Francis Halzen wins Nobel Prize in Physics for work on ‘ghost particles’

Belgian physicist Francis Halzen has received the 2026 Nobel Prize in Physics for his role in developing IceCube, a detector beneath the South Pole that records neutrinos arriving from deep space.

The observatory uses sensors buried in clear Antarctic ice to detect brief flashes produced when neutrinos interact with atomic nuclei. The collected signals help researchers investigate how high-energy neutrinos form and could point to unknown phenomena, the Nobel Academy said.

Halzen proposed the project in 1988. Though hundreds contributed to building the observatory, Physics Today editor-in-chief Richard Fitzgerald said it began with Halzen’s idea. Nobel Committee member Eva Lindroth said IceCube gives scientists a new method for studying the universe.

Halzen, 82, said he had heard predictions that he would win, but the announcement still felt strange. The award ceremony is scheduled for December 10, with members of Sweden’s and Norway’s royal families expected to attend.

The physics award follows Monday’s Nobel Prize in Physiology or Medicine, which went to two American scientists for discoveries that advanced understanding of the brain.