ABSTRACT

Measurement of the solar neutrino flux has been a great experimental
challenge. The fact that the measured flux is less than the predicted
flux by a factor of about 3 has presented another challenge - this time
to solar physicists and to nuclear physicists.  There have been
attempts to explain the discrepancy by modifying our model of the Sun
and by departing from standard nuclear physics.  Another major question
has been whether the solar neutrino flux is steady or variable and, if
the latter, whether the variation can be related to any other known
properties of the Sun.  These issues will be reviewed briefly.  Then
some new results will be presented and discussed.