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October 31

Sense of humour

Does a persons sense of humour depend upon the serotonin levels in the brain? If so, should these mentally affected people be criticised for making jokes that others may not find very funny? (not just on WP but verbally too)--Light current 01:41, 31 October 2006 (UTC)

Serotonin has nothing to do with humour. However, it is something that is not controlled - you do not choose what you find funny and not funny. It is based on many things (listed in humour. Being criticized for making offensive jokes has nothing to do with homour either. It has to do with etiquette, maturity, sympathy, and compassion - among many other things. --Kainaw ^(talk) 01:54, 31 October 2006 (UTC)

Are you really sure about that?

In the central nervous system, serotonin is believed to play an important role in the regulation of mood, sleep, emesis (vomiting), sexuality and appetite. Low levels of Serotonin have been associated with several disorders, notably depression, migraine, bipolar disorder and anxiety.

my links/ bolding. And do you know what mania is? --Light current 01:59, 31 October 2006 (UTC)

Are you trying to claim that mood and depression equate to a sense of humour? A sense of humour is what your brain identifies as being humorous. You can be angry and laugh at a fart. You can be happy and laugh at a fart. You can be suicidal and laugh at a fart. Your mood or state of depression may change how much you laugh, but it doesn't change how your brain reacts to a fart. --Kainaw ^(talk) 03:13, 31 October 2006 (UTC)

They dont equate to it but obviously affect it. Which is what I indicated in the question. Do you laugh more at silly things after a few drinks?--Light current 03:36, 31 October 2006 (UTC)

Also in answer to Kainaws last post:

You can be pissed as a fart and laugh at your brain.

Now is that funny in this context or not?--Light current 11:54, 31 October 2006 (UTC)

Actually, I believe a sign of depression is a lack of ability to laugh at things. So, there is a link between depression and (lack of) humor. StuRat 05:44, 31 October 2006 (UTC)

What I was trying to point out is that a "sense of humour" is not based on how much a person laughs. It is called "sense" because it is a "sense". Regardless of your emotion, an anchovy will taste salty because your "sense of saltiness" still functions to tell you if it is salty or not. The same with humour. Your sense of humour tells you is something is funny or not. It is up to other parts of your brain to control the reaction to that sense. Now, if Light Current asked something along the lines of "Do serotonin levels control how much a person laughs at things they find funny?" I would have had a completely different response. --Kainaw ^(talk) 13:51, 31 October 2006 (UTC)

Yes OK. But I still think I am inclined to find certain things funnier than others do when Im a bit high. When Im low even very funny things may not elicit a response from me. Also the amount I laugh is proportional to how funny i find things at the time. Its funny isnt it? So therefore my sense of humor does get more or less acute with mood. Or am I missing something?--Light current 14:02, 31 October 2006 (UTC)

It is well known that THC affects a person's sense of humour. With enough THC, everything is perceived as "funny", as in "Man, I just broke my leg. That is so funny!" You can chemically override the brain's functions in many ways. Also, it is getting a bit semantic when you say that your mood affects how funny you find things. My opinion is that your sense of humour decides "funny/not funny". A completely different part of the brain decides "how much do I laugh". Assuming you are not chemically influenced, something you do not find funny will not make you laugh regardless of your mood. However, I feel you've missed the point that I was half supporting your apparent opinion and half disagreeing with it. In support, a person's sense of humor is a sense that is not controlled (without chemicals). So, if my brain tells me that watching nuns fall off a cliff is funny, I can't turn off my sense of humour. I'm stuck with it. In disagreement with you, I do not feel that making offensive jokes is beyond a person's control. To switch topics slightly (making a clearer point), my father-in-law talks about boobs nonstop. We take him out to Outback and the conversation goes,

Waitress: "Hi, I'm Kathy and I'll be your waitress."

Father-in-Law: "Are your boobs real?"

Control over what you say (or type) is expected. Blaming everyone else for your inability to socialize is not a solution. You can find things funny, but you are not required to vocalize everything that goes through your brain. As much as I'm disgusted by humans, I would have been banned from Wikipedia long ago if I said everything that I thought. --Kainaw ^(talk) 14:33, 31 October 2006 (UTC)

Well you aint seen it with the filter removed! (be thankful). Whats THC BTW? OK found it. I may be a dope , but I dont smoke it!--Light current 14:44, 31 October 2006 (UTC)

I think the key word of your question is should. Science generally can answer questions about what is, but what we should bame people for (what should be) are not answerable in science. So says, at least, David Hume and the Naturalistic fallacy. We have no answer to what we should blame people for, since normative questions are not in the realm of science. --TeaDrinker 04:10, 31 October 2006 (UTC)

There's a difference between the emotional intensity one gets when receiving a joke and the inability to come up with jokes that are humorous. If your jokes get no laughter it's not due to anyone's seratonin, you're just not funny. Ƶ§œš¹ _{[aɪm ˈfɻɛ̃ⁿdˡi]} 06:21, 31 October 2006 (UTC)

Ah well. Humor is in the mind of the audience I suppose.--Light current 11:23, 31 October 2006 (UTC)

Check your serotonin level: Wikipedia:Reference_desk/Science#Of_mice_and_lab_rats . Worked for me, but I'm on SSRI --GangofOne 07:10, 31 October 2006 (UTC)

I think maybe this should now be moved to Talk:Humour as it has become more of a discussion. Any objections?--Light current 14:54, 31 October 2006 (UTC)

Burnt Stock Pot

I have an Aluminum (might be stainless steel) stock pot which, in a moment of stupidity, I left on high heat with nothing in it for at least 5 minutes (before I removed it, I heard several large BANG noises). A patch of the bottom appears to have burnt and changed color to blue. It's a relatively small patch.

Basically, can I keep using this pot safely? These things are quite expensive and I'd rather not have to buy a new one....

--Wedgeoli 04:39, 31 October 2006 (UTC)

I would say no, from your description it sounds ruined to me, but it's up to you to judge. StuRat 05:39, 31 October 2006 (UTC)

Almost certainly stainless steel rather than aluminum. Stainless steel contains chromium and nickel both of which are transition metals which have coloured oxides. Theresa Knott | Taste the Korn 06:03, 31 October 2006 (UTC)

As long as its only your outside bottom thats burnt, and the inside is still clean, I see no reason why you cant still use it. THe loud bangs will have been the bottom expanding and maybe buckling slightly. If on examination you find no crack in the bottom, then I think youll be ok. OTOH if you have permanently bent your bottom, then it may no longer sit comfortably on the stove. 8-|--Light current 10:27, 31 October 2006 (UTC)

I agree that it was probably stainless steel. Rainbow-like changes of colo[u]r would be charateristic of overheated steel whereas melting would be more characteristic of alumin[i]um ;-). I've never heard that the color changes were hazardous in any way, though, and they can sometimes be completely or partially polished out with a mildly-abbrasive cleaner (in the United States, Bon Ami, Comet/Ajax, or Zud, in roughly increasing abbrasiveness). If it was a multi-layer pot (stainless steel clad aluminum), the bangings might have been ruptures in the bonds between the layers. If this occurred, the pot might no longer heat as uniformly as before. And I agree that if the pot shows any cracks, discard it; you don't want it to fully fail while loaded with hot liquids!

Atlant 18:24, 31 October 2006 (UTC)

I've had experience with metal discoloration if you over heat while cutting or grinding and from experience, it is only the very surface that discolours, I'm guessing it's an oxidisation. I personally think you have nothing to worry about. Unless there is actual plastic deformation to either the top or bottom surface then I think you have absolutely nothing to worry about, even if the "layers" have slightly seperated. Vespine 22:07, 31 October 2006 (UTC)

I second the oxidation idea. Aluminum only has one oxidation state (3), which means that it won't change color when you heat it (it'll melt, but it won't turn blue like you described). Steel, however, is composed of chromium and nickel which certainly could have oxidized. This will not, I am thinking, be toxic or such. However, I *would* wash that pot out well first in case something reacted and got in your pot (unless you like REALLY crunchy beef stew) :) 22:32, 31 October 2006 (UTC)

I've had a similar experience with a small pot. It was/is stainless steel and I'm still alive Nil Einne 18:25, 1 November 2006 (UTC)

Evolution

Do you think it would be possible, given the right environmental pressure, for, in a long time (i.e. few billion years), a population of bacteria-like "simple" organisms to be the descendants of a human population?

No, humans have evolved to the point were they can themselves solve any problems much faster than waiting for evolution to do it for them. Given the pressure to do such a thing, we would just manipulate our enviroment until it suited us the way we are. Philc _T^E_C^I 10:25, 31 October 2006 (UTC)

You missed the questioner's point. I had to re-read it also. He is asking if a billion years of evolutionary pressure could result in simplification of an complex organism back to a form of protista that could reproduce asexually by mitosis. It sounds like the poor guy has had an even worse experience than J Alfred Prufrock, who only wanted to be a "pair of ragged claws" etc. I never thought about this, but there certainly have been examples of size reduction, of chromosome reduction, of abandonment of organs and body parts. I am doubtful if it could happen, but I think it sounds like a good senior thesis project, don't you? I would suggest some eukaryotic organism with a quick maturation time and simple breeding conditions, like a fruit fly. See if you can manipulate the environment to eliminate one feature after another... alteripse 12:25, 31 October 2006 (UTC)

Ok, maybe humans weren't the best example, as we do buck just about every trend. :) Philc _T^E_C^I 17:02, 31 October 2006 (UTC)

That's exactly what I was asking. Wether there was a principle in our theory of evolution that would maybe prevent the "simplification" of organisms over time (is the process reversable). And i forgot to sign Keria 12:50, 31 October 2006 (UTC)

The common misconception is that evolution always leads to larger, more complex organisms. Evolution doesn't care, it goes with whatever works. A classic example is a retrovirus, where "retro" means "backwards from the typical evolutionary direction". A retrovirus is so simple, some are almost nothing but chunks of RNA (similar to DNA). Since they can't eat, grow, or reproduce on their own, they couldn't possible have existed before there were more complex cells around that they could use to reproduce. Think of them like a chain letter that says "copy me", they don't actually do anything, but their existence tends to cause copies of themselves to be produced. StuRat 13:08, 31 October 2006 (UTC)

I don't know if the concencus on retro viruses is that they evolved from more complex organisms. The reason they are called "retro" is they use reverse transcriptase, and undergo the reverse process for protein synthesis than all other life forms. The best example of evolutionary "simplifications" are internal parasites. Once they are within a body, the environment is constant, and therefore easier to survive. Their mouth parts generally become more complex, as they need to hang on, and their defence against the host's defences will also become more complex. But, they will lose all limbs, as well as many internal organs neccesary for terrestrial or marine life. --liquidGhoul 13:21, 31 October 2006 (UTC)

My name is TenOfAllTrades, and I approve this nitpick. Retroviruses are named for their use of reverse transcriptase to transcribe their RNA back into DNA—the reverse of the usual process.

Meanwhile, check out our article on viruses for at least a brief discussion of their possible organisms; note that at least one possible model is based on the same type of simplifications that LiquidGhoul describes above for multicellular parasites. Alternate explanations suggest that viruses developed from short stretches of genetic material and other macromolecules that escaped from existing cells and evolved from there. A third explanation is that viruses evolved in parallel with conventional cells in the RNA world. (It's possible that any or all of those three things could have happened at various times.) TenOfAllTrades(talk) 14:44, 31 October 2006 (UTC)

Thanks for the correction (my equating the "retro" in retro-virus with the "retro" in retro-evolution). I still subscribe to the theory that they are an example of retro-evolution, however. StuRat 18:46, 31 October 2006 (UTC)

Although I do agree with your theory, I wouldn't call it retro-evolution. This suggests evolution is supposed to be increasing complexity. It's not. There is no retro-evolution, just evolution Nil Einne 18:17, 1 November 2006 (UTC)

If environmental conditions changed, it is more likely that the existing simpler organisms just take over. This has happened many times in the fossil record. --Zeizmic 13:15, 31 October 2006 (UTC)

OK I take it that the answer to the original question is "yes". Keria 14:57, 31 October 2006 (UTC)

Probably, yes. There are examples of evolutionary simplification, though none as radical as suggested in the original question. Loss of tail in Hominidae, loss of limbs in snakes and some lizards, loss of gills, and loss of parietal eye seem to be valid examples. So is also the loss of a number of body segments and simplification of respiratory system along the evolutionary path of terrestrial arthropods. Neoteny can probably be considered as a rather general class of evolutionary simplification, too. There are also simplifications resulting from transition to parasitism (as in scale insect or many endoparasites) or transition to attached (immobile) lifestyle (as in barnacles). Please note though that in last two cases the larvae are not respectively "simplified". Keep in mind also that I am a physicist, not a biologist, so my perception of "simplified" may differ from that in the mainstream biological science. It would be very nice indeed to hear from an expert in the field. As for the reason why there are no extreme examples of evolutionary "simplification" - I think Zeizmic got it right. It would take far longer time for a slow-reproducing mammal to simplify itself back to basics than for a pre-existent bacteria to mutate. Thus, mutant bacteria will likely occupy the vacant ecological niche way before your "Homo trivialis" Dr_Dima.

It would strike me as rather unlikely though obviously not "impossible". Complex organisms, like complex societies, usually end up with a lot of distribution of labor. To attempt to scale that back down a point where fewer cells did more tasks seems unlikely to occur. But I'm going with the original question you asked in particular, not the additional ways it has been elaborated. I don't know if losing an eye or a limb makes one biologically more "simple". I would consider "simple" to mean "less complex", which biologically would seem to mean (to me at least, a non-biologist) a lot less specialization among cells. I don't want to say it's impossible (I would just be showing the limits of my imagination) but it does seem quite unlikely to have that occur on an organism-wide level. --Fastfission 15:25, 31 October 2006 (UTC)

Why does it have to be unlikely? The conditions on the Earth can change a lot in a billion years, going "backwards" might be the most favorable thing to do. X [Mac Davis] (SUPERDESK|Help me improve) 15:57, 31 October 2006 (UTC)

———

Wrong, the answer is "No."

We, and every living thing you see about you are at the current endpoints of long evolutionary lineages that have moved in the direction of more complexity from bacteria-like beginnings. While evolutionary changes are random, successful changes are heavily weighted toward increased complexity. The "goal," of course, is best fit with the environment. While it is true that some modifications are toward simplification — the reduction in modern horses' toes from five to three to one with a pair of functionless side splints, or the non-functionality of the human appendix — these are minor matters relating to the availabilty and variety of foods in the niche.

What is being suggested in the question is impossible for three reasons.

1. All of the thousands of necesary modifications would have to fall in the less-likely direction of simplification.
2. The modified descendent individuals would have to complete with their unmodified cousins during the billion-year interim. Loss of sense organs, manipulative organs, and brains would hardly give them an advantage.
3. Even should the inconceivable happen, these neo-bacteria would then be in the same ecological niche as the real bacteria that already occupy it. These bacteria are the product of billions of years of descent with modification which has honed them to fit in perfectly in their environment. They would have a massive headstart on filling any posited neighboring niche that would open up in the next billion years.

So the answer is "no" because the choices are "up" or "out," and "down" is already out.
B00P 16:38, 31 October 2006 (UTC)

What tends to happen is when these pressures arise, instead of retro-evolution or whatever, the complex organisms that cannot cope just die out, leaving the simpler, faster reproducing organisms, which have less requirements, and also reproduce faster. Philc _T^E_C^I 17:04, 31 October 2006 (UTC)

I agree with your point. I don't personally believe complex organisms like humans are likely to evolve in to bacteria like organisms. Not because they can't but because it's never likely to happen that way since there will always be other simpler organisms which will evolve in to these bacteria like organisms Nil Einne 18:20, 1 November 2006 (UTC)

Another example is cave-dwelling animals which lose their eyes. StuRat 18:48, 31 October 2006 (UTC)

---

Thanks! Good arguments.

I still can't find where it doesn't work. Leaving the theoretical principles to go back to an example: could we imagine a scenario where a mamalian population ends up as a microorganism? (ok I stretched it a bit with humans because we have such a control over our environment that we make our own niche).

Say: One species of mammals. Their environment gets warmer, they migrate towards the edge of the sea, warmer they spend half their time in the water, still warmer they become predominently aquatic (limbs become fins, lung turn "back" into gill-like system), surface acidity forces them to the bottom (lose eyes, pigmentation), more acid, less and less oxygen(gills aren't good enough anymore) etc... I haven't got enough knowledge to do the whole evolution backwards but it doesn't seem too difficult.

Of course here we follow the winners in the end, all the other species that branched off (modified or unmodified cousins) along the way are not taken into account.

The argument of the ecological niche of the microorganism being already taken is a good one but it doesn't seem to work that way to me. The taken position is only part of a system. The niche is in constant interaction with all the other "niches". So I don't see a problem with having the two populations (our heroes and the preexisting microorganism) cohabitting in the same environment, like they've always done. Especially as we come from more complexity the existing microorganisms seem like an interesting source of food or even like potentials for a symbiotic relationship.

When BOOP you say that the line of evolution has gone along more complexity, I would say that more complexity has been allowed by the environment and the constant interaction of organisms (I guess the biggest step was from mono- to multicellular). I'm not sure how we can make of "complexification" a general unbreakable rule of evolution. Can an organism go back to being a colony of cells? I'm not sure why it couldn't.

The idea of the possibility of the reduction (almost to the absurd I confess) is seducing because it really place mankind as a carrier of a principle (life) rather than as the pinnacle achievement of that same principle.

Thank you for all your thoughts (although I'm still ready to hear more).

Keria 17:37, 31 October 2006 (UTC)

Actually I'm going to vote "yes" (except for the prokaryote part). We already have human-derived cell-lines, so to go from a lab-hosted cell-line to a unicellular organism doesn't strike me as all that difficult. Guettarda 18:42, 31 October 2006 (UTC)

I would say yes, with one provision: the organisms currently occupying the next biological niche must first be removed, to make room for the new, devolved, organism. That is because those organisms already in the niche will be well-adapted to it, and thus able to out-compete any new entry into the niche, which will still need lots of "fine-tuning" to become competitive. StuRat 18:51, 31 October 2006 (UTC)

Actually that depends. Niches are probably overrated. Anyway, is "lab bench" an acceptable ecological niche?  ;) Guettarda 21:44, 31 October 2006 (UTC)

Again I agree with your points. But I also don't like the term devolution anymore then I like retro-evolution Nil Einne 18:22, 1 November 2006 (UTC)

I know what you mean, because phases like devolution and retro-evolution imply that there is something abnormal, or at least unusual, about organisms evolving into simpler forms. Still, I think the terms are useful shorthand for "evolution counter to the direction that people generally expect". StuRat 20:36, 1 November 2006 (UTC)

---

1. Humans make machines with artificial intelligences.
2. Humans become genetically engineered "pets" of the intelligent machines.
3. Humans are engineered to be totally microbe-free.
4. The intelligent machines take a trip to another star system, thaw some human germ cells out of a liquid hydrogen storage tank, and recreate a colony of their "pets" on a planet with no endogenous life. The only culture that the humans have is to be clean, happy pets; they know nothing about technology.
5. After terraforming the planet by planting kelp and a few land plants, the artificial intelligences all merge into a giant MMORPG, leaving the humans to evolve as the only non-plant organism on the planet.
6. Due to several problems with the terraforming including poor control of the composition of the atmosphere and inability of the atmosphere to control the high radiation output from the planet's star, the human population suffers a high mutation rate, never establishes a technological society, and over the course of a couple billion years, has descendants that fill many of the available niches of the planet's ecosystem, including a population of bacteria-like, single-celled organisms.
   --JWSchmidt 02:12, 1 November 2006 (UTC)

Too many assumptions. Microorganisms are necessary for the plants. Also there are the plants themselves. I think in the most cogent answers, the simpler life forms will adapt to changes more quickly (i.e. the system prefers making simpler organisms more complex). It is more likely that the other life will simply outperform the humans in your example and push them out. Think of mammals that returned to the sea. We already know that fish survive very well. They don't even need to surface for air for example. But mammals didn't retroevolve back to fish. They adapted their existing systems into more complex one. The other choice would be extinction. Nature would seem to prefer starting from a simpler canvas. Tbeatty 06:06, 1 November 2006 (UTC)

dry cell

how dry cell works? what gives rise the currentin a circuit? what is a current? what is direct current? what is alternating current?210.23.196.207 11:41, 31 October 2006 (UTC)

See dry cell , electric current, direct current , alternating current--Light current 11:45, 31 October 2006 (UTC)

There's a kind of cool poetry to that answer+signature that wouldn't be there if anyone else had answered the question.

mysteries of mirrors

I'm short-sighted (I believe the correct term is myopic). without my glasses, objects far away are out of focus. when I look at a mirror - close enough for it's frame to be in focus, why are reflected distant objects out of focus?

thanks Spiggy.

Myopic is correct. The virtual image formed in a plane mirror is as far behind the mirror as the object is in front of the mirror (The article Mirror_image does not seem to mention this !). Imagine the mirror to be a window, which just shows the objects behind you but maintaining all the distances. So when you look at the reflection of a distant object (say at 10 metres in front of the mirror), you are looking at the image of the object which is 10 meters behind the mirror. -- Wikicheng 13:49, 31 October 2006 (UTC)

thanks - now I'm (more) confused. I thought that we see light reflected off objects, and in this case it's reflected off glass (aka mirror) a few inches from my face. (sound of brain melting). how can light be reflected off something in a 'negative' way? spiggy

There are two different types of reflection - see reflection (physics). You see an image of an object when light reflects off it in diffuse reflection. However, a (well polished) mirror reflects light in a different sense called specular reflection, which preserves the relative directions of light rays, and gives the illusion that you are looking at objects beyond/behind the plane of the mirror. You can't normally see the surface of the mirror itself - unless you make a mark on it, when you can see the mark because of diffuse reflection. Try making a mark on a mirror and looking at it close up - you should find the mark is in focus for you whereas the reflected images of more distant objects are not. Gandalf61 14:27, 31 October 2006 (UTC)

Some thing are easier explained with a drawing. Have a look at the following sketch I made for you. Observe that the important property that your eye has to accomodate for the focussing is how much the rays diverge. Rays from a nearby point diverge much and from a point far away diverge so little that they are nearly parallel. A mirror does not change this.

Simon A. 16:43, 31 October 2006 (UTC)

The mirror doesn't change anything to do with focusing, it merely "redirects" the light. If the object is 20 feet from the mirror and the mirror is 2 feet from your face, the light from the object has to travel 22 feet to reach your eyes and your eyes would have to focus exactly the same as if the object were 22 feet away from you in a straight-line path.

Atlant 18:46, 31 October 2006 (UTC)

Expense of PCR

Why is a PCR machine so expensive, if all it does is cool down and warm up at the programmed times and temperatures. I don't understand what could be so expensive about its construction to justify its price. --Username132 (talk) 14:59, 31 October 2006 (UTC)

There's a certain argument to be made that the instrument has to be very precise in its heating and cooling cycles; that it's a specialized tool sold in limited quantities, so there are fewer purchasers over which to spread design costs and other overhead; that it needs to be extremely reliable and trustworthy, and subject to extensive testing during manufacture—but mostly, it's VWR, Fisher Scientific and all the others just charging whatever obscene price the market will bear. If you're selling a tool to drug companies and well-funded institutions, there may be a bit of a tendency to mark up your prices a bit. Take what I say with a grain of salt, of course—I'm just a bitter grad student. TenOfAllTrades(talk) 15:16, 31 October 2006 (UTC)

see Make magazine, vol 07. instructions to build your own PCR thermal cycler. and other interesting biotech stuff. http://makezine.com/07/ --GangofOne 19:19, 31 October 2006 (UTC)

'Specialist' equipment always costs more, regardless if it's actually technically more sophisticated or not. So yes, anything labelled with the 'biotech equipment' label is subject to a massive price markup. I've spent some time hanging out with a friend who works in a biotech lab, and it's something I've cracked more than one joke about. Know what they pay for the aluminum foil squares they use to cover those standard 96-well microplates? About $0.50 a piece! Sure, it's slightly thicker than the household variant, and it's free of any bacterial or DNA contamination, but it's still ridiculously expensive. --BluePlatypus 21:28, 31 October 2006 (UTC)

you all miss the key point: PCR machine manufacturers pay a license fee to the owners of the PCR and Taq polymerase patents. when you buy Taq, you only buy a license to use it in authorised PCR machines. Your machine only gets authorised if as a manufacturer you give a cut to the patent holders. and we all know where that money comes from. to quote:

NOTICE TO PURCHASER: LIMITED LICENSE

A license under U.S. Patents 4.683.202, 4.683.195 and 4.965.188 or their foreign counterparts, owned by Hoffmann-La Roche Inc. and F. Hoffmann-La Roche Ltd ("Roche"), has an up-front fee component and a running-royalty component. The purchase price of this product includes limited, nontransferable rights under the running-royalty component to use only this amount of the product to practice the Polymerase Chain Reaction ("PCR") and related processes described in said patents solely for the research and development activities of the purchaser when this product is used in conjunction with a thermal cycler whose use is covered by the up-front fee component. Rights to the up-front fee component must be obtained by the end user in order to have a complete license. These rights under the up-front fee component may be purchased from Perkin- Elmer or obtained by purchasing an Authorized Thermal Cycler. No right to perform or offer commercial services of any kind using PCR, including without limitation reporting the results of purchaser's activities for a fee or other commercial consideration, is hereby granted by implication or estoppel. Further information on purchasing licenses to practice the PCR Process may be obtained by contacting the Director of Licensing at The Perkin-Elmer Corporation, 850 Lincoln Center Drive, Foster City,

California 94404 or at Roche Molecular Systems, Inc., 1145 Atlantic Avenue, Alameda, California 94501.

So you pay twice. business genius huh? Xcomradex 22:37, 31 October 2006 (UTC)

And the guy who first thought of a way to make PCR practical got $10,000 for his effort. --JWSchmidt 01:21, 1 November 2006 (UTC)

the joy of commercial research i guess. but the nobel prize means a job for life, so you take the good with the bad. Xcomradex 04:08, 1 November 2006 (UTC)

Although you can make Taq yourself. It's unlikely to be as good quality and you could get in trouble in anyone finds out but I have heard people talking about having done it before (in a large lab I believe in the US). Of course, it may not be worth your effort. In any case, aren't tha patents expiring soon? BTW, I believe you can obtain PCR machines without licenses if you have an existing agreement with the patent owners (and could probably produce Taq yourself legally). And by the by, what's going on with all the legal battles anyway? Nil Einne

Also, having worked in a lab myself and a knowing few people who've had some knowledge of the purchasing I think it will surprise a lot of people (but hopefully not too many people actually working in labs) how expensive your work can be. I sometimes used to wonder how much I'd wasted today... Nil Einne 18:14, 1 November 2006 (UTC)

THe PCR patents HAVE expired. --GangofOne 22:24, 1 November 2006 (UTC)

substituents

1. If we arrange the substituents from highest to lowest priority (CIP system) which of the following arrangements is correct?

A) –N(CH3)2 > -OCH3 > -CN > -COOH

B) -OCH3 > –N(CH3)2 > -COOH > -CN

C) -CN > -COOH > –N(CH3)2 > -OCH3

D) -COOH > -CN > -OCH3 > –N(CH3)2

Which do you think? Why? Does looking in Wikipedia for information on likely topics such as "CIP" provide any useful infomation about how to do your homework? DMacks 17:53, 31 October 2006 (UTC)

But mistah, thinkin makes me brane hurt.. Eyez gots no idea watta do yo. Ize gots no ideez wherez to lookz for this teyep of thing. Maybe if I clickz this link??? -_- --AstoVidatu 22:50, 31 October 2006 (UTC)

why human beings can not fly like birds?

Birds use wings to fly which they move in such a way that make them fly in air. Why human can not do same using somthing similer to wings and use of their muscles to put them in motion. If weight is a probelm then electric motor could be use to move the wings in air. could it make man to fly? Is it already tried like this or if yes then do you know what was the result?

Thanks

What you describe is called an ornithopter. They do work, but might be rather unpleasant for a person to ride in as all that flapping motion will likely make them sick. They are also less efficient than an ultralight or other type of conventional airplane. StuRat 18:15, 31 October 2006 (UTC)

As for why human powered wing-flapping flight can't work, it's due to the basic design of people. We have relatively little muscle in our arms, with most of the muscle being in our legs and torso. Thus, even a body-builder wouldn't have enough strength in their arms to support the rest of their body by flapping wings. Total size is also an issue, as people are a bit heavier than the heaviest birds. The larger an animal is, the less able it is to get off the ground, as lift, which is proportional to surface area (I think), only increases with the square of the length, while mass increases with the cube of the length. Thus, the larger an animal is, the higher it's mass-to-lift ratio. Birds also have light weight, sponge-like bones, to reduce their weight further, and are streamlined, to reduce drag. StuRat 18:28, 31 October 2006 (UTC)

Birds have incredibly strong chest muscles, light bones, and special sternums. Humans don't have any of these. Maybe if we wore masks? AMP'd 18:20, 31 October 2006 (UTC)

Birds are also designed to be very light in weight. Hollow bones, big air sacs filling much of their bodies, etc. You might want to look at our Gossamer Albatross article to get an idea of just how hard it is for a human to overcome our natural disadvantages in this area.

Atlant 18:28, 31 October 2006 (UTC)

Thanks everyone. I got more than expected info about this thought.

Don't forget about Feathers! -THB 20:52, 31 October 2006 (UTC)

I think birds are also completely designed around flying. Their are muscles in every part of the body that twist the bird so that it can maneuver and move its side and tail wings. You can't just replace human arms with wings and flap them, flying is an entire system. It is similar to walking on 2 feet, making a robot that can do it well takes more that a few joints and motors. Ed Dehm 21:27, 31 October 2006 (UTC)

Birds also have much more efficent respiratory and circulatory systems than our own. They have a higher metabolism too. A bird's body temperature is about 5 degrees higher than our own. I'm pretty sure that they have a 6 chambered heart too. --84.65.177.120 21:53, 31 October 2006 (UTC)

Number one reason: humans are fat bastards in comparison to birds. We're built around walking/running/storing up fat for winter, and that calls for an entirely different skeletal, muscle, and tissue system than our avians friends. -- Chris 23:53, 31 October 2006 (UTC)

Well, penguins are fat, too. Of course, the only way they're going to get airborne is if you fire one out of a cannon. :-) StuRat 00:20, 1 November 2006 (UTC)

Oh there are other ways DMacks 02:17, 1 November 2006 (UTC)

V8 Engines

Are V8 engines very powerful? What type of cars are they used in?—Preceding unsigned comment added by 70.115.14.36 (talk • contribs)

Welcome to Wikipedia. You can easily look up this topic yourself. Please see V8 engine. For future questions, try using the search box at the top left of the screen. It's much quicker, and you will probably find a clearer answer. If you still don't understand, add a further question below by clicking the "edit" button to the right of your question title. .--Shantavira 18:21, 31 October 2006 (UTC)

Yes, V8 engines tend to be powerful. The same power can also be achieved in smaller engines by using high compression ratios, turbo-chargers, or superchargers. These methods tend to shorten the life of the engine, however. StuRat 18:33, 31 October 2006 (UTC)

OK whats so special about the V formation?--Light current 23:09, 31 October 2006 (UTC)

Power is due to general engine size (number of cylinders, displacement, compression ratio, etc). I don't know of an advantage in that department specifically due to the V formation. OTOH, the V formation gives a more compact overall engine than having all the cylinders adjacent in a single row, meaning one can have a larger cylinder or stroke for a given overall engine-block size. To quote the V8 engine page, Instead of going to a straight-6 like its competitors when something larger than a straight-4 was needed, Ford designed a modern V8 [...] After World War II, greater vehicle size meant that the straight-6 became increasingly underpowered, while lower hoods and more aerodynamic styling meant that the straight-8 was simply too large. DMacks 23:33, 31 October 2006 (UTC)

W formations are usually more powerful, but just because they're two Vs. See also: W18. V and W formations are used I believe due to their symmetry. I heard that from some old guy. X [Mac Davis] (SUPERDESK|Help me improve) 23:45, 31 October 2006 (UTC)

Car top

If a car has a black vinyl top, underneath it does it still have the same metal as the rest of the body? So could you take it off and it look like it never had one? If you could would you have to take to a mechanic or could you just rip it off? —The preceding unsigned comment was added by 70.115.14.36 (talk • contribs) .

Assuming you're not speaking of a convertible (cabriolet, drop-head, etc.), yes, you could theoretically remove the vinyl. But the paint underneath might be in tough shape and there might be a lot of adhesive residue to contend with.

Atlant 18:41, 31 October 2006 (UTC)

The metal also is not designed to be in contact with the elements, so may be likely to rust, unless properly treated. StuRat 19:07, 31 October 2006 (UTC)

Mating/pairing off behaviour in seagulls

Amongst other birds, when spring comes around, I see them performing all sorts of different mating calls and displays in order to attract a partner. Just about all the other birds except the seagulls that is. They don't seem to show any interest in other members of their own species except for the desire to fight with them or steal their food. Then a bit later on, I notice that some of them have just paired up and that there are now two gulls stood closer to each other than gulls normally allow other gulls to get, pretty much just ignoring each other. I never see any affection between them at all. So, what is the gull 'mating ritual'? I've never seen it? Is there even one? Or is it a case of 'you'll do, let's screw'? --84.65.177.120 21:37, 31 October 2006 (UTC)

Kurt shaped box its over to you! You moment of fame has arrived!--Light current 23:11, 31 October 2006 (UTC)

It's probably comprised more of eye contact and body language, which is of course harder for us to pick up on. Or perhaps gulls are simply more discreet, and prefer not to get it on when humans are watching. -- Chris 23:51, 31 October 2006 (UTC)

There's a video of gull courting/mating here . I've never actually seen them 'at it' myself but it doesn't really look like there's much to it in terms of an elaborate display. Apparently, many gulls pair up for life. --Kurt Shaped Box 23:55, 31 October 2006 (UTC)

hollow head

Ok, this is going to sound a bit weird.

My right ear is messed up. Whenever I gently tap my hand against my skull, my head sounds "hollow" almost, with a basis around the right ear. My hearing is slightly worse in that ear too. What's wrong with me? Don't tell me to see a doctor, because I don't have the money. All I have is ya'lls help.

Sounds like earwax. Try pouring some olive oil in nightly for a few weeks to see if it dissolves the wax!. olive oil is perfectly safe to use in the ears.--Light current 23:13, 31 October 2006 (UTC)

If you think there is something wrong with you, you should see a healthare professional. Since you have access to a computer and the internet, you hopefully are in or can get to a place where you can obtain healthcare without needing to pay (US, UK, Canada...) (notice I make no promises about how easy that might be...). That said, it is not reasonable to assume that you can adequately auscultate structures in your own head, especially close to the ear itself. Another individual, however, trained in auscultation, may be able to distinguish tympanic resonation by tapping over the sinuses, particularly the frontal sinus and (though much less likely) the sphenoid sinus, using a stethoscope. Since these sinuses are hollow, this would be normal. I can't personally think of any pathologies which would present as periauricular typanic resonation first ( that is to say, you would be unconscious or dead long before you would have or notice a hollow sound in your skull, e.g. with a very large air embolus or after a hemispherectomy). Tuckerekcut 23:16, 31 October 2006 (UTC)

Yeah good! But do you think he's going to understand all that? I dont! Or are you trying to make a point?--Light current 23:19, 31 October 2006 (UTC)

Yea, that advice, while excellent, likely went over his head. Let me try a simpler version:

There are hollow areas in your head, such as the sinuses. However, they should not extend to the area you described. A smaller hollow area is the eustachian tube, but that isn't normally large enough to create the audible resonance you described. I suspect that it's not an extra hollow space in your head, but rather something wrong with the hearing in one ear, that's causing your brain to hear it slightly later than the other ear. This would cause an inability to locate the source of sounds, and possible nausea and dizziness. I agree that you need to have this looked at by doctors, it sounds potentially serious. Go to a free clinic or emergency room. I also agree that you should try cleaning out the ear first, but think a Q-tip (cotton swab) will do the job nicely, assuming you know how to use one properly. StuRat 00:09, 1 November 2006 (UTC)

This is the person who asked the question again. Whenever I talk, I hear something that sounds like a resonance in my voice. Almost like a slight echo. Would that mean anything?

Have you tried going to the pharmacy to get some decongestant etc?--Light current 23:29, 31 October 2006 (UTC)

The cheapest and best way to clear sinuses is to get plenty of fresh air. I know, I used to hate it when my parents badgered me on this point. But it's completely true. If you never want to get congested sinuses, sore throats, wierd ear conditions, pinkeye, and the like, get plenty of fresh air.

Of course the problem with this is the cold: most people can't stand it, so they stay indoors all day. There's only one remedy for this: improve your diet. When your metabolism is running smoothly you'll feel the cold a lot less, so you can spend more time ourdoors, keep your windows open a little, turn the heating down, and so on. All these measures will reduce cold symptoms, including 'hollow head' syndrome.

That said, the very best time to be breathing outdoor air is the winter. It just feels so clean and refreshing! -- Chris 23:48, 31 October 2006 (UTC)

This question is spiraling out of control! I thought I had an ear problem! Thanks everyone though 130.207.180.86 00:04, 1 November 2006 (UTC)

I'm sorry if I used some jargon in my explanation. However this is an encyclopedia, and just about every word or phrase can be investigated (though I was sad to see that 3 red links popped up. For posterity: auscultate means to listen, tympanic resonation is when something sounds hollow, and periauricular means near the ear.) I would not recommend putting anything in your ear; neither a cotton swab nor olive oil are likely to help you, and both could certainly do damage. Cotton swabs are stiff enough to damage the delicate membranes of the ear, and even if they don't they tend to push ear wax back into a ball when it should be spread out. And if there is any sort of rupture or fistula in the eardrum (which happens all the time even in people without symptoms), the oil can foster the growth of anaerobic bacteria in places where you definitely don't want them, such as the eustachian tubes, which incidentally are potential spaces, and definitely do not participate in resonation. As for the "improve your diet" advice: it may improve your overall health, and is certainly never bad advice, but it won't alleviate your symptoms specifically, and the connection with metabolism is teleological and frankly false.

One question does pop into my head though: what is the incidence of post-surgical lacunar amnesia in hemispherectomy patients? Hey... is that a zebra outside?... Tuckerekcut 03:07, 1 November 2006 (UTC)

No, it's a swan (unless you're looking out a different window). Ignoring the fact that this is an encyclopedia, without looking anything up, let me guess what what you said means. 'How often do people forget about emptiness after they have had half their brain removed'. How close did I get? DirkvdM 17:39, 1 November 2006 (UTC)

On the off-chance you missed the reference entirely (and for any others that do, even if you didnt), Tucker was (I believe) referring to a Zebra (medical) :) GeeJo ^(t)⁄_(c) • 23:38, 1 November 2006 (UTC)

Digital MULTIMETERs

Hi, I would like to know what is the accuracy of a typical digital multimeter that has auto range detection. (for example: +/- 5%)

74.97.61.249 00:46, 1 November 2006 (UTC)

Basic dc voltage accuracy of 1% is no problem these days. But you get what you pay for. If you want 0.1% DCV acc be prepared to pay a few hundred £. Mine (without auto ranging) cost about £35 a few years a go and has dc voltage acc of 0.5% of rdg +/- 1 digit. All other ranges will of course have worse accuracy figures.--Light current 01:11, 1 November 2006 (UTC)

Actually I think all accuracy is rated at full scale, not the reading if I recall correctly. For example, on the 5 volt scale, the accuracy is +/- 1% of 5 volts regardless of whether the reading is 1 volt or 4 volts. that's why you always want it on the lowest range setting for the highest reading. This is in memory though. --Tbeatty 05:51, 1 November 2006 (UTC)

Most high-end digital voltmeters are rated as a certain % of full scale + a certain percentage of reading. This occurs because there are multiple error sources within the DVM and they gave varying effects.

Atlant 18:42, 3 November 2006 (UTC)

No, I was just quoting from the handbook of my cheapo DMM!--Light current 12:29, 1 November 2006 (UTC)

Cheap digital multimeters are more accurate for DC than AC. Unless a meter says "True RMS" it reads the average AC but is calibrated to display the equivalent RMS value. It will be inaccurate for other than DC or pure sine waves. Such meters get fooled by distorted waveforms, such as result from the current going to electronic power supplies, or such as result from unbalanced 3 phase loads, or harmonics.I do not see this discussed in Wikipedia, but it is discussed at [1] and [2]. The problem is not a trivial one, since wiring or transformer overloads may be missed when a cheap ammeter shows low current but an RMS meter shows the actual current producing heating effects in equipment. Edison 18:05, 1 November 2006 (UTC)

November 1

For Better Bio Gas Yield...??

I would like to know the yields of bio gas by anaerobic digestion of Food Wastes(fruit juice,Souce & Jam industry waste) Vs. Brewery industry waste (using malt)...?? Need methane to CO2 ratios (Approximate values) in both cases...!!

Thank You... Malinda

Phospholipase A2

What are the main functions of Phospholipase a2 enzyme. Which r its iso-forms

What happened when you used the "search" box on this (or indeed any and every) page on this site to look for the term "Phospholipase A2"? DMacks 05:43, 1 November 2006 (UTC)

Erotic asphyxiation question for evolutionary biologists, endocrinologists, and maybe embryologists

Hi, I'm thinking(and probably oversimplifying but please be tolerant) that our remote ancestors had radial symmetry which then lessened into mere bilateral symmetry(which is nostly on the outside now our inside organs aren't too symmetric anymore). If the mouth and anus are identified as "historically" isomorphic and symmetrically opposite, then things in the neck like the Adam's apple and thyroid could be presumed to be symmetrically opposite things like the genitals and prostate(in males), if one allows for blurring of the exactness through long evolutionary periods. But the Adam's apple and the genitals in a male both grow larger during puberty. These factors make me surmise that the same hormones, or perhaps hormones that are descended from the same original hormones and could still be similar, regulate the development of structures and nerve endings in the neck and private parts. So here is my question:

• Could hormones(perhaps mainly from the thyroid) which regulate the development of structures in the neck, so closely mirror hormones(perhaps mainly from the prostate) which regulate the development of the genitals in the male and the ability to feel sexual pleasure in that region, that sexual pleasure can be felt in the neck region, causing the pleasure of erotic asphyxiation, hickeys, and the giving of fellatio?--Of course much of the above could be applied to females with the homologous organs. But I haven't read of erotic asphyxiation among women.Thanks,Rich 06:43, 1 November 2006 (UTC)

I am neither of the expert types listed in your heading but still feel confident to argue your hypothesis to sound unlikely. Remember that the move from radial to bilateral symmetry happened extremely long ago. So much more has happened till then. Just observe that not only mammals, not only vertebrates, but even insects are bilateral. I imagine that the endocrine system over this wide range of the evolutionary tree varies tremendously. Furthermore, even a radially symmetric animal such as an earthworm has a distinct mouth and anus. Trying to explain such specific behavior traits as which kind of sexual acts turns somebody on with such a coarse thing as hormones is a bit too blunt. I wonder if they are even hereditary -- if not it would point to psychological, i.e. environment-induced causes. Oh, and I think I have read somewhere that there are women who enjoy sexual play involving choking.That none of them are dumb enough to get killed in the process does not prove that there are none. Simon A. 12:55, 1 November 2006 (UTC)

(EDIT CONFLICT) First, the regulation of sexual maturity in puberty, and by connection the "adam's apple", is controlled by the sex hormones, none of which are secreted by the thyroid (or parathyroid) glands. Also, the thyroid is endoderm while the thyroid cartilage is mesodermal, so they "evolve" from different germ layers, and furthermore are on the same side of the trachea, which doesn't lend itself to the same kind of symmetry as the mouth and anus. It is unclear (to me) what you mean by isomorphism as it applies to the symmetry of the mouth and anus. I suppose they are both holes, but the nearby structures, the thyroid cartilage and thyroid to the mouth and the genitals and prostate to the anus, are not isomorphic in the sense you described. The sexual maturity of all of these organs is controlled, as I said earlier, by the sex hormones. These hormones are primarily secreted by the testes in males (with support from the adrenal glands, adipose tissue, even the brain), thus the prostate is not responsible for maturation of the "genitals", nor is the thyroid responsible for maturation of the "adam's apple". The sexual pleasure one might feel from the activities desribed is created in one place: the brain, and is summarily not due to any similarities, hormonal or otherwise, between the glands of the perineum and neck.Tuckerekcut 12:59, 1 November 2006 (UTC)

Where can a man go to just 'vanish'?

Suppose I was sick to death of society and the human race and decided to get away from it all, drop off the radar, find a nice place in the sun and look after #1 - where would be the best place to go? Are there any isolated, yet hospitable places left on earth these days? I don't fancy the idea of living on some moss-covered rock in the South Atlantic. --84.69.57.172 07:57, 1 November 2006 (UTC)

Kure Atoll, Palmyra Atoll and Laysan are nice this (and pretty much every other) time of year. Assuming you could give the United States Fish and Wildlife Service the slip, it would be just you, the birds, the coral and an occasional scientist. Rockpocket 08:51, 1 November 2006 (UTC)

It depends a lot on how much money you have to spend. There are lots of isolated places to live, but getting to them and having supplies brought in could be quite expensive. StuRat 15:02, 1 November 2006 (UTC)

You'd be suprised how much of the world is still wilderness. Just browse around on Google Maps and you'll see that human settlement really is the exception, not the rule. Even little old England has a great deal of untamed land. -- Chris 17:04, 1 November 2006 (UTC)

No need to look after me, I'm already doing that. DirkvdM 17:45, 1 November 2006 (UTC)

Though the NW Hawaiian Islands were made into a maritime reserve in June 2006.--Russoc4 17:51, 1 November 2006 (UTC)

Pitcairn. A country with a population of 45. No other habitation for hundreds of kilometres around and only an occasional small boat drops by because bigger ships can't approach it. "Leaving the island is hit-and-miss; one leaves when transportation happens by, not necessarily when one wishes to go." And you'll be living with the descendants of the mutineers of the Bounty, which is pretty cool. And if even that handfull is too big a crowd for you, it has a "nearly inaccessible interior" to get lost in. DirkvdM 18:43, 1 November 2006 (UTC)

Fully 10 percent of the population of Pitcairn island is now to be imprisoned for rape and indecent assault [3], in a new prison being constructed for the task... The long arm of the law reaches even there. --TeaDrinker 22:16, 1 November 2006 (UTC)

You are better off going to Henderson Island anyway; no-one there. Batmanand | Talk 17:06, 3 November 2006 (UTC)

There's still plenty of densely forested areas where a man could just disappear and live off the land, if he knew what he was doing. No shortage of food and water there. If you can make fire/shelter, know how to hunt/fish without using modern technology and are the kind of guy who looks at a deer and sees a month's-worth of food and a new pair of warm clothes, you'll be sorted. --Kurt Shaped Box 21:47, 1 November 2006 (UTC)

I'm not even sure he'd have to live off the land. Without paying rent, taxes, and utilties, a hundred thousand dollars could last for decades. I think the key thing is to always assume you're going to run afoul of local or federal authorities, and be read to move on a moment's notice. But, the further you live from the nearest highway, the less you have to worry about this sort of thing. -- Chris 21:53, 1 November 2006 (UTC)

I'd like to find an island solely inhabited by seagulls and, with my superior intellect and knowledge of their ways, rule over them as a living god! Muahahahahahaha!

Or at least hang out with them. I could catch fish, cook it and feed them - they'd probably think I was pretty cool for being able to do that. --Kurt Shaped Box 23:31, 1 November 2006 (UTC)

I'm glad I'm not the only one who daydreams about impressing seagulls! Pesapluvo 02:38, 2 November 2006 (UTC)

I'd like to be to great black-backed gulls what Irene Pepperberg is to African grey parrots. I have searched far and wide but no-one seems to have seriously studied human/gull interaction on a one-to-one basis (though Audubon alluded to it in some of his writings). --Kurt Shaped Box 07:05, 2 November 2006 (UTC)

Just wondering, Kurt, have you read Jonathan Livingston Seagull ?

The Statue of Liberty. Anchoress 04:25, 4 November 2006 (UTC)

Unabomber tried this, and he went nuts. I expect that after living in a tent for a few weeks, especially when its cold, that even the smallest and most squalid room will seem like paradise. I think lots of people do do this - but they realise that they would not be able to stick living off the land for long, and just buy or rent a small house or flat somewhere. You are most likely to be anomymous in a big city. Then there is the gypsy way of life. A few miles away from where I used to live, a man lived out of a lorry for a few years, and may be doing so still. I am very skeptical that you could live anywhere in the UK without being bothered by people.

Big Bang and Big Collapse

Has anyone postulated a Big Cycle, i.e., the point in the Big Collapse when it reverses direction and becomes the Big Bang and vice versa? Adaptron 10:40, 1 November 2006 (UTC)

What, some sort of Big Crunch!? Proposterous! ;-) Philc _T^E_C^I 11:22, 1 November 2006 (UTC)

Oscillating universe?--Light current 12:28, 1 November 2006 (UTC)

These links should do. However, note that these idea are now in contradiction with recent observation which show that the expansion of the universe is not decelerating but accelerating and hence likely to end in the Big Rip. Can it be, BTW, that we have no decent article on this? Simon A. 13:01, 1 November 2006 (UTC)

"Likely" is putting it a bit strongly. This crucially depends on the hypothetical dark energy being phantom energy, which at present is entirely speculative. And if it is phantom energy, it is not clear that its equation of state would remain constant until the bubble bursts.  --Lambiam^Talk 15:58, 1 November 2006 (UTC)

Agreed. Simon A. 19:58, 1 November 2006 (UTC)

I've heard it called the Big Chill. StuRat 14:58, 1 November 2006 (UTC)

I would expect that to refer to the Big Freeze rather than the Big Rip. Any evidence for the claim that this specifically refers to the Big Rip?  --Lambiam^Talk 15:58, 1 November 2006 (UTC)

Well, there's Ultimate fate of the universe, which summarises each of the leading theories. GeeJo ^(t)⁄_(c) • 15:00, 1 November 2006 (UTC)

of course there's always my explanation for the accelerating expansion. If we were falling into a black hole, wouldn't we see everything accelerate away from us? And wouldn't the acceleration be greater for objects further away? So wouldn't a Big Crunch be an explaination for the fact that we do indeed observe that? Alas, every time I put this theory forward, people start punching holes in it. It's pretty leaky now. But I made a controversial prediction that turned out to be correct, and the scientific community hasn't come up with a decent alternative yet, so that keeps me going. :) DirkvdM 17:52, 1 November 2006 (UTC)

And before any of that, you will die. And then the sun will die out. THen the Milky Way will merge with Andromeda and wreak havoc. Tbeatty 18:02, 1 November 2006 (UTC)

I think the Sun might still be around when the Andromeda Galaxy hits us. StuRat 19:29, 1 November 2006 (UTC)

You say hit us, but given the incredibily low density of galaxies (millions of miles between star systems) there wouldnt actually be much hitting involved would there? Philc _T^E_C^I 19:49, 1 November 2006 (UTC)

If you neglect the gravitational effects, then that would be true. With gravity, however, the two galaxies have a major effect on each other, although, Andromeda being much larger, it ends up winning, with the Milky Way being "consumed". Many of the Milky Way's stars will be pulled into Andromeda, and others will be flung into space. The super-massive black hole at the center of the Milky Way will coalesce with Andromeda's. StuRat 20:13, 1 November 2006 (UTC)

I don't know that there's as much gravitational viscosity as the black holes would need to pull that off; moreover, we don't even know that there's truly going to be a collision at all (as discussed in the article). --Tardis 22:14, 1 November 2006 (UTC)

Why do teeth have nerves?

Had a brief search on the 'pedia and rest of the intarweb, but no luck. My guess would be either that the nerves are needed during the growth of the tooth or are vestigial. Any ideas?

Part of the reason I believe is to deter us from biting down so hard that we shatter them. Even human jaws are strong enough to do that. Anchoress 13:21, 1 November 2006 (UTC)

Agreed. Or, more generally, from doing things with your teeth that might be harmful to them. StuRat 14:55, 1 November 2006 (UTC)

Like biting newbies too hard?--Light current 16:01, 1 November 2006 (UTC)

So that we can feel if something is so hot or so cold that touching it with your toungue/throat etc.. will cause a burn. Philc _T^E_C^I 14:22, 1 November 2006 (UTC)

Don't you think the lips would be a better bet for that? Anchoress 14:25, 1 November 2006 (UTC)

Yeh, and they are, but surely it makes more sense to have feeling in your teeth aswell, I wasn't saying it in preference to other ways of feeling, but in conjuction with them. Philc _T^E_C^I 14:28, 1 November 2006 (UTC)

This is a neat link. [4] We should do something as good for students. Basically, there is no such thing as a tooth 'nerve', it is merely the middle gunky part, with bloods vessels and nerves, called the dental pulp. It is necessary for the tooth to form, and later keeps the inside of the tooth hydrated. Later in life it shrinks, and sometimes dies, which means a nasty root canal job. --Zeizmic 15:59, 1 November 2006 (UTC)

Years ago, when I still visited the dentist, I asked the lady cleaning my teeth whether, once grown, they are just static objects that don't change once they're fully grown. Not at all, she said -- they are very much living things. Teeth are only really hard on the outside, and they are well supplied with blood vessels and nerve endings. They also have repair mechanisms for taking care of minor scratches and so on. So it's not like dentists are absolutely mandatory -- healthy teeth are capable of mending themselves, just like everything else in our body. -- Chris 17:01, 1 November 2006 (UTC)

No dentists needed? Heh, well, I beg to differ. - Dozenist talk 03:09, 2 November 2006 (UTC)

Antisocial personality disorder

Can someone help me I would like to know who first came up with the term antisocial personality disorder and about ehn . Thank you.

Speaking of teeth...

What does that dream where your teeth start rotting out of your skull, cracking, splintering and crumbling away actually mean? I have that one fairly often. I remember reading somewhere that there is, psychologically-speaking, something very primal and deep-rooted (pardon the pun) behind it... --Kurt Shaped Box 16:37, 1 November 2006 (UTC)

I'm sure its just your subconscious trying to tell you that teeth are going to fall out if you keep doing the things you do. Teeth being your most permanent possessions, it's a vivid image that is going to have a lasting effect upon your waking hours. -- Chris 16:56, 1 November 2006 (UTC)

It is pretty much impossible to interpret symbols in dreams without context. Your mind is saying something to you; others can only guess at how your mind works, and not even that without getting to know your life situation pretty well first. (I'm feeling very Jungian today...) That being said, a quick googling should find some possible interpretations. In those google results, skip any sites that say "flying = travel, teeth = money, whatever = you'll meet a handsome stranger" :-) Weregerbil 17:25, 1 November 2006 (UTC)

I thought that certain dream themes were pretty much universal? The one where you're falling, or the one where you discover that a woman's vagina is lined with sharp teeth whilst having sex with her, etc. Has that all been discredited now? --Kurt Shaped Box 20:41, 1 November 2006 (UTC)

I have always been of the opinion that the teeth dream relates to self image concern, since losing teeth can be a permanently disfiguring experience. I have them from time to time despite taking good care of my teeth. --Jmeden2000 18:13, 1 November 2006 (UTC)

In my experience, people tend to overanalyze dream imagery. Why should teeth falling out represent anything more unusual than a latent fear of having your teeth fall out -- or at least a general level, death and decay? -- Chris 21:50, 1 November 2006 (UTC)

I just remember being told a long time ago that Freud said that dreaming of losing/damaging your own teeth was something psychologically significant. Just curious as to what it was supposed to be about. --Kurt Shaped Box 01:01, 2 November 2006 (UTC)

• I had that dream pretty regularly -- until I got all my teeth fixed about five years ago! Haven't had it since. I think it's one of those real obvious ones: it means you are worried about your teeth (or, as we refer to them, those "tiny time bombs in your head".) --jpgordon^∇∆∇∆ 00:50, November 2006 (UTC)

• What Dreams Actually Are

has been a topic everyone is always asking about, however I don't understand why people are not aware that medical science figured this out a long time ago. Which is to say, there is a factual explanation as to what dreams are, why they occur...the whole nine yards. It has been quite some time since I learned this in college, but I remember the general idea, which is as follows. When you are asleep, by no means does your brain "turn off". Sleep is an extremely complicated subject so I'm going to try and keep this simple (and brain functions are even more complex), but if you're really interested there is a lot of information on the internet that explains this. Sleep is for the purpose of resting your mind, not your brain. As a matter of fact, the brain can be even more active during REM sleep than when a person is awake. To explain dreams as simply as possible, this is basically what happens. Since the brain is still active during sleep, "thoughts" (not the best term but it's all I can think of) still occur, however because your cognition is resting, the thoughts are fleeting as well as in great quantity. Synapses are one of the major elements of the brains communication systems. For the purpose of simplicity, think of a synapse as one thing, whether it's in your life, your fantasies, or if it's a piece of furniture in your house (there are about one hundred trillion synapses in your brain). During conscious thought process they work together with the neurons and other parts of your brain. When you take away the consciousness variable, thought process is rather impaired. The thoughts are still there, but since they're not in use, the absence of the process part is where dreams come in: a random group of some of the billion thoughts in your head end up together. When you are awake, you select the particular thoughts and your mind fits them all together. But since the mind is not really in play, but the synapses are still firing all over the place, your brain does the best it can to have things make sense; i.e., your thoughts are linked together by whatever other thoughts your brain can use to piece everything together into a "story" of sorts. So the dream you had last night about riding the tea cups with your childhood pet at the Disneyland that happens to be in your living room as you and your deceased cat discuss the benefits of having your tires aligned DOESN'T ACTUALLY MEAN ANYTHING (keep in mind, to have that dream you have to have had a cat once, seen Disneyland, and have something with tires, otherwise those factors won't exist in your head). Since everyone has many dreams every night, on occasion you may remember one that it's totally outlandish. Further, it wasn't until recently humanity has learned about the brain, so for thousands of years people were forced to believe dreams met something. Add to that you have famous people like Freud who insisted dreams have meaning. You put all those influences together and everyone just gets brainwashed they mean something. Though everyone forgets the part about how Freud related everything to sex and was coked up every day. *** By the way, the dream about the teeth rotting/falling out that was discussed above was interpreted by Freud to mean castration due to guilt over masturbating. If none of this made sense, think of dreams as like "Mad-libs". Finally, I apologize if I misstated any facts or neglected something important, but I can't remember everything I learned in school! Therefore, you don't need to yell at me if I was wrong about something. However the gist IS correct. Even common sense can tell you that, since when have you had a dream interpreted for yourself right on? So, in conclusion, dreams do not have meaning. They are literally not much more than your unconscious imagination working randomly. Now you can tell your friends and family what dreams are, although they will likely insist that their dreams give the winning lottery numbers, and they just didn't get around to buying the ticket. SWEET DREAMS ALL!

Tomato Hornworm

I just found a hornworm that is about the thickness of my thumb and at least 10CM in length. I have never seen anything this large. It is unusual?

Our tomato hornworm article pointed me to this link: [5], which says they grow to about 4 inches long, which is about 10 cm. So, you have one on the large end of the normal size range. StuRat 18:59, 1 November 2006 (UTC)

Promiscuity

A bit OT but hopefully still of interest. This article was interesting http://www.iht.com/articles/ap/2006/11/01/europe/EU_MED_Sex_Study.php (I actually read it in my local paper but it's more or less the same). Of course (not having read the published journal paper however) this does appear to rely on people giving accurate reponses so it could be misleading. What was surprising to me tho is that the fact Western people are more promiscious then Africans was supposedly surprising to the researchers. I'd never really thought about it much but I have to say, this was what I personally would have expected. Although I'm aware of the high prevance of STDs I would have put this down to other issues like health care, the kind of promiscuity that's practiced, use of protection etc. And I would have expected that the more liberal and more modern Westernised world to have a higher promisicuity then the more conservative African world. Does anyone else feel the same? N.B. Let's not get in to arguments about whether promiscuity is good or bad and no racism please Nil Einne 17:58, 1 November 2006 (UTC)

I just loved the quote from this piece I heard today on the radio: "People are just as likely to be truthful about their sexual habits as they are about their income or their voting choices"... Is it me or does this mean "Lie like a rug"? --Jmeden2000 18:08, 1 November 2006 (UTC)

Agree with Jmeden2000. I'm certainly not going to accuse an entire continent of lying, but consider that vs 50 years ago, the stats for female masturbation have gone up from something like 50% to something like 95%. It's not because so many more women are masturbating, it's that so many more women are telling the truth. It's amazing how many people lie, even when the survey is completely confidential. Anchoress 18:16, 1 November 2006 (UTC)

I wondered whether the scientists were surprised about the result or only the journalists reporting about it. For the question of accuracy due to untruthful answers: Psychologists have some tricks to lessen the problem a bit: AFAIK, one usually includes a question that is somewhat embarassing and for wich it is known that most people should answer yes (I don't know what they usually use but I imagine it something like asking men whether have masturbated in the recent year.) Then, you use this to estimate how many people have answered truthfully. Simon A. 20:06, 1 November 2006 (UTC)

I'd be interested v/v the study to find out exactly what questions they asked, and of whom. Because there are so many languages in Africa, and things can be mistranslated in ways that may seem innocent, but may cause an unexpected result. Like the question, 'Are you unfaithful to your spouse' might be translated to, 'Do you sneak around on your spouse' and if s/he is NOT sneaking it might give a skewed answer. Or if the question is, 'Do you have intercourse outside marriage,' or 'Do you have intercourse,' wouldn't catch the people having just oral sex. I'm not trying to justify an opinion that Africans are more promiscuous than the study suggests, I'm just speculating. Anchoress 23:34, 1 November 2006 (UTC)

protein hydrolysis and H2S

I'm hydrolysizing big batches of protein and I'm concerned about the production of hydrogen sulfide, for my own safety. I'm testing acid, alkali, and protease hydrolysis. Are any of these methods more likely to produce significant H2S? (I presume the enzymatic method wouldn't produce any, unless there's bacterial growth). ike9898 18:09, 1 November 2006 (UTC)

shelf life and storage of dynamite and pyrotol

Hello...I am a novelist and in the book I am currently working on the 'bad guy' has wired a public place with dynamite. Question: pyrotol was available after WWI, would it still be viable in the early 60's if stored properly? If so, how would it have to be stored? If pyrotol would not be viable, would dynamite still be viable from that time period? Or would dynamite still be avialable in the 60's, if so, how would this need to be stored?...( I know that pyrotol would not be available in the 60's, as they discontinued use of this after the Bath School disaster of 1928). I would appreciate any and all help some one would care to give me...thanks very much, Sandy G.

Oncology Research

Is it possible to go into oncological research without an M.D.? As in, is there a Ph.D. program that will allow one to go into oncology research and still get to work with people/patients?

Thank you!

Maybe sorta if you went into Biomedical Engineering. BMEs often help in the clincal testing of new medical devices, but I think that their role in that case is primarily focused on the performance of the instrument, rather than the patient. ike9898 21:46, 1 November 2006 (UTC)

Also, I think that you could be involved in oncology research without an MD or PhD. As a nurse or lab tech, for example. Also, there are lots of PhD, non-MD scientist in cancer research, but I think these types are much more lab based than clinical (no patient contact). ike9898 21:49, 1 November 2006 (UTC)

Image:Lugano.jpeg

As stated, the image was made between 1905 and 1915. Was it shot in color like several World War I photos or colorized much later? --Brand спойт 19:57, 1 November 2006 (UTC)

Since it was shot by Sergei Mikhailovich Prokudin-Gorskii who pioneered color photography I assume it was shot in color. - Dammit 19:59, 1 November 2006 (UTC)

To clarify, his technique was to take 3 black and white photos of each scene, each with a different color filter (red, green, or blue). His idea was to use a projector to recombine them into a color projection. With modern technology, however, we can combine the three images into an excellent full color image. The only color distortions are when something moved between the three frames. StuRat 20:06, 1 November 2006 (UTC)

Ehrm, the link. —Bromskloss 20:51, 1 November 2006 (UTC)

What is it good for?

"Many waterfowl and some other birds, such as the ostrich and turkey, do possess a phallus. Except [sic] during copulation, it is hidden within the proctodeum compartment within the cloaca, just inside the vent." Vitriol 20:17, 1 November 2006 (UTC)

Sexual intercourse --Russoc4 20:30, 1 November 2006 (UTC)

Does "during copulation, it is hidden within the proctodeum compartment within the cloaca, just inside the vent" mean anything to you? Vitriol 20:34, 1 November 2006 (UTC)

"Except during copulation". I have personally seen a duck's penis FWIW. --Kurt Shaped Box 20:44, 1 November 2006 (UTC)

Close as I can figure, there are no errors in the original source. Why the [sic]? It certainly shouldn't read 'accept during copulation'. -- Chris 21:45, 1 November 2006 (UTC)

I accept that. Vespine 22:02, 1 November 2006 (UTC)

Sorry, I got confused because I thought it was saying they possess a phallus, except during copulation it's hidden. I'll go edit that to prevent fuckups like mine. Vitriol 22:05, 1 November 2006 (UTC)

I see how you misread that. Just change two punctuation marks: ...[they] do possess a phallus except during copulation. It is hidden within the cloaca... Hyenaste ^(tell) 01:38, 2 November 2006 (UTC)

Plane crash

A few days ago, in a question now already moved to the archives, Keria wrote:

Which seats in a big airliner do you think are safer depending on the different types of crashes? It does happen quite often that a plane crashes and it is announced that "189 people died, and 3 survived" or sentences of that sort they never specify where the lucky ones were sitting. I was thinking more towards the tail of the plane, dont know why, it seems stronger somewhat but then that last Kentucky one only the co-pilote got dragged out of the burning plane by the fire brigade if I remember correctly. Any thoughts or statistics? Thank you.

This subject is being covered on the U.S. TV show ABC News Nightline tonight (11:35 pm for Eastern Time viewers), and there is an an online article here on their web site. In summary, the article says that preparedness is more likely to matter than where you sit, but that there is a small advantage to having an aisle seat and, of course, to being relatively near an exit.

--Anonymous, 21:20 UTC, November 1, 2006.

And it happened again last week in Nigeria 96 death and 9 survivors in a 737 crash. Survivors believe God/Allah gave them a hand and they don't seem to have a clue about much.

"I don't know exactly what happened after the plane crashed - we were shouting for help and still praying."

Then some farmers nearby rushed to their rescue undoing their seatbelts to drag them from the wreckage.

from http://news.bbc.co.uk/2/hi/africa/6102618.stm

Keria 09:59, 2 November 2006 (UTC)

The back of the plane typically suffers the least amount of damage on impact. That's where they keep the black box in the bigger planes. I'm not sure if that translates into passenger safety, but it is likely. ---J.S (t|c) 00:35, 4 November 2006 (UTC)

According to The Worst Case Scenario Handbook: Travel Edition, the back of the plane, is indeed, safest. This request to relatives booking flights has resulted in my seat being so far back I don't have a window, and can watch the flight attendants make coffee. Russia Moore 04:51, 8 November 2006 (UTC)

"Psychoelectronic" devices and weapons?

I'm sure that anyone that's been around the net for a while (especially Usenet) will have come across people who believe that they are the victims of "psychoelectronic" attacks - be it from the CIA, MI5, the Elders of Zion, Freemasons, Illuminati, Knights Templar, Scientologists, or whichever group it is that they happen to have issues with. They often speak of devices capable of forcibly reading data from the human brain (a mind probe, if you will), causing great pain and long-lasting side effects to the victim - or technology capable of writing data to the brain (false memories, loud electronic screeches designed to drive the subject insane, etc.). These 'psychoelectronic weapons' are often mounted on satelites but apparently can be used at ground level too, over shorter ranges. The supposed victims of pschoelectronic warfare actually do sometimes sleep in aluminium foil hats or line the walls of their bedrooms (the technology supposedly works better on the sleeping) with thick aluminium/lead plate in order to deflect the waves/rays/beam/whatever. Sometimes, they claim that they are unwilling guinea pigs in the testing of new military technology and that soon it will be possible for the 'mind control satelites' to routinely record everyone's dreams, which will be then kept on file for future use against the subject.

So, my question is thus: Is there actually any theoretical basis to any of this stuff, or is it just sci-fi that certain mentally-ill people have been taken in by because it seems to fit in with the symptoms of their illness?

I wouldn't even know where to start looking for this on WP. Thanks. --Kurt Shaped Box 21:25, 1 November 2006 (UTC)

How about here? Seriously, an understanding of how the mind works is barely in its infancy. These people need to go back on their medications. Clarityfiend 21:45, 1 November 2006 (UTC)

We don't have the technology read people's thoughts with a captive subject, with a "thought reading helmet", let alone from a satellite… If that capability existed don't you suppose we would have heard of it by now with places like Guantanamo? I bet they'd love to be able to do it. Current technology is collectively known as Neuroimaging. As to the indiscriminate beaming out of some kind of waves that can slowly drive people crazy or stupid, that doesn't sound quite as far fetched. I have heard theories that certain types of radiation can affect mood, but I've not come across any real case scenarios. Either way, I don't believe something like this could exist in such secrecy. And the fact that people have been claiming this at least since the cold war, 'the commies were doing it', leads me to lean towards just a classic conspiracy theory. Vespine 21:54, 1 November 2006 (UTC)

Just had a brainwave (heh!). I remember reading something along those lines and now I've found it. Sonic_weaponry#Designed_to_emit_sound_as_an_irritant - I suppose that it's theoretically possible (but very unlikely) that some of these people have had infrasonic weapons used against them (I guess that the security services might have an interest in subtly driving certain 'subversive' individuals insane). --Kurt Shaped Box 22:22, 1 November 2006 (UTC)

Try telling those guys that. The standard response is usually along the lines of "'They' are using their psychoelectronic devices to purposefully manifest symptoms of a mental illness in me in order to discredit me because I got too close to the truth. One day you will understand too.". It's absolutely impossible to reason with them. --Kurt Shaped Box 22:15, 1 November 2006 (UTC)

An interesting theory on what is going on there is Susan Blackmore's idea that the phenomen of sleep paralysis might be responsible for accounts of people who feel controlled by outside powers. She was thinking of medieval accounts of succubi and incubi, and modern talk on abduction by aliens. Maybe this is the same here. Or, we are just talking about good old paranoia and schizophrenia. Taking into account that shizophrenia is a rather common desease, you should not be surprised to meet many of these people on the net -- and not all are aware that they are ill. Simon A. 21:56, 1 November 2006 (UTC)

Tinfoil hat seems like a reasonable place to start, though most of the links there to viable scientific topics aren't likely to contain info about the pseudoscientific applications - you most likely will have to read some of the external links for that. I'm assuming "psychoelectric" means manipulation via EM radiation.

Note that scientists can "read people's thoughts", to a very limited and crude extent, in a laboratory setting. For example, a test subject given a radioactive tracer glucose solution to drink and then monitored on a PET scan device, can then be shown photos of strangers and loved ones. Different areas of the brain will "light up" depending on their reactions to the photos, enabling the scientists to have a rough idea of what each subject is thinking. StuRat 03:57, 2 November 2006 (UTC)

In 1946, an alien ship was stripped at Area 51, revealing an organic conductor with interesting magnetic properties. In 1951 DuPont started manufacturing pillows containing TMS devices that allow the NSA to take control of you brain and make you vote for Ralph Nader. --JWSchmidt 14:00, 2 November 2006 (UTC)

Tickling

Why did we evolve the ability to be tickled?

I fancy it was to protect vulnerable parts--Light current 21:52, 1 November 2006 (UTC)

Isn't that what pain is for? Under the arms I'd believe, but sole of your feet? How is that more vulnerable then a lot of other places that aren't typically ticklish? I'd be more likely to think it's a by-product of a certain level of skin sensitivity, not necessarily a separately evolved ability, so to speak. Vespine 21:59, 1 November 2006 (UTC)

If you dont believe the sole of the foot thing, get a sharp knife and draw the blade along the sole of your foot from heel to toe (or the other way if you prefer) and then youll see what I mean. The skin there is very soft.--Light current 23:59, 1 November 2006 (UTC)

For those who wear shoes all the time. Those who never do (or did, like pretty much all of our ancestors) will have a thick layer of callus. It will actually be the thickest 'skin' of the body. DirkvdM 13:41, 2 November 2006 (UTC)

Our article on tickling mentions some hypotheses. Simon A. 22:03, 1 November 2006 (UTC)

So we'll know when we have spiders or centipedes crawling on our bodies? That 'tickling of tiny legs' feeling is one of the most uncomfortable, disconcerting sensations of all for me, even if it turns out to be a 'false positive'... --Kurt Shaped Box 22:30, 1 November 2006 (UTC)

I would think the enjoyable sensation of being tickled by a loved one serves a social purpose. Note that it's difficult to be tickled by a stranger, showing the "ticklish" reaction involves complex social interactions, not just a raw sensation. Also note that the person doing the tickling is almost always dominant (as a parent) and the one being tickled is submissive (as a child). Thus, it may serve a very subtle purpose of reinforcing power relationships, without resorting to violence, to establish dominance. StuRat 03:46, 2 November 2006 (UTC)

Dizziness during inflation

When inflating something with my lungs (an innertube, an air mattress...), after a while I start to feel a bit lightheaded. Why is this? Does it have to do with the increased amount I'm breathing in and out (essentially I am hyperventilating), or is there a different reason? — QuantumEleven 22:06, 1 November 2006 (UTC)

Rapidly increasing and decreasing blood pressure, so something along the lines of orthostatic hypotension? Thats if it is similar to the 'headrush' experienced when standing after having remained in a relaxed state for a while. Philc _T^E_C^I 23:03, 1 November 2006 (UTC)

Often people Valsalva when they blow up an innertube. Increasing the pressure in your chest decreases your blood return to your heart and lungs, causing decreased delivery to your brain and the feeling of dizziness. InvictaHOG 23:19, 1 November 2006 (UTC)

I think it is simply hyperventilation.  --Lambiam^Talk 02:28, 2 November 2006 (UTC)

You're not hyperventilating when you are blowing up something! You might be taking larger tidal volumes, but your minute ventilation will drop because your respiratory rate drops. InvictaHOG 11:34, 2 November 2006 (UTC)

Have to agree with the hyperventilation hypothesis. Minute ventilation is the product of respiratory rate and tidal volume. The vital capacity used to blow up an innertube might be 2.5-3 litres, i.e. five to six times "tidal volume", to maintain your "normal" minute ventilation you would have to take only 2-3 breaths per minute, which is unlikely as you are trying to blow up this darned inner tube as fast as possible. Hence, hyperventilation and a drop in PaCO2. Mmoneypenny 18:45, 2 November 2006 (UTC)

Thanks to everyone who replied - quite a few interesting links there for me to peruse! :) — QuantumEleven 07:42, 3 November 2006 (UTC)

Phobia of centipedes and millipedes - and why?

Is there a name for this? I have it.

Insects don't bother me at all. Arachnids only bother me if they're close to/on me and I'm taken by surprise. Centipedes and millipedes make me flee in terror at the very sight of them. I can't even kill them because that would mean having to approach them. Certainly seems that for me, more legs = more danger. Why do I have this? I don't remember something terrible happening to me as a child with these foul beasts to trigger it off - I've always hated (yes, it is complete and utter hatred - they disgust me and I would destroy their entire kind if it was in my power) them as far back as I can remember. --Kurt Shaped Box 22:41, 1 November 2006 (UTC)

Entomophobia includes various classes of bugs such as arthropods, which is what Myriapoda are, so that might cover you. Er, I mean that might describe your situation. DMacks 23:35, 1 November 2006 (UTC)

Myriapodaphobia? That sounds like it could be right. Well, there's a Google hit for it anyway. Doesn't look like there's any support groups though... :( --Kurt Shaped Box 23:41, 1 November 2006 (UTC)

You shold force yourself to get over it. It isn't good to have that much of a hatred for a, basically, defenceless animal which does, basically, no harm to humans. They can bite, but pain always goes away, they are not like spiders, of which some species can kill you. Next time you see one, wear gloves, and pick it up. It will probably try to walk onto your arm, at which stage you change hands. If you can stay calm, you should get over the phobia. I was always afraid of them, but I find watching them, and the synchornisation of their legs, really fascinating.

As for the why are you scared of them, it might be a snake things. Their movement looks much like a snake, and we are hardwired to be scared of snakes. --liquidGhoul 01:24, 2 November 2006 (UTC)

Yeah, I know it's not healthy to hate something that much. If, for example I hated Jews as much as I hate centipedes, history would remember me as *worse* than Hitler. It's like I have some sort of mental barrier in place that stops me from accepting centipedes as part of my world. I have nightmares about centipedes all the time and every time I wake up from one, I have the urge to destroy every single last one of them, yet I'm still too scared to go near them, which makes me hate them even more. If I had a gun and I saw a centipede, I would shoot it dead and feel good afterwards. No doubt about it. Heh, that sounds so messed up now I've typed it out. --Kurt Shaped Box 01:36, 2 November 2006 (UTC)

They creep me out, too. I think it's either how fast they move or all those wiggling legs that makes them creepy. I notice I'm scared by any insect quicker than me, as that means it can crawl on me before I can stop it. On the other hand, slow moving or still insects don't bug me much at all. :-) StuRat 03:17, 2 November 2006 (UTC)

Kurt Shaped Box has a phobia. He need hardly equate that with racism and mass murder. The obvious thing to do is to avoid the object of your hatred/fear. The only real problem is whether he is now obsessing about the phobia. If he can't refrain from doing so, then he could use the services of a trained mental health professional.

It is not the dislike of these creatures that is the issue, but the nightmares. It's perfectly okay for Kurt Shaped Box to have the hatred as long as he isn't constantly thinking about it.

B00P 08:12, 2 November 2006 (UTC)

I disagree. If you have such a hatred for something, to the point where you want to wipe it off the earth, you are bound to unwillingly pass that on to others. Centipedes and millipedes play an important role in most ecosystems. I'm sure Kurt won't willingly do anything to cause the extinction of any species of an animal. But it sounds as if he would if he had the technology. We need to encourage and teach others to value biodiversity, and attitudes like this don't help. I don't mean any offence, but talking about extinctifying (I made that up, I'm tired) a huge number of species because of ignorance, when there are so many people in the world working really hard to do the conserve them through intentions which are purely for the benefit of them or human kind, pisses me off a bit. Even if it is in good humour. --liquidGhoul 13:38, 2 November 2006 (UTC)

I don't consider a fear to rise to the level of a phobia unless it interferes with his life in a significant way. As there is very little benefit to allowing centipedes and millipedes to crawl on you, avoiding this is not really a problem. StuRat 18:45, 2 November 2006 (UTC)

Aw, c'mon. liquidGhoul is going over the edge. Kurt Shaped Box is hardly in a position to be wiping out whole ecosystems. And the notion that he will infect the world with his hatred is also quite wrong. My mother had a horror of rodents which she did not pass on to anyone else. I detect a whiff of "Political Correctness" with the insistance that everyone must accept and love everything (with the exception that it's okay to reject anyone who doesn't). Additionally, there is a huge difference between what one thinks and what one does. The danger in the idea that they are the same leads to the belief that once having thought of something, one is already "soiled." And if that's the case, it isn't actually worse to act out on one's negative ideas. Well, that's wrong. Our thoughts come unbidden; it's what we do with them that counts. In the case at hand, the only question id how much they are tormenting Kurt Shaped Box. If they're interferring with his life, then he should get help. Otherwise, it's just a quirk. B00P 23:48, 2 November 2006 (UTC)

Before this gets out of hand, guys - I would just like to inform you all that I was slightly tired and emotional last night. Perhaps the 'Jew' analogy and suggestions of legitimized centipede genocide were slightly ill-advised when perhaps a single line stating "Centipedes really scare me" would have been sufficient. --Kurt Shaped Box 00:10, 3 November 2006 (UTC)

Antisocial Personality Disorder Origon

Do not double post and be patient. You asked this same question all of 8 hours and 5 minutes before asking it again. Have you looked at your original post, where Light current has provided a helpful link (in the question)? That's likely to be all the information we have on the subject. --Tardis 00:01, 2 November 2006 (UTC)

Proton

Could you explain to me which would be the more valued result, removing one proton from each nucleus of a sample of gold or adding one proton to each gold nucleus?

The number of protons in the nucleus of an atom of a given element is called the atomic number. Here you will find List of elements by atomic number helpful. Melchoir 23:42, 1 November 2006 (UTC)

To 64.12.116.74, who asked this homework question and the one immediately following:

Please do your own homework.

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know.. --Tardis 23:55, 1 November 2006 (UTC)

Well, since removing a proton would produce platinum (at a value of £108/g for 99.995% pure), and adding a proton would produce mercury (which goes for around £70/kg at the same purity), I'd say the more valued result would be removing a proton. GeeJo ^(t)⁄_(c) • 23:44, 1 November 2006 (UTC)

This question could be more complex than we assume, if the number of neutrons is also considered. Thus, if we remove or add a proton from/to an isotope of gold, and leave the number of neutrons constant, will it produce stable mercury or platinum, or will it decay ? If so, how quickly will it decay, what will be the decay products, and what are their values ? StuRat 03:04, 2 November 2006 (UTC)

I took a look, and it appears that the only stable isotope of gold, AU-197, would be changed into either PT-196 or HG-198, both of which are also stable. StuRat 03:11, 2 November 2006 (UTC)

(edit conflict) Even before that, what might be the value of a source of those unstable isotopes? If it's just a thought experiment, may as well include in it a physicist being offered a coupla grad students or other cheap labor to do it on a useful scale on demand. DMacks 03:14, 2 November 2006 (UTC)

As long as we're running with the question, the prices should be adjusted by the price of the nuclear binding energy. And, for bonus precision, the price of protons. Melchoir 16:17, 2 November 2006 (UTC)

Periodic table

Why are the atomic masses listed in the periodic table not whole numbers?

Try the first few paragraphs of Atomic mass. Melchoir 23:40, 1 November 2006 (UTC)

Namely the first sentence of the second paragraph (it's an average of all the Isotopes of that element). Martinp23 23:56, 1 November 2006 (UTC)

It's not an average, it is proportional to the isotopes found on Earth, e.g. if there are two isotopes, 50% of which are on isotope, then the AM would be exactly between them the AM of both the isotopes. --liquidGhoul 01:18, 2 November 2006 (UTC)

Yes, a more correct term would be weighted average.

But the occurrence of different isostopes isn't the only reason why atomic masses (or atomic weights as we used to say) are not whole numbers. There are some elements where only one isotope occurs in nature and yet they still have non-integer atomic masses. For example, beryllium is all beryllium-9, but its atomic mass is 9.012+, not 9.000. Carbon-12 is the only isotope whose atomic mass is an exact integer (12.000) and that's because the atomic mass unit is defined in terms of carbon-12.

There are two reasons for this small variation between isotopes. One is that they have a different ratio of protons (which are a bit lighter) to neutrons; beryllium-9 has 4 protons and 5 neutrons while carbon-12 has 6 of each, so naturally beryllium-9 should have an atomic mass a bit greater than 9. But there's a second reason, which is that different isotopes or elements have different amounts of binding energy. which is expressed as mass (see mass-energy equivalence, which is to say, E = mc² and all that).

This last effect, known as the "mass defect" or "packing fraction", is what makes nuclear reactions an energy source. If you could make a fusion reactor that would convert beryllium into carbon (not a practical proposition, but these are the elements I used as my example, so let's stay with it), then the excess mass in the beryllium atoms would provide the energy released. Again, see binding energy for more.

It is sometimes useful to refer to an isotope by as a simple whole number, a count of protons and neutrons; that's what we're doing when we say beryllium-9 or carbon-12. But the term for this is mass number, not atomic mass. And it only applies to specific isotopes, whereas an element consists of a mixture of isotopes.

--Anonymous, 01:20 UTC, November 2.

Squeezing legs

Why is it, if one sqeezes someones leg just above the knee with ones hand, it makes them feel uncomfortable (not ticklish exactly), whereas, if one squeezes ones own leg in a similar manner, it is quite bearable. Is this the same thing as ticklishism?--Light current 23:53, 1 November 2006 (UTC)

Sounds like part of social conditioning in western culture... anything above the knee and on the inside tends to be "off limits" in a "show me where he touched you billy" kind of way.

Then again, expected sensation and self-inflicted sensation is usually more bearable then the surprise kind... ---J.S (t|c) 00:47, 4 November 2006 (UTC)

November 2

Having wet dreams about drinking breastmilk

Posting anonymously for obvious reasons. I keep having dreams about being breastfed by some of my favourite large breasted female celebrities. Really vivid ones too, I can taste their sweet milk, feel its warmth and I get really turned on by it. Sometimes I have sex with them whilst nursing from them. I often wake up having ejaculated in my sleep. When I'm awake, this feels creepy and wrong but still there's a part of me that wants to find a woman with milk in her breasts and do it for real. Am I really fucked up for thinking this? I don't know anyone I can talk to about this.

So...is this actually causing you some sort of problem? or are you just boasting 8-)--Light current 00:12, 2 November 2006 (UTC)

It just feels "sick" to me. Like I subconsciously want to have sex with my mother, or get involved with all that weird adult baby stuff. It's like the idea of drinking breastmilk really turns me on but the implications of why I want to do it scare me, if you know what I mean. My dreams usally involve MILF age women too, which makes the connection with my own mother seem more apparent. For the record, I don't fancy my mother but I'm scared what my head is trying to tell me. --194.164.208.87 00:33, 2 November 2006 (UTC)

Why not take it at face value? --jpgordon^∇∆∇∆ 00:46, 2 November 2006 (UTC)

Meh, lactophilia isn't the most bizarre or disturbing fetish you could have. Just take a look at some of the entries on Template:Paraphilia for some reassurance if you're worried about appearing weird. GeeJo ^(t)⁄_(c) • 01:08, 2 November 2006 (UTC)

LOL! I just found out that I have a smoking fetish. I love the taste of cigarettes in a woman's mouth when I kiss her, the smell of smoke on her hair and clothes, etc. and I do tend to seek out women that smoke. I didn't even realize that it was a 'fetish' as such, or that there was a particular name for it. Knowing that, do I feel any different about it? Hell no. ;) --Kurt Shaped Box 01:17, 2 November 2006 (UTC)

Then you'd love Morticia Addams..."Do you mind if I smoke ?". :-) StuRat 03:38, 2 November 2006 (UTC)

There's nothing to worry about. The female breast is an erogenous zone; according to the erotic lactation article, this fantasy is more common than we might think. The sex-positive movement suggests liberating ourselves from the repression and shame associated with many consensual sexual activities and fantasies that has been foisted upon us by puritanical prudery. If no one is harmed, how are such activities and fantasies to be regarded as wrong? Sexual Puritanism is responsible for shame over the human body, shame over human sexuality, etc, which it justifies with nothing more than bizarre claims of a "war" between the flesh and the spirit, the body as an instrumentality of the devil, and other such nonsense. To hell with that :) Personally, I found the description of sucking the milk from a woman's breasts to be highly erotic -- quite an appropriate word since the ancient Greeks regarded Eros as a divine experience. 75.26.10.224 01:10, 2 November 2006 (UTC)

Doesn't sound like anything to worry about. IMO, breasts are the best part of a woman's body - the bigger the better (as long as they're natural and about the same size on each side) as far as I'm concerned. You can rub them, squeeze them, grope them, squidge them together, use them as a pillow, suck them, bury your face in them, nibble them, lick them, kiss them, hump them, etc. etc. etc. I will never get bored of breasts. ;) If they have milk in them, they'll be bigger still - which is a Good Thing in my book. You're not actually having sexual thoughts about your own mother, so what's the problem? --Kurt Shaped Box 01:29, 2 November 2006 (UTC)

HEY! Don't say that! You'll give the guy who was having wet dreams about his mother a complex ;).. There's nothing "wrong" with having a sexual dream about your mother.. I definitely agree about the comments above about puritanism, I find personally find it disgusting and perplexing that war and death are more socially acceptable on the media and in the news then two people loving each other. Vespine 02:01, 2 November 2006 (UTC)

Heh, sorry. :) I do know what you mean though - gratuitous violence on TV is fine but sex is taboo. The act of destruction is more acceptable than the act of creation. Bringing life to an end is superior, morally-speaking than bringing about new life. That's *really* fucked up. --Kurt Shaped Box 02:10, 2 November 2006 (UTC)

The weirdest example in the US was the editing of Conan the Barbarian (film) (Arnold's first big movie) for TV. The scene where a person is beheaded is kept in, while a scene showing a bare-breasted woman was censored for being "obscene". StuRat 02:54, 2 November 2006 (UTC)

So god damned it people!? HOW do we affect change?? Issues like this make my skin crawl, I can feel it in the deepest part of my being! Let's EVOLVE! There seem to be SO many like minded people yet so much of our lives are led by these evil crypto fascist ultra conservatives. Is it strange to sometimes think you understand why people start cults?? ;) Vespine 04:55, 2 November 2006 (UTC)

WWCD? (What Would Che Do?) ;) --Kurt Shaped Box 06:45, 2 November 2006 (UTC)

Che would execute anyone who disagreed with him. StuRat 01:14, 3 November 2006 (UTC)

If you've been around usenet for any length of time (ten years and counting...) and met all the trolls, kooks, drama queens, stalkers, and pedants, you'd soon start to come around to his way of thinking. First up against the wall when the revolution comes will be the people who use 'we' instead of 'I' in their postings to imply that their opinions have some sort of support outside of their own heads... ;) --Kurt Shaped Box 02:12, 3 November 2006 (UTC)

Electrons

Which electrons are most responsible for the properties of an atom?

Bob and Sue ? :-) StuRat 06:58, 3 November 2006 (UTC)

The ones orbiting it. Would you like a more specific answer? GeeJo ^(t)⁄_(c) • 00:56, 2 November 2006 (UTC)

THe outer most ones. The ones in the valence shell--Light current 01:16, 2 November 2006 (UTC)

Which properties? Optical properties (photon energies of several electron-volts and lower) - the outermost one; that's why an electron in the outermost orbit is called an "optical electron". Chemical - several outermost ones, see previous answer. Interaction with X-rays - depends on the X-rays energy and atomic number. Interaction with gamma radiation - the innermost ones. Nuclear reactions and interactions involving atomic electrons - the innermost ones. And so on. By the way, technically the electrons are indistinguishable, so a better way to ask the question might have been "Electrons in which orbitals are most responsible..."; but those are really technicalities. Dr_Dima

Conservation of momentum

Hi, I have question about the conservation of momentum and energy consumption using the kenetic energy formula, m*v^2/2. It seems to me that, if we had a row boat with a frictionless hull and a man rowing, every time he pulled on the oars he would expend energy and one could estimate the energy consumed by looking at the mass and velocity of the water he was moving. Say that he could accelorate 100 kg of water to 1 meter per second every stroke producing a force of 100 newtons. If he and his frictionless hull massed 100 kg as well, then he would be accelorating 1 meter per second every stroke, using 50 joules each stroke. After 100 strokes he would have used 5000 joules of energy, and would be traveling at 100 meters per second. However this can't be right because the kenetic energy formula for a 100 kg object at 100 meters per second says that we need 500000 joules. What have I done wrong? Thanks 71.7.199.126 01:08, 2 November 2006 (UTC)

So he's accelerating the water and himself? (in opposite directions)--Light current 01:23, 2 November 2006 (UTC)

The "50 joules" part is wrong. Energy = force x distance, so in order to exert a constant 100 newtons against the water, you need 100 joules of energy for each meter you travel relative to the water. So you have to stroke more energetically as you speed up, and need higher power (= energy/time) to keep accelerating while moving at a higher speed. --Anonymous, 01:45 UTC, November 2.

I haven't checked your math, but two points to remember: First, Newton's law is F = ma, not F = mv. Second, and I suspect this is more important, the energy required to cause a given constant change in the velocity of an object depends on the initial velocity of the object. Even if you stay in the rower's frame of reference, it costs an increasing amount of energy to push on the water as it starts going by faster. Melchoir 01:47, 2 November 2006 (UTC)

Yo, the math makes it equal to 500,000 too. K.E. = ½(m)(v²)= ½(100)(100²)= 500,000. --AstoVidatu 02:09, 2 November 2006 (UTC)

Thanks a lot, so on the second stroke the energy required is 50 newtons times 2 meters since the boat is moving at 1 meter per second? --71.7.199.126 02:07, 2 November 2006 (UTC)

If the rower exerts exactly 50 newtons of force during the time it takes the boat to move exactly 2 meters, then yes. However, I wouldn't count on that being the case, since the boat is accelerating during the stroke. Given simple starting assumptions about how much momentum the boat gains after each stroke, it is much easier to just calculate its kinetic energy before and after, and subtract. And remember, this is just the energy required to move the boat; you'd have to do a more sophisticated analysis to add in the additional energy that gets wasted in the water. Melchoir 16:13, 2 November 2006 (UTC)

boiling water and conserving energy

this question stems from a running (amicable) disagreement with my girlfriend. she, when boiling water (e.g. a teakettle), prefers to use a medium or low flame, believing that it conserves natural gas. i prefer to use the highest possible flame: i think one needs X amount of heat energy to raise the temperature of Y amount of water Z degrees, and one has to burn the same amount of gas to produce that much heat whether one burns it quickly or slowly. which one of us is correct? 67.68.215.151 01:31, 2 November 2006 (UTC)

Both. At low flame, heat energy is lost due to cooling basically as a function of time and ambient temperature. At high flame, heat is lost simply because the pot can't capture it all and it's wasted. So there is an opimal point. Personally, however, my time is more valuable than the natural gas and I will put it on the largest flame that the pot can cover. That's the quickest boil.--Tbeatty 01:37, 2 November 2006 (UTC)

You need the optimum energy transfer rate from the flame into the water. This means that you should use an electric kettle! 8-)--Light current 01:41, 2 November 2006 (UTC)

It should be rather easy to tell if you are wasting heat. Since it isn't being absorbed by the kettle, it must escape around the kettle. You will be able to feel a draft blowing out from underneath it. The optimal temperature will be at a point where very little heat rushes out from under the kettle. --Kainaw ^(talk) 01:43, 2 November 2006 (UTC)

thanks! i'll keep these answers in mind next time this comes up. 67.68.243.140 02:02, 2 November 2006 (UTC)

The flame should be almost completely blue. Yellow and orange indicate inefficient combustion. -THB 02:17, 2 November 2006 (UTC)

Also note that whether it is winter or summer makes a major difference (assuming you're in a temperate zone):

• In summer, the escaped heat must be countered by increased air conditioning, at a high energy cost.

• In winter, the escaped heat warms the house, reducing the amount of heat needed. If it's a gas stove and you have gas force-air heat, it's even more efficient to heat your home with gas burners than with the furnace, as they don't suffer from the inefficiency due to the venting of the combustion products. Of course, those fumes are toxic in large quantity, so completely heating your home in this manner would be unwise.

One final thought, covering the pot also makes a huge difference in how quickly it boils and how much energy is used. StuRat 03:32, 2 November 2006 (UTC)

Orbital maintainance as a function of orbital velocity

If the gravity of a body in space increases (say from the accommodation of material coming from outer space) and the orbiting bodies would have to increase their orbital velocity in order to maintain their orbit and there is no limit on the size of a neutron star except the total amount of mater in the Universe is there a neutron star size at which its gravity is so great that no particle, not even one orbiting at the speed of light would have sufficient velocity to maintain its orbit? Adaptron 01:53, 2 November 2006 (UTC)

I'm gonna think and write at the same time, so go with me here. Centripital Acceleration has to be equal to gravity in order for the object not to fall into the star. C.A. = (v²)/r. The speed of light is equal to 299,792,458 m/s. And gravity is equal to (G(m))/r² (assuming that the particle speeding around the star has inconsequential mass). Thus if (6.67 x 10^(-11))(mass of neutron star)/(r²) > (299,792,458)²/r; or if (5.99 x 10^28)(radius) < mass, then even stuff travelling the speed of light should be sucked in. I think we call them black holes (?). Note that r is measured in meters, and mass in kg. --AstoVidatu 02:04, 2 November 2006 (UTC)

IIRC a Neutron star is one that lacked sufficient mass to become a Black Hole. Therefore there is a maximum/critical size where a neutron star will collapse. See also Chandrasekhar limit--Tbeatty 02:12, 2 November 2006 (UTC)

See also Schwarzschild radius. --Tardis 02:23, 2 November 2006 (UTC)

Would this point of collapse of a Neutron star into the formation of a Black Hole then be the point at which no particle, not even with an orbital velocity of the speed of light, be able to maintain its orbit and if so what size would the Black Hole have to be so that no particle in the Universe could maintain an orbit? Adaptron 02:24, 2 November 2006 (UTC)

Yes. As for your second question, "size" isn't the proper term, since the radius of the event horizon depends on the density mass of the object in question - like Tardis suggested, Schwarzchild radius describes that better. The dependence of the Schwarzchild radius on mass ultimately means that a sufficiently large object of any density can become a black hole. And black holes have a large range in sizes.

For a little bit of extra fun, there has been at least one documented instance of a white dwarf which exceeded the Chandrasekhar limit, for reasons which have yet to be documented fully.

Locusts as food for humans

Just been reading a few recipes for locust on the web and I'm now wondering why people who live in areas affected by plagues of locusts don't just go out and gather these fat, tasty, nutritious insects by the sackful and use them as a food source to replace the crops consumed by the swarm. AFAIK, locusts can be ground into flour and used to make bread, can be eaten as meat and also keep for a long time if dried. Why the big panic about them? --84.69.57.172 02:02, 2 November 2006 (UTC)

I don't know about you, but if I had spent two months plowing, planting, growing, and watering my crops, I wouldn't want them to be eaten. Also, one must consider that not everyone shares your interest in eating insects. I know they have lots of protein, but a lot of people, for some reason, don't find the idea of eating locusts appealing. ;) --AstoVidatu 02:06, 2 November 2006 (UTC)

A much better idea is "Locusts as Bait for Food for Humans." Teach cows/pigs/sheep/fish/chicken to eat them. --Tbeatty 02:08, 2 November 2006 (UTC)

God told the seagulls to eat locusts. --Kurt Shaped Box 02:14, 2 November 2006 (UTC)

That's just squeamishness. If people actually tried them, they'd probably like them. They had a rat problem in Vietnam not so long back. In order to counteract this, the government started a campaign urging people to eat more rat meat - it worked. Just about everything that crawls or walks is food. If the human race is going to survive, we'd better start realizing this. --84.69.57.172 02:18, 2 November 2006 (UTC)

What about the Galah? Those things are apparently almost completely inedible, no matter how you cook them. --Kurt Shaped Box 02:23, 2 November 2006 (UTC)

Agreed. There's nothing about insects that makes them inherently less appealing as food than carcasses of dead animals. If appearance is the problem, you can always process them into something that doesn't look like insect bodies. --71.244.111.101 03:15, 2 November 2006 (UTC)

It's an interesting point. There is no real reason why the majority of species that we consider to be pests cannot be used as food, if we drop the 'I don't like it - even though I've never tried it' thing. I'm sure that even rats and street pigeons can be made palatable and safe to eat if prepared in the correct manner. Same with starlings and house sparrows in the US - and obviously Australian rabbits. It's a simple solution and the Vietnamese had it spot on - "if there's too many of them, dine on them exclusively for a time to 'thin the herd'". --Kurt Shaped Box 06:43, 2 November 2006 (UTC)

There is a practical reason to avoid eating small animals. The amount of work to "gut" them becomes greater relative to the amount of meat produced. Thus, most small animals aren't eaten at all or are a rather expensive treat. For insects, however, people eat them whole, assuming that the bacteria in their gut won't be a problem. I'm not quite sure why that's the case. StuRat 18:35, 2 November 2006 (UTC)

Also note that there would be considerable difficulty in gathering the locusts once they've taken to flight. They could, however, be gathered while still on the ground. Since they all move in one direction, on the ground, I would think collection trenches could be constructed for this purpose. If people don't like eating them, they could be ground up (the locusts, that is) and used as protein supplements for livestock or as fertilizer for crops. StuRat 02:30, 2 November 2006 (UTC)

I wish I could find it but there are communities that eat locusts. I saw a video clip of a village in Africa with a huge pile of locusts that the locals had gathered using long "net fences", the women of the village were coming up to the pile and scooping up bowlfulls to take back home.Vespine 04:45, 2 November 2006 (UTC)

There are many societies that eat insects - grasshoppers are apparerntly common in rural cuisine in Mexico with some fancy restaurants in Mexico City serving insects as well. The Yemeni Jews are said to be the only Jewish group to retain the knowledge of which locusts are "kosher" which is mentioned in the very short "Locusts as food" section of our locust article. I think that they would be rather easy to collect by nets in the air. In the U.S. Midwest we sometimes have cicada barbeques during the largest brood emergences (just google "cicada recipe") Rmhermen 15:25, 2 November 2006 (UTC)

Locusts are supposed to go well with wild honey. Edison 18:16, 2 November 2006 (UTC)

What causes Electromagnetic radiation ?

I have been searching through the Electromagnetic Radiation article. It lists properties but I am not sure where to identify the origins of electromagnetic radiation 69.150.209.13 02:12, 2 November 2006 (UTC)

accelerating charged particles. --Tbeatty 02:17, 2 November 2006 (UTC)

There are many sources, depending on the frequency. Stars are one source of certain frequencies, as the radiation is given off by atoms undergoing fusion or decay. Neutron stars, supernovae, and black hole accretion disks given off other frequencies of EM radiation. There are also man-made EMs and some "background radiation" remains from the Big Bang. StuRat 02:18, 2 November 2006 (UTC)

But if this is for school you fill in the blank with "accelerating charged particles." :) You know light counts as EM radiation? Photons are often created in subatomic reactions, symbolized by gamma X [Mac Davis] (SUPERDESK|Help me improve) 05:46, 2 November 2006 (UTC)

Accelerating charged particles aren’t the only source, though, right? Particle-antiparticle annihilation will create EM radiation. So will switching from a high-energy to a low-energy orbital. Anyway, if you’re looking for specific examples: humans, TVs, mobile telephones, light bulbs, and fire are some of the obvious ones that come to mind as I glance around the room. — Knowledge Seeker দ 07:57, 2 November 2006 (UTC)

The simpliest answer: highly energetic objects. You won't get much radiation leaking out of a nuclear core, if you dropped it down a glacial crevasse. Surround it with high explosive, detonate that, and you've got a rather different scenario. -- Chris 16:53, 2 November 2006 (UTC)

Electromagnetic radiation is one of the four fundamental fources of the universe. To get into what causes there to be four fources and not five and what gives each force its properties is something that can't be answered with surety. superstring theory has an answer to this but is, at the moment, an untestable theory. Ƶ§œš¹ _{[aɪm ˈfɻɛ̃ⁿdˡi]} 19:57, 2 November 2006 (UTC)

By the use of wikipedia I have analyzed that the sun is the main source for electromagnetic radiation, it is mostly composed of hydrogen and helium, which seems to give its nuclear fusion reaction. So does nuclear fusion also cause electrons jumping orbitals, hence releasing electromagnetic radiation? 69.150.209.15 21:11, 2 November 2006 (UTC)

Organization of the periodic table

Please help because I am stumped. Strontium, SR(Number 38) is especially dangerous to humans because it tends to accumulate in calcium-dependent bone marrow tissues, CA(#20). HOW does this fact relate to what you know about the organization of the periodic table? I missed this on a test and he will not give us the right answer, so I would just like to know why I was wrong because I have no clue. Thanks!!!!

It's answered on the Strontium article.--Tbeatty 02:46, 2 November 2006 (UTC)

As for your teacher being unwilling to tell you what the correct answer is, that is rather unacceptable, in my opinion, both because it's counter to the overall purpose of education and because students have a right to double-check the grading process, as teachers often make mistakes. I suggest you discuss this with your parents, and have them complain to the teacher and school administration. You might, however, wish to have them wait until the end of the school year, after grades are all in, so he can't retaliate against you. StuRat 03:23, 2 November 2006 (UTC)

odd isn't it. given that school-level chemistry these days is often taught by non-chemists, kind of makes me think the teacher is unsure of their own answer. 132.181.173.233 04:20, 2 November 2006 (UTC)

Bad teachers are universal. You never forget them. I used to be good at Chemistry at school - then I had a crap teacher in my final year who screwed everything up for me, completely turned me off from the subject and didn't get around to teaching us everything we were supposed to know for our exams (he also hit me with his car one time - but that was unrelated). I failed miserably. --Kurt Shaped Box 07:48, 2 November 2006 (UTC)

I, too, am surprised that your teacher could not just admit to the phrase "They're both in Group 2". G N Frykman 07:43, 2 November 2006 (UTC)

• Abbreviations of elements in the periodic table are only written with a capital first letter. The second one is never capitalized. (so it's Sr and Ca instead of SR and CA) - 131.211.210.17 10:01, 2 November 2006 (UTC)

An experiment made to separate oil from Coconut milk.

Dear Sirs,

                       CENTRIFUGE TO SEPARATE COCONUT OIL FROM COCONUT MILK.

I wanted to do above with a motor of RPM 23000, and 1500 W mounted on a Cylinder of 2 ft. heigh and 6" in diameter.In this case Cylinder (bowl) is stationary and it is the roter which revolves the coconut milk with in the Cylinder. I made small holes on the shaft of the roter to bring down the oil if separated from Coconut milk.I used racers and water seals at the top lid of the cylinder and at the bottom of the cylinder, in the mechenism,in order to do this experiment. Also made two ports on upper level of the cylinder and outer (at loverlevel) edge to expell the water and heavy particles respectfully. How ever much I adjusted the shape the size and vertical level of the roter (FAN) I did not get any liquid (expected oil) through the hollow roter shaft with which provided holes to enter oil in to it.I expected to drain out oil through the rotor shaft down wards. The Coconut milk sent to the cylinder moves up to the discharge port provided on the cylinder [to expell only the denser liquid (Water)] without doing any separation . In other wards no liquid touched the roter shaft after passing the upper or lower level of the roter. My question is - What steps and adjustments should I do in order to keep the coconut milk rotation in the cylinder as a whole in order to get the separated oil without being liquid taking a parabolic shape at the middle ?. (Coconut milk which has 30 % oil is a juice extracted by pressing fresh coconut.

--Ishitha777 04:43, 2 November 2006 (UTC) Thank You. K.Samarasinghe.

I'm not an engineer, but I am pretty familiar with machinery, pumps and blue prints, that kind of stuff; I don't think I'm being unreasonable by saying your description is really, really hard to understand, you lost me on "small holes on the shaft of the roter"... I am not particularly familiar with centrifugal separation techniques so someone that is may be able to make more sense. Otherwise, maybe draw a diagram. Vespine 04:40, 2 November 2006 (UTC)

Would it be possible for you to post a link to a drawing of this contraption? Here's a link to a coconut milk centrifuge: X but it doesn't show the actual mechanism. I don't think you can avoid the parabolic shape--my blender makes the shape unless the liquid is too viscous. My thought is that cold pressing would be easier. -THB 04:48, 2 November 2006 (UTC)

Okay, here you go: [6] and [7] have the info you need. -THB 05:06, 2 November 2006 (UTC)

Ear clapping?

What would be the effects of someone jumping from behind you and clapping their hands against your auricles? I hope you know what I mean. X [Mac Davis] (SUPERDESK|Help me improve) 05:44, 2 November 2006 (UTC)

It'd hurt and there's a chance that it might burst your eardrums? We used to do that all the time at school - we called it "Tangoing" (after the UK fizzy drink - one of the ads for Tango had a fat guy running up to people and ear-clapping them). AFAIK, the kids are still "Tangoing" each other. There was a rumour that someone had once been "Tangoed" to death that everyone seemed to have heard but I think it was just an urban legend. The ad got pulled because everyone was copying it (video here). --Kurt Shaped Box 06:27, 2 November 2006 (UTC)

I'd have thought WP would have an article on boxing ears (which is an older term for it), but apparently it doesn't (at least not that I can find). In addition to causing pain, ear boxing can cause some disruption of the eardrum(?) or inner ear, which can disturb the balance of the person being hit. In rare cases, it can also burst the eardrum, leading to permanent deafening - this is unlikely, though. Some of the (nonfictional) devices in the sonic weaponry article may have descriptions of similar effects.

The Tango advert got pulled after a child had his ear-drums perfurated. So, I wouldn't suggest trying it out! Englishnerd 16:33, 2 November 2006 (UTC). Also if you are jumping out at the person, there is every chance they could get some, albeit mild, whiplash. Englishnerd 16:34, 2 November 2006 (UTC)

Pain, anger, retribution, ad infinitum. -- Chris 16:50, 2 November 2006 (UTC)

Fully N-type MOSFETs

I'm doing some research into MOSFET oxides, but the samples I have have phosphorus doped source and drain, on a very lightly phosphorus doped silicon substrate.

I was wondering what effects having all N-type regions will have on the threshold voltage. In the threshold voltage page the definition is the voltage required to push all the majority carriers away from the gate creating a depletion layer (at higher voltages the inversion layer forms). But I don't really have an inversion layer do I? And my majority carriers aren't pushed away. My results do show a threshold voltage at about 0.3 volts, and yes the thing works.

One more question, often one finds references saying that the inversion layer comes from minority carriers in the substrate, but this feels wrong to me? Does the 2DEG come from the source and drain or the substrate? In my case it may be both right?

Thanks very much, Frontier

Depletion mode mosfet. Tbeatty 06:20, 2 November 2006 (UTC)

But it's not always on. There's still a potential barrier when no gate voltage is applied and no current flows. I did a Hall analysis on it and found 0 carrier density at positive 0.2 volts on the gate.

What's the gate material? And then look at the work function difference.--Tbeatty 06:50, 2 November 2006 (UTC)

They're all silicon dioxide. Some are thermally oxidised (dry, wet, dry). Others use other oxidation texhniques. The base is very lightly doped. It's almost intrinsic.

Gate material is usually polysilicon and there is a work function difference between the bulk and the gate due to doping differences. This is MOS, there is no base. --Tbeatty 08:16, 2 November 2006 (UTC)

Oh, sorry I answered a different question. I oxidised a lightly phosphorus doped crystalline silicon substrate in an oxidation furnace; that was the field oxide. Then etched holes for the source and drain with HF, indiffused phosphorus, etched the gate region again with HF, reoxidised in a furnace the gate oxide, then evaporated aluminium for the gate contact. There's more to it than that, but yeah.

AIDS after death

Ok, I watch too much CSI but how long can HIV remain viable after the hosts' death? And, do different viruses have different within-host postmortem survival rates?? --Cody.Pope 06:45, 2 November 2006 (UTC)

Considering that people got HIV from blood in blood banks, probably a good long time.--Tbeatty 08:16, 2 November 2006 (UTC)

Different situation, because donated blood is processed and refrigerated to keep it fresh and 'alive'. Anchoress 08:18, 2 November 2006 (UTC)

I agree. There's a preservative and anti-coagulant added to blood. Not sure what else is done to whole blood. I'm not sure it's any more "alive" than uncoagulated blood in dead people though. --Tbeatty 08:23, 2 November 2006 (UTC)

As far as I know, HIV can't survive in coagulated blood. So it probably won't survive very long in a cadaver. WB Frontier 09:38, 2 November 2006 (UTC)

I wonder: would you get AIDS from eating steak from a poz corpse? I reckon it wouldn't do much good for your immune system, at any rate. -- Chris 16:49, 2 November 2006 (UTC)

Before you break out the Chianti and fava beans, let me advise against this idea. A virus isn't really "alive" in the sense that it actively does anything, it just "exists". It's existence tends to cause copies of itself to be produced, however, in the right environment (a primate's body, in the case of HIV). So, the question is, how long before it would degrade to a point where it couldn't cause copies of itself to be produced. I would expect the body would need to be in an advanced state of decomposition for this to be true. I believe, however, that the virus is damaged by oxidation if exposed to atmospheric oxygen. So, drops of blood which have dried out are probably not potential sources of AIDS (although they may contain other contagions). StuRat 17:55, 2 November 2006 (UTC)

Any virus is guaranteed to be destroyed by enough heat, and the heat of a frying pan is almost certainly enough to destroy HIV. So the answer would probably be "no" as long as the thing is cooked properly. Somebody out there probably knows the exact temperature at which HIV denaturates irreversibly, but I'm pretty sure it's less than 100 C - even the most hardy of RNAs and DNAs melt at less than that. That said, drying is not necessarily enough to denaturate viruses. It's not unreasonable that a drop of dried blood could still be infectuous, at least for perhaps a day or two. --BluePlatypus 19:10, 2 November 2006 (UTC)

Drying does imply oxidisation and HIV is vulnerable to oxygen, so my 'guess' would be that HIV would not survive drying. As for the eating, assuming you are having HIV tataki (very rare) I believe the oral contract rate is quite low. The mucus membranes of the mouth and following tract can absorb the virus but I believe the chance of that happening is relatively low. After that the stomach acids are definitely too much for the virus. I say 'low' but it is still something I wouldn't be willing to personally test! Vespine 21:52, 2 November 2006 (UTC)

No, drying does not imply oxidation. Whatever gave you that idea? Drying implies the loss of water. And for a virus, it doesn't even imply that, in the short term. If you go read the HIV article, you'll see that the virus is contained within a lipid envelope, which does a good job of keeping it from dehydrating (in the short term). And there's no reason to "guess" because there's plenty of experimental evidence on the fact that HIV can remain infectuous for days after being dried. See, for instance van Bueren, et al (J Clin Microbiol. 1994 February; 32(2): 571–574) --BluePlatypus 22:52, 2 November 2006 (UTC)

Tides

why is the tides vigrous during no moon day —The preceding unsigned comment was added by 61.11.77.8 (talk • contribs) .

A new moon is when the moon is directly in line with the sun, thus only the dark side of the moon is visible from earth. Since the moon and sun are in a line (called Syzygy), their gravitational attractions both work together to make a stronger tide, called a spring tide. --TeaDrinker 07:49, 2 November 2006 (UTC)

Just 'cuz you don't see the moon, it don't mean it ain't there. -- Chris 16:48, 2 November 2006 (UTC)

The gravitational attraction of the Moon pulls on the water regardless of the position of the Moon. The gravitational force travels right through the Earth, so the pull exists even when the Moon is on the far side of the planet. The only difference in the pull (other than the direction) would be because the Moon is slightly farther away (the diameter of the Earth) when on the far side. Compared to the orbital distance of the Moon, however, the diameter of the Earth is small. Also note that the Sun has an effect on tides, as well (although less than the Moon, due to it's much greater distance). StuRat 17:47, 2 November 2006 (UTC)

Boiling_water_and_conserving_energy Part 2

This has something to do with Wikipedia:Reference_desk/Science#boiling_water_and_conserving_energy. I wonder if it is more effecient to boil water in a microwave oven than on a stove with optimal flame ?--Wikicheng 13:01, 2 November 2006 (UTC)

What is an "optimal flame"? —Bromskloss 15:57, 2 November 2006 (UTC)

Check the power output of your microwave, compare it to the joules released through the combustion of gas.

Yes, it is more efficient, as microwaves specifically heat only water molecules (well, they also heat metals, but hopefully you don't have any of those inside), whereas the stove also heats the pot and air. However, using the stove may still be less expensive, because natural gas typically costs less per unit of energy than electricity. StuRat 17:41, 2 November 2006 (UTC)

Oops - an editing conflict. For you to use a microwave oven there must be a power station somewhere nearby which burns that same gas you are trying to save, to produce electricity that your microwave oven consumes. What you are asking is whether the power plant is more efficient than your gas stove in bringing a given amount of water to a boil. The ansewr is: I don't know, but it's easy to check. Follow these steps:

1. Find out how much gas it takes to boil the kettle. To do so, take your montly gas bill. Divide the total quantity of gas consumed (per month) by the estimated time (per month) your stove is lit, and multiply by the time it takes to bring the kettle to a boil.

2. Find out how much electricity it takes to boil the same amount of water in a microwave oven. To do so, multiply the power rating of your microvawe oven (in watts) by the time in seconds it takes to bring the water to the boil. The result is in Joules.

3. Burning a cubic meter of natural gas yields approximately 39 megajoules. Efficiency of a typical fossil-fuel power station is approximately 40%, so that's about 16 megajoules of electricity per cubic meter of gas. (see "energy content" section of Wiki natural gas article, and "Super critical steam plants" section of Wiki Fossil fuel power plant article for these data and much more).

4. You do the math :)

Let us know what you've got. Dr_Dima

Note that electricity is typically produced by some method other than burning natural gas (since natural gas is quite useful as is). Those methods include burning coal, nuclear reactors, hydroelectric plants, etc. Also, the monthly natural gas usage is likely to include their oven, furnace, water heater, and possibly clothes dryer. Pilot lights for those devices may also burn gas, even when the devices are not in use. StuRat 18:22, 2 November 2006 (UTC)

Year without a Summer

I have seen some references to weather records dating back to 1816 (the 'Year Without a Summer'), but I've been unable to find them. I am looking for day-by-day temperatures in New England that year, because I want to determine just how anomalous it really was, and do some analysis of the weather pattern. Any way to find weather data back to 1816 would be greatly appreciated.

-[User: Nightvid]

The wiki article is here. I can't help you otherwise, what you are asking is pretty specific. It might be best to ring the New England meteorological group to see if they have it in their archives. Thanks. --liquidGhoul 13:22, 2 November 2006 (UTC)

Although NASA is usually the best place for this, it seems in the New England region it only goes back to 1880. I don't have any data, but I'll advise you that a day-by-day temperature record, of a single year, and of that time is

• highly inaccurate
• fairly useless

Brian Fagan's book could help? Good luck. X [Mac Davis] (SUPERDESK|Help me improve) 20:28, 2 November 2006 (UTC)

What is a "Lewis conjugate" substance?

Hi, wise guys. I have read something about "Lewis acids", etc. but found nothing like "Lewis conjugate" which Señores Hernando et al. chemisorbed on gold in this article: PRB 74 052403. Thanks for your time. 193.232.124.163 13:07, 2 November 2006 (UTC)

You probably want Conjugate acid, except that the article mostly deals with the Brønsted-Lowry definition. Still, a redirect shouldn't hurt. (There are also conjugated Lewis structures, but I don't think that's what is meant here.) —Ilmari Karonen (talk) 15:30, 2 November 2006 (UTC)

Actually, I chased down the cited article, and they seem to mean a conjugated system after all. Now I'm getting confused. I think I'll turn that redirect into a disambiguation page for now. —Ilmari Karonen (talk) 15:38, 2 November 2006 (UTC)

Thanks, Ilmari. I'll try to figure out. 193.232.124.163 15:57, 2 November 2006 (UTC)

SCR's

My question is concerned wthh silicon controlled rectifiers. I don't seem to understand the theory of SCR's too well - but that I can get over, I will study a bit more. As a side question, are there any specific pages which explain the theory and working of SCR from the basics ? The wp page is more like a reference than a step by step explanation (which is how it should be)

My question has more to do with the application of SCR - What are the advantages of SCR over an equivalent diode only rectifier ? In fact, the way we were taught in school, seems to suggest that the output voltage of SCR is "clipped" in the beginning by "alpha" degrees, where alpha is the delay after which a triggering voltage is applied to the gate terminal. Would that not lead to decrease in the output voltage ? Why then, is it said, are SCR's more useful than normal diode-only rectifiers ?

Thanks. --RohanDhruva 13:21, 2 November 2006 (UTC)

The clue is in the name: Silicon Controlled Rectifier. More useful because they are controllable as to the part of the cycle at which they start to conduct and therefore they can be used to vary the amount of power delivered to an electrical load. Ordinary diodes cannot do this. (they always turn with about 0.6 volts forward across them)

The average power delivered to a load depends upon the (square of the) average voltage supplied (See RMS). If you can vary the 'time on' to 'time off' ratio, you alter the time average of the voltage applied to the load and hence the average power.8-)--Light current 17:53, 2 November 2006 (UTC)

For an in-depth discussion, see http://www.allaboutcircuits.com/vol_3/chpt_7/5.html or our article at Silicon-controlled rectifier. --Jmeden2000 18:06, 2 November 2006 (UTC)

Thank you very much for the response, that explains it ! :) --RohanDhruva 02:06, 3 November 2006 (UTC)

KENTUCKY'S SOIL

WHAT IS WRONG WITH KENTUCKY'S SOIL 208.61.241.196 14:40, 2 November 2006 (UTC)

First, do not type in all caps - it is very rude.

Second, the answer to your question is mu. --Kainaw ^(talk) 14:46, 2 November 2006 (UTC)

You do realize you've linked to a monster of a disambiguation page, right? Presumably the one you meant was mu (negative). —Ilmari Karonen (talk) 16:10, 2 November 2006 (UTC)

Nothing's wrong with Kentucky soil. Leave the land how it is for twenty years, and you'll see all sorts of wonderful things sprouting up. Perhaps, not things that you would fancy eating, but I'd wager that there'd be plenty of pretty vegetation. At worst, you could burn that, then your soil will be good again for a few years. -- Chris 16:45, 2 November 2006 (UTC)

I was unable to find any specific info on soil deficiencies common in the US state of Kentucky. However, if you contact the Kentucky Department of Agriculture, they should have info on potential problems and solutions: [8]. StuRat 17:35, 2 November 2006 (UTC)

NOT A DAMN THING. Some people have good luck growing bluegrass, which at least looks nice. Some grow Tobacco, some grow Cannabis (drug), or hay. Farmers grow tomatos and other veggies, corn, & soybeans . Except for the floodplains of major riversand, much of the soils lacks the deep black humus seen in, say Minnesota, and there is a lot of clay soil. But it generally has abundant water and a long, warm growing season. Acid soils are supposed to be good for growing popcorn.

Chemical bonding in the nitric oxide

How does the oxygen bond to the nytrogen? I´ve learned the oxygen can only have two covalent bonds, and the nytrogen, three. If two electrons from each are in the bond, the nytrogen doesn´t have its octet complete. What happens, then? A.Z. 14:54, 2 November 2006 (UTC)

Well, that unpaired electron is what the article means when calling the molecule a free radical. Melchoir 15:52, 2 November 2006 (UTC)

Nitric oxide is a somewhat unusual molecule in that it has an unpaired electron, making it technically a free radical, but an unusually stable one. It structure is best analysed using molecular orbital theory. Effectively, NO has three filled bonding orbitals and one half-filled antibonding orbital (see f.ex. page 8 of this PDF), meaning that there are, in effect, 2.5 bonds between the atoms. For a more in-depth study, see for example this article. —Ilmari Karonen (talk) 16:07, 2 November 2006 (UTC)

Oh, now that last paper is interesting. To me anyway. (Although it's a bit old and the theory is low-level) Unfortunately it doesn't give a population analysis (although this is much more advanced stuff than what the original question was about). But FWIW, the picture in the Nitric Oxide article, with the dashed third bond is misleading. A better one would be *N=O, because (and the article makes the point) it's not significantly contributing to the bonding; The unpaired spin population is highly concentrated to the nitrogen atom and the (Mulliken) bond order is 1.9 and not 2.5. --BluePlatypus 22:31, 2 November 2006 (UTC)

The two normail bonds are shared, and you can also have dative donding, where only one atom contributes electrons in this case, they share an electron from the oxygens now complete outer shell, in order to also complete the nitrogens outer shell. Philc _T^E_C^I 21:35, 2 November 2006 (UTC)

Density and space

Makes sense that an area of space with more matter has a greater density. Does this mean that absolute density is matter without space and if so what would matter then occupy? Adaptron 14:58, 2 November 2006 (UTC)

could you please elaborate? Dr_Dima

Remember the old comedy routine where someone pushes down on a bed spring and another spring pops up? Absolute values tend to do the same thing. For instance: can you reach absolute zero without also having absolutely no heat? If you think of increasing density as simply the process of removing space then at some point you are faced with the dilemma of having to remove absolutely ALL space - in order to achieve absolute density. 16:01, 2 November 2006 (UTC)

Dare I say your question exhibits absolute density. -- Chris 16:43, 2 November 2006 (UTC)

and your response absolute space. Adaptron 17:03, 2 November 2006 (UTC)

I think you mean vacuity (Dictionary.com: 2. absence of thought or intelligence; inanity; blankness: a mind of undeniable vacuity). -- Chris 18:19, 2 November 2006 (UTC)

Isn't the gravitational singularity in a black hole an example of "absolute density" ? That is, as far as we know, the singularity is a geometric point, with absolutely no volume, but a finite mass, thus infinite density of matter. Of course, there is a finite volume within the event horizon, so a black hole does not have an infinite matter density if measured in that manner. StuRat 17:17, 2 November 2006 (UTC) StuRat 17:15, 2 November 2006 (UTC)

However, as you approach the singularity, the density rises asymptotically towrd infinity (the last time I looked). The orig Q, however does not make sense. The Q should have been: Is there a theoretical maximum density? A: No (not as far as we know) 8-)--Light current 17:39, 2 November 2006 (UTC)

Why, unless the black hole was actively "feeding", would there be any mass outside the singularity ? StuRat 18:18, 2 November 2006 (UTC)

THe average density of the sphere formed by the singularity at the centre and you on its surface. Sorry wasnt clear

--Light current 18:21, 2 November 2006 (UTC)

Black holes aren't actually infinitesimally small with infinite gravitational force, the best we can do with mathematics for now is to arrive at that conclusion. X [Mac Davis] (SUPERDESK|Help me improve) 18:41, 2 November 2006 (UTC)

I would say it the other way, that, as far as we know, the gravitational singularity is a point of infinite density (as our article claims). We could be wrong, if there is some yet undetected force that prevents the infinite collapse, but I wouldn't assume that to be the case. The only argument for making such an assumption is that it would make things more like those we are familiar with. This isn't a good way to do things, however, as we already know that things behave in bizarre ways at such different scales, as demonstrated by quantum mechanics, etc. StuRat 18:53, 2 November 2006 (UTC)

Speaking of StuRat standing on the surface of a singularity, wouldn't someone who lives in infinity regard us as living in infinity? In other words, is infinity reversible? (Did I just introduce cultural relativism into Kosmology?) DirkvdM 08:27, 3 November 2006 (UTC)

protocol

can u please provide me a micropropagation protocol for citrus limon? i need it for my tissue culture work... please.. i tried to search it on thenet but was not able to find the apprpriate results.. please help me!!

Flea eggs

Can flea eggs survive and hatch if they are 'squeezed out' of a flea rather than laid by the female? When either my cat or dog has fleas I go for a 2 pronged attack - a good flea collar and regular grooming with a fine-toothed comb (the sort used for head lice is good). the fleas are picked up between the teeth of the comb and then I can pick them up between my finger and thumb to kill them. But, as it's impossible(?) to kill a flea by squeezing between the soft flesh of fingers, I squeeze it between my fingernails instead (I was taught a little rhyme which goes "break their back, they don't come back"). this works well (although is a little messy if you kill a flea which has just fed). However, if you get a pregnant female, squeezing the flea will cause flea eggs to burst from the flea - sometimes quite violently. I'm sure that some must fall back onto the animal. I understand that flea eggs which have been laid conventionally can lay dormant before hatching.

(also, if I might, a related question. Is there any evidence to suggest that fleas know where they're jumping to?)

thanks and sorry for the long question!

simon

• I always found a lighter to be a useful tool in one-by-one flea killing. Roast the ones you catch on the comb. --jpgordon^∇∆∇∆ 16:52, 2 November 2006 (UTC)

If the egg is ready to be laid, then yes, it may well be viable. I suggest you drown the fleas, instead. Keep a bowl of water next to you and stick them in that. Don't just drop them in, as the surface tension may allow them to stay on the surface, then they could escape when they float to the edge of the bowl. On the other hand, if they are under the surface, it becomes a barrier to their escape. Then flush them down the toilet once done grooming the dog. StuRat 17:11, 2 November 2006 (UTC)

I wondered abotu vaccuuming the up then spraying insecticide into the vaccuum?

I suspect they may be able to jump out of the way of the vacuum cleaner if still alive. Try powdering the carpet with a flea pesticide first, then wait until they are dead, then vacuum the floor. Keep the kids and pets out of the room while the powder is on the carpet to minimize their exposure. You might want to wear a breathing mask when vacuuming, to limit the amount of flea powder you inhale. ("Vacuuming" = "Hoovering", for you Brits.) StuRat 18:11, 2 November 2006 (UTC)

Re: vacuuming, water and insecticide: a) a drop of dishsoap will remove enough of the surface tension to allow the fleas so sink; b) rather than insecticide in the vacuum, use a couple of moth balls; and c) borax is a good (and healthy, and environmentally-sound) alternative to pesticide. Just sprinkle it on your floor (and actually fleas prefer floor cracks to carpets), leave it for a bit (don't recall how long offhand, but that's what google is for), then vacuum it up. Anchoress 19:17, 2 November 2006 (UTC)

I always say take a page out of nature's book: Make like a chimp and eat the fleas, no mess, no fuss, no chance of eggs getting anywhere.. Ok, but really, an ex-housemate of mine once had a cat and he didn't look after it, the thing got so flea bitten I could no longer stand it. I'm not a cat person, but it got a bit hard not to notice when you could see fleas in its FACE when you gave it a pat. Anyway, to get to the point, all I did was get those liquid flea drops that you drip on the back of your animal's neck, after about 3 applications (which were all in the one packet), the cat was flea free. i can't remember the specific one I got but it was something like advantage Vespine 21:37, 2 November 2006 (UTC)

Simon,I wash my dogs in Dawn dish detergent,this works well.After I wash them ,I have a cup of hot water with a drop of dawn in it.I pick the fleas off, and put them in the cup this kills them.I find this method works.I hope this helps.Andrea216.218.118.90 01:53, 3 November 2006 (UTC)216.218.118.90 01:24, 3 November 2006 (UTC)

Dogs have less layers of skin than humans, therefore it might be harmful to use dish soap to wash pets. --Wirbelwindヴィルヴェルヴィント (talk) 05:22, 3 November 2006 (UTC)

What is the collective term for a group of Jellyfish?

By this, I mean the kinda thing like a group of fish is called a school, what's a group of Jellyfish called?

According to List of collective nouns by subject I-Z, a "smack of jellyfish" is conventional, with a "fluther of jellyfish" as a slightly uncertain alternative GeeJo ^(t)⁄_(c) • 18:06, 2 November 2006 (UTC)

Booorrriiinnnggg. That should be changed to a "belly" or even a "peanut butter sandwich" of jellyfish. Clarityfiend 18:48, 2 November 2006 (UTC)

Someone needs to come up with one for Reference Desk contributors... Vitriol 19:31, 2 November 2006 (UTC)

Hmmm....how about a "straitjacket"? Clarityfiend 20:45, 2 November 2006 (UTC)

How about a "group"? That's certainly the most common one when we're talking about jellyfish. --Bowlhover 21:41, 2 November 2006 (UTC)

What is the collective term for a group of Reference Desk contributors

How about 'consensus'? OK maybe a 'disruption' or possibly a 'catastrophe'--Light current 02:17, 3 November 2006 (UTC)

This question should be moved somewhere--Light current 02:22, 3 November 2006 (UTC)

Could have an 'addiction' of RD contribs I suppose--Light current 03:56, 3 November 2006 (UTC)

amniocentesis

Does anyone know who developed the technique amniocentesis. The article doesn't say so.

Christopher

I don't know who developed it. Dr. David Brock is well known as the pioneer of the test for checking on the welfare of the fetus. --Kainaw ^(talk) 18:53, 2 November 2006 (UTC)

Well, I am asking because one of my biology lecturers, Dr Roger Sutcliffe said something along the lines of him developing it, and I am wondernig if he said that HE had co-developed it.

Christopher

Four different groups of researchers are credited with the dis­covery in 1955 that the sex of human fetuses could be predicted through analysis of fetal cells in amniotic fluid: one each in New York, Minneapolis, Copenhagen, and Haifa (Shettles, 1956; Makowski, 1956; Fuchs & Riis, 1956; Serr, Sachs, & Danon, 1955). A short while later the Copenhagen group became the first to report that they had performed an abortion in order to prevent the birth of a fetus, diagnosed as being male, whose mother was a carrier of hemophilia (Riis & Fuchs, 1960). Pre­natal diagnosis through amniocentesis was, if you will excuse the pun, born; the year was 1960. [9] --jpgordon^∇∆∇∆ 00:23, 3 November 2006 (UTC)

Thermal Energy loss of a person

Is their a way of estimating the amount of thermal energy a person gives out in different circumstnaces, specifically:

1. When doing a sport? 2. When sitting down?

Also how does this amount change depending on the temperature at which this 'act' is being carried out in? i should add for an average person (whatever that is). A general answer will suffice.

Thanks

Me22ac 19:37, 2 November 2006 (UTC)

All energy that your body used ultimatively ends up as heat. So you can safely use the usual table about how many calories you burn when doing what kind of excercise. For the energy needs withou exercisew, see basal metabolic rate. Simon A. 20:56, 2 November 2006 (UTC)

As for the effect of the ambient temperature, I would model it as three independent events:

• Basal metabolic rate, which is energy used to beat your heart, breathe, etc., and which ultimately becomes heat. This is a constant.

• Exercise related energy, which is used by the voluntary muscles, along with an increase in heart rate and breathing rate, all of which also ends up as heat.

• Energy used to maintain body temperature (this only applies to warm-blooded animals). The rate of thermal loss is proportional to the difference in the temperature from the skin to the environment. Wind, humidity, and clothing, of course, also effect the rate of thermal loss.

StuRat 23:07, 2 November 2006 (UTC)

I think it's relevant to point out that if your energy used to maintain body temperature varies much from the "standard" values associated with room temperature, you notice by, well, feeling hot or cold. So if you're out jogging in winter, dressed more warmly than you would be in summer, but feeling about the same thermally (on average), you should be able to re-use the "normal temperature" jogging statistic. --Tardis 23:41, 2 November 2006 (UTC)

gas turbine

what is a gas turbine engin good for— Preceding unsigned comment added by 69.132.236.116 (talk)

Chrysler experimented with gas turbine engines in cars for a while. See the link for other uses. StuRat 23:12, 2 November 2006 (UTC)

How many fish are in the sea?

Was the caption for the Finding Nemo trailers right that there are 3,000,000,000,000 fish in the sea? If thats right, thats overwhelming! If it is true, are most of them in the Pacific, the largest ocean?— Preceding unsigned comment added by 82.36.182.217 (talk)

Stuff like this is impossible to prove or disprove. It can be an estimateif they're considering how much of Earth is covered by water (about 70%), and how deep fish can live, and a lot of other factors. --Wirbelwindヴィルヴェルヴィント (talk) 05:17, 3 November 2006 (UTC)

News item: "World's Fish Supply Running Out, Researchers Warn" By Juliet Eilperin Washington Post Staff Writer Friday, November 3, 2006; Page A01

"An international group of ecologists and economists warned yesterday that the world will run out of seafood by 2048 if steep declines in marine species continue at current rates, based on a four-year study of catch data and the effects of fisheries collapses.The paper, published in the journal Science, concludes that overfishing, pollution and other environmental factors are wiping out important species around the globe, hampering the ocean's ability to produce seafood, filter nutrients and resist the spread of disease." [10] --GangofOne 06:31, 3 November 2006 (UTC)

protein molecular weight

Which technique gives better resolution of proteins by molecular weight, SDS-PAGE or size exclusion (or gel filtration) chromatography? I realize this depends on many factors, but in general which would choose if you wanted good resolution by size? If it makes any difference, I am interested in peptides smaller than 3 kDa. ike9898 23:25, 2 November 2006 (UTC)

Well, no wonder you're confused: Do you want them by weight or by size? That distinction is quite relevant to which method you should choose. --BluePlatypus 23:46, 2 November 2006 (UTC)

November 3

Chemistry

i need to know the name of the law that states that the mass of what you end with is the same as what you started with in a chemical reaction —The preceding unsigned comment was added by 71.96.48.6 (talk • contribs) .

I think conservation of mass is what you are looking for. --TeaDrinker 00:49, 3 November 2006 (UTC)

Identificiation of a spider

Hi, can anyone tell me what species of spider these are? It was in the bathroom. I live in New Haven, Connecticut and I don't often see spiders this big around here. Thanks. SandBoxer 01:26, 3 November 2006 (UTC)

I would guess some sort of nursery web spider (pisauridae), maybe dolomedes, but how did you expect someone who knows american spiders to figure scale from a queen's coin of no visible denomination? How about we try again with a dime, nickel, quarter, or half dollar? alteripse 02:58, 3 November 2006 (UTC)

Well, it looks to be a British 5p, so just gotta figure out how many nickels that's worth to get a USAian physical scale. DMacks 03:08, 3 November 2006 (UTC)

We have an article on identifying spiders with some links that might be useful. Oddly, it doesn't mention bathroom spiders.--Shantavira 08:05, 3 November 2006 (UTC)

Cable TV wiring methods

Not exactly science, but it is technology. Please tell me if I'm querying the wrong section.

I recently "upgraded" to digital cable, but the diagrams provided by the cable company and box manufacturer don't specify "bypass" methods, so that I have the option of viewing and recording the analog channels as I used to, or to view and record one digital channel. The suggested configuration (from a long time ago, when cable-ready VCRs were new), involves splitting the input cable signal between one feed going directly to an A/B switch, and the other going to the switch through the cable box. Unfortunately, none of my local stores has a coax (cable TV) A/B switch. Since my VCR has an aux video input, I'm thinking of still using the splitter, but, instead of having the "cable" output of the cable box going to an A/B switch, having the video output of the cable box going to the video input of the VCR. Any other ideas? Both the TV and VCR are "cable-ready", but not digital.

Full proposed configuration:

Cable input (from wall) -> splitter -> VCR coax in, and cable box coax in

cable box video out -> VCR video in

cable box coax out (unused)

VCR coax out -> TV coax in

VCR video out -> TV video in

Hence, perhaps I can use the VCR (effectively) as an A/B switch. I don't have all the cabling yet, but, if I understand this correctly, I can

1. record any analog channel and watch any analog channel, by ignoring the feed entirely
2. record a digital channel and watch any analog channel, by seting the VCR to record from line, and using the TV's tuner to process the coax input
3. (optionally) record a digital channel and watch that digital channel, by setting both the TV and VCR to line input.

Have I missed something? — Arthur Rubin | (talk) 01:42, 3 November 2006 (UTC)

Ah, yes, the locale. City is Brea, California, cable company is Adelphia changing to Time Warner Cable. — Arthur Rubin | (talk) 03:48, 3 November 2006 (UTC)

q = cp*delta t * m

why is it cp and not cv? why is pressure always assumed constant ?

Look up adiabatic process and isothermal process. I think they may mean something (to you not me)--Light current 02:23, 3 November 2006 (UTC)

The Harris-Benedict equations

In the article Basal metabolic rate

The original equations from Harris and Benedict are:

• for men, $66.4730+(13.7516*w)+(5.0033*s)-(6.7550*a)$
• for women, $655.0955+(9.5634*w)+(1.8496*s)-(4.6756*a)>$

where w = weight in kilograms, s = stature in centimeters, and a = age in years. (Harris J, Benedict F (1918). "A Biometric Study of Human Basal Metabolism". Proc Natl Acad Sci U S A. 4 (12): 370–3. PMID 16576330.)

What unit is the result of the equation? Watts? Calories per day? Pound force Furlongs per fortnight?

202.168.50.40 02:41, 3 November 2006 (UTC)

If you follow the footnote reference for those equations on that wiki page, you can read the primary-reference article in which those equations were originally published. DMacks 02:51, 3 November 2006 (UTC)

I looked at this at the bottom of the article:

• The original 1918 Harris-Benedict article (free full text)

And it does not say. All it says is

An analysis of the data of actual experimentation
on subjects at changing levels of nutrition shows that the changes
in metabolism are not proportional to those in body surface. Surface area
may not be looked upon as a determining factor in basal metabolism.
The closest prediction of the daily heat production of a subject can be
made by the use of the multiple regression equations,
For men, h = 66.4730 + 13.7516 w + 5.0033 s - 6.7550 a
For women, h = 655.0955 + 9.5634 w + 1.8496 s - 4.6756 a
where h = total heat production per 24 hours, w = weight in kilograms,
s = stature in centimeters, and a = age in years. These equations have
been tabulated for values of weight from 25.0 to 124.9 kgm., for stature from
151 to 200 cm., and for age from 21 to 70 years, so that the most probable
basal metabolism of an unknown subject may be easily determined.
Such tables should render service in clinical and other fields of applied
calorimetry. Their usefulness has been demonstrated in testing the typical
or atypical nature of series of metabolism measurements, in investigating
the differentiation of the sexes with respect to metabolic activity, of the
metabolism of athletes as compared with non-athletic individuals, an'd of
individuals suffering from disease.
The detailed measurements and statistical constants, with full discussions
of pertinent literature, are about to appear in Publication No. 279 of the
Carnegie Institution of Washington.

202.168.50.40 03:48, 3 November 2006 (UTC)

Well that does tell you it's [somethings] per day already. The first place the article uses the variable h is towards the bottom of page 371, and there it states: "h = total heat production in calories per 24 hours". DMacks 04:54, 3 November 2006 (UTC)

Gallium/gallinstan

What metals does Gallium not react with? Would these also not react with Gallinstan?

Gallium also attacks most other metals by diffusing into their metal lattice — another reason why it is important to keep gallium away from metal containers such as steel or aluminum. Gallium metal easily alloys with many metals, and was used in small quantities in the core of the first atomic bomb to help stabilize the plutonium crystal structure. --Light current 03:46, 3 November 2006 (UTC)

Krell

If the human race survives long enough, is it possible we could become like the Krell having limitless energy and knowledge (stored in WP of course)--Light current 03:17, 3 November 2006 (UTC)

This is kind of related to the idea of transhumanism and the related technological singularity. It has fans but has also been described as "Rapture of the nerds." --Robert Merkel 04:13, 3 November 2006 (UTC)

The Krell didn't have "limitless" energy and knowledge, just immense amounts. Any finite amount, no matter how huge is not "limitless." And they appear to have had a major hole in their knowledge of psychology. B00P 05:30, 3 November 2006 (UTC)

But of course, most of that knowledge would be in the form of poor articles about book/movie/televison/game characters ;-) Xcomradex 07:07, 3 November 2006 (UTC)

Dark colored cliffs in Great Britain?

Hello all!

I was wondering where one might find darkly colored cliffs in Great Britain. Specifically, rough/jagged black cliffs. Also, are there any small ports near these places? I'm working on a story for National Novel Writing Month, and currently have no basis in reality for my setting!

Any help would be much appreciated!

Russia Moore 04:45, 3 November 2006 (UTC)

How about these forboding cliffs? [11] They can be found near the fishing town of Hillswick on Shetland, Scotland. Rockpocket 06:38, 3 November 2006 (UTC)

The Stanage area has several miles of spectacular black rocky cliffs, but they are very much inland.--Shantavira 08:10, 3 November 2006 (UTC)

What is this?

http://www4.ncsu.edu/~stdidona/DCP_8386.jpg --Shanedidona 04:57, 3 November 2006 (UTC)

It is 1mm long by the way.

Sure looks like an unfed tick to me but chigger also come to mind. But then I'm not working the reference desk. Just trolling. Adaptron 06:16, 3 November 2006 (UTC)

It's neither a tick nor a chigger: both of these are arachnids. What you have is some kind of insect. I'm afraid it may be a bedbug nymph. Compare with this image of such a critter that has recently fed. – ClockworkSoul 06:49, 3 November 2006 (UTC)

Check out aphids.--Tbeatty 07:09, 3 November 2006 (UTC)

Earthworm and grasshopper digestion times

Any help investigating these two statistics would be greatly appreciated. Thanks, anon.

In humans? Rockpocket 06:29, 3 November 2006 (UTC)

A quick search comes up with this which investigated a species of compost worm's gut retention time. From the abstract, it seems that they found digestion time is dependant on temperature, and possible other factors. Another article (Jeschke and Tollrian, 2005, Ethology 111, pp187—206) listed migratory grasshopper (Melanoplus sanguinipes) digestion time as 42044 minutes per gram of dry mass, carolina grasshopper (Dissosteira carolina) as 12818 min/g(dry) and undulate winged grasshopper (Circotettix undulatus) as 16011 min/g(dry). I did not read the whole article, just skimmed it to find the result. The article also pulled these results from other sources, so there may be problems with different methodologies. --TeaDrinker 06:34, 3 November 2006 (UTC)

Depends on the length of the worm. Depends how well you chew the grasshopper.--Shantavira 08:15, 3 November 2006 (UTC)

Radiation

I was wondering how radiation could be reduced from nuclear style rockets such as the Salt Water Nuclear Rocket? Thanks For Any Help 68.120.69.231 06:34, 3 November 2006 (UTC)

abortion

hey guys?need serious help.my chick got an abortion..shiz 18.two dayz after the abortion she was still feeling pain.took her bak to the doc n was told there was some blood in her uterus.she was cleaned again.now she hasnt yet had her periods.when are they suppose to resume?