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I've got an idea that i would like some help developing

  1. Aug 22, 2007 #1
    Well, first off my question is -Would it be possible to perfectly replicate the big bang digitally?-
    im asking this question for an idea i came up with only 5 minutes ago

    My idea:
    If you perfectly replicate the Big Bang down to the last atom, everything that happened in it would happen exactly as it did billions of years ago.....well if you are able to create that, wouldnt it be possible for us to look at what happened with human kind in the past? I'm not exactly saying that what im about to say is fact, but if you reacreate the big bang, all the atoms would "recombine" (for lack of a better word) and create the universe as we know it. everything would happen exactly as it happened, but then i got the idea of looking into the future, if you were able to recreate the past, wouldnt you be able to "fast forward" time in the reacreated universe? If things happen exactly as they did in real life, then things that happen in the future(on the digital recreation) would happen later in real life also..

    well before i get too far ahead of myself, could someone help me prove or disprove this idea?
  2. jcsd
  3. Aug 22, 2007 #2


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    You already made one "fatal" mistake here. There's no 'atom' at the Big Bang. In fact, for quite some time after the big bang, there were no atoms.

  4. Aug 22, 2007 #3
    ok, so what i truely mean is down to the smallest of details..
  5. Aug 22, 2007 #4
    wouldnt you figure that all of the reactions that happened would happen again?
  6. Aug 22, 2007 #5


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    Zapper is right about the fact that neutral atoms didn't become prevalent until some thousands of years after bang. near bang time it was too hot for neutral atoms to exist.'
    they would have gotten "fried" ionized, their particles broken even further down into quarks etc.

    the first hundreds of thousands of years are a cooling down process. it takes a while before things cool down enough to begin to look familiar.

    the answer to your question is probably NO
    because of the word "perfectly"

    it IS POSSIBLE to simulate the big bang APPROXIMATELY and people are beginning to do that. There is a group at Penn State led by someone with an Indian name (Ashtekar) which has been running simulations for the past couple of years. they do it because they want to study what happened right BEFORE the big bang---their model suggests that there was a collapsing phase that led to a bounce, and the re-expansion we call the big bang.

    the classical deterministic models break down and so people have started using quantum models of the early universe which do not break down but however the quantum models involve uncertainty, limitations on what can be known. They are not fully deterministic in every little detail.

    You asked about models so precise that they could predict details of human history
    give Nature a break :smile:
    she does not care about details of human history.
    it would be wonderful if one could run a model that is precise enough to predict the formation of more or less the right number of GALAXIES.
    think big, broad strokes, dont worry about fine detail

    fun question though
    Last edited: Aug 22, 2007
  7. Aug 22, 2007 #6

    Well, Jeeez....if we could make computer simulations THAT accurate, don't you think we'd have an easier time predicting the weather? :P

    You are dreaming if you think it could be done for the universe down to the last atom.
  8. Aug 22, 2007 #7


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    A computer is a device that takes some initial physical state and converts it to another state by applying physical laws. In the case of what we call 'computers' a string of 1's and 0's are represented by electrical charges and these are converted into a different string of of 1's and 0's that can be interpreted by us as useful information.

    Now the Universe itself then can be thought of as a giant computer. In order to re-create the full complexity of the Universe (and re-create all the information it contains) then we would need something equally as large and complex, i.e. another Universe!

    Any simulation of the Universe that you can do is therefore an approximation. The trick is to make the right approximations that give you the information you want with the accuracy you want without spending to long work out the parts you are not interested in.
  9. Aug 22, 2007 #8


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    Well, this has been answered by a few people above, but I'd like to add my thoughts! The important thing to note is that noone really knows what happened in the very early universe-- it is a time when "normal" physics breaks down, and quantum theory kicks in. Since we do not know precisely what happened then, and of course we do not know precisely what happened before the big bang, we do not have the variables needed to put into a computer to simulate the evolution of the universe. There have, of course, been conjectures and theories made, but these have not, and may not for a long time, been proven.
  10. Aug 24, 2007 #9
    Well Marcus was right. at the point of the bigbang, the whole situation is too hot for atoms to form. Probably just free flowing energy and quarks and other sub elementary particles.
  11. Aug 24, 2007 #10


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    The Particle Data Group has a nice "cartoon" chart on the "History" of the Universe. While there are still many issues that we still do not understand, this is a good starting point in discussing the evolution of our universe. Note that baryonic matter doesn't form until 10^-5 seconds after the BB, while atoms do not form until 10^5 years.

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