STOCKHOLM — Belgian-born physicist Francis Halzen won the 2026 Nobel Prize in Physics on Tuesday for his central role in building the IceCube Neutrino Observatory, a detector buried in the ice at the South Pole that captures “ghost particles” from deep space, the Royal Swedish Academy of Sciences announced.
The academy cited Halzen, of the University of Wisconsin–Madison, “for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.” Halzen first presented the idea of using the clear Antarctic ice to track neutrinos in 1988. When a neutrino strikes an atomic nucleus, it produces a flash of light that buried sensors can record. IceCube, a cubic kilometer of instrumented ice, was completed in 2011, and researchers soon detected high-energy neutrinos originating far outside the solar system.
Neutrinos carry no electric charge and have almost no mass, passing through planets and human bodies unaltered, which makes them rare to catch but valuable as messengers. “Francis Halzen has led an international team of researchers and engineers who have provided us with a fantastic instrument. His tenacity and scientific vision has paved the way for a new kind of astronomy,” said Mark Pearce, chair of the Nobel Committee for Physics.
Halzen, 82, was born in Tienen, Belgium, in 1944 and earned his doctorate at KU Leuven in 1969. Reached by phone in Italy during the announcement, he said: “It was a great surprise and I obviously didn’t expect it.” He added, to laughter: “I am working on a proposal, and I hope that this prize will help getting it approved.” Richard Fitzgerald, editor-in-chief of Physics Today, told Al Jazeera that hundreds built the observatory but it “all started with one person,” noting the physics prize has rarely gone to a sole winner in recent years.
The prize carries 12 million Swedish kronor, about $1.2 million. Monday’s medicine prize opened this year’s announcements; chemistry follows Wednesday, literature Thursday and peace Friday, with the economics prize next Monday. Laureates receive their awards at ceremonies on Dec. 10.
Sources: NobelPrize.org, Associated Press, Al Jazeera
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