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Can we find

  1. Jan 25, 2005 #1
    Can we find....

    Is it possible for us to find the universe point of origin based on location of cellestrella bodies? If so how? If not why?
     
  2. jcsd
  3. Jan 25, 2005 #2

    Chronos

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    No. Everything in the universe started at the same 'location' [big bang] then moved apart. No matter where you are in the universe now, it appears you are still at the center. Why? Because everything you look at appears to be moving away and the recession velocity solely depends on it's distance, not direction. The universe is also homongenous. Matter is not preferentially distributed in any direction.
     
  4. Jan 27, 2005 #3
    But if it was created by an explosion then why cant we take surronding glaxie's distanc from us and the speed there movie as well as the direction and work backwards? Oh and why do we think of our universe as infinite space if it is only going to collaps sooner or later. And at what speed is our universe expanding at?
     
  5. Jan 27, 2005 #4

    Phobos

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    The Big Bang was not an explosion of stuff into space. It was the rapid expansion of all space. As such, there is no center or edge to 3D space. Imagine an infinite grid. Now make each grid square/cube twice as big. In that one instant (let’s call it a second), grid point “A” saw its neighboring grid point (point B) take 1 step away (1 step in 1 second)…but a grid point located 2 away (point C) took 2 steps in that same (2 steps in 1 second)…and so on.

    Two key concepts to understand:

    (1) The farther away someone at point A looks, the faster things appear to be expanding (even though the overall grid has a constant expansion).
    A-B-C (start…B is 1 dash away from A and C is 2 dashes away)
    A - -B - -C (one expansion step…now B is 2 away and C is 4 away…twice as far in the same second)

    (2) Each grid point can see itself as stationary and see all other points expanding away from it.
    (point A sees point C moving 4 dashes away, but C sees point A moving 4 dashes away)

    If the Big Bang was an explosion of stuff into empty space, then yes, you would expect to see a preferred direction (in this case, our imaginary grid would not have parallel lines…they would converge back to 1 point). But what we actually see is no preferred direction of expansion.

    The rate of expansion is expressed by the Hubble Constant...something around 70 kilometers per second per megaparsec...so something 1 megaparsec away from us appears to be receeding 70 kps from us and something 2 megaparsecs away appears to be receeding 140 kps from us, etc.

    If the universe is indeed infinite, then it won't collapse. It would expand forever. If the universe was finite, then gravity would pull it all back into a Big Crunch. Still lots of ongoing research to determine whether the universe is infinite or not.
     
    Last edited: Jan 27, 2005
  6. Feb 4, 2005 #5

    Nereid

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    Another way of saying what Chronos and Phobos have admirably said is "your heart, whatzzupboy, is exactly the point of origin of the universe; you are truly special." Now before you get too high on this thought, remember that it's equally true of all hearts in the universe, whether they be homo sap. hearts or the heart at the core of every one of the 10>80 baryons.
     
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