Light travels basically a foot in a nanosecond. Simple rule of thumb.

光行进的速度是每纳秒一英尺,很简单的经验法则了。

麻省理工公开课 - 计算机科学及编程导论课程节选

People have done experiments through the ages, and they've accumulated the knowledge from these experiments, and they've synthesized these experiments into a few basic empirical rules, empirical laws, which are the laws of thermodynamics.

很长的时期内，人们做了大量的实验，从这些实验中积累知识,将这些实验总结成一些基本的经验法则和定律，这就是热力学的定律,然后，人们给这些定律添加，数学架构。

麻省理工公开课 - 热力学与动力学课程节选

That's actually a really good rule of thumb.

那实际上是一个好的经验法则。

哈佛公开课 - 计算机科学课程节选