Re: GR-friendly Quantum Mechanics
- From: iuval <clejan@xxxxxxxxxxxxxx>
- Date: Sat, 11 Aug 2007 21:53:40 +0000 (UTC)
But these are postdictions, not predictions. Really, this is an
important point, we need to think of non-trivial predictions if we
want to make progress in physics, not just mathematics.>
Aha! I think we hit a bullseye! I suspect that many physicists,
including some of those working in the foundations of physics, are of
a similar opinion, hence no wonder what is going on. To realize how
wrong you are on this point is to acquire a good sense of physics.
If experiment shows that spacetime is four-dimensional, before a
theory of spacetime, saying that it MUST be four-dimensional, is
invented, this does not mean that such a "postdiction" is a trivial
thing. In fact, the lack of such a "postdiction" means that a theory
must adopt this as an axiom, which of course means that the theory
does not explain why spacetime is four-dimensional, as the experiment
shows. Dimensionality of spacetime is of fundamental importance to
everything else, if it was different the consequences would be
unimaginable. The important thing is that this axiom is implicit in
countless other "predictions", so the theory does not really explain
them either.
To summarize, spacetime does not have to be four-dimensional, but
experiment shows that it is. Why?
There does not have to exist a (pseudo- or proper-)Riemannian metric
on it, but it does. Why?
The metric does not have to be Lorentzian, but it is. Why?
I skip other more technical "postdictions".
<We all know that we happen to live during the Einstein-Heisenberg
epoch (GR-QM paradigm). Does GR or QM predict any of this? Does ST,
LQG or, God forbid, NGG predict any of this?
I don't know what ST LQG or NGG is. Probably cosmological theories?
Will look them up.>
ST = String Theory (the gigantic well-funded attemt to describe the
universe via Ptolemaic epicicles); LQG = Loop Quantum Gravity; NGG =
Noncommutative-Geometry Gravity (my apologies for the last one).
Best, Vladimir.
Dear Vladimir, we should probably continue this conversation in
private, since it is getting too philosophical for this forum. I will
post more technical physics when I understand your paper. I didn't
know that ST was also guilty of Ptolemaic epicycles--I thought there
were very few adjustable parameters. Anyway, if I succeed in
understanding your paper, I will try to think of testable predictions
and how to do the experiments. I hope you will think in that direction
also, although it is a free country, at least as far as what you
think. The postdictions are not worthless, especially since you didn't
have any adjustable parameters to fit them, but they are really not as
compelling as predictions.
.
- References:
- Re: GR-friendly Quantum Mechanics
- From: V. Trifonov
- Re: GR-friendly Quantum Mechanics
- From: iuval
- Re: GR-friendly Quantum Mechanics
- From: V. Trifonov
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