Hello everyone! I apologize if my first post is of a problem that may seem like a really silly one. But it was something we were stuck with today in Modern Physics class. It is NOT a homework assignment! We have proved that relativistic force, F = m*(du/dt)*(gamma)3 where gamma is the Lorentz factor. This definition of relativistic force was derived by differentiating the definition of relativistic linear momentum with respect to time. Now the silly problem that must have a simple solution somehow: Theoretically, we say that as we increase the velocity of an object up to the speed of light then the acceleration will tend to get to zero. Meaning we can never accelerate beyond the speed of light. This is the theory. By looking at the mathematics involved: We know from the definition of F above that a = (du/dt)*(gamma)3, the relativistic acceleration. Also, gamma = 1/(1 - (v2/c2))0.5. If we let v approach c (let's say v=c at the extreme) then this would result in the denominator approaching 0 and thus gamma approaching infinity. Which is in contradiction to the previous statement we made regarding acceleration. My question is simple: The theoretical statement is definitely right so what went wrong in the mathematics and messed it all up?