‘Ghost particle’ pioneer wins Physics Nobel

The Royal Swedish Academy of Sciences announced the award on October 6. Halzen, a professor at the University of Wisconsin-Madison, will receive the full prize of 12 million Swedish kronor.

His work opened a new way to explore the universe by detecting neutrinos, elusive particles that pass through matter almost without interacting.

“His tenacity and scientific vision has paved the way for a new kind of astronomy,” said Mark Pearce, chair of the Nobel Committee for Physics, in the Academy’s official announcement.

Halzen first presented his vision for a South Pole neutrino detector in 1988. Completed in 2011, IceCube uses 5,160 sensors embedded deep within a cubic kilometer of Antarctic ice.

Most neutrinos pass straight through the detector. Occasionally, one strikes an atomic nucleus, producing charged particles that emit faint light as they move through the ice. The sensors record these signals, allowing scientists to estimate the neutrino’s energy and direction.

Unlike electrically charged particles, neutrinos are not deflected by magnetic fields. They can therefore point researchers towards distant cosmic sources, including environments around supermassive black holes.

In 2013, IceCube reported evidence of high-energy neutrinos originating beyond the Solar System, helping establish neutrino astronomy.

Reflecting on the project’s early development in an account published by IceCube, Halzen said: “We started small and, to our own amazement, we overcame all these hurdles.”

The observatory continues to investigate some of the universe’s most energetic processes and could reveal previously unknown cosmic phenomena.

Earlier, Qazinform News Agency reported that Karl Deisseroth, Peter Hegemann and Georg Nagel were awarded the 2026 Nobel Prize in Physiology or Medicine for discoveries that made it possible to control nerve cells using light.