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Interview of Nicholas Kurti by Charles Weiner on 1968 September 11, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4725-1
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Family background and early education in Hungary (Ferenc von Kármán). Undergraduate studies in Paris from 1926 (Jacob Salpeter, Felix Ehrenhaft and Paul Langevin); work habits, comments on Prof. A. Guillet, 1928-1931. Studies at Universitaet Berlin, 1929-1931, Max von Laue's weekly seminars; moves to Universitaet Breslau with Francis E. Simon; thesis, "The Thermal and Magnetic Properties of Gadolinium Sulfate," 1931. Social and political climate in Breslau, 1931-1933. Peter Debye's low temperature proposal to Simon (William F. Giauque); Simon and Kurti emigrate to England in 1933; Frederick A. Lindemann's (Viscount Cherwell) involvement; Imperial Chemical Industries (ICI). Settling down at Clarendon Laboratory, Oxford; discussions of their work on production of very low temperatures, production of liquid helium in 1936; the technique of detecting superconductivity in cadmium, 1934; comments on relationships in the low temperature community (the two groups at Clarendon). Collaboration between Clarendon Laboratory and Laboratoire du Grand Electroaiment, Bellevue, 1935-1939; leads to important prewar work. Comments on Leo Szilard and on colloquia and seminars at Clarendon Lab. Also prominently mentioned are: Hans von Halban, Hendrik Anthony Kramers, H. E. Kuhn, Heinz London, Kurt Mendelsohn, Otto Roff, Erwin Schroedinger, Wiershma; and Université de Paris.
This is a tape-recorded interview with Professor Nicholas Kurti in his office at the Clarendon Laboratory in Oxford. We talked informally last night about your early interests in science in Hungary. We should establish what city in Hungary you lived in.
I was born in Budapest and lived in Budapest. My father was a banker, and many of my relations thought that I should follow in my father's footsteps. But I was quite good at school and interested somewhat in science, although in my school years my main interest was music, I studied piano, but I never thought I had sufficient talent to become a musician, I had all along the feeling that if you want to become an artist, then you really must be extremely talented, In most of the professions you can partially replace talent with hard work, sweat and toil, Anyway it was decided that I ought to go to the university and qualify for a profession. I was not terribly interested in law or anything like that, and to some extent it was by a process of elimination that I decided that I should do science, And then came the next question: what type of science?
And, of course, I had to think: with what type of science could I earn money? Now, the idea of becoming an academic scientist was almost as far from the possibilities as becoming a musician, I regarded the rarified atmosphere of academic science as being something far beyond my reach, But I thought, "There must be some form of profession where I can put science to a practical use," and that was the basis of my decision to study engineering. Then I went through the various branches of engineering and came to the conclusion that I was not terribly interested in civil or mechanical engineering — in fact, any of the engineering disciplines where you have to do a lot of machine drawing and so on didn't appeal to me very much, And finally, again by a process of elimination, all that remained was chemical engineering, So by the time I was 16 it was generally assumed by myself and by my family that I would be studying chemical engineering.
Then an odd thing happened. I had a great uncle, my maternal grandfather's brother — his name was Joseph Pinter — who in his youth trained as an electrical engineer in Zurich, and then joined Tungsram, the big incandescent lamp factory in Budapest, which was one of the leading firms in Europe in this field, I believe he had quite a lot to do with establishment of the research laboratory attached to this factory. He died about 1930, and a street near the Tungsram factory was named after him in the late 1950's. Anyway, one of the people in a leading position in the Tungsram research laboratory was Jakob Salpeter, the father of Edwin Salpeter, the well-known theoretical physicist, who knew me a little bit since we met at my great uncle's house.
It so happened on one occasion when my mother was visiting my great uncle, Salpeter was there, and Salpeter in the course of conversation asked my mother what my intentions were — what was I going to study. My mother said that I was going to study chemical engineering. So Salpeter said, "Why does he want to study chemical engineering?" My mother said that it was to earn a living as an engineer and that was the only engineering branch which he thought might interest him, That happened in 1924, and I still regard Salpeter therefore as a very great prophet. He told my mother: "You know, lots of chemical engineers are being trained, If he really wants to enter a profession in which there will be great demand for people, he should become an applied physicist" — technischer Physiker as he called it, So my mother came back home and told me about this conversation, and I said, "All right," because I trusted Salpeter's judgment, and I really didn't have any preference between chemistry and physics, I was not attracted to the one more than to the other.
You had studied chemistry and physics in school?
I studied both, You see, I went through the good old-fashioned Hungarian education system, and I studied Latin and Greek on the one hand, and physics, chemistry and mathematics on the other hand, Of course, I never went as deeply into any of these subjects as do the sixth-formers in England, people who specialize the last few years of secondary school, But it meant that at the end of my secondary education I could have gone to a university to study classics or science or modern languages, pretty well any university subject. So there was not much difference between my grounding in chemistry and grounding in physics or grounding in mathematics, They were all equally general and not too strong.
Had you known anyone in science other than Salpeter?
No, not at all. I had a number of teachers at school, not terribly inspiring teachers, The one teacher who was good was my mathematics teacher, Ferenc von Karman, the younger brother of a very distinguished Hungarian mathematician, Theodor von Karman. I learned quite a lot of mathematics from him — a very kind and charming man he was, I liked him very much, He was rather shy and retiring and very pleasant, He was very helpful. But actually in chemistry and physics I didn't have very inspiring teachers.
When your mother told you that Salpeter had suggested applied physics, what was the next step? You were all of 16 or 17.
Well, the next step was that I got a little bit worried, because when people asked me what I was going to study and I said technische Physik, applied physics, they would say, "What is that?" And I had to scratch my head, you know, because I didn't really know what an applied physicist did, But soon afterwards I had discussions with Salpeter, and he told me a little bit more about what is required, where an applied physicist fits in, in an industrial firm. By that time I was maybe within six months of leaving school, I left school in 1926 — at the age of 18.
And six months before I left school Salpeter discussed with me my future, what and where I should study, and once again gave me excellent advice. He said: "Now, look, although ultimately you will become an applied physicist, you should start with pure physics and generally pure science, and there is no better place for that than Paris," So I must explain that the idea of studying in Budapest really had never occurred to me. First of all, in those days we had the so-called numerus clausus in Hungary. In other words, only 5% of the total number of people admitted to the university could be Jews because that was the proportion of the Jews in the country.
Now, it may well be that thanks to a good school record and, if need be, a little bit of nepotism, I could have gotten into a university. But somehow I didn't like the idea very much. Fortunately, my great-uncle, Joseph Pinter, could give me financial help and so did the bank where my father had worked, He died when I was three years old, and the bank (First Hungarian Commercial Bank) very generously provided a grant for my five years' studies and this was over and above my mother's pension from the Bank, This together with my great-uncle's contribution opened the way for my going abroad, So I became one of those numerous young Jews, Hungarian middle-class Jews, who studied abroad — in Austria, Germany, Italy, France and Switzerland.
In all fields, not only in science.
Not only in science, no, For instance, very many of the Jews who wanted to study medicine went to Italy, to the University of Milan. There was a very great proportion of Hungarian Jews studying medicine — in fact, so much so that I believe Hungarians were allowed in Milan to pass in their first year their examination in German, because most Hungarian Jews spoke German but few spoke Italian, That was in Mussolini's Italy and shows that in its early years Fascism was not at all anti-Semitic.
Not until the late '30s.
Until the middle to late '30s. But anyway I there and then decided that I would go abroad, study abroad. That's why Salpeter could suggest to me to go to Paris. And then he said I should spend perhaps two years in Paris and study physics, mathematics, chemistry and do basic science and then should go to Berlin either to the university or to the Technische Hochschule in Charlottenburg and then drift more into technical physics. So my future was mapped out in this way. And now comes a very amazing thing. I traveled to Paris via Vienna in early October 1926. A distant relative of mine — I think he was a third cousin twice removed — was Professor Felix Ehrenhaft* in Vienna. I had never met him before, but I had some cousins in Vienna who were a little bit more closely related to him and they arranged for me to meet Ehrenhaft, who must have been then about 40 years old, something like that, I went to see Ehrenhaft, and he was very nice to me. He said: "Oh, yes, that's a very good idea."
I should go to Paris; that was fine and he could give me advice on what lectures to go to, I pulled out my lecture list for the University of Paris, and he sort of went through it, Of course, he didn't know anything about the system of lecturing in Paris, the same as I didn't know anything about it, and he started wildly picking them out: "You should go to this lecture, You should go to this lecture." And before he was finished, there were something like 25 lectures a week picked off, It was very funny, that as he went through the list, and saw a course of lectures on radioactivity announced by Madame Curie, he said, I remember to this day his remark in German: "Die Curie die koennen sie sich schenken," ("You can forget about the Curie woman.") But then he said, "Look, perhaps this advice," (though he thought it was a very good one) "should be supplemented, You may want some additional advice from someone who really knows the ins and outs of the University of Paris, I'll give you a letter of recommendation to Professor Langevin, I know Paul Langevin quite well, He stayed with us in Vienna only about a month or two ago." So he got one of his assistants who spoke quite good French to translate his letter, and he read it off to me, It's an unkind thing to say, but he couldn't even pronounce properly French, He started: "Mon cherr collejh," Anyway it was a very nice letter recommending me to Langevin, And the day before I left Vienna I had a telephone call saying that Ehrenhaft would like to see me again because he wanted me to take a small parcel along to Langevin.
The parcel he gave me contained a night shirt of Langevin which he had left at Ehrenhaft's house when he stayed there about six weeks earlier. So I went to Paris with a letter of recommendation and night shirt of recommendation to Langevin. *Ehrenhaft was Professor of Physics at the University and was among the first to measure the charge of the electron. This claim about the existence of a "subelectronic" charge (one-third of the accepted value) in the 1920's and 1930's, and later about the existence of a magnetic monopole made him a controversial figure.
Soon after my arrival in Paris in October 1926 I turned up in Langevin's office, At that time besides being a professor at the College of France, he was also director of the Ecole de Phyique et Chemie, a much renowned institution of higher education (Grande Ecole) and run by the city of Paris quite close to the College de France, and that's where his main office was. So I arrived there and was ushered into his room, He was charming. I gave him the letter, and after I gave him the letter I gave him this little parcel. I was a little bit embarrassed about the whole thing. He opened the parcel and took it out and gave me a somewhat embarrassed smile, Then we started talking.
I said I wanted to spend two years in Paris and I wanted to study physics and all those things that related to physics, and I should be very grateful if he could give me some advice, I said also I had been talking to Professor Ehrenhaft, and he gave me advice on what lectures to go to, So he said, "Show me what Professor Ehrenhaft has recommended," and as he went through this list he got more and more surprised. He smiled and told me not to go to so many lectures; in the French University system, 12 lectures per week is the usual. Then he gave me an advice which I think was very important. He said; "Look, education in a French university is different from education in central Europe." I knew that in central Europe you go to a university and you don't pass examinations until you have been there three or four years. In many German universities in those days the first examination you passed was your doctor's examination that you took at the age of 22-23.
He said: "In France, we have examinations at the end of each year, and I would advise you to work for a "licence es sciences physiques" which corresponds roughly to the bachelor's degree in Britain and in the United States, And he told me: "The best thing for you to do is to take three of the general subjects, three "certificats" one in Mathematique General, another in Chimie General, and the third in Physique General, If you do this, then you will have a good grounding in these basic disciplines." And I would say that if I had not had the advantage of getting this advice from him, I think I would have wasted two years of my time in Paris, You see, there's much less chance in Paris to talk to the professors and get advice, but if you work for a certain examination, then you know what you have to do and there are various ways you can find out what is the standard required. So I took his advice and worked for the licence.
You say there was much less chance. You mean in comparison to Germany, as you learned later,
I believe in Germany in those days in physics it was much easier even for an undergraduate to go and have a word with the professor, In France I think on the whole they were just a little bit more distant, Except there was one professor of physics at the Sorbonne his name was Amedee Guillet, He was not a great scientist, but he was a very enthusiastic lecturer and professor, He was so enthusiastic that his lectures, which were scheduled to last one hour, sometimes lasted an hour and three-quarters. He had a very good custom which I should like to introduce here in Oxford but haven't dared yet. Every now and then he would suddenly say, "Now, let's see, let's find out whether you people understood what I was lecturing about last week," and he would suddenly call somebody from the audience, ask him to come to the blackboard, to be questioned. He would set him little problems and say: "How would you work this out?" With the result that after a certain time people got wise to it, and would occupy mainly the last six or eight rows of the rather large lecture theater. So he would go up and chase people down to the front rows, Anyway he was the one man who was approachable.
First of all, he wanted to talk to people. I recall on one occasion I was walking along the Boulevard St. Michel, and he knew me by sight as he did most of the 100-200 students attending his lectures, I was walking along in the same direction as he, and he came up to me and said: "How are things going? Do you understand everything?" I said, "Oh, yes, but I have some difficulties with a certain thing you talked to us about last week," He said, "Oh, I will explain. I am just going to catch a train at the Care de l'Est. Come into my taxi with me, and I will explain it en route." So I sat in the taxi, and driving from the Boulevard St. Michel to the Gare de l'Est he explained to me my problem, So you occasionally had personal contact, but on the whole not very much.
What about contact with other students? Did you discuss problems in common?
Yes, but that didn't occur so much, You see, there was no community life in the University of Paris in those days, Perhaps it's even worse now with the large increase in student population, On the other hand the reforms resulting from the 1968 revolt may make things better, But in those days I had a number of colleagues whom I knew actually some of them were Hungarian and we would occasionally sit together and discuss problems, but they were mainly examination problems.
There's a very good system in Paris, There are these annual examinations for the licence. What they do there is to set down collections of problems with their solutions you can buy those little volumes, And once you work through those volumes and know how to solve all these various problems that have been set in the previous 10 to 20 years in various universities, you know pretty well your stuff, The most important thing is that in most cases in France the examinations are never essays they are all problems. You really have to make use of the techniques you learn in problem solving.
Were there many other foreign students? You mentioned that there were Hungarians.
Oh yes, there were many of them, Let me see: which nationalities were most represented? Actually many of the Hungarians I met weren't really Hungarian. I mean they spoke Hungarian, but they came from Transylvania, the mainly Hungarian speaking part of Rumania, There were many students from Indochina, who really did not count as foreign. And there were lots of other nationalities, because you could without much difficulty get into the University of Paris, All you had to do was satisfy the authorities of the University that you had finished your secondary education with a degree or school certificate which was equivalent to the baccalaureat. And there is a big book which shows which of the foreign schools leaving certificates have the "equivalence." Once you had that and produced it and your birth certificate and paid a silly little sum, the equivalent of about 10 or 20 pounds a year now that's all you had to do, You did not get anything except the lectures and then the examination, which was free.
How about lab work?
Lab work is included and you don't have to pay extra for it, That was quite well organized. I learned quite a lot, It's rather the type of lab work that we have here in England mainly in the first and second year. Everything, all the components for an experiment were set out but you had to assemble the apparatus, or for an electrical experiment, you had to do the wiring up.
But on the whole you had a very full description of what the experiment was about, how it should be carried out, and then you wrote up the results and you were marked on it by the demonstrator, They had an interesting and convenient system of examinations for the practical course, At the end of each term (they had three "trimestres") you had for practical work a so-called partial examination, "epreuve partielle," And what happened — a very good system — was that you went to the lab where you spent the last eight or twelve weeks, where you may have carried out as many as 20 experiments, and then you were set to repeat without any notes or anything, one of the experiments you had carried out in the previous term.
I found it a very good system because you knew you had to understand the experiments thoroughly so that you could repeat them without help or notes during the partial exam.
If you had more of a theoretical interest, would you still be required to do laboratory work? Or was it too early at that stage?
Oh, in Paris in those days for the Certificat de Physique Generale you had to do lab work, because that was general physics — mainly experimental physics, There was one certificate for theoretical physics, I don't recall what the certificate was called and there probably you didn't have to do experimental work, But with some certificates you could only hope to succeed if you had done previously some or all of these three basic general certificates, But as a result of this you could get a licence, which in principle was called "Une Licence d'Enseignement" — that is, in principle, once you had a licence, you had a license to teach in secondary schools.
How many of the people who took the certificate were really going with that in mind as compared to the number going on to further education?
In physics that's very difficult to say. You see, in physique generale 150 to 200 people presented themselves per year for the examination. But the success rate was only about 25%-30%. Now, you could present yourself again and do so year after year. In fact, there were two examinations per year, one in July and one in October, but even so it meant that quite a number of the students fell by the wayside. In those days I never talked to the people about what they wanted to do eventually. I think quite a few of them wanted to go to teach in lycees, probably as many as half. I just don't know.
Did you complete the licence in two years as planned?
Yes, I did. You can do it in two years, though some people took three years. I found the first year a little bit tough going mainly because in my secondary education I didn't learn physics or chemistry or mathematics really in depth. I had a nodding acquaintance with the subjects. I worked fairly hard, and I decided at the end of the first year in the early summer I would sit only for the mathematique generale, although I went also to the lectures in physique generale and I did all my practical work in physique generale. That was the important thing.
At that time the written examination was the principal, the important one, and I believe very few failed on the basis of the subsequent oral exam, Now the written examination was unlike the British, where you have a large number of questions (on any examination paper you may have a choice of as many as 15 questions, and you are not supposed to attempt more than say four or five), In France it's different, and the system actually still exists, You are given one or two questions, and they are fairly long and involved.
There is no choice, and you are supposed to do these one or two questions. Take physics, which included electricity and magnetism, optics, thermodynamics and mechanics — four main subjects. Now, if you are unlucky and, having been bad in electricity and magnetism, one of your questions is electricity and magnetism, then you may fail the examinations — or, similarly, if the question in electricity and magnetism is in one field to which you haven't paid much attention. I remember in physics I had thermodynamics and optics in my exam. The same system works in mathematics, Your question may be in algebra or geometry or differential equations and so on.
I thought I did terribly badly in the written math exam, but I was relieved to see that I had at least passed when I went to the oral examination. And then the system in France is a very good one. You don't carry for the rest of your life the grade you got in your examination, All that happens is that when the examination results are published, they are put up on a big notice board in order of merit, You first have in order of merit those who passed with the mention "tres bien" and then with mention "bien" and then with "assez bien" and finally with "passable." If you are good, or if you are lucky, you may have the pleasure of showing your friends that you are high up on the list, But that's the first and last time you see your name in an order of merit, The certificate just says that you passed the examination, Nobody really asks after that how you passed.
In this period, did they cover the new quantum mechanics? You came on the scene just after it had been developed.
Not a bit. You see, I came in '26, which were early days and also my course was very elementary.
Were you absorbing any of the atmosphere of what was going on in physics?
No, not at all, In fact, it was not until I got to Berlin in 1928 that I really saw what modern physics was. But quantum mechanics we hardly encountered in Paris in those days. We heard a little bit about the Bohr atom and possibly a very simple bi-relation, but otherwise there was very little quantum theory.
So essentially this is what you did. You took your exam and passed.
Yes. And the next year I passed physics and chemistry. I was very proud. I had some very distinguished people as examiners. For instance, in physics I was examined by Professor Cotton, a very famous man, and in chemistry I had Professor Urbain, the great rare earth specialist and the first to produce them in a metallic state. I'm afraid I didn't cover myself with glory.
But you did that well, and then...
Well, that was rather funny, Strangely enough, it turned out that I did well in mathematics, I thought that I had scraped through and joined the crowd looking at the list of successful candidates but I couldn't find my name among the "passables." I got more and more worried, I felt that I must be there because I didn't do too badly in the VIVA. And then some of my colleagues came by and said: "Well done," And I said, "What do you mean, well done?" Bless my soul, I was up on top of the list, I was about fifth among the handful of "tres bien," and out of a total of about 200.
I don't know how it happened, But then the next year when I had both chemistry and physics, I slipped, In chemistry I got an "assez bien." Mind you, there were no "tres biens," and there were not many "biens," so it was not too bad. But the physics was my last examination, and by that time I was pretty well worn-out, In chemistry I had a practical examination, and then a written and an oral examination, and in physics both written and oral examinations. I did pretty badly.
I got somewhere in the middle of the passables. But anyway I got my licence, and I learned physics and chemistry and mathematics. It was rather funny that when I went to Berlin many of my student contemporaries said that they were amazed how relatively good I was in solving problems, while they were probably very good at abstract theory but somehow they didn't know what to do with it.
And you attribute that to the French system.
Yes. The French system, the insistence on solving problems and so on. It probably was a little bit overdone, but it was a useful technique, I think.
Then where did you go in Berlin?
In Berlin again I had a recommendation to seek the advice of Professor Michael Polanyi, whom you know. He lives in Oxford. I had a recommendation to him, and I visited him in Berlin at the Kaiser Wilhelm Institution, in Dahlem and he was very nice. I told him exactly what I had been doing, and he suggested that probably it would be the best if I spent the first year just to go on studying a little bit more theoretical physics and really learn a little bit more of modern physics and more advanced physics before I embark on a D. Phil. This I did. So I matriculated at the University of Berlin where I spent 3 years, October 1928 - July 1931. I did one year undergraduate studies.
I went to lectures by Schroedinger, who was excellent — did statistical mechanics and I also did optics, with him. I went to Laue. I went to Planck's lectures on electricity and magnetism. He was a very dry lecturer. Schroedinger was excellent; really I learned quite a lot from his lectures. Laue was a very poor lecturer. I don't remember what other lectures I went to. I had, of course, to inscribe myself to some philosophy, you also have to pass an examination in philosophy, and so you at least had to show in your student's booklet where you entered the names of various professors' fees, to whom you had to pay, that you did go or attempted to go to some philosophy lectures. Anyway, the first year I spent merely studying "around."
I think it was that year or the next year that I went to lectures by Wigner. It was '28-'29 or '29-'30. Anyway I spent my first year entirely on going to lectures. I did some practical work in physical chemistry because I hadn't done any in Paris, and I thought that would do me a lot of good. I did this in Professor Bodenstein's Institut fur Physikalische Chemie where Simon already was. He was Ausserordentlicher Professor and "Chief Assistant." (Oberassistent) Then I had to take a decision where to do my doctorate and in what subject and under whom. It was rather interesting — the choice that I finally came to. In those days one read, after all, the recent developments in physics. The one thing that thrilled me very much was the work of Gustav Hertz on the separation of isotopes. He did that around 1928, I think - you know, the isotopes in the porous tube, the first time there was a separation column and you could produce Somehow that appealed to me.
And also there was the name and fame of Gustav Hertz. I thought I would try to see whether he would take me on as a D. Phil. student. So I called on him. He was at that time professor at Technische Hochschule in Charlottenburg. So I introduced myself and told him who I was and asked him whether I could do a D. Phil, with him, and we had a long chat. He said: "Look, I'll show you the lab and then you will see that at present I just cannot take you on because I just haven't got room for another man to work here, But you might like anyway to see what goes on," So he showed me around and showed me all the experiments, all the various projects he had going, And then he said: "Sorry, nothing doing," I think he would have taken me on if he had had more room. I think I must have gone to lectures by Simon, and got interested in low temperatures, Although he didn't know me, I saw him often, So I decided I must try and see whether I could go and work with him, So I went to see him, and he asked a number of questions and then finally said: "All right, but I want to know whether you are really good enough, You see, I don't want to buy a pig in a poke, So could you come in and spend the next month (it was summer vacation) in the lab and just help with experiments, and we'll see how you shape."
That was soon after the discovery of ortho and parahydrogen, It was touch and go who would set these first, Simon was doing some experiments which might have resulted in his being the first to prove conclusively the existence of ortho and parahydrogen, But anyway it was Bonhoeffer and Hartech who "won" the race, Simon's experiment consisted in determining the heat of transformation of orthohydrogen to parahydrogen, And the man who was working with Simon at that time as a research assistant was Dr. Gunther von Elbe who emigrated to the U.S. in, I believe, the late '30's, I think, Anyway, von Elbe was to measure the orthopara conversion, at the boiling point of liquid hydrogen - you first adsorb on charcoal the orthoparahydrogen mixture and then you measure the amount of heat generated, which is made up of the heat of adsorption and the heat of orthopara conversion, If one now makes the gaz which is now almost pure para desorb from the charcoal by pumping it away, one sets the negative heat of absorption, and the difference of the two gives you the heat of conversion, Anyway, this was the experiment, and it was a very nice introduction into low temperature work because all the troubles that usually occur in low temperature experiments did happen, and also it gave me the taste of working long hours night after night, A few weeks later Simon said to me: "Come to my office and let's have a little chat," He then said: "How do you like it? Does it interest you?" I said, "Yes," "All right, I'll take you on," He shook hands with me, and from then on I was his research assistant.
Now comes the really amusing thing, and I don't think I made it up I told Simon what I would like to do, The one thing that thrilled me very much when I went to Schroedinger's lectures on statis tical mechanics in '28 was the beautiful proof of ordinary statistical mechanics, namely, the experiments of Kamerlingh-Onnes on the para-magnetism of gadolinium sulfate, namely how at low enough temperature and high enough field you get the magnetization to saturate and how this follows the purely statistical mechanical predictions of Langevin. That thrilled me tremendously, the combination of magnetism and statis tical mechanics, And so when I talked to Simon I said: "I would like to do some low temperature magnetic experiments, What are the chances?" Simon said, "Well, I don't know. I had one magnetic experiment going here, but it's finished."
And then he suddenly said, "Look, there's been recently a suggestion by Debye (I don't remember his having mentioned Giauque) that with the help of paramagnetic salts one might be able to reach very low temperature. Would you like to have a bash at that and just do some preliminary experiments?" And so eventually I began to work on a substance which led me to work with gadolinium sulfate, and that's why it is I came to this field of very low temperatures, It was mainly that I was thrilled by this lecture of Schroedinger that I chose this magnetism and low temperature subject.
It was also available because Simon was there.
Yes, Simon was there, but he had no new experiments.
That subsequently became the subject of your thesis?
Yes, the subject of my thesis was eventually "The Thermal and Magnetic Properties of Gadolinium Sulfate," I worked on it for two years, There was a rather amusing coincidence, I told you before that Professor Urbain was my oral examiner in chemistry in Paris, When we needed some gadolinium sulfate for these experiments, Simon wrote to Urbain, since he was the only person in those days who could produce this substance, We finally received from him 500 milligrams of gadolinium sulfate, that was all that was available, A few years later when I passed through Paris, I called on Urbain to return these samples to him, We had a little chat, and I told him that six or seven years earlier I was examined by him, He was a very charming man.
You got your degree in '31?
Yes, I got my doctorate in '31, Now, that was a fantastic period in Berlin, You must have heard about the famous Laue colloquium.
I want to hear about it.
This was really a remarkable institution, I don't think that such a thing will ever exist again for various reasons, It was held in the small lecture room of the Physikalisches Institut (Physics Department) of the University. I think there were four tiers of benches. Each one seating about 20 to 25 people. It was very crowded, There were about 80 or 90 people, and some people would sit on the floor and some on the steps. The front row was just fantastic, There you had side by side Laue and Nernst and Einstein and Planck and Schroedinger and then among the younger, less famous people, you had Szilard and Fritz London and Wigner and Ladenburg and Pringsheim, etc. And then you had the more junior people, assistants, postdocs, etc.
and then you had the research students, In those days, in 1929-1931, if you went regularly to the Laue colloquium week after week (and that went on for the whole academic year, roughly 38 weeks), you really knew what was going on in physics. The colloquium was actually a journal club, It covered the whole of physics. Laue must have had a fantastic knowledge of the physics literature, Usually at the beginning of the colloquium, he got up and said that he wanted a number of papers, published in British or American or German or French periodicals to be refereed, and then he read off the authors, titles, subjects, and then asked for volunteers and usually it was expected for a research student at least to have been talking once in a Laue colloquium.
It didn't mean that he gave a talk about his own work, but he gave a resume of a scientific publication in his own subject with which he was supposed to be familiar. Now what was remarkable was that first of all by going to the Laue colloquium you could really keep up with what was going on in physics, and secondly, you really saw these people - these great minds at work with all their failings and all their brilliance, I'll never forget a funny incident and it is absolutely true, It was, I think, Fritz London who gave a talk reviewing a paper on some methods of calculating the rotational spectra of polyatomic molecules, In the discussion Schroedinger suddenly got up and said: "Well, now, that's interesting, but I believe in certain cases you can simplify the formulae, For instance, if you had a triatomic molecule and if you assume that the three atoms (assumed to be points) lie in the same plane, then you get a simpler answer," There was an embarrassed silence, What else can three points do but lie in a plane? Suddenly Schroedinger said: "My God! What have I said?" It showed how even great men suddenly can have these little failings, That was quite a refreshing experience.
Was there much interplay among the students in Berlin?
Oh, yes, Well, mainly within one department, I did my work in the Institut fur Physikalische Chemie where Simon's laboratory was, There was a very active scientific atmosphere, and we took an interest in what people in other research groups were doing. I saw quite a lot of "Mika" (he was of Russian origin) Magat, who emigrated to Paris in 1933 and finished up as Professor of Physical Chemistry at the University of Paris, He died in 1977 or '78, In Berlin he worked with Kurt Wohl on high temperature specific heats of gases using the "explosion method."
He also got interested in the dielectric properties of gases and I remember him saying one day: "Look, we ought to do some calculation taking into account the polarizability of polyatomic molecules which have permanent dipole moments," I don't now remember exactly what the problem was, but the two of us spent, both together and separately, many weeks while we were doing our D. Phils, toiling away on some calculations which had nothing to do with our D. Phil. work.
And we almost got the calculations finished when someone came out with a paper; he did the calculations much more beautifully than we could ever have done it, It would have been rather nice if as a raw D. Phil. student I could have a publication. But at least I learned at an early age that disappointments are a part of the physicist's or scientist's lot.
A good time to learn, What about other people from Hungary in Berlin? Was there a tendency for them to stay together?
No, not a bit, By that time I don't think I had any Hungarian colleagues of the same age group. Of course the fact that Wigner was a Hungarian and Szilard was a Hungarian
Teller was there, too, wasn't he?
No, Teller was in Goettingen. And Wigner came to Berlin, I think, in either '28 or '29.
I think it was '28. He was in Princeton in '30, and then he split his time — six months in Princeton, six months there.
When you did receive your degree you then continued as an assistant in Simon's laboratory?
Yes, actually what happened was this, I started my D. Phil. work in September of '29, and stayed for the next two years in Berlin — until the end of July 1931. And Simon left Berlin on the 1st of January '31 for Breslau to take up his post as an "Ordinarius" (Full Professor). But many of his pupils stayed behind, and in fact, during those six months when Simon was already settling in Breslau, Mendelssohn, his most senior co-worker, who was two or three years my senior, stayed in Berlin and looked after all these people. Simon came once every week or once every fortnight. So I finished my thesis by July 1931, and by that time Simon arranged for me to have a job, a kind of part-time assistant job, a research position in Breslau.
Was this paid for under a specific grant?
No, this was not the case, no. It's quite a funny story. Not being a German citizen, I was in a difficult position, And for me it was very difficult because I was a Hungarian subject. Even in those days — '31 was a pretty bad time financially in Germany; there was academic unemployment in Germany — it was difficult enough for a German to get a job, but for a Hungarian it was just out of the question. However, the various departments — such as Simon's department of Physical Chemistry at the Technische Hochschule in Breslau — had a number of highly paid assistantships, very senior positions. It became a generally accepted practice to split the salaries. Half of it would go to the person who was the official holder of the post and the other half to the "unofficial" assistant. But all this was condoned by the University authorities and both salaries were paid by the University to the two recipients, I shared an assistantship with a Dr. von Laube, a chemical engineer, a few years my senior.
One nice day I received a demand from the Lutheran religious authority in Breslau to pay the religious tax. In Germany all the various religious communities had the right to collect tax from the people of their denomination in the same way as in the U.S.A. the states can collect taxes in addition to the federal tax. You were obligated to pay even though the religion was not state-administered or "established." The religious communities were protected in this way by the state and they could rely on people of their own persuasion to contribute, When I received the demand I showed it to Simon, What should I do with it? I didn't want to pay a tax to the Lutheran community.
He said laughingly: "Sorry, you are getting half the salary of a member of the Lutheran community, so you jolly well have to pay half the tax." However, I had my comeback, because one nice day I received a demand from the Jewish community, so, since I had to pay half of von Laube's tax, Laube had to pay half of my tax, to the Jewish community! I had no teaching duties at all, It was pure research, I spent two years then in Breslau, and I repeated quite a lot of my thesis work under better conditions, I mean I managed to get my D. Phil. and pass my exams and so on.
I would say that I did not complete my thesis experiments until after I passed the exams and got my diploma, I dotted the "i's" and crossed the "t's" in these further experiments in Breslau. My experiments were done on the properties of gadolinium sulfate, It was thrilling that for the first time one was able to predict what sort of temperatures one could achieve if one did an adiabatic demagnetization with gadolinium sulfate, The results were published in a letter to Natarwinenschatten by Simon and myself in January 1933 and a few months later the first actual experiments were carried out by DeHaas, Kramer and Wiersma in Leyden with cerium fluoride and by Giauque and MacDougal in Berkeley with gadolinium sulfate, It was rather satisfying that our predictions fitted Giauque's results quite well,
Did you get some response from people in the field as a result of this?
Oh, yes. I mentioned it I think in my Royal Society Biographical Memoir about Simon. You see, what happened was that Debye told Simon about Debye's proposal to reach very low temperatures by the aid of adiabatic demagnetization and suggested to Simon that he should have a go at it. It was when I looked through the literature that I came across the papers by Giauque where the adiabatic demagnetization proposal is simply mentioned in a footnote ... You see, Giauque made the proposal certainly independently from Debye, but it was never written up properly. Giauque was one of those people who liked to wait with a publication until he had something substantial to report on. So all that happened was that he mentioned it, conversationally to people: this is a method to produce very low temperatures. The only public (but unpublished) statement about it was made by Professor Latimer of Berkeley, who mentioned it at a meeting. This was quoted by Giauque in a footnote to his article in 1927.
Debye's paper came out in December 1926. Who had the idea first? A difficult question to answer and the two protagonists have been rather touchy about it. There are various possibilities. One is that Debye and Giauque got the idea genuinely independently from each other. The other possibility I might mention, especially since Giauque is rather sensitive about it, Giauque's view was that when Debye visited Berkeley in 1926 they discussed all these problems and then six months later Debye published the idea. Now, my explanation is that in one of those conversations Giauque probably mentioned the idea to Debye, who forgot about it and then a few months later, perfectly genuinely reinvented the method without realizing that he had heard about it in Berkeley.
That happens all the time, You can't avoid it, and I don't believe that there was any plagiarism involved. Let me mention in this connection an interesting thing which was characteristic of Simon. He went to Berkeley in 1932, and spent six months in Giauque's laboratory. He was very happy there and he knew that Giauque was by that time building a big solenoid magnet and a large helium liquifier with the chief object of doing the adiabatic demagnetization experiment. I did my final experiments on gadolinium sulfate while Simon was in America, and I wrote to him giving the predictions about the demagnetization of gadolinium sulfate. I also said something else then: "Now we know where we are, Shouldn't we now start doing some experiments on adiabatic demagnetization?"
He replied: "No, no. After all, Giauque is working on it, It would be not nice. I know him very well, Why should we try to steal his thunder?" This was the same remark that he made to Walter Meissner, I found that in one of his letters, Meissner was commiserating about Simon having lost the "race" and Simon replied: "Nein, wir wollten damit warten bis Giauque damit heraus kommt" ("we wanted to wait till Giauque had done it"), So it was not until we came to England that we got involved, By that time, of course, de Haas, Wiersma and Kramer persuaded by Debye on the one hand and Giauque and McDougall on the other had done the first adiabatic demagnetization experiment, and we started work here at the Clarendon on this in the fall of 1933.
In that period, from '31 to '33 in Breslau, what was the general atmosphere in Germany? You talked about your personal work and that it was satisfying. Was there any noticeable change in the university situation in 1931 and '32 and very early '33?
It was in late '32 and early '33 that things got really bad.
No sign of this beforehand.
Not within the Technische Hochschule; it was all right. One didn't feel there was anti-Semitism, But the whole atmosphere in Germany, of course, was getting pretty disagreeable.
In what way?
I mean you could see which way things were going. You could see this very strong movement of the Nazis, All right, although I was not a German, I followed very much how the elections were going on, and it was quite clear that the left and center are pretty well on the losing side and there was a move toward the right wing, But really the thing got bad, as I remember, toward the end of 1932, Simon foresaw it quite clearly even earlier that there was not much hope — so much so that when he went to Berkeley, California, he somehow didn't want his family to stay in Germany during that time. It was from January '32 till the late summer of '32.
He came back, I think, in August. His wife and children and their maid went to Switzerland and spent the whole six months there, worried even in those days about what's going to happen. During that period his house in Breslau was inhabited by Mendelssohn, by me, by Heinz London and by a Bulgarian who was one of Simon's research students, a man called Rosteslav Kaichev, who is now vice-president of the Bulgarian Academy of Science, a very good physical chemist, He visited recently in England.
Did anyone you know make any moves to seek positions elsewhere in anticipation of a deterioration in the situation?
I don't think that Simon was actively thinking about emigrating until late '32 or early '33. But certainly by the 31st of January when Hitler finally became chancellor, he knew that that was the end, Then he became really active, but before that I don't think so, He probably hoped that maybe there would be a shift in the other direction.
How did it first affect you, the change in the situation? When did you first become aware of it?
I don't know. Personally it didn't affect me very much because I was in a circle which had very similar views, was anti-Nazi, and in the laboratory, i.e., in Simon's department, there were really no Nazis, not even people who later drifted over and became Nazis when Nazism became a dominant thing. There was one man who was not quite all right, but I think most of the others were quite decent, There were,however, some very nasty people in the department for inorganic chemistry.
There were three chemistry departments - inorganic, organic and physical in the same building — and the professor of inorganic chemistry was a very distinguished man, Otto Ruff, an old-fashioned German, who probably voted with Deutschnazional at that time. He was of the good sort of conservative right-wing German, His chief assistant was a very ardent Nazi — I don't remember his name. When the Nazi party came to power he always appeared with the Nazi emblem in his buttonhole, There was a famous proclamation, "Gegen den undeutschen geist," against the unGerman...a violent anti-Semitic attack, And this man put it up on the main notice board of the laboratory.
Someone mentioned it to Ruff, and I happened to be there when Ruff came out of his office. He was in a raving fury and got quite red and went to the notice board and tore off the notice and shouted at his oberassistant,"I won't tolerate this sort of thing in my laboratory," and so on. It was wonderful to see that great Nazi sort of slinking away, having been put in his place. Ruff was very decent, It's true, he didn't proclaim his anti-Nazi feelings as did von Laue, but he came to Oxford and visited Simon in the mid '30s. He was one of the few people who, Simon felt (although they didn't see eye to eye on many things), had real decency — and Ruff was really upset about what was going on in Germany.
When did dismissals begin to be feared or when did they begin to take effect?
You see, with Simon it was like this, Under the Nuremberg laws concerning Jews he wouldn't have been dismissed because he had fought in the first World War in the front lines, and moreover, he had one of the highest German war decorations, the Iron Cross first class, and therefore he wouldn't have been dismissed, Even six months after the Nazis came to power, much of the machinery and government finances for science ran in the old ways as shown by the following episode, Simon, I think, made up his mind to leave Germany in January 1933, immediately after Hitler came to power.
Then after his visit to England where he saw Cherwell and Lindemann and Rutherford in May or early June 1933, he decided , and it was settled, that he was going to come to Oxford, He then drafted his letter of resignation. His parents still lived in Germany. Now, several of his relatives (his parents- in-law, his sister, etc.) were going to stay, at least for some time, in Germany so he didn't do what James Franck did, who resigned and published his letter of resignation explaining his reasons. The resignation that really caused a sensation was that of Wolfgang Koehler, the psychologist, one of the few Aryans to resign in protest.
His article denouncing the Nazis was published in the Deutsche Ailgemeine Zeitung, I believe, you know that story, Simon just resigned, just said he wanted to leave. To do otherwise would have made things difficult for his relatives still in Germany. I recall that in late June his resignation was signed, it was ready for posting. And that very morning before he sent his letter of resignation he received a communication from the Notgemeinschaft der deutschen-Wissenschaft, which was the agency to support research, similar possibly to the National Science Foundation, or the Science Research Council in the U.K. Many months earlier he had made quite an ambitious application for funds to enlarge the facilities of his laboratory.
He opened this letter from the Notgemeinschaft, and he found that his application was granted, in its entirety. For one second — I don't think he really hesitated — he just looked at it, On the one hand was the grant of all his requests; on the other hand was his letter of resignation. But he sent the letter of resignation because he knew that it might be all right now and maybe for a month and maybe for six months and maybe for a year, but that in the long run there was no hope.
How about your position?
It's very odd, you know, I really profited from the whole thing, because even if there hadn't been a Hitler regime, it's unlikely that I ever could have got a position in Germany. I mean I could have gone on probably for another year or two in the same way. But then I would have to say: "Where can I go?" And assuming the whole Nazi thing hadn't come, it wouldn't have been so easy for me to write simply to England and say I wanted a job in a laboratory. That would have been out of the question.
But to some extent it was my luck that there was this very great exodus from Germany and that I was at that crucial moment in Germany, albeit a Hungarian Jew, and therefore I in some way benefitted from this, Of course Simon was always very good to me, and therefore when he came over he arranged for me to come at the same time with him,
At the same time?
At the same time, What happened was that I arrived in Oxford a few weeks after Simon. I arrived about the 15th of September, and Simon arrived on the 20th of August.
Before I pursue that, let me ask a question. What about opportunities in Germany? Supposing Hitler hadn't come, as you were speculating. You indicated it wouldn't have been so easy to get a job in England, But what about a job in Germany?
That would have been also very difficult because university jobs only went to German nationals, Now in principle I could have taken out German nationality, but, first of all, it didn't appeal to me very much, and it would have needed a very great change in the general attitude of Germany to enable me to become a German citizen. The German naturalization laws were very interesting.
Although you became a citizen of federal Germany, each of the states (Laender) and there are 20 or 25 of them — had individually to agree to your naturalization, There was an apocryphal story going around that they allocated the nationalities to the various states, and one state refused Italians, another state refused Spaniards, the third state refused the Jews, and so on, you see — or vetoes the Jews, Also there were not many jobs going. I might have been able to find something, but certainly this was a very good solution for me.
When you did come over it was with the support of funds from ICI?
Yes, from ICI.
And did they negotiate directly with you?
No. It was done with Simon and Lindemann, of course. It was rather amusing. What happened was that Dr. Mendelssohn had come over at the end of December 1932 to bring over a helium liquefier to install in the Clarendon Laboratory. And then he went back to Germany, and Lindemann had already invited him to come over in September 1933, so that, having set up this liquefier, he could get the low temperature work started.
But then as things looked too hot in Germany, Mendelssohn simply decided he didn't want to stay any longer, so he came over a few months earlier, while Simon did not come over till later. And then quite a number of negotiations had to go on about the funds for Simon and me, and also there was the hope, which actually did materialize, that Heinz London, who at that time was in Germany, could also come over.
The arrangement was that some of the more discreet things would be done by a special code in correspondence between Mendelssohn and Simon, Everything was done with the help of compressors, you see. And pressures meant pounds. And so Simon was a high-pressure compressor (800 atmospheres meant that he was going to get 800 pounds salary per annum); I was a low-pressure compressor, so that was 250 atmospheres, that's what I got. Heinz London used to say, somewhat wistfully that he was the vacuum pump on this scale .
Then the negotiations were done, Lindemann did it with ICI. It was odd when I looked at those lists (recently) that my name did not figure, nor did Mendelssohn's, and I wondered whether it was because we were in special categories. Mendelssohn possibly because he arrived here early — I don't know whether there was a special deal. In my case, I'm quite sure that I got my grant from Id, because I know one of the first things I did when I arrived in Oxford within a few weeks was to go up to London just to pay my respects to Rintoul, the Research Director of ICI. So I certainly was paid from an ICI grant until 1939, until the war started — 1940 in fact.
I think there was even some reference in 1941 — I'm not sure — but anyway it's pretty close to that.
It might have stopped in 1941 when we started working on the atomic energy project.
I want to respect your wishes as far as time is concerned, but let me just state that the kinds of other things that I'd like to talk about might take a lot longer — I don't know: for example, everything from then on — in the '30s especially; your reactions to your new environment here, the differences in university life, your relations with other colleagues still in Germany who remained and some who wanted to leave. These are all pressing. Do you think that we have time now?
I don't think so. That will have to come in another visit.
I was going to suggest tomorrow because I've taken up enough of your time and schedule.
Perhaps when you return again.
Yes. In that time I can have read a little bit. I'm not prepared to go on. Thank you.