The Alcubierre drive “beats” the speed of light, for the effects described 0.7-0.9c are more than good enough (if slightly unpractical).
We can’t do that either for now, but is way easier on the feasibility scale.
We can’t do that either for now, but is way easier on the feasibility scale.
The Alcubierre drive is only a thought experiment that requires "exotic matter" (aka fairy dust) to work.
> They are only theoretically possible if you allow for negative mass and energy--not an engineering problem so much as a "need to find exotic matter"
Basically people ran the EFE "backwards" to see what matter distribution makes the wanted curvature. You get either negative mass-energy or the bubble doesn't travel ftl iirc.