Physics Nobel to Francis Halzen, who turned the South Pole's ice into a neutrino telescope
The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Physics on Tuesday to Francis Halzen, 82, a Belgian-born physicist at the University of Wisconsin–Madison, for the IceCube Neutrino Observatory and the discovery of high-energy neutrinos from astrophysical sources. Neutrinos, often called ghost particles, barely interact with matter, so catching them takes an enormous detector. Halzen's idea was to use the clear, deep ice beneath the South Pole: he pitched it in 1988, and IceCube, thousands of light sensors strung through a cubic kilometer of ice, was completed in 2011. It records about one astrophysical neutrino a day, and those events point back to sources far outside the Milky Way. Committee chair Mark Pearce said Halzen's tenacity opened a new kind of astronomy. Reached in Italy, Halzen said the prize was a great surprise. The award is 12 million Swedish kronor, about $1.2 million, presented Dec. 10.
Light and radio waves can be blocked or bent on their way to Earth. Neutrinos come straight through, so they carry information from places telescopes cannot see, such as the cores of active galaxies. IceCube made that possible by turning a polar ice sheet into an instrument, the kind of bet funding agencies rarely make.
The University of Wisconsin and the National Science Foundation built IceCube with public money over two decades. Its story is an argument for funding long, uncertain basic science, an argument now in front of Congress in every budget cycle.
Physics Today's editor put it well: hundreds built the observatory, but it started with one person. The prize honors the idea and the persistence. Chemistry is announced Wednesday morning.
DailyDrop U.S. No. 2 · October 6, 2026