Well, I started this thread to explore the possibility of space travel using a technology that did not require the use of the mass-momentum action-reaction principle (that's my description of a fuel-based rocket), that is, a technology that would use pure energy to produce momentum instead of having to expel mass to accomplish it.http://arxiv.org/pdf/gr-qc/9805003v2.pdf
"The present theorem rules out the existence, rather than construction, of superluminal travel, unless there is weak energy condition violation. "
My question would be how can you extract momentum or energy from the lowest possible energy state (Quantum Vacuum)?
I very, very much doubt we're anywhere near accomplishing superluminal motion, if that were even possible... although the two dominant theories (Alcubierre's and Krasnikov's) proceed from people serious enough for their peers to at least consider them for case studies, even if they're only trying to prove them wrong.... which is ok by me, since the foundation scientific method is based on skepticism and experimentation.
Superluminal motion was not the intention of my post, but rather to take a closer look at this proposed fuel-less propulsion technology.