[Sethomas]

Anyone who calls parallel universes "extra dimensions" is a moron.

Yes, you can have "shape" without matter. Those issues with mathematics Einstein spoke of having problems with mostly referred to a unification of linear algebra with Riemannian geometry, if I remember correctly, and it all was to be applied to space itself. Not matter within space, just plain space.

Stephan Hawking is one of the sharpest minds in the world, but his opinions have often been wrong and his books for the masses aren't canon. Even as such, I think you demonstrate that you didn't understand a word of what he said, nor what has been said above in this thread.

There is no "vacuum" beyond the universe. There isn't anything, and in physics language to say that something exists beyond the universe is a non-statement. Either there's matter PARALLEL to our universe or there isn't, and that's a totally different subject. But to speak of somewhere "beyond" the universe is just crazy talk. You can't go in a straight line to the edge of the universe and then leave it because it's a self-contained system. Nobody agrees on what would happen, but it's generally agreed that the curvature of spacetime would either send you to the opposite end of the universe or put you in reverse motion.

And before you talk more gibberish of no curvature of spacetime, it was proven precisely as calculated IN FUCKING 1915. The sun's gravity in an eclipse bent the stellar light, and photons aren't electromagnetically charged and contain no mass. (Yes, they are units of electromagnetic force, but they have no positive or negative charge associations). The fact that light beams can be bent is proof of spacetime curvature, as is the uneliptical orbit of Mercury.