The only thing that is different about these orbitals is their orientation in space.

这些轨道唯一的不同之处,是在空间的方向不同。

麻省理工公开课 - 化学原理课程节选

When we do relativity, we'll be dealing with vectors in space-time and we'll find that different observers disagree on what is this and what is that.

我们学习相对论的时侯,会涉及到时空矢量的问题,我们会发现观测者们对于观测的结果,有着不同的看法

耶鲁公开课 - 基础物理课程节选