Hey everyone, I've searched the threads for an answer to my question but came up short. Basically what I want to know is how does time dilation relate to the twin paradox. I'm a newb to relativity and just started reading about it last night. I hit this bump and I'm trying to get over it. The way I understand time dilation best is through the example of a light beam traveling straight up and down, and hence less distance, to an observer moving with the light emitting contraption. But to a still observer watching the "contraption pass by it forms a triangular type trajectory and hence travels more distance. Since light travels at a constant this implies that time is different in each frame. So, can anyone explain to me how time dilation applies to the twin paradox using my understanding of time dilation. I have no clue why the person on the ship is experiencing a slow down of time. Thanks a lot!