Some remarks concerning the origins and nature of this material.

I learned early on in my undergraduate education that while it is instructive to read, and to attend to the words of informed speakers, I cannot gain the feeling that I "understand" a subject until I have done my best to write about it. So much of my time these past sixty years—even when seemingly involved with other things—has been spent pondering the outlines of what I would write when I returned to my desk, "composing the next sentence."

Which means that I have been engaged more often in trying to write my way to understanding than from understanding. And explains why much that I write begins from (and frequently returns to) motivational remarks, and a survey of the surrounding landscape, but never with an abstract; when I undertake to write about a subject I have a head full of questions and hunches, but seldom a very clear sense of where my thought will take me. My "essays" have really the character of research notebooks—written on the fly, with little or no revision.

The patience of my readers is further tested by my tendency to digress, to "turn over rocks" as I encounter them, to see if anything interesting lurks under. And by the fact that too frequently my notebooks simply stop, without having been brought to a definitive conclusion...this sometimes because I acquired greater interest in some other subject, but more often because my attention was preempted by fresh classroom obligations.

When thinking through a subject in preparation for a class I have no option but to write my way through the subject, and then to lecture from my own notes. I find it much more pleasant and productive to spend an afternoon and evening writing than arguing with the absent author of a published text. And easy to entertain the delusion that what I have written is superior to the text. Inevitably it is at any rate different from any of the candidate textbooks, embodies organizational principles, analytical techniques and points of view that I prepared to "profess" (my responsibility as a professor) rather than simply to regurgitate/parrot. I suppose it is for that same set of reasons that many/most teachers of physics/mathematics (including all of those who influenced me most profoundly) prefer to work from notes.

For centuries, students have been proficient note-takers. But in the second week of my teaching career I was asked by students if I would be willing to distribute copies of my lecture notes. I was happy to do so (after all, imperfect note-taking distracted students from attending to and questioning my spoken words and blackboard squiggles), even though duplication technology was in 1963 still in a very primitive state of development. So came into being twenty-seven volumes of hand-written material (1963-1984), treating— sometimes in successive versions—all of the subjects standard to undergraduate physics curricula plus a variety of more advanced topics. At present the Reed College archivist is (at the recent instigation of Terry Lash, the student— now retired from directing the Nuclear Energy Division of the Department of Energy—who first asked me to distribute my notes) in process of digitizing that material.

In those early times my colleagues often adjusted their interests to conform to the capabilities of computers. This I refused to do. But in about 1990 I allowed Richard Crandall to "store" a NeXT computer (which would otherwise have escaped from the department) in my office. By that time, TeX (1986) and Mathematica (1988) were coming into use, and I discovered that personal computers were able to do at last what I wanted to do. Which made all the difference. I found myself positioned to do physics at a much deeper—and often more exploratory— level than ever before, and to write up and distribute it much more easily than had been possible with paper, pens (always several, with nibs of graded widths), ink and Xerox machines. And the whole exercise had become enormous fun!

I provide pdf versions of various class notes that were written in TeX after about 1995, but have not included the problem sets (which changed from year to year).

At some point in the early 1990s the department (on Richard Crandall's advice) adopted Mathematica as the computational language of instruction (displacing Pascal; the alternatives were Maple (1988) and MATLAB (1984)). In the fall of 2000 it fell my lot to teach the Mathematica labs (taught initially by Robert Reynolds, later by Rick Watkins) that displaced the first fall quarter of the experimental labs taken by sophomores. For that purpose I developed a set of seven autotutorial notebooks ("Mathematica for Physicists"), which were revised and modified as successive versions of Mathematica were released. To reenforce that experience, and to take advantage of the happy fact that my students could be expected to be comfortable with the software, I made increasingly heavy in-class use of Mathematica, first in my sophomore lectures, and later in more advanced (especially quantum mechanical) classes. And in my own exploratory work I more and more often generated notebooks, instead of TeX files. A few—but only a few—of those notebooks are reproduced here. All were either written in or adapted to run in v7. They run in v8 and v9, but I have discovered that v9 (maybe also v8) alters the format in a way that violates my original intentions; it does, however, provide a "Restore Original Format" button.

It had not been my intention to include the Mathematica lab notebooks, partly because they now appear to me to stand in need of major revision (some topics abbreviated or dropped altogether, others introduced in light of my more recent experience), and partly because they were intended by me to serve an educational objective that my former colleagues evidently do not embrace. But I do occasionally still get requests for this material, so have decided to include one version of the final (v7) edition. The labs were presented to students in "unopened" form: commands were presented, but the students themselves were asked to execute the commands and to ponder the results. Here I present the labs in "opened" form (commands already executed), and provide also the final edition of the exercises.