Hiranya Peiris is Cambridge’s new Professor of Astrophysics (1909). She discusses being inspired by Stephen Hawking, the unknown space before you arrive at an answer, and high-risk high-reward research. She is an alumna and Fellow of Murray Edwards College.

For as long as I can remember I’ve been fascinated by science and how the universe works. Growing up in Sri Lanka, where the skies were very dark and you could see lots of stars, was certainly a factor; but it was also that my interests were nurtured by my parents.

I was raised to think I could accomplish anything if I tried. My Mum was my role model – she was one of the first female civil engineers in Sri Lanka. I had aunts who were doctors and teachers, and an inspirational science teacher, Mrs Mendis.

In the early 80s my family got a TV and I watched Carl Sagan’s Cosmos. I remember him talking about huge expanses of space and time, and humanity’s place in the universe – it was these big ideas that really sparked a passion in me.

I was very geeky and loved science fiction. I joined Sri Lanka’s Young Astronomers Association and met other people just like myself. The patron of the club was Arthur C. Clarke. To this day his 2001: A Space Odyssey remains one of my favourite films. That feeling of being in space just bowls me over.

A ship called Logos used to come by the port in Colombo and sell books that were hard to get in Sri Lanka. On board I discovered Stephen Hawking’s A Brief History of Time – it was mind-blowing. During difficult times Stephen gave me such a huge feeling of strength because, despite his disabilities, rather than complaining, he used his mind to unravel the secrets of the universe.

I really wanted to be an astronaut, but I became short-sighted and in those days that meant you couldn’t pilot a space shuttle. By that point, I was in sixth-form in the UK and really enjoying my classes in maths and physics. I was encouraged by my further maths teacher, Dr Egan, to apply for Natural Sciences at Cambridge.

My time at Cambridge was a period of personal growth – I realised that when I talked about science I didn’t feel as shy. After a lecture given by Stephen Hawking, I found the courage to ask him for a thumb print on the inside cover of The Nature of Space and Time. Meeting him was an incredibly special moment.

I spent the summer of my second year at NASA’s Jet Propulsion Laboratory in the US. It was an amazing experience. It was the first time I’d been exposed to research in astronomy, and I thought the people there had the best jobs in the world. I also felt like I’d found a place where I belonged.

During my PhD I studied the cosmic microwave background (CMB) radiation which is a remnant of the Big Bang. For the first time we were able to precisely measure the age of the universe (13.8 billion years) and to form a complete picture of how it evolved.

Before the 1990s cosmology had been viewed as the ‘wild west’ of physics. But the CMB data collected by the Wilkinson Microwave Anisotropy Probe (WMAP) meant that fundamental physics theories could be empirically tested to obtain reliable conclusions. This was the beginning of precision cosmology, which seeks to pinpoint the parameters of our universe.

Analysing the WMAP data as part of Professor David Spergel’s research group was my first taste of collaborative research. It was a wonderfully rewarding experience – it felt like the team’s brains were seamlessly connected like a neural network.

I’m a builder and a connector. I love bringing people together to solve big problems. I truly believe that interdisciplinary research is where all the most exciting discoveries are happening today.

An international project I’m particularly passionate about is the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST). It will create our first “movie” of the universe. We’ll be able to see phenomena like the deaths of stars and study the evolution of galaxies over cosmic time.

I’m interested in the unknown space before you arrive at an answer. I feel like I thrive in uncertainty. I think if you’re happy in that mode then you can solve questions that are right at the boundary of our understanding.

The questions that have haunted me since my PhD are: what is the physics of the Big Bang and where did everything come from? Looking up at the sky may not provide all the answers, but I believe there might be a way to emulate our theories of the early universe in the lab.

It’s high-risk high-reward research. In collaboration with Professor Hadzibabic’s group at the Cavendish Laboratory, we hope to create a quantum simulator that may shed light on the conditions at the beginning of the universe.

I don’t feel like I must be the one to find the answers to these age-old questions, but I want to be part of the story. Research is a tapestry made up of the people you work with, the networks you build and the students you train.

I was incredibly honoured to be appointed Professor of Astrophysics (1909). Titles don’t matter to me, but I feel like the platform will allow me to do something special – I’d like to super-charge interdisciplinary collaborations, raise the profile of women and people from under-represented minorities in science, and get involved in outreach to under-served communities.

How does it feel to return to Cambridge? It feels like coming home.

Published 13 November 2023
With thanks to:

Hiranya Peiris

_{Words:
Charis Goodyear}

_{Photography:
Lloyd Mann}

_{The text in this work is licensed under a Creative Commons Attribution 4.0 International License}