There was a Superman story, back in the mid-'60s, which dealt with this idea. Superman viewed various scenarios in which Jor-El had sent him to planets other than Earth, and on one planet he had lost his powers due to a red sun or Gold Kryptonite, or something, and his chemist-father invented a super-speed serum, enabling Kal-El to become the Flash of that world. Only problem was that, when he reached escape velocity he flung himself off the face of the Earth and was lost in space forever.
This is one of the reasons Mark Waid created the Speed Force -- basically whenever the Flash does something that breaks the laws of physics or otherwise does not follow the laws of physics, all the Flash fans can say "Speed Force" as the explanation, which means about as much as saying "Magic" or "God's will" or something like that. Or, like that episode of the Simpsons which guest-starred Lucy Lawless, in which the explanation for any discrepancy was that "A wizard did that".
