The 2026 Nobel Prize in Physics has been awarded to the Belgian-American physicist Francis Halzen (Francis Halzen) for his decisive contribution to the IceCube neutrino observatory and the discovery of high-energy neutrinos of astrophysical origin, the Royal Swedish Academy of Sciences announced on Tuesday.
"For his decisive contribution to the IceCube neutrino observatory and the discovery high-energy neutrinos of astrophysical origin," says the official wording of the Nobel Committee.
Halzen's work actually opened a new way of studying the universe. Unlike conventional telescopes that record electromagnetic radiation, IceCube makes it possible to observe cosmic processes with the help of neutrinos - extremely light electrically neutral elementary particles that rarely interact with matter.
Neutrinos can pass through planets, stars and other objects almost without interacting with them. They also have no electric charge, so magnetic fields do not change the direction of their movement. Thanks to this, high-energy neutrinos can bring information to the Earth directly from the sources of the most powerful processes in the universe and help scientists determine where cosmic rays of ultra-high energies originate.
Halzen suggested using the transparent ice of Antarctica to register such particles. This concept eventually led to the IceCube Observatory at the South Pole.
IceCube is a giant detector with a volume of about 1 cubic meter. km More than 5,000 light-sensitive sensors are placed in the Antarctic ice layer. When a neutrino rarely interacts with an atomic nucleus, the resulting secondary particles produce characteristic radiation that is detected by sensors. According to the direction and characteristics of such a signal, scientists can obtain information about neutrinos that have arrived from space.
The idea of using Antarctic ice to search for space neutrinos was proposed by Haltsen back in 1988. Construction of IceCube was completed in 2011, and already in 2013 the observatory reported the first detection of high-energy neutrinos coming from outside the Solar System.
In 2017, IceCube registered a high-energy neutrino that was linked to the active nucleus of a distant galaxy. In 2022, the observatory received evidence of high-energy neutrino radiation from an active galaxy approximately 47 million light-years from Earth, and in 2023 - from our Milky Way galaxy.
Such observations have become an important part of the so-called multi-channel astronomy, when the same cosmic process is studied simultaneously by electromagnetic radiation, neutrinos, cosmic rays and gravitational waves.
The Royal Swedish Academy of Sciences notes that the IceCube data make it possible to study the conditions for the occurrence of high-energy neutrinos and in the future may lead to the discovery of previously unknown cosmic phenomena.
Halzen was born in 1944 in Tinen, Belgium. He is a professor of physics at the University of Wisconsin-Madison and principal investigator of the IceCube project. He has been working at the university since 1972.
The size of the Nobel Prize in Physics in 2026 is 12 million Swedish kroner, or about $1.2 million. As Haltzen became the only laureate in this category, he will receive the entire amount of the prize.
The Nobel Prize in Physics is awarded by the Royal Swedish Academy of Sciences for the most significant discoveries and achievements in the field of physics. The award was founded according to the will of the Swedish inventor and entrepreneur Alfred Nobel. The first Nobel Prizes were awarded in 1901.
According to Nobel's will, the prizes are awarded for achievements in physics, chemistry, physiology or medicine, literature and for activities to promote peace. The Alfred Nobel Prize in Economic Sciences was established later by the Bank of Sweden.
Laureates receive a medal, a diploma and a cash prize. The Nobel Prize ceremony traditionally takes place on December 10, the anniversary of Alfred Nobel's death. Prizes in the fields of physics, chemistry, medicine, literature and economics are awarded in Stockholm, the Nobel Peace Prize - in Oslo.
