I just had an Idea and want to write it down before I forget. I was reading an article on dimensions, and circles/spheres and the such, which made me think of conic sections for some reason. I dont know why, but that got me to thinking about world lines (not wure this is it, it is that thing that looks like a conic section in Stephen Hawking's book.... Well anyways, since you can take a plane and intersect it with the conic section so that the plane is perfectly level, you get a circle. So... If you take a plane and intersect it with the World Line/Cone thingy, you would get a specefic point in time.. If you know what the hell I'm talking about, please respond.