The first thing I should say is that I have not yet seen the new Star Trek movie, though I do intend to. (Is it any good?) But I have seen a raft of articles about the science of Star Trek (what should the collective noun for Star Trek stories be? An "enterprise" of Star Trek stories?) over the past week.
All this reminded me that I have the distinction of actually having attended a conference a couple of years ago dedicated to building a warp drive, organised by the British Interplanetary Society, in London. The society's motto is "From imagination to reality..." and that was very much the spirit of the meeting as engineers and physicists met to seriously discuss if, when, and how warp drives could be manufactured, allowing faster-than-light travel. (One participant did wear a Klingon tie, but he did so with irony.)
Jeremy Gardiner kicked off by boldly predicting something that no man had predicted before: that we will be whizzing around in FTL spacecrafts by 2180. His estimates weren't based on evaluations of the physics or on engineering considerations, but--interestingly--he looked at the timescale for other seemingly wild ideas to shift from science fiction to science fact. In particular, he compared the case with the historical development of the technology needed to travel to the moon, identifying six steps society needs to pass through from "conjecture" (1657 in the moon case, when Cyrano de Bergerac wrote about journeying to the moon), passing through the phases of "speculation," "science," "technology," "application," to final "realisation" (1969 for the moon case, with the Apollo landings).
According to Gardiner, we are now in the "speculation" stage of building a warp drive, following a mathematical proposal in 1994 by Miguel Alcubierre for making a "warp bubble" around a spacecraft, contracting space ahead of it and expanding it behind the craft. The craft surfs along in its bubble, without ever technically breaking light's speed limit, but reaching its destination faster than a light beam forced to travel around the bubble.
That all sounded great, but I wanted to know if anyone actually had any ideas for how to practically implement this. One speaker, Richard Obousy, promised that he had the answer. His method was based on the string theory notion that there are extra spatial dimensions. All you need to build a warp drive, said Obousy, is to manipulate the size of the cosmological constant in front of and behind the craft, by contracting and expanding the curled up extra dimensions respectively, to build your warp bubble. Ok, I said, but how would you actually set about contracting and expanding the curled up extra dimensions--given that we don't even know they exist? He wasn't sure, he replied, as it's still a work in progress...
At that point I lost interest in his warp drive. However, since then Obousy has published his work on the warp drive, so you can check it out, along with a video of one of his talks, on youtube.
I didn't follow up the warp drive meeting, or think much more about it until the recent hype around the new Star Trek film. But thinking back, one talk, by Claudio Maccone of the International Academy of Astronautics, did make me stop and think. He didn't make any bold claims, and he didn't have any speculative blueprints. But he did make a plea to physicists on behalf of engineers: sort out your math. The problem with attempting to build any kind of warp drive, he said, was that engineers and computer scientists are baffled by mathematical conventions that physicists use, for instance, their use of natural units, in which certain physical constants (the speed of light, Planck's constant...) are set equal to 1. At the moment, he said, progress was being hampered because scientists in different disciplines simply don't understand each other's conventions. Put another way, if you want a warp drive, Spock and Scotty need to speak the same language.