Quote (Azrad @ Jan 10 2014 07:49pm)
good luck gathering the negative mass material and then accelerating it faster than the speed of light. The problem is recursive, to make something travel faster than light, you need something that travels faster than light...
You are right the only possibility to really be faster then light would theoretically be an imaginary mass, but there is no prove that tachyons exist...
But what StephanePare probably meant is, that there is a possiblility in general relativity where you can bend the spacetime around you, so that u can create some sort of bubble in spacetime, which then can travel faster as light. While you yourself in the bubble do not travel faster as light with respect to your own spacetime and for that reason could travel faster as light without traveling faster as light... But its just some theoretical idea, which was calculated to be theoretically possible, but would need crazy amounts of energy...