From: Lee Corbin (lcorbin@tsoft.com)
Date: Tue Feb 11 2003 - 18:50:46 MST
Anders writes
> Note that the MWI also contains the unlikely worlds, including
> truly bizarre "hell spaces" where there is no order at all.
> But the probability of finding oneself in such a world is
> vanishingly small due to decoherence,
Do you mean the same thing as: whereas there is some low probability
that I will find myself being tortured by Colombian Narco-dealers,
there is a vanishingly low probability that I will find myself in
a completely incoherent world (for one thing, I would suffocate
immediately)?
> that leaves only the classically possible worlds with
> much probability mass. So in one sense there is a continuum of worlds,
> but only a tiny sheave matters - but this sheave on the other hand
> contains many continuums (like the dimension 'where did the electron
> end up?').
Yes, this use of the word "sheaf" is critical, IMO. One imagines
a sheaf of identical universes traveling together. (And on the
Identity of Indiscernibles, some will say, not wrongly, that this
is exactly the same as one world.) Then when an irreversible event
occurs, some fraction of them go one way, and the rest another way.
In an earlier email you wrote
> The mass issue is not really an issue. When a system is in a
> superposition of states (let's say a 4 kg living cat state
> together with a 4 kg dead cat state in a Schrodinger box)
> the total mass doesn't increase to 8 kg.
Quite right. And the way to see this is to imagine that a
sheaf of a thousand pieces of paper has bifurcated to two
sheets of five hundred pages each. In other words, universes
become distinguished.
(Speaking about "splitting of worlds" sometimes has the
drawback of giving rise to notions of increase in quantity.)
I find it easy to think of quantum computation in the same
terms. Suppose that a sheaf of N identical universes is
about to calculate something. Imagine the N identical
universes (say all blue), now becoming a huge variety of
colors, quite a rainbow, and then go back to being blue.
Only now in them all (and again, they're identical, so
some would rightly speak of one world), the anticipated
solution obtains.
Lee
This archive was generated by hypermail 2.1.5 : Tue Feb 11 2003 - 18:47:49 MST