I ran across this question somewhere on line and thought it was interesting.
I read in more than one location that the question of whether the universe, as a whole, is moving through space is irrelevant since there is no way to detect movement where there is no frame of reference. Which I have to admit makes perfect sense.
Then something occurred to me that seemed interesting to consider.
What if, in the deep vastness of infinite space and far beyond our ability to detect, was another universe on a collision course with our universe? Or perhaps multiple universes, all self expanding but also moving through open space independently.
Of course you'd have to accept that the universe that we know has infinite space beyond the borders of known matter that is expanding outward from the Big Bang point of beginning and isn't a massive dark sphere that is itself expanding only as the outer edges of expanding matter expands and no more. Or some other theoretical limitation.
Since light travels so slowly relative to the massive distances involved its also possible that the universes could have already begun to collide into each other. It could have started last Tuesday and we would never learn about it in a hundred lifetimes.
Just something fun to kick around.
