Absolutely fabulous course, explained so well I completely understand now Relativity of Simultaneity.

I've read books and watched many videos explaining relativity of simultaneity but this is the first time that I can say I (sort of) get it. You, Sir, have explained this concept beautifully.

OMG ! That example was just amazing. So simple and easy to Understand.

Note that signalling via light has to be part of the observation process to get this effect. You can set up different schemas where everyone both on and off the train agrees. For example, supposing the presidents sit 10m from each other, set up two poles at a 10m distance from each other on the platform (assume the distance from the pole to the president is practically zero). When each president passes their respective pole they sign. Individuals situated on the platform next to the poles will register exactly the same time as individuals on the train who are standing next to the president.

Let's imagine we are inside of the train, and right when the flash touches both president's eyes. WE STOP TIME. with time being freeze, we jump out of the train, and when we look at it from the outside, we would see that the light has NOT reached one of the presidents. Does that mean we have traveled back in time by moving throughout space? Would we see the flash going back as we jump out of the train?