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Black hole Questions

  1. Aug 27, 2009 #1
    I've been watching too much science channel specials on black holes and need a few things cleared up heh

    On the TV show they said that a black hole is actually not only eating near by stars and gas but actually consuming space time its self. My question is, if space time is being sucked into it at speeds faster then light, how is the graviton force particle able to escape. Do gravitons move faster then light?

    Another question I have is about super-massive black holes. Some black-holes like the ones in the center of galaxies are billions of solar masses while others are only 10. On TV they said that the singularity is infinitely small and infinitely dense but if this is the case is one infinity is bigger then the other one?
  2. jcsd
  3. Aug 28, 2009 #2
    Graviton 'waves' propegate at the speed of light. Gravitons themselves, being the force carriers of Gravity are not subject to its effects.

    As for the size of black holes, if they are indeed singularities, then they are infinitessimally small points. Anything with this 'lack of dimensional size' but with ANY amount of mass, MUST have infinite density. However, it is the mass that is responsible for their gravitational force, and density is irrelevant. Therefore, a 10M(sun) Black Hole will be weaker than a 1 000 000M(sun) Black Hole.

    I don't think that matter or 'spacvetime' is being sucked into Black Holes at speeds greater than light, despite clearly being greatly accelerated. However the pull of gravity can be strong enough to curve any photons' paths by a large amount. Any photons (or matter too) that enter the Event Horizon, even with their immense speed, lack the energy to escape.

    Also, I'm not sure on the space-time being sucked into a Black Hole. Einstein concluded that spacetime itself is warped around mass, the magnitude of warping proportional (inverse square of mass to distance of an affected mass) to the mass itself. This warping effectively IS gravity.
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