Neutrinos in Stochastic Media: From Sun to Core-Collapse Supernovae

Recent work on neutrino propagation in stochastic media and its implications for the Sun and core-collapse supernovae are reviewed. It is shown that recent results from Sudbury Neutrino Observatory and SuperKamiokande combined with a best global fit value of $\delta m^2= 5\times 10^{-5}$ eV$^2$ and $\tan^2 \theta = 0.3$ rule out solar electron density fluctuations of a few percent or more. It is argued that solar neutrino experiments may be able to rule out even smaller fluctuations in the near future.