He buried a telescope in a cubic kilometer of Antarctic ice — and caught the universe's ghosts

In 1988, Francis Halzen made a wild proposal: bury light sensors in a cubic kilometer of South Pole ice and use it to catch neutrinos — ghost-like particles that stream through the Earth and our bodies by the trillions, unnoticed. Colleagues thought he was dreaming. He built it anyway. IceCube, finished in 2011, has since detected high-energy neutrinos arriving from far beyond our solar system, revealing natural particle accelerators in the distant universe. The Nobel committee says Halzen's frozen observatory opened an entirely new kind of astronomy.