And where do we find these things?

那么我们要在哪找到方程式中的这些量呢？

麻省理工公开课 - 固态化学导论课程节选

What can you measure in this equation?

在这个方程里你能测量哪些量

耶鲁公开课 - 基础物理课程节选

You realize it's very subtle, because the very first thing in that equation, which is m, has not yet been defined.

你会觉得这很微妙,因为方程里最基本的量 也就是 m,还没有人给它下定义

耶鲁公开课 - 基础物理课程节选