NetNews Usenet Archive 1992 #20/NN_1992_20.iso/spool/sci/physics/14354

Text File | 1992-09-09 | 3.1 KB | 63 lines

Newsgroups: sci.physics
Path: sparky!uunet!haven.umd.edu!darwin.sura.net!spool.mu.edu!caen!hellgate.utah.edu!lanl!cochiti.lanl.gov!jlg
From: [e-mail] (Jim Giles)
Subject: Re: Hidden variable theories, was: Uncertainty Princi
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: Los Alamos National Laboratory
References: <1992Sep4.170847.235@prim> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 9 Sep 1992 22:36:37 GMT
Lines: 51

In article <[e-mail]>, [e-mail] (Paul Budnik) writes:
|> [...]
|> This is false. The Shannon definition of information is that it allows one
|> to select a limited number of alternatives from a wider range of
|> possibilities. [...]

It is not information either in Shannon's sense or anyone else's.  It
_would_ be information if it permitted something known only at the other
end to be *transmitted* to us.  The possibilities locally are "a particle
is detected" or "a particle is not detected".  The same possibilities exist
at the distant end.  How does our local observation allow us to determine
the distant result?  The widest range is "detection/non-detection", so is
`limited' range *after* the local observation is made.  In other words,
you haven't narrowed the possibilities at all.

|> [...]
|> > Also only the hidden variables theory has to
|> > give up causality; e.g. quantum electrodynamics strictly respects
|> > causality.
|>
|> You are dead wrong again. In a test of Bell's inequality manipulating a
|> local polarizer must instantaneously *affect* what happens at a remote
|> location. [...]

There is no such Effect.  A local observer cannot tell whether the distant
polarizer is being manipulated or not - or vice versa.  The only thing you
can say is that _after_ the fact, the aggregate results of many trials of
the experiment will obey a certain correlation.  Anything else you say
(about waveforms, many worlds, faster than light hidden variables, etc.)
are *models*, not facts.  The EPR experiments are the subject of much
controversy because there are no *testable* models which fit the facts
(none yet proposed anyway).

|> [...]
|> The alternatives we face are a local incomplete theory or a nonlocal
|> quasi-mystical (quantum collapse is caused by a conscious observer)
|> complete theory. I see no reason to prefer the existing
|> collapse postulate. On two occasions I have challenged the readers
|> of this newsgroup to come up with an *objective* reason for preferring the
|> nonlocal theory and none has been forthcoming.

I agree with you about the undesirability of mystical solutions.  But,
at present, there is no *objective* reason for preferring *any* model
that has been proposed.  The wise thing to do is reserve judgement and
to state only those facts which are observable: that there's a correlation
and that it takes such-and-such a form.  In any case, the phenonenon, whatever
its cause, is certainly not caused by conscious observers - but by physical
interaction of the particles with the polarizers/detectors.

--
J. Giles