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Article 6200 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: <1992Jun10.210233.7608@guinness.idbsu.edu>
Date: 10 Jun 92 21:02:33 GMT
References: <1992Jun10.142117.25171@cs.yale.edu> <1992Jun10.173555.27484@cs.ucf.edu> <1992Jun10.190115.6937@guinness.idbsu.edu>
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In article <1992Jun10.190115.6937@guinness.idbsu.edu> holmes@opal.idbsu.edu (Randall Holmes) writes:
>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.

	On reflection, I suppose that the number of branches _could_
proliferate indefinitely, with the probabilities of individual
branches getting very small, but all of the branches would still be
embedded in the original world state, which is in this case perhaps
getting more "chaotic" all the time.  But all these branches are still
embedded in the common world state; there is not the exponential
expansion of needed "resources" which appears to arise if we think of
the world (the particular one we suppose that we are actually
"subjectively" observing) as reduplicating itself continually.

>
>
>-- 
>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


-- 
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


