Wikipedia:Reference desk/Archives/Science/2007 November 18

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November 18

water, ethanol, and dehydration

Drinking ethanol is said to cause dehydration due to a diuretic effect, and drinking water is normally hydrating. What concentration of ethanol in water would have a roughly neutral effect on the body's level of hydration? --Allen (talk) 00:10, 18 November 2007 (UTC)

You can probably find old human studies that report "extra" urine production following ethanol consumption. If I recall correctly ( do not trust me) 10 ml of ethanol can cause about 100 ml of "extra" urine production (this may be an average value obtained with people as test subjects who do not routinely drink much ethanol). Even if that is the correct value, it does not mean that drinking a 10% solution of ethanol in water will result in no dehydration. Ethanol disrupts the normal regulation of water excretion, so you cannot expect things to start to "balance" correctly until the ethanol is cleared from the body. --JWSchmidt (talk) 22:19, 18 November 2007 (UTC)

A hole in a rib?

I was checking out this x-ray (from our AOTD on lung cancer; this is not my x-ray and I'm not seeking medical advice) and it looks like there's a sizable hole through one of this person's ribs (left side of picture, but "right" side of body). It doesn't seem to be addressed in the description pages. Any ideas as to what it is? Matt Deres (talk) 04:45, 18 November 2007 (UTC)

It's a tumour visible on the film. Because the cancerous tissue is much denser than the surrounding lung tissue, it appears whiter on the film. -- Flyguy649 ^talk 05:25, 18 November 2007 (UTC)

Are you looking at the left side of the picture? The right side of the picture has a tumour in it. That's described in the caption. I'm talking about what looks like a hole drilled through one of the ribs on the left side of the picture. Matt Deres (talk) 05:34, 18 November 2007 (UTC)

Could just be the blood vessels in the lungs that happens to look like a hole. Notice that there are similar structures on opposite side. --Diletante (talk) 05:42, 18 November 2007 (UTC)

(EC) Oh, that left. Sorry, I looked at the photo, saw the box, and spewed forth. If you mean the little hole over the fifth rib (roughly opposite the lower third of the box and to the left of the great vessels), I believe that's and illusion. It's just a place where the shape of the lymphatic tissue/lymph nodes have somehow made it look like there's a hole there. I don't think that the hole is any less dense appearing than any other bony tissue. It just appears that way because of the shape of the surrounding dense tissue. Again, that's just a guess. -- Flyguy649 ^talk 05:51, 18 November 2007 (UTC)

I'm fairly sure that circle seen over the right fifth rib is a bronchus seen end-on. --Joelmills (talk) 15:32, 18 November 2007 (UTC)

Ah, that would explain the similar semi-circular mark on the mirror side of the body. It was so much paler, I don't think I even noticed it before. Thanks, that makes sense! Matt Deres (talk) 11:47, 19 November 2007 (UTC)

TIME

WHAT CONCEPT ACTUALLY ALLOWS TO THINK OF GOING PAST OR IN FUTURE IN TIME,WHAT EXACTLY FORMS THE BASE OF IDEA,IS THERE ANY RELATION OF GRAVITY WITH TIME,PLEASE EXPLAIN59.95.46.193 (talk) 10:39, 18 November 2007 (UTC)

Check out the article on time travel. For gravity and time try spacetime and introduction to general relativity. Weregerbil (talk) 11:44, 18 November 2007 (UTC)

Also, please turn off your Caps lock key when typing your question, it makes things easier to read. Exxolon (talk) 18:24, 18 November 2007 (UTC)

We have an article on the Caps Lock Key! I'm cracking up for some reason. WIkipedia is beyond belief sometimes. DeepSkyFrontier (talk) 19:23, 18 November 2007 (UTC)

Dude, the caps lock key is right up in the main purview of Wikipedia; anything with relevance to computers has an article on here. Wikipedia's got way weirder stuff than that. --24.147.86.187 (talk) 00:09, 19 November 2007 (UTC)

Coenzyme Q and statins

When a doctor prescribes a statin, is it common that s/he also prescribes coenzyme Q10, since the latter's production is inhibited by statins? Icek (talk) 11:18, 18 November 2007 (UTC)

According to my biochem prof (in med school), yes, some doctors may prescribe CoQ10 with statins, but I'm not sure if it's "common". (EhJJ) 13:40, 18 November 2007 (UTC)

The role of coenzyme Q10 in statin-associated myopathy: a systematic review. There have been several small studies such as this. The review article concludes that there is not yet enough evidence to know the effects of coenzyme Q10 supplementation on statin side-effects; larger studies are needed. --JWSchmidt (talk) 22:34, 18 November 2007 (UTC)

Thanks. I asked because I think coenzyme Q prescription would be the straightforwad thing to do and doesn't have any expected or known adverse side effects (of course that doesn't mean that there shouldn't be studies done on it). The last sentences of the abstract of the review makes me wonder about the authors' seriousness: "Consequently, CoQ10 can be tested in patients requiring statin treatment, who develop statin myalgia, and who cannot be satisfactorily treated with other agents. Some patients may respond, if only via a placebo effect." ... --Icek (talk) 08:20, 19 November 2007 (UTC)

Some people get rich selling health "solutions" to people. Sometimes it is only after many years that we learn such "solutions" were useless wastes of time and $. When dealing with "solutions" that involve dietary and nutritional supplements, it is often hard to get someone to pay the cost of the large placebo-controlled studies that are needed to determine efficacy and safety. --JWSchmidt (talk) 13:54, 19 November 2007 (UTC)

Certainly, and some even spam Wikipedia articles. However, you can never be totally certain that a medication is beneficial. Given the current state of research (well, I'm no expert, but as far as I currently see things), I probably would take coenzyme Q if I had to take a statin, accepting the risk that it doesn't help. While large placebo-controlled studies are necessary, when estimating the current (subjective) probabilities of the effects, I think one should not ignore the basic biochemistry which is known with far greater certainty than knowledge gained from human trials. Icek (talk) 21:20, 19 November 2007 (UTC)

Addendum: And on the other hand, money is wasted for studies like this one ... Icek (talk) 21:22, 19 November 2007 (UTC)

Space Folding

A while back I saw a movie which presented a very strange effect I'm curious about. A basic example of what happened in that film is that a person on the ground floor of a house enters the door to the kitchen, and finds himself exiting the door to a bedroom on the first floor. He then goes back through the door of the bedroom and comes out the door to a closet in the basement. And upon going back through the door to the closet he finds himself exiting the house through the main entrance. And the explination given was that for some reason space was folding over its self causing the doors in the house to no longer lead to the rooms they were suposed to, but to completly unrelated ones else where. I want to know, is this just hoolywood nonsense or is something like this theoretically possible? —Preceding unsigned comment added by 86.104.53.234 (talk)

Well, there is the concept of a wormhole, but for it to have a directional bias may be a little tough unless there is some moving gravity source inside. But the answer is basically no, based on our current theories and technology. Luckily, computer games like Portal (video game) allow us to virtually live out worlds like these. It is kind of sad, though, that there are limits to our imaginations in the real world. SamuelRiv (talk) 13:12, 18 November 2007 (UTC)

In short, no, it's not realistically possible. However, the term you're probably looking for is tesseract, a cube with four spatial dimensions, or a hypercube, an N-dimensional cube. If the house were a tesseract (or some other hyperdimensional object), it could, for example, be possible to walk in a straight line through four rooms and end up right back where you started. If the rooms shifted in a 4th spatial dimension, then the result could be similar to what you described. Still, yeah, Hollywood nonsense, but that's why it's called science-fiction. -- HiEv 14:20, 18 November 2007 (UTC)

Thank you HiEv. Tesseract is exactly what I was looking for, and now that I found out what it was called I was able to look up the movie and found out that the effect was caused by a device called (wouldn't you know it) a tesseract generator. Thank you for you'r help, this will help me greatly in wrighting the next chapter of a fanfic of mine. —Preceding unsigned comment added by 86.104.53.234 (talk) 22:05, November 18, 2007 (UTC)

I don't know if the movie was an adaptation, but the idea of building a tesseract house occurred in science fiction before it was a movie. But of course that was impossible... Read Robert A. Heinlein's sf-comedy short story "And He Built a Crooked House". My Google search found a copy of it with a note saying that it would not be available after June 15, 2007, so I suggest looking right now. Wikipedia has an article about the story, but don't start with that; it'll just spoil the fun. Read the story. --Anonymous, 22:55 UTC, November 18, 2007.

Economics

when will quantity demanded be at zero

When the price is sufficiently high. See Demand curve. MrRedact (talk) 15:14, 18 November 2007 (UTC)

Or when the product is crap...somehow that never seems to show up in economists (typically unlabelled) graphs! SteveBaker (talk) 19:34, 19 November 2007 (UTC)

Steve: Well, that can be shown easily with a partial equilibrium graph, like the one for the case of free goods (air, etc.). With axes labeled. Nevermind :p.

For anyone else: Also please consider some other causes for demanded quantity being zero. For instance, a low price of a substitute, etc. Greetings.Pallida  Mors 04:08, 20 November 2007 (UTC)

What is E-rosetting?

What is E-rosetting? --Seans Potato Business 14:51, 18 November 2007 (UTC)

it's short for erythrocyte rosetting. Rosetting is a phenomenon that can be seen through a microscope: it consists of cells arranging themselves around a central cell so that the entire cluster looks more or less like a flower with the central cell surrounded by the other "petal" cells. It occurs because of immunologic reactions, usually to molecules on the center cell. In "E-rosetting", the "petal" cells are erythrocytes. The presence of e-rosetting can be used as a test for T-cells (though there are more modern tests available). - Nunh-huh 15:14, 18 November 2007 (UTC)

Thanks. --Seans Potato Business 23:35, 18 November 2007 (UTC)

Keeping eggs in the fridge

Just a silly question that struck me today - why do most people store eggs in the refrigerator when they're just stored on a shelf in the shop? Surely there is no need to refrigerate them otherwise the shop would keep them in a chilled cabinet? I cannot see any benefits from keeping them cold, most people cook them anyway so the fact they're cold just means they'll take a bit longer to cook. GaryReggae (talk) 15:27, 18 November 2007 (UTC)

American eggs are kept refrigerated at the store. I suppose most people here do so at home, too. I do, mostly because I've got nowhere else to put them. My old-timey Fanny Farmer Cookbook said to store them at room temperature in sawdust. That way, they won't chill anything you add them to. The thinking is that you'll use them before they go bad, and they keep pretty long at room temperature, anyway. Big end up! --Milkbreath (talk) 15:41, 18 November 2007 (UTC)

WHAT??!?? No way! Never! Little end up always! (Why do we allow these bloody Blefuscuians to have Wikipedia accounts at all?! Ban them I say!) SteveBaker (talk) 19:42, 19 November 2007 (UTC)

Another yahoo heard from. It's BIG BIG BIG! --Milkbreath (talk) 20:44, 19 November 2007 (UTC)

This is a debate that has been running for some time. Just Google "eggs" and "fridge". Delia Smith (UK TV chef) says you should not store them in the fridge; The Food Standards Agency says you should. No doubt they have different criteria. I believe the only reason supermarkets don't refrigerate them is that the damp would weaken the packaging.--Shantavira|^{feed me} 17:27, 18 November 2007 (UTC)

That and the cost of buyin, installing and running the refrigerators, and the floor space they would take up.DuncanHill (talk) 17:45, 18 November 2007 (UTC)

It's all part of the bizarre mindset North Americans (we Canadians do it too) have about food. We'll eat any garbage served to us in a polystyrene container, but we're deathly afraid of germs in our home. We also refrigerate our pickles, ketchup, cheeses, mushrooms, salad greens, relishes, and mustard. It even tells us to on the containers they come in, "Refrigerate after opening". Even foods specifically created for preservation (before refrigeration was possible) get chilled now, such as smoked or salted meats and sausages, jams, jellies, etc. Now that salmonella can get into eggs, there's at least some kind of reasoning behind it. Matt Deres (talk) 17:43, 18 November 2007 (UTC)

A fertilized egg requires warmth to incubate. Refrigeration, therefore, prevents incubation. Americans have a limited appetite for gross food. We want our chicken fetuses to be as small as possible and early refrigeration helps with that. More to the point: some people take months to finish off a dozen eggs. Seriously. Eggs do go bad eventually. DeepSkyFrontier (talk) 19:32, 18 November 2007 (UTC)

Most commercially produced eggs (in the US at least) aren't going to yield fetuses no matter the temperature, due to the lack of roosters in the production facilities. -- Coneslayer (talk) 20:14, 18 November 2007 (UTC)

That's true of commercially produced eggs. DeepSkyFrontier (talk) 23:37, 18 November 2007 (UTC)

The rooster will be quite exhausted if he managed to fertilise all those eggs each day :p. I still don't get why you have to put things like cheese or pickles in the fridge, when their original purpose is to preserve the food in the first place. --antilived^{T | C | G} 23:28, 18 November 2007 (UTC)

Warm pickles are gross. You don't put cheese in the fridge? Where do you put it then? In a cheesebox? (Come to think of it, the last time I heard that phrase, it referred to a refridgerator, so nevermind :) DeepSkyFrontier (talk) 23:37, 18 November 2007 (UTC)

Usually pickles are cool enough sitting in the pantry, so I don't bother with putting it in the fridge, but I do put cheese in the fridge. What would people do next, put unopened canned food in fridges to prevent botulism? --antilived^{T | C | G} 00:52, 19 November 2007 (UTC)

Certainly the original' intent of pickling and turning milk into cheese was to preserve the food - but modern pickles often come in very sweet/mild vinegar that certainly doesn't prevent decomposition (I've thrown out jars of pickles with blue stuff floating on the liquid even though it has been in the fridge - so certainly not refrigerating them would have hastened that fate). With cheese, the deal is that you want the amount of decomposition that it was intended to have (and with the specific bacteria that produced the blue veins or whatever) - but that's all you want! You don't want white furry stuff on your stilton or blue veins in your brie! SteveBaker (talk) 19:32, 19 November 2007 (UTC)

So basically this is not a clear cut issue. We can, and do, store these things in either way and we are still all safe and healthy. Is that right? Richard Avery (talk) 09:28, 19 November 2007 (UTC)

Most of the reason I put things that might not be perishable in the fridge is because I've got a larger fridge than cupboard. My cabinet I'm using for dry goods is full of various varieties of tea, a few packets of coffee for guests, a good month's supply of ramen, and then whatever boxed mixes we have on hand - cake, muffins, boxed dinners, what not. My other cabinet holds sauces, spices, and canned goods. I've alternately kept onions and garlic and other greens in and out of the fridge, but if they're out they're in baggies on top of the microwave so they might as well go in. And eggs DO go bad, especially if it's hot and humid like it gets here in summer, so I keep them in the fridge to ensure they last until the printed date (they are always refrigerated at stores I shop in so I presume the date is only valid if they're stored according to packaging directions). I like my ketchup and mustard cold - it makes a nice balance to warn hotdogs, IMO. But I keep syrup at room temperature. I recently realized the stupidity of keeping the honey in the fridge when I read about million-year-old fossilized honey being still edible - all it was doing was making it more viscous so it was harder to pour onto the spoon (stupid bear-shaped spouts. From now on I buy honey in jars, since I measure it with a teaspoon anyway). Kuronue | Talk 19:59, 21 November 2007 (UTC)

Douglas Adam's computer called "Earth"

Is there an echo in scientific literature of Douglas Adam's fiction idea that the Earth was created as a superdoopercomputer? Did he just make it up or was he inspired by scientific readings? Keria (talk) 16:14, 18 November 2007 (UTC)

Simulation hypothesis comes close. --Allen (talk) 16:22, 18 November 2007 (UTC)

If you give the Gaia hypothesis a more high-tech spin, it comes even closer. --24.147.86.187 (talk) 16:39, 18 November 2007 (UTC)

Or try digital physics. SamuelRiv (talk) 17:21, 18 November 2007 (UTC)

I think Simulation hypothesis is a better analogue than Gaia hypothesis. The Gaia hypothesis, in its original form, is a completely natural phenomenom -- a planet within the habitable zone that already has sufficient biomass and sufficient biodiversity will, given time, self-regulate the climate as a side effect of biological evolution -- in others words, the fittest fit because they did the fitting. Gaia does not produce data that could be used to adduce questions. --M@rēino 19:44, 19 November 2007 (UTC)

Cancer Funding- Treatment valued over Cure?

I was wondering why hundreds of millions of dollars are spent each year in the search for effective treatments for cancer, while far less money is spent on preventing cancer. Why is this?

I looked on the wikipedia page for cancer but it doesn't cover funding too extensively.

---Liree

This is really a political question more than a scientific one. Doctors can make a lot of money treating cancer, and can make very little money preventing cancer, so medical lobbyists support an emphasis on treatment instead of prevention. And a lot of farmers would be hurt financially if people were to cut way back on consumption of red meat and cheese and what-not, but aren’t hurt financially by cancer treatment, so the agricultural lobbyists also support an emphasis on treatment instead of prevention. It would be a much more efficient use of money to shift some funding for treatment to prevention, but taxpayers don't care about that nearly as much as those people whose jobs would be affected. MrRedact (talk) 18:46, 18 November 2007 (UTC)

So what exactly do you mean by "prevention"? More nagging public service ads? No thanks. I don't smoke or eat red meat; those who do are on their own. I have my own risky habits but I can analyze for myself their costs and benefits and I'll do it (or not) without the government looking over my shoulder.

I could see a rationale for intervening in the meat industry for animal-rights reasons, and that might have side health benefits for humans, but the nanny-state stuff should be the side effect, not the motivation. --Trovatore (talk) 19:01, 18 November 2007 (UTC)

This ignores the fundamental question of whether cancer is (from a medical research perspective) preventable. By and large, if you can't make a vaccine for it, it's not medically preventable. So where should the money be spent? As for the header for the question, though, let's not conflate "cure" with "prevention". Those are two entirely different things. — Lomn 19:22, 18 November 2007 (UTC)

Imagine all the money we wouldn't get from people who already have cancer (and their famlies) if we only focussed on preventing cancer. People donate money to causes they care about, and lots of people care about curing diseases they and their family members have. Further, many forms of cancer just "happen." Between heritable risk factors and random mutations, a lot of cancer is unpreventable. Someguy1221 (talk) 20:28, 18 November 2007 (UTC)

Yeah, the section title doesn’t make sense. I’m guessing the OP just made a mistake.

It isn’t possible to completely eliminate any chance of getting cancer, so I guess from that perspective cancer isn’t technically preventable. But there’s plenty of evidence to support the idea that a change in diet from one with a lot of calorically-dense foods containing a lot of saturated fat to one that’s based more on minimally processed fruits, vegetables, whole grains, and legumes will reduce a person’s statistical likelihood of getting cancer by a given age. So maybe "risk reduction" is more accurate than "prevention", but that’s just a matter of semantics. Risk reduction is valuable, even if it isn’t complete prevention.

Trovatore, I can understand how something like a nagging public service ad would just be annoying to you. But you’re a very smart person, so I suspect that you’re a lot better educated about the health risks associated with smoking and dietary choices and what-not than is the average member of the public. There are plenty of people out there who really have no clue that gobbling down a bacon double cheeseburger for lunch everyday might not be a good idea. Educating a population about health risks related to cancer has got to lower the age-adjusted incidence of cancer in that population. Providing free nutrition counseling for anyone who wants it would be one possibility, but there are probably more cost-effective means of educating the public on the matter.

Education isn’t the only public policy issue that could be changed to reduce cancer rates. For example, right now the U.S. government provides public land to ranchers for grazing for a very low fee. If that program were eliminated, it would cause beef prices to go up somewhat, which would reduce beef consumption somewhat, which would reduce cancer rates somewhat. MrRedact (talk) 20:37, 18 November 2007 (UTC)

To be political in answering the prevention part...Prevention is a question of social engineering. We could raise the price of known cancer-causers, ban them, introduce regulation, do a combination of all this or just pick and choose. The government has to weigh up public-sentiment, civil-liberty, cost-benefit ratio. Public-information campaigns are relative cheap and can have a big impact if they can reduce the causing of cancer. Taxation is revenue-generating but often unpopular with the public. Banning things is almost always fought against by those demanding their freedom to live life to their choices. Regulation is often a politically-viable option as it gets less public interest, can enforce change and also allows banning-like actions without formally banning it (one can regulate something out of existence). A combination is usually the best bet.

As for why more is spent on treatment than the cure... It has less to do with the politically-cynical reasons given above to me, it is to surely to do with logical spending (A cure for cancer would be worth infinitely more than treatment in income). It will surely easy to develop treatments than it is to develop a cure, so spending is focussed on the area which gets the most 'value'. Also the cure will doubtlessly come as a result of that which is learnt in treatment - since treatment focusses on limiting the spread/controlling it it makes sense that new methods of treatment will continue until the treatment itself manages to be the cure. If you were to be more politically cynical you could ask why billions is spent and thousands of highly skilled scientists/medical staff are employed doing body-enhancement research - such as wrinkle-cream, breast augmentation, liposuction techniques etc. There is always going to be focus on developing for profit in private-business, they need to do that to survive (and without their survival who would develop drugs other than public-funded companies?), but then we cannot be precious about spending. Why, for instance, does a government spend 100s of millions on the arts, or national parks? That money might be better spent on education or healthcare, or whatever. The reality is we need to balance spending between the 'vital' and the life-enhancing because both are important. ny156uk (talk) 21:46, 18 November 2007 (UTC)

I’m pretty sure any talk about a "cure" is just a mistake. I think the OP meant to have a section title of "Cancer Funding- Treatment valued over Prevention?", but just accidentally typed the wrong word. The question itself makes no mention of a cure.

I presume there never will be "a cure for cancer", because cancer isn’t really one disease. There are many varieties of cancers, and different treatments work with different effectiveness on different types of cancer. Some cancers, like testicular cancer or basal cell carcinoma can be treated so effectively now that it’s kind of close to saying that they can now usually be "cured". Other cancers, like Glioblastoma multiforme have a very low survival rate regardless of treatment, and are nowhere close to being "curable". MrRedact (talk) 22:27, 18 November 2007 (UTC)

Some funding numbers for cancer prevention. Recent numbers claim about 10% for "prevention and control". --JWSchmidt (talk) 23:20, 18 November 2007 (UTC)

Atomic orbitals

AOs-1s-2pz.png

Am I correct in believing that this illustration shows the (non-excited) orbitals for Neon? I think the atom article is in need of some discussion of atomic orbitals and I thought this diagram would be a good starting point.

This image isn't being used anywhere at present, so I thought I'd check here first. Thank you. — RJH (talk) 19:43, 18 November 2007 (UTC)

It could be Neon, or even a sodium ion, however how can you tell how many electrons are in each orbital? If there was one in each it could be carbon. Or if some had one and some had two it could be nitrogen, oxygen or fluorine. These orbitals would also be in use in atoms with higher atomic number, it's just that they would use more orbitals. Graeme Bartlett (talk) 20:11, 18 November 2007 (UTC)

It can also be hydrogen - each orbital is merely a different energy state - when hydrogen is excited, it can jump to 2s or 2p orbitals quite easily. This picture is general for all atoms and should definitely go on the atom page. Also pretty slick is this hydrogen orbital java applet [1]. SamuelRiv (talk) 22:14, 18 November 2007 (UTC)

The reason this image and a detailed discussion about atomic orbitals are not in the atom page is because we have a detailed page just for the topic of the atomic orbital. That page has images of all the various orbital shapes occupied in the ground state of known elements. DMacks (talk) 19:21, 19 November 2007 (UTC)

Well certainly the atom page can cover atomic orbitals summary-style. That's standard procedure in WP. It's appropriate to cover it in brief on the higher level page, and that serves as a lead-in to the more detailed content when the reader drills-down.

Thanks for the replies. — RJH (talk) 23:17, 19 November 2007 (UTC)

Automotive question

How is it possible to do this? Thanks, Dar-Ape 22:44, 18 November 2007 (UTC)

Once you're pretty much balanced, turning the steering wheel to the right will help make the car fall to the left, and turning the steering wheel to the left will help make the car fall to the right. Keeping the thing in balance is just a matter of practice. MrRedact (talk) 23:03, 18 November 2007 (UTC)

So do you think this would require modifying the car in some way, or could I do it with any old car? Dar-Ape 23:12, 18 November 2007 (UTC)

It’s not really a "trick" car, if that’s what you’re asking. I think the only mods they do are to add roll bars for safety, and use heaver-duty shocks and make other various parts sturdier. I think for learning purposes, they probably also rig the car with a "training wheel" so the car can’t fall too far to the right. Obviously don’t really try this at home with your own car; you’ll wreck your car and quite possibly roll the car and kill yourself. If you actually want to learn this, you’ll need the guidance of a professional driver with expertise in doing this.

More on how it’s done: They use a ramp under one side of the car to get to near-balance initially. Turning to the right involves having the car falling slightly to the right. You then turn the steering wheel a bit to the right, but not quite enough to rebalance yourself. Turning to the left involves having the car falling slightly to the left. You then turn the steering wheel a bit to the left, but not quite enough to rebalance yourself. The car is set down by turning the steering wheel to the right and letting the car fall onto its bottom. MrRedact (talk) 01:02, 19 November 2007 (UTC)

You are maintaining balance on two wheels in much the same way - by rapid steering corrections - every time you ride a bicycle. --mglg_(talk) 01:56, 19 November 2007 (UTC)

Good point. Yes, the balance and steering principles are exactly the same as with a bike. The bike has an advantage in that the wheels provide much more of a gyroscope effect than car wheels do, but the car has an advantage in that the center of mass is higher. The higher the center of mass of an object is relative to what it’s balanced on, the easier it is to balance. For example, it’s much easier to balance a broom on your chin than to balance a pencil. MrRedact (talk) 02:53, 19 November 2007 (UTC)

Actually, it's a commonly believed myth, but bicycle stability has little to do with a gyroscopic affect. See bicycle and motorcycle dynamics for details. -- HiEv 16:55, 19 November 2007 (UTC)

That's true - the gyroscopic thing is largely urban legend. Have you ever seen those bike-like contraptions (Skibobbing) with two skis on them? On snow, they are every bit as stable as a bicycle - and there is clearly zero gyroscopic effect going on there. Also, what about those teeny-tiny wheels on a Kick scooter? There is nowhere near enough mass in them to have a measurable gyroscopic effect - yet you can steer and balance just as well on a scooter as on a bike. SteveBaker (talk) 19:23, 19 November 2007 (UTC)

Actually, thinking about it, I’m not positive the center of mass of a tipped car is higher than that of a bicyclist on a bike. I think it might actually be lower. MrRedact (talk) 03:00, 19 November 2007 (UTC)

The other saving grace for the car is that it has a high moment of rotational inertia - which means that it can't flop back onto the ground or roll over very quickly. This gives the driver plenty of time to correct any wobbles. I've heard (from some friends who did a week-long stunt-driving course in Germany) that this trick isn't actually all that hard to master if you have the correct ramp and know what speed to take a particular car onto the ramp to get it up on two wheels in the first place. SteveBaker (talk) 19:16, 19 November 2007 (UTC)

What always confuses me is how the wheels can be working properly. I mean, they're designed with treads to be ridden on in a certain way, and bicycle tires are the same, but tipping it over that far... I'd be worried about scraping the rim. I mean, the wheels are almost parallel to the ground during certain turns! Kuronue | Talk 19:49, 21 November 2007 (UTC)