Francis Halzen, an 82-year-old astrophysicist and professor at the University of Wisconsin-Madison, has been awarded the 2026 Nobel Prize in Physics. The committee recognized his work in establishing the IceCube neutrino observatory and his role in discovering high-energy astrophysical neutrinos.
The project originated in 1988 when Halzen first proposed building an observatory in Antarctica to detect elusive cosmic particles. The facility is located at the Amundsen-Scott South Pole Station, utilizing a massive array of clear ice to capture rare particle interactions.
The observatory functions by monitoring a 1 cubic kilometer block of ice embedded with 5,160 optical sensors. When a neutrino collides with an atomic nucleus within the ice, it produces a flash of light. These sensors record the timing and nature of the light, allowing researchers to trace the origin of the particles in space.
Neutrinos are characterized by their extremely low mass and high activity, enabling them to travel through stars, planets, and galaxies without losing energy or changing direction. Richard Fitzgerald, editor of Physics Today, noted that while the project required hundreds of specialists, the award highlights the unique vision of its founder.
