In 1972, Frank Wilczek and his thesis adviser, David Gross, discovered the basic theory of the strong force — the final pillar of the Standard Model of particle physics. Their work revealed the strange alchemy at work inside the nucleus of an atom. It also turned out to underpin almost all subsequent research into the early universe. Wilczek and Gross went on to share the 2004 Nobel Prize in Physics for the work. At the time it was done, Wilczek was just 21 years old.
His influence in the decades since has been profound. He predicted the existence of a hypothetical particle called the axion, which today is a leading candidate for dark matter. He published groundbreaking papers on the nature of the early universe. And just last year, his prediction of the “anyon” — a strange type of particle that only shows up in two-dimensional systems — was experimentally confirmed.
Wilczek was raised in Queens, New York, the son of immigrants and the product of public schools. He finished high school in two years and college in three. He has taught at the Massachusetts Institute of Technology for 20 years, though pre-pandemic he spent much of his time flying around the world to his concurrent appointments at Arizona State University, Stockholm University and Shanghai Jiao Tong University, where he directs the Wilczek Quantum Center.
Wilczek’s latest book, Fundamentals: Ten Keys to Reality, comes out today. Wilczek told Quanta that he was “as proud of this book as anything I’ve ever done in my life.”
Quanta caught up with him twice at his home in Concord, Massachusetts, via Zoom in December. The interviews have been condensed and edited for clarity.
Congratulations on Fundamentals. How did the idea for the book come to you?
Well, the original idea was rather different from what the book has turned out to be. I was going to write this little book that told some basic facts about the physical world. I thought of it as something that people could read and feel that they knew more than they did before, something that would give them material to talk about at cocktail parties.
But as I put together a draft, I wasn’t happy with what I’d produced. There are already many books that do that, right? And then when I talked with my nonscientific friends — intelligent people, artists, people in literature — it didn’t seem like anything they wanted to read.
So, I went back to my desk and I thought about when I was a teenager and when I was turning away from the Catholic faith I’d been raised in, what did I look for in a book about science and our place in the universe? What would have been helpful to me then? The book I ended up writing was that one.
There’s a lot of God in your book.
There probably aren’t many scientists at your level who’d go there.
Well, I happen to think these issues are too important for scientists to leave on the table.
You know, science actually has a lot to say about what God is or about what God did. Understanding his/her/its work — that’s a direct way of informing yourself about what God is. There’s a great tradition that goes back to Galileo, Kepler, Newton, Maxwell and Einstein of looking at religious questions. Most of those people were explicitly, deeply religiously Christian.
Einstein, of course, was not. He described himself as having an attitude, similar to that of Spinoza, of a kind of pantheism, a more abstract idea of the world as God.
When I was a teen questioning my family’s Catholicism, I came upon this concept of complementarity that helped me a lot: There can be different ways of approaching the same question. Often there are different ways of describing the same thing. They can be valid each in their own terms, but they may sometimes be very difficult or even impossible to reconcile. So many of the conflicts between religion and science arise because they’re answering different questions. There are many conflicts where religions say things that are just wrong, but there are many other domains in which they are just addressing different questions.
In science, you’re broadly asking, “How does this work?” In religion, you’re asking, “What does this mean and what should I do about it?”
Are you religious?
Physics is my religious belief. In the sense that in physics we discover a fantastically wonderful world out there that’s rich in potential, rich in realization, and that has ample scope for fantasy, because the laws are so strange and there’s so much stuff out there to understand. And when you understand it, you understand how that could be.
I learn that I myself am very small. But I am also very large because I contain multitudes, as Walt Whitman said. I can process information. I can understand things. I can imagine. I can have fun. That’s the essence of my religion. I learn my religion from the study of what the world is and how it works.
Tell us a bit more about this teenage boy who was trying to figure out the universe and his place in it.
I grew up in New York City — Queens. My parents were immigrants. My father from Poland. My mother from Italy.
I’d say we were somewhere between upper-lower class and lower-middle class. My father worked as a technician. My mother was a homemaker. Both were very intelligent, though they hadn’t been to college. My father had to quit high school in order to help support his family during the Depression. But they were very invested in the idea that their children should have a better life than they did.
We were also very fortunate that we lived in New York and had access to the public school system that served me very well. Almost from the moment I entered school, I was given IQ tests. When I scored high, my parents were called in and told, “Frank is exceptional. You should do everything to help him.”
How did they respond to having a prodigy in the household?
Once the school started telling them how smart I was, it changed the dynamics within the family. I wasn’t this little kid they could boss around anymore. Though they were themselves very intelligent, I think they were somewhat intimidated by me.
They allowed me to get toys that were clever, even though we couldn’t afford them — mechanical toys and telescopes. We’d go to a special bookstore for science and philosophy books. I read a lot of Bertrand Russell, who meant a lot to me. I think my parents were kind of puzzled by me. When I wanted to do strange things, they’d let me do them. I think my mother sort of idolized me. It was assumed I’d become some kind of scientist. She always said, “You’re going to cure cancer.”
I’m going to say something very immodest here. The fact that in school I got this kind of validation that was very objective and not faked gave me enormous confidence. I did very well on various tests and competitions. I had a lot of confidence. That’s stayed with me for the rest of my life. Scientists need that sort of confidence to take intellectual risks.
Did you go to the Bronx High School of Science?
No. That was an hour’s commute away. I went to a very large Queens public high school, Martin Van Buren, where I was on the nerd track with about 20 other kids. We all went to the same AP classes and hung out together. We’re still in touch, to this day.
When I went off to the University of Chicago at 16 — I had skipped two grades — on the whole, the students there were not as good as my pals back at Van Buren. On the other hand, the professors were on a different plane. They wanted to understand things in a big way. At Chicago, at least from the faculty, I felt I was getting into contact with the cutting edge of human intellectual exploration. I had a lot of amorphous ambitions. Chicago was a good place to try to figure out what I wanted to do.
For instance, I quickly discovered that lab work wasn’t for me. I saw it can be fussy work, repetitive. So I went on to explore computer science, physics, biology. I was in a holding pattern. Eventually I settled on mathematics because I love to do puzzles, and that merged with the idea of solving equations and manipulating data in the broad sense. I had these amorphous ideas like wanting to investigate the way the mind works using mathematical logic.
Did math work out?
As a college major, it did. I finished in three years and then went off to do graduate work in mathematics at Princeton. There, I experienced a big shock.
Graduate school was not a matter of learning things that others had already figured out, but of producing something new. They gave me an office with a blackboard and said, “Do something interesting.” Suddenly, I was being treated as an adult. I found this really difficult. I went into a kind of crisis.
But then I had a tremendous piece of luck. A miracle happened. I happened to attend some physics lectures, and that got me involved with this project of understanding how quantum field theory worked and whether it could be applied to the strong interaction. That was basically the first piece of serious research I’d ever tried to do. And it worked!
And it led directly to a Nobel Prize. I did hard calculations that nobody else could do. I was collaborating with David Gross, who was a much more experienced scientist. And so brilliant. Working with him, I felt that I was making a real contribution. In subsequent years I was able to spin off one successful application of those ideas after another — or do other creative things like axions, though that was much later.
I knew right away that if the theory we were proposing was correct, it was potentially a very big deal. I remember saying to David, “If the experiments bear this out, we’ll get the Nobel Prize.” Now, the prize came 30 years later, in 2004. But the personal validation was instantaneous. We did the calculations in the winter of 1972, and we published in the spring. That summer I went to my first conference. It was very small, at a place called the Downingtown Inn. But Feynman was there, the Feynman, and he talked about our work. He said, “This is really important.” I was 21.
You could have been crippled by such a remarkable early success. Many people are.
Not at all. I think for the kind of work I do, having self-confidence is pure gold. To break new ground, you need to be willing to go out on a limb and take risks. Because of my early successes, my mistakes, when I made them, were not as devastating as they could have been.
To be honest, I’ve made some. One was a mistake of lost opportunity. I feel I should have discovered inflation. I had all the necessary pieces; I was at the right place at the right time with the right kind of knowledge. I was just thinking about other things.
One of my big successes in recent years was in proposing the concept of a time crystal, which has kind of flourished into a whole field. But in the early paper, my main example turned out to be not very good. It was unstable technically. It was not scientifically sound. The general direction was good, but the detailed implementation was not.
What do you tell yourself when you’ve made a mistake?
I don’t dwell on it. Listen, I like working with imaginative ideas. Mistakes are sometimes the price of doing that.
Let’s talk about one of your imaginative ideas — axions. They are the hypothetical particle that may make up dark matter and thus may be a key to understanding the early universe. You’ve been theorizing and publishing about them for more than 40 years. How did you get started on axions?
One night in the summer of 1977 I took a long walk at Fermilab and decided to think about issues around the Higgs particle or particles. First I thought about how one might detect them. I basically cracked the problem, though that didn’t become clear until much later. Then I thought about whether there might be more than one Higgs field, and if there was anything interesting one could say about that kind of possibility. The most intriguing idea that occurred to me was that with more than one Higgs field you could have symmetry patterns.
The next day I went to the library and looked up what people had done on all these questions. I found that Roberto Peccei and Helen Quinn had not only considered the Higgs symmetry, but showed that it could address a fundamental problem in physics. But Peccei and Quinn hadn’t realized a very striking consequence of the symmetry, namely the existence of a very light particle — what we now call the axion. My first thought was that such a particle would surely have been observed if it existed, so I didn’t work on it as urgently as I did on the other idea.
But as I considered it more closely, I gradually convinced myself that maybe the axion — which is what I called it, from the start — might possibly exist after all, because one after the other my attempts to rule it out failed. It’s not every day that you stumble into new ways of asking and possibly answering such fundamental questions, so I got sucked in.
A few years later I got invited by Stephen Hawking to a now legendary conference, the 1982 Nuffield conference in Cambridge, where early-universe cosmology was the main subject. Stephen asked me to give the summary talk. I felt I should try to live up to the occasion and present some new ideas, so I raised the question of how the axion field settles down after the Big Bang, and whether it might leave an observable relic.
John Preskill, Mark Wise and I worked this out and discovered that in fact lots of axions get left over, and that they would have just the right properties to supply the “dark matter” that cosmologists seem to need.
Given the fact that you and the others were heavy hitters, why were axions for so long the Rodney Dangerfields of the physics world? They didn’t get much respect.
Well, axions were a very different kind of particle, quite different from anything before. Without an understanding of the deep theoretical ideas behind it, axions just seemed outlandish.
That’s changed. The case for dark matter has become much stronger, and axions have become much more popular. Certainly, the case for dark matter in the universe is very strong now, almost universally accepted. That dark matter is probably some new kind of new particle is almost universally accepted, too. It fits many, many independent lines of evidence. And it could be the axion. The axion has all the right properties, which is not trivial at all.
And also, the original fundamental problem that the axion was designed to address, this problem of why the laws look the same forward and backward in time, has been around for almost 50 years now, and axions are the only solution that stands up. So we need it. We need it. I think we can look forward to the discovery that the dark matter is in fact axions.
For a long time, the alternate leading candidate for dark matter was something called a WIMP. Has it fallen by the wayside?
I think so. It was supposed to emerge from supersymmetric unification theories, certainly an attractive idea.
But what’s happened is that at the Large Hadron Collider, supersymmetry was not discovered, and then in a large number of other searches for WIMPs, they were not discovered, and so the empirical case against them mounted. By process of elimination, that left axions as kind of the last man standing. Now, it’s not quite true that all modifications of the WIMP theory have been ruled out. But WIMPs are getting less plausible, whereas axions look better and better.
If axions are proved to be the dark matter, will you have shaken up the physics world a second time?
Well, yes and no. If axions are it, it wouldn’t shake everything up because there’s already a well-established body of theory about it. The basic concepts have been around for 40 years. There are thousands of papers. But still, it’s one thing to have theoretical speculation and another to have the world.
I’ve enjoyed working on the axion — it’s been fun. With others, I started in the early 1980s proposing that it might be a candidate for dark matter, and that opened up new ways to look for it. It was an interesting concept to work on compared to QCD [the theory of the strong interaction], which had been solved. Today, many people are working on axions. And that’s inspiring, and it keeps me connected to younger people.
On the other hand, it’s not yet the same thing as what David and I did on the strong interaction, which is part of the fabric of fundamental law.
What are you working on now?
Several things — an eclectic mix. I’m very actively involved in trying to design axion antennas that will finally detect them. I’m having a lot of fun working with experimentalists and engineering-type people to do that.
I’m working on a state of matter called anyons that I think could open up a whole new area of physics and could change computing. I have another bright idea on something related to quantum information theory.
I’m very interested to follow up on time crystals; I think that has flourished beyond my initial expectations. And it’s gone in different directions.
Have you had to put these projects on hold because of the pandemic?
Oh, no. No! They’ve been fostered because of it. I’m not schlepping around and going to conferences and traveling. I mean, I’m eating better. I’ve lost 15 pounds, taken up juggling, doing exercise. It’s given me time to do creative thinking. In a way I’ve been going back to school, as if I were a graduate student. I want to learn more about machine learning. I’m going to be 70 in May, but I feel younger now than I’ve felt for many years.
You know, when I was a teen and trying to put it all together, I thought that life was a matter of figuring out the answers to questions and that was that. Now I’m learning that good answers lead to better questions, and that the cycle never ends.