Newsgroups: bit.listserv.xtropy-l
Date:         Tue, 7 Apr 1992 19:29:34 EDT
              <XTROPY-L@UBVM.BITNET>
From:         Michael Clive Price <100034.3077@COMPUSERVE.COM>
Subject:      Many-Worlds (was Re: Time travel)
X-To:         "Extropians (mailing list)" <extropians@gnu.ai.mit.edu>,
              "Xtropy-L (mailing list)" <xtropy-l@ubvm.BITNET>

Hal Finney wrote:

> For example, the usual many-worlds interpretation has the universe
> constantly splitting.  This would seem to say that the number of
> universes is vastly increasing all the time.  But another
> interpretation [of MWI] has the number of universes being constant,
> and the splitting is actually the sudden differentiating of two
> previously identical universes.

> In other words, instead of:
                                         AA
                                       AA
                                     AA
                                   AA
> SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
                                   BB
                                     BB
                                       BB
                                         BB

> you would have:


> SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSAAAAAAAA


> SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSBBBBBBBB


> These two interpretations would normally be interchangeable....


I don't think they are interchangeable.  One of the two virtues of the
MWI over the other interpretations of quantum mechanics is that MWI is a
deterministic theory.  It is a paradox of quantum theory that the
equations (like the Schrodinger wave equation) are deterministic, but
that experience (and therefore, it seems, reality) is indeterministic.

In the MWI indeterminism is a subjective artifact of our inability to
view events at the multi-world level (i.e. experience not equal to
reality).  In the splitting view of the cosmos (the first picture) we
have a deterministic universe, where the branches of the universal tree
depict individual, apparently stochastic, occurrences.  But the tree as a
whole is a deterministic entity, consistent with physical law.

The second picture depicts a number of identical parallel worlds which
suddenly differ from eachother.  i.e. each parallel world is evolving
indeterministically and is inconsistent with the deterministic equations
that underpin physics.  IMO it is therefore unscientific.

So the number of worlds (some call them universes) *is* increasing with
time.   This increase can be given a physical basis:  Each macro-event
that releases entropy S causes an {exp (S / k)} -fold splitting of the
branch structure at the macro-event.  This is just the inverse of the
usual Boltzmann-Planck equation:

   S = k ln W

where k is the Boltzmann constant and W the number thermodynamic
microstates (see Steve Harris' recent forwarded posting about information
and entropy).  The dissipation of a joule generates about exp (10 ^^ 23)
worlds.

So turning on the heating creates an awful lot of worlds.  (Egomanics
could use this to generate extra copies of themselves?)  Easier than
uploading and copying, eh?  And your copies get a whole cosmos each to
play around in!

Mike Price



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