Wikipedia:Reference desk/Archives/Science/2008 January 12

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[edit] January 12

[edit] Cyanide

Hello, I was wondering how long it takes for cyanide to kill someone. I know that it bonds to an enzyme and disrupts the electron transport chain, but I can't find anything that clarifies the time frame. Thanks so much. Best, Keilanatalk 01:41, 12 January 2008 (UTC)

  • But that's an advocacy site and referring to death in a specific situation. If you look under hydrogen cyanide you'll find a link to this OSHA page, which says "Death can occur within seconds or minutes of the inhalation of high concentrations of hydrogen cyanide gas." So the action of the poison is very fast. --Anonymous, 05:39 UTC, January 12, 2008.
    • The OSHA link is down right now....--M@rēino 18:03, 12 January 2008 (UTC)


There was a case where a guy got arrested by police and took a 'bottle of coca-cola' with him into the police car. He drank it, and died the next day. The levels of cyanide in his body were 16 times the 'lethal dose', proving that the lethal doses that doctors talk about are a joke. --ChokinBako (talk) 22:38, 12 January 2008 (UTC)
Well, no; it really doesn't. "Lethal dose" is usually expressed as LD50 or something similar, and is a purely statistical measure, with often arbitrary or completely unapparent time-dependence. Someguy1221 (talk) 22:42, 12 January 2008 (UTC)
...if this will help, I know this jewler guy who has been killed 7 or 8 times by cyanide. —Preceding unsigned comment added by 71.100.12.59 (talk) 02:08, 13 January 2008 (UTC)

I have another question...the articles on the cyanide compounds say that it has a bitter-almond smell; does this mean that it has a bitter-almond taste as well? And also, is it soluble in alcohol? --71.117.34.195 (talk) 20:09, 13 January 2008 (UTC)

[edit] Water vapor

Would a planet have to have sufficient gravity to retain water vapor in order for life to exist (develop from elements in the Universe). —Preceding unsigned comment added by 71.100.12.59 (talk) 12:40, 12 January 2008 (UTC)

Read Alternative biochemistry and Origin of water on Earth if you haven't yet. Life could also exist in liquid water beneath ice e. g. on Europa (moon). For water to exist in roughly constant amounts for billions on a planet, the evaporation or sublimation rate has to be low enough, gravity has to be high enough, temperature has to be low enough, and replenishment (e. g. by comets) has to be high enough. The escape rate of the water vapor depends on the fraction of molecules which reach escape velocity in the Maxwell distribution (and don't collide with other molecules on their way out). Icek (talk) 15:00, 12 January 2008 (UTC)

[edit] Procedures for the Laboratory Synthesis of Polymers

What is the most effective way to synthesise polyacrylamide in the laboratory (that is, without radical activators etc.)? Is this most simply acheived by heating acrylamide, perhaps with an alkali, or is there a better way in which the unsafe monomer can be entirely avoided? Thanks very much. Similarly, is there a way to synthesise Kevlar effectively in the laboratory? 86.137.168.61 (talk) 14:35, 12 January 2008 (UTC)

Radical activator is necessary, with a lot of luck you can use UV light to start the reaction. Ionic activation is also possible, but for polyacrylamide not the mest method. H2SO4 or NaOH should start also polymerisation, which might result in opaque polymer. Kevlar synthesis is more difficult, because it is not a radical polymerisation, but a polycondensation. The mixing ratio of 1:1 and a the use of acid chloride or ester as starting material is difficult if you can not use high temperature high pressure polymerisation.--Stone (talk) 15:35, 12 January 2008 (UTC)
I don't think the phrase "that is" means what you think it means. Polyacrylamide is routinely synthesized in the laboratory with radical activators. SDS-PAGE (the 'PA' stands for 'polyacrylamide') uses ammonium persulfate (with the help of TEMED) as a radical initiator to form polyacrylamide. It's as simple as mixing acrylamide & water with APS & TEMED - ~10-30 minutes later you have polyacryamide. It's simple enough that barely trained people do it routinely in molecular biology labs. I'm not sure about residual unpolymerized monomer, but molecular biologists have been working with the stuff for years - I'm sure there is literature out there looking at that. If you want more info, you may want to say more about what you're going to be doing with the polyacrylamide, and why you'd have problems using a radical activator. -- 128.104.112.236 (talk) 20:01, 12 January 2008 (UTC)

Thanks so far. I had heard that most of the methods with a radical activator needed unpractically high pressures in particular; but, if this is not the case, it should be hopeful with ammonium persulfate and TEMED - do you know the details of this, please? I need a solution in glycerine for a demonstration of N3, and there is no major concern about residual monomer, but it may have been a consideration if there were many different methods. 86.137.168.61 (talk) 22:02, 12 January 2008 (UTC)

Not sure where you heard that "most methods with a radical activator need unpractically high pressures". If the monomer is a liquid (like acrylamide), the reaction will be at atmospheric pressure. Delmlsfan (talk) 04:11, 13 January 2008 (UTC)

[edit] Food protein in blood plasma

Related to a previous question of mine, I found this abstract of an article describing experiments with the uptake of oral bromelain. It says that the plasma half life is 6 to 9 hours and the plasma concentration was 5 ng/ml after 48 hours of "oral multidosing (3 g/day)". If one (unrealistically) assumes that the intake was continuous over 48 hours and has reached saturation and the elimination is proportional to the concentration (i. e. like the exponential decay law), then 18 ppm of the original protein make it into the plasma. The real figure could be a bit higher due to the equilibrium not having been reached. Does anyone more knowledgeable know more about that? E. g. is that only valid for bromelain but quite different for other proteins? Icek (talk) 14:38, 12 January 2008 (UTC)

[edit] Metabolism (Not really a medical question)

I was wondering which of the two would be a better boost for metabolism: running 3 miles twice a day (morning and night) or running 6 miles once a day? Just a light question about energy/calories/metabolism/etc, not looking for real medical advice here. Any "gut feeling" responses welcome! Thanks. Sappysap (talk) 15:37, 12 January 2008 (UTC)

I'd lean towards the 2 shorter workouts because you'll get nearly double the amount of the post-workout metabolic increase (where you continue to burn calories after you stop running). Check [[1]] and metabolism Furmanj (talk) 17:02, 12 January 2008 (UTC)

[edit] What if two black holes were near eachother?

Would they both combine? —Preceding unsigned comment added by 24.118.5.243 (talk) 20:56, 12 January 2008 (UTC)

Black holes could orbit eachother (or just fly past eachother) as can any other astronomical bodies. It is also hypothesized that black holes can collide and combine into a single, larger black hole. Such an impact would generate massive gravitational waves, which Kip Thorne claims would carry away 10% of the Black holes' masses. Physicists hope that LIGO and LISA will be able to detect these waves, giving more details on the exact nature of such collisions. Someguy1221 (talk) 22:11, 12 January 2008 (UTC)
  • The History Channel's "Universe" program just did a bit on this. It basically backs up with Someguy1221 says above -- they could orbit each other, fly past each other, or combine. Which, if you think about it, is also your top three possibilities for just about any two heavenly bodies that come near each other. --M@rēino 17:44, 13 January 2008 (UTC)
Also, see this SkyAndTelescope article about two black holes that are each heavier than the black hole at the centre of the milky way that are about to collide, one of them is millions of times heavier than the sun and one is billions of times heavier. They are having shorter and shorter orbits around each other, and could collide in about 10,000 years. Many people are expecting them to merge, although they could release massive gravitational waves, but they might not be at the right frequence to detect. Hope this helps. Thanks. ~AH1(TCU) 00:25, 17 January 2008 (UTC)

[edit] Alcohol through a straw

Hello, Wikipedia-type-people. Quick and painful: Corollary to this - how and why does drinking alcohol (be it beer or wine) through a straw would get one drunk faster (than drinking the same normally)? This is just my morbid curiosity. Thank you in advance. Cheers, Ouro (blah blah) 20:59, 12 January 2008 (UTC)

I've actually never heard of this, but the only thing that comes to me is that my friend's dad, who is a toxicologist, told us that you can speed up the metabolism of alcohol by breathing deeper. This is the only thing I can think of that relates to this, where you probably intake less oxygen when drinking with a straw. Other than that, I have no clue. --Wirbelwindヴィルヴェルヴィント (talk) 21:35, 12 January 2008 (UTC)

My suggestion would be -- suggestion. But I don't have any special knowledge about it. --Trovatore (talk) 21:36, 12 January 2008 (UTC)

The most common (pseudo)scientific explanations offered is that by sucking on a straw:
  • An oral vacuum is created, in these circumstances the boiling point of alcohol drops and more alcohol vapors are created in the straw and mouth. These are inhaled in the lungs, meaning more alcohol can get into the blood faster than by drinking it the normal way.
  • Alcohol gets into the mouth through a straw in very narrow jets, meaning it has a larger surface to volume ratio as it enters the oral cavity. As a result more alcohol can evaporate before it is swallowed and thus it gets in the bloodstream quicker.
While they make some theoretical sense, I'm not sure I buy them practically (for example, is there enough of a vacuum to lower the boiling point of ethanol sufficiently for a significant amount to vaporise at oral temperatures? Does the jet of alcohol the comes through the straw remain long enough for the surface area to have a significant effect? If so, wouldn't a thinner straw work better than a thicker straw?) Rockpocket 00:04, 13 January 2008 (UTC)
Thank you, Ouro, for suggesting some inebriating WP:OR, to be conducted in the service of humankind and the eternal quest of Wikipedia for omniscience. BTW, are you a North Pole or a South Pole ? --Cookatoo.ergo.ZooM (talk) 01:44, 13 January 2008 (UTC)
There may be no direct correlation, just that women often drink their alcohol with a straw, and men do not. Women on average take less alcohol to be affected. So the typical straw sucking alcohol drinker will get drunker quicker, because she is a woman. Graeme Bartlett (talk) 04:22, 13 January 2008 (UTC)
Graeme, your suggestion fits the atmosphere here at WP:RD the best ;) truthfully - I didn't think it mattered how you did it. Research is definitely called for here. Oh, and Cookatoo - I'm neither - much more a cosmopole if I'd be allowed a mediocre semi-successful pun. Cheers, Ouro (blah blah) 07:19, 13 January 2008 (UTC)
This question has been posed several times here before, but I can't find it in the archives. One proposal I've heard is that using a straw allows one to drink more/faster/more-potently because of less awareness of the actual drinking (quick straw-to-throat so less taste and more rapid swallowing possible than if mouthfuls). But I agree, more Original Research is needed. DMacks (talk) 16:49, 13 January 2008 (UTC)

For what it's worth, alcohol (and, in general, other intoxicating substances) tends to have lots of myths surrounding it. Dunno why, but you'll find any number of people who are convinced of things like "Vodka gets me drunk fast, but I can drink whiskey all nite". There's no obviously plausible explanation for this, but many people believe it. Friday (talk) 16:51, 13 January 2008 (UTC)

A surprising amount of your ability to get drunk is not to do with your body but your mind. If you tell someone they are drinking very strong tasteless alcoholic beverage (when you are actually giving them water) then there is a pretty good chance they will start acting as though they are drunk. I am unsure if they will have a hangover in the morning though. TheGreatZorko (talk) 14:51, 16 January 2008 (UTC)

[edit] Weather Balloons

I was curious is there any regulations about launching Weather Balloons and if so what are the regulations regarding thier payload? THank you. 67.125.159.70 (talk) 22:33, 12 January 2008 (UTC)

IANAL, but I'm pretty sure this is going to vary from place to place. What jurisdiction are you interested in? Algebraist 23:01, 12 January 2008 (UTC)
IP traces to Los Angeles, in the United States. --Ouro (blah blah) 07:40, 13 January 2008 (UTC)
I have no doubt that there are regulations of some kind, in most or all jurisdictions. In some of his recorded lectures, Walter Lewin discusses his experiences launching similar balloons for X-ray astronomy in the Australian outback. He states that they had to end the flight (dropping the payload on a parachute, with the balloon breaking up in the upper atmosphere) before the balloon flew over the more populated parts of the country. -- Coneslayer (talk) 20:20, 15 January 2008 (UTC)
You may consider contacting the FAA and asking them what restrictions may apply. The rules can be fairly involved, so I'm not sure we can provide an explicit answer. Someguy1221 (talk) 20:29, 15 January 2008 (UTC)
Not to mention if something goes wrong and the FBI break into your house looking for the terrorist, you're probably better off telling them you called the FAA and followed their instructions rather then telling them you asked on the wikipedia reference desk. Nil Einne (talk) 22:52, 15 January 2008 (UTC)
If you are in the UK that would be the Civil Aviation Authority you should consult.--TreeSmiler (talk) 01:28, 16 January 2008 (UTC)