I think the truth of the matter has to be-- I think the answer right now is, we don't know how to give that story.

我认为,事实上,目前的答案就是,我们还没法做出那种解释

耶鲁公开课 - 死亡课程节选

I know this is the right answer, because if I now find the acceleration, I find it's mg divided by m and I get -g as the answer for all bodies.

我知道这个等式是正确的,因为现在如果我要求物体的加速度,用 mg 除以 m,我就得到 -g,这个结果对所有物体都成立

耶鲁公开课 - 基础物理课程节选