From: ddixon@nyx.cs.du.edu (David Dixon)
Subject: Quantum reality silliness
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Sat, 10 Oct 92 02:54:45 GMT

AAAAAAAAAAAAAAAAAAUUUUUUUUUUUUURGH!  I can't take it anymore!  Bell's
inequality to the left of me, wave function collapse to the right!  I
think I'm going ... MAD!

It seems to me that this situation has become more complicated than it needs
to be, largely because (I think) of prejudice that the world is necessarily
dterministic.  Look, folks, just because we live in a world macroscopically
inhabited by ping-pong ball like objects does NOT mean that there is any
correlation implying that such "determinism" exists in the microscopic
world.  Human beings interact directly with things that behave in the
"thermodynamic limit", where the number of interactions with the quantum
mechanical universe is very, VERY large, such that the probability of us
observing a macroscopic object obeying Newton's laws of motion approaches
a delta function.  It's the same thing as statistical mechanics: it's
possible that all of the air molecules in the room you are sitting in will
simultaneously gather themselves in a corner, but the probability is so
vanishingly small that you would have to wait many lifetimes of the universe
to experience such a phenomenon.

I think a lot of the confusion about quantum mechanics occurs because we
have been imbued with this belief in the wave-particle duality, as if
sub-atomic particles somehow consisted of a "wave" which carried along a
tiny point-like particle with it.  Baloney.  The proper way to think of it
is that the wave function is a field which tells you probabilities of a
certain amount of energy or momentum being exchanged at a certain point
in space-time.  Nothing mystical about it.  Classical electromagnetism
yields field solutions which can be translated into forces, i.e., a given
field strength implies that so much energy and momentum can be transferred
to a particle at a given space-time point.  Quanum elctrodynamics gives a
similar result, except in terms of the probabilites that a particular
momentum transfer will occur.  In the limit of many interactions with a
field (i.e., draw Avagadro's number of Feynman diagrams), Maxwell's
equations are the most probable solution.  The fact that the probability
of observing a "determinstic" behavior in the thermodynamic limit IN NO
WAY IMPLIES THAT THE UNDERLYING MECHANISM IS DETERMISTIC!

As for Bell's inequality:  it's just a mathematical result, just like
2+2=4.  You can wave your hands as much as you like, but the answer stays
the same.  Quantum mechanics predicts one thing, local deterministic
theories another.  Until someone comes up with a rigorous mathematical
argument against this, than all of the argument on the net is just a lot
of smoke blowing.  The *physical* reality of the matter is that Aspect
et al observed Bell's inequality to be violated by TWENTY STANDARD
DEVIATIONS!  From the standpoint of statistics, this is the word of God.
A lot of arguments are invoked regarding the possible "communication" between
polarizers, etc., but it is pretty much straw grabbing on the part of the
determinists.

By the way, I should add that, in one sense, quantum mechanics is a perfectly
determinstic theory:  the evolution of the wave function is completely
determined by the Schrodinger (or Klein-Gordon, or Dirac, etc.) eqaution.
The problem occrus when people start throwing in "observation" as some sort
of external influence.  Observation is just interaction, and the form of
interactions at the quantum level is predictable.   The division between
observer and observed is silly and arbitrary.  It is a bit of bogosity
introduced when one buys too seriously into the Copenhagen interpretation.

None of this is to say that quantum mechanics is a complete, or even correct
theory.  Problems with the theory are numerous, such as the necessity to
renormalize quantum field solutions.  However, the issues of
(non)determinism, wave-funtion collapse, Bell's inequality, etc., seem to
be brought about by people's confusion of the mathematics with the physics.
The mathematics may necessitate the introduction of some concepts which are
physically outrageous.  But such effects are unmeasurable.  The end answer
is what really matters, though: that which can be experimentally verified.
As scientists, it behhoves us to apply Occam's razor whenever possible: if
there is no OBSERVABLE reason the introduce ad hoc hidden variables and such,
why do it?  When somebody comes up with a theory that predicts a superset
of observables of that predicted by current quantum theory, then we should
begin to take notice.  Theories which predict nothing, however, are a waste
of time.  Witness Hannu's space potatoes.

					Dave