I'm trying to understand something about relativity that doesn't seem to add up. I will extend Einstein's carriage example to incorporate 4 clocks. At the beginning all these clocks are running at the same time when they are together. I put two of the clocks far away from each other (100 km apart). I stand in the middle with one clock and a person B is riding in the carriage with one clock. Now lightning hits both of the two far apart clocks at the same time, stopping both of them at exactly 1:00:00 PM. I see the lightning strikes at the same time as I'm standing in the middle. On my clock it happens at 1:00:01 PM. (because the light took 1 second to get to me) Now the person in the carriage that's moving towards one lightning strike sees one hitting the clock at around 1:00:00.500 PM and the other at around 1:00:01.250 PM. Now me and the observer can argue about the time, I can say they two lightning strikes happened at the same time and she can say they happened one after the other. However the two clocks at the spot show that they were hit at the same time, because they both stopped at 1:00:00 PM. We compare clocks/timers after the experiment. I don't understand why people say in another frame of reference there things move slower. The light source may take t time to get to your eyes but that doesn't mean something out there happened at a different time. From this experiment people derive the twins paradox. Stating that moving back and forth at speeds close to the light speed will make one twin brother age less. In my example above there was no physical effect caused by relativity. Even though the observers saw the clocks getting hit by lightning at different times, the clocks showed they happened simultaneously. I don't think it really matters in which frame of reference an event takes place, the "true time/global time" will be the same everywhere for physical phenomena. Can anyone help me understand this?