Wikipedia:Reference desk/Archives/Science/2007 May 8

= May 8 =

Latest vaccines
How exactly does O157 work and what is polysaccharide? —The preceding unsigned comment was added by Sharvanir (talk • contribs) 05:28, 8 May 2007 (UTC).


 * Do you want to know how the vaccine works or how Escherichia coli O157:H7 works? A polysaccharide is a macromolecule constructed as a chain of sugar monomers.  If you want to know how E-coli "works" look at the link I provided.  A vaccine for it would work as most all vaccines do, artificially stimulating an immune response to an antigen naturally present on E-coli, resulting in the human body producing antibodies for it (as well as the various white blood cells that respond specifically to that antigen).  This all results in resistance to the actual bacteria if you're infected, as the body responds more swiftly and more strongly to bugs it has seen before (or thinks it has seen, at least).  I'm not sure what the exact mode of action is for the proposed O157 vaccines.  For more information look at Immune system, as well as Immunity (medical) for a thorough look at it.  Someguy1221 05:52, 8 May 2007 (UTC)
 * Oh, and as for any possible connection between the two items you asked about, the antigen the body develops an immune response to is often a polysaccharide, or more specifically an oligosaccharide, although I don't know if that's the case with O157 or any of its proposed vaccines. Someguy1221 06:05, 8 May 2007 (UTC)

Need help with a citation regarding fitness
I'm looking for something to back up a stat I read in a running magazine about 10 years ago: that the optimal VO2 max improvements happen after 35 minutes of target rate exercise. I don't know if I'm just searching with the wrong search terms; the Wikipedia Google Queen needs a fair knight to rescue her. Thanks in advance. Anchoress 06:22, 8 May 2007 (UTC)
 * Did you see Training effect? I always thought that the greatest improvement came when the system was just at the edge of anaerobic excercise.  I think it might take 35 minutes of typical excercise (i.e. 75% of capacity) to reach the anaerobic threshold but I htink that would vary by individual?  Lance Armstrong isn't going to improve Vo2 max with just 35 minutes of excercise.  Just a guess though.  Might want to search "anaerobic VO2" for extra hits. Also, check on how long glycogen remains in the blood stream.  it can provide oxygen for metabolism.  it's lifetime in the blood may change how effective excecise is.  again, this is a subjective guess.  --Tbeatty 06:42, 8 May 2007 (UTC)


 * "glycogen vo2max" http://www.coolrunning.com/major/97/training/hampson.html not sure it has everything you need. --Tbeatty 06:48, 8 May 2007 (UTC)
 * Yeah thanks a lot, but I'm really not looking for anything that complex and subtle. For my current purpose (although the link you provided was very interesting and your other points were good too), I'm not going to be getting into anaerobic thresholds or glycogen; I'm really just interested in that particular point, if it exists somewhere on the web. It doesn't need to be a complex stat, and it doesn't have to relate to running. And this is for recreational fitness, absolutely not for hardcore competitive training stuff. But I DO appreciate the info and the links, tho. Anchoress 07:11, 8 May 2007 (UTC)

Iron (III) iodide
Why doen't thuis species exist together with iron (III) carbonate? Are there any other reasons except for steric hindrance?Bastard Soap 11:12, 8 May 2007 (UTC)

The ferric ion oxidises the iodide to iodine so that you end up with FeI2 and I2. It would not be due to steric hindrance. For ferric carbonate, carbon dioxide would be given off. GB 11:37, 8 May 2007 (UTC)

Redoxreactions happen if you combine Fe(III) which has the potential to oxidize other compounds with iodide wich has the potential to reduce other compounds. If you look at the redox potential you get out that a reaction is possible and exothermic and therfore it starts. The carbonate is a problem of Mass action law. The carbonate is in equilibrium with carbon dioxide over carbonic acid and if the equilibrium is shifted towards the acid the carbondioxide gets lost and you end up with a iron hydroxy carbonate.Stone 14:35, 8 May 2007 (UTC)

So for the carbonate it's something like this: [Fe(H20)6]3+ CO3   > [Fe(H2O)5(OH)] O + CO2 It's an acid base reaction not a redox right?Bastard Soap 15:35, 8 May 2007 (UTC)


 * Carbonate is CO32-, and needs to combine with 2 H+ in order to become carbonic-acid/carbon-dioxide. If you use H2O as the source of H+, you get OH- as a byproduct. Carbonate (or indeed any base) in water generates hydroxide. DMacks 18:28, 8 May 2007 (UTC)

Equations For A Gas Undergoing Adiabatic Process As it Obeys Van Der Waals Equation
I saw about the  equations for an ideal fluid(or gas) undergoing an adiabatic process  viz p(v g)=constant,   T(V(g-1)) =constant and T(P(1-g)/g)= constant  where g=specific heat for constant pressure/specific heat for constant volume.ref:[]. I also saw about the derivation of van der waals equation ref: [] According to which the van der Waals equation was devised based on a modification of the ideal gas law. The equation approximates the behavior of real fluids, taking into account the nonzero size of molecules and the attraction between them. The van der waals equation is $$(p+a/v^2)(v-b)=kT$$. Are there equations for gas(or fluid) undergoing an adiabatic process if this van der waals more exact equation is taken into account? How to derive and solve them?. I searched web pages and didn't find any. Thank you 121.247.80.107 12:09, 8 May 2007 (UTC)


 * See van der Waals equation. Adiabatic process of the kind you are looking for is the process in which S=const and N=const. It is referred to, speaking more strictly, as an isentropic process with a fixed number of particles. Hope this helps. Dr_Dima.

What The Bleep Do We Know?
In the film What The Bleep Do We Know?, is it true that nothing touches another? What is your opinion of Masaru Emoto theory? Do our thoughts travel forever? If it does, please explain in layman's terms what that means...... —The preceding unsigned comment was added by Juliet5935 (talk • contribs) 13:02, 8 May 2007 (UTC).


 * What the bleep?think that whole touching thing has to do with the atoms electrons and stuff Maverick423 Says Im in ur science steeling ur gravities 13:42, 8 May 2007 (UTC)

There's an article on What the Bleep Do We Know!? in Wiki, in case you wondered. Dr_Dima.


 * Let's take these one at a time:
 * Things touching: Well, at the level of atoms - the idea of 'touching' is a bit vague. The atom has a teeny-tiny neucleus and almost all of its "size" comes from a cloud of electrons - which themselves are not hard little points but fuzzy probability clouds. When two surfaces come close - the atoms start to repel each other - and this repulsive force is what stops the electron clouds of the atoms from overlapping. So in a sense, yes, nothing really touches anything else - but in another sense, the whole meaning of the word "touch" is kinda meaningless in a world where everything is made of fuzzy probability clouds.
 * Masaru Emoto: Nut job. A very simple double-blind experiment would certainly prove him wrong.
 * Do thoughts travel forever? Well, a thought is a series of electromagnetic pulses going through your neurons - electromagnetic waves travel outwards as photons - and whilst most of them are absorbed by your skull, skin, etc - some will probably shoot outwards into space...I guess some very tiny part of our brain waves travel "forever". But I'm sure that's not what was being suggested wherever you read that...asking: Does the impact of our thoughts last forever? Perhaps that's closer to the true issue here - and again the answer is a very cautious "Yes" - chaos theory says that a butterfly flapping it's wings in China can cause a Tornado in Texas 10 years later, everything is tangled up with everything else and the effect of a single thought is just as likely to cause some nearly random macroscopic event to happen a million years from now. But lest we get too self-important - the future effect of a small, irrelevent, unexpressed thought is likely to have a similar impact to shedding a skin cell and a vastly smaller effect compared to taking a really good shit. Let's not get too existentialist about these simple physical processes!
 * SteveBaker 13:49, 8 May 2007 (UTC)


 * Something it seems like some people just can't get over is that human thought, nor emotion directly affects reality. Only our physical actions can change the reality we know around us. This is what physics is about. To respond to SteveBaker's comments, I second him on 1 and 2. On 3, wave and field interference would pretty much eliminate any electromagnetic wave produced by, for instance, a synapse. As for taking a really good shit, well, I love how informal we are on the Desk here :) [' Mac Δαvιs '] ❖ 16:36, 8 May 2007 (UTC)

masaru emoto claims that ice crystals change shape if you are nice to them. But how do they know what is nice? And wouldn't it be much easier to just force them into nice patterns?


 * Indeed. It would be so easy to double-blind that experiment, and yet I can find no mention of a double-blind experiment that shows this result. For all the horrendous science though, the moment I actually walked out of the cinema was when they seemed to be suggesting that the woman could choose not to be deaf. Hey! It's all your fault! O_o Skittle 18:52, 8 May 2007 (UTC)
 * More than that - James Randi has offered the guy a cool million dollars if he can demonstrate this emotional water effect in a double-blind experiment. Surely he would not turn down such a deal if he was even remotely likely to pass it. SteveBaker 22:38, 8 May 2007 (UTC)
 * On the "touch" point, this is just another example of intuitive spatial metaphors not applying well at the atomic much less subatomic levels. If you had a rigorous definition of "touch" then yes, things touch. If you use an unrigorous definition then no, they don't, but all that really does is show why you need to be careful in defining such things if you want a common term to have meaning in a scientific context. --140.247.240.101 19:38, 8 May 2007 (UTC)
 * Exactly - but as is so often the case, this is just a problem of language and human perceptions - the underlying science is quite clear. SteveBaker 22:38, 8 May 2007 (UTC)
 * Emoto is not the nut job, JZ_Knight is the nut job! Vespine 23:03, 8 May 2007 (UTC)
 * Emoto is the nut job: "we have been wasting and ignoring [water]. If I was water, I think I would be mad too". Not the words of a scientist. Aaadddaaammm 02:28, 9 May 2007 (UTC)


 * I was part of a Jeung San Do meditation group (yes, chanting) a few years back. Its a very intriguing experience, and yes, even enlightening.  I can't say I did it for the precise spiritual reasons that the chant leaders would have wanted for me, but I did it because I did perceive to get some benefit and clarity of mind. It's interesting all the thought experiments you can do while chanting!


 * I do seem to remember all kinds of odd beliefs that made little sense if analyzed from what I would consider to be a scientific viewpoint, accounting for all known forces, properties of objects, etc. One of the beliefs was that chanting could change physical characteristics of water, ice, or crystalline structures.  (Of course, certain sounds may have some sort of effect if you hit an object's resonant frequency, but the belief system went far beyond that.)  ... Hmmm... upon my first glance at Masaru Emoto, they may have in fact been showing his particular book.  But, fact is, they ABSOLUTELY believed it, like there was little questioning of it, which I found a touch worrisome.


 * In terms of consistency, though, I think I can see why. They used chanting to cure all kinds of ailments, specific chants for specific things.  I never questioned, knowing they had a particular faith in it.  Chanting does something to the body, its a bit of a workout actually, so I could see that, say you had a headache, and you chanted for 20 minutes, your blood may become more oxygenated or somesuch, and the headache may "go away" because its become much less of a nuisance, or the possibly physical aspect that caused the pain has been nullified. Actively singing for a choir for 20-30 minutes may possibly do the same thing.


 * But the chant leaders, who where Korean, always seemed to extrapolate their beliefs much like, ah, its hard to describe. Imagine a world where the Scientific Method is not taught or has not been ingrained into people's minds.  They don't question it because they don't know how or why.  I didn't read the book. I wasn't really in the mood to read something my mind would quash as utter nonsense, so I don't know if he wrote the book as a quack would sell an elixir or if he actually believed it.


 * It might be right to call Masaru Emoto a nut job, but there seems to be a lot of people ready and willing to accept the nuttiness.


 * (random thoughts by Root4(one) 04:20, 9 May 2007 (UTC))

Can Stars in Foreign Galaxies Be Seen?
I read somewhere a long time ago that it was not possible to resolve individual stars located in galaxies other than the Milky Way (except in some cases when a star goes supernova). It is still the case today?--JLdesAlpins 15:50, 8 May 2007 (UTC)


 * No it is not the case today. In fact, it is not the case since at least 1925, see Andromeda Galaxy. Cheers, Dr_Dima.


 * Indeed, Looking at the galaxy article, it seems that Edwin Hubble was the first to resolve individual stars in a galaxy. Though Immanuel Kant had guessed that galaxies (then called nebulae) were groups of stars in the 1700s. -- Diletante 16:27, 8 May 2007 (UTC)

Are we mostly seeing stars in other galaxies?

 * When we look at a foreign galaxy, are we mostly seeing stars, or dust, or what? Thanks. --TotoBaggins 17:59, 8 May 2007 (UTC)


 * Could you please elaborate your question? We only see that which emits light. Dustclouds aren't as abundant in space as clouds of hydrogen, helium and whatnot in nebulae (where stars may be born). Still, these absorb light a lot, so the vast amount of what we see are stars. I have a feeling this doesn't quite answer your question. :) 81.93.102.185 18:49, 8 May 2007 (UTC)


 * Galaxy and Dark matter shed some light, if I may use that expression. -- Diletante
 * Generally, when you look at the night sky, almost everything you see are stars in our own galaxy. If you know what to look for, you might make out the smudge of a distant galaxy, Andromeda if you are in the north and LMC and SMC if you are in the south, but you need a decent dark sky to see them with the naked eye. The faint glow that you see there is the combined light of all the stars in that galaxy. Vespine 23:00, 8 May 2007 (UTC)


 * OK, thanks to you both. I guess I had always assumed that the bright bits of galaxies were all stars, but then had read that dust could be heated up by various gravitational actions, and then you have nifty things like accretion disks and relativistic jets, and so on, and I was less sure that the diffuse bright areas in galaxies were all stars.  Thanks for the answers.  The whole business never ceases to astound me; it's just mind-boggling how big it is.  --TotoBaggins 01:16, 9 May 2007 (UTC)
 * If you need any more evidence of that have a peek at Ultra Deep Field, if you haven't seen it already. This blew my mind completely. Vespine 04:45, 10 May 2007 (UTC)

Glass heating
Durring chemistry I was heating something in a test tube and after a while the blue bunsen flame turns yellowish and returns blue when you remove the test tube. Any body know why it does this?Bastard Soap 18:14, 8 May 2007 (UTC)
 * Perhaps you have effectively performed a flame test and proven that your test tube is made out of Soda-lime glass. DMacks 18:22, 8 May 2007 (UTC)
 * See Flame. It could also be the test tube interfering with the available oxygen flow and creating soot particles.  --Tbeatty 06:36, 9 May 2007 (UTC)

Tbeatty I think that's highly improbable, I wasn't blocking the bunsen burner hole besides it should take the necessary air from the air hole not from the hole of the flame.Bastard Soap 12:58, 9 May 2007 (UTC)


 * Isn't the entire visible flame the location where combustion takes place? Therefore, if you place the tube in the flame, you disrupt the mixture and create soot.  Soot is what makes it yellow. You only have to create a small amount of incompletely burned gas.  I think you can force a pot to do the same thing on a gas stove.  --Tbeatty 13:27, 9 May 2007 (UTC)
 * One interesting clue is that the color only appears "after a while" (thanks for being a bery careful observer, BS!). I would think that causing incomplete combustion would be more likely when the object is cool, i.e., right away, and become less of a factor as it got up to flame-temp. However, still could be the soot (observations of non-sodium-containing objects are good data points!) if the cool object keeps the soot from being hot enough to glow. DMacks 13:56, 9 May 2007 (UTC)

variable
what are the ttwo different types of variables in experiments. And why aren't they mentioned in the variable article?
 * Are you thinking of dependent and independent variables? As for the article, it discusses the use of variables in an experiment in the introduction, but if you'd like you can link the article I did somewhere in that sentence.  --Tardis 19:05, 8 May 2007 (UTC)
 * Variable does already have wiki links to the in/dependent variable article. I think what confued the OP is that the article says "causal models" instead of "experiment". -- Diletante 23:09, 8 May 2007 (UTC)

I've heard 'key variables' mentioned occasionally, is this what you want :) I suppose there must be a name for non-key variables, but I forget what :( Sorry :( HS7 19:17, 8 May 2007 (UTC)

really need science help
This is not homework. It is coursework. OK, so it's almost the same, but I am supposed to ask for help, look on the internet, read encyclopedias. So I am doing all three at the same time and coming here. And I need to finish it very soon. I need help for both biology and physics. I mostly just need a website where I can find information about βradiation and about starch. I have searched the internet and couldn't find anything, so I am hoping scientists who spend a lot of their time on the internet (you) will be able to point me in the right direction. Can you try to avoid telling me to do my own homework, or I will probably have to ask again in a different way. I suppose what I really want is a science website that can tell me a lot about these two subjects. Thanks in advance from your help (unless you don't help). The end. —The preceding unsigned comment was added by 172.142.10.221 (talk) 19:14, 8 May 2007 (UTC).


 * If you want to learn about a subject here on wikipedia, just look up its article, like Beta decay and starch, wikipedia is first and foremost an encyclopedia. If you have a specific question that is not answered by those articles you can post it here. -- Diletante 19:24, 8 May 2007 (UTC)

i also find that another good site is howstuffworks however this one is more focused on explaining something and might leave some stuff out. the articles here are very informitave and combining these two sites can hook you up with awsome material!Maverick423 Says Im in ur science steeling ur gravities 22:20, 8 May 2007 (UTC)

I think that helps, but one last thing, where can I find a list of isotopes that produce beta particles?
 * You want an isotope table. We have one here, and many more, with different kinds of information, are available online (although a few are not free).  Of course, here's a hint: normal beta decay turns a neutron into a proton, which changes the ratio of N to Z.  In most stable isotopes that ratio is somewhere between 1:1 and 3:2 (with the exceptions of protium, 0:1, and helium 3, 1:2).  So, which isotopes (that is, what ratios) would be likely to "benefit" from going to N-1:Z+1? --Tardis 13:17, 9 May 2007 (UTC)

Yes, but I only have a few days to do it in.

Cards
Apart from games, tricks and balancing them, what fun things are there that I can do with cards? Bear in mind that I have a very broad definition of what is fun. If nothing much comes up here, I will probably resort to sorting them into order, especially if someone can suggest an interesting order to sort them into, instead of the obvious way. HS7 19:41, 8 May 2007 (UTC)
 * Shuffling and probability are always good choices...start with them sorted by value (four-of-a-kind clusters) shuffle repeatedly, seeing how many pairs remain after each. DMacks 20:13, 8 May 2007 (UTC)
 * Chris Ferguson can slice a carrot in half from several feet with a card. Useful if you're ever attacked by unruly vegetables. Or you could practice origami. Clarityfiend 20:56, 8 May 2007 (UTC)
 * It all starts with an Angry Salad. DMacks 21:04, 8 May 2007 (UTC)
 * Yes card throwing is cool. -- Diletante 22:29, 8 May 2007 (UTC)
 * My journey into cards started with a double lift. If you have even a passing fancy with playing cards I highly recommend reading a book, like "The Expert at the Card Table" by Erdnase, one of the seminal texts on card magic. Vespine 22:43, 8 May 2007 (UTC)


 * Encryption! The Solitaire (cipher) - as used in the (most excellent) Neil Stephenson book Cryptonomicon.  Building a house of cards of course (well - I guess that's 'balancing' them). SteveBaker 01:11, 9 May 2007 (UTC)
 * You could shuffle the deck of cards again and again until they eventually wind-up in the original order. Of course, the odds of this happening are 1 in 52!, or 1 in 80 million trillion trillion trillion trillion trillion, so you could be there a long time... Laïka  13:04, 9 May 2007 (UTC)
 * (Or it could happen the very first time you try! There is no telling.) SteveBaker 14:58, 9 May 2007 (UTC)


 * Fortune telling - Tarot cards and all that. I'm pretty sure there are fortune telling methods that "work" with a regular deck of cards - although I can't find a reference for that right now. SteveBaker 14:59, 9 May 2007 (UTC)

It wouldn't happen the very first time, as the cards have be in a different order before you can get them back into the right order.

hello
how can you tell where I am just by my IP number? (172.142.10.221) I have seen it done on here a few times, but can't work out how. And how does the internet know where I am?
 * Our articles on WHOIS or ARIN might answer your question. But in case they don't, the simple explanation is that they are able to find the location of the server that your IP is registered to, not your actual location, just the location of the server-- VectorPotential Talk 19:48, 8 May 2007 (UTC)
 * For instance, you're using AOL, and the server you're connected to is located in Reston, Virginia. The server is registered to AOL, and is loacted in Dulles, VA. It's important to note however, that AOL uses a unique server setup that randomly connects you to servers all over the country, so running a WHOIS on a normal IP usually yields more information -- VectorPotential Talk 19:50, 8 May 2007 (UTC)
 * We also have an article on Geolocation software. --LarryMac 19:54, 8 May 2007 (UTC)

So I am connected to a server the other side of the world? What is the point of knowing where that is, if it doesn't tell you anything?


 * Who said there was a point? --18.214.0.135 14:56, 9 May 2007 (UTC)


 * Hypothetically, a network engineer could use such information to manage or fix network issues. A marketing engineer could use it to track aggregate statistics about the demographics of content subscribers.  I can think of many similar "points" - it all depends on what you're looking for. Nimur 08:01, 10 May 2007 (UTC)


 * Well, the server knows where *you* are, which is extremely important, since otherwise it would be unable to send you all that data you requested. SamSim 14:59, 11 May 2007 (UTC)

Taking the question far to literally, there are lots of points, on the ends of each letter :@ HS7 17:56, 10 May 2007 (UTC)

Or taking it even more literally, knowledge doesn't require words, so there are no letters to have points on, except in the statement of the fact of that knowledge :@ HS7 18:19, 10 May 2007 (UTC)

And one final point, since each point in my first comment is on a separate letter, the aforementioned statement of knowledge would have to broken down into individual letters to show them as separate points, and most letters would then have to be broken apart :] Separating it into letters destroys the entire meaning of the sentence, and breaking a letter in half creates two more points, so everything has an infinite amount of points, unless the letters are broken metaphorically or imaginarily c:) HS7 18:23, 10 May 2007 (UTC)