Francis Halzen wins Nobel Physics Prize for breakthrough neutrino research
Belgian-born scientist Francis Halzen won the Nobel Prize in Physics on Tuesday for his work on a rare group of neutrinos, tiny cosmic particles that researchers believe can offer clues to how the universe evolved. The award was announced in Stockholm by the Royal Swedish Academy of Sciences, with this year's prize carrying 12 million Swedish kronor, or about USD 1.2 million.
Halzen, speaking by phone from Italy in a call broadcast at the news conference, said the honour came as a surprise. "It was a great surprise, and I obviously didn't expect it," he told the Nobel Physics Committee. He said it had been predicted that he would win the 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, drawing chuckles from the audience.
Neutrinos are tiny cosmic particles with no electrical charge and an extraordinarily small mass, which makes them difficult to detect. They are produced by stars such as the sun, and trillions pass through the human body every second. Scientists cannot observe them directly, so they study what happens when neutrinos collide with other matter. Because such collisions are rare, researchers build large detectors to improve their chances of recording them.
Halzen proposed using the vast Antarctic ice as a detector. The Nobel committee said his work was instrumental in the construction of the IceCube Neutrino Observatory in Antarctica, which recorded the first high-energy neutrinos from distant galaxies. When a neutrino interacts with ice inside the detector, it creates a flash of light that is picked up by sensors. The transparent ice helps scientists detect faint signals, while the sensors are buried about 8,200 feet, or 2,500 metres, deep to shield them from interference caused by cosmic rays and radiation.
"This experiment in the Antarctic is a revolutionary way of understanding the universe that we didn't have before," said Michael Moloney, chief executive officer of the American Institute of Physics. Halzen, 82, is affiliated with the University of Wisconsin–Madison in the United States, which operates the observatory. Efforts by The Associated Press to reach him were not immediately successful. A representative of the IceCube Neutrino Observatory did not immediately respond to a request for comment, and the University of Wisconsin-Madison also did not immediately comment when contacted by AP.
In a post on social media, Belgian Prime Minister Bart De Wever said Halzen was the 11th Belgian to win a Nobel Prize. De Wever called the award "impressive recognition for a lifetime dedicated to shedding light on the great mysteries of the cosmos through its smallest components".
Ellen Moons, secretary-general of the Royal Swedish Academy of Sciences, announced the award on Tuesday. She is the first woman to head the academy and present the prize. Last year, three scientists won the Nobel Prize in Physics for research on quantum tunnelling, work that enabled highly sensitive measurements used by MRI machines and also laid the groundwork for better mobile phones and faster computers.
This year's Nobel announcements began on Monday with the medicine prize being awarded to three scientists whose work led to a tool that uses light to help explain how the brain works. The prizes continue with chemistry on Wednesday and literature on Thursday. The peace prize will be announced on Friday, followed by the Nobel Memorial Prize in Economic Sciences next Monday. Halzen's award recognised research that helped open a new way of studying the universe through neutrinos and the Antarctic IceCube observatory.
