On what else do you use theta for, if not angles?

如果不用angles的话，你会用些什么词去描述角度呢？

麻省理工公开课 - 固态化学导论课程节选

We call that a node, r and a node, more specifically, is any value of either r, the radius, or the two angles for 0 which the wave function, and that also means the wave function 0 squared or the probability density, is going to be equal to zero.

节点就是指对，于任何半径，或者，两个角度,波函数等于，这也意味着波函数的平方或者概率密度,等于，我们可以看到在1s轨道里。

麻省理工公开课 - 化学原理课程节选