Wikipedia:Reference desk/Archives/Science/2007 September 30

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[edit] September 30

[edit] Hydrocloride vs Dihydrochloride

Whats the different between dihydrochloride and hydrochloride? I was looking at betahistine and found both versions, the HCL was used in a study and I found the dihydrochloride version online. Are they much different? —Preceding unsigned comment added by 76.167.139.80 (talk) 02:22, 30 September 2007 (UTC)

No - it dissociates anyway. Icek 03:08, 30 September 2007 (UTC)


See betahistine The hydrochloride has formula C8H12N2 HCl, the dihydrochloride has formula C8H12N2 2HCl A dihydrochloride can exist because it has two basic sites - the amine and the nitrogen in the benzene ring pyridine - they are different salts of betahistine87.102.11.118 12:22, 30 September 2007 (UTC)

[edit] solar wind hydro and geothermal energies

how can i get the questions where does the resource come from how its obtained for usage what are its uses what are some of the advantages of it and what are some of the disadvantages of it —Preceding unsigned comment added by 67.60.91.27 (talk) 03:15, 30 September 2007 (UTC)

Solar power, hydroelectric power, geothermal power. When you're looking for general information, you can just type the term of interest into the search bar on the left of this window. Please come back if you have questions not answered in the articles. Someguy1221 03:30, 30 September 2007 (UTC)

[edit] Diagnostic and Statistical Manual

I have read the artical on the DSM but am not clear: is the DSM considered "evidence-based" and, if so, how is the research to establish this conducted? —Preceding unsigned comment added by 209.161.212.229 (talk) 04:42, 30 September 2007 (UTC)

It depends on what you mean by "evidence-based". A DSM practitioner would probably say that the descriptive approach which leads to a DSM classification is "evidence-based" in that it is based on clinical or analytical experience and is often culled from a larger body of work in psychology. However a skeptic of the DSM, of which there are many, would likely argue that it was not "evidence-based" as the categorizations are not established by rigorous empirical standards, and the differentiations between categories are meant to be simply recognized by an experienced professional rather than being testable in a standard empirical sense. That is my understanding of it, anyway, but I am not a huge expert in such things. --24.147.86.187 10:50, 30 September 2007 (UTC)

[edit] Life!...

When will MAN 'give up' religion, and start relying on FACT!? Just been watching too much news. Dave 64.230.233.222 05:23, 30 September 2007 (UTC)

Because humans need something to believe in. If "MAN" gives up religion then he would need to believe in something else.
It's easy to believe in religion because it's requirements are so low. Compare that to quantum physics where you literally need to spend years studying before you can even do the basic problems. 220.239.107.201 06:26, 30 September 2007 (UTC)
Perfect answer, I think. Reminds me of when I asked a certain person, "What would happen if it were PROVED/PROVEN that God didn`t/doesn`t exist?" This person mentioned , and I`m paraphrasing, something that Voltaire once said, "If God died, 'man' would just invent another God."!!! Dave 64.230.233.222 07:35, 30 September 2007 (UTC)
Believing and relying on facts isn't exclusive. – b_jonas 13:24, 30 September 2007 (UTC)
To attempt a proper answer to this question: The fact is that religion appears to have sprung up independently in many (if not all) civilisations suggests that at some time in the past it served an important function. In an era before modern science, perhaps it produced answers to difficult questions and allowed important men to make themselves more important by claiming to be speakers for and interpreters of the greatest possible power in the universe. Nowadays we're able to use the tools of mathematics, astronomy, geology, paleontology, cosmology, physics, chemistry and biology that humanity has worked so hard over centuries to perfect - and over just the last 50 or so years have we produced more straight, clear-cut answers to the difficult questions of life than any of the previous millenia. We don't have to guess anymore - we finally know. The first black hole was found just three years ago - over the last decade, the results of quantum theory are so well understood that we use them to make mundane things like MP3 players. We've only been able to do detailed DNA analysis for a dozen years - but now we have the human genome laid out in detail before us. Those of us who are alive today are the first in all of human history to be able to deal with these questions of "how did we get here" without the need for ancient pseudo-science and myth - we don't have to guess how the universe was formed - we have proof. We don't have to wonder which animals descended from which - we can see it clearly in the DNA. I think it'll take a few more generations for the consequences to fully play out - but I honestly believe that we have no further need for religion - and the terrible wars and apalling deeds that are done in religion's name are things we are definitely better off without. SteveBaker 19:52, 30 September 2007 (UTC)
Another thing that IMHO religion often provided was a resonably simplistic sense of right and wrong and rules to live by guided by other people who help you understand the 'rules'. It also provided a sense of justice and a reason to live by these rules. Note that even nowadays, some religious people opposed to atheism say that without religion/God, people don't have to be 'good'. It is perhaps easier for people to be willing to do good when they believe those that don't will ultimately be punished. Nil Einne 03:29, 1 October 2007 (UTC)
Given the Crusades and recent Islamic extremist terrorism, I reckon that (organised) religion is also good at excusing or encouraging rather immoral behaviour. --203.22.236.14 04:45, 1 October 2007 (UTC)
Organised religion has a lot to answer for in terms of the troubles of the world - but small-scale religion is no better (Branch Davidians, Jonestown, Heaven's Gate, etc). SteveBaker 19:44, 1 October 2007 (UTC)

SUCH ANSWERS SHOWS ME THAT YOU GUYS DONT HAVE A LIFE WELL IF GOD DIDNOT EXSIST WHO CREATED THE WORLD? WHO CREATED THE UNIVERSE? WHO CREATED HUMANS,ANIMALS,AND LIVING THINGS? CAN YOU ANSWER THESE QUESTIONS? I AM COMPLETLY POSTIVE THAT GOD EXSIST AND HE IS THE ONLY ONE WHO GOT ANSWERS TO THESE QUESTIONS AND SOON WE WILL SEE —Preceding unsigned comment added by 212.71.37.107 (talk) 14:50, 30 September 2007 (UTC)

  • To 64.230.233.222: you might be interested in the book Consilience: The Unity of Knowledge by E. O. Wilson. Wilson mentions the idea that given the realities of human nature, it might be useful to create new religions that incorporate scientific facts.
    To 212.71.37.107: Since this is the science desk I'll provide a reply that is found in many scientific publications. If there is a God of the type you mention, then where did that God come from? Most scientists are not satisfied by taking a mystery, putting a name on it and pretending that you are done. --JWSchmidt 15:12, 30 September 2007 (UTC)
I`m gonna read that book JWS. Thank you. I have no reply for 212. Dave 64.230.233.222 15:30, 30 September 2007 (UTC)
212.71.37.107, if you reject the hypothesis that the answer to WHO could be "nobody, no more than someone makes water run off a boulder," there's not much we can say to you. But I'm curious as to what makes you think THAT YOU GUYS DONT HAVE A LIFE. If you think only losers ponder such questions, rather than accepting what someone told them in childhood and never seriously considering them again, I reckon that tells us something about you and I wonder why you're even looking at the Science Desk. (But please note that I'm only making a guess here about what you think, based on the limited evidence available; the Voices haven't spoken up yet on this subject.) —Tamfang 16:22, 30 September 2007 (UTC)

Smart Question JWSchmidt .... but that is why we call him god we humans are not supposed to prove god presence or not god created us to worship him and if you look deep you will find the one true religion in the world that will help us find our way through life why was there prophets remember something god is going to judje us cause god created us look deep and you will find the truth as we know from physics ....everything is there for a reason and i beleive god created these reasons

I have an excellent life without any sign of belief in any god or gods - it's very possible to have a full and satisfying life without religion. No gods were required to make the universe - the Big Bang Theory has the creation of the universe explained down to a fairly exacting degree. Therefore there is no "WHO" in "who created the universe"...and even if there was, that would only push the question back to "How did your god/gods get created?" - adding another step doesn't in any way help you find the answer. Humans, animals and living things come about through evolution from a single random coincidence that caused the first self-replicating molecule to appear (probably in the primordial earth - but perhaps elsewhere if panspermia turns out to be true). Can I answer these questions? Yes, easily - anyone who goes around with their eyes wide open can find these answers. Since you have absolutely no evidence or proof of any kind that your idea of god exists - your belief is merely an act of faith (as I recall your religion teaches you). Blind faith is a risky business - without evidence, how do you know that you are worshipping the correct god. I'm pretty sure the devil worshippers will also tell their supporters to have faith. Anyway, if god is the only one who can answer these questions - and I can certainly answer these questions then I am your god and "SOON YOU WILL SEE" - because I just told you. The only question I find tough to answer is WHY THE HECK YOU CAN"T FIND YOUR CAPS LOCK KEY. SteveBaker 16:44, 30 September 2007 (UTC)

To begin with , we are just discussing so it would be nice to respect each other. i want to ask you a question did u read about old times , and the real prophets that once was present and if you read about them , i suppose you heard about their miracles . what makes you think that god is made or created , then how on earth is he called god. let me go back to miracles of the prophets that was once there and the fact that alot of people beleived in them because they found the truth. another thing how do you explain that everything that consider life science and everything was mentioned either directly or indirect in the holy books of god if you think that someone wrote them then how do expect him to find out about all this so early ,,(was he a genius!!!)

Actually, if you believe in god (or gods) I honestly don't respect you. It's hard to respect someone who bases his or her entire life on something that's exactly as believable to me as Santa Claus or the Tooth Fairy...respect has to be earned and claiming that everything about science is in this one skinny 2,000 year old book does nothing to help you here. Did I read about the old times? Sure - I've read the bible from cover to cover - I have a passing knowledge of world history. The miracles the bible describes would indeed be fairly impressive if they were true - but there is really no evidence that they ever happened. Someone wrote it down in a book - and the book has been repeatedly retranslated from a source language that's confusing as all hell because the written form contains no vowels. How do we know it's true? It could just as easily be a work of fiction. Since it contradicts itself in many, MANY places - it certainly can't all be true.
You say that all of the answers are there. OK - let's try a nice simple test. Let's look at the creation of life itself. What does the bible say in answer to the question "Which came first - animals or people?" - do me a favor. Look it up in your bible and post the answer here - tell me simply and clearly: "Animals came before people" or "People came before animals". It's right there in Genesis - I'd like you to tell everyone here what it says - post your answer here. I want to know what your holy book - on whose teachings you base your entire life - tells you about this very basic question.
SteveBaker 21:00, 30 September 2007 (UTC)
They way "I" understand God and the various religions is that they were invented to give people guidance. Perhaps even to encourage people to behave. Offer them an incredible reward, Heaven, if they behaved and of course, the most hedious of punishments if they didn`t. Almost sounds sane, until you really think about it though. I very much tend to agree along the same lines as SteveBaker, only problem is, how does one change all that brainwashing that has been around for so long? One cannot stop believers from believing. And to force them to not believe, if possible, would surely be unethical/immoral, to say the least. I too, have a very difficult time showing respect towards a person who follows the BOOK err, religiously. I think I`d better stop else this could turn ugly. Thanks for all your thoughts. Dave 64.230.233.222 21:48, 30 September 2007 (UTC)
Reluctantly, I'm increasingly agreeing with Richard Dawkins - atheists have to take off the kid gloves and stop treating religion and the religious with respect. This is not a popular point of view in the middle of Bible-belt America - but that's where I happen to live. The people who believe in this pile of nonsense don't deserve my respect. I now feel very confident about calling them idiots - mocking their beliefs - disbelieving their sincerity because not a one of them is consistent about their beliefs. I intend to continue pointing out the ridiculousness of the crap they are espousing. It's easy to focus on this way of thinking - try my recipe: Whenever they say "God", think "Tooth Fairy" and whenever they say "Heaven" think "Santa's grotto". After all, if you are an atheist, those terms are equally believable - and switching them around enables us to rid ourselves of thousands of years of brainwashing. It's very hard not to giggle when a priest in his silly costume starts telling us (in all seriousness) that if we believe in the Tooth Fairy, we'll end up spending eternity in Santa's grotto...but that's exactly as believable to me as what he's actually saying. SteveBaker 03:12, 1 October 2007 (UTC)
Very few, if any, people entirely rely on 'fact' alone; almost everyone has things that they think or do which are not supported by facts. If you look at populations where few people practise religion, you do not tend to see the majority of the population building their lives on facts; rather, these people practise feng shui, read their horoscopes, mutter phrases to magpies, repeat 'please please please' under their breath after bowling and before the ball hits the pins. They buy lottery tickets, they believe that they have paranormal abilities, or that someone else who wants their money does, they see ghosts, they see UFOs, they press the button at the pelican crossing again when the lights take a long time to change, they think that their loved ones are looking down on them, or have gone on to a better place, or are waiting for them, or have come back to guard them. For whatever reason, most people do not really want to live lives based on fact alone; they get something out of religion and supernatural beliefs that they do not get elsewhere. If you do not, that's fine, but please do not assume that people believe these things just because they are ignorant or stupid, or that they would be happier without them. Oh, and if it's just brainwashing, why so many converts to so many religions and beliefs? 79.65.119.193 22:53, 30 September 2007 (UTC)
Oh, and if it's just brainwashing, why so many converts to so many religions and beliefs? People do "irrational" things because it brings meaning to their lives. Before you jump on that let me tell you that:
People do hobbyX not because hobbyX is rational but because hobbyX bring meaning to their lives. hobbyX can be {swiming, jogging, horseridding, mountain climbinb, sking, dancing}. Now no one suggest that hobbyX is rational or that hobbyX is TRUE or that if anyone insults hobbyX that they should have their head chopped off. No one gets angry if you suggest that hobbyX is a social construct or if you choose to join hobbyX and hobbyY at the same time.
Compare that with religionX. People do religionX not because religionX is rational but because religionX bring meaning to their lives. People gets very angry if you suggest that religionX is NOT TRUE or if you suggest that religionX is a social construct. And people get angry if you choose to join religionX and religionY at the same time.
Religions are just like hobbies, except that it is a philosophical hobby that insists on it's own validity and rejects any other philosophies that suggests that itself is FALSE.202.168.50.40 23:26, 30 September 2007 (UTC)
I understand why many people 'need' religion. They would feel that life was unimportant, for some reason, without it. I just feel that any sort of unsubstantiated belief system is a little silly, that`s all. Humans are so knowledgeable now. Way back when, when just about everything was mysterious, even the wind was a 'god', then I can see how people needed religion. It helped 'explain' such mysteries. The fact that almost everything is fairly easily explainable now makes me wonder how ANYONE can still 'believe'. Dang, I`ve said too much already. I really didn`t want to start anything here. Sorry if I offended anyone. Dave 64.230.233.222 23:52, 30 September 2007 (UTC)
Exactly! The point of religion isn't really to explain things that science explains, it's because it gives people something they cannot get anywhere else. If you see why people need religion, why talk about changing 'brainwashing'? Most people need religion or supernatural beliefs, and it is not to explain the things which are explained. People who read their horoscopes (and many people really, truly believe them, and some even become quite aggressive when you suggest horoscopes are silly) do not do so because they require an explanation for the movements of the planets. People who pray to a god don't generally do so because they want an explanation for why wind blows. With very few exceptions (if even those) people do not want to live only with verified facts. "I understand why many people 'need' religion. They would feel that life was unimportant, for some reason, without it." Does this mean that you feel life is important? Do you have any way of backing that up; is it supported by facts? Does believing it matter to you? :) 79.65.119.193 00:20, 1 October 2007 (UTC)
Very good questions 79.65.119.193. If I`m forced to think about it long enough, I would have to conclude that life is more or less meaningless. It`s neat though. It`s quite a curiosity. But heck, everyone dies. How cruel is THAT? Life can still be important though. Just skip a couple of car or house payments to quickly find out just HOW important a life is, especially to a banker. As for astrology, sheesh! That`s not even worth a comment. I am utterly amazed at all the crap people can be made to believe in. My original question merely wanted to get some sort of 'blanket' answer as to why, or how people can still believe, given all the knowledge at hand. Wouldn`t you agree that religion has caused more harm than good? Just think about all the wars based on it. Thanks for listening. CHEERS! Dave 64.230.233.222 00:50, 1 October 2007 (UTC)
 :) I think you're starting to feel what I'm trying to show. Logically, when you think about it, you can see there is nothing to support the belief that life matters. But, it feels better to believe that life matters. If someone offered to prove to you that life didn't matter, would you welcome it? Equally, if thinking logically, people know that there is nothing supporting the belief that any gods exist. Nonetheless, it feels better (to them) to believe that a god, or gods, exist, so they do. Thinking logically, people know that pressing the button again at the pelican crossing doesn't speed up the change, but they won't welcome you explaining this to them when they do it; it feels good to do it and to believe, at some level, that you have affected the process. No, I wouldn't agree that religion has done more harm than good, any more than I believe that politics has done more harm than good. I have never seen a war that was fought because religion existed; religion is an excuse and a marker, it is useful in propaganda and in countering it, but it is not the cause of the wars. Since religion and politics seem to be pretty much hardwired into humans and their interactions, it's sadly not really possible to do a control study :P Who knows what the human race would be like without them, but they wouldn't be the human race. 79.65.119.193 01:04, 1 October 2007 (UTC)
You have quite a way with words 79. Your points are well taken. Just a quick guess at your last comment: Without religion and politics, I think we`d still be savages. I think humans NEED rules and regulations to live in a civilized sort of way. Thanks for your fine points. I know Wikipedia is important. I love this place. lol Dave 64.230.233.222 01:21, 1 October 2007 (UTC)
I love this place too. Happy thinking :) 79.65.119.193 07:02, 1 October 2007 (UTC)

first , you don't deserve to be respected if you dont respect others whatever their belief is. next the bible is not my book. and if this makes you feel better the bible was changed with by people over time and that's why you cant beleive in it , next do you actually beleive in the bigbang theory if you do so then who created what's before bigbang or was it a coincedince that earth was formed and we were created . no reason just like that , that is impossible —Preceding unsigned comment added by 212.71.37.73 (talk) 08:20, 1 October 2007 (UTC)

To address your points one by one: Respect is indeed a bi-directional thing. It's not just that withhold my respect from people with crazy beliefs - I also don't give a damn whether they respect me or not. Truly - why would I care about the opinions of someone who runs his/her life on a rock-solid belief in the tooth-fairy? That person is a nut-job and I no more care how they feel about me than how they feel about the tooth-fairy. I would be more upset if someone with opinions I can understand (if not agree with) didn't respect me...but those are people I can respect.
So - I can well understand why you wouldn't believe in the things written in the bible - that's a good thing! But without that - what do you know about this "god"? How do you know what she/he/it demands of you? So you are just making up your entire personal cosmology as you go along without any evidence whatever? Don't you think that's a dangerous viewpoint? If you are going to go around just believing in anything on a whim without evidence, what's to stop you suddenly believing that your god wants you to blow up tall buildings with airplanes...or poisoning the Kool-Aid and waiting for the aliens to come and resurrect you? Those who believe in random things without proof or reason are dangerous, scary people!
I do believe that there is strong evidence for the big bang theory - cosmic background radiation measurements pretty much clinched that debate. But this continual demand for "What created the ultimate thing" - then when I tell you, you demand the thing that created the ultimate thing, then the thing that created that. It might make you happier to believe that some god or other created the big bang - but that raises an even nastier question: "How did the god get there?". Most religious people simply say that their god has always been there because god is outside of time - and they are happy with that answer. But why is that a better answer than "The singularity that was the source of the big bang was always there and is 'outside' of time". I don't see how a complex thing like a god (with thoughts and powers and strong opinions and all of these abilities) is a more probable starting point than a simple 'dot' of infinite density.
Describing the formation of the earth as a 'coincidence' is missing the point that science is making. Science says that the universe is VAST - the number of planets that have formed is hugely greater than the number of grains of sand on a beach. The formation of the earth was no coincidence - it seems that there are billions and billions of planets out there, they are formed from simple physical processes that are exceedingly common in our galaxy. Perhaps the only oddity is that this particular planet has all of this complex life on it (although we don't really know whether that's an oddity or not - maybe all planets have complex life on them but we just haven't found them yet). But even if we are alone in the universe, that's not a 'coincidence'. Beings that are capable of asking the question "How did I get here" can only arise on those planets which have exactly the right conditions - so it is inevitable that we live on a planet like this one that is exactly suited to us. If only one planet in the entire universe happens to have those exact conditions - then it is certain that the beings asking the question must be living on it. SteveBaker 14:17, 1 October 2007 (UTC)
Anyone (especially atheists like me) who wants to understand religion, its evolutionary fitness, and its appeal to adherents must watch the PBS Frontline expisode "The Mormons" (available online). This documentary was extremely enlightening to me even though I had already read some books on the subject. Just watch how the young woman's eyes light-up when she describes the mormon concept of marriage in the section "The Family" in part 2 and you will understand how religion is a natural outgrowth (exploitation?) of human evolutionary desires. -- Diletante 15:54, 1 October 2007 (UTC)

I think it's the height of stupidity, and perhaps arrogance, to not believe there is an intelligent Uncaused Cause. There is no logical reason for existence, and to chalk it up to the argument, "Well, who created God?" is tiresome. Believe in the Darwinian goop-to-human theory, and make it your god, fine, but please don't try to explain away the existence of the Universe through nonsensical, essentially nihilistic arguments. --68.63.11.221 15:18, 5 October 2007 (UTC)

[edit] how to test caffeine content??

please suggest a possible experiment(home test) to find caffeine content in common drinks an coffee and tea -sumit —Preceding unsigned comment added by 59.94.140.159 (talk) 06:47, 30 September 2007 (UTC)

Try searching the internet for the two keywords Daphnia and caffeine. You might be able to use the heart rate of Daphnia as a bioassay for the concentration of caffeine. --JWSchmidt 14:57, 30 September 2007 (UTC)
This question came up a few months ago - we concluded that there was no easy test that could be done in the home. But using Daphnia could maybe work with appropriate calibration of the method against samples with a known content. SteveBaker 15:21, 30 September 2007 (UTC)
Here's that thread, easily found by googling 'spider web cafeine site:http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives'. I rather liked my suggestion of using a spider. :) DirkvdM 18:24, 30 September 2007 (UTC)

thanks sir, but i had asked this qn on 30 or 29 sep not a month ago--59.94.146.227 12:59, 1 October 2007 (UTC)

Yeah - we know that - it's just that it's a surprisingly common question and it's easier to point you to the replies that were given last time than to answer it all over again. SteveBaker 13:38, 1 October 2007 (UTC)

[edit] FIRE FIGHTING ROBOT

My question regarding the above topic is

I wanted to know how does the software part has to be explored as on case of fire fighting robot which is basically dependent on the temperature sensors used(LM315). Wanted to know how the KEIL software come into play with the following project. my query was how is the programming going to be used in the above project fire fighting robot. Miki619 09:38, 30 September 2007 (UTC)

OK - back up a bit here. Which fire-fighting robot are you talking about? Do you have link to it? Your question is a bit confusing - so let's take this slowly. The robot uses some temperature sensing mechanism - using LM313 chips maybe - and you want to know what the software does with the data that comes out of those chips? This doesn't sound like a 'real' project. Is it some school project with a home-made robot or something? If so, and if I were programming it for a competition, and assuming the robot has just one temperature sensor pointing forwards, I'd write something like this:
  1. Make the the software turn the robot slowly around in a full circle taking temperature readings all the while and noting the highest reading and the direction we were pointing in when that reading was taken.
  2. Rotate back to the direction where we got the highest reading (so, hopefully we're pointing towards the hottest part of the fire).
  3. Then, I'd look at the actual temperature we detected in that direction and say:
    • If the temperature is lower than a certain threshold, drive forwards for a few seconds.
    • Else, if the temperature is high enough that we believe the fire is immediately in front of the robot we squirt water/foam/CO2 at the fire until the temperature drops below the pre-programmed threshold - or some short time limit is reached (10 seconds maybe).
  4. Then, go back to step (1) and look for a new direction to drive in.
Hopefully, this would cause the robot to drive towards the hottest part of the fire that it can see - put it out - then go looking for the next most hot part - put that out and so on. At the end, when there are no more heat sources hot enough to be fires, the robot will drive towards the next hottest thing it can see - which is probably the sun - which would probably cause it to triumphantly leave the building. Of course in the real world, things would be vastly, insanely, more complicated than that - but for some kind of school robotics class, that would do the job quite nicely.
But we have no way to know whether the robot you are thinking of is at all like that - there are other ways to program the thing. Maybe it has cameras - maybe it has a map of the room - maybe it has temperature sensors pointing in all directions, an infra-red camera. Maybe it has to ration it's water/CO2/foam supplies, maybe it has to distinguish between different kinds of fire so it knows whether it's safe to use water or not. Maybe it has to climb staircases - to put out fires up high on a rooftop or down low on the floor. Maybe it has to be able to smash down doors to get into a room - or avoid fallen debris. Perhaps it has to check that the floor is still strong enough to support it. Maybe it has to give a higher priority to saving lives than to putting out the fire.
You really didn't give us enough information! SteveBaker 15:17, 30 September 2007 (UTC)

[edit] Possible amnesia question.

Is there a certain type of amnesia to where a person only remembers things for as long as they stay conscious? So basically, after they fall asleep, they forget everything they learned when they wake up.--SeizureDog 10:12, 30 September 2007 (UTC)

Anterograde amnesia? --71.175.68.224 14:20, 30 September 2007 (UTC)
You don't have to fall asleep to forget with Anterograde amnesia though - it's a failure of the mechanism that transfers data from short term to long term memory - so memories fade after 20 to 30 minutes because short-term memory can't hold them any longer and long term memory can't kick in. I can't imagine a mechanism that would cause you to forget things only when you fell asleep - so I think the answer to the question is "No". The opposite can happen though - if someone is deprived of REM sleep for too many nights, they become forgetful. SteveBaker 14:54, 30 September 2007 (UTC)
50 First Dates is, I assume, the source of this musing? 79.65.119.193 22:22, 30 September 2007 (UTC)
Could be. The real-world cases are a lot sadder than that. There was a story on the radio about a guy who has this terrible condition - every time his wife steps into the room he greets her like he's been separated from her for years - since the time he suffered the injury that caused the disease. He says that he's "waking up for the very first time" - and the poor woman has to explain to him what the problem is and that this happens all the time to him - dozens of times per day. 50 First Dates sugar-coats it to hell and back! SteveBaker 13:36, 1 October 2007 (UTC)
  • At least he can hide his own Easter eggs. --Sean 18:12, 1 October 2007 (UTC)

[edit] Amiodarone

Many sources refer to the chemists Tondeur and Binon as the original discoverers of amiodarone, working for the Belgian company Labaz. Despite this, I could not find a reference to their original publications even in the 1985 Cordarone FDA approval documents[1]. Anyone? (Reply on my talkpage please, or on Talk:Amiodarone.) JFW | T@lk 10:16, 30 September 2007 (UTC)

It's allright - PubMed worked. How odd that Google does not index all pubmed abstracts?? JFW | T@lk 10:28, 30 September 2007 (UTC)

[edit] Mitochondria

How would you count the number of mitochondria within a liver cell? Using a series of images from a transmission electon microscope, or could a image from a scanning microscope be used,( or does a scanner produce an image of the exterior of the cell?) 88.110.203.63 11:11, 30 September 2007 (UTC)

[edit] (Carbon) Emissions Data

I am looking for comprehensive, standardised, reliable emissions data please —Preceding unsigned comment added by Canuinti (talk • contribs) 13:58, 30 September 2007 (UTC)

Emissions from what? SteveBaker 14:48, 30 September 2007 (UTC)
And where and over what period. I assume you mean antrhopogenic emissions of CO2, probably in connection with global warming. Is that correct? Googling 'co2 emissions' gives loads of results on that, so you'd have to narrow it down a bit. If you mean worldwide, then the IPCC might be a reliable source for that, such as the fourth assessment report]. Alas, they're bloody pdf's and I don't know how to search through those. DirkvdM 18:36, 30 September 2007 (UTC)

[edit] DNA

can DNA be manupilated to add or remove certain characteristics ? can this possibly be true ? i mean as a good mutation!! —Preceding unsigned comment added by 212.71.37.108 (talk) 14:53, 30 September 2007 (UTC)

Try reading Genetic engineering. --JWSchmidt 15:54, 30 September 2007 (UTC)
Yes, and we're getting better at it all the time. It does bring up many moral issues, however, like stem-cell research. StuRat 22:32, 30 September 2007 (UTC)

[edit] Calculus needed?

Hello. I am just a high school student. I am considering studying thermodynamics as well as the methods used to date geological strata and the age of the Earth. I want to know about these things so I can evaluate claims in the creationism vs. evolution debate. Is it necessary to know calculus to have an adequate grasp of these subjects? Thanks. 68.77.186.32 16:23, 30 September 2007 (UTC)

I linked a couple of the keywords in your question.
You might find some useful info in http://www.talkorigins.org/origins/faqs-youngearth.html
As a layman I can think of a couple of points where differential equations are relevant, but they seem to be simple ones requiring only the basics of calculus – or you could use a "cookbook" approach, i.e. plug in numbers to a formula without needing to understand the formula. —Tamfang 16:33, 30 September 2007 (UTC)
I would say it depends on how deeply you want to go into these subjects. Calculus turns up in many, many areas of science when they are studied at a deep level. However, I think you could get a good overall understanding of both these subjects with only basic math. ike9898 17:25, 30 September 2007 (UTC)
Common sense and simple arithmetic should suffice, butif during your research you run into the need for higher math, please come back and ask for help. Someone here may be able to either help you with the math or direct you to a simpler way to handle the particular problem. You will need higher math if you proceed to University-level thermodynamics, of course. -Arch dude 17:30, 30 September 2007 (UTC)
If you're doing 'real' thermodynamics using numbers and energies and things, rather than just vaguely talking about the rules of thermodynamics, then you definitely need calculus; there's a lot of integrating and differentiating. So it depends how much thermodynamics you want to understand. I'd recommend you study calculus if you get the chance, if you're interested in science at all; it isn't as hard as cartoons would have you believe, and it lets you learn at lot of other things. 79.65.119.193 22:21, 30 September 2007 (UTC)
I'd say you would need to use logarithms for calculating ages based on decay of radioactive isotopes. That's the most complex math that comes to mind. StuRat 22:28, 30 September 2007 (UTC)
  • I would also like to point out that calculus is very useful for the lifetime of thinking you have ahead of you, even if you only have a qualitative ("calculus for poets") understanding of it. You should definitely learn it if you're curious about the world around you. --Sean 18:16, 1 October 2007 (UTC)
  • Slightly off-topic, but regarding thermodynamics (specifically entropy and the Second Law) and creationism vs evolution, and claims about entropy and disorder from order being a natural consequence of systems (and therefore, supposedly, of evolution being "false") I was reminded of the following point (thanks to M.C. Hawking):

"Creationists always try to use the second law, to disprove evolution, but their theory has a flaw. The second law is quite precise about where it applies, only in a closed system must the entropy count rise. The earth's not a closed system; it's powered by the sun, so **** the damn creationists, Doomsday get my gun!"

Hope this helps in your evaluations :) -Wooty [Woot?] [Spam! Spam! Wonderful spam!] 23:25, 1 October 2007 (UTC)

Hey, thanks for your help everyone, and sorry for the late thank-you. 69.218.205.188 00:25, 5 October 2007 (UTC)

[edit] Graphics of a X-box 360 to graphics of a ps3

Can I get a website that shows a comparison of the graphics for the x-box 360 and ps3. It would be nice if it would be a same game comparison. Thank you in advance for your help. (Wookiemaster 17:35, 30 September 2007 (UTC))

It's a really complicated trade-off. I can't reveal what I know because I've signed non-disclosure agreements (I'm an Xbox360/PS-3 game designer - and my job is the graphics). I would say this though. There isn't that much to choose between them. The horrific cost of designing video games these days means that most (if not all) games that come out on both platforms will have pretty much the same graphic design for both of them. The result is the games looks pretty much identical - no matter whether one is better than the other or not - it's a compromise between what the two machines can do. If you want to choose which one to buy - look only at whether the games you want are available on the console you want and ignore the millions of fanboi sites because not a single one of them know all of the facts (because to find them out you'd be under NDA and unable to write about them) - and for sure none of them are unbiassed. SteveBaker 21:50, 30 September 2007 (UTC)
You may have already said too much! Anyway, there's been an awful lot of computer-related questions on the science desk. I'm not sure how video-game graphics are a good fit for the Science Reference Desk... Nimur 04:20, 2 October 2007 (UTC)

Search for "xbox ps3 graphics comparison" like this http://ww.google.co.uk/search?hl=en&q=xbox+ps3+graphics+comparison&meta= and as the above says - mostly the stills look exactly the same - though sometimes the dynamic range or brightness differs...87.102.19.191 21:56, 30 September 2007 (UTC)

[edit] ionosing gas

i would like to know about the best ionising gas121.246.251.238 17:43, 30 September 2007 (UTC)

Best for what? Best at what? --Mdwyer 17:55, 30 September 2007 (UTC)
A gas with low ionisation energy is good - such as Xenon, or maybe sulphur hexafluoride.. Radon is a good ionising gas as it is radioactive and a such self ionises.87.102.19.191 21:58, 30 September 2007 (UTC)

[edit] Physics Phenomena i don't understand

1) If a plane with two jet engines has the left one fail, the plane will deccelerate, and rotate left, is this correct?

2) Why does your reflection run at you twice your speed

3) i understand circular motion, so why do the planets move ellipcically?

4) if i shot a bullet out of a gun pointed in the opposite direction to my motion in a car that is travelling say 50 m/s and the bullet also travels at this speed what wil happen, does the bullet just stay in the gun?

5) I'm sitting here trying to figure out this damn questions, its not homework i promise, in fact i've changed the numbers. ok so lets say there are 40 chlorine particles per 10^7 air particle (made that up), and your lungs together can take 1 litre of air, atmospheric pressure is 1.0x10^5 Pa, how many chlorine molecules would you breath in?

78.146.4.0 18:10, 30 September 2007 (UTC)

1) Thankfully, all planes have some form of yaw control, usually a rudder. 2) If you are running towards a mirror that is facing you, from the perspective of someone standing next to the mirror, you are both running towards eachother at the same speed. Therefore, the distance between you two is closing at twice whatever that speed is, so from your perspective your reflection is approaching you twice as fast as you are running (assuming you're not running near the speed of light). 3) A circular orbit is merely the perfect orbital situation, where an orbiting object has the exact right velocity and altitude that gravity cannot pull it any closer, or let it go any further away. As you can imagine, in the chaos that was our early solar system, the chance of a planet forming in such a perfect situation was about nil. You might want to check out orbit. 4) No, the bullet exits the gun at 50m/s with respect to the gun. Anyone standing on the road sees the bullet plop out of the gun and fall harmlessly to the ground with no horizontal motion. According to the laws of special relativity, there is no preferred frame of reference. I am sitting still in my chair typing at my computer, but i'm on a spinning globe, which is hurtling around the sun, which is hurtling around the milky way galaxy, which is hurtling in some direction I don't know with respect to nearby galaxies. So what makes the road any better a frame from which to measure velocities than any other frame i can think of? Any inertial reference frame (a frame with constant velocity) is a valid one from which to draw physical conclusions. So as long as your car is moving with constant velocity, you can say that, from the car's perspective, the bullet will leave the gun with the same velocity that it would if the car were stopped. This is actually a better reference frame to use than the road because with the road you have to deal with a bullet from a moving gun, which is more complex. 5) One liter of gas at that pressure contains about 0.045 moles of particles. Someguy1221 18:35, 30 September 2007 (UTC)
1) If a plane with two jet engines has the left one fail, the plane will deccelerate, and rotate left, is this correct? -- Well, it would - but such aircraft are designed to still be flyable under those circumstances - so generally one has to throttle back the one remaining engine and apply rudder to keep it flying straight. In some kinds of aircraft you get other ikky problems due to the flow of the exhaust gasses over the tail plane being asymmetrical so that when you climb or dive, the plane wants to roll slowly to one side or the other. But again, the remaining controls are designed to be sufficient to keep the plane flyable.
2) Why does your reflection run at you twice your speed - you run towards the mirror as speed X, your reflection runs towards the mirror at speed X. Relative to you, you are stationary and the mirror is moving towards you at X - so your reflection is moving towards you at X+X = 2X.
3) i understand circular motion, so why do the planets move ellipcically? - To move in a circular orbit, you'd have to be moving with a velocity that's exactly at right angles to the line between you and the star/sun. If your initial velocity is pointing at some other angle (inwards towards the star, for example) then you are going to start moving closer to it instead of staying at the exact same distance. Because you are moving closer, you start going faster and faster - but this increases the amount of centrifugal force - which eventually pushes you away from the star. So now you are moving further away from it, you will gradually slow down and then move back towards it again. If the speeds are just right, you remain in a stable - but elliptical - orbit forever. Another way to look at it is that all orbits are 'elliptical' but a circle is just a special case of an ellipse.
4) if i shot a bullet out of a gun pointed in the opposite direction to my motion in a car that is travelling say 50 m/s and the bullet also travels at this speed what wil happen, does the bullet just stay in the gun? -- We have to be very careful about what you mean by the speed of the bullet. If you mean that if you were standing still (in a vacuum) and you fired the gun then the bullet would come out of the barrel at 50 ms-1 - then when you fire it from the car (still in a vacuum), the speed imparted to the bullet by the propellant in the barrel will be added to the speed of the car - so someone beside the road would say that the bullet was travelling at 0 ms-1 - the bullet would come out of the gun and fall to the ground. In reality, things will be much more complicated because of air resistance. The pressure of the air in the barrel of the gun will be lower because the speed of the car is pulling air out of the barrel creating a partial vacuum. So the pressure of the explosive propellant behind the bullet minus the air pressure in front of the bullet will be more than it would be if you were firing the gun in still air. In the case of a real gun, the difference would be almost negligable - but your gun is an AMAZINGLY slow one - so it might not be so negligable. Certainly, the bullet would come out of the barrel - but nowhere near as fast as it 'should'.
5) I'm sitting here trying to figure out this damn questions, its not homework i promise, in fact i've changed the numbers. ok so lets say there are 40 chlorine particles per 10^7 air particle (made that up), and your lungs together can take 1 litre of air, atmospheric pressure is 1.0x10^5 Pa, how many chlorine molecules would you breath in? -- Well, I'm not doing this one for you - check out Gas laws to figure out the number of molecules in the air from the pressure and volume - divide by ten to the seven and multiply by 40 - but it's made very messy by the fact that air is a mixture of lots of gasses. SteveBaker 21:32, 30 September 2007 (UTC)
for 1), see ETOPS. -Arch dude 02:33, 1 October 2007 (UTC)


THANKS guys! for question 5, can i use pV=nrT, but i do not have a value of temperature, what do i do? 89.240.40.152 17:08, 1 October 2007 (UTC)
When unspecified, you normally use either STP (273K) or room temperature (293K). Since you're talking about breathing, I'd imagine it would be the latter. Someguy1221 17:24, 1 October 2007 (UTC)
  • Perhaps a more practical example than the bullet one, since gas pressures and high muzzle velocities would not play a role, and you could titrate the amount of force used, would be to shoot an arrow backwards from a car. It's interesting (and counterintuitive to many) that the bullet or arrow would not hang suspended in the air at all, but would fall at the same rate as if you just dropped it by hand. --Sean 18:23, 1 October 2007 (UTC)
People are not good at those kinds of thought experiment. We used to ask job candidates: "If you are driving along in a car at constant speed with a ball in your hand. There is a bucket beside the road. You need to drop the ball into the bucket. Should you drop the ball (A) just before you reach the bucket, (B) exactly as you pass it, or a (C) little while after you pass it?" - an amazing number of people answer "as you pass it" or "after you pass it" - the latter group usually tell you "because of air resistance" and the middle group often say "assuming we can neglect air resistance" (which is a shame because they are closer to having the right answer if we take air resistance into account). It's very sad. SteveBaker 19:27, 1 October 2007 (UTC)
Hmm. Are you sure the question was stated the same way you posed it here? If so, it's difficult to comprehend how the incorrect answers could be appealing even in an intuitive sense. Even if you were sitting in a stationary chair with a stationary bucket in a total vacuum, the ball is still going to take time T > 0 to reach the bucket, so (C) doesn't even seem to make sense. My guess: there were other considerations (such as time pressure) you haven't mentioned here. dr.ef.tymac 21:45, 1 October 2007 (UTC)
Still dr., talk about a simple problem. I`m guessing your candidates are college graduates? Sheesh! That is VERY sad. Dave 64.230.233.209 21:54, 1 October 2007 (UTC)
Yep - college grads. Their thinking goes like this: When I stick my hand out of the window of the car - there is a really strong wind blowing. Balls aren't very heavy so they're going to be blown backwards really fast. So I need to let go of the ball after we've passed the bucket so that the ball gets blown backwards into the bucket. Yeah - I'm well aware of all of the fatal flaws in that logic - but that's what they say. I'm not putting them under time pressure - but then they never seem to take time to come to their conclusions - they always think it's so "obvious". In fact, I prefer that they take time and think - because I wasn't in the business of needing people who could come to a snap decision - I wanted people who'd take the time to get the right answer. The nastier question we used was "If you are in a boat on small 10' deep pond with a large, heavy, iron anvil on board - if you chuck the anvil over the side, will the water level in the pond go up, down or stay the same?" It's not a trick question. SteveBaker 22:54, 1 October 2007 (UTC)
I know you`re not asking me, per se, but I believe the water level would drop some. Briefly: With the anvil in the boat, being so much more dense than water, it would displace its whole 'mass worth' of water. Once completely submerged, it will only displace its equivalent volume of water. This would be much less water than it would displace while in the boat. Of course, the water would be at its lowest level while the anvil was in the air, before submerging. Do I get the job? lol Dave 64.230.233.209 01:15, 2 October 2007 (UTC)
Yep - that's it exactly. When it's in the boat, the anvil displaces it's own weight of water - when it's in the pond it displaces it's own volume of water. Since water is less dense than iron, it displaced more volume when in the boat than it did when it sank - so the water level goes down. It's a great question because the answer is the opposite of intuition - and most people who think scientifically but don't take the time to reason it out will guess "no change". Good candidates are the ones who stop to think about it - and even if they get the answer wrong, the point is that they didn't jump to a conclusion. I'd give you the job - but I don't work there anymore! SteveBaker 14:47, 2 October 2007 (UTC)
Aw shucks! May I get a recommendation at least? lol Dave 64.230.233.209 15:01, 2 October 2007 (UTC)

[edit] Perfect sharpness?

Is it possible to achieve a nearly perfect sharp blade by making it as much thin as possible (about 1 micron or something like that, assuming that the blade is of very firm material), so one would be able to cut up a considerable parts of nearly every material even by a slight strike? --85.132.14.38 18:43, 30 September 2007 (UTC)

some diamond knives can do close to this (can cut apart a cell) read "The Hot Zone" —Preceding unsigned comment added by 12.217.195.89 (talk) 00:00, 1 October 2007 (UTC)
Considering we can move separate atoms these days (can someone provide a link?) it may be becoming more science than fiction. However, when you use such a blade, it will become blunt again, so it's a one-off thing. Unless it's extremely tough material, like diamond. But then I suppose one cannot make diamond with the method I cannot find a link to. So maybe more fiction than science after all. DirkvdM 08:15, 1 October 2007 (UTC)
Hold on, what about this? Cover a knife in some insulating material, then use a laser (how thin can that be?) to cut out a strip right at the edge. Then put it in a galvanising bath and a perfectly sharp edge will form. Of course, this will still suffer the problem that it will go 'blunt' very fast. It might help if this was done in several stages, ever narrower, so the edge will be wedge-shaped. DirkvdM 08:23, 1 October 2007 (UTC)
I always wondered whether you could do this by electro-plating ultra-thin layers of progressively harder metals onto some kind of substate - ending with the hardest metal you can find - then adding more layers of progressively softer metals. Remove the substrate and you have a sandwich of a spectacularly thin layer of hard metal encased in softer metals on both sides. Sharpen it so the hard metal is the cutting edge of the V-cross-section blade. Now, as you use the knife, the softer metals will wear away faster than the hard one - leaving a perpetually ultra-sharp knife that maintains it's own sharpness as you use it. I imagine there must be a terrible problem with this idea because nobody seems to be doing it already - but if we're postulating nanotech solutions - that's the way to go. SteveBaker 15:41, 1 October 2007 (UTC)
That sounds a bit like the Dayak method of machete-making taken several steps further. See the last paragraph of the Dayak people#Society section. I wrote that. :) (how does one make a proud emoticon?) DirkvdM 18:57, 1 October 2007 (UTC)
1 micron is pretty achievable. Obsidian-bladed surgical tools can get as sharp as 3 nm (well, according to our article, anyway.) GeeJo (t)⁄(c) • 19:56, 3 October 2007 (UTC)

[edit] What is the whitest substance ?

I recently read an article on research to create the whitest substance using nanotechnology, but I can't find it anymore. I looked at wikipedia hoping to find a definition of what being "whitest" means, and a list of very white natural substances (such as the foam of a breaking ocean wave). Any information on these subjects ? Pcarbonn 20:09, 30 September 2007 (UTC)

Well, I suppose 'whitest' would mean 'reflecting all of the visible wavelengths of light equally' - but a mirror does that pretty well and it's not what we'd call 'white'. So I suppose it also has to be a diffuse reflector. Most tests that are done where a perfectly white diffuse reflector is required (eg in calibrating a camera or something) use very pure calcium carbonate blocks - but I guess it's not perfectly white or the question would never have arisen. SteveBaker 21:09, 30 September 2007 (UTC)
Are you sure it was a substance and not a light? There have been many advances towards producing pure white LEDs using nanotechnology. -- kainaw™ 21:45, 30 September 2007 (UTC)
Titanium dioxide seems to be claimed to be the whitest, but I recall hearing that there are coatings used on the fibres of white clothes which absorb UV light and re-emit it in the visible spectrum to make the clothes look whiter (or at least brighter). —Preceding unsigned comment added by 203.22.236.14 (talk) 04:17, 1 October 2007 (UTC)
UV dyes are mixed in with your detergents for exactly that reason. Look at your washing detergent under black-light for a fun time. --Mdwyer 05:07, 1 October 2007 (UTC)
Thanks for the answer. I guess 'white' is a mix of reflection and scattering, and nanostructures can contribute to building a good diffuse reflector. The article I mentioned was not about LED. Pcarbonn 07:16, 1 October 2007 (UTC)
There was an article a while back on an extremely white beetle. http://news.bbc.co.uk/2/hi/science/nature/6272485.stm 71.226.56.79 02:01, 2 October 2007 (UTC)
Wow! That's amazingly cool! SteveBaker 14:40, 2 October 2007 (UTC)
Spectralon bills itself as having the highest diffuse reflectance of any known material or coating over the UV-VIS-NIR region. It's mostly used for spectrophotometry.146.139.76.94 17:12, 4 October 2007 (UTC)

[edit] Calories in alcohol

Does alcohol have any calrories? If so, how many (per ounce or what have you)? Please do not respond by telling me how many calories alcoholic drinks have; I'm only interested in how many calories are found in ethyl alcohol itself.--The Fat Man Who Never Came Back 20:19, 30 September 2007 (UTC)

7 calories per gram. More than portein and carbohydrates, less than lipids. I imagine that that number is just an average though, and that specific types of alcohols will yhave different energy densities based on their chemical structure. --YbborTalk 20:47, 30 September 2007 (UTC)
  • The question was about ethyl alcohol, which is the only alcohol used in beverages, so the "specific types of alcohols" bit is irrelevant. --Anonymous, 21:23 UTC, September 30, 2007.
There's plenty of different types of alcohols.--YbborTalk 21:59, 30 September 2007 (UTC)
It is however true that ethyl alcohol/ethanol is the only one that really matters when it comes to alcoholic beverage. While other alcohols are consumed like sugar alcohol & propylene glycol, this is usually only im minor quantities. Also, as anon said, fat man did specify ethanol in particular near the end of his question Nil Einne 03:08, 1 October 2007 (UTC)
Perfect, thanks. Now how many grams are in an a shot of alcohol... maybe an ounce or so? Not that I'm going around doing everclear shots... I'm just curious.--The Fat Man Who Never Came Back 21:14, 30 September 2007 (UTC)
Well, a US fluid ounce is about 29.57 ml, and ethyl alcohol has a density of 0.789 g/ml, so one US fluid ounce of pure ethyl alcohol would be 23.33 g or about 160 calories worth. --Anonymous, 21:23 UTC, September 30, 2007.
I suspected as much.... more calories than bread, less than butter. Thanks, folks.--The Fat Man Who Never Came Back 21:47, 30 September 2007 (UTC)
Also bear in mind that most alcoholic drinks will also contain calories in the form of carbs and some will also contain calories from protein and fats (such as those with milk in them). StuRat 22:07, 30 September 2007 (UTC)

[edit] big bang theory

although there are many explanations given as to how earth came about from the "big bang" theory, i wanted to no how the material and atoms actually got there in the first place to create this big bang? how was this material invented from nothing?

thanks liam —Preceding unsigned comment added by 86.4.197.35 (talk) 22:23, 30 September 2007 (UTC)

I don't think anyone really knows the answer to that. —Preceding unsigned comment added by 12.217.195.89 (talk) 23:57, 30 September 2007 (UTC)
Timeline of the Big Bang#The very early universe lists links to some proposals. It is important to note that the big bang theory is actually entirely meant to describe what happened right after the universe started existing. For the actual moment of the big bang itself, or what, if anything, came before it, there is no accepted theory. Someguy1221 00:05, 1 October 2007 (UTC)
The big bang supposes that an infinitely small 'dot' of infinite density is the start of it all. In a sense, that is nothing - it's zero sized - but space itself is also scrunched up to zero size, also time, information - everything that ever was or ever will be is in this infinitesimal dot. Like the singularity at the center of a black hole perhaps. Since no information can pass through a singularity - it would be impossible to know what (if anything) created the singularity. One popular suggestion it that it arises from a 'big crunch' of some previous universe. But we can never know. It has also been suggested that time itself would be crunched up in the singularity - so that time would be kick-started up by the same process. In that sense, the singularity would have created time too. Without a 'before' - there can be no thing that 'created' it because the thing that created it would have to have been around before...no before - no creator.
There is a serious problem with asking the question "What was the ultimate cause of everything?" - and when you get the answer 'X' (a space-time singularity in this case) - going on to ask what caused 'X'? When someone provides the answer 'Y' - you're just going to ask "What caused 'Y'?" - if there is some kind of ultimate answer - then that something pretty much has to have no cause - to have been around for infinite time or to have created time. A zero sized, infinitely dense dot that's crunched up time too - through which no information can pass...that's a pretty definite "ultimate" beginning.
SteveBaker 02:36, 1 October 2007 (UTC)
The big bang theory is based on the FLRW solution to general relativity, which has a singularity at the beginning, but physicists do not give this mathematical singularity a physical interpretation. It's just a sign that the theory doesn't work there. Big bang cosmology is about the evolution of the universe, not how it began. The name "big bang" is very unfortunate. It was, as you might know, originally invented as an insult (by Fred Hoyle). Imagine the confusion if the theory of natural selection were known as the tornado-in-a-junkyard theory, after his (senseless) criticism of it. -- BenRG 11:00, 1 October 2007 (UTC)
Stephen Hawkins writings indicate that he is talking about a literal singularity with scrunched up time. It's explained reasonably well in 'A brief history of time' - although you need to read his published papers to get a proper mathematical grasp of the idea...of course he could be wrong, there isn't any actual evidence until a fair amount of time after the actual start of the universe. SteveBaker 13:25, 1 October 2007 (UTC)
Ok, I`m going out on a limb here. This might very possibly be complete rubbish, but this idea came to me not very long ago while trying to explain, to my own satisfaction, if nothing else, to attempt an explaination to how 'our' Universe began. Here goes...please don`t laugh TOO hard!
While reading-up on the possibility(ies) of there being multiple universes, I thought, "What happens when a black hole is 'created' in another 'neighbouring' universe? Where does the matter go?" I`ve coined the term 'white-burster'. This white-burster is what 'could be' the beginning of OUR universe, as we know it. Of course, I coined to term to make reference to its connection with the 'other side' of a black hole. I know, this is totally unfalsefiable, so therefore not science, but I think it 'could' work. One of course, would have to presume that that 'other' universe, if it exists, would be many magnitudes bigger than the one we presently know. Carl Sagan's most famous, I think, quote obviously comes to mind right now: "Extraordinary claims require extraordinary evidence." Of which of course I have none. Sorry if this just wasted everyone`s time. But, if I may just add: Despite being impossible, I think, to prove true, I think it may be just as impossible to prove untrue, which is, of course, nearly assinine as an argument. I`m very afraid to click on "Save page". lol CHEERS! Dave 64.230.233.209 14:29, 1 October 2007 (UTC)
See White hole and White holes in fiction - it's hard to come up with something we don't already have an article about! SteveBaker 15:34, 1 October 2007 (UTC)
I don't know about that; Wikipedia has some hefty gaps in its coverage. A search for slightly obscure items turned up these redlinks: biopsy punch (or punch biopsy if you prefer), pin joint, drip mat, bar runner, and the humble ice bucket (the fact I'm posting this from a pub may've influenced my search terms :P ). Even concepts like the dancing bear and the pauper's funeral, with which most will have at least a passing acquantaince, come up blank. Still, nice to know that there's still so much more out there to write about :) GeeJo (t)⁄(c) • 19:01, 3 October 2007 (UTC)
Simply amazing! I swear I hadn`t heard of any such thing before. Only reason being, I refused to call 'my' white-bursters 'holes'. Maybe I could get the name changed to bursters. I DID however read Hawking`s Black Holes and Baby Universes, but I did not think of each Black Hole being a White Hole someplace else. "MY" white-burster was coined to 'explain' OUR Universe, not other baby ones. So, a little bit of a twist there. Perhaps WE are one of those huge universe`s babies! Thanks for finding that for me. QI! Dave 64.230.233.209 15:57, 1 October 2007 (UTC)
For the record though - I don't think the material that falls into a black hole goes anywhere - it stays right where it is - in the middle of the black hole. That's why these things get gradually bigger. As more material falls in and is compressed down into the singularity, the mass of the hole increases - an the event horizon gradually increases in diameter. If the material somehow fell through and popped out of someplace else (either in our universe - or in another) then the black hole would presumably be unable to grow - and therefore no black hole would ever be any bigger than the star that formed it. Since we know there are 'supermassive' black holes (like the one in the center of our very own Milky Way) - there must be some way for them to grow. Hence, no white holes of the kind you are thinking of. SteveBaker 19:15, 1 October 2007 (UTC)
Yes, I know that Steve. I didn`t get 'into it' as deeply as I could have, just for clarity and conciseness sake. I`m thinknig that maybe there`s some sort of theoretical limit to just how massive a black hole can get, or maybe even a finite age for a huge black hole, then BOOM!...it 'disappears' from huge universe, to create a baby. Maybe once it gets to a certain theoretical limit, the 'dimensions' can no longer hold onto it, and it disappears, creating said 'new' universe. I know, still totally unfalsifiable. This will be my last post right here. Thanks all. Dave 64.230.233.209 20:47, 1 October 2007 (UTC)

[edit] What is meg

Look at this picture. http://www.theoildrum.com/files/Slide7_0.png

At the bottom half, it says "O2/N2 (per meg)", can anyone explain what meg is? Thank you. 202.168.50.40 23:18, 30 September 2007 (UTC)

this site www.eol.ucar.edu/~stephens/talks/stephens_occc0508.ppt claims it is mol/m^2/year —Preceding unsigned comment added by 12.217.195.89 (talk) 23:50, 30 September 2007 (UTC)
I would think megaliter as a volumetric measure of atmosphere.
However, I'm not sure where you got that from, but it looks fishy all around. I wouldn't source it or anything.
Mrdeath5493 03:50, 1 October 2007 (UTC)
Well "per mille" (also "per mil") means thousandths (i.e. 5 per mille = 0.005) in the same way "percent" means hundredths (5% = 0.05). Maybe "per meg" is meant to convey millionths or something like that but its terminology I've never seen before. I dislike 12.217...'s answer because O2/N2 (i.e. a ratio of concentrations) should be a number and hence dimensionless. 76.240.228.205 03:58, 1 October 2007 (UTC)
If you look at the original graph the O2/N2 (per meg) axis has a numeric scale going from 0 down to -500 - so it can't be anything like a percent/per mil/per million thing because those numbers can't be negative. Also the top graph does everything in ppm (parts per million) and if per-meg were a per-million thing then surely that would have been a 'ppm' scale too. At least 12.217.195.89's suggestion of mol/m^2/year would be a negative number - as CO2 builds up, oxygen declines and the ratio of oxygen to nitrogen would decrease. But a rate of decrease of a few hundred moles per meter cubed per year would have us all gasping for breath a long time ago!
This article [2] has a definition of 'per meg' that says:
per meg = ((O2/N2)/(O2/N2)ref - 1} x 106 - in other words the ratio of present-day oxygen levels to the oxygen level at some reference date - messed around until it's some kind of reasonable number scale that looks good on a graph.
This graph [3] in that same article appears to be presenting the same data as the bottom half of the graph that our OP posted - except that there is a 'delta' symbol in front of the "02/N2 per meg" axis - indicating that this is the rate of change of oxygen nitrogen as expressed in this peculiar 'per meg' notation. Both graphs are attributed to 'R. Keeling' - I suspect they are intended to represent the same underlying data - but the version our OP found has been 'messed about with' by people who didn't know what they were doing. I wouldn't pay too much attention to a graph that spells 'dioxide' with a 'y'. Without that delta symbol (and especially without telling us what reference date is being talked about), the numbers don't make much sense. Urgh. SteveBaker 13:21, 1 October 2007 (UTC)
I was skeptical of the dioxide with a 'y' too, but I guess some Euro languages do that. —Preceding unsigned comment added by 12.217.195.89 (talk) 08:53, 2 October 2007 (UTC)

[edit] tick + blade of grass

why is it recommended that when you submit a tick to a lab for analysis you put it in a plastic bag with a blade of grass?

Here is a guess: The grass is a plant, taking in carbon dioxide and giving off Oxygen. That way the tick can continue to breathe and it will stay alive and retain all the diseases so they can be detected. John 03:57, 1 October 2007 (UTC)
Is it even possible to get a tick off you without killing it? I thought that the things have to be dead before you can safely twist them out of your skin? --Kurt Shaped Box 09:14, 1 October 2007 (UTC)
No, you're supposed to twist them off alive with tweezers (preferably ones specially designed for the purpose). If you kill them first (how?), they're more likely to spit some possibly infected fluids back into you as they die. —Ilmari Karonen (talk) 09:58, 1 October 2007 (UTC)
Whenever I've had a tick, I've doused it with isopropyl alcohol (or vodka) until it stops moving, *then* twisted it out with tweezers. A doctor once told me to do that! I had no idea! I have also burned them (and the surrounding area) away with a cigarette when nothing alcoholic was available. I was under the impression that if you tried to remove the tick whilst still alive, then the head would 'lock', snap off and stay firmly attached to your flesh (ticks being tenacious little buggers) and cause an abscess. It's probably lucky that I haven't had a lot of ticks! F-ck me!
How do the 'tick tweezers' work, as a matter of interest, then? At the end of the day, it's a smallish bug - how can you apply enough pressure to the thing to get a grip on it without squashing it flat? --Kurt Shaped Box 13:30, 1 October 2007 (UTC)
When "in their shells", They are extremely hard, almost like an unpopped popcorn kernel. 86.153.44.115 20:28, 1 October 2007 (UTC)
Cool. How are they 'constructed'? Any idea? --Kurt Shaped Box 22:46, 1 October 2007 (UTC)
There are a number of different types of tick tweezers, but a general trait they all seem to share is fairly sharp tips shaped so that they go around the tick's body and only grab the head. The kind I have here (and of which I'll upload a picture of as soon as my camera battery is charged) also have a spring-loaded mechanism which keeps the tips closed unless actively pulled apart: you pull the tweezers open, position them around the tick and let them close. Once you've got a good grip on the tick's head, you can then twist it off without having to worry about the tweezers slipping. (By the way, the second link above has some pretty firm but good advice on the hows and whys of tick removal.) —Ilmari Karonen (talk) 21:12, 2 October 2007 (UTC)
U.S. patent 5002323 seems to describe exactly the type I have here. Click on "images" to see some illustrations. —Ilmari Karonen (talk) 21:25, 2 October 2007 (UTC)
I have also heard the “burn or douse in pesticide first, then remove” advise about leeches. In both cases it was ostensibly to prevent bits of the mouth parts from remaining in the wound. I saw both bits of advice in first aid books. Not sure what is the right answer though. --S.dedalus 00:22, 2 October 2007 (UTC)
Thinking about it, I suppose the advice given might depend on what sort of diseases the local parasites are likely to be carrying - whether the risk of an infection from leaving the head/mouth stuck in your flesh is worse than the risk of the dying critter vomiting god-knows-what into your bloodstream. --Kurt Shaped Box —Preceding signed but undated comment was added at 00:27, 2 October 2007 (UTC)
That’s a pretty picture. :) --S.dedalus 00:51, 2 October 2007 (UTC)
The ideal method of tick removal is with a biopsy punch. You'll get the entire tick out without encouraging it to discharge anything into your bloodstream -- but on the downside, it also removes a chunk of your skin. --Carnildo 00:07, 3 October 2007 (UTC)
Would a blade of grass, presumably snapped off near the base, continue to provide gas exchange? I learned the hard way what happens if you burn a tick before removing it. I had always been taught to heat up a needle and apply that to the tick to convince it to back out of its own volition. One day I didn't have a needle so I heated up the tip of my knife and applied the blade tip to the tick. Too much heat. The tick died in place, vomited into the skin and caused cellulitis which persisted for months. That was the last time I applied heat to a tick. 152.16.59.190 04:07, 6 October 2007 (UTC)

[edit] DEET

what is the metabolic pathway (if there is any) that makes DEET effective at preventing insects from attacking me?

From DEET:

DEET is believed to work by blocking insect receptors (notably those which detect carbon dioxide and lactic acid) which are used to locate hosts. DEET effectively "blinds" the insect's senses so that the biting/feeding instinct is not triggered by humans or animals which produce these chemicals.


Someguy1221 00:10, 1 October 2007 (UTC)

[edit] Deserts

Hi

I've had a look at deserts, but surprisingly it's a little scarce on this topic. My question is: what's the biodiversity really like in deserts in general? I want to say that there are few animals but more insects/microorganism/plants than you'd expect. Would I be right? Comments appreciated. Aaadddaaammm 23:54, 30 September 2007 (UTC)

Sounds about right. Even though there are more than you'd expect, there are fewer than in most other land types (arctic tundra may be an exception). StuRat 01:49, 1 October 2007 (UTC)
Comment: an insect is an animal Nil Einne 02:57, 1 October 2007 (UTC)
I wonder if he appreciated that one. :) DirkvdM 09:11, 1 October 2007 (UTC)
Thanks for your input, guys! Helpful comments (yes, even Nil Einne's - I'll have to specify vertebrates). Aaadddaaammm 23:06, 1 October 2007 (UTC)
BTW, believe it or not I didn't actually purposely include the comment: part because of the 'comments appreciated' part of the qunestion. I had that style of answer on my mind since I'd been discussing stuff at other places and because my comment was unrelated directly to the question I answered like that. The comments appreciated part may have had a subconscious influence obviously. The 'insect is an animal' part was a bit tongue in check since I suspected Aaadddaaammm was probably aware of that (and it seemed a harmless jibe if he/she was) although it was also serious since it was possible he/she didn't. Just saying this to remind everyone including myself that sometimes things come out in strange ways quite by accident :-P Nil Einne 19:12, 2 October 2007 (UTC)