That's because the ideas of physics don't fall into 75-minute segments and sometimes they spill over a little bit.

因为物理的知识不是死板的75分钟课程,所以我会有时候做一些微调

耶鲁公开课 - 基础物理课程节选

who is studying Physics, typically something pertinent to your class.

学物理的，一般都会学与你专业有关的课程。

学习和交际都重要 - SpeakingMax英语口语达人