Martin Perl at Michigan

Martin Perl (b 1927 Brooklyn; 1995 Nobel Prize for discovery of the tau lepton)

Below we have intermingled excerpts from Perl’s Nobel autobiographical memoir and his Nobel Prize speech that give aspects of his early training, his graduate studies at Columbia ,  and his eight highly-successful years at Michigan working with Jones, Meyer, Longo, Ting and Glaser.


I was sixteen when I graduated from James Madison High School in Brooklyn in 1942.  … I enrolled in the Polytechnic Institute of Brooklyn, now Polytechnic University, and began studying chemical engineering.

One of the first courses I took in college was general physics, using the textbook by Hausman and Slack. The course was all about pulleys and thermometers; physics seemed a dead field compared to chemistry.  So, just as I was blind to the fascination of physics in high school, I was once again blind to its fascination in college. I ignored physics, and continued studying chemistry and chemical engineering.  … Chemistry was a very exciting field in the late 1930’s and early 1940’s  … There would always be a good job in chemical engineering.

Studies interrupted by war

I wanted to join the United States Army, but I was not yet eighteen and my parents would not give me permission. However, they agreed to me joining the United States Merchant Marine, I was allowed to leave college and become an engineering cadet in the program at the Kings Point Merchant Marine Academy. …  In 1945 when the war ended with the atom bomb, I left the merchant marine and went to work for my father while waiting to return to college. I knew so little about physics that I didn’t know even vaguely why the bomb was so powerful.

I didn’t get right back to college. The draft was still in force in the United States. I was drafted, and spent a pleasant year at an army installation in Washington, DC, doing very little. Finally, I returned to the Polytechnic Institute and received a summa cum laude bachelor degree in Chemical Engineering in 1948.
The skills and knowledge I acquired at the Polytechnic Institute have been crucial in all my experimental work: the use of strength of materials principles in equipment design, machine shop practice, engineering drawing, practical fluid mechanics, inorganic and organic chemistry, chemical laboratory techniques, manufacturing processes, metallurgy, basic concepts in mechanical engineering, basic concepts in electrical engineering, dimensional analysis, speed and power in mental arithmetic, numerical estimation (crucial when depending on a slide rule for calculations), and much more.

I was trained as an engineer at and I always begin the design of an experiment with engineering drawings, with engineering calculations on how the apparatus is to be built and how it should work. My strong interest in engineering and in a mechanical view of nature carried over into my career in physics.

Industrial Interlude

Upon graduation, I joined the General Electric Company. After a year in an advanced engineering training program, I settled in Schenectady, New York, working as a Chemical Engineer in the Electron Tube Division. I worked in an engineering office in the electron tube production factory. Our job was to troubleshoot production problems, to improve production processes, and occasionally to do a little development work. We were not a fancy R&D office. I worked on speeding-up the production of television picture tubes, and then on problems of grid emission in industrial power tubes. These tasks led to a turning point in my life.

I had to learn a little about how electron vacuum tubes worked, so I took a few courses in Union College in Schenectady specifically, atomic physics and advanced calculus. I got to know a wonderful physics professor, Vladimir Rojansky. One day he said to me “Martin, what you are interested in is called physics not chemistry!” At the age of 23, I finally decided to begin the study of physics.

Graduate Study in Physics, I.I. Rabi, and Learning the Physicist’s Trade

I entered the physics doctoral program in Columbia University in the autumn of 1950. Looking back, it seems amazing that I was admitted. True, I had a summa cum laude bachelor degree, but I had taken only two courses in physics: one year of elementary physics and a half-year of atomic physics. There were several reasons I could do this 1950; it could not have been done today. First, graduate study in physics was primitive in 1950, compared to today’s standards. We did not study quantum mechanics until the second year, the first year was devoted completely to classical physics. The most advanced quantum mechanics we ever studied was a little bit in Heitler, and we were not expected to be able to do calculations in quantum electrodynamics.

Second, there was no thought of advising or course guidance by the Columbia Physics Department faculty – students were on their own. I was arrogant about my ability to learn anything fast. By the time I realized I was in trouble, but the time I realized that many of my fellow students were smarter than me and better trained then me, it was too late to quit. I had explained the return to school to my astonished parents by telling them that physics was what Einstein did. They thought if Einstein, why not Martin; I could not quit. I survived the Columbia Physics Department, never the best student, but an ambitious and hard-working student. I was married and had one child. I had to get my Ph.D and once more earn a living.

Just as the Polytechnic Institute was crucial in my learning how to do engineering; just as Union College and Vladimir Rojansky were crucial in my choosing physics; so Columbia University and my thesis advisor, I.I. Rabi, were crucial in my learning how to do experimental physics.

.As is well known, Rabi was not a “hands-on” experimenter. He never used tools or manipulated the apparatus. I learned experimental techniques from older graduate students and by occasionally going to ask for help or advice from Rabi’s colleague, Polykarp Kusch. I hated to go to Kusch, because it was always an unpleasant experience. He had a loud voice that he deliberately made louder so that the entire floor of students could hear about the stupid question asked by a graduate student.

Thus as in the course work, I was on my own in learning the experimenter’s trade. I learned quickly, as I tell my graduate students now, there are no answers in the back of the book when the equipment doesn’t work or the measurements look strange.

I learned things more precious than experimental techniques from Rabi. I learned the deep importance of choosing one’s own research problems. Rabi once told me that he would worry when talking to Leo Szilard that Szilard would propose some idea to Rabi. This was because Rabi wouldn’t carry out an idea suggested by someone else, even though he had already been thinking about that same idea.

It was Rabi who always emphasized the importance of working on a fundamental problem, and it was Rabi who sent me into elementary particle physics. It would have been natural for me to continue in atomic physics, but he preached particle physics to me – particularly when his colleagues in atomic physics were in the room. I think that most of that public preaching may have been Rabi’s way of deliberately irritating his colleagues.

My doctoral thesis research (Pert, Rabi, and Senitzky 1955) was carried out at Columbia University in the early 1950’s under Professor Rabi.  [I used an extension of the atomic beam resonance method invented by Rabi (for which he received a Nobel Prize in 1944) to measure the  quadrupole moment of the sodium nucleus.] This measurement had to be made using an excited atomic state, and Rabi had found a way to do this

My experimental apparatus was boldly mechanical with a brass vacuum chamber, a physical beam of sodium atoms, submarine storage batteries to power the magnets – and in the beginning of the experiment, a wall galvanometer to measure the beam current. I developed much of my style in experimental science in the course of this thesis experiment. When designing the experiment and when thinking about the physics, the mechanical view is always dominant in my mind.

Michigan, Bubble Chambers, and On my Own with Larry Jones

When I received my Ph.D. in 1955, I had job offers from the Physics Departments at Yale, the University of Illinois, and the University of Michigan. At that time, the first two Physics Departments had better reputations in elementary particle physics, and so I deliberately went to Michigan.

I followed a two-part theorem that I always pass on to my graduate students and post doctoral research associates:
Part 1: don’t choose the most powerful experimental group or department – choose the group or department where you will have the most freedom.
Part 2: there is an advantage in working in a small or new group – then you will get the credit for what you accomplish.

At Michigan I first worked in bubble chamber physics with Donald Glaser. But I wanted to be on my own. When the Russians flew SPUTNIK in 1957, I saw the opportunity, and jointly with my colleague, Lawrence W. Jones, we wrote to Washington for research money. We began our own research program, using first the now-forgotten luminescent chamber and then spark chambers.

In eight wonderful and productive years at the University of Michigan, I learned the experimental techniques of research in elementary particle physics (scintillation counters, bubble chamber, trigger electronics, and data analysis) working with my research companions, Lawrence Jones, Donald Meyer, and later Michael Longo. We learned these techniques together, often adding our own new developments. One of the most pleasurable experiences was the development of the luminescent chamber by Jones and me with the help of our student Kwan Lai (Lai, Jones, and Per1 1961). We photographed and recorded the tracks of charged particles in a sodium iodide crystal using primitive electron tubes which intensified the light coming from the track.

Jones and I, using spark chambers, carried out at the Bevatron a neat set of measurements on the elastic scattering of pions on protons (Damouth, Jones, and Perl 1963; Perl, Jones, and Ting 1963). Later, after I left the University of Michigan for Stanford University, Longo and I, working with my student Michael Kreisler, initiated a novel way to measure the elastic scattering of neutrons on protons (Kreisler et al. 1966).

These elastic scattering experiments pleased me in many ways. The equipment was bold and mechanical, with large flashing spark chambers and a camera with a special mechanism for quick movement of the film. Data acquisition was fast, and the final data was easily summarized in a few graphs.  But I gradually became dissatisfied with the theory needed to explain our measurements.  I am a competent mathematician but I dislike complex mathematical explanations and theories, and in the 1950’s and 1960’s the theory of strong interactions was a complex mess, going nowhere.

I began to think about the electron and the muon, elementary particles which do not partake in the strong interaction.  ——(Perl’s lecture continues to describe the work on leptons that won him the Nobel Prize)


It is interesting that three of Perl’s fellow Columbia graduate students were also on the Michigan physics faculty in those days: Peter Franken (Kusch, Nobel 1955), Gabriel Weinreich (Rabi, Nobel 1944), and , arriving just after Perl left for Stanford, T. Michael Sanders (Townes, Nobel 1964)

Don Meyer: Spark Chambers and Early Experiments

Presented by Donald Meyer at the memorial symposium for
Kent M. Terwilliger held at the University of Michigan,
Ann Arbor, on 13-14 October, 1989

 In 1954 I was at Brookhaven for a couple of years, shortly after the bubble chamber was invented. Don Glaser brought a small bubble chamber to Brookhaven with a group including Marty Perl, Dave Rahm, and John Brown. They needed help learning their way around Brookhaven, and not yet being deeply involved in a project, I joined their group to learn how bubble chambers worked. As a result of this interaction, I came to Michigan in 1956 as an Assistant Professor. When I arrived in Michigan I worked with Don Glaser’s group for a year, after which Marty and I decided we wanted to do our own thing, as young physicists often do. Marry went to work with Larry Jones, and I went to work with Kent. While still working with Don Glaser, I had been trying to make a gas tracking detector by putting a large microwave field on a gas filled cavity, the idea being that the microwaves would localize the gas discharge. I fiddled around with this for about a year and managed to get the chamber to the point that it was sensitive to radiation, but I never could get any spacial resolution. As soon as the gas started to ionize, ultra violet light went in all directions, and the whole chamber lit up. About this time, I got a call from Leon Lederman who, it happened, was doing the same thing, with the same results at Columbia. While I was pondering ways around the problem, Fukui and Myamoto published their first paper on the spark chamber. When I read the report I talked to Kent, and he said “You know, MURA is sort of winding down, I’d like to start doing some physics, let’s try to build a spark chamber and see if we can do some physics with it”. In approximately a week, Kent and I put together the necessary ingredients to make a spark chamber work. Kent’s very thorough knowledge of how to use high voltages made this particularly easy. He even knew where to go in the department to find the proper thyratrons to make the circuits. This was the start of our collaboration which lasted for 6 or 7 years, until I went to CERN on sabbatical.

After we’d made the original little spark chamber, which was about 3″ in diameter, we decided we should plunge into an experiment. Again, being young people and very enthusiastic, we put together a large spark chamber to do experiments at the Cosmotron. It was about 2 feet on a side, with thin foils for electrodes, and again, being very impatient, we didn’t even bother to make a jig to stretch the foils. We just glued the chamber together, with one of us holding the foils tight, while the other epoxied it together. The problem was, the epoxy took about an hour to dry, but we decided that this was the fastest way to get a chamber made so, I would hold the foil for about 15 minutes, then Kent would come into the room and hold the foil for about 15 minutes. After an hour it was set. Then we’d start on the next foil. In a few days we had a chamber that was about 2 feet thick and it turned out to be the best spark chamber that I ever saw. It was exceedingly efficient, worked exceedingly well, and it was only later that I found out how important it was to control gas impurities, and put in the right kinds of things like methane and so forth, in the right proportions, in order to really make things work right. But this chamber worked the first time we turned it on. It was just absolutely beautiful.

I know everybody has seen spark chambers now, but at that time no one had seen a spark chamber work. Kent already had tenure. I didn’t. I was still an Assistant Professor, and Kent said “I’m going to get you tenure, we’re going to have you give a colloquium on the spark chamber, and we’re going to show them the spark chamber”. So we took the spark chamber to the colloquium and I thank Kent because, I got tenure 2 months later. Kent operated the spark chamber, I talked, and the combination was devasting. As soon as we turned out the lights, and turned on the spark chamber, the whole room broke into applause. There was no question as to whether it was a success or not. We took the spark chamber to the Cosmotron, and did a couple of experiments that involved looking at associated production of A°s and Y*s. This was our first experiment together. It was a big success because at that time there were very few associated production events which had all been obtained in diffusion cloud chambers. There just weren’t very many.

We managed to collect something of the order of a 1,000 to 2,000 K ° – A ° events in a very short run. For a first experiment, it was very good. The things we put up with at the time were characteristics of the era, and people these days do not really appreciate these things. We didn’t have very much money in our DoE contract, we rented a house on the north shore of Long Island. Tris Coffin had joined us by that time. Tris, Kent and I, with 3 graduate students (one of whom is here, Larry Curtis), the six of us, lived in a I bedroom house that had enough sleeping capacity for about 4 people if you used the couch in the living room. It was quite a summer. There was a nice beach about 2 blocks away. We would go down to the beach to swim, but we really kept the beds warm all the time. It was lucky we were running 3 shifts a day or we would never have been able to stand each other. The experiment was a success. I was back looking at Larry’s thesis a few days ago, and I found we actually measured the spin of the Y*. I had forgotten that. We measured the spin and the parity of the Y*. The experiment was really a success.

I think the most interesting thing about it, was working with Oreste Piccioni. Oreste was using the same beam we were. We had an agreement with the Cosmotron that we would run for 3 weeks and then be off for 3 weeks. Oreste would take the beam 3 weeks, then we would take 3 weeks. Oreste has no sense of time. He would come in when he felt like coming in, and would leave when he felt like leaving. Sometimes there was no one running on the Cosmotron, the beam was going around the machine, and the beam was coming out, but there was no one there, and there were other times when we were both trying to use the machine. It was amusing. The other thing that happened was that Kent and I became known as spark chamber experts. Mel Schwartz was just starting work on the Neutrino chambers for the AGS experiment, which was so successful. We had many conversations with Mel giving him advise on what to do, what not to do, and so forth.

One of the things that we realized during this experiment was that you collected enormous amounts of data, very very fast. When we finished the experiment, we decided to spend some time developing an automatic scanning system for spark chambers. At that time, all spark chamber data was recorded photographically. As spark chambers developed, of course, magnetic readouts were used but in these early days, up to 1966, when I went to CERN, all spark chambers employed photographic techniques. Kent and I tried to put money together to buy a computer, so we could develop an automatic scanning system. The best that DoE could do for us was a half of a PDP-1, a giant computer that occupied an enormous fraction of a room and did almost nothing by present day standards. We bought half of the PDP-1. The other half was funded by psychology. So we had psychology experiments going on in the same room that we were trying to do automatic scanning. We eventually bought a somewhat bigger computer as we became more experienced, and could get more money together. We were able to develop a reasonably good automatic scanning system for which Kent deserves most of the credit.

One of the things I should remark on is that Kent never really gave up being an accelerator physicist. Wherever we went, whether it was Brookhaven, or Argonne, he was always designing magnets, always designing beams for the experiment. He loved that kind of work, he was good at it, he loved it, and any time there was a beam to design Kent was there. This was really his forte; this is what he really enjoyed the most.

In looking back over students theses, and looking back at the way in which experiments were done in those days, there are two things that contrast greatly with the present. Between 1961 and 1966, Kent and I did 4 complete experiments on 3 different accelerators. This was typical of the time. When I look around now and see experiments, including our own last experiment, that go on for a decade I am amazed. I don’t think it’s just because we worked faster. The experiments have increased so much in complexity, and the accelerators have gotten so much more complex to run, that it is inevitable.

The other thing that has changed is the group size. We had 3 students and 3 faculty members on our first Brookhaven experiment which was relatively typical of the time. When I look at present collaborations I just shake my head. How do you know all the people who axe on them? What are they all doing? Why don’t they get in each other’s way? That’s what surprises me the most. Why aren’t they fighting for positions around the experiments? I just don’t understand. Well I do understand of course. I’ve been involved with it myself. It’s really quite a different lifestyle.

The last experiment that Kent and I worked on together was the first experiment of the ZGS. We did a very extensive elastic scattering experiment, Tris Coffin, Kent and I worked together on a very extensive experiment in pion-proton elastic scattering. Looked at in retrospect, the physics was not as interesting as a lot of things one might do. Again this is a contrast between the physics then and the physics now. Particle physics, when we first worked in the field, from 1961 almost up until the discovery of the psi was to a certain extent unfocused. You didn’t know where you were going. You were collecting data, hoping eventually it would fit into some kind of a pattern that would be useful. Now the experiments that are done, because there is better theoretical understanding largely due to the earlier exploration, are much more focused. You are looking for very specific things. You are disappointed if you don’t see them. I have a hunch that we may go back to the other scheme. Maybe we are again at a stage in physics where there is going to have to be a lot of data gathering and searching. We are entering a new realm of High Energy Physics now, with these bigger machines.

When I returned from CERN, Kent and my physics interests diverged. We have never collaborated on experiments again, but were always close friends. We ate lunch together many times a week. Our families grew up together. In the past few years while Kent was associate chairman, and I was in charge of space planning for the department, we consulted with each other many times each day. I always enjoyed working with Kent. He was a great person.


Nobel Prize winners with Michigan connections (1)

A half-dozen winners of the Nobel Prize in Physics have worked at Michigan: