I have touched on what I will say before, and I don't remember the results,
so I may step onto a landmine I stepped on a year ago. The problem I have
with the many-world hypothesis is that it would have a universe (ours) in
which I am a Christian. There would be others in which I am a Christian.
But there would be still others in which I decided to become an atheist
during my crisis of faith a few years ago. Thus, in the multiverse (the
existence of all universes) there is are many non-christian Glenn's and many
Christian Glenn's. What then does redemption mean? I don't know the answer.
Here is the landmine. Assuming two things, neither of which is certain, we
may get a test of the many-world hypothesis. The two things are 1. the
invention of a quantum computer and 2. the solution of a mathematical
problem of more than a certain complexity.
A calculation requires the manipulation of a physical object. In the case
of computers it requires the manipulation of electrons and atoms. Now,
there are 10^80 particles in the universe. Assuming that a quantum computer
is capable of solving in 5 minutes a problem requiring 10^500 calculations.
The question would have to be asked, where are all the particles which are
being manipulated in these calculations? The obvious answer to most would
be the manipulations of particles in other universe's. This the solution to
this kind of problem would be considered evidence of the other universes. An
interesting easy level article is Tim Folger, "The Best computer in All
Possible Worlds,' Discover, Oct, 1995, circa p. 95
Foundation, Fall and Flood