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Black Holes and wormholes

  1. Nov 7, 2007 #1
    I have been reading a book about black holes and I picked up a lot of information, but some things still bother me. First I don't understand why they think a wormhole exists. I understand that as you get closer to the singularity space time is curved drastically. But if you look at common sense, it should tell you that this is just a ball of matter so tightly compact that there is no hole and that anything that goes inside it will be destroyed. It seems that they took a graph of the curvature of space that approaches infinity and desided to say that is never reaches infinity and therefore there is a hole in the graph that they actually think is transversable. But how could it be infinity if there is a finite density. This makes no sense to me.

    I can't think of the other questions but I will post them soon. thanks
  2. jcsd
  3. Nov 8, 2007 #2

    Chris Hillman

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    What book?

    They? As in, the authors of the book you read? Or as in, astrophysicists?

    A (traverseable?) wormhole? Or a black hole?

    Assuming the answers are "astrophysicists" and "black hole", see for example the review article by Martin Rees inhttp://www.press.uchicago.edu/cgi-bin/hfs.cgi/00/13535.ctl [Broken] ; see also http://arxiv.org/abs/astro-ph/9701161 for an update to 1997. The existence of black holes has not been doubt for several decades. (For a long time this notion was viewed a theoretical speculation with little observational support, but this changed drastically with the discovery of Cyg X-1.)

    If the answers are ""astrophysicists" and "Einstein-Rosen bridge" (old name for so-called "throat" of "eternal Schwarzschild hole"), try some of the posts in my sig.

    If the answers are "astrophysicists" and "traversable wormhole", try http://www.arxiv.org/abs/0710.4474 for a review of arguments pro/con regarding the (im)-plausibility of "exotic matter" and "traversable wormholes" (note that the author is in the pro camp; most physicists seem to be in the "con" camp, as I am).

    Your common sense probably doesn't agree with what gtr actually says about the interior of the Schwarzschild vacuum, the model you probably have in mind. I urge you to obtain and read the excellent popular book by gtr expert Robert Geroch, General Relativity from A to B, which specifically aims to convey an accurate geometrical picture.

    If possible I urge you to obtain the book I mentioned and read it first. The thoughts you are trying to express appear to correspond to some common misconceptions. Geroch's book will clear these up much more authoritatively and probably more clearly than we can do at PF.
    Last edited by a moderator: May 3, 2017
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