Re: SCI: slow light

From: Anders Sandberg (asa@nada.kth.se)
Date: Thu Feb 25 1999 - 10:47:03 MST


KPJ <kpj@sics.se> writes:

> 0. The theory predicts that the total zero point energy in the vacuum to be
> infinite when summed over all the possible photon modes.
>
> 1. The energy of the vacuum should act gravitationally [like an infinite mass].
>
> 2. Infinite mass create infinite gravitation [gravitational law].
>
> 3. Infinite gravitation would create a instant black hole of the universe
> since there exists no force which can withstand this infinite force.
>
> 4. Empirical data does not indicate that [3] has happened.

3 wouldn't occur, since the universe is topologically unable to
collapse into a schwartzschild geometry. It is actually not clear that
something nasty would occur in this case, even if the infinities show
that the theory obviously need refining - quantum gravity, where art
thou?

A quick "fix" would be to assume a corresponding negative cosmological
constant cancelling the infinite mass. Ugly.

You get something similar when deriving entropies for continous
probability distributions - they become infinite - but if you only
care for relative measures, then the infinite terms cancel and you get
a perfectly consistent theory (where you can do nice things and prove
that gaussians are the distributions with the most extropy for a given
variance, and so on). The trouble in GR is that the theory is
nonlinear, and relative measures are not.

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