For every action there are infinite possible choices and solutions. If there are several choices, each must be enacted. Also, there are multiple different emotions that one person can have as well as the different outcomes for the several choices that could be made. The outcomes are not just merely lost when a person makes a choice, they are enacted in other universes.
Whether I decide to type the next word or not in this opinion statement are both equally possible- and therefore equally real- scenarios. Since time is spacial- in that the events of space are a line- you can go up a dimension and make a "plane" of events. This plane has many points that are not in continuum but rather possibilities that are fulfilled by the act of observing them.
When I type the next word of this opinion, my consciousness is "teleported" into a different subset of the 5th dimension where everything I just did lines up perfectly. It becomes real BY my act of observation.
If you are a firm believer in logical positivism, then you would agree with me.
If you believe in absolute evidence before logic, then you would be agnostic about my opinion.
Can we predict something that we never seen with our eyes? Where is the evidence? Mankind has not even out of this galaxy yet and we try to assume that there is parallel universe? We defined Universe just because we defined Universe does not mean that definition applies to universally to everything that exists even that we yet have not seen
I don't have much evidence to support my case, but it's kind of like debating the existence of a god. I use string theory as my main support, which basically says why couldn't there be infinite universes. Your reasoning is understandable, but like I said, its hard to debate it; just like its hard to debate a god.
For the main part, it's ad hoc. It solves some problems while completely ignoring others. Also there is absolutely NO, I repeat, NO scientific evidence for it. It's in the realm of metaphysical and philosophical thought. And if it was true, and there are multiple expanding universes, then some of them would have collided by now.
Yes, there may be other "universes" outside ours with different laws of physics etc., but then what do we call all the "universes" together? The definition of universe is "everything"; surely if there were more than one it would cease to be "everything"; having more than everything is a theoretical impossibility. Therefore there would still be one universe, albeit with different "universes" inside it. Therefore, while there is no proof that there are not bodies like our universe outside our own, all together they'd still be classified as one universe.