Re: Many Pasts? Not according to QM...

From: Saibal Mitra <smitra.domain.name.hidden>
Date: Wed, 25 May 2005 01:24:23 +0200

----- Oorspronkelijk bericht -----
Van: "Patrick Leahy" <jpl.domain.name.hidden>
Aan: <everything-list.domain.name.hidden>
Verzonden: Wednesday, May 18, 2005 05:57 PM
Onderwerp: Many Pasts? Not according to QM...


> Of course, many of you (maybe all) may be defining pasts from an
> information-theoretic point of view, i.e. by identifying all
> observer-moments in the multiverse which are equivalent as perceived by
> the observer; in which case the above point is quite irrelevant. (But you
> still have to distinguish the different branches to find the total measure
> for each OM).

This is indeed my position. I prefer to define an observer moment as the
information needed to generate an observer. According to the ''everything''
hypothesis (I've just seen that you don't subscibe this) an observer moment
defines its own universe. But this universe is very complex and therefore
must have a very low measure. It is thus far more likely that the observer
finds himself embedded in a low complexity universe.


One of the arguments in favor of the observer moment picture is that it
solves Tegmark's quantum suicide paradox. If you start with a set of all
possible observer moments on which a measure is defined (which can be
calculated in principle using the laws of physics), then the paradox never
arises. At any moment you can think of yourself as being randomly drawn from
the set of all possible observer moments. The observer moment who has
survived the suicide experiment time after time after time has a very very
very low measure.


Even if one assumes only a single universe described by the MWI, one has to
consider simulations of other universes. Virtual observers living in such a
simulated universe will perceive their world as real. The measure of such
embedded universes will probably decay exponentialy with complexity....


Saibal
Received on Tue May 24 2005 - 19:28:16 PDT