Time reversibility and Bohm QM

Date: Mon, 13 Nov 1995 03:15:41 -0800
From: Vic Stenger <vjs@uhheph.phys.hawaii.edu>
To: quantum-d@teleport.com
Subject: QUANTUM-D: Time reversibility and Bohm QM

With reference to,

    http://www.teleport.com/~rhett/quantum-d/posts/vjs_11-8.html
    http://www.teleport.com/~rhett/quantum-d/posts/sarf_11-9.html

I went back to a paper by A. Kyprianidis and J. P. Vigier in "Quantum 
Mechanics Versus Local Realism" ed. Franco Selleri, New York, Plenum, 1988, 
p. 273.  I think I now understand why Jack and others may have associated 
spacetime zigzagging with Bohm.  Vigier has worked with Bohm and tends to 
think in terms of the quantum potential.  But this paper makes it very 
clear that his zigzagging picture is part of a stochastic model for QM, 
not Bohmian deterministic QM.  They call it the "causal stochastic" 
interpretation, but in fact it is really acausal.

They mention some interesting ideas, though do not show them in in detail 
and some of the references may be hard to get, such as Astr. Nachr., 
whatever that is.  Anyone have access to this?  If you do, perhaps you 
can send me the paper mentioned below.  

The model is one of random fluctuations in spacetime, including 
backward-time impulses that lead to "apparent" spacelike jumps, exactly 
as I have outlined (I did not mean to lead people to think this was 
original with me; I did reference Feynman and Wheeler, but will try to 
make this clearer in the next draft).

They refer to a 1966 paper by E. Nelson (Phys Rev 150, 1079) in which the 
Schr. eqn. is derived from stochastic processes.  The original 
assumptions seemed a bit contrived, but Vigier claims all is well when you 
allow time-inversion (J. P. Vigier, Astr. Nachr 303, 55 (1982)).  They 
also claim that quantum statistics  can be deduced from the 
Maxwell-Boltzmann distribution by setting the probability weighting of 
phase space states random instead of constant.

I will look up the other references - the ones I can find.  But my general
point is that Vigier is not really promoting a Bohmian theory.  Just
calling the vacuum a quantum potential does not make it Bohmian.  The
quantum potential is trivial, just another way of writing the Schr. 
equation.  What is not trivial about Bohm's hidden variables theory is the
notion that subquantum forces, yet to be discovered and required to be
superluminal (not just "effectively nonlocal" over deBroglie wavelength
distances, which is all zigzagging in spacetime does for you) determine 
quantum phenomena.  Vigier's interpretation is the opposite of this, and 
stripped of the Bohm baggage, is close to what I have been trying to say.