Wikipedia:Reference desk/Archives/Science/2012 March 11

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March 11[edit]

throat swab[edit]

will anaerobic bateria show up on a throat swab culture? — Preceding unsigned comment added by (talk) 01:52, 11 March 2012 (UTC)

This sounds like homework (I could be wrong) so I'll be a little coy. Ask yourself what anaerobic means. A throat swab is wiped from an exposed area inside the throat, through which you are constantly breathing. Now, if you want to muddy the waters, consider facultative anaerobes - for example, Listeria monocytogenes can be isolated from a throat swab.[1] Wnt (talk) 03:04, 11 March 2012 (UTC)

Gallstone question[edit]

Note: the discussion below generally concerns treatments for gallstones, not diagnosis or treatment of any particular case. A thread discussing a Refdesk guideline has been opened at the talk page. Wnt (talk) 15:16, 11 March 2012 (UTC)

Can we treat gallbladder stones in a non-surgical way? I know a non-surgical treatment method is mentioned in the article but is there another non-surgical method? Eugene CKG (talk) 03:06, 11 March 2012 (UTC)

I added a title (and resisted the urge to call it "Galling question from stoned user"). :-) StuRat (talk) 03:12, 11 March 2012 (UTC)
Out article lists several ways, under the "Medical" and "Alternative medicine" sections of Gallstone#Treatment. However, these don't appear to work if the stones are lodged in the common bile duct. StuRat (talk) 05:38, 11 March 2012 (UTC)

(ec)I trust you've followed ursodeoxycholic acid and bile bears, extracorporeal shock wave lithotripsy, and Endoscopic retrograde cholangiopancreatography from the article.

As a first step, popular website remedies were surveyed to get the feel of what's going on out there; the results of this were not intended to be taken as scientific fact
The following discussion has been closed. Please do not modify it.

In addition to these I'll list from a quick search of top Google hits some online remedies without claiming they work or don't. It's clear that there is quite a lot of interest, and sales, from people seeking cheap easy herbal alternatives to surgery, and it would be well worth trying to figure out if any of this is effective. The research may not have been done, though. As you'll see, there are quite a few hypotheses here and it would/will take quite some time to evaluate them all; however I will say that it is my impression that consumption of large amounts of oils to "flush out gallstones" ([2] etc.) is a fraud, where the oil simply forms lumps that people take for the flushed gallstones, and is slightly hazardous in the manner of any high-fat diet. I won't even mention the acupuncture, yoga poses, etc. - not that I rule out the conceivable possibility of effect from the latter by some physical push or loosening, but I'd like to focus on things that don't require good technique from the user. It should be interesting to look up how much if any of this has any identifiable support from research:

  • "Lysmachia, Jin Qian Cao, "Gold Coin Herb" is used for gallstones and for kidney stones. To optimize its use for gallstones, combine this herb with Artemesia Capillaris (Yin Chen), Bupleurum (Chai Hu), and Gardenia seed (Zhi Zi). Ingesting mixtures of oily and acidic foods, such as olive oil and lemon juice are said to act as solvents to dissolve the fatty gallstones." Also the Chinese patent medicine Li Dan Pian is mentioned. [4]
  • [6] agrees on artichoke, attributing activity to Caffeoylquinic acid and Cyanarin, which it claims "out-performs conventional gallstone treatments in some European nations." Also mentions milk thistle, turmeric, and even has a few references.
  • [7] mentions "An Ayurvedic practitioner may recommend taking an Ayurvedic formula containing six herbs, including musta and shilajit" in addition to that "flush" nastiness with three tablespoons of olive oil. Not to leave anything out, it also suggests "Combine equal amounts of tinctures of wild yam, fringetree bark, milk thistle, and balmony, and take a teaspoonful of the blend several times a day. Drink chamomile or lemon balm tea or a combination tea of balmany and fringetree. ... Other beneficial herbs for treating gallstones include catnip, cramp bark, dandelion, fennel, ginger root, and horsetail." It also makes a nod to common sense by reminding people to drink lots of fluids, which I'm prone to think is a Good Thing where any precipitation disorder is concerned (though I should look that up too...). And "Corydalis Formula, Liver Strengthening Tablets, Minor Bupleurum Formula, Rhubarb and Scutellaria Formula, and Lidan Tablets. For gallbladder pain, Corydalis Analgesic Tablets"
  • [8] "To alleviate the abdominal pain at the start of an attack drinking a full glass of water may be helpful since it will regulate the bile in the gallbladder. If this doesn’t help, it is recommended to take magnesium followed by any bitter liquid (coffee or Swedish bitters) an hour after, it is proved that bitter flavors stimulate bile flow." Also recommends barberry bark, ginger root, any mint leaf, turmeric, gold coin grass, milk thistle.
  • Still on the first page of popular Google hits, we get to high weirdness. [9] "Like with all other degenerative diseases, calculus has a metaphysical etiology. Metaphysically speaking, stones (calculus) are the result of noxious and "bitter" thoughts which are chiefly rooted in jealousy and envy and which are carried around, unwisely unresolved and unexpressed over a long period of time. Since rigidity pertains to "stiffness" and "hardness" ... Rigid people are more likely to be astro-zodiacally "fixed" sign individuals such as Taurus, Leo, Scorpio, and Aquarius." Then, somewhat more plausible, but not to the degree they say - "Just as a person cannot develop high cholesterol without eating animal and animal products (meat and dairy), likewise a person cannot develop stones (kidney, bladder or gall) without eating meat and dairy products. A vegan diet is greatly advocated for healing purposes as well as overall qualitative lifestyle purposes." This site gives a broader list of herbs "Chanca Piedra, Gravel Root (a/k/a Queen of the Meadow), Buchu, Uva Ursi, Hydrangea, Stone Root, Cornsilk, Parsley Root, Horsetail (Shavegrass), Juniper Berry, Dandelion Root, Burdock Root, Devil's Claw, Agrimony, Celery Seed, Sassafras, and Safflower (Saffron)." I should note that sassafras has its detractors, some of the others are simply herbs for pain relief, and to cap it off, this site advises a full glass of olive oil nightly! I think this site illustrates well what happens when some people wander over to the wrong side of the bar. ;)
  • The site after this is the commercial site for the aforementioned Yidan, but the one after that: "Traditional choleretics and cholagogues, herbs intended to increase the production and flow of bile, include barberry (Berberis vulgaris), burdock (Arctium lappa), dandelion root (Taraxacum officinale), fumitory (Fumaria officinalis), globe artichoke (Cynara scolymus), goldenseal (Hydrastis canadensis), greater celandine (Chelidonium majus), milk thistle (Silybum marianum), Oregon grape (Berberis aquifolium) and peppermint (Mentha x piperita)."; it then makes sane-sounding arguments for silymarin and peppermint, claiming "Menthol belongs to a class of compounds called terpenes that, for decades, has been studied for the treatment of gallstones. Studies suggest that terpenes keep cholesterol crystals from forming in bile and may even dissolve existing stones. A terpene mixture derived from purified plant essential oils, known as Rowachol, has been used in Europe since the mid-1950s for treating gallstones. Although Rowachol is unavailable in the United States, health care practitioners can request a generic form from a compounding pharmacist. Michael Murray, N.D., in the Encyclopedia of Natural Medicine (Prima Publishing, 1998), suggests that enteric-coated peppermint oil might also act as a suitable substitute."

As you see from this list, we're starting to have a lot of repetition, but new suggestions keep trickling in. Covering the ideas out there exhaustively will be difficult, and of course, figuring out which are somewhat supported by evidence, more so. I'll set this down now and hopefully get around later to actually evaluating the claims. Wnt (talk) 06:06, 11 March 2012 (UTC)

Now to start sorting... Hmmm, [10] is very helpful for reviewing the Chinese medical approaches. Wnt (talk) 17:18, 11 March 2012 (UTC)

  • [12] found a 0.67 ratio of relative risk for symptomatic gallstones in men when top and bottom quintiles for magnesium intake and/or dietary magnesium, in a study of 40,000 people/2000 gallstone incidents. (also [13]) This is a study of ordinary dietary magnesium as opposed to the extreme levels described in [14], and it proves correlation rather than causation.
  • Silymarin is well known for hepatoprotective qualities, but use for gallstones is a bit of an oddity. [15] It might have an effect on cholesterol level in the bile. [16] It is more known for having a role in opposing cholestasis [17][18][19] and liver damage subsequent to biliary obstruction. [20] Because it's entirely possible for some people to suffer a gallstone attack, do nothing, and then have the condition resolve spontaneously, I think a substance that would reduce the damage involved might indeed be very useful.
  • Shilajit is truly a mysterious substance. But it was found in one study to have antiinflammatory properties [21] - which is not unusual, and so not implausible - and so it might simply be an aspirin for the pain. Too little data to say. Wnt (talk) 04:25, 12 March 2012 (UTC)
  • musta turns out to be Cyperus rotundus, a familiar herb from the Western/Islamic tradition; though there has been preliminary research into a grab bag of beneficial effects, I don't see anything on NCBI about gall stones or cholestasis. Google Scholar turns up references describing traditional use only, at first glance. "cyperus+rotundus"+gallstone Wnt (talk) 03:19, 13 March 2012 (UTC)
  • There is some evidence for dandelion leaf and root acting as a cholagogue and increasing bile flow in rats and dogs, respectively, by 40% and 100%. [22][23] The NYU source points out that this activity isn't proved to do anything more, but honestly, I find it hard to believe that increasing the volume of bile flow would not reduce the solute concentration and thereby at least slow stone formation. However, note that "Germany's Commission E has recommended that it not be used at all by individuals with obstruction of the bile ducts or other serious diseases of the gallbladder, and that it be used only under physician supervision by those with gallstones." Wnt (talk) 19:23, 14 March 2012 (UTC)
  • Globe artichoke leaves also appear to have such effects, described as choleretic (some sites use this interchangeably with a cholagogue,[24] but apparently many sources describe an increase in production of bile as choleretic, whereas a cholagogue might merely encourage its release from the liver or gall bladder.[25]) [26] It also apparently reduces cholesterol biosynthesis and serum concentration to some degree. [27][28]

Is any evidence against fluctuations in the early universe expansion rate allowing baryonic dark matter?[edit]

In my continued quest to get to the bottom of the dark matter composition controversy, at e.g. Talk:Dark matter#Draft table (where I have moved my reference desk question from last week), while it seems that the gravitational microlensing summaries cited there would otherwise allow for objects larger than a few dozen solar masses as dark matter, the principle of big bang nucleosynthesis is thought to generally exclude the possibility of baryonic dark matter, in that the observed ratios of light element abundances depend on a particular density while the early universe was cooling. If post-inflation early universe expansion occurred at a relatively constant rate, the density involved rules out the possibility that dark matter is baryonic. The alternative advocated by proponents of baryonic MACHOs instead of non-baryonic WIMPs is that the rate of expansion in the post-inflation early universe might have sped up and then slowed down such that the density would have allowed for the nucleosynthesis of much more baryonic matter, and also the production of primordial black holes. This is not such an absurd theory because we generally accept that the universe initially expanded at a rapid rate of speed and then slowed down, and is now again accelerating. So the idea that perhaps it sped up much more than a naive interpolation prior to the temperatures involved in baryonic nucleosynthesis and then slowed down afterward does not seem too far fetched.

My main question is: (1) Is there any evidence which excludes the possibility such fluctuating expansion rates in the pre-nucleosynthesis early universe which would allow for baryonic dark matter? If so, what is it?

A slightly more general question: (2) Is there any data which could be used to assign relative likelihoods to the two possibilities? If so, what is it?

And a third tangential but related question: (3) Are there any theories of supermassive black hole formation from any kind of matter which do not depend on their aggregation from smaller black holes over time?

As far as I can tell from my initial reading on this, it seems that while the overall rate of expansion in the post-inflation early universe is generally well understood, there is absolutely no way to determine whether fluctuations in that rate existed or not. Thus we only have the argument that the absence of fluctuations is preferred, limiting the extent of baryonic dark matter, for no reason other than that it is the simplest possible description of events. That seems to be a flimsy argument if there is no way to quantify the relative likelihoods. Does anyone know of anything more on the subject than that? Npmay (talk) 05:08, 11 March 2012 (UTC)

Fluctuations in the rate of inflation have a direct impact on the cosmic microwave background and are among the most precisely measured quantities in cosmology. Waleswatcher (talk) 13:20, 11 March 2012 (UTC)
How can that be? Nucleosynthesis was finished by 20 minutes after the big bang, but CMB photons are from the recombination era at least 70,000 years later. Aren't the details of post-inflation era expansion strictly cosmic variance parameters?[29] Npmay (talk) 22:52, 11 March 2012 (UTC)
I see the problem! I am asking about fluctuations in the rate of expansion after the inflation era, which lasted only a tiny fraction of a second, but before or during nucleosynthesis, which lasted several minutes. You are absolutely correct that quantum fluctuations during inflation proper resulted in the large scale structures and resulting polarization and ansitropy properties of CMB radiation. I have edited my question above to clarify that and used italics to show where I edited. I'm sorry to be so confusing. Npmay (talk) 06:58, 12 March 2012 (UTC)

Quantum tunneling[edit]

What happens to a tunneling electron as it passes through the barrier? It can be located in the barrier, only either side. So where is it located during the time of transit? Plasmic Physics (talk) 07:57, 11 March 2012 (UTC)

This seems not a valid question to ask. It is important to realise that our understanding of electrons etc is not a "real" understanding, like say understanding how a lever works, or how a hammer driving a nail works. What we have is essentially mathematical theory which is of great value because it gives the right results agreeing with experiment instument readings - and because we don't have full/real undertstanding, we use terminology eg "tunnelling" based on analogy. Its like the terminology of waves versus particles. It doesn't means that electrons etc somehow choose to be particles for some situations and sometimes waves to suit other sistuations. They are neither, they never are either. But for us mere humans, who don't know the actual situation, the terminology and mathematics of particles gives the right results for certain aspects, and the terminology and math of waves gives the right results otherwise. Like any analogy, you can take it too far, leading you to ask invalid questions or making incorrect conclusions (though incorrect conclusions is what leads to new insights and better theory) Never make the mistake of thinking theory is reality, even if the theory is very solid. The math of statistical mechanics etc shows that electrons that were on one side of a barrier can appear on the other side, and instrumented experiments confirm it. Other theory shows that a travelling electron mut have a transit time, and experiment presumable would confirm it. But is it located somewhere during the transit? Bad question - because it is a question that arises from the theory, not the un-undertstood reality. Ratbone124.182.23.156 (talk) 09:55, 11 March 2012 (UTC)
If I understand your question correctly you're looking for a "freeze-frame" of the moment the electron digs through the barrier with its head sticking out the one side and its butt still on the other side. Well unfortunately that's not how it happens. Heisenberg's uncertainty principle forbids us from simultaneously knowing the exact location and momentum of a particle. Roger (talk) 13:37, 11 March 2012 (UTC)
The short answer is that the so-called "forbidden region" is not forbidden. The particles do enter it, and sometimes make it to the other side.
The following analogy is highly imperfect but may help. Imagine a somewhat drunk guy walking home along a desolate road. While on the road he walks roughly in a straight line, but at an angle, so eventually he walks off of it on one side or the other. The road is surrounded on both sides by rocky terrain, and on this terrain he stumbles and changes direction frequently. When he leaves the road, with high probability he'll reverse direction very soon and end up back on the road; in any case he will eventually end up back on the road, since there's nowhere else for him to go (the rocky terrain continues "forever"). That's called total internal reflection. It's "total" in the sense that no matter how long the road home, he'll almost certainly be on the road or fairly near it when he gets there. But if there's a second road that temporarily runs parallel to the first, he may stumble across the rocky terrain at that point and end up on the wrong road. That's analogous to tunneling (also called "frustrated total internal reflection") between nearby optical fiber cables that are separated by an air gap.
An important feature of wave tunneling that's missing from this analogy is that it has a funny atemporal character that often leads people to claim (incorrectly) that it happens faster than light. I can't think of a particle analogy for that. -- BenRG (talk) 21:06, 11 March 2012 (UTC)

I know about particle-wave duality. So, the electron can be located within the barrier? If it can, then that would make my question null. Plasmic Physics (talk) 00:48, 12 March 2012 (UTC)

Yes. Although the electron's probability amplitude drops off exponentially within the barrier, it isn't zero within the barrier. See Probability amplitude#Example: One-dimensional quantum tunnelling. Red Act (talk) 03:44, 12 March 2012 (UTC)

Thank you, that's all I needed to know. Plasmic Physics (talk) 05:18, 12 March 2012 (UTC)


Hey there! I'm trying to convert position in ECI frame to ECEF frame. The rotation matrix rz_raan_tetha=[cos(-raan+theta) sin(-raan+theta) 0;-sin(-raan+theta) cos(-raan+theta) 0;0 0 1] is used for it. Im trying to know about the value of theta. what could be the other way for knowing its value other than calculating it with using polar motion and GMST etc etc.. Any help will be highly appreciated. Thanks.--Mike robert (talk) 15:54, 11 March 2012 (UTC)

We'd need more information there. Frankly, the matrix seems like just a distraction to me right now - might as well write it out as equations in x1 y1 z1 -> x2 y2 z2. The point is, you haven't given us either variable. I assume one depends on the longitude (I assume "earth centered inertial" and "earth centered earthbound frame" or something?) and the other depends on the time of rotation. Wnt (talk) 23:54, 11 March 2012 (UTC)

Sleep-wake cycle[edit]

It seems self-evident that, for most humans, the "natural" sleep-wake cycle is delayed with respect to sunlight. In other words, when you don't need to adhere to a schedule, you establish a sleep pattern where the midpoint of your sleep does not coincide with solar midnight. A person who needs 8 hours of sleep would fall asleep at 8 PM solar and wake up at 4 AM solar if his cycle were perfectly aligned with the sun. Almost no one does that. For many, the delay is as much as 4-6 hours. (Maybe we are better synchronized with the sunrise, that is, there is a tendency to wake up a fixed number of hours after sunrise?)

This is a big part of the reason why we need daylight saving time: were we all aligned with the sun, additional hours of summer sunlight would always fall on the waking hours until the day length reaches 16 hours. At that point, you would wake up at sunrise and go to sleep at sunset. DST would be almost, or completely, unnecessary.

Our article on DST alludes to this fact by simply asserting "many people will tend to sleep in the early morning hours..." but does not go any further. I have tried to find some research on this subject, but did not have any luck. Can anyone find some scientific backing for this? --Itinerant1 (talk) 19:19, 11 March 2012 (UTC)

There are lots of things we don't quite understand about sleep cycles and what is natural or optimal. If you take away artificial light, its not even clear that sleeping eight continuous hours is normal: [30]. And even though many people express a desire to lie in bed for longer, it isn't necessarily optimal for performance: [31]. I'm not sure what evidence there is of the effect of DST on sleep cycles, health, and performance, but given how much we have yet to understand about sleep, I'd be surprised if there was an unambiguous result. Dragons flight (talk) 19:40, 11 March 2012 (UTC)
Temperature also lags behind the sun (it takes the sun a while to warm things up), although not usually by 4-6 hours. I have no reliable sources suggesting it, but it is possible that has something to do with it. --Tango (talk) 22:32, 11 March 2012 (UTC)
I can sleep any time of the day, although having bright light in my eyes would prevent that, so I have black-out drapes. Day-time noises are also a problem. If there was no light or noise issue I think I would fall into a longer than 24 hour cycle, with sleep still being about a third of the total. StuRat (talk) 22:59, 11 March 2012 (UTC)
Caffeine is a factor (see e.g. [32]) though I have to say the study mentioned doesn't match my personal impression. Wnt (talk) 23:46, 11 March 2012 (UTC)

Chickens (O chicken, why art thou?)[edit]

Why is a chicken? I'm curious about the subject — Preceding unsigned comment added by (talk) 22:35, 11 March 2012 (UTC)

Can you clarify the question? Do you want to know how chickens came into existence? Provide more information, please. Bus stop (talk) 22:39, 11 March 2012 (UTC)
Why is a chicken? Because an egg ;-) AndyTheGrump (talk) 22:40, 11 March 2012 (UTC)

I guess I was concerned more with the chicken's beak. How is a chickens beak? Why chickens? — Preceding unsigned comment added by (talk) 22:47, 11 March 2012 (UTC)

We have an article on chickens. You can start there and come back with specific questions of yours that weren't answered. Someguy1221 (talk) 22:52, 11 March 2012 (UTC)

That article doesn't explain why is a chicken though? I thought it sounded like basic chicken info to me but I could be wrong — Preceding unsigned comment added by (talk) 23:08, 11 March 2012 (UTC)

We have an article on abiogenesis. It is, however, somewhat sparse on the specific question on the ontology of chickens. --Incognito.ergo.possum (talk) 23:20, 11 March 2012 (UTC)
Creation ex nihilo, creation from nothing, for no reason, just because. In a universe that disallowed chickens or chicken observers there would be nothing that could ask "why is a chicken." You just happen to find yourself in a universe with chickens and chicken observers, and so you ask "why is a chicken," because it is a possibility in this universe. You may wish to look up Multiverse for more on this idea. SkyMachine (++) 23:51, 11 March 2012 (UTC)
I is a chicken, but only on the fifth sunday of a leap year, king me! Plasmic Physics (talk) 00:37, 12 March 2012 (UTC)
Even Chico knew why a chicken:[33]Baseball Bugs What's up, Doc? carrots→ 00:42, 12 March 2012 (UTC)
Because somewhere there is a road that needs to be wantonly crossed for no apparent reason. Clarityfiend (talk) 01:55, 12 March 2012 (UTC)
For one answer to that perennial question, go to about 2:10 in this video.[34]Baseball Bugs What's up, Doc? carrots→ 02:43, 12 March 2012 (UTC)
To the OP (and assuming good faith), maybe you should try to post your question in your native language, because "why is a chicken" has no meaning in English. -- (talk) 10:30, 12 March 2012 (UTC)
New Zealandish? ←Baseball Bugs What's up, Doc? carrots→ 12:20, 12 March 2012 (UTC)
...Hence all the comical answers. Plasmic Physics (talk) 10:36, 12 March 2012 (UTC)
It is like asking "when is a wall?" It sounds like half a sentence. Plasmic Physics (talk) 10:41, 12 March 2012 (UTC)

If you had only asked Why a Duck?. Then we could have answered.Sjö (talk) 11:55, 12 March 2012 (UTC)

hilarity aside, what the poster meant[edit]

This question is hilarious the way it is phrased, especially the followup questions. ("That article doesn't explain why is a chicken though? I thought it sounded like basic chicken info to me but I could be wrong"). However, translating literally into another language I know, the question makes perfect sense, and should be asked: "Why is there a/the chicken" or in other words "Why are there chickens?" This explains the specific reference to beaks, etc. So the question is one of pecking, etc, and, for example, are there chickens because of people who domesticated something that pecked on human's crumbs? I don't know where the OP geolocates to, though, so I don't know if this interpretation is the right one. (talk) 13:36, 12 March 2012 (UTC)

It's a good question, You'll never see chickens in the wild, unless someone put them there. The stupid bird can't fly more than a few meters. Did they survive evolution only by breeding like rabbits? (talk) 14:04, 12 March 2012 (UTC)
Well, as for how they survived evolution it's probably just by being wary: if they saw a predator, they'd just cross the street. (talk) 14:15, 12 March 2012 (UTC)
Do all creatures have to evolve "in the wild"? Bus stop (talk) 14:49, 12 March 2012 (UTC)
Assuming good faith, the answer is the perfectly evolutionarily fit Red Junglefowl plus some artificial selection, as Charles Darwin and anybody familiar with his ideas knew/knows perfectly well. I remember a similar query here a while back about how something so like a defenseless meal on legs as a cow could have evolved, from someone who was evidently unfamiliar with the Aurochs, once one of the most dangerous animals on the planet.
Personally I think the OP was more likely along the lines explored by Eric Frank Russell in some story or other, which included the classic query "Why a mouse when it spins?" {The poster formerly known as} (talk) 15:33, 12 March 2012 (UTC)
I've seen feral chickens in the wild, in New Zealand and on Norfolk Island. Not many predators in those places, and the creatures seem to thrive. HiLo48 (talk) 16:51, 12 March 2012 (UTC)
Key West is famous for its feral chickens as well. Buddy431 (talk) 18:22, 12 March 2012 (UTC)
I still say they survived mainly because the breed like mad, see Fowl: Galloanserae are very prolific; they regularly produce clutches of more than 5 or even more than 10 eggs, which is a lot for such sizeable birds. For example birds of prey and pigeons rarely lay more than two eggs. (talk) 18:30, 12 March 2012 (UTC)
You underestimate chickens. [35] [36] --Itinerant1 (talk) 22:18, 12 March 2012 (UTC)

Mixing ammonia and bleach[edit]

Why exactly do they tell you never to mix ammonia and bleach? What chemical reaction occurs and what toxic chemical is produced? Whoop whoop pull up Bitching Betty | Averted crashes 23:41, 11 March 2012 (UTC)

See Sodium hypochlorite#Safety. You can end up with a lungful of chlorine gas. Note that bleach and urine can be a nasty combination too. [37] AndyTheGrump (talk) 00:18, 12 March 2012 (UTC)
Not chlorine, chloramine I think. We should have ammonia and bleach, bleach and ammonia redirects, I think. :)
Er yes - should have looked more closely. Nasty stuff, either way. AndyTheGrump (talk) 00:46, 12 March 2012 (UTC)
As an aside. When people say their tap-water tastes of chlorine, what they are actually tasting is chloramine, due to their poor quality water supply being so high in organic matter that it reacts with the chlorine added to disinfect it. People with blessed with good quality water can't taste any chlorine despite the same amount being added ( Sturat says he has good water where he is situated – maybe he can confirm). A water purifier helps in these poor water quality areas. Personally, I think the only way to make water fit to drink is to dilute it in equal parts with a good single malt. The wives prefer gin, but then again they would, just to be awkward.--Aspro (talk) 23:11, 12 March 2012 (UTC)
My water doesn't taste of chlorine, but then I rarely drink it straight from the tap, but rather make tea from it, giving it a chance to outgas for a bit. I also suspect that part of the reason water with more organics in it tastes of chlorine is that they add more chemicals to disinfect it. My brother once encountered a "safe well" while backpacking in an area of polluted wells, but what made it safe was apparently that it had more chemicals added to it than a swimming pool. StuRat (talk) 23:17, 12 March 2012 (UTC)
Mine also (in the south of the UK) doesn't taste of chlorine, but when I run a bath I catch a noticeable smell of chlorine, even in the corridor outside the bathroom. {The poster formerly known as} (talk) 02:45, 13 March 2012 (UTC)

Relative toxicity[edit]

I've often wondered, since both chlorine bleach and ammonia are noxious alone, and should only be used in a well ventilated area, how much worse is the combo ? StuRat (talk) 23:18, 12 March 2012 (UTC)
Don't wonder. Read: [38] It probably won't cause an explosion... AndyTheGrump (talk) 23:25, 12 March 2012 (UTC)
That doesn't answer my Q. I know that the product is toxic, but so are the constituents. What levels of each are considered toxic ? StuRat (talk) 23:29, 12 March 2012 (UTC)
Do you want the LD50 values for the reactants or products, or do you you want something else? Plasmic Physics (talk) 00:33, 13 March 2012 (UTC)
I was thinking in terms of how many parts per million (or billion) of each gas is considered hazardous. I suppose we should also consider how volatile each chemical is. Neither bleach nor ammonia all evaporate immediately, so perhaps that's what makes them somewhat less dangerous. StuRat (talk) 03:47, 13 March 2012 (UTC)
I'll renovate the chembox for choramine, it should take about 40 minutes or so. Plasmic Physics (talk) 05:44, 13 March 2012 (UTC)
I couldn't change much, there isn't much available on the pure chemical. Chloramine appears to not be stable at STP conditions, rapidly decomposing into ammonia and chlorine gas. Plasmic Physics (talk) 06:28, 13 March 2012 (UTC)