Ok, so I was just in physics class today and we were talking about special relativity... anyways, the instructor refered to how the universe is expanding, and so much so that there are places we could never ever get to because it's expanding fasterling than the speed of light. Anyways, this got me thinking about Space itself and I was wondering. Is Space in of itself a 4th dimensional object? Because clearly it can't be NOTHING if it is expanding... right? It's just intangible to us... so couldn't it just be a really big object perpendicular to the 3d matter on/in/around it?