And that the fact that it split into two was telling them that there must be some new property to the electron, and what we call that now is either being spin up or spin down.

它能一分为二的,事实告诉我们,电子一定有某种新的性质，我们叫它自旋向上或者自旋向下。

麻省理工公开课 - 化学原理课程节选