Thread: I just can't understand Einstein...

Okay, So I was reading about the Large Hadron Collider in WTF, and I searched Time Travel on google for some more info. I came to the Nova Time Travel website: http://www.pbs.org/wgbh/nova/time/

The third link they give you is an experiment to "Think like Einstien" in which you come to the conclusion that Time Travel is possible by looking at the relativity of distance to time. For Instance, you on a train throw a ball (the train moving 50 mph, the ball thrown at 20 mph) to a person on the sidelines the ball seems to be moving 70 mph. But f you show a light on the train, no matter if you are on the train or watching the train, the light only moves at 186,000 mph.

Then they come to the conclusion that if you traveled a year going the speed of light into space, and a year comming back at the same speed, it would only seem like 2 years to you, but theoretically 200 years to those on earth.

I don't understand that conclusion. Can anyone give me some insight?