From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: Hidden variable theories, was: Uncertainty Princi
Date: 10 Sep 92 15:37:29 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Sep9.223637.24769@newshost.lanl.gov>, jlg@cochiti.lanl.gov (Jim Giles) writes:
> 
> 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.

But of course it does. It tells us something about what *combinations* of
polarizer angles and detections that happened at the other end.

>  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.

To test bells inequality you must determine if certain bit streams are
correlated. The information that produced that correlation was transmitted
instantly at the time an observation was made. If no information was
transmitted the bit streams would not be correlated. If the information
was not transmitted at the time an observation was made, but was contained
in the photons when they were created, a local hidden variables theory could
account for the results and Bell's inequality would not be violated.

>...
> 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. ...

It is a fact that a distant manipulation instantly produces a local affect
according to the instantaneous collapse postulate.
That you cannot detect the effect *at the time it occurs*
does not make it any less real. You are able to verify experimentally that
it did occur and you can measure the exact time that it happened.
This violates either Lorentz invariance or causality. Several physicists
writing in this area have made this point. If you do not believe me, please
read the relevant literature. This is discussed in great detail and very
clearly in P. H. Eberhard, Il Nuvo Cimento 46 B, 392, (1978).

> |> 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 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.

It seems to me that you just gave one. Objective models even incomplete
ones are preferable to mystic solutions. Local models are certainly
preferable to those that are not.

> 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 phenomenon, whatever
> its cause, is certainly not caused by conscious observers - but by physical
> interaction of the particles with the polarizers/detectors.

Experiments will ultimately decide the result and we must always reserve
final judgement for that verdict. But science only makes progress if we
pursue the paths that seem most likely given the limited knowledge we have
at any time.

I think most physicists agree with you that
there is an objective cause for quantum collapse. What they do not seem
to realize is that this implies that quantum mechanics is, as Einstein
always said, an incomplete theory.

Paul Budnik