I also believe that space time is an additional dimmension. But I think it needs to be intertwined with relative existance. In order for space time to be a constant...which I'm very sure everyone would agree that it is everyone must experience an altered speed of light which is affected by your position in curved space. Which leads to all sorts of interesting possibilites of the actual events happening to everyone at the same time...whcih is just fuggen...wierd shit.