Albrecht Wagner

Zierler:

Okay. This is David Zierler, oral historian for the American Institute of Physics. It is January 6th, 2021. It's my great pleasure to be here with Doctor Albrecht Wagner. Albrecht, it's great to see you. Thank you so much for joining me today.

Wagner:

Thank you for joining me, and I'm looking forward to our interview.

Zierler:

Wonderful. Okay, so to get started, would you please tell me your current titles and institutional affiliations?

Wagner:

Well, I'm first of all retired, which in Germany is the normal state of affairs after 65 or sometimes older. I was the chair of the board of directors of the Deutsches Elektronen-Synchrotron, or DESY, in Hamburg and at the same time, professor at the University of Hamburg.

Zierler:

Now, "retired" in Germany may or may not mean something different in the United States. Physicists in the United States never actually retire, they just stop getting paid. Is that the case for you as well?

Wagner:

To some extent, yes. However, I think I widened my activities a little bit after having retired. Having been the last 20 years essentially in science management, I felt that it didn't mean a lot if I try to bug my colleagues about what they were just doing. I was following, of course, the development of science. But I no longer did science myself. At least not in an active way like programming and so on. The second thing was that I moved away from Hamburg after I retired, and therefore the links to the university were weaker. However, I didn't sit around totally lazy, but I had to, or I was asked to chair the board of overseers of the University of Hamburg, which I did for 12 years, just until last summer. I was also asked to be on the board of overseers of a foundation in Hamburg, a task which is still ongoing but will end this year. Since 2011 I have been involved with the Okinawa Institute of Science and Technology, and as you have heard my name from Jonathan Dorfan, so you know what this place is. There, I was first member of the Board of Councilors, and then became the chair of this board. In 2015 I was asked to replace Jonathan for four months as an acting president. Since then, I am also a member of the Board of Governors which oversees the university. So you see, retirement means a little less work than before. But I can decide what I want to do and am active, but not really in particle physics itself, except that I follow, of course, closely what is happening.

Zierler:

Albrecht, I'd like to ask before we start going back in developing your life narrative, a very in-the-moment question. Of course, we're coming up nearly, unfortunately at this point, a year in which we're all dealing with the pandemic. I'd like to ask you in what ways has the pandemic and the way that we've all been forced to work remotely and be physically distant. In what ways has this been difficult for the work that you do, and in what ways have perhaps you had been able to get more done than you otherwise would have?

Wagner:

There are two aspects. One is that I certainly have saved a lot of normally not very effective time sitting on trains and airplanes.

Zierler:

Right. (laughs)

Wagner:

And so I could concentrate on the things under discussion. On the other hand, a video conference like Zoom never will replace in-person contact. For some meetings it's fine. For more subtle things, you need to be face-to-face. You have, in a meeting, to make a short coffee break and then talk to people over coffee, which you can't do over Zoom. Etc, etc. So yes, for the routine work it works. And I think it is actually quite effective. For the more spontaneous and the more subtle things, I think there are definite limitations for this way to interact. But in general, most of the work continued. What was missing last year was the annual trips to Okinawa, because one couldn't fly. The last meeting, which I chaired as the board of overseers of the University of Hamburg took place remotely, which was unfortunate as the university had planned a good-by party. The foundation board, being a somewhat smaller group of people, actually met once in person, so that was okay. So in general, I think I have certainly not suffered too much in what I was doing, but I got rid of the many trips I have been doing in past years. And that was definitely an advantage.

Zierler:

Albrecht, of course you have so much experience in particle physics, and given that you remain interested, there's so much exciting that's going on right now, and probably more than you can keep up with on a detailed level. So what are the things in particle physics currently that are most interesting and compelling to you, that this is the area that you want to pay attention to closely right now?

Wagner:

Particle physics, over the last ten, 15, 20 years, has been extraordinarily successful in verifying the predictions of the Standard Model, the underlying theory of particle physics. I think it started with the harvest of LEP, then continued through HERA and now continues at the LHC. I know of no theory in physics, which has been so successful in predicting things we haven't measured yet. That's a glory and a curse at the same time. The curse is obviously that we know that this theory is not explaining everything. It has its artificial elements, which have to be put in by hand. Everyone expects a more fundamental theory of which the Standard Model is a part. And so we desperately are looking for a crack in the wall through which we can glimpse something which shows us where to look for this theory. Unfortunately, so far, I am not aware of any really great, visible crack where we see in which way to go. That's why I pay a lot of attention to the more exotic experiments. The LHC is charting unexplored territory, and the number of results it has been producing is fantastic. But again and again these results are the proof of how powerful a theory we have with the Standard Model, and how difficult it is to find something behind it, like super symmetry which has been, at least for me, for a very long time the main contender for a theory beyond the Standard Model. So this is unfortunate.

Many people were therefore looking over the last 20 to 30 years for other ways to do experiments at very high energies. They concluded, and this is also my personal belief, that the next step should be a accelerator complex in which electrons collide with positrons at very high energies. The decision to build such a collider, the International Linear Collider, in global collaboration has been dragging on for a very long time, mainly due to its large cost. So I'm still hoping that it will materialize, because I think such a collider is a very good complement to the LHC. And I would guess that through precision measurements, like in the past, we get a glimpse on the future.

I don't need to remind you how quantum physics came about. It came about because people measured something really dull: What does the spectrum of a black body radiation look like? If you heat a body, it radiates over many wavelengths. How does that spectrum look like? And theory fits the data best? As the measurements became more and more precise between 1890 and 1900, people realized that none of the existing theories agreed with all data. Max Planck discovered that he had to introduce a new concept, that energy comes in packages (quanta), that the energy in quantized, in order to make the spectrum fit. So precision measurements were and will be the basis for discovering something which otherwise you might not have found. So that's one example, and we hope for something of that sort.

Zierler:

Albrecht, over the past 20 and 30 years, as you note, so many particle physicists have gone into astrophysics and cosmology. I'm curious in terms of your purview and your interests if you're following those developments as well, insofar as what they're discovering is also relevant for the advance of particle physics?

Wagner:

Actually, this was one of the triggering elements, why I went into particle physics. And there has always been this link between the very smallest and the very biggest. And this link has, over the time I was active, become more and more evident and more and more used, also. Because we would only be guessing about what happened in the early universe if it would only rely on theories. But as we have these powerful accelerators and as we can perform experiments which reproduce, in a way, in the lab today, how the universe looked a nanosecond after the Big Bang. Thus, we can actually make measurements which verify or falsify the theories we have. And that has led, together with very brilliant measurements of the details of the sky, such as the cosmic microwave background radiation and many other things, led to this flourishing of astrophysics, but at the same time, it had strengthened the link between particle physics and astrophysics in general.

Zierler:

I would like to ask--

Wagner:

So yes, I'm following with great interest the discoveries in astrophysics and cosmology. And when I was saying that some of the today's experiments are looking into exotic corners, like search for the axion, they are falling into this category of exploring something which links to the early universe and to the question we just addressed.

Zierler:

I would like to ask. We'll develop this theme as we go into our discussion, but I'm curious at this point, as you survey developments in particle physics, given your international purview and all of your collaborations and all of your fellow researchers, which is truly international and global in scope, do you tend to think in nationalist terms? In other words, do you tend to think, "What are the developments that are happening in the United States? In Switzerland? In Italy? In China? In Korea?" And so forth. Or do you not tend to think in nationalist terms and prefer to establish the linkages that connect these countries and their researchers together?

Wagner:

I think particle physics has developed because one was not thinking nationally, but internationally. And I think I grew up, when I was still in high school, reading newspaper articles about CERN. CERN as a place fascinated me, but not only because of particle physics, but also because of its international environment. So I grew up with that. And I'm a fervent believer that we can only make progress if we pool resources, if we have several goals and we try to distribute them between the countries in order to make the in-house or in-country activities stay alive and vivid, and attract young people. And that is only possible if you and your students are not only working on an experiment which physically sits on another continent. When I was director of DESY, I spent considerable thought about where the International Linear Collider could be built, and what would happen to those laboratories which would participate in its construction but not be the host. How could they keep their culture and know-how alive? Of course we tried to get the linear collider to be built at DESY, in an attempt to have a project of outstanding importance at DESY. For the same reason, Jonathan Dorfan tried to have it built at Stanford, but the project was always seen as an international and collaborative endeavor. I proposed that we would not only build the collider jointly, but also operate it jointly, really remotely. There would be no more night shift, because the responsibility would rotate around the globe with the clock and everybody could work during day, and sleep during night while others takes up the baton and run with it. So you see, the concept was from the beginning very, very international.

The linear collider was a global project from the very beginning. My predecessor as director of DESY, Björn Wiik, founded the Tesla Collaboration, which united really all the experts in the technology of superconducting accelerators from the three major areas, Asia, America, and Europe. This led to the remarkable progress, which was made over the years in this field. So to give you a very short answer, I think the field of particle physics and accelerators would not be what it is, were it not for international collaborations. Motivated by a common goal these collaborations, find balance between collaboration and competition. To progress you need also an element of competition, but I think competition doesn't contradict collaboration.

Zierler:

Right, right. Well, Albrecht, let's go all the way back to the beginning. First I'd like to ask about your parents. Tell me a little bit about them and where they're from.

Wagner:

Both of my parents are German, and my father comes from the Eastern part of Germany, a town called Dresden, which was famous as a cultural center in the eastern part of Germany, but also known for its bombardment in 1945, because so many people got killed during that time. My mother comes from Düsseldorf, which is in the west of Germany. They met in Munich and they lived the rest of their lives in Munich. I was born in Munich. My parents were both more interested in literature than science. My father was high school teacher for English, French, and German. My mother was interpreter for English and French, and my father had actually worked as a German lecturer in the early 30s at a university in Bangkok for two years, and then came back to Germany. At home we had essentially no discussion about science. My parents, sent me to a type of high school which is called in German “Humanistisches Gymnasium,” with a focus on languages, mainly Latin, Greek, and German. And so I had nine years of Latin, six years of Greek, four years of very little English. German of course. Mathematics, physics came later. I had very little physics in high school. As a result, my main education was in the general spirit of the old Greek and Latin Roman culture. My interests in physics came from the philosophical side. From the Democritus, the atom, the atomos, the undividable thing, and it started me thinking., During the last two years of high school, I started to hear a lot about CERN, which just had started, and particle physics. CERN together with accelerators in the U.S., was producing lots of new results. Those totally unexpected results, a flood of newly discovered particles got me interested in physics, especially in particle physics, without having any knowledge about the mathematics or the theory behind it. That there is something which is smaller than the atom, and which you can discover and study in an experiment and which you can analyze, got me going. So I started to think what I wanted to do, and only very briefly before my final exams decided that I wanted to go into physics.

Zierler:

Albrecht, did your parents talk about their experiences during the war? Or similar to generations in other countries, that was something that they had trouble talking about?

Wagner:

I wouldn't say they had trouble to talk about it; we had occasional discussions on it. But this was not a daily subject. And yes, at the end of the war, as my parents were not politically involved, it helped them to be fluent in English. My father was lucky, he was a prisoner of war of the Americans and as he spoke fluent English, he was immediately asked to serve as interpreter, and my mother, having had training as an interpreter, applied after the war with the Americans, who were controlling the Bavarian radio, for a job as a journalist, and she was taken because she spoke English and German. She then made a quite remarkable career in the Bavarian Broadcasting Corporation. I can remember certain things after the end of the war, but otherwise, not so much. What I do remember, and I must have been four at that time, was my first encounter of Americans. My mother was staying with me in the Bavarian mountains in order to get away from Munich, and she was taking me for a walk or going shopping, and all of a sudden, behind some bushes, there was a group of American soldiers. And one who was black, got up with a big smile, and you can imagine, a little child who has never seen (laughs) a black man, smiling with these white teeth, looking, smiling. And he waved me to come to him, and he asked me to open my hands, and poured sweets into them. I was so deeply touched. (laughs) Instant love.

Zierler:

Albrecht, it's a very complicated question, but I'm curious if you got the sense from your parents, if they needed to do any moral reckoning, just by dint of being Germans during this era, or if they felt, no, that this was a worldwide conflict, and they personally didn't do anything wrong, and there was nothing for them to atone for as a result?

Wagner:

I don't think, I cannot answer in a straight line. My father had in high school many very good friends who were Jewish, and who had to leave., At that time he was no longer in his hometown where he was at school. But he stayed in contact with them. So he knew that one of his best friends emigrated to the States and that his parents committed suicide when they were being taken away from home. So it was always a theme which was present, but I don't think there was any feeling that they should have done things differently, although they might have thought about. They never talked with me about that. I think one has to see the development of the Nazi movement over time. In the beginning, when, at the end of the first war, Germany was taken as the only culprit and the Treaty of Versailles put very strong punishments on Germany. There was a sentiment that this was overdone. If you study the history and the preparations for the First World War, you see that every major country in Europe was actually getting ready to fight, for different reasons. The Germans were seen to endanger the interests of the other countries., The French, in addition, were looking for revenge for their defeat in 1871. So the reason for the Great War was much more complicated than for the Second World War. The Second World War was clearly started by the Germans. The Nazi movement gained real strength after the Big Depression. Hitler was getting up saying, "We have been punished too much.". And then people started to be lured into that movement. But where this was heading only few people wanted to see, although it became obvious as early as in 1933, when for example all the Jewish people were thrown out from universities. Nobody objected to it, or said that this was something one should distance oneself from.

Zierler:

Given that your parents were so educated and cultured, I wonder if they ever talked to you, or you got the sense that they grappled with the incredible mystery of how Germany, which for so long was really the world center in culture and science and the arts, how it possibly could have descended into the barbarism that it did in the 1930s and 1940s?

Wagner:

Can I turn this question around?

Zierler:

Please.

Wagner:

Can you explain the last four years of the United States to me?

Zierler:

(laughs) Perhaps you--

Wagner:

I think we, I'm not joking, it's always difficult to make a parallel.

Zierler:

Yes.

Wagner:

But what I see there is someone with a very clever demagogic talent getting the worst out of people, and uniting them around some fictitious goal, etc. Now, fortunately the situation didn't generate in the United States to the point which I see in Germany, obviously.. But Germany in the 1930s was like a fresh ground, lots of manure, and you just had to put the seeds in and it will grow. And as I said, the many friends of my parents were Jewish and highly educated. My father were sharing similar interests and were getting along very well, and the political situation was never a theme, never a topic when they were younger. And then, all of a sudden, somebody comes, generates hate, jealousy, the burning of books, and encourages persecution, etc.. And I think many people were totally stunned and closed their eyes. Today, one asks oneself, "How did they not know about the deportation of Jews?" And then you read biographies of people who grew up in Germany and were able to leave I have a very good friend, who emigrated the age of eight to the United States because he came from a Jewish family. His father thought they were not in danger. It was his mother who decided they had to leave. After having arrived in the States the father, who was a highly acknowledged lawyer in Southern Germany, had to go from door to door as salesman in order to make a living, because German law is different from American law and he didn't speak the language well enough to practice law. A question or puzzle, which occupied me all my life, was to try to understand what people really knew about what was going on? Were people blind? Why didn't people speak up? Why didn't the universities at the very early time simply refuse to enact this very strange law, that they had to get rid of all the Jewish professors? There was an underlying resentment against Jewish professors at many universities, frequently because they were brilliant. I've recently been looking into some of the personalities in the Hamburg University in its early years. The university was founded only in 1919, as a reaction to the end of the First World War, and was immediately attracting the most outstanding professors. Erwin Panofsky was an art historian who is the father of Wolfgang (Pief) Panofsky, the founding father and first director of the Stanford Linear Accelerator Center (SLAC). Erwin Panofsky was the leading figure in history of art, introducing a totally new view on how to do that. I was asking once a person from this field: "What do you think of Erwin Panofsky?" And then he simply said, "What do you think of Heisenberg?" (both laugh) So it was for me putting the things in perspective.. And so all these people, like Panofsky, were in Hamburg right after the foundation of the university and were extremely productive., Then, in 1933, all of a sudden, all of them were thrown out. I think this was the victory of mediocracy over talent, because all the people who were not as clever were actually not objecting to the fact that this happened, but they did probably also not know where this would lead to.

I believe that even the Nazis in the beginning didn't know where this would go. This was like if you start an avalanche and the avalanche becomes bigger and bigger. In the end it is very lethal.But this is a very difficult, very broad and very, very complex issue, which I think goes beyond the scope of our discussion today.

Zierler:

And as you noted, this hits a little too close to home, which is perhaps why I asked it, because it's on my mind today.

Wagner:

No, no. It's not. I of course realize that, and I hope I didn't say anything which created a negative feeling for you, because I am struggling with this. Because it goes so, so much beyond what I can understand. I try to understand things which is “un default professionel”, as the French say. Sort of a problem of physicists, linked to our profession, when trying to analyze and get a rational handle on problems. That's why I made the parallel to the United States, because I was getting worried, and I said, "Okay, you cannot compare this one-to-one." But here I stand, and I ask how is it possible that in your country, nearly all of the Republicans still don't accept that the vote was legal and the ballots were checked and checked again? This goes beyond my understanding, and then I realize that I can apply the same question to Germany in the 1930s, and it goes beyond my understanding. I think the problems were then as now generated by an element of jealousy, and of deep, inside resentments. This was, of course, as you know, not the only time in history that this happened.

Zierler:

Of course.

Wagner:

Each time, the Jews were accused when something didn't go well. One always needed a scapegoat, and here, the scapegoat was obvious: In addition, at the beginning of the 20th century, Germany had a very big influx from Eastern Jews. I don't know where your family came from, but that created even a tension between the educated, Germanized Jews and the East European Jews in Germany. It was not black/white, (Zierler: Of course.) it was 50 shades of grey.

Zierler:

(laughs) Albrecht, a general question about your upbringing in Germany, you know, up until university. To what extent was the Cold War and the division of Germany a part of your reality? Was this something that was remote, or did you feel it and did you feel those divisions and the pressures from the Soviet Union?

Wagner:

Let me say much simpler. It was a daily presence. I told you my father came from Dresden, and his family had remained in Dresden, then in the part of Germany controlled by the Soviet Union. So Dresden was all the time on the map, and the wall was all the time mentally present. When I was in school, I went two times to see my grandparents. That was the only time I saw them. Later on, I saw them a few times more. But I saw my grandfather, whom I really liked, only twice. My father spent his entire life sending once a week a parcel to his mother and his sister-.His father, mother, brother and sister lived in Dresden. His brother was professor of electrotechnics, at the Technical University of Dresden. He was very apolitical, and his children were not allowed to study, because they came from an elite, and were punished for being the children not of workers but of the elite, etc.. If my uncle had been in the party, then probably his children would have been allowed to study. Anyway, the GDR was a daily presence, and of course, the Soviet Union threat was very real. Later on, when I was a student, there was this question of the stationing of the Pershing rockets, etc., which let to students riots. I was not very political in the sense, that I would go and demonstrate. But I followed what was happening. Concerning my feelings about the Soviet Union and Eastern Germany I remember very well my fear, when I was a kid. When crossing the border into East Germany to visit my relatives, there were deep looks by my parents which meant, "Shut up from now on." And nobody spoke and there was this eerie feeling when the train stopped at the border with barbed wire left and right. There were people controlling, coming through the train. This was a very awkward feeling. I don't want to repeat that anymore.

Zierler:

And Albrecht, to be clear, your budding interest in CERN as an international collaboration, as you called it, to be clear, we have to understand that within the context of the Cold War. It might have been a European collaboration, but it was decidedly a Western European collaboration for which the East bloc had no access.

Wagner:

That's not quite true, and let me give you one example.. The GDR had established after the war an Academy of Sciences, following the example of the Soviet Union. One of its institutes is located at Zeuthen near Berlin, doing particle physics. Originally, the scientists of the institute worked at Dubna, the Soviet Union’s equivalent of CERN, an international research center in Nuclear Physics north of Moscow. Through Dubna, they were also able and allowed to work at CERN. Dubna was not a member, but a user of CERN. So certainly in the beginning, CERN was founded in order to get the broken pieces of the war together and to work together., —The founding nations of CERN included Germany from the beginning in order to work together as a way of looking forward.

Zierler:

Albrecht, in the late 1980s, I’m curious generally if the fall of the Berlin Wall and subsequent unification of Germany came as a surprise to you, and what, specifically, both in the short term and the long term, did you see as the impact of unification on DESY? And by 1991, did you see German unification as the first stage toward greater collaboration with scientists throughout the East Bloc and the former Soviet Union?

Wagner:

The fall of the wall came definitely as a total surprise to and due to my family relation to Dresden I was very happy. But the German unification was for us at DESY, and also for CERN and other research centers, not the beginning but the continuation of a long history of collaboration. Let me illustrate this by explaining which changes happened at DESY in the aftermath of the falling wall. The institute I just mentioned, located at Zeuthen near Berlin, was doing particle physics. Originally, the scientists of the institute worked at Dubna and CERN. At the same time, they were searching, together with Russian collaborators, for high energy neutrinos coming from the universe. They did this by installing phototubes in the deep waters of Lake Baikal. But, when HERA started, a group from Zeuthen got the permission to work at DESY. Such a permission was very unusual at that time. So a strong link formed between Zeuthen and Hamburg. After the unification, the Academy of Sciences in the former GDR was evaluated and Zeuthen got a very good rating, the basis for its future. It was recommended that Zeuthen should become part of DESY which happened in 1992, shortly after I joined DESY. As there were already strong links, both labs profited from this fusion. Today, Zeuthen’s main activity is in the field of astroparticle physics, with the roots for this in Lake Baikal. The collaboration across the iron curtain was, however, not restricted to the GDR and Zeuthen. Russian and Chinese scientists and engineers participated through hardware and manpower in the construction of HERA and in all four experiments. This close collaboration with a large number of institutes in the Soviet Union, and on a smaller scale with China, had therefore a long and fruitful tradition at DESY before the wall came down and is still very strong.

Zierler:

Albrecht, as you developed your interests in science as a child, was it mostly from your own sort of innate desire to understand the natural world, or it was more that sparked from your imagination as a result of your education?

Wagner:

(laughs) That's a difficult question. You cannot separate these two. I think that your education fuels your imagination and so both came together. I remember that when I was in high school, we were asked to produce a paper on a topic of our interest, and so I actually chose rockets and space exploration as a topic, and so I went to the library of the famous Deutsches Museum, in Munich. It was founded as the first big technical museum, and was always a great attraction for me because I wanted to understand things, and there you could look at it and then get explanations, etc. And so I sat in this library to look at many books, and then prepare the paper on that. That was also not at all in the spirit of what my high school had taught me, but it was my own interest. The other thing which helped fuel my scientific interest was that every year at Christmas, I got a book call “Kosmos”. I don't know if they exist today, but for me, this was the biggest present. It had articles not only cosmology, but all aspects of science and technology. I remember that in one of these books there was a little sample of a seamless, stainless steel tube, which you get by extrusion. I was sitting there looking at and asking myself, "How do they do that? (laughs)" Not knowing about extrusion etc. So events like these sparked my interest. I was just simply curious, and in class I like biology or physics, I got learned a lot simply by listening. I picked up some subject and follow them up. But as most of my classmates were more from the language side, I was frequently asked to help them (laughs).

Zierler:

Albrecht, between your academic performance in high school and perhaps your family's financial capacity, what opportunities were available to you as you started to consider university?

Wagner:

You know that in Germany, it's really not a question of being capable to pay for your university, which is free of charge, provided you get some kind of support from your parents to cover your living costs. So this was never an issue. When I told my parents that I wanted to go into physics, my father asked me if I didn't want to do law. And law at this time didn't interest me at all. This had two aspects. One, it was as a subject which I didn't find it interesting, and secondly, I think I had always wanted to go abroad and work in an international context. And it was clear that law was regional. If you're a lawyer in Germany, you can't easily immigrate to the United States or to anywhere else. At times, I was considering also to become medical doctor, is a subject which still interests me today, as well as engineering. My father had a colleague who was an engineer and who came and started talking to me and told me about what he was doing. I went back to my room and looked things up, started designing machine, etc. But with time it became clearer and clearer that the questions of particle physics, trying to understand the innermost structure of the world, was for me something way more interesting than the other things.

Zierler:

Now, in the German system, is it more similar to the British style, where you declare a focus and a major right away as a freshman? Or is it more similar to the American style, where there's a general education, and you specialize later on?

Wagner:

No, because final exams of high school in Germany qualify you for the entry into university. My understanding of the American system is, that in the first years of college you catch up on those things which were not on your high school curriculum. Now, the German system assumes that all you need when you enter university is what you learn in high school. And I never complained about what I didn't learn in high school, because I could learn it later on. However, we had to take a class fortwo hours per week for two semesters, in a subject which was not directly related to our basic curriculum. I chose philosophy at that time, because of the link I mentioned already. That was an introduction to Wittgenstein, which is also probably more mathematic than anything else. At that time at least, we didn't get grades every term. We only had one set of exams after two years, called pre-diploma (“Vordiplom). Then you went to the higher courses and specialized more. The final exam was called “Diplom”. I started my studies at the Technical University in Munich, which included in addition to the curriculum of physics, also electro-techniques, electrodynamics, and a basic introduction into mechanical engineering, which taught me how to design things very professionally, and which turned out to be quite useful later on when you had to make drawings for your workshop.

Zierler:

Albrecht, either by the classes that you took or the talents that you felt you had, at what point did you reach a fork in the road in your education in terms of a decision on focusing either on the theoretical side of physics or the experimental side of physics?

Wagner:

There was never really a fork. After having passed my pre-diploma, I stayed one more year at the Technical University in Munich, and then moved on to Göttingen. Essentially because I had a good friend there, and he told me about the glories of Göttingen in the 30s when it was the mecca of quantum physics. So I went there. I was rather disappointed except for one professor, who taught theoretical physics. And I really profited enormously of his introduction into electrodynamics and quantum mechanics. It was really the basis on which all my understanding of that part of physics was based. He was famous, because he was one of the inventors of the so-called CPT theorem. His name is Gerhard Lüers. I very much enjoyed his lectures, but never to the point that I considered to become a theoretical physicist. This was not my thing. I liked hands on things. Talking about hands-on reminds me of a present when I was in high school. I also box with experiments in chemistry. This was a total success. I built rockets and all sorts of things and did chemical experiments. So chemistry was very hands-on, which interested me, and I was curious to see what happens when you mix ingredients, and to understand, how machines function. But I never built a radio, I must say. The environment was probably not made for that. There was no workshop (laughs) in the house, etc. While I was in Göttingen, a possibility came up of passing some time as a summer student, either at CERN or at DESY in Hamburg. And not being too far from DESY, I asked this professor, if he could write me a letter of recommendation for DESY, because I wanted to be a summer student there. And he said, "Well, yeah, yeah, there's absolutely no problem, but I really discourage you to do that. Why don't you sit down and read this book on theoretical physics?" (laughs) And stupidly enough, I said, "Okay, I'll do that." I didn't insist on getting a letter of recommendation to go to DESY.

Zierler:

Albrecht, on the social side of things, in the late 1960s, there were student protests on campus all over Europe as well as the United States. I'm curious if this was a direct experience on your campus, and if you were politically inclined in those years at all?

Wagner:

A good question. I told you before, I'm not the type of a demonstrations person. But as luck had it, I started doing my PhD thesis in 1967, and I was sent to CERN. So I spent all the time of student unrests in CERN. So this whole period passed by, except for what I read it in newspapers. I was sitting in this international center, and Geneva, being in Switzerland, was a quiet town. They had no demonstrations in downtown Geneva, which was far away from CERN and it was not practical to go there. And I had work to do 24 hours a day. There was just no time for thought about what was going on, except for the occasional news from my colleagues in Heidelberg where I was enrolled as PhD student. so this whole student unrest essentially passed by me.

Zierler:

I'm curious for you, how did you go about selecting a graduate advisor, or alternatively, how did your graduate advisor select you?

Wagner:

Oh, this is a good question. When I was in Göttingen, I met a friend of mine who was a few years older, also a physicist, in Munich. I was visiting my parents who still lived in Munich. I met my fried at the opera, we started talking and he asked, "What are you planning to do?" And I said, "I'm looking for a place to do particle physics, and Göttingen is definitely not the place I want to stay”. And he said, "There are two places I can recommend. One is Heidelberg and one is Bonn." So I said, "I'll start with Heidelberg." And he said there are two young professors who just had been appointed there, and they do interesting experiments at CERN. So I went there. Now, as they were working at CERN they were not there at the time. and so (laughs) I did not meet them. As I walked through the corridors of the institute, I met another young man, who turned out to be an assistant professor, who said, "What are you doing here?" I said, "I'm looking for a diploma thesis." And he said, "Oh, well what is your interest?" And I told him, particle physics. He said, "I have a topic which might suit you." He didn't talk about his colleagues who were active in the field. There was a second assistant professor with whom he worked together. He joined us and we discussed the project which sounded quite interesting, and I said to myself, "I am lucky. I come here, I'm hardly one hour in the institute, and I already have a diploma thesis”. So I accepted. The project was in fact nearly a mission impossible. I was a totally ignorant diploma student and working by myself. The goal of the project was actually interesting, to build a source for polarized protons, with their spin all pointing in one direction. Coming out of the source would be accelerated to do experiments with them. The underlying technique which was suggested by W. Lamb, who is known for the Lamb Shift, which is a test of the quantum electrodynamics. Lamb had said, you in hydrogen you could create hydrogen atoms in an excited state which is called metal-stable. You de-excite all those atoms, in which the electrons are not in one particular spin state. Then you ionize only those atoms with an excited electron, where also the spin of the proton is pointing in the same direction. And then you get a beam of only polarized protons. This is a very good, clever idea. Like always, the problems are in the details, making enough meta-stable hydrogen atoms, and keeping them in that state while you ionize them, etc, etc. I worked for three hard years on that, and in the end I said, "I have failed" That was okay for a diploma thesis. Later on, people succeeded to do this experiment, but this was a team of ten people. Once I had finished my diploma thesis, I went directly to the person who I came to work with originally. He and his colleague worked closely together and had an arrangement that one of them was in the Institute doing all the lectures for two, and the other one was at CERN conducting the research, and after one year, they would switch. They were Joachim Heinzte and Volker Soergel. Volker Soergel was later on one of my predecessors as director of DESY. Both together were doing very exciting experiments at CERN, and so I finally joined this group. When I came to Heintze asking, "Do you have a diploma thesis?" he told me the topic and I found this very interesting. I had also two other options at that time, both were, and that touches on the question of my desire to work in an international environment, were in Germany. One in Karlsruhe and one in Heidelberg. And I decided in favor of the CERN project, not only because of the topic, but also because of being able to work abroad.. So that's where my international career started.

Zierler:

Albrecht, I'd like to ask on a more general level, during your time in graduate school, there's so much fundamental discovery that's happening more broadly in particle physics. And I wonder, either from your own sensibilities or instincts or perhaps some of the advice you got, to what extent were career considerations a part of the decision-making in terms of the kind of research to pursue? In other words, did you ever think, "Maybe I should or should not be a part of a particular collaboration because it either will or will not be relevant five, six years down the road as I start to think about an academic career." Was that part of your reality at all, or were you exclusively focused on the science in front of you?

Wagner:

The second is the absolute clear answer. I was actually not at all thinking about an academic career. I was actually rather skeptical about seeing myself in an academic career. I had enormous fun, and probably a certain ability in what I was doing. And so I pursued that, Actually, at one point in time, I asked my senior colleagues, Heintze and Soergel, "I think it is time for me to take a decision of what to do." And the simple answer was, "Just continue to do what you are doing." Which for me was enough to continue. But they'd also pointed out things I could do in order to advance my career. I never really had a career minded sense. Simply, I loved what I was doing, and I did it.

Zierler:

More generally, what was the research culture like at CERN? Was there a spirit of intellectual cooperation? Would there be seminars that you would be able to go to? Would you be able to interact more generally with people outside your immediate research group?

Wagner:

Yes, because first of all, there were summer student lectures, which not only the students attended, which were very good. In addition, there were weekly seminars. Sometimes too many because one had work to do. The culture of going to colloquia to broaden one’s horizon was very developed in Heidelberg already. Everybody shows up for the weekly colloquium, which is a specially developed tradition in Heidelberg well-attended and usually excellent. Later, when I returned to Heidelberg as professor, one had a way to convince the graduate students to attend those colloquia, by asking them, during their diploma exam, pretty regularly a question linked to the topic in one of the most recent seminars. At CERN most colloquia were focused on topics close particle physics. Your second question about meeting and interacting with other people: I met other people not so much to talk about physics, but to do other things like to go skiing.

Zierler:

(laughs) I'm curious, who were some of the people that you met, either peers or mentors at CERN, who would remain lifelong friends or be important to all of your future research endeavors and collaborations?

Wagner:

The members of my CERN were mainly mainly from Heidelberg, including my mentors, the two professors I mentioned. In addition, and we had CERN fellows joining us.. CERN has a scheme of fellows which join the experiment of their liking. With some of them I kept contact with, or our paths crossed later on. Because being a rather small group, we had all sorts of things to solve, to fix, to make work, etc., that we hardly had any time to do anything much beyond that. So we had our weekly group meetings, everybody had his or her job assigned, etc. But as I said, some of the group members I kept contact with all my life.

Zierler:

I'm curious, as international as CERN is, given how closely-focused your research was, I wonder if your worldview in particle physics was still rather parochial at this point? In other words, in the United States, for example, were you generally aware of what was going on at places like SLAC or Brookhaven?

Wagner:

Oh yes, because these were the topics of the seminars and that was an essential input. I mean, you might be parochial for your own work, but of course that work is imbedded in the development of the field. And of course, we went regularly to these seminars, because then we got an idea about what was going on. I remember lectures by Feynman, an Italian physicist Zichichi, Gell-Mann and others. Everybody with interesting ideas and results of course came to CERN. Every of these lectures was fascinating. Not that I understood everything, but it was certainly, you went away and you had the feeling you had gained some insight in some deep thoughts. It was totally clear that this was an international field. The colleagues in my experiment, who were not from Heidelberg, they were mostly non-Germans. As we were sharing an office, people dropped by and had scientific discussions with my colleagues or with my mentors. This spirit was simply everywhere, this international atmosphere.

Zierler:

Of course, this is--

Wagner:

But the groups were much smaller at that time. We were, I think, ten people in this experiment, few for a fairly big task, in terms of the number of detectors to be made work and the analysis. All that was really stretching one's resources to the end.

Zierler:

Of course, this is a question that every graduate student grapples with. At what point for you did you feel like you had conducted a sufficient amount of research that you were ready to defend a thesis presentation?

Wagner:

It was very easy. My thesis experiment was on a rare decay of the lambda hyperon. And I had to measure certain parameters. We built parts of the detector, took the data and I was then responsible of the whole analysis of the data, and of course the final result. There was a second, and later on a third, PhD student, and each one had a certain topic. This was not a one single question experiment, but a at least a three-question experiment, and so each of us did part of the general work and then part on his special thesis topic. This worked extremely well. So it was very clear that once I had my analysis done, including the error analysis, the comparison with theoretical predictions and the interpretation of the result, the work was finished. The only thing is, which every graduate grapples with, is to sit down and start writing (both laugh) what you have been doing.

Zierler:

Albrecht, more generally, in the history of physics, this is a time of incredibly important interplay between theory and experiment, where there was a mutually beneficial relationship. So on that point with regard to your research, what were some of the advances both in theory and in technology and experimentation that were vital for the conclusions that you drew in your thesis?

Wagner:

Difficult question. There was a famous paper by Feynman and Gell-Mann on weak interactions, on the vector and axial vector structure of the weak interactions. The paper made very precise predictions. This work was a cornerstone for analysis, although it was not totally new. It triggered, to some extent, this whole set of experiments on rare decays of hyperons, which started with measuring the decay of psi hyperons and then of lambda hyperons. There was this very clear theoretical framework. To do this experiment, one needed no totally new technology. The new technologies and then my own involvement in developing detectors came later. It started when I was working as postdoc on another CERN experiment. It was the first time we used drift chambers as a new tool, which still had just been invented. I remember a talk by Georges Charpak presenting his proportional chambers to a packed CERN auditorium. That was really a milestone. The drift chamber was pushing the idea further. By measuring the drift time one can reduce the number of wires per centimeter and the number of electronic channels. This idea was developed by Heintze at Heidelberg together with a PhD student. Later on, this drift chamber approach was applied to cylindrical detectors. And there I started to get really heavily involved.

Zierler:

So to flip that question around, during your thesis research, were there any theoretical or experimental limitations up to that point that prevented your research from progressing father than it otherwise might have?

Wagner:

No, I don't think so. We had a goal in terms of how many of these decays we wanted to see. And this was substantially more than anybody else had so far seen. But we had a limited amount of beam time, so we had to be very efficient and succeeded to collect over 100 lambda beta decays as they are called. This was absolutely sufficient for the statistical accuracy we needed, because there are always also theoretical and systematic. So there was no real limitation there. Also in the whole analysis, nothing came up which, where I had the impression that something was limiting me. Of course, ten times more statistics would have made the error even smaller, but that was out of the research with the amount of beam time we were allocated.

Zierler:

Perhaps this is a grandiose question for a graduate student, but looking back, what new questions were able to be raised as a result of your findings?

Wagner:

That's not a grandiose question, it's a very classical question. And the answer I have given you in my (laughs) introductory statement about the state of affairs in particle physics. Our results confirmed the theoretical predictions. They did not, however, open windows to something new or detect a crack in the wall, and therefore didn't open up totally new questions. At least not to a graduate student like me.

Zierler:

What opportunities or interests were most compelling to you for postdoctoral research after you defended?

Wagner:

First, it happened to be another experiment in which Heidelberg was involved, measuring a rare decay of K mesons. This interested me because it fitted very well with the spectrum of research we had done. During that time, I started to explore if I could go as postdoc to the United States. So I tell you briefly how that worked for me. When I had finished my thesis, there was a conference on weak interaction at Brookhaven National Lab. I was sent there by my collaboration to present the results on our studies of the decays of the lambda hyperon., This was the first international conference I attended. There were some people I had heard about, like Jim Cronin sitting in the first row and listening and nodding quite a lot of times where I was explaining something, which for a young, freshly-PhD carrying student, was a kind of very nice thing. I had booked an open return flight. So, when during discussions over the coffee breaks, several people talked to me and ask me to present my results at their universities, I could accept and so I went to Amherst, Chicago, Fermilab and to Berkeley. And later on, I got offers from several places to come there as postdoc. But as I had fallen in love with Berkeley, I went there. That was independent of what exactly the research question was. At that time, Berkeley was doing something new, which was not really in the line of what I had worked on, but which because it was new, I thought I should do something fresh. And so I joined the first experiments after the Bevatron was converted to the Bevalac. It was accelerating actually heavy ions, from deuterons and up to carbon at that time. The person who led the experiment, Herbert Steiner, became one of my close friends and mentors. He had suggested I work with him because they wanted to measure total cross-sections of the proton-carbon, neutron-carbon, carbon-carbon particle production with these heavy ions, etc. It was something nobody had done so far, so I said yes. And while I was doing these first heavy ion experiments, it became very clear that e+/e- physics had an enormous potential. Not only because the SPEAR storage ring and the Mark 1detector at SLAC had just being finished, but also because experiments in Cambridge, Mass. and at Frascati in Italy had shown anomalies in the behavior of the total cross-section of hadron production between 2 and 3 GeV in e+/e- colliders. And I liked e+/e- colliders from the beginning because of their very clean configuration: If you collide a particle and an anti-particle, nothing remains but energy and everything can happen out of this energy, and so you have a very well-defined initial state, and then you can do what you want. So after one year, I talked to Herb Steiner, and said, "I'd like to join the Berkeley part of the Mark 1 experiment, under Gerson Goldhaber and George Trilling. So I went to them, and worked for one year with them. And now we come to the big deception in my professional life: During my stay in the United States. I was on leave of absence from Heidelberg. This had certain advantages because it kept my links to the institute in Heidelberg and my position in Germany intact, so I didn't have to worry about going back. I was hesitating of staying in the United States, but the forces pulling me back became stronger and stronger. Heintze and Soergel both asked me —to join their team, Heintze had shifted his interest from CERN to DESY in order to do the first e+/e- experiments on the DORIS storage ring, and Soergel continued experiments at CERN. I had to choose between one of these projects, and the physics at e+/e- colliders was the thing which really interested me, and it stayed that way for the rest of my life. And so I returned to Germany end of October 1974. You might guess by now the deception which was waiting for me.

Zierler:

That's right. (both laugh)

Wagner:

I was actually leaving Berkeley at the end of September to cross the United States by car before departing from New York. I had a close colleague working with the Goldhaber group whom I called twice during a the time I was travelling. By the time I arrived at CERN, every colleague I met in the corridor jumped at me and said, "What is this new result from SLAC?" I said, "What new result?" I had called Berkeley on the 30th of October, and my friend said:, "We are just heading into the high energy run." This was planned, this was the schedule. And nobody told me anything about a possible J/psi discovery. The only thing I knew was that one of members of the Berkeley group, (John Kadyk)), had found a strange deviation of data taken earlier that year. In the summer of 1974, the operators at SPEAR storage ring had gone on strike, and Burt Richter and Roy Schwitters took over the machine. They had the ambition to produce more luminosity, so they turned the knobs, —and explored new operation parameters. Actually, they did quite well. What they hadn't realized is they didn't run the machine at exactly the same energy they were intending to, operated at an energy closer to the mass of the still unknown J/psi. It’s production cross section, the J/psi being a resonance, is falling off rather rapidly. They were actually sitting somewhat closer to the J/psi than before, and therefore the cross-section was substantially higher than the old one. John Kadak said, "This is very strange. How can it be that we measure twice at the same energy and there such a difference?" So, rather than going to higher energies, they decided to have a scan in that area in order to understand this discrepancy. And this was the scan which led to the discovery of the J/psi.

Zierler:

Albrecht, when you say Berkeley, just for the record of course, you mean Lawrence Berkeley Laboratory.

Wagner:

Lawrence Berkeley Lab, yes.

Zierler:

I'd like to ask, though, to what extent, if at all, did you have interactions with the physics department at UC Berkeley?

Wagner:

Well, there is a big overlap between the Lawrence Berkeley Lab staff and the physics faculty of UCB. All of the leading persons were members of the faculty. So you couldn't really distinguish. The same is true for SLAC and Stanford University, or DESY and Hamburg university.

Zierler:

How much interaction did you have with SLAC physically? Would you be there presently frequently? Or was that not a frequent occurrence?

Wagner:

During my second year in Berkeley commuting was a rather routine thing. Sometimes a little bit dangerous, especially if you drove back after a night shift and you risked to fall asleep in the car. But yes, drove back and forth. We had to built a new piece of equipment, which was supposed to be very important in the higher energies., These were new tracking detectors in the so-called endcaps of the detector, which turned out to be very useful later on. We built them at Berkeley, installed and we tested them, and at that time I left. Apparently, they worked very well (laughs) I had no part in that.

Zierler:

To get back to the discussion about the spirit of collaboration versus competition, how did that play out from your perspective, being at Berkeley Laboratory, but doing so much work at SLAC?

Wagner:

I think I sensed considerably more competitive spirit at SLAC than at Berkeley, and definitely a more competitive than anywhere in Europe.

Zierler:

And in terms of broadening that same question out internationally, was your sense that SLAC was looking to become a world leader, and that CERN would positively take that in the spirit of competition for there to be better and grander research there as a result?

Wagner:

I never saw it with these eyes. Clear was, as I said before, there was collaboration and competition and they go together. Everybody tried to do the best possible experiments they could do with what they had. Meaning in terms of accelerators. CERN couldn't at that time do e+/e- physics, and SLAC couldn't do hadrons. The more direct competition was actually between SLAC and DESY because DESY entered the game, and both labs were very similar in their whole research programs, and still are actually, as a matter of fact. CERN and DESY always tried to not do the same things, but complement each other. The orthogonality changed then later on, when CERN built the e+/e- collider LEP, while DESY was looking for the next project. Because of DESY’s experience with DORIS the next generation e+/e- collider would have been the logical choice, but CERN decided to build it, because it was considered THE most powerful discover tool at that time. DESY therefore proposed to build an electron-proton collider, which turned out to be also very interesting and very good. But that's the way, how it works. The guiding principle is always to do the best possible physics, to build the accelerator which leads us furthest into uncharted territory, and one is trying not to repeat what is happening elsewhere.

Zierler:

There are so many life considerations for a young scientist at these career junctures, I'm curious on the personal side of things if you ever thought of making a career for yourself in the United States, and if so, given how compelling e+/e- was to you, if there were opportunities in the United States to stay on that track? Or e+/e- was so compelling and returning to Europe was so obvious that it made that decision rather easy for you?

Wagner:

I think this is a complex question. The answer has to do both with the science opportunities and with where you feel at home. I loved my time at Berkeley, and when I had talked to Herbert Steiner about going back, because I felt being heavily pulled back, he said, "Would you like to stay on?" And I gave this a thought and I said, "No, I think I better go back." I can't tell you really why, I didn't produce a list of (laughs) pro and cons, etc. This was more of an overall gut feeling. I felt that this was really a very important period in my life, but I had come the United States on a limited amount of time, and I had said back home that I would be coming back. Therefore, I decided to go back and do something new and see what happens later on. I really loved being in Berkeley, in the Bay area. And so it was not an easy decision, but also not a very difficult one.

Zierler:

And just in terms of the scientific opportunities, if, let's say, you did want to stay in the United States. Was there e+/e- physics that was available that would have been interesting and compelling for you to stay put?

Wagner:

Yes, SLAC. There was only SLAC.

Zierler:

There was only SLAC.

Wagner:

There's only SLAC.

Zierler:

Did you enter into serious consideration? Was there anyone there that tried to recruit you to stay?

Wagner:

No, nobody tried to recruit me, but I didn't put my antennae out either.

Zierler:

What was your first stop back in Europe? Where did you go next?

Wagner:

Just because I had left from Geneva, I went back to Geneva, but only for two weeks, and then I went to Hamburg.

Zierler:

And what was the position at Hamburg? What was your title?

Wagner:

I was still, postdoctoral researcher?. During the first five years in Hamburg I was a member of the Heidelberg team working in Hamburg. The formal job title in Germany is Assistant (something, what is like an assistant professor without teaching requirements), When the end of my contract approached, my mentors recommended I should apply for a Heisenberg fellowship. Heisenberg fellowships were new, introduced at that time by the Alexander von Humboldt Foundation. This foundation is well known in the scientific world because it is prestigious and supports brilliant scientists from all around the world to come to Germany. As at that time essentially all the chairs in physics in Germany were occupied by relatively young people, and nobody wanted to cause a generation gap in hiring new professors, the foundation, which is financed by the Federal Government, introduced this fellowship for high potential professorial candidates. The fellowship corresponded to an associate professor position for five years, without tenure. I applied and became for five years a Heisenberg fellow. After these five years I was still in Hamburg, but in that time, I started to work not only in Hamburg but was heavily involved in the proposal for an experiment at the next e+/e- collider, LEP at CERN. During my five years as Heisenberg fellow, I started to apply for professor positions. In Germany we don’t have the same kind of career ladder which you have in the United States, where you move from Assistant to Associate and to full Professor. In Germany one is expected to change university with each step up in the career in order to avoid the older generation professors to appoint their pupils. It's like changing blood, to avoid “Inzucht”. What is the English word for this?

Zierler:

Inbred, maybe?

Wagner:

Inbred, yeah. Inbred. So I was applying for several positions, and finally I was appointed full professor at Heidelberg.

Zierler:

In Hamburg, was this strictly a research position, or did you have opportunity to teach and take on graduate students yourself?

Wagner:

I supervised graduate students from Heidelberg, but not from Hamburg. My link was really to Heidelberg. The Humboldt fellowship allowed me to choose a university and I chose Heidelberg, just because we had so much done together and wanted to do so much together that this was the natural place. I kept going to Heidelberg, and therefore also the students came from Heidelberg.

Zierler:

And in terms of the gut feeling you had to return to Europe, as far as the science was concerned. Did you feel this was the right move? Was this the right place for you to continue your research?

Wagner:

I think it was. This was really the most interesting time in my life. The first experiment in Hamburg was on DORIS, the first e+/e- at DESY. We were all totally excited by the results which came out of the SLAC e+/e- collider SPEAR and their Mark I detector. DORIS was clearly lagging behind SPEAR, but we did some original experiments. The big harvest, however, came from this quite unique detector, Mark 1, and the many people working there. At DORIS, three experiments competed for two interaction zones. One was a big experiment called DASP, one was Pluto, and the third one was simply called the DESY Heidelberg Experiment. I was on the third one, which was rather small compared to the other ones. We were only ten people. And this was really a lot of work: Using a totally new detector technology on a new accelerator, which doesn't work yet as intended, and doing totally new physics. It was the first use of cylindrical drifts chambers at a collider, surrounded lead glass and sodium iodide crystals detectors. So that was hard work. I went to DESY in the fall of 1974, and then we quickly also observed the J/psi, we did the best mass determination of the newly-discovered tau lepton, and we did a number of other interesting measurements. DESY became much more international as it started to build its next and more powerful e+/e- collider, PETRA. DESY changed from a laboratory for users who mainly came from German universities to a place for international collaborations. With PETRA began also an element of competition. Until then, SLAC always was ahead of DESY.DESY was under a new director, Herwig Schopper, who later became director of CERN, and a new head of the accelerator divison, Gustav-Adolph Voss, who had built one of the first e+/e- colliders, CEA at Harvard. They had the vision to build the next high e+/e- collider, PETRA. Again, DESY compete with SLAC which built a similar collider, PEP, but this time DESY was first. That was a fantastic time. At PETRA the gluon was discovered and many other important measurements made. My group had formed with others a collaboration called JADE, which stands for Japan, Deutschland, England. The Japanese team was led by Masatoshi Koshiba, who was awarded the Nobel Prize for his proton decay and neutrino experiment Kamiokande. His Japanese group had very good young people. From Germany Heidelberg, DESY and the University of Hamburg participated. The English groups came mainly from Northern England: Manchester and Lancaster. This was a very good collaboration with a very distinct spirit. The JADE collaboration (and the other PETRA experiments) did very interesting physics, by participating in the discovery of the gluon, testing quantum electrodynamics at very high energies, deriving a mass range for the Z-Boson from the angular distribution of the production of mu pairs from e+/e-. Unfortunately, the search for the top quark failed as the PETRA wasn't energetic enough.

The spirit of JADE continued when, later on, we started the next experiment, namely the OPAL experiment at LEP at CERN. The JADE team was among the founders of OPAL, attracting people from CERN, Canada, France, and the United States. We could speak a lot about collaboration building, —it is based on shared scientific interest, but is also on human interaction and chemistry. Same mindset. I spoke before about this sense of competitiveness versus collaboration, and it's a difficult equilibrium you have to find. Of course, one wants to be the first to see something, but this should not influence the willingness to collaborate, and also the openness to talk about everything you do with other people.

Zierler:

Albrecht, as you reflect on these years, and as you say, they were among your best in terms of the research, there could be so many reasons for that, and so I'd like to ask you why. Was it because the experiments were so elegant? Was it because the research was so fundamental? Was it because the collaborations and the human connections were so personally meaningful to you? What was it that makes this such a highlight in your career?

Wagner:

I think you said it in the perfect way. It's a mix of these things. You can have the most fantastic detector. but if the team is not what you want or what you like, it is not satisfying, it's very difficult to define what exactly it is.

Zierler:

Yeah.

Wagner:

You notice this with friends. You have certain people you are friends with, and certain people you are acquainted with, and it's sometimes hard to tell why you link with one person and not so much with somebody else. It's a mixture of this and I think the success also, of a collaboration, depends on this chemistry from this interaction between the individuals.

Zierler:

Albrecht, how successful were the experiments by the measure of the original research questions that sparked the creation of the experiment in the first place?

Wagner:

I think they were fully successful. Both in terms of the luminosity which was provided by the machine. There was always pushing and pulling to get the luminosity up, because luminosity means the number of events, which determine the statistical accuracy with which you can make your measurements. It is worth looking at the proposal of the JADE experiment. The proposal outlined what the experiment intended to measure. But a possible discovery of the gluon was not mentioned, it was not on the agenda. But then it very quickly became clear that PETRA would be an ideal tool. And therefore, very quickly, I mean within the first half year, the gluon first was sighted and then, at the Lepton-Phton symosium in 1979 at Fermilab, all experiments were presenting results. And these results agreed.

Zierler:

So we have the chronology and your titles correct, in 1991, when you moved to the University of Hamburg, is the director of research position at DESY, is this a joint appointment? Did you come to Hamburg on the basis that you'll also be director of research at DESY?

Wagner:

I remember this because the first question arose in 1989. When was selected as scientific associate at CERN for one yearned on leave of absence from Heidelberg at that time. And I got a phone call by the director of DESY, who said, had I seen an advertisement about a professorship in Hamburg? I said, "No, I'm not reading advertisements." And he said, this comes together with the position of research director of DESY, and if I would be interested in that position. I said, in principle, no. I'm very happy in Heidelberg, and have spent eight to ten years of my time preparing for this experiment at LEP which just takes first data, and I want to harvest that the results. I was physics coordinator of the experiment. But then he knew how to pull, to ask the right question. He asked "Don't you think it's time for you to take over some of the responsibility other people have taken over to pave your way and make your research possible?" What do you answer to such a question?

Zierler:

(laughs) Albrecht, I must ask, you know, director of research. If there would be an equivalent position at a place like Brookhaven or SLAC, this of course would be a full-time position. It would be unthinkable to have a joint appointment as a full-time professor. So can you give a sense, both of your responsibilities and expectations in terms of how much of your bandwidth you would have to give, in the university environment, versus the DESY environment?

Wagner:

That's easy to answer. First of all, I believe that both SLAC and Brookhaven and Fermilab have research directors, who also are involved in universities, so they're in the same situation.

Zierler:

Yeah.

Wagner:

But it was clear from the beginning in this position I would have reduced teaching duties, only two hours per week. I did this by supervising my PhD students which was counted as teaching. At DESY there existed the general rule that DEY physicists should not work on experiments at other laboratories. But I asked for an exception, because I had spent so much time and effort into preparing the OPAL experiment and wanted now to exploit my investment and have my students and postdocs. I asked for f postdocs and students. And my wishes were granted, I could no longer say no. I started in Hamburg building up my group to work at CERN, and two of my postdocs were stationed at CERN, and two at DESY. Quickly, I had a group of 8-10 students, masters students and PhD students, who were supervised mainly by my postdocs. But we had a weekly meeting which continued for all the time I was the director of research. In these meetings we discussed one by one the results of the week, obstacles, physics issues etc. Everybody reported and we discussed the problems and possible solutions, etc. Interestingly, I learned there that even if two PhD students shared the same office, they realized what the other ones had done only by sitting in this meeting.

Zierler:

Yeah. (laughs)

Wagner:

This was rather amusing to me, and it taught me that regular meetings have their use, even if you go to coffee with your colleagues. These meetings were very effective for all of us and I did my duty as university professor at the same time as being a research director. Being research director meant doing many different things and having many meetings. This was at the time when HERA started. In 1992, HERA observed its first collisions and the experiments started to take data. I had weekly meetings with the collaborations. There were new collaborations starting from fresh that needed to be taken by the hand, because they had not too much experience in working on colliders, etc. I had to deal with staff, infrastructure and funding issues. There were discussions with the accelerator. There was discussion about budget allocations between divisions during the weekly directorate meeting. These are always chaired by the chair of the board of directors, and I had to attend and argue and defend the research budget. And, above all, there regular in-depth discussions about the future of the research at DESY and the most powerful future facilities. So being research director is a full-time job.

Zierler:

Albrecht, of course at this point, you're a long way from your naïveté as a postdoctoral presenter at Brookhaven. I'm wondering, as you grew in seniority, if your acceptance as a joint position between being a university professor and a director of research, I wonder in some way if you sensed that the university professor appointment would provide you with a safety valve to remain close to the science, even as your administrative responsibilities would increase and increase?

Wagner:

I wouldn't even call it a safety valve. This was the the “conditio sine qua non”, the condition without which I would not have accepted. I believe that a successful science administrator has to be fully committed to science. I had to abandon my group when I became chair of the board of directors, because that was no longer possible. There were too many other things. The political discussions, both in Germany and abroad, had to be done by me, and could not be delegated to somebody. But it was a natural step after being research director.

I forgot to mention one thing. At the time when I was contemplating accept the DESY position, the head of the scientific advisory committee of DESY, who was from CERN, had a long talk with me trying to convince me to accept. And he said, "What we're really discussing at DESY as future project is an e+/e- linear collider." That was so much along the line of my own work and interest that I said, "There I can really make a difference. I can participate in making this project advance, by helping with the science part”. This was definitely a decisive element in my decision to accept the Hamburg position.

Zierler:

In the United States, of course, so much of what happens at the National Laboratories is as a result of political decisions that happen at the Department of Energy. What is the relationship between DESY and the state of Germany? And how did that play out during your time as director of research?

Wagner:

Very interesting question, because I had many discussions concerning this issue with the Department of Energy as well as of course with our ministry. First of all, we have two ministries which provide the budget. DESY receives 10% of its budget from the state of Hamburg. Germany has a federal structure, so the state in which your institute is located pays typically 10% of the budget and that is essentially the same for all national labs. And 90% comes from the federal government. Now we always had a very good, direct link to the federal government, and we were in the extremely lucky situation that we had very competent people at the government level. And I still have close contacts with the person who at the federal ministry was responsible for basic research at the national labs while I was director of DESY. The decisions were always on the quality of science we wanted to do, so first of all, we had to make a good case. And secondly, our plans had to fit into what the government had as plans. Before I joined DESY, there was a very interesting period which illustrates this. How could DESY with its project HERA become a truly international lab, where one third of the accelerator and experiments was actually financed by outside partners, including the United States? And the answer is that the idea for this project was developed in meetings of international groups interested in electron-proton colliders. And then at some point in time, there were so many people discussing possible experiments and forming collaborations and also being interested in the accelerator side of HERA, that the DESY director, Volker Soergel went to the ministry and said, "We have this following situation. We have an international group of people, and the support of ECFA, the European Committee for Future Accelerators, and of a similar committee, PPARC, in the United States. which both gave the project their blessing. The goal of HERA is to understand the inner structure of the proton with 1000 times higher resolution than anything achieved so far. And we have all these international scientists interested in contributing to the project." Then the minister said, "Yeah, okay. If you can prove to me that you have contributions from these other countries, then I'm willing to take a decision." And this is what happen. And Soergel together with Björn Wiik and Gustav-Adolph Voss, both responsible for the accelerators, brought all those people together who were contributing to the accelerator and to the experiments. That convinced the ministry and the minister then gave green light. This shows you also the difference to the United States, you have to go through gateway processes and you have establish work breakdown structures. You have weekly project meetings both in the US and at DESY, but we did not have people from the ministry sitting all the time in our lab supervising. We had to write a quarterly report on how we were doing, where things were, where things had problems, where and how the money was spent, etc. So DESY was on a very, very long leash. And we were effective-- probably more effective than people who under permanent control and possible interference. Now, you're not the first one I tell this to. (both laugh) I told this example to many people at the Department of Energy, and they never really believed me, I think.

Zierler:

One other perhaps parallel or not with the US system, and one of the reasons that so many experiments at the national labs have been successful is because the physics community had an inside person in the Department of Energy. In other words, a physicist in the Office of Science, or even as Secretary of Snergy itself. Were there any physicists, academically-trained physicists, within the government structure, the ministry in Germany, whose background was particularly useful as you advanced the agenda of DESY?

Wagner:

Yes, but the person in the ministry I mentioned is mathematician, with a keen interest in physics. His collaborators were, I think, at that time all physicists. So yes, we have this know-how. But these persons are not coming directly from the community and go into the ministry. This is a different career path if you want, but with a solid science background. Now, of course, I had to simplify to some extent the way how the decision-makings go. Now I'll tell you, again taking the example of DESY, how the interactions between the ministry on the one side, DESY on the other side, and the third partner, the users of the DESY facilities, functions. The users came from the universities in Germany for whom the first accelerators were built. These users were part of the Scientific Council of DESY which advised the directorate on the science strategy of the lab. This Council was originally having only German members, but became international when users from other counties stared to work at DESY. And also the political side, the funding agencies, met at DESY twice a year to analyze the progress and the future plans, etc. Also this body has representatives from the scientific council and of course the management of DESY. So you're always in very close contact both with the users and the funders. When we had situations where things didn't work out, I was taking the next train or plane to Bonn, where the ministry was sitting, in order to report. So there was full transparency. Thus, there was trust established, which is the prerequisite for good relations. We didn't have to have people at our place who surveyed the books. It was not necessary.

Zierler:

Albrecht, the outside perception, perhaps it's stereotypical or perhaps it's true, is that in sum, the German government lavishly supported DESY. Was that generally your experience? That you got everything that you needed, both from a budgetary perspective, but also from a scientific perspective in terms of the kinds of science that you wanted to support and your authority to deem what was important and what was not?

Wagner:

Well, let me start with the second aspect, because I think this is the first element. You have to make a credible case for what you want to do, and it is clear that if you have a lab and you have the responsibility for a lab, you have also the responsibility for its future. And we might come back to that when we talk about the change in direction of the lab, similar to the SLAC. And I told you about the process. The users are strong. They have a strong role to play. Actually, a very central role, because we are not doing experiments for the few DESY scientists. We're doing this for the users. And the future depends on interest on the user side, and that's why these bodies, like ECFA and the workshops preceding that decision are so important. Because that reflects what the community wants to do. At those times, we didn't have ECFA roadmaps yet, as we have these days, but we had these well-defined groups of people interested in doing certain projects, and if we have enough interested scientists, it convinces the government. And if you show to the government that you get funding from them, it of course enhances your case. I would not say that we were lavishly funded, but we were appropriately funded., We had to justify every Euro of it, and of course we had our beatings, our setbacks and budget shortfalls. Germany, like other countries, has an budget, which is annually allocated. But in addition, the ministries have a medium-term plan. And if you are not doing something really stupid, they will stick to the medium-term plan. So they will do not only an annual planning, but a longer-term plan, especially for projects which have a ten-year construction time or even a five-year construction time. They have to have an outlook. To balance their budget as they track which project is approaching its end, and what is the next one which comes in? They want their labs to flourish. We as lab are not the only players, so the ministry has to make sure that the quality is served first. The project following on HERA was originally a linear collider was associated x-ray free electron laser. It was presented to the government, and the minister , asked by the state of Hamburg to have an international evaluation and comparison with other big projects, initiated this evaluation process. At the end of the process, there was a clear decision namely not to build a linear collider, unfortunately, but to go and focus entirely on the x-ray laser, as it had an outstanding science case and at the same time was a kind of prototype of the linear collider. So you see, this gives you hopefully a glimpse of how processes work and I think this is pretty much the same in Europe. But I would say it has less of what to an outsider seems sometimes an erratic decision process in the United States.

Zierler:

(laughs) In terms of being, as you say, "appropriately-funded" but also needing to justify every last euro, I must ask, what was the basic divide, both in terms of your own sensibilities as director of research, what was the divide in terms of pursuing science that was basic research, and science that was relevant to some of the larger social and economic challenges that Germany, as in DESY, as in service to the German state, might have wanted to see come to fruition during this time? Thinking for example in terms of energy, just to take one example.

Wagner:

First of all, you might know that there exists something called the Helmholtz Association in Germany, which is the roof over the national labs. DESY had to join, to put it in my words, the Helmholtz Association. We did that because we saw that there was no way out, and this was also the wish of the government, although we were feeling that we lost our direct contact to the government through that. I was for the first six years Vice President for the research field “Structure of Matter”. So I noticed how the government was interacting with the Helmholtz Association through its senate on your questions of general interest. It was always very clear that you cannot drop basic research in the interest of applied research. And I think this is a thing which people probably have understood by now, but you have to repeat this every time you say it. And DESY, more or less since its early days did research with synchrotron radiation together with particle physics. This made it easy for us to argue that we are serving societal needs by synchrotron radiation and do basic research, both in synchrotron radiation and in particle physics. Of course, particle physics' direct use for society is less direct as the one of synchrotron radiation.

Zierler:

Was there a club of directors of research, both within Germany, in Europe, or even in the United States, that you would be in touch with generally at your level to see what was going on? Particularly, I'd like to ask, to ensure that research at the various laboratories was complementary and not redundant. In other words, wouldn't it be terrible to learn just as a major project was getting underway, you were to find out that the same thing was happening at another laboratory?

Wagner:

That was excluded by very good relationships between all the major labs. We had regular meetings of the directorates of DESY and CERN. We had meetings with SLAC. As we didn't overlap with Brookhaven, we didn't have regular meetings, but we had regular meetings with KEK in Japan. I mentioned ECFA. In addition, there exists its international equivalent, ICFA a really very important body, because that's where all the lab directors get together and discuss the future. And the question which developed in the time of the linear collider is really, how can we do a kind of job sharing? This has happened by now, that neutrino physics is essentially the domain of the US in Fermilab with some things being done at KEK, because they existed previously. Hadron colliders are being done at CERN and the location of an e+/e- colliders is planned to be built in Japan. This development, seeing the size and the complexity of these great projects, was both, necessary and natural. It took its time because you have communities in every lab. I think if you had left decisions to the directors, that would have happened easier. But they had also to make their community and constituency happy by giving them interesting science to do “at home”.

Zierler:

At what point did you realize that you were being groomed for leadership of DESY? Did this happen quickly, or was this a longer process?

Wagner:

What do you mean, groom?

Zierler:

That you got indication that this was the next step for you, perhaps as a--

Wagner:

I never had-- I had never seen that coming. It was really the phone call which I mentioned to you which made me think and so I had to balance my future-- I mean, Heidelberg pulled very strong on the other end to keep me. And I had to balance the possibilities. By going to Hamburg, I had the impression that I could move more and would also enter a new territory which was unknown to me, namely management, on a larger scale and on a scientific basis, if I would accept a job at DESY. But it was at that time not at all clear that I was in line to become the director general. That happened through an unfortunate event, because my predecessor Björn Wiik died in an accident, and I had to take over first at interim, but then I was elected as his successor for ten years.

Zierler:

Did you see any feasible plan just as you had your university professor appointment, as a way to remain close to the science? Was there any feasible or realistic opportunity for you to continue functioning in your role as a particle physicist? Or was this simply off the table in this position?

Wagner:

I think in the position as chair of the board of directors the idea is to remain an active particle physicist was off the table, because my responsibility was not only to assure the running of DESY, it was to defend DESY's interests and actually the German interests in the research field of exploring the structure of matter, being vice president of the Helmholtz Association. In this position I was the representative of all the basic research done in nuclear and particle physics. So that's a large additional responsibility. In addition, there were the international responsibilities. At that time, which was the hot period of getting an e+/e- linear collider off the ground, I don't know how much time I spent only on looking at all the aspects of a global project. And this was fascinating and required a lot of talking, a lot of thinking, and lot of acting, a lot of political discussion, so I was traveling a lot and so on. You must have heard something similar from Jonathan Dorfan, I guess. It was quite interesting, I must say. I never regretted it.... Given the room a DESY director has to help shape the future, sometimes also by shutting down an accelerator. I'll make a comment on that afterwards. Is it was the greatest job I could do. I think the director of CERN has more constraints than the director of DESY.

Zierler:

Why? Why is that? Why do you say that?

Wagner:

Because DESY is fundamentally a national lab and does not have many member states, each with their own agenda.

Zierler:

(laughs) Albrecht, I'd like to ask--

Wagner:

Let me, no--

Zierler:

Please.

Wagner:

Before you ask, I'd like to say what I consider as the most difficult decision in my career. And that was to decide that HERA would end its operation in 2007. HERA started in 1992, and ended 15 years later, having essentially reached everything originally on the program. But of course, there was a large community of four experiments, each with a few hundred people. We started a discussion about the future HERA program, and up a body, led by the then-research director, who later became the director of CERN, Rolf Heuer, to look at all the options DESY had for running HERA longer. But at the same time, it was clear from looking at the budget that if we wanted to do something new in the next few years, we had to concentrate our budget. It means that we had to ask us the question, how much of our budget would go into operating HERA. this was about a quarter to a fifth of the budget. Then we asked the question, what else could we do to advance the science and compare this with HERA. At HERA we could collect 20 to 30% more data, slightly decreases the error but these additional data would most likely not lead to a major scientific breakthrough. This is a very difficult discussion, especially in a laboratory which has been driven by particle physics. The synchrotron radiation was always part of the DESY program, but not in the driver seat. This would change, once HERA would stop delivering data.

Zierler:

Yeah.

Wagner:

The scientists doing research with synchrotron radiation considered themselves always as the underdogs, or parasites, somebody used that word unfortunately. I didn't ever see them like this, because as my original responsibility as director of research, I was also responsible for the synchrotron radiation. But as anyway, this was the mental or psychological thing. And to make a convincing case and say, that we need to invest this money in other activities, and we end this at a point HERA, as it really has achieved what it originally set out for, was difficult. I tried to be as clear as possible in my arguments. Not all people were happy, but they accepted my arguments.

Zierler:

Albrecht, in what ways was being research director the ideal preparation for being elevated to chairman? In other words, I assume in this position, you had the greatest scope of all of the science that was going on, and so my question is, when you became chairman, what was lacking in your experience for which there could be no preparation except in real time, on the job?

Wagner:

I think until becoming chairman, I was very little confronted with political aspects. This was always done by the chairman. Only a few months after I became chair I was flying to Russia for some meeting, when in the Frankfurt airport, while I was walking from one plane to the other one, I heard over the loudspeaker, "Mr. Wagner, could you contact the next information desk." And it was DESY. A colleague of mine informed me that a leading German news magazine, Der Spiegel, would publish the coming Monday a five-page article, "Close DESY down". And this was Saturday afternoon. (both laugh) All hell broke loose. How do we react? Etc. And I had no experience in that, absolutely zero experience.

Zierler:

What was the basis for the article? Why were they demanding this?

Wagner:

The Spiegel normally doesn't say who wrote an article. In this case it was an opinion piece, and it was a physicist who had written this article. And I think, frankly speaking, he had grudge. His statements were incorrect. But if you are faced with a situation like this, it's very difficult how to define the best way, how to react. How to deal with the newspaper, how to deal with the public. How to deal with the ministry, etc. I didn't have to cancel my trip to Russia, which was only short, but I had lots of work to do afterwards. And I learned certain lessons on how you deal with a situation like that. Which I didn't know before, because I had never been in that situation. The positive thing I learned, also through the many public talks I gave, was to see that if you manage to explain things in clear terms and a logical way to the general public, to the politicians, they at least nod. And they feel they understand why you are doing things and why you want to do new things and why it's essential to do those. Sometimes they have so many boundary conditions that they not always can fulfill your dreams, but at least they are positively inclined. And this is, I think, very important.

Zierler:

In what ways did you realize that you had political and diplomatic skills that you had never tested before in your career?

Wagner:

I just did the best I could, and I didn't think about it because otherwise you get confused, you start to read manuals, or whatever. (both laugh) Which I never did. And you have... I think what you have to develop is a sense that you understand what the other side thinks. You have to listen, listen and watch. You have to see the reaction of other people, and then you know what the right tune is that you have to play in order to make them understand what you want.

Zierler:

Albrecht, to return to an earlier comment, the extent to which the experiences at DESY during this time and the experiences at SLAC, in what ways were the advances or not in the world of particle physics, in what ways did that lead to something of an existential question about DESY's future? And what did you feel were the most opportune and productive ways to stay ahead of those questions? To insure that DESY remained relevant and at the cutting edge.

Wagner:

Yeah. I can illustrate this with a question of what DESY should do after 2007 when we stopped HERA. It was clear that the particle physicists at DESY were wholeheartedly wishing to participate in this linear collider project. That was a tradition in the lab, secondly it was the most interesting project to move forward. And so a lot of effort went into that the linear collider. But in addition, there was so much knowledge gained at HERA which was very important for the LHC. Having done all these deep inelastic scattering experiments at HERA had provided a detailed knowledge on how the proton was actually built up. It's not just three quarks. It's three quarks in the soup of gluons. Having understood this very precisely was one of the big prerequisites to understand what happens at LHC, where you shoot a bag of gluons and gluons against another bag of gluons and quarks. So there was an openness and interest also in working at the LHC. It was clear that if you wanted to keep a leading role for the lab in particle physics, even if you have no longer an in-house experiment, then you have to keep being active in a linear collider, and making a major contribution to the LHC. Because this justifies your existence. This attracts people to your lab, and this provides the basis for the future of the lab in this area. DESY itself had of course a future because it has been strong in several fields. It had particle physics, which included astroparticle physics, which was mainly done in Berlin. It had synchrotron radiation, and it had accelerator physics. We were among the leading accelerator developers in the world. These three areas became later four, when astroparticle physics became such another dominant field of the DESY focus. The balance between the fields required constant attention. There was always an interplay and feeding of knowledge from one domais to the others. This interaction between the fields was one of the biggest strengths of DESY. And this keeps continuing and, in that sense, the overlap area where several of these fields have strong interlinks, the knowledge gained in one area positively influence the other areas.

Zierler:

I'd like to ask a rather retrospective question that asks you to compare your tenure both as director of research and as chairman. And that is, what were the different feedback mechanisms that you used in both roles to determine if you were on the right path? I would assume that as director of research, that the mechanisms would be rather straightforward. Were the experiments getting funded? Were they getting good results? Were the feedback mechanisms that you determined to know if you were on the right path as chairman, was that more difficult to ascertain?

Wagner:

No, but it was more international. When I came to DESY, I inherited existing collaborations in HERA. So there was no question of getting new collaborators, or getting them being interested. The feedback as a director of research, was through weekly meetings with each collaboration. The feedback I got feedback during the weekly meetings of the directorate who had broader views. I got feedback during international conferences and from the supervisory board from the ministries. The same is true being in the chairman position. There, the feedback comes from meetings where the future plans for DESY are discussed, from talking to the staff at DESY, to specific working groups for example. You're constantly on the emission and receiving mode. So there's never any question that you go down a blind alley and all of a sudden find yourself in front of a wall. It's like being the captain of a large ship. You have to know where you want to go and you have to constantly adjust the direction in order to arrive where you want to be.

Zierler:

Albrecht, in both positions, either scientifically or administratively, what was your proudest accomplishment?

Wagner:

I can't identify one single accomplishment. I would say the fact that the TESLA project got such an excellent review was one of my greatest satisfactions, but this was not my accomplishment, but the result of the work of many very talented people. But I think we did a good job in convincing first of all the body which evaluated us, such as the German Science Council. That's the body of scientists established by the ministry to look at major questions of universities, but also at research institutes. And I think we really convinced them that TESLA was an outstanding project. And to have such a positive feedback helps of course in being reassured that one is not doing something stupid. There were many PhD students and staff, when the evaluators came for a site visit. You know how site visits go. You have to have stars in your eyes, sparkling from ideas, etc. It's this team spirit which makes it. And to have such a team spirit is not the doing of a single person. It's just making you happy about what happens, but it's not your doing. You can help a little bit. You can create an atmosphere.

Zierler:

And to flip that question, Albrecht. With the power of hindsight, if you had the chance for a do-over, either administratively or scientifically in either position, would you take one?

Wagner:

No, no. This question touches the way one approaches problems and problem-handling which in my case is scientific: You analyze a situation with all the elements you know and you can get your hands on. And then you discuss with people and you listen to their opinion in view of all these facts. You formulate your conclusion and opinion. You discuss it with the other people, and from that you get the feeling —if you are on the right track. —Once I conclude that there is no better way forward, I move forward, and stop thinking about the question if I made the right decision or not. So I never came back if something had been the right decision, such as “What would have happened had we worked HERA another year?” It takes you nowhere.

Zierler:

Albrecht, at the level of chairman, part of the decision making for when to go emeritus, I assume part of it has to be the point at which you feel confident that you have put in place a system that is stable in the long term, and you can feel confident that your successor can build on that. So when that decision came for you in 2009, what were you most confident about in terms of DESY's long-term viability and what gave you cause for concern that maybe in the back of your head you thought to yourself, "Maybe I should stay on a little longer to make sure that things turn out okay."?

Wagner:

First of all, this date was fixed, and I had already by three years past my retirement age. So there was never even a thought or a discussion of me staying on. And I would not have wanted to do that. Because it was the right time, I believe that a regular change of management is a very useful thing. Especially in this situation, where a new field was just getting off the ground. Not a new field but a new project, the European X-Ray Free Electron Laser. Which is strongly interlinked with DESY. It's going off the ground, and it should be somebody from that field who has also the credibility, who is interested enough in topics of particle physics, but who is credible to all these people working on the new field. So the choice-- it was not me who made the choice, but the choice was quite obvious, and I think also the correct choice, and so there was nothing which should have been done differently. Everybody has his or her style, so that is part of each change. I think the logic of the change was totally clear.

Zierler:

Albrecht, of course the opportunities available to you in the world of advisory work were quite broad when you decided to step down. Did you think at all about any opportunities to get more directly involved in the research from earlier parts of your career?

Wagner:

No, because I think the projects I had to review later on were in fields where I learned something new. Just when I came back from a four-month stay in Okinawa, I had to at a very critical point to review the ITER fusion project. I was the chair of an international committee and we had to evaluate if ETA was on track. ITER had changed the director general, one and a half years earlier. Was the project on track, was there a realistic schedule, what is the budget and schedule, are there show stoppers? And are the planned steps meaningful? That was a very interesting experience. We had an extremely short time window because the DOE needed the independent review for political reasons. , So we had even three months' time. I came back from >Japan beginning of February. The first meeting was middle of February, and we had our last meeting during the second half of April. At the end of this meeting, we had the minutes and the recommendation written. And unanimously approved. The review was full of potential stumbling stones, as you can imagine. But I think our review was in depth, objective and positive. The ITER management was happy with the recommendations. The DOE was happy with the recommendations. But this was more than a full-time job. So that was that. Soon after I was asked to chair another ETA-related evaluation. So there was no time for any other activity., I would have actually refused to be on any particle physics committee, because there are younger people who are actively involved in the ongoing projects which are part of their future, and I think they should be the decision-makers.

Zierler:

Perhaps as--

Wagner:

I was also never asked.

Zierler:

(laughs) Perhaps as a bookend anecdote to your experiences in the fall of 1974, where were you when the Higgs discovery was announced and what were your reactions to it?

Wagner:

I was in front of a TV screen. Where was I? At home or somewhere. The director of CERN who chaired the colloquium on the search for the Higgs is a very good friend of mine, For many years we worked on the same projects together, the JADE experiment at DESY, OPAL at CERN, and the preparation of the linear collider when he was research director at DESY. I had some inkling of what was happening, but I was very, very curious to see how this was presented, how people reacted to, etc. This was really a moving moment.

Zierler:

I'd like to ask a question that's perhaps as much about the philosophy of science as it is about science itself. As you well know, I'm sure, there's a common reaction in certain parts of the world of physics that tended to downplay the significance of the discovery of the Higgs on the theoretical basis that, "Well, it's no big surprise because we knew it was there anyway." What is your general reaction not just to that specifically, but more broadly to that approach to experimental physics?

Wagner:

I don't think that the people who say that would say the same thing in their own field. Possibly they don't have such a beautiful theory like particle physics. But what would happen to a Gothic arch if you don't put the cornerstone in? It would collapse. You can have many beautiful theories. If you don't have the corner stone, the theory doesn't stay up. So I think this opinion is either reflecting a lack of understanding of how science works, or just jealousy.

Zierler:

And so to come back to what you call the classical question and not a grandiose question, from your perspective, because of the significance of the discovery, what are we able to do now, or what are we able to ask, as a result of confirming experimentally the Higgs, and not just theorizing its existence?

Wagner:

Well, the next points on the program are really to understand all the properties of the Higgs, because that is really where the Higgs mechanism is being manifested, and that is coupling to the masses, its branching ratios, etc., etc. LHC makes, in my mind, a fantastic effort to measure these quantities, but there are some limitations which come simply from colliding protons with protons. And that's the point where linear collider comes in. It would allow to really measure these key parameters to precision, which might allow us to see discrepancies, which so far do not show up if you just look at it with the resolution the LHC can provide. If you have a telescope and you see something fuzzy in the sky and then you build a 100 times better telescope, you see what the fuzzy thing is. We are in that situation at the moment. And that's why so many people still think that our next logical step is linear collider as a Higgs factory in order to do that. Because so far, the direct searches for new things have neither worked at HERA nor have they worked at LHC.. The direct observation and measurement of the top quark at LHC was predicted by theory and therefore not really something new and the Higgs boson was also a first observation but not something that had never been seen before.. But the most precise information about the Higgs and the top came from precision measurements, made us confident in the power of the underlying theory. And so we are at that point at the moment.

Zierler:

To come back to the metaphor of the cornerstone in the arch, of course one major cornerstone we're missing is the fact that the SSC never got built, and the loss of that obviously is incalculable. And I mean incalculable in both senses of the word. One would be that we simply don't know what it would discover, but we probably do know that whatever it would discover would be major. My question is, to what extent was CERN able to pick up the mantle of the research that would have been done at SSC? And what would CERN still to this day not be able to do because of the energies that were planned at SSC?

Wagner:

This is looking in a crystal ball, because we don't know. We have not the slightest hint of any energies threshold, beyond which we might see new particles, because there is no sharp energies threshold. This is different from e+/e- physics, where you say, "If I go to 170 GEV, I will not see the top. But if I go to 175 GeV, I will be able to measure it." At a hadron collider like LHC or SSC you have a spectrum of the energy of the colliding constituents, in which the number of events you can produce in collisions decreases with energy. The SSC would have reached higher energies than LHC and would have had therefore a greater potential for discovering something new. But I have not heard of any very precise prediction Of signals which could have been seen at the SSC, but not at the LHC, at least to my knowledge.

Zierler:

Do you think it's feasible that there will be a post-SSC project that will replicate the energies that were anticipated in Texas?

Wagner:

I think it would go beyond that. And I think this is would be necessary. Ideas are being pursued at CERN and in China. But these projects are so big I have no good feeling of how realistic they are. We hope that the high luminosity LHC will go part of the way, that new types of particle physics experiments discover something, either in dark matter searches or in axion searches, or that we get some astrophysics hints, which tell us in which way we can focus better on what we do with accelerators. It could also be that the next step lies at much higher in energy, so we will no longer be able to do that with our present knowhow. You can ask the question how far new accelerator technologies might take us one day. With these the challenge is less the energy than the luminosity or the number of interactions one can get. The energy gain one can reach over distance of millimeters is absolutely remarkable, But the limitation lies in the number of electrons one can accelerate and in the repetition rate. So this is a path to go, and I find it fantastic that so many people put their intelligence into these projects. I think the money is well spent, even if the technology might in the end have a different implication than particle physics. I don't know where the real answer to your question lies.

Zierler:

To the extent that collider physics and particle physics has a physicality that forces us to think in terms of location and even nations, where geographically or nationally do you think these next generation projects would most likely take place? Do you see them taking place in Europe? Perhaps China?

Wagner:

China is very difficult to judge. China is also politically not an easy country these days. It comes down to the question, how much does it cost? Which fraction of the cost will be picked up by the host nation? How much are people willing to spend if it's not in their nation or not in their region? Because of course, it enhances the visibility of another region. But one has also to think about what I mentioned in the beginning of this. Seeing these things more globally also in the visibility. That's why it's important to have strong activities at home. Both DESY and Fermilab are involved in the LHC, because the data taken at the LHC can be analyzed at DESY or Fermilab by their strong teams, which also give talks, develop in improvements, etc., and bring all their intelligence into the project, which makes the project also succeed better. I think it's really an international game.

Zierler:

Albrecht, what were the circumstances leading to your appointment at OIST?

Wagner:

...You should ask Johnathan [Dorfan] not me. (both laugh)

Zierler:

Well, what did he say to you?

Wagner:

He told me what problems he had, and which I needed to tackle in the four months I was there. I must say, I had been on his board of counselors for five years, so I knew pretty well what was going on, but I didn't know the details. And he told me the details, and I said, "Well, I see what I can do." And I did what I could.

Zierler:

What were those challenges--?

Wagner:

It was for me, it was not entirely new…

Zierler:

Please.

Wagner:

No, what I wanted to say, what helped me also was, that I had some idea about the internal operation of universities, from my work on the supervisory board of Hamburg University, which is of course a totally different thing. We had already been responsible for the supervision for eight years by that time, I had a fairly clear idea what universities could do and what could not be done, and how they differed from research institutes. The essential point being that in a research institute, you have one or at most two communities who think alike. Not ten or 100 fields with different cultures, such as social scientists, economists, philosophers, linguists, and scientists. t. They think differently, they speak differently. You have to get them together in one way or the other. So at least I knew that. It took me some time to understand this difference between research labs and universities. So what were the challenges? Challenges were budget, as usual. And the human aspects, because OIST was a rather young university which had no example to follow, so everything had to be invented from scratch. And so it underwent the typical problems you face when you have young children, when they go through all sorts of child sicknesses, and you have to deal with the one after the other. Jonathan of course had to face most of them, but I had to face a few of these in four months. There were organizational challenges, but the biggest were budgetary challenges and hiring the right new people. But then, in four months you can’t do very much. I finished one hiring, which was important..

Zierler:

Albrecht, to bring the conversation right up to the present, of course the academic model and mission of OIST is so unique. And today because of the pandemic, there are so many bedrock assumptions about higher education that are being questioned. In what ways, perhaps, is OIST very well-positioned for whatever comes next in higher education?

Wagner:

Because it's a small enough institution which can allow good ideas to be tested without possibly fatal consequences. Of course, one has to think carefully about what to try and what to implement. One idea, which is already implemented to some extent, is to foster more the interdisciplinary or the trans-disciplinary research. And what are the right steps to take? If you do the wrong step, or not the optimal step, you can correct it in a small institution. Interdisciplinary research was actually one of my main reasons why I accepted going there. Because I wanted to see from the inside, how this works at OIST, because I believe that this the future direction, and I wanted to see from the inside how it works and where the drawbacks and stumbling stones are.

Zierler:

Albrecht, at this point in our conversation, now that we've worked up to the present, for the last part of the interview, I'd like to ask a few broadly retrospective questions, and then one looking forward. My first is, surveying your long career in particle physics, and given the fact that you started your academic research during such a formative time, and in fact today one of the challenges is, where does the field go next? Perhaps as a result of advances in technology, or theory, or just the hard work, what were some of the most mysterious aspects to particle physics in the 1960s and 1970s that are truly well-understood today? And what remains mysterious despite all of the advances and all of these different sectors?

Wagner:

The 60s and 70s are pretty easily answered. It is, you were seeing a wide set of phenomena which each in itself was interesting, but there was no cohesive theory. And then came up two things. The unification of weak and electromagnetic interaction, and the theory on strong interaction (quantum chromodynamics). And they are linked together, the Grand Unification, if you want. This is a theory which is really describing, as I said in the beginning, only too well what we have not yet studied and which we are studying in the hope of finding the deviation. So, on the one hand, this still is a mystery. Why is this theory never, in no place we have been looking, violated, although we know it is not the final theory? And I think this is for me the biggest mystery, and as I said, the theory itself is the biggest success I can see in all of physics.. Starting from symmetry principles and other basic, very basic assumptions, people come up with a theory which describes correctly any cross-section, any branching ratio you can think of. even if you look as hard as you can to find deviations. Sometimes might see a new decay channel, but it is not unforeseen, it is simply no one has seen it so far. Unfortunately, it doesn't add anything new to the model. So glorious and at the same time a curse. I can only repeat what I said before.

Zierler:

Albrecht, of course, over the course of your career, perhaps the most important connecting thread has been the centrality of international collaboration. That's part of everything that you've done. I'd like to ask, besides simply the geographic diversity, what have you learned about the value of culture? Different cultural approaches and how that not just because people are far apart, but because they take different cultural approaches to the science. What have you learned about diversity and the value that brings to pushing the science forward?

Wagner:

I would go beyond the science. I would say any human collaboration across boundaries of traditional environments requires that you are free of prejudice. You are open to first of all see differences in cultures, differences in values, differences in approaches. And being open to them means you understand the people, understand where they come from. Not necessarily that you adopt what they do. It is partly in their culture. But that at least you understand where they come from. And then you can much better work together, or do something together, talk together. Develop a common policy together. But this requires an openness of mind, and leaving prejudice behind which you might have at the beginning. You can still say, "I don't like this and this feature of this culture." This is totally clear. There are cultures which have features I don't like. But this is my perception. I will not go and tell them to their faces, it's not what I like, and I don't like you because I don't like this feature. First, I have to look at the person, because every person reacts differently to its cultural upbringing. I mention one story from my four months in Okinawa. I had a bi-weekly meeting with all new employees, telling them about the work culture at OIST. It was called "respectful workplace”. And I hate these kinds of slogans. So what I said was that I was supposed to talk about a respectful workplace. But what I really want to talk to you is what you probably don't realize, because you have never worked in any international environment like OIST. It's that there are cultural differences. And people react differently coming from different upbringings. You have always to be aware that if you react in a way you are used to react, it might be received totally differently by the other person. And so what you have to learn is to tune in and to be a little bit more careful that you are when you talk to your colleagues of the past. When you talk to somebody from Japan you have to really be more polite and not too direct. Cultures, certain cultures don’t have the word, "No," in their language, at least they usually don’t use it. I was trying to make them aware that this is something they have to be very careful about and to pay a lot of attention and put a lot of effort in in trying to understand that. Because otherwise, collaborating doesn't work. Neither they are happy, nor the others are happy.

Zierler:

Albrecht, looking to the future, I always like to focus on optimism. And so for you, both administratively and scientifically, what are you most optimistic about with regard to international corroboration and scientific discovery? What are the things that are most compelling and interesting where you're confident you can see these things come to fruition?

Wagner:

You should have asked me this a few years ago, then I would have given you an entirely positive answer. But we see in the political area, and not only in the United States, is that some of the basic principles which I cherish and which I share with many people, are to take into account facts, to avoid lies to base oneself on honesty, on clear expression of one's interests. But not interests at the cost of somebody else, but trying to find a situation which is a win-win situation. This is of course the ideal world. I know that the real world doesn't function entirely like this. It has been very well-functioning in the science. So my optimistic hope is that the way science works is more closely studied and applied on the political level, because I think everybody would profit from that. And we are too global in order to think —and act according to "make country X great again", because making country X great means making country Y less great. And if we look at Africa, for example, I think the only way how we can solve the problem of emigration is to educate people enough so that they see a future in their own country, rather than running away to other countries. This will take a lot of time and I don't know if we will reach this goal, but I think we as scientists must tell and tell again how we do it, how well it works, what is required in order to do it, and encourage other people to follow this example.

Zierler:

Albrecht, for my last question, I'll make it personal. For you, for the rest of your career, what else do you want to accomplish? How do you want to leverage your long accomplishments both in science and administration? Both as an advisor and as a mentor?

Wagner:

Well, I try to give the best advice I can think of if I'm asked. I'm not going around lecturing how to run a research lab, etc. This has worked so far. I think this is also the time where I think it's fine to let go, to some extent. I'm not letting go on the things I'm also interested in, but which never got enough time when I was working. So have to feeling that I'm leading a very fulfilled life. And as I said, when people have questions, for example of the kind you have been asking, and which I found very interesting and very, very challenging, I give the best of advice I can., I feel I have been extremely lucky in my research life, in my life in general, and through the fact that I have also a lot of interests beyond science, which I can enjoy a little more now than I could in previous times.

Zierler:

Albrecht, this has been an absolutely riveting and entirely illuminating conversation. I'm absolutely delighted that we connected through Jonathan, and your insights are really invaluable for the historical record. So I'm so glad we were able to do this. Thank you so much.

Wagner:

I thank you for the questions, as I said before. And I enjoyed very much our discussion.