While we're on the subject of ancient history, Prof Jim Roberge's course on feedback systems (6.302) famously included a final lecture incorporating his love of

While we're on the subject of ancient history, Prof Jim Roberge's course on feedback systems (6.302) famously included a final lecture incorporating his love of model trains. The goal of the lecture was that the train should have a constant speed despite hills introduced into the track. In order to measure the speed of the train, he noticed that there was a small glitch that would occur as the motor's armature switched polarity, and so a time measurement of the glitches was proportional to the speed of the engine. [I took the course in 85 and still remember it, so he left something of an impression. A couple of generations learned analog feedback from this course. RIP Prof Roberge.] Edit: By some lesser miracle, his lectures are on youtube. The train lecture was last. https://www.youtube.com/playlist?list=PLUl4u3cNGP62in17jH_DiJMkCGNM6Xni- https://www.youtube.com/playlist?list=PLUl4u3cNGP62in17jH_Di...