Is time travel a fact or is it just science fiction? Thanks to time dilation and Einstein’s theory of relativity, we know that time travel can and actually does happen, albeit only in extremely tiny increments at the speeds and distances we can travel in space. If you add up the accumulated speed cosmonaut Sergei Krivalev has traveled in space – the most of any human with a total time spent in orbit of 803 days 9 hours and 39 minutes – he has actually time-traveled into his own future by 0.02 seconds.
Sergei Krikalev is a Russian cosmonaut and mechanical engineer. As a prominent rocket scientist, he is a veteran of six space flights.
One way to achieve time travel into the future would be travelling at the speed of light in space, as first theorized by Albert Einstein.
Indeed Cosmonaut Sergei Krikalev technically has lived in the future due to his extended period on the International Space Station.
This is how time travel works
Under accepted theories of time travel engineers would have to build a space ship which could travel at the speed of light (186,000 miles-per-SECOND), and head out into space.
Imagine you go out for six months and you turn around and you come back for six months. While you are traveling at the speed of light, time stays slow relative to the people who are standing still back on Earth.
When you step out of your ship, you are one year older, but Earth has gone through many, many years. It can have gone through 10,000, 100,000 or a million years depending on how close to the speed of light you traveled.
The International space station travels at around 7.66 km/ per second when orbiting around Earth, and due to the high speed and length of time which Sergei Krikalev spent in space, the cosmonaut actually arrived back in Earth 0.02 seconds in the future thanks to a process known as time dilation.