Six Not-So-Easy Pieces: Einstein's Relativity, Symmetry, and Space-Time (Helix Books)

I felt, however, that his simplified account of the Einstein field equation of general relativity did need a qualification that he did not quite give.

First figure out why you want the students to learn the subject and what you want them to know, and the method will result more or less by common sense.

We have to understand what we mean when we say that the phenomena are the same when we move the apparatus to a new position. We mean that we move everything that we believe is relevant;

that’s not how it seemed at the time. Many of the students dreaded the class, and as the course wore on, attendance by the registered students started dropping alarmingly. But at the same time, more and more faculty and graduate students started attending. The room stayed full, and Feynman may never have known he was losing some of his intended aud