Now there many ways I can connect these two points together. The simplest way is to draw a straight line. It's called the linear interpolation. My line is not so straight, right here. You could do a different kind of line.

最简单的办法是,像这样画一条直线,这叫线性插值,不过我的这条线画得不太直，你也可以用别的办法,比如一条抛物线。

麻省理工公开课 - 热力学与动力学课程节选

That's a choice, and that choice turns out to be very interesting and really important, because if you connect these two points together, you get a straight line that has to intercept the x-axis at some point.

在这一选择下,我们会发现一件非常有趣，而且极其重要的事,当你把这两点用直线连接起来，你会发现这条直线,将与x轴在某点相交。

麻省理工公开课 - 热力学与动力学课程节选