Technion physics professor Amos Ori has a paper in the July issue of Physical Review that not only says time travel is possible, but also simplifies the physical requirements. Ori first proposed a more realistic model of time travel in a letter to the journal in 2005.
Einstein’s General Relativity theory is the basis for theories about time travel, and time travel research is based on the idea of bending space-time so far that the time lines actually bend back on themselves to form a loop.
In 2004, Ori outlined a set of conditions that would allow for the creation of a time loop without the need for exotic matter—matter predicted by quantum field theory to exist, though only in quantities too small for the construction of a time machine. That theory called for the time loop to form as a donut-shaped vacuum, inside which time would curve back on itself, so that a person traveling around the loop might be able to go further back in time with each lap.
Ori says serious questions remain about the overall stability of a time machine, the evolution of which would be dependent on a very narrow range of initial conditions that might be difficult—or even impossible—to achieve. He is working to show ways such a configuration could be achieved.
But you can forget about going back in time to visit Moses, Ori says.
“If we were to create an area with a warp like this in space that would enable time lines to close on themselves, it might enable future generations to return to visit our time,” Ori said. “We, however, could not return to previous ages because our predecessors did not create this infrastructure for us.”
In other words, if we started building the time-travel infrastructure now, we could expect to get a visit from the future. Let’s just hope it isn’t the Terminator future.