To draw a straight line from A to B, you need a ruler. But how do you draw a random line from A to B? And what does it look like? Bart Zonneveld’s research goes one step further. Instead of random lines, he describes random surfaces. To be more precise: random surfaces with constant internal curvature. These surfaces have a relatively simple interior, but wild, fractal edges. So how do you describe these random surfaces? In his thesis, Bart demonstrates two methods: in the first method, the surface is constructed from so-called ‘pairs of trousers’. These are surfaces with three edges, just like a pair of trousers. By ‘sewing’ these pairs of trousers together, you can create more complex surfaces. And by sewing them together at random, you also obtain random surfaces. The second method is more complex, but mathematically more powerful: Bart shows that random surfaces can be related one-to-one to random tree structures. As these tree structures have already been extensively studied mathematically, this approach can also be used to determine properties of the random surfaces. This research is motivated by a major open question in fundamental physics: the combination of quantum mechanics (randomness) and gravity (geometry, i.e. surfaces).
Bart Zonneveld grew up in Amsterdam and moved to Nijmegen in 2015 to study Physics. There, he was particularly interested in fundamental problems. During his studies, he conducted research into quantum gravity and quantum mechanics in curved spaces. In 2021, Bart began a PhD programme under the supervision of Dr Timothy Budd. As well as conducting research, Bart was also active as a lecturer and as team leader of the university’s internal fire brigade. Bart is now engaged in a completely different line of work. In February 2026, he took up the post of policy officer for cyber resilience at the Ministry of Infrastructure and Water Management. The defence of his thesis is therefore the final chapter of his academic career.