Dr Suzie Sheehy: ‘The eureka moment may come once in your career, or never’ | particle physics

B.orn in Australia in 1984, Dr Suzie Sheehy is an accelerator physicist who runs research groups at the universities of Oxford and Melbourne, where she is developing new particle accelerators for applications in medicine. As a science communicator, she received the Lord Kelvin award in 2010 for presenting science to school and public audiences. Her first book of her is The Matter of Everything: Twelve Experiments that Changed Our World.

How did you first become interested in physics?
At university [in Melbourne]when I was studying engineering with science on the side, I started asking questions in my lectures, and I remember one [physics] lecturer saying, “Oh, we don’t know the answer to that.” And I thought, how is it possible that I, aged 19, can ask a question that nobody has ever asked before? Suddenly engineering seemed a little more boring and physics a little more exciting.

Where did that lead you?
I ended up moving to the UK to do my PhD, via a short stint at Cern, where I first saw the Large Hadron Collider. I got intrigued by the idea that we could use particle accelerators to do things like treat cancer, and that it could have a direct societal impact.

You structure the book around 12 experiments from 1895 to 2012. Why?
That’s really the story of modern physics and the development of particle physics. I sat down and made a spreadsheet of all the major discoveries, from the discovery of the electron through to the Higgs boson, and what we’re discovering today. Then I had to ask, what did people think back then, and how did they learn what we know now? Which was incredibly difficult, because in physics we often give this reverse history, starting from what we know. Getting into the headspace of someone in the 1890s and how they thought about the world was really challenging.

Some of the recent technologies are awe-inspiring, but earlier physicists were doing groundbreaking experiments using really makeshift materials.
Yeah, I always found that inspiring, the resourcefulness of people like [New Zealand-born physicist and Nobel laureate] Ernest Rutherford. It blew my mind to think that if I had been doing graduate study back then, I would have spent a significant amount of my time blowing glass or melting wax seals. A lot of the detailed skill now is designing computer systems that interact with the experiments. But even still, in my small lab in Oxford, I’m making little wire connections and using big wrenches to get bolts on and off the lid of the vacuum vessel.

Rather than lone geniuses plucking great discoveries out of thin air, you write that a lot of experimental physics is inching along in the dark and feeling out details, until eventually it clicks. Do you need a high threshold for boredom?
If you were to believe a lot of the historified versions of these discoveries, you would think that science is exciting day-to-day and if you’re smart enough, you’re going to have that eureka experience. That’s extremely damaging. Patience and persistence absolutely are key skills. The eureka moment may come once in your career, or never, but you can have many small victories along the way, and I make sure I celebrate those small victories.

The story of physics is overwhelmingly male, but you’ve managed to shine a light on a number of women who made important contributions over the past century. Were their stories difficult to find?
In places, very difficult. Some of the women I came across in a photograph in a biography of one of the male scientists. That was how I found Harriet Brooks, who was Ernest Rutherford’s first graduate student. I saw her looking at the camera and thought, who’s this woman? It became important to me to make sure women’s stories were written back in, because in other versions they were erased entirely, not even mentioned as a sidenote.

Does physics still feel like a boys’ club?
I’ve worked quite hard to make sure that the research groups that I form are more diverse and representative. My field, though, is still quite male-dominated – about 85-90% male. If we stick with the current rate of change, it will take about 75 years for physics to reach parity. Obviously, we’ve got a long way to go and people still face large barriers, but this is a societal problem as well as a science one.

As a prominent female physicist, do you feel more obliged than a man to do public-facing work and engagement? And does this ever feel like a time-consuming tax on the progress of your academic career?
I’ve always done public-facing work, even as an undergraduate, so for me it’s a little different. I find it really important to understand what people who aren’t physicists think of the work that we do, and what matters to them. It means I can translate between my physics colleagues, debating some technical detail, and other people going, we don’t understand why this is important. It’s actually a kind of superpower to be able to combine the research and the public-facing work, and that’s partly why I now work on things that matter more to people outside of physics, because I hear that it matters to them.

The amount of money invested in big physics projects from the 1950s onwards – the Large Hadron Collider at Cern is just one example – is colossal. How can these sums be justified, especially when so many other fields of research are underfunded?
There’s a whole research field that analyzes the value for money and economic and societal impacts of science projects. I was just reading one about the Human Genome Project, and the return on investment of that was at least 4.5. So even though we do this purely out of curiosity, to create knowledge, because we’re fascinated to understand the world, and even though on the surface it looks like enormous amounts of money, actually the return on investment is not just positive, it’s huge.

I don’t like to be pragmatic about it like that. At the end of the day, it’s about people understanding the world that they live in, and that has value – societal and philosophical value – even if it doesn’t invent another widget.

You write that in almost every case, scientists who discover different particles and forces believe they will have no practical use. What’s an example?
We discovered muons from cosmic rays. Nobody expected them. They’re traveling through us all the time. We can’t make electronics out of them or anything like that, because they decay in a few 100 microseconds. So OK, maybe it’s just a curiosity. But within a number of years, people were using them to image inside the Great Pyramid of Giza, where they found an extra room. They use them to image volcanoes, to get a time-based measurement of what the magma is doing. And there’s no other imaging technology we can really use for that, because nothing else travels through in quite the same way that a muon does. It’s like a CT scanner, but to scan enormous objects on the Earth.

You write about Big Science bringing together different nations to collaborate on extraordinarily complex projects. What effect is the war in Ukraine and the isolation of Russia having on this?
We are already seeing it in some projects. For example, Germany has instructed their researchers not to collaborate and publish with Russian researchers. One of the big international projects being built in Germany is a very large particle accelerator project called Fair – the main goal is towards nuclear astrophysics and understanding the development of heavy elements in the universe. About 30% of the equipment was supposed to come from Russia. Now that has been completely changed.

Meanwhile Cern has announced that it has suspended Russia’s status as an observer nation. That’s sent a shockwave through the community there. There’s a really strong sense that this is a big shift, not a temporary blip. What it’s shifting into we have no idea, but there’s a huge concern around it. All I can do at the moment is look back to what happened post-world war two, and the way that people really felt very strongly about using science for peace, and crossing those divides, and that knowledge should be for the good of humanity. And I’m hanging on to that right now.

You end the book with the Large Hadron Collider and the discovery of the Higgs boson – a hard act to follow. What’s next?
We’re at a really interesting time in history. A lot of people saw the search for the Higgs boson as the final piece of the standard model, but they were looking for a lot more than that. There are indications that we only know something like 5% of the mass energy content of the universe, and the rest is dark matter and dark energy, but we have no idea. And then there are neutrinos, whose behavior we can’t quite explain. So there’s so much that we don’t understand. Imagine you’re doing a 1,000-piece jigsaw puzzle, and you’ve just completed a corner, and you have that little feeling of success, but the rest of it is still lying there. The role of the Large Hadron Collider, and what comes after that, is to find those next pieces.

Did writing this book change the way you approach your own research?
It really reinvigorated me, and shifted some of the doubts I had as a scientist. You go to the lab each day, and make mistakes, and you do it again, and eventually you produce a result, and you think, am I the only one who does it like this? Do other people just go in and do beautiful experiments and feel like a genius all the time? Learning about all these revered intellectual heavyweights who won Nobel prizes and how they struggled, you realize, this is not just me, it’s the process. It’s given me a sense of humor about it and made me more resilient in what I do.

Your book got a very nice blurb from Philip Pullman. Are you a fan of his work?
And it is. We had a bit of a chat back and forth about cloud chambers and cosmic ray particles and things like that. I still need to reach out to him to show him a real working cloud chamber, because I’m not sure he’s ever seen one, and we’re both Oxford-based, so if he has the time…

  • The Matter of Everything: Twelve Experiments That Changed Our World is published by Bloomsbury (£20). To support the Guardian and observer order your copy at guardianbookshop.com. Delivery charges may apply

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