Wikipedia:Reference desk/Archives/Science/2010 February 25

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February 25

salt in water

since i got my wisdom teeth out recently ive been drinking warm water in half a glass with half a teaspoon of salt to clean the mouth. anyway today i heated up the water for 30 secs in the microwave, then put the half teaspoon of salt in the glass. i then stirred the glass with the teaspoon. as i was stirring, the spoon made a low scrapping sound, and as the salt dissolved, the sound grew louder. when all the salt was dissolved, stirring the glass sounded normal.

i was wondering what was happening with the sound. was the salt absorbing the sound? it was really cool.--Minor330 (talk) 01:16, 25 February 2010 (UTC)

I would think it would be perfectly obvious: so obvious in fact that I will resist the urge to explain. I think you are testing the reference desk to see just how stupid people can be. But if you are not, well, the sound ceased when the salt disappeared, because the salt was making sound as it scraped the glass. Come on. Vranak (talk) 01:52, 25 February 2010 (UTC)

Is that really an appropriate tone to take in answering a question that appears to have been asked in good faith? Particularly since you seem to have missed the key part: that the sound got louder as the salt dissolved, which is what the OP is querying. Possibly related to the change in pitch as you stir a hot chocolate? 131.111.248.99 (talk) 02:16, 25 February 2010 (UTC)

We had a very similar question before - (someone should check the archives - I had a quick search but couldn't find it) I'm 99% sure the salt and the heat has nothing to do with it. What I think makes a big difference is that when the liquid is already swirling it makes a dramatically different sound than when it's stopped or moving slowly without turbulence. SteveBaker (talk) 03:59, 25 February 2010 (UTC)

This question was similar. Cuddlyable3 (talk) 17:24, 25 February 2010 (UTC)

Yeah - that's the one I was thinking of. Thanks! SteveBaker (talk) 03:19, 26 February 2010 (UTC)

Good faith has its limits. Even so I have accounted for the possibility that the questioner did not know what was happening even though he already explained exactly what was happening. Groan. Vranak (talk) 04:00, 25 February 2010 (UTC)

How do you propose to explain why the sound grew louder as the salt dissolved? If the salt was responsible, shouldn't the sound become quieter? --99.237.234.104 (talk) 04:54, 25 February 2010 (UTC)

Related : The Straight Dope : When I stir my coffee, why does the sound gradually change pitch? APL (talk) 15:41, 25 February 2010 (UTC)

I would surmise that it is due to the changing speed of sound in different strata. Vranak (talk) 18:49, 25 February 2010 (UTC)

After the last time we were asked this (Thanks Cuddlyable!) our OP claimed that (s)he could reliably "reset" the sound by stirring the liquid. If that's true, it busts the dissolved gasses theory - so I think "The Straight Dope" guy is guessing. SteveBaker (talk) 03:27, 26 February 2010 (UTC)

Chemical looks.

I have six out of: 1-aminobutane, benzaldehyde (according to wikipedia - colourless liquid), benzoic acid (according to wikipedia - colourless solid), butanone (according to wikipedia - colourless liquid), benzophenone (according to wikipedia - white solid), ethanamide, ethylbenzene carboxylate and benzonitrile. Two of my substances are white flakey powder. Two are clear liquids. One is a clear solid in small wet-ish picces like powder. One is a slightly yellowy liquid. Could you please help work out the which would be which? Particularly which the clear solid is and the yellowy liquid is? Also, one smells absolutely vile, which is it? All help is greatly appreciated. —Preceding unsigned comment added by 81.157.96.6 (talk) 02:00, 25 February 2010 (UTC)

Please do your own homework.

Welcome to Wikipedia. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. --ColinFine (talk) 08:59, 25 February 2010 (UTC)

Sorry, I forgot my login details before.

It's not a homework question but a question for mock coursework practical. We're allowed to do as much research as we want and take in notes, so I've tried to find out elsewhere but I can't; this is far from my first port of call. It would be extremely useful to find out which the yellowy liquid is. Thank you for any help you could possibly provide. Chocolate muffins in a basket 11:12, 25 February 2010 (UTC)

Right, I strongly suspect the stinky stuff is 1-aminobutane (there's an article here on n-butylamine, I might put in some redirects later so it's all IUPAC'd up). Amines in general are fishy or ammoniacal as far as smell goes. It should also be the slightly yellow liquid. You could probably work out which one is benzoic acid with universal indicator (or, to show off, an acid-base titration). As for the others, I'm sure you can come up with something. Brammers (talk) 11:26, 25 February 2010 (UTC)

Thank you very much. I've looked at previous experiments and it looks like it is 1-aminobutane that smells. I also have which is benzoic acid. And I can easily work out the other two solids using Brady's reagent. Thanks. Chocolate muffins in a basket 11:33, 25 February 2010 (UTC)

You're welcome! Also, just remembered that benzaldehyde smells strongly of almonds, which could be handy too. Good luck with the coursework! Brammers (talk) 16:29, 25 February 2010 (UTC)

Do you have access to the samples? Dissolve some sodium hydroxide in aqueous solution and dissolve a little of the suspected benzoic acid in it. If the suspected sample doesn't dissolve, it's not benzoic acid. Acetamide is a very common solvent -- it can hydrolyse into ammonia and acetic acid (both of which smell). You need very little hydrolysis to notice this -- just heat acetamide with a little sulfuric acid or sodium hydroxide until it boils. Both benzaldehyde and benzonitrile smell like almonds. Ethyl benzoate (a liquid) hydrolyses into benzoic acid and ethanol -- it'll smell a little like vodka when you do this, essentially. Benzophenone should be the reagent behaving like an aldehyde/ketone not smelling like almonds.

Your problem might be distinguishing the benzonitrile and the benzaldehyde. They have similar boiling points (about 10 C apart), But benzonitrile will hydrolyse into benzamide and then benzoic acid. Benzaldehyde can't hydrolyse and will turn a positive for aldehyde detectors. John Riemann Soong (talk) 05:27, 28 February 2010 (UTC)

Nonrenewable Energy

Coal, oil, natural gas, and nuclear fuels such as uranium are nonrenewable. So if we continue to use them at the current rate, when will they be used up?

Bowei Huang 2 (talk) 09:13, 25 February 2010 (UTC)

Our fossil fuel article gives the estimates below.

Years of production left in the ground with the most optimistic proved reserve estimates (Oil & Gas Journal, World Oil)

• Oil: 43 years (or 43 years using proven levels and flows in the fossil fuel article)
• Gas: 167 years (or 61 years using proven levels and flows in the fossil fuel article)
• Coal: 417 years (or 148 years using proven levels and flows in the fossil fuel article)

but it's a big assumption to say we continue to use them at the current rate. Currently our use is growing, but Hubbert peak theory claims that use will decline as reserves run out and prices get higher.

Estimating how long uranium reserves will last is also tricky, because it depends on whether breeder reactors are used (and because the industry is currently experiencing a regrowth). World energy resources and consumption gives an estimate of 70 years and then says most industry observers disagree (which is helpful). AlmostReadytoFly (talk) 11:38, 25 February 2010 (UTC)

The French authority NEA gave 100 years based on 2006 consumption rates.[1] AlmostReadytoFly (talk) 11:48, 25 February 2010 (UTC)

This link World_energy_resources_and_consumption#Nuclear_fission gives the reserves of nuclear fuel as 2500ZJ. With a worldwide total energy consumption of 474EJ (your first link) I calculate more than 5000 years reserves of nuclear fuel even if we would stop using any other energy sources completely. 95.115.141.196 (talk) 13:40, 25 February 2010 (UTC)

Does this presume 100% energy recovery from the 2500ZJ,or is that already factored in? Googlemeister (talk) 17:29, 25 February 2010 (UTC)

Dunno, that's just what the article says. Let it be pathetic 10% and it still will be enough for a good 500 years. (Don't get me wrong, I'm not into soapboxing today (I said: todoay) and not saying anything about nuclear waste.) 95.115.141.196 (talk) 18:06, 25 February 2010 (UTC)

For the fossil fuels (coal, oil, gas), we can't run out because if we burned all that there is, the greenhouse gasses produced would make the earth virtually uninhabitable. Uranium is a much bigger unknown. If we manage to get fusion working reasonably - then there are truly vast reserves of hydrogen to work with...although a lot depends on the final technology. While you're worrying, you might want to consider the world reserves of copper, helium and the "rare earth" stuff from which high powered magnets are made. All three will run out long before fossil fuels - and at least copper and rare-earth magnets are essential to the very energy reduction efforts in things like electric cars - and in renewables such as wind turbines. Several other rare metals that are frequently used in batteries and high-tech electronics come only from single sources in places that are politically unstable. Not good! SteveBaker (talk) 14:14, 25 February 2010 (UTC)

From Rare earth element: "rare earth elements are found in relatively high concentrations in the earth's crust". 95.115.141.196 (talk) 14:51, 25 February 2010 (UTC)

They are called "rare" for a reason. These concentrations aren't generally high enough to be economically viable. See this, for example or this. SteveBaker (talk) 03:08, 26 February 2010 (UTC)

So the problem is not the world reserves as such but the ore quality. It takes more energy to concentrate and extract the metals. So it boils down to the availability of energy. Is China politically unstable? 95.112.185.232 (talk) 08:47, 26 February 2010 (UTC)

Copper can be easily recycled. Same for the rare-earths (although it does require quite a bit more effort to separate them). Helium can be extracted from the air by liquefication and distillation, with a significant expenditure of energy. So, despite what SteveBaker says, we won't ever really "run out" of any of these. 24.23.197.43 (talk) 06:57, 28 February 2010 (UTC)

I clearly remember when I was still at school (about 1976?) reading an earnest newspaper report saying that the world's oil reserves would be exhausted in 1984. Prediction is not a precise science. Alansplodge (talk) 17:32, 25 February 2010 (UTC)

There was a very obese American pundit who around that time was well known for saying that the world would get increasingly materially wealthy. Who was he, and was he right? 78.147.93.182 (talk) 21:21, 25 February 2010 (UTC)

We could use all the fossil fuels very slowly without global warming being an issue. The half-life of CO2 in Earth's atmosphere is, perhaps, a few thousand years (it is unclear), so if we take 50,000 years to use it all the fossil fuels, we should be ok. --Tango (talk) 03:23, 26 February 2010 (UTC)

We've had 40 years worth of oil left for at least the last 50 years. Take all such estimates with a tablespoon of salt. They are usually based on known reserves accessible with current technology, so are just a lower bound. As we search more and our technology improves, we find more oil we can access. We will never actually run out, of course, since as we get near the price will go up and people will switch to alternatives that will be cheaper. --Tango (talk) 03:23, 26 February 2010 (UTC)

The price is already going up. Haven't you been living in this planet the last few years? Dauto (talk) 03:44, 26 February 2010 (UTC)

The price hasn't gone up anywhere near enough to have a significant impact on demand. People aren't going to stop using energy, so demand will only go down if people switch to alternatives. That means the price has to get higher than than the cost of the alternatives. We're still a long way off that (although a carbon tax or cap-and-trade scheme could achieve it artificially). --Tango (talk) 22:24, 27 February 2010 (UTC)

moon mission

why is it that no other country other than us has been able to sent a man on moon. while us had done it almost 50 years ago. do all other countries cant create such a mission even after so many years.....piyush (talk) 09:15, 25 February 2010 (UTC)

They probably didn't think it was worth the cost. Watch an expert explain it.

Ben (talk) 09:44, 25 February 2010 (UTC)

There was a lot more prestige involved in a Cold War space race. Clarityfiend (talk) 10:17, 25 February 2010 (UTC)

Could it be done at all today? 95.115.141.196 (talk) 11:53, 25 February 2010 (UTC)

It is worth mentioning that some people think it didnt happen Moon_landing_conspiracy_theories. If it did happen 50 years ago, it should be orders of magnitude cheaper and easier to do now, due to advances in technology and industrial processes. Therefore, a billionaire could easily do it himself. —Preceding unsigned comment added by 194.196.95.89 (talk) 11:58, 25 February 2010 (UTC)

Well, this is not a place for soapboxing, so I leave it like that. 95.115.141.196 (talk) 12:16, 25 February 2010 (UTC)

Computers have been getting cheaper because the components have shrinking and mass production has been encouraging research, (and probably because computation is a fundamentally easy thing to do, with the laws of physics we have). Even if we were mass-producing moon rockets, that wouldn't change the fact that the only way to get to the moon is to strap yourself to a thirty-story tower of explosives. (the Space Shuttle has a comparatively easy job, since it only goes to low earth orbit.) Paul Stansifer 14:35, 25 February 2010 (UTC)

The reason other countries didn't bother is the same reason why the US stopped going there and has never returned...there was prestige value to being the first (and the US was really desperate for the Soviet Union not to get that prestige) - there was (and still is) no prestige value in being second. Aside from that - there is little reason to go to the moon. Until we have the technology to create robotic factories that could do something interesting with the moon's resources, it's essentially an entirely boring place. With robotic factory technologies, there are a few interesting projects:

1. Build massive solar power generation facilities at the lunar poles and beam power back to earth from them. (Although, arguably, doing that at a suitable Lagrange point might be easier).
2. Build a telescope on the back side of the moon where it could see without the earth being in the way - and a radio telescope would not pick up all of the radio pollution from here on Earth.
3. Mine Helium3 and ship it back to Earth to make it easier for us to build fusion power plants.
4. Use solar power and water from deep craters near the poles - make hydrogen and oxygen for deep space missions - and to provide for an eventual human colony on the moon.

But none of those things could usefully be done by a handful of people going for a few days as in the Apollo era. It takes massive construction equipment - and that means either a large group of humans (which would be ruinously expensive) or fancy autonomous robots (which we don't yet have the technology to provide).

So there is literally no reason to go there. It's a very dead, boring place. We have moon rocks to study and we have really detailed photos...what more do we need? 14:05, 25 February 2010 (UTC)

A French expedition to the Moon found it occupied by an alien civilisation. Cuddlyable3 (talk) 17:18, 25 February 2010 (UTC)

Hmmm - good point. A very dead, boring place...with Frenchman - that's an even better reason not to go there! :-) SteveBaker (talk) 19:30, 25 February 2010 (UTC)

50 000 000 != wrong. Cuddlyable3 (talk) 20:18, 25 February 2010 (UTC)

It is important to distinguish between not being able to go to the Moon and not trying to go the Moon. The US is the only country to ever fail to land on the Moon (see Apollo 13). --Tango (talk) 01:37, 26 February 2010 (UTC)

So they say... ;-) --Mr.98 (talk) 04:20, 26 February 2010 (UTC)

By that logic Tango, I am the greatest professional baseball pitcher ever, because not only have I never allowed a run, I have never walked a batter, given up a hit, or even failed to get a strike on every pitch! A sample size 0 offers no data whatsoever. Googlemeister (talk) 19:22, 26 February 2010 (UTC)

I never said least failure corresponded to greatest. --Tango (talk) 21:36, 27 February 2010 (UTC)

The truth is getting to the moon was exceptionally difficult in 1969 and had not a huge amount of payoff other than propaganda. Could the US do it again? Probably, but it would take a lot of specialized work to do it. Sending up satellites and even ISS missions is a very different sort of work than landing on the moon. You don't immediately go from sending unmanned probes to making manned craft again in a short working order. A space shuttle can get people and things into space and back again (with still some difficulty), but it is not the same thing as landing on a totally different body with different gravity and etc. It's a non-trivial task, even today. The reason no one else has bothered is because there is great risk, great cost, little reward. --Mr.98 (talk) 04:20, 26 February 2010 (UTC)

1. The United States was extremely wealthy during the heydey of the space program, compared to other nations.
2. The cachet of having gone there first is now obviously gone.
3. The hubris of the American government before Obama was incredible (excluding chilled-out presidents like Clinton and Carter), so it would be far more amenable to grandiose, ridiculous projects than more meek governments in old world nations like China, Russia, France, the UK and so on. I think I can speak for my nation, Canada, by saying that we'd see little reason to go to the moon, even if it were easy. It's much nicer down here! Vranak (talk) 17:51, 27 February 2010 (UTC)

Canada has fare more unexploited resources per capita than most other countries, including the USA. So I agree that there is very little use for such a rich country as Canada to venture to the moon. Not all countries are blessed as much as yours. Where can I apply for residence? 95.115.180.185 (talk) 21:30, 27 February 2010 (UTC)

I would love to go back to the Moon — me personally, if possible, but otherwise just any humans from a liberal country, which means in practice that the only country that could conceivably do it, and that I wouldn't want them to, is the PRC. But not just go back to go back — that's been done. So I'm of two minds about Obama's cancellation of the project. Some experts believe that the project as conceived could never have been successful; it wasn't allocated the necessary resources, and there wasn't a realistic political prospect of getting them.

I want to see permanent human settlement of space, and I want to get to Mars. Was the Bush Moon project the best way to achieve one or both of those? I am no expert. Obama doesn't sound like he means to give up on human space flight; it sounds like he eventually wants the same things. If so, could be he made the bet call. --Trovatore (talk) 21:51, 27 February 2010 (UTC)

Don't discount the possibility of a private mission to the moon. There are two real reasons for a country to go to the moon: glory and science. The glory has already happened - there can only be one first man on the moon. Science is generally done just as well and at far lower cost by robots. So there is really no reason for a country to go to the moon. A company, on the other hand, does things for money. If you can make a moon mission profitable, a company can and will do it. That won't be the case any time soon, but give it 20-30 years. Virgin Galactic will (unless something goes wrong during testing) soon have sub-orbital tourism happening on a regular basis and, sooner or later, be making money out of it. Bigelow Aerospace are pretty close to having a functioning man-rated space station. Making the jump from sub-orbital to orbital won't be easy, but I'm fairly confident it will happen. I wouldn't be at all surprised to see a working space hotel in orbit within 20 years. Once you can get to and live in LEO, getting to the Moon isn't actually that hard. The only issue will be whether it can be done profitably. Tourism should be enough for LEO missions to make money. The Moon will probably need something more. Exporting He-3 for fusion reactors is one possibility, but we need some fusion reactors first. The other major possibility is supporting other space missions. While there may not be enough people wanting to refuel on their way to Mars (one common suggestion) to make it profitable, there are existing space missions that could benefit from help from the Moon. Geostationary Earth Orbit is, in terms of energy, roughly equidistant between the Earth's surface and the Moon's surface. That means sending ships from the Moon to refuel/repair/boost to graveyard orbits geostationary satellites could be more efficient that doing it from Earth (basically it isn't done at all now). There could be a lot of money in that. If you have a few tourists as well and a few scientists, you start to have a working business model. --Tango (talk) 22:20, 27 February 2010 (UTC)

I'd love to see a private mission. Any budding John Galts out there? Convince me you have a realistic, workable proposal, and I'll invest. --Trovatore (talk) 22:46, 27 February 2010 (UTC)

(... or maybe I should say Delos D. Harrimans). --Trovatore (talk) 22:50, 27 February 2010 (UTC)

Another reason for us to (eventually) go back to the Moon would be to mine ilmenite ore for titanium and zirconium -- there's lots of it on the Moon and it's very valuable. The big problem would be how to bring it back to Earth... 24.23.197.43 (talk) 07:03, 28 February 2010 (UTC)

Steam

I was given two questions, to which I'm pretty sure I know the answer to, but I would like to confirm them.

Q1: "When given a bowl of chicken soup, which way does the smoke go, and why?" My answer would be that it travels upwards, because the water vapour rising off the surface of the bowl is hotter, and therefore less dense, than the surrounding air. However, I have an auxillary question (this is my own): would the fact that this steam has more water vapour significantly affect it's relative density?

Q2: "When a cold box is opened, which way does the smoke go, and why?" My answer would be that it goes downwards, because the vapour is now colder than the surrounding air. Auxillary question: why is there vapour in the first place? Is it because air trapped inside the box when it's closed gets cooled down, which causes the water in the air to condense? —Preceding unsigned comment added by 173.179.59.66 (talk) 09:44, 25 February 2010 (UTC)

First vapor is not smoke. What you see when you open a cold box, vapor apparently going out, is in reality cold air condensing water vapor that was outside the box. Non Zero-sum Ed (talk) 11:33, 25 February 2010 (UTC)

Q1: See the article Steam. What you see as smoke consists of hot water vapour (invisible) plus a visible white mist of water droplets where the vapour condenses in contact with external cold air. The mist is an Aerosol that is slightly denser than air and eventually falls as it cools.

Q2: What you see as smoke is invisible cold air plus a visible white mist of water droplets where external water vapour condenses in contact with the cold air. Otherwise your answers are correct. Cuddlyable3 (talk) 16:41, 25 February 2010 (UTC)

So, to confirm: in Q1, the smoke will first rise, due to higher temperatures, but then fall as it cools due to higher density; in Q2, the smoke will fall due to the combination of being both cooler and denser than the surrounding air? —Preceding unsigned comment added by 173.179.59.66 (talk) 05:13, 26 February 2010 (UTC)

Donating plasma

According to the American Red Cross [2], referring to plasma: The "best blood type to donate: AB+, AB-, A+, A-" Why are these blood types better?--Non Zero-sum Ed (talk) 11:30, 25 February 2010 (UTC)

According to blood type "Type O plasma, containing both anti-A and anti-B antibodies, can only be given to O recipients. The antibodies will attack the antigens on any other blood type. Conversely, AB plasma can be given to patients of any ABO blood group due to not containing any anti-A or anti-B antibodies." This indicates why AB is good and O is less useful. I'm not sure why they prefer A over B --Normansmithy (talk) 12:00, 25 February 2010 (UTC).

According to blood type type A is more common - therefore type A plasma can be used to transfuse more peoplem and is therefore more useful. --Phil Holmes (talk) 12:15, 25 February 2010 (UTC)

In my fantasy world, where everyone who can would donate some blood product, I would want especially O to donate whole blood rather than "just" plasma, since universal-donor is particularly useful itself (as opposed to "O plasma is not as useful as others'"). Totally speaking from my own head only here. DMacks (talk) 21:10, 25 February 2010 (UTC)

You have to separate out the red blood cells from the plasma before you can give O blood to a non-O patient (otherwise the antibodies are still there and will attack the recipient's RBCs). Doesn't that means you can take whole blood from an O donor and benefit from both the RBCs and the plasma? I don't think we need to choose between the two. The advantage of plasma-only donations is that you can donate more often. As far as I know, you can donate whole blood once every few months and donate plasma every few days, so there still isn't a need to choose. --Tango (talk) 22:31, 27 February 2010 (UTC)

milk ph

milk is a basic ph but i heard when it is drunk it is converted by the body to a acid, is this true? is drinking milk beneficial or detrimental to raising the bodys ph ? —Preceding unsigned comment added by 67.246.254.35 (talk) 15:40, 25 February 2010 (UTC)

You are probably talking about lactic acid. Some are affected more by it than others. It isn't really beneficial or detrimental to the body's ph level. -- kainaw™ 15:46, 25 February 2010 (UTC)

im not referring to lactic acid —Preceding unsigned comment added by 67.246.254.35 (talk) 16:26, 25 February 2010 (UTC)

Milk isn't basic pH, it's slightly acidic at around 6.4-6.8. I doubt it would have either a detrimental or beneficial effect on the body with respect to the pH. Someone feel free to prove me wrong. Regards, --—Cyclonenim | Chat  17:53, 25 February 2010 (UTC)

The body is strongly buffered. I don't think you could drink enough milk, even if it were converted to acid, to change the body's pH. As an aside, acid lowers pH (bases raise it). DMacks (talk) 18:03, 25 February 2010 (UTC)

We are mammals. We've evolved to drink milk. We're capable of spending the first year of our lives living on nothing else whatever! If you have the gene for lactose tolerance (as a good majority of humans do) then your digestive system should work just great with stuff that has whatever pH milk has. Why would you think otherwise? SteveBaker (talk) 19:27, 25 February 2010 (UTC)

Actually Steve, a good minority of humanity has the gene for lactose tolerance; the majority become lactose intolerant as they grow up, like most mammals. A good majority of European humans have the gene, relatively recently evolved, for lactose tolerance. 86.177.121.239 (talk) 20:04, 25 February 2010 (UTC)

yes i understand milk is about 6.8 ph but what i heard is that for some reason the body coverts it to about 4.0 or lower is this true? —Preceding unsigned comment added by Thekiller35789 (talk • contribs) 19:32, 25 February 2010 (UTC)

I still don't get where you thought milk was basic then, if you understand that milk is slightly acidic and you thought it went even more acidic. Anyway, no, it won't be as low as 4.0 because all that is happening during digestion is the bonds are breaking and new products are forming, mostly protein and lipids. Neither would be at pH 4.0, I don't think. Regards, --—Cyclonenim | Chat  20:55, 25 February 2010 (UTC)

I was always told milk was basic when I was younger, and that it can be used to neutralize battery acid if a battery leaks. It wasn't until later that I found out that it was acidic. Falconus^{p t c} 02:47, 26 February 2010 (UTC)

Yes, I used to think milk was alkali... anyone know where that misconception comes from? --Tango (talk) 03:02, 26 February 2010 (UTC)

Milk is buffered, which is a fancy chemical way for saying that it resists changes in pH. Essentially, regardless of whether you add an acid or a base to milk, it tends to rebound back to near its native pH level, which is how buffers work. Add a base, and the pH snaps back to the pH of milk. Add an acid, and the pH snaps back. Which is why people have vague recollections of being told to drink milk to treat either acid or base poisoning. Also, the buffering effect of milk is why drinking too much milk can make you throw up. The classic "you can't drink an entire gallon of milk in one hour" is because your stomach expects a very low pH. There are biofeedback mechanisms which, if your stomach pH is out of whack, causes you to throw up. Because milk is a buffered solution, when you drink a lot of it, it causes your stomach to think you've ingested something which is bad for you, and causes your vomit reflex to kick in. You can easily drink a gallon of plain unbuffered water in the same time period, because it isn't buffered, and so will not drastically change your stomach's pH as much as milk will; even though pure water is at a more basic pH than milk. --Jayron32 05:41, 26 February 2010 (UTC)

Fascinating - thank you. --Tango (talk) 06:15, 26 February 2010 (UTC)

Articles about plants and animals

Well, this is a question that might sound like a complaint. If so, it's against the world as such, not against the contributors of wikipedia. And it's hard to put it in a question.

I was looking at Jerusalem artichoke and would have liked to know plants that grow in similar climate/soil. No way to search for them before I know the names already?

I was looking at Rock samphire and would have liked to know how it manages to grow practically on stones.

When looking at articles about animals I'm generally not much interested in their dental formulas but in their ecological niches and, for example, what a lynx does better or worse than a competing fox in the same wood.

Am I somehow perverted to be interested in such things, or why is wikipedia lacking such information? 95.115.141.196 (talk) 16:25, 25 February 2010 (UTC)

Curiosity is healthy and Wikipedia is still a work in progress with room for improvement. Cuddlyable3 (talk) 16:45, 25 February 2010 (UTC)

The questions are great and when I have similar questions, and I don't have the resources to find the answers, I go to the "discussion" page of the article and add a new section asking for a knowledgeable editor to add a section with the information. Some day someone may do it. Comet Tuttle (talk) 18:00, 25 February 2010 (UTC)

I agree entirely with that - but people should recognize that there are limits to the depth of information that an encyclopedia can offer. I absolutely guarantee that the information that's being sought here isn't in (say) Encyclopedia Britannica. There comes a point when searching for very deep knowledge when you have to say "Well, I need to get a proper textbook on that subject". If we wanted to say everything there was to say about (say) Foxes - then the article would probably be 1000 pages long - about the length of a handful of books and a few dozen scientific papers about the animal. There is little likelyhood of that much information being written about every single animal, plant and Japanese railway station in existence (well, maybe there is a chance for the railway stations!). SteveBaker (talk) 19:25, 25 February 2010 (UTC)

I agree that an article cannot contain everything. But have you had a look at Rock samphire? Can you tell me seven articles about animals that refer to their ecological niche in comparison with their competitors? In the previous millennium (exaggeration intentional) Encyclopedia Britannica and dental formulas were the state of art, and a hand full of people making celluloid pictures of African animal wildlife became the avant-garde of zoology. (And finally I can't avoid soapboxing: we have fallen far behind our possibilities, in many aspects; pluck lost, all lost.) 95.115.141.196 (talk) 19:48, 25 February 2010 (UTC)

Steve Baker is conscious of the Information explosion. But Wikipedia has presently 3 200 000+ articles (English version), it's still growing and we are told WP:DWAP. Moore's law seems eternal so what can stop Wikipedia ìncluding everything? Software bloat? Search engine overload? Vandalism? Editors departing to jobs that pay real Money? Cuddlyable3 (talk) 20:42, 25 February 2010 (UTC)

There's more between client and server than a linear search algorithm could imagine. Disk space lost, little lost. Information lost, much lost. Pluck lost, all lost. 95.115.141.196 (talk) 21:06, 25 February 2010 (UTC)

What the pluck? Cuddlyable3 (talk) 22:48, 25 February 2010 (UTC)

I've always thought that a free online database and Wiki about garden flowers (and vegetables) would be very useful. There must be around twenty different pieces of information that a gardener would like to know when choosing flowers to grow in their garden. Even the best gardening books are incomplete and only give some of the information you need. 78.151.155.128 (talk) 01:00, 26 February 2010 (UTC)

There are lots of kinds of information that I'd love to have in Wikipedia too - but wishing it were here and actually getting it done is a very different matter. Category:Garden_plants links to about 300 articles about garden plants, List_of_garden_plants appears to link to several hundred also. Researching, referencing and adding all of that information would a very considerable effort. If someone wanted to undertake that, I doubt there would be any objections to creating an infobox to collect the relevant stuff in a uniform manner. There are a lot of subjects that would benefit from that treatment - but it takes some dedicated enthusiasm to make it happen.

I often joke about articles about Japanese Railway stations - but just marvel at List of railway stations in Japan - there are by far more articles about Japanese railway stations than about garden plants. Each one has a photo, a list of other stations on the same line, the history of the place, what bus stops there are there. It's crazy! I doubt that those articles get one visitor a year each! There are articles about all of the railroad companies, all of the rolling stock - you name it, if it's anything remotely to do with Japanese railways - and there is a really good Wikipedia article on it! Wikipedia:WikiProject_Trains_in_Japan is an entire user group set up entirely to create and administer these articles and standards for quality for them.

I completely agree that keeping all of that information about what kinds of soil, light, watering and feeding each kind of garden plant needs is vastly more useful than having 500 articles about Japanese railway stations in an English-speaking encyclopedia. But it's a labor of love. A small group of editors does that (and probably very little else) and it's an incredibly detailed record. If some person (or small group) were to attack the garden plant articles with the same enthusiasm as the Japanese railway folks - the encyclopedia would be better for doing that. But we can't possibly do anything to make it happen.

If someone with the knowledge and enthusiasm comes along, we'll get it. If not...not. But again, compare us to other encyclopedias. Aside from specialist gardening encyclopedias - I doubt most general purpose encyclopedias have half the coverage we have at half the depth we have.

SteveBaker (talk) 02:54, 26 February 2010 (UTC)

The information about flowers would get really useful when you can search all of it. The BBC has an online database of flowers which is the best I've seen anywhere but only some of the information is searchable - you cannot for example search for those flowers that should be sown in february. I wonder if it would be possible to use existing AI to search through all the existing flower articles in Wikipedia and construct a database automatically? 92.29.32.229 (talk) 21:07, 26 February 2010 (UTC) 92.29.32.229 (talk) 21:04, 26 February 2010 (UTC)

One of the directions I'd passionately like to see Wikipedia diversify into would be to start a formalization of the knowledge that Wikipedia holds into something like the Cyc representation. This is a formal language that represents raw factual knowledge in a form that computers can readily understand. There have already been some some investigations into this possibility. Some examples from our article are:

(#$isa #$BillClinton #$UnitedStatesPresident)  --"Bill Clinton belongs to the collection of U.S. presidents"
(#$genls #$Tree-ThePlant #$Plant)  -- "All trees are plants".
(#$capitalCity #$France #$Paris)   -- "Paris is the capital of France."
(#$relationAllExists #$biologicalMother #$ChordataPhylum #$FemaleAnimal)  -- All objects that are Chordata have a mother who is a female animal.

Cyc systems use relatively simple inference systems to answer complicated questions using this kind of database: "Did all United States Presidents have mothers?". Cyc could check that United States presidents are required to be human and that humans are Cordata's and therefore, yes, they do - but then it could check all of our articles about US presidents and see if each one has an explicit mention of a mother - thereby causing us to be notified that there are three articles about US presidents whose mothers are not mentioned. It would be wonderful to have the ability for software to automatically extract knowledge from the encyclopedia - as well as do complicated things like check it for consistency and automatically find references from one article that could be used to verify facts in others. Our existing system of links and categories could become something much more intelligent. It could easily replace the "Category" system with something completely automatic - because "Category:UnitedStatesPresident" would automatically be populated with people for whom there is a "(#$isa #$xxxxx #$UnitedStatesPresident)" entry. Obviously we'd want to wrap this horrible syntax with a nice GUI that lets you enter facts in this way.

The power of having the whole of human knowledge stored in a computer-understandable way would be phenomenal. I think that such a thing would have as big an impact on our society as the Internet itself. SteveBaker (talk) 22:04, 26 February 2010 (UTC)

Ah, that's the kind of answer I wanted to see. How can we do this? How can I help? 95.112.185.232 (talk) 22:29, 26 February 2010 (UTC)

We are closer than you might think. See DBpedia. --Stephan Schulz (talk) 22:31, 26 February 2010 (UTC)

Mood Rings

Please explain in layman's terms how the stone on the mood ring changes color. Thanks --12.170.106.12 (talk) 18:28, 25 February 2010 (UTC)

Have you tried reading Mood ring? Is there something specific you don't understand? --Tango (talk) 18:34, 25 February 2010 (UTC)

It said something to the type of crystal it is but how does this crystal change color? What makes it different say when you touch a quartz crystal? --12.170.106.12 (talk) 18:36, 25 February 2010 (UTC)

The Liquid crystal article explains this in a reasonable amount of depth. APL (talk) 18:50, 25 February 2010 (UTC)

They use the same principle as one of those plastic-strip thermometers - it uses a liquid crystal that changes color as a function of temperature. The theory (and it's a terrible one) for how they tell your "mood" is that your body temperature is supposed to change when you get angry, etc. The trouble is that to the extent that this is true (which is to say "not much") is far FAR less than the color changing chemical will require to change color. By far the most significant thing that determines the temperature (and hence color) of the ring is how warm the air is around it. Proponents of these pieces of junk claim that in women, their "time of the month" affects their body temperature - and also their mood - but even that is really hard to justify. Basically, mood rings are junk. SteveBaker (talk) 19:11, 25 February 2010 (UTC)

At least they're less gaudy than a hypercolor shirt. APL (talk) 20:06, 25 February 2010 (UTC)

I hear they are really good at telling you the mood of your pet rock though. SteveBaker (talk) 02:27, 26 February 2010 (UTC)

Ah! Then they're obsolete! Modern pet rocks are USB compatable. APL (talk) 06:14, 26 February 2010 (UTC)

Killing those fun guys.

Fungi are annoying, often pathogenic, and because they're eukaryotes they're a bitch to treat. Therefore, when treating, presumably we have to develop drugs which primarily disrupt a fungus' unique characteristics. One such characteristic would be the presence of hyphae, and I can think of several very prevalent diseases which use them such as oral candidiasis. Why, then, is thrush so hard to treat? If we could target the mechanisms by which hyphae are used, or prevent them from growing at all, why haven't drug companies exploited this fairly obvious difference between humans and fungi? Is it simply that there isn't a known drug which can disrupt hyphae activity without harming humans (due to a similar protein or such things)? I'm not a pharmacist or pharmacologist so there must be a decent reason why this has been excluded from drug companies checklists? Regards, --—Cyclonenim | Chat  19:06, 25 February 2010 (UTC)

To answer your specific question, hyphae are not clinically useful antifungal targets for several reasons. First, hyphae, if anything, act as protective structures that insulate the fungal cell to a certain degree (similar to the bacterial capsule of certain species such as the one that causes gonnorrhea), and the fungus is perfectly able to get along without it. I should also note that most fungi that parisitize humans do not grow as molds. Candidiasis is caused by candida albicans, which grows as a yeast. Yeasts by definition do not grow as hyphae. Currently available antifungals do exploit differences between human and fungal cells. Most antifungals work by inhibiting the production of a molecule incorporated into fungal cell walls, called ergosterol. Some have other mechanisms, though the cell wall is a handy target being that it is chemically very different from human cell membranes. It is true that there is a small minority of fungi that causes some degree of human grief, however I will remind you that, in addition to being very useful in our food supply, a fungus gave us the first clinically useful antibiotic: penicillin. Tuckerekcut (talk) 02:54, 26 February 2010 (UTC)

Despite what you might infer from some Novartis advertisements, drug companies are motivated by revenue. They thoroughly enjoy marketing drugs that treat (but do not cure) widespread, chronic, perhaps mildly degenerative conditions that are at least somewhat life-threatening. This way, many patients will stick to their drug regimens for the remainder of their lifetime. Oral candidiasis does not fit well into this category because of low morbidity and mortality related to infection and relatively low incidence (such as in comparison to diabetes). Moreover, current forms of medication (such as clotrimazole troches and various other gels and rinses) are pretty good at reducing fungal levels to normal, allowing bacterial oral flora to re-establish their usually more prominent levels -- so why spend time, money and effort to try to develop better medications? DRosenbach ^{(Talk | Contribs)} 05:10, 26 February 2010 (UTC)

Fascinating, thanks. Though I've heard that candidiasis will effect 75% of women once, 50% twice and 25% reoccuringly, though I don't have a statistic to back that up, just heard it in a lecture yesterday. If someone found a cure for thrush, they could make billions of it straight away and then continue to make money as newborns will still get it. Regards, --—Cyclonenim | Chat  10:23, 26 February 2010 (UTC)

In the United States, the unified move to eradicate the widespread prevalence of syphilis was generated not by any of the terrible sequelae of the disease except for it leading to birth defects and/or spontaneous abortion. It was only because of this maternal-fetal public health initiative that the CDC and/or other disease prevention coalitions pushed for curbing the disease. Appreciation that the signs and symptoms of syphilis (which, by today's standards are incredibly horrifying) did nothing to really create a great worry of morbidity, one can then see why the sequelae of candidiasis (even by today's standards) do not generate greater concern (and excluding young infants who contract thrush primarily because of their still-undeveloped immune system, it would mainly be found among the HIV+, who, as a cohort, are often less disturbed by their oral health, either due to other more pressing systemic health issues or because of indigence. DRosenbach ^{(Talk | Contribs)} 18:34, 26 February 2010 (UTC)

What is A and what is AH2?

There are several articles with the generic format:

In enzymology, a Delta12-fatty acid dehydrogenase (EC 1.14.99.33) is an enzyme that catalyzes the chemical reaction

linoleate + AH₂ + O₂ $\rightleftharpoons$ crepenynate + A + H₂O

The 3 substrates of this enzyme are linoleate, AH2, and O₂, whereas its 3 products are crepenynate, A, and H₂O.

Notice that those articles (listed below) link to A and AH2, which are not chemical substances!

The articles, as far as my search could go, are:

• Delta12-fatty acid dehydrogenase - from where I extrated the above quote
• Progesterone 11alpha-monooxygenase
• Steroid 9alpha-monooxygenase
• Taxadiene 5alpha-hydroxylase
• Estradiol 6beta-monooxygenase
• Carotene 7,8-desaturase
• Ecdysone 20-monooxygenase
• Kynurenine 7,8-hydroxylase
• Linalool 8-monooxygenase
• Thiophene-2-carbonyl-CoA monooxygenase
• Glycine dehydrogenase (cyanide-forming)
• etc

What is A and what is AH2? Albmont (talk) 20:08, 25 February 2010 (UTC)

I've seen AH2 applied to enthalpy change (no idea why) and to ascorbic acid (see here). Regards, --—Cyclonenim | Chat  20:58, 25 February 2010 (UTC)

Adenine. It looks like the usual cofactor for this class of enzymes is NADH or NADPH, which acts as a hydrogen donor to form NAD(P)+ as byproduct. DMacks (talk) 20:58, 25 February 2010 (UTC)

That'd probably make more sense than my suggestions... :) Regards, --—Cyclonenim | Chat  20:59, 25 February 2010 (UTC)

Ascorbate is a reasonable possibility for a redox-active item as you found. I searched for these specific enzymes (using the links in the infobox for the first example), which gave me a slightly more explicit reaction. Man, biochem is hard enough without having a pile of undefined and mis-wikilinked terms unless the reaction really does take place on a highway in Asia. DMacks (talk) 21:03, 25 February 2010 (UTC)

I traced the KEGG entries that mention "AH2", and they all appear to point to just a generic type (based on reactivity) rather than a specific compound (different enzymes work with different structures perhaps?). AH2: "Reduced acceptor; Hydrogen-donor". DMacks (talk) 20:16, 26 February 2010 (UTC)

Are we all immortal?

Hear me out on this. When you are born you can first be observed by the universe. When you die you no longer can be observed. However relativity only permits information to travel at the speed of light. Therefore (assuming the universe is infinite) there's a wavefront heading away from you at the speed of light from the moment your born and it only ends when you die. Yet that wavefront will propagate forever. A wavefront that contains all the information that is you. A shell maybe 80 light years thick forever expanding out across the universe. Anywhere in that shell you will always exists. TheFutureAwaits (talk) 20:33, 25 February 2010 (UTC)

No, I think you would not exist, only the photons bouncing off of you would exist, or perhaps a radio signal or similar with your voice on it. Googlemeister (talk) 20:37, 25 February 2010 (UTC)

See that initially seems like the easy answer. But consider to an observer hundreds of lightyears away I won't exist until that light reaches them. TheFutureAwaits (talk) 20:41, 25 February 2010 (UTC)

Your image is not you--it's neither the complete information content of you nor the actual embodiment of that info. There's some plausibility to the idea "if there was a completely precise and accurate description of you, you could be recreated exactly as you are using that dataset". The photons bouncing off you are not that complete dataset (although they are influenced by some/much of it beyond the skin surface). DMacks (talk) 20:46, 25 February 2010 (UTC)

This seems like it's just a semantic argument about what it means to exist at a particular time and place. If you want to define existing at a particular time as still having an impact on events, then sure you exist forever everywhere inside of your future light cone. Is that a useful way to define it? Rckrone (talk) 20:50, 25 February 2010 (UTC)

From any given point of view you will exist for only a finite period of time.

More to the point (I think), you will only ever being observed having a finite number of interactions with the world around you. If you don't learn to ride a bicycle now in your (locally observed) life time, no one in the Andromeda galaxy will ever observe you riding a bicycle. APL (talk) 20:55, 25 February 2010 (UTC)

True, you can't change things but to an outside observer you will be making those decisions in realtime. TheFutureAwaits (talk) 20:59, 25 February 2010 (UTC)

When you talk about your existence do you mean just the image of your warm body that a camera can capture? If so then by your understanding "you" are indeed an expanding shell. The catch is that some of us think we are not just images. You can't see me so do you think I exist? Cuddlyable3 (talk) 20:57, 25 February 2010 (UTC)

We aren't just images but we ARE all information. Your actions can only have an impact within their light cone. So until a place intersects that lightcone you won't exist. TheFutureAwaits (talk) 21:01, 25 February 2010 (UTC)

(after ec) "A wavefront that contains all the information that is you." Ah, but that's not you. That's just a total encyclopaedian record of you, a dead thing, unable to act by itself and unconscious of itself. (I'm always fond of an intellectual discussion where I postulate that a candle flame is alive and squash away those counter arguments like not having a soul by asking what would be a proof for anything/anyone to have a soul.) 95.115.141.196 (talk) 20:58, 25 February 2010 (UTC)

Only the soulless need that truth proven. Cuddlyable3 (talk) 21:13, 25 February 2010 (UTC)

Quantum immortality is far more interesting. --Tango (talk) 21:17, 25 February 2010 (UTC)

I think the OP is reaching for something more holistic (along the lines that each of your movement has a subtle gravitational impact on everything in the universe...). arguably true, and karmically interesting, but hardly constituent of any realistic form of immortality. --Ludwigs2 21:30, 25 February 2010 (UTC)

I'd rather agree if you'd say we are all eternal (leaving aside all possible as well as unprovable religious metaphysics). 95.115.141.196 (talk) 21:45, 25 February 2010 (UTC)

Well, there's provability, and then there's truth. Which are you really more interested in — whether it can be proved that your consciousness can exist forever, or whether your consciousness will in fact exist forever?

If you're genuinely more interested in whether it can be proved, then fine, you can probably ignore the question. But I doubt that's what most people really want to know. -Trovatore (talk) 21:54, 25 February 2010 (UTC)

I'm really more interested in provability, as an intellectual exercise, for I know about truth already. 95.115.141.196 (talk) 21:58, 25 February 2010 (UTC)

There is a whiff of arrogance hopefulness about assuming immortality from a mechanical argument. The OP's prized shell of existence gets tenuously thin walled as it expands. Given the size of the Universe our OP gets stretched down to something thinner than a balloon, then down to a membrane of Nanoparticles and eventually down to subatomic particles that are unknowably adrift in the background radiation of the Universe that certainly won't stop expanding just so the OP can catch up. Cuddlyable3 (talk) 22:22, 25 February 2010 (UTC)

Doesn't one continue to exist after death even if their body is in a mausoleum or some such place? Bus stop (talk) 22:31, 25 February 2010 (UTC)

The wall would not get thinner. Let's say you lived 80 years. The shell would be 80 light years thick, always. The physical volume of space it contained would grow but the thickness would be the same.TheFutureAwaits (talk) 23:14, 25 February 2010 (UTC)

actually, that's not true - relativistic effects would ensure that the width of the "wall" would expand/contract/bend in interaction with gravitational wells... just saying...--Ludwigs2 23:20, 25 February 2010 (UTC)

You've got the right idea, but a bit backwards. The first fact is that you exist -- the universe is only tertiary to your consciousness. When you dream, your mind is imagining things, but those imaginings mean something, while all the goings-on outside your mind are totally irrelevant until you awake. Anyway we may be all theoretically immortal, but when you die, you lose all your memories, which is not preferred! So it's a yes-but-no kinda answer. Vranak (talk) 00:24, 26 February 2010 (UTC)

When you are born you can first be observed by the universe. When you die you no longer can be observed. You existed before birth, as a fetus, an embryo, a zygote--which existed before as egg and sperm, and so on. You exist after death, as a corpse, as physical matter. We aren't just images but we ARE all information. Your actions can only have an impact within their light cone. So until a place intersects that lightcone you won't exist. Physical matter is information just the same, interacting with its environment, changing, having an effect and being effected, being "observed by the universe". Why must "your actions" only begin with birth and end with death? Are "your actions" only those done with conscious attention and intent? You digest food without conscious attention and intent--it just happens. After death your body decomposes without conscious attention and intent. I don't see the difference in terms of being "observed by the universe" or "information about you" or "actions" that "have an impact". Perhaps the question to ask is not "are we immortal?" but "what is it that lives and dies?" Pfly (talk) 11:17, 26 February 2010 (UTC)

Perhaps the question could be rephrased : "Are we radiating enough information, brain waves, gravity, etc, that the information exists, however inaccessible, to reconstruct the information that constitutes our minds."

If true, then I suppose the answer to the question would be "Yes, but not in a useful way unless some benevolent god-like alien decides to reconstitute you." APL (talk) 16:20, 26 February 2010 (UTC)

The uncertainty principle may get in the way there. --Tango (talk) 18:22, 26 February 2010 (UTC)

Tallow

where can i buy Tallow or Suet ?

A decent supermarket? --Tango (talk) 21:23, 25 February 2010 (UTC)

Suet you can get at any birding store - it's a common element of winter birdfeed. tallow is odder - it only has industrial uses in the modern world, and I don't know of anyplace to get it as a commercial product. if there's a rendering plant in your vicinity, you might give them a call and ask. or you can probably shop for it online. --Ludwigs2 22:12, 25 February 2010 (UTC)

Tallow is (was) used for caulking in wooden boats. Try asking at a chandler. CS Miller (talk) 22:20, 25 February 2010 (UTC)

In the UK you can find suet in most supermarkets, both beef suet and vegetarian 'suet'. Look by the baking supplies. As CS Miller says, tallow will be more difficult. 86.177.121.239 (talk) 22:23, 25 February 2010 (UTC)

I'd just like to caution you that bird-grade suet and industrial-grade tallow aren't made with human hygiene in mind, so don't eat them. If they were made hygienically then they'd be safe (they are just purified fats), but probably wouldn't taste that great. Should be fine for candle making tho. Tallow was used for candles, not sure about suet. CS Miller (talk) 22:38, 25 February 2010 (UTC)

I think suet can be used for candles as well (it's not that different from tallow) but I suspect it would smoke and stink badly... --Ludwigs2 23:05, 25 February 2010 (UTC)

Like most things, you can buy tallow on eBay. Or try Google products search: [3].

As general advice, if you want a better answer to this sort of question you should specify (a) where you are (b) what sort of tallow and suet you want, e.g. for what application (c) how much you want to buy and (d) whether you're looking for online or real-world shops. --Normansmithy (talk) 18:00, 26 February 2010 (UTC)

If you want tallow, you will probably have to make it, by rendering beef kidney fat, which you can probably obtain cheaply from a butcher by asking them to put some aside for you. It isn't very hard to do -- I've done it myself in an experiment at making old-fashioned pemmican. Looie496 (talk) 18:53, 26 February 2010 (UTC)

Is this Edge Peak?

Hello, I live in Langley, BC. I saw this mountain to the North. Is this Edge Peak? --The High Fin Sperm Whale 21:06, 25 February 2010 (UTC)

This shot, from a slightly different angle, is still clearly the same mountain and is called Mount Robie Reid, and that article is in need of a photo. Mikenorton (talk) 21:43, 25 February 2010 (UTC)

Messing around with Google Earth, if I approach Mount Robie Reid (using the article's coordinates) from the south-southwest at a suitably low elevation, I can get a view that looks convincingly like your photo. Mikenorton (talk) 23:10, 25 February 2010 (UTC)

Edge Peak lies North-East of Langley. Does the OP's picture fit the profile? Cuddlyable3 (talk) 22:39, 25 February 2010 (UTC)

Thanks a lot guys, that would be it! --The High Fin Sperm Whale 03:50, 26 February 2010 (UTC)

Fog

Does fog occur worldwide? Thanks in advance. Rimush (talk) 23:12, 25 February 2010 (UTC)

I would think so, and there's nothing in our article on Fog to suggest that it doesn't. —Steve Summit (talk) 23:25, 25 February 2010 (UTC)

all fog requires is sufficiently high humidity, a temperature below the dew point and above freezing, and condensation nuclei. I can't think of anyplace that would preclude those conditions (except possibly in the heart of a dessert, if there is a dessert where humidity is always negligible). --Ludwigs2 23:35, 25 February 2010 (UTC)

As our article states, some deserts are in fact quite well known for their dense fogs. Some animals are keenly adapted to that phenomenon, indicating that, in some deserts at least, it's a very regular thing. Matt Deres (talk) 04:25, 26 February 2010 (UTC)

It occurs with varying frequency, but it can occur anywhere. Some deserts may get fog only once every 10,000 years, or something, though. --Tango (talk) 00:42, 26 February 2010 (UTC)

According to this info, the highest recorded temp at the south pole is 7 degrees Fahrenheit. It would have to get quite a bit warmer to permit fog. Looie496 (talk) 02:04, 26 February 2010 (UTC)

You don't have to have liquid water for fog: ice fog. (As well, even with sub-freezing temperatures you can still have supercooled liquid droplets — small water droplets can remain liquid down to thirty or even forty degrees below zero.) TenOfAllTrades(talk) 04:16, 26 February 2010 (UTC)

Many deserts have fog, for example the Atacama Desert in Chile experiences fog that allow machines to capture the water vapor for water supply, as this desert is caused by the cooling effects of the Humboldt Current. However, I'm not sure about fog formation within desserts. ~AH1^(TCU) 00:07, 28 February 2010 (UTC)

I'm willing to bet you never get fog next to a glacier. Does anyone have any data on this? I have read that a glacier sucks all the available moisture out of the air for many miles around, and am guessing (just guessing) that this would eliminate fog as a local possibility.