Neutrino experiment pioneer Francis Halzen wins Nobel Prize in physics

Open this photo in gallery:Eva Olsson, Ellen Moons, and Mark Pearce sit as they announce Francis Halzen as the recipient of the 2026 Nobel Prize in Physics at the Royal Swedish Academy of Sciences in Stockholm, Sweden, Tuesday.Christine Olsson/TT/ReutersFrancis Halzen, a University of Wisconsin-Madison professor who pioneered the detection of ghostly particles from outer space has been awarded the Nobel Prize in Physics.On Tuesday, members of the Royal Swedish Academy of Sciences announced that Dr. Halzen is the sole winner of this year’s physics prize.Dr. Halzen is best known for his work establishing the IceCube Neutrino Observatory at the South Pole. Using a one cubic kilometre volume of the Antarctic ice sheet as its detection medium, the experiment has been able to spot flashes of light that occur when high-energy neutrinos from the distant universe occasionally interact with atoms in the ice.Completed in 2011, the experiment ushered in a new era of particle astrophysics. “It was a great surprise,” said Dr. Halzen when reached by phone during the announcement. “When I reflect on this moment I have to emphasize how lucky I was because when we started this project, everybody realized this was maybe a good idea but very few thought it would work, including myself.”Born in Belgium in 1944, Dr. Halzen received his PhD from KU-Leuven university in 1969. In 1971, he began his research career in Wisconsin where he continues to lead the IceCube project This year’s physics prize recalls the 2015 physics Nobel when Canadian scientist Arthur McDonald was named a co-recipient for leading an earlier neutrino experiment built in a mine under Sudbury, Ont.With today’s announcement, the physics prize has been awarded 120 times to 230 individuals since it was established in 1901.The most recent Canadian winner was Geoffrey Hinton, a University of Toronto professor and pioneer of artificial intelligence who was awarded the physics Nobel in 2024 for is work on neural networks.