I mean maybe up the street we whisper, but here we know it. And, so here is a different kind of system where we have a constant external pressure.

或许在街上你们低声细语，但在这里不应该这样，这是另一个系统,我们有一个恒定的外压强。

麻省理工公开课 - 热力学与动力学课程节选