From: Anders Sandberg (asa@nada.kth.se)
Date: Tue Feb 11 2003 - 11:53:00 MST
On Tue, Feb 11, 2003 at 09:25:40AM -0800, Charles Hixson wrote:
>
> So if there are parallel universes, then they will usually stay closely
> similar, but on rare occasions one will make an improbable transition,
> or rather a transition in an improbably environment, that will lead to a
> cascade of changes such that the two resultant universes would
> observably different at the macroscopic level. And I think that a good
> argument could be made that such transitions are rare.
Hmm, why do you think that?
What to look for is noise-amplifying processes, i.e. chaotic phenomena
or systems that very sensitively can move into two attractors (like a
GM counter or a neuron). Both are rather common in the world. Quantum
transitions likely color much of the thermal noise in our environment,
noise which in turn influences air movements and hence weather patterns
- here individual quantum 'choices' are invisible because there are so
thermodynamically many of them that we cannot make out any individual
contribution. But they would cause an ensemble of systems diverge with
a speed set by their lyapunov coefficients.
My guess is that the divergence is fairly steady most of the time, with
occasional spikes.
> (It's
> interesting... I began this with a model of a continuum of universe
> states, and have ended up much closer to the sheaves of similar
> universes that are a stape of parallel worlds in science fiction.)
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 onself in such a world is vanishingly small due
to decoherence, 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?').
> A question might exist as to whether or not this differentiation is
> instantaneous, propagates at the speed of light, or perhaps propagates
> at the speed of Wigner's paradox ... i.e., only with the transmission of
> information. OTOH, this may not be a meaningful question.
If you view the universe as a single state vector then there is no need
for superluminal transmission or anything; the whole universe is a
single object.
> It's not clear that it's possible, even in principle, to distinguish
> between these variants. Which is, itself, the major argument against
> the multi-worlds hypothesis. There's no obvious way to test it!
Well, the MWI is a falsifiable hypothesis: if you ever observe
non-unitary evolution of quantum systems, it is out. So far it has not
been seen, not even with C60 'atoms'.
I think Tegmark explains it nicely in the paper that got this thread
started.
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y
This archive was generated by hypermail 2.1.5 : Tue Feb 11 2003 - 11:52:08 MST