Owl explained about the vector potential. He had explained

this to Pooh and Christopher Robin once before, and had been

waiting ever since for a chance to do it again, because it is a

thing you can easily explain twice before anybody knows what

you are talking about.

To me, some of the greatest joys of physics lie in searching for ideas, in developing ideas, in pursuing ideas. So preparing lectures is usually a creative outlet that I greatly enjoy. Something new is always waiting to spring forth: an implication or analogy, a new question or direction, perhaps just a nice quotation. To communicate these ideas and questions and quotations is an irresistable impulse. I need an audience!

As entertaining as I find my own lectures to be, my goal is to educate my students. Towards that end I try to create an environment which is highly interactive: it almost always turns out that there is a strong synergism to sharing ideas. So, in my ideal class there would be a near symmetry between my own efforts and those of my other students.

I often ask that students e-mail questions (on any topic!) to me by a certain time of day - and I begin every class by reading some of the questions and opening the floor for discussion. This has been enormously successful. Students ask a wide range of questions, but somehow - through the interconnectedness of all things, I suppose - they usually seem relevant, not only to the course material, but to whatever I happen to plan on discussing that day. Students often approach new material with very few points of reference and it is necessary to motivate everything (Why is this interesting? What is the interesting part? How can this be used?). Somehow, through our discussions at the beginning of each period, the class becomes self-motivating.

When I first started teaching (at Haverford), I really wasn't sure of how to keep students engaged throughout a 90-minute class. While I saw clear advantages to "active" learning over "passive" learning, I wanted to create involvement through low-key activities that didn't "count" and didn't embarrass. My first concern was to build student confidence levels. So I scoured my collection of texts for good discussion questions (with greatly mixed results) and I made extensive use of Eric Mazur's ConcepTests. Each of those efforts remains worthwhile, but a real breakthrough came when I decided to let the students share in my search. The resulting levels of class participation and interest in physics have been very gratifying. Even the use of office hours has increased dramatically. Despite taking time out from traditional lecturing we have been able to cover the material I expected to cover. On the other hand I now view the material in our text as little more than a "substrate" for a process of mutual learning and interaction: brainstorming for ideas, developing ideas, pursuing ideas - and, throughout it all, sharing ideas. The trick, I think, is to instill that full progression in students, who may feel that physics is something only really done by the great geniuses of the ages.

When you're an undergraduate in the traditional classroom, there is a god: every problem has a solution which is attainable on some fairly short time scale and the universe can seem to be a very orderly place. Certainly, this has an appeal; especially if confidence building is a key goal. However, encouragement takes many forms - and it is probably just as reassuring to show, through open discussion, that there are normal people, who don't have all the anwers, teaching physics courses and doing world-class research. I also take time to highlight, where possible, examples which relate to what we are doing in the department - or more particularly, what our students are doing - and to point out the students who did much of the work behind the great discoveries.

It is a recurring theme of mine that anybody - at any stage in their education - can do good work, can be a craftsperson, can be creative and imaginative. Perhaps creativity cannot be taught, but it should be given every opportunity to flourish. A course which begins every meeting in the spirit of co-exploration supplies such opportunity and is, at its core, inclusive.

I find a diversified style helps to keep students engaged and, in any case, different people learn best in different ways. For example, even though we emphasize deductive reasoning and the understanding of concepts over memorization, most students need associations to help them remember (for example, if teaching about Schubnikov-de Haas oscillations, I mention that Schubnikov was shot by a firing squad and more students seem to remember his work). Simply put, material is to be tied to its historical roots, its relevance to society, philosophy, or any other anchoring point. At this juncture, I support liberal use of demonstrations, cartoons, humor, and just about anything else that might spice up the proceedings. For example, I usually have my sophomore-level students try to read a section from Newton's Principia in Latin!

Holmes, though personally gifted, was clearly a lousy teacher. When teaching classroom physics to overworked students, it becomes - at times - a challenge to keep the material from seeming an endless stream; therefore, we need to supplement the sort of straightforward lecturing promoted by Holmes. Moreover, the goal of a teacher, whether in the classroom or in the laboratory, is to bring students to the point where they not only can but will circumnavigate their own obstacles, where they develop their own momentum - something Dr. Watson never seemed to do. My prime goal as a teacher is to explicitly address potential prescriptions for helping people over their many different barriers to this "momentum transfer".