Originally Posted by Choker

Thats whats really hard to wrap your brain around. The universe is all there is and it expands itself and there is nothing outside of it. What's realy hard to think about is the distance between galaxies. The universe is not a big sphere nor is it a box, it's shape depends on where you are in it and what you are viewing. And gravity is not caused by a objects mass, it's not two objects pulling on each other. It's the warping of space the two objects create by their mass.