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Expanding Universe Problem

  1. Jul 8, 2014 #1
    Universe is expanding. I know that all the galaxies are getting away from each other due to the expansion. So in theory is it true that we along with every other system of particles are getting stretched with the space ( or the distance between our constituent particle is getting bigger and bigger (no matter how small the expansion is at this scale) )?
  2. jcsd
  3. Jul 8, 2014 #2


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    Expansion is only an intergalactic phenomenon.
  4. Jul 9, 2014 #3
    Space is expanding and there is no difference between intergalactic space and space in which we are present right. So why would you not agree on the fact that we are also 'expanding'?
  5. Jul 9, 2014 #4


    Staff: Mentor

    Dark energy forces act on the universe at very large time scales and make it expand.

    At short distances, gravity, electrical and other atomic forces are much stronger and they overwhelm the dark energy force.

    Therefore, things far apart expand, things close together don't.
  6. Jul 9, 2014 #5
    Gravity, Electromagnetic Forces, Strong and weak force acts among the particles and I think that space is not affected by them. These forces do not stretch or contracts space except gravity which only curves it. So I think that expansion of universe has nothing to do with these forces.
  7. Jul 9, 2014 #6
    Oh I got it... Now what I got is that small bodies do not get stretched with space but the space in which they are located gets stretched.
  8. Jul 9, 2014 #7


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    There is no "force" driving the expansion, nor is dark energy needed. Dark energy is thought to drive the recent accelerated expansion of the universe.
  9. Jul 9, 2014 #8


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    But there is a difference between intergalactic space and local space: the former is homogeneous and the latter is not. The geometry of space dictates the cosmology.
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