Andrea Weibel discovered that galaxies grow up surprisingly quickly
Prix Schläfli 2026 for Astronomy: He has always been interested in the “big questions of the universe” and immersed himself in the origins of the universe for his thesis at the University of Geneva. Andrea Weibel will now receive the Prix Schläfli for his work on the emergence of very young galaxies.
Astrid Tomczak-Plewka
Perhaps you too have gazed at the clear night sky and experienced the feeling of really being nothing more than a tiny speck of dust. "It makes us realise how small and fragile we are, but at the same time it is something that connects us." The person saying this has looked deeper into the skies than most. Astrophysicist Andrea Weibel in fact travelled a great distance for his thesis – back to the first couple of hundred million years after the Big Bang.
His thesis focuses on the question of how the very first galaxies came into being and how they developed. He worked with data from the James Webb space telescope, which makes it possible to look in greater detail and focus more than ever before at these very early stages – an optical journey through time. The timing was, in fact, perfect. Andrea Weibel started his dissertation six months before the James Webb telescope delivered the initial data. Then things became hectic. "There was great competition for the new data because everyone wanted them," he recalls. As a young PhD student, he was sometimes overwhelmed but says, "I never had a major crisis." Weibel adopted two approaches to his work: He investigated whole galaxy populations statistically by counting how many galaxies there were at different points in time in large data sets. At the same time, he conducted a focussed search for individual, unusual galaxies. One of his discoveries – a high-mass, "quiet" galaxy that ceased forming new stars in the universe very early on – is particularly sensational. "We expect that all the galaxies will form stars like crazy in the early universe," explains Weibel. The fact that such a galaxy is "quiet" so early on indicates that it must have developed its mass in a very short time. His work therefore shows that big structures in the universe can obviously form more quickly than was previously assumed, and provides new insights into how today's galaxies were created.
The how and why question
Andrea Weibel has been interested in the question of how everything came to be for a long time. As a young man he asked himself: "Why do we exist at all? How does everything work?" He could have studied philosophy, but he enjoyed the "eureka" moments during physics lessons so much that studying physics therefore became a natural choice. "But I wasn't particularly enthusiastic. The basic course was very technical." It was not until his undergraduate dissertation that he turned to astrophysics and realised that he found it "really exciting". He moved from the University of Bern to ETH Zurich to study for his Masters because the range of astrophysics options there was greater, and he then chose Geneva for his PhD.
Despite moving around Switzerland, Andrea Weibel has always remained close to his roots. He grew up in Matten, near Interlaken, "in a very loving home", with a younger brother. His parents don't have an academic background, but are very supportive of his scientific career. "I had a lovely childhood by the mountains and the lake," he says. He really only appreciated the fact that he grew up in picture postcard scenery later. "When I travel to Interlaken by train, I often think, “It's really beautiful." It's not just the view of the mountains, but also talking to people who don't care in the least about his work, that has repeatedly helped him to ground himself. "Science is a bubble," he says. "It's good to escape it." Escape – what does this mean to him? Bouldering with colleagues, skiing. Before he was also a drummer in a band. "But that's no longer possible."
He wants to stay at home
His post-doctoral appointment in Geneva ends in the summer; he's then planning a research trip to Hawaii, which presents both an opportunity and challenge. After all, as he says, "I've always been based in Bern." Despite his position in Geneva, he has a room and his social circle in Bern, where he also spends the weekends with his girlfriend. "I'm very settled here," he says, "and would like to stay here longer term." This doesn't necessarily have to be in an academic institution though. "One thought that sometimes bothers me is that I would like to do something that makes a direct impact. I sometimes feel that this is what is lacking in what I have been doing for four years now," he says. "I don't have a definite idea, but am sure that I can apply the skills I have acquired during my doctorate in another field."
Ultimately, perhaps it is this that influences him: not always having a definite answer, but asking the big questions.
