The Solar Neutrino Problem—A Progress(?) Report

The conflict between observation and theoretical prediction of the flux of electron neutrinos from the sun has advanced in the past year from being merely difficult to understand to being impossible to live with. We review here attempts to explore the nature of the conflict, to seek possible ways out of it, and to inquire into additional experiments that have the capability either of resolving the conflict or at least of deciding which branch of physics or astrophysics is responsible for it.