The Royal Swedish Academy of Sciences don decide to award Nobel Prize in Physics 2026 to Francis Halzen of University of Wisconsin–Madison, USA for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.
Francis Halzen realise say ice at the South Pole fit track particles known as neutrinos. Him vision and scientific leadership don be fundamental for the IceCube Neutrino Observatory, one cubic kilometre of ice wey dem equip with light sensors. Using IceCube, researchers fit capture neutrinos from extremely energy-rich processes in distant universe.
Neutrinos dey everywhere, but dem no dey make themselves known. Dem pass all the way through the Earth and through our bodies without us noticing. Very rarely, one neutrino go interact with an atomic nucleus, which make am possible for person with the right equipment to discover them.
Scientists don know long say the cosmos get natural particle accelerators wey dey fire out particles with energies up to a million times more than labs on Earth fit achieve. Much about these sources still mysterious: what are they, where are they, and what be the main processes inside them? Neutrinos with extremely high energies dey created in the same environments as other types of particles. But unlike other particles, neutrinos reach us without changing direction or losing energy. This mean dem fit provide information wey no other way fit provide.
Francis Halzen first present him vision for capturing neutrinos at the South Pole in 1988. When a neutrino collide with an atomic nucleus, e dey produce a flash of light wey sensors fit track inside clear glacial ice. South Pole ice get many advantages: e free from various types of interference and the area geologically stable, with no earthquakes. Halzen and him idea soon gain support from other researchers and, just a few years later, preliminary testing happen on sensors in ice.
Cosmic neutrinos with extremely high energies very rare, so an enormous volume of ice dey needed to observe enough collisions. IceCube cover an entire cubic kilometre and dem finish am in 2011. Researchers soon discover the first high-energy neutrinos and, a few years later, publish discovery of neutrinos wey must originate far outside our solar system. The search for the universe neutrino sources fit begin in earnest.
Mark Pearce, Chair of the Nobel Committee for Physics, talk say, ‘Francis Halzen don lead an international team of researchers and engineers wey provide us with a fantastic instrument. Him tenacity and scientific vision don pave the way for a new kind of astronomy.’
The neutrino interactions wey IceCube dey collect continuously go provide researchers novel knowledge about the violent settings where high-energy neutrinos fit dey created, and e fit even reveal previously unknown cosmic phenomena.
Halzen, Belgian-born physicist, born 1944 in Tienen, Belgium. Him PhD 1969 from KU Leuven, Belgium. He be professor at University of Wisconsin–Madison, USA. Prize amount na 12 million Swedish kronor.
Halzen lead the development of IceCube at the South Pole, which use a cubic kilometre of Antarctic ice fitted with light sensors to detect particles called neutrinos. These dey carry information about violent, high-energy processes in the cosmos. The Royal Swedish Academy of Sciences talk say him vision and scientific leadership don be fundamental for IceCube.
Halzen, who now be US citizen at University of Wisconsin–Madison, tell a news conference say he surprise say him idea work so well. ‘I have to emphasise how lucky I was. Because when we started this project, everybody realise this was maybe a good idea, but very few thought it would work, including myself.’
Neutrinos na elusive subatomic particles. The Sun dey produce vast numbers of them: every second, billions pass harmlessly through an area the size of your fingernail. But IceCube dey search for much higher-energy neutrinos, those produced by violent processes far beyond our Solar System, in distant galaxies. It get thousands of sensors on long cables wey dem drill and freeze into a 1km cubic block of ice.
Neutrinos fit be astronomical messengers wey dey point to those fundamental events. At the observatory, most neutrinos pass straight through the ice, but occasionally one go interact with it, producing particles wey dey give off a telltale flash of light. These rare signals carry clues to where the neutrinos come from and the extreme conditions wey produce them, allowing scientists to investigate places wey ordinary telescopes no fit easily see.
On the rare occasions when a neutrino strike an atomic nucleus, e dey produce fast-moving charged particles. Na these dey race through the ice, and dem dey give off a blue glow wey sensitive light detectors fit pick up. The pattern and timing of that light allow scientists to estimate the direction the neutrino come from, helping them trace its origins in the cosmos.
But these interactions rare sotey the observatory need an enormous volume of clear ice. Halzen idea na to use a vast natural ice sheet in Antarctica. So began an audacious plan to build a neutrino observatory at the geographic South Pole, with thousands of light sensors embedded deep in the ice.
The neutrino ghostly nature, the very thing wey make am so hard to detect, also make am a powerful messenger from the distant Universe. Neutrinos rarely interact with material in dia way, so dem fit go right through dense regions wey light no fit easily penetrate. And because dem no get electric charge, magnetic fields no dey bend dia paths through space. That mean dia direction of arrival fit point scientists back towards dia source. Dia energies carry further insight into the processes wey create them, helping scientists investigate how exploding stars and the environments around giant black holes accelerate particles to extraordinary energies.
Louis Barson, director of science at the Institute of Physics in London, talk say the IceCube Observatory don enable astronomers to investigate phenomena wey conventional telescopes no fit see. ‘The discoveries that have followed are helping us understand some of the most energetic and mysterious processes in the universe – and that be thanks to Professor Halzen work,’ he add.
Prof Subir Sarkar, physicist from the University of Oxford, quote French novelist Marcel Proust in describing him assessment of Halzen contribution to science: ‘The only true voyage of discovery, the only fountain of Eternal Youth, would be not to visit strange lands but to possess other eyes, to behold the universe through the eyes of another, of a hundred others, to behold the hundred universes that each of them beholds, that each of them is.’ ‘Francis Halzen has led the IceCube collaboration on just such a voyage of discovery and opened a new window on to our Universe.’
