Very interesting thread!
With the centre of the universe; the other day my computing teacher was explaining wormholes to me.
He said that they are theoretically formed because spacetime is curved like a ball, and black holes create infinitely deep pits in the surface of the ball. Each of these pits leads to the centre and can connect to other black holes somewhere else on the surface of the ball. Would the place where the black holes connect be the gravitational centre of the universe?
And if this ball was expanding, every point on the surface of the ball would be moving away from every other point. Could we then replace the 2D surface of the ball with our 3D space?
I think I may have raised more questions than I solved.
