The overhead projector is perhaps passing out of use, but it is still a useful device with which to do lecture demonstrations. In my early years at Kenyon I was teaching the pre-med course, and found that the overhead projector was an ideal platform for showing the phenomena of polarized light. This note is a discussion of how I learned to use the…

As I approach my 70th year in physics, let me tell my younger colleagues about my adventures with computation. When I was 14, my father gave me a slide rule because I appeared to be headed toward a career in physics. Since then, I have had experience with many other calculating devices.

Many years ago I was running the standard laboratory experiment on thin lens optics. The source was the usual self illuminated object mounted on an optical bench, and a converging lens formed a real image on a screen. One of the students sitting near one wall of the darkened lab was having some trouble with the idea of image formation. Her face…

The finale of the weekly physics department seminar series at my college is my annual demonstration lecture. Normally, the front of the room is filled with apparatus, but in May 2008 I had only a giant kaleidoscope and a leaning tower of Pisa (Fig. 1) on display. Instead, there was a pile of overhead projector transparencies that showed examples…