What's created is not a strain, what's created is a velocity.

造成这一现象的不是应力而是速度
The top plate is going to move,

如果我对顶板施加一个持续性的力
and if I apply a constant force,

一个持续性的剪切力
a constant shearing force to the top plate I will measure a velocity.

顶板发生位移我就能检测到一个速度
Does that make sense?

明白了吗
What's really happening in the fluid here is that within this fluid,

当我给上面的板施加外力的时候
when I apply the force on the top plate,

这儿的液体其内部究竟发生了什么
the molecules of fluid that are right next to the top--

液体分子紧贴顶部的--
let me call it a plate now instead of a desktop

我们权且用板来代替桌面
because that's a shorter word, that molecules of fluid

这样更顺口些液体的分子
that are right next to this top plate, when I start to move it,

和顶板紧贴在一起当我移动顶板时
they move along with the top plate.

液体分子随之移动