[extropy-chat] Mangled Worlds

[Hal Finney]

Nothing like a discussion of horrific suffering to pull Lee back onto
the list!  :-)  That's a smiley.  I too want to welcome him back.

> But I infer that Robin's "small relative-sized" universes in 
> configuration space get wasted by their big neighbors awfully
> fast. I'm just guessing, but phenomena with salient quantum
> (non-classical) aspects I would expect to transpire quickly.

That does make sense.  The time scale for quantum events tends to be
very fast, unless special precautions are taken.  It's just that in
this case the physics are still unknown, so we can't be sure.

> Also, wouldn't the chaos afflicting the victim universe have as
> one of its first priorities the disruption of complicated systems
> like our brains?

One would hope so.  Again, the worry for me is the possibility that
somehow brains continue to function even as these mangled worlds operate
under a sort of dual-world physics.  Somehow the large worlds impact on
what happens in the small ones, but it's not yet possible to say exactly
how that happens.  I came up with these fantastic speculations like
that we would have some kind of double-image, perceptually superimposed
realities.  We would see what would happen in the small world if it were
isolated, along with what is happening in the oblivious large world.
Probably this isn't anywhere close to correct, but this kind of bizarre
effect might be compatible with a degree of brain function, for a while.

> So: doesn't this then devolve into the usual
> mild worry over the small measure hell-branches of the MWI?

Well, the point of Robin's paper is to eliminate this mild worry by
showing that (sufficiently) small measure branches (hellish or not) get
"mangled" and hence (hopefully) are uninhabitable.  In that way he solves
the mystery of why we don't experience those small measure branches,
not by an ad hoc assumption that the Born rule governs our epistemic
experiences, but simply because life is impossible there.

The philosophical question I see is this.  Suppose these mangled
worlds are much more numerous than the "large", conventional worlds.
And suppose that it turns out that consciousness can survive in such
worlds, but only for a few moments before it is destroyed.  Then,
of the total number of conscious observer-moments in the multiverse,
the great majority are in mangled worlds.

If this turned out to be the case, would Robin's theory be philosophically
adequate to explain what we see?  On one hand, we might say no, because if
most observer-moments are in mangled worlds, then that is what we would
predict we would experience, yet it seems that we do not.  OTOH we could
say yes, because the mangled-world experiences all lead to death (possibly
painlessly) and by an extension of the anthropic principle, we can only
experience worlds where there is memory and continuity of consciousness.

Hal