Why this struggle, and why must Milton struggle with such awkward metaphysical categories in order simply to address properly the power of light?

为什么弥尔顿必须,与这样一个奇怪的抽象的东西斗争,仅仅是为了恰当的描述光明的力量？

耶鲁公开课 - 弥尔顿课程节选

So, for example, we were talking about a threshold frequency as in a minimum frequency of light that you need in order to eject an electron from a metal surface.

举个例子来说，我们谈论的临界频率是,光从金属表面逐出一个电子,所需的最小频率。

麻省理工公开课 - 化学原理课程节选