Francis Halzen has won the Nobel Prize in Physics for his research into neutrinos

The Royal Swedish Academy of Sciences has awarded the 2026 Nobel Prize in Physics to Francis Halzen of the University of Wisconsin “for his decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin”. Following the announcement of the prize, the Belgian physicist said: “I hope this is a tribute to the truly courageous people who joined me at the start of this project, when no self-respecting conservative physicist would have wanted to do so, but many talented people did, and that is why I am here.”

Physicist Francis Halzen laid the foundations for a completely new branch of astronomy. His idea was to use glacial ice at the South Pole to capture the elusive particles known as neutrinos. When a neutrino collides with an atomic nucleus, it produces a flash of light that can be detected by sensors within the transparent glacial ice. The ice at the South Pole offers numerous advantages, as it is free from various types of interference and the area is geologically stable, with no earthquakes. Halzen and his idea soon gained the support of other researchers and, just a few years later, preliminary tests were carried out on the sensors in the ice. The result was the IceCube Neutrino Observatory, completed in 2011, capable of detecting neutrinos from the distant cosmos and consisting of one cubic kilometre of ice fitted with light sensors. Thanks to IceCube, researchers can detect neutrinos originating from extremely high-energy processes in the distant universe.

Researchers soon detected the first high-energy neutrinos and, a few years later, were able to publish their discovery of neutrinos that must originate well beyond our solar system. The search for neutrino sources in the universe could thus begin in earnest. The neutrino interactions continuously detected by IceCube will provide researchers with new insights into the violent environments in which high-energy neutrinos can form, and may even reveal previously unknown cosmic phenomena.

Last year’s Nobel Prize winners in Physics were John Clarke, a professor at the University of California, Berkeley; Michel H. Devoret, a professor of applied physics at Yale University and the University of California, Santa Barbara; and John M. Martinis, “for the discovery of the macroscopic quantum tunnelling effect and the quantisation of energy in an electrical circuit”. Meanwhile, for the 2026 awards, the winners of the Nobel Prize in Medicine – Karl Deisseroth, Peter Hegemann and Georg Nagel – were announced yesterday, whilst tomorrow will see the announcement of the prize for Chemistry, followed by the prize for Literature on Thursday the 8th. Finally, the Peace Prize will be announced on Friday the 9th.