Re: black holes again

From: Anders Sandberg (asa@nada.kth.se)
Date: Tue Aug 05 2003 - 02:35:40 MDT

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    On Mon, Aug 04, 2003 at 02:52:47PM -0700, Lee Corbin wrote:
    >
    > I maintain only that the event horizons of this object and
    > other black holes have not *yet* formed, and there are as
    > yet *no* singularities over which to worry.
    >
    > It's just a frozen star, as all the Russian scientists in
    > the 1950's would have told you.

    And how do you distinguish between frozen stars and black holes? Your
    complaint seems to be against the existence (in whatever tempus) of
    singularities, and to a lesser degree the existence of event horizons.

    But the singularity is not necessary to have a black hole, e.g. some
    quantum gravity theories propose that local inflation creates a baby
    universe with a different but finite topology. The black hole picture is
    really about the outside and "surface" characteristics of the structure;
    the interior is just theory playground (until we get the chance to drop
    wormholes into it).

    Event horizons appear naturally even in classical physics if you view
    them as the effect of superluminal escape velocities. Even in GR they
    are no "real" objects but rather the spacetime hypersurfaces with
    limit light rays.

    The Schwarzschild solution is rather inescapable for any spherically
    symmetric static object, and perturbations don't seem to alter the
    essential characteristics. Do you disagree with GR altogether, or assume
    that some other effect causes the interior to behave wildly different (a
    la the baby universe example above or some weird force preventing
    collapse)?

    > Surely there're have been other people who see through all
    > this besides just me.

    http://antwrp.gsfc.nasa.gov/htmltest/gifcity/bh_pub_faq.html#evaporate

    (seems a bit too popular to me. Maybe the best way of finding out is
    simply to make a model of a classical black hole with a slowly
    decreasing mass and follow where the geodesics go)

    -- 
    -----------------------------------------------------------------------
    Anders Sandberg                                      Towards Ascension!
    asa@nada.kth.se                            http://www.nada.kth.se/~asa/
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