Interview with the 2022 Nobel Prize laureate in physics John Clauser on 6 December 2022 during the Nobel Week in Stockholm, Sweden.

Where does your passion for science come from?

John Clauser: Oh, I think that’s very clear. My dad was a scientist and when I was a kid, he was a professor, in fact chairman, indeed the creator of the Aeronautics Department of Johns Hopkins University in Baltimore. I would add, all of my primary life leading up to this, every question I asked he would answer in detail very patiently with me, and I just soaked it all up. Then when I was in high school, I would take the bus up from Baltimore Polytechnic in Baltimore and walk across the campus to his office where I was supposed to be doing my homework waiting for when he would drive us home. Instead, I would just wander all over the campus into all various laboratories, into his laboratory and I would walk in and look at all these marvellous pieces of devices sitting around and say, Boy, when I grow up, I want to be a scientist. Look at the great toys you get to play with.

I’ve just been bathed in it since I was a very young kid. I loved science, my dad taught me lots of it. I was a high school whiz kid in electronics, built a whole bunch of computer science projects, even won a few national affairs, and I was just having fun. My parents left me as a free-range kid, I could do pretty much anything I wanted and did, wandered all over the city. One of the things that I enjoyed, I was a member of a high school radio club, went out and just built a lot of electronics and I was having a blast doing it all.

When did you know you wanted to pursue quantum mechanics?

John Clauser: When I went to Caltech, originally I was thinking about electrical engineering, but very quickly realised, No, I think I want to do physics. Caltech was a marvellous place, some of the greatest physicists in the world wandered the halls there. Very quickly got enamoured with doing physics, and all of which I was just having fun. I enjoyed doing a lot of it. I was not as good a student as I probably could have been. I was the social chairman of our residence house, the Dabney house at Caltech. Threw some great parties and flunked out a bunch of freshmen who really weren’t going anywhere anyway, so probably the best thing for them. Somehow – I have no idea how – I got into graduate school at Columbia. There I was working on my thesis project, on the cosmic microwave background. Originally we were going to put a radio telescope in a U2 high-flying U2 apparatus, where I learned a little bit about the spectrum of water vapor in the atmosphere that could relative to climate change. We ended up not doing that, ended up looking at interstellar cyanide and making the third measurement of the microwave background.

Would you consider yourself to be a good student

John Clauser: In order to I get your degree at Columbia, there were, I think, five important courses you had to get a b or better, otherwise you were considered having flunked. Quantum mechanics, I had flunked twice. I think finally my Nobel Lecture will explain why I flunked – what was driving me nuts and why I still don’t understand quantum mechanics.

What was the reaction people had to your theories?

John Clauser: Much to the distress of my thesis advisor, in fact, much of the distress of the whole Columbia physics faculty, everybody told me I was totally nuts in doing this. Everybody knew that Einstein was wrong, that he was getting senile was frequently the claim, and that Bohr had it all right. I couldn’t understand Bohr at all. Then I ran across John Bell’s paper, and that started my whole career in studying quantum mechanics. That was while I was still a graduate student. Columbia had more physics Nobel Laureates than I think Caltech did. They all told me, You’re nuts doing this. When I was doing the experiment at Cal Berkeley my dad, who was then on the physics faculty, he was Dean of Applied Science and Engineering at Caltech, and I would go home to Pasadena for Christmas and his birthday and Thanksgiving and whatever, so I was down there for Christmas. Then he said, Oh, I have made an appointment for you to talk to Richard Feynman. Oh, okay. I was doing the experiment, so I walked into Feynman’s office, and he threw me back out instantly. He was actually angry, as best I could tell that I was a challenge doing an experiment to test the predictions of quantum mechanics. Everybody knows predictions of quantum mechanics are perfect, don’t even need to look. I think his line was, if you find something wrong with the prediction of quantum mechanics, you can come back then and we’ll talk and figure out what your problem was, or what your problem is, and dismissed me immediately. He was rather abrupt.

Did you find people who supported your work? How did you do so?

John Clauser: When I was at Cal Berkeley trying to do the experiments, the really only two people, or maybe three later on, that thought it was actually a good idea, Charlie Townes, he is a Nobel Laureate, of course, and Howard Shugart was a great atomic physicists there, fortunately allowed me to stay there for I guess from 1969–76, where I did like four different experiments. I had a great time. I was having fun even though I had destroyed my hero Einstein’s work. I was not very happy about that, but that’s what the data kept telling me. I got to report what I see, that’s what experimental science is all about. Literally you’re talking to God, and God has spoken. It was not easy getting into a position to do the experiment, absolutely not, I had to struggle to do that. It was only through the kindness and generosity of Townes and Shugart that I stayed on.

What was the hardest part of getting people to pay attention to your work?

John Clauser: The hard part was getting around this, this was a religion among physicists, and in fact even in the Bohr-Einstein debates, and with Schrödinger also, the universal religion was quantum mechanics makes correct predictions, period, no, off the table. What Bell’s theorem and in particular our version of it, the Clauser-Horne-Shimony-Holt experimental prediction, showed that either that had to be wrong, nor Einstein’s whole legacy had to be wrong. I think at the time people who were critical of doing the experiment didn’t realise really what was at stake, that it was that cut and dried between two religious icons, if you will, the field of physics. Since I kind of was the inventor of the CHSH inequality and the CH inequality and all that, I knew exactly what it was all about. But it took a long time for that to filter in.

What advice would you give to a student or young researcher?

John Clauser: If you’re not enjoying it, find something else that you are enjoying and then you can put your heart into it and really be good at it. Totally silly to waste your time if you’re not enjoying what you’re doing.

How do you see science? Why do you think science is so special?

John Clauser: Okay, to start out with, I’m an atheist, for that point of view. But literally when you go into – at least I feel this way – when you go into a physics laboratory, you’re talking to God. It’s like going into a church, asking a question of God. It’s not often that people will walk into a church and say, All right, God, what’s the mass of an electron? But nonetheless, if you ask a question carefully, you’ll get a definite answer. It’s an unusual church from that point of view. If somebody else asks the same question and walks into another church he or she will get exactly the same answer. Find me another church for which that is true, that two people could walk into different churches, ask the same question and get the same answer. Enough said.

Nature is beautiful. There is great majesty in all of the natural patterns. You probably heard the comment about to look on Maxwell’s equations is to look on the work of God. There is great beauty in the symmetries that are built in, and if you’re the first guy to see something new, some new patterns in nature that nobody has noticed before, it’s an awesome experience, realising that you’re the only person in the whole world who knows this, and you have communed with nature as no one else has in the past. It’s a truly marvellous feeling, it gives you a great spiritual feeling.

What qualities do you need to be a successful scientist?

John Clauser: One of the things that my dad did that helped me along was taught me to be sceptical of everything, especially other people’s interpretations of experiments. He would say, Okay, go back and look at the original data, if you possibly can. What was really done and be sceptical that they have drawn the right conclusions. And I do that to this day on everything. I am the world’s worst critic of pseudoscientific claims.

What has sailing taught you as a scientist?

John Clauser: I’ve raced across the Pacific Ocean any number of times, and you learn a lot about clouds. I was using solar power for the instrument systems, and I was just sitting there in my berth watching, and I had an air meter on the solar panels and watched every time we go under a cloud, the total current charging their batteries would drop to one half. Why is that? Almost exactly one half every and in and out of clouds, flick, flick, flick, flick goes the needle. Amazing. It gave me a whole different opinion of how climate change works. I spent a lot of time trying to figure out what makes sailboats go fast, how to win races, built a lot of hardware. The present boat the rudder that came on the boat was a total joke. It was slow, you couldn’t steer the boat, it had a lot of drag so I just tore it out and built a whole new one in my backyard with starting rolls of carbon fibre cloth and buckets of high-tech epoxy and boars of polyurethane foam and put the whole thing together. It was fun. I didn’t know how to do it to start with, but I taught myself along the way. It’s not that, doing the stress analysis is pretty straight. If you’re a physicist, it’s piece of cake. It’s just straightforward handbook engineering.

Watch the interview

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