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Article 6042 of comp.ai.philosophy:
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>From: holmes@opal.idbsu.edu (Randall Holmes)
Newsgroups: comp.ai.philosophy
Subject: Re: Quantum mechanics (no AI here, sorry)
Message-ID: <1992Jun2.161131.11780@guinness.idbsu.edu>
Date: 2 Jun 92 16:11:31 GMT
References: <1992Jun1.201556.24184@news.media.mit.edu> <1992Jun01.234940.40210@spss.com>
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In article <1992Jun01.234940.40210@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
>
>Now, your idea that the universe does have "real states" even if we can't
>(yet?) observe them is not new; such "hidden variable" theories can be
>built which are compatible with quantum facts.  However, it's been
>pretty well established that such theories can't explain the facts without
>recourse to faster-than-light signalling.

If you think that the waves are real physical phenomena, then FTL
signalling is involved.  I think it is quite reasonable to suppose
that the universe has "real states"; the particle side of the
particle-wave duality is real; the wave side encodes restrictions on
what information we can have about the real situation.  There is no
reason why we cannot know that there are correlations between the
facts about two events which have a space-like separation, while we do
not know the actual facts; once we acquire further information about
one of these events, we immediately gain information about the other,
but there is no superluminal communication involved (the correlations
between the two facts derive from their common relationship with a
third event which has time-like separation from each of them!).  The
illusion of superluminal communication comes in when you suppose (and
I believe this is built into the axioms of the arguments against
hidden variables) that the waves are physical phenomena (and so behave
"locally").  Heisenberg's step from "we cannot know the position and
momentum at the same time" to "the particle does not have a position
and a momentum at the same time" was motivated by philosophical
considerations (and mathematical convenience); the physics does not
dictate this.  Also, I believe that it has been argued that we _can_
determine position and momentum of a particle simultaneously in
retrospect (we can't know both when they would be any use to us...).

>
>For further reading, I'd recommend Richard Feynman's _QED_, Nick Herbert's
>_Quantum Reality_, and J.C. Polkinghorne's _The Quantum World_.


-- 
The opinions expressed		|     --Sincerely,
above are not the "official"	|     M. Randall Holmes
opinions of any person		|     Math. Dept., Boise State Univ.
or institution.			|     holmes@opal.idbsu.edu


