http://www.advance.uconn.edu/01091012.htm
some physicists are trying to make a time machine with lasers that bend light, i believe its connected with relativity, as a lot of space time research is.
and about the discussions of going back and stopping wars, the theories are that you COULD stop something from happening, but it wouldnt change anything in the worldline that you came from.
"If you traveled through time, you could encounter yourself in any of the alternative scenarios, but you could not alter the flow of your own space-time continuum. It's physically impossible."
as we all know, its possible to slow time down, and possibly even stop time for certain observers. i wouldnt rule out time travel as just science fiction, but then again its way too much to comprehend at this point, well for my puny brain anyway