Professor Didier Queloz, winner of the Nobel Prize for Physics in 2019, attributes his decision to focus on the subject to two seemingly contradictory childhood impulses – an excessive curiosity, and a lack of ideas on what to do practically.
“I was frankly super curious,” he recalls. “But I was curious about everything, so physics was one of them. You know, the reason why I went to physics is that I was unable to choose. I was interested by too many things…. I realised I was kind of gifted for learning, for mathematics …and then I just fell in love with physics, but I went to physics because I knew that then I didn’t have to choose what to do. I thought ‘by physics I can do anything I want’ because it’s so generic.”
Queloz pushed this idea of the limitless applications of physics to its furthest possible reach, discovering the first planet orbiting a star beyond our solar system in 1995 when he was still a PHD student. Now termed ‘the exoplanet revolution’, the breakthrough was not immediately acknowledged as such.
“The beauty of science is you never realise what you’re doing when you’re doing it,” he explains. “It’s years after that you say ‘oh my God!’. So at the beginning, and you know, you have to go back 30 years, we were completely on the margin of the core scientific interest. For a couple of years after we made the announcement, because it was so weird, so challenging, people were very sceptical. They thought ‘well it may be something else, it’s not really a planet.’ And it’s only with time, with the increase of other detections, the fact that nobody has demonstrated that there is another way to explain what we found, that it became evident that what we had done was right.”
However gradual, that recognition eventually transformed scientific understanding of the universe, and our place in it.
“In science, revolution means when you change, a bit, the paradigm. And that’s what we did. I think we had this picture of solar systems, our own solar system, as being the absolute model, the standard model, that would explain any other planetary system you have in the universe. And actually, that is wrong, it’s completely wrong. It’s really kind of refocused what we are and where we are. So in terms of astrophysics it really is a revolution.”
Despite having spent several years developing a new form of spectrograph, ELODIE, with the specific ambition of detecting planets external to our solar system, Queloz was taken by surprise by the speed of its success.
“Detecting a planet needs time, and the equipment we built was designed to do that – otherwise we wouldn’t spend three years of our time making a machine which is so good. But the plan was for me to just start the programme, and it would take years to detect a planet. So the big surprise was that it didn’t take four years, it took me a couple of months. And that was a big shock.”
The scale of the discovery, and its implications, took time to process, even for its instigators.
“Most of the time, scientists do things that they know, and that everybody’s expecting. It’s still thrilling, because you just improved this, you realised this, and it’s fun. But when you face a complete dramatic change, then that’s completely another game, and I tell you it’s not fun at all. I mean, it became fun for me 10, 15 years after. Then I started to enjoy it, because then everybody realised what we’d done!”
Since that initial discovery, Queloz has participated in the detection of hundreds of planets, working to understand their formation and the potential for life. In 2013 he joined Cambridge as Professor of Astrophysics at the Cavendish Laboratory, and is now Director of the University’s newly created Leverhulme Centre for Life in the Universe. It has been a turbulent decade for British science, thanks to uncertainty around European collaboration and funding as a result of Brexit. But Queloz has a firmly optimistic perspective on what he sees as the country’s unique approach.
“When I decided to move to the UK, I lost my very generous Swiss income, I lost my mountain, and I lost a lot of sunny weather. So why do you think I did so? It just demonstrates that in the end there is way more that this country has to offer than just being obsessed by a few details. I think there is a culture of science, a culture of collegiality to operate science, and at the same time a high competitiveness, which is to me very interesting because…you don’t have both in many countries. I don’t really know what it is, frankly, but it works. So I really fell in love with this country because this is, I think, the perfect way to do science.”
The audience at Friday’s Darwin Lecture will be taken on a journey, from Queloz’s experiments of the 1990s to the future which they are leading us towards.
“I want to show them what it is to make a major discovery which works…and explain the jump it has created, this kind of new perspective. And I just want to take a little bit of a forward look by demonstrating that this detection of a planet is way more than a planet, because this has triggered a larger and wider interest into the true concept of life in the universe. So this connection from the major discovery that is resetting the position of earth and the solar system, is way bigger than just a question of exoplanetology, and that’s where I want to bring the audience, just to show them what’s going on, and the expectation we have in the next decade to a hundred years, in the future.”
The childhood curiosity which compelled Queloz to study physics led him to seek answers in the stars for reasons he presents as wryly casual:
“I went to astrophysics because I thought it would be cool for me to do things outside. And astrophysics is about telescopes and mountains – you go out and you travel a lot. We’re a sort of aristocratic club, the astronomers. We don’t have any much money, but we travel everywhere in the world in amazing locations.”
It’s a mindset, and a determination to find answers, which has enabled him to transform not only his subject, but human understanding of the most fundamental questions. Queloz credits his career with the retention of this childish fascination.
“I think the fascination and the curiosity is in every mind. Of course, kids need it because that’s just the way you learn. For some reason that I just can’t explain, when you become an adult you kind of lose curiosity, and the only ones who don’t lose it are people like me. I am exactly the same as I was as a teenager – I could get bored very rapidly when things weren’t exciting – so I think some people keep it for some reason I don’t understand. And these people become scientists, I guess.”
Didier Queloz’s lecture, The Exoplanet Revolution, will take place at 5.30pm on Friday 16th February.