Is Time Travel Really Possible?

Short Answer: Based on the available theories, you can travel in future.

Explanation: Technically, we are already traveling in time at the rate of 1 hour per hour. The actual question is can we travel faster or slower than this rate?
It’s already been done. The Russian cosmonaut Sergei Krikalev time traveled into his own future by 0.02 seconds. He spent 803 days, 9 hours, 39 minutes orbiting our planet. Traveling at 17,500 miles per hour he experienced an effect called time dilation.

Einstein’s Special relativity theory says that when your travelling speed relative to other objects is close to the speed of light, time goes slower for you than for the people you left behind. That’s the reason clock of GPS satellites disagrees with the clock on earth by seven millionth of a second daily.
Suppose you are a 10 year old boy who left Earth in a rocket traveling at 99.5% of the speed of light (impossible to achieve at present) and you return after 5 years at the age of 15. You would find that all of your classmates were 60 years old. Because time passed more slowly for you, your 5 years on space would be equivalent to 50 years on earth. And that’s how you can get ahead 45 years in the future.

Einstein’s another theory called General Relativity says that time passes more slowly for object in gravitational field than object far from such field. There are all kinds of time-space distortions near black holes, where the gravity is very intense. Over the past few years, some scientists have used this distortion to find possible ways of traveling in future. Some like the idea of “Worm holes”. But still we don’t know whether they are possible for real objects.