FOM: Further pointless backchat (ongoing) (continued)

Vaughan Pratt pratt at cs.Stanford.EDU
Fri Mar 6 00:57:55 EST 1998

>[request for Pratt to respond to Silver and Feferman]

>You may be forgetting that I already did, in FOM mail dated respectively
>Thu, 22 Jan 1998 16:12:05 -0800 and Thu, 20 Nov 1997 10:16:03 -0800.

>Apparently not satisfactorily, since neither Silver nor Feferman discussed
>your (Pratt's) statements.

Who do you respond to on FOM, Harvey, those you agree with or those you
disagree with?

>Despite Einstein's famous quote about not believing that God plays dice, his
>fundamental objection to quantum mechanics as developed by the Copenhagen
>school was *not* its indeterminism, but rather its anti-realism.
> ... To be more precise, Einstein demanded that
>a physical theory be "local" and "realistic",

Let me say very simply what Einstein set out to show, and leave it to
the readers to judge whether or not Einstein was at all bothered by the
indeterminism of physics.

Einstein just wanted to refute Heisenberg uncertainty.  With Podolsky
and Rosen he described a gedanken experiment in which the momentum
and position of a particle could be determined simultaneously, both to
arbitrary precision.

EPR pictured two identical particles P and Q, initially joined and
stationary, being violently blown apart.  Much later, two experimenters
measure P's momentum and Q's position simultaneously, each with great
precision, permitted by quantum theory.  The particles are too far
apart at this point for these measurements to interfere immediately, by
special relativity.  But by conservation of momentum the measurement of
P's momentum yields that of Q.  Hence our experimenters can now pool their
knowledge to learn both the momentum and position of Q very accurately,
in contradiction to Heisenberg uncertainty.

From: Friedman
>I am reluctant to let you have the last word defending this kind of
>pseudo foundations since over 300 people are listening, and some of
>them might benefit from being warned about this. This may help people
>see what kind of work has to be done to make structual f.o.m. a reality.

Oh dear, and here I've gone and left the readers to draw their own
conclusions.  I hope I haven't overestimated their intelligence by as
much as you've overestimated their number (fom-request's "who" command
reports 191 readers.)

My apologies to everyone for my part in keeping the tone of this portion
of the proceedings on a par with professional wrestling.  No reflection
on other FOM threads intended.

Vaughan Pratt

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