Originally posted by Surfer's Rules
Well the speedforce, which DC themseflves created to nullify the effecs of physics on Flash's movement precludes the accumulation of said mass. That's the whole point of the Speedforce, to allow him to exceed superluminal speeds without killing himself and destroying his surroundings. The energy accumulated is absorbed by the Speedforce so that Flash can actually move. Think about it. If Flash was attaining infinitely increasing mass...well, he would die, but he would cease to be able to move before that. The speedforce allows Flash to be the greatest speedster without the burden of energy buildup, so why DC introduces the IMP and essentially nullifies the effects of the speedforce is beyond me. You can't have the speedforce and the IMP at the same time.
Logically, realistically, in THIS world...you'd be right.
However, as the scans that were just posted recently prove, it doesn't matter.
Flash IMP'd Zum without destroying himself or the Earth. Obviously you CAN have the speedforce protecting the Flash, protecting the environment, AND letting the Flash attain nigh-infinite mass.