According to Stephen Hawking, one of the world's smartest physicists, time travel might be possible. Hawking doesn't hold out much hope for time traveling through wormholes, even though he muses about the fantastic conditions that might someday make them work. Nor does he think we'll ever be able to travel back in time, because of paradoxes. His example: "What if a scientist travels back in time and shoots his earlier self? He is now dead. So who fired the shot? It's a paradox."
Traveling forward in time is another matter. Hawking says it would be possible if you could build a gigantic spacecraft, "a truly enormous machine," carrying a huge amount of fuel, enough to accelerate it for six years at full power. That would bring it to a velocity almost as fast as the speed of light.
"At this speed, a single day on board is a whole year of Earth time. Our ship would be truly flying into the future. The slowing of time has another benefit. It means we could, in theory, travel extraordinary distances within one lifetime. A trip to the edge of the galaxy would take just 80 years."
Unfortunately, this would probably be a one-way trip. Or, this advanced civilization could build a ship with a fuel tank that's many times bigger, and once the ship reaches its destination, it could turn around, accelerating back toward Earth at that same speed. But then by the time they arrive back home, another method of time travel might have already been invented.
Via Daily Mail