I'm currently reading Bill Bryson's "A Short History of Nearly Everything", and I came across a profound idea, and for lack of anything exciting happening today, thought I would share:
If you could travel in a spaceship as fast as you wanted, could you ever reach the edge of the universe? The (theoretical) answer is "no". Apparently, according to Bryson, "space curves, in a way that allows it to be boundless but finite."
He then continues to explain using an analogy: Assume there is a man in this world that has never seen a round object in his life, and therefore also doesn't know that the world is round. If you had him walk in one direction forever, we all know that he would eventually return to the exact spot he started. Chances are he would be absolutely astonished -- he wouldn't get it at all.
I guess that is what it is like when it comes to space. If you traveled forever in the same direction, you would eventually end up back where you started -- and not because space is round, but instead because the universe bends-- in conformance with Einstein's theory of relativity. And the reason it's so hard to fathom and seems like it can't be true is for the same reason the guy that's never seen a round object can't comprehend how the earth is a giant ball. We've never seen any physical thing like it, and the average person surely doesn't study such theories, so we just simply don't understand.
I just find this amazing...