狭义相对论讲义之同时的相对性（The relativity of lectures on special relativity at the same time）.docVIP

狭义相对论讲义之同时的相对性（The relativity of lectures on special relativity at the same time） The relativity of lectures on special relativity at the same time Material: at the same time the relative hypothesis of a long train along the straight track fast speed. The car has a central light source emits a flash flash illumination to the front wall and the rear wall of the car, this is the two car events. Observers think that the two event is at the same time. In his opinion this very good explanation, because the car is an inertial system, light forward, spread the same speed, light and in the middle of the car, the flash will certainly arrive at the same time before and after the two wall (figure a). Under the car of the observer is not to regard it as right. He observed, first arrived after the flash after the wall, before the arrival of the wall. His explanation is: the ground is an inertial system, flash forward, spread speed on the ground is the same, but in the process of the two wall to flash, car along a long distance, so the light travels all the way forward The process is longer, and the time to reach the front wall is later (Fig.). These two events are different at the same time The above is our standard language interpretation of relativity at the same time. Many students can describe the exact words, but still can not understand their own ideas. The following stresses my understanding of simultaneous relativity. First of all, why do observers in the car think that the two events are simultaneous? According to (or reason, reason) what is it? Because the car is an inertial system, the light travels forward and behind the same speed. The light source is in the center of the car, and the flash will reach the two walls at the same time (figure a). Originally, the car is an inertial system. Since the car is an inertial system, the light travels forward and behind the same speed, and because the light source is in the center of the car, the flash will reach the two walls