Ladies and Gentlemen, please picture this,
Our lives, a journey along the branches of the tree of possibilities.
Shortly before the war my first branching points were passed and in September 1940, after Rotterdam had been bombed, I was born as a boy in that city.
In the fifties Mr. Barends was my cigar smoking physics teacher at the H.B.S.-B, my secondary school, and everything could be calculated on the back of an envelope. It seems that he wrote a paper for his Masters Degree on a gravitational subject for Zeeman. As an artillery captain of the reserve he was involved in the attempt to safeguard our country against a German occupation in the May-days of 1940. Ballistic trajectories held no secrets for him. Proudly he told us about the self-made radios in the prisoner of war camp somewhere in Poland, where he had been the representative of the Dutch soldiers. Obviously there was peace and quiet in his classroom.
After my bachelors degree in Leiden in 1962 another branching point approached. The low temperature research at the Kamerlingh Onnes laboratory did not appeal to me. Restlesness, longing for change gained the upperhand and I decided to try my luck in Amsterdam. How did I end up among the elementary particles? Those who studied the subject experimentally were located in that splendid place along the Plantage Muidergracht, the Zeeman laboratory.
The beauty of the building settled it for me, I suspect. Have a look for yourself, it is listed as a monument and open to the general public free of charge for a few days every year. You come into a spacious hall where the light enters from above through the windows in the roof. The marble staircase rises towards the light and to the entry of the regents room at the back looking out onto the water of the canal. The building is a tribute in stone by the bourgeoisie of the city of Amsterdam to physics and to one of its learned laureates. The ideals of those years at the beginning of the twentieth century: Onwards and Upwards, Enlightenment of the People, To the Light, seem to have taken shape there. Something like that was evoked at least, when I visited again some weeks ago. The peaceful and splendid little library, where I prepared myself in the mid-sixties for my physics examinations is almost untouched. Alas the books and their content have changed, sociologists occupy the building, "Institute of Social Studies" can be read at the entry door.
The director of the lab in those days Jan Kluyver, my future thesis advisor, occupied the room of the regent. In practice the daily supervision of the elementary particle group was in the hands of Armin Tenner. Politically the situation could be called "Early Purple"(Purple politics in the Netherlands being the co-operation of the bourgeoisie with labour in the last decade of the previous millennium up to the present day). The regent kept the purse, the left controlled the means of production.
It took a while before I understood that balance of power. Armin was the jack-of-all-trades for the emulsion as well as the bubble chamber group. He led the entry into the computer age. Imagine: instead of files or ntuples on a disc, card-boxes with colored little indicators and shelves filled with files full of paper. Making one histogram could take days, even weeks.
My first official trip to CERN with the night train to Geneva in the beginning of 1965, was made under the supervision of Willem van Leeuwen. Then as now he is far more competent with computers than I am. We added a few punched cards to a database contained in a drawer full of card-boxes. For the first time I met Bob Jongejans and his wife. With Walter Hoogland I spent another six months there later that year. My lifelong friendship with him and his wife Celine Leopold started then. I was assistant to the physicists who designed and ran a particle beam to the 80 cm Saclay bubble chamber.
Back in Amsterdam in the beginning of 1966 the city was in turmoil. Erik the Lijser, student at the lab and I in the wake of Sietze Bosgra, Ph.D. student in the emulsion group and leading pacifist, got involved in the first Vietnam demonstrations, organised at the Quaker center in the Vossiusstreet near the entry to the Vondelpark. American Quakers on a trip through Europe encouraged their counterparts here as they also did in Berlin and Stockholm. We lent a helping hand to the people who put together the Vietnam Bulletin. Mary Duyvendak, later the mother of our son David, translated articles from the English, the language of her American mother.
Saying goodbye to Kluyver at the end of 1967, when I started my first of three long stays at CERN, he told me:``You will find out that the world is not as bad as you think it is.'' It surprised me, his saying a thing like that. He had made such statements before. The morning after the smoke-filled events in the Raadhuisstraat on the wedding-day of our present queen and prince Claus in 1966, I was chattering excitedly about the things I had experienced there. He got angry and snarled at me: ``What do you think you are doing, spoiling the wedding-day of that girl.'' And: ''Of course she married a German boy, she is a German girl herself after all.'' And this from someone who was rounded up during the war, like Dick Harting, and put to forced labour in Germany. Makes one think, does it not?
I have paused quite a while at the spot where my first birth pangs as a physicist took place. The plans for another birth, the one of our institute were conceived in the same building and in that regent's room looking out onto the canal. There are others in Utrecht, Geneva and Nijmegen who played their part, but the unrelenting pressure exercised by Kluyver on the FOM and the government-department in the Hague was the largest.
Many years as a trainee at CERN and from August 1974 at DESY in Hamburg were necessary to make someone out of me at last. So when in December 1975 the provisional directorate of NIKHEF, a foursome consisting of Harting, Kittel, Sens and Veltman, encouraged me to undertake something at PETRA, the latest accepted DESY plan, I was ready for it. I can still see the approving nod of a cigar smoking Veltman. With two collegues, Bartel and Büsser, I was writing a proposal for an experiment at the new e+ e- machine. At the first match-making opportunity for collaborations at Frascati, Italy, at the beginning of 1976, two similar proposals were presented: one by Ting, the other by Becker, both from MIT. Later that year the realisation of the Mark J collaboration became a fact.
Bert Diddens was my first director. He hauled me in as a staff member of the institute in 1977 and the Mark J experiment became an official part of the NIKHEF scientific program. I can still hear his voice through the telephone with that special Groninger accent when I asked for money from Hamburg: ''Go ahead boy, we are not a savings bank.'' The photograph shown was taken in January 1978 shortly after the arrival of the first group of physicists from the Peoples Republic of China, who had joined our collaboration.
The assembly and installation of the experiment in the summer of 1978 was the most hectic time of my life. Imagine, I was in the prime of life and I knew what it was all about. I was the deputy spokesman with Ting as my boss. Everything that came my way there and needed a solution I took on. DESY did not have enough personnel to install four detectors within schedule. We got the necessary funds and had to take care of the rest ourselves. I was responsible for the assembly and installation of the detector and directed the dockworkers and all the other extra people we needed. My birth - my father was a teacher and my uncles on my mothers side were unskilled labourers - and my summer jobs in the fifties as an ordinary seaman along the coasts of the North Sea and in the docks of the E.N.C.K. (the First Dutch Co-operative Fertiliser factory) in Vlaardingen, finally bore fruit. Physics and my background came together for the first time in the pit behind the DESY ``Wohnotron''. It gave me wings and extra strength. My respect for Ting started there, his respect for me came after an angry shouting match.
In December that year we were in the beam and could start. At the official opening of PETRA that same month I was going to be presented as a young European scientist to the president of the Federal Republic of Germany, Mr. Scheel. For that special occasion I purchased the solid suit made of German cloth in which I am standing in front of you now. Due to a change in the ceremony at the last instant, the president, in contrast to you, did not behold this stylish three-piece costume.
We took the first data in the same month and soon afterwards we published our first results. 1979 is recorded to be: ''The year of the discovery of the gluon.'' To be the discoverer of the carrier of the strong interaction - source of the fire in sun and stars - together with Jan Bron, Dick Buikman, Douglas Fong, Graziano Massaro and the others is the most important event that occurred to me in my scientific career. The energy vectors from which the Mark J jets were constructed and which made the above possible were invented by Graziano.
Everywhere in the world I preached the tidings of the Mark J experiment: ``Gluons exist.'' In the U.S.A. I once started a talk with: ''From the gospel of Mark, chapter J.'' In the controversy with our competitor Tasso on the question of who can write the discovery of the 3-jet events to his name, I participated wholeheartedly and with passion. At this moment they lead in Europe, everywhere else in the world the race is still on.
Cheerfully on the road now to my last experiment at LEP. The first in a row of test wire-chambers for L3 was made in the beginning of the eighties. I see Bob Hertzberger and Fred Hartjes in my mind's eye as I write this. In 1983 Bert Diddens was of the opinion that I should come back to Amsterdam. He wanted to see the workshops of his institute filled with work, he told me. As vigorousely as I could I have tried to fulfill his wish. The FOM even accepted a special proposal for that purpose. Those years in the Watergraafsmeer up till the end of 1988 belong to the dearest I have had at NIKHEF.
The co-operation with the technicians was essential: Nico de Koning, Joop Buskens and all the others from the mechanical workshop; Henk Schuijlenburg, Gerard Faber and Hans Postema from the design office; Paul Rewiersma, Henk Groenstege, Wim Gotink, Gerard Evers and many others from the electronic workshop. Always first the drawings and designs and then the purchasing orders for which Hans Geerinck was especially appointed. Order, order, order I told Paul and Henk, the lot must be ready in time. There are meetings from those days that still pester me in my dreams. We had files full of paper in the purchasing department of the people of my managing director, Jan Langelaar, and lorries full of driftchambers and other stuff going to CERN from the workshop of Nico, who had some thirty people coming in every day.
Fortunately Harry van der Graaf joined at an early stage for the calibration of the Rasnik systems, the chambers, the electronics and for playing the lute. The first Ph.D. students, Xaveer, René, Peng and Hans with later Tim and Zhang presented themselves. It is too much to mention everything. The photograph taken in the assembly hall of NIKHEF around that time has a place of honour in my home.
When preparing this speech the memories of the earlier period, from the years of my birth as a physicist came back to me, not so much those from the L3 period. It is such a short time ago and harder to formulate and also I should not take too much of your time. "Hurry up", I still hear my mother saying when I was engrossed in reading a book and had not heard her earlier urgings, "your food is getting cold."
All those activities could unsettle every now and then my second director Walter Hoogland. The financial situation had changed, possibilities decreased, the public debt was growing. There were months in which at his request I made a new five year plan every fortnight. Of course he had to make sure that enough room was available in the workshops and design office for the other large experiments DELPHI and ZEUS. Due to his pressure part of the L3 production went to Nijmegen.
As a consequence the co-operation with the Nijmegen group intensified, as was already sketched by Wolfram Kittel and I thank him for his kind words. I thank Remy Van der Walle, his efforts gave me my special professorship. Our friendship developed later in Geneva. The possibility to lecture on the topic of elementary particle physics was handed over to me by Wolfram and I am obliged to him for that. I relished the surprised and even sometimes, though rarely, the admiring looks in the eyes of the students when the lifetime calculation of the neutron from the first-order Feynmann diagram again leads to a number more or less in agreement with the measurement. I enjoy remembering that.
The period from 1991 to the middle of the nineties found me in Amsterdam again under my third director Karel Gaemers. New Ph.D. students came along, Els, Monty, Bob, Kees and Sandra joined us. The activities for the firstLHC committee, for which I was invited by Rubia, kept me from the streets. Dear Karel, your laudatory and friendly words surprised and touched me.
My last stays at CERN were during the time of the LEP operations, at the Z in the beginning and at the higher energies at the end. The scanning of the first Z events with Jaap Schotanus, the Ph.D. students of that time and the many others, was right up my street. My bubble chamber years turned out to be of some good after all. Around Christmas 1989 it dawned on me that there would be nothing new under the sun. Precision work would be the order of the day. My participation in the last great hunt of LEP for the Higgs I enjoyed tremendously. We even thought we saw the shadow of the beast, the price for its hide was already being discussed. I fear now that it was a passing dream. A bit late I hear some of you thinking. Indeed you are right.
There is one more thing I need to say. All results of LEP do not carry the same weight for me as the discovery of the 3-jet events at DESY in Hamburg. It is great to know that the LEP results contributed their share in the decision of those people in Sweden to honour the two Dutchmen ,'t Hooft and Veltman. That is very good indeed. But this continuous agreement of the measurements for ten long years with the Standard Model drives me nuts. I want to shout to the youngsters: "For God's sake do something about it. Find something in disagreement with it. It cannot be true that we have to wait till Kingdom come, I beg your pardon, till the Planck mass, before the deviation of the electron from a pointcharge will show up."
Dear Jos, you are now my last director and the team captain of us all. I thank you and all the others who organised this farewell party. I wish you strength. Hold on to your enjoyment of life. The present financial difficulties at CERN and the completion of the preparations for the future "expeditions" will give you enough to worry about as it is.
Members of the institute, you all are on the branch named NIKHEF of the tree of possibilities. Make something of it. Realize that it is a privilege to partake in the adventure called fundamental research. Outside the gates of our institute part of our bourgeoisie is struck by money madness. Don't let it discourage you. Keep your nerve. The reports by members of our species from the whole of recorded history in all languages tell us that bread and games alone are never enough. The elementary questions are always posed. I thank you all. Farewell, all the best and do know that my future will have moments that I will miss you dearly.
27 november 2001