by Jillian Scharr, Live Science
The concept of a time machine typically conjures up images of an implausible plot device used in a few too many science-fiction storylines. But according to Albert Einstein’s general theory of relativity, which explains how gravity operates in the universe, real-life time travel isn’t just a vague fantasy.
Traveling forward in time is an uncontroversial possibility, according to Einstein’s theory. In fact, physicists have been able to send tiny particles called muons, which are similar to electrons, forward in time by manipulating the gravity around them.
Time travel to the past, however, is even less understood. Still, astrophysicist Eric W. Davis, of the EarthTech International Institute for Advanced Studies at Austin, argues that it’s possible.