We are on our bikes on our way along the Göta älv towards Sockerbruket. I’m navigating Bernhard Mehlig to the photographer and we are talking amongst other things about life, physics, and classical music. Bernhard is professor at the Department of Physics at the University of Gothenburg and he researches theoretical physics of complex systems. Bernhard’s lack of vanity is refreshing, his smile is cheerful and his passion for teaching is obvious. In other words, the signs of every good teacher.
When Bernhard came from Germany to University of Gothenburg in 2001 as a lecturer he changed his research field. He was hired as a solid-state physicist and while teaching masters courses he got in touch with subjects that he knew little about, computational biology and neural networks for example. He became curious and so his research interests evolved.
Nowadays, Bernhard and his group members, about seven at the moment, look at systems that exhibit chaotic dynamics and irregular motion and they try to describe the observations with fundamental physics laws and principles. Once you think about it, you realise that we are basically surrounded by chaotic systems. Bernhard’s list of examples includes particles from diesel engine exhausts, plankton in the turbulent ocean, sand carried by turbulent air, rain droplets in turbulent cumulus clouds and, a bit further away, dust grains in the turbulent gas around growing stars.
Bernhard has a remarkable drive for solving problems and understanding things. “He wants to go to the root of problems”, Erik Werner tells me, who is one of his postdoctoral researchers. “Even when he has got to a rigorous mathematical solution of a problem, he is not satisfied until he has an intuitive understanding.” When I speak to Bernhard about how he works as a scientist, I realise how rarely I meet physicists who do analytical calculations. Apart from a computer, his most important equipment appears to be paper, pencil and eraser. Though not just any pencil, and not just any paper, and not just any eraser. The pencil should be a certain model by a certain German brand, the paper should be yellow, and the eraser of good quality.
The two white boards in his office are full of equations and schematics. With his fellow group members, Bernhard tries to develop all theories and problems that they want to work with from scratch on these boards. As far as it is possible without looking anything up, not in textbooks and not on Wikipedia. “In that way”, he says, “we can learn to develop our ideas independently, be independent in our judgements.” I wonder if he has read Nietzsche. Not surprisingly, this technique requires confidence and skill. And it will involve failure. “Paper and pencil alone are not enough, you need the eraser”, Bernhard explains.
Teaching how to ask questions
This approach of intellectual independence requires that people are not afraid of asking questions. More precisely, those questions that lead forward. Because that is not easy, one essential part in Bernhard’s style of teaching is showing students how to ask questions. He loves to discuss with his students, and we both seem to agree on that Swedish students are particularly confident and can call the teacher into question. “When that confidence is coupled with knowledge and sound judgement, that is really a wonderful combination”, Bernhard concludes. Teaching is a topic that takes up a large part of our conversation. And so it does in a typical workday of Bernhard. He usually teaches all year round, at times it takes about half of his time. For many years, he was responsible for the master program in complex adaptive systems and he contributed to substantially develop it. The program grew and it became an international Erasmus Mundus program.
Bikes and classical music
Bernhard tells that he keeps thinking about the problems he currently works on throughout the day. “The thoughts just come and take over”, he says. But there are also other aspects in his life, such as music. “With my family I spend much time on music.” He plays the bassoon, his wife the flute and they play together in the evenings, often with friends. Also their children who are now 17 and 19 years old developed a passion for music, and play their own brass instruments.
This journey Bernhard has spent on a beautiful and classy dark green Raleigh bicycle from the fifties that he found in England. And that is not a coincidence. As a birthday present, he and his colleague Stellan Östlund renovated a bicycle for Henrik Johannesson, another professor in the physics department. Repairing old bikes is one of Bernhard’s hobbies. We part after defeating the hill that the physics department is located on, and I feel unusually energised after this battle. Later I realise that I am not the only one who feels that Bernhard almost radiates energy. Måns Henningson, a physics colleague, confirms my impression: “Bernhard is always in a high momentum state.”
Anna ClemensAbout the writer: Anna Clemens is a freelance science writer and editor who lives in Gothenburg. She has a PhD degree in Materials Science from the Department of Physics at Chalmers and loves baking vegan pizza in her free time.