In March 2025 I wrote a piece about neutrino telescopes. I’ve been fascinated with these little particles for decades and, when I saw this year’s Nobel Prize announcement I was thrilled for the entire neutrino astronomy community.
The announcement from the Royal Swedish Academy of Sciences noted that Francis Halzen, a professor at the University of Wisconsin, had received the award “for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.”
Neutrinos interact only reluctantly with matter, and when they do they emit a characteristic a tiny flash of light. The problem is that other particles emit the same sort of light when they interact with matter. But since neutrinos interact so seldom that they can pass through our entire planet while the other particles won’t. What Halzen realized was that he could use the Earth to filter out all particles that weren’t neutrinos, if only he could detect those flashes of light…and that the ultra-clear ice deep in the glaciers at the South Pole would transmit that light perfectly. More than two decades later his vision was realized and the Ice Cube neutrino observatory has been collecting valuable data ever since. The value of that data? Well – it was worthy of a Nobel Prize