Two babies are born in a moving train, one in the compartment adjacent to the engine and other in the compartment adjacent to the guard. According to the train frame, the babies are born at the same instant of time. Who is elder according to the ground frame?
Since, the frame is moving, the clocks will not record the synchronized time. The clock at the rear end leads the clock which is at the other end by L v/c2 where, L is the rest separation between the clocks and v is the speed of the moving frame i.e. train. Thus, the baby born adjacent to the guard cell will be elder.