Wikipedia:Reference desk/Archives/Science/2006 October 3

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Dying in sleep

Hey there everyone! I got another curious question! I've heard for most my life from teachers, peers, and sometimes colleagues about death from sleep because you die in your dreams. Is it possible that if you do die in your dream you really do die in real life? Just curious if anyone has any articles, people or any stories about this --Agester 00:02, 3 October 2006 (UTC)

There's an easy answer to that - if it were true, how the hell would we know? Confusing Manifestation 00:12, 3 October 2006 (UTC)

I've heard of dreams (including my own) where the person involved would have died if the situation was in real life. There's no reason to think that dieing in a dream would kill you in reality, except that it makes for an interesting novel / paranormal kook book / movie / etc. Heck, since one doesn't even know what dieing really is like until arrival, there's no reason to think you even can experience "death" in a dream.

Not doubt you'll find articles, stories, and probably even books on this if you look hard enough, but they'll all be oogy-boogy nonsense, if anything. -- Consumed Crustacean (talk) 00:24, 3 October 2006 (UTC)

Sounds like a FAQ to me (or it will be)--Light current 00:27, 3 October 2006 (UTC)

You know, this would make a mediocre Twilight Zone episode. Clarityfiend 01:00, 3 October 2006 (UTC)

No. I've died tons of times (and killed myself) in my dreams, and here I am. Friday the 13th (film series) is not real! No harm from a dream will be there when you wake up. Unless you have a heartattack or a stroke or something. Yeesh. — X [Mac Davis] (SUPERDESK|Help me improve)02:15, 3 October 2006 (UTC)

There's actually a movie called Friday the 13th? When I saw the commercial, I thought they put "Friday the 13th" in there because it's going to be released on Friday, October 13, 2006. --Bowlhover 03:10, 3 October 2006 (UTC)

Yeah, there are 11 of them. :P -- Consumed Crustacean (talk) 03:17, 3 October 2006 (UTC)

What did it feel like?--Light current 03:09, 3 October 2006 (UTC)

From myself, not like you'd really imagine death. Usually something interrupts the dream, or it shifts to another dream that may be partially related (but without any real explanation of how I got from the one dream to the other). No tunnels with light at the end, just dream nuttyness and such fun things. Try falling asleep in a dream, that's a trip ;) -- Consumed Crustacean (talk) 03:17, 3 October 2006 (UTC)

Well I have a junior psychology text book claiming that there is no evidence of what you are describing. I've also "died" in my sleep and am still here on Wikipedia, so it couldn't be that dangerous. AmitDeshwar 06:12, 3 October 2006 (UTC)

Another such experience here. I once dreamt I fell off a tall building. I truly believed I was going to die. The only time I experienced that sensation. Quite frightening. When I 'hit the pavement' what happened was what one would expect - I woke up with a start.

Now that I'm on the subject of dreams mixed up with reality. A week ago or so I dreamt I could fly. Oddly, I was aware that I was dreaming and (because of that?) the scene became extremely realistic (as if I weren't dreaming) and I got an almost orgasmatic feeling, with my body tingling all over. Well, not really tingling, it was more a feeling of exaltation ... of floating (or flying, appropriately). I suppose the dream caused some endorphin to be released in my brain. Alas, I instantly woke up on this occasion too. DirkvdM 06:31, 3 October 2006 (UTC)

Maybe if you keep realising, you'll move onto proper lucid dreams without waking up. Incidentally I died in a dream once, very thoroughly, and I didn't wake up until my mind had completely died away in the dream. I wouldn't recommend it as it was very upsetting, but it did take away my fear of dying. Needless to say, I survived. Skittle 22:00, 4 October 2006 (UTC)

my friend's friend's dad had a recurring dream that he was falling into a black hole, and he was going to a shrink and everything, and then one night, he hit the bottom. the end. Xtraqewl

Big Bang / Black Hole ...?

If the early universe was contained within a small volume of space, wouldn't it be inside it's own Schwarzschild radius? If so, how did it get out? Or did it? -- 84.65.71.50 00:18, 3 October 2006 (UTC)

A heck of a lot of interesting links at Google. Not trying to be rude by saying that, I'm just pointing out that there's some really cool shtuff there. -- Consumed Crustacean (talk) 00:24, 3 October 2006 (UTC)

It came out the white hole the other end!--Light current 00:28, 3 October 2006 (UTC)

Actually, we can't know. The laws of physics as we know, including the ones we use to determine the Schwarzschild radius, break up at that level of energy density in the earlier Universe. ☢ Ҡi∊ff⌇↯ 01:47, 3 October 2006 (UTC)

We could still be inside the primordeal black hole!--Light current 03:10, 3 October 2006 (UTC)

I agree. See [1]. Pfalstad 03:32, 3 October 2006 (UTC)

No, no, this is based upon a common misunderstanding: see this entry from the sci.physics FAQ. More generally, the Cosmology FAQ] maintained by Ned Wright (a working cosmologist) is well worth bookmarking. ---CH 04:31, 3 October 2006 (UTC)

Thanks very much, that link clinched it for me. 84.65.71.50 13:56, 3 October 2006 (UTC)

And Pfalstad please note: the page you cited actually is an attempt to explain why the Universe is not, in fact, a black hole, so consistent with the two sources I just cited. HTH---CH 04:33, 3 October 2006 (UTC)

The following is merely my opinion and more than one PhD would flame me for it, but here goes anyway : The Big Bang is first and beforemost a mathematical construct, and sadly enough, like other such constructs of modern physics, built upon self referencial logic (the universe "expending" into itself, "time slowing down" ...). I'm not claiming to hold the truth, however, I invite you to adopt skepticism toward theories that bend vocabulary. Equendil Talk 13:04, 3 October 2006 (UTC)

The theories don't bend vocabulary. The "lay-person" explanations of them sometimes do, but only because the real explanations involve things like tensor calculus (whereas I'm still struggling with the basic kind). 84.65.71.50 13:56, 3 October 2006 (UTC)

Terrifying, recurring nightmare I used to have...

From being a small child, all the way up to early adulthood, I used to experience a really, really bad dream, perhaps once a month or so. It was always the same - I was lying in my bed, looking up towards the ceiling and there would be a large, shadowy male figure leaning over me, with a balaclava over his face, only his eyes and mouth visible. His hands would be around my neck, choking the life out of me, pressing down on my windpipe with all his weight (I could feel his fingers digging into my throat). I'd try to struggle but I couldn't move my body at all to fight back. Then I'd wake up screaming and screaming and screaming, clawing at the air, gasping for breath. It was always exactly the same - I'd also tend to lash out violently at anyone that tried to approach me when I awoke. It'd often take me half an hour or so of being curled up in the foetal position in a corner to realize that 'it was only a dream' (no matter what anyone told me). One time, I picked up a hunting knife (that I kept near my bed 'for my own protection', heh) and started slashing madly at the air, not even realizing that I'd picked it up by the blade and had sliced my own hand open...

I haven't had that dream for nearly five years now but I still occasionally think about it and it still scares me, slightly. Anyone have any explanations as to what would cause such a violent, vivid dream like that, the same every single time I had it? I don't recall any traumatic event from my childhood that might've brought it on. --Kurt Shaped Box 00:43, 3 October 2006 (UTC)

Your muscles are paralysed whlst dreaming- so how dod you pick up the knife? Do you do sleepwalking?--Light current 00:49, 3 October 2006 (UTC)

I think I sleepwalked a couple of times when I was really young. I think the knife thing happened in the 'just awoken in terror - not sure if my assassin is still there/don't really know what the hell I'm doing' phase of sheer panicked frenzy. In the past, when it happened, when one of my parents ran into my room because I was screaming, I'd sometimes bite them, punch, kick or try to scratch their eyes out before I fully regained my senses. --Kurt Shaped Box 00:58, 3 October 2006 (UTC)

Sounds like a night terror. I remember watching a video about them, and a common occurence was for people to sense a man in black or a large dark woman who was strangling them. Hyenaste ^(tell) 00:56, 3 October 2006 (UTC)

How do you get the 'large (sexy) dark woman' dream please? 8-))--Light current 00:59, 3 October 2006 (UTC)

Have you tried summoning a succubus? ;) --Kurt Shaped Box 01:03, 3 October 2006 (UTC)

The large woman is not sexy. Hyenaste ^(tell) 01:23, 3 October 2006 (UTC)

Who says so? 8-)--Light current 01:31, 3 October 2006 (UTC)

It also usually happened within an hour or so of me getting to sleep, if that's any help. --Kurt Shaped Box 01:05, 3 October 2006 (UTC)

Is an hour enough time to get to stage 4 sleep? The article doesn't say! Hyenaste ^(tell) 01:23, 3 October 2006 (UTC)

Actually, this sounds more like me... --Kurt Shaped Box 01:49, 3 October 2006 (UTC)

Nope, hypnagougia is a lot different. Your parasomnia is a night terror. They are not uncommon. — X [Mac Davis] (SUPERDESK|Help me improve)02:12, 3 October 2006 (UTC)

If requesting medical advice, please consider asking a doctor instead of Wikipedia. That said, there are sleep disorders in which the paralysis normally present during dreaming is absent, and a dreamer may jump up and "fight" with the boogeymen attacking him, injuring himself or a bedpartner. This is a related to sleepwalking. Some medications may make it more likely. A sleep study can be done for a few thousand dollars at a sleep center of a hospital. The dreaming about someone choking you suggests obstructive sleep apnea.Edison 04:57, 3 October 2006 (UTC)

About the knife-grabbing and the paralysed muscles. I once did grape picking for two weeks and the result was that in my dreams I saw vines full of grapes. I had the scissors with which I cut them at the head of my bed. One morning I woke up with the sissors in my hand. Apparently I had grabbed it in my sleep and starting cutting those grapes. I immediately checked my left hand (the one I grabbed the grapes with before cutting), but all my fingers were still there. But my point is, I have never walked in my sleep (afaik), so that doesn't seem to be an explanation. DirkvdM 06:44, 3 October 2006 (UTC)

Yes but obviously there is something wrong with that part of your brain that inhibits you acting out your dream. I once dreamt I could fly like a bird high over fields. But then I started losing altitude and tried to flap my arms harder-- all to no avail. Eventually I came to rest on the ground exhausted and unable to fly anymore. Sad 8-(--Light current 08:23, 3 October 2006 (UTC)

• Kurt, did any of those dreams occur when you were ill or stressed with regular kid stuff back then? - Mgm|^(talk) 08:40, 3 October 2006 (UTC)
• Were you overweight or obese as a child? That can contribute to sleep apnea. zafiroblue05 | Talk 11:53, 3 October 2006 (UTC)

Come to terms with death. - R_Lee_E (talk, contribs) 16:24, 3 October 2006 (UTC)

Dreaming of dying

Has anyone here dreamed of life after death? If so, what is it like? I've always wondered this since I dreamed of falling from a high place. However, in that dream, I woke up before I hit the ground. --Bowlhover 03:15, 3 October 2006 (UTC)

Falling is quite a common dream I believe. When I used to have that one, I would slowly decelerate and end up on a very soft pile of pillows-- end of dream!--Light current 03:18, 3 October 2006 (UTC)

Like an episode of ReBoot, combined with purple dogs. Really, dreams are incredibly variable from person to person and night to night (and I am serious about that dream). -- Consumed Crustacean (talk) 03:30, 3 October 2006 (UTC)

I am either an intangible entity, or there is just another of me. — X [Mac Davis] (SUPERDESK|Help me improve)03:43, 3 October 2006 (UTC)

What if we dreamt of dying without any life afterwards? Just the mind dissolving away. Skittle 21:51, 4 October 2006 (UTC)

See various scriptures for other dreams of life after death. --GangofOne 04:38, 3 October 2006 (UTC)

ive been shot in my dreams . but hen i've also had lots of sex, edited Wikipedia and drove a JCB. you're points is ?

Sex with hens sounds pretty kinky. Maybe you're a turkey in real life.  :--) JackofOz 23:24, 3 October 2006 (UTC)

You drove a JCB while having sex with a hen? Thats a very original way of making the earth move 8-)--Light current 01:48, 4 October 2006 (UTC)

I've never dreamt about life after death, but I've dreamt of dying: in one dream 1000 times (each different); I've dreamt of having a near-death experience, complete with defibrillation (it was very painful); and I've dreamt of becoming friends with the angel of death, who is apparently a spotty teenage girl with greasy blonde hair. HTH :-) Anchoress 21:56, 4 October 2006 (UTC)

Measuring Mass/Volume

I need to know how to measure the mass and volume of an object like a rock or a nail. Can someone please help me?

-Thanks, anon

Mass: buy a scale, put the object on the scale, and take a reading.

Volume: Buy a graduated cylinder, fill it partially with water, and take a reading. Then throw your object in (making sure it's completely submerged) and take another reading. Subtract the first reading from the second, and that's the volume. --Bowlhover 04:11, 3 October 2006 (UTC)

• If you ask this question, it looks like you need to read up on what mass and volume are. Once you have a better understanding of what they are, you have a better idea on how to measure it. - Mgm|^(talk) 08:36, 3 October 2006 (UTC)

Using a scale measure weight, not mass. A balance would measure mass directly.Edison 16:16, 3 October 2006 (UTC)

A balance compares two weights. So how would it measure mass?--Light current 03:10, 5 October 2006 (UTC)

Because the acceleration on both sides is the same. Because, in a classic two pan balance, what you know about the reference weight is its mass. As far as Edison's comment, the word scale is a broader term than the word balance is, normally including the latter. But in any case, it depends on how the weighing scale is calibrated, among other things. Normally they measure mass, in the physics jargon meaning, but of course one of the biggest problems in discussions such as this is the failure to recognize the simple fact that both weight and mass are ambiguous words, with more than one meaning. Gene Nygaard 20:37, 5 October 2006 (UTC)

That stuff between your toes

Wher does it actually come from & what is it?--Light current 05:06, 3 October 2006 (UTC)

It's the ichor of the Sons of the Bird. It was put there to make them fearful. And no, I'm not going to tell you what your profession is; you should have figured it out by now. --Trovatore 05:32, 3 October 2006 (UTC)

Everybody's a critic. Oh, wait... Clarityfiend 05:48, 3 October 2006 (UTC)

I'm guessing that it's similiar to Navel lint. Mostly material from your socks. -- Consumed Crustacean (talk) 05:41, 3 October 2006 (UTC)

You have sock debris in your navel? - Nunh-huh 06:48, 3 October 2006 (UTC)

Lactation is believed to have evolved from fatty substances released from the skin of primitive mammals to nourish the young. Fermented exudate from the skin between the toes and under the nail of the large toes might be a vestige of this early mammmaiian trait, since "toe jam" (article needed) has much the same odor as Limburger cheese. Mass spectrometry might be able to shed light on whether the substances are chemically related.Edison 16:06, 3 October 2006 (UTC)

Is this like the white goo you get by squeezing the pores in your nose? It sure as hell smells cheesy, but hardly the edible variety. (I can't believe I just asked that question. But there you go, there's no limit to man's search for knowledge.) JackofOz 23:19, 3 October 2006 (UTC)

Nose grease? Apparently some photographers use it to hide scratches in negatives before printing them, and you can even utilize it to make scratched CDs/DVDs readable, because its refraction index is so similiar. All that, and it even combats beer foam. Good stuff. -- Consumed Crustacean (talk) 01:55, 4 October 2006 (UTC)

OK both of you, the white stuff between your toes and in your nose pores is mostly dead skin cells. The clear stuff in your nose is nose grease. The cheesy smell is bacteria. And the idea of feeding young with sweaty, greasy, fetid dead skin is almost enough to put me off sucking my toes. :-) Anchoress 22:04, 4 October 2006 (UTC)

Nose grease isn't what's in the nose, no one would be crazy enough to spread that stuff on their negatives. Nose grease is just the oil excreted by the pores on the nose's surface. It's quite different from the dead cells in toe jam also :P -- Consumed Crustacean (talk) 22:10, 4 October 2006 (UTC)

Sorry, you've misunderstood me. By 'in your nose' I meant in your nose pores. And I distinguished between nose grease and 'the white stuff that comes out of your pores'. The clear, waxy contents of human pores is sebaceous secretion. The white stuff is dead skin cells. Anchoress 22:17, 4 October 2006 (UTC)

Clue: Smells a bit 'cheesy'--Light current 01:49, 4 October 2006 (UTC)

how is newton's 2nd law modified when things reaches the speed of light?

The title says it all how would it be modified? Thanks :)

See Newton's laws of motion#Newton's second law: historical development, about six paragraphs down. --ColinFine 08:28, 3 October 2006 (UTC)

germanium

What kind of tests can be done to identify Germanium

Most elements can be identified using mass spectrometer technology. I do not think the gasses can be done this way, though, but Germanium is not a gas.

it depends of course, in what form, and for what purpose. some form of atomic absorption spectroscopy would be my pick for most cases, but the precise method depends on the amount of sample you have, the likely amount of germanium in it, and the amount of money you are prepared to pay a professional to analyse it. and pure mass spec is not terrifically useful for routinely analysing complex mixtures, except for hyphen techniques such as ICP-MS. Xcomradex 21:04, 3 October 2006 (UTC)

Dead Leg

Yesterday during a soccer game I accidentally got kneed in the thigh while jumping for a ball, and I got what is considered a dead leg...I'm curious as to two things. Firstly, how does this relate to a "Charlie Horse" (I've never understood what that was) and secondly, for this kind of minor minor injury, is it best to keep it warm by playing (as i did) or to ice it? then, after the fact, any tricks to getting the minor pain/limping to leave? thanks. ChowderInopa 14:27, 3 October 2006 (UTC)

Strangely, i've been limping for the last two days since it happened...ChowderInopa 02:36, 4 October 2006 (UTC)

A charlie horse as I know it happens when the big fat guy in your class slams his massive fist into your thigh (impacting your femur) and eventually causing a bruise. If he is significantly burly, it can cause temporary difficulty while walking, but I've always found they're usually not nearly as bad as a "dead arm", which is what happens when the fat guy aims at your arm instead.

I imagine "dead leg" is the same thing, which would make sense as there is no "arm charlie horse", although "dead leg" seems to imply the not-being-able-to-walk part, whereas "charlie horses" are simply known to hurt a lot. If there is no damage to the muscle or bone, and you're the kind of person who likes to grit his teeth through the pain, then shrugging it off is probably the most manly thing for you to do. To keep the swelling down and possibly reduce the forthcoming bruise, ice is the typical prescription.  freshofftheufoΓΛĿЌ  12:56, 5 October 2006 (UTC)

vortex ring gun question

http://en.wikipedia.org/wiki/Vortex_Ring_Gun

Would i be right in assumeing that the simplistic explanation for the effect of this weapon is is that the air propelled by the discharging of the cartridge is channeled into the vortex ring so it can be transported to the target and the impact caused is from the air pressure caused by the accelerated air, if so is this weapon classed as a shockwave weapon?

Rob

I think this is just a more powerful Airzooka. This figure shows the formation of a vortex ring [2] There is no supersonic air motion, and no shockwave. The weapon looks like it would be used for riot control, and may be more humane than bullets (lead, rubber, etc). --Zeizmic 15:44, 3 October 2006 (UTC)

BP cuff one-way-valve

Let's say that I'm using a sphygmomanometer [<--- who deleted this??? wierd] on a patient with a BP of 120/80. If I were to make the pressure in the cuff 100mmHg, and keep it there for a long time, what would eventually happen to the patient's arm? Would all of the capillary beds rupture? Would the blood just pool up and end up in stasis at high pressure? Yesterday during a demonstration I left a cuff on between my systolic and diastolic pressures for just a few seconds as I answered a question while attempting to take my own pressure, and immediately my arm felt like it was going to explode. I'm just curious as to what the eventual outcome would be if this condition was allowed to progress.Tuckerekcut 15:24, 3 October 2006 (UTC)

Just to clarify, in this condition blood would be going into the arm during systole, but would not exit the arm because the cuff pressure is higher than the diastolic pressure (and thus blood could not escape through the veins, nor reflux through the arteries).Tuckerekcut 15:38, 3 October 2006 (UTC)

If requesting medical advice, please consider asking a doctor instead of Wikipedia, although the question implies you are a medical professional. That said, I have noticed that hospital blood pressure monitors deflate between measurements to allow blood flow during the whole systolic/diastolic cycle. Polygraphs use a sphygmomanometer cuff left on the interviewee's arm throught the interview, but I do not believe it is inflated even to the diastolic pressure. It is used more as a plethysmograph. Since a cuff can have the effect of a tourniquet and cause damage leading to amputation if left on too long at too high a pressure, what good could come from the experiment you propose? Edison 16:14, 3 October 2006 (UTC)

As I've said before, the BP cuff is painful, and pain likely effects my BP. This, along with the risk of doing permanent damage to the blood vessels, should be enough reason for them to develop non-cuff methods for reading BP. StuRat 16:20, 3 October 2006 (UTC)

If a few seconds of compression were expected (or at least had a non-negligible chance in virtually all cases) to cause serious or permament damage, I doubt it would be used so commonly. Long-term cut-off effects?—sure, but that's not how the thing is (supposed to!) be used. Alternatives do exist, but running a pressure gauge into an arterial catheter doesn't seem like a good front-line technique:) There are other non-invasive ways, for example, doi:10.1213/01.ane.0000171231.29328.9f. Given it's just now being studied and has a trademarked name, it's probably not gonna be cheap and not widely available anytime soon. I don't have that journal available here, so I can't get enough info about this thing to add to the Measurement section of the Blood pressure page. DMacks 18:30, 3 October 2006 (UTC)

If there were long term damage to the veins, arteries, and capillaries, it wouldn't be evident that BP cuffs are the cause, unless carefully studied. Other medical devices, like the fluoroscope, and, to a lesser extent, x-rays, were once assumed to be harmless, but later discovered to be potentially harmful. StuRat 19:56, 3 October 2006 (UTC)

OK - Just did it. My BP was 118/92 (not identical to the question, but close). I then reinflated to 100psi as stated in the question. After a minute, I felt a lot of pressure in my arm. I waited a few minutes, same pressure but my arm was a lot more purplish. After ten minutes, same pressure and my arm was still purplish. I released the pressure and the purplish color quickly went away. I checked my BP again and it is 114/88. Maybe my BP went down to account for the back-pressure. --Kainaw ^(talk) 20:03, 3 October 2006 (UTC)

I'm betting your BP went down due to lost blood when they amputated the arm. :-) StuRat 23:13, 3 October 2006 (UTC)

Kainaw, that took some balls, my arm started throbbing after just a few seconds. Though the pain was bearable, I felt like I was gonna do some damage. Let me know if you have any petechiae or erythema tomorrow. Did you notice how the feeling was much more "urgent" than just the feeling of ischemia (tingling, numbness, &c.)? That said, do not repeat the experiment, we wouldn't want you to hurt yourself.Tuckerekcut 00:20, 4 October 2006 (UTC)

It just felt like my arm feels when I sleep on it wrong - swollen and numb. No real pain. But then I've never felt pain from a BP cuff (or having blood drawn for that matter). As for turning purple, I can do the same thing to my face by just tensing my neck. Goes away when I relax. But, if you want to talk about pain, I'm dealing with a severe case of epididymitis right now. Got the (relatively) good news today - it is definately epididymitis, not cancer. Of course, I'm drifting onto a completely unrelated topic that I'm sure nobody wants to think about. --Kainaw ^(talk) 01:16, 4 October 2006 (UTC)

I can't help wondering if you've been tying a ligature around your balls to make them turn purple, and hence your medical condition. :-) StuRat 04:07, 4 October 2006 (UTC)

A book from the Vietnam War era said U.S. forces had a polygraph machine with a sphyg cuff used for the plethysmograph aka "bloodpressure" input on the lie detector, for interrogating Viet Cong prisoners. One group went for the most direct approach: They pumped the cuff up too 300 mm hg and left it there, and told the prisoner they would use it to chop his arm off if he didn't talk!Edison 07:09, 4 October 2006 (UTC)

moving shock tables

who developed the moving shock tables?

I believe that was an invention that contributed to the decline of Spiritualism in the 1920's. Once the table started to move, everybody got a shock, which strongly discouraged a repeat performance. The person who invented it is now dead, but nobody dares to try to get a confirmation out of him. --Zeizmic 20:01, 3 October 2006 (UTC)

Do you mean 'shaker tables'--Light current 13:00, 4 October 2006 (UTC)

Pink Discolouration Of Clothes

A number of items of my clothing over the years have developed a strange pink/peach staining that doesn't wash out. This has happened to a dark green 90% coton/10% elastane sweater and a kahki 100% cotton shirt. I also once had a sky blue sweater to which the colour change occured right before my eyes upon application of deodorant. What could be causing this and is there a way it could be reversed? --Username132 (talk) 17:12, 3 October 2006 (UTC)

Washing them with something red is the usual culprit. It might be an item with only a small red area. StuRat 19:26, 3 October 2006 (UTC)

Acidic sweat? --jpgordon^∇∆∇∆ 19:30, 3 October 2006 (UTC)

Hard water? User:Zoe|(talk) 00:36, 5 October 2006 (UTC)

properties of sulphur

why is sulphur used in the making of ointments

• Because it has germicidal, fungicidal, and parasiticidal properties, and is generally regarded as safe in topical applications. --jpgordon^∇∆∇∆ 18:27, 3 October 2006 (UTC)

...and then there's that wonderful smell. :-) StuRat 19:29, 3 October 2006 (UTC)

ugh at my school on a floor with all chem. labs... they use sulfur in like all their experiments so that floor with all the labs smells like cat piss. --Agester 15:04, 4 October 2006 (UTC)

Cryonics

hi, do u guys think that cryonics is a realistic option?realistic and safe? or is it just a scam or a good intentioned silly illution?. --Cosmic girl 19:31, 3 October 2006 (UTC)

There are currently no means for repairing cells heavily damaged by freezing. After thawing, your frozen body (or brain) will be nothing more than goo. Youth in Asia 20:13, 3 October 2006 (UTC)

Safe? Yes--if you die, you won't know anything, so it doesn't matter what people do to your body. Realistic? Well, you can freeze someone and hope that a scientist in the future can revive them. But currently, and also in the foreseeable future, reviving the dead is impossible. --Bowlhover 00:35, 5 October 2006 (UTC)

will there never ever be enough technology for this purpose?...maybe ...uploading minds to computers?.--Cosmic girl 20:35, 3 October 2006 (UTC)

That's a completely different concept from cryonics, and one which is totally based in science fiction right now (ie. without even hair-brained guesses or hypotheses). On the other hand, some scientists apparently managed to freeze dogs and revive them many hours later, but I'm unsure if that's been independently replicated. It sounded iffy. -- Consumed Crustacean (talk) 21:28, 3 October 2006 (UTC)

This is just my personal opinion, but I think it will be possible some day. The cell damage from freezing has been overcome with respect to bacteria for quite a long time--just mix some glycerol in with the cells before freezing. It's not that easy with multicellular organisms, since we're not just a bunch of unattached cells floating in liquid, but I don't think the problem is insurmountable.

Before I'd be willing to subject myself to cryopreservation, however, I'd want a demonstration in which a large mammal (e.g., a dog) was frozen for a significant period of time (several months), revived, and have it shown that the revived dog retained memories it had from before when it was frozen (one method might be teaching it to run a maze, then demonstrating after thawing that it retained the knowledge of how to find the goal in that maze). After all, if I'm frozen and then revived, but my revived body doesn't have any of my memories, the revived body doesn't seem very much to be "me." Chuck 21:31, 3 October 2006 (UTC)

This would be a good time to read the Cryonics page, if you haven't already. DMacks 21:29, 3 October 2006 (UTC)

If there was any sign it would actually work, I'm sure the Bush admin would put a freeze on all research funding in the US. StuRat 22:59, 3 October 2006 (UTC)

The wood frog and some other animals can survive freezing, so it may be possible, but not enough is known at this time. Clarityfiend 00:49, 4 October 2006 (UTC)

Mmmm. So its fresh frog straight out of the freezer?--Light current 13:03, 4 October 2006 (UTC)

Interpreting a sentence about biology

Hi all. I'm a little slow. Can I get some help interpreting this bit?

Surprisingly, on scanning electron microscopy, Dr. Shi found curved bacilli on the surface of the gastric mucosa, sometimes so small that it was difficult to differentiate them from the residual mucus flaskes, but as the morphology and size of the organisms were similar, they were considered to be bacteria. At that time it was considered that these were "passenger" bacteria and not the pathogen for gastroduodenal disease, because in gastric biopsy specimens the bacteria were seldom seen, a result of the mucus on the mucosal surface having been washed out in the preparation process. Although it was well known that gastric acid and enzymes were capable of killing bacteria, the presence of a few "passengers" in the stomach was not uncommon.

This is from an article about the history of Helicobacter pylori, and this episode transpired before people knew about this bacterias existence (or the existence of any bacteria in the stomach). My question is, what does "passenger bacteria" mean in this context. If it was so common, why didn't it contradict the study which "demonstrated" that bacteria couldn't survive in the human stomach? Thanks for your help! --best, kevin [kzollman][talk] 19:59, 3 October 2006 (UTC)

"Passenger" bacteria => bacteria being passed through the digestive system because they were ingested with food, rather than living there because they've found an amenable ecological niche and/or causing disease. Your 2nd question however: the passage doesn't say anything about "demonstrating" that bacteria couldn't survive in the human stomach. So I'm assuming it's mentioned before the quoted passage. (The passage says that gastric acid and enzymes could kill bacteria, it doesn't say it always killed all bacteria.) Finding bacteria, and finding live bacteria are of course, different things. And, obviously, finding living bacteria in the stomach does contradict any theory claiming that living bacteria cannot be found in the stomach! The finding just needed to be confirmed, and was eventually widely, and now universally, accepted. That's how science works :) - Nunh-huh 22:56, 3 October 2006 (UTC)

Great thanks. I should have mentioned the context of the second question, although your answer gives me everything I need. There was a 1954 study by Palmer that "demonstrated" bacteria couldn't survive in the stomach, which set back ulcer research for some time, since as it turns out, bacteria cause ulcers. The study referred to above occurred after this 1954 study but before the existence of bacteria in the stomach was conclusively demonstrated. Thanks again. --best, kevin [kzollman][talk] 01:58, 4 October 2006 (UTC)

geography

trying to locate the 5 european nations with the highest % of muslim relative to the national population

Demographics of Islam could be helpful. - Dammit 22:56, 3 October 2006 (UTC)

Islam by country is better; demographics just compares Sunnis to Shiites. Turkey will of course be top, followed by the Balkan nations(Bosnia and Herzegovina, Serbia and/or Montenegro (the article hasn't been updated to include the separation, so can't give better info), Former Yugoslav Republic of Macedonia especially) and Cyprus. If you're thinking just of the European Union, Cyprus is top of the list, with France, The Netherlands, Switzerland and Germany following. Laïka 17:06, 4 October 2006 (UTC)

Tim Clutton-Brock

How come Tim Clutton-Brock doesn't have an article?

^{Superscript text}

Because he/she/it isn't worthy of an article or because nobody who knows who or what it is has taken the time to research he/she/it and write the article. DMacks 21:27, 3 October 2006 (UTC)

Timothy Hugh Clutton-Brock, SCD FRS.

unit cells

How many sulfide anions are in a unit cell of ZnS? Also, what would the density of this unity cell be, with a cell edge length of 0.5411 nm? —The preceding unsigned comment was added by 130.207.180.23 (talk) .

welcome to wikipedia. might i suggest typing "zinc sulfide" into the little box on the left, clicking Go, then reading the results. i bet it's even quicker than writing profane responses to the very people you expect to answer your questions. Hope the Georgia Institute of Technology gives you good marks. Xcomradex 00:36, 4 October 2006 (UTC)

Go Bulldogs!Edison 07:12, 4 October 2006 (UTC)

Blood Alcohol

A Friend was trying to convince me this evening,(in the pub of all places),that the body has what he calls a "background" level of alcohol. He claims this is due to fermentation in the gut and other perfectly normal processes. Is this true? Or is he, as I suspect, full of c**p? Scrivens 22:33, 3 October 2006 (UTC)

Full of crap. The expected value for blood alcohol, in the absence of oral intake of ethanol, is zero. No measurable amount of alcohol should be present in the blood if there's been no ethanol intake. Can a small amount of alcohol be produced by fermentation in the gut? Yes. Can a large enough amount be produced that will overcome the normal alcohol metabolizing capacity of the liver, and so enter the peripheral blood? No. . - Nunh-huh 22:47, 3 October 2006 (UTC)

I read a case study about this guy who had no endogenous alcohol dehydrogenase. I guess he got pulled over for something and the cop smelled booze on his breath, and he ended up blowing a .08 or similar, even though he didn't drink. He said that he never did drink because he got wasted so quickly and for so long. Turns out that he had just eaten a series of meals that had both increased the alcohol-producing flora of his gut and then fed them simple sugars. The result was that he ended up "endogenously drunk". But of course this is ridiculously improbable. In real life, though there are microbes that live in your belly and make alcohols, they don't make enough to be measurable in breathalysers, or to have a physiological effect. As Nunh-huh points out, the stuff probably doesn't even make it out of the portal system.Tuckerekcut 00:33, 4 October 2006 (UTC)

This has the same credibility as girls who get pregnant from a swimming pool.Edison 07:13, 4 October 2006 (UTC)

Indeed... This case was laid out in a vignette about genetic enzyme deficiencies like PKU and Lesch-Nyhan, and may have been a joke. But then again, you never know, it is a possibility as long as only the zinc dehydrogenases are affected. And methanol wouldn't be a big deal as long as it couldn't be metabolized. I don't see why the patient wouldn't be able to survive, but maybe there is something obvious I am missing.Tuckerekcut 12:52, 4 October 2006 (UTC)