When you lead the meditation, I think kneeling is fine, but for me it's really painful, not everybody can do that.

当进行冥想时，我觉得跪地可以接受，但确实感到疼痛，不是人人都可以坚持。

普林斯顿公开课 - 人性课程节选

What makes the law surprising is that if I only gave you half the law, namely every body will remain at rest if it's not acted upon by a force, you will say, "That's fine. I accept that, because here's something, you leave it there, it doesn't move.

这条定律妙就妙在,如果只看定律的前半段,即,如果物体不受外力作用,将保持静止状态,你肯定会觉得,"这没什么,我能理解,因为你把一个物体放在那里,自己肯定不会动

耶鲁公开课 - 基础物理课程节选