So, you could condense my knowledge of physics to an index card, but here we go...time seems like it's always based on the measurement of a regular thing. Say t

So, you could condense my knowledge of physics to an index card, but here we go...time seems like it's always based on the measurement of a regular thing. Say the oscillation of a quartz crystal. So we have no proof there of time, just that certain phenomena can be very regular in intervals/cycles. I've heard things like, "if you go the speed of light, or at least really fast, time will move differently." But that seems like it would be a side effect of that local system moving at a rate that interferes with its physical interaction relative to what we consider normal. There are probably tons of holes in that. But my point is that we tend to think of time almost as an invisible "thing", and I really have trouble wrapping my brain around that. It just feels like things happen and we call it time, but really its ordered intervals of effects.