There is an interesting story in the March issue of Popular Science
on the subject of time travel and displacement. This along with some
diagrams on the physics of the idea on page 52.
Though I feel from the story the leaders of this cutting edge concept
are fumbling the ball somewhat. The theoretical idea of getting into
a spaceship and traveling very fast at the rate of 99% the speed of
light. Then going out 500 light years and returning. Then finding the
earth has aged 1000 years while you have only aged 10 is not the big
scientific payoff this phenomenon has the potential to deliver.