Time travel has long been a popular theme in science fiction, but can it…

Time travel has long been a popular theme in science fiction, but can it actually exist? The Daily Mail reported that Professor Brian Cox says it can. He goes on to say that it can only take you into the future, though, and once you’re there, you can’t come back.

The theory is based on Einstein’s Theory of Special Relativity that is based on two principles. One is that the laws of physics don’t change, even when objects move at constant speeds to each other. The other is that the speed of light is the same for everyone, no matter how they move in relation to the light source.

If two objects are both moving through space and want to compare what they see, the only way to do that is to compare how fast the objects are moving relative to each other. The Special Theory specifically includes that the objects’ movement must be in a straight or uniform line, and at a constant speed. In order to travel through time, an object must approach the speed of light. As an object nears the speed of light, the clock slows down, but only for the object in motion. Everything else is still moving through time at the same rate.

This brings us to Russian Cosmonaut Sergei Krikalev, who has spent more time in orbit than anyone else in the world-803 days, 9 hours, and 39 minutes. If you add up all the accumulated speed from the time he has spent in orbit, Krikalev has actually moved ahead into his own future by about 0.02 seconds, according to Universe Today.

Who has spent more time in orbit than anyone else in the world?