John Clark, <jonkc@worldnet.att.net>, writes:
As an example of the second interpretation, see the Many-Worlds FAQ,
http://www.cs.mu.oz.au/~fjh/many-worlds-faq.html:
: Q7 When do worlds split?
John's version is the second one above, Mike Price's (author of the FAQ)
is the first. Both versions are fairly widely used.
> hal@finney.org <hal@finney.org> On Tuesday, August 17, 1999 Wrote:
>
> >This points up an ambiguity in the MWI, which is, when do other universes
> >exist? That is, when does the universe split? You can give two answers.
> >One is that it splits whenever there is an alternative which is explored
> >in the quantum realm. The other is that it splits whenever there is
> >a measurement which causes what would conventionally be called wave
> >function collapse.
>
> I've never heard of that second version of the MWI before, I always
> thought it's entire advantage was that it didn't have to explain what
> a measurement is.
: ---------------------
: Worlds irrevocably "split" at the sites of measurement-like interactions
: associated with thermodynamically irreversible processes. (See "What
: is a measurement?") An irreversible process will always produce
: decoherence which splits worlds. (See "Why do worlds split?", "What is
: decoherence?" and "When does Schrodinger's cat split?" for a concrete
: example.)
: [...]
: The advantage of linking the definition of worlds and the splitting
: process with thermodynamics is the splitting process becomes
: irreversible and only permits forward-time-branching, following the
: increase with entropy. (See "Why don't worlds fuse, as well as split?")
Hal