Nobel Lecture

Raymond Davis Jr.'s Nobel Lecture was held December 8, 2002, at Aula Magna, Stockholm University, by his son, Andrew M. Davis, Department of the Geophysical Sciences, University of Chicago. He was presented by Professor Mats Jonson, Chairman of the Nobel Committee for Physics.

Summary: It took 50 years for Davis to progress from theories for detecting neutrinos to trapping sufficient numbers of this mysterious, almost massless particle. Using a tank filled with around 390,000 litres of a dry-cleaning agent, buried almost 1.5 kilometres underground in a gold mine to trap neutrinos emitted from the Sun, the Homestake experiment began taking data in 1967. Capturing 2,200 solar neutrinos over the course of 25 years, the spectacular results were published in 1995, which discovered only one-third of John Bahcall's calculated rate at which the detector should capture neutrinos. This significant discrepancy in numbers was eventually explained by neutrino oscillations, a concept once proposed by Bruno Pontecorvo.