http://en.wikipedia.org/wiki/Twin_paradox if you don't know what I'm referring to


I don't really understand this. Why would acceleration and change of velocity effect the age of a person in relation to another?

Relativity; the relevant principle being the faster you travel, the slower time goes.

^Why?

Also I don't understand how this is a paradox, strange, interesting but probably not a paradox

Don't forget to study up on Lorentz geometry before you begin these type of paradoxes.

Check out the video, it tries to break down time travel and explain time in regards to relativity. Don't think of time as numbers and hours. Think of time on a grander scale. Time was here before the Earth and time will be here after.

http://www.youtube.com/watch?v=V7vpw4AH8QQ

Thanks that was quite helpful

Photon clocks don't exist, like in that video, right?