There are worse places to hold an international conference than the Swiss Alps. Math-related outreach and communications activities offer a lot of possibilities for playfulness and hands-on experiments.
Our team of four Doctoral researchers attended the Matrix x Imaginary conference on the future of mathematics engagement in the small mountain village of Les Diablerets, located in the Swiss Alps. The conference was held at the turn of August and September 2024 and was jointly organized by MoMath, IMAGINARY, and G·EM (Genève Évasions Mathématiques). This conference had a refreshingly different perspective on mathematics compared to the more academically oriented or research area-specific ones we usually attend. Instead of new theorems, proofs, or datasets, the conference presentations and workshops focused on math outreach and communication, as well as showcasing creative ideas for mathematically inspired games and art.
Many new faces
There were 117 attendees from 22 countries, so we had the opportunity to network with many new people. Usually, you see (more or less) the same familiar faces at different conferences and workshops around the world, as the inverse problems community is not that large. It was very interesting to discuss mathematics with people who do not have the exact same background as you.
We had the pleasure of getting acquainted with Cindy Lawrence, the executive director and co-founder of the National Museum of Mathematics (MoMath) in the City of New York. Some memorable presentations at the conference included an inspired keynote speech by Kyne Santos, a drag queen math communicator, also known as the Math queen. Hearing first-hand about the efforts to establish a new mathematics museum in Kyiv, Ukraine, in the midst of war was very inspirational but heartbreaking at the same time.
Workshopping
Our main contribution to the conference was a two-part hands-on workshop on X-ray tomography. As you probably know, it is not the best idea to get handsy with x-rays, so our first day approach was to use light and shadows to introduce the idea of indirect measurements and the notion of inverse problems in general. The participants measured the width of the shadow of a hidden rotating object and used these data to reconstruct a cross-sectional image of the mystery object. You can find videos about these shadow mysteries on YouTube from Samun Tiedekanava.
On the second day, we gave a gentle introduction to the mathematics of X-ray tomography. The participants attempted to solve different kinds of X-ray tomography puzzles, designed in the inverse problems research group at the University of Helsinki. In the first task, the idea was to try and guess what the unknown object is, based on a video of simulated line integral data. For the human eye, this is a surprisingly difficult task, as the target gets more complicated!
Hands-on experiments during the workshop. The post continues after the images.

The second task was a sudoku-like puzzle, where the goal is to recover the unknown target on a pixel-grid from simple, numerical measurements. Both puzzles are available in the University of Helsinki’s Summamutikka material bank if you want to try it yourself! The tomography puzzle is also available in English. Links to the tasks: task 1, task 2, task 3.
In the end of the sessions, we had time to introduce the novel sticky-pokey tomography game to the participants that were ready with the main tasks. You can see how the game works here.
The workshop got a good reception, and several people stayed to discuss the topic and suggested improvements and possible collaborations. It was nice to see that the tasks we had prepared challenged more experienced math experts also.
Excursion to Glacier
Due to unpredictable weather in the mountains, the highly anticipated conference excursion to a glacier, ending with a fondue dinner, was rescheduled to be in the morning with a picnic lunch instead. After a short bus ride, we took a 15-minute cable car ride from Col du Pillon to Scex Rouge. The main activities were a glacier walk to the edge of the glacier and the peak walk, which was a suspension bridge spanning across two mountain tops. Unfortunately, the wonderful views of the Alps were mostly shrouded in clouds, but at least you could see over to the next mountain face every now and then.
On the field. The post continues after the images.

If you got worried that we missed out on the fondue, you can relax as the conference dinner with fondue was just moved back to the conference hotel in the evening.
Take home messages
- Thanks to the active participants and their feedback, we got some great ideas to develop the content of the workshop to make inverse problems accessible even better for a broad audience.
- I wish we had mountains in Finland.
- If you ever have the chance to go to a conference that looks at your field of research from a different perspective, take it!
- Seems like there is such a thing as too much cheese.
The next MATRIX x IMAGINARY conference will be held in New York City 18-21 July, 2026 (just ahead of the International Congress of Mathematicians conference).
About the authors: Markus Juvonen, Elli Karvonen, Siiri Rautio, and Heli Virtanen are Doctoral reseachers at the Deparment of Mathematics and Statistics at University of Helsinki. The first three are working on Inverse problems research and Heli is focused on mathematics education and coordinating the science class Summamutikka.
Photos: Authors | Top photo: Siiri Rautio (left), Cindy Lawrence, Markus Juvonen, Heli Virtanen, and Elli Karvonen.