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Black hole collision

  1. Jun 7, 2009 #1
    what would happen if a black hole collides with a black hole with the speed of light
  2. jcsd
  3. Jun 8, 2009 #2


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    Hi jontyjashan! :smile:

    Black holes have mass, and so can't travel at the speed of light.
  4. Jun 8, 2009 #3
    Gravitational waves will probably be the result, isn't this what LIGO is looking for?
  5. Jun 8, 2009 #4
    Any black hole collision results in the fusing of the singularites and gravitational waves. I'm guessing the faster they collide, the more energy is probably put into the gravitational waves. So, nothing really special would happen. Tiny Tim is right though... nothing with mass can travel at speed c.
  6. Jun 9, 2009 #5
    Well if u ignore the fact that if would take an "infinate" amount of time (well even longer cause there are two black holes) for them to abosorb into eachother. Wouldnt the larger black hole tear apart the smaller one. How do u tear apart something with a volume a zero? Now say that are the same size wouldnt they just absorb eachother for an actually infinate amount of time, transfering mass to eachother at the same rate while never colliding? Only appearing to fuse but never doing so.
  7. Jun 9, 2009 #6
    From who's reference frame are you talking about?

    It happens, black holes fuse. The singularities orbit each other until they fuse.
  8. Jun 9, 2009 #7
    Well i know this is stupid, but from our referance they would appear to fuse. Also from our referance they never actually fuse because it would take an infinity to reach that point. My curiosity is would the masses not fusing have noticable effects on the orbiting masses or hot gas (forgot what its called exactly). Maybe im just confused on the infinity it would take the masses to reach eachother relative to us. Or has that theory changed. I never really like the idea of infinate time anyway.
    Last edited: Jun 9, 2009
  9. Jun 9, 2009 #8
    I was always under the assumption that the fusing of two singularities took a finite time.
  10. Jun 9, 2009 #9
    Well from my understanding if light cannot escape (aka event horizon) then the curve of spacetime at that point is in fact infinate. However from what I read the acceleratrion of the falling object would allow it to pass the event horizon. I read some more sources on the Schwarzchild solution to the gravitational field and it does not take an infinate time to cross the event horizon only to merge with the singularity itself. So im guessing the singularities would never merge they would just be very close so the effect on gravitational pull would be negliable.
  11. Jun 9, 2009 #10
    I'm not sure on this. I'll do some reading. I better get to bed. It's 3 am where I am now.
  12. Jun 9, 2009 #11
    lol me too~Chi-town
  13. Jun 15, 2009 #12
    Shouldn't in our view it fuses but in the view of the black holes they never get to fuses because it takes infinite time?
  14. Jun 15, 2009 #13
    This is correct. Time is infinite from the reference frame of within the black hole. To us though, it is still finite. So, yes, they merge in a finite amount of time from our perspective.
  15. Jun 16, 2009 #14


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