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Gravity = Megnetic Attraction?

  1. Nov 1, 2007 #1
    I'm a first year physics student, so I don't know too much about advanced physics, though I try to read a lot of physics books, mainly on Grand Unified Theories and such. Yesterday when I was in my physics class, a thought came to me. Could gravity be completely be explained by magnetism? What I mean is, could the net charge of the entire planet account for gravity? And since objects (like people, animals, etc.) all experience the same basic attraction since we are all so small (and therefore a small net charge) in comparison to the Earth?

    I tried to look some of this up on the Internet, but I couldn't really find anything that made sense to me. Could someone explain to me if this idea has been tried before (I assume that it has been), and if this is possible? And if so, could it help with Quantum Gravity, as in both cases magnetic attraction would be acceptable?
  2. jcsd
  3. Nov 1, 2007 #2
    Well, then we should have repulsion also.
  4. Nov 1, 2007 #3
    If you look at the the magnetic component of the Lorentz force you'll see that it's different from the gravitational force and it depends on the velocity of the particle. So, the answer is no.
  5. Nov 1, 2007 #4


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    You need to reconcile these before you make up such a hypothesis:

    1. There are no "sources" of magnetic field, i.e. no monopoles. But we have sources of gravitational field (objects with masses).

    2. Because of #1, you can have a non-zero divergence of gravitational field (i.e. you can have a Gauss's law). You don't have that with magnetic field.

    3. Try to find the curl of gravitational field and then do the same with magnetic field. Do you get the same type of result?

    There are many things that may look "similar" when looking from "very far", but the DETAILS are usually what kill these similarities. This is before delving into the more exotic aspect of quantum field theory.

  6. Nov 1, 2007 #5
    Thanks everyone, I just wanted to know a bit about it. Looks like I'll have to wait a few more years before I'll really be able to understand this well though.
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