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Looking back in time to the Big Bang

  1. Oct 25, 2008 #1
    If the universe is uniform no matter in what direction you look , then looking in two opposite directions, two observers, if each looks far enough will see the Universe at its earliest time -- The Big Bang. Therefore, the event of the Big Bang cannot be from a point singularity. It does not exist in any one (singular) direction, but can be observed in any direction you cast your gaze. Like the electron, then, the Big Bang must be "spread out" in an "orbit" around all that is. The concentration of matter around the time of the Big Bang "spread in all the furthest directions that you can see might be what causes the tug of matter toward it and away from any present observer. Couldn't it be that the universe is actually contracting outward toward the Big Bang instead of expanding as if away from a center?
  2. jcsd
  3. Oct 26, 2008 #2


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    Can you explain that? A sound wave originates from some source which we usually consider to be a point source, yet the wave front spreads out in all directions. You can observe it from anywhere.

    Also, note that "looking far enough" is a nice statement but without physical meaning: we can only see so far as the light has been able to travel so far.
  4. Oct 26, 2008 #3


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    That's right! Good point. We can only see matter which is 46 billion lightyears away from us, at present.

    Because in the whole age of expansion (estimated 13.7 billion years) that is the farthest light has been able to reach.

    It's good to think about those numbers and to help visualize you can try some of the basic visualization stuff in this sticky thread:

    It's basic cosmo one----if you have any questions or don't understand, just ask.

    Keep in mind that all matter, including earth rocks and our bodies, derives from what issued from the Bang.
    And the farthest matter we can see----the stuff which is now 46 billion lightyears away at present---has by now presumably evolved into stars and galaxies and planets looking pretty much like our local neighborhood.
    The assumption of uniformity covers them as well as us. The heavens to them presumably look very similar to ours. They too are uniformly surrounded, in all directions, by stars and galaxies.
    The uniformity that poeteye mentioned means that all space is uniformly filled with matter, more or less evenly distributed----as far as we know there is no space outside space: no emptier place.
    Again, the balloon analogy in the Cosmo Basics sticky thread may help visualize.
    Last edited: Oct 26, 2008
  5. Oct 26, 2008 #4
    Take a look at the diagrams on Ned Wright's website: http://www.astro.ucla.edu/~wright/cosmo_02.htm#DH
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