Main Question or Discussion Point
I'm having trouble understanding the simultaneity experiment with Alice on the railroad car, and Bob observing from the ground. If 2 lightning bolts hit the front and back of Alices car at the same time in Bob's frame, it won't be instantaneous in Alices due to simultaneity. My question is simple, if instead of 2 separate lightning bolts, we use 1 laser pointed directly at Bob and Alice at t=0, where both persons have 2 beam spliters to send some of the light to the left and some to the right in both frames to the front and back of Alices car where she has two detectors that will emit flashes once light is detected, how can simultaneity still hold? If for any reason Bob and Alice disagree about the simultaneity of flashes at the end of her railroad car, then in at least one frame, the right or left moving light went slower or faster than the other which is obsurd.