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B Spacetime questions

  1. Nov 6, 2016 #1
    I would like to know about this:
    Is there a limit to how much spacetime can warp?
    If there isn't, can there be?
    If we imagined an isolated object in the universe, how much would it warp spacetime per 1 cubic meter if it had the mass of 1 kg. No other gravitational forces are acting on this object. So how much wuld it warp it?And also, is there a chance that spacetime might have potential energy. It has the potential to curve. Is there a thing in GR that strictly says: No! There is NO potential energy in spacetime?
  2. jcsd
  3. Nov 6, 2016 #2


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    Science Advisor

    Gravity is curved spacetime. There is no single number that measures curvature, essentially because the full description of curvature at a point is a four-index tensor called the Riemann tensor, which has 20 independent components. There are a number of ways of summarising this information but, naturally, these are all incomplete descriptions. Many (if not all) can go to infinity. We don't quite believe this, however, and suspect that quantum gravity will become important in regions near the infinite curvature points, so these will not be physically relevant.

    Gravitational fields do carry energy, yes (for example, gravitational waves). Defining it in general, outside simple cases like an isolated mass, is... complicated. You may also be thinking of the cosmological constant, which is a (very small) energy everywhere in spacetime.
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