I am currently a twitter user. One of my followings is Jeri Ryan. She has been Seven of Nine in Star Trek Voyager saga.
Yesterday, it comes out of the blue what I read in one of her twits: NASA is developing warp drive! Indeed, Jeri was pointing to this link. This is a Gizmodo’s post that was describing an effort by NASA to develop warp drive and it seemed like something consistent was in hand. Indeed, this is all true. It is a lab at NASA, Eagleworks, headed by Harold White that is working on a technical realization of the most recent ideas from physics in the area of “spacetime engineering”. This is somewhat of a new term as, so far, no ways were at our disposal to modify spacetime even if, in principle, this is a possibility offered by general relativity. If one would be able to do so, we would have warp drive but also time machines, wormholes and all that. White’s group claims to have found some loopholes in all the hurdles encountered so far in this kind of researches. The most fundamental one is that one needs a huge quantity of exotic matter to get some of these devices work. Nothing that is manageable in practice. So, all this matter was always put in an area of research much theoretical oriented. In a quite recent paper, Stefano Finazzi, Stefano Liberati and Carlos Barceló (see here) show that Alcubierre drive is unstable with respect to quantum effects: Indeed, if you go faster than light, Hawking radiation will kill you.
So, there are some important difficulties to overcome to change the situation from theoretical to a practical one. One of the Editors of Physical Review Letters, Robert Garisto, commented as follows on twitter:
NASA warp drive story: Not sure which is less plausible, that it’s allowed by physics or that we could implement it if it were.
White’s group claims that they are on the verge to realize an experiment comparable to the Chicago Fermi’s experiment on the nuclear pile. This would imply that they have overcome all the difficulties seen so far in this kind of studies and are able to provide a working realization of the effect. You can find a paper by White here and is worth reading. They can controvert any skepticism by a sound experimental proof.
My view is always the same: As a physicist I have a blind faith on experimental facts and I would like to see accomplished one of my lifetime dreams arisen with that small step by Armstrong on the Moon. NASA is never a disappointment.
Stefano Finazzi, Stefano Liberati, & Carlos Barceló (2009). Semiclassical instability of dynamical warp drives PHYSICAL REVIEW D 79, 124017 (2009) arXiv: 0904.0141v2
Miguel Alcubierre (2000). The warp drive: hyper-fast travel within general relativity Class.Quant.Grav.11:L73-L77,1994 arXiv: gr-qc/0009013v1
The Gauge Connection 
Alcubierre’s original paper didn’t address the issue of how a warp bubble could be created, it just analyzed a spacetime where one already existed. I wonder, has White or anyone else actually found an exact solution to the equations of general relativity where a warp bubble is created in a previously bubble-free region of space, perhaps using a theoretical model of the “White-Juday Warp Field Interferometer”? If there are no exact solutions, are there numerical simulations that show this happening? If neither, I’m skeptical that there’s much good basis for the claim that the White-Juday Warp Field Interferometer might plausibly be used to create one (I would imagine the argument would be fairly handwavey).
Dear Jesse M.,
The interesting matter here is that NASA decided to fund such studies and, possibly, White’s arguments should have been very good to convince the administration. Said this, it is plausible to think that, changing the geometry of the matter generating the bubble, the requirement can be significantly less demanding. I would like to remember that in a previous geometry it was required a quantity of exotic matter as Jupiter mass. This is what one needs to generate the bubble and a lot of literature discussed a lot on this. While we wait for further results on 2012 to be announced, I invite you to read all you can find, just googling around, about White’s work. All the details are filled in.
Marco
I was under the impression that when they talk about the amount of exotic energy required, they are just talking about what’s needed to keep the bubble at a constant size, not necessarily saying that any GR solution (or numerical simulation) had been found showing how the bubble could be generated in a region of space where it didn’t exist already. Do you know of any papers dealing specifically with the issue of creating new bubbles?
Also, NASA devotes a small amount of funds to a lot of “blue-sky” ideas, including ones that are thoroughly outside the mainstream of physics–see for example the page here where they talk about the possibility of using vacuum energy for propulsion, specifically mentioning the ideas of “Haisch, Rueda, and Puthoff” which I’ve seen several mainstream physicists dismiss as nonsense, see John Baez’s comments here. So, the fact that NASA decided to fund Dr. White’s research doesn’t really tell us much about its scientific respectability.
Dear Jesse M.,
I agree with you that there is a lot of room to be skeptical and I share your view that Alcubierre drive is, at best, problematic. Of course, as already said in my post, I believe in experimental facts. If they are able to give extraordinary evidence to their claim I will be happy to change my skeptical view in a strong support.
Marco
[…] Warp drive at NASA « The Gauge Connection […]