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Sizes of black holes

  1. Dec 12, 2012 #1
    If a black hole is a stellar structure that has collapsed on itself to a singularity does that mean it has no size? But is so defined by its mass and schwarzschild radius?
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  2. jcsd
  3. Dec 12, 2012 #2

    Drakkith

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    Staff: Mentor

    The black hole has a size defined by the event horizon. The actual volume and such is a bit more complicated to determine due to spacetime curvature I believe. A singularity, IF it exists at all, would have no size.
     
  4. Dec 12, 2012 #3

    mathman

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    Current physical theory is unable to accurately describe what is going on inside the event horizon of a black hole. Quantum theory and general relativity don't mesh, and they both come into play.
     
  5. Jan 3, 2013 #4
    The thing to realise is that the term 'black hole' doesn't mean: 'the bit at the center where all of the mass is concentrated, that may or may not be a singularity'.

    'black hole' refers to the whole volume inside the event horizon, which clearly can have a radius, surface area and volume.

    my understanding is that non-rotating black holes are perfect spheres with a radii equal to their Schwarzchild radius, and that rotating black holes are distorted into oblate spheroids, as are most rotating stellar objects.
     
  6. Jan 4, 2013 #5
    A Schwarzschild blackhole singularity is a mathematical point, yes, and so is a Nordström black hole singularity. But Kerr and Newman black hole singularities are one dimensional - they have no thickness, but they have circumference, radius etc.
     
  7. Jan 6, 2013 #6
    How can it be one dimensional with a circumference and a radius? does that make it 2 dimensional?
     
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