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This transcript is based on a tape-recorded interview deposited at the Center for History of Physics of the American Institute of Physics. The AIP's interviews have generally been transcribed from tape, edited by the interviewer for clarity, and then further edited by the interviewee. If this interview is important to you, you should consult earlier versions of the transcript or listen to the original tape. For many interviews, the AIP retains substantial files with further information about the interviewee and the interview itself. Please contact us for information about accessing these materials.
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In footnotes or endnotes please cite AIP interviews like this:
Interview of Charles Townes by William V. Smith on 1979 June 18 and 20,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
For multiple citations, "AIP" is the preferred abbreviation for the location.
Childhood and youth; his family life and siblings; eduation at Furman during the Depression, 1931-1935; merit scholarship. Graduate study at Duke University in 1936; shifts to Caltech during second year; early interest in astronomy; works with Fred Zwicky. His first job and Bell Telephone Laboratories, from 1939-1947; scientific associates (Deal Woodridge, William Schokley). Discussion of work on microwave spectroscopy and NH3 spectrum; competition with Bleaney and Good. Accepts I. I. Rabi's offer to join Columbia University faculty in 1948. Interest in molecules, atoms (not solid state physicians), and in short microwaves; comments on teaching, students and faculty; department head from 1952-1955. Inventions of the maser and laser in the 1950s, background ideas; Teshkas' and Lambs' writings on stimulated emission. Purcell, Pound, Dicke did not think of maser; discussion of effects contributing to the appearance of stimultaneity of inventions. Masers in radioastronomy; consultantship at BTL; joint laser invention with Arthur Schawlow. Interactions with Gordan Gould; BTL's interest in the laser.
OK, Charlie, I think what we'd like to do is to start at the beginning. I know you were born in South Carolina, and what would be a good background is, if you would say something about your parents and what they did.
All right. Of course, let us just talk about the question of confidentiality. I assume that, so far as you are concerned, you don't repeat any of this.
That so far as the tapes are concerned, that's a matter of where I would designate what should be confidential, for some length of time.
My present feeling is that it would be wise to say all of it is confidential, until I have a chance to edit it.
So we'll just say, it's all confidential, until let's say a year after the death of anybody that is talked about or referred to. So then when I edit it, I can loosen that up some.
OK. Now, let's see, your question was about my parents?
Any particular aspect?
Well, for instance, what was their occupation when you were in your teens, which would be a formative time?
All right. Fine. Well, my father was a lawyer. My mother was a mother and a housekeeper. She had worked for her father at home, as was the style of ladies of that time. My father didn't want her to go out and do business work, but she worked for her father who was an insurance adjustor, and so she had done some office work, but when she got married, she was a mother. My father was a lawyer, as was his father, as was much of their family and so on, plus planters. You know the custom in the South, that running a farm is a good thing and it doesn't mean you do hoeing yourself. We had tenant farmers. On the other hand, I did some hoeing. Hoeing was dignified enough. It was just time consuming. And so I picked up a little money working on the farm too, basically working with our tenants. My father enjoyed farms, but he was basically a general practitioner lawyer in a modest sized town.
OK, fine, and that I think tells me automatically the type of education that your parents had.
Yes. Well, my mother went to college at the Greenville Women's College, and took her degree there, a fairly general kind of degree. She may have majored in English or something like that perhaps. But she just took all the courses that were given at the college. My father went to Furman University which is in the same town, and again I think he took a rather general kind of degree. He studied law. He taught school for a while, and during that time studied law at night so that he could pass the bar examinations. He didn't go to law school, which was not unusual during that period, for people to study by themselves; passing the bar exam was the critical thing. So he studied law on his own and passed the bar exams. Then after he passed the bar exams, he stopped teaching school and went into law practice.
OK, fine. And how about the rest of the family? Did you have brothers and sisters? Were you oldest, youngest, whatever?
Well, I have two brothers and three sisters. I was the fourth in the family, and it's often said that the oldest or youngest has some advantage in the family. I think I did have some advantages because I was the youngest of four for some time. My younger sister and younger brother came along a considerable time later. I guess my sister when I was eight years old, my brother still later. So for some time, I was a kind of a youngest, and this gave me a certain opportunity to be taught by the older children and to learn things by doing things with my older brother, and adopting a certain kind of competitiveness between us, and I would say that seemed to me a rather helpful --
Going along with your father's position as a lawyer, your family had a certain social position, a certain financial position. What effects did they have in the preparation for your scientific career?
Well, both my father and my mother were from very old families and very prominent families in those areas, my mother from Charleston, my father from Greenville, but I wouldn't say that they were social. They were not at all interested in society as such. In fact they rather looked down on it. They were also not wealthy. My father made a perfectly adequate living, and in his later life, after I'd grown up, he was fairly wealthy because he liked to invest in land, in part. But the whole South was poor at that time. We never felt the family was poor but still, I didn't have as much spending money as a lot of my friends did. My father was a substantial citizen and had adequate money, but not wealthy. Now, I think, probably he himself would have been a scientist in this modern age. Of course, when he was brought up, he was -- there was no opportunity for science In the South. I think he was rather scientifically oriented. He was certainly interested in all sorts of natural history, knew a good deal about it, and astronomy, plants, animals -- he was just -- had read a great deal, particularly Shakespeare and the Bible, as again was the custom of those times, but a good many other things too. And he read a great deal to us, as did my mother. She too was interested, not I think as widely interested in the real world, at least not as widely knowledgeable as my father. On the other hand, they both encouraged us to find out about things, and put up with a lot of sort of hobbies like collecting insects, raising caterpillars in our room, having lots of pets around and so on, the usual mess that boys can that when they room with pets and bring in all sorts of things, because we lived on a 20 acre place, which was the home place, and then they took us out to the farms quite frequently, to roam around and bring turtles back and so on. And I would say my parents not only tolerated that, they sort of encouraged us to be interested and to find out about these things. My father also knew something about the stars. And so he was generally, I would say, rather expected us to be interested and know such things. He also, wherever there was a discussion about some question that wasn't known, particularly factual matter, he made a point of hunting it up in one of several encyclopedias, dictionaries, that we had, and really finding what seemed to be the most likely answer. So he was rather persistent in running things down, when questions came up in the family, and I think undoubtedly that helped me, both in accumulating information, and also in taking an attitude of getting an answer. Finding out what at least was known about things. I wouldn't say that he, on the other hand, while he had toot kind of interest, I wouldn't say that he encouraged myself or my brother particularly to go into science. My brother became an entomologist, and my father wasn't very enthusiastic about that because he didn't think it was much of a living. He thought it was very interesting, great as a hobby, but not much of a living, which it isn't.
Felt the same about physics?
Physics, I think, he was a little happier about that. But again he felt, if I want to do physics, that was fine. But there was no special overt encouragement. It was just that, if that's what I decided to do, he certainly didn't discourage it. The general intellectual interest was there. But I think, if I'd decided to study Shakespeare, he certainly would have been as happy. And any one of the sciences -- he knew we were both interested in science. I have to say, my brother had a great deal of influence on me, because he was strongly interested in the sciences, and we did things together a great deal, and that helped me, get me started, although I went onto the physical sciences then, while field biology is what he’s been doing.
I can understand that as a very positive background, then, to get you going. Your early schooling, then, it was mostly in school or partly at home?
Oh, it was all in school, excepting that my parents made a point of teaching us, encouraging us along. I think I learned to read first at home, because my mother helped me and encouraged me. I remember very well my father teaching me some Latin because I wanted to start Latin before the school actually started it, and so he started in and taught me Latin, some. They always sort of listened to our homework and recitals if we wanted them to. In fact they sort of encouraged us to tell them how we were doing. My formal schooling was all in school, but I think my parents had a fair amount to do with it. I also had some tinkering interests, and my father used to bring home gadgets of various kinds, broken pieces of machinery, clocks am what not, that he thought we might enjoy working with. I had an uncle who taught electrical engineering in a nearby college, Clemson, who gave us some useless circuits and his old radio once and a few things like that, to help get us started when radios were scarce.
Very good. And you didn't have interruptions due to ill health? No long interruption that came along?
No. No, I had no health problems particularly.
I presume you read a lot in that environment. Any particular books about science influence you at that stage?
Well, I was particularly interested in natural history, broadly, and I read a good deal, but I tended to read sort of for information, more. I read some boys I books. I remember Ernest Thompson I enjoyed, my brother did, and I guess I read more of him than almost any other one author. His TWO LITTLE SAVAGES I remember particularly, and trying to imitate some of the things, making things that those boys had done. I say I read for information because, I had a recent conversation with my oldest sister, who read a great deal, and she said she could never understand why, when she gave us books to read, I wasn’t awfully interested, and she finally recognized that her interest in reading books was for the story, the esthetics, the feeling -- my interest was for information, and I just read a completely different kind of a book.
How would you learn of a particular book? Your parents, the library?
Yes. There were adequate libraries in the town. My parents also would buy books, give us books as presents, and then, I bought a few myself; once I got acquainted with some of the things I wanted, I bought them. I read some novels -- SWISS FAMILY ROBINSON was another book that I enjoyed very much. I remember my mother reading us SWISS FAMILY ROBINSON, and of course Mark Twain. VOYAGE OF THE BEAGLE I read a little later, and that I enjoyed a lot. My brother had read that too. We had the Harvard Classics at home. A number of the Harvard classics, I read. But again, I tended to read them from the point of view of learning things. More than just for the sake of literature. That didn't interest me per se.
Getting on into the secondary school and the teachers, people -- you mentioned some of the people, your uncle -- but secondary school teachers, did they influence you particularly?
Well, I would have to say, mostly, no. I think my mathematics teachers in high school perhaps did. There was a teacher in my junior year at high school and my senior year at high school in mathematics that I found good and interesting. One in history also that I found interesting. But perhaps I should say something else about my outlook at that time, and what I think I got from my family. My family was, I suppose you might say puritanical, although they were not puritans. They were rather strict about questions of morals and ethics. They were Baptists, quite religious, as I am myself. And they sort of looked down on many of what they considered the foibles of society, and that's one reason they weren't' terribly interested in society -- in drinking and wasting time, and so on, and if there was an ethical question they were just very firm about it, very clear what ought to be done. Hence they were rather different, and I felt a little different from people in the neighborhood and most of the people in the town, in that I was just taught to not do some things that other children were doing, and I never had any very hard time about it. Of course I regretted not being able to do some things, but it seemed to me very reasonable, and it was so engrained in our family that that tended to make me a little different, and a little bit picked on by other people, as being somewhat too puritanical and so on. Now, personally I think that too was an advantage, and I suspect that most people who feel themselves in a kind of a minority position tend to turn towards intellectual things, different things, and tend to look at the world a little differently and be somewhat more independent. My parents themselves were very independent. Just, whatever they decided was right -- they never made any fuss about it. They just went ahead and did what they thought was right, trying to minimize any disruption of anybody’s else's ideas. They did it in a very gentle way but very firmly, what they thought was right. I feel that's probably the most important influence, other than the general intellectual interests, and my guess is, it's pretty important to almost anyone who goes into science, to have that kind of sense of independence. Now, that meant that I was a little difficult at school, I guess. In some ways I was the favorite child of the teacher, in that it I was generally top of the class. But as I got into high school, I tended to find the teacher's mistakes, am I remember very well one science teacher in particular that got quite cross with me, because I would point out where she had made mistakes, and I guess I was a little difficult. On the other hand, I found that was one of the things that kept the class interesting. It was kind of a game to see, well, how much did the teacher know? Where could I find the mistakes? And while that may have been objectionable to the teacher, I think it was very good training. That doesn't mean that the teacher inspired me particularly. They were probably (crosstalk) -- that's right, it was a foil, really, am I think it was a fairly good kind of training. The high schools that I went to had generally good standards. Mathematics teachers, on the other hand, they were playing games themselves, in a sense, of trying to examine theorems and so on, and it was very different. If they made a mistake they were very quick to recognize it themselves. So I would say, the mathematics teachers I found a little more inspiring. In addition, my family and my brother knew, and I recognized partly from them, that science wasn't very well taught in the schools at that time. So I took no more science than I had to, except for mathematics, which was well taught. Mostly I studied the normal kind of requirements, a certain amount of Latin, languages and mathematics, and I just didn’t take any science really until I got in college, essentially because I felt it wasn’t well enough taught. It was a kind of childish type of science. I’m sure it is taught better in the schools now. All right. You were about to ask about college, I guess?
Well, I was. I think you've also answered, sort of summed up what I was going to ask you -- which of all these influences were the greatest at this point? I assume your answer is, the family environment, if you wanted to sum it up.
Oh yes, I would say, there's no doubt about it, the family environment. I would include my brothers and sisters as well as my parents, but the parents set the style anyhow. I would say my older brother was quite important in stimulating me, and the fact that I was a little younger and trying to keep up with him was quite stimulating. I also, I got a little bored in school, and when I found it boring, the only thing that helped was to somehow get a change in a different kind of school. By the time I'd gotten to the 6th grade I was pretty bored, and so my parents suggested, "Maybe you'd like to skip a grade?" So I studied at home and they helped me and I skipped a grade and went on into high school, and it was interesting again for a while. But by the time I got through high school, it was getting a little boring. Then when I got into college it was interesting again. So I pretty much always enjoyed school, but it was a result of keeping it something, a little bit… of a challenge anyhow. I think that skipping a grade was again a very good challenge to me. It of course made me socially in a little more difficult position. And I had some modest difficulties. I never felt terribly badly about it, but I was teased a certain amount by the older boys and so on. Again, it may have been a good thing, from the point of view of developing a little toughness and independence. In any case, that was the situation, and by the time I got into college, I was pretty young for college, because high schools at that time in the South had only 11 grades and I had skipped a grade too. Now, from my point of view, I think that was a great advantage, to get on with your education fast. In fact I think many of our young people spend much too much time in school now, too old, but let us just talk about myself, I guess, I won 't worry about the rest.
I assume you planned to go to college then from a very early age?
Oh yes. That was sort of automatic. Both my parents had been to college, and my grandfather was a lawyer, and his father had been a lawyer and so on, so it was just the general expectation of the family. All of my older brothers and sisters went to college, and that was not -- that was a fairly normal thing to do anyhow in the town at that time, at least among my friends.
At the time when you first went to college, what did you expect your education to lead to? Were you already thinking of physics or whatever? What were your expectations when you first went to college?
Well, I really was sort of looking for what it was that I might do. I guess that I kind of automatically assumed that I probably would go into science, that I probably would go into teaching of science, which seemed to be the only thing known to do with science, other than learn it, which I enjoyed. And I felt I would enjoy teaching. So I more or less expected somehow to teach science somewhere, but I didn't know what kind of science, and I wasn't even completely sure of that. I just went to college to learn what I could and find out what I liked, and I liked a variety of things, so I could see various things I liked to do, but the choice between them wasn't easy. In fact, I would have probably, if I'd made a choice at that time I would have chosen biology, which I had done more of than anything else, because I'd done a good deal of field biology and I knew a fair amount about it by then. I think it was probably the fact that my brother was so good in biology that made me think, well, I ought to look at some other things. He was exceedingly good in it, and while I was pretty good too, he was always a step ahead of me a little bit, and while I didn't mind following him all that much, I think that probably made me look a little more broadly. I liked mathematics, but I felt mathematics was a little dry and not close enough to the real world. Actually, I took the first physics course I ever took as a sophomore. So by the end of my sophomore year, I liked the physics course so much that I decided, physics was what I really wanted to do. I didn't like chemistry very much. Initially, my first course in chemistry, I don't feel was well taught. Another person came along after that and I think taught well, but I never liked laboratory chemistry, and I didn't really think very much of chemistry until I started doing research, which is so closely related to chemistry that I think I'm sort of a half chemist. But I did like physics very much, and I liked mathematics. And I liked languages. I majored in modern language in my first degree. The only reason for that was that, well, my brother had taken two degrees, one in science and one in modern languages, just I think perhaps as a sort of lark. And since I was young, my parents didn't want me to leave home too soon and go to graduate school. So I had finished everything that was necessary to get a degree after three years, but rather than leaving, since they were against it and I wasn't all that eager to leave town, leave my parents -- I was thinking of going to graduate school, but they urged me to stay another year, so after three years, I took a degree, finished up a degree for modern languages which I liked and thought would be useful. But my real intention was to go into physics, so I finished up a physics major the fourth year. It wasn't so easy to finish up a physics major, because I had taken my first physics course only as a sophomore. I had to take four courses. There weren't four courses at the school normally given actually, so the fourth course, I doubled up on and I read a book and worked the problems and just reported to the professor from time to time. It was Jauncy, and I would say Jauncy's book did have a substantial influence on me. It's an excellent book, Jauncy's MODERN PHYSICS, excellent book from the point of view of being at fairly rigorous, interestingly written and at the same time taking a rather broad perspective on what this are interesting, what things are new, and I think it was an unusually good book for me at that time. But I had already decided to go into physics anyhow, and then after that it was a question of, which graduate school.
I think you already answered the question then of why you chose to go to Furman, because it was home.
That's right. It was cheap. Of course this was during the Depression.
Was it a financial burden on your family at that time?
Well, I think it probably was. My father never said so, but yes, I think it probably was. In fact, I remember his talking with me at the time, that he had to be very careful, to be sure that he didn't run too close to going under, because he had bought a good deal of property. He was paying off mortgages. He was doing fairly well before the Depression hit, and could afford it. Then the Depression hit and he still had all these mortgages. In addition he was a very conscientious lawyer, and he dealt in real estate a good deal, and in doing that he had lent money to clients. Clients would come to him, say, "Here's some money that I'd like to put on a mortgage, will you see that it's lent for me?" "On some land?" He would recommend land. People would come in wanting mortgages and so he would hand them the mortgages. Well, as the people who owned the land and had taken out the mortgages went under, he felt that he had to make good to his Clients. It wasn't a legal requirement but he felt it was an ethical requirement. So he would always payoff the mortgage himself and own the land, and it was not easy for him to take care of all of the expenses at that time. As I say, I remember his talking to me about this, although no enormous toll, but I'm sure that it wasn't earlier. On the other hand there was never any complaint about it. But it was very clear that I needed to go there. Furthermore, I felt Furman was a good school. My father had gone to Furman. My mother had gone to the corresponding women's college, and one of my father's uncles had been a president of the other college. It was all a kind of a timely thing. We thought well of the two colleges. We knew they weren't great, but felt they were good and one could get quite an adequate education. So it really wasn't much question of my going away to another school. My sisters had been sent away because my family didn't think the women's college at that time was quite good enough, so they went to another school in South Carolina, went away to school, and my brother and I went to Furman.
Did you have to raise some of the money yourself, or did it all work out --?
No, I didn't. I raised it in a sense by getting scholarships and working in the lab, and I did as much as I could there to take care of my expenses, which seemed to me the natural thing to do. But my father never asked me to go out and earn money to pay tuition. I did take some competitive examinations before I went into college, and won a scholarship, which helped some. And I worked in a museum there, to pick up some money. That, as I remember, though, was money that I used for pocket money. My father didn't ask that I pay that to the university. Then I taught in the physics lab some, and that did go to the university. So I helped put myself through to a certain extent. I had some other aid from university scholarships. My father however was very firm that I should not have a scholarship which was given because of need. He felt very strongly that need had to be a very real need, and that any scholarship I had would be an award for outstanding scholarship, not an award because of need. So I had, I would say, scholarships that paid some money, but not a large amount, and he paid the rest. But I stayed at home and things were pretty inexpensive then, but there was certainly never any question about my having to possibly to drop out of school or anything of that type. I felt quite secure about that.
You were quite comfortable about attending a college in your home town.
Yes, I was quite comfortable about it. I knew that I wanted to go into graduate school, you know, and that was the time to go away, so I'd have the experience away from home. I wasn't particularly interested in fraternity life.
…undergraduate teachers of courses, did any of them make a particular impression on you? Would you have specific names even, perhaps?
Well, I liked a lot of my teachers at the university. Some of them I didn't, but many of them, I liked. Professor Ives, who taught biology, I was quite fond of, and I found him interesting. I had been to biology camp before I'd entered college even. I got a job in biology camp collecting things, and so I was pretty close to the biology department. These camps were run by Professor Ives. Professor Cox taught the physics course. The thing that I liked about physics and about Cox, and I think the way he taught physics, was that he was very rigorous. He was very careful and very rigorous, sure that problems were really thought through and that the physics was really thought through. He was not a highly educated man. He had a Master's degree, had never done any research, but he was a high quality intellect, in the sense of really understanding things and generally having high standards. Professor Earle in mathematics, I was quite close too. I graded papers for him. He was an excellent teacher, very kind to the students but also very demanding at the same time. He also happened to be a cousin of my family, and so, typical of the situation, I was in the home town in the place where my family had been a long time, and they knew everybody. Professor Bowen was another teacher of mathematics that I found good, but Earle was perhaps my favorite among mathematicians. Then there was a Professor Bradshaw who taught modern languages, Professor Gardner who taught modern languages, that I liked, and a Professor Epps who taught ancient languages. I liked his courses very much, even though it wasn't something that I expected to use widely. He taught Latin and Greek, and I took some Greek. They were small classes, and Epps in typical classical tradition used the study of languages as a way of studying civilization and philosophy and so on. We had great discussions of the meaning of texts and so on, and the significance. Professor Poole taught religion, and I thought it was pretty good. Gilpatrick taught modern history, European history, modern history, and he ran the International Affairs Club, and I found him very stimulating, very interesting…I joined that club, as well as a variety of others. So those are people that occur to me. Oh yes, Odell in English, I liked. Odell was a rather challenging type, generally thought to be a little leftist in his politics, a little loose in his devotion to religion, but -- you know, in the modern context that kind of charge would be ridiculous. But he was a very interesting man, very intellectually oriented, rather jovial, challenging, and I liked his English courses, and I made a point of taking an Anglo-Saxon course with him, which was a small course in which he personally kind of enjoyed himself. I think I had the real advantage in going to a small school in that there weren't that many courses in science, so I could basically take all of them that I thought were good, and then take other good courses around, Where I thought there was a good professor who was teaching a class that was small and interesting, and I could pick out the courses that I liked, and I got a smattering of a fairly wide variety of things.
Did you have any specific ideas that sounded -- it sounds like you interacted well with the teachers and liked a lot of them. Were any of their ideas particularly stimulating and exciting? Did you particularly strongly disagree or strongly agree with any particular thoughts?
There were not really -- I would say, the first approximation, there weren't any such thoughts. No, the teachers taught the textbook material, and they discussed on it and made it interesting, but they were not research people. I did some research, a little ecology. He taught an ecology course which, I find later, was unusual, and he did a little research on local biology, but really nothing that would be considered Significant these days. So it was an atmosphere of some scholarship, and, however, it was textbook scholarship, second hand scholarship, rather than first hand scholarship, largely. Now, I suppose Odell and Epps, were a little bit closer to the realm of challenging ideas, but that was in philosophy and general talk and literature rather than science per se.
Your teachers had close relationships with the students more or less, friendly, didactic?
Oh yes, they had generally good relationships with the students. It is a small college and classes were all small, and these were dedicated fine people. They were people of the highest quality who today probably would have been doing research, but they weren’t doing research, didn't expect to do research at that point, in that location.
How about, in such a small college, laboratory courses, equipment, things of that sort?
Well, the laboratory courses could be faulted. I'd say. The chemistry lab I found rather miserable, and I never enjoyed it, because I guess my experiments never came out terribly well. I think in part it was, large groups of people not very well taught, and the chemicals perhaps weren't entirely pure at times and so on. The physics lab was fairly trivial, from my point of view at that time, although I didn't mind doing the experiments, but they’re experiments whose outcome was obvious, and simple apparatus. I always did them, but I had done things like that at home, tinkering around with things, and so, I never particularly enjoyed the laboratory, even though I liked experimental work generally. The laboratory simply wasn't challenging. Biology laboratory also was nothing very much, with the exception of field work. The field work was interesting because it was not predictable. Field biology in the South had not been written on very much. The textbooks all came from other places, and there were some new things around. But I would have to say that research seemed to me strange and exciting rather than being present and real.
Was the extent of your introduction as an undergraduate to research, a little bit of biology?
Yes. Well, there was a chemistry professor who came, Professor Sampey. I should have mentioned Professor Sampey because he was a man I liked and admired. He came the last year or so of my being at Furman, and I took some courses with him. He was a good research chemist. He’d come from Johns Hopkins. He was a son of a minister. He decided to come back to Furman because he felt he wanted to dedicate himself to teaching at Furman, and he did introduce something of a research atmosphere, the last year I was there. Did a little research himself. On the other hand, by then chemistry was already a little distasteful to me. It was only the physical chemistry and some of the theory that was involved that I found enjoyable.
On that sort of thing, how much modern instruction, from your present perspective, would you say the school had? Latest theories, quantum theory, relativity, anything like that?
No. No, they had no courses of that type. I think the closest thing to that was Jauncy’s modern physics book, which had a smattering of some of those things, but the professors themselves simply were not acquainted with that.
And at the time you felt that already, or not?
Oh yes. I knew they weren't acquainted with it. I knew they weren't acquainted with it. They knew they weren't acquainted with it. Quantum mechanics was, after all, still pretty new in that period, too. They certainly were not ashamed of not knowing it. It was just new things that had come up that they'd never had any contact with, that they found interesting, but they weren't prepared to teach it. No, I think the -- I never regarded that as a great handicap. I didn't know very much physics when I left Furman, in a sense. I think the most important thing that those professors did was a sense of quality, rigor, thoughtfulness and some enthusiasm. I think those are perhaps often more important than any formalities of how much they happen to know.
You mentioned one book. Any other book that had a particular impact at that time?
Well, there was a book by Stewart that was my first course in physics, and I think that was a good book, but perhaps other books would have been as good. In physics, I had electricity and magnetism book that was rather poor, a classic book that was rather poor. The mathematics books I thought were all perfectly good. They were straightforward text, the usual sorts of subjects. I really think, Stewart I would have said was a rather good book. Jauncy was an excellent book for me. Otherwise, I'm not sure the books made any difference.
Maybe you already covered it, but do you have any why as to why it had an impact on you? You described it as a good book, covering modern physics is that pretty well it?
Well, it was -- let's see how I could describe it. It was historical, in a kind of a philosophical way. It brought up new ideas, things which were rather recent, some of which were unexplained. It discussed even the discrepancies of viewpoint about these things. It discussed quantum mechanics in an interesting way and relativity. Relativity, well, it may have said relativity wasn't -- relativity actually was in the second course of physics that I took, a book I believe by Miller. I don't remember which Miller. I learned relativity through that book, and special relativity. Special relativity after all can be fairly compact and succinct and mathematical, and I enjoyed that. I remember very well puzzling through that, and thinking that I had found where Einstein had made a mistake, and being very excited about that, and thinking about it some more. In the course of about two days, I decided that it was I who had made the mistake. But still that was exciting, stimulating, and made me think about it a little more clearly. But that was all done on my own. Professors sort of knew something about it, but they were not entirely clear about it either. Jauncy was both interesting and philosophical and presented controversy and at the same time, a good deal of rigor. I think one has to go back to read it. I don't really know of any other book with exactly that kind of tone today. Maybe there are some, more because I haven't read all the more recent books. I haven't been very close to undergraduate teaching recently. It was, I thought, an admirable book. I wouldn't say though -- it isn't clear that any of my future depended on that. Because I'd already decided to do physics and was already sold on it, primarily because it was mathematical and rigorous, tightly organized and yet it had something to do with the real world, and that was the combination that I enjoyed.
How about your fellow students? Do you remember any of them well, or did any of them later become colleagues or anything?
Well, Furman graduated about one physics major per year at that point, a few biology majors and a few chemistry majors. There was a fellow student, Jack Yost, who was in some of my classes. I believe he finished a year after I, or maybe a year before, I'm not very clear now. He eventually worked for an oil company in oil seismology am I think did quite well there, but I've seen him only a few times after that. George Crouch was a second major in physics in the same year that I was there, and the only other major. He took many courses with me. George of course took his PhD with Plyler and worked with Plyler for some time, and it's a rather strange coincidence that he gave a prize in Plyler’s name which then later I was awarded. Another strange thing about it is Plyler was a cousin of mine. So it's all very, that prize is all very incestuous.
Did you work together with these students, or separately pretty much?
Oh, I never worked with either one of them, in the sense of doing homework with them or things like that. We were in class together and good friends, but we never studied together particularly.
You didn't try to get special courses? It was a very small location, one that wouldn't set up special seminars.
No. No. There was just not a big enough group for that. There was a sort of a science club that met occasionally there, that professors would arrange, but no other science discussions
You had free time to pursue these studies of your own, do some things of your own, and you were not too pressed for time, you had time to do that?
Well, I was pressed for time because I was fairly busy. I was taking a very heavy load of courses on a wide variety of subjects and working too in the museum and doing other things, I worked in my father's law office to pick up some money, did various kinds of chores for him, delivering papers and serving papers and what not. And then, I did a certain amount of field biology, so I was really very busy. At the same time, I enjoyed most of my courses and tended to do them fairly thoroughly, particularly the science courses. There were a few courses I didn't enjoy particularly and I guess I didn't pay that much attention to them. The physics course on the other hand, I tried to always really think through. I understood it. And once I understood it, I didn't then branch out into looking up other things that weren't in the course. I just did the course and tried to do that well, and that seemed to be enough.
I think, covering the various outside interests which you've already covered to a large extent, you mentioned philosophy a little bit too. Did you pay much attention to that at that time?
Philosophy? Yes, I enjoyed philosophy. It wasn't very much taught per se. There was a professor who purported to teach philosophy, that I was not highly impressed with. I think maybe he gave a course in philosophy which I sat in on, but I didn't find that especially well taught. I did however take several advanced religion courses, comparative religions, given by a man name Poteat, who was a returned missionary. He had previously been president of Furman University, a very fine interesting stimulating person, very challenging, and I enjoyed that. I was, any courses of that type that were around, I tended to take, but there were not all that many. I was also playing in the school band and I as on the swimming team and various other kinds of things, and I wrote for the school paper a little bit. I was involved in a large number of branches of the university, so I was perhaps as busy as I've ever been. It seems to me I'm always too busy.
Well, you've already told us that you decided on a career in physics, essentially while you were an undergraduate, I believe -- and basically at that time to be a teacher, I believe also to do research, or, hadn't you gotten that far?
Well, I certainly wanted to do research. I guess I had research sort of vaguely in mind, whenever I started going into science. I think any scientist would, think of trying to do something that's new, but it was rather vague. By the time I finished college, clearly I wanted to do research if that was possible. It wasn't clear that it was going to be possible, except to do some research for a graduate degree. Jobs were quite scarce, and I felt, I hoped to get a job teaching somehow, and if research was possible, I would certainly want to do that. Most of all I wanted to get a job where I could teach and do research.
Did you think of yourself as an experimentalist or a theorist at that point?
I was open minded about it at that point. I enjoyed some kinds of experiments, but the laboratory experiments that I had seen there at college were not very inspiring. On the other hand, I enjoyed apparatus and doing things, and I'd done a good deal, of that kind of thing at home, so it wasn't clear to me at that point.
I think you've already answered basically the sort of life you expected. You'd get a job teaching and doing as much research as you could, and the job prospects, you didn't know. It was the time of the Depression. What was your family's attitude to all this, then? When you'd gotten that far?
Well, they found what I had chosen to do quite acceptable. I suppose my father might have preferred me to go into law, but he never said so, never really gave any positive indication, and in fact talked about it -- he made some jokes about a friend of his that was a lawyer, said that if his son ever tried to go into law he would first try to beat it out of him. But my father never looked down on the law. I think it was clear that he was trying to make sure that I understood that I didn't have to go into law. So he was open minded about it, and I think, reasonably pleased and encouraging. I felt just no pressure one way or the other, and once I had decided, they felt it was all right. They weren't awfully eager for me to leave home, go off to school! On the other hand, my two older sisters and my brother had already been in graduate school by then, away from home, so it was sort of expected. I guess if I had done anything other than go to graduate school, that would have been surprising to them.
When did your interest in astronomy develop?
Well, that's interesting, because I've just been through what I thought was my memory there. In the first place, I've always been interested in astronomy just as a part of nature I history, just that it's the world around you and it's interesting. And I tried to learn about it. But the first research oriented astronomy that strikes me in particular was. I thought I remembered reading in Jauncy’s book a paragraph about the discovery made by Jansky of these radio waves coming in from outer space. They were unexplained according to Jauncy, very interesting but unexplained, and they’d just recently been discovered. That stuck in my memory not with the expectation that I would do something about it, but rather that here was something that is interesting and unexplained. The next time I had anything directly to do with astronomy was when I was a graduate student at Cal Tech and I always found astronomy enjoyable and I made some trips to observatories and I didn’t do research in astronomy, except that while I was engaged in research already, I asked Professor Zwicky if there was any small job in research that I could assist him with. So that I could learn a little bit about it. And he gave me a little job. Basically looking for variable stars as a kind of a chore, which I did for a while and found it of some interest. But it was a little too much of a chore and I didn’t do it very long. Then some years later, when I was doing a lot of military work but had some time nights and Saturdays on my hands. I didn’t particularly enjoy military development world but thought it was necessary during the war. I said, well, I’m going to start thinking about some physics. If I can get a little bit of a break and start looking at something that I basically find more interesting and so I picked up the idea of trying to understand where Jansky’s radiation was coming from, and paper on the general theory of did in fact then write the first free radiation, including integration over Maxwellian velocities I talked with some variety of people about it at that point, too, and thought seriously after the war of going into radio astronomy, but I'd also gotten started a bit in thinking about, microwave spectroscopy, and its potentialities, and felt that at Bell Telephone laboratories, where I was, the opportunity was better in microwave spectroscopy, so I did that instead, even though I had written this one paper on free-free radiation and some things associated with that.
OK, good. Well, backing up --
-- I should say, about Jansky's work in Jauncy's book, I remembered that very clearly I thought in Jauncy's book, but I went back the other day to see if I could find it, because somebody asked me just where was it, they would like to see it. I couldn't find it in Jauncy's book. So either I had a differentiation of Jauncy's book or it was some different; book that somehow I have a visual memory of as being Jauncy's book instead.
I'm not familiar so I wouldn't know, and my idea of the time scale isn't that good, but it did sound to me like something pretty good and modern to have gotten into--
Yes, well, it's just the kind of thing which Jauncy did. He picked up a number of the latest things as being interesting. It is the kind of thing that he did, all right, but when I went back, I didn’t see it. I somehow feel pretty certain that it must have been Jauncy but I may be mistaken. It is some book that I read at that point.
Well, how did you choose to go to Duke then? That was your next step, I believe.
Yes. Well, I wanted to go to the best graduate school that I could go to, and the schools I knew of included Duke, that I felt was good in physics -- included Columbia, Cornell, MIT, and maybe Michigan, I've forgotten whether I thought of Michigan. I applied to those places for some kind of financial help, because it was clear that I had to have some financial help to go there, and I wanted a teaching assistantship or something like this. But I realized, it was improbable that I would get one, or at least not highly probable, so I also applied to two local places, namely North Carolina and Duke, which were closer by. Being from a small school, not really knowing a whale of a lot of physics, I felt it was uncertain that I would be able to get in and get some financial help at any of the bigger places. I mentioned Earl Plyler, who was my cousin, whom I didn’t know personally although he knew my parents well, quite well, had lived in Greenville as a boy -- he was then in the department at North Carolina, and I wrote him. My father said, "Well, of course, he won’t help you out. He is your cousin, he can’t help you out --” I wrote him, and sure enough, I did not get any help at North Carolina, nor did I get any offers of anything at any of the other places, but I did get an offer of a laboratory teaching assistantship up here at Duke. And Duke I felt was a pretty good place. So I came to Duke, although I recognized it was secondary to some of the other bigger schools that I’d hoped to go to, and I then wondered about whether I should stay here or not stay here, and I don’t know whether I was lucky or not, but I didn’t get a particularly good fellowship that was given in the department the next year. I applied for it, a rather nice fellowship, and there was somebody who I’d just come down to graduate school from MIT who got it instead of me. And so I had the teaching assistantship, but I decided, well, if I don’t get that, I really ought to go to a bigger school. And I had applied again to all the big schools, including at that time I remember Cal Tech, but I didn’t get any offers from anywhere, and it is very different, of course, from modern times, but there were relatively few teaching assistantships. The Depression was on and it was not easy to get those and I did not have the right kind of background for it, anything to recommend me very highly, although I had a very high record all right at my own school. It just was not a well-known school. So at that point, I decided, just to finance my way to Cal Tech. I was determined to go to the best place I could, and Cal Tech seemed both good and interesting to me, because it was in California, and I’d never been to California. It seemed like an interesting place. So I worked very hard that summer, trying to pick up enough money to pay as much of my way as I could. I undertook all kinds of jobs and I had saved up, I think, about $500, with all the amount that I saved during my younger career, so I set out to Cal Tech. Then by midterm or middle of the year, second semester, I was given a teaching assistantship at Cal Tech so I could continue on. I think my $500 wouldn't quite have lasted through a full year, so I was taking a chance, but I probably could have stuck it out some way or other. By the second semester, however, I had this teaching assistantship. Then I had a perfectly normal adequate student stipend, which wasn't much, of course, but was enough to live on.
Now that you're in graduate school, how about your graduate teachers? Specific ones there that made a particular impression on you? Or Duke before you went there?
Yes. I enjoyed my stay at Duke. I did a Master's thesis with Woody Constance.
Well, shall we discuss your first job, you’re scientific career, perhaps? Perhaps you might just go over why you went to Bell Labs a bit, and who recommended you and your working conditions when you got there.
Well, as I mentioned, I really wanted to go to a university, expected and hoped to go to a university. And I even thought that I would have a fellowship at Princeton, probably, although it had not been awarded me, but I'd been given some encouraging reports. But the Bell Telephone Laboratories job came along. My professors advised strongly that I ought to take it, simply saying, there just aren't going to be any other jobs, that's just the way things are and you can't possibly find a better job. So I took it, after thinking about it for a while, and I took it in part because I knew Davisson and Germer had worked there, and it was obviously a place where good quality research could be done. It must have the right kind of atmosphere, in addition to having enough financial backing that one could get apparatus, and I knew some other people who had been there. I even knew that a few people had left Bell Labs and gone back to teaching in universities. So I agreed to go, even though I didn't have any special interest in industrial firms. And when I got there, Bell Labs gave me a really very special treatment which I've always appreciated. I think I was the only person that they had tried this on, the only one of a group of about 15 or 20 people, new PhD's that came in that year, that they handled this way. They explained to me, they were going to send me around to several different departments, during a period of 12 months, so that I'd get experience in a number of departments. I could see what they were like and they could see how I'd get along, but it basically was education. So, I was to be for three months in several different departments. I was in the magnetics group, which was a good group at Bell Telephone Laboratories. And then I was in a microwave group, which was designing microwave circuits and microwave tubes and so on. Then I went to the electron tube group, and worked on cold cathode tubes for a while. Then they suddenly changed their minds and said, “Well, that is probably enough. Now what about getting to work on something, and how about working on cold cathode tubes?" “We need a cold cathode tube to operate at a much lower voltage, namely, the basic battery voltage of the telephone system, and what about doing research on something like that and working with Wooldridge?" who was in the general field of electron emissions and so on. So they cut my training a little short, I don’t know whether it is because they got impatient or dissatisfied with me or what, I don’t know. But maybe they decided that was it. I had in fact done some research on electron tubes by then, but I’d done some things in the other fields too. And so I started that kind of work and was getting going, I felt, with some moderately promising things. The war was coming along, and United States was not yet in the war but, I think it must have been something like September of 1941, that -- perhaps it was a little earlier than that -- I was called in to see the head of the laboratory, with Wooldridge. Dean and I went in. They’d already talked with Dean some about it. So he was tipped off. But I knew nothing about it until that time. They said, ''Well, from now on, you I’m going to be working on bombing systems using radar." Well, that really was my first bad experience with industrial laboratories. I didn't like that at all, being told the next morning I was to be doing something else. However, I recognized that obviously it was within their power to tell me to do whatever they thought they wanted me to do. And in addition, we were all getting rather worried about the war, and I thought we did have an obligation, and so I did it with reasonably good spirit, and started to work on radar bombing systems. I worked with those until the end of the war, and even had to stay on for about six months after the war in order to finish out some things that Bell labs felt were important. That was one of the few periods when I was doing something that I clearly would not have chosen, really found non-ideal. At the same time I did it reasonably, somewhat philosophically, but with the clear understanding that that was not what I wanted to do permanently.
Did you associate the fact that that shift came toward applied research primarily because of it being an industrial lab, or primarily because of the war?
Well, it was a combination of the two. The fact that it was an industrial laboratory gave them the privilege of telling me what to do. The fact that it was the war made it more acceptable to me, and also I'm sure was one of the reasons they did it that way. On the other hand, I'm also sure they wouldn't do it that way today. Certainly Bell Labs wouldn't treat people that way. But Bell Laboratories was forward looking for the time, and in addition, they had started along about in there, they had started a seminar which was very forward looking, unheard of. They told us to take time off, have tea and cookies, discuss solid state physics and electronics and other interesting things with a selected group of the best physicists in the Bell Laboratories. We all got together, about ten of us, once a week. They gave us time to do this, in fact encouraged us to do it. At the time, that was absolutely fantastic. Now, it's commonplace. So they were doing forward looking things, but in this day and age, it doesn't seem very vast.
What specialties were encouraged at Bell Labs at that time?
Well, it was electronics in one form or another, but including solid state. The solid state program had been begun by Kelly there, and I think in a very forward looking way. Some people say that he envisaged the electronics revolution and the transistor. I'm quite sure, that's not the case. What he envisaged was important use of solids in electronics. They thought of such things as switching contacts and other things, materials, resistivity. It was quite clear that was important, and I think it was very intelligent of Kelly to get that program started, and get in the best bright young solid state physicists that he could, and that included Bill Shockley and Dean Wooldridge and a variety of other people with whom I had a long and very useful association. And out of that then came a variety of things, including the transistor. I think transistors really came out of that activity of getting such people together and encouraging basic solid state work.
And what effect did this experience have then in you choosing your own direction?
Well, it was very important. Of course always what one does grows out of his past experience, to some extent. You branch off in new directions, but you have to start from some base. And during that time, I was working, using radar -- I did not design radar myself, although I'd been in the microwave group, but I was using radar, and designing analogue computing systems for very flexible navigation and bombing systems, learning electronics. I hadn't really known much electronics, and I learned circuitry, design of the day, very thoroughly then. I found that -- that's part of the reason I did radio astronomy, because I was interested in radio waves, and felt I might know enough about it to figure out where Jansky's radiation came from. In addition I clearly started on microwave spectroscopy because of that background. Now, I would have to say also that these seminars, in combing through solid state we also combed through some physical chemistry, and we worked over Linus Pauling's book on the chemical bond, which was very illuminating to me and helped me a great deal in understanding properties of chemical bonds and waves getting me started in spectroscopy, microwave spectroscopy. But I think the thing that really started me was more or less accidental. We were working with X band radar for some years, and Wooldridge and I were designing a radar bombing system to use a certain X band radar. I felt that the system was too fancy, and it was more Wooldridge's taste than to mine, but I was a junior man and I was not interested in design problems. I think it was too fancy, because it came along slowly and would have been expensive to manufacture and maybe somewhat unreliable in the field. In any case, a little later it was decided to toss that. Well, our work really started with 10 centimeter system. That was tossed over in favor of X band because X band gave better resolution. Eventually that was tossed over in favor of K band. And I felt strongly, well, if this is going to be useful in the war, we ought to keep going and we ought to do it with X band. There is just no time to build that fancy a system for the war. And furthermore, I knew there could be some problem with K band absorption of water vapor. So I spent some time looking into the water vapor absorption, and in particular read Van Vleck's treatment of this, which I think was a good treatment and the best for the time, of the possible absorption of water. I became convinced that it really would absorb a good deal, and tried to convince all the decision makers around that I could, that it was unlikely that K band would really work very well. But by then the decision had been made. I remember talking with Rabi, and he was quite adamant, and he was one of the people involved in decisions. Various British colonels and scientists too said, “Well” -- they had no really strong argument against it, but they thought, we've made this decision; we'd better just go ahead. I talked with my own bosses. I was really rather frustrated about it. But we went ahead and designed a new system, and of course it didn't work, in the field. As soon as they got some in airplanes, they recognized that there was water absorption. Meantime I'd looked into the theory well enough to recognize that the line shape was quite interesting, and there was a possibility of high quality spectroscopy, particularly the line shape got narrower and narrower without decreasing in intensity. Now, that was experimentally a rather new phenomenon, and I remember very well talking with Jim Fisk about it, who by then was my boss, and explaining to him its importance. I wrote memos to Bell Laboratories, explaining why it would be important to do spectroscopy of this type, and its possible use in circuitry eventually. Jim Fisk, I'm not sure had time to look into it. Certainly he didn't understand it, but he asked Arnold Nordsieck who was a good theoretician and was at Bell Telephone Laboratories what his opinion was, and he agreed, yes, it could, I don't really see anything wrong with that. So I wanted very much to get going on spectroscopy, and I had a kind of a program lined up, particularly to look at ammonia. Ammonia had already been tried in balloons, and people were playing with it at high pressure, but I wanted to go down to low pressure, and demonstrate this narrowness, and measure the frequencies exactly, and I was thwarted in that again somewhat however, again by the Bell Laboratories, because we designed this K band system, and then they’d switched back in to the X band system, and they wanted me to go on and finish the design, see that it worked, and this meant another six months work after the war had finished. I said, "Look, I'm willing to do war work while there's a war, but really I don't want to do this.” The Laboratory was rather offended by that, that I was saying what I wanted to do, and I remember being lectured to by Jim Fisk -- "I understand, but at Bell Laboratories you've got to explain it in terms of what's good for the Bell Telephone Laboratories, not what you want." You can imagine again, that’s a little out of context for present day attitudes, but that was the situation then, and another one of my bosses, I remember very well it being reported to me that he had argued high up in the organization, that Townes mustn't be allowed to go back to physics, by now he's a good engineer. And that's what we need. He shouldn't be allowed to get back to physics. I just said, to myself at least, engineering's all right but it isn't what I want to do. They don't understand. I'll just have to leave and get something else. But they eventually let me go into spectroscopy, with a six months delay -- however, saying that I had to find a replacement, somebody to take my place, and I got in Howland Bailey, my old Cal Tech roommate, who took over, and those systems did get into use after the war. So, I got started that way on microwave spectroscopy, selling it to the Bell Laboratories in part as a kind of a resonant circuit which in the long run, as we got down to the millimeter waves and beyond, it would have something to do in replacing capacitances and condensers and resistors and frequency standards and so on. I made a point to them, however, that tone mustn't expect to get much energy out because of the thermodynamic limit, that you couldn't heat a gas up very hot so you couldn't expect any very high intensity energy. And of course that turned out to be completely wrong, but it was clear that --
-- state of the art at the time.
That's what I thought at the time. I thought I had a nice solid proof that that was the case. I did at least foresee the possibility of use in controlling electromagnetic waves, and I thought I made a good case with the laboratories that it would be useful. In any case, they let me work on it. But sort of under a physical chemist, who was a very good boss, very helpful, a man named Morgan, and I set up six months after the war and got started, on that project. Now, I knew already that some people had tried ammonia at about half atmospheric pressure, and had gotten sort of a vague, some kind of change in shape of the curve, but it wasn't anything very much, and I wanted to get on down to still lower pressure and see what happens, if the line really, what it did. I had talked with Van Vleck, should the lines split up at all? The lire looked to me a little broader than it should be. At half atmospheric pressure, should it split up? No, he assured me, no, there was no reason it would split up. So I went ahead and tried it out. Now, of course it did split up. By then I had found a paper, a theory by Dennison, showing why it split up, due to the different rotational modes. But Dennison's theory was off about an order of magnitude. The splitting should have been ten times less than it was. And so I sort of redid the theory: basically the calculations, the complex calculation -- a numerical calculation -- was wrong, numerically wrong. My recalculation turned out to fit, however -- So, I wrote a paper, a letter to the editor. I guess I did that before I had worked out the new theory. I had the lines, and it got through the patent department of Bell laboratories after a certain delay. I remember very well, I had it in my mail box addressed to the PHYSICAL REVIEW, and then it came, in the mail, a copy of something from Bleaney. It may have been NATURE or it may have been a preprint, I'm not certain, but it came in from Bleaney and he had the lines resolved. He’d pumped it down to about a millimeter or so pressure, and they'd been resolved. So I pulled it back out of the mail box, and said, “Well, Bleaney has done it already --” Although I had swept all the lines and made them much narrower. But I pulled it out of the mail box -- “Well there’s no point sending in the letter now.” So, I did a more thorough job and then I worked out the theory and so on, wrote a paper on it, sent it out. At that time, it looked very difficult to do anything else. In fact, I remember some of my colleagues saying, ''Well, that's all right with ammonia, but there's nothing else that strong.”
A unique molecule -- that’s right, there’s nothing else that strong so the --
-- spectroscopy isn’t going to go any further. Hence, finding the next line, which I guess was water, was a real boost. Then after that a few more molecules came along. At the same time, along about that time, Good had also resolved these lines at Westinghouse, so really there were three independent places. But Bleaney certainly had done it first, and I've always felt he should have had a Nobel Prize for that. I think the problem was, he didn't follow up the work as vigorously as he might have. I know the Nobel Committee was around a few years later. I was still active in microwave spectroscopy, and I remember the Nobel Committee was around and was investigating this, and Rabi told me they were quite interested in this, they wanted to ask about it some. I told them Bleaney did it first. So nothing ever happened. I think they should have given it to Bleaney really. But no prize was ever given and I think simply because Bleaney didn't vigorous follow up the field.
Essentially to get microwave spectroscopy started, is what you have in mind.
Yes. That's right. That's right, yeah. But I think that Bell Labs may in a sense have robbed me of a Nobel Prize for microwave spectroscopy by delaying six months. I don’t feel bitterly about it, I was disappointed at the time. On the other hand it’s just one of the accidents of physics that way you know, sometimes you’re ahead and sometimes you’re ahead and sometimes you’re not quite ahead.
It's hard -- we can philosophize over the practices of patent departments and industry versus -- but we'd better not get into that too much. It did put in a delay.
It put in a delay. But that work clearly grew out of the wartime work that I did.
And also (crosstalk)
-- that's right, the work that I did -- see, I didn't find engineering really objectionable. It just wasn't the thing that I wanted most to do. I didn't find it as stimulating somehow. Yet I learned a great deal from it, and I am very much indebted to it, for learning electronics, microwaves and so on, and certainly my work in microwave spectroscopy grew out of that. And I guess my work in masers and lasers and so on in a sense grew out of that too, because I wouldn't have been as aware of oscillators and amplification and so on as I was otherwise, having worked in Bell Telephone Laboratories.
Speaking of it being engineering work that they got you into, at the same time, there were research aspects to it that were very important. What would you say in terms of time, how much you spent in research, how much you spent in other things at this period at Bell Labs?
Well, during the war, for about five years there, plus or minus six months or so, I haven't counted exactly, I was simply doing design engineering.
And it was instructive and useful, and I talked to a lot of interesting people. I learned a lot. I was close associated with Sid Darlington, whom I enjoyed very much. He was full of ideas. And with Hendrick Bode and learned about general theory of circuitry, and it was all interesting, in a sense, but it was designing useful things. That's what I did. And I tested them. So considered there was no research in physics. It might be considered engineering research. We were pushing the boundaries of engineering. It was some of the first extensive analogue computers. But we didn't invent the analogue computer. I suppose at Bell Laboratories that was invented by Lovell, in the sense that he was the first to use potentiometers in that particular way, although the details of more distant history, I don’t know. We were simply following up his work and applying it in this way, but many new techniques have to be worked out, and we did a certain amount of invention, I would say, innovation, but nothing that I would call research, excepting this work that I did on the side on Jansky’s thing. And then after I got started, microwave spectroscopy, that of course was research.
How about the hours and the work schedule? What were they like?
Well, I almost always worked Saturdays or at least Saturday mornings, and I would work some at night. Bell Telephone Laboratories normally was a 9 to 5 operation, -- however, it was a kind of a standing joke among the physicists there, of which there was some modest number, well, the good people are the ones who come in Saturdays. We made a certain point of that. You know, we were there to do interesting things, and that was when we did them.
That happened both during the research phase and the engineering, or only during the --?
-- no, during the engineering, we worked Saturdays, but with pay. It was wartime work. Everything was hurry up. We worked Saturdays, worked nights, when necessary, but that was with some overtime pay. Otherwise it was without overtime pay -- I'm talking about immediately after the war: it was without any pay and even the Bell Laboratories was a little bit hard to get into, and the stockrooms were closed and the library was closed and so on, on Saturdays, and you couldn't get in at night at all, but on Saturdays in the morning you could. But things were pretty closed up. But I would say, there would be a dozen people about in the labs who would work extra that way, at that time.
Well, it's a sort of a split job here, and I would think we'd move over toward the research aspect of it, because it's a scientific career that we are thinking about. So, with whom did you associate then, when you were now over to the scientific part of it? Who was your department head?
Well, my department head was Stan Morgan, a physical chemist and an excellent department head. He didn’t know too much about the electronics part of what I was doing, but he was an understanding kind of a boss. His boss was Jim Fisk then, and Jim was OK, although he eventually made some decisions that I think turned out not to be wise, not that they were particularly his fault, but he was generally reasonably helpful, I guess. Stan Morgan, I have a very warm spot for Stan. Stan was always helpful and would do anything he could, and quite understanding as a research manager. Then I had a technical assistant, and I saw also a good deal of Alan Holden, who was a chemist, and he helped make molecules and talked with me, and he was quite interested in microwave work. He didn't do it himself but urged me on, also helped invent molecules and things to look at. Those were my close associates. Then eventually, John Bardeen, whom I called in to ask for some theoretical help, and John was very helpful. He thought it was an interesting theoretical problem and he worked on some of it. I saw a moderate amount of the solid state physicist, people like Bill Shockley but we never worked together at that point. We discussed Pauling’s book, other things, some general course work that we did together. Conyers Herring, Ed White, Foster Nix, most of the better physicists and physical chemists, I saw a moderate amount of at that time, but Alan Holden was my closest associate, and was very helpful.
These people who were helping you there, they were all from the United States? Were there people from abroad in the Bell Labs, people who had come, European scientists?
Well, let me see. These were all from the United States. I did have one British visitor who came on a British Fellowship, Commonwealth Fellowship I believe, and applied to work at Bell Telephone laboratories with me, although his work was somewhat different. This is David Whiffen. He worked with me for a year, possibly more, maybe two years. He was doing dielectric relaxation work. He had worked with Thompson on dielectric relaxation, and he thought, Bell Laboratories has microwave techniques, and this would be a good place to go, and eventually wound up working with me. But the people directly in Bell Labs were, all that member were American citizens. I don't -- oh well, let's see, there was a Swiss guy, Wannier, Gregory Wannier I saw something of. He was at Bell Telephone Laboratories at that time am a good friend of mine. He's the only exception I think of.
Things were essentially -- well, I have here in my notes something that asks whether the people trained abroad may have had a particular effect on the research, and perhaps… OK, so, we were just getting into things going on in your first job, and talking about your associates, and I think you had in fact already covered the fact that there were some -- not too many visitors or at least permanent visitors from abroad. On the other hand -- and you had mentioned that there was a seminar I believe at Bell Labs that was useful.
Yes. That was a very valuable seminar. I think everyone there -- it was unique to the organization at that time. There were about a dozen people or so. I think I mentioned some of them, Jim Fisk, Bill Baker, many people who became leaders in the laboratory and scientifically prominent. Walter Brattain was another one in that group. A very enjoyable group of people and I took it seriously and learned a great deal.
Did you also have, was that where you exchanged your ideas?
Wait a minute -- I said Bill Baker was in that group. I think he was not. Correction. He was one that wasn't.
Is it in that seminar where you exchanged ideas about research, or did you have other places for that?
It was really kind of an advanced discussion of various topics. I mentioned that we went through Pauling's book rather carefully. But we discussed research papers and so on. It wasn't so much that we talked with each other about research ideas. Of course, if one of us had done something, it was likely to be discussed. It was rather more an advanced seminar for learning about a field mutually and with good people. We got very substantial and useful discussion.
Did you have much after hours socializing as well?
Oh, a moderate amount, yes. Those were my friends and I saw a moderate amount of them here and there socially. I guess among my social contacts, those are the people that I saw most and enjoyed most because we had mutual interests, and they were mostly younger people who were fairly recently married, as I was.
Did you stray off of science into politics, philosophy, things of that sort?
Not in the seminar usually. But in other ways, of course. We did various things together. I remember Bill Shockley was very interested, somewhere along in there, I guess it was a little later, during the war, he was very interested in rock climbing, and he took me on a few rock climbing expeditions. We did various things together. I wouldn't say, though, that it was a great intellectual life, other than in science and engineering. I knew -- some of the engineers I enjoyed too. I had some close friends among the engineers.
Comparing your work at Bell with your work as a graduate student at Cal Tech, did you, particularly in the early years, did you -- how did those two things compare?
Well, Cal Tech was a much richer environment, intellectually and scientifically, and I enjoyed it more, even though I was of course much better paid at Bell Telephone Laboratories. It was a completely different environment. It was sort of a 9 to 5 work day for most of the people, and not nearly as rich an environment in terms of people interested in ideas. People were designing things and doing things, many of them necessary jobs. On the other hand, it was reasonably enjoyable, but I remember, for a while there, thinking, well, graduate school at Cal Tech were the best years of my life, but that lasted only a while. After I got back to science, then I enjoyed it pretty well again. After I got back to the university I enjoyed it still more.
It was in 1948 I guess that you left Bell Labs for Columbia. And how did you learn of that position? What motivated you to make the shift?
Well, basically I made the shift for two reasons. One, I always wanted and expected to be in a university. It was a kind of intellectual environment that I had wanted, and I was rather broadly interested in things in addition to science, wanted to be able to talk with people in a variety of other fields. The other reason was because the specific science that I was doing was s imply not very richly represented nor terribly interesting to the Bell Telephone Laboratories. They were quite generous with me in allowing me to do it. I had written a sales pitch to them, explaining why I thought it was important for the company to do this and it might be important for communications in the long run. They accepted that, and I worked on microwave spectroscopy. I think they were pleased about the work that I was doing, in the sense that it was good scientific work in their view and brought some credit to the laboratory, and I wanted, however, to expand the work. I had one assistant. They gave me a second technical assistant. These are people trained about at the high school level, and with some technical training beyond that, and I urged them to appoint another person in the field on regular staff. But after a little consideration, the answer came back, no, they didn't want to do that. They thought it was not of adequate interest to Bell Telephone Laboratories, that they were quite content for me to continue, as long as the work was fruitful scientifically I could continue, but they wouldn't want to expand it. I think I mentioned earlier that Jim Fisk was involved in a decision which I felt at the time was a mistake. I think basically this was Fisk's decision, although it was relayed to me through Stan Morgan, who was my immediate boss. And it's an interesting decision because, as I have written one or two places, I would not blame the Bell Telephone Laboratories for that. It's very difficult to foresee what kind of research is going to be fruitful. I thought I could foresee that this would be fruitful to them, and I think I had some good reasons for it. On the other hand, if you look at the other industrial laboratories around, they’re all doing the same thing. Hershberger at RCA as kind of closed down. There were some other problems there, but his work was closed down. I know at General Electric that Sharbaugh who was a friend of mine, doing microwave spectroscopy, he lamented to me that he was simply told that he had to do something else, that this was not useful to the company, that he should be measuring dielectric constants of Solids, and that -- at Westinghouse the same thing was true. There was a good effort there started by Good and going along very well, and then it was sort of closed down, and Good I think himself transferred, and Coles, who was a Cal Tech student I had known there, continued with it some, but he told me that they were more or less closing it out. So it was a universally made decision by industrial companies of that time. Clearly in retrospect a mistake. I think it was somewhat foreseeably a mistake, but then I was an enthusiast mistake, and people who weren’t didn’t see it that way.
History proved you were right, but looking at it --
One can’t blame them for the decision, let me say. Except in general I think it was a narrow minded decision in general, as many of these decisions are. People stick too close to what they think is appropriate. That pretty well made me decide to look for a university position, which I probably would have taken if it had been offered to me anyhow. But I began to inquire around activity. This particular situation came up, amusingly. There was a kind of special meeting at Brookhaven National Laboratories on the question of how to measure nuclear spin. Brookhaven of course was in the nuclear energy field, and interested in nuclear things, and by then microwave spectroscopy had done some nuclear spin and quadrupole moment work, and I had done some of that, particularly with chlorine and bromine by then. And I had also proposed the idea of how to determine what is known as little of the coupling constant within the molecule, and so I was invited to this conference, how to measure spins, particularly in the sense of radioactive nuclei, and a number of people gave talks, and I gave my talk -- Rabi was there naturally. He had measured a number of spins, and molecular beam work was very prominently thought of as a possibility, and has in fact been very fruitful. I gave my talk, and discussed molecular structure and how one could interpret the coupling constants to get credible moments, and I remember very well Rabi got up after my talk and said, "Well, that's a very pretty picture you paint, but it has absolutely nothing to do with physical reality.” In his usual blunt way. We talked about it some. I said, ''Well, what are our objections? Let's name them, one, two, three, four,” and we talked about it a bit. But Rabi, in spite of his gruffness at the time, obviously looked at the work I was doing a little more kindly, because we went off to the beach to go swimming, and while we were out there, he asked if I would like to come to Columbia, and offered me a job, which I then of course thought about quite seriously and eventually took. I wanted however to finish up some work at Bell Telephone Laboratories. I guess it was during the summer that I had agreed to go, but I stayed at Bell Telephone Laboratories until the end of the year in order to finish up some projects there, and to move efficiently then over to Columbia. I got to Columbia January 1st, ‘48
It was basically a combination of more freedom of research and perhaps the desire to teach also?
Yes. It was environment that I wanted, teaching --
-- more contact with graduate students --
Yes. Yes. And contact with a wider circle of physicists interested in things that I was interested in. There was a strong solid state group at Bell Telephone Laboratories. I was not specifically interested in solid state. I was more interested in atoms, molecules, nuclei and things that I considered a little more fundamental. Now, Columbia University also had worked on magnetrons during the war due to Rabi in part who had been up at the MIT Radiation Laboratory. They had a lot of microwave equipment in the K band region and the X band region. Lamb was there, and Kusch and Rabi, and then a substantial staff of other people and students, and they had a lot of equipment. They were eager to see that it was used well, and this was why they wanted me to come. And I was glad to come because they had all of this equipment so that I could get started very fast, and I even got things a bit started there before I myself moved, and so it was very efficient. Since microwave spectroscopy was developing rapidly, I wanted of course to get going again very quickly at Columbia, which I was able to do.
They had actually more appropriate equipment for the field you were interested in than Bell Labs had?
No, I wouldn't say more. A comparable amount. Both places were well equipped with surplus war materials.
Any difference in the pressure to do research at the university compared to the industrial laboratory?
Well, I never felt external pressures to do research, from my associates, but on the other hand, the climate of research was quite different. People at Columbia, the professors at Columbia were in fact working longer hours than the ones at Bell Telephone Laboratories. The place was open all the time, and the interests were different and more actively oriented personally towards research. So far as pressure is concerned, I never particularly felt pressure, except the general idea that, if I did a good job, why, the management and my associates might appreciate it, but never any specific pressure. It was rather a change of atmosphere, a change of working habits and so on. I remember also that Rabi told me rather jokingly that he had inquired about what I was doing at the laboratory and found I was working Saturdays, and he said that was one of the things that made him decide. Well, that was a somewhat common saying among physicists at the time too, that those were the people who were interested.
Besides the specific of greater encouragement of spectroscopy, were there other specialties that were encouraged, and did they have any effect on your further choice of research actions?
Well, there was some pressure within the radiation laboratory which I had joined to work on magnetrons, or something associated with it, because it was considered the bread and butter job. It was the Joint Services Laboratory. It made magnetrons during the war. The idea was to push magnetrons down to shorter wavelengths. I was not at all interested in that. It seemed like a pure engineering design problem, and I generally avoided that -- I think maybe a little bit to the annoyance of some of the other people around. But what pressure there was to look for something in which I could contribute to the applied job of the laboratory. But not wanting to do that, I wasn’t heavily pressured to do it, and so I entered into molecular work, of course nuclear also in connection with the molecular work. And I think it was reasonably appreciated, although the strongest interest there was in atoms, nuclei what was considered somewhat cleaner physics than molecular physics.
What courses did you teach?
Well, I taught optics, advanced optics, that was one of my favorite courses. And atomic physics, the general atomic physics course for graduate students, and I enjoyed that. I taught mechanics at one time. I made a point of not teaching any course more than three years in succession. So I rotated around several courses.
Any particular books important to you at that time?
Well, Born’s book on advanced optics was I guess the one from which I learned some things. Atomic physics was interesting but I didn’t really learn anything from it. They were things that I more or less knew. Born’s book was advanced enough that there were some new things in it. As I taught it I learned things. On the other hand, teaching I regard as very important in learning things, understanding things thoroughly. It doesn't necessarily depend on the book.
How about students, should we discuss some of them, relationships you may have had with them?
OK. Well, when I came in there were two or three students that were sort of assigned to me, Stan Geschwind, Cal Rusinow were definitely assigned to work with me. They were already there. And then, Irving Weingarten was Lamb's student, but I was told, maybe I would be interested in talking with him and following his work, because he was doing absorption of microwaves by water vapor, and I hence got going on building a spectrometer. Rusinow later dropped out. He was a nice guy, not really a strong student, and Geschwind finished after a while. My first new student after I got there was Willie Low, who is now in Jerusalem. Willie Low was a hard working student and did a lot of work fast. He was my first PhD. I personally built the apparatus and how it would go together, and I fixed the leaks and did everything with the electronics, with the students helping me. That's rather different from the way I have to work now. Mostly they are the ones who know the apparatus, and I stand around and talk with them. But at that time I was doing essentially all the work first hand. Then I interacted a good deal with the chemistry department, which I was glad to do. I needed some chemical help and advice, and Benjamin Dailey was either there when I arrived or came shortly afterwards. He was doing microwave spectroscopy, and pretty soon, in the chemistry department, and Ralph Halford was another chemist, another person -- George (???) theoretical chemist, whom I saw a good deal of. So with Kusch, Rabi, Lamb, Kroll, was an advanced students initially there, but I saw a great deal of Kroll. He and I talked a good deal socially also particularly at the Faculty Club. Physicists, mathematicians and the lawyers typically had associations with each other at the Faculty Club.
Interesting to find the lawyers part of that group. But then you had lawyers in your background.
Well, that's true. That's true. But I think there was some affinity between the lawyers and the physicists. I think actually the thinking is not all that different, between science and law. But the physics table at the Faculty Club I considered very both interesting and important, in that, well, there were a lot of comments about politics and smart aleck remarks and cracks and so on -- still, there was a good deal of freewheeling discussion of physics and what was being done and what was important, and I think that the Faculty Club had an important influence on Columbia.
How about thesis topics? Did you have any important thesis topics at that time?
Well, I was already going into microwave spectroscopy and trying to do more molecules and more nuclei, and it was pretty straightforward, as to what to try to do. So my research was in full swing, and it was just a transfer of location from one place to the other. But I was interested in all aspects of microwave spectroscopy at that time. Gradually looking into new ways of generating microwaves, particularly short microwaves. It was obvious that the shorter microwaves were going to be better for microwave spectroscopy if they could be controlled and handled well. So I from time to time worked on various projects for shorter microwaves. I suppose also feeling that that was a replacement for working on magnetrons, the bread and butter thing that I didn’t find particularly interesting. So I did generation by Cherenkov radiation for example, various other schemes that I looked into, not many of which I carried very far, because I didn't see all that much promise in most of them. I did do some work on harmonica generation, using the shortest wave magnetrons that they'd produced there, but those weren't really terribly satisfactory sources. Then I worked on a variety of new kinds of spectroscopy, many of which are in my book.
So, let me see -- at this point, how much time did you spend in research compared to teaching? Did you do any administration at all?
Well, I taught about two courses, or I guess maybe one course one semester, two courses the second semester or something like that. Then otherwise I spent almost a hundred percent of my time doing research. After some two years, I was doing administrative work in the Radiation Laboratory. Rabi was officially head but never really bothered and I was the actual head. I've forgotten just what my title was running the Radiation Lab. That was not a heavy load, however. A small group of people and it was not a very heavy load. Eventually in 1952, I guess '52 to '55, I became head of the department, and that was rather more of an administrative lead. But other than that I didn't do very much administration. I tried to strictly avoid it, and various committee meetings and things, although I did get caught up in a few committees, including one committee for the Navy that has some connection with the maser and we can talk about that in time.
OK. I have rather what looks to me like a strange question here, but is there such a thing as a typical work week, that you could reconstruct?
Well, let's see. I was working most of the time, and except Sunday; I never worked Sunday, partly because I'm religiously oriented and partly also because I think there are good reasons for not working every day of the week. I never worked Sunday. But otherwise I worked all day, starting in about 8 o'clock in the morning and going into the evening. I lived nearby to Columbia. But I also gave some time to my family. My wife and I had more or less an agreement that I would work in the laboratory two nights a week but not more, after a while. So that was about my schedule. I worked all day and then I worked two nights in the laboratory, and otherwise I was home, although I might be doing some work at home.
OK, that's a strong work week. Did your colleagues do the same thing?
Some did. Some did, yes. I don't think I was very unusual. Maybe I worked a little harder than some, than the average, but I don't think I was very unusual in that respect.
I think you probably have already run through the people that you associated with most at that time. And let me see -- ultimately you were the department head. When you came in, Rabi was?
You commented somewhat I guess on his style as a leader, that he didn't go too much into administration. Have you any other comments about his style as a leader?
Well, he was not doing administration in the Radiation Laboratory, because basically it was too much trouble. And that could be delegated. As chairman of the department, he was active in administration and certainly active in making more important decisions and I considered him a rather good department chairman, effective and adequately active. Rabi of course is most noted for supposedly being able to pick out what is good physics, and for having ideas in physics, and also picking out good physicists. And I think, by and large, he did pretty well there. I could name a few mistakes, but on the other hand, I think he did pretty well, and had generally good taste. He was very much against solid state physics, for a long time, thought it didn't really belong in the department, wasn't good physics, and there's some reasonable arguments about that. I think he also didn't particularly like molecular physics, and some of the things I was doing, he thought were pretty trivial or not interesting for physics itself -- maybe chemistry. But then, he never really looked into molecular physics enough to appreciate it. In fact, I had this longstanding argument with him about little Q. He never believed it was a -- it was serious, about little Q, except maybe long, long afterwards. He would frequently want to try to argue about it, and I finally just gave up. There was no point in talking with him. On the other hand, he was very stimulating to talk with about most other things, and was always challenging. I think I seldom agreed with him, or he with me, but on the other hand, we had a bit of a friendly relationship, in terms of being able to talk about most physics in a very useful way, and… Rabi was an interesting person. As I say, I considered him a very useful, a real statesman, in a sense, and yet very petty in some ways, and this little q business, he would just never try hard enough to understand, but always disagreed with me strongly. He was a difficult person, and yet I enjoyed him, and I think he helped create an atmosphere in the department that was very important in physics. There were some tensions in the department. Dunning was there at the time, and Dunning and Rabi didn't see eye to eye at all. They were very different personalities. Dunning eventually moved over into dean of engineering. But the department was small, in a sense pretty well integrated, except for Dunning, but on the other hand, there was a kind of a sense of tension, in addition, more or less friendly tension, and after Rabi moved out as chairman, he was still a person one always had to deal with. It was difficult to do anything in the department that Rabi didn't approve of. As I said, this was disadvantageous, and yet much of his influence I considered very good, and I always felt that, while he could be petty, that his judgment was fickle at times, and yet when it came to something really important for the department, that he was almost always on the right side. He was dedicated to the department and to physics and almost always on the right side. There were a few times where his judgment of people clearly was wrong, and I think the only time that I was chairman, the only time that I overrode Rabi, which I was very slow to do, was in the appointment of T. D. Lee. And Rabi did not want T.D. Lee to be appointed, for reasons which I may be understood but they were somewhat peculiar, and he was very much against it. Every other member of the department was very much for it, so I decided we would go ahead. T.D. had been there only a few months, and Rabi came around, which is not common for him, and said, "Well, you were right." So that is the kind of -- that is where he stood. On the really important things, he was statesmanlike.
Have you a way to compare his leadership with that at Bell Labs? The environments of course are quite different and the objectives of the places.
Well, at Bell Labs, there was no strong scientific individual anywhere. The management at Bell Labs was a management, not a scientific stimulus or leadership. And my own boss had been really somebody to see that things went smoothly. He’d been a good scientist, but at the time he was making no real scientific contribution. There were a few stimulating people around, like Bardeen and Shockley and some others, but they weren’t in the line of comma and for me, at least, and were just people that I would talk with occasionally, and they -- in no sense were they characterizing the scientific work of the laboratory. They were doing their own work.
You commented on some of the individuals in the department. I suppose you already covered the ones that were outstanding. Do you have any further comments, like those from abroad, experimentalists vs. theoreticians, any more to say about the department or do you think you've covered that pretty much?
Well, at Columbia there were a number of foreign visitors who came and went, and that were important. I invited Bleaney to come over, for example, spend a year at Columbia, which he did, and I enjoyed his association, and there were lots of lecturers that came in, invited in for colloquia and so on. So the contacts with foreign scientists were rather more plentiful there, and with scientists around the country too, for that matter. There was a much more open kind of scientific atmosphere, and of course New York was a little easier to get to than New Jersey, so I saw a lot of visitors, and we generally made a point of trying to get interesting people to come to give talks.
Was there any particular, not administration or not I think university politics, but politics in a general sense? Was it a big subject at Columbia?
No. Columbia for a long time had the advantage; I suppose one might call it, of not having a strong president. Nicholas Murray Butler was very inactive in his later years, and he was there when I came in, and one never saw him. He was blind and not very well. And then Eisenhower came in, with a gap in there with Fackenthal who was really Butler's secretary, and he ran things, sort of on a temporary basis. Eisenhower came in and he was just learning the job when he disappeared again. Then we had Grayson Kirk, who I don't think was a very strong president. Kirk is a nice man but not a very strong president. And the result was that the university was not well integrated, but those departments which knew what to do and could get outside support could go ahead on their own and create their own existence and future, and the physics department was one of those which knew what to do. Departments which were weak then stayed weak. There was simply very little administration, and the thing that I regretted, there was relatively little interaction between departments, except for certain specific cases, like physics and mathematics, and I myself interacting with chemists. But there was not very much of a campus life really. I made a point of trying to create some, with various techniques but by and large Columbia was just not that kind of campus. And there's relatively little campus politics, in that sense.
Coming back to the seminar, I believe you probably covered it by saying you had lots of visitors. Anyone or two in particular? Bleaney was here for a year or so. Or were there just so many, in with New York in its central location?
Well, there were lots of them. There were lots of them, and I attended colloquia seminars, very actively, and made a point of trying to keep up with a wide variety of physics at that time. I suppose, I think of somebody in particular that had an influence on us, had a by chance influence but an important influence on what I was going to do, was Paul, who came by, and simply talked a little bit just informally with me, am I read his papers on focusing a very high intensity beam, which sort of seemed interesting. I was of course getting familiar with molecular beam work, because it was all around me, and I wasn’t doing any, but had this way of quadrupole focusing, and using a very high intensity beam, which simply struck me as intellectually kind of interesting, and that then turned up later in the maser. Now, I don’t think of any other sort of specific event from which I obtained a useful idea. I’m sure there were some. Fermi was -- taught, talked there. I remember some of his talks well saw something of Fermi out at the Brookhaven National Laboratory. I have an enormous admiration for Fermi, both as a person and as a scientist, and then, out at Brookhaven, I also saw a wide variety of other people -- Norman Ramsey, I saw a moderate amount of, from time to time, and he was always full of ideas, and enthusiastic talk. But if you ask, was there someone or a few people who influenced me particularly, I couldn’t pick out anyone.
OK. And where and how did the staff exchange research ideas, any particular thing?
Well, we had colloquia in which people presented what they were doing, along with inviting other people in. I myself ran a little seminar, largely with the chemists, but I tried to get the physicists involved too; Kusch and Lamb in particular from time to time would talk about their work, in the seminar. It was basically a microwave spectroscopy seminar, but all related areas were included. Other groups had other small seminars. We also had a theoretical seminar, run by some of the theorists, I guess Bob Serber -- they got Bob there, I think while I was chairman, and he was an important addition, particularly in maintaining a little more theoretical interaction within the department. He ran a theoretical seminar. I suppose I might as well mention a couple of others. Hans Bethe was there for one year, and I remember his theoretical seminars, and I attended his sort of series of somewhat specialized lectures. Yukawa was there and I attended his lectures, which I got a little bit out of, but Yukawa was not a notably good lecturer. He didn't know English all that well. But everybody was eager to hear what he had to say, and Yukawa had a permanent appointment at Columbia somewhat later, following a visit for a year. I also saw a moderate amount of Aage Bohr, whom I liked very much. So those were a few other people that were around, I remember well, I learned things from, but I wouldn’t be able to pick out anything that I used especially.
Was there much after hours socializing?
A moderate amount. A moderate amount. But my own social contacts were partly there and partly also through some of my wife's…[missing page]… friends, and people we knew at the church. We were attending Riverside Church and had young children at the time that brought us into church circles a good deal, and so, I shared activities with members of the department but also with a variety of other people. People interested in languages. Some people around International House where my wife had worked earlier. We had moderately -- and some of the people near where I lived. I eventually moved up to Spuyten Duyvil which was a short drive from Columbia but a completely different group of people, and we knew some of the people up there.
Is there any more you would have to say in comparing things at Columbia and Bell, or have we covered that pretty well?
I think we've covered that. I was enormously more satisfied. I was not dissatisfied after the war at Bell Telephone Laboratories, after I'd been able to get going on research, nor was I dissatisfied when I first came there. I would say, during the war, I was not unhappy, I simply knew perfectly well that I didn't want to continue to do that kind of thing. In fact Dean Wooldridge and I used to talk about it, how we'd get back to physics as soon as the war was over. Dean Wooldridge got back to physics about one year, and then he really turned to big management and engineering difficult to believe, after our conversations, but -- Then I was reasonably happy at Bell Labs, but there was no doubt that I would prefer a university atmosphere, and I was glad to be at Columbia. My only regret was, I would have liked a better integrated campus, not a big city campus quite so much. But the opportunity to come to Columbia -- and I was invited to go to Berkeley a couple of years after I got to Columbia. Berkeley had always been one of my favorite places. But I felt it was too inefficient for me to move at that point, so I decided not to go there. And that indicates of course that I was reasonably well satisfied at Columbia. It's hard to find a place that's much better, except possibly in terms of physical environment.
I know in the late fifties you consulted for Bell Labs. Did you also consult for them in your early years at Columbia?
No, I didn't. I was very busy Just minding my business at Columbia. I got involved a little bit with a few committees in Washington. I became a consultant at IBM. IBM Watson Laboratories -- their laboratory was right next to Columbia, and they wanted me to consult and do some things there, and I did; after the maser came along, they wanted to tryout the maser, and they did a relativity experiment there. So I was consulting for IBM, and after a while Bell Laboratories asked me if I wouldn't consult for them too, which I then did in a very loose kind of way. But that was fairly late.
How do you value the consulting experience?
Well, in how it was I found it useful. They were exceedingly generous in how it was run. Sid Millman had it setup. I first told him, no. I didn't think I could consult with them because I was consulting for IBM. There might be some conflict of interest, and Sid said, "Well, we would fix it so it wouldn't be inconvenient, and we would leave it to you to decide on where the proper credits and interest should be. Just consult with us whenever you feel like it. We’ll pay you and you can work at your desk, come around and talk with people at Bell Labs whenever you can, and just do whatever you want," and I checked with IBM to see if they felt it was a conflict of interest and they said, no, they thought that was all right. I would of course sign patent agreements for anything done on consulting time with both parties, and they agreed, it was up to me to decide whom I was working for, when. So it was a very loose kind of agreement, and I enjoyed it because it gave me a good reason and opportunity for talking with scientists in both places, and there were very good scientists in both places that it was a pleasure to talk with and see what they were doing. And I guess they felt it was useful for me to interact with them. So the consulting -- it was not a specific job in either case.
Well, coming now to your invention of the maser. I know that in your '64 Nobel Prize lecture, your earliest reference to your own work is in 1951. Can you trace the inception of this work in your own mind?
Yes, I think so. I think so. I've written this, but let me just go through it quickly again at least. I'd been interested for some time in producing shorter microwaves, as most people in microwave spectroscopy were, but I was looking for good ways of doing it, and I was asked, partly for that reason, by the Navy to form a committee to advise them on millimeter wave research. They had the idea at the time that millimeter waves might be useful, for some of the reason they are thought to be useful now. And they would like to sponsor work for generating millimeter waves or handling them, but especially generating them, and would I form a committee? Which I did then, putting together a combination of engineers and physicists around the country, people that I knew and they knew something about too. It was a very fine group of people, various types of physics that might possibly bear on the subject. For a couple of years, we reviewed various proposals, including some proposals of my own. We talked about proposals of various other members of the committee, proposals from all over the country. I’ve tried to encourage things that might lead in the right direction. None of them were particularly good. There were some that were innovative, and weren't very good, and others that weren’t very innovative that were just hard work in extending the present techniques. I think the only possibly interesting one which I generated and discussed with the committee, that I wasn't already doing, was use of very sharp electron spin resonances, as circuit elements for delaying a wave, and thereby allowing interaction with beams of microwaves. And that I felt has some interest, but then I decided it really didn't work well enough to try to do anything about. I was working on Cherenkov radiation at that time as a way of generating short waves, which it can do, but it didn't work terribly well. And after having combed over all of these things for, I suppose it must have been a year and a half, and we were meeting maybe four times a year, and it just seemed to me there wasn't anything that really looked awfully good. I had gone down to Washington at the time of a Physical Society meeting, in the spring, but we were going to have a meeting of our committee, and partly to save money, I was rooming low with Art Schawlow, in the Franklin Park Hotel, as I remember. Art had been working with me by then. I got up, early in the morning. In order not to disturb him, I went out in the park and looked around. A nice fresh morning. The azaleas were blooming. I sat down and tried to get myself organized for the coming meeting -- I had to think over, now, what kinds of things should we say, in order to really size up the situation, and why was it we hadn't really run into anything that was good. And summarizing it to myself, I went over the problem that one needed to produce very small structures, in order to get resonators. That these small structures had to be activated with electron beams, and there's a lot of power dissipation, and you just couldn't get that much power into most of them, with the given size that they had, and dissipate that much power. That basically was the problem, and we had to find some way of making resonators both accurate enough and so, also so that this interaction of electrons was feasible. At that point, I realized, well, there were natural resonators, and I'd already been thinking about spin resonators as a possible resonance circuit, the natural resonators really were molecules. Yet molecules, I had told myself before, could never generate anything above black body radiation. And suddenly I realized, that really isn't true. After all, they don't have to be in thermodynamic equilibrium. They could, populations could be inverted, and they can amplify, and -- well, but then how do you interact with them? I thought of Paul’s work, in sending a molecule through a cavity and I thought of work, in sending a molecule through the cavity, separating states and through the cavity and you had an ideal system, and it didn't take very long to calculate, I remembered the numbers quite well, as to how much, about how many molecules Paul could get, and -- well, I could calculate pretty readily that, yes, it could just about work. That was, say, that was in the spring of '51. I didn't talk about it at the meeting because I thought, well, it’s still kind of a wild idea, and while it looks good to me, I ought to think about it some more before talking with a group about it. I had already talked with them about these spin resonances, and that didn't pan out very well. So we talked about normal business, and I went home, and with-in a couple of days or so, wrote it down in my notebook. And I had Art Schawlow read it over, as a patent witness, and I talked with people in the lab about it, including Nethercot who was a postdoctoral person at that time -- with me, and I felt it would probably work, but it was marginal, as to whether one could get enough molecules to put it over the oscillation boundary. Now, there are, there's a lot of interesting and I think important prior background to this, that I can come to. But I more or less laid it aside at that time, thinking, well, it's marginal but it would be interesting, and if I find a good student and I have a little more time, I'll give it a try. In the meantime Nethercot had gone to some meeting in Illinois where millimeter waves were being discussed. And the time came for – the chairman said, “Well, let's just talk about ideas, anybody else wants to present?” and Nethercot then talked about this idea.
I don't think you wrote that in your article, at least I didn't --
I perhaps didn't. I perhaps didn't. But he came back and said, “Well, I talked about this to the group, I hope it's all right." I said, "Sure it's all right, its fine." That I think was the first time it was publicly presented. When there became some reason to look into the patentability and the early records on this, I talked with Nethercot about it -- just what had he done and when had he done it? And I was sent some transcript of that meeting. It did not have Nethercot’s remarks in it, because, they told me, those were sort of informal remarks right at the last of the meeting and they didn’t record those, so there is no permanent record of that. Now, it was the next fall when I actually started to do more serious work on this, and I could pick up from there, but there are some other thing's that I'd like to comment on, about the general background of the ideas there. I suspect this is the kind of thing that may be important to anybody studying the situation, is where the ideas came from, how far along the ideas were and so on. I think it's important to note really how difficult it is to tell in physics what's obvious and what isn't obvious. The problem with science is, once you understand something, it's obvious. If you don't understand it, then you don't understand it at all. And I find myself continually in difficulty on that regard, with respect to who had what ideas and, first -- Many ideas which were around and seemed quite obvious, suddenly somebody would have and then think they'd discovered it. I believe one can sort those out to a certain extent, but it's not easy. For example, just the general idea of amplification by stimulated emission. Some people who have that idea, that you can do that, think that they've discovered the maser, say. That was a very common idea among some people who were theoretically oriented, and in this kind of spectroscopy. As it turns out, the possibility of amplification, in the sense of power amplification but not coherent, had been mentioned many times in the past, which I didn't know about. But on the other hand, I had studied the theory well enough to know pretty much all about stimulated emission and had taught it in optics, and I had thought about doing an experiment to demonstrate stimulated emission, which had never been directly demonstrated, and I rigged up some kind of an experiment. I said, "Well, this could be written" -- give a little demonstration of stimulated emission -- I decided, well, it wasn't very spectacular. It wasn't really worthwhile doing. It wouldn't be an appropriate thesis problem just to demonstrate stimulated emission. I remember talking with Rabi about it at one point, and Rabi, had the sudden idea at one point to, how to shovel stimulated emission. No question, of course, he and I understood stimulated emission .But he had a certain idea how to do it. We talked about it for about five minutes. I said I'd thought about it some and thought I had a way but I'd decided really it wasn't quite interesting enough. And well, he thought he was interested for a while and then he decided, well, it wasn't -- it probably could be done, but it wasn't all that easy, and so he dropped the idea. I found another person working with Rabi, Trishka, who was probably quite unknown now, but he was -- I believe he was a post-doctoral person for a year with Rabi at that time. He had done his thesis there too. I had a talk with Trishka. Well, Trishka had had an idea how to do that with molecular beams, and I found later, had written it down at some length in his notebook -- how to show that there was stimulated emission. It was such an obvious thing for molecular beam work and even from resonators and so on. It turned out that Lamb had written basically this in a paper he wrote on the hydrogen atom, and one can find that in the record about 1950, I think, his publication, where he said, well, he was using separated atoms in the lower state, but if they’d been in the upper state, they would have done the other thing, and -- it was a casual remark. And hardly, you know hardly worth talking about particularly, but he just happened to mention that: well, it did this, but if it had been the other way around it would have done that, and I would have said, at least around Columbia and around Harvard and around people in microwave and radio spectroscopy there, it was a commonplace idea. Not that it was used, but rather that of course people understood that. There was also certainly by that time, there was the nice experiment at Harvard by Purcell, Ramsey and Pound. I think we’re all involved, in inverting the spins in a crystal. They put a crystal in a magnet, turned off the magnetic field, then they’d take the crystal out and wave it around, and the spin stayed. They could turn it upside down, put it back in the magnetic field, and they were inverted and they could show that they were inverted, and they turned the spins over. That was very pretty, and people talked about it from the theoretical point of view, and I don’t remember, as I said on the park bench, I don’t remember specifically thinking of that experiment. On the other hand, I certainly knew about it, and it may well have been in my mind. I just don’t happen to remember that specifically. I do remember thinking about Paul’s work, and Paul had been through, a few months before. Now, I remember also, a while, shortly after I had had the idea of how to make it useful, and I was absolutely not particularly interested in just demonstrating that it could exist, or even thinking that anybody would be surprised that it did exist, but rather I wanted to make an oscillator, and so the point was to get something that would produce energy. And of that, I was a little more doubtful, and I didn't, wasn't particularly interested in amplification initially, rather in oscillation, generation of waves, and amplification, I considered a kind of a secondary thing, after I got -- after Jim Gordon agreed to start work on this, I explained to him, I wasn't sure it would work. It was marginal. It was clever. Maybe he could make it work. But I thought he would get a thesis on it. Because if it couldn't oscillate, at least it would amplify some. I could not realize, at that time, that in order to get real amplification and a net gain in power, one had to also be able to make an oscillator. Those two things come together. One can demonstrate stimulated emission, amplification by the stimulated emission, but unless you get the circuit losses down sufficiently low, you can't get a net amplification, then, unless you can also make an oscillator. But my reasoning at the time was, well, if it won't oscillate, at least it will amplify, and Jim can get his thesis, and we'll get as close to oscillation as possible, and it was only after we got onto the work that I realized that real amplification required also oscillation. But the oscillation and the generation of energy and coherent nice energy and short wave lengths was the problem. In my original intent and in my notebook, I worked out the case for the first rotational transition of ammonia, down in the half millimeter range, because that was the frequency, the kind of frequency range that was interesting. But pretty soon I decided that well, millimeter wave techniques weren't very well worked out. Even detection of millimeter waves that wavelength, was kind of tricky. And it would be better to try it in the centimeter region, where we knew all the techniques and we had apparatus, try it there first, and then once we get it working, try to go on down in wavelength. Now, consider what things were new. I frequently have thought over that. I remember many of my conversations with people, and I think I have a pretty clear idea what really was new at that time. The new things were the things that people would argue with you about. Particularly sophisticated people like some of my friends at Columbia of course, just a new combination of things is considered new from the patent point of view, but I'm talking about science. Invention is on a slightly different kind of a plane -- although a gadget which does new physics is very important apparatus -- it may be an invention but it's also experimental apparatus, and that is what I was after. When I told Kusch, Rabi, Lamb, you know, the idea of doing this -- "Oh yes,” they said, “so it will take off and oscillate. Well, if you can make it work, that's very nice.” The theoretical ideas were obvious to them too. The combination, they hadn't particularly thought of. And they weren't at all certain that I could get enough molecules. This was many orders of magnitude more molecules than what they had ever worked with, using different kinds of beams, the thing, however, which I did have some arguments about, and with people that I respected, from the theoretical point of view, was the question of, whether it would really be monochromatic. And that was a little more tricky. The basic reason was that the physicists' approach was one from the uncertainty principle, so the molecules had a finite interaction time, and therefore, the band width had to be finite. And I had a fair number of arguments about that -- one I remember particularly with L. H. Thomas who is a fine theoretical physicist. I think he never believed it until it really oscillated. And he's a person I respect enormously from the theoretical point of view. I never sort of went through it step by step with him, but I talked with him many times, and he said he'd think about it, but he didn't believe it. I also had a bet with one of my younger colleagues, who was sort of a theoretician from Germany, Danos, and he insisted on betting me a bottle of scotch that it would not be narrow. So the coherence was the thing. New, that was where I referred back -- I remember very well, checking just to be sure I was right, going back to Houston’s notes and looking at the mathematics very carefully. And I felt also, I understood why it disobeyed the normal application of the uncertainty principle namely, many atoms; you weren't measuring the level of a single atom. But that was a difficult thing. I remember also talking with von Neumann about it, and in an interesting way. I could tell you many stories about different people and their reactions about masers which I think are rather revealing, and maybe it's the kind of thing that ought really to be recorded, because I had many personal conversations which are not in the public literature. I was down at Princeton, for some function, and met von Neumann somewhat socially. Maybe it was a kind of a social occasion after a committee meeting of some kind. I told him very eagerly about what I was doing. I believe that it was after the maser was going. “Well,” he said, "but how can you get that kind of width? It's not possible.” And he went through the usual arguments. And I talked with him some, and about five or ten minutes later, he said, "Oh yes. I guess that's right.” But he challenged the result. It took him a while. Then he went on to say some things which I didn't understand at the time, why he pressed them so. He said, ''Well, now, can you do this in a semi-conductor where you would get an infra-red optical frequency? Why can't you do this in a semi-conductor? If I said, "Well, sure, in principle, but you know the energy levels are broad, so you don't get something that's highly resonant, and you can't keep many electrons excited, and it's pretty difficult--” I said, “Yes, sure, a person can do it. I know you can do it in principle, but I don’t know how to actually do it in a semi-conductor thing and anyhow you have very broad levels and it wouldn’t be an exact frequency and -- Well, he kept pressing that, and never said that he had thought about it himself. John Bardeen, in editing von Neumann’s papers, showed that von Neumann before I had talked with him about this, -- I don't know, I think it was about probably '52 or something like this, that he had this idea he had the idea of doing it in semi-conductor. He was going to do it by exciting the semi-conductors near a pile, exciting them with intense neutron radiation. He wrote a letter to Edward Teller, a rather detailed letter with calculations, and he made really very lengthy calculations on what to do and how he might do it, wrote a letter to Edward Teller explaining this and asked what he thought of it. There was no answer in von Neumann’s papers from Teller. I even went to the extent of writing a note to Teller and mentioning this to him, and asking him, had he replied and what had he thought at the time, just for historical reasons. I never got a reply from Teller, so I don’t know what Teller thought. Obviously he didn't reply and perhaps didn't think about it very seriously. Von Neumann wasn't going to tell me, "Well, I thought of that." There are many other people who did tell me that, and had thought of it, in a sense. Now, the thing that von Neumann didn't know, however, and it's very characteristic, he didn't recognize the coherent photon character of the radiation. He thought of it as a photon avalanche. He also didn't have any feedback. He didn't think about feedback, as sharpening up the line or allowing a continuous generation on a discrete frequency. I think that those were the two things that were missed, and they were missed primarily because it was a physicist who knew enough about quantum mechanics to know about spontaneous emission, but the physicists had been so… thoroughly taught to treat photons as photons and discrete particles that they simply weren't looking at it very much as a continuous wave, which an engineer of course had been taught to do. And I can show you over history, all the early suggestions except perhaps Lamb -- Willis Lamb certainly understood coherence, I believe -- but he didn't say so particularly in his article, and one of the others either said so or seemed to understand the coherence. And that goes way back to the twenties -- Richard Tolman wrote an article, a statistical mechanics article, that was his field, in which he discussed this, and he said, “Well, if you -- the population was the other way around, the photons would be multiplied --" That was in the late twenties. Well written, very clear, he understood that perfectly, but again, no mention of coherence. No mentions of feedback, no mention of coherence. I had a discussion with Houtermans after the maser came along, and Houtermans said, “Well, you know, I thought about this back in the thirties. The people in my laboratory were getting some peculiar spectroscopic results, in a hydrogen discharge or something. The line was stronger than it should be, a different shape, and I thought, well, maybe this is a photon avalanche.” I remember his calling it photon avalanche. “And I worked it out, suggested to them, and then they found it had to do with something else, and so I dropped the subject.” Houtermans then later, after his conversation with me, wrote a paper, which is on the record, about this idea that he had. It was clear too that that was a specifically discrete photon avalanche idea. I think you'll find -- let us see, there was this Russian along in the fifties, also had an idea, and I think was fairly close maybe to producing or thinking about amplification seriously. But again, there was no idea about coherence and feedback. I think that came really out of electrical engineering, my own contacts with circuitry, electrical engineer oscillators; Of course Rabi, who had been making magnetrons, Kusch, they understood those ideas, but they didn’t happen to think about it. Purcell, Pound, I can’t understand why Purcell and Pound didn’t think of it. I absolutely can't understand it, because they're such clever people or Dicke. Really very clever people. They understood all the principles. They were accustomed to oscillators I can understand why --
(crosstalk)… lower frequency range where the thing wasn't strong enough --
-- that's right. That's right. Mostly they were, and it was impractical to do it there. Yet they were so interested in theoretical ideas, and Dicke was so inventive. Dicke was writing about all sorts of inventions, that it is still --
-- Dicke, you might think…
-- it's still surprising that they didn't think of it. So maybe it wasn’t as obvious as I thought it was. But I would say that stimulated emission certainly was obvious to many, many people. But the feedback and coherence I think was the thing that had to be brought in from a little different point of view. And the other thing that I think is important, and people missed, is simply the idea that this might be worthwhile. I really feel that interest, focusing interest on something and understanding what is worthwhile is very important, and if these people had really been very much interested in producing high frequencies, as I was, they likely would have run into it. It was important to me. It wasn't terribly important to them. And most of my friends didn't think what I was doing -- well, they thought, sure it's kind of a cute idea. They weren’t all that interested. In fact, my friend Ben Dailey with whom I had a strong association and have written papers, after I got the maser working, I remember very well, told me, "Well, I'm glad you've got it working… That's just great, that's fine, that's very nice, but you know, I hope you'll get back now to the really important things you were doing before this,” which was molecular physics. I felt I saw something different in it from what other people saw. It was basically my own drive and interest in what I felt it might hold in the future, that it was important. And I respect that that sense of importance and need was a very important, very, very crucial reason why some of these other people did not develop it.
It sounds very reasonable. And in the case of the Russians, it was a matter of simultaneity more or less, I mean the others, Basov and Prokhorov.
Well, now, that's an interesting story. There's a little history there that needs some correction, because it's been published erroneously in a number of places, and I've never felt like writing. In a letter to the editor, something like that. I'm just emotionally against that. Let somebody else correct the record. Even PHYSICS TODAY, after the Nobel Prize, wrote about the Russians and said that they had made an ammonia maser independently of me and so on. That really isn't true, and the Russians will tell you that themselves, that they did not make an ammonia maser before reading my papers and reading how to make it.
I had the wrong impression of that too.
Weber has written articles in which he has stated that, and it’s really just that he hasn't read the Russian literature or something. PHYSICS TODAY carried it. Also, the strangest thing to me was in the introduction to the Nobel Prize in Sweden by Edlen, in which he said he wanted to make it plain that we were doing things simultaneously at exactly the same time. Well, I can’t believe that was true, because the first date that the Russian claim to have said something about it in a meeting in 1952, an all-Russia meeting 1952 -- that’s the first date that they claim. My first date is very clear, 1951. They have no record of that meeting. I have asked them about it and they said no, there wasn’t a record. The official historian for the Swedes, a man named Rydbeck -- Rydbeck I have known for some time, and after Edlen said this officially, of course at the time I didn’t want to embarrass the Swedes, no point in saying anything about it at the time but I asked Rydbeck about it shortly afterwards. I said “Edlen said this was simultaneous, and I know you’ve looked in the history. You wrote the history for the committee. What’s back of this?” He said, "Did he say that?" I said, ''Yes." He said, "Well, I wouldn't have said that." I said, "What is the situation?" He wouldn't tell me anymore. He wouldn’t tell me anymore, and I wrote Edlen and asked him. I didn't make a point of that particular statement, but asked him what information I could get.
Probably some international politics gets into these things.
Well, it's easy to make that supposition, of course. But I think historically the question is, what really was behind that. I think it was Edlen leaning over backwards to try to make things seem equal, and he said in some general way which is not real. But Rudbeck did tell me, I asked him about this meeting because Rudbeck had gone to Russia to try to look into that meeting. He said well, as far as he could see, there was never any such on the other hand maintained that that was the first time they said something about it, and there’s no reason to dispute that. The Russians did write something in 1953, a theoretical idea. They used one of the alkali halides, as I remember, in a beam and in a cavity, and they wrote down the basic equation for the threshold condition. And I would say yes, they understood the coherent properties and they understood the feedback. I think that’s very clear that they had a much more complete idea than anybody else besides myself. And do far as I know, it was independent. Now, Wilber had an idea without feedback. And his system had a number of scientific errors in it. He just -- when he made estimates, he showed that he might get a little bit of gain, but his estimates were off many orders of magnitude, and his system really is quite unworkable. But the Russians, I would say, had a fairly complete idea. They showed that they would need a Q of about 106, which wasn't practical of that time. I needed a Q of about, I felt about 104, which was just marginal. And Prokhorov, after I had met him, I asked him if they had gotten one going, and he said no. I asked him later and he said, “Well, we’ve got one going now after we read your paper on the focuser.” I don’t think -- in the first place, they did not suggest ammonia. Secondly, they hadn’t used Paul’s focuser. They had a rather weak beam. Now, I’ve forgotten a little bit about details of the focus, but I’m pretty sure that they never mentioned anything about a focuser. They mentioned to me using my focuser too, -- so, they got one going after that. Now, it's interesting to speculate whether, to what extent Weber and the Russians were independent. I've always said publicly that they had independent ideas. It's quite clear that it was subsequent to my idea. And one wonders whether there was some – some inadvertent leakage or some leakage of information which may not even be aware of. But I think that's an important phenomenon in physics, that once somebody focused on an idea, other people who have been thinking in the general area may have had the idea but not done anything about it -- suddenly they have that same idea and do the same thing, and the fact that they know someone who has focused on it is very important to making things seem simultaneous, or at least parallel. And there will be some such effect here. But in the case of Weber, it's very much more likely, as Weber visited my lab very regularly. I showed anybody who came around what we were doing on the maser. And I -- Weber made a point of being in my laboratory every six months or so, to see what was going on. He was working in microwave spectroscopy. He was always very friendly at that time, and appreciative of being able to talk about it. I think he must have seen the maser in construction there. I'd given him public credit for an independent idea, for the following reason, that I remember, in the fall of 1953, I believe it was, I'm pretty sure that was fall of ‘53, he came into my office. I was chairman of the department then. I remember his coming into my department office and talking with me, and he said, as physicists are wont to when they think they've had a cute idea, he said, "Well, you know, I have an idea how to get amplification I gave a talk about it to some of the engineers. It's a kind of interesting idea. I don't really think it will work. But it’s amusing.” He began to tell me about it, and I said, "Well, yes, I think that is an interesting idea, but I have been working on a similar thing that I felt would work and we've got it under construction upstairs. I'd be glad to show it to you. I personally think it will work now." And he then, I showed him around, but my belief is that he at least at that time wasn't aware that he had seen our laboratory. My guess is, he probably actually saw it, forgot it, some of the idea might have come back to him -- yes, it might have come back to him. But it's clear I don't think he overtly copied from what we were doing. And in fact, his general scheme was enough different, and rather unworkable, and he didn't have feedback. He didn't put in a circuit, because if he did put in a circuit he would have had too many losses even on his calculation, and his calculation was optimistic by about, well, a number of orders of magnitude. But still he understood the coherence. I would say Weber understood the coherence. And was somewhat interested in amplification, but then had dropped it. Now, he gave a talk, apparently in June of that year, I guess, and it came out in publication as a report of that meeting, in a publication in any case I think probably by December of '53 -- I didn't pay much attention to it because, again, I thought that idea was fairly obvious at the time. I thought, well, everybody knows that, so if Weber wants to write it up, that's fine. Most people wouldn't have written it up unless they had a system that they thought would work. Still, it was very clear that it was quite unknown to the engineers. The engineers didn't know anything about stimulated emission. They knew all about feedback but they didn't know anything about stimulated emission. And Weber had given the talk to the engineers. I think it was completely appropriate that he would do that. Now, the Russians, I never had any personal contact with. Officially they didn't get information that we had written up. We started writing -- well, besides this meeting that Nethercot talked at, which probably didn't get back to the Soviet Union, though it was not classified, but I doubt if it got back to the Soviet Union, rather a semi small meeting -- but our Radiation Laboratory reports were written up regularly. Officially they weren't supposed to go back to the Soviet Union. They were not classified but they were sponsored by the armed services, and they had to be some special reason for sending them abroad. They weren't supposed to go abroad excepting to friendly laboratories, but they might have gone to England, to France.
They were probably dispersed one way or another.
Yes. Well, there were many copies that were sent out. Any physicist who was interested in the United States would get a copy, and all commercial laboratories interested would get couples. We wrote up a fairly complete treatment of the idea in the fall of '51, when Jim Gordon was about to start on it. My name wasn't on that, as it happened. Somebody picked that up, said, "Oh, you didn't have anything to do with it?" Well, that was just my habit at the time in those reports. I had the students sign their names to it. They were the ones who were specifically working on that project, and I was overseeing it. I had gotten Dousmanis to do calculations on just how many molecules one could get into the beam. They were more complete calculations than I had done. Jim Gordon had just agreed, he was a good student, he was familiar with molecular beams, he'd worked with Zacharias, he was familiar with molecular beams and I thought, a suitable student -- he seemed interested, and was willing to give it a try. I knew it was somewhat hazardous and he understood tilt, but he was willing to give it a try, so the two of them wrote up this description. I explained the idea to them and they wrote it up, Dousmanis as a result of his calculations, and so on, and so in December of ‘51 that first report came out. Now, while those things weren’t supposed to be public, I happened to know something about distribution, because again this came up in the patent situation. Bell Labs challenged the validity of my maser patents, saying, lid published it already and had not applied for a patent inside of a year of publication, so this amounts to publication. And the lawyer representing me said that that was not publication that was a private thing circulated to a large number of people, it’s true, but not official publication. They then went around and found that it had been on the open shelves, listed in the Harvard Library and on the open shelves, as well I think as to some others, and our lawyer had to agree, well, OK, it was published. His next point was that well, it wasn’t really complete enough to show exactly how one would work. It was a description of the idea and discussion of how to go about it, but it wasn’t complete enough really, was not a valid patent disclosure. That more or less stuck, although there was continued argument about that. In any case, it was officially public information clearly on the public shelves in a number of libraries. And the interesting question is, to what extent that got back to the Soviet Union? Presumably they were keeping track of our technology. Presumably they would let their scientists know something about it. But I don’t know. I’ve never asked Basov and Prokhorov about that. Of course I wouldn’t. They probably wouldn’t tell me anyhow. And my belief is that, well, they might have had some idea about what I was doing. On the other hand, their version of it was different enough that it certainly was not clear that it came directly from what I was doing. They had a different set of molecules, which were worse than what I had proposed. So again, I've always said publicly that they had an independent idea. It was in fact about a year later. And I never knew for sure whether they worked on it before they found that I was working on it. I just don’t know for certain. It’s clear they didn’t have one going, because I asked them specifically about that, and Prokhorov I think was very honest about that and straightforward, said, no, they hadn't had one going until after they read about what I was doing, then they got one going, and they improved it some with some additional poles on the focuser. So, so that's what I know about the extent to which these really were independent things, to what extent there might have been some inadvertent, let us say, leakage of information, of what these people weren't aware. I think that is rather prevalent in physics. Now I do know that Basov and Prokhorov were following what I was doing later, because, the first time I ever met them was at an international meeting in Great Britain, a meeting on chemistry, basically, Faraday Society…(off tape) Well, because I was excited about the maser at the time, and I wanted to give a talk, the easiest thing to talk about was the maser, so sent over an abstract saying I had this new device working, and something about it, and the Faraday Society said, Well, that's not appropriate for our Society, we want talk about something else. So, I sent another abstract. Basov and Prokhorov appeared, gave a talk, which had not been previously announced, and they talked about the possibility of building what turned out to be a maser. I said, well -- I got up and said, "Well, that's very interesting, and we have one working." And of course Basov and Prokhorov -- and I had a great time talking together. My belief is that they were specially sent over there to stake a claim, so to speak, and talk with me about what I was doing. The society of course didn't turn down the Russians about what they wanted to speak about. It was, that was what international politics was at the time. And it was terribly interesting to talk with them. They did not have one going at that time, I believe. At least they didn't say they had in their tall and I asked them and they said they didn't have one going. But they kept plying me with questions about, what other ways of getting an inverted population are there? And I remember saying, “Well, there are lots of ways. You can do it this way and that way and so on, but this is the only one I know that works at the moment." "But of course, there are many ways it could be done” and again, as I say, I had difficulty thinking about what's obvious and what isn't. I remember when they published on this three level system, I said, well, of course that in principle can work. They didn't have a working system. In principle it would work but it seemed kind of silly to talk about it. Everybody knows that. Yet, probably to somebody that was important. Actually Bloembergen of course made the first workable three level system. I don’t believe he knew about the Russian paper at that time. I think it was a separate invention. And just to indicate what I see as the stimulus of knowing that something is interesting, there is a fairly well known story which is second hand to me, but I remember it very well and I'm sure it's correct, that the people at Bell Labs. Scoville in particular, Bloembergen said something to him about, he had an idea for a maser, and he was obviously quite excited about it but said I'm not going to tell you till I've got it all worked out. Scoville went home, overnight -- what is it that Bloembergen would be thinking about? And the next morning he had the same idea. And he talked with Bloembergen and said. "Is this it?” And he said “Yes.” So that shows you how obvious or non-obvious these things are, and when you focus attention a little bit, the ideas are bound to be somewhat similar if you know the general area in which the person is interested. And Bloembergen's idea was independent. I believe that's quite correct, independent of the Russians, for a three level system. But the Russians had published first on it, on a three level system, and I think they made a point of tending to publish theoretical ideas early, partly because -- and they've always done it. It's a practice in Russia. It was a practice in the early days in Japan, because they were somewhat handicapped in doing experimental work. They're simply slow with it. So this was their way of staking a claim, when other people would have not published until they had a more complete idea. But I do remember their sort of casting around for all of the possible ways of doing it at the time, talking at considerable length about what our resonators were like, and our focusers and so on, and I had a very enjoyable time talking with them. They were very cautious politically at that time, of course -- first time they had been out and first time I had had any substantial contact with people of that type. OK, now, maybe I'll pause there to see what directions you want to ask about.
OK, well, your work you did on government funding, is that correct?
And it wasn't difficult for you to get the necessary equipment you needed. That came out equally. And you gave your motivation, am in a sense it was an application type of a motivation, -- how did the applications that came out of the maser compare with the ones that you envisaged as you were going after it?
Well, they were different. My primary purpose initially was to produce high frequency oscillators and sources with which to do spectroscopy. Now, of course, much of the development of quantum electronics, has it turned out to provide very good sources of spectroscopy, eventually. The first thing I did though was to check out the idea at 1 1/4 centimeters, which seemed to me the easiest place to make it work first, -- and after I'd gotten fairly far along with that, I realized it was a very, very constant oscillator, and hence particularly interesting as a frequency standard. And there was a good deal of talk of frequency standards at that time. That was something that was -- atomic frequency standards were sort of current and heavily emphasized. So I got interested in that. Then I also, by then, ha d recognized that it would be a very low noise amplifier, and I got interested in the amplification prospects, and before going on down to the infra-red, I had also gone off sabbatical. I went into sabbatical for a long time. I came to the end of my three year term as chairman of the department, and I had wound up a book, microwave spectroscopy I thought, well, now microwave spectroscopy has come to a stage where I feel it should be primarily done by chemists, and that I wanted to move on to some different field, I wasn't sure what, and it was time to take sabbatical and think about it. So I went off to Europe and Japan with still the interest in constant oscillators and amplification, but without then pursuing immediately the high frequency oscillation. Of course the system wasn't very tunable and we talked about, could things like that be tunable? I thought, yes, they can, it's hard but they can be tunable, But it was not immediately promising, certainly no wide applicability. And I thought seriously of going on to other fields. I went to France, and sort of looked into a variety of fields, particularly astronomy at that time, radio astronomy and some other fields of astronomy, various kinds of physics. However, I happened to run into a former student on a fellowship there, who was working with impurities in semi-conductors, which turned out to have very long relaxation times, which I hadn't realized, so I -- it suddenly occurred to me that those would be nice things to produce a broad band tunable amplifier. And he and I and a French physicist named Combisson(?) worked on that for a while there, played with the spins, and how much density one could get, and we wrote a paper on it. I was convinced that one could in fact build a tunable amplifier that way. Then I had to leave France. I went to Japan. By then I was thinking more about the amplifier and trying to figure out, just how good will it be? I thought perhaps it would be possible to detect quantum fluctuation, fluctuations in the population at low temperature of the numbers of photons, and I wanted to work that out, see if you could amplify, could you do that? I talked with a Japanese physicist named Takahashi, and Shimoda, who had come to work with me at Columbia before that, whom I knew a quite well, and I think it was perhaps Takahashi, well, no I'm a not sure it was Takahashi -- I think I got started on trying to work out some equations about, how to examine the noise in amplification, and was taking with Takahashi, and Takahashi is a good applied mathematician, and he recognized just how to solve them. I had already partially solved them and got kind of a rough answer, but he understood how to do it completely. He was also familiar with partition noise, which electrical engineers are acquainted with through partition of electron beams, partition noise associated with the fluctuation of the photons and so on, and we worked out then a fairly complete theory for a traveling wave amplifier. I was very pleased about that. Shimoda was very helpful. Shimoda back at Columbia had done some theory on maser amplification, and he and I had already published on that with Wang, who was a student of mine, postdoctoral man who worked on oscillators and trying to compare the constancy, so, when I got back to the Unites States, I found that Bloembergen had had his idea, that Strandberg of course knew about beam maser work. I don’t think he was acquainted with my work in France. It was published in French at Comptes Rendus and the French told me that was a fine way to bury a paper, and it turned out to be so, but I felt a little obligated, since I was a guest in France, to publish in French in the French journal, though I think very few people are acquainted with that. But Bloembergen I believe did know of that work. I think we’d given it a talk at a meeting in Europe too. But I believe Strandberg did not, but he did know about it when he was promoting what he called a versitron at the American Physical Society meeting, and I couldn’t figure out what’s the difference between a versitron and this thing that we’d already published, and it turned out, nobody else could figure out what the difference was either. But I do think Strandberg had the idea independently, and then he eventually recognized that what he was saying was the same as what I was saying, and he then sort of dropped the subject. But Bloembergen had heard Strandberg give a seminar on this idea, and Bloembergen after having heard Strandberg give a seminar on this idea -- which was a flipping of spins, as I was trying to do -- then went home and overnight thought of the pumping scheme. The reason he thought about that was quite clear. He was familiar with these energy levels and more complex energy levels. I kept thinking in terms of uniformly spaced spin levels, but I didn’t recognize the crystalline field. Bloembergen knew all about those, so it was a fairly natural idea for him, and he has told me that he attended Strandberg’s talk and that’s what got him starting to think about it. It was quite clear that by the time Bloembergen published, he knew of our paper, and how soon before that he knew of it, I don’t know. Then there was his interaction with Bell Telephone Laboratories that generated the idea separately, in a sense. By the time I got back, amplifiers were the rage. I had decided by then, well -- by the time I left Japan, I said, well, I'm trying to figure out what I should do next after microwave spectroscopy. Basically I decided it was more of the same, but in particular, masers. Masers to do some radio astronomy. So I came back and built some solid state masers to do radio astronomy. I did that for a while. Now, I still had in mind trying to get the high frequencies, and I felt I could do it, in the way I originally thought of doing, with an ammonia beam, but it didn’t look all that attractive to me. It wasn't tunable. And it would just, I felt, be more or less of a stunt. Sure it could be done, probably, but I wasn't sure I wanted to do it. I thought, well, there must be a way of making something that's more usable, and I'll think about it some time, but in the meantime I'm still going to go ahead doing other things, building amplifiers and that was exciting. And I even had Bill Otting from the Air Force, who was supporting the Radiation Laboratory, it laboratory, it was a joint services laboratory -- Bill Otting came around to see me and said, 'Would you be willing to work on infra-red masers?" “We'd like to see something in infra-red." I said, “Well, sure, I'd be willing to work on them, but exactly I really don't know/how to build one that I would feel is interesting." He said, ''Well if you ever do, just let us know. We've got the money. We’d like to see something." I think it was primarily his own interest and idea. Bill said. "It must be possible in infra-red, "and I said "Well, yes, I think I could do it but I'd like to wait until I have a better idea, then maybe I'll do it…" He said, "Is there anybody else who would work on this?" I said, “Well, Ali Javan is a very smart guy and he's working in our laboratory, ask him.” Well, Ali said no, he didn’t want to work on it. Then Bill asked me, then he asked Ali, would we write a kind of a theoretical article saying what the possibilities are? And we both said we don’t like to write just speculative articles, review articles, when we’re basically busy doing research, and if we had some good ideas, why, then we’ll do something. So Ali turned it down too. I guess it was six months or so after that, I said, “Well, I’ll try to see if one can’t do something at shorter wave lengths.” “Since I hadn’t a good casual idea, I’d sit down and say: “Now exactly what could one do?” That was the point at which the laser began to develop.
Do you view those sort of as a continuous invention? In your mind are they continuous in a way, the maser to the laser?
Oh yes. Yes. To my mind it's the same thing. The principle is all the same, of course.
Sort of inevitable, the extension of the maser to you know, when you got into it, did you say. Well, it's just a matter-of time, it is inevitable that --?
Oh yes. I said -- obviously I'd tried to start down in the far infra-red, and I felt, sure, it could be done down there and I would do it some time when I had a good idea. However it was the infra-red and not the visible that I was thinking of. It was the far infra-red, really. That was a natural extension of the wave lengths we were working on, and so, the next step was to go on down shorter and then shorter than that, and maybe later, and so on. It was not -- the visible was not in my mind, what's that?
The visible wasn't in your mind.
The visible was not in my mind at that time. The far infra-red was what I was interested in and looking forward to, and thought, well, of course that can be done. So it was short wave lengths, but not the visible. (crosstalk) There's another aspect of this -- I believe this is in the public record, but I have a comment here about another interesting thing that, there's a man named H.W. Shultz who was working at the time at Carbide Carbon, who was a Columbia graduate, graduate of the chemical engineering department there. He had blinded himself in the laboratory while working at Carbide and Carbon, and they had sent him back to school to get a doctor’s degree and try to keep him going, and he had a very good theoretical head. Maybe because he was blind, he sort of thought of advanced theoretical ideas. And he pointed out to them that maybe with enough infra-red, one could excite specific energy levels in molecules. And get very specific reactions, and hence get high yields on certain specialized reactions which would be valuable to industry. And however, he didn’t have powerful enough infra-red. And he thought somebody ought to try to develop powerful infra-red, and persuaded them to put up $10,000 to give to some laboratory to try to produce infra-red. So he came around. He didn’t know me. I suppose he must have found I was working with microwaves. He asked would I be willing to work on producing powerful infra-red, and I said "Well, yes, but I really don't know how to produce that power. This was along about. I would say, ‘49 or ‘50, probably ‘49, and I was busy with microwave spectroscopy and he saw what I was doing. I said "I’m doing microwave spectroscopy. If I had a good idea how to produce a lot of infra-red. I might well do it, but I really don’t have any good ideas. Well he went over to see some of the engineers and talked with them on microwave generation and eventually came back to me and said. “Well, I like what you’re doing, and I'd like to have you see if you could use this money well. If you have some ideas on infra-red, please do it, but in the meantime, I'd just like to encourage your research and I've got this money. That's what its purpose was but I haven't found anybody who feels they could do what we want." “What would you need?" he said. “Well," I said, "the biggest thing I need is a young postdoctoral man to work with me. I've got students but I need a postdoctoral man, to give him $5000 for a fellowship and $5000 for apparatus, which would be just great." So he gave me money, and I believe it was the second one of those post-doctoral people who was Art Schawlow who came to work on spectroscopy, and he and I have had a close long very fruitful relation, but it was not to generate infra-red that he came. The third man was Herb Zeiger. By then I had the idea of the maser. Zeiger had been a student of Rabi's, worked on molecular beams. He was looking for a post-doctoral position. I said, “Well, here's a man experienced with molecular beams. Obviously he's the person to put together with Jim Gordon to work on this thing." So he worked for me a year and contributed certainly importantly because of his experience and the fact that he's also a good physicist. That money turned out to be quite important. But it only the maser at that point. And yet later, Art Schawlow and I had this idea for a laser, and eventually of course it is doing some chemistry. About 25 years later. I must say, I think Schultz deserves a certain amount of credit for a kind of foresight which is rare in industry, of being willing to push and put some money on something that's really pretty far out, and yet has some good ideas in it. He was wrong, in a sense. As it turns out excitation with infra-red tends to be spread around all modes pretty quickly and you can't get many specific expectations, yet you can get some. And so, that chance accident maybe turned out to be quite important. Otherwise I probably wouldn't have met Art Schawlow for a long time and who knows what else would have happened. Art Schawlow, I was -- it was really his collaboration with me and vice versa that's been quite important to a lot of the science that I've done. But in particular, it's peculiar how much Schultz's money contributed to just what he was after, in a way which was quite unpredictable.
So while there was a certain amount of a push both from government and industry toward the higher frequency, it wasn't a strong concerted push, and it was just sort of fortuitous that it actually helped get you that way.
Yes, that's right. It all eventually came together, but, you know, it's one of many things, that people would like you to do this or like you to do that, and this particular direction is one of course that I remember, because things developed. OK, let's see, we're about as far as the beginning of the laser. Do you have any specific things you think ought to be explored?
Well, a couple of questions. For instance, how key was your consulting at Bell Labs to this joint invention with Art Schawlow?
Yes. Well, I'll go into that now. Let me just pick up on the specific history of the laser. It was along about in September of '57 that I just overtly said, "Well, let me sit down and think about this and figure out what's the best way to do it. Now I was trying to move on to that and find out what's the best way of producing shorter wave lengths, and if it looks good enough, I'll then get going on it. I hadn't had any brilliant ideas; just casually as I say. So I started thinking about it, what would be used, particularly how to build a resonator. Now, it was clear that a resonator could be made smaller, the same kind of resonator I'd used before could be made smaller, but the interaction distance was shorter, and the total number of molecules you'd feed in would be smaller, and so it would be harder, but it seemed quite possible but not all that exciting. It was marginal. It seemed clear to me that the resonator was the problem. I remember also very well saying, "Ah, yes, of course, if the broadening is a Doppler broadening for the line, then the formula for the threshold says that the threshold is independent of the number of atoms you have to have or molecules, independent of the frequency. So, it's true, one could go way up in frequency if one could get a cavity. I said “Well, you can go way up in frequency, why not the optical region?" For example? The far infra-red is possible if you extend from microwaves, but if you're going to have to have a new kind of a cavity or something different, then really the optical region is easier, because optical techniques and pumping and spectroscopy is all so much better known. And why not just jump right over into the optical region? The threshold conditions are independent of frequency. The problem is to find that cavity. Well, I thought somehow you have to go to a multiple cavity, because unless you just strain things and try to extend the present techniques, you can't, there's no good simply single-mode cavity that you can practically build. So I tried to work out a cavity. I really didn't feel that I had the right idea yet, but I had something that would work. I had a multi-mode cavity... I put holes in it to put the exciting light in, and I said, well, some of the possible modes won't get generated, because they'll go out through these holes, and maybe one can make the holes fairly big, and those modes won't be there, but then there'll be a lot of modes -- now, what would that do? Would it really oscillate cleanly on a single frequency? I decided, yes, it would, temporarily, but then any slightest motion of the cavity would make it jump to another frequency. So what's it going to do? It's going to be putting out energy -- momentarily a single frequency, but it will be jumping around, and that's not terribly good. But after all, it won't jump more than the line widths of the atoms that are in there, and anyhow, maybe I should go ahead and get started. This isn't a terribly good oscillator, but it is an oscillator, am I can get started, be able to and as we go along maybe I can/control it and think of better ways to control it, and anyhow, it can be more intense, and -- then other sources -- and still confined within the line widths of the atoms, and maybe if you can keep everything still, it will be pretty monochromatic. And so I wrote this down in a notebook. I tried to calculate about how much power you'd need to pump the atoms and the structure you'd need.
This is a specific system you had in mind?
A specific system, yes. That's in my notebook, on the record, I think about late September of '57. And here comes in Mr. Gordon Gould now. Gordon had a laboratory about two doors from mine. He was a student of Kusch's. And Kusch -- I think he liked my maser, but he and Rabi had been not terribly warm about the maser. In fact, I'd have to say at one point shortly before the maser was working, about three months before the maser was working, I guess the laboratory was a little short of money, Kusch and Rabi came in -- one of the few times that they ever really put pressure on me. They came and said, "Well, look, that maser is" -- they didn't call it a maser at that time, "that thing you're doing, that's not going to work. We're in the molecular beam business and we know this, it's not going to work, you've been working at that for a couple of years now, it hasn’t gotten anywhere, you are just wasting money. This is the laboratory is money and you really ought to stop that.” That is the kind of time where it is important to be a professor. Rabi of course was the boss. Kusch was more senior than I. Both had Nobel Prizes by that time. But being a professor, I could say, ''Well, you know, I think it still has a pretty good chance, and by golly, I'm going to keep on going." They knew that they couldn’t just take the money away from me. They simply put pressure on me. They put up quite an argument that here I was wasting the laboratory’s money and I ought to know better and they were sure it wasn’t going to work and I should admit that. It actually worked in about three months after that, as I remember, sometime like that. A few months later, Poly Kusch -- we were talking about something else, and he said, “Well, you know. I guess we must recognize that I don It know as much about the things that you are doing as you do."
That was nice of him.
Yes. They didn’t do it in an inimical way. They simply needed the money. They felt that they also knew the molecular beam business, it was somewhat new to me, but… (off tape) I mention that as an illustration of what I think is very important, for a person to have enough self-confidence -- and I don't feel I have all that much self-confidence, and yet, I think I can reason with myself to figure out whether I believe I'm right or not, and that's very important in science, particularly if you're going to do something that's slightly out of the way. A great deal of science is easy to carry on, what everybody knows is important and so you do it, but the things that are more fun to me, where you surprise people, are the things that other people don't believe in, but you discover may be there. For innovation -- a certain kind of toughness and self-confidence is important. Well, now, to get back to the laser picture, Rabi and Kusch were moderately impressed with the maser, but not really all that interested in the maser per se, and their students were doing other things. Gordon Gould was making a thalium beam to study the hyperfine structure of thalium. I knew he had been having trouble getting enough intensity, and worked very hard on getting us a very intense lamp, for thalium. Also thalium was one of the atoms that I thought might be interesting for pumping, because of its energy levels, and interesting for an optical system. So I asked Gordon about it. He came into my office. I told him what I was doing I said, "You know, I think it's possible to make an optical maser, one that will oscillate in the optical region, and you’d need a fairly powerful lamp for pumping. I'd like to know just how much power you’ve been able to get out of this thalium lamp." So he told me roughly. I put down some notes. It's well recorded in my notebook, precisely what the date was. And I said thanks and so on. Then he came back a few days later -- I have this recorded again -- really with a good deal of information on commercial lamps and so on. I told him again, "Thanks very much. It looks rather promising to me, that one can build an optical oscillator." I think it was then that he said, just as he went out the door, "Well, I think maybe so too." That's the only hint I had that Gordon was ever thinking about it at that time, and I can't say --
You were open with him but he not with you?
That's right and I can't say for sure whether it came from my first contact with him, when I had explained, it to him -- I explained it to him both times. Normally when I ask somebody like that for information, I would normally tell him what it was all about, why I needed it, and anyhow, I'm generally not very secretive about scientific things. And then I never heard from him any more on the subject for a long time. I would see him in the hail. He was working away on his thesis supposedly, after a while he dropped out. He never finished his thesis. He went to work. I understood he needed the money and so he took a job at TRG. Now, that, one has to recognize, is contrary to what at least he's telling the newspaper, what the newspaper says he's saying. His version, as it reads in the newspaper, is that he heard from a telephone conversation, something I said on the telephone made him think that I was working on it. He wasn't sure but it made him think that I was working on it, so he quickly wrote down all of his information and his ideas and had it notarized. His actual notebook record and notarization was about three weeks after my second contact with him. So it's very clear to me that the story is not correct. What I don't know is whether he was or wasn't thinking about it before. I don't know what his ideas were before he talked with me. But it's quite clear that h is written record is about three weeks after my second talk with him. His written record is dated and notarized. My record is dated in my notebook. It may not be exactly three weeks, but it's approximately that. So I can't say to what extent he had any independent ideas. But now, it's clear though that by that time he was interested and he did write down some things. Those are not the things for which he has gotten a patent, The things for which he has gotten a patent came about a year later, things on which his patent is based came later in early December, in a second long series of notebook entries, December, in a second long series of notebook entries, December, ‘58, just two weeks before Art Schawlow’s and my paper was published. And again, I'm really not quite uncertain how much of that is original with him. I wouldn't want to pass judgment on it one way or the other, simply to point out that our paper was widely distributed by then. It was published two weeks after his notebook entries. He wrote a proposal for the Pentagon -- well, he and his boss at TRG wrote a proposal for the Pentagon. I think much of the engineering and application part of it was written by his boss, but Gordon provided the optics and the spectroscopy. I'm sure he must have provided that for this proposal. And the proposal was sent to me by the Pentagon. They wanted me to review it. I told them I was pretty busy and didn't want to review it. They said, "Well, TRG especially told us not to show it to anybody but you. Because they consider it proprietary and they wouldn't… trust anybody but you to see it. I said, "Well, OK, if I seem to be the only one, OK, I'll take a look at it." So I looked at it, and it was clear that a good deal of it was rather similar to some of the things that we'd had in our paper. And by then, Gordon, I think maybe he'd looked me up to talk about the proposal, because he knew I had it, and I asked him if he had seen our paper and he said yes. So it was along about -- it was about that time, 1st of January, somewhere along in there. Our paper was officially published December 15, '58, but it was a couple of weeks or so late in actually coming out, so he had seen our preprint, and I don't know exactly when I got it, but I feel it's pretty, very, very likely he had it before he sent the one -- because we'd distributed it in the summer to most people, ideas and again, how many of those ideas were really original, I just don't know. But in any case, it's a December '58 notebook entry on which he has some patent claims at the moment. Well, now, so much for the Gould situation. Unless you have some further questions about it?
No, I think that covers that.
The -- oh yes, there are some the flow of ideas. But let me get back other things, to illustrate but let me get back to Art Schawlow. I was talking about ‘57, the fall of ‘57, when I talked with Gould a couple of times. I talked with him before I talked with Art Schawlow. And I had these entries in my notebook, showing a primitive system, what I would call a primitive system, that was sort of schematic and would work but it didn't have a good cavity. We needed a multi-mode cavity with some openings in it which would cut down the number of modes. I didn't consider it terribly good, but I was prepared then to go ahead and try to build it, because I thought at lease it would be a start and maybe we'll find ways of improving it. I had been consulting for Bell Telephone Laboratories by going out there once in a while, and that was interesting. The only handicap was the lack of time. I went out to Bell Telephone laboratories after that. I had some contact with Art's boss, I'll get it in a moment, solid state physicist, theorist to some extent -- Al Clogston. I'd had some contact with Art before. Art had been working on superconductivity, doing something that hadn't panned out particularly well. Al Clogston said, "Well, you know, your brother-in-law is kind of at an impasse for the moment, a crossroads, and I wish you'd talk with him and see if you can help him get going and solve some of his problems or something." Well, I've always thought very highly of Art and it was very fruitful to talk with him, a very fine person to talk with, too. He's willing to sort of coast along and talk, in a useful way, and he and I had a very good relationship, and we talked about things easily. Of course I was glad to go around and talk with him, and I told him about this optical maser idea I had. I was calling it an optical maser at the time. And he said, "Well, I've been thinking about that some too, and it would be nice, should be possible to build something." I pointed out what I felt was the real problem there, was finding a suitable cavity, and why that was the bottom line and what this present cavity would do, and -- well, you know, some of the modes would be damped out this way, these holes, but I could see how you could -- I don't see how you'd get a single mode. There's where he made his very important contribution, saying, “Well, now what about a Fabry-Perot. That is still more open and has fewer modes and so on.” That was really the key new idea that was needed. He was primarily thinking of elimination of transverse modes, though of course he realized there would also be discrete longitude modes. After our discussion, I went back and worked it out, came back next time I saw Art, and said “Well, you know, I find that actually one can pick a Fabry-Perot cavity which not only will get rid of the transverse modes, but also, you can pick it so that there will be only one longitudinal mode that falls on the frequency line, so you can really completely control the mode, pick out a single mode. The longitudinal mode question was of course quite simple, but in addition to this I had an estimate of the losses in transverse modes.” It’s interesting, why I previously missed that idea because whereas, in -- well, Art had had background in Fabry-Perot systems, as that was his thesis, to do spectroscopy with Fabry-Perot, but we had at Columbia a Fabry-Perot for microwaves, just as a wavelength measuring device. We’d developed them at Columbia. That was a kind of a staff member, non-PhD who had developed them, and I had been close to him, had seen his work, sort of corrected his publication for him, and I knew perfectly well about microwave resonators and I wasn’t unfamiliar with Fabry-Perots in the optical region, but it simply didn’t occur to me to obtain such extreme openness with a Fabry-Perot. And I don't know why I really don't know why. It's just one of those questions of, what's obvious. Yet that was a critical thing, I felt at the time, for really making it good. Not that it couldn't be made, but this would really make it good. Now, the second time I came back I said, “Well, look, Art, you know, I think we ought to work together on this…” He said, "Oh sure, that would be fine, let's work together." So he kept batting ideas back and forth and writing out details, working out details it was a while before we started really writing things -- and eventually by summer, we had decided -- I talked with Art along about November, I guess, probably -- by summer we had written a paper on this. Now, it's interesting to think also what, again, what was known and what wasn't known. I worked out an approximate view of the damping of the transverse modes, just using diffraction theory, and I felt, well, yes, clearly you can damp the modes by approximately this much, and otherwise it’s a plain wave, except for diffraction which gets left over, and you lose that much, so that’s approximately the damping, and then you can get the walk off which is a damping of the other modes, and I felt, well you know, pure plain waves are a perfectly reasonable approximation, not precise, but in terms of the general behavior and approximate evaluation, why, that’s all right. Then we had written a paper. We sort of fed it up through Bell Telephone Laboratories. Clogston challenged the mode discussion and he felt, no, you can’t talk about modes that way, that’s not right, these really aren’t modes. I have never really understood why actually almost the whole Bell Laboratory structure felt that these weren’t really cavity modes. They weren’t modes at all. They were just against it. Clogston said, “No, that’s not right. You haven’t proved that that’s going to have a resonance.” I said, “Well --”
They really weren’t any encouragement to the project, in a way.
Well, no. Not particularly. Bell Laboratories wasn’t awfully interested in optics. I can comment a little more on that. But strangely, Clogston, who was a good theoretician, a good physicist, didn’t believe that. The electrical engineers at Bell Laboratories didn’t believe it. And Clogston objected to what we had written, said, “You haven’t proved that. It’s not sound.” I told Art, “Well, let me rewrite it. Let me rewrite it, I’ll put down some more mathematics and show it’s all right. It’s just a question of making it plain, because surely, it’s perfectly obvious, but I’ll write some mathematics so it will satisfy Clogston and Bell Labs” -- which I did then. I wrote it out rather more fully. This is another thing which makes me believe that I did most of the actual mathematics work on that, but in any case, I rewrote the paper, that part of it, and Art was writing some of the paper and I was writing some of the paper. We started to write it up. I rewrote that part. Art handed it back to Clogston. He still didn’t like it. He showed it to Ali Javan who by then was working for Bell Telephone Laboratories, and asked Ali if he thought it was right, and Ali said, “Sure.”
That’s good. I was going to say if he said not too, I’d be surprised.
Ali said, “Sure, that’s all right,” and so Clogston let it pass. Now, to show more about why that seems to have been a difficult idea, which I’ve never understood, Fox and Li then took this up, I think basically to try to disprove it, that this really wasn’t right, and they did a more complete mathematical theory, obviously a much better approximation, and I think a very good thing for them to do. But I remember their first talk about it. They primarily wanted to show that you couldn’t treat this like a plane wave. This was just not a plane wave. It was different. And it was the result of the general belief that, well, this resonance really was not a resonance. And then, for some time the Bell Laboratories engineers kept talking about, what did they call it? Open resonances or something. They had some special name for resonances or something. They were surprised. I remember Bill Baker talking about it, said “Well, you know, your idea about these open resonances, we’re having a great time with it now --” “What’s that, what do you mean?” It turned out to be just an extension of this idea that you could have something completely open, and feed through, and yet there was no resonance. To Art and me it seemed perfectly obvious. To Ali it seemed perfectly obvious. And of course we had demonstrated resonances, and nobody was surprised at the resonances, in the observed resonances in the Fabry-Perot in the microwave region. But there was this mindset that obviously made it difficult, for some reason that I don’t yet understand. Well, I might say also about the general interest; to indicate what I think was a very important aspect of this whole thing -- that most people weren't interested. The physicists by then were interested in atomic clocks and they were interested in amplifiers and people recognized that. Bell Laboratories had hired Jim Gordon. I remember talking with John Pierce, who had been on my Navy committee, about it, and “Well,” he said, "yes, I guess you do have amplification then.” But he wasn't all that interested. And then Jim Gordon was looking for a job and they said, “Well, we ought to hire Jim Gordon, he knows about these things,” and they had Jim Gordon at Bell Labs. But Bell Labs was generally looking for people then and they hired Ali and they hired Art and a lot of my friends and associates went there. And they sort of thought, well, this is something we ought to know about and look into. Light, on the other hand, was clearly something they weren’t interested in, officially. Now, I think very highly of Bell Labs, and I have said some things that may seem critical of them, but I want to be clear about that. I think Bell Labs is a great laboratory, the best there is industrially. It's simply a reflection of the limitations of the human mind, in my view. I told Art, “Well, go around to the patent lawyer," and I told him I'd heard from Bill Shockley that there was one very good patent lawyer there who had done his transistor patents and we ought to try to see him, I guess it is, “Why don't you go see him and have him write a patent, because we want to publish a paper on it and so we have to go through the patent process." Well, next time I saw Art he said, “Well, Torsiglieri said that he didn’t think Bell Laboratories ought to patent it, because" -- for a long time in the past, they had thought about using light for communications, and it had never been useful and they didn't expect it would be useful, and Bell Laboratories wasn't eager to get outside of the communications business. They felt it was wrong for them to be just patenting things that weren’t connected with their business. Hence they shouldn't patent it, but if we wanted to patent it, we could just patent it ourselves. And they had done that for some friends of mine that I knew. Well, first place, I wasn't sure it was Bell Telephone Laboratories property, because at least the first idea, I had had at my desk. On the other hand, Art was involved in it, am I had decided by then, well, after all, the maser patent covers all of this, and I had given that to Research Corporation to get patented. I'd already made the decision on that, and that covers all of these things, and the laser patent, whether it was or wasn't Bell Laboratories' idea originally, initially, still clearly Art is at Bell Laboratories and I'm consulting. They've left it up to me to decide when I'm working for them, and I ought to lean on the generous side and say, yes, OK, I was working for them then, and it’s all theirs, let them patent it. Art came back with that message and we laughed about it, and said, well, "Gosh, you'd better go talk with them again. It's obvious that he doesn't understand the situation." So Art did, and Torsiglieri said, "Well, OK, if you think it can be used in communication, come back and write down a schematic, something that shows it can be used for communication. Show me how to use it for communication and then I can patent it and it won't be against Bell Labs policy" and so on. We said, "That's easy”, after all -- (crosstalk) yeah. Well, it’s kind of humorous to Art and myself then, but again, to show you, something that's completely new -- different modes of thought, different backgrounds produce really quite different results. So we fixed up a communication system, basically just modulating the light signal, and so the patent was labeled “Light Communication System, Optical Master,” something or other like this. (???) then patented it, and everything was fine. Bell Laboratories still wasn’t terribly interested but they were perfectly happy for Art to work on it, and so on, and then, Ali Javan began to work on it, and I’d have to give Sid Millman a lot of credit. Sid had faith in Ali. He liked Ali. He was impressed by his style and originality, and I told him Ali was good, and Sid backed Ali to the hilt, and he hired Bill Bennett to come work with Ali. He said, "Ali needs some experimental help,” and -- but the interest didn’t go much above Sid, which was adequately high for Ali to work, and it was perfectly all right, but Bell labs wasn't all that interested itself. Interest arose, interestingly, again through personal contact. Bill Baker, who was president of the lab by then or director of research, I guess Jim Fisk was still president, Bill Baker was director of research by that time -- but otherwise pretty much the boss -- he was down at a meeting with me, a Welch meeting on chemistry, and he's sort of a trustee of the Welch Foundation, or he's on the committee to see about meetings, Bright Wilson was there. I'd been invited to come in and talk about spectroscopy. Well, by then I was interested in the laser, so I gave a kind of impromptu talk about the laser. Bright Wilson got up and said, "This is just tremendous. You mean you think you really can do that?" I said, "Oh yes. By now there are a number of people seriously working on it and they're sure it can be done.” “That's the most fantastic thing I've seen.” Well, Bill Baker has a lot of respect for Bright Wilson, a fellow chemist. Bill was there. And it’s quite clear to me that that was the point when Bill Baker got interested. And Bill Baker talked with me. I said, “Yes, Ali Javan is working on this right in Bell Telephone Laboratories.” From then on, it had lots of backing. And of course Ali eventually made one work then. I -- He worked very intensively on it. Art was not particularly interested in trying to make one. I talked with Art about it, “Should we try to make one of these?” Art said, “Well, it's clear that it can be made, but I'm doing some other things." Well, I think it ought to be tried. I think one of these ought to be built." He said, “Well, OK, if you're interested, that's perfectly all right. Why don't you go ahead and make one at Columbia?" By then he was doing some other sort of semi-optical things, and resonances, and Ali then left Columbia and pretty soon was at Bell Laboratories and was working. Ali got involved in our paper, sometime later, because the paper -- he reviewed the paper back in the summer, when I talked about starting work. So, I started work I suppose some time along in the spring of ‘59, serious work on one. Now, my view at that time was that it’s clear that a system can be built. There’s no doubt about that. And the numbers come out right, not nearly as marginal as the original maser had been. The numbers come out right. It’s clear it can be done. But why is it somebody hasn’t made one long ago? Or run into one accidently? Clearly they haven’t. People have worked with optics a long time. They’ve worked with gas discharges and mirrors and so on. They’ve never seen anything like this, never have done anything like this – obviously it must be rather rare and difficult. And so hence one has to plan the situation very carefully, be sure that everything is just right and works and then it has to work, but you’ve got to set things up in just the right way, otherwise, it won’t work properly, because somebody would have run into it accidentally. This is why I’m particularly interested in the alkalis. Everything was known about them. You could say exactly what would happen. You knew, if you put a certain amount of light on them, they would work. Whereas, there were a lot of other interesting systems that might work, but you couldn’t show numerically that they would have to work. So, we set up an alkali system, and Oliver Heavens I got to come over. I was looking for some person knowledgeable in optics that could work with me, because I hadn’t worked in optics, except in my thesis, for a long time, and Oliver Heavens was an optical spectroscopist, good man. I remember talking with Bruce Billings about it, said “Well, if you know anybody around who would like to do his doctoral dissertation, or come in and work with me on this?” He said “O. Heavens.”
And you didn’t know quite what he said when he said that. (laughter)
But he happened to know that Oliver was an interesting guy, and kind of looking around for something to do. So, I got hold of Oliver. I’d gotten hold of some money from the Navy by then. I’d made proposals to work on this thing, and they’d given me some money, and Oliver came over, and by then, a student showed up, Herman Cummins, he wanted to work on it and had been assigned. So we worked then --
What system was this?
Well, this was for pumping sodium. I was going to pump sodium with a sodium lamp.
I think you may have said alkali halide earlier.
Oh, no, alkali, yes. I was going to pump sodium with a sodium lamp, and if that didn’t work, I was going to pump cesium with a helium lamp, which Art and I had had in our paper. Because helium… (off tape)