Oral History Transcript — Dr. Willard F. Libby
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Interview with Dr. Willard F. Libby
Willard F. Libby; April 12, 1979
ABSTRACT: This interview is concerned primarily with two periods in the life of Libby (1927-1940 and 1945-1954). After briefly discussing his early life and education, considerable attention is focused upon Libby's undergraduate, graduate, and post-graduate years (1927-1940) at the University of California, Berkeley. Major topics included are: growth of Berkeley science; Gilbert Lewis, Wendell Latimer and Ernest Lawrence; Libby's development of low-level counters; radiochemistry and discovery of isotopes; cross-disciplinary collaboration; Libby's interest in carbon-14; association with Samuel Ruben and Martin Kamen; hot atom chemistry and nuclear isomerism; Libby's experiences at Princeton during 1940-1941 (hot atom chemistry, development of heterogeneous catalysis and research on tritium) and his work on the chemistry of the diffusion process during WWII at Columbia University (Manhattan Project) are mentioned; the other major portion of the interview concentrates on Libby's development of the radiocarbon dating technique at the University of Chicago (1945-1954); special attention is devoted to: measurement of half-life of carbon-14; importance to Libby of Harold Urey; secrecy policy; collaboration with Aristid von Grosse, James Arnold and Ernest Anderson; improved counting technologies; first contacts with archaeologists; Viking Fund and cross-disciplinary collaboration; communicating ideas; Sunshine Project and fallout; AEC appointment; concluding remarks.
TranscriptSession I | Session II
Marlowe:Dr. Libby, presently professor emeritus of chemistry at the University of California, Los Angeles, has had a long and distinguished scientific as well as public career, but is perhaps best known for his work on radio carbon dating while at the University of Chicago. That work ultimately won him the 1960 Nobel Prize in Chemistry. This interview is being conducted by Greg Marlowe, graduate student in the history of science at the University of California, Santa Barbara. The interview is being conducted for the Oral History Program of the American Institute of Physics. Dr. Libby, I know you were born on December 17, 1908, in Grand Valley, Colorado, but I know very little else about your early background and your family. Could you tell me, for example, your parents, who were they and what did they do?
Libby:Well, my father (Ora) was a farmer. My mother (Eva) was married when she was 16, and her father ran a stage coach in Colorado. After the marriage, they, of course, lived on my father's farm near Grand Valley where I was born in 1908. Then, in 1913 when I was five, they moved to California. They had two more children.
Marlowe:Were those children born in Colorado or California?
Libby:The last two children — there were three boys; two more boys were born in Colorado.
Marlowe:So you were the oldest?
Libby:I was the oldest. Then in California twin girls were born in 1914. So, after batting around in a number of jobs, my father became the manager for a large ranch which was owned by a family in San Francisco, and with the job came a large house, gorgeous vegetable garden, cows and horses, and we grew up there, a wonderful life, on the ranch, just five miles north of the little town of Sebastopol, which is about ten miles west of Santa Rosa.
Marlowe:Can we take it back for a moment in terms of the Colorado experience? For example, could you tell me a little more about your parents? What degree of education did they have?
Libby:Well, my mother was a grammar school graduate. But my father left grammar school in the third grade. So they weren't highly educated. However, my old daddy was a very sagacious and sharp individual. He was a tough Maine Yankee. He used to go into the Maine lumber woods every fall and come out in the spring — spent his teens in that way; Tough hombre. Yet a very kindly man, but with the crews on the ranch he never had any problem.
Marlowe:How old was he when he moved to Colorado?
Libby:Let's see, he was married when he was 27. I don't really know how long he'd been in Colorado before he was married. I suppose a couple of years. I never understood why he left Maine. While we were in Colorado, his half-brother came to visit us. I was named after him. He was considerably older than my father. My mother's parents were from Georgia, and Southern people. Interesting marriage, Maine Yankee and girl from the South. Their name was Rivers, and Rivers' name in Georgia is well respected.
Marlowe:When you left Colorado and ultimately ended up in Sebastopol, why did your father decide to leave farming in Colorado and come to California?
Libby:I never really understood it. I never really knew. Of course, in those days, California was kind of a frontier.
Marlowe:When he came to California, he came into a management position in a business?
Libby:Well, he tried to get hold of a ranch, but the ranching and farming business in California is very different from other places. That country around Sebastopol is ideally suited for fruit, and vineyards; that's what it's used for. He'd never had any experience growing orchards and vineyards. He had to learn some. He learned quickly, though. He was the finest farmer in the whole region.
Marlowe:And did you work on that farm?
Libby:I worked on that farm.
Marlowe:While you were going to school?
Libby:In the summers but in a rather special way. Apple processing is a rather sophisticated business. You pick the apples, without bruising them. All hand-picked. Then they're wrapped in paper, first put on a sorting belt and sorted for size, quality — they were getting $3 a box in the mid-twenties for those apples. They're really a prize. And what I did was to do the box-making, and after the apples were wrapped in papers and packed in the box, I neatly put a lid and nailed it on. I was the champion nailer; the fastest one. We used to make good money there.
Marlowe:Was your father a pretty handy person, in terms of being able to work with his hands?
Libby:Well, he was a fine pruner and a fine horse handler. And he was very good with a double-bitted axe. Do you know what a double-bitted axe is?
Libby:It has blades on both sides. Yes, very good.
Marlowe:Can you tell me a little bit about your early schooling, particularly in high school?
Libby:Well, I went to a school called Analy Union High in Sebastopol. It had about 400 students at that time. It's much larger now. We were up there for the 50th anniversary of my class. It's grown. Still seems to be the same old buildings and the same general attitude. Out of 100 students in my class only two went to college.
Marlowe:What was the nature of your academic interest in high school?
Libby:Well, I was interested in everything. I was particularly interested in literature, English literature and history. But I enjoyed my chemistry and physics and I took four years of math, enjoyed that. So when I did go to Berkeley, I was pretty broadly trained in fundamentals.
Marlowe:Do you remember anything about the facilities for science at your high school?
Libby:Well, they were adequate. They have just got a brand new building there, which I'm pleased to say they named for me. We didn't have any such fancy laboratories for teaching in those days, but we got along fine.
Marlowe:Were there any individual teachers that you felt later to be influential?
Libby:Yes, there was a man named Crump, John Crump. He's still alive. He did a very good job on me. There were several others.
Marlowe:Did Crump teach science?
Libby:He taught chemistry. Then we had an English teacher, Miss Bradway, who did a superb job and Miss Schmidt, who was another fine teacher. I believe she taught home economics, something like that, but she also took interest in our plays. I was active in the theatre.
Marlowe:Do you recall, in terms of your interest in chemistry and science, any particular books? You were quite an avid reader in high school, were you not?
Libby:Yes, I was. But I didn't really get interested in science until I went to Berkeley. I was reading everything, particularly in literature and history. Then I was on the football team, not a very good football player, but I was one of the largest ones. I was student body president and so on; did everything.
Marlowe:Did your parents encourage you to work hard on your school studies, even though in terms of formal education they were not particularly well-educated themselves?
Libby:No. They didn't feel that was necessary. My grades were adequate. B.
Marlowe:But they did think that schooling was important.
Libby:Oh yes. They certainly did.
Marlowe:After you graduated from high school, your decision to go to college, ultimately Berkeley — your parents supported that idea?
Libby:Well, let me tell you a little more about that. When I graduated from Analy, I went to work for a year on my father's ranch, which wasn't his, but which he managed. It was a magnificent ranch. I worked as a farm hand for him for a year. One of the wisest things I ever did. At the end of that year, I wanted to stay.
Marlowe:Oh, so you did not entertain ideas of going to college directly out of high school?
Libby:Well, yes and no. But I told my father that I preferred to stay and work on the ranch and buy up the country.
Marlowe:A budding entrepreneur of sorts.
Libby:And that's what some of my classmates did. I spoke to the Chamber of Commerce there a couple of years ago, at a ceremony, the 50th anniversary. There were a lot of millionaires in the room who were my former classmates.
Marlowe:And you went to college and none of them did.
Libby:Yes. But my father's position was: "Look, I graduated from the 3rd grade, now you go to Berkeley." So I went to Berkeley.
Marlowe:When you decided to go to Berkeley after a year of working on the farm, were your parents able to give you any financial support at all?
Libby:I didn't need it. I was able to earn money all the time.
Marlowe:When you worked on the farm, did you save that money with the idea of going to college?
Libby:Sure. I didn't have any rent to pay; just living with them. Then I had this nailing job in the summers that paid extremely well. I used to make $100 a week.
Marlowe:And that was real money.
Libby:So I went to Berkeley for four years and never worked a day and paid my way all the way and graduated with some money in the bank which I promptly lost in the Crash.
Marlowe:How and why did you choose to go to Berkeley? Was it because of the geographical proximity to the area where you lived?
Libby:I think so. We had no idea what a great school it was. The junior college hadn't really taken on by that time. See, this was 1927. Maybe Santa Rosa Junior College had just then started, but it certainly wasn't established. So if you're going to college, you went to college. Nowadays, of course, it's not at all frowned on to go to a local junior college and then transfer.
Marlowe:Initially when you entered Berkeley, had you declared a particular major?
Libby:My purpose there was to delay the decision as long as possible, because I didn't really know what I wanted to do. So I enrolled in petroleum engineering, the point being that it had the most courses and therefore the most alternatives. If you left the curriculum you could go into more different majors. The first thing I decided was, much as I loved English and history, that that was no way to make a living. So, it had to be the sciences or engineering. So I enrolled in petroleum engineering. I remember, they required 147 units to graduate. This course caused me to take subjects I would not have otherwise taken, such as drawing. I'm a pretty good draftsman as a result of that, and I'm a pretty good surveyor. I remember one delightful summer, we had a six-week course in the field, surveying. And we ate extremely well and we enjoyed ourselves tremendously. This was a good time for thinking things out. I had a number of courses, not in the general petroleum engineering curriculum, which I elected to take just for general interest. Berkeley was a very fine University then, and still is. Even though I was an engineering student, they would welcome me into classes in any field. It turned out, I graduated with three majors. When I went to Berkeley, I lived in a boarding house. I was invited to join a fraternity, but I'd been a pretty social animal in high school, and I knew if I were really going to do a serious job at Berkeley, I'd better not join the fraternity. So I went to a boarding house, and this was an amazing coincidence, because it was largely populated by graduate students from the college of chemistry. There was my first serious contact with chemistry.
Marlowe:Now, would this have been in your freshman year?
Libby:I went there in my freshman year. I lived there the whole four years. It was kind of an austere place — not many distractions. We had good meals and we could talk. Occasionally we'd do a little drinking. But most of the time we were working. But the important thing was the people I met there were graduate students in the field of chemistry. There's where I began to see about chemistry and how exciting it was. That led to my transferring from petroleum engineering to chemistry, to become a major in chemistry.
Marlowe:That was in your junior year?
Libby:End of the sophomore, beginning of the junior.
Marlowe:Ok, now after you'd decided to direct your attention to chemistry, at that stage, which figures if any in Berkeley science had the greatest influence on you at that initial stage?
Libby:Well, of course, the initial contact was through these graduate students, who were Dr. F. H. Spedding — these two gentlemen, old friends of mine, George Cady and Harry Spedding, were telling me about their exciting researches. Harry Spedding then was a post-doc. George Cady was a graduate student working for his PhD. He was working with Joel Hildebrand on fluorine chemistry. Absolutely frontier smashing thesis he wrote. Well, then I began to get interested in what others were doing, and I realized that this department was the finest in the world. There was no place that matched Berkeley in those days for chemistry. The head of it was Gilbert Newton Lewis, a remarkable genius. I remember several things about Gilbert. He was a very affable type and yet austere. He seldom took graduate students himself. He took post-docs.
Marlowe:For example, Wendell Latimer, was he a post-doc of Lewis's?
Libby:Well, I don't think Wendell was a post-doc, but he was a faculty member, a professor. Gilbert had a number of professors in his department, which he had appointed almost single handedly. There was no real democracy in that place. He took a liking to me. My thesis work was "The discovery of new naturally radioactive elements." I remember he invited me into his office one day and he asked, "Do you think that's chemistry?" I said, "Yes." He said, ''I agree with you.'' So this was the beginning of the chemical atomic age at Berkeley. I built the first U.S. Geiger counter right there. The first one in the country was built in that building. And, of course, following on that was the great Manhattan District. (Glenn) Seaborg came in, and grew up there and so on, far into the night.
Marlowe:Now, Lewis was a physical chemist, and you had mentioned before that in some respects, Lewis really built modern physical chemistry. Could you explain something about that, about Lewis's contribution to modern physical chemistry?
Libby:Well, he was one of the greatest men who ever lived. It's surprising he isn't more famous, but among scientists, he is. He was a great admirer of Einstein. Too bad he isn't alive to tell things. But he died in '45, I believe it was. He wrote papers on Einstein's relativity work shortly after Einstein's 1905 work was published. Here was a physical chemist thoroughly cognizant of relativity theory, personal friend of Einstein's. In 1916, he wrote the first definitive paper on the nature of the chemical bond, pointing out that the bond required a pair of electrons. That was his idea. It was a new one. He was the first one to propose that the stars run off of nuclear reactions. He did that in 1921.
Marlowe:When was Lewis brought to Berkeley?
Marlowe:Who was responsible for that, Benjamin Ile Wheeler?
Libby:Benjamin Ile Wheeler, very far-sighted man. We were talking at breakfast about university presidents. My neighbor, was former head of the department of architecture and urban planning at Columbia, he was talking about Nicholas Murray Butler. I mentioned Benjamin Ile Wheeler. There do not seem to be very many presidents of that stature these days. Well, President Wheeler offered Lewis a quarter million dollars a year salary.
Marlowe:God, that's unheard of.
Libby:Well, it was $10,000 then. No income tax. You figure it out. It would take a quarter of a million right now to match that. He was offered a college of his own, and something like six professorships.
Marlowe:Lewis was brought there specifically to build up Berkeley science?
Libby:Right. Now, his predecessors included Cottrell of the famous dust precipitator company, Frederick Gardner Cottrell. So Berkeley had made a little mark on the record before Lewis, but nothing like after Lewis came. For example, Richard Tolman was a student of Lewis at Berkeley, and he ended up being the top theoretical physicist at Cal Tech. All the famous people were coming through Berkeley. Lewis hired Robert Oppenheimer. But more important, he hired Ernest Lawrence and got the whole atomic trip going at Berkeley.
Marlowe:Could you be more specific in terms of Lewis's role in the development of physical chemistry?
Libby:Well, he educated all the physical chemists, or most of them, and the descendants of those — for example, his students include 14 Nobel Laureates. There should have been 15 because he should have had one for that 1916 thing. But any department of substance in physical chemistry has either a direct or secondary or tertiary connection with Lewis's offerings. He's an interesting fellow, in the sense that he graduated in English literature as an AB, and it was only when he went to graduate school that he took up chemistry. He always wrote beautifully. His scientific papers are a pleasure to read, they're so beautifully written. He was an incredibly brilliant person, extremely widely read, knew many, many people. For example, when atomic chemistry began to take off — remember, I was the first one, working with Wendell —
Marlowe:The first nuclear chemist.
Libby:When it began to take off, here's this very famous man who's in his sixties. We had a Monday night seminar which ran for nine years. We would meet at 7 or 7:30 and we would go to all hours, just reporting and discussing the new papers. This field was just blossoming.
Marlowe:It took off when you were an undergraduate?
Libby:No, this was in graduate work. No, my undergraduate work was mainly consumed in doing the required courses in chemistry, but also in physics and math. I graduated with three majors. My first paper was in mathematics.
Marlowe:You were working with Wendell Latimer now as an undergraduate?
Libby:Well, that wasn't the system. He was my advisor, shall we say. But then when I became a graduate student, he was my main advisor.
Marlowe:Did the emphasis on the triad, math, chemistry, physics, did that differentiate Berkeley from other chemistry programs or was that pretty standard?
Libby:No, I think that anybody who is going into physical chemistry had better know physics, better know math. It's that simple. At the cost — I never had any biology. I've regretted that, to some extent. But now with the new biology coming along, maybe it was all right. It was largely a descriptive science. But our preparation there, by coincidence, was ideal for the development of atomic energy. Berkeley did a vast proportion, the major proportion, of the chemistry of atomic energy.
Marlowe:Now, getting back to what you began as a senior project, building the first Geiger counter. You mentioned one time in a speech when you were dedicating Latimer Hall at Berkeley, that Latimer allowed you to undertake this, obviously, and I underscore the word obviously, referring to the Geiger counter — very chemical research. He gave wide latitude to you in scientific endeavors. Was that something peculiar to him and Berkeley in general?
Libby:Gilbert's definition of chemistry is "what goes on in Gilman Hall." That's chemistry.
Marlowe:Do you think that was something peculiar to Berkeley?
Libby:It was pretty unique. Like when Gilbert took his degree at Harvard, he took it from Theodore Richards, who was the first American Nobel Laureate in Chemistry. But he was interested in only one, that is, the atomic weights of the elements. They didn't know about isotopes in those days, and so it was a great and important subject. But Gilbert learned thermodynamics from Harvard. Once he left Harvard, he turned loose a series of papers and performed a series of researches which are classic. He measured free energies — practically none of them had been measured before, like the free energy of water — (he analyzed) a number of pure substances — established the technique that is the determination of the heats of formation and then the measurement of the specific heats, from low temperatures up to whatever temperatures peak. This is all Gilbert Lewis. And Gibbs had written down the basic theory.
Marlowe:J. Willard Gibbs?
Libby:Right. But Lewis was the first one who did it. The chemical industry owes Gilbert an enormous debt. And he continued to read in English literature. Some of his best friends were in the English department. He was very well informed on everything except business. He seemed to have no interest whatever in business. He had this fantastic salary. He didn't have to have any interest in business.
Marlowe:So to sum it up, would you say that the nature of undergraduate, and then later graduate training at Berkeley, especially in physical chemistry, and in the willingness to let you roam wide, the great degree of latitude, was unique to Berkeley?
Libby:I would think so. But it also has this quality, that once you find a breakthrough, you quit roaming, you start concentrating. Nobody has to tell you that. The first element I tested proved to be radioactive. How lucky can you get? Not only was it radioactive, but it was a unique type. It was an alpha emitter, the element samarium. It's the only one still known that is an alpha emitter below thorium; now turning out to be one of the most valuable daters for things like meteorites. That's the first thing I put in my Geiger counter. It worked. I thought, ''My God, I'm going to have my thesis in 90 days." Well, the next one wasn't so — and so on and so on. But you begin to be drawn into what obviously is a major breakthrough. Radiochemistry was a major breakthrough. Then Lawrence's cyclotron started working. I did the Geiger counter in 1930, got my Bachelor's in 1931 —
Marlowe:When you received your Bachelor's in chemistry in 1931, did it ever enter your mind, especially given the fact that the nation was in the midst of the Depression, not to go to graduate school?
Libby:No. No, I knew I could make money. I'd already shown that. So I wasn't worried.
Marlowe:Did you ever consider going to another graduate school or perhaps going abroad, as many did?
Libby:I considered it, but then I began to realize that Berkeley was pretty unique in this new thing I was interested in. And so I was very pleased when they let me stay at Berkeley instead of going. Their policy in general was to send their students elsewhere.
Marlowe:After the BS?
Marlowe:Ok, now when you were accepted into graduate school, how were you supported? What was the source of income?
Libby:TA's. But I also had the summer work. I could make enough money in the summer to live on.
Marlowe:Was Wendell Latimer particularly helpful in this respect? Did you find you required his aid?
Libby:I never had any money problems. If I needed money I'd go home and work a while.
Marlowe:At this stage when you were entering graduate school, had you ever given much thought to what sort of life you might expect or desire to live as a scientist, now that you were pretty much committing yourself to a scientific career?
Libby:Well, I had a problem, because I had to get my thesis finished. You're in that yourself and you know what I mean. And then I had a love affair, all the distractions that that involves. And — but I did have a kind of shocking experience. When I got my Bachelor's degree, the math people wanted me to go into math. They offered me a good TA-ship in the math department. But once again, I think, you can make a hell of a lot more money in chemistry than you do in mathematics, and have more effect. You can do more for mankind in chemistry than deriving a new math theorem. I love mathematics and I was pretty good at it in those days, but — So I once again turned towards the more practical.
Marlowe:Did your family encourage you to continue on to graduate school?
Libby:They certainly didn't discourage me. The basic decision was made when I went to Berkeley in '27. From then on, I was supposed to become famous and do a good job. My other brothers would make the money.
Marlowe:Your other brothers now, were they of college age? Had they decided to go to college?
Libby:One went and one didn't. Strangely enough, the one who went became a veterinarian, and he's worth millions. And the other one is a real estate dealer type thing, well off. Funny how people develop. My sisters went to junior college. I think it was for two years. They were identical twins. One married and had five children. The other never married, passed away a few years ago. Pretty normal family. But, the question of what happened to me — you see, I kind of grew away, because they didn't know what chemistry was. They were always sympathetic and I tried as best I could to tell them, but it's very hard to really explain what we were heading into.
Marlowe:Yes. When you entered graduate school in physical chemistry at Berkeley under Latimer, could you tell me something about the course requirements, curriculum for graduate students in physical chemistry?
Libby:There were no requirements. We were allowed to take courses if we wanted to but we weren't required to. Perhaps the only thing that was really quite seriously enforced: we had to come to weekly seminars. That seminar was something. Everybody came. And that's still the tradition at Berkeley, whereas at UCLA you're lucky if you can get 50 people to come. But at Berkeley, 250 is the standard group.
Marlowe:You've mentioned that Gilbert Lewis did not usually have graduate students per se, but he did run his weekly seminars which you attended.
Libby:Well, he didn't run them. I ran our little seminar. But he attended, as a member. And the same thing in the departmental seminar. See, we had the big departmental seminar, and then we'd have one on nuclear chemistry, which I was chairman of, one in this, that and the other thing, surrounding the main — so that was the way the graduate students learned. By the way, they had to give presentations.
Marlowe:With Lewis sitting in the wings.
Libby:Smoking like hell and making smart cracks.
Marlowe:Did he smoke cigars?
Libby:Like burning rope; Filipino cigars. He'd had a stint in the Philippines when he left Harvard. It was his first job. He went over there for the Bureau of Mines and lived in the Philippines, and he learned to love Filipino cigars and he smoked them all his life. And my God, it was something to be in a room with him. He'd sit in the front seat, and here's the poor graduate student.
Marlowe:He must have been a particularly inspiring man in these seminars.
Libby:Oh my yes. I remember one night, frequently they were in the evenings — we had a paper that said, "If you cool off helium liquid by pumping on it with a vacuum pump, it becomes superfluid and loses all viscosity." Immediately he said, "That's the Bose-Einstein liquid." Boy, that's something. This is now the accepted explanation. He got it in 30 seconds; never heard this before. He was the same way in nuclear chemistry. The stuff was all brand new. I explained about my work on the alpha radioactivity in samarium and how it was a soft alpha particle, much softer than any one discovered from uranium and thorium. He said, ''Well, obviously, that's the tunneling barrier." My God, the guy knew everything. He was probably the greatest teacher of our time. He built the University of California. In 1963 I was honored by the Alumni Association at Berkeley, given their Alumnus of the Year Award, and I spoke about Gilbert Lewis, and Bob Sproul was sitting right there applauding like hell. He had the same idea.
Marlowe:When you undertook your thesis research, and you were working with radioactivity in the lanthanide series, who chose that topic?
Libby:I did. Wendell was always that way. We would discuss, and he helped me enormously to get rare earths, which in those days wasn't a trivial thing, as they were pretty darned rare. There was only one guy in the country making them, and he was a friend of Wendell's. So Wendell invited him out once a year to visit. They took him over to San Francisco. We used to have great dinners. We'd go across to San Francisco to a good restaurant. It was wonderful. Herbert McCoy was his name. Dr. McCoy left in his will the bequest to the university to give a prize each year to the UCLA chemistry department. Anyhow, it was Dr. McCoy who gave me the rare earths which I tested and it was through Wendell.
Marlowe:Can you tell me a little more about the thesis project? Were there any problems? You mentioned before that you discovered what you thought was radioactivity and it turned out not to be so?
Libby:Well, I said I was lucky. The first one I looked at was samarium and that is still the most important and significant of all of the radioactivity, and that includes the zillions of fission products — its alpha particles — 1011 years.
Marlowe:Why did you not get credit for samarium?
Libby:Well, it's a very interesting story. There was a very famous German physical chemist who discovered it independently and published it before I did. I gave it in my seminar. So all the Berkeley people knew I had it. They allowed me to have my PhD, providing I'd find one more. Well, it took about a year to find one more.
Marlowe:That's another classic example of multiple discoveries in science.
Libby:Yes. I never knew Dr. (Georg von) Hevesy until later. He researched it, so everybody calls the alpha activity of samarium "the Hevesy discovery.''
Marlowe:Instead of the Libby discovery.
Libby:Right. Well, Hevesy was a very famous German chemist; internationally known. It was a good lesson for me.
Marlowe:Then what was the other radioactivity you discovered, for which you received your PhD?
Libby:Well, now I have over the years discovered about seven natural radioactivities. I don't know if there's any point in listing them, but some of them are quite important. So the search for natural radioactivity was a good thesis, and it taught me a lot, because I had to purify these things. See, you don't just take a bottle off the shelf and put it in your Geiger counter, because it may have some junk in it. And it takes very little of certain radioactivity contaminations to totally foul you up. Roughly, what you have to do is add all the other elements and then separate them away, and take the residuum. Now, you don't add all the other elements, but you add families. To purify the rare earths, is a good month of hard work on the part of a good chemist, I mean an expert so each one of these took a lot of that. Roughly speaking, you throw anything in the Geiger counter and you'll get some count. The Geiger counter is very sensitive. But what it means remains to be cleared up by two things, the chemical purification, and to measure the characteristics of the radiation. But that's what radiochemistry is all about, is to identify the isotopes, and you know most of the isotopes that are in the isotope table were discovered by that gang at Berkeley. In fact, they're called the Seaborg Tables.
Marlowe:That must have been ideal training then for the later radiocarbon work with the purification.
Libby:Oh yes. Sure.
Marlowe:After you received your PhD in '33 in physical chemistry, what did you do then? Did you think again of leaving Berkeley?
Libby:Well, but once again, with the burgeoning growth of radiochemistry, there wasn't any place to go to that compared. See, the cyclotron was working. Gilbert had just isolated heavy water, and the deuterons were going into the cyclotron, and that makes the hottest damn beam ever invented because you give off neutrons and protons because the deuteron comes apart. We didn't know then why the deuteron was so much more effective than the proton. But now we know and that's what it was. And people were coming through there from all over the world, just to see what we were doing. Next to the Fermi group in Rome, I think we were the hottest group. So to leave Berkeley was insanity. So, it was hard times. There weren't many jobs.
Marlowe:Did you receive any form of fellowship?
Libby:A half of one instructorship was what I got, $1000 a year was my salary.
Marlowe:And that was plenty of money to get by on then?
Libby:Well, with other means. Money's never stopped me. But I don't rob banks! But you know, when you're working 16 to 18 hours a day, about all you could do was have a few beers and that's about your total cost. We lived in a boarding house, you know. Though by that time I was going into an apartment and sharing an apartment with other graduate students. But Berkeley was really some place. And the discoveries made during that time are still the main bulwark and substance of chemical nuclear chemistry. The seminar ran the whole nine years, and we began to be major contributors to the whole field.
Marlowe:Now, Ernest Lawrence, for example, had come to Berkeley.
Libby:He came to Berkeley in '27, as a young assistant professor, the year I came in as a freshman. And he went to work on his cyclotron, and five years later he had it running.
Marlowe:Did Lawrence participate in these seminars?
Libby:Not particularly, but a number of his students would. He had his own journal club, as they called it, and you can only go to a certain number of these things, and, of course, our interest was chemical and he's a physicist.
Marlowe:Did you have contact with Lawrence early on?
Libby:Oh yes. He was on my doctoral committee. He was very sustained and supportive. The only real goof I ever made in science Ernest advised me not to publish and he was dead right. I was just plain wrong. He sensed it. I published a paper which was just 100 percent wrong. He saw that. He said, "Bill, lay off, that's wrong." Of course, that made me want to publish it all the more and I did. He was dead right. That kind of taught me a lesson, how some people can sense it, what's right and what isn't right. But he was very supportive. I remember, at one time, I was doing an experiment on Sunday morning, and had an explosion. He was hiking in the hills behind Berkeley and he heard it. That was two miles away. A miracle I wasn't killed. One of my graduate students was there with me, just watching the experiment, and I said, "Sam, get behind those tanks.'' I saw the needle start wiggling. I was two feet away from it. Sam was 20. We took Sam to the hospital. I've been living on borrowed time ever since. But it was Ernest Lawrence who came to see how I was. He didn't pay much mind to who was in chemistry, who was in physics. He brought his brother, John Lawrence, and I did a lot of work with him. We were finding isotopes like mad, you know. And John was an MD. He brought in another MD, Joe Hamilton, and then various people from medical schools around the world became interested in what we were doing, namely, we were isolating and identifying important new uses of radioactive isotopes in medicine. For example, radio-iodine was discovered and its sequestration in the thyroid was discovered — and far into the night. Most of the present uses of radio-isotopes were found at Berkeley in the thirties.
Marlowe:Now, this cross-disciplinary cooperation among scientists that was something that was in general peculiar to the Depression and more peculiar to Berkeley. Were you working with individuals from other disciplines right out of graduate school?
Libby:Oh yes. Sure. I had the only Geiger counter.
Libby:Still. Physics people didn't get onto it till four or five years after I built the first one.
Marlowe:Why the long delay, do you think?
Libby:Well, they went down the road of using electroscopes. Now, if you have plenty of radioactivity, an electroscope is a very good way to measure it. You can do it accurately and cheaply. I remember one time, about 1928, Rutherford came to Berkeley on a visit, and he built an electroscope in front of the class. Takes gold leaf trims off a strip of it and hangs it over a pin — and then proceeds to show that it would measure a bottle of uranium or something.
Marlowe:When did you first take on graduate students? You received your PhD in 1933. Who were they?
Libby:Well, my first graduate student was named Donald Hull. He's now retired. He worked most or all of his professional career for Chevron as a research chemist; Chevron lab in Richmond, California. I've had 101. I don't know how far you want to go into this. A lot of them. The next one was named Donald Lee, and he again went into industry and worked for DuPont.
Marlowe:When did Samuel Ruben come along?
Libby:I think Sam was my third. We were discovering these isotopes, and it's obvious, the most important isotope is radiocarbon, if you're going to do medicine and biology. So Sam took as his thesis to find Carbon 14.
Marlowe:When would this have been, approximately?
Libby:About '36. We saw, we were building up the isotope table, we could see there was a hole there. Then we had some people come from the University of Chicago as post-docs with Ernest, who had worked with William Harkins, professor of physical chemistry at Chicago. Harkins had shown that neutrons bombarding nitrogen gave protons. Just arithmetic shows you, the other part was carbon 14. So we bent our backs to bombarding nitrogen with neutrons.
Marlowe:Was one of the people that came from Chicago, Martin Kamen?
Libby:Martin Kamen. The other one was Franz Kurie.
Marlowe:So were you all working together then, Ruben and yourself and Kurie and Kamen?
Libby:Well, they were pretty busy working with Ernest, like Martin was running the cyclotron. He was cyclotron foreman and things like that. He didn't have much time. But he'd come dragging around occasionally to see what we were doing.
Marlowe:Now, what role did your Geiger counter play? Were you or Ruben using the Geiger counter in your attempts to isolate Carbon 14?
Libby:Well, we kept improving the Geiger counter. The Geiger counter was now being developed world wide. We kept improving it and we were on the forefront. Whenever anybody would publish a change or improvement in the technique, we had it, and usually it was our publication. Not often were we beaten out by anything. So we developed a Geiger counter called the screen wall counter. One of the problems with Geiger counters is, they have a wall, and a lot of the radioactive isotopes have very soft radiations, like tritium is extremely soft. So we developed this instrument which had a screen, and wasn't absorptive. This allowed us to make measurements of the very weakest radiation. So when Martin and Sam finally did find radiocarbon, they used my screen wall to do it. If they hadn't had it, they wouldn't have found it. But what Sam and I did, which in retrospect was probably stupid, was to assume that the half-life would be three months.
Marlowe:Why did you assume that?
Libby:Well, by analogy, just looking at sulphur 35 for example, with a half-life of three months, and we could calculate the energy of the beta ray from Carbon 14 because we knew the energetics of the reactions on nitrogen. We knew what there was it would be about 150 kilovolts. Well, a beta ray of 150 kilovolts was almost exactly the same amount as sulphur 35, and the half-life was 87 days. Ok? Recently, at the seminar to honor Martin's (Kamen) retirement, we discussed this point. My paper was: ''Why Martin discovered C-14 and I didn't." It was essentially the remarkably long half-life of radiocarbon, totally surprising. Then in the last paper in that symposium was a theoretical physics paper explaining why it might be reasonable. Of course, I still don't know. It was an absolute bolt out of the blue, to find carbon 14 had such a long half-life. But for that reason, Sam couldn't find it. We put ammonium nitrate gunnysacks around the cyclotron.
Marlowe:This would have been 1936-37?
Libby:Right. And a lot of neutrons were spewing out of that. And then we processed it. Everything we did was right, except, we didn't realize that we weren't making anywhere near enough for detection. So what Sam and Martin did afterwards was simply take a slab of carbon and beat it with deuterons. Then they found it. But they used the screen wall and the techniques that Sam and I had developed. But then unfortunately Sam was killed; a very great scientist, no doubt.
Marlowe:Now, Ruben began working on this along with you in 1936. From '36 until the discovery in 1940, of carbon-14, did Ruben take his PhD on another topic?
Libby:Most of my students always worked on more than one problem. I never had more than one student on one problem. So they talked to the others and got the experience of several problems. No, we had six other papers. There was no problem with his committee. One of them was iodine resonance neutrons, where, take a neutron source, and a Geiger counter or a neutron counter — and we had by then discovered the neutron counter. The boron-tri-fluoride neutron counter was discovered at Berkeley, almost simultaneously elsewhere at NYU with Dr. (Serge) Korff — but entirely independently, we discovered it. ·And so we had the neutron source and the neutron counter, then we put various things into it, in the beam, to see what they'd do in the way of cutting down the transmission. And this way we discovered that the iodine, which is a mono-isotopic element, had selective energies, where it would absorb neutrons. You could do this by moderating the neutrons with paraffin and so on, much as you do in reactors, and going down the energy. So Sam had a perfectly respectable thesis topic. In addition to this iodine resonance, he'd been doing photosynthesis research with carbon-11, which is a 21 minute isotope.
Marlowe:Did he hope to apply carbon-14 to photosynthetic research? Was that the primary reason for undertaking it?
Libby:Well, the primary reason was the obvious thing, the obvious importance to biochemistry and medicine. It's still not applied to medicine. It's used like mad in research, but still not in the doctor's office. It takes years and years.
Marlowe:When you had the problem in terms of creating sufficient carbon-14, what other activities were you undertaking in the period say, between '36 and 1939-40?
Libby:I was building up a number of fields in the general area of using nuclear radiochemistry for chemical purposes not only in medical applications, but in physical chemistry. For example, we developed a field called hot atom chemistry. This is the effects of the recoil. When one of these atoms gives off a beta ray, or an alpha particle or even a gamma ray, it's given quite a jolt. And we were studying the chemical effects.
Marlowe:You say "we" — who besides you?
Libby:My students and myself. I had several PhD theses. For example, nuclear isomerism was rediscovered in this way. That's where a given nucleus, namely bromine 80, could have two half-lives, two radio activities for one isotope. Of course, the point is, they have a different configuration, and so we had the challenge of figuring the relation between the 41/2 hour bromine and the 18 minutes bromine. It turned out the 18 minute was the daughter of the 41/2 hour. Well, that's pretty exciting stuff. But it was only done chemically. The physicists could never have found it. And we actually separated physically the 18 minute from the 41/2 hour. Put them in two different bottles. That was important.
Marlowe:On the topic, isomerism — some of the creationists today have tried to use that argument about isomerism to deny the validity of carbon dating, have they not?
Libby:Well, I'm not familiar with that particular argument. There are thousands of people who have criticized.
Marlowe:Looking at the same period, from '35 to '39, for example, John Lawrence was using the cyclotron for medical and biological applications — he was using radioactive isotopes, he was also bombarding tumors with beta beams. What did you and some of your colleagues think about those projects?
Libby:I thought they were great. As I say, I worked with John Lawrence and with Joe Hamilton and with people in other medical schools.
Marlowe:Ruben was using isotopes for his work on photosynthesis. Did the two of you continue to collaborate with scientists in other disciplines during this period — for example, with biologists?
Libby:Well, I kind of turned Sam loose in that respect, because he was getting pretty close to his PhD, and I had plenty of fish to fry, believe me. He more or less did that on his own. I suggested that he ought to get with them and make use of their advice. But Sam more or less — and, of course, that led into the Carrel work and the Nobel Prize he got for that work. It was a great idea to use carbon-14 on photosynthesis, but that was Sam's idea. My general idea was to get the carbon-14 so we could use it for general purposes in biology, and organic chemistry. That was the way it was.
Marlowe:Now, can you tell me, what role did the research and funding climate of the Depression, play in your choice of research projects?
Libby:Well, let me tell you. I didn't even have a telephone. There was one secretary in the whole department. We’d stand in line to get our manuscripts typed. I remember when I invented the boron-tri-fluoride neutron counter, I went to Gilbert and I said, "Would you buy me a cylinder, would you give me $50 to buy a cylinder of boron tri-fluoride?" I had it all in my head, you see. He looked at me and he smiled and puffed on his cigar, and he said, "You're a chemist, go make it" — which I did. And that was very fortunate, because the first time I filled the counter, it worked. There was so much neutron work going on that the word spread like wildfire. Also Korff had discovered the same thing at NYU. But he was having a hell of a time getting his BF3 free of impurities. Mine was pure and worked great, and that was because Gilbert made me make it. See, the stuff that was commercially available was quite impure. It was, you could use it in oil refineries, etc. — so things have a way of working out.
Marlowe:So we would be justified in drawing the distinction, then, between the kind of projects you pursued, which were of a minimal cost, and those undertaken by, for example, Lawrence. Now, Lawrence, building his ever more expensive cyclotrons, justified his requests for foundation grants by suggesting that his research had biological and medical applications. That wasn't a problem for you because your projects required far less money?
Libby:Well, I must say, all I wanted was $50, but those were Republican dollars. I suppose it would be $5000 today. But I remember making that. I had on a blue serge suit, and at one step in the synthesis, concentrated sulfuric acid. And the glass broke, and I had concentrated sulfuric acid all over my suit. I just went to the shower. Any good lab has a shower, for just this kind of accident, and rinsed it out thoroughly and it didn't even turn red; just beautiful. That's pure wool. If you ever check whether you've got pure wool, just put it in concentrated sulfuric. It'll stand it. But anything else will dissolve.
Marlowe:Were Lawrence's projects using the cyclotron, then, mostly the exception? At Berkeley were most of your colleagues undertaking research projects that didn't require a great deal of outside financial support? Would you say that was true or not?
Libby:I think so. There wasn't any outside financial support. We had a certain amount of university money. But boy, we were poor. But look at the publications out of that place. I wouldn't say that any more conclusions… too much money can be a problem.
At this point, the first interview was concluded; a second will take place April 16, '79, Santa Monica.
Session I | Session II