The Nobel Prize in Physics 1999
Gerardus 't Hooft, Martinus J.G. Veltman
I was born on Saturday June 27, 1931, in a town called Waalwijk in the south of the Netherlands. My father was the head of the local primary school. One brother and two sisters of my father were primary school teachers as well, and in my family learning was held in high regard. My mother came from more practically oriented people: her father was a contractor and also ran a café. I have a bit from both sides. I was the fourth child in what became a six child family.
The town of Waalwijk had approximately 20 000 inhabitants. It was dominated by the shoe industry. For many life was not easy in the depression years but a head teacher was relatively well off. Consequently the life of my family was quiet and relatively uneventful.
In 1940 the Netherlands were overrun by the German army. I saw them marching in, and I heard people speak of the difficult times coming. In this part of the Netherlands things were not as bad as in the big cities, and the main thing I remember is that my father's school was requisitioned by the Germans and troops were lodged therein. In the fall of 1944 we were liberated, contrary to the part of the Netherlands "above the rivers" that would have to endure till the capitulation in May 1945. This was due to the failure of the operation Market Garden; the last bridge near Arnhem was not taken. Thus we escaped what is called the hunger winter of 1944-1945, in which many Dutch people died of hunger.
The period of the war in which we were liberated, while the north was still occupied, was characterized by lots of artillery fire from our side, as Waalwijk was very near the front line. The allied troops were not very careful with their ammunition, and as a young boy of 14, I was very interested in playing with that. I remember how we would extract the powder from a failed tank grenade found in a ditch near where tanks had been firing. We would take the grenade by the point and then beat the lower end on the ground till the point came loose and we could then shake out the powder. I do not know how I survived this, but I did. We also survived the VI flying bombs that came over on their way to Antwerp. Two of them actually fell on houses in Waalwijk, one of them at about 100 m of our house. With me is still the memory of dead bodies being extracted from the ruins.
In 1943, I went to high school (the Dutch HBS). The war period was marked by irregularities and at one point our class was in a horse stable. While I had been a very good student at the elementary school, I was quite mediocre at the HBS. Much of that was due to my bad aptitude for languages, which is a real handicap when they require you to learn three foreign languages. So it happened that I narrowly passed the final exam in 1948, at the age of 17.
In those years I had (and still have) electronics as a hobby. This is a somewhat exaggerated qualification, because there was practically no electronics material around. The Germans had confiscated all radios, and there was a great scarcity of anything that could catch a radio signal. I remember spending a whole day walking around in the nearby larger town of 's Hertogenbosch, trying to get a radio tube. Finally some kind person, having pity on me, gave me one.
I acquired my knowledge of electronics from the local plumber. I used to spend many evenings in his house, and during the holidays I would work for him. I thus also learned plumbing. When I started to understand radio's a bit better I became the local radio repairman. My only measuring instrument was my right index finger. If I touched a sensitive connection the radio would produce a hum. If a connection had the correct high voltage (about 200 V) I would get a shock. Commercially I was a failure, as I would usually not dare to ask money for my services.
When I passed the final high school exam the big question was: what now? Traditionally somebody like me would go to a medium level technical school in 's Hertogenbosch called MTS. However, given my low grades this did not go smoothly. At this point my physics high school teacher came to my home and suggested to my parents to send me to the University. This was a big thing, practically nobody did that in Waalwijk in those days. Universities were still very exclusive, and the south of the Netherlands was quite backwards in this respect. As the money situation was very tight the main point was to find a University where I could go to by train. This was possible with the University of Utrecht. For three years I commuted back and forth from Waalwijk to Utrecht, a 90 minute trip each way. I am still grateful to this high school teacher, Mr Beunes, as he did the extra thing, going to my parents house. Since then I have found out that many physicists owe their career to a good high school teacher.
Worse however was the state of the education at the University. The war had left the Netherlands ravaged, many good physicists had left the country or were killed. In retrospect, it is really a pity that Abraham Pais left Utrecht to go to the US. The teaching in Utrecht was uninspiring, and failed to awake much physics interest in me. After three quite mediocre years I left home and started to live in Utrecht. At that time I had no income as my father could not support that, and I was forced to work on the side. My main activity was typing lecture notes. Sometimes it was even difficult to get decent meals. But by and large I lived a happy life, mainly bumming around.
I also got involved in another job, trying to sell some rather silly tools to the unsuspecting citizens. In this I was a complete failure. I cannot sell anything to anybody. In some sense that has remained true in my scientific life.
After five years (2 years longer than normal) I passed what was called the candidaats exam. Then I happened to stumble on a popular book on the theory of relativity. Mind you, up to then no teacher had ever mentioned this. This booklet really excited me, and I went to the Institute of Theoretical Physics to get a real book on the subject. After some nagging they gave me Einstein's book "The Meaning of Relativity". Since then I was hooked. Also my financial situation improved slightly: given the very big shortage of high school teachers in the Netherlands it was not difficult to get a job as parttime teacher. Actually, I started as a teacher at a lower technical school, teaching plumbers about physics. None of that was helpful in speeding up my studies.
After my candidaats exam I started initially as an experimentalist. I worked for some time studying medical physics, in particular the physical aspects of percussion sound (the sound that is produced when a doctor pounds your chest). Later I worked on a mass-spectrometer, mainly doing the electronics. I found out that this was not my real destiny, and switched to theoretical physics. However, I still have a considerable fondness for experimental physics.
In 1955, I landed a job as assistant to Prof. Michels, of the Van Der Waals laboratory in Amsterdam. Michels was an experimental physicist, involved in high pressure physics. My task was the upkeep of the library, remarkably well stocked, and occasionally preparing a talk for Michels. I remember that as a good period, and it brought me also into contact with the members of the theory institute in Amsterdam. Mostly they were interested in statistical mechanics, a subject that has never evoked the slightest enthusiasm in me. Sneeringly I used to say: you guys average out anything of interest.
Science wise my life improved greatly with the coming to Utrecht of Leon Van Hove, I believe in 1955. He was an excellent lecturer, and I volunteered to make official notes of his lectures. I finished my graduate studies in 1956, after which I had to go into military service for two years, coming out of that in February 1959. Van Hove was so kind to take me as a PhD student despite my relatively advanced age (27 years). Thus I started doing real theory.
As Van Hove did statistical mechanics like all other theorists in Utrecht there was some problem, because I wanted to do particle physics. At that time many European Universities did not have anybody doing research in that field, and the way to learn that was via physics schools. Typically, such schools would run over a period of two weeks, with internationally known speakers. In the spring of 1959, I went to such a school in Naples, where among others Kurt Symanzik and Bruno Zumino lectured. In August 1960, I went to yet another school, in Edinburgh, and that school has been of quite some importance to me. I met Shelly Glashow, at that time a student there, who was working on the subject for which he was to get the Nobel Prize. If someone had told him that, he would have been quite surprised. At these schools I became friends with several other students, among them Nicola Cabibbo and Derek Robinson (who went astray into statistical and mathematical directions). They have remained friends to this day. From the Edinburgh school I do remember fondly the lectures of Dave Jackson, now in Berkeley.
In 1960, Van Hove became director of the theory division at CERN, Geneva, Switzerland, the European High Energy laboratory. I followed him in 1961. Meanwhile, in 1960, I was married to my present wife Anneke, and before joining me in Geneva she delivered our daughter Hélène in the Netherlands, living in the house of my parents. Hélène followed in my footsteps and in due time completed her particle physics thesis with Mary Gaillard at Berkeley. She now works in the banking world in London. She is the one member of our family that understands what I have been doing.
At first I felt a bit lost at CERN, since my elementary particle physics knowledge was quite sketchy. For some time I had been working on a rather field theoretical problem, namely unstable particles. When that was finished I wanted to go into something closer to the experiments. This happened thanks to Sam Berman, an erstwhile student of Feynman. He was aware of the situation at the CERN theory division at the time, and he did put up an advertisement: If you have nothing else to do and wish to be kept off the street please knock my door". So I did, and I am still very grateful to him. He suggested a calculation: Coulomb corrections to the production of vector bosons in the CERN neutrino experiment. This, after consultation with Van Hove, was then to be the second part of my thesis.
The problem consisted of two parts. One, a part very analogous to a previous calculation of Bethe and collaborators (Coulomb corrections to pair production), and secondly a part that was not solved by Bethe. I remember sitting in my offce for several months, staring at a single differential equation, trying to solve it using confluent hypergeometric functions. These are very disgusting functions, and after a while I felt that perhaps I should consult the world expert on that matter, Eyvind Wichmann. He happened to be in Copenhagen at the time, and I made a pilgrimage. Seldom have I made such a useless trip. Wichman tried to understand what I wanted, but he did not get it. He looked at me as if I was some strange animal.
Well, at some point I solved that problem, and that then completed my thesis. In due time (April 22, 1963) Van Hove and I went back to Utrecht for the ceremonies, in tails and white tie. I now understand that this is a preparation for the Nobel Prize. The thesis contained my work on unstable particles as well as the treatment of Coulomb corrections for vector boson production by neutrinos. Title of the thesis: Intermediate particles in S-matrix theory and calculation of higher order effects in the production of intermediate vector bosons.
At CERN, meanwhile, the experimentalists were gearing up for the CERN neutrino experiment. I was asked to speak at one of their meetings on vector boson production. I became almost instantly very good friends with Bernardini, the leader of the group. They then wanted me to do extensive calculations for them concerning vector boson production, as that would be needed for analysis of the data. Computer calculations of that type had been done already by Lee, Markstein and Yang, and when Lee came to CERN I took the occasion to ask for those programs, which he curtly refused. I then asked him if he could give me some advice, to which he answered: "don't make mistakes". I thought this funny, and started to laugh, but that was not appreciated by Lee, who took some moments to teach me the seriousness of this enterprise. Well, even if in the making of computer programs the not making of errors is usually the main problem, I still feel that I did not really need that advice!
The CERN neutrino experiment was a very big happening in my life. When they started I was more or less permanently around, looking at the pictures as they came out. When no spectacular events came out the enthusiasm of the experimentalists waned, and after a while the only ones to look at the pictures were Bernardini and myself. And so it came to pass that I became the spokesman for the group at the Brookhaven Conference in 1963. Somewhere in that period I acquired two lifelong friends, the experimentalists Mel Schwartz (Nobel Laureate 1988) and Val Telegdi.
The 1963 CERN neutrino experiment left me with an interest for experiments that never went away. I am a deep believer in the importance of experiments for the progress of physics. Also, the experiment left me with a feeling for these things, to recognize what is important and who are the good guys. All theorists ought to go through some such experience. These days, however, that is not really practical any more. The experiments have become gigantic enterprises, involving hundreds of physicists and a large number of engineers. The modern experimentalist is often more manager than physicist.
In 1963, I went to SLAC at Stanford, where Pief Panofsky was building a Iinear electron accelerator. Also Sam Berman was there, in fact he was much of the reason for going there. Meanwhile, at CERN, I had become good friends with John Bell who was one of the very few theorists that had any interest in the neutrino experiment. He also came to SLAC, and in fact we wrote a paper together that we however never published. He became quite involved with what is now known as the Bell inequalities, while I started constructing my symbolic computer program Schoonschip. That also had its origin in the neutrino experiment: in doing the necessary algebra for vector boson production I was often exasperated by the effort that it took to get an error free result, even if the work was quite mechanical. In a discussion on the CERN terrace, including among others Mike Levine, we concluded that somebody ought to write a program to do that type of work. I started doing that at SLAC, in the autumn of 1963. Many good things have been invented at the CERN terrace. Mike Levine later successfully completed the first QED sixth order calculation.
In the spring of 1964, I went back to CERN and worked there till my departure for Brookhaven in 1966. There I had the pleasure of getting to know Maurice Goldhaber, then the very successful director of Brookhaven National Laboratory. A man that impresses me to this day. He liked me as well, and in fact tried to get me to that laboratory, which I did not. I do remember getting a phone call from Brookhaven while sitting with my parents in law in the Dutch town of Leeuwarden. How they ever found me there is still a mystery to me.
In the meantime, just prior to going to the US, our son Hugo was born. He now runs a restaurant called Solstice in Los Angeles. If I want a really good dinner that is where I go. I hope the reader gets the hint.
September 1966, I went back to Utrecht, as successor of Van Hove, i.e. professor of theoretical physics. There was still nobody doing particle physics there, so I started to build that up. That took some time; it was really a big change after the rather hectic CERN life. I made a mistake: I thought that being relatively isolated in Utrecht it would be a good idea to become editor of Physics Letters. Indeed, it is a way to keep in touch with the action in the field; however, I received on the average 1 article a day, and I rejected about 90% straight away. In other words, the big majority was junk, just cluttering up my mind. As far as I can see it has become worse, not better. Many a physicist has come to hate my "high handedness", as one of the victims called it. I was happy to get out of that job by the summer of 1968.
A turning point in my scientific life occurred during a one month visit (April 1968) to Rockefeller University. In the quietness of that institution I embarked on the scientific venture that has now been honoured with the Nobel Prize. I am still indebted to Bram Pais who got me there and counseled me in that period. Too bad that he left the Netherlands in 1945; I am sure that he would have kept Dutch particle physics on a high level. One man can make a big difference.
In the summer of 1968, I went to Orsay, near Paris, on the invitation of the French physicists Claude Bouchiat and Philippe Meyer. The stay lasted till September 1969, it was a sabbatical year (after two years in Utrecht…). As Utrecht partly paid me during that period, I told the French people that I did not need much in the way of a salary, and subsequently they did put me in some low job. This had an unpleasant consequence; Christmas 1968, I was fired, as de Gaulle had decided on some cost saving operation. Luckily they succeeded in patching it up, in some mysterious French way. Some well known French physicist told me: luckily that it happened to you and not to T.D. Lee. That made me aware of my place on the totem pole.
Back in Utrecht I continued my work, and had several students under my supervision. Among them Peter van Nieuwenhuizen, now director of the C.N. Yang Institute at Stony Brook, Bernard de Wit , now holding my former position in Utrecht and Gerard 't Hooft, my co-laureate. Our group became known, especially so after the work of 't Hooft and myself that is cited in connection with this years prize. Besides my own research I was very busy in that period: reforming the physics educational system in Utrecht (see my complaints above), and trying to get a good computer system. The latter required endless meetings, mainly caused by some mathematician who insisted that the machine could run Algol, a by now largely forgotten computer language. I had literally to learn some 6 or 7 computers inside out to get to the final result: a CDC 6800 computer. During one of these meetings (January 1971) I received a phone call telling me that my wife was about to deliver another child; I went out of the meeting to the hospital and came back after about one hour. I gave everybody a cigar, celebrating the birth of my son Martijn and continued with the meeting. Martijn is now working in Hollywood, in the movie industry.
't Hooft and I worked together for a few more years, after which we drifted apart. I went my way doing calculations of radiative corrections, something that he was not interested in. The fame of Utrecht had spread, and two young Italian physicists came to work with me: Giam-Piero Passarino and Maurizio Consoli. Some Dutch students at that time were Jochum van der Bij, now professor at Freiburg, Germany and Michel Lemoine, now a free lance Senior Petroleum Engineer. The latter has convinced me that theoretical physics is a good science to be educated in, it prepares for no job in particular but the scientific methods learned are of use in many positions in modern society. So never worry too much what kind of job you will get after finishing a theoretical physics education. For example, the first Prize in Economic Sciences in Memory of Alfred Nobel went to Tinbergen, a former theoretical physicist. And nowadays the banking world is full of particle theorists.
In the summer of 1979, I received an invitation from Ed Yao from the University of Michigan to spend a sabbatical year there. I knew Yao from his scientific work, and I immediately called my wife, asking if she was interested in a year in Michigan. For reasons that I have now forgotten we left in March 1980, to stay till December of that year. In Michigan we were asked to stay, but initially we answered rather firmly that I was not interested. In November we started wavering, and in fact Fermi lab (under the directorship of Leon Lederman, another experimental friend of mine) started to express interest as well. In December a nice house was auctioned near were we lived in Ann Arbor, and my wife told me: if you buy that house I will stay. I did not get the house, some richer medical person got it, but this somehow made us decide to stay in Ann Arbor. Part of it was a certain unhappiness with the situation in the Netherlands, and another part was the happiness of our sons with the American school system. My Utrecht colleagues were quite upset when I told them and they did sent me a telegram asking me to remain in Utrecht. But we decided to accept the offer of Ann Arbor, and when we came back in Utrecht I started preparations to leave, which we did in September of 1981.
I did my part in the scientific life in the United States, serving among others on the various committees that decide on experiments at the big laboratories, Fermilab near Chicago, SLAC at Stanford and Brookhaven National Laboratory, Long Island.
Shortly after we arrived I was offered a named chair, the John D. and Catherine T. MacArthur chair. Europeans think that this means an extra income, but that is not true. There are other things however. Apart from the prestige of this chair it had a really nice feature going with it: a yearly amount of $ 35000 that I could spend for scientific purposes. While it may seem a small amount, it nonetheless made quite a difference. I could pay certain deserving students during the summer, buy computer stuff, help the group with little things, visit conferences, invite colleagues etc. It is wonderful that you can buy a new computer almost immediately if there is a need for it. In Europe that took often a long time, you had to put it on a budget and wait for approval etc. This is one aspect of the greater flexibility of the American system. If you want something done you either use discretionary funds at your disposal or you go around and try to find money (discretionary funds) from people or groups that feel it is also to their advantage to support the purpose. For example I remember supporting a Russian scientist partly from my MacArthur fund, partly from a fund from the astro-physics group.
In hindsight we do not regret this move to the USA, but it would take me too far to explain that. Too many strictly personal considerations are involved here. The University of Michigan has been good to me, and I feel loyal to that institution. Also the life in Ann Arbor was quite nice, and Anneke felt very much at home there, enjoying membership of a great many clubs. Among others she learned to make beautiful stained glass windows. Nonetheless, it was quite a step for a 50 year old man and his family to emigrate. Dutch people abroad have a saying: rather nostalgia than Holland. I would not go that far, we had certainly many friends in the Netherlands, and also most of our families (from my wife and me) live there.
My main tie with Europe during the US period (1981-1996) was with the University of Madrid (the Autonoma), Spain. There was a particle theory group headed by F.J. Yndurain. I would go there up to two months during the summer time, and conversely he would often come to Ann Arbor. This type of collaboration is usually very fruitful, not only for doing science, but also because it fosters the exchange of graduate students.
It was just in this period that Spain decided seriously to catch up with the rest of Europe, and that was an interesting and exciting thing to watch. While not everything went perfect, I would say that Spain made enormous strides forward in a relatively short time. Up to this day I have very good relations with Spanish physicists, both in Spain and at CERN. I should perhaps add that to them CERN is of crucial importance, as it has been to me.
On retirement we decided to return to the town of Bilthoven in the Netherlands that we had left in 1981, to find still many of our old friends there. That is where we now live happily. Our children however did not go back, they would really not fit anymore in the Dutch society. It rains too much.
From Les Prix Nobel. The Nobel Prizes 1999, Editor Tore Frängsmyr, [Nobel Foundation], Stockholm, 2000
This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/Nobel Lectures. The information is sometimes updated with an addendum submitted by the Laureate.
Copyright © The Nobel Foundation 1999