Wit Busza

Zierler:

This is David Zierler, oral historian for the American Institute of Physics. It is October 26th, 2020. I'm so happy to be here with Professor Wit Busza. Wit, good to see you. Thank you so much for joining me today.

Busza:

Nice to meet you, David.

Zierler:

To start, would you please tell me your title and institutional affiliation?

Busza:

It is Francis L. Friedman Professor of Physics Emeritus, MIT

Zierler:

And who was or is Francis Friedman?

Busza:

Oh, he was a professor at MIT, it must be in sort of fifties or early sixties. In addition to his research, he was well known for work related to education. He was a good teacher. Unfortunately, he died when he was young. I'll be honest with you—one of the things that comes with age is memory goes down the hill. So, I can’t remember now exactly—

Zierler:

Was his research related to yours at all?

Busza:

Yes, some of his research was in nuclear and cosmic ray physics, which are loosely related to my work. I'll tell you, I got this particular chair not only because of my research but also because of my teaching, Friedman’s other passion.

Zierler:

Yes, we'll talk about that.

Busza:

And so, they gave me this chair. It came as a big surprise, but it was nice.

Zierler:

Well, Wit, let’s go all the way back to the beginning. I want to hear first about your parents. Tell me about them and where they are from.

Busza:

Okay. It’ll help you understand if I tell you that I was born right at the beginning of the Second World War, to be specific in January 1940. It might explain my childhood.

Zierler:

And this is in Poland?

Busza:

No, I was actually born in Romania as we were escaping from Poland. Now my background. My grandfather was quite a well-known medical doctor, but he was—some people would say today a bit crazy, a fanatic, in many ways ahead of his time. He believed in how physical exercise, good diet, fresh air, intellectual stimulation, et cetera are the magic to lead a healthy life or cure chronic ailments. And as a young man in the 1890’s, he built something original. There is no good word for it in English—sanatorium is probably the nearest equivalent. It’s some combination of a rehabilitation place, a spa and a cultural retreat. It was extremely popular amongst the Polish intelligentsia—intellectual elites. He built it in southeast Poland, in Kosów Huculski (today Kosiv in the Ukraine)—what was, in those days, part of the Austro-Hungarian Empire. This is the father of my mother. His name was Apolinary Tarnawski. His daughter, Celina Tarnawska, was my mother. She went to University in Lwów and studied agronomy.

You're asking where my parents come from so, I have to tell you about my father. There was a young doctor—this is where Busza comes in—in Pozna? that came to my grandfather to learn about rehabilitation and to work at the sanatorium. That’s where my mother, the daughter of Apolinary, met and married my father, Alfons Busza. So, these are my parents. Now, this sanatorium was in the mountains, in the foothills of the Carpathian Mountains—a beautiful area, fantastic climate—and before the First World War it was in the so-called Galicia which was a part of the Hapsburg Empire. Poland—before that, did not exist for 150 years. So, what later becomes Poland was divided between Russia, Prussia, and the Austro-Hungarian Empire. Then in 1918 Poland gains independence. And our part of the world became part of the country. In fact, it became the southeastern corner of Poland. Then came 1939. The Germans invaded from the west. And at first my parents felt relatively safe, since the war was taking place far away.

Zierler:

What about the Russians, Wit? Were your parents concerned about them?

Busza:

That’s the whole point. In August 1939, a pact was signed between Russia and Germany, the Ribbentrop-Molotov Pact, according to which they between themselves agreed to attack Poland from both sides. So, on September 17, Russia invaded Poland. We were suddenly three hours away from the Russians. All right? Now I have to add one more thing. Germany invaded Poland on the first of September, right? After a few weeks, the Poles were outgunned, et cetera. And the Polish government, and some of the leaders—I have to say, looking back, I don’t think they behaved very heroically—withdrew from Warsaw to the southeast of Poland. They needed places to stay. And there was our sanatorium. So actually, as well as other members of the government and the military, the president of Poland and some of the high brass stayed at or near my grandfather’s sanatorium. Now, I'm bringing all that in because this affected us directly. So, when the Russians crossed the Polish border, staying at my grandfather’s place were senior members of the government—the—what would you call them? I can’t think of the right word—

Zierler:

The partisans?

Busza:

No, no, that have intelligence information. The—

Zierler:

Intelligence. Military intelligence.

Busza:

Yes, military intelligence. Some of the high ups of the military intelligence were staying at my grandfather’s. So, the minister of foreign affairs comes to my family and says, “Look, in three hours’ time, the Russians will be here.” I'm giving you a lot of facts, but there’s logic in this.

Zierler:

Wit, anyone born in that part of the world in 1940 has a lot to explain. [laugh]

Busza:

Yes. [laugh] Right. So, what happens—so my family had three hours to decide, and they decided that it was not a good idea to stay. They knew the Russians too well, living so close to the Ukraine in the thirties. It was pretty bleak what the Russians did to the Ukrainians in the 30’s. But anyway, so they decided to get into a car and cross the border, to Romania. That’s how I get born in Romania. I was born in Ploe?ti, which is not far from Bucharest and was not very far from the Polish-Romanian border

Zierler:

What was the border crossing like? Did they have the necessary papers?

Busza:

I tell you, I don’t know exactly. There was obviously chaos. But the Romanians—I have not heard of that being an issue.

Zierler:

And what was your citizenship?

Busza:

Polish.

Zierler:

Even though you were born in Romania?

Busza:

Yes. I have never checked with the Romanians whether I had—see, the first time that I was interested in passports, what passport I had, was in the late forties, when we were in England. And at that stage, the passport that I had was issued by the United Nations, under the Geneva Convention of 1949 for stateless refugees. But recently, among some of my mother’s papers, I found a passport, with my photograph in it, which is a Polish passport issued by the consulate in Jerusalem—and I can tell you later how Jerusalem comes in, in which I find a photograph of myself, a couple of years old, in my mother’s passport. So, my guess is—I've never tried to find out exactly—my guess is that when I was born, legally I was Polish. I doubt whether the Romanians—with all the chaos going on, refugees galore, I doubt whether they would have worried about whether I am a Romanian or not.

Zierler:

With the consulate, is there a Jewish connection to this?

Busza:

Well, hold on. In the sense that it’s in Jerusalem, yes, but not—I don’t have—I'm not aware of any Jewish ancestors. The chances of there being some are extremely high in Poland. I think almost every Pole has some Jewish blood in them—even the anti-Semitic ones! And then to cut the story short, because that’s not what—well, you have to tell me what interests you—

Zierler:

Well, my question is, where were you as a small child? Were you in Romania?

Busza:

No, no, no. Okay, then I have to tell you—so I was born in Romania. At that time, Romania was neutral. But then, in less than a year—and now my history is not that good—the fascists took over in Romania, under pressure from Germany, and so Romania became fascist. At that stage, the refugees who were there, whether Polish or Jewish or both, were trying to get out. Now there were various organizations and individuals in Romania, for example the Quaker Relief Movement and the humanitarians Joice and Sydney Loch who were trying to help the refugees. To the best of my knowledge it was the latter two who managed somehow, with the help of the British, to organize the evacuation of some thousands of people. And they wanted to take out those most threatened or who might be most needed in the future.

Now, because the brother of my mother, my uncle Wit Tarnawski—after whom I am named—was very active in organizing the refugees—he was actually a medical doctor, but had strong organizational skills acquired at my grandfather’s sanatorium—now, this is getting so complicated and I don’t know the details well—anyway, he was offered to be evacuated. He said he would only accept if his sister and her family are also taken. That’s my mother. In the meantime, my father had gone from Romania through Hungary, France, to the UK, and became a doctor in a military hospital in Scotland. So he was out of the picture. So, there was my mother with her parents, and two kids—my brother Andrzej who was one year older than I, and me starting at time zero. Okay? And we got offered to be taken out of Romania. And the British took us from Romania to Cyprus, which was then a British colony. So, before the end of 1940 we ended up in Cyprus.

Zierler:

How old were you then, Wit, when you were in Cyprus?

Busza:

One to two years.

Zierler:

Okay, so obviously you have no memory of any of this.

Busza:

No, no. my memory kicks in later. In the meantime, the Germans invade Crete—the first time in history where there is a successful parachute invasion. So they occupied Crete. The Brits thought Cyprus would go next, and so they evacuated the refugees from Cyprus to what was then Palestine—at that time Palestine was a British mandate. So we ended up in Palestine. And we lived in Palestine from 1941 to the end of 1947.

Zierler:

Also a very exciting time to be [laugh] in Palestine. [laugh]

Busza:

That’s right. In fact, it was more exciting than you may think. Let me tell you about it—do you know the history of that region? Are you by any chance Jewish?

Zierler:

I am Jewish, and I'm a historian, so I'm all set for all of these stories.

Busza:

Oh, so this will certainly interest you—you'll be amazed what I'm going to tell you. But first. So, we ended up in Palestine. My uncle, the one through whom we got there in the first place—became the doctor in charge of all the Polish orphans, who—there were lots of refugees who ended up in Palestine. And there were quite a lot of Polish orphans, mainly from Russia. Because the Russians, once they took over eastern Poland, they—I can’t think of the word—they deported educated people—teachers, doctors, priests, et cetera, to Siberia, with their families. And many parents died and so there were orphans, and they—again, for complicated reasons, many of them ended up in Palestine. And so, he was in charge of looking after them—bringing them back to health, et cetera. Actually, I'm not sure why I'm telling you all of this—that’s not that relevant—not of direct relevance to me. But anyway, so we lived in Palestine until 1947, at the time when the war between the Arabs and the Israelis started, and the English offered to evacuate the refugees from Palestine to England. And that’s why, in 1947, we ended up in England, at the end of November 1947. But back to what I think will interest you. If you know anything about the history of that region, you won’t believe this—I am a witness of the blowing up of the King David Hotel!

Zierler:

Wow!

Busza:

That’s what I thought. Most people wouldn't know what the heck I'm talking about.

Zierler:

Wow!

Busza:

I was probably about half a mile, quarter of a mile from it, when it was blown up.

Zierler:

So your family was in Jerusalem.

Busza:

Nearly all the time. At the very beginning, no. I can’t remember—at a place called something like Beit Hakerem. But only for a short while. But then—do you know Jerusalem?

Zierler:

Yes. Yes, I do.

Busza:

Okay. Well, for most of the time when we lived there, we lived either in Talpiot or Katamon. Do these mean anything to you?

Zierler:

They do, although demographically, I don’t know—at the time, were they Jewish neighborhoods? Were they Arab neighborhoods?

Busza:

There were three places where we lived—as I said, Talpiot, Katamon, and at the very end, Beit Jala. All of these are between Bethlehem and Jerusalem, the first two very close to Jerusalem. These are not big distances. I don’t know what’s the distance between Jerusalem and Bethlehem. It’s probably, what, ten miles, something like that? We're not talking about big distances. But anyway, Talpiot was a Jewish neighborhood. That’s where I have my first memories. We lived very close to a kibbutz. And I remember that kibbutz, but I can’t remember its name now. It was quite a big kibbutz. And then—and I don’t know exactly when—probably around 1945 is my guess—we moved to Katamon, which was ethnically mixed… there were certainly Jews there, but also—Armenians, Germans—sort of a mixed neighborhood. And the final place, Beit Jala, was an Arab neighborhood.

Why we moved from one to the other, I don’t know. Can’t remember. It may have been for economic reasons—cheaper accommodation… I don’t know. But, the interesting thing that I remember to the present day—when we lived in Katamon, we started going to a kindergarten, my brother and I, and the kindergarten was in Talpiot. What I distinctly remember is that each morning and afternoon, my mother taking us—and these are not big distances—we walked; we didn't have a car or anything—we would walk from our house to this kindergarten, and we would have to go through a maze of bags filled with sand and there were these British troops. After the attack on the King David Hotel, they had subdivided Jerusalem. Because… now I don’t want to get into politics. At that time, the name that was given to the Jewish resistance was “terrorists.”

Zierler:

Right. The Irgun.

Busza:

That was one name—well, there was—Haganah, Irgun Zvai Leumi, and Stern Gang.

Zierler:

The Stern Gang, right. The Stern Gang.

Busza:

These three I remember. And at the time, they were called terrorists, right? And so, Jerusalem was divided into sectors, to make it harder for them to operate in. And it so happened that in one sector was my kindergarten, and in another sector, we lived. And so every day, going to and back, we had to go through this maze. And you know, a kid of five or six, it’s fascinating. You know, you go through this maze, soldiers with guns. They would play with us. I remember that. That, I remember. So I remember that. I remember the kibbutz. And then, I remember, as I said—this was probably the most memorable thing in my life, was that explosion. Because I still remember stones falling near us from that explosion. I don’t think we were really in danger. They were sort of falling maybe 50, 100 yards from us. But I do remember that—the raining of the stones. And probably some of it is in—one’s memory or imagination, all confused—but I think I remember that. And another thing which I remember again was—and here, my memory and my brother’s differ—I remember that on the same day; he says it was on another occasion—but my memory is, we were in the house, that evening, after the explosion, and outside there was a shootout. You see, near where we lived, there was a monastery, an Armenian monastery—I believe it was Armenian—and in the grounds of that seminary, there was some kind of a battle going on between the British forces and whoever it was, one of those three organizations, having a shootout. So that I also remember. Okay, so where are we?

Zierler:

Wit, what languages are running through your head at this point?

Busza:

I don’t think there is a language—do memories have a language? Let me tell you, at that time, in addition to Polish, apparently I spoke, reasonably good Hebrew. Unfortunately, I've completely forgotten it. I regret that very much.

Zierler:

And this was because of school. Not at home, obviously. No one was speaking Hebrew at home.

Busza:

At home, I spoke Polish. Also, we were surrounded by Poles. For example, I remember holidays. We would nearly always spend them at a Polish military camp—tents in the desert where my uncle was working. It was part of this network of—places where the Polish orphans between the age of about 12 and 16 would be looked after, I know exactly where the camp was, because years later—I've been twice since then, no, three times, in Israel. And this camp was given a Polish name, Barbara which is the girl’s name Barbara. But when I looked for it later, it was not there—there is a town—it’s called Barbarit. So clearly the Poles changed the Jewish name from Barbarit to Barbara—or is it the other way around? It’s very close to Ashkelon. I don’t know; do you know Ashkelon?

Zierler:

I do, sure. Right on the coast.

Busza:

Right on the coast. Well, we used to swim often there, and I remember it must have been sufficiently close to Ashkelon that although I was five or six or whatever, with my mother, we would sometimes walk from the beach to the town, to buy ice cream or something. So it must have been the part of the beach which almost touches Ashkelon. When I saw it in the late seventies—yeah, late seventies—boy, had it changed!

Zierler:

Wit, another citizenship question. Before independence in 1948, what is your status in Palestine? Are you a refugee, subjects of the British Empire—?

Busza:

No, we had some kind of travel documents—hi, it’s my wife, [laugh] [phone rings]

Zierler:

Wit, the question was your status during the British mandate.

Busza:

Oh, I don’t know exactly—see, nobody is alive for me to ask. We were some kind of refugees—but what I do know from the pieces of paper, or documents we have—we still—my parents still had Polish passports—I found two passports belonging to my mother, one which was issued still in Poland, and it had expired. And that was issued before I was born. And then a brand new pre-war Polish passport, issued by the consulate in Jerusalem, in which I'm listed, with my photograph. So I certainly had Polish citizenship—at least until 1945. After 1945 there was in London a Polish government in exile, not recognized by most countries, and in Poland, a communist government installed by Stalin—so who knows what my status was between 1945 and 1948?! After November, 1947 we are in England—officially “stateless” refugees. And we were treated very well in England. You know, if I compare it to what’s happening on the border with Mexico, I want to cry, you understand…

Zierler:

Yes.

Busza:

[laugh] I'm sure our views would agree. We won’t talk about it. [laugh]

Zierler:

[laugh] Wit, let me just ask you, at this point here—the decision to go to England, did your family ever consider searching for their Jewish roots, in case they wanted to assert citizenship for a newly independent Israel? Did they see that as a possibility looking forward to 1948?

Busza:

Well, see, in 1947, when the war started, there was not an Israel state.

Zierler:

No, I know, but were they looking ahead toward the possibility of an independent Israel?

Busza:

I can’t answer that. I don’t know. I don’t think so. Remember that by that time my father ended up in Scotland. Also, at the end of 1947 it was not clear what will happen in Palestine. When did the United Nations officially recognize Israel? What year?

Zierler:

I think it was 1948.

Busza:

So, look, if that’s correct—in 1947 it would have been a non-issue for us. Palestine was still a British mandate and the Brits were leaving under pressure. They probably felt responsible for the refugees.

Zierler:

Yes, yes.

Busza:

And so they had to do something with them. Unless there was an alternative, they decided to move them all to England. At first, we were moved to Egypt, but only for a short while.

Zierler:

So it sounds, Wit, like your family’s own wishes were not really relevant to these decisions.

Busza:

No. No, I don’t think—

Zierler:

Like my question about if they considered searching for Jewish roots, that presupposed that maybe they were happy in Israel and they were looking for a reason to stay. But it sounds like that was not really available to them regardless.

Busza:

I don’t think so. But I'll tell you what I do remember—well, not remember; I don’t remember, but I know—that in 1947, they were given the choice, which was either to go back to Poland, or to go to England. Now, by 1947, the Russians had taken over Poland—the Russian Army, after having gone all the way to Berlin, stayed behind and installed a puppet communist government. So basically, the country was occupied. And it was a tough decision for my family, what to do? I remember, for example, my best friend—he was probably also seven—his mother decided to go back to Poland. Now, we decided to go to Britain. For one, my father was there, so it made sense for the family to get reunited.

Zierler:

Meaning he did his training in Scotland?

Busza:

No, no, no. Sorry, I have to remind you—my father was a medical doctor. And his first job—

Zierler:

Oh, yes.

Busza:

—was for my grandfather. And so he crossed to Romania with our whole family, and then immediately decided to help with the war effort as a doctor in the armed forces.

Zierler:

And he spoke English, obviously.

Busza:

I don’t know whether he spoke English.

Zierler:

He must have. To practice medicine in Scotland, he must have.

Busza:

No, no, at first, he worked in a Polish military hospital. You see the Polish Army—when it disintegrated—tried to re—form—

Zierler:

Right. A government in exile.

Busza:

Yes. So, they first tried in France—but then in mid—1940 France collapsed, so they moved on to Britain and from then on, they stayed as a unit—it was a Polish Army, but under British command, or whatever. They were part of the British Army. But speaking Polish, you understand. Let me give you one example. The famous—I'll give you the one that they're most proud of—the famous battle for the monastery of Monte Cassino. Have you heard of that monastery?

Zierler:

That I have not, no.

Busza:

There was a monastery—it’s not far from Rome. It was tragic it got destroyed. It was a big, historic monastery built by Saint Benedict—you know the Benedictine priests. Anyway, the point is that it was on top of a mountain overlooking the main road to Rome. So, the Germans put incredible defenses there. And for month after month, the Allies tried to conquer it, and they failed. The English failed. The Americans failed. The New Zealanders failed. And the Poles are very proud of it, that it was the reconstituted Polish Army—who finally conquered it. Tremendous losses, but it was considered worthwhile. So that’s an example of what was going on—there would be Polish forces, speaking Polish, with Polish generals and their own hospitals, but within the overall Allied Command, in particular British. Another example is North Africa—where they fought with Montgomery against Rommel. But anyway…

Zierler:

And how old were you when you got to England?

Busza:

To England? I was almost eight. I was seven. In January ’48, I would have been eight.

Zierler:

And where did your family end up?

Busza:

Okay, now you want that. This is an unpleasant part of the history of my family, but that too has to be said. Without us knowing it, my father turned out to be a bit of a rascal. We discovered it later. It turned out that, to the best of my family’s knowledge, he married my mother for money. And so when my mother lost everything—

Zierler:

He wasn’t so interested anymore.

Busza:

He wasn’t interested. So he basically abandoned the family. But, played one useful role [laugh]—we ended up in England. Sorry, I've now lost the thread. What were you asking? [laugh]

Zierler:

Where your family ended up in England. Where you settled.

Busza:

Okay, so we ended up in London, and it was a very hard time. Because—

Zierler:

London was decimated after the war.

Busza:

Yeah, London was—but also—my mother didn't speak English. Imagine, here is a woman, she’s in her forties, has with her—my grandfather had died in the meantime, in Jerusalem—but she had her mother to look after, two kids, can’t speak English, and has to make a living. The next 14 or so years were very hard for my mother. Although she had a university education, at first, she was working packing ice cream at a factory, and then as a waitress at a coffee bar, and then cooking at a home for kids from broken homes. Very hard.

Zierler:

Did you maintain a relationship with your father after you learned about this, or he left? He was out of your life?

Busza:

I would say—the answer is no, I did not, but it was more he did not. Strangely enough, he ended up as a doctor in America, specializing in rehabilitation!

Zierler:

Huh!

Busza:

Yeah, but he never wanted to see me.

Zierler:

Did your mother remarry? Did you have any other father figures in your life?

Busza:

No, no, no. Well, I had this fantastic uncle, who was like a father.

Zierler:

Well, that’s good.

Busza:

Yeah, yeah.

Zierler:

And what kind of school did you enroll in?

Busza:

Right. So, kindergarten [laugh] was in Jerusalem, right? [laugh] And that was a Polish kindergarten. But I was surrounded by Jewish kids and I learned Hebrew. That’s the kindergarten. Then when we ended up in London, at first we went to a local not very good school and I had to learn English. But, a stroke of good luck happened. Although my father, I’d say, behaved terribly, he was forced to pay a small alimony. And my mother or he or both decided to—because it was very hard for my mother to look after us two kids, one seven, one eight, and she had to earn a living, et cetera. And so, we were sent to a boarding school. This was a Catholic boarding school run entirely by religious people. And, I have to give it to them—they were extremely generous—my mother paid for one of us, and the other came for free. So that made it possible. So the next nine years, I was in a boarding school. And here I have to say—it’s always good, when something good happens—one hears of all these terrible English boarding schools, how kids are badly treated and sexually exploited and God knows what else—we did not experience that. The school was run by a religious order called the De La Salle Brothers, and I have to give them a lot of credit, because I owe them much.

I'll give you one example that always surprises people. And that’s why I'm saying it—what I distinctly remember them teaching me is that if ever my conscience disagrees with the teaching of the Church, I must follow my conscience, and not the teaching of the Church. So that gives you a flavor of the place. And I owe a lot to that school. Yeah. I have to confess, I'm not very religious today, but that’s a different story. But I have to be fair to the teachers I had, who I think did me a lot of good. Without them, I would not be talking to you now.

Zierler:

Wit, was your childhood financially stable? Did your family have to worry about where the next meal was coming from?

Busza:

Oh, yes. Oh, yes. Yeah, yeah, yeah. My mother was—look, as I said, here is a person with a university education, and she was cooking at a sort of orphanage. And the reason why she did that was so that for the holidays, we had somewhere to stay. She couldn't afford to both pay for our education, herself, and a place for us to live when we came for holidays. Look, just to give you a sense of how hard life was for my mother I remember—she was a cook at this boarding home and in addition to her meagre salary we got a tiny room—where the bathroom was an outhouse. So I mean, it wasn’t exactly luxurious. And at that time, no, we did not have much money.

Zierler:

Wit, when did you start to get interested in science? Was it early on, even before you were exposed to high school science?

Busza:

Oh. Before high school—no. Let me tell you. Until about the age of 12—no, older—until about the age of 13 or 14, I was under the influence of my family and thinking I would become a medical doctor. Because, see, my grandfather was, my uncle was, my father was, all doctors. So I thought of becoming a doctor. And then at the age of about 14, I switched. I realized that I would hate being a doctor. And then I wanted—I was very curious, and so I wanted to be—I wanted to understand how the world worked, where it came from. You know, the classic questions. This was encouraged by two things. One, I had a fantastic teacher, or even two—two teachers. One took an interest in me, a chemistry teacher, and the other one—you've never been in a boarding school?

Zierler:

No.

Busza:

No, no. So, one of the—you know, they've got to occupy the kids. And one of the things we had was once a week what we would call today a “colloquium.” Remember this was school. There would be a class for an hour where this one teacher would talk about something. He would try to explain how a jet engine or atom bomb worked, often it would have something to do with physics. And I loved those weekly classes. So, a combination of this wonderful chemistry teacher who took interest in me, and this guy who actually officially was an English Literature and Latin teacher, and gave these colloquia, and he—and again, I'm giving a lot of credit to these guys—for nine years, I had only one lay teacher, I think. All of the teachers were these religious people. And they spent their life teaching. That is their life. They live together—it’s a religious order—and they’re genuinely interested in education. And so they had a big influence on me. And I'll add one more thing which had a big influence on me. When I was older, about 15 or 16, we would be taken to the Christmas Lecture at the Royal Institution in London. A tradition started by Michael Faraday in 1825.

Zierler:

Yes.

Busza:

And Michael Faraday at first was a technician there.

Zierler:

Yes.

Busza:

And this institution, at Christmas time, would have a lecture for high schoolers given by leading scientists—for instance the two Braggs, Dewar, Fleming—with demonstrations. And they were fantastic! And so, it’s the combination of these teachers, these lectures, that convinced me that I love chemistry and physics. I didn't know—my school did not have the resources to have also biology—so we had no biology. So I cannot—so I only had mathematics, chemistry, and physics. And I have to go back for a second and tell you something. Until I was about 12, I was near the bottom of the class. And strangely enough, looking back, it didn't worry me. I had lousy grades, but I loved learning. It’s hard to understand, because when—once I started teaching, I tried to understand the problem students had with motivation. And in America, certainly often, students are not motivated. I'm not saying all, but enough. And again—why did I get onto this? Hold on. I was trying to tell you—

Zierler:

The question is when you started to become interested in science.

Busza:

Oh, yes—sorry, sorry. Yes. So, when I was in class, until about the age of 12 or 13, I had bad grades. And in those days, the schools were not so worried about the psyche of the kids. In our school, every week, on Saturday, the headmaster would come to our class—and the typical class had 40 kids. So, you're sitting with 40 kids, and he comes in, and he would give out paper certificates, on which there was a number, telling you—in public—which number you were in class that week. Every week, you received, if you were brilliant, a one or a two or a three, and if you were a dummy, 35, 36, 40… And I used to get eh, something like 27, 34, 37…

Zierler:

Wit, of course there are many reasons why one gets a bad grade. One could be a bad student or one could not understand the material. How did you understand your performance at this point?

Busza:

I'll tell you, what completely baffles me today—I had full confidence that “I'm going to do well.” I don’t know where it came from. See, this is the thing I don’t understand where this—is it from my mother? From God knows what. I was not worried. I knew this was some kind of an aberration and I will succeed. Okay? And the only thing it did—it forced me to try to excel in something. And what did I excel in? Billiards, chess, and table tennis.

Zierler:

[laugh]

Busza:

And later tennis. Those were the four things. So I became the school champion at table tennis. I was the champion at chess. I was the champion at billiards, and later of tennis. That’s where I put all my—to satisfy my ego, I suppose. And I was among the worst in class. Okay? And then comes the age of about 14 or 15. Over a period of one or two years, I switched from being near the bottom to being near the top. Don’t understand it.

Zierler:

Something clicked for you.

Busza:

Who knows?

Zierler:

And what specifically, Wit? What subjects or what areas did you all of a sudden get really good at?

Busza:

It was the importance of mathematics and science compared to arts and languages. To the present day, I can’t spell, and I'm useless at languages, et cetera. But we got off the subject of my interests. At that same time—a little later, I decided I'm not interested in medicine, and I wanted to do chemistry, physics, and mathematics. So, when it came time to apply to university—in England, unlike in America, you apply to study a subject. Showing my ignorance, I wanted a subject which does chemistry, mathematics, and physics. Obviously, that’s chemical engineering! So, I wanted to become a chemical engineer.

Zierler:

And in the British system, you have to make these decisions early on.

Busza:

When you enter. Okay? So hold on. Fortunately, I had a friend at school whose family knew a chemical engineer at Imperial College London. And this student said, “Oh, I must introduce you to this chemical engineer at Imperial College.” So, I go, one Saturday afternoon, from school, and I meet this chemical engineer, and I discover—the last thing I want to do is chemical engineering!

Zierler:

[laugh]

Busza:

It’s nothing what I thought it was! And that made me think what I really want, and I knew, “What I really want is physics.” Not be a bloody chemist or anything else. So, these accidents—the various—if I look at my life, there were many accidents which made me what I am—and just to finish the story—so I want to do physics. So, I have to go to university. I can’t apply to Cambridge or Oxford, because I don't have Latin. In those days, you had to have Latin. And my school did not have the resources to teach me both chemistry and Latin, so I had no Latin. So, I couldn't apply to Cambridge or Oxford—in retrospect, thank goodness, it would have been a terrible mismatch! So where to go? Well, my brother in the meantime—he decided to study English literature. And it’s interesting—I'll just—as a sideline—he then finally ended up as a professor of English at the University of British Columbia, and you had this Pole teaching the Canadians English [laugh].

But anyway, so he in the meantime got into University College London. And he said to me, “Why don’t you try University College London?” “All right. I’ll try it. Not a bad place.” So, I apply and I don’t get in. Not good enough. So they put me on a waiting list. And then come the exam results. Sorry I have to brag because we're talking—I had fantastic results. I got a state scholarship, which meant I could go anywhere and be given money to live on. So this was fantastic. And, University College, when they discovered that they made a mistake, they immediately let me in.

Zierler:

[laugh]

Busza:

So, I go to UCL to do physics. Have I worn you out? [laugh]

Zierler:

Not even close. Wit, what were the emphases on the program there? Did you do more theoretical-based classes or experimental-based classes?

Busza:

Again, nothing’s simple. First of all, In England, the bachelor’s degree is a three-year and not a four-year course. Because—the so-called A levels, studied in the English system in the last two high school years, are equivalent to the first year at university over here, roughly speaking. In my days, for the first two years, there were no choices. Everything was fixed. What subjects you have to take, everything. Not a single choice. There was this physics degree. And just for your interest, it’s interesting how much experimental stuff—I had nine hours of experiments every week.

Zierler:

Oh, boy. [laugh]

Busza:

It was incredible—it was, to a large extent, a waste of time. Because we did standard experiments, no imagination. But anyway, after two years, you had a choice. You did an experimental thesis, or you did some advanced subjects, more theory, higher level. And at that stage, I was ambitious. I decide to do both. But after about three months, I can't hack it, so I drop the theory, and get my degree doing the experimental version of the degree. And I don’t know what kind of a physicist you are, but—

Zierler:

I'm no kind of physicist. I'm a historian of physics.

Busza:

Okay, but you got a degree in physics, no?

Zierler:

No. History of science.

Busza:

Oh, that’s fun! I have always been fascinated by history! But anyway. I did my senior thesis on measuring the temperature of a plasma. I had to install a big vacuum tube, produce a plasma in it, measure its temperature and learn something about the plasma. It was for this guy who was my advisor, a certain Professor Robert Boyd—later Sir Robert Lewis Fullarton Boyd—Director of Mullard Space Science Laboratory in England. He was building a probe for a satellite experiment, and he wanted to test his idea in the lab, so he got me to work on it. But back a year, at some time during my second year in College, I realize that I want an academic career—I don’t know where it came from. And again—I don’t know why—I knew I would make it. I realize it may be difficult, but I knew I would succeed. Doubt wasn’t an issue—although, as you see, things are not going that well—I had to drop the theory because I couldn't hack it. Too much work and too hard.

And then on top of that—I discover that I can't do a PhD—I am not a British citizen—I can't get funded—and I have no money. As a student, I was as poor as a church mouse! Just to give you an idea, as a student I shared a dilapidated room with my brother—miles from the university—and can’t afford to buy lunch at College, at least on a regular basis. I just don't have enough money for that. And trying to do a PhD—where would I have the money? But then I discover that, if I get a first-class honors degree, even as a stateless person I'll be able to get a grant to do a PhD. And lo and behold, there luck strikes again. Normally, in every year at University College, one or two students get first-class honors in physics, out of a class of about 40. Well, in my year, eight people got first-class honors, and I was I think number seven or number eight.

Zierler:

[laugh]

Busza:

[laugh] Right? Right you are! So, with this luck I got a grant, then did my PhD at University College London, doing experiments at CERN in Geneva.

Zierler:

Was there a professor that you specifically wanted to work with for graduate school?

Busza:

Yes, and for a crazy reason. There was a guy, a South African, a guy called Franz Heymann. He taught me mechanics the first year, and I loved the guy. He was such—he was not only enthusiastic, but he was a fantastic human being. Actually, he got his education in South Africa, he left because of his disgust with the apartheid system, and he was a Communist. Great idealist. I was left leaning but with my background I was very much an anti-Communist. That’s not all—he even—this, you may not know, because it’s a long time ago—there was a movement in the world, but particularly in London, for nuclear disarmament.

Zierler:

Yes.

Busza:

And he was very active in that. And he, with a few other professors at University College, were working extremely hard to build a little transmitter with which they could superimpose a nuclear disarmament badge on the newscaster’s lapel during the TV news program. And they finally semi-succeeded. The problem was it was hard to superimpose—to get the timing right simultaneously for the whole country. They managed for a small area. About a kilometer by a kilometer, it worked. But to make it work, you had to be very close to the location where the transmitter for the news was located. So they basically failed. But anyway, that gives you some idea of the kind of guy he was. He later became the head of the department at University College London.

Zierler:

Now, Wit, was your work at CERN, was that baked into your curriculum from the beginning, or you developed that later on?

Busza:

That’s for the PhD. My bachelor’s degree was simply in “physics”. I don’t think it even said “experimental physics”.

Zierler:

No. I mean, when you started graduate school, was the plan that you would be doing research at CERN? Was that part of it right from the beginning?

Busza:

Yes, right from the beginning. I knew that Franz Heymann was doing an experiment at CERN.

Zierler:

What was he working on at CERN?

Busza:

In those days—these were the early days of CERN. We're now talking 1960. And the biggest accelerator at CERN was a 600 MeV proton synchrocyclotron. Tiny accelerator. It would fit in my house. Have you been to CERN?

Zierler:

I have not. Not yet.

Busza:

If you ever go there, there is an experiment called ALICE. Have you heard of that?

Zierler:

Yes, of course.

Busza:

They have offices at CERN. And guess where the offices are? They are built—they had to do something with this accelerator, and I think it was too heavy to move and useless, so they built offices around it. So, if you go to the ALICE offices, and if you go around, you will notice there are no offices on one side of the corridor—you’ll get a feeling there’s something not right, it’s because there is an accelerator buried in the middle. Well, that’s the accelerator where I did my PhD. So, I knew when I joined Franz’s group, I knew that we would be doing an experiment at CERN.

Zierler:

And what would you be doing there? What was your work going to be?

Busza:

That, I will tell you. It’s interesting in itself. Roughly, in 1960, just as I was joining Franz Heymann’s group, he finally got a US visa, and was willing to go to the United States. As a Communist, at first, they were not going to let him in, but finally he got a visa, and since it was an international conference—he decided to go, even though it was the US! Remember this is the tail end of the McCarthy era. So, Franz went—and he met Jim Cronin.

Zierler:

Ah. Yes.

Busza:

At the time, Jim Cronin was at—Princeton? Yeah. At the time, he was in Princeton. And Jim was trying to make a so-called spark chamber to work. Do you know what a spark chamber is?

Zierler:

Of course, yes.

Busza:

Oh, you do! Ah, I'm impressed! Okay. So, Cronin and some Japanese, who came up with the idea in the first place, were trying to make it work, and were making progress. A multi-plate spark chamber finally did work. After seeing what Cronin was up to, Franz came back and said to me, “I want you to build me a spark chamber.” So, the assignment for my first year of graduate work was to build a 32-plate spark chamber—a big box which could be evacuated and filled with a noble gas, in which there were parallel plates, equidistant from each other, with alternate plates electrically connected to each other.

Zierler:

How far developed were spark chambers at that point?

Busza:

They were not yet used in any experiment.

Zierler:

So there really wasn’t any data coming out of spark chamber experiments yet.

Busza:

Not by 1960, as far as I remember

Zierler:

Right, this is really early.

Busza:

Yes, it was early.

Zierler:

What were some of the major research questions that the development of spark chambers were designed to answer at that point?

Busza:

Rather than be specific, let me tell you the general issue. At that time nuclear emulsions and, more important, bubble chambers existed and were a fantastic tool to give you a visual picture of high energy particle collisions. You know what a bubble chamber is, of course.

Zierler:

Yes, yes.

Busza:

So, Glaser, when he invented the bubble chamber—produced really high-quality pictures of events, but there was a problem; there was no time information. So, if you were looking for a rare event, you would have to take millions of photographs, and have scanners—you know, there were rows and rows of scanners in the labs, looking at photographs, and making measurements by hand—and later using rudimentary automated systems. So the problem was, you had a beautiful technology for making pictures, but no time information. Alternatively, you had counters of various kinds—Cherenkov counters, scintillation counters—which had good time resolution but terrible spatial resolution, since each counter needed its own photomultiplier—a big device, and you couldn't at that time make the devices small enough. So, you could have good time resolution but with crude spatial resolution, or good spatial resolution and poor timing. But not both. Spark chambers were supposed to solve this problem. You had simultaneously good spatial—not as good as bubble chambers, but pretty good—with good time resolution.

So, for the study of rare events, where you needed reasonable spatial resolution, spark chambers filled the gap. For example, spark chambers proved to be fantastic in the study of neutrinos. People like Steinberger, Lederman, and Schwartz—the Nobel Prize—they basically got it by building huge efficient spark chambers. Now, why did they do so well, when we and others had difficulties at that time? Looking back, it’s very simple. They did something so obvious, so it may sound strange. Most people were trying to build something like a bubble chamber—many gaps, each capable of having many sparks—so you could see many tracks in it—like in a bubble chamber. So, for example, in our experiment, we needed a spatial detail given by a 32-gap spark chamber. And we were trying to make every gap fire efficiently. Do you know how a spark chamber works?

Zierler:

Yes.

Busza:

OK, so you apply a single high voltage pulse to alternate plates of the spark chamber, and you want sparks in every gap, wherever a charged particle crossed. What we soon discovered—that the gap width had to be incredibly uniform. And the voltage that was applied had to come on very fast. Otherwise, one spark would sometimes rob another. So, for example, in our chamber which had 32 gaps, sometimes a single crossing particle would give say seventeen sparks instead of 32. Once some gaps fired, they robbed the other plates of the voltage and so they didn’t spark. The problem was how to make a 32-gap chamber work efficiently. And looking back, the answer was obvious: you build 32 single-gap spark chambers, each triggered separately.

The problem then shifted to cost. The thyratrons which were used to fire these chambers were expensive. Making many two-plate chambers, with plates isolated from each other, inside its own gas container, was also not cheap. The brilliance of Schwarz, Steinberger, and Lederman was that they found an easy way to make a single gap chamber and a cheap way to fire them using spark gaps. They took two aluminum plates, and placed a Lucite frame to hold them apart, no vacuum containers but flowing gas—really cheap construction, and it worked—and if I remember correctly—they made their own spark gaps which also worked well. In short, they found a way to mass produce a cheaper device. As a side remark, my memory is that in those days the Americans seemed to be more ingenious, richer and bolder and overall more successful. This may have still been an after-effect of the devastating war.

Zierler:

Did you spend your time equally at CERN and back in England, or you were at CERN exclusively?

Busza:

No, no, no. In those days, at least the smaller experiments, were done differently. We basically did all the work in England. Once we had the experiment ready—

Zierler:

And how large was the collaboration? How many people would you be working with?

Busza:

Six. Yes, Order of magnitude, six.

Zierler:

At what point did you determine that you had enough material to develop your own dissertation?

Busza:

[pause] I'll tell you—if I am honest, the British PhD in those days was not at the level of an American PhD today. And it was almost like clockwork. In other words, you were expected to finish in about three or four years. And when three years passed, you’d have a chat with your advisor about what will be good enough for a PhD. And again, being honest, if a student today at MIT brought to me my thesis, I would fail him or her!

Zierler:

[laugh]

Busza:

[laugh] Certainly my PhD was nowhere near at the level of an MIT PhD today.

Zierler:

Well, it’s also many years ago.

Busza:

Different times, yes.

Zierler:

Wit, self-deprecation aside, what were your findings in your dissertation? What did you conclude?

Busza:

Oh! I will gladly tell you since it had consequences on my future interests. At that time, people were very interested in the size of cross-sections when different particles collided. For example, what is the cross-section when the negative pi-meson collides with a proton. And this particular cross-section can be directly measured. However, the neutral pi-meson colliding with a proton cross-section cannot be directly measured. Because you can't produce a neutral pi beam. And for reasons I don’t really remember now, it was one of the cross-sections of significant interests. Oh, no, sorry—no, no. No. What people really wanted to know was the cross-section when a pi collided with another pi—yes, I misspoke before. The problem is, of course, that you can't have a pi target, for a pi beam to collide with. And two guys whose name I'm sure you're familiar with—Francis Low and Geoff Chew—these two worked together, and people tell me that they were both good, but if you put the two together, they were much better than twice as good!

Zierler:

[laugh]

Busza:

I think that was true. Their best work was done when they worked together, and not later, when they went their own way. So Chew and Low did some theoretical work, and they came up with the so-called Chew-Low extrapolation. And this was a way of extracting cross—sections like the pi plus a pi cross section, which is not directly measurable, from the study of a measurable process such as a pi plus a proton producing a pi plus a second pi plus a proton. And we wanted to test this procedure—see if the Chew-Low extrapolation method really works. And I'll give you a simple explanation of the Chew-Low method—but first to continue—we wanted to determine the neutral pi colliding with a p cross-section, by studying the process p plus a p producing a p plus a p plus a neutral pi and using the Chew-Low extrapolation. And check if our result agrees with that derivable from the known positive pi and negative pi-p cross sections. Now back to a qualitative explanation of how the Chew-Low extrapolation works—it might help explain my future interests—future passion. Let’s imagine—stop me if I'm going too fast or too slow or something.

Zierler:

No, please, you're fine.

Busza:

Imagine a p p collision.

Zierler:

Yes.

Busza:

Sometimes a neutral pi-meson is produced. So, you have a proton hitting a proton and outcome two protons and a neutral pi. You can imagine this to be the following: you have a proton coming in and you have a stationary proton, which for a short time violates energy conservation and gives off a neutral pi-meson. So a proton, a bare proton in the target, occasionally will become a proton plus a pi-zero or a neutron plus a pi-plus, et cetera. Because of quantum mechanics it fluctuates like this. So, for a short period of time, your proton is a proton and a pi-zero. If at that instant of time, you send another proton at that system and catch it unawares, occasionally the incident proton hits the pi-zero. So occasionally you have a p pi-zero interaction. What comes out? Two protons and a pi-zero, because you've got proton coming in, you've got a target which is a proton and a pi-zero, you hit the pi-zero, the proton still stays behind, and the p pi-zero elastic scattering producing a proton and a pi-zero. So you have two protons and a pi-zero coming out. You with me?

Zierler:

Every bit.

Busza:

Oh, great! So by studying p p goes to p p pi-zero, I effectively can study p pi-zero. And the calculation to do that—for that I use the Chew-Low extrapolation. It basically calculates the probability that the proton is a proton plus a pi-zero.

Zierler:

Wit, another thing to mention here—maybe this wouldn't be impressive by today’s MIT standards, but in particle physics, this is really a fundamental time in the history of the field. New things, major things, were being discovered all of the time at this point.

Busza:

Yes, correct. But, also let me tell you—if I'm talking about 1960—yes, lots of exciting things happening! But, as often happens—you don’t always have great minds or ideas around, so this period is followed by a few years, roughly from 1960 to 1967, which looking back, superficially, seemed boring. There were all these resonances being discovered and it felt like stamp collecting—almost everybody just searching for new resonances or measuring their spin and parity. Of course, we know now—it was a time when crucial groundwork was being laid for the great explosion—the more than decade long renaissance of particle physics. As a side remark—today there are many fields where people are measuring things just because they can be measured. Who knows—

Zierler:

Sure. Well, this has always been a problem in high-energy and particle physics.

Busza:

[laugh] Okay, so you understand. What’s your background? Oh yes, you told me—it’s history—you're not—but anyway. But you at least follow this stuff. So, this is a very valuable period, because it collected lots of data. And, you know, this should be interesting for you—history repeats itself—back at the end of the 19th century, people were measuring spectra. Everybody was measuring spectra, right? Boring like anything. But, it formed the foundations of quantum mechanics, in a sense. All these spectral lines brought in some order and understanding. Plus it was so lucky that they didn't have good resolution. If the resolution of the spectrometers at the end of the 19th century was better, physics would be set back years—the complexity of the spectra would have killed them. You know, the split lines, the fine structure, the hyperfine—you know, all that. By having poor resolution, they saw the essential features—more understandable—less confusing. Well, now, go back to the sixties, it’s the same. Studies of particle physics phenomenology had just the right resolution—so people like Zweig and Gell-Mann saw in the data SU(3), et cetera. No doubt the 1960s are important from a historic point of view. Work was fun but, if I am honest, particle physics seemed to be getting a little boring. But back to me—1965—here I am lucky that I have a PhD, I look across the Atlantic, and I see most of the exciting stuff is over there.

Zierler:

Wit, did you know Sam Ting at this point?

Busza:

That’s later.

Zierler:

That’s later, okay.

Busza:

Yeah, that’s later. I'll come to that in a second. So, we see the green pastures across the Atlantic. In addition, for personal reasons, family reasons, with my wife—Wanda, whom I married in 1964—we wanted to leave England for a while. So everything aligned, “We should go to the States.” I was so lucky at that time to have Franz Heymann as an advisor. And another guy who was an emulsion physicist, Eric Burhop. I don’t know whether you ever heard of that name—Eric Burhop?

Zierler:

No.

Busza:

A good physicist. And they both said to me, “Look, everybody in the world is interested in proton accelerators. Don’t do it.” They said, “You want to go to Stanford. For two reasons. They're building an electron accelerator, the Standard Linear Accelerator. And there is a director there that is unique in the world—Pief Panofsky.”

Zierler:

Yes!

Busza:

Okay? And I can tell you a lot about him. That’s probably more interesting for you than Romania or Cyprus. Anyway, keeping as far as possible their advice in mind, I wrote four letters. Just four—shows how times have changed. I wrote to Jim Cronin at Princeton. I wrote to Richard Wilson at Harvard, and at Berkeley I wrote to—oh God, I forget his name, was it Crowe? because he didn't reply, but Perez-Mendez replied. He was in the same group. And, of course, I wrote to SLAC. And I cannot remember whether it was to a specific person or just to SLAC, to Panofsky. I don’t remember. But anyway, what happens: Cronin—no reply. Wilson offers me some crummy fellowship at half price. When everybody was getting $9,000 a year or so, he offered me four and a half thousand. And likewise Perez-Mendez. The stroke of luck was that Stanford in those days wasn’t that known. People weren’t flocking to go there. So, at SLAC they were looking for physicists to come.

Zierler:

Wit, what year is this now?

Busza:

Now, we're talking about 1965.

Zierler:

Okay, so SLAC is up and running at this point.

Busza:

No, no.

Zierler:

It’s not?

Busza:

It’s being built.

Zierler:

It’s being built, still.

Busza:

Yeah.

Zierler:

Not even the Monster is up?

Busza:

No. No, no. No, it is still being built. It so happens that at that time there’s a conference in Oxford that Marty Perl attends. And I was doing an experiment nearby at the Rutherford Lab. This is after my CERN days. And Marty interviews me. So, I had an interview with Marty Perl, and, you know, because in England at that time we had fewer resources, we did more things ourselves. So I was building some hardware. I was actually building some of the circuits myself, et cetera. And I think Marty was impressed—I was at the accelerator showing stuff that I actually built with my own hands, not bought. It was not that I was brilliant with my hands but an American was impressed. In those days, for example, the first 1 GeV synchrotron was built by students, at Birmingham. They actually wired the magnets! So, Marty Perl interviews me, and the other stroke of luck was, when I was at CERN, I was in a counting house which was shared with another experiment, I can’t remember whose, in which a guy called Robert Diebold was—you've heard the name?

Zierler:

Yes!

Busza:

You don’t by any chance have his phone number? I've lost touch with him.

Zierler:

No. We could look for that, though.

Busza:

If you can find him, I want to write him an email, because I am grateful to him—when we first arrived in the US, he and his wife helped us a great deal. So anyway, we shared a counting house—he was a hands-on guy, working days and nights. I was at CERN also working days and nights. And so we got to know each other quite well. And then you won’t believe this—shortly before I applied to SLAC, that summer, with my wife, we went to Spain, and in a street, in Spain, unplanned, we bumped into Robert Diebold and his wife. And so we renewed our acquaintance, and then Robert got a job at SLAC, and when I was applying, I wrote to him and said, “What do you think of SLAC?” And he said, “It’s a fantastic place, but in particular, if you come, make sure you work with Richter.” So, looking back, I get interviewed by one Nobel Laureate [laugh], Marty Perl, and I'm told I should apply to another, to try to get into Richter’s group. They didn't have the Nobel Prize yet, that was to come. And so when I was offered the job, I said, “I want to go to work with Richter.” And, he said, “Fine.” And then come three years which occur once in a century. There was the era of Rutherford at Cambridge, there was Bohr at Copenhagen, and now there is Panofsky at SLAC. Panofsky should have had five Nobel Prizes!

Zierler:

[laugh]

Busza:

That lab was incredible! It was relatively small in those days. All the young guys had the same contract. It was called the beam-plus-three. Didn't matter when you came; your contract ended three years after the accelerator switched on. So Bob Diebold was there for five years. I arrived at SLAC one month before the accelerator switched on. So I was there three years and one month.

Zierler:

Oh wow, wow.

Busza:

And all the young people were in that situation. It had only one disadvantage; at the end, we all were looking for a job at the same time. That’s the only disadvantage. But the atmosphere there was phenomenal. People were so good, and they were genuinely interested in what they were doing. I've worked in many places. I did an experiment at the Rutherford lab shortly after the accelerator NIMROD was constructed. I went to Fermilab even before the construction of the main ring accelerator. And I was at CERN in the early days—when the PS was being built. And I've been at MIT, which isn’t a bad place, either! But, for particle physics, that period of three years at SLAC between 1966 and 1969 was—unique. And I give the credit mainly to Panofsky. The others, they were not bad. You know, Richter and Perl, they were not bad. And theorists—Bjorken and Berman, Drell, et cetera—not bad. And visitors—Feynman and Bell—not bad—but I am joking of course! The place was full of brilliant people. And the atmosphere was fantastic. I'll give you just a few examples.

Zierler:

Please.

Busza:

One example was that, on Monday evening, Panofsky would invite—nearly every Monday—all the physicists, and all the guests at the lab, to his house, for coffee and cookies. And one of the visitors would be roped in to give a talk.

Zierler:

This was family. He treated this like family.

Busza:

Yes. Well, what made it easier—in those days around SLAC the traffic was not bad. Everybody lives not far. So basically in 15, 20 minutes, you could get to his house. So it was not like taking a two-hour journey, so it’s 15, 20 minutes. Pief and Adele, the Panofskys, did it just right—cheapo cookies and some coffee—otherwise—every Monday—it would have killed them with all the effort. So, the focus was not on food. It was talking to people, the lecture, discussion—the physics. More about Panofsky—some of these stories you may have heard from others.

Zierler:

I want to hear from you.

Busza:

I'll give you two more examples—to give you a sense who Panofsky was. In 1966, before I left England, University College, I picked up the phone and I called the head of the department, Sir Harry Massey. Have you heard of him?

Zierler:

No.

Busza:

He wrote a well-known book—Mott and Massey. He became a Sir Harry. The queen knighted him, et cetera. He was quite an influential English physicist. He was one of Rutherford’s boys at Cambridge. But anyway, he was the head of our department. And I pick up the phone, call his secretary, and I say, “By the way, I've been here for nine years.”—an undergraduate for three, four as a graduate student—and then two as a postdoc—So, “I’ve been here for nine years, and I would like to say goodbye to Sir Harry Massey and thank him, et cetera. Do you think in the next three months there is a chance he would have the time to see me?” “Oh, no problem, no problem. I'll let you know.” Two months later, I call again. And I say, “I'm leaving soon. Any chance?” She replies: “You know, he’s so busy.” Anyway, never saw him. Okay? I arrive at SLAC, and I pick up the phone and say to Panofsky’s secretary, “I've come from England. I'm here to work with Richter, et cetera. In the next three months, is there a chance I could introduce myself to Professor Panofsky?” And she said, “How about at 2:30 pm?”

Zierler:

You weren’t ready for that so quick. [laugh]

Busza:

Yes! He was just amazing in that way. The other story is: one day—stop me if you've heard the story, but these are facts—one day, his secretary got a new job—was being replaced. And if you've ever been to SLAC in those days, Panofsky had a very long office. At one end was the secretary’s desk, and at the other, his. Have you already seen the photograph of Panofsky?

Zierler:

Yes, sure.

Busza:

A tiny guy with dirty clothes on, a torn sweater, all right? So, he gets this new secretary, and she sits at her desk, the first day.

Zierler:

Who was there? Marybeth Beerbohm?

Busza:

I tell you, I don’t remember, unfortunately. No, I don’t remember. But anyway, in comes Panofsky, this scrappy fellow. And she points to the garbage can, all right? And so, this tiny guy goes, picks up the garbage can, takes it outside, throws out the garbage, comes back, puts the can by the secretary, and goes—sits at his desk. [laugh] And this was typical. And at lunch—I must have had dozens of lunches with Pief. He would join whoever is there, whether it was a young postdoc like me, or Bjorken or Feynman. And all the fantastic people—I remember Bell coming in to tell us about the Bell inequality, not bad eh? I remember Feynman coming numerous times, giving talks and discussing. It’s no accident that partons were discovered at SLAC. Look, when I was there, I was working with four future Nobel laureates—I worked for Richter, and we worked on an experimental facility jointly with Friedman, Kendall and Taylor. At the time, we didn't know it, of course, but that time was just—as I say, the atmosphere was phenomenal.

Zierler:

And what were you working on at that point?

Busza:

I'll tell you—looking back—the actual experiments I was working on were not that important. But, from the point of view of my evolution and career, they were super important. Let me try to explain. First of all, starting with this pp, going to pp pi zero, I have a sort of a split thinking in my head. And by that, I mean the following: I fully realize and I would even use the word “understand” that nature cannot be described in words. Okay?

Zierler:

Nature can only be described in math, is what you're saying.

Busza:

Yes, yes. And it’s always—so often students would come to me when I was teaching—“Can you tell me, how can you be a particle and a wave at the same time?” And I would always answer, “If you ask a stupid question, you will get a stupid answer.”

Zierler:

Meaning those are just words. Particles and waves are simply words.

Busza:

Words. And there is—

Zierler:

Of course Einstein had this problem as well.

Busza:

Sure. Look, most people have this problem! In fact, I think that’s the hardest thing to explain, in particular to non-physicists, but even to physicists—that the world cannot be described in English, in Chinese et cetera. I mean, just today, entanglement has become popular, right? I mean, there is no way you can explain entanglement in words. It’s as difficult a concept as consciousness. Try to explain what consciousness is in words, right?

Zierler:

[laugh]

Busza:

It’s the same sort of thing. Words are a kind of analogy and we don’t have the right analogies—to describe nature as it is—in words. But anyway, so back to how my brain works. On the one hand, I fully realize that nature cannot be described in words. On the other hand, I think in pictures. So, for me, this pp goes to pp pi zero is a picture. I know the picture is not the reality, nevertheless such pictures—give me insights—better understanding—point in the direction of what needs to be studied. Succeeding to translate a mathematical description of a phenomenon into some sort of a picture, however crude or approximate, is what gives me great joy. And here I must add something very important—when I think of a physical process in pictures, I think of it in various frames of reference and different magnification or focus. Because of special relativity and quantum mechanics, a process can look completely different at different size scales and in two reference frames—often deep understanding comes from this difference—how did we get here? Oh, yes—at SLAC, I was involved in two experiments. With Richter, directly, on the study of photoproduction—you know SLAC could also produce a high-energy gamma beam from the electrons, and then you could study gamma scattering and productions of particles, et cetera. These experiments in reality—were useful at the time, but they weren’t great. And then I was asked to help David Leith—sadly a couple of weeks ago he passed away. A super decent and nice human being. And with him we studied—in some ways something analogous to what I did at CERN—we studied the cross-section of the rho-meson, a particle that lives for an infinitesimal fraction of a second, colliding with a proton. I have to explain. If you have a high energy gamma hitting a proton, the first thing that happens—the gamma turns into a meson such as the rho. You know what I'm talking about?

Zierler:

Yes.

Busza:

And it turns out that if you do this process using a nucleus—in other words, gamma hitting a nucleus and producing two pi-mesons—you can analyze the whole chain as first a gamma becoming a rho, the rho then elastically scatters off the nucleus and finally decaying into the detected two pions. If you do such studies using different size nuclei, you can, using the so-called Glauber model, that’s a big word—it’s a technique—you can calculate the rho proton cross-section. At that time, the two questions—how does the gamma become a rho; in other words, how is it that a photon, an electromagnetic particle, can have hadronic properties—and what is the size of the rho, were of significant interest. The second—the size of the rho meson, today we know that the rho is a qq-bar pair, but in those days, we did not know whether it was an elementary particle, or was it like a molecule, a two pi-meson molecule. Today, it sounds strange, but then we did not know. So, if we measured the rho proton cross-section, the question was, is it 25 millibarns, like that of a single pi-meson, or 50 millibarns. If it’s a molecule, it would be something like 50 millibarns. But if it’s an elementary particle, it would be more like 25 millibarns.

This experiment, in retrospect, was not too important. But at that time, it was a hot topic. And something interesting happened. There were three experiments in the world studying this. There was Ting’s group studying it at DESY, Silverman’s at Cornell and Leith’s at SLAC. And we all got different answers. This was an important question at that time and emotions were running high, so it was difficult to sort out the facts. Now, in Vienna, there was the Rochester conference, and Panofsky was reporting on this, and it occupied center stage. Who was right? What are the results? Et cetera. Looking back, my recollection is that of a comedy of errors! All three groups were wrong. We at SLAC screwed up, because our colorimeter was saturating. The Cornell group screwed up because of a programming bug. And the DESY group screwed up because they didn't understand the theory and did not analyze the data correctly.

Zierler:

And what was your position in these debates? What did you think?

Busza:

At first, I could not understand what was going on—here are three experiments, all getting different answers. Once we realized our colorimeter was saturating—of course, I knew why our answer must be wrong. The DESY group was the closest to getting the right answer—but by accident—I realized that they made two mistakes which cancelled each other! So, why was this study of the production of rho mesons off nuclear targets and the saga of three groups disagreeing so important for me? Most important—it stimulated in me this interest of using nuclei as tools for studying particle physics—and this has stayed with me for the rest of my life. I credit it for my pioneering studies at Fermilab of proton-nucleus collisions—results which were among the facts that led to the birth of the field of relativistic heavy ion collisions. You see, for me, from visualizing a proton hitting a proton and producing a neutral pion or a photon turning into a rho-meson and then scattering off a nucleus, it’s not a big extrapolation to the questions that led to my future research interests—I started to think, for example, what happens when you collide two protons at high energy and produce many particles—What goes on? So you have these two protons colliding, and twenty particles come out, all roughly the size of a proton. How is that possible? What happens at the very beginning of the collision? What is the state that is produced at first? Theorists thinking in terms of equations did not seem to be concerned about such questions. But I did. And in my mind, I had these pictures of two glass—like spheres shattering, or of two liquid drops coalescing, oscillating and breaking up. Which is closer to reality? It is this kind of questions which led to my experiments at Fermilab, RHIC and LHC—the questions in turn have their origin in the fact that I always try to think in pictures—even Feynman diagrams—for me they are pictures of real processes.

Zierler:

They're real because you think in pictures, as you say.

Busza:

Yes. But I must repeat—I fully realize the pictures are not the reality [laugh], if you see what I'm saying—pictures are not the language that can be used to describe nature as it actually is. But anyway, so that’s the main reason why the rho production experiment at SLAC was for me so important. The other is that it led to me getting a job at MIT.

Zierler:

Wit, let me ask—was your term at SLAC, was it a specific term? Could you have stayed on longer there if you wanted?

Busza:

As I said before—no. Hold on. There was one possibility, but I was not good enough. All of us had this beam-plus-three (years) contract. About seven or eight—maybe a few more, I can’t remember—but a whole bunch of us. We all—had in writing—that three years after the SLAC Linac produces the first beams, our postdoc will end. So, I could not have stayed on as a postdoc. If somebody was good enough, he could have been offered a faculty position or group leadership or something. And I don’t remember if there was anybody who was offered this option. There were some on the research staff who had different contracts right from the beginning, to do more technical work. They were the people who were building the actual accelerator or facility. I remember there was a guy called Fatin Bulos with whom I worked, and Rudi Larsen et cetera. They had different contracts. But the postdocs who were brought in to do the first experiments with the new Linac, all had the same contract, and at the end we were all looking for jobs at the same time. Furthermore, over that three-year period, the fiscal climate changed. It was very hard to get a job in 1969.

Zierler:

So how did MIT come together for you?

Busza:

Okay, how? By complete accident.

Zierler:

This is a theme, I see, in your life.

Busza:

But it’s true and I think it’s the case for most people. Accidents or luck play an incredibly important role in life—whether we use it or not—ah, that’s…

Zierler:

Yes.

Busza:

MIT—So how did that happen? Ting came to SLAC, and he gave a talk. And I met him. I was trying to understand who was right. And I pointed out to him the error made by his group.

Zierler:

Which was what?

Busza:

They misunderstood the theory—how to extrapolate the data as a function of transverse momentum. Now, he must have been impressed with my comments—he asked me whether I wanted a faculty position at MIT. No doubt recommendations from one or more of my bosses at SLAC must have helped.

Zierler:

So this was assistant professor? You would be joining the faculty.

Busza:

Yes. That’s how I came to MIT.

Zierler:

Wit, at this point, were you ready to make a life for yourself in the United States? Did you think you would return to England after SLAC at any point?

Busza:

[pause] One year after coming to SLAC, this guy I mentioned earlier, Eric Burhop at University College London, offered me a job, as assistant lecturer, I think that’s what the position was called. And at that time, with my wife, we discussed the question of going back, and we decided that it was too early. It wasn’t that we didn’t want to go back to Europe, but it was too early. We had a real choice. I had an offer, and we decided not to take it. I have to say—I lived in England for 18 years, and we liked England in many ways, but after six months at SLAC, in America, I felt less foreign there than I did in England after 18 years.

Zierler:

That’s very interesting.

Busza:

What’s even more interesting or amusing—my older daughter Joanna, who was born in the United States, educated in the United States, is now a Professor, in England, at the London School of Hygiene and Tropical Medicine. [laugh]—a few hundred yards from the office that I had at University College, just before we left for the US!.

Zierler:

Wit, I wonder for you if that can be explained by the fact that England has a more cohesive national identity than the United States does. It’s just a bigger and more complex place, easier for you to fit in, perhaps.

Busza:

Yes. The English are more insular—I don’t think Brexit would have happened in America.

Zierler:

Yeah, yeah.

Busza:

I think things have changed in England. It has become more cosmopolitan. But still—Brexit has happened,

Zierler:

Wit, what were your impressions of MIT when you first got there? Of the physics department?

Busza:

Oh, I loved it from the beginning.

Zierler:

And who was chair at that point? Was it Weisskopf?

Busza:

Yes. Weisskopf was the chair.

Zierler:

Did you get to know him well?

Busza:

Yes, very well, for many reasons—I have to go back. When I was a graduate student—my income was barely sufficient, so I used to teach one or two evenings a week at the Northern Polytechnic—it was something like a junior college—it was a place attended by those who wanted to catch up with their education. And I was teaching physics to people twice my age. But, as a result, I got a few years of experience teaching, and it had two consequences—I realized I love teaching and I became an experienced teacher.

Zierler:

Yeah, yeah. And at SLAC, you didn't teach at all. There was no opportunity to teach at SLAC.

Busza:

Zero.

Zierler:

So your abilities as a teaching professor only occur to you when you were actually a professor.

Busza:

Yes, yes. And so, when I arrive at MIT, I am immediately recognized as a good teacher. I had an advantage over other guys who had not taught before.

Zierler:

Wit, I wonder if because of your preference or ability to think in pictures, that you found that this was a very effective way to communicate physics concepts to undergraduates.

Busza:

Yes, oh yes, yes, I am sure that’s the case.

Zierler:

And what kinds of courses did you teach?

Busza:

They always got me to teach the freshman and sophomore courses.

Zierler:

The big ones.

Busza:

The big ones. Sometimes to a thousand students. But why did I bring it up now? Oh yes—very early on, whether it was the second or third year—I can’t remember—the department became concerned that our teaching was not very good. Before that time, teaching was not considered very important. Over the years, one of the great changes that I have noticed in our department is the emphasis on good teaching. Today, it’s really important. It can help you get tenure. So, what happened was that the department became concerned that students did not like the freshmen physics courses, and Weisskopf decided he’s going to teach freshman Electricity and Magnetism. So, he said, “Look, I want to teach this course, and see if I can do better”. But, to teach to a thousand students, you need to have demonstrations, et cetera. So, he decided he was going to ask two assistant professors to help him, Mike Feld and me. And the way it worked was—now, you would never have this happen in Europe—you have to be in America—once a week, Weisskopf, Feld and I met for three hours, discussing what Weisskopf would teach the following week. Can you imagine?

Zierler:

Oh, wow. He wanted your input on what he would teach?

Busza:

Yes. And he wanted to see how it can be done better. We had to produce, not a book, but a handout for the students. We prepared the demonstrations. And I learned so much. Let me tell you, I learnt a great way of how to write a paper or a book collaboratively with someone—meet weekly and discuss, in detail, the content or message of everything that you are in the process of writing. Here is one example of a discussion we had with Weisskopf before he gave one of his lectures.

Zierler:

Please.

Busza:

One day, Weisskopf comes in and says, “I don’t understand how a battery works.” And he says, “Look, here is the homework. You are only allowed to use Newtonian mechanics and Maxwell’s equations, and explain to me how a battery works.” Next week we met; I failed. Feld failed. Following week, Weisskopf calls the head of the Department of Chemistry. He comes back, and says, “he failed.” Here we are, at MIT, with these great chemists, great physicists, and we don’t understand how a battery works!

Zierler:

[laugh]

Busza:

“I therefore”—this is Weisskopf speaking—“I therefore come to the conclusion that you cannot explain a battery with only Newtonian mechanics and Maxwell’s equations. There must be another law of nature that doesn't follow from these.”

Zierler:

What was he thinking of? What could it be?

Busza:

Now, there’s the homework. Do you want to do the homework, or shall I tell you now? [laugh]

Zierler:

You tell me now, because we need to get it on the record.

Busza:

It’s entropy, probability, chemistry, and all that.

Zierler:

Oh. Aha, aha.

Busza:

It’s something that cannot be derived from Newton’s laws and Maxwell’s equations. It’s Boltzmann’s work—and in fact, there are aspects to the present day that bother me and probably bothered Boltzmann. You know, we—you and I and everybody—believes that what will happen is the maximally probable thing. You know, statistically. But why? The world occurs only once. Why should the maximum be what happens? It’s not that we do this experiment ten times. Why is it that the maximum is what actually happens? I don’t have a good answer for that—unless an infinite number of universes exist—but I don’t believe that!

Zierler:

Wit, of course that’s as much a philosophical question as it is a scientific question.

Busza:

Okay, but anyway, the battery, you need entropy. Otherwise, it won’t work. [laugh]

Zierler:

Wit, what you're saying about Weisskopf asking you for your input—I've heard this said about him, that he was specifically good with junior faculty, with making junior faculty feel included and as peers to senior faculty in the department.

Busza:

He was great in many, many ways. I first met him at CERN. And it’s amazing—here I was, 20 years old, okay? Beginning graduate student. And I don’t know how it happened, but I remember having a discussion with Weisskopf! I don’t know whether we met after some seminar, or he invited me into his office. I can’t remember. But I do remember—Weisskopf was then director general of CERN, and I remember being amazed that I had this opportunity to talk with him about physics. So, he must have been approachable.

Zierler:

Wit, what were your lab affiliations when you got to MIT? Where were you going to be conducting your work?

Busza:

In those days, the structure of the physics department was almost like a fiefdom of some kind. The influential professors like Kendall or Friedman or Ting or Pless or Deutsch, et cetera, they were like independent dukes. It’s crazy; I got the job at MIT by an offer from Ting. This is a faculty position. I didn't have an interview with the other faculty. Sam offered me the job. And for the first two years, I worked with him, at DESY and Fermilab—and then I decided I want to work by myself. And so—

Zierler:

Were you involved in the J particle at all?

Busza:

Hard to answer that question. I'll tell you the facts, and you can think what you want.

Zierler:

[laugh]

Busza:

The facts are the following. I was working with him at the time of the proposal. The day the proposal got accepted, I decided to leave his group.

Zierler:

Ooh. [laugh]

Busza:

That’s right?

Zierler:

[laugh]

Busza:

And I've never had any regrets.

Zierler:

No?

Busza:

No. Absolutely not. Zero. Because that’s when I started doing my own work, and I loved it.

Zierler:

Meaning that what you were doing yourself was even more precious than possibly winning a Nobel Prize.

Busza:

Yes, that’s right. Plus, in any case, it’s highly unlikely I would have been included in it.

Zierler:

Of course. Of course.

Busza:

In fact, if I'm honest, if I look at the collection of people at that time in Ting’s group, the person who should have got it with Sam is Ulrich Becker. He, from the beginning, from the proposal, to the designing and building… he should have got a Nobel Prize. And I think he didn't, for the following complicated political reason.

Zierler:

Well, first of all, there’s also Burt Richter. There’s only so many people to be able to recognize for this.

Busza:

You've put your finger on it. Exactly. That’s the point. See, Richter and Ting both should have got it. Now, you've got room for one more. Three is the maximum. So who is it? Roy Schwitters? Marty Breidenbach? Ulrich Becker? You've got a problem. Is it from this collaboration or that collaboration?

Zierler:

Right, right.

Busza:

—and even if you favor one of the collaborations, there are still a few characters in it. So, your question isn’t really relevant.

Zierler:

It’s hard to say.

Busza:

Yes. But the probability that I would have got a Nobel Prize for the J/Psi, is zero. And the fact that I started something new—I've had years and years of fun—not to mention that I feel that my work had a real impact on the new and exciting field of relativistic heavy ion collision physics—all so satisfying!

Zierler:

Wit, let me ask you like this—what compelled you to leave the proposal? What did you want to do when you wanted to go out on your own?

Busza:

[pause] Tough question. [laugh]

Zierler:

You knew more of what you wanted not to do than what you knew you wanted to do.

Busza:

Yes, yes, you are right. I knew more—yes.

Zierler:

But of course, you would go on to do other research. What did you go on to work on?

Busza:

What did I do? Oh! The short answer is—I started working on the kind of physics that the relativistic heavy ion program has evolved into—of understanding QCD at high temperature and high energy density—of the state of the universe at about a microsecond after the big bang. But coming down to earth—more concretely what physics interested me at that time? I wanted to address the question I mentioned earlier—what actually happens in space—time when two protons collide at very high energy and many particles are produced. How does that happen? Is there an intermediate state? If so, what is it? What are it’s properties? And I would go to theorists—nobody could tell me. In those days, most particle physicists did not think in space-time. It was foreign to them. They had mathematical equations in their heads. And some of them couldn't even understand what I was asking. But that’s what I wanted to study—and I, with one student that I had—Charlie Young, who’s now at SLAC, head of the SLAC part of the ATLAS collaboration—do you know Charlie Young?

Zierler:

I know of him. I don’t know him, but I know of him.

Busza:

He was my first student.

Zierler:

And of course the SLAC contribution to ATLAS has been phenomenal.

Busza:

Well, he was my first graduate student. I'm not exaggerating when I say that he and I did a complete high-energy experiment by ourselves at Fermilab—Experiment E178. If you ever look it up, it’s interesting, because on the proposal you will find my name, the names of two Nobel laureates and that of one full professor: Jerry Friedman, Henry Kendall and Larry Rosenson. Why? Because my MIT colleagues thought that Fermilab would laugh if I put only my name and one student on a high-energy experiment proposal. [laugh]

Zierler:

[laugh]

Busza:

So they said: “Put our names on. It may help to get you approved”—and they were right. It did help and I should add—I think that another person—Leon Lederman—helped a lot.

Zierler:

Why Lederman? What was he able to do, to get the approval?

Busza:

I think he was the lab director at the time. My memory is failing. He certainly was a lab director—was it then or later? I would be amazed if he did not play a role—he liked oddball ideas! But anyway, certainly those three names helped to get the experiment approved. And then when we started taking data there was only the two of us—Charlie Young and I—and we had to find students or volunteers from other experiments to help us cover the shifts. And so finally, the publication—I think has six names—none of those three big-shots but included four “adjunct members.” And the experiment I proposed was very simple.

Zierler:

Wit, let me ask you at this point—what are some of the theoretical advances in the field that are helping you to conceptualize these collisions? What was going on in the world of particle theory at this point which was relevant for you?

Busza:

Nothing.

Zierler:

[laugh]

Busza:

Nothing. No, I'm serious. For me personally—it was the coherent production of the rho experiment, about which I told you earlier, and my way of thinking about physics that influenced my experimental program.

Zierler:

Meaning the idea was that the experiment at this point was driving the theory, not vice versa?

Busza:

To address the kind of issues I wanted to understand—yes—What goes on in space-time—nobody could tell me. But perhaps I am a little unfair to the theorists. Already in the 1950s Pomeranchuk asked the question what degrees of freedom should be used for the state produced immediately after a pp collision, and Landau even developed a hydrodynamic model of that state. I am ashamed to admit that, at the time I was thinking of studying these questions at Fermilab, I was not aware of those works. However, at that time, I was aware that there were some theorists starting to get interested in such questions—Kurt Gottfried at Cornell, with his energy flux cascade model, is a good example.

Zierler:

And what years are we talking about now?

Busza:

1972. But back to my experiment—so I thought: how can I distinguish between the various possible intermediate states that exist between the instant of collision of two particles and the final outgoing multiparticle state. It occurred to me that the study of proton-nucleus collisions could give some answers and I proposed—something you will immediately understand—you know about electromagnetic showers, right? You know what that is?

Zierler:

Certainly.

Busza:

Well, so I thought, how do you know there is a shower in a chunk of lead through which a high energy photon or electron passes, and how do you study it?—You look how many electrons, photons come out as you change the thickness of the lead—and you find that the number of particles coming out grows exponentially as you increase the thickness. So, I thought, okay, let me do an analogous experiment—have a proton hitting various size nuclei, and see how many particles come out. As I mentioned earlier, we proposed the experiment to Fermilab—it was Experiment E178—we were approved and lo and behold we immediately got a surprise. So did the theorists. No exponential growth, instead, the total number of particles that come out is simply proportional to the thickness of the nucleus. Its linear with thickness. Today, there is even a name used for this scaling. It is called “participant scaling.” We didn't use that language then. We called it nu-bar scaling and Bialas, a theorist, even came up with a model—the “wounded nucleon model” to describe this behavior.

We also saw that there was very little dependence on the nuclear target of the number of particles produced in the forward direction. We concluded that our results are inconsistent with the shattered glass picture of particle production in proton-proton collisions. The results suggested that the production process, in the pp center of mass frame, looks more like the collision of two droplets, producing a single excited droplet which stretches, vibrates and oscillates, and over a long time gradually decays into the outgoing final particle state. Now, why am I telling you this? Today, one of the most important discoveries of the relativistic heavy ion collision research program is that the system created is some kind of a super liquid, one with extremely low viscosity to entropy ratio, and there are even studies of the hydrodynamic properties of the system created in p-p collisions!

Next, to get a better understanding of the physics I was seeing, I followed these measurements with as many other measurements as I could, given my very limited resources. I sort of feel that I piggybacked on the existing large experiments at Fermilab—I would say to the leaders: “Look, let me replace the proton target in your experiment by various nuclear targets and see how different the results are.” And they and the lab would let me do it—let me add that I think that one of the reasons why they were so cooperative was a review that I wrote in 1977 for Acta Physica Polonica: “Review of Experimental Data on Hadron—Nucleus Collisions at High Energies”. I have the impression that it influenced the particle physics community, which at that time was almost completely unaware of what can be learned from studies involving nuclei. In this way I did or participated in Fermilab experiments E451, E565 and E665.

This brings me to something I should have told you earlier and now I can’t resist telling you—Let’s go back in time. Earlier you asked me something about what it was like looking for a job, at the end of my SLAC days. Well, at that time, there was a prestigious faculty position posted at either Penn State or University of Pennsylvania. I can’t remember which. And I applied for it. The application asked: what will I do? And I wrote, “I'm interested in using nuclei for studying particle physics.” In those days, that sounded crazy. I didn't even get an acknowledgement that they received my letter. [laugh] Obviously they thought it was nuts! And just a few years later, even some of the big research programs in Europe—did you hear of the EMC effect? Have you heard of that?

Zierler:

No.

Busza:

EMC—The European Muon Collaboration came up with a big surprise. They were doing experiments similar to the classic SLAC experiments—studying the structure of protons but using muons as probes. And in order to have a higher event rate, instead of using protons as the target, they used various nuclei. It did not occur to them that the structure of nucleons inside nuclei could be different from that when the nucleons are free. And everybody—as far as I know—everybody in the world was convinced that that would be the case. But it turns out that that is not the case! This was a big shock. It goes under the name of the EMC effect. And later this effect was confirmed not only at Fermilab but also—and listen to this—in Ari Bodek’s reanalysis of more than 10-year-old SLAC data. Then Cronin got a similar surprise when he studied hadron production at very large angles using nuclear targets instead of a hydrogen target, again for no other reason than to get a higher collision rate. Now it is called the Cronin effect. And today, if you look at the heavy ion program at the LHC—there are many studies looking in detail how different are the nucleons inside nuclei from free nucleons.

The moral of the story is that what at one time is completely obvious often turns out to be wrong, and certainly not so obvious. To continue, we got much information on the A-dependence of various phenomena and some people became very interested in our data. Bjorken, Bialas, Freddie Goldhaber, Al Mueller and Bo Anderson are all good examples. Unfortunately, we had neither the resources nor the appropriate accelerator to follow up on our measurements with more detailed studies. That happened years later. The E178 experiment cost about $20,000. Millions and the new RHIC were needed for the next step!

Zierler:

That’s peanuts—$20,000.

Busza:

Yeah. It was about that, plus one student, not including his salary! It was Charlie Young and about $20,000 of equipment. And here I must give a lot of credit to MIT. My senior colleagues, encouraged me like crazy. Dave Frisch gave me—paid for that student. Rather than have Charlie help him, he saw this young assistant professor, and he wanted to help me. Herman Feshbach, our head of the department at the time, was another strong supporter. That reminds me—there is something that I forgot to say earlier. Do you know Larry Jones, from Michigan?

Zierler:

Yes!

Busza:

You do?

Zierler:

Yes.

Busza:

I also want to give him a lot of credit.

Zierler:

When did you get to know Larry?

Busza:

1972, when I was at MIT thinking about this sort of physics, Larry Jones came and gave a seminar. In this seminar, he told us that he did an experiment at Echo Lake. Have you heard of Echo Lake?

Zierler:

Yes.

Busza:

I am amazed! Do you have a phenomenal memory? How is it that you know?

Zierler:

Wit, I talk to physicists every day. This is what I do. I gather a lot of information.

Busza:

Okay. So, Larry Jones built an experiment on top of a mountain in Colorado, near Echo Lake. And I don’t know why he did it. It may have been to look for free quarks. I've written to him, in particular recently, but he never answered. Anyway, in the process he looked at cosmic rays going through different materials. He used—was it spark chambers, or streamer chambers? It’s probably spark chambers interleaved with plates made of various materials—And the results looked strange—and I was extremely excited with them, because this was exactly what I was planning to do—but with accelerator beams of known energy. He certainly influenced me. I told him that when we met. Is he well? Do you know?

Zierler:

I believe so.

Busza:

But anyway, so that’s how I got to know him—he gave the seminar. He never published that work. It was a preprint, but he never published it. Don’t know why.

Zierler:

Wit, I want to propose—we're almost at the three-hour mark. Let’s take a five-minute intermission, stretch our legs a little bit.

Busza:

Splendid. Sure. No problem.

Zierler:

We'll come back, and then we'll get into Fermilab.

Busza:

Oh, yeah! Time flies!

Zierler:

It does. It does. I'll see you in five minutes.

Busza:

Look, we're covering 60 years of physics.

Zierler:

We'll come back refreshed. I'll see you in five minutes.

Busza:

At four. Yeah. Okay.

[break]

Busza:

Okay. So now that we've had three hours, let me ask you—is this what you wanted from me? [laugh]

Zierler:

Every bit. Exactly. This is exactly right. Wit, let’s switch to Fermilab. Tell me first, how did you get started? What was your initial connection with Fermilab?

Busza:

So, you want to hear more about my connection to Fermilab—OK—where should I start? When Fermilab was being built, Sam Ting wanted to do something there and he was trying to decide what to do. At the time we were working together in Hamburg.

Zierler:

At DESY?

Busza:

Yes, at DESY. And Sam thought he would repeat the kind of experiments he was doing at DESY, at a higher energy, at Fermilab. In particular, he thought that looking for heavy vector mesons might be interesting.

Zierler:

Yes, yes.

Busza:

Not the ones you're thinking of—the rho prime.

Zierler:

Ah.

Busza:

Nothing to do with the J/psi. It was looking for a heavy version of the rho meson—at the time it was of interest—I don’t remember why. And he formed a small collaboration—his group, some Canadians and some physicists from SLAC. And he sent two of us—Min Chen and me—to join the other members of the collaboration at Fermilab to come up with a proposal. I don’t think Becker was involved. But anyway, it was an interesting cast of characters. And this was at the time when the accelerator was being built at Fermilab. The high-rise did not exist. Our offices were in the Village—it was where the lab director and most of the staff had their offices. You know, the Fermilab Village?

Zierler:

No, I don’t.

Busza:

Do you know Fermilab as it is today?

Zierler:

I do.

Busza:

Okay. As you come in through what I call the main entrance—I don’t think it has changed—it’s the one from—Warrenville.

Zierler:

That sounds right. Yes.

Busza:

If you come in through the—you cross a railway line, an old railway line—maybe it doesn't exist anymore—there is the entrance. And then the road turns to the right, and there are some old houses. At the time there were the remains of a village and a few barracks built by Wilson to house the lab director, administration, and the few physicists who came to work on proposals for experiments. It was the beginnings of Fermilab—everyone has to have a badge—there is a different sequence for the employees and for the visitors. Ours had a VS number—Visiting Scientist. And I still have it, and, for the record it is number VS11. So, I am the 11th visitor to Fermilab, known at that time as the National Accelerator Laboratory, NAL. And we must be talking about 1971. Something like that.

So, we were there and were trying to come up with a proposal and Sam wanted it to be a spectrometer, like all the others he worked on. I can’t remember the number of that proposal. Was it 144? It’s easy to look it up, because Fermilab does have a history section with a record of all the experiments. It’s even on the web. Anyway, proposal E144 was rejected by Fermilab—that was a real stroke of luck for Ting—as a result he needed to quickly find a research program for the group—he decided to try BNL—in typical Ting fashion he decided to build a two-arm spectrometer with superb resolution—better than required by the physics he planned to do—the proposal was accepted and the result was a Nobel Prize for Ting, jointly with Richter, for their independent discoveries of the J/Psi! As a final word on this topic—of course it is conceivable that we would have discovered the J/Psi if E144 was approved—the proposed experiments were similar.

Zierler:

Wit, what were your impressions of Fermilab when you got there? You had been to so many other National Laboratories; what struck you about Fermilab?

Busza:

Something unimportant; in the sticks—the emptiness. Starting from scratch. No town nearby. It’s not like CERN in Geneva, or Rutherford lab near Oxford. This is the middle of nowhere. An episode struck me which—nothing to do with the lab—I remember—Min Chen and I, we went to a restaurant, and halfway through the meal, a couple who were at another table approached us, and they were so curious who we are, what we were doing—when did we arrive, did we land from outer space? This Chinese guy and I speaking English in strange accents. And at the end, they said, “Oh, on Sunday, you must come to dinner to our house.” And they invited us, and we went for dinner to their house. The hospitality of the Midwesterners is amazing. I will never forget it. Now, what memory do I have of the lab? Well, clearly Wilson had a lot of charisma—Bob Wilson, the lab director. It was his idea—I think. He put a lot of emphasis on art, beauty and ecology. I remember, for example—nothing important, but I'll tell you anyway. It occurred to him that—when he was building the housing for the bubble chamber—he can make the roof out of used coke cans. Did you hear about that?

Zierler:

Coke cans?

Busza:

Yes. Okay? So, he collected—asked everybody to collect discarded coke cans. Then he removed the tops and bottoms and was left with an infinite number of cylinders. These would then be squished between two sheets of some plastic, and bingo you have roof material. The idea was that he would have cheap and beautiful material for the roof of the building.

Zierler:

[laugh]

Busza:

—and at the same time it would be a way of reusing waste coke cans.

Zierler:

[laugh]

Busza:

And the biggest joke was—halfway through the project, some local company offered to produce the identical kind of roofing material, at a cost less than cutting and washing waste coke cans! [laugh]. But the style was—you're asking me—everything was much more on a shoestring than at SLAC.

Zierler:

And did the project have to take place at Fermilab? In other words, was the experiment tailored and could only be done at Fermilab?

Busza:

If you are asking about the accelerator, I think it was to do with politics. Senator Dirksen wanted it and supported it. It was that or probably nothing. It was unavoidable—but unfortunate—you see CERN is near Geneva and near the Alps.

Zierler:

It’s a draw. It’s a nice place to be.

Busza:

And SLAC is in California. At Stanford, in a fantastic climate

Zierler:

What are you saying about Batavia, Illinois, Wit? [laugh]

Busza:

Exactly. Exactly. So, it was not as attractive as were CERN or SLAC. I think that was the problem. A problem. And there was no Panofsky with the charisma of Panofsky. Now Wilson did have some charisma, but it was a different kind of charisma. He was more of a technically brilliant artist—a renaissance man! He prided himself making everything on the cheap. As a result, he sometimes got burned. For example, once when he saved a significant sum on a part of the project, he thought that what he saved he can use to do something else. And DOE: “Okay, thanks for coming under budget. You don’t need some of the funds—so we will take them away.” There were things of this kind. But here my memory may be letting me down. Certainly, at one stage, he was saving money by not heating the tunnel. Do you know that story?

Zierler:

No, I don’t. I assume, though, it must have messed up the experiment.

Busza:

Well, it did worse. And I cannot remember now whether it was the original accelerator or the collider tunnel. I don’t remember which of the two. But the point is that he decided not to heat the tunnel—to save money. The result was the magnets absorbed moisture, and they had to be replaced—it was a catastrophe. Or, if you look at the high-rise, it is beautiful, but it isn’t very practical. So, art wins. Also, Wilson had an obsession with open plan offices. And they didn't work. People want a bit of privacy. So, guess what—the first people who caved in were the director’s office staff. And for some reason, Fermilab never had—maybe it has to do with me rather than with reality—the excitement of CERN or SLAC. But I am a little unkind to Wilson. He was a great man—as I said—a renaissance man. I will end with my recollections of Wilson’s exchange with senators at a hearing. When asked something like: “Will Fermilab help in the defense of our country?” His answer was: “No, but it will make it more worthwhile defending!”

Zierler:

Wit, what were the findings of the experiment?

Busza:

Experiments?

Zierler:

Well there’s all the “E”s—there’s E178, 451, 565, 665.

Busza:

Oh, you mean my experiments.

Zierler:

Yes.

Busza:

OK—I will tell you what we learnt from these experiments—but first, since you were asking about the atmosphere at Fermilab—let me continue with a few words about my first experiment—E178—it will give a flavor of early days at Fermilab—it’s the experiment I did with Charlie Young—it’s the one which had two Nobel laureates on the original proposal. Formally it was a “parasitic” experiment. Today, people can’t believe it—the original proposal got accepted, and they awarded us 40 hours of beam time. And we built a very simple experiment, using the facilities that were built for other experiments and constructing as much as possible by ourselves. We even pulled our own cables, 100-meter-long cables, from the detector to the counting house, and we did it—Charlie and I, by ourselves, with our own hands!

Zierler:

[laugh] What an image! [laugh]

Busza:

Yes. We had no choice—we had to do things on the cheap. But back to your question.

Zierler:

I suppose, Wit, for this—what were some of the big questions for which these experiments were designed to answer? What were you focusing on? What did you learn?

Busza:

Fine. So, my focus—as I said before—was to answer the question: what happens when high energy hadrons:—protons, pi-mesons et cetera—collide. Many particles are produced. You have energy converted into many particles? How does that happen? How long does the process take? What is the state of the system between the instant of collision and the final production of many objects, each as big as the initial colliding particles? From the answers, what can we learn about high energy density and temperature QCD matter? In today’s language: is a Quark-Gluon Plasma, or QGP formed and what are its properties?

Zierler:

Wit, and what were the findings of the experiment?

Busza:

OK—briefly and crudely—and some of this of course I am repeating—we observed that when a high energy proton hits a heavy nucleus—lead for example—there is no cascading of the produced particles—rather the resultant total number of particles produced is proportional to the number of nucleons that are struck inside the nucleus by the incident state—today this is still not well understood and called “participant scaling”—furthermore, independent of the energy of the incident proton, it loses on average about two units of rapidity or 85% of its energy. From our proton—nucleus collision data we concluded that in proton-proton collisions at high energies the particle production process is more like the collision of two liquid drops rather than of the shattering of glass spheres. That the production process takes a very long time—there are good reasons to believe that, for example, a 100 GeV pi-meson gets produced over a distance of some 700 femtometers—a distance of 50 lead nuclei in a row!

We also learned that following an inelastic proton—proton collision the force that slows down the protons as they recede from each other has a strength of about 1 GeV per femtometer. Furthermore, together with others, we discovered extended longitudinal scaling, a phenomenon which is a direct manifestation of some kind of saturation occurring when particles interact strongly. Looking back, something which was not so obvious at the time and ahead of its time, these results were a precursor to the relativistic heavy ion collision program, including, as I mentioned earlier, the first data based estimate of the energy that will be released in RHIC collisions—that it is a large fraction of the incident energy—large enough to be interesting and that between the instant of collision of high energy particles or nuclei and the final free streaming particles some kind of a not well understood, evolving over a long time, system is formed. Also, that the maximum baryon density that is achievable in heavy ion collisions is somewhere between 5 and 10 times that of normal nuclear matter—in short that RHIC will be interesting! Today we still do not know how best to describe the state which is produced immediately following the collision of two protons. For head on collisions, when many particles are produced at the highest energies studied, most likely it is the so-called Quark Gluon Plasma—QGP. In the collision of bigger systems—of heavy nuclei or heavy ions, as they are more commonly called—it is almost certainly the QGP.

Zierler:

Yes.

Busza:

The above covers E178, E451, E565. But I did not to tell you about E665.

Zierler:

No.

Busza:

Well—in Chicago there was a cyclotron which was no longer in use. And Fermilab managed to get hold of its magnet, brought it to the lab, and used it to build a big experiment for the study of muon scattering—similar to the SLAC deep inelastic scattering experiments, except that it used muons rather than electrons to study the structure of the proton, the neutron, et cetera. This was the E665 muon scattering experiment. It was a collaboration of physicists from the University of California at San Diego, Harvard, Fermilab, MIT, et cetera. Now, it occurred to Tom Kirk and me, that if we use nuclear targets of different size, we could use the E665 experimental set-up to study how quarks propagate through nuclear matter. The idea is simple and similar to the work I did on the propagation of hadrons through nuclear matter—you clobber a quark hard inside a nucleus and see how its motion is slowed down as it passes through nuclear matter of different thickness. So, we proposed that such measurements be made. And the results were again a surprise—no observable slowing down of the quarks, at least of the ones with the relatively low energy we could access! By the way, I should give the full credit for this work to John Ryan, my graduate student who did all the work. This research program did not have a separate name at Fermilab. It’s still E665. It reminds me—you've probably heard the statement that everybody repeats over and over again his PhD experiment, all his life, right?

Zierler:

[laugh]

Busza:

But in my case, it’s not my PhD experiment—it’s my postdoc experiment—at SLAC I was studying rho-meson propagation through nuclear matter, at first at Fermilab and later at RHIC and LHC I was studying hadron propagation through nuclear matter and in E665 and at the LHC I was studying, or more honestly said, I was participating in the study of quark propagation through nuclear matter.

Zierler:

How long did you stay involved with this work?

Busza:

Well, on and off, for the rest of my life. Let me tell you a little more how the proton stopping measurement, one of the more important findings I mentioned earlier, came about—and now I am moving forward, up to about 1983. Freddie Goldhaber—have you heard of him—

Zierler:

Yes.

Busza:

—at Stony Brook—was thinking about this question of nuclear stopping power, the amount of energy that will be released in high energy heavy ion collisions—and we met, and he brought up this question, and we came to the conclusion that E451 results could answer it. And so, we wrote a paper together. It is the first experimental measurement which shows that the proposed RHIC will give interesting results—85% of the incident energy will be released in each central gold-gold collision. This result drew the attention of BNL management and community in general—there was a quark matter conference—I think it’s ’82, ’83. I can’t remember now—see the introduction to the proceedings—Tom Ludlam states that our result is a great relief for them—to know that RHIC will not be a bust. So how did I get to this—oh, yes, you asked—so, my first contribution to the future RHIC physics was the study of the evolution of the stuff produced in p-p collisions. This then led me to look, with Goldhaber—at the question of nuclear stopping.

Zierler:

Ah. This is very important.

Busza:

Yeah.

Zierler:

The whole project hinges on this.

Busza:

Yes. Now, to be fair, the project would have gone forward with or without that information.

Zierler:

But it would have probably ended sooner than it did.

Busza:

Well, no. No, no. Sorry—the politics was that RHIC would have been built whatever answer we got.

Zierler:

Because the support was already there, you mean?

Busza:

Yes, yes. Put it this way—not so much the support; the momentum was there. Brookhaven needed to have a big project—to build RHIC. After all, Isabelle or CBA or whatever it was called at that time, was terminated in favor of the Desertron. You remember that history?

Zierler:

I do.

Busza:

Oh, you do, okay. So, lab director Nick Samios needed something to build, so he was going to build RHIC—Nick is an excellent physicist and a smart strategist—he knew that there was the Bevalac community and others in nuclear physics who would push for RHIC to be funded and I am sure he thought that even if heavy ion physics turns out to be uninteresting you can always use RHIC for high energy physics!

Zierler:

Did you work with Sam Aronson at all during this time?

Busza:

No.

Zierler:

Separate.

Busza:

We interacted, but not on the same experiment. No, no. But we know each other well. He became BNL director in 2006, after I stopped doing experiments at the lab.

Busza:

But anyway, you wanted to hear about Fermilab. What else can I tell you about Fermilab? It certainly did not have the spirit of SLAC.

Zierler:

But you went back to SLAC?

Busza:

Ah. Yes. As I told you earlier, after I got as much as I could out of the pA experiments at Fermilab, I neither had the resources nor good ideas of how to study further, at existing accelerators, the questions that fascinated me. Without fully realizing it at the time I was waiting for RHIC—and while waiting—I focused on teaching—developed a better way of teaching these monster classes for freshman—the professor in charge would meet with the whole class only once a week, during which he/she would outline the big picture of the subject being taught and do spectacular demonstrations—instill excitement—in a fashion similar to the Christmas Lectures at the Royal Institution that I mentioned earlier—then the students would breakout into smaller groups, where the details were discussed and explained. Together with Alan Guth and Susan Cartwright we wrote a textbook for this course: “Introductory Classical Mechanics.” Also, I introduced a slower version of freshman physics for students with a poor background. All of this worked out well and was very satisfying—I was elected a MacVicar faculty fellow—MIT’s highest honor in education. On the research front, the opportunity popped up to pay back my senior colleagues Henry Kendall, Jerry Friedman and Larry Rosenson, for the years they supported me and encouraged me to do my own physics. Now they needed someone to administer our research group and manage construction of the muon detector—the Warm Iron Calorimeter WIC—for SLD at SLAC—their student Marty Breidenbach’s project, to which they had made a commitment. Do you know Marty?

Zierler:

Ah!

Busza:

You know Marty! Well, Marty and I, at SLAC, in the sixties, were cabling and commissioning the spectrometers.

Zierler:

Yeah. [laugh] You go way back with Marty.

Busza:

Oh, yes! I worked with him when he was a student! I tell you, when I met Marty, I knew he would get far.

Zierler:

[laugh]

Busza:

If anything, he’s an underachiever.

Zierler:

[laugh]

Busza:

A great experimenter, Marty. But, to continue, I became the formal group leader of the Particle Physics Collaboration (PPC) group at MIT and co-manager (with Marcello Picollo from Frascati) of the construction of the WIC for SLD—So from 1986 to 1990 I was commuting backwards and forwards, between Boston and San Francisco, moved my family to California, and rented a room in Harvard Square. Whenever I could, I would be at SLAC—I still had to teach—a double load every other semester—that’s how I was at SLAC again.

Zierler:

It was good to be back.

Busza:

Absolutely! Especially that I liked very much the SLD crowd. Marty Breidenbach and Charlie Baltay were leading the effort—they complimented each other well and overall were superb.

Zierler:

Wit, I imagine that you perceived how much SLAC had changed since your time as a postdoc.

Busza:

Oh, yes. And since then, even more.

Zierler:

Yes.

Busza:

It’s not the old SLAC—maybe for condensed matter physics—but certainly not for particle physics.

Zierler:

Who was director when you were there the second time? Was it Jonathan Dorfan?

Busza:

No. Richter

Zierler:

It was still Richter.

Busza:

Yes, yes. I can’t remember when Panofsky retired. Richter took over from Panofsky. It was a very stressful period for the lab—they had no end of difficulties trying to make the SLC work—it was a novel, difficult machine—and on top of that—to save money they made some bad decisions. In fact, throughout the four years I was there, there was very little beam. It was frustrating. The golden SLAC era for particle physics—which I could still remember so well—was over.

Zierler:

That’s the frontier. It’s the Wild West.

Busza:

Yeah, yeah. I'm sure you've spoken to others about it.

Zierler:

By this point, the later history, it’s much more bureaucratic. The DOE is much more involved.

Busza:

Yes, yes. Did you hear how SLAC was originally funded?

Zierler:

I've heard this.

Busza:

I heard that in 1957 Panofsky’s proposal to build SLAC was something like ten pages long, and he got $114 million for it!

Zierler:

Yeah. [laugh]

Busza:

That’s the consequence of Sputnik.

Zierler:

That’s what Sputnik will do for you.

Busza:

Correct. No—Sputnik plus Panofsky.

Zierler:

Yes, of course. Of course.

Busza:

That’s the crucial thing.

Zierler:

What did you accomplish at SLAC? What were some of your big achievements during your second time there?

Busza:

I learned a lot—in particular how to manage a big project—and how to work with Italian physicists—I am joking! Biggest achievement was that we delivered on time a working WIC. But no—look, in the real sense of the word—

Zierler:

You can speak generally. What did the SLD program accomplish?

Busza:

Oh! The SLD program—I tell you, if I'm honest, if SLC and SLD did not exist, today you would not know it.

Zierler:

So, it was not as significant as was once hoped.

Busza:

I think that LEP wiped us out. If SLC worked as planned—collisions in 1986 instead of 1989—it would have been a different story.

Zierler:

Yes.

Busza:

Maybe I am a little harsh—polarized beams, small beam size, CCD pixel vertex detector—did result in some unique standard model precision measurements. But it would be a hard push to argue that SLC and SLD were crucial—maybe for future e+e- collider development.

Zierler:

There’s also of course people leaving SLAC to join SSC at this time, as well.

Busza:

Yes! Absolutely.

Zierler:

Which must have negatively affected SLAC to some degree.

Busza:

Sure. I'll tell you—one sees—a repeating phenomenon. A lab has a heyday, fantastic progress, great results, and then exponential decay. CERN is an interesting counter example—a slow start—a different economic model where the infrastructure and solid foundations are so emphasized—followed by impressive recovery

Zierler:

And it’s not just one country supporting it. It’s a consortium.

Busza:

Yes. But on top of that, at first, this model didn't work that well. I still remember—when Brookhaven built the AGS and CERN built the PS, they roughly were ready at the same time. The Europeans went for slow, systematic, high precision, high quality work. Brookhaven had cowboys, with names like Steinberger, Schwartz, Lederman, Lindenbaum et cetera. They tended to be fast and dirty—I'm exaggerating a little!

Zierler:

No, I understand.

Busza:

And they just wiped CERN out. They did it right. But later, when the U.S. tried to go on the cheap—the SLC and the SSC—they failed

Zierler:

CERN got smart.

Busza:

Yes, and they in a systematic way—the LHC worked within hours of switch on. Oh, but we must not forget—they had one mishap—explosion of the superconducting magnet system at one location in the tunnel—but that was really—but still, that should not have happened. That was a bad mistake.

Zierler:

Wit, how did you get involved in the CMS program? How did that happen?

Busza:

Wait—I have to first tell you about RHIC and PHOBOS—review the whole period 1989—2005. It was one of the most productive and enjoyable periods in my life as a physicist! To do that you need to understand a little about the origins of RHIC. Let’s start by looking back how this big research field, known today as the study of relativistic heavy ion collisions, evolved. There were two research paths that led to this field. The first had its origins in a question raised already in the late 1930’s and 1940’s, by giants like Heisenberg, Heitler, Oppenheimer, Fermi and Landau—what is the mechanism of multiparticle production in high energy collisions? How can more than one particle be radiated at a single point? And initially tackled by cosmic ray physicists, in particular by those using the cloud chamber and nuclear emulsion techniques. My involvement was a continuation of this path, but using high energy particles of well-known energy, produced by accelerators.

There was another path—led by nuclear physicists colliding low energy nuclei at the Bevalac, in the late 1970’s—with origin in the late 60’s when a neutron star was discovered, and which led to interest in compressed nuclear matter—what is the equation of state of nuclear matter? Does Lee-Wick matter exist? et cetera. Here is an interesting example of how science evolves. The Berkeley people had a much greater influence on getting money to collide relativistic heavy ions—without the Bevalac crowd I doubt that RHIC would have been built! But if you look at the direct contribution to physics of the Bevalac—it is a different story. At the time, most particle physicists did not think the Bevalac physics was particularly interesting and today we know that the corner of the QCD phase diagram studied at the Bevalac—low temperature compressed nuclear matter—hardly touches the region of the phase diagram studied at RHIC and the LHC, where the high temperature, low baryon density region is primarily probed. On the other hand, the first path—the one I followed—and feel I gave a shot in the arm in the early 1970’s—is a direct precursor of the current studies at RHIC and LHC.

Zierler:

But right, it’s related, though. It rests on that work.

Busza:

There were two paths is a better way to put it—which probe different regions of the QCD phase diagram; the first along the temperature, low baryon chemical potential region, and the second, along the baryon chemical potential, low temperature region. Or perhaps an even better way of saying it is that one path sought to answer the question “what is the mechanism of multiparticle production of particles?” and the other “what is the nature of the state you obtain when you squash nuclei more and more?

Zierler:

You're saying people now don’t recognize this.

Busza:

Overall that’s the case. History gets distorted. The first path is largely forgotten. But don’t get me wrong, I don’t wish to minimize the second path—their contribution to getting the relativistic heavy ion research program launched, on a big scale, was colossal.

Zierler:

It’s established and people have moved on.

Busza:

Yeah. But back to me in 1989—So I was the group leader of the high—energy PPC group at MIT and working at SLAC. Then, with SLAC still struggling to make SLC work properly, and RHIC on the horizon—with a call for proposals—I started thinking about launching a research program at RHIC—after all it opened up a fantastic opportunity to work on topics related to my earlier studies—physics closest to my heart—of QCD matter at extremes of energy density and temperature—with bigger hotter volumes to study. On top of that I had some ideas of what to measure and how to measure it as soon as RHIC starts colliding heavy ions. I was excited by the possibilities—I stopped working on the high energy program and formed a RHIC focused group at MIT—consisting of both particle and nuclear physicists, with Steve Steadman leading the latter.

I also formed a small (70 or so scientist) US—Poland—Taiwan collaboration to work on a RHIC experiment. I was impressed and amazed that P.K.Williams in the high energy office of DOE continued to fund me despite the fact that RHIC was formally a nuclear physics project. Now I adopted the philosophy—right from the beginning—to build a relatively small and simple experiment and treat it as an exploration—is there interesting physics accessible with RHIC?—how best to study it? I did not want to build a hundred-million-dollar device which would force us to pursue a single path for years to come and not give us the flexibility to change courses as results dictated. Furthermore, we knew that a bigger machine—the LHC—was on the horizon at CERN—it would dump 25 times as much energy in each collision as RHIC does and we would very likely want to move our research effort to the LHC. For us this philosophy actually worked fantastically well—but not at first—we almost had a disaster—our proposal—was rejected. It was called MARS—M-A-R-S—Modular Array for RHIC Spectra. It was going to cost about $11 million.

Zierler:

That’s real money.

Busza:

Real money. Got thrown out. Oh, that was a low point in my career. However, it turned out to be a blessing. In retrospect the MARS proposal was not so brilliant! Then, my involvement with SLD and interactions with Marty Breidenbach paid off. Without him even knowing it, he influenced my thinking. Marty wanted to build an electron-positron experiment that would fit on a tabletop. And he failed. He couldn't. Okay? That’s where the name comes from—Stanford Little Detector, SLD.

Zierler:

Ah, very good.

Busza:

All right? That’s where it comes!

Zierler:

That’s great.

Busza:

And Marty can tell you, I'm sure, the whole story of it. Now I was on the management of SLD, so, for about three or four years, I used to meet with these guys once a month. These meetings were fun and instructive. And when BNL threw out MARS, I thought, “Look, Marty’s no fool. It must be possible to do RHIC physics with a small detector.” And I scratched my head, and decided, in essence, to rebuild the detector that I constructed in 1972 and which cost at the time some $20,000, but now using silicon detector technology and adding a magnet, for a cost of some $5 million, to achieve a device with vastly superior properties—well suited for a first quick look at the new physics made accessible by RHIC. The research director at BNL was Mel Schwartz, and he was a maverick. He liked the idea of a small detector—these $50 or $100 million monsters needing 500 people to build and operate where not his style. So, I think it was he who pushed for approval of our detector. We called it PHOBOS. In essence it was a detector with which we could crudely look at all the charged particles produced in a collision and in detail at a small fraction of them, the most interesting ones. We hoped it would give us a quick “big picture” of RHIC physics. We were particularly interested in particles with very low transverse momentum which, by the uncertainty principle, I thought should carry information about the extent of the volume where particles are being produced. This intuition turned out to be wrong—the low momentum particles behaved completely normally and gave us no useful insights. Finally, I'll give you the answer to a question that frequently people ask, “Why the name PHOBOS?”. Do you know the answer?

Zierler:

No.

Busza:

Okay. MARS got rejected because it was too big and expensive.

Zierler:

Ah. [laugh]

Busza:

All right? And who invented the name? John Negele. So, he says to me, “Look, if MARS is too big and too expensive, build its larger moon PHOBOS. And if that fails—

Zierler:

[laugh]

Busza:

—build DEIMOS.”

Zierler:

PHOBOS. It stuck.

Busza:

That’s what it is. That’s how it happened. Here I must add that there was something else which proved crucial in the approval of PHOBOS—MIT Dean Robert Birgeneau’s and BNL lab director Nick Samios’ moral and financial support at various crucial moments! Now I mentioned earlier that our philosophy to go small served us well—we really did a lot of good stuff. And we learned what are the most interesting questions that needed to be answered in the future. And it was obvious that LHC was the way to go next. When we proposed PHOBOS, in our minds, we expected that we would take data only for a few years, get a first view of the interesting physics, and go to the LHC. And it worked! That was our philosophy. It paid off—we worked like crazy to get quickly data from RHIC. And you won’t believe it, we got the first result after the first night of RHIC gold-gold collisions at our detector—June 13, 2000. Submitted our result—on the number of particles produced near mid rapidity in a head-on gold-gold collision—a quantity related to the energy density produced in such collisions—to PRL, six weeks after the first RHIC collisions—Jul 19, 2000. And listen to this—

Zierler:

[laugh]

Busza:

A manager from DOE, who will remain nameless, complained and said, “That’s not playing cricket.”

Zierler:

[laugh]

Busza:

Do you know the English expression?

Zierler:

Yeah, yeah. [laugh]

Busza:

They were upset!—that we didn't wait for the big experiments to get some kind of a result before we published our paper. And I was surprised…Was that a tradition of nuclear physicists? I don’t know. Anyway, so we got the first results. Now of course, over all we did not publish as many results as our big sisters. However—per dollar, I think we did well. PHOBOS was one of the four experiments that announced the most important discovery at RHIC—that the QCD matter created could be described by a hydrodynamic liquid of unbelievably low ratio of viscosity to entropy. Our philosophy was right. We achieved our goal—but I forgot to tell you who is “we”—PHOBOS was a collaboration of some 70 people from ANL, BNL, INP in Krakow, MIT, NCU in Taiwan, UIC, Univ. of Maryland and University of Rochester. I was extremely lucky, this relatively small group turned out to have a very large number of absolutely brilliant experimentalists, who since then have had highly successful careers. After five years, we said, “Time to quit! No point of continuing. We've learned as much as we're going to with our equipment. We no longer can compete. We have learnt what are the most interesting questions to address.

So, we at MIT decided to move to CMS. That’s the answer to your question “how I got involved with CMS”. I was still the group leader, but I didn't have the energy to lead the group’s research program. It was time to hand over the leadership of our group in the very able hands of my colleagues Bolek Wyslouch and Gunther Roland. For a while, until 2011, I was formally still sort of the manager of the group, but the scientific leadership of the CMS heavy ion program at MIT passed on to the next generation. My role at first was to continue and worry about group finances and give moral support to the young people. I supervised three graduate students, one of whom—Yen-Jie Lee—is now an Associate Professor with tenure at MIT. I tried to help with the students. I shouldn't be bragging—but I will—one of the things that gave me great satisfaction is that everyone whose work focused on PHOBOS—when they were up for tenure—got tenure! Another that I was elected to the Polish Academy of Arts and Sciences (Polska Akademia Umiejetnosci). And lastly to learn that at the time I decided to retire in 2012, our group was judged by DOE as the best nuclear physics group in the country.

Zierler:

Cool!

Busza:

It was following a DOE national evaluation of nuclear physics programs. They didn't publish the results. I received the information privately. However, I must emphasize and repeat that most of the credit for the CMS part of the program is not mine. It belongs to my younger colleagues.

Zierler:

Wit, did the original motivation for CMS—has that stayed fairly constant in terms of what CMS was designed for initially, and what has resulted in it since?

Busza:

Hold on. The main reason for CMS and LHC was to study p-p collisions, not heavy ions. It’s the Higgs and searches for physics beyond the standard model. That’s why LHC was built. The heavy ion program was a tolerated add-on—and I use these words intentionally—CERN needed more money, and there were some rich groups who were interested in heavy ions, in particular in Germany. And so LHC expanded its role to attract more money and people. And I have to say they did it very gracefully, because the collaborations, which were mainly particle physicists, ATLAS, CMS and LHCb—accepted the heavy ion groups with open arms. We were not treated like enemies, stealing beam time. CERN promised heavy ions about 10% of the time, and management looked upon it as an efficient way of utilizing the facility. Your question, which I rephrase as “have the goals of the LHC heavy ion program been achieved”, is not easy to answer. First, I have to answer: “have the goals of the RHIC program been achieved”. And this is somewhat easier to answer, since at the time of proposal submission for the first round of RHIC experiments, everybody wanted to discover the Quark-Gluon Plasma—and get the Nobel Prize! In short, the goal of RHIC was to observe the phase transition from normal hadronic matter to the QGP. You've heard of the Quark-Gluon Plasma?

Zierler:

Of course.

Busza:

Now, what is the Quark-Gluon Plasma? The Quark-Gluon Plasma—let’s say in 1989—was a system of quarks and gluons which is so dense that their momenta are so high that, as a result of asymptotic freedom, they interact weekly. Finally, free quarks and gluons! And the hope was that the transition from hadrons to the QGP is a first-order transition, and thereby it should be possible to easily see the transition, at least in some physical observable. And that was what RHIC was built for, to find that. But there is a problem. Big problem. So defined QGP is not produced at RHIC. Today we know enough about QCD, to realize that in the early universe, or at super high energy density or temperature there has to be a QGP. But not at RHIC. Not at LHC. And so, what does a community as a whole do under such circumstances, in particular when funding agencies want guaranteed results? How do you respond to a situation where you've promised you're going to find this QGP, but it isn’t produced in your machine? Not that you've missed it, it simply does not get produced. And so, the community did the obvious thing—redefined what the QGP is—defined it as the medium produced in heavy ion collisions at RHIC and LHC! And that’s what happened. Now in some ways, what was found at RHIC was in fact more interesting. Instead of finding a weakly interacting system, we found an incredibly strongly interacting system which has liquidlike properties, with unbelievably low ratio of viscosity to entropy. It flows. It quenches jets. Et cetera. The QGP we were looking for would have been much less interesting. If found, it probably would have been a disaster for the field—an uninteresting non-interacting gas! Furthermore, we now know that there isn’t a first-order phase transition from hadrons to the QGP, as was hoped for. So, we did not find a first-order phase transition—instead there is a crossover. Do you know what a crossover is?

Zierler:

Yes.

Busza:

So, there is a crossover—very hard to see a crossover experimentally. So how do we know that in this liquid, the quarks and gluons are deconfined? We know it primarily because of lattice gauge theory, not experimental data—if you do QCD calculations on the lattice—and today our theorist friends are making fantastic progress with such calculations—

Zierler:

You mean recent progress?

Busza:

Yes. They tell us that if you produce an energy density which is higher than a certain amount, or a temperature which is higher than a certain amount, we can no longer be in the hadronic phase. And we trust enough our experimental determination of the energy density to know that we have crossed over from a hadronic phase to some new state which, as I just told you, we call the QGP! By the way, PHOBOS was the first to have, in essence, measured the energy density—but we could not publish our results as an energy density—only as the number of particles density—because at the time nobody knew how to make a decent estimate of the volume of the produced system. To continue. So, RHIC found interesting physics, but not what was promised—in many ways it is more—it’s a great success. Now back to answer your question—what are the goals of the LHC heavy ion program? From my point of view it is to continue getting a better understanding of every aspect of the whole process of particle production in heavy ion collisions, from the instant of impact of the nuclei to the final outgoing particles. However, more important and fundamental, it is to get an understanding of how a strongly interacting liquid emerges from a system that at short distances is a weakly interacting gas of deconfined quarks and gluons. Understanding the latter might give us insights into how, in general, complex forms of matter emerge from simple systems. Unfortunately, it is not so obvious how to extract from data insights on this fundamental and deep question and, this time round, so far theory has not supplied us with good guidance.

Zierler:

You're saying the theory follows the experiments.

Busza:

Yes, yes. Theory is following the experiments. And the data is very complicated. You can imagine—you are throwing at each other two nuclei—a complicated system of particles and fields which get intertwined with each other—tremendous amount of entropy released—producing an elongating firestorm which ends with thousands of particles streaming out. It’s a hell of a mess—a real challenge for the theorists to make sense of it all! The real answer to your question will probably only come when, some-time in the future, we look at Feynman volume IV and see how much there is written about the results extracted from RHIC and LHC heavy ion collisions, studied in the early twenty first century! But it is important to add that the quantity and quality of the data recorded and analyzed by the LHC groups has been absolutely incredible, way beyond my wildest expectations! Much interesting phenomenology has been discovered and much understood. The number of publications is off scale though, for my liking, too often the publications still end with: “and we hope that this will help us understand that”! Looking back at history, maybe it will prove to have been a very exciting period, answering profound questions about the condensed matter of QCD at ultra-high energy density and temperature. When I was thinking of doing a PhD, it didn't occur to me to do atomic physics. It didn’t occur to me to do condensed matter physics. Why? Because, at that time, it was not obvious what fundamentally new physics will come out of these fields. Move forward 60 years—think what you can do with single atoms? It’s mind-boggling what we can do today! Look at condensed matter physics. Again, it’s mind-boggling, right? Now, these fields have one advantage over the heavy ion program, and that is that there are practical consequences. Whatever you measure, any new phenomenon, before you know it, somebody has produced a factory, doing something useful for humanity, or otherwise, and making billions! We don’t have that luxury. So, it’s like the question I always ask students for fun at orals—why doesn't a QCD mouse exist? By mouse, I don’t mean a computer mouse; I mean the real thing. Why doesn't it? QCD is much richer than QED—more degrees of freedom, more particles. Why? Maybe it does. But the odds of it existing and being useful and Wall Street making money out of it, boy, are low. So, if somebody told me that in a thousand years’ time, a heavy ion collider has some incredible practical use, I won’t be surprised. But today, for heavy ion research, let’s say it, is a challenging period!—I hope my colleagues will not kill me for one or two of the things I have said!

Zierler:

[laugh] Always the chance to edit it.

Busza:

—have you interviewed any other heavy ion physicists?

Zierler:

Not as many as I’d like to.

Busza:

But have you any at all? No, none?

Zierler:

People define themselves in different ways.

Busza:

Okay, because I am curious whether there are many who are really confident that they know where we are heading. I'm not. Certainly—it has been a very exciting period. We have found some fascinating matter that surprised everybody. I hope this answers your question about the goals of LHC and if they have been satisfied.

Zierler:

I think we can say, though, that just as you were saying before, things that seemed uninteresting 60 years ago—

Busza:

Yes! That’s right. If you do that—but! I add—these other two fields had one advantage—practical consequences—have byproducts that are useful.

Zierler:

Well, Wit, let’s bring the narrative right up to the present for the last part of our talk. Obviously, you're so similar to so many of your colleagues—physicists never really retire. They remain active, they remain engaged. What are some of the things that you've been working on in recent years, in your retirement?

Busza:

Well, for one, together with theorists Krishna Rajagopal and Wilke van der Schee we have written a review for “Annual Review of Nuclear and Particle Physics Vol. 68”—the title is “Heavy Ion Collisions: The Big Picture and the Big Questions”. It was fun working on it, I have the impression that it has been well received and I am extremely pleased with it! Also, I have tried to keep up with all this physics by playing an active role in reviewing CMS heavy ion publications—and of course criticizing them—which is always easier! Furthermore, for fun, I've been looking a little bit at history. I find it fascinating, how often I and my community are ignorant of its past, and how much one can learn from history.

Zierler:

There you go! I couldn't agree with you more. [laugh]

Busza:

I can’t resist giving you one example of what I have learnt and enjoyed—back in the thirties, late thirties—’37, ’38—you'll find some Physical Review Letters where there is the following debate going on between Heisenberg and Janossy and it’s the following question—no, not Janossy. It’s Heitler—the one who is always thinking about radiation. So, they look at cosmic ray data, and they see particles radiating—electrons radiating photons—and they understand it. But then they see some data where you have a particle producing three or four new particles, and they are shocked. How can you radiate more than one particle at a time? I was not aware of these papers at the time when the very same question bothered me—in 1972—how absurd! Anyway, then Janossy comes to their rescue. He notices that if you look carefully at these experiments, the particles always seem to be produced when the incoming proton is passing through the structure of the apparatus or through some foils containing large nuclei, but never when it is passing through the volume of the detector—containing only small nuclei. And so, the theorists say, “Oh, of course—you cannot produce more than one particle in a single pp collision but in a collision of a proton with a large nucleus, which contains many nucleons, the proton can make several sequential collisions, each producing particles—problem solved! And they were happy! But then Powell sees an event which is clearly a proton-proton collision producing many particles—the explanation fails!—it encourages Landau and Fermi to work on the question of multiparticle production in pp collisions. —I find it wonderful that giants of physics many years ago were asking the same questions that we are asking today!

Zierler:

CMS remains compelling to you.

Busza:

[laugh] Let me be honest—I don’t know what’s the horse, what’s the cart. I know that the moment nature stops fascinating me, I'll just go senile.

Zierler:

[laugh]

Zierler:

But just to state the obvious, you could be doing so many things. You choose to do CMS. Of all the kinds of things that you could choose to do to stay connected to not be senile as you say, you do choose CMS.

Busza:

Yes, because of—my colleagues and I enjoy it. But look, I would be lying to you if I said I am still useful scientifically. The nearest to that is my talking to you—I can share some information that maybe you don’t know. And with speaking to students. I enjoy exciting students with the past and it bothers me how little interest some of them show for it. You must know that.

Zierler:

Of course.

Busza:

And it’s sad.

Zierler:

There’s not the recognition that all that we know now, it came from a narrative of discovery.

Busza:

But it’s also a fact that things get rediscovered, and people don’t know it. I intentionally mentioned the discussion between Heisenberg and Heitler. I have no doubt that Landau, Fermi, Heisenberg, to mention a few, would be incredibly excited if they saw the current heavy ion results.

Zierler:

Of course.

Busza:

Heisenberg would probably say, “Boy, we basically understood it! It was just the details that needed to be worked out!.

Zierler:

Wit, on that basis, then, let me ask you—for my last question, it will be a counterfactual question. Because you say now that your value is in the recollection, it’s in the memory, it’s in knowing all of these people and all of these experiments that you were involved with. Let’s flip the tables chronologically, and let’s say now, somehow magically, knowing everything that you know, but you're 20 years old, you're just starting your career now. What would you focus on, for your career?

Busza:

Okay, I have to add one thing.

Zierler:

Please.

Busza:

You make me smarter—

Zierler:

[laugh]

Busza:

—particularly in mathematics—

Zierler:

Okay—

Busza:

—I would be a theorist.

Zierler:

Maybe if you had a little more continuity in your childhood, perhaps.

Busza:

Maybe. So, this is what I've always told students, when they come to me—“Should I be a theorist or an experimenter?” My answer is simple. “If you are brilliant, be a theorist. If you are only very good, be an experimenter.” Because an only—very—good theorist will achieve nothing. It’ll be done by the brilliant guys. You can be a pretty lousy experimenter and do a lot of interesting and valuable stuff.

Zierler:

I wonder if you know that this was exactly the advice that Uhlenbeck gave Sam Ting when he was a graduate student.

Busza:

I didn’t know that.

Zierler:

That’s exactly what he said to Sam Ting.

Busza:

He did?

Zierler:

Yes. I can share with you what Steve Weinberg said in response to that. He said, “I would add to Uhlenbeck’s remark that even theorists whose work does make some difference spend most of their time getting nowhere. I said somewhere that if you want to do creative work in theoretical physics, you have to resign yourself to spending most of your time not being creative.”

Busza:

You know, let me add something—that Weisskopf told me. I once said to him “Look, I am jealous that you can sit there at your desk and have the satisfaction of making these great observations, while we have to slog, soldering iron or voltmeter in hand, et cetera.” And you know what he said to me? “Wit, what you don’t realize—how depressing it is to sit at your desk, have four white walls, and no good idea.”

Zierler:

[laugh]

Busza:

[laugh] All right?

Zierler:

It’s like you're in prison and the wilderness, all at the same time.

Busza:

That’s right. Okay?

Zierler:

[laugh]

Busza:

Now, if you take away the brilliance and leave me with my abilities, today I would not do particle (including heavy ion) physics. Why? It is not that particle physics has no more fascinating and deep questions to be answered—on the contrary—for example, questions to do with dark matter or dark energy or how highly complex forms of matter emerge from simple underlying laws, I find absolutely fascinating. For me the problem is that particle physics has been too successful in the last 60 years. I do not see important questions which can be answered by a relatively small number of experimentalists in a time short compared to a human lifetime—the field has become more and more mismatched with the way I like to work. I would probably still be a physicist, but not necessarily so. Something involving the brain and AI might be fun—here I have to be careful what I say—this answer may be the influence of my younger daughter Ania—a neuroscientist. But back to physics—recently, condensed matter has started to fascinate me—I am amazed with all this marvelous physics that results from QED in action. I don’t think I would go into atomic physics—I hated looking for leaks in vacuum systems!

Zierler:

Still. [laugh]

Busza:

Still. Oh, I tell you what I would do for fun—in fact—even in 1960, if I was starting from scratch, and I had the guts to do it—I would do some of those experiments that directly test quantum mechanics—entanglement over long distances. Like this guy in Austria, used to be in Innsbruck, what’s his name? Zeilinger?

Zierler:

When they did the fiber optics, the light pulses.

Busza:

Yes, yes, yes. Something where you know the answer.

Zierler:

[laugh]

Busza:

But by Jove, it’s fun to see. To see it. I mean to see things entangled over many miles.

Zierler:

That’s the key word, Wit—the fun.

Busza:

Yes! I'm saying, the fun!

Zierler:

Must be.

Busza:

Life is too short for it not to be fun.

Zierler:

Well, Wit, on that note—on the note of fun—it has been so fun spending this time with you. As you say now, just being able to share these stories with me is—it’s remarkable and very special to hear your perspective.

Busza:

Thank you very much. You are kind. And it’s fun talking with you. [laugh]