Re: PHYSICS: Black holes on demand?

From: Hal Finney (hal@finney.org)
Date: Wed May 28 2003 - 14:53:59 MDT

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    Here is an abbreviated repost of a message I wrote last year when this
    topic was previously discussed:

    It's amazing to see how an *extremely* speculative prediction has now
    migrated to conventional wisdom. Another article claiming the same thing
    is http://www.nature.com/nsu/011004/011004-8.html:

    : Physicists at may soon be manufacturing copious quantities of black
    : holes. When the Large Hadron Collider (LHC) at CERN, the European particle
    : physics laboratory near Geneva, is completed in 2005, it could produce
    : a black hole every second.

    It's only when we follow the link at the bottom of that article to
    http://xxx.lanl.gov/abs/hep-ph/0106219 that we see:

    : If the fundamental Planck scale is of order a TeV, as the case in some
    : extra-dimensions scenarios, future hadron colliders such as the Large
    : Hadron Collider will be black hole factories.

    See? It's only true in theories of extra dimensions, where the
    universe has something like 10 spatial dimension. These theories are
    extremely speculative to say the least. The LHC will be a good test of
    the existence of these extra dimensions but I doubt that many people
    seriously expect the theory to be confirmed. The conventional Planck
    scale is 10^19 GeV, and these guys are assuming it is about 10^3 GeV.
    Their prediction is 16 orders of magnitude different from conventional
    physics! It can't be ruled out but it is far from the mainstream.

    So we have gone from a test of extra-dimensional physics at the LHC to
    the fact that the LHC is "expected" to generate black holes. Somebody
    is being awfully sloppy.

    Hal

    P.S. The really interesting thing is that if this prediction were true,
    and the LHC really did create black holes, it would essentially spell
    the end for particle physics! From the TeV energy scale on up, particle
    dynamics would be dominated by gravitational interactions. All higher
    energy particles would be cloaked in black holes. There would be no
    way to learn anything more about the nature of particles beyond that
    energy barrier. You could still learn about the nature of the universe,
    of space-time, of the size of the various dimensions. But you'd be
    stuck with guesses and theoretical modelling as far as the particle
    zoo.



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