From: Eric Cordian <emc@wire.insync.net>
Date: Thu, 29 Jan 1998 08:37:31 +0800
To: cypherpunks@cyberpass.net
Subject: Re: EPR, Bell, and FTL Bandwidth (fwd)
In-Reply-To: <199801282331.RAA09988@einstein.ssz.com>
Message-ID: <199801290030.SAA09986@wire.insync.net>
MIME-Version: 1.0
Content-Type: text/plain



Jim Choate writes:
 
> Um, actualy no. Since the photons are coupled we know that the second
> photon has actualy changed it's polarization, either that or your
> original assumption they are coupled is not true.
 
No.  Doing something to the first photon does not do anything to the
second, much less change its polarization.  The operators for
polarization for the two photons commute, so they are simultaneously
measureable.
 
The statistical correlation of measurements done on many pairs of
photons, with a choice of axis for measuring the polarization selected
on the fly, reflects that predicted by quantum mechanics for non-local
collapse of the overall wave function.  It is wrong to interpret this
as something done to one photon having a physical effect on the other.
 
> The polarization between the two photons *must* be zero. Otherwise you
> arent' playing with our physics.
 
Sorry, *OUR* physics explains all of this quite nicely.
 
> Correlation is not a function of any quantity conservation operation.
> The values of the photons are actualy opposite and therefore sum to
> zero. Foo is not the inverse of Bar, as is the case for horizontal and
> vertical polarization.
 
This isn't even wrong.
 
> True, but the swap of polarization was *not*. That occured later and
> is what changes instantly irrespective of distance.
 
There is no "swap of polarizations." The wavefunction of the entire
system changes quite smoothly with time, under the influence of the
usual operator.  Measurement places the system in an eigenstate for
the thing measured, and simultaneous measurements on branch systems
may show correlations consistant with non-local collapse of the
wavefunction.  None of this implies any physical effect on one photon
as a result of something done to the other.
 
> Yes, it causes the correlation to be destroyed. You are not taking
> into account the correllation or polarization dependency between the
> two photons. Our base assumption is that when photon A is horizontal
> then photon B is vertical. This *must* occur to preserve symmetry.
 
This isn't even wrong, either.

--  
Eric Michael Cordian 0+
O:.T:.O:. Mathematical Munitions Division
"Do What Thou Wilt Shall Be The Whole Of The Law"