While there are patterns we can study...

虽然可以通过研究案例

that characterize any

都会有的

because the atoms are constantly in motion, vibrating.

因为原子是不停运动的 它们会振动

an atom that's off on the end of something is more floppy than one

处在分子末端的原子比连结很多键的原子

So, the remarkable property of simple harmonic motion

所以简谐运动的重要性质是

If you pull it by two inches, compared to one inch,

如果振幅是两英寸 与振幅是一英寸相比

We call that stage I. Then you get successively deeper,

我们称它为第一阶段 然后你会睡得越来越深

and then once you reach stage IV you start going up again,

一旦进入到第四阶段 又开始变浅 经过第三和第二阶段

and the way to think about it is,

你想象的方式变化

And if you draw a picture of that,

如果你据此画一张图

so the kinetic energy stays the same.

所以动能的值是不变的

because that scales with the curvature.

因为振幅的大小是与曲率同步变化的