Art Bell had Dr. Ron Mallet from U of Conn. Dr. Mallet thinks he figured out how to make time travel possible. Here's a brief Wiki page on him, with links to his main papers on it:
What I find interesting about this is it involves some things I was rambling about from the Coriolis metric and the "Sagnac" circularly constrained null (light) geodesics.
Frame dragging is apparently the "key" to time travel, which in GR means closed time-like geodesics and/or world lines are possible. Frame dragging is the way time-like curves can be bent around into closed paths. So far, the mass-energy-velocity needed to "close the loop" has been so enormous that it is just an academic thought-experiment (such loops are thought to exist between event horizons in the Kerr metric -- but "thankfully" hidden behind the outer horizon where we would never be able to see it or learn any information about what would happen).
But Mallet thinks he's figured out a way to do with much less energy. He claims that the space-time metric of a beam of light going around in a circle can do the proper frame dragging contortions --actually two beams of light going around in opposite directions (note this would have sort of a "shearing" effect).
Now, normally, as above with regular mass, the energy to close the loops would be astronomical, but he says that the "slowing of light" to a crawl by those Bose-Einstein condensates has the effect of amplifying the effect. [And there are criticisms of his EFE solutions here, before anyone gets too excited -- they say he's wrong, but he thinks he's right].
Anyway, from what I understood him to say last night, he needs a few terawatts of laser power, going around in circles in some BE condensate near absolute zero, and he thinks he'll make a region with closed time-like curves just big enough for some neutrons to squeeze through and be able to observe any funny effects he expects.
I think he said he needs about $1/4 million to do that, and now has the funding and is going to try it.
Now, I pose to you all, what do you think?