The moon, too, was widely believed to be a perfect sphere of fiery ether.

月亮，也广泛的被认为是炽热的天空中完美的球体。

耶鲁公开课 - 弥尔顿课程节选

And that's true. An atom's not a defined sphere, for example.

这没错，原子并不是一个确定的球体，比方说。

麻省理工公开课 - 化学原理课程节选

We are modeling them as hard spheres.

我们把它们想象为硬球体。

麻省理工公开课 - 固态化学导论课程节选