hello everyone i am new here. i have been to some websites about relativity but still kind of suspicious about it. here i have a problem. could anyone give me a mathematical answer. by the way this is not a homework. i am not a student. say we have a railroad from point A to point B and the length btw A and B is L=ct. c is the speed of light. now we have 2 trains, train1 and train2 pass point A towards point B at midnight or at time 0 oclock. train1 travels at v=c/2 relative to point A and train2 travels at v=3c/4 relative to train A. if there is a person at point B, when will he see train2. and why? thanks.