Can I return from space young

First, we need to clarify the concepts of "time" and "rate of aging."As such, the time - a concept invented by man.Count arrow seconds, days, months and years - all these people use for their own convenience.But time itself - an abstract concept.If we talk about the passage of time, it is the same everywhere: in space, on Earth or any other planet of the solar system.Likewise, the same would be a process of cell aging and the human body.

Where did the theory that the space people do not grow old?It's simple.Referring to the theory of relativity.From the location really does not depend on time, but it may depend on the speed with which you move.When vehicle speed exceeding the speed of light, the time it actually flows slower in relation to time,
such as in the world.The astronauts themselves will not notice the difference - because their frame of reference is stable: space and time are flowing at the same speed.It's like a train that is racing past the platform: the passengers in the car quietly drink tea and play cards, and the people at the station can hardly distinguish their silhouettes - so fast they rush past.

time dilation

In relativity there is another interesting aspect concerning the passage of time on Earth and in space.According to him, the gravity of the planet has some effect on the speed of the flow of time.The gravity is greater, the greater the curvature of space-time at this point and time flows more slowly relative to the observer located far from the massive body, creating a curvature.

According to this theory, far from the planet time to flow a little faster.It may seem that the theory of relativity at this point contradicts itself, but do not rush to conclusions.The fact that the change in flow rate so little time, they can easily be ignored.Most ultra-precise clocks at the cosmos, distant from our planet, because it will show the effect of time, with a difference in the 45900 ns / day faster than a precisely similar clock, set in the world.