translation.en: So you can't tell much from just making the ball drop there, but if we drop the ball and run the movie at the same time, we can see that we have come up with an accurate physical model.
translation.zh: 单单是扔一个球是很难看出效果的 假如我们在抛出球的同时 播放短片 我们就能发现 我们得出了一个非常准确的物理模型