Jasper's day
Jasper Knoester is the dean of the Faculty of Science. How is he doing, what exactly does he do and what does his day look like? In each newsletter, Jasper gives an insight into his life.
A day of spring, physics, and security
Monday 24 March 2025
'At 8 in the morning, I happily cycle to the station. Spring has officially begun—three days ago, to be exact—my favourite season. I love the rapidly lengthening days and the increasing amount of sunshine. And today, I foresee a great start to this first full week of spring!
At nine, our faculty board is welcomed at LION, our physics institute. It’s the first stop in a tour we’ll be making over the coming months, visiting all the institutes. The aim this time isn’t to discuss governance—that happens twice a year in formal meetings with each institute. Today is about being inspired by the fantastic education and research happening at LION. In fact, we should really do a round like this every year, but schedules tend to get in the way. This spring, we’ve made it a priority, and as a board, we’re very happy about that.
We’re welcomed in the Oort Building, where scientific director Sense Jan van der Molen gives an introduction, painting a great picture of this impressive institute. Then, professor Carlo Beenakker presents on the Lorentz Institute for Theoretical Physics. He also highlights the special AQA group—Applied Quantum Algorithms—a collaboration between LION and LIACS. Leiden is making a name for itself in quantum computing worldwide, and this group is a big part of that. After the presentation, we head to the Huygens Building to visit two experimental physics groups.
First, we visit Wolfgang Löffler’s group, which focuses on quantum optics. One of their key projects is creating a reliable source of single photons—quantum light particles—crucial for various quantum applications involving light. PhD candidate Kirsten Kanneworff gives us a short lab tour, showing us exactly what experimental quantum optics research entails. Experimental physics at our faculty has been thriving for over a hundred years, thanks to top-tier expertise in instrument development, and we see that in action here again.
Next, we visit Daniela Kraft’s group, which works on soft matter—specifically creating (sub)micrometre structures from polymers. This group gained global attention with the world’s smallest boat, small enough to fit inside a human hair. Now, they’ve moved on to more flexible and active materials at this ultra-small scale. Postdoc Mengshi Wei gives us an impressive demo of 3D-printed flexible micro-snakes that can move across surfaces, avoid obstacles, and even interact with each other.
After this fascinating visit, I have a series of internal meetings before heading to The Hague in the afternoon for a session at the Wijnhaven building. The topic: possible collaborations with the Ministry of Defence and various branches of the Dutch armed forces. With growing concerns over European and Dutch security, innovations are urgently needed, and universities have a big role to play. Our faculty has already been involved in several discussions on this. Of course, there are questions and challenges, such as: Do we want this? How do these collaborations work? Could they clash with the highly international and open character we strive for as a faculty? One thing is clear: we have valuable expertise to offer, and this will certainly be an ongoing discussion in the coming period.
Back home, my family is surprised to see me before six—a rare perk of a meeting in The Hague. We have an early dinner, and I get some household tasks done. Lately, I’ve been swimming almost every day, and tonight, I manage to squeeze in another session. I always come back with more energy than I left with, so I’m glad I went. After that, I spend some time helping Jasmijn prepare for a maths exam later in the week. Calculus is much more my thing than statistics, which was the main focus last term. By the time we close the books, it’s past midnight. Tomorrow, another spring day awaits, with the sun rising early—time to get some sleep!'