  This talk summarizes the results of recent calculations of how fluctuations
within the solar medium can influence resonant neutrino oscillations within the
sun. Although initial calculations pointed to helioseismic waves as possibly
producing detectable effects, recent more careful calculations show this not to
be true. Those features of fluctuations which maximize their influence on
neutrino propagation are identified, and are likely to have implications for
supernovae and the early universe.
