Re: Question on quantum computing and many-worlds interpretations of Quantum Mechanics

Thanks for all the responses that will give some food for thought over
whether the quantum computer necessitates the existence of parallel
universes. However, I don't think this quite addresses the point I was
trying to make.

It was simply this - that even if it were true that such a device implied
the existence of real parallel universes in which the computations were
carried out simultaneously, it only implies the existence of parallel
universes that have precisely the same history as ours. If Iain Strachan
types in a 400 digit number and hits the "Factorise" button and the
calculation takes place simultaneously in an atronomically large number of
parallel universes, then even so, those universes all had an Iain Strachan
who decided at that precise moment in time to type in those precise digits
and hit the factorise button at the same time. It does not, therefore imply
the existence of parallel universes in which Iain Strachan makes different
decisions - is watching football at that time, or is an atheist, or doesn't
exist at all because his mother didn't fancy his father etc.

So if all the parallel universes "necessary" for the quantum computing
device to work really exist (in some sense), then they must be all the same,
so it doesn't really prove much, and indeed doesn't mean that interpretation
is better than any other interpretation.

Iain (thinking for a moment about whether to send this or not and the
corresponding divergence of discussion ...)
Received on Fri Mar 3 02:00:13 2006