Secondly, the book, you can see, one of you had a book here, it's about 1,100 pages and when I learned physics it was, like, 300 pages.

第二点,教材,你们可以看到,这位同学手上就有一本,大概1100页,我当初学物理的时候,教材只有300页

耶鲁公开课 - 基础物理课程节选