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Big Crunch(es)

  1. Jul 20, 2010 #1
    Random musing:

    Could it be that sufficient expansion of the universe that leaves behind only black holes that have gobbled up all the mass, lead to several big crunches, and eventually several new universes?
  2. jcsd
  3. Aug 6, 2012 #2
    Based on my understanding, this wouldn't happen for a couple of reasons:

    First, while all the matter being gobbled up into black holes is a possibility for the fate of the universe there is still further development that increases the entropy of the universe even further (following the entropy based arrow of time). This is Hawking radiation, where black holes slowly decay, leaving behind a featureless and constant collection of particles - the highest entropy point (equilibrium).

    Also, the collection of matter in a black hole is not the same as the Big Crunch. The Big Crunch, if it occurred, would result from the gravity of the matter in the universe slowing the universe's expansion to a halt and re-collapsing it into a singularity. This is not the same thing as a black hole, although both involve singularities. For a simple explanation of the difference between the Big Bang (or Big Crunch) singularity and that of a black hole visit: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/011030a.html
    Or for a more technical explanation visit: http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/universe.html

    It's a cool idea though and something sort of similar is being tentatively explored by physicists right now. I read about the idea of multiple baby universes being created in Sean Carrol's From Eternity to Here. It is a great book exploring the arrow of time and entropy, as well as some speculative stuff based off of that. A link in Physics Forums discussing the idea is: https://www.physicsforums.com/showthread.php?t=469255
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