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Help with GRT: Masses on a sphere

  1. Aug 28, 2010 #1

    I have a question about how to explain GRT best, exactly the cosmological "situation".
    Since a 4D manifold which is imbedded in itself is too much for our brains (at least mine) I still like the comparisn with a 3D sphere surface (unfortunately embedded in 3D).
    Let us distribute mass on this sphere, all physical laws applied where every law is to be reduced as a projection with respect to the surface, what would we get?
    I am very sure we would get over time a universe on a sphere since we have (for example) gravity.
    A typical beginners question is: "If the universe is an expanding sphere (*) we need to have a center of gravity, it is in the middle...".
    * I don't know in english the correct word for a sphere with filled space, not only the surface :(
    This beginners fault can be easily answered with this reduced "surface reality" since there is no centrum.

    So my first question: Would you say this is a proper way to explain the reality?

    The second one, ashes over my head... wouldn' the expansion of the sphere significantly
    influence the physical laws? I would say: clearly, since this is the ART and not Newtonion physics - it should be a proper description of the differences.

    The third one: If you would say that this thoughts are reasonable, is there some material about it, for example animations, videos?

    Thanks a lot,
  2. jcsd
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