In the comics, the writers of Superman and the Flash posited that there was a “Time Barrier” that one could cross with sufficient velocity, in analogy to the “Sound Barrier. read more
Because many Flash fans presume the Flash is ALWAYS moving at the speed of light or faster just to get a loaf of bread from the store. He isn't. From a narrative point of view he shouldn't be any faster than he needs to be to tell good stories. read more