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B Why does "gravity" need to be unified?

  1. Sep 6, 2017 #21


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    Strictly speaking it doesn't predict that. For example what do you mean by zero radius? I am guessing that you have in mind ##r=0##, where ##r## is the usual coordinate. But this coordinate cannot, even if you stretch the meaning, be interpreted as a radius. It is not even spacelike, it is timelike. Any statement about zero radius is at the very least inaccurate and misleading.
  2. Sep 6, 2017 #22


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  3. Sep 6, 2017 #23
    Can you briefly, perhaps with a simple reference, provide your understanding of the difference between the two terms "gravitational wave" and "gravity wave". It is seems the two are clearly defined differently. I'd appreciate an understanding of that difference if you have the time.
  4. Sep 6, 2017 #24


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    Both have Wikipedia pages, which describe them:

    So beside their similar names, they have few in common.
  5. Sep 6, 2017 #25
  6. Sep 15, 2017 #26
    - As far as looking to gravity as a force ; nature may respond to us with 'guys : why do you insist on calling everything a force' ?
    Of course it can't be 'denied' but it is 'human-centric' and lays deeply within us and comes from our experience on which we
    interact with the world. And that is ofter forgotten, when making all those complex theories , trying to integrate gravity with everything else...

  7. Sep 16, 2017 #27
    If we assume that 1 and 2 are true:
    1. The EP (equivalence principle)
    2. The principle of general co-variance

    a) Then gravity is not force?
    b) Then gravitons do not exist?
    c) Then running coupling constant of gravity do not exist?

    I gave a question also here so that an answer will not be repeated.

    My opinion about OP: Gravity is maybe not a force, but it should be quantized.
    Last edited: Sep 16, 2017
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