他的想法是，如果你从我这里到你这里，顺时针旋转，你从你这里到我这里是逆时针旋转。

The idea that he had was, if you go from me to you, with a clockwise rotation, you go from you to me by a counterclockwise rotation.

youdao

现在我真的很沉迷机械装置，但是你可以想象重物掉落的时候会带动桨轮旋转。

Now I'm really fantastic at drawing this mechanical device, but you can imagine that dropping weight can cause a paddlewheel to turn.

youdao

如果你看不明白这个旋转的话，我可以在黑板上再做一次。

And, in case you have trouble reading the rotated picture, let me redo it on the board.

youdao