It has been said that energy cannot be created or destroyed. If energy is matter in motion, and if matter stops moving, than why can it not be said that; where there was energy, there is no more? After being in motion could matter only stop moving and therefore cease to be considered energy, if matter elsewhere increased in terms of velocity? As I read over this which I have wrote, I realize that it most likely should not have been posted under the general and special theory of relativity section. This possible mistake was made by me because my post does deal with the concept of relativity. If you've been in a stationary vehicle which has next to it a vehicle that is moving ahead, then you've might have had the thought that you were moving going in reverse. Imagine a highway where there is bumper to bumper traffic. A new car moving quickly enters onto the highway. That new car can come to a complete stop if it crashes into the line of cars that are hardly moving. My question above is then illustrated by the fact that the other cars on the road must increase in velocity for the car entering onto the highway to come to a halt and when it does...when that car, when the object, the segment of matter, is no longer moving, then why could this not be called the end of motion and therefore the destruction of energy?