Francis Halzen wins Nobel Prize in Physics for work on ‘ghost particles’
Belgian physicist Francis Halzen has won the 2026 Nobel Prize in Physics for creating a giant detector in Antarctica that captures neutrinos, the so-called “ghost particles” from space that scientists believe offer clues to how the universe evolved.
The Royal Swedish Academy of Sciences announced the prestigious award in Stockholm on Tuesday, crediting Halzen with a central role in building the IceCube Neutrino Observatory.
The neutrino interactions collected by the observatory provide information about how high-energy neutrinos are created and may even reveal previously unknown phenomena, the Academy said.
“It was a great surprise, and I obviously didn’t expect it,” Halzen said, speaking to the committee by phone from Italy, in a call broadcast at the news conference to announce the winner.
The 82-year-old said it was predicted before that he would win the Nobel Prize, but the announcement still made him feel “strange”.
“I am working on a proposal, and I hope that this prize will help getting it approved,” he said to chuckles from the audience.
Neutrinos have nearly no mass and carry no electric charge, so they can cross between planets, stars and human bodies without being altered, making them rare and hard to catch. There are roughly 100 trillion solar and cosmic neutrinos that pass through our bodies every second.
Halzen first proposed the IceCube project in 1988, realising that the clear ice beneath the South Pole could act as a detector, so on the rare occurrence a neutrino strikes an atomic nucleus, it gives off a flash of light that buried sensors can record.
Richard Fitzgerald, editor-in-chief of Physics Today, said although hundreds of people built the observatory, it “all started with one person”, noting that the physics prize has rarely gone to one sole winner in recent years.
“People joined him in the quest for these neutrino messengers. The messenger is bringing information from cosmos,” committee member Eva Olsson said during the news conference. “They opened the door to distant galaxies and tell us about the processes of exploding stars.”
Eva Lindroth, a researcher in Stockholm and a member of the Nobel Committee, told Al Jazeera that Halzen’s observatory has helped scientists understand high-energy particles.
“The nice thing with neutrinos is that they come straight at us,” she said. “That way we can ultimately understand these sources of high-energy particles and understand more about how things in the universe, like how galaxies are formed and the roles of the black holes in that process.
“It gives a new way to study the universe,” Lindroth added. “They give us information which we cannot get in any other way.”
Last year’s award went to John Clarke, Michel Devoret and John Martinis for experiments on quantum physics.
On Monday, the Nobel Prize in Physiology or Medicine was awarded to two American scientists for discoveries that helped explain how the brain works.
The next award will be the Nobel Prize in Chemistry, which will be announced on Wednesday in Stockholm.
Nobel laureates will receive their awards in a ceremony on December 10, marking the anniversary of Swedish chemist Alfred Nobel, who established the award; members of the royal families of Sweden and Norway will be in attendance.
