Bell's spaceship paradox

Bell's Spaceship Paradox is a scientific thought experiment that explains how the movement of time can be different when we look at it from different perspectives. Imagine a spaceship flying away from Earth and then turning around and flying back. To someone on Earth, the journey would take two years (one year going away, one year coming back). But to someone on the spaceship, the journey would seem much shorter, because of the way time moves differently in space. The closer you get to the speed of light, the more time seems to slow down, so to the people on the spaceship, it could feel like the trip lasted only a few seconds, even though to people on Earth, it took two years.