Q: Is the Alcubierre warp drive really possible? How close are we to actually building one and going faster than light?
Negative mass, which is fundamentally different than anti-matter, would experience gravity as a repulsive force. Too bad nobody has ever discovered any negative mass floating around out there or made any substantial amount it. It’s probably best negative mass doesn’t exist, because it’s incredibly creepy! For example, imagine you had a chunk of normal mass and a chunk of negative mass in space. The negative mass would fall towards the regular mass, but at the same time create “repulsive gravity” which would then push the normal mass away.