Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Time affects on blackholes?

  1. Nov 24, 2009 #1
    It is stated that nothing can escape a blackhole and they are gigantic and powerful enough to rotate a galaxy. The gravitational force of space acting on the blackhole is immense. On this level of gravity could time it self be stopped in the blackhole?

    Therefore the amount of mass taken by the blackhole could be a lot less then we think it just takes longer as time is slowed down.

    Your thoughts…………
  2. jcsd
  3. Nov 24, 2009 #2
    My thoughts are that you put your question(s) in pretty unclear fashion, except for time slowing down, which is true for outside observer.

    - Black holes are not necessarily gigantic. It is mass/volume ratio, or density, that qualifies region of space, occupied by that mass, to become a black hole.

    - Mass is the one that causes gravity, not the space. But it is true that space - time is the "medium" through which gravity acts, so you can tell that space - time is the one who exerts "force" on a object.

    - What do you mean by "Therefore the amount of mass taken by the blackhole could be a lot less then we think it just takes longer as time is slowed down". It just takes longer for what?
  4. Nov 24, 2009 #3


    User Avatar
    Gold Member

    BHs come in all sizes. Some are small, some are huge and live at the centre of galaxies (they do not "rotate the galaxy" - galaxies will do just fine without them.)

    It is the gravitational force of the BH that acts on space, not the other way around.

    Why would it?

    The changes in the gravitational field around a black hole propogate at the speed of light.
  5. Nov 25, 2009 #4


    User Avatar
    Science Advisor

    Er, well, not quite. The supermassive black holes at the centers of galaxies sound impressive, but they still only make up a tiny fraction of the total masses of the stars in galaxies.

    Well, time dilation is fully taken into account by the gravitational field predicted by General Relativity.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Time affects on blackholes?
  1. Stable Blackhole? (Replies: 3)

  2. Blackholes and galaxies (Replies: 15)

  3. Parts of Blackholes (Replies: 1)