The Enterprise's Impulse Drive

Moving back to the sub-light-speed world: We are not through with Einstein yet. His famous relation between mass and energy, E=mc 2 , which is a consequence of special relativity, presents a further challenge to space travel at impulse speeds. As I have described it in chapter 1, a rocket is a device that propels material backward in order to move forward. As you might imagine, the faster the material is propelled backward, the larger will be the forward impulse the rocket will receive. Mater...