Wikipedia:Reference desk/Archives/Science/2006 December 8

= December 8 =

B Cell Activation
Certain details I find confusing in this area. B Cell activation (signals): 1. BcR/antigen binding 2. co-stimulation by Th2 (cytokine secretion)

So, where does CD40/CD40L interaction fit within the scheme of things? I think that this is during the germinal centre reactions (produce isotype-switching Abs), but am not sure. Appreciate any help. Omalé 04:42, 8 December 2006 (UTC)

Musical dyslexia
Does it exist?--Light current 02:23, 8 December 2006 (UTC)


 * Dyslexia means difficulty in reading and writing, not music. Or did you mean whether there's people who have a normal intelligence but can't learn music?  If so, of course there's people like that.  I'm one example.  --Bowlhover 03:16, 8 December 2006 (UTC)


 * No its people who can read music but get the notes in the wrong order or cant read a certain pattern of notes!--Light current 03:17, 8 December 2006 (UTC)


 * tone deafness? I myself am dysnumeric. Adambrowne666 10:02, 8 December 2006 (UTC)


 * There is a form of auditory learning disability that has a strong musical component for sufferers. The typical elements of this form of disability include being unable to take notes from verbal communication, having difficulty conversing via phone or IM, difficulty maintaining focus in environments with multiple sound sources, difficulty multi-tasking, misreading emotional cues etc. The musical elements include the inability to differentiate where different pitches occur in the scale in relation to each other (for instance, they can tell when they are singing off pitch, but they can't tell whether they are sharp or flat), inability to learn to sight-sing, inability to learn to read rhythms, and great difficulty clapping contrapuntal rhythms while singing. There's an article on it here on WP, but I have a horrible migraine and am too lazy to look for it right now. Anchoress 10:21, 8 December 2006 (UTC)


 * Dyslexia itself is a specific difficulty with processing written language. It should not affect musical aptitude or the ability to read musical notation, as musical notation is highly structured and logical. Indeed, dyslexia itself has a language-dependent componet - our article says "some studies have concluded that speakers of languages whose orthography has a strong correspondence between letter and sound (e.g. Korean, Italian and Spanish) suffer less from effects of dyslexia than speakers of languages where the letter is less closely linked to the sound (e.g. English and French)". However, there are other conditions such as asfedia which might be inaccurately diagnosed as dyslexia and which will affect the ability to read music. Gandalf61 11:15, 8 December 2006 (UTC)


 * As a composer and performer, I can tell you without a doubt that I have seen and experienced this with both performing music and writing music. It has also been documented that Beethoven periodically had this problem - though now I cannot remember the source.  (Maybe one of Maynard Solomon's book?)  If you look through his existing sketches of the development section of the first movement of his 3rd symphony, it's clear as day.  Shostakovich also had this problem periodically in his early works.  Bernstein has had this problem in performance.  I heard a performance with the Chicago Symphony in which Pinchas Zuckerman had this problem with the Elgar Violin Concerto (or maybe he was just bored and not paying attention...entirely possible with that piece of music).  The real question, which was being address above, is whether of not this is technically dyslexia.  Maybe it would be called something else when it's regarding music.  Ironically, I have not experienced dyslexia in written or spoken language before...it has only occurred with me regarding music.  Hope that helps.  :D Coolsnak3 20:13, 8 December 2006 (UTC)

Wiki Article 'Antibody' - Activation of complement
Quote: "....initiate activation of the "classical" complement system..." It goes on to say that opsonisation or membrane attack complex (cytolysis) can occur.

Shouldn't it be the activation of the Alternate (pathogen-binding) because cytolysis can not occur for a protein antigen? Omalé 04:42, 8 December 2006 (UTC)

Did you find Antibody-dependent cellular cytotoxicity? A fairly recent article that talks about ADCC is Complement-mediated mechanisms in anti-GD2 monoclonal antibody therapy of murine metastatic cancer. --JWSchmidt 22:54, 8 December 2006 (UTC)

Black hole mystery
I have gone through many books where they say that due to the excessive gravitation of black hole nothing can come out not even light from a black whole.my question is where do they go inside a black hole?And if black hole attracts things inside it will it be saturated one day?203.145.188.131 07:40, 8 December 2006 (UTC)Arjun ghosh


 * I hope the "they" who go inside a black hole are not the same "they" who say that nothing can come out. A black hole can be entered from any direction. It is never saturated; as more stuff enters, the black hole just grows. Maybe you will find our article Black hole useful. --Lambiam Talk  07:48, 8 December 2006 (UTC)


 * There is something that can come out of black holes, see Hawking radiation. The micro black holes (made in a particle accelerator) evaporate in a fraction of a second, the star-sized black holes last much, much longer (longer than the current age of the Universe). Don't imagine the black hole as an empty box, sucking in matter and eventually becoming full. It is a singularity in space, where the whole structure of spacetime is totally different from what we can experience here on Earth. --V. Szabolcs 10:58, 8 December 2006 (UTC)


 * I thought a black hole was just a very very heavy very compressed thing - that has sufficient gravity to attract just about anything into it that goes near it. So anything that goes in will be compressed onto the 'black dot' in the middle. Does it actually have to be a singularity - couldn't it just be a very dense very heavy planet sized object? If so it would just continue to attract mass - maybe one day it would have sufficient gravity to compress the matter further..causing a phase change (super dense solid to supersuper dense solid), perhaps making a 'type 2 black hole'87.102.37.17 12:39, 8 December 2006 (UTC)


 * To the best of my knowledge, here's what a black hole is. In general relativity, the world is a four-dimensional place, having three space dimensions and one time dimension. Objects (people, atoms, planets, …) move about in this four-dimensional space according to certain mathematical rules (which are intended to represent the laws of physics). Now, if you have some piece of matter that is sufficiently dense, there is a region around it, out of which there are no paths that satisfy the rules. That is, if you find yourself in there, you won't get out without breaking the laws of physics (as we know them, of course). —Bromskloss 13:02, 8 December 2006 (UTC)

As far as I know, a black hole is not actually a hole (correct me if I am wrong) but it is a tiny piece of matter about the size of a pin-head, but with enough gravity to attract anything, including light, to it's surface. In other words, matter is just getting stuck to the outside of the 'hole'.Herbynator 20:56, 8 December 2006 (UTC)
 * Yes that what I though - no idea why it's often refered to as a singularity - maybe someone could explain.87.102.37.17 21:35, 8 December 2006 (UTC)


 * So in theory, it's not "the size of a pin-head", but actually has zero size, a true mathematical point. It's a "singularity" because space is not a smooth manifold there -- it's like a place where space turns a corner, rather than following a curve. Matter doesn't get "stuck to the outside" -- the "outside" means outside the event horizon, which can be any distance from the singularity itself. Nothing prevents matter from crossing the event horizon (though it takes infinitely long, in the frame of an outside observer, for this to happen). --Trovatore 21:39, 8 December 2006 (UTC)

Couple of minor corrections and clarifications:

Matter as we know it, exists because forces such as the electromagnetic force and others keep the subatomic particles apart. As the particles get closer this force bvery strongly keeps them apart, otherwise they would be pulled together by gravity. But if there is enough matter in a small enough space, gravity ends up winning, and the matter collapses - electrons cannot stay distant from the atomic nucleus, and so incredibly dense matter forms, and then even this cannot maintain its structure and collapses into itself further. In a way that is hard for people to imagine, nothing can stop this collapse if enough matter gets into a small enough space, and the matter collapses literally to a point. Not a pinhead size, or any size, but a literal point, zero wide, zero high, zero deep. We cannot imagine such a thing, but physics says that is what happens, and that is a black hole, matter that is so dense it is no longer "matter" in any real sense, but some kind of singularity (or anomaly) in space. Anything that gets too close will also collapse with it the same way, whether matter or energy, even light itself, the fastest thing in the universe. That is why it's called a "black hole".

To the surprise of physicists, it was later found that energy can escape from black holes in a sneaky kind of way. In space, virtual particles are continually coming into existance and vanishing on a microscopic scale so small they cannot easily be detected. That's a consequence of quantum physics and only works on a tiny (subatomic) scale. Usually these particles appear in pairs, and vanish billionths of a second later again so they don't get noticed. But near the very edge of a black hole, the event horizon, even in that billionth of a second, the gravity is so intense the two particles get pulled apart. One may be absorbed into the black hole, the other escapes. From our perspective all we see is the second of these, so it looks like energy is being created. In fact this is energy that escapes from the black hole, and in this was paradoxically a black hole can "evaporate". FT2 (Talk 04:55, 9 December 2006 (UTC)


 * Very good explanation. Thank you!  192.168.1.1 12:35pm, 9 December 2006 (PST)


 * Wow, was this previous message (192.168.1.1) written from a Wikipedia server? :) -- 127.0.0.1 23:38, 9 December 2006 (UTC)

Odd nausea
I know, not supposed to ask for medical advice here - but it's not major, and I promise I won't sue :P

Ever since a few years ago, I've had extreme nausea when drinking liquid (not alcohol, water, juice, hot drinks, anything). It was most major about a year ago, when about 40-50% of the time I drank more than about 1/3rd of a cup of water at a time, I would get this feeling in the pit of my stomach. I don't throw up anymore, but it used to be so bad I did. It is intense, lasts about 15-30 seconds, and then fades away. It still happens (once in a while), and I'm still puzzled as why. Does anyone have any suggestions on whether this matches any known, for lack of a better word, disorder? I could see it being something like just drinking too fast, but this happens even when I'm drinking from a drinking fountain, etc. --Wo o ty Woot? contribs 07:54, 8 December 2006 (UTC)


 * Well, what did your doctor tell you, and why do you doubt his diagnosis? And if you haven't consulted a physician, why not?   TenOfAllTrades(talk) 16:02, 8 December 2006 (UTC)


 * My doctor just told me to keep a record of it happening, which makes no sense because it's situation dependent. I was asking not for advice but whether this matches anything anyone's heard of. If it doesn't, I'll just continue on my merry way; if it does, then I can research it more. --Wo o ty Woot? contribs 20:03, 8 December 2006 (UTC)


 * The problem is that it could be any of a very large number of things. Some are scary, some are not, many are treatable, some you have to live with, some amount to 'it's all in your head'.  We can't diagnose you here with the information you've provided&mdash;and even if there was enough information, we'd still tell you to see a professional.  If you're concerned, stand up for yourself the next time you see your doctor.  Lay out your concerns; tell him that you're very worried about this, or that it's affecting your quality of life (be honest about these).  A referral to an appropriate specialist may be required (perhaps a gastroenterologist).  If you're unhappy with the care that your personal physician is providing, seek another&mdash;you need to be able to trust your doctor.  TenOfAllTrades(talk) 17:30, 9 December 2006 (UTC)

The history of constants
Have constants (mathematical and physical) always been called constants? Did ancient scholars call pi a constant, or did they use another term? And while I have your attention, can anyone tell me when the term 'constant' first came into use in this context? Thanks Adambrowne666 10:00, 8 December 2006 (UTC)


 * Because "constant" is an English word introduced in the Middle English period, likely from the French "constare", it is highly unlikely that ancient scholars used that specific word. But, they would have probably used something of similar meaning because the drive behind much of what predated math and physics was to find the rules about the Universe that do not change - the constants.  I'm sure they came up with a lot of "constants" that were later found to be less constant than the discoverer hoped - such as the year being 365 days long. --Kainaw (talk) 13:53, 8 December 2006 (UTC)


 * Looking at the word "constant", rather than the concept of a constant, the earliest use in the mathematical sense referenced in the Oxford English Dictionary is from 1753, in a supplement to Cyclopædia; or, an universal dictionary of arts and sciences by Ephraim Chambers, which is quoted as saying "The semi-diameter of a circle is a constant quantity; for while the absciss and semi-ordinates increase, it remains the same." The earliest use of the word to simiply mean unchanging given in OED is from Chaucer's Clerk's Tale in 1386: "She ay sad and constant as a wal, Continuynge euere hire Innocence oueral."  The word itself comes, via French, from the Latin constans. -- AJR | Talk 14:30, 8 December 2006 (UTC)


 * Wonderful answers, thank you. So can I ask, given that the idea of constants was around before we started calling them such, how were they were referred to before 1753? Adambrowne666 00:55, 9 December 2006 (UTC)


 * I'm not saying that they weren't called constants before 1753, merely that the earliest documented use found by the OED's editors is from then. Presumably readers of Chambers' work would have known what he meant, suggesting that the word was in use in the mathematical sense by then.  Also, at that time (and earlier) most scholarly writing would have been in Latin, so people wouldn't really have been writing much about maths or science in English.  Our article  about Chambers' Cyclopædia says that there wasn't much like it written in English at the time -- AJR | Talk 02:13, 9 December 2006 (UTC)


 * Thanks again - so, another question: can anyone tell me what the Latin term that was used to describe constants before the English word 'constant' came into use? I realise I might be asking a bit much here... Adambrowne666 08:43, 10 December 2006 (UTC)

Medical practice in France 1820
What advances were being made in France in medical practice around the 1820's? What would have been the hot topics of medical science development around that time ?

213.38.76.170 10:59, 8 December 2006 (UTC)Jonathan Choat [[Category:]]Medical history
 * Timeline of medicine and medical technology gives "1816 - Rene Laennec invents the stethoscope". Also perhaps anaesthesia being investigated around that time. Rmhermen 15:54, 8 December 2006 (UTC)

Must I really use "alkaline cells LR6"
I have recently had installed a central heating control installed which takes two "AA" batteries. The instructions for the batteries say "Use only new similar type alkaline cells LR6", and it says it in bold no less. Now, I currently have some rechargeable NiMH batteries in there. Does it matter? What is the reason they would insist on alkaline? Is there a good scientific reason why I should not use my rechargeable batteries? Thanks! Rugops 11:17, 8 December 2006 (UTC)


 * The difference is the voltage:
 * Nickel metal hydride battery 1.2V *
 * Alkaline battery 1.523V
 * Most of the electrical devices have no problem, some might have.--Stone 11:29, 8 December 2006 (UTC)


 * I think that another reason some devices make this requesst is that NiMH and especially NiCd cells can deliver a much higher short circuit current than your typical alkaline primary battery. So if the device failed in certain ways, it might catch fire when loaded with rechargeable batteries whereas it might not burn when loaded with primary batteries.


 * But I'd agree that the lower voltage of rechargeables (when lightly loaded) is probably the principal reason for the request.


 * Atlant 13:06, 8 December 2006 (UTC)

Use alkalines for low-drain applications, such as clocks and thermostats. The NiMH batteries self-discharge, and can become useless in a couple of months. --Zeizmic 14:37, 8 December 2006 (UTC)
 * I echo Zeismic's opinion. If you are going to use rechargables, work out a time-based replacement schedule, to try to avoid having inconveniently dead cells. Just testing the voltage regularly is not very helpful, since NiMHs go from good to nil quite quickly. -- Seejyb 15:09, 8 December 2006 (UTC)


 * Right the regulation of the heating is long term application and with a rechargable you have more maintainace to do than with a alkaline.--Stone 15:23, 8 December 2006 (UTC)

Criminology
Which of the theories of decision-making within the policy making process is the most persuasive? —The preceding unsigned comment was added by 161.112.232.36 (talk • contribs).


 * First of all, If you want somewhere to start, you might want to explain a little more of what the question is asking! Give it a little context. What do you know so far, that kind of thing. We want to help, but like I said, we can't do it all for you! One more thing, what does this have to do with science in the first place? :-)   Laur  ə  n whisper 14:54, 8 December 2006 (UTC)

Medicine
I've wondered this for quite some time, and being a chemistry major, I may learn it in future classes, but how can drugs of similar structure sometimes do the same thing, while other times do something quite different. For example, the structures of pseudophedrine and phenylephrine are similar, give or take a methyl and a phenol, while methamphetamine, similar to both, and made from one, affects the body in very different ways, yet again, with small variations in structure. Can anyone suggest some good readings on drug synthesis and design? --Russoc4 15:21, 8 December 2006 (UTC)

Phenylephrine Pseudophedrine Methamphetamine


 * The "lock and key" model of enzyme activity states the specific side chains of the substrate are one of the main factors in deciding what works with what enzyme; the enzyme controled by methamphetamine is the wrong shape for the extra OH group on pseudophedrine, so it is only activated by meth. Likewise, the enzyme that is activated by Phenylephrine needs two OH groups, which is not provided by the Pseudophedrine or meth. For the further reading, try the books referenced by Drug discovery. La  ï  ka  17:12, 8 December 2006 (UTC)

Yes the 'lock and key' mechanism seems to work here - on 'neurotransmitters' as well as enzymes. For 'psychoactive drugs' ie drugs that have an effect on the brain the phenylethylamine backbone seems to be key (or more specifically a aromatic ring connected to a nitrogen with two carbons in between).It's found in a lot of illegal drugs, including LSD, all the amphetamines and ecstacy derivatives, mescaline, ephedrine (which is a stimulant), the trptamines and is supposed to be one of the active ingrediants in chocolate. Actually amphetamines aren't that different from phenylephrine/pseudoephedrine (but it is more dangerous) It is good for asmtha - and pseudoephedrine is a stimulant too if you take enough. Suggest reading phenylethylamine for more info on this class of compounds. The natural equivalents are dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline), it's the adrenaline like properties that aid breathing in astmatics and dopamine is a neurotransmitter - hence the stimulant properties.
 * So it's as simple as not having the OHs? Interesting. Any thought on what the Nitrogen is for, in these cases? --Russoc4 17:21, 8 December 2006 (UTC)


 * (edit conflict) It's a very good question, and gets to the heart of drug design and medicinal chemistry. "Give or take a methyl and a phenol" is actually perhaps quite critical. As you know from chemistry class, reactions are quite localized and specific, and subtle differences in sterics and elecrtonics of a molecule can have a large effect on their reactivity. What matters isn't just the overall general shape of the molecule but each functional group's presence or absence, and the position of one relative to another. I don't know most of the pathways involved in these particular molecules, but consider if the increased polarity of an added phenol makes phenylephrine less reactive in "whatever reaction is responsible for its biological activity" or makes it more reactive in "some other reaction, thereby consuming it before it can do the desired biologically active function". Maybe methamphetamine, being much less polar and having a sterically less hindered nitrogen, is a better fit for the binding pocket on some receptor than the others and is a poorer fit in some other receptor. DMacks 17:22, 8 December 2006 (UTC)


 * Interesting stuff. I bring this up partly because our last lab involved using combinatorial chemistry to test different hydrazones for their antibacterial properties against E. Coli. The one that worked best was derived from 5-nitro-2-furaldehyde and aminoguanidine bicarbonate. We asked our professor what the structure had to do with it's properties and she honestly told us "I don't know, I'm not a biologist." Any idea what's special about the compound? --Russoc4 20:14, 8 December 2006 (UTC)




 * That's an almost impossible question based on the info we/you have available, but it is a good kind of question to ask:) On the literature side, one would look for structurally similar compounds that have similar effects and that have different effects, and try to figure out what feature(s) correlate with that activity (QSAR). On the practical side, what does "antibacterial properties" really mean...kill vs slow growth, kill by DNA cleavage vs cell membrane leakage vs whatever else, /cell produce some recognizeable effect other than "colonies no longer proliferate", etc. That would give a clue about how (in a chemical/biochemical sense) is really works. One could tag the molecules with a certain isotope and try to see where it goes and what it binds (does it go to the nucleus vs attach to the cell surface vs whatever else? Make a library of related compounds and do your own QSAR analysis. DMacks 20:32, 8 December 2006 (UTC)
 * All I could say is that it prevented the growth of an E. Coli culture. A second compound made from the same furaldehyde, but a different hydrazine prevented some growth. Other than that, there's no other information I can give. Again, the point was to practice combinatorial chemistry, and to go ahead and start building and testing more compounds is a little out of our league, for now. Still, it's always good to know these things. --Russoc4 20:49, 8 December 2006 (UTC)

Apollo moon landing hoax theory
My younger brother (he's 18) saw some documentary on TV, and now believes that the Apollo moon landing was a hoax. I don't have any scientific background, and when I try to argue with him my arguments amount to "It seems unlikely!" Can you think of any good, simple argument against the hoax theory that doesn't require me to become an expert on the moon landings? My brother is very smart, but easily swayed by appealing ideas. --70.112.100.172 16:46, 8 December 2006 (UTC)


 * I find that Occam's Razor usually cuts any conspiracy theory to shreds. That's the single most useful principle of logic in demolishing nutty ideas. You'd have to invent too many improbable circumstances, i.e. "extra entities" to explain the moon landings as a hoax:  hundreds of people who keep quiet, other hundreds who pretend to have done something they really didn't, and who never ever tell, and so forth.  Does he also believe that the Mars mission, Titan mission, space shuttle, satellites, and other technologies are hoaxes?  Antandrus  (talk) 16:53, 8 December 2006 (UTC)


 * It was during the cold war. Russia would have had great joy in proclaiming it a fake should it have been one. They would have had scientists analysing the footage. The fact that they didn't state it was a fake suggests that it wasn't a fake. Readro 17:09, 8 December 2006 (UTC)


 * You could try http://www.clavius.org/. Also moon hoax. I find that the most compelling argument is the enormous number of people involved. Either none of them have opened their mouths to give away the hoax (hard to believe), or they didn't know. If that's the case, then they were building hardware which was supposed to go to the moon. So why not just send it to the moon? Also there's the fact that the Soviets could listen in on the communications and track the spacecraft, so they would have blown the lid immediately if it were not true. - anonymous6494 17:15, 8 December 2006 (UTC)


 * Our article Apollo Moon Landing hoax accusations has much of the discussion.  howch e  ng   {chat} 18:19, 8 December 2006 (UTC)


 * Mars orbiters can now see the Rovers on the surface of Mars. If there were Moon orbiters with similar optics, shouldn't they be able to see the equipment left at the Apollo landing sites, like the vehicles and the landing stages? If it were an internationally controlled orbiter and could see the landing sites and vehicle tracks as shown in the 1960's and 1970's that might help dispel doubts. And the Soviets could at the time track the Apollo capsules all the way from the earth to the moon and back and could tell relative velocity by the slight doppler shift in frequency. They would have shouted to the housetops that it was a fake if anything suggested a hoax. Edison 18:24, 8 December 2006 (UTC)


 * The Lunar Orbiters did not have similar optics but rather imagers that were far inferior to those found on Mars Global Surveyor or the new Mars Reconnaissance Orbiter. I beleive MRO was the first spacecraft to capture an image of a man-made object on the surface of another satellite or planet.--Nebular110 20:11, 8 December 2006 (UTC)


 * Another requirement of the Apollo Hoax Theory is that, somehow, NASA put things on the Moon without going there. List of artificial objects on the Moon shows the coordinates of all of the Apollo mission artifacts left behind.  They are visible from Earth - no need for a Moon orbiter.  So, since they can be seen sitting there on the surface of the Moon, how did they get there if there wasn't a launch?  Some theories go so far as to claim that everyone who has taken a photo of the moon's surface through a telescope is "in" on the hoax and photoshopping the artifacts in. --Kainaw (talk) 18:33, 8 December 2006 (UTC)


 * No artificial object on the moon is visible from Earth. -anonymous6494 20:00, 8 December 2006 (UTC)
 * Correct, the smallest features you can see on the Moon from Earth using average ground-based telescopes are roughly 0.25 miles in diameter. -Nebular110 20:06, 8 December 2006 (UTC)


 * The arguments for the hoax are too simple. "There are no stars visible in the background." WOW, what a discovery! for more than 40 years nobody has noticed this, but now a simple average person suddenly discovers the "truth", that there are no stars on the pictures, so the whole thing must be fake. This can be said for most of the arguments. They are so simple that any TV-viewer can understand it in a second, and slap on his forehead that he understands everything, and he won't bother to think about the counter-arguments. Surely millions and millions of people must be in the conspiracy just to fool him. --V. Szabolcs 20:23, 8 December 2006 (UTC)


 * Aha! That's the solution!  Just fight conspiracy with conspiracy.  Talk to your brother; focus on Fox News and its CONSPIRACY to make the US moon landings look like a hoax!


 * After all, if the Fox TV program wasn't true, it could only get on TV if Fox Inc. was intentionally trying to fool people.  Or perhaps their intent was much darker, and there is a CONSPIRACY between the current political party and Fox television.  To get something dishonest and misleading onto national TV, lots of people would need paying off, right?  And isn't the Apollo Hoax "documentary" a perfect piece of disinformation?  They didn't even have to do any work.  The Fox TV hoax just involves accusing someone else of being a hoaxer.  Slap on some faked pictures which make stupid people think that the moon landings weren't real.  Very Republican, very Neocon, eh?  Yes, that's right, the Moon Hoax Theory is obviously an element in the vast right-wing conspiracy to destroy the American way of life.  :)  --Wjbeaty 20:40, 8 December 2006 (UTC)


 * Science fiction writer Arthur C. Clarke noted the relative brightness of the starts versus the lunar surface and the absence of stars when the lens is stopped down for correct exposure of the bright lunar surface long before the first lunar landing, so I was aware of that notion before the landing, and I assume NASA was too. As for seeing thins left on the moon from earth based telescopes, corner reflectors were left on the moon during some Apollo missions, and the reflections of earth-based lasers from them could immediately be detected from earth based telescopes at observatories in various countries as soon as the astronauts ssaid they had deployed them. It would have been necessary to deploy them by a robotic mission to make them part of the hoax, just like it would have ben necessary to have a remote control tape recorder on board an unmanned spacecraft which orbited and landed on the moon, to fool earth based radiotelescopes, with carefully scripted conversations between mission control and the tape recorder. Not easy on either count with 1969 technology. Edison 22:31, 8 December 2006 (UTC)


 * Is there any solid evidence (a tape, for example) that proves the Soviet Union tracked the Apollo spacecraft? The article apollo moon landing hoax accusations seems to suggest there isn't.  --Bowlhover 03:44, 9 December 2006 (UTC)


 * The Soviets were in direct competition with the U.S. for the prestige of moon exploration. They had a robotic moon lander which could theoretically land and bring back a sample. They had to have radiotelescopes/antenna arrays capable of operating their own moon lander, so it is implausible they would not have tracked Apollo to derive technical data or to detect any failure of the U.S. program, such as death or illness of astronauts, should it happen and the U.S. try to conceal it. This is further born out by the ubiquitous presence of Soviet "trawlers" near every U.S. missile test, laden with antennas to monitor every transmission. The British also tracked Apollo from their radiotelescopes, and they were not exactly U.S lapdogs in the 1960's. It is like the Sherlock Holmes case of the dog that did not bark in the night: if it were a hoax, the Soviets would have spilled the beans. Edison 17:45, 9 December 2006 (UTC)

Two words: Moon rocks. Also point out how utterly stupid most conspiracy theories are and point out how he has joined their ranks. People beieve the earth is flat. They believe that the World Trade Center was caused by star wars laser weapons from space. They believe Kennedy was killed by rabid space aliens. Some even believe that NATO conspired with mobsters and allied themselve with Al Qeada. Some of those theories are vigorously defended by whackos to the point that they are overrepresented in Wikipedia as fact. --Tbeatty 05:06, 9 December 2006 (UTC)


 * also Moon rock has been analysed and is a unique substance due to "shocked quartz" if i remember correctly and so it cannot be made on earth —The preceding unsigned comment was added by 84.70.15.136 (talk) 11:17, 9 December 2006 (UTC).


 * Curious straw poll: Do any of the non-US contributors here know of anyone outside the US who believes the landing was a fake? VirogIt's notmy fault! 11:23, 9 December 2006 (UTC)
 * Yeah, quite disturbingly one of my high-school chemistry teachers believed the moon landing was fake, and kept a portion of one wall of his classroom covered with a display of "proof" that this was the case (this being in England). I also had a biology teacher who didn't believe in human evolution (though she still taught it as fact), and a religious education teacher who was forced by the curriculum to mostly focus on Christian viewpoints, despite being Bahá'í. Thinking about it, my school was probably kinda weird. GeeJo (t)⁄(c) &bull; 19:57, 9 December 2006 (UTC)


 * Another counter-conspiracy argument nobody has mentioned: as at the beginning of the 20th century not even aircrafts could be made, and in the '50s and '60s there were nukes, artificial satellites, faster-than-sound aircrafts and spacecrafts, the majority of the scientific community thought that space exploration will continue to develop in this manner, and by 2000 there would be hundreds of space stations and cities on the Moon, Mars, etc. Look at all the sci-fi novels of the 1970s predicting space travel (or even intergalactic travel) in 2000. Would anybody at the NASA be such a fool to make a fake landing with the fear that in a few years or decades space travel will be common, and everybody will find out the lies? --V. Szabolcs 15:54, 9 December 2006 (UTC)

Astronomers around the world could track what was going on, and geologists from around the world have examined the moon rocks. They can't all be in on the conspiracy... or can they? —Pengo talk · contribs 23:30, 10 December 2006 (UTC)

reaction of ammonium sulphate with sodium hydroxide.
Dear Sir/Madame, Could you please give a chemical equation for the reaction of ammonium sulphate with sodium hydroxide (in which ammonia gas is evolved)

-Sruthi —The preceding unsigned comment was added by 59.93.87.216 (talk) 17:10, 8 December 2006 (UTC).


 * Yes, this makes Sodium Sulfate and Ammonium Hydroxide, when then decomposes. From that you can finish your homework yourself.


 * Try ammonium sulfate, sodium hydroxide, sodium sulfate, ammonium hydroxide, and stoichiometry--Russoc4 20:17, 8 December 2006 (UTC)

Dark Matter
Just exactly is Dark Matter? Where does it come from? And how much of the Universe (approximately) is made up by it?Herbynator 21:01, 8 December 2006 (UTC)
 * See Dark matter. Friday (talk) 21:02, 8 December 2006 (UTC)