You know, if you want to measure the potential energy of something in a gravitational field, you have to define the zero somewhere, right, because it's arbitrary. You can set it anywhere you want. It's the same with enthalpy.

你知道，如果你想测量重力场,中某种东西的势能，你需要，在某处定义一个零点，对吧？,因为势能的值是任意的,你可以把它设定在。

麻省理工公开课 - 热力学与动力学课程节选

- But there's one potential gotcha here -- and this is where you have to be kind -- of piecing together the little clues along the way -- what have I done that's interesting here that had I not, I would have had a mathematical error?

但是这里有一个可能性-,这就是你需要把,一些线索拼凑在一起-,我这里所做的是很有趣的，如果我不这样做，我可能已经犯了个数学错误？

哈佛公开课 - 计算机科学课程节选

You all could still do that if you decide too, but it's going to be harder for you than if you would have started when you were ten, so you're losing some potential around - along the way.

如果你想的话也许还可以,但会比起你从十岁开始努力,会更困难一些,因此你们在成长的路上失去了一些潜能

耶鲁公开课 - 生物医学工程探索课程节选