Parallel Universe

The parallel universe model of quantum theory is based on Schrodinger's mis-interpretation of quantum theory. David Deutsch champions the same mis-interpretation.

Schrodinger uses the word "and" rather than "or" to describe his cat in the box (to describe his problem with quantum theory). He thinks of the cat as in some sense both alive and dead.

Confronted with this same artificial problem, subsequent thinkers have then tried to solve it by proposing a multiple universe theory, eg. in one universe the cat is alive and in another universe the cat is dead.

However the problem can also be solved by not constructing it in the first place. We can say there is one universe (or one part of the universe) in which the state of the cat is unknown - or more specifically: we can say the cat is alive or dead.

And in another part of the universe (eg. at a later time) the cat is then observed to be dead. Or (ie. quantum theoretically) the cat is then observed to be alive.