When I first became a regular faculty member at Caltech in 1953, I was asked to teach some graduate courses. I found myself quite dismayed about the course program for the graduate students. During the first year they were given courses only in classical physics—mechanics and electricity and magnetism. (And even the E and M class covered only statics, no radiation theory at all.) I thought it was disgraceful that these hotshot students were not exposed to the ideas of modern physics (many of which had already been around for 20 to 50 or more years) until their second or third year in grad school. So I began a campaign to reform the program. I had known Richard Feynman since our days at Los Alamos, and we had both come to Caltech a few years back. I asked Feynman to join the campaign, and we outlined a new program and eventually persuaded the physics faculty to adopt it. The first year program consisted of a course in Electrodynamics and Electron Theory (taught by me), Introductory Quantum Mechanics (taught by Feynman), and, as I recall, a course in Mathematical Methods, taught by Robert Walker. I think that the new program was quite successful.
At about that time Jerrold Zacharias of MIT was stimulated by the appearance of Sputnik to push for a program to revitalize the teaching of high school physics in the United States. One result was the creation of the PSSC (Physical Science Study Committee) program, and the generation of many new materials and ideas, as well as some controversy.
When the PSSC program was nearing its completion, Zacharias and some colleagues (I believe among them Francis Friedman and Philip Morrison) decided that it was time to tackle also a revision of university physics. They organized a couple of large meetings of physics instructors, out of which came the formation of the Commission on College Physics, a national committee of a dozen university physics instructors, which was supported by the National Science Foundation, and was charged with stimulating some national endeavors for the modernization of physics teaching in colleges and universities. Zacharias invited me to those first meetings and I later served on the Commission, eventually becoming its chairman.
These activities prompted me to begin thinking about what could be done with the Caltech undergraduate program, with which I had long been rather unhappy. The introductory course in physics was based on the book of Millikan, Roller, and Watson, a very fine book that had been written, I believe, in the 1930s, and, though revised later by Roller, had little or no modern physics. Further, the course was taught without lectures, so there was little opportunity to introduce new material. The strength of the course was a set of intricate “problems” compiled by Foster Strong1, which were used for weekly homework assignments, and two weekly recitation sections in which the students discussed the assigned problems.
Like other physics faculty, I was each year assigned to be the advisor to a handful of physics majors. When talking with the students, I was often dismayed that by their junior year these students were getting discouraged about continuing in physics—it seemed at least in part because they had been studying physics for two years, but still had not been exposed to any of the ideas of current physics. So it was that I decided not to wait for the national program to mature, but to try to do something at Caltech. In particular, I wanted to see some of the content of “modern” physics—atoms, nuclei, quanta, and relativity—brought into the introductory course. After discussions with a few colleagues—most notably Thomas Lauritsen and Feynman—I proposed to Robert Bacher, then head of physics, that we should start a program to reform the introductory course. His initial response was not very encouraging. He said, in effect: “I have been telling people we have a very fine program that I am proud of. Our discussion sections are staffed by some of our senior faculty. Why should we change?” I persisted and was supported by a few others, so Bacher relented, accepted the idea, and had soon secured a grant from the Ford Foundation (for, if I remember correctly, something more than a million dollars). The grant was to be used for the costs of devising new equipment for the introductory labs, and for developing new content for the course—in particular, for some temporary faculty to pick up the regular duties of the ones who were devoting time to the project.
When the grant was received, Bacher appointed a small task force to lead the program: Robert Leighton, as chairman, Victor Neher, and me. Leighton had long been involved in the upper division program—of which his book Principles of Modern Physics2 was the mainstay—and Neher was known as a brilliant instrumentalist. I was, at the time, miffed that Bacher had not asked me to be the leader of the group. I guessed that it may have been partly because I was already fairly busy running the Synchrotron Laboratory, but I have always thought that he was also worried that I might be too “radical” and that he wanted to balance the project with Leighton’s conservatism.
The committee agreed from the start that Neher would concentrate on developing new labs—about which he had many ideas—and that we should work toward presenting a lecture course in the following year—feeling that the lectures would provide the best mechanism for developing a new course content. Leighton and I were to design a syllabus for the lectures. We began by working independently to produce course outlines, but meeting weekly to compare progress and to try to reach a common ground.
It soon became clear that a common ground was not easily to be found. I usually saw Leighton’s approach to be too much of a rehash of the content of physics courses that had been in vogue for 60 years. Leighton thought that I was pushing impractical ideas—that freshmen were not ready for the “modern” content I wanted to introduce. I was, fortunately, bolstered in my resolve by frequent conversations with Feynman. Feynman was already well known as an impressive lecturer, and was particularly adept at explaining the ideas of modern physics to a general audience. I would frequently stop at his house on the way home from the Institute to sound him out on what I was thinking, and he would often make suggestions about what might be done, and was generally supportive.
After several months of these efforts, I became rather discouraged; I didn’t see how Leighton and I could ever come to an agreement on a syllabus. Our concepts for the course seemed to be completely at odds. Then one day I had an inspiration: Why not ask Feynman to give the lectures for the course? We could provide him with the outlines of both Leighton and myself, and let him decide what to do. I immediately proposed this idea to Feynman in the following way: “Look, Dick, you have now spent forty years of your life seeking an understanding of the physical world. Here is an opportunity for you to put it all together and present it to a new generation of scientists. Why don’t you give the freshman lectures next year?” He was not immediately enthusiastic, but we continued over the next few weeks to discuss the idea, and he was soon caught up in the notion. He would say maybe we could do this or that. Or this would fit in here, and so on. After a few weeks of such discussions, he asked me: “Has there ever been a great physicist who has presented a course to freshmen?” I told him that I didn’t think that there ever had been. His response: “I’ll do it.”
At the next meeting of our committee I presented with great enthusiasm my proposal—only to be dismayed by the cool response of Leighton. “That’s not a good idea. Feynman has never taught an undergraduate course. He wouldn’t know how to speak to freshmen, or what they could learn.” But Neher saved the day. His eyes lit up with excitement and he said: “That would be great. Dick knows so much physics, and knows how to make it interesting. It would be fantastic if he would really do it.” Leighton was persuaded, and once persuaded, supported the idea wholeheartedly.
Some days later I faced the next hurdle. I presented the idea to Bacher. He didn’t think much of it. He considered that Feynman was too important to the graduate program and could not be spared. Who would teach quantum electrodynamics? Who would be working with the theoretical graduate students? And besides, could he really bend down to the level of the freshmen? At this point I did some lobbying with some of the senior members of the physics department, who put in some supporting words to Bacher. And finally, I used the argument dear to academics: If Feynman really wants to do it, do you want to say that he should not? The decision was made.
With six months remaining before the first lecture, Leighton and I talked with Feynman about what we had been thinking. He started to work intensively on developing his own ideas. At least once each week I would stop by his house, and we would discuss what he had been thinking. He would sometimes ask whether I thought that some particular approach would be accessible to the students, or whether I would think that this or that sequence of material would “work” best. I may mention a particular example. Feynman had been working on how to present the ideas of wave interference and diffraction, and was having difficulty finding a suitable mathematical approach—one both straightforward as well as powerful. He was not able to come up with one without the use of complex numbers. He asked me whether I thought the freshmen would be able to work with the algebra of complex numbers. I reminded him that the students admitted to Caltech had been selected primarily on their demonstrated abilities with mathematics, and that I was confident that they would not have problems dealing with complex algebra, so long as they were given some brief introduction to the subject. His twenty-second lecture contains a delightful introduction to the algebra of complex quantities, which he was then able to use in many of the following lectures for the description of oscillating systems, for problems in physical optics, and so on.
Early on, a small problem surfaced. Feynman had a long-time commitment to be absent from Caltech for the third week of the fall term, and so would miss two class lectures. We agreed that that problem was easily solved. I would substitute for him on those days. However, in order not to break the continuity of his presentation, I would give the two lectures on some subsidiary topics that might be useful to the students, but were not related to his main line of development. This explains why Chapters 5 and 6 of Volume I are somewhat anomalous.
For the most part, however, Feynman worked alone at developing a complete outline of what he would do for the whole year—filling in enough detail to be sure that there would not be unforeseen difficulties. He worked intensely for the rest of that academic year, and by September (now 1961) was ready to begin his first year of lectures.
Originally it was considered that the lectures given by Feynman would form the starting point of an evolution of a revised program for the two-year introductory course—one required of all of the incoming students at Caltech. It was thought that in succeeding years others of the faculty would take over responsibility for each of the two years, developing eventually a “course”—with a textbook, homework exercises, a laboratory, and so on.
For the first years of the lectures, however, a different format needed to be devised. No course materials were available and had to be created as we went along. Two one-hour lectures were scheduled—at 11 a.m. on Tuesday and Thursday, and students were assigned to a one-hour discussion section each week, which was led by a faculty member or a graduate student assistant. There was also a three-hour laboratory each week, under the direction of Neher.
During the lectures Feynman carried a microphone, suspended from his neck and coupled to a magnetic tape recorder in another room. Photographs were periodically taken of the contents of the blackboards. Both services were managed by Tom Harvey, the technical assistant in charge of the lecture hall. Harvey also helped Feynman devise an occasional demonstration for the lectures. The recorded lectures were transcribed to a rather legible form by a typist, Julie Cursio.
That first year Leighton took on the responsibility for seeing that the transcripts were edited for clarity, and as quickly as possible, so that the students would have the printed lecture notes for study soon after the lectures were given. It was thought at first that this job could be done by assigning each lecture to one of the graduate students who were leading the discussion sections and labs. That didn’t work out, however, because it was taking the students much too long, and the resulting product reflected more the ideas of the student than those of Feynman. Leighton quickly changed the arrangement by taking on much of the work himself, and by recruiting various faculty members (from physics and engineering) to take on the job of editing one or more of the lectures. Under this plan, I also edited several of the lectures during that first year.
For the second year of the course some changes were made. Leighton took over the responsibility for the first-year students—giving the lectures and generally managing the course. Fortunately, the students now had available from the beginning the transcribed notes of Feynman’s lectures from the previous year. I became responsible for looking after the details of the second-year course, for which Feynman was now giving the lectures. And I was left with the responsibility of producing in a timely manner the edited transcripts. Because of the nature of the second-year material, I concluded that it would be most appropriate to take on the task myself.
I also sat in on nearly all of the lectures—as I had done during the first year—and took one of the discussion sections for myself, so that I could see how the course was going for the students. After each lecture, Feynman, Gerry Neugebauer, and I, occasionally with one or two others, would usually go to lunch at the student cafeteria, where we would have a discussion about what might be suitable homework exercises to be given to the students on the subject of the lecture. Feynman would generally have in mind several ideas for these exercises, and others would emerge from the discussion. Neugebauer was responsible for collecting these exercises and producing a “problem set” each week.
It was a great pleasure to sit in on the lectures. Feynman would appear five minutes or so before the scheduled start of the lecture. He would take out of his shirt pocket one or two small pieces of paper—perhaps 5 by 9 inches—unfold them, and smooth them out at the center of the lecture bench at the front of the lecture hall. These were his notes for his lecture, though he rarely referred to them. (A photo reproduced at the beginning of Chapter 19 of Volume II shows Feynman during one of his lectures, standing behind the lecture bench, with two sheets of notes visible on the bench.) As soon as the bell would ring, announcing the start of the official class period, he would start his lecture. Each lecture was a carefully scripted, dramatic production, which he had, clearly, planned in detail—usually with an introduction, development, climax, and denouement. And his timing was most impressive. Only very rarely would he finish more than a fraction of a minute before or after the end of the hour. Even the use of the chalk boards at the front of the lecture hall appeared to be carefully choreographed. He would begin at the upper left of board number one on the left, and at the end of the lecture would have just completely filled board two on the far right.
But the greatest pleasure was, of course, watching the development of the original sequence of ideas—presented with clarity and style.
Although we had not initially contemplated that the lecture transcripts would become a book, that idea came into serious consideration at about the middle of the second year of the lectures—in the spring of 1963. The thought was stimulated in part by inquiries from physicists from other schools about whether transcripts could be made available to them, and in part by suggestions from several book editors—who had, of course, got wind that the lectures were going on, and had perhaps seen copies of the transcripts—that we should consider a book and that they would like to publish it.
After some discussion we decided that the transcripts could, with some work, be turned into a book, so we asked the interested publishers to make proposals to us for doing that. The most attractive proposal came from representatives of the Addison-Wesley Publishing Company (A-W), who proposed that they could provide us with hardbound books in time for the class of September, 1963—only six months after the decision to publish. Also, in view of the fact that we were not asking that the authors receive royalties, they proposed that the books could be available at a rather low price.
Such a rapid publication schedule would be possible because they had complete facilities and staff in-house for editing, and typesetting, through to photo-offset printing. And by adopting a novel (at that time) format consisting of a single wide column of text together with a very wide “margin” on one side, they could accommodate figures and other ancillary material. This format meant that what would normally be galley proofs could be used directly for the final page layouts, without any need to reset textual material to accommodate figures and the like.
The A-W proposal won the day. I took on the task of making any necessary revisions and annotations in the lecture transcripts, and generally working with the publisher—proofreading the typeset material, and so on. (Leighton was at this time heavily involved in teaching the second round of the freshman course.) I would revise each lecture transcript for clarity and accuracy, then give it to Feynman for a final check, and as soon as a few lectures were ready, would send them off to A-W.
I rather quickly sent off the first few lectures, and very soon received back the galleys for proofreading. It was a disaster! The editor at A-W had done a significant rewrite, converting the informal style of the transcripts to a traditional, formal, text-book style—changing “you” to “one”, and so on. Fearing a possible confrontation on the matter, I telephoned the editor. After explaining that we considered that the informal, conversational style was an essential part of the lectures, and that we preferred personal pronouns to the impersonal ones, and so on, she saw the light and thereafter did a great job—mostly leaving things as they were. (It was then a pleasure to work with her, and I wish I could remember her name.)
The next stumbling block was more serious: choosing a name for the book. I recall visiting Feynman in his office one day to discuss the subject. I proposed that we adopt a simple name like “Physics” or “Physics One” and that the authors should be Feynman, Leighton, and Sands. He didn’t particularly like the suggested title, and had a rather violent reaction to the proposed authors: “Why should your names be there—you were only doing the work of a stenographer!” I disagreed, pointing out that without the efforts of Leighton and me, the lectures would never have come to be a book. The disagreement was not immediately resolved. I returned to the discussion some days later, and together we came up with a compromise: “The Feynman Lectures on Physics by Feynman, Leighton, and Sands.”
After the completion of the second year of lectures—near the beginning of June, 1963—I was in my office assigning the grades for the final examinations, when Feynman dropped in to say goodbye before leaving town (perhaps to go to Brazil). He asked how the students had performed on the exam. I said I thought pretty well. He asked what was the average grade, and I told him—something like 65 percent as I recall. His response was, “Oh, that’s terrible, they should have done better than that. I am a failure.” I tried to dissuade him of this idea, pointing out that the average grade was very arbitrary, depending on many factors such as the difficulty of the problems given, the grading method used, and such—and that we usually tried to make the average sufficiently low that there would be some spread in grades to provide a reasonable “curve” for the assignment of letter grades. (This is an attitude, incidentally, that I wouldn’t approve of today.) I said that I thought that many of the students had clearly got a great deal out of the class. He was not persuaded.
I then told him that the publication of The Lectures was proceeding apace and wondered whether he would like to provide some kind of preface. The idea was interesting to him, but he was short of time. I suggested that I could turn on the dictating machine I had on my desk, and that he could dictate his preface. So, still thinking about his depression over the average grade on the final exam of the second year students, he dictated the first draft of Feynman’s Preface, which you will find in front of each volume of The Lectures. In it he says: “I don’t think I did very well by the students.” I have often regretted that I had arranged for him to make a preface in this way, because I do not think that this was a very considered judgment. And I fear that it has been used by many teachers as an excuse for not trying out The Lectures with their students.
The story of the publication of the second year of lectures is a little different from the first year. First, when the second year came to an end (now about June of 1963) it was decided to split the lecture notes into two parts, to make two separate volumes: Electricity and Magnetism, and Quantum Physics. Second, it was thought that the lecture notes on quantum physics could be greatly improved with some augmentation and rather extensive reworking. To this end Feynman proposed that he would, toward the end of the following year, give a number of additional lectures on quantum physics, which could be blended with the original set to make up the third volume of the printed lectures.
There was an additional complication. The federal government had a year or so earlier authorized the construction at Stanford University of a two-mile-long linear accelerator to produce 20-GeV electrons for particle physics research. It was to be the largest and most expensive accelerator yet built, with electron energies and intensities many times higher than any existing facility—an exciting project. For more than a year W.K.H. Panofsky, who had been appointed Director of the newly created laboratory—the Stanford Linear Accelerator Center—had been trying to persuade me to join him as Deputy Director, helping to build the new accelerator. In the spring of that year he prevailed, and I agreed to move to Stanford at the beginning of July. I was, however, committed to seeing The Lectures through to completion, so part of the arrangement was that I would take that work with me. Once at Stanford I found my new responsibilities more demanding that I had expected, so that I found it necessary to work on The Lectures most evenings if I was to make suitable progress. I managed to complete the final editing of Volume II by March of 1964. Fortunately, I had the very capable assistance of my new secretary, Patricia Preuss.
By May of that year Feynman had given the additional lectures on quantum physics, and we began to work on Volume III. Because some major restructuring and revision was required, I went several times to Pasadena for long consultations with Feynman. Problems were easily overcome and the material for the third volume was completed by December.
From the contact with the students in my discussion section, I could have a pretty clear impression about how they were reacting to the lectures. I believe that many, if not most, of them realized that they were having a privileged experience. I also saw that they were often caught up in the excitement of the ideas and learning a lot of physics. That did not apply, of course, to all of the students. Remember that the course was required of all incoming students, though less than one-half were planning to be physics majors, and so many of the others formed, in effect, a captive audience. Also, some of the shortcomings of the course became evident. As an example, the students often had difficulty separating the key ideas in the lectures from some of the secondary material introduced to provide illustrative applications. They found this particularly frustrating when studying for examinations.
In a special preface to the Commemorative Issue of The Feynman Lectures on Physics, David Goodstein and Gerry Neugebauer have written that “. . . as the course wore on, attendance by the registered students started dropping alarmingly.” I don’t know where they got this information. And I wonder what evidence they have that: “Many of the students dreaded the class . . .” Goodstein was not at Caltech at that time. Neugebauer was part of the crew working on the course, and would sometimes jokingly say that there were no undergraduate students left in the lecture hall—only grad students. That may have colored his memory. I was sitting at the back of the hall at most of the lectures, and my memory—of course, dimmed by the years—is that perhaps 20 percent or so of the students were not bothering to attend. Such a number would not be unusual for a large lecture class, and I do not remember that anyone was “alarmed.” And although there may have been some students in my recitation section who dreaded the class, most were involved and excited by the lectures—although some of them, very likely, would have dreaded the homework assignments.
I would like to give three illustrations of the kind of impact that the lectures made on the students of those first two years. The first dates from the time that the course was being given, and though that is more than 40 years ago, it made such an impression on me that I remember it clearly. It was at the very beginning of the second year, and, by an accident of scheduling, my discussion section first met just before the first of Feynman’s lectures for that year. Inasmuch as we did not have a lecture to discuss, and no homework had yet been assigned, it was not clear what we should talk about. I began the class by asking the students to tell their impressions of the previous year’s lectures—which had finished some three months earlier. After some responses, one student said that he had been intrigued by the discussion of the structure of the eye of the bee, and about how it had been optimized by a balance between the effects of geometrical optics and the limitations from the wave nature of light (see The Feynman Lectures on Physics (FLP), Vol. I Section 36-4). I asked whether he could reconstruct the arguments. He went to the blackboard and with very little prompting from me was able to reproduce the essential elements of the argument. And this some six months after the lecture, and with no review.
The second illustration is provided by a letter I received in 1997—some 34 years after the lectures were given—from a student, Bill Satterthwaite, who attended the lectures, as well as my recitation section. The letter came out of the blue, prompted by his encounter with an old friend of mine at MIT. He wrote:
“This letter is to thank you and everyone else for Feynman physics. . . . Dr. Feynman’s introduction says he does not think he served the students very well. . . . I disagree. I and my friends always enjoyed them and realized what a unique and wonderful experience they were. And we learned a lot. As for objective evidence about how we felt, I don’t remember any other regular lecture in my Caltech career getting applause and my memory says it happened fairly often at the end of Dr. Feynman’s lectures. . . .”
The last illustration dates from a few weeks ago. I happened to be reading the autobiographical sketch written by Douglas Osheroff, who was awarded the Nobel Prize in physics for 1996 (together with David Lee and Robert Richardson) for the discovery of the superfluid state in Helium-3. Osheroff wrote:
“It was a good time to be at Caltech, as Feynman was teaching his famous undergraduate course. This two-year sequence was an extremely important part of my education. Although I cannot say that I understood it all, I think it contributed most to the development of my physical intuition.”
My rather brusque departure from Caltech immediately after the second year of the lectures meant that I had no opportunity to observe the subsequent evolution of the introductory physics course. I have, therefore, little knowledge about the effectiveness of the published lectures with later students. It had always been clear that The Lectures, by itself, could not serve as a textbook. Too many of the usual trappings of a textbook are missing: chapter summaries, worked out illustrative examples, exercises for homework, and so forth. These would have to be provided by industrious instructors, and some were provided by Leighton and Rochus Vogt, who took responsibility for the course after 1963. I had at one time contemplated that these might be provided in a supplementary volume, but it never materialized.
In my travels in connection with the Commission on College Physics I would often meet with physics faculties at various universities. I would hear that most instructors did not consider The Lectures suitable for use in their classes—although I did hear from some who were using one or another of the books in an “honors” class, or as a supplement to a regular text. (I must say that I often got the impression that some instructors were wary of trying The Lectures, because of fear that students would ask questions they would be unable to answer.) Most commonly, I would hear that The Lectures were found by graduate students to be an excellent source of review for qualifying exams.
It appeared that The Lectures may have been making more of an impact in foreign countries than in the United States. The publisher had arranged for The Lectures to be translated into many languages—twelve, as I recall. And when I would travel abroad for conferences on high-energy physics, I would often be asked whether I was the Sands of the red books. And I heard frequently that The Lectures were being used for courses in introductory physics.
Another unfortunate consequence of my leaving Caltech was that I could no longer keep up my active association with Feynman and his wife Gweneth. He and I had had a cordial collegiality since the Los Alamos days, and in the mid 1950s I had participated at their wedding. On the rare occasions after 1963 when I would visit Pasadena I would stay with them, or when I visited with my family we would always spend an evening together. On the last such occasion he told us the story of his most recent surgery for the cancer that not long afterward claimed his life.
It is a source of great pleasure for me that, now, some forty years after they were given, The Feynman Lectures on Physics are still being printed, bought, read, and, I would venture, appreciated.
Santa Cruz, California
December 2, 2004
1The exercises in Chapter 5 of this volume include more than a dozen problems from Foster Strong’s collection that were reproduced with permission in Exercises in Introductory Physics by Robert B. Leighton and Rochus E. Vogt.
2Principles of Modern Physics, by Robert B. Leighton, 1959, McGraw-Hill, Library of Congress Catalog Card Number 58-8847.