There are two observers, A (stationary) and B (in the middle of a train moving towards A). At each end of the train is a lamp. At a point in time in the frame of reference of B, both lamps emit a pulse of light directed at B (middle of train). When the pulses hit B, they scatter in all directions. To B, the two pulses should hit him at the same time since the speed of the two pulses and the distance between B and each lamp should be the same. To A, the pulse from the lamp at the head of the train should hit B before the pulse from the lamp at the tail of the train. I believe that something is wrong with this scenario, but am unsure of where I went wrong . This would seem like the common example used in high school textbooks to explain how simultaneity varies in different frames of reference, but I am not considering when the two beams reach A, but instead I am considering when A perceives the two beams to reach B. Apologies beforehand if this question is juvenile; I am not too familiar with the special theory of relativity. And this really isn't a homework question if anyone is wondering.