Recognition in Turin
Belgian-American physicist Francis Halzen learned of his 2026 Nobel Prize in Physics on 6 October 2026 while visiting Turin, Italy. The 82-year-old professor at the University of Wisconsin-Madison traveled to the city to participate in the International Evaluation Committee of the National Institute for Nuclear Physics (INFN). University of Turin rector Cristina Prandi received Halzen at the university rectorate, while INFN president Antonio Zoccoli joined him to discuss the award. Colleagues including INFN evaluation committee president Jorgen D'Hondt and Gran Sasso National Laboratory director Ezio Previtali gathered with Halzen at his hotel the following morning. Halzen reflected on the long timeline of the research, noting that early discoveries occurred more than ten years ago.
The work that deserved the Nobel goes back many years. I always felt like, by not having received it yet, I was letting down my extraordinary collaborators. So I am just happy that this issue is now resolved.
IceCube observatory and machine learning
Halzen led the construction of the IceCube Neutrino Observatory, an array of 5,484 optical detectors drilled into deep Antarctic ice using hot water. The project required 35 years of development and 250 million dollars in funding from the US National Science Foundation. Early in the design phase, Halzen referred to the instrument with the phrase "Deo volente" due to uncertainty over whether blue light could travel through the ice sheet. Measurements confirmed that blue light travels hundreds of meters through pure ice formed from Antarctic snowfall 50,000 years ago. Halzen also pioneered computational approaches to particle detection, authoring a paper in 1991 proposing neural networks for physics data. Recent machine learning systems enabled his team to identify neutrino emissions originating within the Milky Way.
- Francis Halzen publishes a paper proposing neural networks for physics data analysis
- Royal Swedish Academy of Sciences awards Nobel Prize in Physics to Francis Halzen
- Halzen presents cosmic ray research objectives at INFN meeting in Turin
Career perspective and project scale
In discussions at the University of Turin, Halzen addressed students, stating that scientific work requires passion and problem-solving drive rather than financial goals. When asked about childhood ambitions, the Belgian-born scientist explained that he originally hoped to win the Tour de France cycling race. Regarding the economics of particle astrophysics, Halzen stated that IceCube remained inexpensive relative to space satellites and particle accelerators, adding that multiple new neutrino observatories are preparing to begin operations worldwide.
Fundamental research and cosmic ray objectives
Halzen identified locating galactic sources of cosmic rays as the primary unresolved challenge for astrophysics. While observatories register high-energy gamma rays, corresponding neutrino sources remain elusive, suggesting that future detectors may need ten times greater sensitivity. INFN leadership noted that the award acknowledges basic scientific discovery at a time when funding frequently favors applied technologies.
We live in a society focused on technology, AI, quantum, but in this case it is a clear recognition of the importance of fundamental research. Therefore not only technology, but also understanding our nature and our origins.
Halzen concluded that transient cosmic explosions represent the most significant potential data source for neutrino astronomers.
What would really give an enormous boost to neutrino astronomy would be to observe a supernova explosion in our galaxy. In a few seconds, neutrino astronomy would provide us with particle physics and astronomy data on which we could work for decades.