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Is there any proof that big bang actually happened ?

  1. Feb 9, 2008 #1
    People give me the reason--"As everything is moving apart, at some time in the past, all things were concentrated at a point!"

    Duh! How do they know that everything is moving apart if nothing is fixed ?
     
  2. jcsd
  3. Feb 9, 2008 #2
    Things are moving apart from each other, not some arbitrary fixed point. There are plenty of evidence for the Big Bang, such as redshift, uniform background radiation, H/He ratio etc.

    Do you have some sort of ideological issue with the Big Bang? I'd be more than happy to try to attempt to resolve it if you wish.
     
  4. Feb 9, 2008 #3

    ZapperZ

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    I'm not sure why you posted this in the philosophy forum, of all places, unless you don't really wish to get proper scientific answer. It has been moved to the appropriate forum.

    Zz.
     
  5. Feb 9, 2008 #4

    cristo

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    Actually, the big bang theory does not explicitly say this: it says that there was once a time when the universe was a lot more dense than it is today.

    The fact that we observe every universe to be moving away from us, along with the cosmological principle, gives evidence for the big bang theory.
     
  6. Feb 9, 2008 #5

    russ_watters

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    Since you're clearly familiar with Google, try "pillars big bang"... You may need to make sure your crackpot detector is on, but you'll get some good links to the theoretical and observational pillars of the theory.
     
  7. Feb 9, 2008 #6

    malawi_glenn

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    cosmic microwave background radiation, Hubble expansion, Big Bang Nucleosynthesis (abundance of deuterium and H vs. He ratio) are the best three "proofs" for BB.
     
  8. Feb 9, 2008 #7
    Ok then, I assume the universe was a point long time ago, but who lit the matchstick to set the universe blast out ? God ?

    If it was a point, it could have remained in the point form forever. Why did it expand ? What factor made it expand ? God ?
     
  9. Feb 10, 2008 #8
    'God' is not a scientific explanation of anything. Nobody knows but there are theories in string theory about string branes the size of universes that collide into each other and lead to the big bang(and most likely many more big bangs in such a scenario.)
     
  10. Feb 10, 2008 #9

    marcus

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    They don't know what the theory actually says. I don't think you do either. The first thing you should do is read this Scientific American article Misconceptions about the big bang March 2005. Here is a PDF.


    http://www.astro.princeton.edu/~aes/AST105/Readings/misconceptionsBigBang.pdf

    Here is an HTML link to the same article

    http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147

    The article had some very useful SIDEBARS giving pictorial diagrams with a question together with right and wrong answers explained. For easier access, here are links to individual sidebars.

    http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p39.gif
    What kind of explosion was the big bang?

    http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p40.gif
    Can galaxies recede faster than light?

    http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p42.gif
    Can we see galaxies receding faster than light?

    http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p43.gif
    Why is there a cosmic redshift?

    http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p44.gif
    How large is the observable universe?

    http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p45.gif
    Do objects inside the universe expand, too?

    The scientific theory does not say that at some time in the past "all things were concentrated in a point." That is what you think it says, so it is useless for you to argue against it----you are not arguing against the real theory. You must first find out what it really says.
     
  11. Feb 10, 2008 #10

    russ_watters

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    Sure, why not. To a scientist, does it really matter?
     
  12. Feb 10, 2008 #11

    marcus

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    Yes, to those scientists who study the early universe, it matters a great deal.
    Different models have different explanations for "Why did it expand? What factor made it expand?"

    The original poster's premise is wrong, however. I don't know any scientist who says that the whole universe was concentrated in a point. Extremely concentrated for a moment, perhaps in a finite region, but not infinitely concentrated and not at a mathematical point.

    The people who make a specialty of this have various models, expansion beginning after something else happens, expansion beginning as a result of this or that, and so on.

    So to them it matters a great deal! The question "Why did it start expanding?" is one of the most interesting questions to investigate.
     
    Last edited: Feb 10, 2008
  13. Feb 10, 2008 #12
    No - there's no reason to assume that. According to that Misconceptions About the Big Bang Scientific American article at the point of the Big Bang the universe could potentially have been three-dimensionally infinite in size.

    I think the thing that confuses people is the “ant on the surface of a balloon” analogy that's used in that article and elsewhere. It's really analogous to the third-dimensional surface of an expanding fourth-dimensional balloon, if anything (but there's no certainty the universe is shaped like that). They ought to change it to “ant on a rubber sheet that's being stretched in all directions.”
     
    Last edited: Feb 10, 2008
  14. Feb 11, 2008 #13

    marcus

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    Here is another related post

    This was from the thread Ulnarian started called "What lies outside the universe?"

    Personally i find myself at a loss as far as responding kindly but consistently with cosmology forum norms. Maybe someone has an idea?
     
    Last edited: Feb 11, 2008
  15. Feb 13, 2008 #14
    my guess is he's one of those gap theorist and no matter what evidence shown he will find something new missing ad infinitum.

    should all humans instead bow down and give up learning :|
     
  16. Feb 13, 2008 #15

    russ_watters

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    Dunno how relevant this really is, but....
    What a mean God! I would think that if God exists, he would give us only as much power has he wants us to use (it would be pretty pretty capricious to give us powers, then get angry when we use them). So if we can figure these things out, we should. And there is certainly nothing wrong with the pursuit even if it is ultimately futile.
     
  17. Feb 13, 2008 #16
    The big bang is only one of the theories!!! the other more probable one in my opinion is the collision theory... i think thats what its called... but thats in chemistry for atoms and stuff. Any who its the one when all the particles of dust in the universe collide with eachother and build up and create planets!!!
    If God does exist then the only thing he really could have done on the grand scope of things is get the living from the non living.
     
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