@6a30a78d 

Hmmm.  Small as in eventually curves back on itself?  Or as in some kind of edge?  In either case, the temptation is then to ask what lies outside the curve or beyond the edge?  It seems like all cosmological answers are eventually absurd. 

 @6d0c46b2 Either the Universe is infinite or its finite. If it's finite, we can't measure the curvature in the Universe today, so that sets a minimum size. But yeah, it would wrap around on itself, like a 3D game of asteroids.