Re: SCI: slow light

Anders Sandberg (
25 Feb 1999 18:47:03 +0100

KPJ <> 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!                  
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y