that's always of interest to me,

仍然能挑起像我这样
of people who've been practicing this business for a long time.

在这一行里已经浸淫了多年的人的兴趣
So I welcome that,

我十分欢迎大家提问
and that'll make it more lively.

这样课堂气氛就更活泼
All right, so I think last time

上一节课中
I got off on a rant about all the different pedagogical techniques,

我一开始就啰嗦了很多不同的教学方法
some of which I don't endorse fully.

其中的一些我并不完全认可
I'm going to go back now 300 years in time,

让我们回到三百年前
to one of the greatest laws that we have because--

有一条十分著名的定律
look at the power of this law, right?

来看看这条定律的效力
Here is the equation,

这是那个方程
and all the mechanical phenomena that we see, around the world,

世界上我们所能观察到的所有力学现象