Hello all. New user, novice thinker. I searched the forums but didn't see any relevant response - apologies if this is redundant. Everyone knows that the universe is expanding. But, to where is it expanding? Doesn't the mere fact that it's expanding indicate that there is something on the other side of the expansion? I'm thinking of it like an expanding balloon, pushing the air away as it expands. Also, using the balloon analogy (maybe that's where I'm mistaken), a balloon expands because it fills with air. So if the universe is expanding, with what is it expanding? Thanks for your input.
