I met John Bardeen in the spring of 1950, when he was still at Bell Labs and I was a graduate student in physics at Princeton. That semester John came once a week to teach a seminar on the physics of semiconductors. Although I was in the midst of my thesis research, I regularly attended his lectures, which I remember as being clear, informative and low key. (The notes for this seminar formed the basis of EE‐PHYS 435, Bardeen's famous electrical engineering course at Illinois, described in the ar...