Yes, I wonder about this also. Wouldn't need to be toroidal - could just be spherical, but would need to wrap in a 4th spatial dimension. It would explain a l

Yes, I wonder about this also. Wouldn't need to be toroidal - could just be spherical, but would need to wrap in a 4th spatial dimension. It would explain a lot of things, like the expansion not having a clear centre, the requirement for dark matter (expansion would happen in an orthogonal dimension), background radiation (which I never quite understood) and the size of the universe. But that was a high-school idea, and I'm sure some clever physicists and astronomers will tell me why this isn't the case.