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Interview of David Rittenhouse Inglis by Steve Heims on 1977 May 9, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4690-1
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The interview ranges from Inglis’ youth and family origins to his current (1977) activities. Topics include his student days (Amherst College 1924-28, Ann Arbor 1928-31), contact with European physicists and rising Nazism (1932-13), the physics departments at Ohio State, University of Pittsburgh, Princeton, and Johns Hopkins in the 1930’s, and the last of these in the 1940’s; atomic spectroscopy, ferromagnetism, uses of the vector model, shift from atomic to nuclear spectroscopy, the Thomas precession and spin-orbit coupling in nuclei, shell and droplet models for nuclei, intermediate coupling model for light nuclei, the earth’s magnetic field, wind-dynamos and nuclear reactors; Los Alamos during World War II, Argonne Laboratory in the 1950’s and 60’s; expression of social concern, especially in relation to the nuclear arms race, in the 1950’s through the Bulletin of the Atomic Scientists, the political victimization of Donald Flanders, the Federation of American Scientists, congressional testimony concerning Lewis Strauss’ (nominee for Sec. of Commerce) experiences at Pugwash Conferences, obstacles to slowing or reversing the arms race.
If it’s OK with you, we will start at the beginning, and I will ask you about your family background, and that sort of thing.
OK. I know that you were born in Detroit.
You must have been there long before the automobile industry…
No, I was born about the same time as the automobile industry began to get healthy — 1905. Henry Ford was already at it, a few years before that. My dad had already wrecked an 1899 Oldsmobile against a telephone pole by the time I came along, and consequently wouldn’t drive a car. We never had a family car again until 1927, when my mother learned to drive. [laughter]
Well, let me ask you about your parents. What kind of work was your father engaged in or your mother?
Oh, well, I’ll tell you about them both. Let’s start with my mother. She graduated from high school and learned how to calculate with logarithms and was employed for a while at the National Observatory in Washington as a computer, until she took nurses’ training and became head nurse at one of the hospitals in Washington before she met my father. They were married in her late twenties. My father by that time was about 40 and a young industrialist, a small businessman, in Detroit. He met her on a weekend excursion with a friend, down to a beach in Rehoboth, Delaware. Well, too much about their meeting. My father’s occupation — he did not get to go to college. His father had come to Detroit straight out of medical school in Edinburgh, back in the early fifties (1850s). Father was born in 1867 and by the turn of the century he had gotten through the process after high school of grocery clerking, going into exercising his penchant for mechanical drawing by getting into, first, a sort of a mail order business in the iron accessories business, and then finally building up his own factory, which, when I was a boy, employed some 40 people in a little factory in downtown Detroit, Gratiot Street and Harper, I think — down near the river. It was quite an experience for me as a boy to go in there and see those three or four floors of great machines that were run by flapping belts from overhead shafting. It was all run from one 25 horse motor down on the first floor somewhere. That’s how industry worked in those days.
His business was Ornamental Iron and Wire Work. He was proud of the name — back in those days acronyms had to be graceful, and the acronym for the William Inglis Wire and Iron Works was WIWIW. His brother, my uncle David Inglis, had been a medical student at Ann Arbor quite a bit earlier, and the family started drifting toward Ann Arbor. So we were about the third contingent of the family to move there, when I was a boy of 9 or 10, after having spent a year living in Atlantic City, Ventner, partly because I had such trouble with colds and the doctor thought that the sea air would be good for me. We just spent one year in Atlantic City. One memory of that time, by the way: Father liked to come down occasionally. At one time — this must have been late in the summer of ‘14 — he wanted to come down for a month or two, for a little late summer vacation with the family down there. But he wrote, “I won’t be able to come for several weeks, with this war starting in Europe. I don’t think this is going to clear up for a little while.” [laughter] That’s a strange memory. But it tells you a little about my father. My father was a fine man, philanthropically inclined, and did a lot of good things in his life. He had a brother who was a big businessman, James Inglis, who was president of three banks and evolved American Radiator Company into American Blowers Company and later had a big home in Ann Arbor that now belongs to the University. My father was the little man of the family, with his little manufacturing company. I mean, of that pair.
It sounds like you were introduced to a certain kind of machinery and technology, and maybe tinkering with things, through your father, is that right?
No, Father wasn’t very much for the mechanical. He loved to draw pictures. He was good as sort of an uneducated artist, you might say, and so he got into the business because he could sketch out an ornamental grill so nicely for his customer, and got other people to do the mechanical part. He must have had a good deal of understanding of machinery, but he did very little actual tinkering himself. He was a pencil and paper man, and a genial spirit. And a good salesman, I guess. In moving to Ann Arbor, he felt that Ann Arbor was a better place than Detroit to bring up kids, and besides, having been deprived of a university education himself, he still felt an affinity to intellectuals, and found that living in Ann Arbor, living with university professors on both sides of the house, and being invited to join the University Club, which would tolerate a few non-academics among its members — the faculty club of the university… He very much prized his faculty acquaintances, and friendships. So he lived in an academic community without being an academician. And Ann Arbor was a great place to grow up.
I wonder, when you were very young, were there things that predisposed you toward science? Or did you have any interest in physics or mechanical things?
You know, I was thinking the other day that my interest in science, in so many things in science, was an offshoot of the military. Not because I got into the military. I never did. Well, indirectly — I did work with the military a lot during the last war. An uncle of mine (on my mother’s side) was a lieutenant in the Signal Corps. He was also not educated beyond high school, but he was clever in an engineering way, and in World War I, as a young lieutenant, he lectured to the generals about the electronics of these newfangled things that were good communication for trench warfare these little wireless sets, in which you could tap out the code and they could hear it several miles away. So when he came back from the war, he had a gift for me — a surplus crystal receiver, very, very well built, rugged, and it worked quite well. I think that got me started. I immediately got — I guess I was 11 or 12 at that time — I got very much interested in the electronics of radio and learning about all those different frequencies — high frequency and the low frequency modulation and all that. That was fascinating. So all through high school, I built a variety of radio sets. I had fun starting with crystals and spark gaps and things like that, and I think maybe my first big thrill in radio communications was… Well, I must tell you how primitive things were in those days. First, I wanted to learn the code, of course, because you communicated by code. So I got some heavy brass and made myself a very nice key. Well, that was tinkering already. I used taps and dies and things, and made this little — it was a nice brass telegraph key that I made, a pretty good replica of the ones they sold, but buying it was out of the question. We made things in those days. I connected that up with the buzzer.
The Signal Corps radio receiver had a buzzer on which you pushed a button to test whether you had a sensitive spot on the crystal. The cat’s whisker, on the crystal, you explored around until you got a sensitive spot. Then the hearing was good. So that buzzer was there. I connected the key to it so I could tap out code. And I practiced my code that way, transmitting code, learned the Morse Code fine. In Ann Arbor at that time, the university had a 15 kilowatt rotary spark transmitter, and that was a tremendous thing. Walking home from school I could hear it three blocks away, but at home I could hear it a mile away with my radio set. The spark made so much noise. Well, anyway, I practiced reading code by copying down from that, and once the radio station sent out a “CQ.” That means, “Anybody who hears me and wants to talk to me — answer.” It’s the code for that. So I answered, “CQ, CQ — dadidadit — dadaditda –- dadiditditdit —” that’s CQ from DI. My station number, DI. And I was bowled over when he answered me back!
A great moment.
I’d thought I was the only one hearing it. But this little spark was connected to the oscillatory system, so it would radiate on my receiving antenna, enough so with a good vacuum tube receiver — down at the university they already had vacuum tubes. He had a sensitive enough receiver that he could receive me. [laughter] Well, I had lots of fun with that amateur radio. I learned quite a bit, so that by the time I came to physics courses, I found it fascinating to learn more about physics and it was sort of easy because I’d already had an introduction to a lot of physical thought through radio.
Did you have friends, people you did this with, who shared some of that interest?
It turned out that the fellow who answered me back from the big XA station a mile and a half away, on the campus, was Prescott Schlottenbeck who was my assistant scout master — a university engineering student who was our assistant scout master. So he was a friend. And of course, through him I learned a good deal about radio. There was a small coterie of people In amateur radio in those days, and one even made friends by radio and then got acquainted with them later. But I had some friends whom I knew otherwise who got interested in radio too. I think by biggest endeavor was along about probably my 15th birthday or so. I inveigled Dad into giving me a 60 watt transmitter tube — nothing but the tube. It was a big thing, eight, ten inches high, and a bayonet base, and it cost $30, only I found a place where you could get 10 percent off — and that was a big thing. From there on, and with buying two meters at $3 apiece or something like that, I made all the rest of the transmitter. I cut out pieces of sheet iron, and made the core of a transformer, that I had to wind thousands of turns on one side and hundred on the other to get it — I guess 5 kilovolts for the plate current. I first used raw AC, and then I gradually made up some aluminum-borax rectifiers. I made a 50 kilowatt transmitter with buying essentially only the tube. That’s the sort of thing you never would do now. A boy would never have the incentive to put that much time in, down in his basement workshop, to put together that sort of thing. And I think it did a lot to keep me out of mischief. And I wish boys had more of that sort of thing to do today — that was as challenging.
Did you have brothers and sisters?
Yes. I was the oldest in the family. I had a brother — well, next was my sister Carol, who now lives in Ann Arbor, married, and is closer than I am to my 102 year old mother, who is still barely alive there. And then my brother Bill is next, three years younger; and there was another one, three years younger still, John Lockwood Inglis, after whom my son is named, who died at the age of seven. So there were four of us. There are now just two left.
Is Rittenhouse your mother’s family?
Yes. My mother was born a Rittenhouse, and that’s an old Philadelphia name which was introduced to Philadelphia as Reuterhausen back in the middle of the 17th century when William Penn made a grant to my many greats grandfather, inducing him to come down and build his paper mill at Norristown, Pennsylvania, or Norriton as it then was, instead of building it in New York as he came over from Holland to do. And the name Rittenhouse has been in Philadelphia ever since, and my mother is one of those.
There’s a whole story back there.
Yes, and along the way there was an interesting story, too, in David Rittenhouse himself. He was America’s first astronomer, and the second president of the American Philosophical Society, following Ben Franklin, his good friend. 
He is then one of your ancestors?
Yes, a collateral ancestor. He had no son to carry on the name. I’m descended from his brother.
And, by the way, the physics department at Penn is named after him — David Rittenhouse Laboratory.
Was it a foregone conclusion that you would go to college, having moved to Ann Arbor, or was that…?
Yes, it was, essentially. I was doing well enough in school. Dad took it for granted he was going to send me to college. He wanted me to go to Ann Arbor. In fact, that was one of the reasons to move to Ann Arbor, so that after high school we would have college right there. But my very good friend Mack Langford, who was a year ahead of me in high school, came to Amherst, and he came back so enthusiastic about Amherst College that he talked me into talking Dad into letting me go away to college. [laughter]
How about high school teachers? Were there any ones that were particularly important to you or inspiring or encouraging?
Yes. Yes, I think — it will surprise you, perhaps — it was my history teacher who influenced me most. Not my physics teacher. I got along fine with my physics and chemistry teachers, sort of sailed through and found it easy and fun. Yet Professor Wolfe in physics was a very good teacher, and I’m sure I learned something from him. Edith Hoyle was a history teacher who was one of these motivated people who didn’t only teach history but did some extracurricular activities, and her interest was in international contacts. She was the high school sponsor of the Foreign-American Club, and she interested me in getting into it. There were quite a few foreign students in Ann Arbor High School because of — largely Orientals, but some Eastern Europeans too, whose families decided to send them to the University of Michigan, but they got here and found that they weren’t prepared. So they went to Ann Arbor High School for a year or two, before going into the university. So we had a special little group of Oriental future intellectuals there, and the Foreign-American Club — it was a nice idea of Edith Hoyle’s I think. I suppose it was her idea. She was a very genial sponsor of it, and eventually I became president of it, and I had good contacts there. She once asked me, as I was getting toward graduation, what was I going to do? What was I going to go into? And I really didn’t know. She said, “How about my profession?” I thought, “Is that a profession?” She said, “Yes, teaching.” Well, I hadn’t thought of that. Well, eventually I combined my interest in physics and that suggestion, too. But I suppose that my interest in the social, political side of science probably stems in part from Edith Hoyle. She taught me the civics course, as well as history, and sort of got me a little bit motivated — “Well, let’s understand these foreigners and make them at home here, and have some doings with them —.” I suppose that was in the nature of our early awakening of social concerns, of Pugwash, in my development. Oh, there were other teachers who influenced me. I took Latin and Greek and things like that in high school, and those teachers influenced me quite a lot — to think hard, anyhow.
Yes, right. I wondered too where — who besides Ms. Hoyle might have had a point of view that would make it natural for you to express social concerns, be articulate about them, see that as part of your function later on? Maybe one doesn’t have to look back — for that point of view?
Well, I’ll tell you two things. First I’ll start back a little earlier. Very soon after we moved to Ann Arbor — I mentioned that several segments of the family moved from Detroit to Ann Arbor — I had about four uncles and aunts in town, including Aunt Agnes, who was the maiden lady of my father’s family (my father’s sisters and brothers). She was a thorn in the flesh of her two commercially oriented and successful brothers — Big Businessman Uncle Jim and Small Businessman Dad — because she was interested in the labor movement. And that was anathema in those days to capitalism. But she was a great admirer of Gene Debs and these people, and knew them, knew several of them — Emma Goldman and people like that. She was socially concerned. And in spite of her radical ideas, when it came to dividing up the patrimony among seven kids, Dad and Uncle Jim I believe donated their share to Aunt Agnes, because she was the maiden lady and they were making their own living.
I think they supported her a little beyond that. They were very charitable towards Aunt Agnes’s radical views. But Aunt Agnes felt the need to reach to the younger generation, and I was her instrument in that she said, “You know, wouldn’t it be nice to have a boys’ club? You can come, you can get some of your friends and you come to my house on Tuesday afternoons after school, and we’ll do things. What shall we do? Would you like to make bird houses? I’ll get some thin lumber and we can make bird houses, or anything you’d like to do like that.” She said, “I’ll provide the place, and I’ll try to help you get the materials, provided you listen to me for 15 minutes.” [laughter] Well, Aunt Agnes told us about the inequities of the world, and I remember one of them because I impressed her on this one. You know, one remembers particularly the places where one is embarrassed and the places where one was proud. This is one where I guess she made me proud, just because she crowed about it so much, my reaction. It was a very simple thing. She was talking about the inequities of the distribution of land in the world, and she talked about other countries, but she said, “Do you know that in this country there is room enough for every family in the United States to have half an acre in the state of Texas. Wouldn’t that be nice if every family could have half an acre?” I said, “That doesn’t sound quite right.” But I went home and I looked up some numbers in the encyclopedia. I came back the next week and said, “Yes, Aunt Agnes, you were right.” Well, perhaps this is a sample of the kind of thing that we talked about. Aunt Agnes went on later — she spent the last years of her life in the library of the University of Michigan organizing what I think is known as the Larraby Collection of clippings and papers about the early labor union movement in America. She was the dedicated member of the family from whom I may have caught a little of this. But around high school — oh, there was the Hi-Y Club. I was president of Hi-V at one time, and I remember one of the first speeches I made was when I was put up for president over in Battle Creek — the big convention, with a lot of kids from all over the country, all over the state — as Ann Arbor’s candidate to be state president, and I didn’t make it.
That was my last political campaign. [laughter] But there was one other thing. Earl Dunn was our debating coach. Of course, people were expected to do some kinds of extracurricular activities. You didn’t go home from school at 2:30 in those days. You finished school at 3:30 and then did something else. I didn’t go out for football and that type of thing, and I had to wear glasses already, so I was no good, in spite of my size, for basketball. They didn’t have contact lenses yet. And so, I was relegated to the debating team. That, and being business manager of The Optimist, our school weekly. I did a lot of going around town soliciting ads for our school weekly, and composing those ads and things. But the debating team was my main extracurricular activity, I guess, and that was a matter of studying social concerns of some kind. We talked about the St. Lawrence Canal, and the advisability of the government investing money in the St. Lawrence Waterway, and things like that — social affairs.
Pro and con?
Pro and con, yes. You take the affirmative one week and the negative the next week. But you examine questions that way. And — well, at least I’m sure that got me accustomed to the idea of getting up in front of people and expressing my ideas, and that was an important step.
I’m sure. I suppose when you went to Amherst…
Amherst. [Pronounces it “Amerst.”]
Yes, you went to Amherst, and…
No “h” in it.
You read an “h” but you don’t say it — “Amerst.”
Did you major in physics already as an undergraduate there?
Yes, I came thinking I would either go into history or medicine or physics. These all attracted me, and Samuel Robinson Williams had just come from being head of the department at Oberlin. He came the same year that I came as a freshman, to Amherst as head of the physics department of the college. He was a magnetic personality, as well as a very good explainer of physics, and that was the deciding straw that got me into physics. It was simply Williams’ personality. Very fine professor, and his research interests were in simple magnetic problems, what looks simple today — the phenomenological experimental physics in the realm of magnetism. He wrote a very nice book on magnetism.
Did you actually engage in some undergraduate kind of research?
Yes. My undergraduate career was — I took a freshman course with him… at the end of which he sponsored me for one of the college’s prizes — the Porter Philosophical Prize. Samuel Robinson Williams. You’d probably find his book on magnetism in the library still. The second year I took a course in — well, I took a couple of courses. The one I remember mainly was with “Toggles” Thomson as we called him. A funny old professor who always told me about how Helmholtz trained him.
Yes. Well, that was his nickname, “Toggles.” His real name was John Osgood Thomson. He was a very intent old gentleman, who leaned over one’s shoulder while one was doing experiments -— very intently. He told about how he worked in Helmholtz’s laboratory, and how Helmholtz would come into the laboratory every other day and say something like, ‘Haben sie heute, eine kleine kurve?” [German] Well, that was just training in experimental techniques mainly. Largely in magnetism, too. Then, I went away for my junior year. I spent my junior year abroad. This perhaps had something to do with my world interests. I learned that Dad was sending my brother Bill — who’d been talked into it by some teacher-salesman he knew at Ann Arbor High School — into joining what was then the “University Afloat.” You may have seen ads a few years ago about a grand new idea called the University Afloat — did you see that? The steamer Ryndaur. Well, that was the Ryndaur II. We went on the Ryndaur I, and the strange thing is, that was — what happened a few years ago was history absolutely repeating itself, almost. Except that that was a one semester deal, the more recent one, and ours was a full year deal. Boats were slower in those days.
1926, something like that?
Well, this was 1926-27, yes. But the original University Afloat was quite an experience. I didn’t learn any physics. Well, not on the boat. I went to summer school in Ann Arbor after sophomore year and took a course with Karl Herzfeld — a bit over my head — in statistical mechanics. Herzfeld was on his first visit to America…
Heavy German accent?
Very heavy German accent, which he got over later. At any rate, when I heard that Dad was putting up the money for my brother Bill to go around the world, I tried to figure — Dad was already paying for most of my college education since I was going to Amherst, and I didn’t want to be hard on Dad, so I communicated with the Holland-American Line ship’s operator, trying to see if they would hire me since I had a first class commercial radio operator’s license — to see if that would buy me a trip around the world. Well, it turned out it didn’t. But I told Dad about my disappointment that it didn’t work and he said, “Well, I guess I could send you too.” So that was a year of travel — getting in a summer school beforehand, which was very instructive in physics, and getting a little taste of theoretical physics — and then, at the end of that year, I spent six weeks with a French family, on the 6th floor of a Paris dwelling, so as to learn how the French really spoke and get my ear adjusted to that language. Better than I could have at home or than I had in my freshman and sophomore French classes in Amherst College with a person who had no better French accent than my Professor Jeffrey Atkinson — that doesn’t sound very French, does it. Then I went to — still not learning any more physics, having studied first year German on the boat on the way around the world — I went to Heidelberg, to a “Verienkurse fur Auslander,” and there I caught on to German — the way the Germans speak, to some extent. So I did a little brushing up on languages in that junior year. I came back and senior year I had almost enough credits to graduate — since the dean agreed. I think I was the only one to do it, since the academic program of the University Afloat pretty much fell apart. There were a few individual things that went pretty well, but I wangled enough credits out of it when I talked to the dean here at Amherst that I was just within one credit, I think, of graduation at the end of my junior year. So I signed up to take a Master’s degree my senior year, and that meant doing a Master’s thesis in experimental physics, which naturally was on the subject of magnetism.
It was experimental in magnetism.
I notice that your earliest publication is something about the measurement of a magnetic field.
It was magnetic susceptibility. A low susceptibility alloy that was being used quite a lot then, and you couldn’t measure it by some of the standard methods that were used for a high susceptibility ferromagnetic — it was ferromagnetic but very weakly ferromagnetic. So I wanted to do a magnetization curve on it, and so I devised a method for doing it, which involved a torsion pendulum in a magnetic field — a torsion pendulum that could be heated, because it had to be measured as a function of temperature and the Curie point, and so on.
That was your Master’s thesis?
That was my Master’s thesis. 
And it was published in the REVIEW OF SCIENTIFIC INSTRUMENTS or similar kind of journal? 
Yes, and this was under S.R. Williams. His interest in magnetism suggested the problem. So my senior year I did this, and…
There was no question, you were going to be a physicist, by this time?
Yes, by that time I was going to be a physicist.
Medicine was out?
And the other alternatives were out.
By sophomore year I had decided I was going to be a physicist. So much so that even going around the world, I visited Cambridge and I considered myself a physicist enough that I went around and introduced myself to a couple of professors there, and listened to a lecture or two that were above my head.
Cambridge? Rutherford and Bragg?
Yes, it was Bragg I saw. He said, “Come and hear my lecture.’ But I’d made up my mind about physics by then, but I was having this wonderful year going around the world, getting acquainted with people’s languages and problems and attitudes. It was a terrific experience. Then, back here to Amherst for polishing off my senior year — also a good experience. I was mentioning courses I took, and you asked me about people who influenced me. Sophomore year, I took a course from Lawrence Packard This course was in the history of the origins of the First World War. And that bowled me over, to understand the kind of finagling that went on behind the scenes in politics. I’d just learned history, you know, as something out of the books that happened — cut and dried — this happened, that happened. But to learn the kinds of irrational decisions that led up to the First World War made a pacifist out of me, essentially. I just got to feeling how terrifically foolish it all was, that people couldn’t settle these things without war. I saw how it could have, it should have been done without war, but one thing led to another, and when you go so far, and one decision leads to another until somebody loses face and refuses to back down and so we have to have a war. And then thousands of people at the front go “over the top” and into the maw of machine guns and get mowed down — all on account of a poor decision at the top. And I think that that’s what’s got me so interested in seeing that decisions should be made right at the top.
Senior year — at the same time — I took a course in theoretical physics.
Did you get quantum theory?
In 1927? No, not here in Amherst College yet. It had just been invented. It wasn’t in the textbooks yet.
What was theoretical physics then?
Well, the one thing I remember is that I learned about calculating the energy levels of the Bohr atom.
Oh, you did?
Yes. It seemed so arbitrary but it was sort of fascinating. One of the things that I was going to have to know was how you derived all those things. And my professor reminded me years later, after I’d become a theoretical physicist, of a remark that I made in that connection, when I’d said, “Well, I understand it and it’s all very interesting, but why should I remember the sequence of those arguments, when you can see it in the book and it’s all so clear?” [laughter] I hadn’t quite caught on yet.
Many students would sympathize with that. Relativity?
There was a bit of relativity.
At the undergraduate level?
It was mentioned, but I didn’t get anything out of relativity till I got to graduate school.
How much mathematics would one learn as an undergraduate physics major?
It wasn’t very profound. Calculus wasn’t until sophomore year. Then I skipped junior year so far as mathematics was concerned, and senior year I had a course in analytic geometry and theory of functions, but that wasn’t very profound either. Not nearly as much as today.
Then you decided to go to Ann Arbor. Again, that sounded like the nearly inevitable choice, for various reasons.
It was the obvious choice, except it wasn’t obvious to me, because S.R. Williams was a tremendous admirer of Robert Andrews Millikan, and Millikan was just making a big thing of Cal Tech, and he thought that would be a great place for me to go. I learned afterwards that there was a letter from my father to Professor Williams asking, couldn’t he perhaps — he said, “There are some new people and a new program at University of Michigan,” couldn’t he perhaps turn my enthusiasm toward home? And he did. That worked fine, because…
Michigan was really beginning to thrive.
It was just starting to be a real center of theoretical physics in the United States, and it was the right place to go and I’m awfully glad I did. That was superb luck, that I happened to live in Ann Arbor at the time when that department grew the way it did.
Yes. Yes. So, well then, maybe I should ask you about Ann Arbor at that time. It was really one of the exciting places in physics —
— in the country, if not the most exciting place. Let’s see, Uhlenbeck was there and Goudsmit.
And Randall was the chairman of the department?
Randall was the chairman of the department, and he had built up the department for a good many years, he and colleagues had built up a very fine classical physics department which specialized in infrared. They were doing infra-red spectroscopy I think better than elsewhere in the country. At least they had a very fine start, in recognizing research as a part of the university physics work, in their infra-red business. And Colby was the theoretician of that generation of physicists. Myers was there and Barker, and all of them interested in infra-red and things associated with infra-red, and acoustics. Myers was more in acoustics. And there were about three experimental physicists in other specialties. So that was a good department that way. But I think it was Colby who appreciated that quantum mechanics had been invented, and there were some bright young Europeans, and he made a trip to Europe and picked up the then “physics twins,” Goudsmit and Uhlenbeck, discoverers of electron spin, and Otto LaPorte. Oh, I should say, a native son, Dave Dennison — had graduated from Ann Arbor, I believe. I’m not sure of that. And had gone over to Europe for some training, and he was back there just before Goudsmit and Uhlenbeck came, I believe. But at least there were four - in addition to Colby, who was a very fine theoretical physicist of the classical school — there were Goudsmit, Uhlenbeck and Dennison, as the three young shining lights, which renewed the department, you might say.
And that was a great contribution. Dave Dennison was away on leave of absence most of the time I was there, so my real influence was from Goudsmit and Uhlenbeck, and they were my joint thesis advisors. I also took Colby’s course and learned a great deal from them. But that was the time when Ann Arbor was interesting not only during the school year, but they’d instituted those Summer Symposiums. I went to what I guess was the first one, or practically the first one, in my sophomore year, with Herzfeld. But after my first graduate year, and for the second and third, there were just constellations of stars from all over the world. Oh, I met all the greats — Dirac and Milne, Kramers and Breit, Sommerfeld and Pauli, and a number of others. And Fermi — perhaps the most important. It was a great assemblage. Oppenheimer, as a very young instructor from out in the West, and the young people who came to listen became quite a stellar lot too, some of them my life-long friends.
Yes, who was important to you among those people during the Summer Seminars? Is there any particular person that stands out? When they were all stars?
I can’t distinguish which I learned the most from. Fermi’s style I think impressed me most, and he came twice. He was there once while I was a graduate student, but then again a few years later. I guess it was ‘36, he was there again, and lecturing on thermodynamics as well as quantum electrodynamics. Wonderful. Well, I’m not sure I can say there was a lot of excitement. I found Oppenheimer very fascinating but hard to keep up with.
Let’s see, oh, Linus Pauling was there too, writing a book with Goudsmit in the summers. He wasn’t quite so stellar in those days. But these people — I kept meeting them through later life too and was glad I’d known them for a long time. Of all of them, I think my later friendships were with Pauli and Fermi mostly I had nice discussions with Sommerfeld but we weren’t as close.
Well, what’s it like to work with Uhlenbeck or Goudsmit? What was the pattern of a graduate student doing his research under Goudsmit or Uhlenbeck?
Well, they were very different. They were “physics twins” who were very different personalities, as you know if you know them.
Yes, I know.
You can imagine, in those days, if you look back at the pictures of those days, we were all so young — all looked so young. They were just a couple of years out of graduate school themselves, but from a more advanced graduate school of Leyden; with the European custom of students taking a little longer to get their graduate degrees.
And they were both Ehrenfest’s students, I think.
Yes, both Ehrenfest’s students. I didn’t mention Ehrenfest among those at Ann Arbor in the summer one of the greats that we mentioned.
Oh, he came too?
Oh, he was there too, and he was a very sympathetic personality. I have some very fine memories of Ehrenfest. We became quite close friends for a short time. But Goudsmit was a specialist in atomic spectra, and he was very enthusiastic and somewhat offhand about it all, and almost always with a bit of humor in everything he said. His classroom style was such a contrast to most of the teachers, who seemed to take what they were doing very seriously, in that he would be so offhand for two-thirds of the hour, and his repartee, practically, and anecdotes… Then all of a sudden, he’d get down to realizing, “Well, I have to get this far today,” and he’d start very methodically putting on a nice explanation of some aspect of atomic theory that would work out very nicely, but you had to be rather quick to catch it before the hour was over. But that repartee session was one of essentially communicating enthusiasm for the subject, before getting down to brass tacks. It was the sense of enthusiasm that sort of stood out and led the whole thing, kept everything stirred up. Uhlenbeck was the analyst. His courses were very systematic lectures with notes on the board, all written out so that if you hadn’t heard the lecture you could still understand it. You heard the lecture anyhow. He always started off with a column on the right hand side of the board, then moving out from in front of it another column — so you could always see what he’d written before, and a good well-organized lecture style, communicating things that were not available — well, in statistical mechanics, it was a wonderful course in statistical mechanics.
He gave that course?
Yes. It wasn’t in the books yet, but he worked it through, and it was in the research articles, and he had it all so beautifully organized.
Yes, these sort of men were good to learn from. But how about research?
Well, when it came to doing, when I got far enough along so that it was appropriate to do some research work, I remember, I got started with Otto LaPorte who was the fourth member of this group of young people who had invigorated the department, coming from Sommerfeld. So we had both Ehrenfest and Sommerfeld students to work with, as well as Dennison. He was more influenced by the English school.
Who taught quantum theory there? Who did you listen to on quantum theory or did you read it?
That was with Uhlenbeck too. The textbook then was Sommerfeld’s ATOMBAU — WELLEN-MECHANISCRER ERGANZUNGSBAND, in addition to his older book on quantized atomic spectra.
An addition to the classical…
Yes the classical ATOMBAU UND SPEKTRALLINIEN was about 3 centimeters thick.
Yes, this is like an addendum to Sommerfeld’s theory —
The WELLEN MECHANISCHEN ERGANZUNGS BAND was about 1-1/2 centimeters thick.
Then Kemble came much later?
Yes. And I should say that, coming to Michigan, I still was going to be an experimental physicist. That was clear. I liked experimental physics. It was so much like all the tinkering I’d done with radio, you know, in which you have to understand the general principles, but mainly you do it with your hands. Well, when I came to Michigan, I looked at the list of courses, and there was quantum mechanics and statistical mechanics and all those things, and I thought “oh my, I’m going to have to take a year off and learn some theoretical physics before I go do experiments.” So I took that “year off” — and it took quite a while. I didn’t get back to experiments again until — when was it? 1939, I guess. And that was only a short interlude.
Theory got you.
Yes. Even before I was ready to start a doctor’s dissertation, when I was taking — I guess it was my second graduate year — well, I had been through some atomic spectroscopy.
That would be with Goudsmit?
I was taking Goudsmit’s course, but Otto LaPorte said, “I have a little problem I’d like to work on here. It’s a pretty small one, but there are some things to work out. Wouldn’t you like to work on it with me?” Sure enough, we worked on essentially transferring things from particles to holes, how the spectrum of neon compared with lithium, things like that — from the beginning to the end of a shell, before a shell model was really in, but we recognized shells all the same, in atomic spectroscopy. So I worked out — doublet — separations in almost closed shells, with LaPorte, as I think my first endeavor in theoretical physics. And I was a little bit more than a computer in that. I was to LaPorte somewhat more than a desk computer is to the physicist today. We worked on it together. I began to learn how you assemble evidence, and figure out how things agree with theory that way. The theory was very simple.
That’s this paper, “Resonance Separation and Configurations of the Type P.5 and P.9”? 
Yes. Well, that was somewhere along toward the end of my second year as a graduate student. And from there I went on to various other things, before I finally got around to a thesis dissertation. One of those things was suggested by Uhlenbeck. But then when I got on the thesis it was suggested by Goudsmit, but it was something that he and Uhlenbeck were both very much interested in, so I talked almost equally with the two. Uhlenbeck sort of helped keep me going in the right analytical direction, and although I used simplification methods that had been developed by Goudsmit, it was very much between the two. I worked more with Goudsmit than Uhlenbeck but Uhlenbeck was very helpful. They were both my sponsors.
They were both available to talk with?
Oh yes. That was very fine. We were a dozen or more graduate students, but they found time to talk with one of us, part of one afternoon, and another an hour the next afternoon or something.
Very different — how would you describe the difference from a graduate student’s point of view? I think of Goudsmit as being much more empirical, Uhlenbeck as much more concerned with formal theory.
Well, this was true then. But Goudsmit was very clever at seeing the simplicity behind… I learned some of, but I wish I’d learned more of. But it was an inspiration to work with him.
Yes. You mentioned there were ten or so fellow students who were graduate students. Any one that you particularly remember, who was important to talk to?
Well, I suppose I should mention — on the theoretical side — ones I talked to more in later life: E.J. Konopinski and Lloyd Young. Konopinski was a little later. He was a beginning graduate student when I was finishing. Lloyd Young was I think the year before me. And I got to know Lloyd Young much better later, when we both lived in Pittsburgh. But that’s a later part of the story. Then, on the experimental side, I remember John Strong, who is here in Amherst now, a colleague here in this department, who was also a colleague of mine at Johns Hopkins, on the way from there to here. Michigan, Maryland and Massachusetts. My office mate was Lorne Matheson, a Canadian experimentalist, with whom I did an awful lot of discussing, and perhaps I kept in touch with experimental things a bit through talking with him.
In spectroscopy, your early ideas were in terms of the vector model, classical vector model?
And I suppose the intuitive ideas still came very much thinking in terms of the vector model.
And then, the use of more formal quantum mechanical computations were used to check the vector model, the intuition of the vector model, or…?
Well, there was a transition, of course, from one to the other, and gradually it became increasingly apparent that the vector model was expressing things in a simple way, that was the result of quantum mechanics. But I think first came — Well, the idea of mixtures of states in one representation being the states of another. The vector model would be two extreme representations for different situations. Take the LS coupling vector model and the JJ coupling vector model. It was recognized before the days of quantum mechanics that if certain types of energy are large, one model works. If other types of energy are large, the other model works. In the problem I was particularly interested in, it became apparent that this was a result of quantum mechanics, that these were just two representations of the same matrix, and that there was an intermediate condition where quantum mechanics would do the job and vector model won’t.
Right, and that’s a theme that comes up again with your nuclear physics later on.
Yes. Sure. The vector model continued to be very interesting, very important, as a visualization of some simplifications of quantum theory.
I notice you mention in one of your papers Van Vleck’s book.  Is that a book you recall reading?
Yes. Yes. John Van Vleck was another one of the people I first met in the Summer Symposium at Ann Arbor, and later we were colleagues at Princeton for a year. This, perhaps, is one aspect of quantum mechanics having filled in for the vector model. Suddenly we had tremendous realization that the things that we’d been talking about in the vector model are really justified, now we can explain them — the business of magnetism had that same kind of transformation. People talked about magnetism in terms of the Weiss theory and all that type of thing, and then, Heisenberg came along, with the idea that this field Weiss was postulating was really an example of the same sort of effect that separates singlets from triplets in atoms. The stability of solid state physics, you might say, mathematically. Rather, the forces within the atom that make triplets lie below singlets, and also make the spins associated with adjacent atoms in solids lie parallel or anti-parallel.
It’s the same thing, and all of these are the result of a combination of the Pauli principle and electrostatic interaction. But all those things are bound together by quantum mechanics. Whereas Weiss was talking about little magnets that point together with some mysterious force, finally the mystery of the force was traced to quantum mechanics. And the little magnets were the electron spin that Goudsmit and Uhlenbeck discovered.
Was there a question at the time whether the Heisenberg explanation would be rather localized?
Oh, yes, of course —
— there should be some question whether there might not be some other long range —
— well, of course, the Heisenberg — yes, the detailed Heisenberg explanation is one thing. But the notion that the force came from that interaction was another, much more general. The general thing was true. His particular explanation contained the element of truth, but there’s so many loose ends in the way of non- convergence, and you can’t prove that — a lot of little contributions aren’t as big as the big contribution, that type of thing. I think his original explanation doesn’t quite hold water, in the details. And that was a large part of my interest, in those days. A couple of years of my life I devoted to just that question.
You took the Heisenberg model with —
Yes, what I tried to do — Slater got into this act in a very interesting way shortly after Heisenberg did — trying to show what it was about the size of the atomic shells in iron, nickel and cobalt, that made these three elements ferromagnetic and the others not. All that business fascinated me very much, and I tried to see how much one could quantify that thing. I spent a couple of years with a long slide rule and a lot of paper, doing what you could code in perhaps a month now and run off on a computer in an hour! Trying to see, to what extent one could quantify these notions of overlapping of S-shells and P-shells. The question of whether it’s ferromagnetic or not ferromagnetic depends on the competition between two effects, one that arises from the interaction of two electrons from a neighboring atom, and one which arises from the interaction of an electron mostly on one atom with the nucleus of the next atom. The electron on the atom has a negative sign, and the nucleus has a positive sign — these two contributions have opposite signs — and one has to quantify both contributions, in order to decide whether the thing should be ferromagnetic or not. That’s really what I attempted to do, and in the course of it —
— the computation is really formidable.
Yes. In the course of it I came to realize that there are terms, in what should be a long series, that Heisenberg hadn’t gotten to yet, which raised a very serious question of convergence of the whole thing, whether it means anything or not — whether there are a large number of small terms that overwhelm the small number of large terms. And that’s a question which I never solved, and John Van Vleck took it up from where I left off, and got much closer to a solution, showing that the convergence was better than I’d feared.
That’s a hard problem.
Yes, it’s a very hard problem. Well, solid state physics nowadays goes about it in quite different ways, more akin to molecular orbitals. And they have different answers. Well — the whole problem looks rather different in their terminology.
The heirs to Slater’s group are computing exact shells.
Yes. Well, that’s a question which — arising from my experiences, from S.A. Williams and magnetism, and then quantum mechanics, and then atomic spectra — it was a natural sequence.
That’s beautiful, coming from a very experimental phenomenological theory to quantum mechanical theory.
The Curie point interested me very much. Very early in the game I published a little Letter to the Editor showing that Heisenberg’s calculation of where the Curie point was was somewhat ambiguous. And it was just after doing that that I took a leave of absence from teaching and decided to be with Heisenberg in Europe.
The Heisenberg theory of ferromagnetism — I think it’s that paper you’re referring to?
Well, there were several papers that had to do with that.
You wrote a paper on a generalization of Dirac Theory to two body —
Yes, that was earlier. That was before I did my thesis, at the beginning of my last graduate year.
You learned Dirac’s theory from somebody, somewhere.
Oh yes. I think I probably learned about Dirac’s theory in the course with Uhlenbeck, though I’m not sure. I think probably Uhlenbeck suggested that approach, in that paper.
What was the topic of your thesis?
My thesis was in this intermediate coupling business that I mentioned to you. It had been done, in two body problems, and I carried it on to a three body problem. That was — let’s see — “Energy Relations in Complex Spectra.” 
At that point, did you have scholarships or fellowships to help support graduate students in Ann Arbor?
Yes, there were such. And most of my friends had some kind of a scholarship or other. They were largely lab assistantships and things like that. This was before the 1929 crash, when I first went to graduate school in ‘28, and Father was still not pinching pennies as much as he was after the crash. But at least Father had, very generously, I think, philanthropic man that he was, felt that the scholarships were for the people who really needed them. And since I was going to university at home where I didn’t have any dormitory expenses and so on, and a state university where tuition was relatively light, I think, compared to now, that he was happy to support me through graduate school. I learned economical habits by appreciating that Dad was doing this, and not trying to be hard on him. I tried to go easy on him. But all the same, I had a very pleasant life, and I didn’t really need the scholarship. I think Dad was right, that another person could come to the university — perhaps one of the good friends that I made — with a scholarship. But one thing that it did mean was that I didn’t get the teaching experience, elementary and laboratory assistant type of teaching experience, that my fellows were getting. And as I was getting within a half a year of my doctorate, Professor Randall realized this. He said, “You’d better take a lab section.” So I earned a little bit of money from the lab section. He said, “I’d just like to have something about your teaching experience for me to write about, when you graduate.” The only scholarship I had was, I think, one lab for a year, and it was just incidental. It wasn’t for the money.
You graduated after the Crash?
So that it was the beginning of Depression times.
Oh, by then it was quite hard to get jobs, yes. Incidentally, I applied for a National Research Fellowship. Oh, the number came down by a factor of ten or something — at least there were very much fewer of them than there had been — and I think Bob Bacher and I were competitors for one and he got it. [laughter] So that left me without a job.
Yes. You mentioned traveling in Europe, and Heisenberg was there. Was that after you finished at Ann Arbor?
Yes, it was after I’d taught a year. It was part of this business of not having fellowships available during the Depression. They were very rare. Yes, I graduated without a job, and I thought, “Well, I’d saved up a little money, and maybe I’d have to sponge on Dad a little longer.” I thought I’d spend a year in Europe, and conclude my studies that way. I’d gotten fascinated with Europe anyhow, through this business, and —
Did you learn Dutch?
I didn’t. “Steam vort Mad chipie” are the only words I know practically. I can read it a little bit. I’ve been to Holland. But I never learned Dutch. I only speak French and German. Smattering of Italian, Spanish and those things, slight contacts. I thought I was without a job for the next year, and I went off to the Rockies with two friends for the summer and had a wonderful time. Got back toward the end of the summer and learned that there was an inquiry for a candidate down at Ohio State. Professor Randall dispatched me down there — I hitch hiked down to Columbus and had an interview, and came back with a job. So, I worked for the school year in Columbus. It was a job that was meant for a married man, an instructor — not much in those days. I had frugal enough habits so that at the end of the year I had spent half of my salary, and made myself my own fellowship to Europe for the next year. By that time I’d gotten interested in Heisenberg’s theory of ferromagnetism, and I’d known Heisenberg at Michigan enough to know that I’d like to be with him. So I went to Europe, right after school was out. I first went to Copenhagen because my colleague, Harold Nielson at Ohio State, was being married to a Danish girl that he met when he’d been at the Bohr Institute a couple of years before, and invited me to come and be his best man. So I had that acquaintance with Copenhagen’s high society for a week or so. And then I made my way to Gottingen by way of Stettin, Berlin. I looked up Wigner in Berlin, I remember, in Charlottenburg. We talked over a few things. But Gottingen, that was quite an experience.
Did you meet Wigner at a summer seminar there?
I think I’d met Wigner very briefly before. At Gottingen that summer — well, Born was of course the center of things in theoretical physics, and he incidentally was paralyzed in one half of his face, so he gave lectures out of one half of his mouth. He wasn’t later. But as I mentioned, it was so strange that in her later years, Maria Goeppert-Mayer, who was Born’s student, and whom I saw that summer at Gottingen, had that same affliction.
Oh, you saw her that summer?
Yes, but it was many years later that she had that. I’ve only seen two people in my life that ever had that affliction — Born and his former student, Maria Goeppert-Mayer.
What people did you see in Gottingen there? Was Heisenberg there?
Heisenberg only came for a couple of days. But there I first met, most importantly, Edward Teller — we’ve become fast friends for a long time since, Also, Felix Bloch, whom I got to know quite well; Heitler, and Lothar Nordheim. Well, Joe Mayer and Maria were there — they were just married, I think. I had met them also at Ann Arbor, but it’s Maria’s home town and I met her parents there. But the important thing was —
Ann Arbor is her home town?
Gottingen is her home town. That’s Maria’s home town.
There were some other Americans there. I don’t know if that would be at the same time — Condon and Oppenheimer and Norbert Weiner?
They were there at other times. Oppenheimer had been there.
Had been there?
He was there way back in ‘27, ‘28. Or ‘29. This was the summer of ‘32, when I was there. I didn’t have any very definite program or anything, but I just made acquaintances and attended some of Born’s lectures, and had my discussions. The discussions I remember were mainly with Edward Teller. I found that he and I more than the others liked the idea of trying to visualize, as clearly as you can, in as simple terms as you can, what’s going on, in quantum mechanics. I remember it wasn’t until then, talking with Edward — he taught me the real point of triplets lying below singlets has to do with averaging — averaging the fields between the electrons, and depending on (as compared with the interaction with the nucleus) — depending on whether there is a node in their relative wave function, between them or not, so as to make them either more probably close together, or more probably far apart. That was associated with whether they are parallel or anti-parallel, through the Pauli principle. It’s simple and every graduate student knows it today. But it took a long time to come to it then.
— it’s a very physical way of seeing that.
A very physical way of seeing it. But it was that interest in this type of seeing things clearly, that — was slow to come out in quantum mechanics. But Edward was very much interested in drawing it out. I liked that. We got very well acquainted, knocking around together in the summer and discussing things.
Gottingen is very famous for its — even Born too — for the emphasis on formal mathematical —
Rather than the emphasis on physical intuition.
Yes. Heim: When you’re talking about Gottingen, you’re talking about Teller, who emphasized the other. That must have interested you most at that point.
At any rate, another person I met at Gottingen that summer was Walter Heitler who was interested in these same things from the point of view of molecular interactions. He invited me to join him and his family in the Alps after the summer semester was over. And he and his family went to a little place in Austria, in the Tyrol, to a little town of Trins bei Steinach am Brenner. The little town’s name was Trins. They were going there for the first two weeks of September or something, so I was to join him there later. We left Gottingen the 1st of August or so. In the meantime, I went to join a friend of mine who had asked me to come and visit his family, south of Tubingen in Schwabenland in southern Germany. This is a friend who was an exchange student at Amherst during my senior year, and I traveled with him in the Rockies that summer after my senior year, and another Ann Arbor friend — three of us. Well, I lived with his family for a month, practically as a third son, and so I got well acquainted with the “du” form of German. Well, I went from there on to this lovely little place, Trins in the Tyrol, Heitler and I. He wanted to climb mountains. His parents didn’t climb them, and so my function was friend and climbing companion, and I learned from him about those nice mountains there. I usually hike in very light shoes in the mountains here, but there they insisted, we had to cross glaciers, and you had to have real hiking boots for that. So r went into Steinach and the cobbler measured out my foot carefully, and four or five days later he had my boots ready for me, all built. We climbed the mountains and hiked across through the glaciers and things, with a path trodden out a little bit. Oh, we didn’t do anything very dangerous, didn’t even carry ropes most of the time. It was very nice climbing. I remember, once when we got up to the top of the highest mountain around, and Walter pointed way off this way, to the northeast, and said, “There is the Wildspitze.” I looked around and I said, pointing down toward the southwest, “No, it’s off that way.” He scratched his head and said, “You are right. You Americans, you grow up in cities where all the streets point north and south and east and west, and you know which is which…” (laughs) All this in German, of course.
That’s great hiking country there, Austria. Tubingen, that’s more forest, isn’t it?
Yes. Well, it’s more farm country, really. It’s east of the Schwarzwald, 50 miles or so. Actually Tubingen has more forest, I think.
When you think of physics discussions there, did you see Heisenberg?
He was at Leipzig or —?
He was at Leipzig, yes. Yes, that’s where I — I was leading up to getting to Leipzig. This was a period in my life when I was wandering around from place to place and making acquaintances, and I still remember it very vividly.
Very much a traditional activity — some time after college, to spend a few years wandering about Europe.
Yes. I only afforded one, but this one was a good one for me. Well, I decided I wanted to go to Heisenberg, and I wrote to Heisenberg and asked him if I could — I just reminded him of our acquaintance, and asked him if I could join his group for a year, and he wrote back a very cordial letter, I think sometime during the summer. But the winter semester didn’t start until about the first of November or later November at Leipzig, and that left me with a month and a half, in which I decided to go down to Rome. Fermi’s semester started early, down south, and so I spent a month and a half in Rome, just as a sort of adjunct to Fermi’s group — they were just starting to get interested in neutrons that had just been discovered, and they were very excited about those things. It all seemed very strange to me. Hearing about it in Italian didn’t do much good, but we talked about it some in English too. And Rudolph Peierls was there, by the way. He was there as Fermi’s assistant that year, and I think that’s the first place I ever knew Rudi. Yes, I think I met Rudi then, and he was there with his new Russian wife. He’d been in Moscow the year before, I think it was, and came back with a sergeant out of the Soviet Army as his wife! Well, that was a fine year.
Fermi was doing nuclear physics?
Yes, he was just starting to do experimental nuclear physics. He saw some opportunities there. He was doing mainly theory.
1932 was the discovery of the neutron. That was the time when nuclear physics really got boosted.
That was the beginning of real nuclear physics, I think. The discovery of the neutron. When we finally found out, it was neutrons and protons — not protons and electrons, as we’d thought. But — well, that was a pleasant stay in Rome. Of course, Rome was a beautiful city to get acquainted with. And Gene Feenberg was there — in the same sort of capacity I was — as a visiting American scientist. We knocked around town a lot together. I remember, in our discussions in restaurants — one was careful about what one said — so we just made up code words: “Al Capone” for “Mussolini,” and then everything was safe! (laughter)
Yes, that was the time.
So we did a lot of talking about Al Capone and his policies.
Did you in Germany notice the undercurrents already?
Oh, very much. Yes, that was later in the same year.
Nazis coming to power, or on the verge of it? That was interesting — that must have affected physics, too.
Yes. The first time I was in Germany, in the summer of ‘27, when I was at Heidelberg, one practically didn’t hear of Hitler. He was just getting started. But in ‘32, ‘33, he was pretty well along. In Gottingen, all the students — the people I knew rather — the young Privatdozenten and so on, were interested in this phenomenon of Hitler, and how it seemed to be taking on in the country and beginning to look really dangerous — so many people rallying around him. When Hitler came to give a talk at a big rally outside of Gottingen, a group of us went out to hear him. It was interesting, this awful phenomenon that was happening. I think it hurt our conscience very much that we had to pay a mark to get in, which meant we helped him. But maybe it was 50 pfennig — it wasn’t a very big boost. So we heard him give a harangue. We were interested in the organization — all these black-banded Schutzstaffel guys marching, very smart, and the crowds around to get them out, and this tremendous outdoor place where people stood around in front of a big rostrum, and no Hitler for about half an hour while people waited for him to arrive by airplane — and harangue for about 15 minutes, and that was it. It looked like an awful force coming on.
Yes. You know, it’s been claimed that the universities unintentionally gave him a lot of support, because many of the university professors in Germany were opposed to the democratic regime at the time, as watering down “kultur,” so they were very conservative, and in this way made common cause — with the conservative right wing groups, not with the radical right wing groups. In the end, they ended up supporting each other.
Well, I think there’s some truth to that — at least a part of the academic community — but I didn’t experience it. No, my next experiences with Nazism were in Leipzig, where I lived, first, in an apartment house almost next door to the physics department, where Arnold Siegert had a room close by — in a rooming house. A place of surprisingly primitive plumbing and what not, an old place that gave you almost a taste of the ways of Medieval Europe, I thought, before I moved into a more modern pension downtown, where I had to ride my $5 bicycle back and forth some distance to the university. But when down there, I heard a good deal of shots down the street, and street fighting and what not. I sort of stayed in and I didn’t participate in any of it. But I knew that serious things were going on, and there was discussion in Heisenberg’s group of this menace. But it really didn’t affect us very much that winter semester of ‘32-‘33.
In terms of physics, was it an exciting group, or were you —
Oh, yes. I can tell you more about that, but first about the Nazis.
OK, good. You know, there’s always been some controversy about Heisenberg’s own view of —
Well, first let me go on and just finish this sequence. Sommerfeld’s semester ended a week later than Heisenberg’s semester. So I went down and was one of the visiting post-docs, you might say, at Sommerfeld’s group in Munchen for just that week, and heard a couple of Sommerfeld’s lectures and talked with his students, and that was pleasant. Sommerfeld invited his graduate students and me around to his house one evening, a Thursday evening, the 5th of March, and we went there. I’d read a little in the papers about something going on that day, but I didn’t pay much attention to it, and we arrived at his house expecting a pleasant evening of discussion, and it was that, except that Sommerfeld was very sad. And why? He explained to us that the Bayrische Wahl, the Bavarian election vote had gone in favor of Hitler, and while this was only in Bavaria, Sommerfeld sort of appreciated, as none of the rest of us did, that this was the turning point. That this made it inevitable that this man was going to come into power. He was very sad about it.
This was ‘32, or —?
This was in the spring of ‘33, now. The 5th of March, ‘33, was the turning point. And that was my experience. There was another Nazi thing, a little later. During that week, I inquired about going to the Alps to do some skiing for a week or so, and some friend introduced me to a girl who was a member of the Munchener Ski-Verein which was the ski club of the University of Munich, and suggested it was easy to join. You didn’t really have to be a student. So I joined, went off on an “Ausflug” — a skiing excursion — to Tyrol again — a little bit east of where I’d been with Heitler and indeed, among other things, we climbed the Wildspitze. This time I was closer to it than when I’d pointed it out to Heitler. And on the way down — that Alpine skiing in the Tyrol is out of this world, when you get above the timberline. Those tremendous snow fields. This was a matter of, first a trek on skis up to a little hut — well, a little group of huts that had been transformed into kind of a chalet for visitors. They could take a hundred visitors, I guess, in that group of chalets there, and the club had reserved this space for us, for our hotel. But you could only get up to it on skis. I think they hauled a little baggage for us up to it by a mule or something on a sledge. At any rate, we were about at timber line, when we started out on the expedition. A group of us went way up a valley and passed a little Alpine hut, the mountaineer’s variety of Alpine hut, up where the glaciers started, and put up there for the night. And then from there we climbed the Wildspitze, the highest mountain in the Tyrol, I believe.
In those days, it was essentially what we’d call nowadays cross country skiing. It had more control than what we do as cross country skiing now. You could buy real seal skins in those days. We had skis without even steel edges, but we had genuine seal skins, which is great for climbing mountains because you just walk up without any slide back. It’s just as good as snow shoes but easier. Then you take them off when you get to the top and slide down without them. Well, on the way down I dislocated my shoulder. This is something that I had done on that trip to the Rockies just after graduation, and I’d done it a couple of times playing tennis. So I had a dislocatable right shoulder, and unfortunately I dislocated it up there, not far below the top of the Wildspitze. And this was really too bad, because it meant that some of the fellows had to help me down, rather than skiing free down, having climbed up for the ski down, as we did in those days when there weren’t any lifts. But they managed to get me down on a litter made out of a couple of pairs of skis.
I will skip my horrible tale about the horrors of getting put back together on the operating table down there, after having been filled with schnapps in place of an anesthetic. It didn’t work. But after considerable struggle and some instructions from me — in wildly ungrammatical German — as to how to do it, they finally got me back together, so that I could hike down to the other hut the next day. Well, excuse me for putting in this irrelevant part of the tale, but the part that has to do with Nazism comes with the fact that I arrived in Zurich a couple of days later, with my arm in a sling, thinking I would be in Zurich a couple of weeks until the semester in Leipzig started again. But there I met Felix Bloch, and Bloch said, “Dave, Geh nicht wieder nach Leipzig. Man kann da nicht mehr studieren. Die Nazis machen zu viel kracht.” “The Nazis are making too much commotion. You just can’t study any more in Leipzig.” So I decided, well, I’d already had my discussions about the subject I was interested in with Heisenberg and Weisszaker up there. I liked Pauli and thought that was a great idea, to stay in Zurich for the rest of the year. So I had my second semester in Zurich, and that again was a great —
But you had spent some time with Heisenberg.
I’d been, the first semester, and the second semester I spent in Pauli’s institute, E.T.H. (Eidgenossische Technische Hochschule) in Zurich. And just down the road, down the Gloria Strasse a little way, was the physics department of the University of Zurich, where Greger Wentzel was. So that was a great combination, too.
Yes. Before you get there, I wonder, is there anything that would be worth mentioning about what happened when you were at Leipzig with Heisenberg, in terms of discussions or people or interaction with Heisenberg?
Well, actually, Heisenberg is a wonderful grasshopper physicist. He jumps from one thing to another, and conquers each one on his way. So ferromagnetism was not his first interest, by the time I caught up to him there. But he had sort of a vestigial interest in it. So it was more or less in a condescending way that he went back to his interest and looked at my interest in filling out the details of his theory. But he and Bloch both — I’d already published this little paper and they looked into the details of that, saw what I was aiming at, and I discussed a little what I was intending to do by way of going further. I think r really didn’t get anything much more than inspiration. A little bit, in the value of the discussion. So the experience was valuable more for my contact with Heisenberg’s lectures, which I listened to some of the time. And I heard some lectures of Wentzel’s, which were nice. But also contact with students, the social contact with the students. We used to go up, a couple of evenings a week, and have a social evening in the little quarters that the theoretical people had there, and I think then Heisenberg still lived in the Institute. But at any rate, I remember ping pong and chess were amusements, those evenings. And among the graduate student friends that I made there, Arnold Siegert is the one I ran into most later, when we were in the Chicago region. Wolfgang Knoll I ran into teaching in Taiwan many years later.
Maybe Zurich became for you the more interesting place.
Yes, my contacts, getting into the physics of the place, was more successful in Zurich than in Leipzig.
Pauli was there?
Yes, and Casimir was Pauli’s assistant that year, and he was unattached, as was I, so we became extremely close cronies for the semester. Here’s a story I would like to tell you, for the record. Rather early in our visit there, Pauli came to that wonderful point where he had passed his driver’s exam. — He’d tried it with 50 driving lessons and flunked it, and then he’d gone on, after 100 driving lessons, he had finally passed, just the last week. He had had his nice 8 cylinder Ford that just came out that year waiting for him at the Ford agency for a month or so, until he would have passed his license, and had just received delivery on it. Would I go with him over to the Physical Society meeting, the “Luzerner Tagungen” — over in Lucerne, which is 50 kilometers, maybe. So, he invited the four of us who were post-docs with him, Casimir and Bloch and Elsasser and myself, to drive over to Tagungen with him. We started out boldly from Institute early that morning, and started driving down the Gloria Strasse which goes winding down the hill with a double streetcar track on it — we used to have them in those days. The first exciting incident was when coming down hill, Pauli saw that there was a space between the upcoming cars further down and the downgoing car which had stopped. So he went alongside one car and in between the two cars, very successfully, missing the oncoming car, and started saying this wonderful expression of Europeans, that he repeated several times during the day: “Doch, doch ich kann fahren.” It means, “Sure, sure, I can drive.” Having just passed his driving license. And our hair was standing on end already. But this set the stage for the rest of the trip. It was like that all the way over, several rather hair-raising incidents, so that when we got to the Tagungen — well, we got there OK. Pauli was somewhat interested in the meetings, and of course, also, being Pauli, somewhat interested in the bar. I should say, the Tagungen was held in the casino, the biggest building in Lucerne, with all kinds of side attractions. And Pauli loved his cups. He held it well. Pauli was a very genial friendly man — to those toward whom he was friendly. He was very sharp to those he wasn’t.
People have said how he intimidated people.
Oh, he did. Yes, he could intimidate people too, but he was very warm-hearted. So I attended some of the meetings, and he did too, and we both heard a talk that was given by an experimental physicist from the University of Zurich, talking about some peculiar measurements he was making that had to do with the hyperfine structure of mercury, a complicated spectrum, as affected by a magnetic field. He’d developed some very odd methods. It was quite different from any other experimentation I’d ever heard of. And he was getting some very peculiar results. Pauli right away sort of nodded to me and said, “You know about atomic spectra. Why don’t you tackle that?” This was my assignment for the semester.
The hyperfine structure of mercury?
Yes. I did work on it. Did a paper on that. It gave me something very definite to do, and it was quite a challenge, and it was not so different from some of the things I’d done before. I was able to unscramble some funny stuff, and make some sense out of the experiment. But when I got around to writing it up, and I did this all in those three months or so I was there, I got to the point of writing up the results, and I decided — you know the reverence we had for German physics, all during my graduate school, and the ZEITSCHRIFT FUR PHYSIK was sort of what the PHYSICAL REVIEW is now.
Is that what you read, as a graduate student?
We read the ZEITSCHRIFT more than the PHYSICAL REVIEW probably, although there was very good stuff in the PHYSICAL REVIEW too, already, with Slater, Van Vleck, and people like that coming along. Well, when I got around to writing this up, I decided I’d like to publish something in the ZEITSCHRIFT while I was there, in the German language, even though I was in Switzerland, I’d publish in the German ZEITSCHRIFT. Well, I think Wentzel thought maybe that was a bad idea because the ZEITSCHRIFT wasn’t going to amount to so much now that the Nazis were getting where they were. Maybe I’d better put it in the HELYE.TICA PHYSICA ACTA, but I held out for the ZEITSCHRIFT. I remember that after I’d written it up in my German, Walter Elsasser was very nice about reading the paper and doing a little bit of red penciling and getting it in shape, and I remember that Elsasser, not having specialized in atomic spectroscopy, expressed great wonder at it being possible to unravel that stuff. I made that contact with what was going on in Zurich. It was a pleasant experience.
Was Elsasser already at that time interested in the emergence of the earth’s magnetic?
No, that came later. More about that later, if you like. But let me get us back to Zurich. I left us at the casino. Well, we sort of stayed over for some of the extracurricular activities in the evening, and it became apparent that we had a problem here, because Pauli was a very insistent person, and he holds his liquor well, but he’d had a lot of it. So a plot was made whereby, when we got to the car, there would be a sudden insistence that Pauli was not going to drive, and of course the natural driver would be the American, since all Americans drive. But the plot failed to work. Pauli’s insistence prevailed, and the ride back was even more hair-raising than the ride over, being at night. I remember one time when the road turned rather sharply to the left, but Pauli did not, because there was a driveway going straight ahead, which went right through a barn with both doors open, front and back, and we went through the barn and around the barn and back on the highway again. Very quickly. Every time, “Doch, doch, ich kann fahren.” (laughter) We got back; merkwurdiger Weise. Well, now I’ve got us back to Zurich. My contacts, by the way, with Casimir were the most valuable that year. Casimir was there, a Dutchman speaking German. I had met Casimir already at Ann Arbor, when he and Kramers had been there. Kramers was another one of the great physicists I met at Ann Arbor. Casimir was sort of Kramers’ assistant when Kramers had come to lecture.
Casimir did some detailed work on rotation groups?
Was he doing that at that time?
He was doing that already, yes. He had done it before he was with Pauli… Later, I started my own “Faltboat. In English, it’s called a collapsible kayak, a two seater, which I later sold to E. Bright Wilson of Harvard, who used it for many, many years after I’d given it up as ready for replacement.
I see. You mentioned the admiration you had for European or German physics, but once you were over in Germany you began to become aware of American physics again. It appears that there was in some sense a transition, wherein the center of physics shifted from Europe to the United States, from the ZEITSCHRIFT to the PHYSICAL REVIEW. Could you identify that in any way with your own experience? Especially in nuclear physics, I think that must have been the case.
Well, I think it very much reflects the fact that America didn’t suffer in the war the same way Europe did. The war was more of a stimulus to us than it was a depressant. But it started before that. Perhaps the First World War had a little of that effect. America was prosperous, and so, I think the fact that Goudsmit and Uhlenbeck were two of several bright young European physicists who brought European physics to America, in a very missionary type of way. It’s much more than just reading. The dissemination of information finally spread to us — we were ripe for it. In the first place, we had — Americans have a type of approach — the sort of thing that I did with my radio sets — monkeying with automobiles and all that sort of thing, that required a little bit more of a flair for experimental physics. In those days, it contrasted with Europe more than it does now. I mean, the influences have worked both ways. We’ve gotten much more similar with time. But the spread of theoretical physics, Gibbs to the contrary notwithstanding, was definitely from Europe to America, in the dissemination of information. The time was ripe for good American experimental physics, well-supported, to graft onto the more high-powered theoretical physics, and it did. And Europeans were attracted here partly for that reason, partly because there were jobs available.
Yes, it was quite a conscious effort, funds were made available, by the Rockefeller Foundation and others, to bring —
Yes. Even during the Depression, it was very hard for American theoretical physicists to get jobs, but some of the Europeans had had more intimate contact with the growth of the new theories that we’d had, and sometimes took the jobs instead. They could get the jobs, even from abroad. People like Goudsmit and Uhlenbeck, and later Bloch and Nordheim and others. Well, I don’t want to put those two in the same class. They added a great deal to the strength of American theoretical physics, and some very bright young Americans who benefited from that, and if you look at the Julian Schwingers and the Willis Lamb; and all the rest, who became to what they were because of contact with these people who came over from Europe, you see that it took a little time for the transition, but it surely came about.
Yes. You’d gotten the job at Ohio State, Columbus?
What was that like? Did they have a physics department that was interesting? Did they have adequate funding, laboratory facilities?
It had those things. Adequate? No laboratory facilities were adequate in those days in the U.S. We didn’t have government funding. It had people with ideas, who had very modest funding. Willard Bennett, experimental physicist, inventor of the tandem Van der Graaff. He had maybe $400 to build his predecessor of the tandem Van der Graaff, and it was a crude, remarkable affair. But it was an idea, whose time had not yet come. I was one of five young instructors who were brought in — you didn’t go to the university as an assistant professor in those days. I had four colleagues as instructors in the department, including Harold Wilson, who has recently been head of the department, Hestenal, who was very interested in astronomy. And Ernest Poole, who was an experimental physicist with whose judgment I disagreed. These were the young people. The old people — the most influential were the two Smiths, Alfeus and Alvin. Alfeus was the outgoing head of the department, a man who appreciated what Colby had done at Michigan. Ohio State was trying to beat Michigan in football all the time, but they were also trying to catch up with the physics department. Colby had brought some European theorists; Alfeus Smith did too. So, I found myself down there in the very fine company of Llewellyn Hilleth Thomas, L.H. Thomas of the Thomas procession and , other things — a very fine theoretical physicist, and Alfred Lande, a physicist with more flamboyant ideas, I would say, and a flair for picking out the appropriate problem of the time, and less analytical ability than Thomas. But the combination was a good one to be with. Physics was not so munificent — Lande had to take me as an office mate. Conditions there for us instructors were 12 hours of teaching a week. Beyond that we could do pretty much what we wanted, and we were encouraged to do research.
That would be relevant to promotions?
Well, I suppose. It wasn’t explicit, but one was expected to do his 12 hours of teaching, which was teaching of sections of engineers, and we were selected as those who wanted to do research. So research was rather natural — I mean, it was always applauded when we published a paper or something, but no one was urging us to do it. That was a good place to be, a lucky place to be, considering the situation. I did not feel that I wanted to stay at Columbus the rest of my life. Alfeus Smith let it be known that he hoped I would stay and be head of the department some time. Well, that was far in the future.
I think you wrote a paper together with Lande?
That was an amusing thing. A paper appeared over my name and his. 
Oh, that’s right, there was that funny footnote. 
Is there a footnote somewhere?
On your paper, saying that your co-authorship of the earlier paper was an error, and your name should have been omitted.
You have delved carefully into my —
— sampled. Sampled.
You have sampled carefully my writings of the past. I am sure, I think you must be the only one that has read these things for many years.
You might be surprised.
Well, I’ll tell you that story, then. By this time, the discovery of the neutron had sunk in, and it had been appreciated that nuclei were made of protons and neutrons, and then it became a game to understand how much similarity there might be between nuclear spectroscopy and atomic spectroscopy. And most of the information about nuclear spectroscopy came from measurement of nuclear magnetic moments.
Yes, Stern and Gerlach.
Stern and Gerlach type of experiments, and the Rabi type of experiments just hadn’t come in yet — it was a couple of years later they came in, to introduce much greater accuracy and they’ve been a boon to this business. But Lande had the perspicacity to look into the regularity of nuclear magnetic moments, and think he could see something that was analogous to orbit and spin of contributions, some of the few magnetic moments that were known. He put in orbital contribution from the proton, and I believe also an orbital contribution from the neutron. The deuteron magnetic moment was known, and the proton magnetic moment was known, so one had an inference of the neutron magnetic moment. He pointed out a couple of things where this difference should make a difference in the magnetic moment — I mean, the contrast between neutrons and protons. But he had the orbit thing wrong, not realizing that the neutron is uncharged and wouldn’t make an orbital moment. So, his empirical analysis of these things was unjustified. I mentioned the error to him and suggested how I thought it should be done. I got married the end of winter quarter, and my bride and I were setting off on our honeymoon, which was to be spring quarter. We taught by quarters then. We could teach during the awfully hot, without air conditioning summer quarter down there, and take off one of the other quarters as vacation. So our honeymoon was spring quarter, and we went off to Yucatan and other parts of Mexico, starting off with a Faltbot trip down through some southern rivers. I was away for a semester — actually a quarter. The PHYSICAL REVIEW LETTERS came out very quickly in those days, and by the time I got back, there was a paper in the PHYSICAL REVIEW LETTERS by Lande’ and Inglis, in which Lande remembered that I had been very helpful about some points, so he put my name on that paper — but forgetting the point that I had corrected, and it was still in there, wrong! So I was a bit miffed about that.
Right. So you disowned the paper?
I think I later put in a footnote disowning it. [laughter]
But you had a paper on nuclear magnetic moments, about that time, I think — about ‘34.
That was a year later, I think. Actually I wrote up this idea that I tried to correct Lands on, and it was a sequel to Lande’s interest in this, I’d moved down to Pittsburgh by then. There I wrote a little paper on nuclear magnetic moments. 
And you fit in a lot of experimental data. You put in the neutron magnetic moment.
And it comes out the right sign, but too small —
Yes. There are some regularities that seemed to fit in, but not very accurately. The magnetic moments weren’t known very accurately then anyhow.
Yes. Good measurements of the neutron moment came only later.
Good measurements. You make out not too badly if you take just the deuteron and the proton; a 10 percent difference.
Did you have students there that you think ought to be mentioned?
Well, there were two students. Arnold Nordsieck, who did a Master’s degree with me on spectroscopy, later made out very well in physics. And then Leonard Schiff was an undergraduate, a senior, during my last year there, working with L.H. Thomas. Thomas got him started on something which was in solid state physics, something that I found myself way behind Thomas on. Thomas went away for the summer. It was that summer I came back after my honeymoon, and taught that one summer, my last experience at Ohio State — but Schiff was left with me by Thomas, and I couldn’t help him out very much, but I still got better acquainted with Leonard than I had been before. It was a very nice acquaintance, and I marveled at Leonard’s ability, as a senior, to get into that. He seemed to have a pretty good comprehension of it, so he was teaching me things that I wasn’t aware of, instead of my teaching him things. He’s one of the people that I have great admiration for.
Your 1935 paper shows you moving from atomic spectra to nuclear physics.
Yes. That was, I think, the beginning of the move.
I want to ask what motivated you to make that shift?
It was just that the thing that was most fascinating and least understood is always the most attractive. I remember as a graduate student, when Professor Smith at Michigan was teaching the radioactivity courses, I took a little interest in that, but very little because it all seemed so mysterious. The nucleus was some physics you just didn’t understand. It did some funny things. All of a sudden, when the neutron came in, and it began to fall apart (even the mistaken paper of Lande) — Heisenberg about that time really introduced the basis of shell structure when he introduced the oscillator model in what we would call Russell-Saunders coupling. That sort of showed that there was a great similarity there. I guess maybe Heisenberg’s paper came out just after that one you mentioned. You could see there was a similarity, and it became a great puzzle, then, how do these neutrons and protons behave? It was much more exciting than working out the last details of a subject that was already pretty well in hand. In atomic spectroscopy it was always a question of, certainly you can do it to another decimal point and you can do a more complicated spectrum, but you know the fundamental principles. So you’re not going to find out anything very fundamental any more.
Yes. You used the Pauli principle, and the shell structure idea is there in the ‘35 paper.
And already that goes a long ways, and Stern-Gerlach type of data —
Yes. By the way, there was also hyperfine structure; hyperfine structure was important in giving magnetic moments roughly.
Yes. One of the things that came later was the equivalence of the neutron-neutron and neutron-proton force. Charge independence.
Well, it was coming in, but it wasn’t in that paper.
You said that you weren’t interested in staying at Ohio State?
Well, only because I was teaching engineering sections.
Not many physics students?
Yes. One term out of the year or so, I got to give a theoretical course. But — and that was where I ran into Arnold Nordsieck. He did a Master’s degree paper with me, on a little detail of atomic spectra, which was a nice little paper, and after that went on to Oppie and did his Doctor’s degree with Oppie. [Robert Oppenheimer]
Let’s see — you moved to University of Pittsburgh for a few years?
Yes. The only improvement was that I was the only theoretical physicist in the institution, so that teaching theoretical physics was up to me. I didn’t have Lande and Thomas ahead of me taking all the good courses.
How did you land that job? This was still Depression times.
Well, let me tell you a little anecdote. I’m having fun doing that. [laughter] This anecdote is about George Shortly, who was my successor at Ohio State. George Shortly, I had known him — he worked with EU. Condon on some very interesting spectra, and wrote a book with Condon on the subject — but I had known him from the time I was writing my thesis and he was doing his thesis with Condon. He was at Princeton that year. I heard from Lloyd Young, whom I’d known as a graduate student, a good friend, that there was a position open. Lloyd had the year before taken a position in a little modern physics enclave in Carnegie Tech, which consisted of Stern and Esterman. He was the “house theoretikian” for Stern and Esterman, and he was rather alone in Pittsburgh as a theoretical physicist. So, he urged me to apply for this position at Pitt, which is right next door to Carnegie Tech, so we could both be there, and be a pair of nuclear physicists, in different institutions, so we didn’t interfere with each other’s teaching responsibilities — which was a great arrangement. It turned out that the job was open because George Shortly had been sought for the job at Pittsburgh and had applied and was turned down, for a very strange reason. George Shortly is a religious person and an idealist — I mean, a formally religious person, let’s make that distinction. (I may be a religious person but not formally.) So being an idealist, he thinks that things should be in their proper place, and after being told he had the job, he had some formalities to go through. He made out a formal application which was to be taken by the head of the department to the chancellor for approval, and when it came to religious preference, I think he’d either left it blank or written “irrelevant.” I think he wrote “irrelevant,” and went on. And on that basis the chancellor turned him down.
Irrelevant was too irreverent?
Or maybe he just left it blank, I’m not quite sure, but anyway, the failure to indicate religious preference was a serious offense in the mind of the chancellor, whose name was Bewman. (I’m pretty sure that was the chancellor then.) So, the job was suddenly open in the middle of August. And I was available in the middle of August. I was teaching at Ohio State, and I was right there in summer school, so I heard about it, corresponded, and Archie Worthing, head of the department, invited me over, and I took the job. And decided to move right away. We’d just bought our furniture that summer quarter in Columbus when I decided to go to Pittsburgh. So it was a last minute decision. The thing that made me almost decide not to go was that after an interview which went very satisfactorily and so on, and it was practically sewed up, we went out at mid-day, out in Pittsburgh, and we could look up high and just barely see the sun up there in the grey sky, and Worthing said, “Well, it’s nice you came over on such a lovely day.” But I went in spite of that. And we had some troubles with it.
It was already a steel town?
Already? It had been for a century. They had the pollution problem then that much of the rest of the world has gotten since. And they got rid of it in the meantime. But it was so bad that my wife, who’s pretty sensitive to some of these things, physically, got coughing spells, such that we got to making a habit of, instead of going on a trip, we just went to a rooming house or sort of motel, 15 miles north of town, up by North Park — we frequently went up to North Park for hikes — but for weekends we’d go out there and stay two nights to try to cure up her throat a little bit. Pittsburgh was bad that way. Otherwise, it was a good arrangement, in that I did have the challenge of learning theoretical physics. I went along teaching those courses, as it was changing so fast in those days, and at the same time, having the stimulation of Otto Stern and his little special enclave over there at Carnegie Tech. Lloyd Young and I became even better friends than we’d been in graduate school, and worked together, calculated things together quite a bit. He’d married a graduate school flame of mine, and it was all a very nice arrangement.
You didn’t have much contact with other theoretical physicists, except those mentioned?
Yes, of course. It was almost entirely — Lloyd Young and I were just a very nice pair, for exchanging ideas, and we published a couple of papers together.
You didn’t travel to talk to other people?
Oh, I wouldn’t say that. I did all the usual Physical Society type of thing and so on — to which we went at our own expense in those days, driving mostly. And during our Pittsburgh days there were Ann Arbor Summer Symposia still. And there was the Harvard Tercentenary. I remember those contacts very well.
What kind of intellectual group did you have, outside of physics, for philosophic or political discussions? Was that lively at the time?
Not very. That was the time of my life when I really concentrated on physics to the exclusion of much of that. We enjoyed musical affairs. We had friends in the musical world there, and they included some relatives of Phil Morrison, whom I met when he was an undergraduate at Carnegie Tech. A bright young guy. His aunt was musical and a friend of ours. I don’t remember — these were the first years of my married life, and very pleasant. Elmer Hutchinson was a rather specialized theoretical physicist at Pitt. It was a great opportunity for me, just from the point of view of having to teach the courses I had to teach. And I had a very interesting contact — perhaps the most interesting contact I ever had with any student was with Sydney Dancoff, who became a very fine theoretical physicist, starting, I guess, with a course we had in nuclear physics. And during the course — he was a first year or early graduate student — the first year I went there, he said he’d like to learn some relativity.
Well, I’d studied relativity at Michigan and knew some of it, but it hadn’t appealed to me as a thing to specialize in, so I didn’t feel I knew relativity well enough to really give a course in it. I hadn’t advertised a course in it. But he said he wanted to learn it so I said, “OK, let’s learn relativity together.” He was obviously a a bright student. I had been very curious about Thomas’ explanation of spin-orbit coupling, the origin of spin-orbit coupling — the Thomas precession. But I never understood it. So I set us a goal, as we were studying relativity, “There’s a relativistic effect. Let’s see if we can understand it.” By the end of the year, we did. And then, I urged him to go on to where theoretical physics was a little more powerful than here. I’d known Oppenheimer at the Ann Arbor Symposia, that connection was made, and he went out to join Oppenheimer’s group and became a stellar performer of that group. But I think his first introduction to that group was carrying our idea about spin-orbit coupling to Oppie. That summer I checked in rather late after having spent a little vacation in Northern Michigan at the Ann Arbor Symposium, and Fermi was there, and Gregory Breit was there, and Condon was there and several others. It was a good group. I’m afraid I don’t straighten out, between the different Symposia, which others were there — Bloch was there, I think, too.
Well, Breit told me about some experiments of Tuve and Hafsted in which they had discovered the first excited state of lithium -7. It showed up in the rough kinds of experiments that one made with range measurements through foils in those days, about half as intense in a deuteron-proton reaction as in the ground state. Breit pointed out, “Gee, if the intensity was the other way around, this might almost be due to spin-orbit coupling.” Something like that. At least, he gave the idea that there was something wrong with that, that you couldn’t interpret it right. And so I, right there in the summer symposium in a few days, I said, “Oh, I see how that comes from the Thomas Precession that Sid and I were just talking about. It comes out right, not wrong.” So that was perhaps the best on-the-spot idea I ever had, because it gave a good explanation. It’s been superseded by a different explanation since, but it gave an explanation that seemed to work out pretty well, except —
— right at the seminar?
No, I was talking to Gregory about it, and he told me he’d just been down and talked to Tuve and Hafsted and it was word of mouth, that there was this interesting intensity ratio, that nobody seemed to understand. I went home — I don’t know if I thought of it while waking up from sleep, or what, but it just occurred to me that it is just as it should be. But it was just because I’d been through this thing with Sid Dancoff that I saw it and nobody else did. So it was sort of a cute thing, and worked out very well, and I wrote it up as I was leaving, stopping off on the way in Pittsburgh a couple of days — and then I went off to Harvard Tercentenary, where I talked about it.
What kind of event was the Harvard Tercentenary?
That was the 300th anniversary of the founding of Harvard University, a big scientific celebration, with all kinds of symposia and things for a few days.
The emphasis was on science?
Oh, I think they had other things too, but it was — well, something more special than a Physical Society meeting, with a lot of invited papers. And a lot of prominent physicists. When I had this idea during the Ann Arbor summer symposium, Wendell Furry then picked it up and said, “Oh yes, I remember something that Oppenheimer said in a seminar which applies here, and he had a way to derive this from the Dirac equation. Derive the same the same thing, take my physical idea and see how it fit. Thomas and Dirac had different ways of explaining the doublet separation. And Wendell Furry remembered a point from a course with Oppenheimer on Dirac theory. I had the idea how to do it, the Pauli way, and he translated it into Dirac’s way, which was nice. So I remember, when I was at the Tercentenary, at some cocktail party or other, Oppenheimer — I was impressed by him more than by anyone — Oppenheimer was such a genius for going around and gathering ideas and understanding them quickly. When I came in he said, “Now I understand how Furry says it, but I don’t understand how Inglis says it — how is it, Dave?” So I explained it to him, and it was clear to him right away. He just picked it up like that. Oppie was a real genius. He knew so much. And the strange thing is, he contributed some important things, but not in proportion to his genius. Well, you asked me about contacts while I was at Pittsburgh.
I’m trying to identify your paper that might be — The Thomas Procession, that was with Dancoff?
Well, the two are right together; it’s called “Spin-Orbit Coupling in Nuclei.  When I published it, there were two aspects of it. The Thomas paper was a very erudite one, and the main point was hidden in there so it was very, very hard to dig out. We had to understand a lot of relativity until we could understand what he was talking about. But then once we understood it, we could explain it very simply. So Dancoff and I had just written this article, “On The Thomas Precession of Accelerated Axes,”  explaining it simply. And then I went to Michigan, and I suddenly had an idea for the application of the Thomas Precession — which were two different aspects of the same understanding. So I wrote another paper. I wasn’t with Dancoff by then. I wrote the other paper, and Dancoff hadn’t sent in the first paper yet, so I sent them both in together. On the way home, by the way, from the Tercentenary, I remember drawing a diagram that went into the PHYSICAL REVIEW, in a tourist room on the way home from Cambridge to Pittsburgh. Gee, the time has gone so fast. And you still have a lot of things you want to ask me. What would you like to ask?
You’ve just told me of your circumstance of leaving Pittsburgh, and Edward Condon’s part in it. I think, now that the machine is on again, that that should be on the tape.
Well, I told you that it was in the summer of ‘36, I had a discussion with those people about the sign of spin-orbit coupling in nuclei. It was a little idea I had. And among the people I discussed it with was Ed Condon, who had been interested in atomic spectroscopy and then nuclear spectroscopy, and he found it very interesting. The next summer, Betty (Mrs. Inglis) and I had finally saved up on the Depression salary enough that we could go to Europe, and so we had a full three months in Europe, spending a little bit of it in Rome, seeing some physicists, and more of it in Zurich, also seeing some physicists, and then some paddling on the rivers of France and bicycling in France — all very nice. But during the course of this, I got a letter — I think the first letter caught up with me when I still had an address in Zurich — from Princeton, asking us if we wouldn’t come to take a visiting assistant professorship for the year. In Pittsburgh that last year the smoke in particular was getting us down, and I’d already had the nice experience of teaching the courses I wanted to teach. It was time to escape from Pittsburgh, and this seemed to be our escape route — to Princeton. So we arranged it by cable and had some trouble even with their accepting a cable from me for Princeton, because they said I had to have a street address. I didn’t know my street address, but I knew it wasn’t needed. And so it took quite a while to convince the people in Paris, at the telegraph office, that they could get a cable through to Princeton with no street address. They knew it was an important place because they’d heard of Princeton. They’d had two cables through that week (to me) from Princeton. Well, they finally took it as to a small town. I thought afterwards, we doubtless were thought of by Condon when he decided late in the year to take a job — I think with New Jersey Zinc — making his transfer from academic to industrial life, as he did, and then government life. But I always suspected it was because he remembered some of those discussions we had in Ann Arbor about spin-orbit coupling that he thought of me enough to trace us down to Europe and bring us to Princeton.
But Princeton was a very different place than Pittsburgh. You had a lot of leading physicists there.
Oh yes, Princeton was a very active place, and a very healthy department, and I felt myself in a department at last surrounded by a lot of eminence, and I enjoyed it.
Did you meet Wigner?
Wigner wasn’t there that year. He came the next year. He was at Wisconsin. I think he had had a year at Princeton. He was at Wisconsin, with Gregory Breit, and was to come back the next year. I think he had something to do with the decision as to whether Princeton would take me or Johnny Wheeler as the successor to Ed, when it turned out that Ed Condon was really leaving. And Johnny Wheeler got the Princeton job, and I got the job at Baltimore, where Wheeler also had been considered.
If you had to compare the departments at Princeton and Johns Hopkins, how were they different? In terms of resources, personnel, the flavor of it?
Well, they were both in the highest traditions of Ivory Tower, and wonderful places. Princeton was the larger department, and I think currently, the more active. It had more emphasis on theory and less on experiment. I even think probably, even if we count Henry’s time at Princeton, probably Hopkins was a little ahead in experimental physics, and Princeton quite a bit ahead on the theoretical side. Let’s see — at Hopkins there had been that tradition of Rowe, R.W. Wood, that had really done wonderful things, from the early days of spectroscopy, and Wood did a great variety of experimental endeavors. I don’t think there was anything quite to match it at Princeton. But on the theoretical side, it was quite different. At Hopkins, my main theoretical colleague — Herzfeld left just the year I came — of course, he had been there, so they were accustomed to theoretical physics — was Gerhardt Dieke.
Did he also come from Holland?
He came from Holland, yes. He was the third contact I had with Paul Ehrenfest students. Hopkins was a considerably smaller and less eminent department, in terms of recognition, in spite of its emphasis on the experimental side and its history in the experimental side, and a history of having promoted advanced graduate study almost earlier than any other university. It was still riding on the momentum of that early push, quite well. It was much smaller than now. We were a small department. Quite a bit smaller than Princeton.
Let’s see, Princeton has the reputation, although maybe that’s later, of being highly formal and theoretical — that being the Princeton approach, field theoretic and so on.
Yes, well, that grew up later. The experimental side had already gotten more modern in the nuclear direction than the one at Hopkins — having a rather sick little cyclotron, as the machine out of which Milt White and his colleagues squeezed out a lot of information, in a painful way. Ladenberg had a little accelerator in the attic on which he did some early nuclear experiments. Sheuston was doing good atomic spectroscopy. Hopkins had no nuclear physics at all, but a tradition of excellent spectroscopy and that type of thing.
In terms of funding?
Oh, I think Princeton was way ahead, probably. At Hopkins the salaries were notoriously low, for a good Ivy League type of school. The funding has since changed a great deal there. It was a little on the slim side, but we made out very well. Funding of research projects was amusing, by today’s standards. It was there that I sort of drifted back into doing some experimental physics — back from my undergraduate days — in that I felt that Hopkins had no nuclear physics, and a department without nuclear physics in those days was beginning to get a bit behind the times. And so, I undertook to build us up a nuclear lab. Well, I asked for money for this, and there was a grant of $1000 that had come out of the blue and wasn’t committed — and we discussed whether to put this all into a nuclear lab, or half into building up the nuclear physics, and half into building up some nuclear spectroscopy of the Rabi type.
All for a thousand dollars?
Yes. So with $500 I started out to build a statatron as they called them in those days — a Van der Graaff accelerator. There, with great imposition on the graduate student, Burridge Jennings undertook a great deal of the construction himself. Jennings later went to Westinghouse. Between us, out of our own handwork and stretching out that $500 and getting a few hundred more as a couple of years went on, we got an electrostatic accelerator working, just as the war came on. And then it went into desuetude during the wartime, and when I came back to it after Los Alamos, I managed to get the munificent sum of $6000, I think it was, to do the job all over — better! And that one, I put a great deal of my own lily white hands’ work into it. I was doing theory and experiment both in those days, and I had graduate students in both theory and experiment, and I had the good luck of having a colleague sort of join me out of the blue. There was a young graduate student by the name of Stanley Hanna who finished up I think in ‘46, as I was just getting going on this new accelerator — maybe it was ‘47 — and he finished up his degree in molecular spectroscopy with Dieke, and was taken on as instructor for a couple of years. He came to me and asked to join me and become a nuclear physicist. So Hanna and I together finished up the machine that I had just got pretty well under way, and I’d already gotten some experiments started with it. He came into the program. When I left a year or so later, he carried it on. We got some nice little bits of research out of it, at a time when rather little was being done. There weren’t a lot of accelerators working yet, so there were still some nice nuggets to be picked off. It seems strange to look back on it, but I got the feeling about ‘39 — before we were going to make more progress in theoretical nuclear structure physics, we were going to have to have better experimental results; that we were trying things, trying theories that would work in sort of a qualitative way, but the data weren’t good enough. And it just seemed to me, the challenge was to start getting the data out, and that looked like the most interesting thing for the moment.
Yes. When I looked at your papers, you were always very close to connecting the theories to the data, and checking back and forth.
Yes, well, there was that. But — I sometimes think I wasted a lot of time going into experimental physics then — I think there was more to be done in nuclear theory than I appreciated. In some of my theoretical work I came very close to finding the correct shell model, the Mayer-Jensen shell model, a couple of years earlier. I just missed it, I think, because I was mixing my attention, both ways. It was in that work that I came very close to seeing the shell model, as I look back on it — trying to straighten out the spectrum of potassium-39. I saw a difficulty that was a very striking one, that just didn’t come out the way I was trying to do it. If I just imagined that the spin-orbit coupling might be larger than I was prejudiced to think it was, it would have worked out so prettily.
But, I went back to doing experiments, instead of thinking that problem through.
I wondered, the shell model was something you were very close to. You were using the Hartree method, the self-consistent field?
Well, it’s somewhat equivalent to that, but not really enough that I would call it a Hartree method.
How about the administration, if you were looking at the department at Princeton and the department at Hopkins? Could you make comparisons? How the department was functioning and administered, and if there were differences that were interesting? I gather both departments thrived in their own way.
Yes. There were different personalities involved, but I don’t think the methods were very different. I think that perhaps there’s a little bit more decision by the whole department, including the assistant professors, at Princeton. At Hopkins, it tended to be perhaps the Big Three — perhaps the decision made by four, by Wood and Dieke and Beaviden and perhaps Pfund. And the couple of younger people didn’t have much to say as to what was going to be done. There wasn’t a really formal department meeting, with everybody, very often. Just before I came, James Franck was there, and Herzfeld. And I remember, when I came down from Princeton to be interviewed for the job, Franck was still there, just leaving Johns Hopkins. But I remember particularly his warmth and cordiality during that interview, something quite outstanding, and lacking in the other members of the department.
At Princeton, the relation of the department to the Institute of Advanced Study — you mentioned that you were both in Fine Hall.
There was really no barrier between?
Yes, that’s right. The building for the Institute had not yet been built. The Institute was very young. So there was a good deal of mutual discussion, and mutual attending of seminars and things like that, of course.
Thinking again about the nuclear physics at the time — I guess one of the things that had come into use, like Heisenberg forces and Wigner force, semi-empirical, expressions for the interaction between nuclei —
I think you made use of those?
Oh yes. And I felt after my stay at Princeton, that I had stuck to a computation that I’d started to do before I went there, so much as not to leave my mind open enough for receiving more ideas of things to work on, while I had the great stimulation of being at Princeton. I was working on a problem that involved just those phenomenological forces — and in this case it amounted to pretty much like a Hartree calculation — to try to see if I could reconcile the large binding energy per nucleon of helium with the much smaller one of lithium -6. I thought those were two problems that I could carry out, numerically, with those forces, enough to get a meaningful binding energy result, and, of course, without computers, it took a lot of slide rule work. And I spent too much of my time at Princeton in that kind of drudgery, because I had something by the tail that I wanted to finish up, and I stuck to it — as t wonder if I’m doing now with my book on power sources. I expected to be done with that months ago, and I’m still at it, polishing. I want to finish this up and get onto some other thoughts — but I don’t let myself do it.
You also tried other models, you worked with the alpha particle model as well.
I have the impression, through the history, in contrast to what you were saying, you were not stuck on a particular model.
No, it was just that year.
You later used the droplet model and —
— oh yes —
— pretty near all of them, it seems to me, you’ve used in your papers, and tried out.
I kept doing things in a rough approximate way, trying to find which model would, through the rough approximations, come closest to seeming to explain things. And so I guess I did start some of the discussion of some of those models which were treated later by more erudite calculations, as more people with computers got into the act. But the alpha model, I guess Henry Margenau had been investigating that one, too, and for some purposes, it seemed to explain data better, so I played around with it for some time in ‘38, ‘39. But that was quite a ways ahead of the droplet model, that came after the war.
Yes. Yes, I was jumping. Where did you meet Teller?
First at Gottingen.
First at Gottingen, and then you met him again?
When we were colleagues — in the Greater Washington-Baltimore area.
He was one of the important people you talked with?
Yes. He and Gamow were the professors over at George Washington University.
We should say something about your interaction with them, or what role they played for you.
As I guess I said, Edward (Teller) and I, way back in the Gottingen days, thought we had a little something in common, in our desire to understand the quantum mechanical effects in the semi-classical terms or as pictorial terms as we could, so that — when we found ourselves within 40 miles of each other — first we collaborated a bit. We did it largely by means of exchanging weekend visits at our two homes, and our wives were cordial in helping this along and got to be good friends. We had some very nice collaborations. In fact, I guess that’s what kept me going on theory, when I was doing some of this experimental work too. I mean, collaboration with Edward. But even before that, I got deflected into experiment, for a while. We’d work hard for a few hours on the weekends, and then have some pleasure too. It used to be that when we came to a stopping point, where I felt like getting my breath and working out a detail of a calculation that Edward had been able to see intuitively, or something, we would take a break, and I would stay in my study upstairs, and work on some point for a while, while Edward would go down and play Mozart duets or some symphony two handed on the piano for a half an hour or an hour.
Then we’d get going back at physics again — Edward was just as enthusiastic and driving at his two hands of the four hands on the piano as he was upstairs in physics. Those were some fine times. We continued knowing the Tellers very well out at Los Alamos. Edward always seemed to be a little bit at odds with what was going on out there, and wanting to do something a little different, having ideas at a great rate — we even climbed the highest mountain around there with Edward, once going camping in the rain. He was having trouble with his bad foot, but making out very well all the same. Oh, there were many happy occasions with the Tellers — seeing their kids grow up out there, also. Our association with the Tellers just kept on going. After I left Johns Hopkins, after the experimental going got too tough in competition with national labs that were so highly funded, I decided to go where the experimenting was easier, out at Argonne. I had perhaps that as one motivation, but another was the fact that the University of Chicago had such a stellar array, including three that I’ve mentioned before — Enrico Fermi, and James Franck and Edward Teller. Oh, there were lots of others. It’s not fair to mention those without mentioning some of the others, but I’ll not try to — at least Edward was part of the attraction to go to Chicago, even though I was going to be at Argonne and he was going to be on the campus. I made a regular habit of going in to the campus on Thursday afternoons and having discussions with various people, at a seminar or colloquium. I kept rather good contact with Edward, along with the others, during those years. It was only a year or two until he left. But it was one of the motivations in making the move away from Hopkins.
Yes, that’s interesting.
Well, since we’re talking about Teller — some years later, when he was well ensconced at Berkeley, I’m sure it was through his initiation, I was invited to go out to Berkeley, to be a visiting professor out there, and by that time, our political differences had become very apparent — we saw the dangers of the world in two different ways. He — I think, largely influenced by his youth in Hungary and the temporary Soviet invasion of the country and all that when he was very young — he judged the whole thing more on the basis of military opposition to the Soviets, and I judged it more on the hope that, different though our ideologies are and hopes for the world, that we could appreciate our mutual interest in avoiding nuclear war, by restraining our efforts and our preparations for even greater nuclear war. And that somehow a breakthrough could be made, in spite of all of our reasons for distrusting and disapproving of the way the Soviets did things. So I think, in a sense, we parted company on this interpretation of how we approached the dangers of the world.
Did you discuss politics with him at that time?
For the first few weeks. And I think, almost up to Thanksgiving, even. They invited us to Thanksgiving Dinner at their house, if I remember right. I think it was just before that that we agreed: we can’t enjoy it if we go on discussing these things, let’s forget it. We went on for the rest of my visit out there, haying dinners back and forth, and — oh, a trip out to Mt. Diablo, for a picnic all day; that kind of thing, very nice association of families. Music and all that. And we just agreed that we disagreed so why talk about it? And it was all very pleasant.
Yes. That was 1955-56, your year at Berkeley?
About Los Alamos — who brought you in to work at Los Alamos?
I suspect Edward did, I don’t know. I think it was because Edward knew me better than Oppie did. I’m quite sure that Edward suggested to Oppie that I be among the small group that went out there at first, and in fact, I think Edward broached the subject to me, first, once when he was coming through Baltimore. He made an appointment for me to see Oppie over in Washington the next weekend, or sometime soon, and I discussed the thing with Oppie They were both in the East sort of recruiting, working together on recruiting the first group, I think. Out of the first group that went to Los Alamos — there had already been people working on the project, mostly in New York and in Chicago, before that.
What was it like when you came to Los Alamos? Did you know at that time what the objective of the work was?
That much — yes.
That, you knew?
In recruiting, I learned that. I had learned about fission. I’d learned about the fact that some people had hopes that fission could be used to make a bomb, during the period before we entered the war. I learned about fission at a little meeting at George Washington University. No, at DTM, the Department of Terrestrial Magnetism, of the Carnegie Institution, there in Rock Creek Park — there, was a little nuclear physics meeting that was the antecedent of the big nuclear physics conference. This was a very small conference. This was the one to which Bohr came, having just arrived in this country. He came down and told about fission.
Was this about 1939?
1939, yes. Early spring of ‘39. It was discovered in late ‘38, and nobody in this country knew about it until I think Bohr brought the news over. We learned about it on the first day of that conference, and there were four people, or groups of experimental physicists that went home that night and tried the experiment that hadn’t been done in Europe — the experiment of observing fission in a proportional counter. And one of them was Joe Mayer, who was in the chemistry department at Hopkins, but married to Maria and with a great interest in nuclear physics. After, we drove home together and told the news to his colleague, Bob Fowler, who had a source of neutrons, and they were one of the four groups that reported back the next day that you could observe large pulses in a proportional counter if you put neutrons on uranium. [laughter] Well, this is a digression, but that was the first I heard about fission — pretty much from the horse’s mouth. And then for the next couple of years — during the time I was still teaching at Hopkins, and then even when I went out to the Aberdeen Proving Ground, after we got going in the war, I was still in Hopkins on and off. And I learned — particularly from R.W. Wood, who couldn’t keep a secret, and was very high in the councils of the Physical Society — that people were really taking this fission bomb business seriously. He and I discussed it. We knew that you can separate out isotopes, in a mass spectrograph, and you can get out microgram samples, if you worked very hard at it.
But this thing was going to mean kilograms — “you can’t do that,” was our reaction. It sounded like, an awfully neat idea, a kind of ominous one, but it just sounded as if’ the difficulties were such that probably it shouldn’t be taken too seriously, for a while anyhow. So I think that was my attitude toward it — until — I think it was Edward who first told me, and Oppie probably, that all this had been going on; not only that the experimental pile worked, but that there were plans for separation that looked as though they might work; and that it had been taken so seriously by the government that “now we’ve got a General to boss us. So we can go and do big things.” And — “It’s not, decided yet, we may all have to get into uniform and take commissions, to work under this general, so if we go into the thing, we’ve got to be willing to do that. But we’re going to have some fine apparatus — we’re moving the cyclotron from Harvard, and one of the electrostatic generators, maybe two of them, from Wisconsin, and there’s all this nuclear physics that’s got to be done. We’ve got to have some good nuclear physicists, and it really looks as though it may be the thing that can be done, and if it can be done — well, the Germans got the start on this, discovering this thing, and you just can’t tell what Hitler’s people will be doing. After all, he’s in a position to kind of organize people and get them to doing whatever he wants them to do, and there’s a real danger that Hitler might get this thing, if we don’t work on it very hard — he might get it first and that could be terrible.” So — “We don’t know if it can be done, but if it can be done, we’ve got to do it in a hurry.” And so on.
You took a leave of absence from Hopkins?
I did, yes. War work was something that was approved, in those days. I remember, when I asked for a leave of absence, the question was, “Now, who shall we get to take your place?” And one strange thing — Pauli was just then looking for a job. I suggested Pauli. Well, Pauli went to Princeton, it turned out. But that would have been a strange anomaly, to have Pauli taking my place because he wasn’t in a position to do war work, and I was! But it turned out, it was Charles Hubbard who took my place. He stayed on at Hopkins afterwards, as a colleague. Incidentally, he took over teaching my undergraduate mechanics course, and I had just organized my notes in a way that I was thinking of getting published, and he sort of got together the first mimeographed publication of my notes, which turned into my first book after I got back.
Was it a textbook?
Yes, it was an classical mechanics textbook. For Los Alamos, it was a matter of taking a leave of absence and getting a replacement. But I couldn’t tell them what I was going to do at Los Alamos. I’d been told, but of course under very great secrecy. I couldn’t tell anybody what it was about. I couldn’t tell them exactly where I was going 1 was going out to the Southwest I would give an address. I couldn’t tell my wife any more than that we were going out to the Santa Fe region.
Your wife was coming with you?
Yes. This was going to be for three years. And so we couldn’t tell our friends. We were vanishing for war work. There was difficulty about getting gas rationing to drive out there, but you couldn’t say what you were going to do. Betty managed it. The ration came through dust in time. Actually, they told me all of a sudden, “We’re having this conference. It’s very important for everybody to be there for this conference.” And I had to pick up and go by train, without having closed up the house. I left that job for Betty to do, and she did it valiantly and found a friend to drive out there with her, later.
Did your wife have any scientific interest, before you met her?
No. She was a graduate student at Ohio State University, in mathematics. She was a secondary school teacher of mathematics and French, out of a job because of the Depression and going back to get along with mathematics a bit, when I met her, and interrupted her career. Then at Los Alamos, her mathematics came into use, because electronic computers were not yet in — we were just a decade ahead of that — and so it was female human computers instead. And she was one of them. Until she finally got into teaching out there. She also helped organize the local school out there in Los Alamos.
What can you say about Los Alamos? I suppose some things are still classified. But what group did you work with there?
I wonder if anything is still classified? The freedom was slow in coming, but finally it came. Oh, there were so many years when we couldn’t say anything about it! I was in the theoretical division.
In your publications, most of the things are not listed here — probably government reports.
Oh, they were government reports out there, a lot of them — regular reports — and for a while I got settled with the job of doing some sifting of reports and editing them. For example, the last summer I spent out there — I went back for a summer, after I’d come back to Hopkins, and I undertook to write what was called, what I called ‘Fermi’s Super-lectures,” which was sort of a pun, because it was about what we called a “Super.” But I would go to his lectures, which were almost daily, absorb the ideas without writing them down, and then immediately go to my dictaphone and write down the lectures as best I could.
What particular work were you engaged in at Los Alamos?
Well, it was really about bomb configuration design of which I don’t have a record. Bob Christie came up with the big idea we were all fishing around for, the implosion. And I worked more on the assembly of the gun machine, and the details of how best to pass criticalities swiftly, that type of thing. That was the first year. Then I got into some of the interpretation, the nuclear physics, and what fission cross-sections had to do, what we were going to do. It was shifting around from one detail to another of the big problem. The lovely thing out there was something, I think, that Oppie insisted on before getting going with General Groves at all: to change the Army’s idea that there should be compartmentalization of information, that all the responsible scientists at Los Alamos should be allowed to know everything that everybody else was doing, because the most important thing is to have ideas crop up, and you can’t tell where they’re going to crop up. The best thing is for everybody to know about everybody else’s difficulties, as well as their specialty. So there was a great deal of just being informed and trying to think of ideas.
Yes. The way people have described it at Los Alamos, as very exciting, partly the time pressure, partly the location, on the mesa there, and the community as a very lively intellectual community.
Oh yes. It was that way. I’d subscribe to that completely. Yes, the intensity of it, still, in the midst of all that beauty, was a marvelous experience, I felt. Even though all of us were being distracted from our main purpose in life. Most of us were dedicated to understanding the secrets of nature, you know, that wonderful challenge of, here we are with all of these ways of finding out how the most intimate secrets of nature down in the atomic and subatomic realm — that is the real challenge in life. Since the war was so pressing, and we had decided, we’ll forget that and do the other thing. It was an exciting pursuit, in spite of being a substitute one.
Yes. Now, somewhere along the way, the consciousness came about the long term import of producing nuclear weapons — not just in winning the war, which was the rhetoric of the time, but in changing the world. Do you recall at all that kind of shift of awareness, or when that came?
It was rather late in the development of the bomb. I think that the first two years I was out there, probably… I think I had and most of the people I was in contact with had relatively little thought about that — mainly because we were so dubious about whether the whole thing would work. There were still so many difficulties, in the way of adverse cross-sections of absorbing neutrons and stuff, and it was the challenge of trying to get past these difficulties. Some people were more optimistic than others, about whether it was going to work. But I don’t remember having thought very much beyond the “if Hitler gets it” stage, until, I suppose, maybe six months before Alamogordo, when preparations were getting pretty definite, that there began to be talk around the mesa that I got into. I think there’d been a little before I got into it. A feeling of apprehension, that now this is going to work, and where is this going to leave the world? Even after there’d been some months of this kind of thought, in sort of off times, when we turned our attention away from the working details, evening discussions and what not, I think that perhaps on this account, when we went down to Alamogordo for the initial test — the one that finally answered the question, would it work? — and initiated the explosive nuclear age — I think most of the people on those school buses that went down there were sort of hoping that it wouldn’t work. Here we’d put three years into making it work, but there was a feeling among a good many of us that it would be better if we failed, for some fundamental reason that we hadn’t foreseen. And it was very hard to imagine such a reason, because there had been discovered barriers that, particularly adverse absorption cross-sections, that had been discovered and eliminated, by good chemistry mainly, to such a degree that — calculations showed it would work. But it was such a new thing, so preposterous, compared with anything that had ever been done before, that there seemed to be a feeling that, maybe we’ve overlooked something and it wouldn’t work all the same.
Do you recall the feeling or the sense, after you saw it, saw that it did work?
Yes. And to me, it was a mixture of elation and apprehension. Gosh, isn’t that wonderful? — but, where do we go from here? Where does the world go from here? By then I think the awareness was very much there, by Alamogordo, that this not only solved a problem but posed a problem. Hitler was out of the picture by then. We were sort of carried on by that momentum the last few months, and now we had the Japanese to dispatch, and hopefully they could be convinced without its use, but there wasn’t very much thought of that at Los Alamos. There was more at Chicago.
Did you have contact with the group, the James Franck people?
Only indirectly. You see, we didn’t get around very much. And I think the thought somehow had been mentioned at Los Alamos. But Oppie was a very influential figure, and r think he was able to convince us that probably the military were right, that it would have to be used, and actually the use was organized from Los Alamos, and some of those at Los Alamos who were most active in the experimental details, and even some of those who were not, but who were very enthusiastic about seeing it used, went off to Tinian and helped see the Enola Gay off. Prepared its going And of course, some of the personnel — Captain Deke Parsons, later admiral, was very prominent in carrying out the Hiroshima mission. I think Phil Morrison was too.
Yes. Apparently Niels Bohr was unique as an individual who thought about that a lot and talked about it.
Did you have any contact with his concern? He seemed to stimulate other people to —
— yes, and I think, I was going to say, some time, maybe six months or a year before, I’m not quite sure how long it was, there started to be thoughts about this. Niels Bohr was there, and at that time we had to call him Uncle Nick, because very prominent people were using false names so that we wouldn’t be recognized in Santa Fe as a bunch of physicists. We were all listed as engineers. I don’t know why engineers are more harmless than physicists, but that was what we were — we were working for the Army Corps of Engineers, anyhow. But Niels Bohr came there as Nicholas Baker, with his son Jim and Aage — his worthy successor as a great physicist — and Jim was about 16 then. I now know Aage much better, at a later age. Bohr was of course, even then, thinking of his message, openness — openness will be the solution. The Russians are secretive, but somehow we’ve got to let everybody know about this, and everybody will know what everybody else is doing, and we will get down and discuss, and be so frank with each other that we can make some agreements.
Did he discuss that with physicists then?
I’m not sure just when openness became the name of Bohr’s endeavor. But I do know, I mean I’ve read since, that during that time, he went to the top and tried to talk with Roosevelt and Churchill about those things, and was sort of ignored as a fuzzyheaded professor. That is my impression of the kind of reception he got. But he was very much concerned about those things, and when I saw him years later, he still was. I think after Los Alamos, the next time I saw him was at an Oxford conference in about ‘51. And he then was very much worked up about the lack of openness, and the great need, and wanted to talk to the Americans interested in those problems. Since there were very few experimentalists operating in those days (1951), I was invited to give a partly experimental paper at that Oxford conference. I had to relate what I was saying to the speaker preceding me. I had the last half of the morning, somebody else had the first half of the morning. I wanted to relate to what the speaker ahead of me was saying, but just at that time, Niels Bohr took me by the elbow and said, “Let’s walk around in the park, I want to discuss some things with you,” and then with his very low voice we talked as we walked, while the paper was going on that I should be responding to. Then I got back and had to give my paper. [laughter] I have seen him several times since. Well, maybe we ought to quit for the day.
He built clocks and orreries and telescops, was the original discoverer of the diffraction grating, a Philadelphia city official preparing defenses against the British who were stopped at Trenton, and first director of the U.S. Mint.
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