So, what we are going to study now is a non-living object and we're going to pick it to be a mathematical point.

我们现在所要研究的的,是一个没有生命的物体,我们要把它看作一个数学上的点

耶鲁公开课 - 基础物理课程节选

I cannot make the object simpler than being just a mathematical point.

找不到比质点更简单的模型了

耶鲁公开课 - 基础物理课程节选

And our job is to find out what is the mathematical description of this path, this line in p-V's case that connects these two point.

我们的任务,就是找出，描述这条曲线的方程。

麻省理工公开课 - 热力学与动力学课程节选

So the object is a mathematical point.

这个物体就是一个数学意义上的点

耶鲁公开课 - 基础物理课程节选