Princeton University Department of Physics Colloquium

The past decade has brought a revolution in our understanding of the neutron. It has been established that neutrinos have finite mass and commonly exist in quantum states that are mixtures of mass eigenstates. This new knowledge has come from a series of remarkable experiments that demonstrate that neutrinos are much more amazing than Wolfgang Pauli ever imagined. I will review our current understanding of the neutrino and speculate about what we are about to learn.