The cool part, which what's his name didn't get to, is Maxwell's field equations, which explain why light can even move at all. Light is an electro-magnetic wave, with the electro part moving with respect to the magnetic part. Remember wrapping a wire around a nail in elementary school and connecting the ends to a battery and the nail became magnetic? Works in reverse too, otherwise no house current. Something like that. It's both so it keeps itself going. Cool.