Submission + - Warp Drives may be slightly less impossible (arxiv.org) 1
RockDoctor writes: Everyone loves a warp drive. The problem is that typically, they require "unphysical" (i.e. very large) amounts of energy, and "exotic" materials (materials with a negative energy density). There has been progress since Albucierre formalised the idea in 1994 ; energy requirements have reduced to using the mass of the Sun to create a "warp bubble" of a whole 10^-15m external diameter (we don't have microscopes that can see that small), which is an improvement. And the progress continues : a recent paper on Arxiv (submitted to Classical and Quantum Gravity ) asserts that a warp drive "can be constructed based on the physical principles known to humanity today." That's a generic warp drive — not an Albucierre warp drive — but that's probably close enough for non-specialists for the moment.
Some of the constraints of the Albucierre drive "may seem artificial" (their words), compared to the more general types of drive which these authors consider, and by relaxing those constraints they say they can construct (mathematically) warp drives without the "exotic" requirements. Unfortunately one of the requirements they relax is (if I understand the maths adequately) that time inside the warp drive travels in the same direction as time outside it. So ... a warp drive may be possible, if you're willing to accept that you travel back in time while doing it.
fun? violation causality Isn't
Of course, that exposes us to the large Fermi Paradox, in addition to the regular Fermi Paradox. ("Where are the aliens from the next trillion years?", instead of "Where are the aliens from the last few billion years?")
Some of the constraints of the Albucierre drive "may seem artificial" (their words), compared to the more general types of drive which these authors consider, and by relaxing those constraints they say they can construct (mathematically) warp drives without the "exotic" requirements. Unfortunately one of the requirements they relax is (if I understand the maths adequately) that time inside the warp drive travels in the same direction as time outside it. So
fun? violation causality Isn't
Of course, that exposes us to the large Fermi Paradox, in addition to the regular Fermi Paradox. ("Where are the aliens from the next trillion years?", instead of "Where are the aliens from the last few billion years?")
