5 ms·
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
by nimish 5y ago
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.
- kadoban 5y agoGp is talking about forward-only time travel though, you don't need anything exotic for that at all, just lots of energy and an efficient way to turn it into thrust.
- xondono 5y agoThe 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.
- lovegoblin 5y ago> The Alcubierre drive “beats” the speed of light The Alcubierre drive is only a thought experiment that requires "exotic matter" (aka fairy dust) to work.
- xondono 5y agoI know, I was making reference to this > 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.
- baja_blast 5y agoPapers have been published that have found ways to create warp drives without the need for exotic matter: https://arxiv.org/pdf/2006.07125.pdf https://arxiv.org/pdf/2006.07125.pdf
- xyzzyz 5y agoNo, for forward time travel you don’t need any sort of exotic matter. You just need a really fast rocket.