Why is E equals MC2 in Star Trek?

Answer 1

E=MC2 was a formula which explains that energy is the sum of mass and velocity squared, meaning that as something speeds up and hits something else, the energy is transferred to it from the weight and speed of the object hitting it.

That formula was written by Albert Einstein before or during the second world war. In Star Trek, this formula would be considered as mundane as many technologies were developed to counter the effect, like the inertial dampers on all vessels that prevent the sudden movement of anything aboard when they jump to light speed. (Tom Paris, on Voyager, explains that they cannot go to warp with the inertial dampers offline because they would become "stains on the back wall". This is where E=MC2, or rather, Newtons third law of motion comes into effect. For every action, there is an equal and opposite reaction.)

Basically, Einstein only interpreted this formula which has nothing to do with a science-fiction TV series.