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Can things exist/develope without gravity?

  1. Jul 1, 2009 #1
    Particles, life, etc.
     
  2. jcsd
  3. Jul 1, 2009 #2

    negitron

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    Highly doubtful. Without gravity, the only long-acting force is the electromagnetic force. Since (as far as we can tell) the matter in the universe tends toward electrically neutral, there would be very little in the way of attraction going on. Stars could not form and the universe would be a cold, cold place.
     
  4. Jul 2, 2009 #3

    Chronos

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    Particles are possible, life is not. Without planets, life is hugely improbable. Life needs soup from which to evolve. No gravity, no soup.
     
  5. Jul 5, 2009 #4
    I had understood that the electromagnetic force was explainable by spin-like photon exchange (QED) and I've see other proposals that imply gravity might be explained by another photon exchange.

    If so, it would appear, that the electromagnetic and gravity forces might come as a 'set'.

    So I guess I'm saying that its unlikely to be able to have particles without some equivalent of gravity as well. Maybe not 'scaled' as we observe in our universe, but still both.

    So I guess, I'm saying that existence will always include 'a gravity'?
     
  6. Jul 6, 2009 #5

    Chronos

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    Gravity is a given, life is not.
     
  7. Jul 10, 2009 #6
    so does everything has mass?
     
  8. Jul 11, 2009 #7
    Probably so from the perspective of mass energy equivalence....maybe a perfect vacuum without external wave influences would not, assuming ground state conditions...
     
  9. Jul 11, 2009 #8

    malawi_glenn

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    I like soup :biggrin:
     
  10. Jul 11, 2009 #9
    not likely so..... because the very early universe was a charged particle soup, a plasma early on...so as things cooled, electromagnetic attraction and,say the strong force, would pull ions together to form particles...but after that not much would happen...hydrogen and helium might form,just a few simple particles, but gravity is needed to pull such inert gases together and provide the potential energy to get nucler reactions (fission/fusion) started.... a few basic particles drifting far apart would seem to be rather inhospitable to the beginnings of life....
     
  11. Jul 11, 2009 #10

    malawi_glenn

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    No gravitational attraction is not needed for Big Bang Nucleosynthesis. However, gravity is needed to stellar formation.
     
  12. Jul 11, 2009 #11
    Thank you -- a very interesting point.
     
  13. Jul 11, 2009 #12
    And God said -- Let there be General Relativity.

    (sorry couldn't resist upon reading -- after the Douglas Adams quote.)
     
  14. Jul 11, 2009 #13

    malawi_glenn

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    Amen :-)
     
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