I've heard all the theories about Brane Universes, other dimensional spaces etc, and if you think about just the simple statement that there are more stars in THIS universe than there are grains of sand on the whole of the Earth.... well, wouldn't that truth if extrapolated a bit further explain why we can't see other universes?
Think about the relative sizes and distances:
Sand grains (1)
Stars (2)
Universes (3)
We cannot see all the stars in the universe, because the stars are so big they need a lot of space to co-exist in the universe, so perhaps the obvious reason why we cannot see other universes is simply that they are too far away for our current technology to have reached as yet.
We can't even see to the edge of this universe.
There could be a humoungous amount of universes, well beyond the edge of ours, even if the other universes began directly at the edge of ours, we couldn't see them until we can see the edge of our own universe - and beyond.
Membrane Universes is an interesting theory, but do we need it?
You might need something to puncture our universe, and penetrate into another.... and once you did that you might create a singularity, which would probably start a big bang thus creating a new beginning and a new universe - maybe that's how our universe started - a curious scientist poking his finger into other realms!
Perhaps talking about membrane universes being just a nano distance away, but in a different dimension, gives us a chance of one day reaching them, having to travel to the edge of our universe could otherwise take a while.
Perhaps wormhole technology will one day enable us to travel between universes without causing a singularity and thus destroying everything in a great collapse.
Hmmmm..... what do you think?
