Tashkent, Uzbekistan (UzDaily.uz) — The Royal Swedish Academy of Sciences has named Francis Halzen the 2026 Nobel Prize laureate in Physics. The University of Wisconsin-Madison scientist was recognized for his decisive contribution to the creation of the IceCube neutrino observatory and the discovery of high-energy neutrinos of astrophysical origin.
Halzen’s work is based on the idea of using Antarctic ice as a detector for particles that interact only very rarely with surrounding matter. Located at the South Pole, IceCube is a giant system of light sensors embedded in an ice volume covering about one cubic kilometer.
Neutrinos constantly pass through the Earth and the human body, leaving virtually no traces. Their interaction with atomic nuclei is extremely rare, but the flash of light produced by such a collision makes it possible to detect the particle.
Neutrinos with extremely high energies are particularly valuable for astrophysics. Natural particle accelerators exist in the universe that can give particles energies up to one million times higher than those achievable in laboratories on Earth. At the same time, the nature and locations of many such sources remain insufficiently understood.
Neutrinos have an important advantage for studying these processes. Unlike other particles, they can reach Earth along an almost straight trajectory without losing a significant amount of energy. Their detection therefore provides information about cosmic sources that cannot be studied using traditional methods.
Halzen first proposed using the South Pole to search for neutrinos in 1988. His idea was to detect the light signal produced when a neutrino interacts with an atomic nucleus inside transparent ice.
Antarctic ice is suitable for such observations because of its low level of background interference. In addition, the South Pole is geologically stable and free of earthquakes. Following support from other scientists, tests of detectors directly inside the ice began.
The rarity of high-energy cosmic neutrinos required a detector on a huge scale. IceCube, which covers one cubic kilometer of ice, was completed in 2011. Researchers soon afterward detected the first high-energy neutrinos.
In subsequent years, scientists obtained data on neutrinos that were believed to have originated from regions beyond the Solar System. This marked the beginning of a systematic search for the sources of such particles in the universe.
“Francis Halzen led an international team of researchers and engineers who created a fantastic scientific instrument. His persistence and scientific vision paved the way for a new type of astronomy,” said Mark Pierce, chair of the Nobel Committee for Physics.
IceCube observations are continuing. Neutrino interactions recorded by the observatory provide an opportunity to study processes occurring in the most powerful and active cosmic environments and may help reveal previously unknown phenomena.
Francis Halzen was born in 1944 in Tienen, Belgium. He received his PhD from the Catholic University of Leuven in 1969. Halzen is a professor at the University of Wisconsin-Madison in the United States.
The 2026 Nobel Prize in Physics is worth 12 million Swedish kronor.
The Royal Swedish Academy of Sciences was founded in 1739. The academy is an independent organization dedicated to advancing science and strengthening the role of science in society, with particular emphasis on the natural sciences and mathematics.
