Dear PF forum, I have a problem with Train experiment. Perhaps someone can take a look at it and tell me where did I go wrong? V = 0.6c; Gamma = 1.25 Train length = 1500 Platform length = 1200, so the light can reach the observer at the same time. I draw the space diagram for that problem: Where the train (Green) is at rest first. The cars in train synchronize their clock. And preprogrammed at S1 (for the train Stern) and B1 (for the train Bow), it moves to the station. But in platform frame, S and B can't reach the platform at the same time wrt platform. See, the zoomed section. And if I draw this as Pic 2 Then, S1 and B1 don't start at the same time wrt train rest. This means that S1 (stern) starts first then the bow follows. Shouldn't it derail or destroy the train if the back car moves first? Where did I go wrong? Can anyone help? Thanks.