Hi! I am studying special relativity and I still don't understand completely the relativity of time dilation: each twin sees that the time of the other twin is dilated, so how can exist the asimmetry in the measurements (only one twin at the end has really dilated his time)? I'll make an example: two objects (A and B) are in the same reference frame. B object accelerates to a very small speed (near to 0) and continues with costant speed for a very long time, so that the difference between time intervals of the two object becomes arbitrarily big. The object B thinks that A time is dilated but if he decelerates back to 0 speed, he must discover that he was wrong, and B time is dilated instead. I.E. if he measures that A time is retarding by 100s, when he decelerates, the time difference must switch from 100s to -100s. Can a very small deceleration do this? (time difference can be arbitrarily high.) P.S. I hadn't study yet general relativity, so maybe I'm saying lots of bull****s ... :D Thanks. KKnull.