[net.physics] Many worlds view

weemba@brahms.BERKELEY.EDU (Matthew P. Wiener) (02/08/86)

>>Perhaps Torek and Rimey should arrive at a consensus,
>I am offended by your implication that Torek and I have been abusing

I have no idea what Torek and Rimey are saying.  Since some people want
to discuss many worlds, but don't want to jump into T&Rs discussion, I'm
just going to state my opinions.

Disclaimer: My knowledge of MW comes from what other people have told me.
It never seemed interesting to me.  (Similarly, endless metaphysics does
not interest me.)

Abbreviations: MW=many worlds (interpretation, view, universe, etc.),
               Cp=Copenhagen (interpretation, view, universe, etc.),
               wf(s)=wave function(s).

The only difference I see between MW and Cp is one of ontology, that is,
underlying assumptions on what *exists*, and where the arrow of time comes
from.  [Anyone know a good word for that, a la chronogenesis?]

They make the same predictions in all known experiments.  Indeed, they are
mathematically the same in non-relativistic quantum mechanics.  In particular,
Schrodinger's cat is irrelevant here (except as a mental exercise to convince
yourself you understand what's going on!).

Cp assumes that the observer following wfs sees them collapsing according to
a probability distribution.  How the collapse occurs is a mystery/definition.
The arrow of time is set by continually collapsing wfs.

MW assumes there is an underlying universal deterministic(?) wf, and that an
observer undergoes a probabilistic multifurcation into distinct observers,
each seeing different parts of the universal wf.  How it occurs is a mystery/
definition.  The arrow of time is set by continual multifurcation.

In other words, an observer in MW is forced to observe Cp, and will always be
unaware of any MW doppelganger making different observations.  He rides one
branch of an ever-branching tree.

Of course, future developments of a quantum field/gravity nature may lead to
an unforeseen distinction between the two interpretations.

ucbvax!brahms!weemba	Matthew P Wiener/UCB Math Dept/Berkeley CA 94720