The Quantum Universe

Our speaker this month will be Professor Stephen Wilkins from the University of Sussex:

Quantum physics is the foundational theory that governs the behaviour of matter and energy at atomic and subatomic scales. Marking a century since its earliest breakthroughs, the United Nations has designated 2025 as the International Year of Quantum Science and Technology. As part of these global celebrations, I will explore how quantum physics underpins our understanding of the cosmos, focusing on two powerful examples.

First, the energy that powers stars—including our Sun—comes from nuclear fusion. Classically, the temperatures inside stars are too low to overcome the repulsive forces between atomic nuclei. However, quantum tunnelling allows these nuclei to ‘leap’ through this energy barrier, making fusion—and therefore starlight—possible.

Second, the large-scale structure of the Universe—its galaxies, stars, and planets—can be traced back to tiny quantum fluctuations in the very early Universe. During the period of cosmic inflation, these quantum variations were stretched to astronomical scales, seeding the structures we observe today.

These examples highlight how quantum physics, though born from the study of the very small, plays a pivotal role in shaping the vastness of the Universe.

Stephen Wilkins is a Professor of Astronomy and Public Understanding of Science at the University of Sussex, located just outside Brighton. He earned his Master’s degree in Physics from the University of Durham and completed his PhD at the University of Cambridge. Following a research fellowship at the University of Oxford, Stephen joined the faculty at Sussex in 2013.

His research centres on understanding the formation and evolution of galaxies, with a particular focus on the earliest stages of cosmic history. To explore these questions, he combines observations from cutting-edge telescopes—including the James Webb and Hubble Space Telescopes—with advanced supercomputer simulations.

Beyond his academic work, Stephen is a passionate advocate for science communication. He has led three exhibits at the prestigious Royal Society Summer Science Exhibition and delivered dozens of public talks aimed at making the wonders of the Universe accessible to all.

Arrive from 7pm for a 7:30pm start.

For this meeting we will be at Wagner Hall on Regency Road, Brighton. Attendance is free, but we would be grateful if those of you who are able to could donate a few pounds to help cover the cost of hiring this event space. We will have a card reader and a money box you can drop your donations in on the night. We also have a bank account you can donate to electronically.

Brighton Astro is inclusive and welcomes everybody.

Please note that the venue has a bar that sells alcohol.