On Wed, 01 Sep 2004 13:56:57 -0700, Bob Cain
wrote:

relative motion modulates relative distance which
modulates relative time, because the speed of sound is
constant.

Did you see my proof of why a piston in a tube will evidence
no such behavior with any signal including constant
translation of the piston? I believe it is a refutation of
that (unless, of course either I still don't understand what
you are saying or someone can refute my proof.)

Isn't this (and the case of coupled infinitely extended
planes) just a special case with no relative motion?
Chris Hornbeck