Time travel has long lived in the realm of fantasy, but a growing body of research is quietly shifting it into a serious scientific conversation. Instead of DeLorean-style leaps into the past, ...

Time travel has shifted from pure fantasy to a serious, if highly constrained, topic in modern physics. The equations that describe gravity, quantum fields and the structure of spacetime now allow ...

This month marks 40 years since Michael J. Fox, as Marty McFly, jumped into a souped-up DeLorean and went back in time, putting his very future existence at risk. (SOUNDBITE OF FILM, "BACK TO THE ...