Time travel seems impossbile and about science fiction, but scientists from all over the world have suggested some new and plausible theories that could make time travel possbile.
Here are some of the theories:
Although this would could be plausible if wormholes existed, it would only allow us to travel as far back as the point in time when it was created. So we would not be able to travel to the past to see ancient civilizations, important scientists...
Another problem is that we'd need a method for creating wormholes, and once created we should move nearly the speed of light between the mouths of the wormhole.
This is the most plausbile and the easiest to reach, for example if we somehow traveled with a spacecraft or something similar, and were near a black hole, it's intense gravitational pull would produce an incredible time dilation, so time would go much slower for the people inside the spacecraft than for people in earth.
If we wanted to go to the future to see all the technological advances and science discoveries we would only need to go near a black hole, but it has major problem, not refered to technology, but humanity, because all the people we love and know would probably be dead due to the years passed for them in the earth.
Maybe in the future some discovery could prove Einstein theories wrong, because after all we are humans and make mistakes, even the most intelligent people that have ever lived.
We only have to wait some time to really know it, and it shouldn't really matter for us if it's not possible because although the past is interesting we should focus on the future an try to make it better.