Now these quantities were useful because you could relate them. The slope of changes, with respect to volume or temperature of the energy with respect to quantities that you understood, that you could measure.

去得到这些量,这些量很有用，而且你们已经知道了，怎么把它们相互联系起来,像这种比例形式的量，能量比上温度或体,或其它你们懂的可以测量量。

麻省理工公开课 - 热力学与动力学课程节选