The year 2005 has been designated "The World Year of Physics" by the United Nations in celebration of the centennial of Einstein's miracle year. In 1905 Einstein produced five papers which are the cornerstone of modern physics.

As part of the celebration, the Department of Physics has decided to initiate a series of public lectures by leading faculty covering the most recent developments in our understanding of the physical world.

Thursday, November 1, 2007, TCC 1.110, 7:30pm

'Like Dustmaids Down a Drafty Hall': Catching Particles from the Center of the Sun

Abstract:
Over four decades ago, Ray Davis and his colleagues set out to learn something new about the Sun by observing its neutrinos, particles that pass through the Sun and the Earth more easily than light through glass.

What Davis found was a surprise: although he could see neutrinos, there were far fewer of them than expected. Six different experiments followed Davis's, and all found that a large fraction of the neutrinos expected to be arriving from the Sun appeared to be missing. Although it was possible that the experiments were wrong, or that the theory of how the Sun worked was wrong, physicists began to believe that perhaps what was `wrong' was our understanding of the neutrino itself.

The Sun's missing neutrinos were finally found by the Sudbury Neutrino Observatory (SNO) thirty-five years after Davis's first observations.

SNO is located a mile and a half underground in the world's most productive nickel mine, and contains over 1000 tons of heavy water. The heavy water is what gives SNO the ability to see the neutrinos Davis could not. With SNO's results, not only was a great puzzle about the Sun solved, but we learned that neutrinos are more mysterious and interesting than we had previously believed.

This event is free and open to the public.

download poster in pdf (large file):