyway so you should get some feedback on your general health as well as getting an answer to this problem.87.102.8.103 19:44, 5 February 2007 (UTC)

Hmm Could be diabetes. Go to see a doctor soon! —The preceding unsigned comment was added by 88.109.41.162 (talk • contribs).

Dog breeds -- Help!

Why are chihuahua, poodle, pit bull, labrador retriever, and alaskan husky considered different breeds of the same species, while lions, mountain lions, tigers, jaguars and leopards considered diffirent species of cat? they seem equally unsimilar to me. our Species article says something about a species being a group of animal that can succesfully reproduce and produce fertile offspring. is it even possible for chihuahua and the large domestic dogs reproduce togeher!? if so, is that what makes them one species? and thers so many species of jackal, coyote, and wolf. why arent they lumped together? they cant interbreed?

members of a specis also have to have physiological, morphological, biochemical and behavioral similarities, but this is mostly just for taxonomy which hardly anyone uses now

This discussion cover some aspects of dog breeding. However, the major difference is that the dogs you list are domesticated, while the felines are not. And thus the generation time since the last common ancestor of the dogs is much, much shorter than the last common ancestor of the cats. The cats have become speciated, the dogs have not. Rockpocket 20:00, 5 February 2007 (UTC)

All breeds of dogs -- even a chihuahua and a great dane -- can reproduce and create fertile "hybrids". The fertility of the feline species in question is a bit more complicated, however. Also note that, for example while a coyote and a wolf can interbreed, their offspring tend to be less fit than a pure-bred and often die in the wild, whereas an interbred dog has about equal survival-ship (i.e. fitness) as a pure-bred. Check out speciation and hybridization. --Cody.Pope 07:50, 6 February 2007 (UTC)

Do you have data for the assertion "an interbred dog has about equal survival-ship (i.e. fitness) as a pure-bred"? The common held belief is that a mongrel has a greater fitness than a pure-bred, due to a reduction in inbreeding depression. While I'm sure that isn't the case all the time, I would propose that on average, first generation outbreds would be fitter than first generation inbreds, due to a reduction in homozygosity. Rockpocket 07:45, 7 February 2007 (UTC)

On that note, have a chihuahua and a great dane ever mated and produced offspring? I'd imagine the mother would have to be a great dane, as great dane puppies would probably be too big for a mother chihuahua... but then how would a male chihuahua... erm... "reach" the female great dane? And what would the offspring look like? --Candy-Panda 09:27, 6 February 2007 (UTC)

I don't know if they have done it, but usually when breeders try to mate two creatures of very different sizes, they use artificial insemination. Certainly, new cat and dog breeds are sometimes started by crossing existing breeds. Skittle 00:41, 7 February 2007 (UTC)

Using digital sound recorder as decibel noise meter?

I've just bough a digital sound recorder - a Tevion Digital Voice Recorder ET-880 to be exact. It can communicate with a computer via USB. It can record in "ACPCN", "ACTPC", and possibly "WMA" sound formats. I'm wondering if I could use it as a decibel noise meter by measuring the average sound intensity when the recorded file is transferred to the computer? — Preceding unsigned comment added by 62.253.44.193 (talk • contribs) 22:16, 5 February 2007 (UTC)

(This answer is aimed at digital audio recorders in general, not this specific one which I only find very little information about.) I don't see how you could end up translating this into db. For one thing, whatever mic is built into the recorder is going to have certain compression characteristics. Also, the level of the sound in your digital recording is going to depend on where your level was set when you recorded, assuming the recorder lets you do this. Long story short- I think in order to measure sound pressure levels, you need a device specifically intended for this. Friday (talk) 22:34, 5 February 2007 (UTC)

You you do, do you? And what do you knoew about anything/ —The preceding unsigned comment was added by 88.109.41.162 (talk • contribs).

All the same I have known professional noise pollution specialists use a calibrated mic (don't know how calibrated, don't know brand) and a high quality portable recorder (Nagra back in the analog recording days) to record ambient sound on site before a plant is built, then run it through an analyzer back at the lab to determine the dB of noise pre- and post- plant operation. If they had just stared at a meter dial and written down the dB of ambient noise before the plant was built, they could have waited until a truck went by. If someone doubts the high pre-plant noise level, they can haul out the tape and show that it was the pig farm, birds, or bullfrogs. In general mics do not compress sound in the usual sense, but they have a certain gain, like -50dB and a certain frequency curve and directionality which has to be taken into account. The trick would be having a calibrated mic with a calibrated preamp, so that a certain sound pressure level produced a certain level n the recording, then to filter the sound per the applicable Weighting filter to get dbA, for instance. See Weighting filter and decibel for more info and more links. If the desire were to use the system for litigation or environmental health legal applications, an ad-hoc system would be subject to criticism, but if it were to satisfy curiosity, you might be able to conjure up a system. Edison 00:47, 6 February 2007 (UTC)

Quality of radio reception dependent on where I stand

When I have the radio on in my room, sometimes the reception is good when I stand in a certain spot (even in a certain position) and turns crappy as soon as I move from there. How does this happen and is there a (easy) way to improve the reception? Thanks Lukas 22:32, 5 February 2007 (UTC)

Yeah dont stand where the sound is crappy —The preceding unsigned comment was added by 88.109.41.162 (talk • contribs).

I think that the reason you see the effect is generally capacitance between you and the antenna. To improve reception, either stand where reception is good the whole time, or try moving the antenna higher up. anonymous6494 23:33, 5 February 2007 (UTC)

(Edit conflict) At about 3 metres, the wavelengths of broadcast FM signals are roughly the same size as you, so you can interact pretty strongly with those FM waves, diverting them around you or reflecting them. This can produce constructive or destructive interference at your radio's antenna. You may be able to reduce some of this by changing the position of the antenna (remembering that many table radios use their power cord as their antenna). In particular, if the antenna is oriented vertically (as you usually are when walking around), try orienting it horizontally.

Atlant 23:39, 5 February 2007 (UTC)

weather

What type of weather does low air pressure usually indicate?24.34.194.200 22:47, 5 February 2007 (UTC)

Stormy weather —The preceding unsigned comment was added by 88.109.41.162 (talk • contribs).

See also Cyclone. – b_jonas 20:33, 6 February 2007 (UTC)

more for the poison question above

ok guys first i wanna say thanks so much for helping me understand the effects of the poisons and everything. its really grea and secondly i wanna say thanks for not sugar coating the effects!! now ok here we go as for cyinade posion. if you were to keep the heart beating and the lungs working (via CPR or another method) would it be possable to survive a normal Leathal dose of cyinade once it goes through the body (since it does so at a fast rate) ?? or will the cell damage the cyinade causes be too great to survive?? thanks again Maverick423 22:55, 5 February 2007 (UTC)

You asked a similar question recently, and the first reply had a few errors in it, I would encourage you to scroll up and see the corrections if you haven't already done so.

So as stated above, ATP is the fuel with which the cell carries out many functions. Cyanide causes death by disabling ATP synthesis, and cells and by extension the entire human organism dies as a result. ATP acts on the enzyme cytochrome C oxidase by binding to it and preventing it from performing its normal duties. Cyanide also denatures the cytochrome, preventing further use. There are drugs which help avoid interaction between the cyanide and enzyme, but you are asking whether someone could be kept alive through CPR until the cyanide has the chance to exit the cells. The answer is, unfortunately, no. Cytochrome c oxidase takes four electrons (originally from NADH produced in the TCA) and adds them to molecular oxygen, creating (with dissolved protons, or hydrogen ions) water. This powers the Cytochrome c oxidase to push four hydrogen ions into a space in which they can power the transmembrane protein that creates ATP from ADP. The entire purpose of oxygen, despite the fact that it propagates toxic molecules and is itself reactive to vital cellular structures, is to accept these electrons from cytochrome c, as mediated by the oxidase. Oxygen, that vital substance, is just an electron sink. Without cytochrome c oxidase, oxygen is useless to the human body. Since CPR is little more than an artificial method to keep the body perfused with oxygenated blood, you can see why even perfect oxygenation of cells during cyanide poisoning is useless. Also note that, since the cyanide destroys the enzyme discussed, the body would have to make new cytochrome to replace it, which requires ATP, which is not available. All medicine can do in the case of cyanide poison is prevent it from interacting with cytochrome in the first place (and other important molecules) by introducing an agent which the cyanide prefers to bind with. See methemoglobin. ^tucker/_rekcut 02:12, 6 February 2007 (UTC)

Thanks much tuckerekcut you have been very helpful in my quest for intellect. Maverick423 14:20, 6 February 2007 (UTC)

dental hygienist/therapist

Hi, I am applying for a job as a dental nurse in Scotland, hoping to progress to a hygienist/therapist. What kind of uniform would I be wearing typically, and would I use a stethoscope etc in the latter jobs?

Yours, Alan

Hello Alan. Having been to a few dentists in Scotland, my personal experience is that the nurses and hygienists tend to wear tunics like this chap. I have never seen a stethoscope being used in a dental office. Rockpocket 01:05, 6 February 2007 (UTC)

....Nor by a hygienist or therapist, though there are many different kinds of therapist, and some might have a use for a stethoscope. Stethoscope will explain what it's for.--Shantavira 08:40, 6 February 2007 (UTC)

February 5

The 'pill' equals weight gain?

A couple of days ago I was reading the local newpaper's science page. One of the columns was a Q&A about science topics. The question was wether or not the 'Pill' really caused weight gain (or how). The answer was that, while older types of the pill did cause weight gain, newer ones had a different balance of hormones that did not cause much weight gain. The Doctor went on to say that the reason so much weight gain was from a natural increase of weight around the typically time the pill started to be used (IE 16 years or such)

Is this true? --Honeymane_{Heghlu meH QaQ jajvam} 00:16, 6 February 2007 (UTC)

The authors of an academic study into that very question (Gallo M. F., Lopez L. M., Grimes D. A., Schulz K. F. & Helmerhorst F. M. Cochrane Database Systematic Rev., doi: 10.1002/14651858.CD003987.pub2. (2006)) conclude that:

'cause and effect' is merely anecdotal, and that patterns of weight gain among new pill users are no different to those seen in the population at large. The most logical explanation is that all of us, men and women, gain weight with age. The average American, for example, gains about one pound (0.45 kilograms) every year, but most people seek out something to blame for this other than their personal behaviour. [10]

Rockpocket 01:22, 6 February 2007 (UTC)

Should the article be changed to reflect this?--Honeymane_{Heghlu meH QaQ jajvam} 23:10, 6 February 2007 (UTC)

Why not be bold? Rockpocket 07:35, 7 February 2007 (UTC)

air in potato chip bags

why is there so much air in potato chip bags? Is anything else a factor for their freshness?

It's in part to discourage breakage. Anchoress 00:46, 6 February 2007 (UTC)

Air would actually make the chips spoil faster because of the oxygen; I believe nitrogen gas is used instead of air. (Potato chip makers in Korea state that they use nitrogen.) --Kjoonlee 00:55, 6 February 2007 (UTC)

Was that a response to my comment? Because my point was that when the bag is inflated (with whatever gas) to maximum size the chips are less likely to break due to compression or impact during the journey from manufacture to sale. Anchoress 17:54, 6 February 2007 (UTC)

I'm sorry, I meant my reply to point out that the original question had a weak point. I agree wholeheartedly with your comments. :) --Kjoonlee 18:36, 6 February 2007 (UTC)

I always thought air in the bag was just to make it look more full then it is so that the person buying it wont feel as bad when they pay $3 for 10 ounces of chips. Maverick423 14:37, 6 February 2007 (UTC)

Except it isn't air, as mentioned above; Korean manufacturers state it very clearly: "Filled with nitrogen to protect contents." --Kjoonlee 15:09, 6 February 2007 (UTC)

Ooh, the potato chip article confirms the use of nitrogen. Isn't Wikipedia wonderful? :) --Kjoonlee 15:15, 6 February 2007 (UTC)

Yes very intresting info well i guess you learn something new everyday =) Maverick423 16:30, 6 February 2007 (UTC)

Point to point Rocket travel: How is it possible to get from any point on Earth to another in just 45 minutes?

Hello Volunteers:

I've tried to research Point to point Rocket travel: How is it possible to get from any point on Earth to another in just 45 minutes? All I'm able to locate is information about rocket/space travel and how point-to-point rocket travel can be done in 45 minutes etc...but I haven't been able to locate any info on how it works...why does it take only 45 minutes... ?

thanks in advance for all the answers

Shaum76 01:09, 6 February 2007 (UTC)

An object in a low Earth orbit (LEO) takes about 90 minutes to complete one full orbit of the Earth. Now, think of a point-to-point rocket journey as a rocket in a slightly flattened (elliptical) orbit that intersects the surface of the earth at your departure point and at your destination. Neglecting the (relatively short) periods of acceleration at takeoff and landing, the furthest point on Earth from you will be no more than half the circumference of the Earth away (half an orbit): 45 minutes.

It is in principle possible to get from point to point even faster, but only at ruinous cost of fuel. A faster trip would essentially require you to burn fuel the whole way, instead of coasting for most of the trip. TenOfAllTrades(talk) 02:03, 6 February 2007 (UTC)

You can do better than 45 minutes (actually about 42) using a Gravity train. Bunthorne 06:56, 6 February 2007 (UTC)

Light: Vector or Scalar?

Me and a few of my friends at school have been debating whether or not light is a vector or scalar quantity. Is it the SPEED of light, or is it the VELOCITY of light? What is the convention used and how does light actually travel, and what are the reasons for this?67.70.30.223 02:01, 6 February 2007 (UTC)Adam Reid

Light is neither; its speed is a scalar and its velocity is a vector. Scalars and vectors are not mutually exclusive. I don't understand what you mean by how light actually travels. Clarityfiend 02:49, 6 February 2007 (UTC)

Light is vector. It has energy and a direction. Interactions with other particles with vector properties preserves the vector/vector rules, not vector/scalar rules. Light has momentum which is the inherent vector quantity. Tbeatty 03:22, 6 February 2007 (UTC)

I don't think you can classify light as vector just because it has energy and momentum. For example, you can not say that a moving car is a vector. Scalars and Vectors are physical quantities and not objects. But as Clarityfiend mentioned, if you say velocity of light, then you need to mention the direction too, because velocity is a vector. You can say 'the speed of light is so and so' but if you say 'the velocity of light', then you should specify 'in the eastern direction' or something like that. -- WikiCheng | Talk 13:15, 6 February 2007 (UTC)

If you're thinking of light as an object, the above answers are correct: its speed is a scalar, but it's velocity is a vector. To muddy the waters, and not at all because I think this is what you were debating about, in electrodynamics, light is described by the electromagnetic four-potential; in quantum electrodynamics (the quantum-mechanical version), individual photons are little localized packets of this field. From this perspective, light is a vector after all, and photons are one example of a vector boson. (Any particle with spin of 1 unit, like the photon, is a vector; those with a spin of 0 units would be scalars.) -- SCZenz 13:38, 6 February 2007 (UTC)

Too much tea?

I drink a lot of tea - at least 3 and sometimes up to 6 or 7 cups a day of green tea, white tea and regular black tea. I drink soy milk with black tea but I don't use sugar. I also consume other antioxidant-rich things like red wine and cranberry juice on occasion. Are there any possible negative side effects of so much tea consumption? --Grace 02:39, 6 February 2007 (UTC)

Yes you can have too much caffein and get the jitters or insomnia. Also your teeth may be discoloured by too much tea. Is soy milk with black tea called white tea though? GB 05:52, 6 February 2007 (UTC)

By the way, you know consuming too much antioxidants can be unhealthy, mostly happens with vegetarians though, but you seem like you get a lot. [Mαc Δαvιs] X (How's my driving?) ❖ 07:06, 6 February 2007 (UTC)

Overconsumption of too much of one particular antioxidant chemical has been linked to health problems, but tea contains so many I don't think it's something to be worried about. (I don't think anyone has ever been diagnosed with antioxidant overconsumption from food, vegetarian or not). There are many folks who drink many cups of antioxidant-rich green tea a day with only positive effects that we know of. Also, white tea is a different variety of tea, similar to green tea. Frankg 15:28, 6 February 2007 (UTC)

You might be interested in this article: Heart study pours cold water on adding milk to tea. Anchoress 15:33, 6 February 2007 (UTC)

Dirty Glass Recycling

Some people put dirty jars in glass recycling bins. Are these jars just fed into a the glass melting machine all dirty or what? What about the label? What about the glue residue that attaches the label to the glass? --Seans Potato Business 04:28, 6 February 2007 (UTC)

When I talked to the local recyclers about this they said there was no need to wash out leftovers or remove labels. The glass material is sorted out and the company washes it anyway, and then melts it down. However they don't want light globes, window glass, pyrex or any other weird kinds of glass that muck up the mix. You may wish to wash out the remains to cut down on odor as it decomposes though. The same story applied to metal cans for recycling. GB 05:50, 6 February 2007 (UTC)

I'd agree with GB. Glass melts at such a high temperature that most things would just burn off. Any other oddities left behind (metals etc.) could just be separated out by density. --Cody.Pope 07:36, 6 February 2007 (UTC)

Yes and no. Plenty of organic stuff, I'm sure, burns off without a trace. But glass is a pretty weird substance, and even when molten it's still very, very viscous. Lots of metals and minerals can remain intermixed with it and do not by any means separate out by density. Trace amounts of various metals and minerals are routinely added to glass to give it desired colors or other properties. But those elements, if present in waste glass, can't be used to make a new batch of glass if those elements aren't desired in the new batch. That's why window glass is not welcome in the recycled glass stream. Also, I learned during a visit to a glass recycling plant that even one green bottle mixed in with several thousand clear ones can ruin a batch of clear glass. —Steve Summit (talk) 13:10, 6 February 2007 (UTC)

[Footnote: I said that "even when molten glass is still still very, very viscous". Let's not hear anything about the urban legend of its alleged viscosity at room temperature, 'kay? —s]

A lot of recycled materials are not sold as "virgin" versions of the same substance, such as paper. Old milk cartons go to make park benches, not new milk cartons. I wonder if old recycled glass likewise gets downgraded to brown or green glass or non-seethrough glass products. It would seem silly to try to have perfect clear windoe or bottle gmass when one speck of adulterant would tint it. The glass gets smashed to bit, then a furnace burns away bits of paper or glue or spaghetti sauce, then I expect some of the other undesired substances float to the top as scum or slag and get skimmed off. I have always been doubtful of the need to run empty jam jars through the dishwasher or to scrub them in the sink, due to the water and fuel energy wasted. Edison 18:26, 6 February 2007 (UTC)

Trees

what is Adenanthera pavonina,L.?

It's red sandalwood, here's a page I found via google: http://www.tropilab.com/adenan-pav.html. By the way, in future, it's probably a lot quicker for you to search on google, or some other search engine for that matter. All the best. - Akamad 05:04, 6 February 2007 (UTC)

Torpedo away

According to U-Boat#World War II, a magnetic torpedo worked by exploding underneath a ship, creating an air bubble that displaced the water supporting the weight of the ship; the unsupported hull then buckled. Is this true? Clarityfiend 04:39, 6 February 2007 (UTC)

It does not sound like a true statement, as an exploding torpedo would increase the pressure, lifting the ship. The gas bubble should be able to support the ship due to its high pressure. Much of the damage would be due to the blast shock wave. GB 05:45, 6 February 2007 (UTC)

My mistake. The article mentioned the air bubble, but the rest was my hallucination. Clarityfiend 06:42, 6 February 2007 (UTC)

Actually I've heard the exact same thing - twice - from ex-naval people - though not torpedos - more mines - the mine explodes - releasing a lot of gas - the gas expands becuase it is under pressure - creating a huge gas bubble under the target - and because gas doesn't have the buoyancy of water the ship sinks - that's the theory - just because I heard it from a good source doesn't mean it has to be true.87.102.37.127 06:55, 6 February 2007 (UTC)

It's not accurate. Refrence [11] for a complete description. Hipocrite - «Talk» 14:33, 6 February 2007 (UTC)

Effect of radiation/nuclear bomb on U.S. currency tests

I heard from a reliable source that the U.S. had conducted tests concerning the effects of radiation/a nuclear bomb on United States currency. However after doing a little reaserch I was unable to find any information on any test or tests pertaining to this subject. If anyone knew any information concerning this (i.e. date, place, test name, results, ect.) please enlighten me.

Mattheyborne 04:53, 6 February 2007 (UTC)Matt

If the currency (notes or coin) was near enough to the bomb, it would be destroyed (vaporised)--DarkFuture 06:19, 6 February 2007 (UTC)

Despite what Mattheyborne says: I have heard about different types of Nuclear Weapon which are designed to produce a huge amount of fallout without much actual explosive yeild. for example to kill the inhabitants of a city without actually causing much damage to infrastructure. the information about this type of bomb can be found here. Not sure if this helps, but i hope so. Ben

You're talking about a neutron bomb, although why the government would be overly concerned about the survivability of currency in the event of a nuclear war is beyond me. You'd think it would have more immediate worries. Clarityfiend 17:21, 6 February 2007 (UTC)

Governments generally assumed that nuclear warfare would not in fact end the world or their governments, but that it would be seriously disrupting. This is the "thinking the unthinkable" that think tanks did best at, realizing that there would in fact be survivors in almost any conceivable nuclear war and that one shouldn't simply close one's ears to the possibility because it was horrific. On the other hand, Lynn Eden at Stanford has recently published a book (Whole World On Fire) which in my mind conclusively demonstrates that the think tank theorists did not adequately take into account the fire effects of bomb shots, concentrating instead only on blast, heat, and radioactive effects, and in that sense probably severely underestimated the effects of nuclear weapons on inhabited areas. --140.247.250.21 17:38, 6 February 2007 (UTC)

They definitely tested the results of atomic blasts against a Mosler bank vault during their civil defense-related testing at Nevada Test Site in 1957 (it is still there). These tests were done in the context of houses and facilities not at the epicenter of the blast, but some distance away. The assumption was that the world would in fact not end in such a salvo (and in the 1950s there were not enough warheads to really be "world-ending" in the possession of the USSR) and that things like material property would still be quite important. This was two decades before the so-called "neutron bomb" was developed. --140.247.250.21 17:35, 6 February 2007 (UTC)

Job requirements: Spectroscopy and chromatography

I have an interview for a co-op job that asks for knowledge of ultraviolet-visible spectroscopy and infrared spectroscopy, as well as gas chromatography. Now, I have experience with spectrophotometry and spectroscopy, but not specifically UV/VIS nor IR. Also, I have done paper chromatography, but not gas chromatography. This one seems more complicated .

My opinion is: spectroscopy is spectroscopy is spectroscopy. Am I being cocky, or are UV and UV-VIS quite different from regular (emission / absorption) spectroscopy?

Also, gas chromatography seems much more complicated than paper chromatography. Are these techniques that I can quickly learn, considering my previous experience? − Twas Now ( talk • contribs • e-mail ) 06:53, 6 February 2007 (UTC)

uv spectroscopy is a type of electronic emission/absorbsion spectroscopy.

Gas chromatography (see http://www.gchelp.tk/ from that page for help) is more complicated than paper chromatography.

My guess is that they would like people who have experience operating uv spectra machines and gas chromatograph machines.

If you've used any spectroscopy machine (eg IR spec) before then using a iv or uv/vis machine should be simple for you to grasp - there's not a big difference in the way they are set up.

Gas chromatography is more complex - there's an oven, temperature control, it all depends on how much you are expected to do - just running a spectra would be simpler than setting up the machine, which in turn is simpler than knwoing how to set up a machine for a given sample. I'd expect at least some training - but anyone with experience would probably get first choice..

Recommend you read the two links above for GC and good luck. That's the best I can offer.87.102.37.127 07:02, 6 February 2007 (UTC)

Thank you, that external link is great! If anyone else has some other comments, they would be appreciated. − Twas Now ( talk • contribs • e-mail ) 08:11, 6 February 2007 (UTC)

Sodium laurel sulphate and sodium laureth sulphate.

I was just wondering... what are sodium laurel sulphate and sodium laureth sulphate and what do they do? Either one of those chemicals seems to be one of the first ingredients listed on all my shampoo bottles. --Candy-Panda 09:37, 6 February 2007 (UTC)

Both are detergentia or tensides or simply spoken soap. --Stone 10:43, 6 February 2007 (UTC) Sodium laureth sulfate might help.--Stone 10:45, 6 February 2007 (UTC)

Also Sodium dodecyl sulfate is sodium lauryl sulphate - they are quite similar - but not the same. Note detergent is a better term than soap - soap is typically Sodium tallowate or very similar - as found in a bar of soap. Sodium laur-- sulphates are more likely to be found in a liquid detergent such as Fairy Liquid.87.102.13.26 14:06, 6 February 2007 (UTC)

They're the primary cleaning agents in shampoo.87.102.13.26 14:06, 6 February 2007 (UTC)

1,3 butadiene

Do you have any information about a plant in India and Poland manufacturing butadiene from ethanol by two step process?

JACS paper 1949 might be an old process?--Stone 11:59, 6 February 2007 (UTC)

Ethanol to actaldehyde to crotonaldehyde to butadiene with Ta₂O₅ at 350°C. The paper was first hit in google scolar with butadiene from ethanol

Heart deposits

Suppose you had HDL deposits in your heart, and you were to have a totally fat free diet, would they then melt away??

Fat is synthesized in our body! HDL free or better cholesterol free would also not benefit, because it is a key component of cellmembranes.--Stone 13:06, 6 February 2007 (UTC)

High density lipoprotein (HDL) is the so-called "good cholesterol". A totally fat-free diet would be quite unhealthy, as fats are required! For example, they help in hormone production and the digestion of vitamins A, D, E, and K. Check out the article on essential fatty acids. − Twas Now ( talk • contribs • e-mail ) 14:04, 6 February 2007 (UTC)

Acidity level of free fatty acids from waste cooking oil

Greetings,

How to check the acidic and content level of free fatty acids from waste cooking oil WITHOUT going thru lab tests..?As in..Can we use cetain chemical or device which we can test on our own...?

A flask some phenolphthalein, pipet, sodium hydroxide solution of a known concentration, and you can start your job. Titration os simple!

I would have liked to have said that but oil doesn't mix with water - making the titration most difficult.87.102.13.26 15:42, 6 February 2007 (UTC)

Mixtures of alcohols help!--Stone 17:52, 6 February 2007 (UTC)

Wellbrutrin

I read that Wellbrutrin increases sexual urges in women. How does this happen?

It could suppress inhibitions. Corvus cornix 16:52, 6 February 2007 (UTC)

I think I would have to disagree. I believe that something chemically is happening...

for info on stuff like this check here http://people.howstuffworks.com/valentines-day.htm

and for more percise info on it check here http://health.howstuffworks.com/aphrodisiac.htm

Maverick423 17:41, 6 February 2007 (UTC)

Does anyone know what takes place chemically?

Speculations on what takes place chemically are located on the http://health.howstuffworks.com/aphrodisiac.htm article. however i dont think anyone knows forsure what happens with aphrodisiacs because there are alot of factors to consider.Maverick423 18:27, 6 February 2007 (UTC)

The thing is is that this is a anti-depressant, as in the description under Bupropion in Wikipedia: "Patients who complain of sexual dysfunction as a result of their SSRI have sometimes been prescribed small doses of bupropion, amphetamine or methylphenidate to correct it.[5]" Does anyone know how chemically this is affecting the human body?

A 2006 article (doi:10.1093/annonc/mdl304) notes "The mechanism by which bupropion has prosexual effects is unknown." DMacks 19:54, 6 February 2007 (UTC)

Does anyone else find this question a bit creepy? − Twas Now ( talk • contribs • e-mail ) 07:06, 7 February 2007 (UTC)

How to make?

Asked this question on the nitrocellulose page however seeing as how people dont really respond to them on there im asking it here .

how do you make gun cotton or where can i get flash paper and is it possable to make flash paper??

the reason for this is for a film me and some friends want to make however we cant find flash paper (not even in magicians stores)

Also how does one go around making that Fireball from flash paper? you know the one that looks like its a supernatural power comming from the persons hand? in anyways thanks in advance !!! One more thing whats the safest distance to be at when making a fireball from your hand? (in the term of the other "object") Maverick423 17:33, 6 February 2007 (UTC)

My heart bleeds for you! When I was a kid, I read books on how to make home-made explosives, rocket fuel, etc. I ordered flash paper through the mail, and I made my own guncotton. In this day and time, I wouldn't touch your request with a ten foot patch cord... :) --Zeizmic 17:55, 6 February 2007 (UTC)

The synthesis is easy, but dangerous. The ingrediants are hard to get and even harder to dispose. And if you really search for it you will find a good synthesis description from a person which is careless and stupid enough to distribute it over the net.--Stone 18:03, 6 February 2007 (UTC)

• crys on Zeizmic's sholder" WHY!!!!! man dude your lucky! i remember just once seeing flash paper in a magic shop but the store closed down. So with what you state i take it that the substance is now illegal right? Darn! but still i just wanted to know how to make it so ican show the real deal on that short video we are ganna make instead of adobeing it :( so i take it there is no or little chance that i will find this info anywhere eh? and i suppose u cant just buy the ingredients (as it was stated is hard to get) and just mix them up (as far as i know mixing chemicals without knowing the true danger is a death warrnt in itself) in a bucket or something Maverick423 18:13, 6 February 2007 (UTC)

Yep, if you read nitrocellulose (redirect from gun cotton) you'll find it explains in some detail how to make it.. including "...very careful preparation of the cotton: unless it was very well cleaned and dried, it was liable to explode spontaneously.." - so maybe it's for the best the ingrediants are hard to get hold of (hopefully).87.102.13.26 18:25, 6 February 2007 (UTC)

so its an extreamly unstable compound then... i take it you will need face masks and some sort of protection as a precaution from a accidental explosion then. hmmm but cotton is acctually used? thats intresting. Maverick423 18:32, 6 February 2007 (UTC)

Explosion is not the problem during production, but a boiling burning nitic acid if the reaction gets a little bit hasty.--Stone 18:34, 6 February 2007 (UTC)

The pure compound is quite stable on it's own (in the absence of sparks etc) - but impurities can make the gun cotton unstable. (I think)87.102.13.26 18:44, 6 February 2007 (UTC)

Why are they so distrusting of young folks in the making of explosive and incendiary materials? Oh yeah, now I remember my experiences. The book says make a gram of something and note that it explodes with a pop. I thought that an ounce would be more fun, and it went off with a boom and I was lucky not to lose an eye or fingers. A friend burned down his grandmothers porch (wise enough to take his experiment outside). Fifty or 100 years ago was the golden age of chemistry sets, when the home experimenter could buy literally and reagent. Now kids are taught to be afraid of chemistry and science, except for maybe somesolution changing color. Edison 18:39, 6 February 2007 (UTC)

20 years ago I bought a winchester of 98% sulphuric and over a litre of ~70% nitric from a 'pharmacist' - don't think I could do that now.87.102.13.26 18:44, 6 February 2007 (UTC)

ehhg tell me bout it i bought a chemistry set with NaCl as the main compound it was very very "cool" at that time now im angered that everyone that was around 20 40 years before i was born had so much more stuff to play with in their chemistry set. and edison is right! in schools they always say (becareful around the lab if you get any liquid on you tell us so we can wash it off even if its just water) i mean comeon thats enough to cause a kid to crap his pants if he gets anything on him. 20 years have gone by for me and the only chemical reactions i have seen is a barbque pit lighting up, fireworks, and water evaporaiting. (of course i seen a bit more but u get my point) Maverick423 18:50, 6 February 2007 (UTC)

God and science

Has science disproved God? Darkhorse06 18:00, 6 February 2007 (UTC)

Science can only disproof things which are bound to the laws of physic!--Stone 18:03, 6 February 2007 (UTC)

you know i always wondered that however i remember one thing

science still hasnt proven or showed how ,that pleage that moses used to kill all the first borns, occored or anything to explain the weird reactions that the pleage had on only targeting the first born and passing over the ones that had blood on the doors. (even though im a man of science seeing things that cant be explained makes me just wonder) Maverick423 18:22, 6 February 2007 (UTC)

Plagues of Egypt#Historicity incidentally. Also, your last sentence suggests you witnessed the plagues yourself. How old are you? Skittle 19:55, 6 February 2007 (UTC)

The existence of an omnipotent deity is (arguably) not within the realm of scientific discovery. Also, from at least some point of view, science cannot "prove" anything to an ultimate degree of certainty. It can only make predictions based upon past observations. These predictions become the laws and theories of science that we use. Theories in themselves can easily be disproved; in principle it takes only one repeatable experiment that disagrees with the theory. We sometimes call theories "laws" when they have been proven time and time again. Science could only "disprove" God if the existence of God made certain assertions or predictions that experiment and observation disagrees with. Whether that is the case depends largely on exactly what a person thinks a belief in God entails.

Can science disprove that some intelligence caused everything to be? Not really. Taking big bang theory as an example, we cannot answer what there was "before" the big bang, because, in the paraphrased words of Hawking, "that's like asking what is north of the north pole". Science is generally limited to what we can observe and measure somehow. If we cannot observe a god and quantify it, there's very little science can do to prove or disprove its existence. The very basic question is really a philosophical one, so you'll see lots of opinions. Now, as to individual claims that come along with many peoples' ideas of God and creation, those may be answered on a case-by-case basis. -- mattb @ 2007-02-06T19:47Z

ah sorry about that i didnt intend to make it come out that way. i ment that seeing as how science hasnt figured out what caused it; that gives me doubts about science being correct on evolution and stuff like that. thanks for the link i will start reading it right now. Maverick423 20:23, 6 February 2007 (UTC)

Evolution is a pretty sound theory that is observable on the small scale. The concepts of mutation, variation, natural selection and adaptation can all be observed in a reproducable laboratory environment. People who claim that evolution is mere postulation are usually under one or more misconceptions. Perhaps it's abiogenesis that you doubt? -- mattb @ 2007-02-06T20:36Z

P.S. - If you want to get into the philosophy aspect of this question, Existence of God does a nice job in covering the high points. -- mattb @ 2007-02-06T20:20Z

Science is not complete and doesn't have all the answers at this time (or even ever for some things), which can be a very unsettling idea. It doesn't mean that what it has figured out is not well established. And you also seem unsettled by a distinction between how vs what. People long knew that things fell when dropped even without knowing what was going on. Even long before anyone had a clue how gravity actually "works", we had the law of gravitational attraction. DMacks 20:41, 6 February 2007 (UTC)

Yes i admit im caught inbetween both these issues. the fact that both of them seem real at times is just confusing. god does this and that one person caught in the middle of it is spared while everyone around him dies. science cant explain what happened. yet... it has rumors of what might of happened but they cant confirm it. a higher being? God? or just a series of events that led to the persons survival while everyone else died. like i said its not a very good position to be in when your stuck in the middle. Maverick423 20:59, 6 February 2007 (UTC)

Yes, the point about completeness is worth remembering. The best scientific theories stand only because nothing has yet proven them to be incorrect. Some of today's theories may be a footnote in tomorrow's science history books. A fun example is that of quantum mechanics (QM) and general relativity (GR), the two principle modern theories of "almost everything". The former describes three of the four fundamental interactions observed in nature (electromagnetism, strong and weak nuclear forces) while the former describes the fourth (gravitation). Both theories are widely accepted and are backed by plenty of experimental evidence. The theories also contradict one another; they cannot both be correct and we're not yet sure how to reconcile them (or whether they really can be reconciled).

I think QM in particular presents a more interesting case. Even if you know everything QM can tell you about a system (let's call it a "wavefunction"), you cannot predict with certainty what the result of a given measurement on that system will be, only probability. This presents an enormous philosophical debate: is quantum mechanics incomplete, and there is some other unknown factor outside QM that determines the characteristics of a system (the so-called realist view) or is there something fundamental about the act of measurement that causes a system to suddenly have a measurable parameter? Some of the greatest human minds have grappled with this and been unable to agree upon an answer yet. Science is constantly evolving and along with it our understanding of the universe; it's hard to say whether everything can be explained with science (another philosophical debate).

Anyway, I wouldn't feel too bad about being a little bewildered by all this. Nobody even remotely can provide all the answers (save for, perhaps, an omnipotent creature, if you believe in such a thing). Perhaps you'll find some solace in The Answer to Life, the Universe, and Everything. -- mattb @ 2007-02-06T21:02Z

Heh thanks much you been quite the help mattb. Maverick423 21:17, 6 February 2007 (UTC)

I suggest reading God, the Failed Hypothesis: How Science Shows That God Does Not Exist for a talk about controlled experiments in search of God. [Mac Davis] 72.188.92.255 21:34, 6 February 2007 (UTC)

It really depends on what you mean, if you mean. God does not 'exist' if you think of the bible or other such documents as theories, then yes, god is disproved, because a theory must be falsified (have proof). While personally I don't believe in a divine being(s), You really should do your own reading. Religion, god, etc, are all taken in faith, and thus, it's something personal, and something you much answer for yourself; does god exist?--Honeymane_{Heghlu meH QaQ jajvam} 23:18, 6 February 2007 (UTC)

Mattb was right in saying that science, or at least empirical science, only works through present and observable events. While it's true that you can't absolutely prove the 10 plagues in Egypt because they're not repeatable events, evolution too falls upon the same rut. You cannot do evolution in a lab, (Although I have heard of scientists have claimed to do this by creating amino acids, which are not life, but merely the building blocks of life.) Evolution also has a lot of history that lacks evidence (ever heard of missing links?), putting both viewpoints in a state of controversy. This is because you can never prove through [empirical] science whether if God existed or not, or if evolution is fact or not because history is not repeatable through experiments (although you can reconstruct a past). Does that answer your question?

So what, does that mean we can rely on nothing now? Is everything just theory, and no one can ever be sure? Well, if that was true, then we can never prove anything in court, because all events took place in the past. But in a court they have what's called proof beyond a reasonable doubt (or if you want to do some further reading, read prima facie), which tells that while there is not enough evidence to absolutely prove something, it is enough to hold up in a court of law. However, there are a lot of arguments for both sides.

Those who support evolution quote of differentiation within species through allopatric speciation; those who support creationism (God created the world) ask why punctuated equilibrium relies on evidence of 'no change in species' to support that 'species do change'. Those who support God's existence quote first hand accounts of answers to prayer; those who reject this belief ask why can't people believe that was merely a 'freak accident'. Basically, both sides say that they're right. Yet what it really boils down to is not "which argument is right", but "which argument is more logical". Therefore, the court of law illustration is probably not the best one for this case, but a better one may be is two kids arguing about their past. So the answer is no, science cannot disprove God.

I hope I have answered your question thoroughly enough. For anyone who wants to know, I believe that God's existence is more logical. However, I have tried to provide sufficient evidence for both arguments, but if you do find any flaws to my answer, tell me, I'm not perfect. (As entertaining is the thought of having God answer questions on the Reference Desk, Bible text indicates Jesus wants you to receive Him personally [12]. :) ) I hope this helps, Darkhorse.--JDitto (talk to me!) 03:36, 7 February 2007 (UTC)

Not meaning any disrespect, but your post indicates that you yourself are under several common misconceptions about what evolution is and what it asserts. Evolution and abiogenesis are different concepts, as I indicated earlier. It's untrue that evolution cannot be observed; it has been observed on many scales, from viruses to fruit flies. Further, you seem to be treading the line of misunderstanding what "theory" means in the scientific sense.

Please don't take this as an attack, I mean no ill will whatsoever. It's just that it really helps to be as informed as possible when discussing this subject. -- mattb @ 2007-02-07T05:24Z

It is rather natural for people to latch onto the idea that we can use reason and logic to decide what is true. Through millions of years of biological evolution, our brains have been crafted to do a good job of making such decisions about questions like: "Who has more bananas, Og or Urk?" Philosophers such as Wittgenstein have made the point that we easily get ourselves in trouble by using our intuitions, logic and reason to deal with abstract ideas that exist beyond the reach of objectively verifiable data. Proof is just an argument that other people accept. Carl Sagan suggested that we should all practice skepticism and apply this rule of thumb: "Extraordinary claims require extraordinary evidence." --JWSchmidt 05:18, 7 February 2007 (UTC)

Here's another philisophy: we can always use reason and logic to decide "truth". The question of God however, falls outside of truth. truth has rules. Omnipotence has no rules and is therefore not subject to truth. The existence of God is a claim of Faith, not a claim of Truth. --Tbeatty 05:26, 7 February 2007 (UTC)

To be valid, scientific theories have to be testable. The test may not be possible technologically, but it must be conceivable and not contradict the theory it is trying to prove. For example, the Theory of Relativity postulated certain relationships velocity, mass, time, energy and the speed of light. Actual measurements were then compared to the theory, which corroborated it. It is not "proved" but the lack of disprrof as well as it's ability to predict future events makes it science. In this context, the existence of an omnipotent being is non-testable because the outcome will be whatever the omnipotent being chooses (the beauty of being omnipotent). This simply moves the "question of God" out from being a question of Science to a question of Faith. They are complementary questions, not competing ones. --Tbeatty 05:26, 7 February 2007 (UTC)

My own personal observation about evolution is that it is currently mostly an observable. Certainly there are genetic inheritance theories which have both testable, predictive value. But a lot of evolution is simply an obervable of current events. Much like the knowledge that an apple will fall from a tree and it occured long before Newton had his theory. Evolution has almost no predicitve value. Natural Selection is an obervable, not a theory. Sceintifically, we have no idea why certain species were "selected." We simply rationalize what is here vs. what is not but we can't predict what a future adaptation will be. What will the next predator on the Serengeti look like? What will the prey look like? We use the observables of extinct species and non-extinct species to try to identify what the distinction was, but we really have no way to predict what future species will out compete its neighbors. We only look in hindsight. If Hyenas live while Lions die we will look at distincitons and make broad claims. If lions live and hyenas die, we will rationalize their survivor traits. But we currently can't predict what Natural Selection means and what survivor traits are, only that some survive and some don't. We make up the rhyme and reason to fit the facts. --Tbeatty 05:26, 7 February 2007 (UTC)

Nicely put. -- mattb @ 2007-02-07T05:45Z

Richard Dawkins' God Delusion has a chapter on why God is improbable (i.e. highly unlikely) and points out the fallacy in assuming that because two things cannot be proved 100% they must be treated equally. For example, noone can prove that fairies aren't pushing things down to cause gravity, but it's very unlikely, if it had been written down in a book nearly 2000 years ago people probably would believe it though! When it comes to something like the biblical plagues mentioned above. The statements made show the problems in disproving God. The Bible can make a statement about what God or Jesus did which is scientifically impossible. A sceptic might say science has proved this is impossible and therefore disproved God as described in the bible. A believer might say science can't explain this, therefore science is wrong (taking the truth of the bible as given). So how is it possible to prove or disprove God in these circumstances? But to me the likelihood of some supernatural being creating things seems much more unlikely than any scientific explanantion, when most of the evidence for God seems to be an old book, tradition and the fact that science isn't 100% perfect.137.138.46.155 08:17, 7 February 2007 (UTC)

^^^ This made me remember about a old show i saw once. in it they brought up a question that stated something like this " was it god that created man or man that created god?" it does make me wonder like IP dude stated above all the proof of god is an old book. man could of created god to belive in something that something else something greater is out there. they might of used this as a way to explain how they came to be and now that science has found the truth they refuse to belive it because man is stubborn. BUT like i stated before i still have doubts about it but well we can only move forward and see what comes out of it Maverick423 14:34, 7 February 2007 (UTC)

Pet rats and Guinea pigs

What are the chief behavioral differences between pet rats and guinea pigs? --Andreas Rejbrand 21:22, 6 February 2007 (UTC)

Search engine syntax

If I want to look for Martin Luther rather than Martin Luther King, what should I do? Let's say I want to list all ML-only, MLK-only and ML+MLK web pages, how do I do it? I just want to know it this is possible. This question is not specific to any search engine or database service (e.g., Internet and other proprietary databases). -- Toytoy 21:23, 6 February 2007 (UTC)

"-King" without the quotes should be what you're looking for. Most search engines will exclude results containing a word with a minus in front of it. Additionally, putting a plus sign in front of a word will force results to contain it. You can also force the exact phrase to be searched for by putting it in quotes, as in "Martin Luther", but that may still pull up results about Martin Luther King if king has not been explicitly excluded. Cyraan 22:04, 6 February 2007 (UTC)

-King or more specifically -"King Jr." will typically exclude all references to the man who "had a dream". The easiest way to look only for King is to search for, in quotes, "Martin Luther King". This will require "King" to be next to Martin Luther as a complete phrase. To get both, just search for "Martin Luther", but be aware that different search engines will optimize this differently (Google will return primarily hits about Martin Luther, not MLK, because of the way it indexes terms). --24.147.86.187 23:51, 6 February 2007 (UTC)

It is possible to retrive "Martin Luther"-only entries: "martin luther" AND NOT "martin luther king".

-king, so search for Martin Luther -King, and in the unlikely event you get results for people names Martin, and people named Luther, use "Martin Luther" -king. On almost all search engines, putting a minus in front of a word will force it to exclude results that contain that word. Cyraan 05:00, 7 February 2007 (UTC)

How do I retrive "Martin Luther King"-only entries? "martin luther king" BUT NOT "martin luther" will return nothing! I mean only "King" can go after "Martin Luther". -- Toytoy 04:52, 7 February 2007 (UTC)

Put it in quotes, Martin Luther King will search for all of the words, no matter their placement on the page or order, putting it in quotes like this: "Martin Luther King" forces it to search for only that phrase, and only in that word order. Cyraan 05:00, 7 February 2007 (UTC)

No "Martin Luther King" would retrieve entries with both "Martin Luther King" AND "Martin Luther". Example: "In 2000 B.C., Martin Luther King drove a second-hand Toyota to Nepal to visit Martin Luther." -- Toytoy 05:04, 7 February 2007 (UTC)

Hmm, what search engine are you using? "Martin Luther King" on google doesn't turn up any results on Martin Luther for at least the first 5 pages (as far as I looked). On any engine I've used, using quotes forces only results that match the quoted phrase exactly to show up, if it doesnt have "Martin Luther King" in exactly that order, and containing every word, its not shown. "Martin Luther" might pull up both because both would match the quoted criteria, but thats where -king would come in. Cyraan 05:05, 7 February 2007 (UTC)

I think the question is about pages that have both the strings "Martin Luther King" and "Martin Luther <X>" where <X> is anything other than "King". I think the answer is "you can't exclude these" (when looking for "Martin Luther King") and you probably don't want to, either. Searching for "Martin Luther King" will find pages that have this exact string on them, as well as pages that have this string AND other occurrences of "Martin Luther not King" and "Martin not Luther King" and "not Martin Luther King" and "not Martin Luther King", but all of them will have at least one occurrence of "Martin Luther King". -- Rick Block (talk) 05:37, 7 February 2007 (UTC)

physics books

What is the best physics books escpecially in quantum physics for engineering ascpects?84.36.150.67 22:57, 6 February 2007 (UTC)mostafa elashram

Best is certainly a superlative. What criteria would you have us consider? If you're interested in QM (I'm assuming you don't yet have a solid grounding in the theory), a good introductory book is "Introduction to Quantum Mechanics" by David Griffiths. -- mattb @ 2007-02-07T03:11Z

P.S. - What field of engineering are we talking about? I'm a semiconductor person on the engineering side, but I can't think of too many other non-physicists outside the realm of semiconductors that would need to use QM regularly... Nuclear engineering, perhaps? -- mattb @ 2007-02-07T03:18Z

Rockoon

How powerful would a Rockoon have to be to reach the ISS? Lets say it was launched from 50Km and it was using todays technologies.67.126.140.7 00:08, 7 February 2007 (UTC)

What do you mean "how powerful?" How much payload do you want it to carry to the ISS? Or do you just want to know the required delta-v? --Robert Merkel 07:41, 7 February 2007 (UTC)

lightning

Where does lightning come frome? Aidan Age 9

I suggest reading our article on Lightning. Splintercellguy 00:51, 7 February 2007 (UTC)

In a nutshell, lightning is the result of an electric charge buildup in the clouds. When charges are separated (the Earth itself has a charge), there is an electric field between those charged bodies. Once the electric field reaches a certain critical strength, the medium that separates the charged bodies (mostly air) breaks down (ionizes), creating a conductive path on which the charge may flow. This ionization and subsequent rapid current flow is what you see as lightning. -- mattb @ 2007-02-07T03:09Z

Reaction to rice...?

I have this strange reaction to rice: Whenever I cook a bowl of rice and add a can of vegetables or tuna or especially when I eat the cooked rice by itself it gets stuck in my Esophagus or if it makes it down gives me violent and quick sucession hiccups. What is going on? 71.100.10.48 01:53, 7 February 2007 (UTC)

It would be helpful if you could elborate a bit more. Food getting tempoerarily stuck in the esophagus on its way down is a very common occurance (eating too fast, or trying to swallon too big lumps of food). If you've accidentally got sticky rice instead of normal rice, then i wouldn't be surprised at all. Hiccups is also a very common occurance, and generally do occur in quick sucession. Eating too fast also commonly gives people hiccups. I can't really see anything particularly strange in what you have described. --`/aksha 05:36, 7 February 2007 (UTC)

• It could also be the result of something psychological. Do you like rice? If you don't, your dislike of the stuff is probably part of the reason why you're reacting this way. - Mgm|^(talk) 11:24, 7 February 2007 (UTC)

I guess at a sticky rice theory - When I've boiled rice I often 'fry' (it's more like just heating through) in a big pan with a small amount of butter or oil - this really helps separate the grains - you could try that - and see if it still sticks. Hiccups often means you are eating too fast or swallowing too big mouthfuls - I get them all the time.83.100.251.239 12:26, 7 February 2007 (UTC)

Car B has 5 times the mass of car A...

Car B has 5 times the mass of car A and car B has kinetic energy 25 times the kinetic energy of car A. What is the ratio:(speed of car B)/(speed of car A) 02:09, 7 February 2007 (UTC)

I do not think they answer test or homework questions on this board. 71.100.10.48 02:20, 7 February 2007 (UTC)

Kinetic energy is calculated using E=1/2 mv^2m, which is 0.5 multiplied by the mass, multiplied by the square of the velocity. Try to work it out from there. --Bowlhover 03:12, 7 February 2007 (UTC)

A prettier version: $E={\begin{matrix}{\frac {1}{2}}\end{matrix}}mv^{2}$ --antilived^{T | C | G} 11:06, 7 February 2007 (UTC)

why is there no native human population in Antarctica?

Is it because it is simply too cold or infertile for human life, or is it because there were simply no humans there when continental drift occurred? The Mad Echidna 02:50, 7 February 2007 (UTC)

Well a) continental drift is still occurring; but b) the answer is (your) a. Humans had not yet evolved by the time Antarctica was split off. Anchoress 02:58, 7 February 2007 (UTC)

Also, since Antarctica is such a harsh environment, with little flora and fauna, even if there had been humans on it when it separated from the other continents, there is a good chance they would have died out as it drifted further south towards its current location, and its climate and ecosystem became progressively more inhospitable. Maelin (Talk | Contribs) 03:52, 7 February 2007 (UTC)

Your guess is as good as any. The reality is that if there were people in antarctica and the question was "How did people evolve in Antarctica?" there would be just as valid scientific answers as the variables and permutations on life are nearly infinite. --Tbeatty 05:53, 7 February 2007 (UTC)

Antarctica broke apart from South America about 23 mya. Modern humans only evolved around 100,000 years ago, and the split between what would eventually lead to humans and chimpanzees occurred 6 mya. In fact, according to Dawkins' The Ancestor's Tale it was only 25 mya that humans, chimps, gorillas, orang utans, gibbons, and Old World monkeys all shared a common ancestor! − Twas Now ( talk • contribs • e-mail ) 06:57, 7 February 2007 (UTC)

electromagnetic pump

What equations govern the force exerted by a magnetohydrodynamic (electromagnetic) pump on the fluid running through it?

The Lorentz force is a good starter. $F=q({\vec {v}}\times {\vec {B}})$. -- mattb @ 2007-02-07T05:14Z

Basis for claims about the economic cost of poor eyesight (among other things).

I heard once on the radio that poor eyesight costs the Australian economy something like $1 bn. a year, or something like that (it may have been in the 100s of millions instead). How do people work out the economic costs of things like that? The Mad Echidna 07:24, 7 February 2007 (UTC)

Just pulled out my bird's tail feathers by mistake

I was just trying to catch my budgie to give him his eye drops when I accidentally pulled out most of his tail feathers. He doesn't like being picked up and he flutters/runs all around his cage to get away from my hand. He's very quick. I thought I had him but he managed to slip through my fingers as my grip closed on him, so I only had him by the back end. He pulled away before I could reposition my hand, leaving me holding his long tail feathers.

The tips of the feathers have blood on them and he squeaked in pain when they came out but he's not bleeding from his body. He's just sat there looking unhappy now, giving me evil looks, shaking his backside and preening a lot.

Will his tail grow back eventually? --84.64.216.148 08:47, 7 February 2007 (UTC)

According to the article on feathers, "a bird's feathers are replaced periodically during its life through molting, new feathers are formed through the same follicle from which the old ones were fledged." Do you know the state of the follicle? − Twas Now ( talk • contribs • e-mail ) 09:29, 7 February 2007 (UTC)

No, sorry. I don't want to pick him up again and stress him out today. I wouldn't even know what I was looking for if I did anyway. :( --84.64.216.148 10:46, 7 February 2007 (UTC)

If there was no substantial bleeding, he should be okay. Birds molt at least once a year and new feathers ought to turn up at that time. I actually wonder about the feathers pulling out; it sounds like it happened relatively easily. Maybe it's already molting time where you are?

There's a slight risk that your budgie will become habituated to not having those feathers,and may pick them out when they start to grow again, but I think this is a low risk for tail feathers. On the other hand, I could introduce you to one Sun conure who has become very habituated to having a naked chest :-(.

Atlant 13:20, 7 February 2007 (UTC)

Meatomy

How do you define the medical term, meatomy?

• Try reading this site. Basically it involves a scalpel and a penis. - Mgm|^(talk) 11:21, 7 February 2007 (UTC)

(Site doesn't seem to work? I'm not sure if I should be pleased about that!)83.100.251.239 14:06, 7 February 2007 (UTC)

x-rays

i want information of x-rays

• Try reading our article on x-rays. - Mgm|^(talk) 11:18, 7 February 2007 (UTC)

green electricity

What is the need for using green electricity in place of hydroelectricity? How is it useful? - Manavsi 11:54, 7 February 2007 (UTC)

Well, there isn't enought hydroelectricity in many regions / countries. Also hydroelectricity isn't *that* green in certain areas - it is suggested that if you are flooding large areas of forest without having cleared away the vegetation then the anaerobic breakdown of it will cause enough methane to be released to offset CO2 savings from the dam for a couple of decades. --Neo 12:54, 7 February 2007 (UTC)

I'd suggest that the total CO₂ available in say 10 square kilometres (is that reasonable for a resovoir) is piddling compared to the savings from the hydroelectric generation..Or look at it this way - if you burnt all the stuff in the flooded area to make electricity - how long would that last at the same level of production of power - it's nothing like decades.83.100.251.239 13:11, 7 February 2007 (UTC) Sorry - ignore me I was in unreasonably grumpy mood.!83.100.251.239 14:05, 7 February 2007 (UTC)

More possible chess moves than particles in the universe

I've heard it said that there are possible moves in a game of Chess than there are particles in the universe. Has anyone else heard this and does anyone know if it is true; it sounds absolutely ridiculous to me but I have no proof.--Ukdan999 12:20, 7 February 2007 (UTC)

From Chess#Mathematics_and_computers: "..the number of legal positions in chess is estimated to be between 10^43 and 10^50, with a game-tree complexity of approximately 10^123.."

So thats half the question answered. The number of possible moves will be much greater than 10^43.83.100.251.239 12:40, 7 February 2007 (UTC)

But surely there are way more particles in the universe. If there are around a 200-400 billion stars in our galaxy and around 100 billion galaxies in the universe, that's many trillions of stars, each with possible planets orbitting them. So how many particles in a typical star. And that's not even counting all of the asteroids and other bits and bobs floating through space. --Ukdan999 12:50, 7 February 2007 (UTC)

I don't know but I'll ask - then the answer will come..

OK assuming most of the mass of the solar system is the sun, and most galaxyies are similar and have suns like are own that gives.. mass of sun = ~2x10³⁰kg x ~300x10⁹ (suns in galaxy) x ~100x10⁹ galaxyies per universe = ~60,000x10⁴⁸ = ~6x10⁵² kg of matter in the universe... Assuming most of that is hydrogen atoms that gives ~6x10⁵⁵ moles of hydrogen = ~6x10⁵⁵ x ~6x10²³ (atoms per mole) = 36x10⁷⁸ atoms... So thats still less than the number of chess games that can be played - but more than the number of positions..83.100.251.239 13:05, 7 February 2007 (UTC)

No. of particles in the universe

See Wikipedia:Reference_desk/Science#More possible chess moves than particles in the universe Could someone who knows please give us the (estimate of) the total number of particles in the universe. Thank you.83.100.251.239 12:56, 7 February 2007 (UTC)

Google says somewhere between 10⁷² to 10⁸⁷. -- mattb @ 2007-02-07T13:19Z

Thanks83.100.251.239 14:02, 7 February 2007 (UTC)