Ivan, are you familiar with Ronald Mallett? I saw a documentary about his research into time travel on a special that TLC did back in December. It was very interesting. For the first time I started thinking this could be a form of "time travel" that might work, but it is not the type of time travel that we are familiar with from books and films. Power is the main drawback people see to this working.
Basically here is the gist of what he's thinking, this from an article I will also post a link to.
Why you haven't met someone from the future
However, putting Ronald's theory into practice presents plenty of problems. For example, the temperature of the ring would have to be close to absolute zero (-273°C), so humans would find it difficult to use. It would also be impossible to travel back to a time before the machine was switched on.
This explains why people from the future haven't visited us - we are yet to build a time machine for them to exit from.
Ronald hopes that travellers from the future may be able to overcome these difficulties and use the rings of light that we construct today as portals to our time.
http://www.abc.net.au/science/slab/wormholes/default.htm
This is an excerpt from a "layman's explanation" of Mallet's paper.
Nearly 50 years later, Mallett may be on the verge of building the world's first operative "time machine," though it will bear little relation to that of Wells, or to the DeLorean sports car of the movie Back to the Future, or the Tardis of Dr. Who or any of the other hundreds of time traveling mechanisms that have been imagined since Wells first took a crack at it.
Mallett's machine, as laid out in his May 2000 paper in Physics Letters entitled "Weak gravitational field of the electromagnetic radiation in a ring laser," is based on Einstein's formulation that light and matter are both forms of energy.
We know that matter can bend space-time and according to Einstein's theory, matter and light are both forms of energy. So why can't light bend space-time?
This fall, with UConn colleague Dr. Chandra Raychoudri, Mallett will begin work on building a "ring laser"--basically, a device that will create a circulating light beam, perhaps within a photonic crystal that will bend the light's trajectory and slow it down.
Then, a neutron particle will be sent into the space in the center of the beam. In short, the beam--perhaps two beams in one model, with the light traveling in opposite directions--is expected to twist the space-time inside the circle into a loop.
Think of a spoon stirring thick gravy in a pot and creating a vortex, only the vortex in this case is the fabric of space-time twisting, with past, present and future, circling one another so that the future precedes the past.
Then--and while this might not seem very exciting--a neutron, a small particle of matter--will be sent into the center of the beam. If its spin is affected, then it is being affected by warped space-time.
In a further experiment that Mallett has considered, two identical samples of a radioactive substance could be put into the center of the ring, one going in the direction of the beam. The other in the opposite direction. Since radioactivity decays at a measurable rate, it would be possible to measure, in effect, the time that both particles had experienced within the beam. If the time proves to be different, then time will have been measurably altered.
Eventually, says Mallett, "what would be neat is if you saw another neutron in there that you hadn't introduced yet." In essence, the same neutron "visiting itself from the future."
So you've moved a neutron. So what?
What Mallett will have shown--if it works--is that the fabric of time itself can be altered by light, and a thing can be moved into the past. If it works for a neutron, in theory, it would work for you and me.
http://www.walterzeichner.com/thezfiles/timetravel.html
Mallett's paper "Weak gravitational field of the electromagnetic radiation in a ring laser"
http://temporology.bio.msu.ru/EREPORTS/mallett.pdf