The 2026 Nobel Prize in Physics: IceCube and the Discovery of Cosmic Neutrinos — History and Scientific Impact

The real voyage of discovery consists not in seeking new landscapes, but in having new eyes.”_ wrote Marcel Proust over a hundred years ago in his monumental novel “In Search of Lost Time”. Anyone who looks into space at wavelengths other than those of visible light is doing something similar. The most extraordinary view of all unfolds through observations using neutrinos. It goes without saying that this also takes us into uncharted territory: the detection of low-energy neutrinos from the interior of the Sun and from a neutron star are examples of this and were honored with the 2002 Nobel Prize in Physics. The 2026 Nobel Prize honors the opening of yet another window into the universe: the window of high-energy neutrinos. This lecture describes the motivation for searching for such neutrinos, the adventurous journey that led, after a quarter-century, to the IceCube neutrino telescope at the South Pole, and the scientific achievements to date that were recognized with the Nobel Prize.