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Article 6197 of comp.ai.philosophy:
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>From: holmes@opal.idbsu.edu (Randall Holmes)
Newsgroups: comp.ai.philosophy
Subject: Re: Quantum consciousness
Message-ID: <1992Jun10.190115.6937@guinness.idbsu.edu>
Date: 10 Jun 92 19:01:15 GMT
References: <1992Jun10.142117.25171@cs.yale.edu> <1992Jun10.173555.27484@cs.ucf.edu>
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In article <1992Jun10.173555.27484@cs.ucf.edu> clarke@acme.ucf.edu (Thomas Clarke) writes:
[...]
>
>Many worlds is a consistent interpretation of quantum mechanics 
>in that it produces exactly the same observations and predictions 
>as the standard model (otherwise it would probably be wrong since it 
>would violate some experiment), and because of that I still maintain
>many worlds is isomorphic to the standard interpretation.  
>--
>Thomas Clarke
>Institute for Simulation and Training, University of Central FL
>12424 Research Parkway, Suite 300, Orlando, FL 32826
>(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu

Its physical predictions are the same as those of the usual
interpretation; thus the characteristic features of the usual
interpretation (collapsing wave functions, etc.) are _not part of the
physics_. 

Some comments on the way that "many-worlds" looks to me:

a.  The universe in the "many-worlds" interpretation actually has a
single state, which never collapses; we are not really in a "garden of
forking paths" with massive proliferation of universes.  The
particular state which we observe locally is not the whole thing.

b.  Only certain states of an observer are "suitable" as subjective
states (identified with certain physical eigenstates); superpositions
of these "suitable" subjective states are interpreted as "parallel
experiences of versions of the observer in different worlds (again,
identified with physical phenomena)".  This is no more problematic
than the idea that a spin 1/2 particle has either "spin up" or "spin
down" as eigenstates, and other states are a superposition of these
basic states, and the interpretation of this situation with particles
is handled the same way in "many-worlds" (except that the particle
situation is much simpler).  [there _is_ a problem for some members of
the audience, which is that I am flatly identifying subjective states
with concrete physical states, but this is a philosophical position
"orthogonal" to questions about QM]

c.  A "suitable" state of an observer can evolve through interactions
into a superposition of "suitable" states; this corresponds to a
bifurcation in the "garden of forking paths" metaphor.  But we are
_not_ in the garden of forking paths; don't lose sight of the overall
state of the universe.  Further bifurcations will _not_ proliferate
endlessly; they will start to "interfere" with one another.
_Locally_, as long as we are talking about relatively few decisions,
the number of separate future worlds for an observer seems to increase
exponentially; interference within the overall world state prevents
this from actually happening.



-- 
The opinions expressed		|     --Sincerely,
above are not the "official"	|     M. Randall Holmes
opinions of any person		|     Math. Dept., Boise State Univ.
or institution.			|     holmes@opal.idbsu.edu


