🚀 go-pugleaf

In article <4NOV199214480442@csa1.lbl.gov>, sichase@csa1.lbl.gov (SCOTT I CHASE) writes:
> In article <336@mtnmath.UUCP>, paul@mtnmath.UUCP (Paul Budnik) writes...
> Good.  We agree on the phenomenology.
> 
> >I suspect that all the standard interpretations of the wave function
> >are wrong. 
> ...
> >That there is more than one interpretation is one
> >indication that this is true. 
> 
> This is certainly a false statement.  There is almost always more than
> one way to interpret the equations of physics, with each way giving you
> a somewhat different insight into what the equations are telling you.
> Let's take an example from an entirely different field. ...
> 
> The difference between this example and QM is that QM strikes in a more
> fundamental way at the meaning of reality, which you expect naively, to
> have an unambiguous nature.  But the nature of reality, so far as it 
> can be understood through physics, is determined by the equations of 
> the theory.  All interpretations, however distinct or discordant they 
> seem to you, are equivalent.  If one is wrong then all are wrong.  Your
> attempt to distinguish among them is doomed to failure.  The best that
> you can hope to do is to demonstrate that one or another of the interpretations
> does not in fact follow from the principles of QM, and therefore is
> not a valid interpretation.

The problem with interpretations of QM is different from the example you
gave. All experimental observations and manipulations occur in what appears
to be a classical world. (There are some possibilities for directly observing
macroscopic quantum phenomena but the observations and manipulations are
still inherently classical.) The equations of QM deal only with the wave
function that has no classical meaning. The interpretations provide a
connection between these two. This differs from deriving
identical laws from different perspectives. The interpretations are not
a different way a viewing the same laws but an integral and necessary
part of those laws if they are to be experimentally validated. 

> >I object to teaching and discussing interpretations of the wave function 
> >as if they were established fact instead of the philosophical speculation 
> >that they are.
> 
> They are not philosophical speculations.  They are interpretations of the
> equations.  That is how it is taught.

They go beyond the equations. They are integral part of the theory without
which the equations are meaningless. You can argue that there are
interpretations in classical mechanics. We have to relate the mass in
F=MA to a physical object and thus we need to interpret it. But we do not
speak in this way of classical mechanics because the interpretation is
direct. Mass has an objective physical existence corresponding to objects
in the classical universe. In classical mechanics it is not a matter
of philosophical speculation but of definition.

> 
> >For the same reason I object to the statement that the wave function does 
> >not define a shape. 
> 
> Well, now we're back to square one.  You do not understand the meaning of the
> wavefunction, if you can continue to make this statement.  Any book on
> QM will illustrate how you can describe point-like particles by a wave 
> function, which has nothing to do with its shape, or lack thereof.

Its not that I do not understand the meaning that most physicists ascribe
to it. I understand and *disagree* with this meaning.

> >If the wave function is an objective physical phenomena
> >it does define a shape albeit a highly mallable one. This is an open
> >question subject to experimental test. To treat it otherwise is a mistake.
> 
> You keep saying this, but you do not tell us what experimental test you
> have in mind.  How do you plan to determine the shape of an electron by
> measuring its wave function?  

I said what the experiment is the first time I brought it up in this
discussion. It is tests of Bell's inequality. If quantum mechanics does
violate locality, this would be experimental evidence for a nonphysical wave
function. If, as I suspect, the manipulation of polarizers and the detections
that are influenced by these manipulations never have a space like separation,
this would be strong evidence for a physical wave function.
The observed time delays would be a direct measurement of the
shape of the wave function as it undergoes quantum collapse. In addition to
proving that the collapse postulate of quantum mechanics (or any equivalent
formulation is false) it would also suggest that the interpretations of the
wave function that deny it has a physical existence are false.

The central point I have been making in several years of posting on this
subject is that that physicists, in this area, have gone well beyond what has
been justified by experiment. They are teaching philosophical speculation as if
it were established scientific fact. Most of quantum mechanics has been
verified to an extraordinary degree. However, the collapse postulate and the
interpretations of QM that deny a physical reality to the wave function
have no experimental verification. One can construct an equivalent
theory with respect to all verified predictions by replacing the collapse
postulate with the following:

    Quantum collapse is engendered by experimental conditions designed to
    observe the classical parameters of a system. It is an objective event
    that occurs for a variety of reasons that are not fully understood or
    part of current theory. It has a local Lorentz invariant structure and
    will occur spontaneously before an experiment would violate locality.

Bell's results provide an experimental test to distinguish between this
postulate and the standard formulation of the collapse postulate or
any formulation equivalent in its predictions. One should not consider
the question of which of these two is correct as being undecided until
nature tells us through experiment.

Paul Budnik