2026 Stuttgart Science Festival —Quantum at Karls
On 27 June, the MPI FKF took part in the Stuttgart Science Festival with its event "Quantum at Karls", hosted at the Karls-Gymnasium. Throughout the afternoon, visitors enjoyed a wide range of activities, from science slams and hands-on workshops to demonstrations of superconducting levitating trains.
Quantum at Karls
From 25 June to 4 July, the streets of Stuttgart are overflowing with science.
The occasion? The Stuttgart Science Festival, of course. From science pub quizzes to art exhibitions exploring sustainability, the festival brings science into every corner of the capital of Baden-Württemberg.
Naturally, the MPI FKF could not miss the opportunity to be part of the program.
On 27 June, the institute organised "Quantum at Karls", an outreach event made possible thanks to the collaboration and hospitality of the Karls-Gymnasium in Stuttgart-Süd.
On this very hot summer day, people strolling along Tübinger Straße, desperately looking for some relief from the heat, found some inside the thick, insulating walls of the Karls-Gymnasium, a high school curiously open on a Saturday.
To their surprise, they discovered not only a cool refuge but also a building buzzing with scientific activities and workshops.
Visitors entering the courtyard were welcomed by a demonstration of a superconducting levitating train. For a material such as YBCO to become superconducting, it must be cooled to temperatures around 100 degrees below the freezing point of water—a feat that can easily be achieved using liquid nitrogen.
However, over the past decades, scientists at the MPI have discovered that cooling materials into the superconducting state is not the only purpose liquid nitrogen can serve.
As a matter of fact, pouring water into a container, adding liquid nitrogen, and stirring the mixture has become the institute's well-tested recipe for making delicious slushies.
After enjoying both a slushy and the spectacle of the levitating train, visitors could also explore a hands-on activity using 3D-printed hexagonal lattices. By twisting two lattices relative to one another, they could discover the fascinating Moiré patterns that give rise to exotic quantum phases of matter. Besides their scientific significance, Moire’ patterns are as aesthetically enticing as an arabesque.
Inside the building, visitors were greeted by a food stand organized by the students of the Karls-Gymnasium, offering fresh fruit, cakes, and cold drinks, alongside a topology workshop. Here, they could solve topology puzzles, create their own Möbius strip using nothing more than paper and scissors, or even extract bismuth crystals to turn into topological jewellery worthy of impressing guests at the next gala.
On the first floor, visitors could join "Meet a Scientist." As the name suggests, they had the opportunity to spend fifteen minutes talking one-on-one with a researcher about any scientific topic that sparked their curiosity. From quantum physics and black holes to simply discussing what life as a scientist is really like, our researchers were delighted to share their experiences.
Also on this floor, visitors could learn about quantum phenomena—from wave-particle duality to quantum entanglement—while creating their own miniature science magazine. We called this activity ScienceZinis, combining creativity with an introduction to some of the most fascinating concepts in quantum physics.
While chatting with a scientist or assembling a ScienceZini, visitors may have found themselves unconsciously nodding along to an infectious beat, only to realise the music was coming from the second floor. As they climbed the stairs, the rhythm grew louder and more immersive.
The second floor of the Karls-Gymnasium had been transformed into the stage for Lab Beats.
Over the past few months, two researchers—brilliant scientists with a knack for music—wondered through the laboratories of the MPI recording the sounds of science. They then transformed these recordings into an original techno track created especially for this event.
Between the scientific rave, the liquid-nitrogen slushies, and the many hands-on activities, boredom was hard to come by. Yet even those who found themselves with a spare moment were quickly awakened by another highlight of the afternoon: the Science Slams.
Students from the Karls-Gymnasium worked together with researchers from the MPI to prepare engaging short presentations on scientific topics. Throughout the previous month, the students met regularly with scientists to learn about their research and develop concise, entertaining talks for the general public. The result was a series of engaging presentations about the research carried at MPI.
We would like to thank everyone involved in organizing the event, especially the many researchers from the MPI FKF who dedicated their time to bring science into the heart of the city.
It was wonderful to witness the enthusiasm and genuine curiosity of our visitors. Events like these demonstrate the importance of scientific outreach in strengthening the connection between researchers and society. Building this bridge between science and the public is essential—not only for inspiring future generations, but also for fostering an informed and vibrant democratic discourse.
