Confused about relativity??? I have a question regarding the following explanation I have been given as below: If an astronaut were to travel at or near light speed to another star, there would be a difference in the time elapsed on Earth versues the time elapsed as perceived by the astronaut. The end result being that maybe 1 year would have passed for the astronaut, whereas 10 years have passed on Earth, when he got back. What I am confused about is the reference frames. If the Earth is viewed as the stationary reference frame, then they see the astronaut zooming away at light speed. If the astronaut is taken as the stationary reference frame, then he sees the Earth zooming away at light speed. When the astronaut returns, it is just the opposite. So why the difference in perceived time between the two reference frames? I do not get it? Wouldn't it just balance out?