So, what we are going to study now is a non-living object and we're going to pick it to be a mathematical point.

我们现在所要研究的的,是一个没有生命的物体,我们要把它看作一个数学上的点

耶鲁公开课 - 基础物理课程节选

"Life's always worth living; " it's always better than non-existence."

活着总是有它的价值;,“活着总比不存在要好“

耶鲁公开课 - 死亡课程节选