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Interview of Milton White by Charles Weiner on 1972 May 11, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4961-1
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Family background, early education and interests; undergraduate at Sacramento Junior College and University of California, Berkeley; first independent physics work under Harvey White; graduate work at Berkeley, career choices, joining Ernest Lawrence on cyclotron work; work on ion sources, taking over running of small cyclotron and verifying creation of high energy proton; reactions to discovery of the neutron, developing Geiger counters with Donald Cooksey, announcement of Cockcroft-Walton discovery of artificial disintegration, work on disintegration of lithium; work schedule; work on boron, 1935; comparison of Van de Graaff and cyclotron machines; ideas about p-p scattering, new cloud chamber; financial difficulties; White’s refinement of process for extracting protons; completion of Ph.D. Physical Review paper, 1935; marriage. Postgraduate work at Princeton University, fellowship arranged by Lawrence; setting up Princeton cyclotron, research program, funding of the cyclotron; Princeton atmosphere and colleagues, appointment as assistant professor, 1938; relationship of theory and experiment in nuclear physics, Eugene Wigner’s influence. Research on the tachyon, magnetic monopole, 1973; reactions to Niels Bohr’s new model; its dissolution. WWII work at MIT Radiation Laboratory, 1940-1945; administrative tasks, relationship with the military, with engineers; advisor to Eagle Radur at Alamagordo; reactions to the dropping of atomic bomb. Return to a depleted Princeton Physics Department, rebuilding the cyclotron and the department; government funding of science, consulting projects. Work on the Brookhaven National Laboratory Cosmotron, beginning 1946; White’s variation on the Livingston, Richard Courant and Snyder strong focusing synchrotron. Return to Princeton as professor, proposals and designs for the Princeton-Penn Accelerator (PPA), construction and problems, scientific management of the machine under Harvey White, his philosophy of administration, relationship with the Princeton Physics Department. Budget cuts; government administration of science funding; closing down of PPA.
It might be good to start with your California background. I know you were born in California and I assume that you lived there until the time you completed work at the university in Berkeley. It would be good to know where you lived, something about your family, and your early experiences leading up to your college days.
Well, let’s start with, I guess, my home town of Claremont, California, where I was born. That is, as you know, the seat of Pomona College, the Claremont Colleges, and my father was professor of history and English there at Pomona College. I was the last of six children. I had four brothers and one sister, and there was a large gap between myself and the next youngest. I guess my mother was surprised when I came along, but I did. I guess fairly early I showed interest in at least technology, if not science, because I recall being very interested in building radio sets when I was about 10, 11 years old — this was 1920, ‘21. I built a crystal detector set, with the help of an older friend, but I did a large share of the construction, and it was terribly exciting. I first put up an antenna, and tweetled the knobs, and suddenly in came a voice from out in space.
This certainly had a very profound effect on my feeling for technology and science, because this was an extraordinary emotional experience, to hear the voice from a man who was 45 miles away or so in L.A. [Insertion in transcript made on May 13, 1973 by Dr. White] I would like to add a few words about the role played by my interest in scientific “toys.” My parents bought me chemistry sets, Mecano sets and, especially, electrical sets for Christmas. Of all Christmas gifts I believe these most excited me and provided many weeks, even years of pleasure. Most of these sets were given to me before I was twelve. My interest in reading was intense. My father owned a beautiful edition of the Encyclopedia Britannica, the 11th I believe, printed on fine Bible paper and bound in soft black leather. The Britannica was on a book shelf behind the sofa; so my habit was to take down a volume and sit on the floor behind the sofa and read it “secretly.” This began at about the age of 10, but I loved that Britannica so long as I remained home with my parents, until about the age of 19. [insertion ended] So I was very early interested in making things, like model airplanes and rubber band airplanes and a glider, which I once tried to take off with from the barn, but the glider busted and I came down with a thump. I didn’t break anything.
Luckily I hadn’t hopped very far. I was, I think, very early pointed in that direction, towards technology rather than toward the humanities, because I was not interested in history or English or any of the reading subjects. I’m sure that a fair influence on my life came from my uncle, David Fairchild, who was a world famous botanist, and who had written a number of books, Exploring for Plants, The World Is My Garden, and so on. He had married a woman who died very early. I’m sorry, I’m mixed up with another uncle. David Fairchild married the daughter of Alexander Graham Bell, and so clearly had an association by marriage with Bell. I heard about this from my parents frequently and I’m sure that also had a certain effect on me, because you do tend to wonder where you come from, and though I didn’t come from the Bell side of the family, obviously, the mere fact of a marital association I’m sure helped interest me in technical things. But David Fairchild, my uncle, was a very very warm person, and when he came out to see us in California with his wife and one of his two daughters, he was overwhelming with his personality. Interested in every single thing around him, every plant, seed, bird, bug, whatever. Though I didn’t like the life sciences much more than the humanities, and found the life sciences less interesting than chemistry and engineering, I certainly found him very exciting as a person and as a scientist. He didn’t insist that I be interested in the life sciences at all, but just interested, period, in something — just not sit back like a lump on a log but interact.
He gave me a small hand microscope, to look at seeds and bugs’ legs and so on, and this really had an effect on my scientific view of life. We left Claremont when I was about 11 years old and went to Berkeley for one year, the reason being my father had resigned from Pomona College for reasons unknown to me, and also his orange groves which he had invested in on the side weren’t doing too well. There had been a series of droughts and bugs and so on which nearly wiped him out. So he went to Berkeley for one year, then returned to Upland, California for one year to live in a small house on one of his two orange groves, and then returned up north to Sacramento where he became the State Labor Commissioner for upper California. He was always interested in people who were down on their luck and had been very active in Hull House and such things way back in the l900s when it wasn’t very common to be interested in the common man.
May I ask about Berkeley? When he went up there for one year, the whole family moved, was it for a position there?
No. He had no work. He just lived off his orange grove income, which was close to zero, I think, and his savings. I think he left Pomona College with a certain amount of pressure on him. I don’t know the history of that, but I think he had a falling out with the president. He had already invested in orange groves. He thought he could make it financially without being a professor. At that point he was already in his late fifties, I guess. It took quite a bit of courage, I think, to leave a life of teaching college. It turned out that the orange groves were not profitable. He was not a particularly good farmer, and didn’t really, I think, have a nose for orange ranching, so he turned to being Labor Commissioner at which he was very good. We moved to Sacramento. By this time my brothers and my sister were all out of the house and gone. They’d gone to college and on to marriage, most of them. And so I was really alone with my parents from about the age of 11 or 12 onward. So in a way I was an only child, but of parents who had raised five children, so I got a lot of attention from my parents.
In Sacramento I carried on my interest in radio and built a large number of radio sets and even built a transmitter. I never got a ham license, but I had a transmitter which I operated illegally for awhile, but 1 didn’t like it enough to stick with it. I was much more interested in designing and building than in operating. By this time I was interested in Boy Scouts and was very active in scouting for quite a while, and really enjoyed it, and also enjoyed being a scout leader. It turned out that in my troop the scout master left the troop at one point and they had no one else around to run the troop. I was not the oldest person but I guess for some reason the most interested, and I ran the troop as scout master for about a year, and really enjoyed taking charge of things and people, and I guess this was my first experience of not just doing my own thing but also trying to organize others into doing things. I found I had some flare for it. It was kind of painful but I guess I enjoyed the pain, and my troop even won the local annual Boy Scout Field Day, by a great deal of effort on all our parts — fire by friction contests, and recall one contest where we had to get undressed, run 100 yards, come back and get dressed, and have every button in place. You practiced that by the hour.
Then we had a contest to build little bridges, model bridges, and we went out and built, quite literally, 500 bridges, and put them in a truck and carried them down to headquarters the day before the contest closed, and won the contest. They were a little angry with us for making them have to store 500 wooden bridges at headquarters. It wasn’t quite in the spirit of the competition. But I think this probably also indicated I was interested in competing, as well as in directing people. So that, plus making radio sets and also being interested in the girls to some extent, pretty well occupied my time when I was at Sacramento. Also I became a devoted tennis enthusiast at the age of 19. I was also a pretty good student in high school and junior college. I went to junior college in Sacramento. I applied to go to Cal Tech, Stanford, Berkeley, and was admitted, if I recall correctly, but I wasn’t quite sure I wanted to go to Cal Tech. I felt, looking at their catalog, that was pretty rugged, and I wasn’t sure that I was that much of a student; that I wanted to really knuckle down to what seemed like a terribly cerebral exercise. Also Stanford looked pretty tough and Berkeley didn’t appeal to me — too big. So coupling thoughts with the rather modest state of my parents’ finances, I went to the Sacramento Junior College that had just been formed, a brand new one, in Sacramento, and it turned out, to my good luck anyhow, that it was a very very good one.
You were accepted at all three, Stanford, Berkeley and Cal Tech?
I am not really clear about this. I am not sure that I completed all the application formalities, but I do recall some word from Cal Tech that I could be admitted.
The second question is about the interest in radio and so forth. What turned you on, in particular, for that? Were you reading any magazines, or was there any kind of a thing that came to your attention which made you follow up your technical interests specifically with radio?
Well, I subscribed to QST Magazine, the radio ham magazine, for one, and then there were Popular Mechanics, magazines with how-to-make-it articles on radios. I was not initially drawn so much to the pure physics side of radio (that came later on) as I was to the technology, the making of something with my own two hands. I was quite willing early on to make it, not fully understand it, just so I could make it work. And it wasn’t until I was about a sophomore in college, junior college, that I began to be unhappy with not understanding deeply why things functioned — not understanding at the level of physics. I didn’t know what physics was when I was in high school. If you’d asked me, who was a physicist, I would have had no idea what they did for a living, i.e. who employed them. I was very unclear about their way of life.
Did you have any physics courses in high school?
I had a course in physics in high school, and it was given so poorly that actually I gave part of the course. The man who taught it was really a very poor teacher, and when it came to the part on radio, he said, “Now, I don’t know much about it, I’ll have Professor White give the lectures.” So I didn’t know really a thing about it myself, but I knew more than he knew. It was a big high school, several thousand students, and they had three teachers in physics, but they were very poorly trained. I had a friend who also played a very important role, I’m sure, in my interest in radio. His name was George Moynahan, and he was very interested in making radios and also rebuilding racing cars. He would take the rear end out of a Ford and the engine out of a Dodge, and the frame of some other car and assemble them, and he’d go off across the country 90 miles an hour, with no seats in the car, just sitting on the frame work — lucky we weren’t killed. In fact, he almost was killed one day when the piston rod went through the crank case and froze the engine, and it stopped short and tossed him into the cornfield about 30 feet. So I was lucky to come out with my skin intact. But he and I were close friends, and I think that looking back on it, and even at the time, I was aware of the fact that part of my pleasure in technology and science came from doing it with others. Though I later on spent lots of time studying by myself, still it quite early appeared that part of the fun was in working with someone else in science. I was not a lone wolf by any means.
Another question I have is about your brothers, just curiosity. What fields did they end up in?
I was the only one interested in science in the whole family. My oldest brother was a statistician and worked for the Interstate Commerce Commission. My next brother was a banker, a stock broker. Well, actually initially he was a scientist in one sense. He was an ornithologist, collected various very strange birds and reptiles for museums. I wouldn’t have called it science, but he was a collector, taxidermist, interested in classification of birds and animals. But when he married, his wife didn’t like traveling around the desert area of California, and so he settled down and became a stock broker. In 1929 the stock market crashed. After a year or so he became a vice president of Bank of America in charge of locating new accounts. His job was to find a way to get former depositors money back out of the sugar bowl, and out of the mattress, into Bank of America’s coffers. He was very good at that. The next brother, Alan, was a paint salesman who traveled around California selling Pabco Paints, and he married a woman with an M.D. in pediatrics. They really made a lot of money between the two of them. Then he bought, stills owns, a Culligan Soft Water Service. His wife died and he remarried.
So he did extremely well financially and was a very important influence in my life in part because when I needed a job after hours in high school, I talked to him, sort of complaining about why couldn’t I find jobs. “Well, go offer yourself for free to somebody and then they can’t turn you down — like a little radio store — and just propose that you work for them preparing radio sets.” I did that and to my surprise I was taken on by a radio store after hours, and they said, “Well, we can’t have you here for free, we’ll pay you $2 a day” — for an afternoon’s work, two hours of work. So I worked in that store many years, weekends, holidays and summer times. So his business sense is what got me started working for a radio store. Then my sister, Helen, who married Roland John, taught piano for many many years, 40 pupils a week, and raised a family of three children and was very effective in teaching piano. Then my brother Irving, next in line after myself, was also a salesman.
He sold Fuller Brushes for a good many years, married a very lovely woman, had a very nice family, and changed from Fuller Brushes to a finance company which helped small builders to get small loans, building loans from banks, and he got a small rakeoff for this loan finding process, and also I guess he located the materials for them. So there was one brother who was a scientist, an ornithologist, but not a physical scientist. My father was very unscientific. Also he was not particularly good with his hands. My mother was more mathematical than he by far. When I had a problem with algebra in high school, which I certainly had, it was my mother who encouraged me in algebra and kept me at it and got me through.
She knew it pretty well.
She had raised four children, five, before me, so she had been exposed to algebra five times. That’s a good way to learn.
Well, that fills in the picture pretty well on the family. The courses in high school, the physics course, you described. Were there any other science courses?
I took high school chemistry, and enjoyed that pretty much, more than physics just because the man who gave the course was much better prepared and knew quite a bit about it and I liked his personality. I did not take any high school life sciences. I felt that biology was not very interesting. I hadn’t looked into it of course to be sure of that view, it was just my interpretation. But I found high school mathematics very trying. I did very well in geometry and then I flunked algebra the first time around. The teacher I had was a person I didn’t like at all. Then I repeated it with someone else and got an A in the course. Then I flunked second year algebra, again a teacher I didn’t like at all, and repeated the course under a fine woman and got an A in the course. So I was up and down and reacting very strongly to the teacher. There’s just no question that I was turned off by both of the teachers who flunked me. Even before they flunked me, I was turned off by them. So the mathematics did not obviously come to me very easily. In other words, I would not have flunked with better teachers. I didn’t study algebra the first year — I had to be more or less encouraged to do it by someone I admired, and I didn’t admire these two whom I flunked under.
What did you do for summer vacations? For a California youngster that seems no real problem, but I’m curious whether you got to travel at all. It would have been difficult in those days because of the Depression, I guess.
Well, my parents always went off for about a month, either to the seashore or the mountains, so I was exposed to Yosemite two or three times, and to La Jolla and Laguna Beach and went up into the old Baldy region above Pasadena. So, in other words, we camped out, and in those days there were far fewer resort hotels. Anyhow, my parents couldn’t afford them. So we had a portable tent, camping outfit, and went up in the mountains, Lake Tahoe several times. So each summer I spent about a month, I’d say, camping. Then when I became old enough to go off by myself with the Boy Scouts, we went on scouting trips, and I was in the so-called Pine Tree Patrol which was for older boys, in scouting, and we went off with a trek cart, a two wheeled cart packed with tents and food and pots and pans — pulled that thing all the way up in the Sierras, all around, and then came out by truck eventually, but we were on our own for quite a long time. I think I felt the mountains were the most pleasurable of all my summer time experiences. The seashore I liked, but it was — a small bit went a long way. I much preferred the mountains.
It was the western world then, California and nearby regions.
I didn’t leave California till I was 25. Hadn’t even left the state. My parents were not great travelers. They stayed pretty well close to home when they went on vacations.
So by the time you applied for college, the reason you selected those three institutions at first was with science in mind, or was it already physics in your mind?
My initial thought really was engineering, and in particular electronic engineering. The word hadn’t been invented yet. “Electronic” wasn’t even known — electrical engineering. And I still didn’t know what physics was all about, by the time I was in college. It was a No-No Land for me. So I took at Sacramento Junior College the engineering curriculum for the first year, and I soon became very bored by it because, although I think it was given fairly well, it was much too descriptive and much too easy, and the one thing — this sounds like bragging but it’s not — that cured me of engineering was that I got a perfect 100 percent in all the problem sets and all the examinations for one year in a course in electrical power engineering, and I felt this shouldn’t be so. It couldn’t be that interesting a subject if you can get 100 percent in everything. So the physics teacher, whom I was taking physics under, was much tougher. I felt he didn’t know a lot of physics, but the book was sure crammed full of very exciting things. And so this friend of mine, George Moynihan and I, we were both in the same EE course, both felt the same way, that the engineering course was much too trivial, and so we switched into physics.
Even at that low level in junior college, you can do this? You’re only supposedly there for two years — you can make an elective preference?
That’s right. They had some kind of engineering preparatory path in the college, and I left that one for another large physics path in the second year, and it was very enjoyable, because classes were small. The teacher — his name was Gayman — was not obviously himself a very great physicist, but was a very fine person, quiet, a man of high standards, rather colorless in his personality, but nevertheless, you had to respect him. And he allowed us a lot of liberty in the laboratory, and I decided to take on a project of trying to measure the elongation of an iron bar when you magnetized it, because I saw in the books where this was supposed to happen. And of course it had been measured many times before but I didn’t really realize that.
By Joseph Henry principally.
Did he? So I set up an iron bar and solenoid and a little optical light lever, and turned the field on, and sure enough, the thing got longer; and turned the magnetic field off, and unfortunately it got still longer. The reason was that the iron bar was getting hot, and heat was seeping into it, and it was elongating from thermal expansion, not from magnetic effects. So I learned about background phenomena the hard way — but just doing this for a few months, by myself, nobody around. Scrounging equipment was a lot of fun. And I certainly wasn’t aware at the time that it was “forming my character,” but I’m sure it had a certain effect, because it was quite different from the engineering school approach that was followed there.
What was the name of the textbook you used, the one that was crammed full of things?
Well, there were two textbooks. The one that was used in the course was by Ferry, and that was an awful book, as a matter of fact, but it was thick and full of things. But the one that really caught my eye was written by Knowlton, who was at Reed College. This book was a complete eye opener to me. It really put physics in the foreground rather than the background, because the Ferry book was again a bit more sort of a gee whiz book, technology and optics and levers and pulleys and the physics, let alone quantum mechanics, was hardly mentioned in the book. And Knowlton’s book I saw in the library just by chance, just while browsing there. That’s why I’m all in favor of open stacks. If I’d had to go to the library and ask for the book by call card, I never would have seen Knowlton, I don’t think. But seeing this I fell in love with it, and I bought a copy myself, and maybe I still even have it for all I know. Maybe at home. But that book, I still feel had a very fine appeal for people who weren’t already committed to physics but who were ripe for it. A very simple Bohr atom. He showed color spectra and Frauenhofer lines, and it was the first of the modern textbooks. It certainly played a very important role in my being certain I liked physics.
You switched to physics while you were still in junior college. Then probably towards the end of your sophomore year, you had to re-apply to the full college of your choice?
Well, at the end or middle of sophomore year, I decided to go to Berkeley. I went to Berkeley, again, in large part because of the Depression years — it was 1929, now — see, I’m mixed up. I went to junior college in ‘27, and went to Berkeley in ‘29, so the Depression came while I was in college, and that’s why I, at that point, didn’t go on to Cal Tech or Stanford.
It was at that point that you applied.
That’s right, yes. (I did consider going to Cal Tech, etc. straight out of high school as I mentioned in my corrected version of my post high school planning for college.)
So your decision was to go to junior college first, then shift over.
I went to junior college first — I now see from these dates — partly because I didn’t think I was really ready for leaving home.
I was 17. I was a late bloomer. I was a skinny kid. I was active in Boy Scouts and so on, all that kind of business. I was happy enough to live at home that couple of years while going to junior college, and it was cheaper, to be sure, but I think the major reason was that I was not certain of myself at 17. I see kids coming to Princeton now at 17, and I sympathize with how kind of lost they may feel. I certainly felt a bit lost at 17 — lost in a social sense, not in terms of a developing intense interest in studying. I was not a complete social loss since I had an intense interest in girls. So I was 19 then when I went to Berkeley, and I went to Berkeley rather than Cal Tech or Stanford largely on economic grounds. But also, by this time I knew Berkeley pretty well because I had two brothers living in Berkeley, in the town of Berkeley — my brother Halstead who was the ornithologist, lived there, and I’d been to his house many times, Christmas and so on, and had gone down to the Berkeley campus just to browse around. And Irving, the one who sold Fuller Brushes, lived in Berkeley also. And we were a fairly close family, always very friendly, but not I’d say as intimate as some families are, but still when I, went to visit Berkeley I stayed with my brothers. And the third reason was that my oldest brother’s wife’s sister married Frederick Brackett, a physicist at Berkeley, and this was the Frederick Brackett who discovered the Brackett series, in Berkeley, the infra-red spectrum.
They lived, of course, in Berkeley, and so when I went to see my oldest brother Arthur, who was also in Berkeley — three of my brothers were at that point in Berkeley — I met Frederick, who was really a rough cut diamond in certain respects. Nevertheless, I respected him, and he took me to the laboratory, and I saw this darkened room, the spot of light moving across the galvanometer scale, back and forth, as he scanned a rock salt prism, the infra-red spectrum and I saw the Brackett series, coming out on this spot of light on the wall. And the room was full of nice smells of sealing wax and strange chemicals, and there was a sort of a hot summer afternoon feeling in the room, well darkened, and I found that kind of activity just to my liking. By the time I went to Berkeley he was gone, so I didn’t go there to work with him, but I got my associations with physics at Berkeley. So then when I went to Berkeley in ‘29, in the fall, I went there as a physics major, and took the usual courses, and did pretty well and made Phi Beta Kappa as a junior By this time I knew how to study. I was not repeating my algebra problem of high school over again. In fact, I guess I got all A’s pretty much in sciences and mathematics in college. And they didn’t come too hard, but mathematics was — well, I could handle it, but it was not a part of me in the same way that the laboratory was a part of me. In my senior year I went to work for Harvey White, the spectroscopist and author of books. He was the Harvey White who organized the Hall of Science, right?
Why is it that you went to work with anyone in particular your senior year? Was this open to all physics majors? Was it required, or was it just something you do if you have good enough grades?
It was not the usual thing, but there were a few who were doing it. I think that — well, one was encouraged to do so very indirectly. No one came around and gave you a pep talk, “fellow, get behind it now, get into physics.” But if you showed interest at all in some professor’s work — in fact, I recall when I was thinking of it. I was walking down the hall, and I saw a door open, and pitch black inside. The walls were painted absolutely dense black, and inside was Harvey White, whom I’d had for a course in optics. He was a very nice looking guy, very friendly, pleasant fellow. I walked in. He said, “Hello.” I said, “Hello. My name is Milton White.” He said, “Yes, I know it is.” I said, “What are you doing?” “I’m making some etalons.” “What are etalons?” He said, “Well, they’re for looking at spectra with very high resolving power.” So he showed me around the laboratory, the equipment and what he was up to, and I don’t know whether he said, “Come on back some time” or whether I said, “May I come back?” but I did come back, and before I knew it I was in there, just another pair of hands, helping him to wash pieces of glass very clean, to begin a deposit of half-silvering. He taught me how to half-silver etalons, and to assemble them. He wanted them for research work, his own research work, on the hyperfine structure of, I guess it was neodymium, cadmium, a couple of things of this kind. And he had an unused grating spectrometer in one corner, and he said he wouldn’t mind having it put into shape, and did I want to put it into shape? I said, “Well, what do you do?” and he explained what he wanted done, and then he walked out of the room and just left it to me. So I fiddled around with this thing. I’m not sure I ever really got it going with anything like the kind of precision he needed or that it even could have been achieved, but anyhow, it was my little project. So I came in there evenings and weekends and afternoons, just fooling around, and in between time helped him making etalons for his experiments. Just fun.
Where did you live in Berkeley when you were there?
Well, let’s see. Berkeley in those days had very very few dormitories. And they were expensive, and I was not very well off, to say the least. So I lived in a boarding house near the campus, and — on Telegraph Avenue — and it was an interesting boarding house. I learned a lot about people and life there. It was just a bunch of fellows who had by chance knocked on the door and been taken in as boarders. We all slept there also. The food was, I thought, pretty awful but probably it was pretty good by most people’s standards. But in that boarding house, there were instructors in zoology, instructors in engineering, mathematics, as well as a graduate student or two and undergraduates, and a football player or two, and a couple of drunks. It was all male. Women probably wouldn’t even be allowed in those days to have a co-educational dormitory. That boarding house had an important effect on me too, because one of my best friends was a zoology instructor who was a very sharp witted fellow, and we used to sit up all night throwing the bull, and if I’d make some remark which was a bit poorly thought out, he’d really jump on me and tear it to shreds. It was quite an experience to have this happen. I’m sure it was better than if I’d had a room off in some detached house. It was important to have this experience. I lived, in short, in various boarding houses around Berkeley all the time.
I interrupted your story of Harvey White. You then proved yourself, essentially, with him.
I don’t know what I proved but anyhow I guess I didn’t turn him off. To finish off this junior and senior years in Berkeley — I also was interested in tennis, which I had in fact taken up for the first time in my life as a sophomore in college. I’d had scarlet fever in my last term in sophomore year, and when I was recuperating I went out to the public park. My brother Irving had given me a tennis racket, so I hit the backboard for a while just to run around and kill time. A new teaching pro, Dick Stevens, came to Sacramento at this time and took me under his wing; so I became hooked on tennis, and I still am hooked on tennis. Then I went to Berkeley, and, unfortunately, there are very few courts there. In fact they still have very few courts at Berkeley for a California school, and in order to be able to play I joined the team, even though an utter rank beginner. I had played for only one year. Luckily the tennis coach was a professor of Spanish rather than a tennis coach, and the team was not so hot, so I was allowed to try out for it, and to my surprise I got on the second team and even played in a couple of matches, doubles mostly, and so I was playing a lot of tennis in the afternoons in my junior year.
In my senior year, I caught measles, right in the middle of the season, and I’d had some slight hopes of getting on the first team when I was a senior, but the measles canceled that opportunity. So tennis played a very important part also in my life, because as a student I certainly studied very hard, and stayed up late nights studying. I think having every afternoon a couple of hours of tennis was a good thing for me, helped me from the point of view of physical strength, and gave me a way to relax. I think it’s good, at least in my case, that I had that outlet. Let’s see — I guess I was about to graduate from Berkeley, and I had nothing lined up for a job, and my landlady had a friend who knew somebody in San Francisco who was starting up a little television laboratory, this was back in 1931, and these people were the Varian brothers. I think I’m right in saying Varian. Also Farnsworth was involved too. Let me see — well, there was some mixture between Varian and Farnsworth. I’m not quite clear about the relationship, but I think the Varians worked for Farnsworth or vice versa at one point. In any case, this lady got a letter of introduction from her friend. I went over to San Francisco to talk to Varian, (I am really unclear as to whether it was Farnsworth, or one of the Varian brothers whom I talked with in 1931), and I got there, and this red head was stuck into a radio cabinet and he would hardly pull it out to talk to me, and I was little bit bothered by his being unwilling to stop his research to talk to a possible employee.
We did talk, but I was — I thought he should at least give me 15 minutes of his time to discuss what he was doing and what my chances were. So I went back a bit depressed, but it still was an open question if I might not work for them, and I might very well have, if I had not gone to the chairman of the department of physics, Raymond T. Birge, to talk to him about my job hunting experiences. I mentioned the fact that I had gone to see Varian-Farnsworth people on television, and he said, “Well, why do that? You’re wasting your time in industry. You belong in physics.” I said, “Well, how do you make money in physics?” He said, “We’ll give you a fellowship.” I said, “You mean me, next year?” He said, “Yes.” That’s the first I had any inkling that I rated that kind of support. I would really, if I hadn’t talked to him, have gone on, I’m sure, into engineering. And so he said, “No, you should become a graduate student and get a Ph.D.” I didn’t know any Ph.D.’s in physics, really, except the few who had some contact with teaching of undergraduates, and I really had a very, very dim idea of what it meant to be a graduate student in anything, let alone physics. Even when I worked for Harvey White that time during senior year, and walked around that part of the building in Leconte Hall, where graduate students were doing thesis problems, looking back I’m amazed at how naive I was about the ways of the world, and professors. Kind of shocking in a way but still there I was, and I think I probably wasn’t all that unique, because most of my friends in physics, even those who were better students than I, didn’t go on in physics, but went on into business. I think part of the reason was that they also didn’t have the faintest idea in ‘31 how one would go about making a living in science or in physics.
You say they went on to business — with a physics bachelor’s degree?
Oh, they changed their field, or didn’t use their physics. There were some who went into industrial laboratories, as was trying to do. One man became a seismologist working for the U.S. Geological Survey, maintaining their seismic equipment. And he was one of the brightest boys I ever ran across, yet he spent his whole life as a technician essentially, just maintaining the equipment. In mathematics he was far better than the rest of us were. My guess is, he didn’t have any feeling for what it meant to become a professional scholar; somehow that idea hadn’t gotten across in the faculty-student relationships.
Did anyone go on, other than yourself?
Yes. One of my colleagues, an undergraduate, was Bob Varney, R. N. Varney who is now at Washington University, St. Louis, I believe, or at least was there when last seen. He was a very fine student and he became one of Leonard B. Loeb’s students. Then there was a student who was behind me a couple years, her name was Elizabeth Ann Higley; I later married her. She went on as a graduate student, took her master’s in physics. I can’t …apart from Varney, think just the two of us went on to graduate school. If there were more, there may have been more, I certainly was not aware of it. They may have gone to other universities and so I lost track of them. Our class had a number of students in it who were also in optometry, because the School of Optometry was on the top floor of Leconte Hall in those days.
Part of the physics department.
That’s essentially right. And so a number of the people with whom I associated eventually became optometrists.
Who were you close to as teachers? You mentioned Harvey White. What about Birge, did you have any courses with him?
I had no courses from Birge as an undergraduate. I had a course from Bob Brode, and I enjoyed that very much. He was a good teacher, and I had a course from L. B. Loeb in theory of heat. I missed the first two years at Berkeley, having been at junior college. Sam Allison was very much part of my undergraduate experience at Berkeley, because he used to come in, tousle haired, to lecture in the morning. He gave a course in modern atomic physics — it was my first exposure to quantum theory. He’d been up all night doing experiments in X-rays, and he’d walk in looking half dead, bleary-eyed, his hair all tousled, and talking very slowly as a man would in a pooped state. Then he’d go home and go to bed. He’d been up all night long. So I guess those are the primary ones I can think of in physics. Those whom I had in mathematics were not very impressive, either as people, or as scholars — they were very remote from physics. It was taught in the math department, of course, by people who didn’t know any physics at all really, and I think it was one of the great weaknesses in the teaching of mathematics at Berkeley and I think at most universities. The people in mathematics know little physics and have not much interest in it, and make no attempt to tie it into physics. I think this was a very great lack. I would have learned, I’m sure, much more mathematics had there been this connection to a subject which I really loved.
What about chemistry?
I took chemistry in junior college one year, but none in Berkeley as a junior or senior. It wasn’t required for the physics upper class curriculum. Also at this point I was a bit turned off on chemistry. Basically on the ground, I think, of fundamentals. I felt that chemists dealt in what happened when you mixed things, without understanding the detail, and I was becoming much more of a reductionist by this time, wanting to know, down, down, down, down, to a deeper level, what was going on. And I think this was a developing feeling I had, as a junior. Looking at the things I wrote to myself and comments I made on the flyleaf of this book by Knowlton, “What is E, what is H really?” Fundamental questions. And I felt the chemists were not dealing with fundamental questions.
The Berkeley tradition though included Gilbert Lewis who was in physical chemistry. Did that not get through to you at that stage?
Not really. Again, I think I was probably not as aware of the world around me, across that courtyard, over at the Gilman Hall, as I might have been, and that department seemed as if it was worlds away. Gilbert Lewis was a famous name. I knew who he was. I didn’t read much of what he’d done. I felt that thermodynamics was pure mathematics and did not have much to do with the elementary nature of things. I didn’t appreciate the fact that he was actually very deeply interested in what I would call the physicist’s view of life, and there was a tendency, I would say, in the department of physics to talk physics students out of taking much chemistry. I can’t recall specifically anyone’s advice that I should not take chemistry, but you know, there just wasn’t enough time for it. I had a full course with physics and mathematics and there wasn’t any time left to take a course in chemistry. So in the end I had a number of friends who were chemists, undergraduates and graduate students, so I knew them socially, but not in terms of what do chemists really do with their intellectual activities. Among my friends were such people as my roommate Angel Samaniego, a Ph.D. candidate, Billy Libby who was developing screen wall counters for detecting low intensity sources of low energy radiation, and Bob Fowler who developed very intense hydrogen ion sources for possible use on linear accelerators.
When it came to the discussion with Birge about the fellowship and about graduate work, then you explained that you hadn’t known what this meant. Was there some hesitation in your mind and some way that you tried to fill yourself in, in order to make a decision?
I don’t think I paused very long. I think I was very easily persuaded. I guess my major concern was how I was going to make a living in physics, and he provided that way, and I had had a somewhat depressing experience talking to the Varian brothers over in San Francisco. If they had been enthusiastic about me, I might have gone there, but they weren’t. So the contrast, between Birge’s flat statement that I should be a graduate student and just don’t argue with it — and you know Birge, of course, he’s a very positive person. Having told me I should of course become a graduate student, he then went on to explain how he had managed to play the violin so well while being a brilliant graduate student at Wisconsin. So that was sort of that, and of course the term came to an end and I returned to Sacramento to look for a summer job.
That would be June of ‘31, May?
June, yes, ‘31, to work, to earn some money to return to graduate school, because the fellowship wasn’t nearly enough to pay for the whole year. So I returned to Sacramento, and got a job working, I think it was that summer, I’m fairly sure, when I went to work for a refrigerator repair depot. Majestic Refrigerator had just been brought out, and this was one of the very early electric ice boxes, as they were called in those days, a sealed motor unit in contrast to the old-fashioned, open belt, clackety, clack kind that leaked all the time at the gaskets. So I spent the summer repairing refrigerators, and this was quite an experience because the place was on the top floor of a building in Sacramento, 110°F in the shade sometimes, and this room also maintained a furnace to bake out the refrigeration equipment, to get rid of all moisture so that the sulfur dioxide wouldn’t form H2SO3 on the parts. Those rooms went to 125 Fahrenheit and I used to be stripped to the waist, then walk out on the back fire escape to cool off, or sneak out to a nearby ice cream parlor for ice cream soda while baking out the refrigerators. And I almost had my head blown off once. We put these compressors — with their soft-soldered metal dome — on a little rack where you assembled the controls and pipes and other things lying near this compressor.
Well, one of our procedures was to unsolder this dome with a blowtorch, but only after you’d taken out all of the gas inside, which I thought I had done, but apparently I hadn’t. I loosened the solder with a blow torch. The dome blew off with a roar. It missed my head by no more than a half an inch and went through the roof. I would say it knocked out a two-by-four up there, broke the plaster out and came back down again. But it broke the whole ceiling above and fell down, releasing thereby a lot of SO2 in the building. I proceeded to go out the fire escape and just forgot it all for half an hour, while the SO2 crept through the building. The manager of the store, hearing this boom and smelling SO2 from upstairs and not finding me in, was quite worried I might have been blown out the door. So I learned about safety the hard way. Then I returned to Berkeley in the fall and became a graduate student. My first thought was to return to work with Harvey White, whom I had met that senior year, and I did work for him for a while. This was ‘31. But before very long it became rather plain to me that at least the technology involved in hyperfine structure study wasn’t terribly interesting. I wasn’t sure that I was interested in the physics that he was doing. It was kind of fun but seemed to have no great future.
At this point, Ernest Lawrence gave a talk, if I recall, in the department colloquium, which was held I believe on Wednesdays in Berkeley, on the cyclotron which he had just invented. At least I heard about it there, the first cyclotron. He was a very impressive guy, and to a young graduate student, Lawrence, full of bounce and fire and enthusiasm, with lots of interesting electronics hardware, radio transmitters and all, involved — it seemed pretty plain to me that this would be far more exciting than hyperfine structure work. The clincher was that the cyclotron (actually called then the magnetic resonance accelerator) produced million volt protons which could be used to extend Rutherford and Blackett’s work on the nucleus, a very little understood object. So I talked to Harvey White, and he not only encouraged me to leave him but he almost insisted that should join up with Lawrence, if Lawrence would have me. He saw a big future in nuclear physics. So I went in to see Lawrence, and he said, “Sure.”
Was this the first time you’d seen him or been aware of his existence?
Oh, I certainly was not keenly aware of him as an undergraduate. As a senior I must have seen him around, but I must say I don’t think — I can’t recall an episode of talking with him. I had him in no class, and I didn’t see the cyclotron, as far as I know, as a senior. I didn’t know Livingston as a senior. Edlefson, who had made the first cyclotron, so-called, with Lawrence, I was dimly aware of, because I think he must have been a teaching assistant, and if I didn’t have him in a class, there certainly was some small association since I knew his name, at least, even if I didn’t know what he was doing. So I went to work for Ernest, and the first thing he assigned me to do was to make a better ion source for the cyclotron than they had in those days. I must say that this was a fairly interesting experience, because he took me down to a room and said, “This is your room. Now, we want a better ion source,” and walked out. I didn’t know what an ion source was. So I started to read the literature.
Had you seen the instrument?
I’d seen the cyclotron that Livingston was still working with and he had taken it apart regularly. In fact about every three or four days it came apart, having sprung a leak or burned an ion source filament out, and I knew what he had there for an ion source, a little coil of tungsten wire. The plane of the coil was at right angles to the magnetic field, so that the I cross B force was always radiating outward, making the spiral more or less stable in the magnetic field, and it wouldn’t flip over. But quite plainly as you raised the gas pressure to make more ions, you reached the point at which gas scattering of the accelerated pistons would cost you a reduced accelerated ion current, and even worse, as you raised the gas pressure, you couldn’t hold the rf voltage on the dees. They sparked over. So there was a limit to what you could have in the way of gas pressure.
Now, the idea that Lawrence had, was to shoot ions into the cyclotron, somehow, from the outside. Presumably to come down through a hole to be drilled in the pole tip. There were no holes in the pole tip, so we would have had to take it out and drill it. It wasn’t at all plain to me how you were going to get the ions in there once you made them, and it wasn’t until many years later that people did, in fact, have external ion sources and shoot the ions into the cyclotron. For many years this approach was not regarded as the way to go about it. In any case, I built an arc discharge and a canal that the ions were supposed to travel down, and learned glass blowing and built power supplies, and got properly burnt by hot glass and broken glassware and all that kind of practical stuff.
Did you have any technical help?
The only help I had was with the glass blowing from Eddie Guyon, who was a glass blower. I think he had eight, ten children, something like that. He had a lot of kids. He was always talking to you about his children when you asked him about glass blowing. In the room behind my room was Frank Dunnington, who was one of Lawrence’s students, and Frank Dunnington was measuring e/m, using the cyclotron principle. Now, Frank Dunnington was a very nice fellow, but an older man. To me, a young graduate student, he seemed quite ancient, because he had married, had several children, a thing which wasn’t done in those days by graduate students; but he was in fact older than the average. He must have been at least 36 - 39. He was useful to talk to, always very willing to stop and talk, but was very much engrossed in what he was doing, trying to get a precise measurement of e/m. [Interruption]
Getting back, you were talking about Dunnington, the e/m measurements using the cyclotron. I’m not quite sure how far we got. My question originally was, did you get any technical help? You did from a glass blower.
And some from Dunnington, but not a great deal. I think that his interest in physics was rather new. He had been an engineering student before he became an e/m expert. Before e/m, he had done some very nice work on short time spark breakdown, using Lecher wires and traveling waves which opened and closed a Kerr cell. You look at a light flash 10 - 9 seconds after the spark gap broke down and made a flash of light. This was very pretty work which he did. So even though he was a man who did very nice work, he was not as broadly interested in a variety of things. He’d worked in depth rather than in breadth. So in being busy in his work, he didn’t give much time to my problems, and I guess probably I didn’t know how to ask the questions either that would have been useful, because before very long I felt that, and I guess Lawrence felt too, that my ion source work wasn’t getting anywhere. Lawrence himself gave no help.
At this point Livingston was about to leave the small cyclotron to go off and build the next bigger one, and so Ernest gave me the opportunity to take over the small machine, after Stan left that one. In fact he gave me my choice of either joining Livingston and others to build the bigger machine, or having the small one to myself, and I picked the small one for myself because I just felt that I would learn more and have more fun doing it that way. So I forget how long I spent on the ion source problem, but it couldn’t have been more than, gee, two or three months I guess. Then I went upstairs to the cyclotron room and took it over, and my first job was to more or less learn how to run it and repeat what Stan had done, and let’s see — I’m not dead clear at what point — yes, I spent the first several months up there fixing up the haywire. Stan naturally enough was just developing and not making it run stably, so I rewired the oscillator and improved the pumps. All the controls were extremely antiquated.
All the rheostats were open coil wound things and knife blade switches which could kill you if you stuck your hand across them. They had 440 volts on them, and absolutely open, totally unsafe by today’s standards. They would make anybody’s hair stand on end. We had a 15 kilovolt, power pde transformer witting behind the magnet, out in the open, a pair of wires dangling, going to the oscillator. And so my first job, which I guess I probably assigned myself, was to prove that, in point of fact, Livingston and Lawrence really had achieved acceleration of protons to a million volts or so. Because what they had shown was that the current to the Faraday cage went through a maximum at the right magnetic field to correspond to resonance between the cyclotron frequency and the radio frequency on the dee. Now, the earlier work had been criticized by some people on the ground that what they might have observed was a magnetic resonance phenomenon all right, but it was ultraviolet light which was excited in the background gas in the center of the chamber, which then went over, hit the Faraday cup, and kicked out electrons making it therefore go positive, thus simulating protons arriving rather than electrons leaving. Now, as I recall, this was Livingston’s criticism of the first, earlier claim by Edlefson; that he really had not proven that he had high energy protons.
You may have more dope on that than I have. In Livingston’s next size cyclotron — they did a small round one first and then the big square one — in the square one that I took over, there was a pair of parallel deflection plates on which to put a few kilovolts in order to bend the protons away from their spiraling path and thus into the Faraday cage. The voltage which we put on that was the correct one to correspond to the velocity of a one Mev proton. I still wasn’t convinced because I felt that ultraviolet light could sneak in, so I built a little mica-foil-changing device to put in front of the Faraday cage. I then measured the Faraday cup current as a function of the mica thickness, and found that it did correspond to the stopping power of mica which went with the one Mev protons. That is, I measured the range of the protons in mica and found that it corresponded to 1 Mev. I have a notebook around. My notebook, I must say, in those days was awful. I wish I’d had enough brains to realize then how historical my notes were. I guess the notebook is home someplace. My writing was terrible and my comments were incomplete. In any case, I plotted the current as a function of foil number, and then I went to my little table of numbers in which I had recorded the foil number versus foil thickness, replotted the data, and sure enough, I got the nice sharp cutoff that goes with the well defined range. That was very exciting. Then —
When was this?
This was the last part of ‘31 or early ‘32.
That’s something you didn’t publish?
That’s right. Having proven to myself that they were actually in fact 1 Mev protons, which Lawrence never doubted — I’m sure he wouldn’t have wanted me to publish it.
That was immediately after they’d come up with it, because the earliest that I know of is around November of ‘31 that they’d come up with it.
That’s about right. Then, I could be fuzzy about the exact dates, but I know I first started in the fall of ‘31 with the ion source, and then —- well, first Harvey White, then the ion source, then took over the cyclotron. Sometime in late ‘31 or early ‘32, and then —
Well, they had a paper in January, ‘32, on the 1.2 Mev.
January ‘32, that’s when it appeared or was submitted?
It appeared. It probably was submitted only a few weeks before then, maybe December at the earliest. It’s not in your bibliography, but I have the exact date. I’m pretty sure it’s January, ‘32, that the actual — something happened in November, there was a paper in January [My error! Paper by L & L, “Prod, of High Speed Ions …” PR 40, April 1, 1932, received Feb. 20, 1932 - C.W. note.]
Here’s the paper, September 13, ‘32.
That’s the disintegration paper.
That’s right. Now — so let’s see, I guess all I did with the cyclotron during this period of ‘32, was, having proven that there were 1 Mev protons or so, I tried to raise the beam current. Shimming was a very important part of that cyclotron, and you spent hours poking little metal sheets around the poletip trying to shape the field to give more beam current — well, I wasn’t sure what I was doing, frankly. No one knew what the shimming process was doing physically. There’d been no theories of focusing that were worth a darn, and I think we were quite unaware, certainly I was unaware of the dynamics of the cyclotron in late ‘31, ‘32. So one lucky thing was that the best shim, which was shaped like an exclamation point, worked best if struck in from the side of the magnet which happened to be one you could get at. If you put it in from the far side, which you could do only with great effort, it didn’t do any good. So had the magnet been turned around by 180 degrees, that shim probably wouldn’t have worked. I think luck came in there and made the right side of the magnet come up so we could put the shim in.
That was a busy time, because a couple of announcements occurred, too, in the rest of the physics world. Do you recall the neutron announcement in February?
Do you remember how you heard of it and what the reaction was among people you knew? February ‘32, toward the end of February, the letter in NATURE. I’m just wondering if it came up as a normal thing in the colloquium or the journal club, or whether it was in the newspaper. I know it was in the papers but I don’t know how the information reached the people at Berkeley. Or maybe you have no recollection of it?
Yes, but I must admit that I’m sure people like Oppie and Lawrence and the older graduate students appreciated it far more than I did, as a young first year graduate student, still relatively naive and not always with it. Nobody said, “We certainly must go and make these right away on our cyclotron.” I’m sure that nobody said, “Let’s race down and look for them.” So I’m not sure that the full impact really sunk in quite that quickly out there. It wasn’t until later on that they were being made with deuterons in the bigger cyclotron. In fact, I had a portable cloud chamber which I built for my proton-proton scattering, and I trotted it over to the big cyclotron, the 27 incher, and I had the first look at man-made neutrons anybody had ever had. I had my head up in the poles of the magnet practically, looking at my cloud chamber, and seeing recoil protons, and there was great excitement then, but this was I guess a couple of years later. So I think that the full impact of neutron discovery didn’t really develop instantly, not in my mind certainly, and I don’t recall people saying, “Oh, boy, we’ve got to take the cyclotron right away and make them.”
Well, the cyclotron wasn’t being used for anything really.
Well, it could have been used. It produced neutrons without anyone knowing of it, of course, with the proton beam, but no one thought to come in and say, “Boy, oh boy, put up a neutron counter.” Maybe someone had made a calculation showing that at the small, l0-9 ampere proton currents which we had, and taking into account the small production and detection probabilities; that we would never see any neutrons. I doubt this was done. Certainly no one talked with me about it.
How about later that spring, the Cockcroft-Walton work, do you remember that?
Well, that’s the thing that really, I guess, probably burns everybody up, most of all me, because came the summer time I had to earn some money; so I left Berkeley for a few summer months. I think that again people in Berkeley, and I guess one should say in this case Lawrence, didn’t perhaps fully realize how close they were to great discoveries. If they had, maybe he would have found some money to keep me there working in the summer time doing physics. But no, I took off blithely as a graduate student did in those days. The lab was going to pretty much close down for the summer. And off I went to Sacramento, to work again in this lousy refrigerator repair depot. And while I was gone, Jim Brady took over the cyclotron for the summer time. When I came back in the fall, Don Cooksey and Franz Kurie had come out from Yale, and Malcolm Henderson I guess about that time too — yes — and the thing was that we didn’t know how to make Geiger counters in Berkeley in those days. Ernest Lawrence imported Cooksey and Henderson and Kurie from Yale who had some prior experience.
About the only portable detector in those days was the Geiger counter, and for our problem, Don Cooksey introduced us to the ball Geiger counter. This was a most unreliable, tricky detector which consisted of a fine platinum wire, on one end of which a small ball was produced by sticking the wire in a hot flame and melting a bit of platinum. The ball diameter and smoothness were very critical. The wire was placed on the axis of a small, metal cylinder made gas tight by a thin mica window over one end, the other being closed by an insulating plug which supported the platinum wire. With a voltage of 1500 volts on the wire, applied through a few megohms, the counter became sensitive to the passage of a charged particle. Of course an amplifier was also required. So Don and I built these first counters, mostly Don Cooksey; so I guess Don had come that summer, I suspect, summer of ‘32, I’m not quite sure when, some time in there, a very dapper, urbane Easterner, who to my Westerner eyes looked very different from the usual people that I’d see out in California. So then we really got the thing going. As far as I know Brady had to leave just at this point, at least leave the cyclotron, for a job, I guess. So I came back in early fall or August of ‘32, and I heard, when I came back, of Cockcroft and Walton’s announcement that they had discovered artificial disintegration. I hadn’t been aware of it before I went away, as far as I can recall. Now, I don’t know what date their announcement had been made.
Late April or May.
Is that when it became public knowledge, I wonder, or just —
It was in NATURE — I will clarify dates.
A paper in NATURE?
No. I can’t give a date, but I know Rutherford wrote a letter to Bohr the 21st of April saying that next week a letter about this will appear in NATURE. [The important paper came out in PRS in mid June - C.W.]
I must have already left Berkeley, because as far as I can recall, I was unaware of this discovery when I left. Had I been aware of it, I don’t think I would have left Berkeley that summer. I would have found some way to stay there and confirm their work. Because when I came back, you see, this paper of ours was submitted September 15, so I must have come back the end of August probably, and then very soon I had these few points on this curve.
Well, then, there was no detection equipment prior to the building of the Geiger counter?
No. And that was all we had — it didn’t occur to me to build the equipment. I was a naive graduate student. And it took experience — Ernest Lawrence knew we had to have it; so he imported Don Cooksey, an old friend of his, and Franz Kurie with his cloud chamber experience and Malcolm Henderson because he was good at dc amplifiers. He built the first linear amplifier, at Berkeley, which was rather a feat in those days because they were terribly unstable, and of course all vacuum tubes, no solid state devices in those days, and it took quite a bit of doing to make these things really operate, and not oscillate and still have high gain.
You came back then, you figure, in late August. Did you hear about Cockcroft-Walton as soon as you came back?
Yes. That’s right.
How far were the detectors developed by that time?
As far as I can recall, they had some indication that the Geiger point counter was in fact picking up radiations which resulted from the protons hitting a lithium target, but they weren’t sure of it, and I recall spending quite some time, several days, doing various check tests to be sure that the counts were in fact due to the protons hitting the target, because there were background counts, both cosmic rays and just spurious counts. The spurious counts came from just plain breakdown. So in short then, I think the Geiger counter was working before back, but no one was quite sure of it. And so my first task verify that it was.
Then what did you do? You ran these tests. Was there any sense of urgency about it?
Oh, yes, yes. The place was beginning at this point to catch fire. I think Ernest was in there every day. He’d come in at 2 or 3 in the morning wanting to know why we hadn’t gotten more data, what’s holding us back, and he was really putting the pressure on at this point.
Prior to this publication or after?
Prior to it, during this whole thing of disintegration of lithium. Actually, by this time he and Livingston were totally off on their big machine so these points are all essentially ones that I took. Henderson did some. Cooksey didn’t do very much, because he joined Lawrence and Livingston to design a new machine, so most of the lithium data I did by myself, with nobody around except that Henderson came in occasionally. Yes, this is even my printing on the published data. I could print better there than I can now.
You mean on the data.
Well, did you work nights, days? It would be good to have a description of that. Or was it a pretty steady kind of a thing?
I worked all the time. Of course I was also a student, taking classes at the same time, so I couldn’t — I had to do my homework. One problem was that the magnet at top energy overheated, in about one hour, and then took 13 hours to cool down. It wasn’t water cooled. It was a non-cooled magnet. So you ran it for one hour, and then couldn’t come back on again for 13 hours, so I would run it let’s say from 1 to 2 p.m. in the afternoon, and then come back on again from 3 to 4 a.m. that night, then let it cool down and come on from 5 to 6 p.m. the next day, so my time was all mixed up, ending up by my not going to bed at all regularly, just days or nights as time went on. That was even more the case when I did my proton-proton scattering work, because that problem went on for two years.
Did you accumulate the data over a period of time, or did it all begin to come in a cluster, even given this kind of a schedule?
For this lithium disintegration thing right here?
Yes, for the published paper.
Oh, that came over a period of, I think, a couple of weeks or so, three weeks.
When was it clear that you really had it? From the beginning?
Not until the counting rates began to show evidence of increasing with energy of the proton. And that was done by raising the magnetic field, and I had to retune the oscillator, to match the field, and as the count rate went up in energy, then I felt pretty sure that it was not an artifact, it was the real thing. And furthermore, (I haven’t read this thing in a hell of a long time), yes, I guess the fact that we joined in with Cockcroft-Walton’s data and went on –- we only had three points, after all, those three circle points. Two of them were on their curve and the third one is way up here, at 700 kilovolts. But to get to 1.2 million volts, you had to drive the magnet pretty hard and we didn’t try to do that at that time. Yes, I think as soon as this top point was up here, and with a strong increase over the Cockcroft-Walton, then one felt, I felt pretty sure that we had something.
Did Lawrence agree? Was he the first one you discussed it with?
Well, he was in and out constantly, you know. These counts were of course growing over the days, and there was always the problem of background and some runs you had to throw out because you knew very well the counter had gone sour. This little ball at the end of this platinum wire would sometimes develop a little sharp point; then the counter would go into a spontaneous discharge, and you had to know when to throw away the data. So the data came in, apparently, pretty soon after I returned from Sacramento.
Was there a good feeling around the laboratory at that time?
There was great good feeling, but also I think there was a certain amount of shamefacedness that we hadn’t been the first, because we had it right in our hands. This could have been done a year before, practically speaking.
You didn’t have the counters, though.
Well, they should have been there. They could have been there. The hard part was the cyclotron, if you want to look at the technology. But the other hard part of it is to know what you want to do. Of course Lawrence said he knew that he was going to disintegrate things eventually, and one certainly can’t fault him for not having brought this technique into the laboratory sooner. Looking back at it, again with Monday morning vision, it might have been smart if my first job had been to make counters, rather than to make an ion source. In fact, I thought so as of that time. Not the ion source time. Later on I said, “Gee, why didn’t I work on the counters?” But that’s expecting — well, a lot of me, certainly — I was not that bright. Others might have been well advised to have gotten into the counter business.
What did you do next, in terms of your own work?
Well, next I turned to boron, and it was the paper on boron that came out next, I guess.
The machine, the cyclotron model that accomplished this disintegration was not the one that you were working on, or was it?
That’s right. That’s right, the square one.
It was the one you were working on?
I see. That’s the one you’d left for the summer.
That’s right, yes.
The one I showed, the chamber I showed in my slide in Washington was —
Well, the picture you have in Physics Today is the right one.
I know, that’s different from the one I showed.
But the one in Washington, the circular one, that’s not the right one.
Where does that one date from?
That’s prior to the square box, and prior to my time. It was Livingston’s first model of the cyclotron, the first one actually to work.
OK, it’s an early model.
Right. I think the round one didn’t get past, what, 75 kilovolts or something like that, I believe.
So you began to work on boron with the same instrument.
Same instrument, that’s right.
Well, did you give any attention to — you got a cloud chamber too, didn’t you?
Well, having done boron, and — see, no one knew really what to do with these darned things. Now, one could have, with more beam current, and bombardment time, very carefully run a cross-section curve, and one would have found, we now know, a very complicated structure in here. It’s all full of very complicated wiggles. There is an enormous amount of structure in that whole thing. That wasn’t found till later on with the Van de Graaff machine, because the cyclotron energy spread was fairly large, for two reasons. One was that the beam itself had a big energy spread, and furthermore it wasn’t very stable in time. And so the energy wandered back and forth, and one could, I’m sure, and we did later on, remove these instabilities. Modern cyclotrons are in fact quite well defined in energy. But in those days, there was a very big battle between the Van de Graaff boys and the cyclotron boys. These two camps were distinctly at loggerheads. The Van de Graaff people said the cyclotron was just a rough ready tool whose only virtue was its high energy; if you want to understand nuclear structure, you’d better get a Van de Graaff, they said, with a kilovolt energy spread. Well, in those days they had a 20, 30 or 40 kilovolt energy spread, and the cyclotron energy spread was probably on the order of 10 percent, or more, probably more, 15 percent, for fundamental reasons — until one invented the synchrocyclotron, then the energy spread became a lot smaller. So after doing the work on boron, which I guess happened in the next ... do you have a date there on boron?
Yes, I have it, boron was ‘33. It doesn’t give the month. January, ‘33. January 27th it was submitted, right, and published February 15.
Well, it also just went up, and didn’t show any structure. I couldn’t see any point to trying to do a precise job. No one had seen any kind of structure in those days. Furthermore, I was already engaged in the fundamentals of proton-proton forces, because back in 1933 — R. D. Evans had a course on, a seminar on nuclear structure, and —
You mean at MIT?
Oh, he left in ‘34, right. At the end of ‘34.
No, I don’t recall exactly when he gave this course, or seminar, all of us gave papers — and there were papers on all aspects of radioactivity. He was of course more concerned about radiation health aspects, and radon in rocks, and he was pulling radon out of all kinds of material. My paper for that course was to review all of the pre-cyclotron work on disintegration of nuclei by alpha particles. So I read all the papers. You could do it in those days. Every last one of them. In all the journals, on disintegration by alpha particles. And I was very impressed by Blackett’s scattering of alpha particles by helium in the cloud chamber, I recall being very moved by seeing a picture of alpha-alpha scattering, two particles 90 degrees apart, and I really felt I was getting down to the fundamentals of “stuff.” And then of course it occurred to me that the alpha particle really wasn’t very fundamental, because it was composed of two protons and two neutrons, and therefore the next step would take just two protons and do the same scattering thing. And I had them in my cyclotron.
So right away I knew what I wanted to do. And proposed to Lawrence that I should at that point do that experiment, and he said right away, “Sure.” At about this time I mentioned the p-p scattering idea to people such as Professor L. B. Loeb, R. Brode and others. Most of them said, and I remember Loeb most vividly, “Why bother? You’ll surely find that two protons scatter like pure, Coulomb, point particles down to 10-16 centimeters and at your energy of 1 Mev you can’t get them closer than about 10-13.” Now the reason they believed that a proton had a radius of 10-16 centimeters was that in those days all the mass of an electron or proton was thought to reside in the electromagnetic field; so, as shown in Jeans’ book, the radius of a charged elementary particle should be given by r = e2/mc2. If one sticks in the proton mass this becomes about 10-16 cm. I recall saying that even if this were the case I wanted to prove it. I recall having some pretty vigorous arguments with Professor Loeb, but we remained good friends — for one thing he was the science advisor of my wife to be. He was noted for his fighting abilities. I also recall Bob Brode ending up a discussion by saying that, though he was convinced wouldn’t find anything except Coulomb’s Law down to 10-16 cm, physics was still an experimental subject and that’s what we experimentalists are here for. Oppie, with whom I talked at some point in the game, was very interested in seeing that it was done, but he didn’t say it would clearly come out to be non-Coulomb. Eventually it has to be at some distance, because nuclear forces are such that it’s going at some point to show a deviation.
People were very unclear about nuclear forces in those days, and not at all like today when you sort of visualize a short range force and Coulomb force and spin dependent forces and so on. So anyhow, I picked on the cloud chamber as the way to go about this problem, for two reasons. One was, by analogy with Blackett’s alpha helium scattering, and secondly, the beam currents that I had were quite small, so that a counter experiment, it turned out, would have been impracticable, unless I had a 4Π solid angle counter, and in fact, having finished the proton-proton scattering experiment in the cloud chamber, I next was going to tackle proton-deuteron scattering or deuteron-deuteron scattering, and I was going to build a 4Π counter. In fact, I called it my toilet ball counter because I made it out of three, concentric toilet balls, which were supposed to operate as Geiger counters, or would have eventually. I never got around to finishing the counter. But I knew I had to have that large a solid angle, to get enough counting rate, at the currents that we had available to us. Well, anyhow, the cloud chamber was the obvious thing to do. At this point Franz Kurie had already been in Berkeley for a year or two building a cloud chamber, having built one before at Yale, and he was building one using Merle Tuve’s newest design, which instead of having a piston, as in earlier models, which had to have piston rings and slide back and forth in a honed cylinder, Merle Tuve used a simple bellows, a big sylphon bellows, a corrugated bellows which you could compress or pull out.
And he drove it by a second bellows down below which he connected to a vacuum tank or pumped up. Then, so it wouldn’t bounde, he had a magnet to hold the thing once it expanded. The magnet latched it, held it there, and then slowly it would return to its normal position. So Kurie built this contraption, rather elaborate mechanically. At that point, C.T.R. Wilson came up with a new chamber design, which had a rubber diaphragm which he blew up from below with compressed air into the region to be alternately compressed and expanded, and then you pulled the bung on the compressed air pipe, and the pressure in the region where you wanted to do the scattering pushed the rubber diaphragm back down again and thus expanded. And this was very cheap to make, and so I quickly abandoned any attempt to copy Kurie’s design, which was very expensive, and I recall that I built the whole thing in about one month’s time, I made a wooden pattern for the brass casting, and got it cast outside. Then the shop was too busy to turn it down, so I was a mechanic for a while and turned this brass casting in a beat up old lathe which they had in the student shop, and fixed it up for operation with the rubber diaphragm. And the thing worked fine, and was much cheaper to build than Kurie’s and had a far more reliable record.
How did you learn about these other cloud chambers, about Blackett and about the new one with C.T.R. Wilson?
In the scientific journals.
There was no correspondence between Lawrence and them?
Not to my knowledge. I wasn’t aware of any. Wilson’s paper came out I believe in Proc Roy Soc. About 1933 or some place in there.
You saw it soon after it came out then?
Yes, and I built a chamber very soon thereafter. I first built a little model, just using a pair of brass rings and rubber sheeting and a piece of glass, waxed on the top, and the thing worked right away. Then I built a proper one for the experiment.
Now, what time did this take you to? You were covering a lot of ground with this cloud chamber experiment. Was this still in ‘33?
I will have to figure this one out.
Because there were no publications in this period, so I assume that you were working on it, also — did you continue to go away and work during summers, or did you this time stay there the summer of ‘33?
I don’t know how I would have eaten if I’d stayed there the summer of ‘33.
There’s one thing in the —
— they didn’t have any physics departments jobs at the time, and my parents couldn’t have supported me — I. didn’t ask them to support me anyhow. I have a feeling somehow that I did not go away that summer, but damned if I know how I supported myself.
There’s something in here about your leaving for the summer, but that might have been the previous summer. The problem with this biography is that you forget to put in the years. No, I think that was a reference to the summer of ‘32, so that doesn’t answer our question about ‘33.
This boron I finished in January, ‘33. There was a period of time when I stopped doing any experimental work, while I was studying for exams, too. Let’s see, January, ‘33 — it could very well be that that was the spring when I didn’t run the machine to speak of and no one else ran it, and I was studying for my orals. I bet I was, yeah. I wasn’t doing it at all. And I think I must have spent the summer there in Berkeley. I don’t know how I managed to eat. During the school year I was a teaching fellow and also I was awarded a small fellowship at some point. Also, I now recall, I did borrow from my parents to some extent, for I was paying them off for a couple of years after I left Berkeley and went to Princeton.
During the cloud chamber work that you did, and the subsequent experiments, were there extra expenses involved which you had to obtain from Lawrence or from the department?
Well, I kind of recall, the cost of this casting was about $15, $20. This took a bit of doing. And then also I needed a Selsyn phase shifter which cost $19, and this took an awful lot of finagling to get the department to buy that. Couple of months.
Who did you have to deal with on that?
The guy who ran the purchasing and stock room, a Mr. Vees. Mr. Vees was a great big guy, cigar-smoking, bald head. He was from the Bronx and he talked about “looyers” and “erlberls” when referring to lawyers and oil barrels — he was my idea of a typical New Yorker. He was a very rough kind of a guy, rough in his talk, and in fact he was really full of some pretty raw stories, really raw stories. Risque stories. He and Leonard Loeb used to go off in the corner and tell dirty stories, and then roar like hell. They’d get into fights too. They had some real rough, verbal fights. He’s the guy you had to fight with to get money, and I suppose he must have gone to Lawrence to get approval, I wasn’t aware of that, but it took a long time to get this $19 odd dollars for the Selsyn. See, I had to be able to phase the expansion of the cloud chamber with respect to the phase of the 60 cycle power lines, which were used to excite the RF oscillator which drove the cyclotron dee.
The point was that unless the proton entered the cloud chamber at just the right time after the expansion was complete, you wouldn’t know the pressure in the chamber, and therefore the number of atoms per cc, and therefore the scattering cross-section. And furthermore the track quality would be impaired, because if you came in too early, then the ions drifted before you expanded, doubling the tracks. If you came in too late, then the chamber warmed up and there was no water to condense upon. So it had to come in pretty well timed. So I had in the bottom of the cloud chamber a little switch, which was hit by the rubber diaphragm, and that switch then actuated the thyratron which ran the oscillator transformer, and I had it all phased so that I expanded the cloud chamber and the diaphragm came down, only when there was power ready to come in and start accelerating the protons. So this was a sort of an innovation. The other thing that I had to do was to get the protons out of the cyclotron. Up to this point, they were only internal to the machine.
They’d never been brought out. They were always inside. It was a great handicap, because they were in a magnetic field, in a vacuum, and difficult to work with. So my technique for getting them out was to have the beam go through a very very thin piece of foil, in fact aluminum leaf, and in going through the foil, the protons, a few of them, picked up electrons, became neutrals, and then the neutral came directly out of the magnetic field, went through a final exit window, and entered the cloud chamber. Whereupon of course they then re-ionized, by going through the gas. So this was a thing I was sort of proud of, that — that was my major technical contribution to the machine, the extraction process. It wasn’t very efficient, but it was plenty good for my cloud chamber. You couldn’t stand more than about 10 or 15 protons in the chamber per expansion. Otherwise you would get too much confusion of tracks. But it was not a practicable way to extract an intense beam from the machine.
Your work then for this period, probably up to your leaving, was concerned with experimental use of machines simultaneous to these kinds of developments of techniques. Were there any other people doing that kind of thing, or were they pretty much occupied with successive models of the larger machine? Did you have any role in those other models? Did you get involved at all in the 27 inch and the beginning of the 37?
Not a great deal. I was pretty well occupied at my proton-proton scattering experiment, though I spent a good deal of time with people in the barn, with the cyclotron. Lawrence’s technique when problems went awry was to call in the whole gang and ask for ideas. So we all got together every so often to see the latest wreckage around the place, and he would either make a very impassioned speech, or he’d put us on the carpet for not having done better, raise a little hell with the people who goofed off. He really drove them pretty damn hard. So in that sense, I had a small input. As you probably know, in the barn along with the cyclotron there was the Sloan resonant transformer at the same time, and also there was Kinsey and Thornton, with a lithium ion accelerator, which has some funny stories that go with it. Then there was also in the same barn a chemist, guy named Fowler, who was developing a very big proton ion source. A really big one. And so lots went on over there. But mostly technology of accelerators and such matters. Of course, Luis Alvarez came and Ed McMillan. They began to do experiments and developed Geiger counters and amplifiers and electroscopes and all these things; I was in and out, learning more than I was contributing, I would say.
Were you working separately from where the larger cyclotron development was going on?
Where was your —?
On the second floor of LeConte Hall, about 100 yards from the cyclotron barn.
Now, we only have a few minutes left before we take a break, but let me ask about the courses you took — the orals you had covered not only your research but certain courses, prescribed courses that you were required to take. What kinds of fields were covered in your orals? What categories were you responsible for?
Well, the Berkeley system of examining you for a Ph.D. was to have oral examinations, not written, in a number of fields. Now, each course had course exams, written exams in the courses. You were required to take the courses and required to take the exams. But in addition to that, there’d be an oral exam in mechanics, an oral exams in E and M, an oral exam in optics, oral exam in language, French and German, and these exams you took at your leisure; whenever you got the subject up you announced this to the chairman of the department, and he’d appoint an exam committee, which would then sit down with you, two or three people, you’d go to the blackboard, and they’d proceed to ask you questions for about an hour and a half. This was standard for everybody. I suppose if a person were heading for some — for, say, theoretical physics, they’d hit him hard on the mathematics and quantum mechanics. An experimentalist as I was, they would hit harder on things nearer to the experimental work. So it had the advantage of being able to adjust itself to each person’s particular field of interest, unlike our system here at Princeton, where we have a written exam for everyone, the same exam for everybody. That means you expect the experimental man to be as adept at theory as the theorist. It’s a little tough. The oral exams we have here, however, we do adjust it to the man’s field, but the system at Berkeley was simpler, was easier, I must say, than it is here.
How much theory were you exposed to in the formal course work on the graduate level?
Well, I had a course in E and M from Ernest Lawrence, which really wasn’t terribly profound, because he was so interested in research, and sitting up all night long with the cyclotron and raising money. The course he gave lacked rigor. On the other hand it was the course I most remember because it was the most interesting and vital course. I think that probably I studied more on my own in that course than I did in say mechanics, given by Victor Lenzen, who gave a very beautiful series of lectures, highly polished, and when you came out you felt that you had really been exposed to a very complete resume of the field, and why study anymore? It wasn’t true at all. Lawrence’s courses were given by the students more than by Lawrence. Sometimes he’d assign problems which he himself didn’t know how to solve, I suspect. But at least if he didn’t know how to solve them in detail he knew hop, to do it in principle but didn’t really know the mathematics. Then I had quantum mechanics from Oppenheimer, and I wasn’t really prepared for Oppenheimer. He was much too erudite for me. I enjoyed it. I worked at it pretty hard, but I would have been probably better served by someone not as high powered at that stage of my career. I think if I’d had Oppie as a postgraduate it would have been great, but for a graduate student I would have been better off with someone who wasn’t nearly as profound as he was. I wasn’t able to really follow his use of medical terms in physics, where he referred to equations as being “morbid” or “pathological.” I wasn’t sophisticated enough to catch onto what in the world was a pathological equation. But the other graduate students — Frank Carlson, Bob Serve, Arnold Nordsieck who were all in the course with me — thought he was just great.
But they were all theoretical people?
Yes, they were all theorists, and Nedelski, Melba Philips, they all understood — and I went to them for my instruction, as a matter of fact. So I learned most of my quantum mechanics from Arnold Nordsieck and from Bob Serber and people like that, which was all right, nothing wrong with that.
Who examined you on your orals? Who were the various people?
The oral team varied. In mechanics you always had Lenzen and you had Williams, whom nobody’s ever even heard of, and I don’t know who else. In E and M I’m sure I had Lawrence and Brode. In optics I’m sure I had White and Birge, always plus one or two more younger people who sort of came and went, and of course in the languages you had somebody who was presumed to know the language, which was not always the case.
You didn’t have any theoretical exam, nothing in quantum mechanics?
Yes. The exam in quantum mechanics was — I can’t recall all that distinctly, but Oppie was there, I know, and I didn’t know nearly enough to satisfy him, and I felt a little red-faced, but he was nice to me and said, “Well, apparently you’ve been doing proton-proton scattering and haven’t had time to study quantum mechanics,” which was correct. I was right in the middle, you see, of my research work, and that unquestionably cut into my time for studying. I just begrudged the time for study when I was “making history,” as I put it, rather than reading it.
Yes, right. Now, we have a problem, it’s 10 to 4.
I’ve got to quit.
Yes — to remind me, next time we’ll take it to completion of your Berkeley period, the completion of thesis, decision to leave, choice, etc.