I remember reading that E=mc^2 doesn't say that it's impossible to go faster than light, but rather says that accelerating something from less than the speed of

I remember reading that E=mc^2 doesn't say that it's impossible to go faster than light, but rather says that accelerating something from less than the speed of light to the speed of light will take infinite energy. The subtle difference is that if something just, uh, is going faster than light then everything works out. They're are two implications though, one is that it could never be decelerated below the speed of light and the other is that it'll probably have to be traveling backwards in time. Making something that goes backwards in time and faster than light (without using infinite energy) is left as an exercise for the reader.