So I know it has to do with reference frames and such, and I know that it is all about time relative to different observers, what I don't understand is how exactly is it that when you're moving at a speed close to 'c', you actually physically experience a different time interval than someone who is "motionless," as opposed to simply percieving a different time interval but physically undergoing the same time interval as the "motionless" person. And by physically expierence I mean aging. I was reading something, I don't recall exactly what it said but it was talking about time slowing as you condense space, and it sparked this thought. From a certain perspective if you move across a space you're effectively shrinking or expanding the space by going faster or slower, respectively. So by traveling at such a great velocity you are "shrinking" the distance that you travel, from your perspective, so it takes a shorter amount of time than witnessed by the "motionless" bystander to travel that distance. Is this a good/accurate way to think of time dilation? or am I completely off? And to clarify my credentials, I have none. So anything I think of idependently, that is I don't read it verbatim from something else, I assume wrong, this is no different. So if/when you tell me I'm wrong, please elaborate, I would very much like to know the answer to the original question, What exactly is Time Dilation?