Neutrinos: Messengers from a Violent Universe

In this 45-minute presentation Alex Himmel, Wilson Fellow at Fermi National Accelerator Laboratory, explains how neutrinos might provide the answers to many questions that scientists have about the universe. The neutrino is a type of subatomic particle. They are produced in copious quantities by celestial objects -- trillions of neutrinos from the sun will pass through your body while you read this sentence -- but they interact so rarely with other particles that only a handful will strike an atom in your body during your entire life. Yet these benign little particles can tell us about some of the most energetic processes in the universe. In order to detect these elusive particles, scientists build enormous particle detectors deep underground, using tanks full of liquid argon in an old gold mine as well as a cubic kilometer of Antarctic ice. In this talk Himmel works his way from the sun to galactic supernovae to the possible extragalactic sources of the highest-energy neutrinos ever observed. Himmel also answers audience questions from members of the Naperville Astronomical Association.