Every since I saw "Back to the Future" .. I always wanted my very own Flux Capacitor so that I can travel back in time or forward!! but too bad that is only possible if I star in a movie...
To think of it even the great Albert Einstein never dismissed the possibility of time travel in his equations, he said that time and space are inter-linked into something called "Space Time" and if you can bend that then you can travel in time that's of-course easier said than done and no one who has ever lived on this planet has managed to figure that out!
But thinking about it the only way to bend space-time is by using extreme gravitational force and by extreme I mean EXTREME and where do we find this in the universe? Near a black hole YES! so lets go near a black hole right?! aaa No! If we ever dared come close to a black hole in the universe the only way you will go is inside that and probably be dead in minutes!
Another theory is to travel at nearly the speed of light in a space ship and then come back, becasue if you travel that fast then time for you goes slow as compared to the people who are still on Earth, which has been experimentally proven too...
What people did was they placed a clock on a space aircraft and then measured it when the journey was completed and when it landed back on Earth and they found that there is a very small difference in time between the two clocks.. the clock on the spacecraft moved a slower as compared to the one on earth and the space craft was no where even close to travelling at the speed of light.
The sad part is that nothing can travel faster than light as yet and even if we figure out how to fly a space craft faster than light where would be get the energy from to make that happen? and by energy I mean fuel.
Its also possible if we discover a Worm Hole in the universe.. but more on that later!
So time travel at this point can only happen in fiction!