by lcwelch » Sat Sep 13, 2014 9:41 am
I claim it a matter of belief (and not science) that our universe has room for everything.
There is a formulism in mathematics called "analytic continuation" which one can be used as a metaphor to go beyond our visible universe. If we were to travel in direction "x" at a high velocity (relative to the center of our galaxy), the visible universe - in the direction of "x" (in front of us) expands while in the direction of "-x" (behind us) is contracted. Thus the definition of the "visible universe" is dependent on where we are - and represents nothing more fundamental. Thus there is no reason to expect "our universe" that happens to be beyond what is visible to be any different from what we can see. Thus no room there for an alternative universe.
The semantics in this subject can get murky. I define "our universe" as everything we see, or in principle, could physically travel to (even though it may take eons.)