摘要：This paper discusses an absurdity that is rooted in the modern physics’ interpretation of Einstein’s relativistic mass formula when v is very close to c. Modern physics (and Einstein himself) claimed that the speed of a mass can never reach the speed of light. Yet at the same time they claim that it can approach the speed of light without any upper limit on how close it could get to that special speed. As we will see, this leads to some absurd predictions. If we assert that a material system cannot reach the speed of light, an important question is then, “How close can it get to the speed of light?” Is there a clear-cut boundary on the exact speed limit for an electron, as an example? Or must we settle for a mere approximation?