Parallel Universe?

Question

What are your thoughts on parallel universes? Do you believe? Why or why not? Do they exist?

Answer 1

I like to think that they do. It helps for me to reinforce the idea of free will. Every choice you make, form getting up in the morning, to going to work, to going to bed, can be made differently.

In theory every decision point the world would split into two parallel universes because in one you make choice A, where as in the other you make choice B, and in a third you do choice C.

Now I also think that many of these universes are so close in reality (does it really matter if you wash your hair first or last in the shower?) that they would reconverge, whereas other would deviate farther and farther apart because of different decisions made (for example if you killed someone who would have otherwise become president that would be changing the future, and one reality would have that person dead another would have them as president.)

So for me it reinforces the free will concept, I can make any choice I want to and at least in some small way I am changing the world around me. I believe they exist but on a plane that we cannot currently reach, or who knows me may cross between so many nearly identical universes everyday that we don't notice the difference because the are so close.

Answer 2

I have a totally open mind on the subject of parallel universes. There are any number of phenomena related to quantum mechanics that can be explained by assuming parallel universes. Until it's proven that they *don't* exist I'll continue to consider it a very plausible concept.

Answer 3

Certain aspects of quantum mechanics rely on them. The quantum computers that various research groups are trying to develop are supposed to work by doing large numbers of simultaneous operations, by creating parallel universes for each one. However, the universes themselves cannot be directly observed- only their effect on particles.
Of course, the fact that these universes cannot be directly observed must inevitably lead one to debate whether they can be considered to exist in the strictest sense. The problem is, that if something can be observed, then it exists and must therefore be considered to be part of the universe (since the universe is defined as being 'all that is'). If it cannot be observed under any circumstances ever, then it cannot be part of the observable universe. But in that case, in what sense can it be considered to exist? If things that can never be observed may be considered to exist, then what is the distinction between the real and the imaginary?
(So, it is probably reasonable to conclude that alternative universes are only as real in any meaningful sense, as my imaginary friend, Herbert the Talking Radish).