Wikipedia:Reference desk/Archives/Science/2010 June 3

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June 3

Propagation of bloodline

From Malaria:

Endogamy along caste and ethnic lines appear to have confined these to the Tharu community. Otherwise these genes probably would have become nearly universal in South Asia and beyond because of their considerable survival value and the apparent lack of negative effects comparable to Sickle Cell Anemia.

Do we have an article about this? I'm interested.. say that 100 Chinese people marry into the United States, and no more chinese people after that are allowed in. After hundreds of generations, in the absence of any particular traits that give Chinese people a genetic advantage, will the percentage of Americans who "have Chinese blood" from the original 100 people increase to near 100% or decrease to near 0% over a long period of time? .froth. (talk) 00:14, 3 June 2010 (UTC)

Assuming random intermarriage, the average fraction of the genome that comes from the Chinese immigrants would stay roughly the same (except for random fluctuation), but it would become more and more widely dispersed. So the fraction of people who "have Chinese blood" would steadily increase, but their average proportions of "Chinese blood" would correspondingly decrease. Looie496 (talk) 01:36, 3 June 2010 (UTC)

Genetic drift might be of interest.--Lenticel ^(talk) 01:59, 3 June 2010 (UTC)

Specifically, the section on fixation. At such a low introduction frequency (100 foreigners into a population of 300,000,000), the alleles that are distinctly Chinese will be inevitably lost, given enough time, as a consequence of random fluctuation. Basically, this is because the frequency will fluctuate over time, and if it ever reaches 0, it will never change from that; and because of the low introduction frequency, it is highly unlikely to reach 1, from which it would also never change. Someguy1221 (talk) 05:48, 3 June 2010 (UTC)

I really can't see how a resistance to malaria wouldn't have spread throughout Asia in a few thousand years no matter how strong their rules are against marrying outside. There must be something else in it which is a disadvantage which we don't know of yet. Dmcq (talk) 15:07, 3 June 2010 (UTC)

If the female in a marriage is of a specific ethnicity, then her mt-DNA will be passed down to all her offspring, but there is as much variation in this within an ethnicity as there is between two different ethnicities. ~AH1^(TCU) 23:22, 3 June 2010 (UTC)

That's just because of the meaninglessness of the concept of "ethnicity" from a biological point of view. What does any of that have to do with this? What makes you think the relevant gene(s) is mitochondrial? --Tango (talk) 23:50, 3 June 2010 (UTC)

Chemical solution for producing infrared liquid.

Hello I have a problem. I ve made the chemical solution that produces infrared light, but only lasts for 5 mins when not in a airtight container. I need to find out, how can i make it last for a few hrs in an open aircontainer. Thanks for your time, I am eagerly awaiting your answer.If you could be kind enough to e-mail it to me on (email removed) I will be gratefull to you. Thanks. Amit —Preceding unsigned comment added by 118.90.116.113 (talk) 01:15, 3 June 2010 (UTC)

I'm sorry, but the reference desk does not provide responses via email. You'll also need to provide a lot more detail about what this solution is for us to try to answer your question. Someguy1221 (talk) 05:44, 3 June 2010 (UTC)

(EC)I do not think your question is specific enough to be answered as you've stated it. I doubt there is a generic way to increase the length of an unspecified substance's IR light production in an unsealed container. Maybe if you give us specifically what your substances are and what the reaction is that produces the light, we might have a better chance. I'm not a chemist but at a guess, your reaction is oxidizing, either accelerating or otherwise interfering with the reaction, I'm not sure there is much that can be done short of inhibiting the oxygen availability by sealing the container or flooding it with an intert gas like argon or something. Then you'll of course have to worry about what argon will do to your reaction. Vespine (talk) 05:51, 3 June 2010 (UTC)

This seems kinda basic. "the chemical solution that produces infrared light" could be a bucket of hot water. Anything that's hot (or even just warm) radiates in the infra-red...you don't need some special "chemical". The thing is probably going to stop producing IR because it's cooling down more in an open container. Just stick a heating element in the bottom of a large container of water and stop it from boiling - and it'll radiate in the IR for as long as you keep the thing plugged in! If you need more IR light than that, pick something with a higher boiling point and heat it up more. SteveBaker (talk) 14:43, 3 June 2010 (UTC)

Not a chemist, but I'd also suggest that you might be looking for something that can only reflect infrared light when exposed to only red/infrared light and not normal white light, which has a very different emission curve. Remember that reflected light is an absorption-reemission phenomenon that will depend very much on the energy of light coming in. Also, as an alternative to Steve, any kind of algae or plant life is a great emitter of infrared (aerial surveys usually use infrared cameras to quickly distinguish plant life, especially useful over water). SamuelRiv (talk) 16:07, 3 June 2010 (UTC)

You have an interesting definition of "warm" - according to my calculations, anything above 10K will have a peak thermal radiation in the IR (or higher), and that's just the peak so even things colder will emit a significant amount of IR. --Tango (talk) 21:40, 3 June 2010 (UTC)

I imagine we're talking about IR emissions observable over the background, so i doubt the OP was talking about a warm bucket of water.. I could be wrong, but that's the way i interpreted it. Vespine (talk) 03:54, 4 June 2010 (UTC)

Actually, I'd love to see what the OP had put together as his solution, and maybe I can play around with some quantum mechanics calculations to see if I can get some idea (though it has a 99% chance of being completely fruitless). Beyond that I'm completely lacking in chemistry knowledge, though I know there's plenty of literature on UV-peak solutions - maybe you can do it all backwards :). SamuelRiv (talk) 05:06, 4 June 2010 (UTC)

Cooking oil contamination?

I have a large frying pan and cook raw chicken thighs/legs for about 45/50 minutes on a low/medium setting-the oil bubbles and seems to reach high temperature for long periods. But I change the oil once a week. Bearing in mind carbonised residue build up at the bottom of the pan, could bacteria build up even in boiling oil, and how often should it be changed? The food is for my own consumption, not anyone else. —Preceding unsigned comment added by 80.1.80.13 (talk) 07:27, 3 June 2010 (UTC)

According to our cooking oil article, you should be more concerned about degradation of the oil due to exposure to air and light. Bacteria could develop in the oil when stored in the pan, and our article especially mention the risk of botulism. However, the botulism article also states that a long cooking period breaks down the botulism toxin. For more information it would probably be a good idea to look up guidelines and routines specific to restaurant and take-away kitchens.

As a side note, bacteria and fungi in general are killed by boiling, but the poisons they leave behind could survive. I seem to recall this is a problem with some yeast/fungi. EverGreg (talk) 09:33, 3 June 2010 (UTC)

"45/50 minutes" - you like your chicken well done then. What sort of oil is it, because different oils boil at different temperatures. 86.4.183.90 (talk) 18:00, 3 June 2010 (UTC)

Cooking oils don't boil at all, they break down first. There is no chance of bacterial buildup in oil that is used daily or almost-daily to fry chicken. The main reason you will want to change the oil is because stuff will leak out of the chicken and start to break down, causing it to taste gradually more nasty. Your oil will also contain steadily larger fractions of chicken fat, which is exuded by thighs and legs in large quantities when you cook them that way. Looie496 (talk) 23:07, 3 June 2010 (UTC)

...And let me add that I can hardly imagine a more unhealthy diet than eating chicken cooked that way multiple times per week. Looie496 (talk) 00:57, 4 June 2010 (UTC)

Come now, you can't being trying very hard. A diet made up of 50 Mars bars a day would surely be worse, especially if some of them were deep-fried. Or nothing but rabbits. Or, indeed, nothing but carrots. There are many more unhealthy diets that I can easily imagine, and we don't know why the OP feels the need to eat the way they do. 86.164.69.239 (talk) 20:05, 4 June 2010 (UTC)

Don't quibble - the diet indicated by the OP is still likely to shorten their life by decades, compared to an optimum healthy diet. In addition to the fat and saturated fat, high-temperature cooking creates nasty unhealthy chemicals that I do not know the details of to describe. Re-using frying oil or fat is I believe particularly bad for creating carcinogens. As I never fry food, I do not know enough to describe the details. 92.15.3.53 (talk) 10:16, 5 June 2010 (UTC)

Don't quibble? What else are we here for? :) You don't know anything about them, or what an optimum diet for them is. Certainly, most people would be well advised to have more variety in their diet, and less fat. And there is a danger in creating carcinogens with high-temperature cooking. But, again, we know nothing about this person and why they are doing what they are doing. Just for example, when my younger sibling's friend with cystic fibrosis stayed with us, they were on a high calorie, high fat diet. If they didn't eat enough fat and sugar in the form of things like mars bars, they had to eat a disgusting high-calorie paste that they hated. I made a load of buttercream which helped avoid the paste. For me, that much buttercream would be a bad diet. For them, it was a good option. So no - we do not know why the OP is eating what they are eating. We do not know what else they are eating. And there are indisputably worse diets they could be eating. 86.164.69.239 (talk) 12:40, 5 June 2010 (UTC)

There's a restaurant whose fryer hasn't been completely-emptied/filled-with-new-oil since 1912.[1] DMacks (talk) 20:21, 4 June 2010 (UTC)

I read somewhere, years ago, that when cooking oil is repeatedly used it reacts with the steam given off to create a byproduct that causes less of the oil to be absorbed, so that cooking in used oil may actually be healthier than cooking with fresh oil. In any case I find that repeatedly used oil develops an interesting flavor that can't otherwise be duplicated. When I lived in Tucson I would sometimes buy Indian fry bread. The most flavorful was always made by dumpy Navajo women with names like Nellie Begay, and their cooking oil always looked like it had been used for decades. Fry bread made with fresh clean oil tastes disappointing in comparison. Looie496 (talk) 16:57, 5 June 2010 (UTC)

I'm very skeptical about that. The discovery of the carcinogenic danger of re-using frying oil was done with a proper scientific study, although I do not recall enough to cite it. 92.24.182.48 (talk) 20:08, 5 June 2010 (UTC)

Looks to me like it would be fairly straightforward to find in Web of Science or something, if you have access at the moment (I don't).

Columbia University says, "Reusing cooking oil has been done for ages. There really isn't a problem, if done properly" and that the carcinogen danger comes from rancid oil, which is oxidised oil. Heating the oil to the smoke point will increase oxidation, so using oil with a high smoke point and keeping below that will probably help. When the oil smells and looks rancid, don't use it.

This paper from 1973 is probably interesting, if anyone can access the whole thing to skim it. Seems to be about frying chicken in new and reused oil.

This one from 1984 claims to find no mutagenic effects.

There are some other interesting looking ones I can't access at the moment, although many seem to focus on the dangers of inhaling fumes. Looks like a fun project for someone with access and some free time. 86.164.69.239 (talk) 23:16, 5 June 2010 (UTC)

Water boiling question

Firstly the actual question: "At what temperature does water boil, and how could this be confirmed experimentally?" (I'm posting this in response to some disscussions elsewhere on wiki :) )

A simplistic answer to the question might be: " Water boils at 100 degrees C. To confirm this heat some water in a kettle and measure the temperature of the steam produced."

However, there are a number of flaws and pitfalls within that answer, I can think of 3 already. :) Sfan00 IMG (talk) 14:04, 3 June 2010 (UTC)

I'm not a chemist, but if I remember my high school chemistry this assumes standard pressure. You would need a phase diagram to correctly answer this question. --Shirik (Questions or Comments?) 14:09, 3 June 2010 (UTC)

Don't you mean high school physics? Dauto (talk) 14:42, 3 June 2010 (UTC)

Well, in the UK at least, this is covered in secondary school chemistry. Vimescarrot (talk) 18:22, 3 June 2010 (UTC)

I suspect that this is in response to a previous question asked by this OP on the Ref Desk Wikipedia_talk:Reference_desk#Reference_Desk_Scope about how original research is handled at Wikiversity. The OP had suggested that doing an experiment to find the boiling point of water was a simple matter. I pointed out that there are a bunch of experimental mistakes you could make - even for such a simple question - that would mess up the answer. Hence if someone claimed to have done the experiment and gotten some value other than 100C, then I'd ask:

1. Did you measure the temperature when the bubbles just started to appear - because gasses come out of solution before boiling point.
2. Were you doing this at sea level or at an elevation where the air pressure is lower?
3. Did you put the thermometer into the water as it was heating up - or just dunk it in quickly (thereby lowering the temperature of the water immediately around the thermometer)?
4. How long did you wait for the temperature to settle down?
5. Did you remove the thermometer from the water in order to read it? (Hint: Rookie mistake - seen it a million times!)
6. How pure was the water? Even if it was distilled water, could contaminants have gotten into it from the container or the thermometer?

I'm not sure what else is being asked here - but I believe that's the background to this question. SteveBaker (talk) 14:50, 3 June 2010 (UTC)

More questions for completeness's sake:

1. How did you heat the water? If it was a pot of water heated on a stove, there could be a significant temperature difference between the bottom and top of the water.
2. If you are measuring the steam and not the water, is there any condensation on the thermometer? The latent heat of condensing water could lower the temperature registering on the thermometer.

-RunningOnBrains^(talk) 20:45, 3 June 2010 (UTC)

Thanks Steve :) , This was indeed a question not only about the actual physics (for which I have a basic idea) but on scientific technique (and the pitfalls thereof)

Of the pitfalls I can think of, the one's Steve mentions do exist :), I was also considering...

• Given the phase diagram, it's maybe possible for 'vapour' to form before the water actually boils?

Meaning that the temperature read might be of the vapour cloud, not the steam...

• Although the simple answer states to measure the steam, it isn't more specfic, This is a consideration because (conjecture)

given how a typical 'cloud' of steam from a kettle disperses, you might get different readings depending on where in the cloud you measured, owing to variations in pressure?

• How is 'water' defined? Steve makes a valid point about impurities. A releated consideration if not using distilled water

would be the potential for substances in solution(?) or dissolved gas, (water being a solvent IIRC)

• The simplistic answer assumes a single measurement with a thermometer., but depending on the type of thermometer there

may be characteristics of the thermometor which affect the result obtained.

All considerations.

I suppose revised questions should be

' How do you determine the temperature at which pure water boils given identical inital conditions, in a repeatable manner?' ' What external factors would potentialy have an influence on the boiling point of 'water' ?'

which are slightly different question to those asked initially. Sfan00 IMG (talk) 15:17, 3 June 2010 (UTC)

And while we're being uber-picky, let's toss in:

• Did your ultra-pure water have the correct ratios, deuterium, tritium, O¹⁷ and O¹⁸ in it?

SteveBaker (talk) 13:47, 4 June 2010 (UTC)

It all depends on what level of precision you want. Just sticking a thermometer into boiling water will give you the correct answer to within a few degrees every time, I can assure you. If you want to get down to a few hundredths or thousandths of a degree you need to start eliminating unknowns: Heat everything equally (atmosphere and thermometer too!), use ultra-pure water (reverse osmosis works great supposedly), and use other methods to control your environment as much as you can. -RunningOnBrains^(talk) 20:45, 3 June 2010 (UTC)

Water is rather a very difficult one to measure, partly due to the very high latent heat, which means that one has to apply a high heat source to get a good boiling mixture - thus the reading in the water can be a bit higher than you expect - just try making jam, it will vary where you locate the thermometer in the pot. Another point is that thermometers are calibrated for a fixed dip - may be 76mm, may be total immersion - you need to get that correct. The ideal way is to measure a mixture of steam and boiling water far away from its initial heat source - and the only bit of kit I have ever used that works well is a "Gillespie Still" - the boiling water/steam mixture is carried up away from the heater to the thermometer. The accuracy is very good.  Ronhjones  ^(Talk) 20:33, 3 June 2010 (UTC)

Could you clarify what you mean by a Gillespie Still as they doesn't appear to be an article yet?

( although as an item of lab equipment it shows up in a number of scientfic links when looked for on Google..) Sfan00 IMG (talk) 22:16, 3 June 2010 (UTC)

IMHO the answer you're providing begs the question, 100 degrees Celsius is an arbitrary constant BY DEFINITION the boiling point of water. It is more correct to say that you get 100 C at the point when water boils, as opposed to water boils when you get 100 C. IMHO, to prove 100 C is actually the correct boiling point you have to NOT take it for granted, a more meaningful answer would be to prove that water boils at 387.15 K. Vespine (talk) 03:48, 4 June 2010 (UTC)

That's a very misleading statement - and our OP should ignore it. The tie between definition of a degree and the boiling point of water only holds under very specific circumstances. If you measure the boiling point of water at the top of Mount Everest, it'll be around 69 degC. We don't change the temperature represented by a degree centigrade when you're standing on the top of a mountain...so your assertion that the answer begs the question is quite untrue. You can meaningfully measure the boiling point of water and end up with an answer that isn't 100C...so "BY DEFINITION" doesn't hold here. It is also untrue that the definition of 100C is simply that of the boiling point of pure water at standard air pressure. That definition was changed in 1954 and again in 1967. These days, it's defined by the triple point of Vienna Standard Mean Ocean Water which is not just pure water, it has to have precisely the right mix of hydrogen and oxygen isotopes - so even ultra-purified water might have too much or too little deuterium or tritium in it or the wrong amounts of O¹⁷ and O¹⁸ to get precisely that 100C result. So, again, this fixed relationship concept is bogus. SteveBaker (talk) 13:47, 4 June 2010 (UTC)

Water doesn't boil at 387.15K (at least not at standard pressure) according to the relevant article..

Follow on question : ' How to define the boiling point of water in manner that allows it to be used as

a reliable calibration point?' Sfan00 IMG (talk) 11:41, 4 June 2010 (UTC)

Vienna Standard Mean Ocean Water has that explanation. SteveBaker (talk) 13:47, 4 June 2010 (UTC)

Yes you need a standard composition for the water, and you also need to measure the bp under specific conditions - the atmospheric pressure is one of the most significant factors affecting the boiling point of water. pressure/bp data here. For reliable accuracy you need to know how the bp will vary with impurities as well - so you know whether the error in experimental variables will affect the bp measurement significantly.87.102.32.39 (talk) 15:41, 4 June 2010 (UTC)

I'm considering bookmarking this thread, clear yet interesting discussions. :) Sfan00 IMG (talk) 16:22, 4 June 2010 (UTC)

Another thing you can do is to define (and/or measure) the bioling point of water as a function of different variables (such as pressure) - then when you measure the boiling point another day you can look up on a table (such as given above) - to find out what the temp. should be under those conditions - ie use a barometer as well.

if you bookmark this thread the URL will change in 2-5 days when it is archived. the actual URL will probably be http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2010_June_3#Water_boiling_question 87.102.32.39 (talk) 16:29, 4 June 2010 (UTC)

Weller soldering

Good Morning, My question refers to Soldering and Weller. I've learned that my relative is Mr.Harry A.Ungar who invented the Ungar soldering pencil, Ungar soldering system, Soldering toys etc.. This has become a genealogical search as well. It seems Harry Ungar left Hungary, either from the Slovakia or Austrian areas. I've learned Mr Ungar had a plant located at 1401 Redwood, California, There is little to no biographical information that I've found but dearly need to track him back to my Great grandfather and to find living relatives.

Mr.Ungar it seems had a government contract to make soldering pencils for WW2.

Merged with Karl Weller.

Ungar/Weller sold to Cooper.

Listed in the southern Ca business directory listings1958,1961

Sidney Ungar Donated to save the Hollywood Bowl.LA Times Aug 21, 1951

His Children may be : Sidney, Leon, and Ruth Ungar(Marks).

Toys Manufacturer Assoc LA Times Dec 21, 1950 pg 25 Sidney Ungar.

I beg you! with your wonderful resources, can you help to find biographical information from any sources /media. The genealogists have accepted my hundreds of dollars but claim they are stuck. Even the above information is my work not theirs. I really need to give my children some attention and stop wasting their time as I search W/O result. Thank you in advance. Perry Urany <email redacted> —Preceding unsigned comment added by Perrykesan (talk • contribs) 16:03, 3 June 2010 (UTC)

• I've reformatted your question slightly to avoid an ugly layout of boxes and removed your email address so you don't get spammed to death. Any answers will appear here - we don't email answers out. Exxolon (talk) 16:32, 3 June 2010 (UTC)
  • Both Ungar and Weller are very well respected companies in the soldering business, and I have been a proud owner of their products. At Google Book search the earliest ref I found to Harry A. Ungar was Boys Life, Nov 1936 page 40, where he advertised a "woodburning" kit using a little heated stylus much like a soldering pencil. (I remember getting a nice third degree burn from one at summer camp crafts). The soldering pencil as such shows up in Popular Mechanics, December 1944 page 144, for a 17 watt soldering pencil which reached full heat in 90 seconds. On page 6, his company was listed as the maker. An ad showing some models of the pencils was in Billboard Nov 24, 1945 page 96. At Google News Archive there were several stories about persons named "Harry Ungar" (including a manager of the Stewart Products Service Station in California) back to 1919 but no idea if they are the same one. The first certain one is a pay per view from the LA Times, Feb 1, 1953 about a new factory in Venice CA, where it said "Sidney D. Ungar" was company president. Edison (talk) 04:00, 4 June 2010 (UTC)

cold fusion

OK, suppose somebody invents cold fusion in order to make electricity. On an industrial scale, they take water, hydrolyse it to its constituents hydrogen and oxygen, and then fuse the hydrogen to form helium. In doing so, they save the world from global environment change. However, might this cause other separate problems? Wouldn't water run out eventually? If tonnes of helium and oxygen are released into the earth's atmosphere, wouldn't they become pollutants? Bobble hobble dobble (talk) 17:36, 3 June 2010 (UTC)

According to World energy resources and consumption: "In 2008, total worldwide energy consumption was 474 exajoules (474×10¹⁸ J)." If we use the proton-proton chain reaction as an example (there are lots of different fusion reactions - this is the one that dominates in the Sun), then we get 26.73 MeV for every 4 hydrogen nuclei being turned into helium (and some positrons and neutrinos and things, that we can ignore). Google says we need about 4x10³² hydrogen nuclei a year. That corresponds to about 6.6 million litres of water. The Earth has about 1,360,000,000 km³ of water. That's 1.36*10²¹ litres. So even with a massive increase in energy consumption, we still wouldn't use even a noticeable fraction of the water in the billions years or so the Earth will be habitable for. The 2x10^³² atoms of oxygen that would be released a year compares with about 4x10^⁴³ atoms of oxygen already there, so again it wouldn't be significant over the remaining habitable lifetime of the Earth. The 10^³² atoms of helium released corresponds to 4x10³⁹ atoms already there. So that would be significant over timescales of millions of years, but wouldn't be a problem since helium is a noble gas, so is very inert. Basically, the amount of energy released by the creation of each atom of helium is so great that you don't need to make many to meet our energy needs. --Tango (talk) 18:19, 3 June 2010 (UTC)

If there was a dirt-cheap form of energy, the first side-effects would be the collapse of the current energy infrastructure and those nations dependent on them, like Saudi Arabia. In the long term, cheap energy might lead to "bad behavior", such as heating outdoor areas, like beaches, with radiant heaters. We might eventually get to a point where global warming created by actual heaters and A/C would surpass that due to greenhouse gasses. Also note that while total water consumption isn't an issue, water levels in lakes near large populations might eventually decrease by a detectable level. StuRat (talk) 18:57, 3 June 2010 (UTC)

Simple answers: No, no, and no. Dauto (talk) 20:27, 3 June 2010 (UTC)

Release of molecular hydrogen into the atmosphere on a large scale could severely deplete the ozone layer [2]. It would depend on how much hydrogen you would need to create, and how leak-proof your systems are.-RunningOnBrains^(talk) 20:55, 3 June 2010 (UTC)

You could always collect the wast H2 for portable fuel needs. Googlemeister (talk) 21:04, 3 June 2010 (UTC)

The point is to transmute the hydrogen into helium. I don't think helium would have much effect on the atmosphere, being inert. APL (talk) 21:27, 3 June 2010 (UTC)

...and very light. Atmospheric helium evaporates into outer space pretty readily, is the reason the concentration is so low even though "so much" is being released terrestrially. DMacks (talk) 21:31, 3 June 2010 (UTC)

You can burn off any leaking hydrogen and turn it back into harmless water. --Tango (talk) 21:29, 3 June 2010 (UTC)

I remember hearing about an electronic device in Germany that uses water molecules to produce electricity, but the voltage is on the order of <1.0V. ~AH1^(TCU) 23:18, 3 June 2010 (UTC)

I believe the water just serves as a catalyst. The energy comes from something else in the fuel cell. Water is a very low energy state, so it is extremely difficult to get energy out of it (fusing the hydrogen is the only method I know, and the device you remember certainly doesn't do that). Of course, the media when the device was announced said it used water as a fuel, but the media were talking nonsense. --Tango (talk) 23:54, 3 June 2010 (UTC)

Would my voice start to sound squeaky with all that helium? Edison (talk) 03:58, 4 June 2010 (UTC)

No - the amount produced is utterly negligable. Of course hydrogen would also make your voice sound squeaky - but I strongly recommend that you DO NOT try that! SteveBaker (talk) 13:11, 4 June 2010 (UTC)

I've heard that the Alaska Brewing Co. actually makes beer that's "carbonated" with hydrogen instead of your least favorite gas CO₂ (well, used to make it, at any rate) -- there even is (or used to be) a karaoke contest where the contestants (all men) would drink this beer and then sing high soprano songs while blowing fireballs from their mouths (using a cigarette or other ignition device to ignite the gas). I don't know if they still do any of this, though. 67.170.215.166 (talk) 01:36, 6 June 2010 (UTC)

variations of h2o

It is my understanding that H2O can only be in three states: liquid (water), gas (steam) and solid (ice) and that regardless of the state the chemical configuration is the same. So, are there other states of H2O and does the formulation remain independent of the state? 69.77.185.91 (talk) 18:26, 3 June 2010 (UTC)

The chemical formula has to stay the same, otherwise it wouldn't be water any more. There are 15 known phases of ice (Ice#Phases). It can also exist as a supercritical fluid, which is sort of a another phase of matter and has properties in common with both liquids and gasses. --Tango (talk) 19:20, 3 June 2010 (UTC)

Is it possible to create water plasma? Googlemeister (talk) 19:40, 3 June 2010 (UTC)

In a plasma the atoms are ionised and do not form chemical bonds, so it wouldn't be water anymore. A supercritical fluid isn't technically a different phase since it can be reached without going through a phase transition. Dauto (talk) 20:26, 3 June 2010 (UTC)

That's why I said "sort of" - I didn't want to get into details. I guess the closest thing to a water plasma would be a mixture of oxygen and hydroxyl ions. --Tango (talk) 20:47, 3 June 2010 (UTC)

Water is a molecule with strange properties, for example one test showed water to have a chemical formula of H_1.5O even though it is not possible. ~AH1^(TCU) 23:17, 3 June 2010 (UTC)

I'd love to read about that test - do you have a link? Water definitely does some odd things, but I can't think of any interpretation by which it would have a fractional chemical formula like that. --Tango (talk) 23:55, 3 June 2010 (UTC)

I don't see it mentioned in Water (molecule), but see [3] for example. DMacks (talk) 00:09, 4 June 2010 (UTC)

That article says it isn't a property of water, but rather just the way hydrogen works - they tried the same experiment with benzene and got very similar results. --Tango (talk) 00:31, 4 June 2010 (UTC)

Perhaps you're thinking of the self-ionization of water (though I think that water is not the only thing that does that)? Paul (Stansifer) 00:50, 4 June 2010 (UTC)

It's not; the article talks about properties of certain molecules containing hydrogen where, under certain circumstances, on very short time scales, some of the hydrogens seem to not exist when neutrons are bounced off of them. It appears to be some sort of quantum effect. Buddy431 (talk) 01:20, 4 June 2010 (UTC)

With self-ionisation, the ratio of hydrogen atoms to oxygen atoms stays at 2:1, they just aren't joined together in the same way. This is something quite different and it seems nobody really knows why it happens. --Tango (talk) 01:29, 4 June 2010 (UTC)

There are alternate forms of solid ice, such as ice IV. Also under extreme pressure you may form a metallic phase. Graeme Bartlett (talk) 05:36, 4 June 2010 (UTC)

Other variations with different formulas are: Hydroxyl radical, Hydroxide, Hydrated hydroxide ion H₃O₂⁻, Hydronium and on a side track Dioxygenyl and peroxide. Also you can get Supercooled waterand Superheated water. Graeme Bartlett (talk) 05:57, 4 June 2010 (UTC)

interactions of colloidal gold

How strong is a bond between the surface of a gold nanoparticle and say, a lipid compared to most lipid-lipid interactions? What about polar molecules and aromatics? John Riemann Soong (talk) 18:27, 3 June 2010 (UTC)

Colloidal gold particles are charged, so they might have a small effect on polar molecules, probably not much else on any other molecules. --Chemicalinterest (talk) 20:34, 3 June 2010 (UTC)

see also Chrysiasis. Rmhermen (talk) 20:38, 3 June 2010 (UTC)

They're charged? I'm pretty sure the gold nanoparticles I am using are Au(0)... would some atoms be charged and not the others? John Riemann Soong (talk) 17:10, 4 June 2010 (UTC)

See Colloids#Interaction between colloid particles. Since they are often charged...--Chemicalinterest (talk) 23:10, 4 June 2010 (UTC)

An odd one - gold colloids are indeed Au(0) - the charge is often from citrate (from sodium citrate) stuck to the surface of the gold [4] or Cl- [5] - but they carry a negative charge - you can demonstrate this by using an electric field, see also 87.102.32.39 (talk) 00:38, 5 June 2010 (UTC)

Why do negative anions like to bind to Au(0)? Is it because of the increased surface energy of nanoparticular gold, making colloidal gold slightly electrophilic? (In a manner similar to boron?) John Riemann Soong (talk) 14:43, 7 June 2010 (UTC)

Reduction potential of selenium

What is the reduction potential of selenium? (Se + 2 e^- ←→ Se^2-) --Chemicalinterest (talk) 20:36, 3 June 2010 (UTC)

-0.67V, if this tattered piece of paper in my disused chemistry notes folder is to be relied upon. ~ mazca ^talk 21:10, 3 June 2010 (UTC)

Sounds right. Oxide is +1.23, sulfide is +0.14, selenide is -0.67, telluride is -1.14... Thank you. --Chemicalinterest (talk) 21:18, 3 June 2010 (UTC)

Mmmh [6] gives a totally different figure - wonder why. The Table_of_standard_electrode_potentials gives a figure for Se <> H2Se - which is what would happen in standard conditions - it should be possible to work backwards from that if you've got figures for the acidity constant of H2Se87.102.32.39 (talk) 15:16, 4 June 2010 (UTC)

It could be that too, it still fits in with the periodicity of the chalcogens. --Chemicalinterest (talk) 23:07, 4 June 2010 (UTC)

That's why I didn't include any figures in the selenide article, just said they're moderately reducing. --Chemicalinterest (talk) 23:08, 4 June 2010 (UTC)

cell phone

how come my cell phone gets very hot if i talk for awile ? —Preceding unsigned comment added by Alexsmith44 (talk • contribs) 22:06, 3 June 2010 (UTC)

Its microprocessor is doing more work, e.g. digitising your voice, converting incoming sound to analogue, and ancillary electronics are also doing more - driving the speaker and the aerial system. And the battery is doing more work to provide the current for all of this. When you're not talking, very much less is happening in all departments and so it keeps its cool. (What I'm not sure about, and perhaps someone else will be, is whether there's any significant microwave -> heat thing going on with it.) --Tagishsimon (talk) 22:13, 3 June 2010 (UTC)

it feels like it the battery that gets hot —Preceding unsigned comment added by Alexsmith44 (talk • contribs) 22:26, 3 June 2010 (UTC)

It is the battery that get's hot. Your phone is using more energy. (Mostly through its radio transmitter, not its CPU) The more electricity your battery has to put out, the hotter it gets. APL (talk) 22:52, 3 June 2010 (UTC)