Belgian Physicist Halzen Wins 2026 Nobel Prize in Physics
Belgian-American physicist Francis Halzen has been awarded the 2026 Nobel Prize in Physics for his role in creating the IceCube Neutrino Observatory and for the discovery of high-energy neutrinos of astrophysical origin, the Royal Swedish Academy of Sciences announced on 6 October. The 82-year-old, born in Tienen, is only the second Belgian to win the physics prize, after Francois Englert in 2013.
Halzen received the full prize share as sole laureate, worth 12 million Swedish kronor (about one million euros), according to the official Nobel Prize press release. The citation praises his “decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.”
A detector buried in Antarctic ice
Neutrinos are among the most elusive particles in the universe. As the Nobel committee noted, they “pass all the way through the Earth and through our bodies without us noticing.” Capturing them requires an enormous volume of transparent material and highly sensitive light sensors.
Halzen’s solution was to use a cubic kilometre of clear, geologically stable Antarctic ice at the South Pole. When a rare neutrino collides with an atomic nucleus in the ice, it produces a faint flash of light that thousands of optical sensors, buried up to 2,400 metres deep, can detect. He first presented the concept in 1988; construction began in 2005 and the detector became fully operational in 2011. In 2013, IceCube reported the first clear detection of high-energy cosmic neutrinos originating outside the solar system.
According to RTBF, Halzen led most of his career in the United States, where he is a professor at the University of Wisconsin-Madison and has published more than 1,000 scientific articles.
A surprise award and a tribute to supporters
Halzen said the announcement caught him off guard. “It’s a great surprise, I certainly did not expect it,” he told the Nobel Foundation by phone, as reported by RTBF.
He framed the prize as recognition for those who backed the project when it was unfashionable. “I hope this highlights the truly courageous people who supported me from the start of this project, when no conservative physicist wanted to support me,” he said. “But many talented people eventually did, and that is why I am here today.”
Mark Pearce, chair of the Nobel Committee for Physics, credited Halzen’s persistence. “His tenacity and scientific vision has paved the way for a new kind of astronomy,” Pearce said. Because neutrinos cross the universe without being deflected or losing energy, they can carry information about the most violent cosmic environments that no other messenger can.
Belgian pride and an institutional tussle
The award triggered a wave of national pride, with federal and regional leaders quick to congratulate the laureate. “He is the eleventh Belgian to be awarded a Nobel Prize and the second to win a Nobel Prize in Physics,” Prime Minister Bart De Wever said, according to RTBF. “An impressive recognition for a life dedicated to unlocking the cosmos’s greatest secrets from its most infinitesimal expressions.”
Foreign Minister Maxime Prevot tied the discovery to Belgium’s Antarctic heritage. As a founding signatory of the Antarctic Treaty, he wrote, Belgium has long promoted the continent as a place of “peace, science and international cooperation,” making the IceCube award a point of diplomatic pride. Flanders’ Minister-President Matthias Diependaele offered his own framing: “From Tirlemont to the South Pole: Francis Halzen pushes the limits of our knowledge.”
Even so, the celebration came with a familiar Belgian subplot: competition between the Dutch-speaking KU Leuven and the French-speaking UCLouvain over which institution can claim him. Halzen earned his master’s degree in 1966 and his doctorate in 1969 from the Catholic University of Leuven before the institution split along linguistic lines in 1968. The Nobel press release credits “KU Leuven,” while UCLouvain’s own announcement claims him as a graduate and highlights current ties through astrophysicist Gwenhael Wilberts Dewasseige, who leads a team of 12 researchers contributing to IceCube and to the Mediterranean neutrino detector KM3NeT.
A tradition, not a coincidence
The Belgian Physical Society argued the win reflects a deep national tradition in fundamental physics. “This undoubtedly testifies to the quality of scientific teaching in Belgian universities and our tradition in the field of fundamental physics,” the organisation said, pointing to Georges Lemaitre’s Big Bang theory, the Higgs boson work of Englert and Robert Brout, and Belgium’s founding role in CERN in 1954. Halzen’s official Nobel profile confirms his birthplace, prize motivation and 1/1 share.
Halzen becomes the eleventh Belgian Nobel laureate, or twelfth counting the Institute of International Law, according to the prime minister’s tally.
What to watch
The IceCube collaboration continues to collect neutrino interactions, data that could sharpen understanding of black holes, supernovae, and neutron-star mergers — and perhaps reveal cosmic phenomena never before observed. For Belgium, the question now is whether the prize will translate into sustained investment and momentum for a new generation of particle physicists, as UCLouvain hopes. The award’s full prizes in chemistry, literature, peace and economics were announced during the same week, spotlighting the 2026 Nobel season.