Time travel is the stuff of fiction, of dreams. We all want to be able to either travel into the past to fix a wrong, or into the future to see what things would be. It comes as no surprise that scientists have also wondered if traveling through time is indeed possible according to our current understanding of the laws of physics. In this video from PBS spacetime, host Matt O'Dowd, explains the various ways in which theory allows us to travel through time. The most intuitive is...