On Thu, 29 Apr 1999 hal.domain.name.hidden wrote:
> This is from http://xxx.lanl.gov/abs/quant-ph/9904004
> : Observational Consequences of Many-Worlds Quantum Theory
> : Authors: Don N. Page (CIAR Cosmology Program, University of Alberta)
> : The observational distinctions
> : occur as a result of processes in which observers are created
> : or destroyed. One example is whether you may expect to observe
> : anything within this universe after a time long compared with your
> : life expectancy.
>
> Ah, yes, living forever as a consequence of the MWI, our favorite topic.
> The paper discusses the (in)famous quantum suicide, following the
> conventional reasoning that an observer in the MWI would always find
> the suicide machine failing.
Don's no fool, but I think he's wrong on a number of topics ...
I've cc'd him since I hope he could be persuaded at least not to publish
the paper until answering for it.
Don, don't forget you still have yet to defend your position that
religion is compatible with the MWI on the mwi list. If you're wondering
what this everything-list is, see
http://www.escribe.com/science/theory/
and
http://www.sns.ias.edu/~max/toe.html Basically it's arguments about
the idea that all mathematical structures exist.
I have argued numerous times on this everything-list that "quantum
immortality" is NOT implied by the MWI. (e.g.
http://www.escribe.com/science/theory/msg00287.html,
http://www.escribe.com/science/theory/msg00306.html,
http://www.escribe.com/science/theory/msg00313.html,
http://www.escribe.com/science/theory/msg00349.html, etc.)
The basic arguments are very simple. The predictions of the MWI
are very clearly no different from the predictions of a one world
interpretation in an infinite universe. (Cosmological predictions are a
little more interesting but I'll get to that below.)
It's true that in a one world universe, the probability of me
surviving to 2100 is very low. But if I find myself in that year, that's
no argument for the MWI, because the fraction of observers who have lived
that long is no larger in the MWI. In either case I just got 'lucky'; the
effective probability distribution in the MWI is proportional to the
measure distribution which is heavily weighted toward shorter lifetimes.
(Note to Don: what I call measure, you called quantum measure x
number of observers.)
Note also that if one believes that the MWI does imply
immortality for the average observer, then it would be a disproof of the
MWI, because we don't seem to be drawn from an immortal distribution of
effective probability, but rather from the usual distribution of
lifetimes which merely has a long time tail that decays.
> There is also some discussion of the role of measure in probability:
>
> He suggests that in MWI you should multiply the QM measure of a universe
> times the number of observers to get an effective measure of the
> likelihood of being an observer in that universe. This gives a boost to
> universes with lots of observers and could conceivably make the universe
> be big even in a cosmology where it was overwhelmingly likely to be small.
Yes, that's obviously true and I've been saying it all along, but
it's not anything new - people have been saying it for years under the
name 'anthropic principle' - and it's not an argument for the MWI per se,
just an argument that other universes exist in some way. For example, Lee
Smolin has proposed (or at least made the case in his book) that black
holes spawn baby universes, and yet he argues against the MWI of QM. See
my discussion at
http://pages.nyu.edu/~jqm1584/anth.htm
- - - - - - -
Jacques Mallah (jqm1584.domain.name.hidden)
Graduate Student / Many Worlder / Devil's Advocate
"I know what no one else knows" - 'Runaway Train', Soul Asylum
My URL:
http://pages.nyu.edu/~jqm1584/
Received on Fri Apr 30 1999 - 16:25:14 PDT