  There are four important facts about solar neutrinos. They are listed in
order of importance in this abstract and discussed more in the text of the
talk. First, solar neutrinos have been detected in four experiments with
approximately the energies and fluxes predicted by the standard solar model,
confirming the hypothesis that the energy source for the solar luminosity is
the fusion of light elements. Second, the measured event rates are significantl
less than the event rates predicted by the combined standard solar and
electroweak models in all four experiments. Third, a comparison of the event
rates measured in the chlorine experiment (threshold 0.8 Mev) and the
neutrino-electron scattering experiment (Kamiokande II, threshold 7.5 MeV)
indicates that the deficiency of electron-type neutrinos at the earth is energy
dependent, if the rates and the uncertainties in both experiments have been
correctly understood. The inference that the deficiency is energy-dependent
conflicts with the simplest version of standard electroweak theory. Fourth,
experiments are being constructed that have the capabilities to determine
conclusively if new neutrino physics is required.
