Reality or Fiction

It is uncertain if time travel to the past is physically possible, and such travel, if at all feasible, may give rise to questions of causality. Forward time travel, outside the usual sense of the perception of time, is an extensively observed phenomenon and well-understood within the framework of special relativity and general relativity. However, making one body advance or delay more than a few milliseconds compared to another body is not feasible with current technology. As for backward time travel, it is possible to find solutions in general relativity that allow for it, such as a rotating black hole. Travelling to an arbitrary point in spacetime has very limited support in theoretical physics, and is usually connected only with quantum mechanics or wormholes.

In 2009, Stephen Hawking ran an experiment that required champagne, balloons, and hors d'oeuvres, to demonstrate that backward time travel probably isn't possible. It was a time travelers' party, but no one showed up. And that was the point.
"I have experimental evidence that time travel is not possible," Hawking told reporters at the Seattle Science Festival in 2012. "I gave a party for time-travelers, but I didn't send out the invitations until after the party. I sat there a long time, but no one came."