17.12.2025
Professor Dr. Klaus Blaum, Director at the Max Planck Institute for Nuclear Physics (MPIK) and Honorary Professor at Heidelberg University, has been awarded the Gottfried Wilhelm Leibniz Prize 2026. With the Leibniz Prize, the German Research Foundation (DFG) honors Klaus Blaum for his outstanding contributions to the high-precision experimental investigation of fundamental constants and symmetries ( DFG Press Release ).
His work has set international benchmarks and makes central contributions to the experimental testing of fundamental theoretical concepts in modern physics. Klaus Blaum’s research is characterized by a consistent pursuit of accuracy. In his precision experiments on individual ions confined in electromagnetic traps, the goal is to test the laws of nature with ever greater sharpness and to further refine theoretical models.
For many years, Klaus Blaum has been closely associated with Heidelberg University. As an Honorary Professor at the Faculty of Physics and Astronomy, he contributes his expertise to teaching and works closely with students and early-career researchers. This close integration of university-based and non-university research is a defining characteristic of Heidelberg’s research landscape.
In the following interview, Klaus Blaum speaks about the moment he learned of the award, the fascination of high-precision basic research, and what makes Heidelberg a special place for research from his perspective:
Professor Blaum, do you remember the moment when you learned about receiving the Leibniz Prize? What was the first thing that went through your mind?
Yes, I remember it very clearly. It was Thursday, 11 December 2025. I was sitting in my office when my phone rang at 9:58 a.m. — an unknown number. On the other end, a voice said: “This is Christina Elger from the DFG, I have a pre-Christmas surprise for you …” I was deeply moved, because I was aware of the significance of the Gottfried Wilhelm Leibniz Prize. My immediate thought was: “This afternoon is our department’s Christmas party — it couldn’t have come at a better time.” The first person I called was my wife to share the news.
Your research is highly precise and fundamental. Why are fundamental constants of physics still so fascinating today — and why is there such passion about every additional decimal place?
Fundamental constants determine how strong forces are, how stable atoms are, and how fast processes occur — this is exactly what makes studying them so fascinating. With our precision experiments, we try to find out whether there are gaps in our understanding of the forces at work. This requires the highest possible accuracy: even the smallest improvement can provide valuable clues.
The DFG describes your work as “groundbreaking.” Was there a moment in your career when you personally felt that you were truly testing the limits of what is known?
Our experimental breakthroughs usually rely on significant technical advances that we achieve, as well as on innovative measurement ideas. It is therefore less a single event and more the sum of many world records that we have set, for example in the determination of atomic masses or in stringent tests of interactions, that can be described as groundbreaking.
You confine individual ions in electromagnetic traps to test the laws of nature. What fascinates you about addressing big questions with extremely small systems?
What fascinates me in particular is that these are often comparatively small experiments that can be operated by a single person. Nevertheless, six to eight years of intensive work may be required to develop a new Penning-trap experiment and achieve record-breaking measurements. When, after this long and arduous development phase, everything finally works exactly as hoped, it is an indescribably wonderful feeling — a moment that more than justifies all the effort.
Precision plays a central role in your research. In everyday life, where are you a perfectionist — and where deliberately not?
That’s a good question — one you should probably ask my family 
The Leibniz Prize opens up great freedom. What would you most like to pursue with these new opportunities that may not have been possible before?
We are considering starting a completely new experiment with a particle species that we have never investigated before. This will also require new personnel. At this point, I would prefer not to reveal more.
You are an Honorary Professor at Heidelberg University and closely connected to the Faculty of Physics. What does this connection mean to you, especially alongside your work at the MPIK?
This connection means a great deal to me. I have great respect for my university colleagues and greatly value the many joint research activities we have been able to realize over the past 18 years. The opportunity to be involved in teaching while also having access to exceptionally well-trained students is of central importance for our research at the Max Planck Institute for Nuclear Physics.
What do you particularly value about Heidelberg as a place for science?
Our students are distinguished by outstanding quality and enjoy a high level of recognition both nationally and internationally. This is complemented by an exceptionally collegial working environment within the faculty.
And finally: if you had to explain to young people today why basic research is worthwhile, what would you say?
Basic research expands our knowledge and thus forms the foundation for innovation and societal progress. At the same time, it makes a substantial contribution to the education of highly qualified specialists.
The Faculty of Physics and Astronomy warmly congratulates Professor Dr. Klaus Blaum on this distinguished honor!
STEFANIE AUMILLER /MPG
