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Matter and Antimatter - Gravity

  1. Feb 19, 2009 #1
    Matter and Antimatter,

    I have always wondered what happens with regard to the gravitational field when matter and antimatter annihilate each other.
    Consensus among physicists is that matter and antimatter behave the same as far as gravitational potential is concerned, i.e., both will attract matter and antimatter, so that a particle of antimatter would fall toward the earth and not fly off to space.
    According to the currently accepted cosmological theory, essentially equal amounts of matter and antimatter were initially created in the big bang.
    Matter and antimatter promptly annihilated each other but there was an imbalance in favor of matter by about one part in a billion. This imbalance is what was left and now constitutes all the matter in our universe.
    The radiation that resulted from the annihilation is now dissipated with the expanding universe, and is now seen as the cosmic microwave background (CMB) radiation.

    But what about the gravity?
    In the Big Bang, was there briefly the gravitational field of a billion additional universes before the annihilation took place?

    The possibilities seem to be:
    No there was not. This means that after annihilation there was also no residual gravitational field, in which case, contrary to what we currently believe, maybe matter and antimatter do in fact have opposite gravitational potentials.
    Yes there was. This would mean that after the annihilation the naked gravitational field was radiated away as gravity waves. Maybe those gravitational waves, fields/potentials are still out there somewhere and can be detected or measured similar to the CMB
    The question is, what would this residue look like today and how would we go about looking for it?

    Any clarifications from you physicists or cosmologists?

    Thanks and cheers,
  2. jcsd
  3. Feb 19, 2009 #2


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    By E=mc^2, the two (free energy and mass) are equivalent so the same gravitational effects would be observed regardless of whether or not it was particles or free energy.
  4. Feb 19, 2009 #3
    Thanks Nabeshin.
    I take it then, that the observed mass of stars,galaxies and dust, accounts for only a tiny fraction of the gravitational field holding back the expansion of the universe.
    By far the strongest effect (by nine orders of magnitude) is the gravitational effect of the residual CMB radiation.
    Is this what current accepted cosmolgical theory contends?
  5. Feb 19, 2009 #4


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