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Seeing the entire future of the Universe

  1. Jul 11, 2013 #1
    What does " Sees the entire future of the Universe" mean? I can't even imagine seeing one minute into the future let alone the 'entire future'...

    The interior structure of rotating black holes 1. Concise derivation

    [From the third paragraph, INTRODUCTION]

  2. jcsd
  3. Jul 11, 2013 #2


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    Well, if you were to hover sufficiently close to the event horizon of a black hole, you could imagine, for instance, looking out and seeing the universe age at 1000x the rate at which it would age if you were out of the BH's gravity well.

    So now all you need to do is imagine that factor of 1000 going up without bound - higher and higher - until you approach infinity, to understand what the paper is talking about.

    Of course if that did happen, you wouldn't be alive to see it, because there'd be no way to survive an infinite blueshift, there is some maximum "survivable" blueshift based on your radiation tolerance.

    The other issue is that even if you could survive that, the Kerr metric assumes that the amount of matter infalling isn't large enough to disturb the metric. If you've got a potentially infinite amount of energy infalling, obviously the idea needs to be re-examined.

    Current thinking is that the Kerr metric isn't stable, and that the actual metric of a rotating black hole is "something else". The paper describes what that something else may be, the section you are reading is justifying why the authors feel the Kerr metric isn't really adaquate.
  4. Jul 11, 2013 #3
    Ah, that I did not know.....thanks
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