My question here borders on philosophy, but I'm posting it here because I'd like to discuss it in a scientific context. I was thinking about time and motion the other day, and how I cannot distinguish between a motionless universe and one without time. For example, if everything were to stop for a million years, and then start moving again exactly as it was, this would be indistinguishable from no time having elapsed at all. In Einstein's equivalence principle, he notes that the effects of gravity are locally indistinguishable from the effects of inertial motion. From this he promotes the "coincidental" equivalence to a "law of nature". So I was wondering if it would be possible to make a similar step with the equivalence of time and motion. For example, we might decide that if we transform to a frame where everything is motionless, then no time elapses in this frame. I know what I'm saying is a bit rough around the edges but I'm interested in how to take what seems like a philosophical concept and turn it into a testable theory.