[ExI] Postal QM was against Many Worlds QT

Lee Corbin lcorbin at rawbw.com
Mon May 18 05:37:36 UTC 2009

Keith writes

> I have never managed to get a QM wonk to explain how this thought 
> experiments fails to reproduce the observations.
> Imagine an experiment where a person in a dark room shakes up a dice cup 
> with a black marble and a white marble.  Then they put one of them in a 
> box and mail it off to a thousand miles.
> When the recipient opens the box, she *instantly* know the color of the 
> marble in the other box.
> This can be extended to more colors, but the essence is that if the 
> splitting process is random but correlated this way, there is no mystery 
> to the observations.

Right, if it were only correlated in that way,
then there wouldn't have been any mystery, and
all the people like David Bohm who worked so
desperately to come up with a classical
explanation wouldn't have had to.

"Bertlmann's socks" is the familiar statement
of the point you've raised. The professor was
said to always wear socks of two different colors,
and so if you saw one of them, you instantly knew
something about the color of the other.

Here is part of J.S. Bell's book "Speakable and
Unspeakable in Quantum Mechanics" (I hope that
the Google book search link works).


The article is a bit too technical in places,
but the introduction is great.

Basically, as I see it, both quantum theory
and quantum experiment rule out two EPR
particles actually being in definite states
as they flee away from each other. (Unlike
the socks, or those postal marbles.)

"Bell's Inequality" turned out to be a formal
proof that no ordinary realistic account is
possible. (David Deutsch maintains, and it
makes sense to me, that the MWI is a completely
local, realistic theory.)

Here is what happens in the MWI handling of EPR:
http://www.leecorbin.com/EPR_MWI.html , my essay
on why EPR is not a mystery under MWI.


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