Hopefully this doesn't sound too stupid from a science noob like me but here it goes...
I've come across one interesting idea that, if I interpreted it correctly, states that our 3-dimensional existence is merely the "surface" of a higher dimensional object, as in a 3-dimensional manifold existing in hyperspace.
This would explain why many members here keep arguing that space does not expand from any particular center point, but expands uniformally, as in the analogy of blowing up a balloon.
Is this the same thing as the model of a "closed" universe? And in general, what is the most accepted model regarding the size/shape of our universe?