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Questions about Universe expansion

  1. May 15, 2012 #1
    I have two questions about the expansion of the Universe. 1. Why is there no local expansion around us, is local gravitational field strong enough to prevent this? How does the vector of gravity act to prevent expansion in multi-directions? 2. When scientists observe the expanding Universe, and comment that "further Universe expands even faster", have they considered the fact that what they see "at the edge" had actually happened nearly 14 billion years ago? Thank you.
     
  2. jcsd
  3. May 15, 2012 #2
    1) Yes you are correct. Theoretically universe expansion holds on all levels, but any expansion on the stellar, or even close galactic level is canceled out by gravitational attraction.

    2) Yes they do.
     
  4. May 15, 2012 #3
    thanks Vorde!
     
  5. May 15, 2012 #4

    phinds

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  6. May 15, 2012 #5
    thanks phinds, that is very useful. I always feel uneasy when I hear scientists say "the farther Universe expands faster"----this seemed to commit the same mistake we made centuries ago----placing the Earth at the centre of the Universe. Cheers!
     
  7. May 16, 2012 #6
    The Earth is at the center of the Observable Universe but this doesnt imbue it with any preferential frame - all points are at the center of their own observable universe - due to the expansion of the Universe and the finite speed of light.

    The furthest places we can "see" do appear to be accelerating away from us but in actuality it is just the consequence of a scale factor over a bigger area of space - its quite a logical assumption.
     
  8. May 16, 2012 #7
    thanks Cosmo Novice!
     
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