Professor Lerothodi Leeuw’s message to physics students is one we can keep in our back pockets.
Pretoria (13 October 2025) – The University of Pretoria’s new head of Physics, Professor Lerothodi Leeuw, was fascinated with astrophysics from the start, with one of the biggest questions. How did the universe begin?
After growing up in the Northern Cape, Leeuw went on to become a student at the Massachusetts Institute of Technology (MIT) in the USA. There, he discovered that scientists were doing work towards quantitatively answering the burning question he had posed for so long.
Leeuw went on to become the first black South African to obtain a Bachelor of Science degree at MIT, and one of only three black students from anywhere in the world to major in Physics there. He then completed his MSc degree in Astronomy at UCT and later, his PhD degree in Astrophysics from the University of Central Lancashire in the UK.
An excellent academic record set him up for a career in studying the universe.
Over the years, Prof Leeuw has worked at NASA’s Ames Research Centre, Rhodes University, the University of Chicago and the University of Johannesburg. His research is complicated.
In a nutshell, it’s about trying to understand how galaxies change and grow over time. He studies elliptical galaxies in particular, using powerful telescopes that can pick up information across different wavelengths of light. Some of the galaxies he looks at are ‘gravitationally lensed,’ which means their light is bent by invisible matter on its way to us. That invisible matter is dark matter, the mysterious stuff scientists know is out there but still can’t see directly.
By studying these lensed galaxies, Prof Leeuw hopes to learn more about how dark matter is spread across the universe, and what role it plays in shaping the galaxies we see today.
He’s published more than 300 scientific articles, exploring these topics. Along the way, he’s scooped the NRF Special Recognition and the Hamilton Naki Awards for his work.
Now, as the newly appointed Head of Physics at UP, he’s continuing that work and encouraging SA’s brightest to reach for their most astronomical goals.
We love his advice, because it applies to anyone, really.
Keep your curiosity alive.
“As a student, keep doing that throughout your career. Keep it going. Crucially that means when you read a textbook or attend a lecture, don’t be afraid to question,” he says.
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