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Relativity plus gravity

  1. Sep 16, 2010 #1
    when you factor relativity into the interactions of charged particles you get magnetism. Relativity says that magnetism is required to make the laws governing the interactions invariant.

    What about gravity? When you factor relativity into gravitational interactions do you get yet another field?
  2. jcsd
  3. Sep 17, 2010 #2


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    If you start with Newton's theory of gravity and add relativity, you don't get a theory that predicts what we observe. There is a well known paper by Currie, Jordan & Sudarshan that shows that it's not possible to have a relativistic interaction term in Hamiltonian theory. So it would appear that a proper theory of gravity can't be constructed this way.

    General relativity is built on SR so it is already there. GR and SR are kinematic systems. In GR, the sources of gravity don't interact directly with each other, but affect the spacetime, which is the background of the kinematics.

    I've got a feeling I've not answered your question, but that's how I see it.
  4. Sep 17, 2010 #3


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    If you start with special relativity and add Newton's law of gravity, it will be very difficult if not impossible to avoid inconsistencies in the theory (because the force propagates with infinite speed).
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