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Article 3911 of comp.ai.philosophy:
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>From: daryl@oracorp.com
Newsgroups: comp.ai.philosophy
Subject: Re: QM nonsense
Message-ID: <1992Feb21.033409.15845@oracorp.com>
Date: 21 Feb 92 03:34:09 GMT
Organization: ORA Corporation
Lines: 62

Matthew Wiener writes:

>>I don't think that either position is justified. Everett, DeWitt, and
>>others working in the 50's developed a so-called Many-Worlds
>>interpretation of quantum mechanics (although that name is misleading,
>>in my opinion). According to this interpretation, there is just one
>>type of process, and that is described by the Schrodinger equation.
>>The appearance of type-2 processes is purely subjective.  [...]

>One must still explain why mind has this subjective relationship to
>the "many worlds". It does not eliminate the QM/mind question, it
>just calls it something else.

As I said, I think the phrase "many-world" is misleading, if not
mistaken. Everett called his idea "the theory of the universal
wavefunction" rather than "the many-worlds interpretation", which was
a phrase coined later by DeWitt. The way I understand it, there are
*not* many worlds, there is one wave function describing everything.

I agree that the many-worlds interpretation doesn't solve everything,
but it does more for the question of the relationship between mind and
QM than calling it a different name. Among the features of the
Many-worlds interpretation that makes it differ from some
interpretations of QM is that it suggests that it is perfectly fine to
treat human beings as quantum mechanical systems which are capable of
being in superpositions and are describable (if with enormous
difficulty) by the Schrodinger equation. The observer is not special
for having a mind, it is simply a division of the universe into two
pieces: the measuring device, and the rest. The Everett theory is a
step forward, in my opinion, because it shifts the question from some
mysterious interaction between mind and matter to the question of
deriving the subjective consequences of a physical theory. This
problem of course is relevant to the issues discussed in this group
about whether existence of subjective experience or qualia can in some
sense be predicted by physical or functional theories of mind.

> The approach that I favor is the MW-inspired interpretations of Zeh,
> Zurek, Gell-Mann, Hartle, and others.  Some of the most recent work on
> this can be found in Zurek (ed) COMPLEXITY, ENTROPY AND THE PHYSICS OF
> INFORMATION.  Briefly, their view is that the environment is part of
> the measurement process, and you can achieve decoherence by letting
> the environment absorb QM coherence.  Model calculations provide, for
> example, an answer to Einstein's "is the moon really there when no one
> looks at it?"--yes, since the cosmic microwave background absorbs the
> moon's quantum uncertainty.

I will look it up. However, it doesn't sound too promising to me from
that short description. I am very suspicious of attempts to eliminate
the subjective aspects of QM by invoking supposedly "objective"
concepts such as irreversible processes or incoherence. Such concepts
don't seem very fundamental to me; irreversibility depends on the time
scale you are looking at, and incoherence seems to me to be a matter
of our *lack of knowledge* of the phase relationships, rather than
anything objective.

The Everett interpretation makes the entire wave function objectively
real, so I don't see that there is any problem with the moon being
there when we aren't looking.

Daryl McCullough
ORA Corp.
Ithaca, NY


