Before an electron can reach the speed of 'c' it stops going faster an
all the energy to push it harder ends up as increasing its inertia it
just continues to get heavier,but no increase in speed. Einstein knew
that before accelerators proved he was right. At 99.999999999 of 'c' an
electron weights 70,000 times its rest mass. as proven by the Cern
accelerator Reality is if you used all the energy of the universe the
electron would equal the weight of the universe. and that's the way it
is Bert