Fundamental physics with cold and ultracold neutrons

Cold and ultra-cold neutrons are ideal tools for testing fundamental symmetries of the electroweak interaction. The emphasis is on precision measurements of the intrinsic properties of the neutron, the neutron lifetime and correlation coefficients from the neutron beta-decay spectrum and the determination of the strength of the hadronic weak interaction. The science opportunities are discussed with emphasis on the Spallation Neutron Source upcoming program at the Oak Ridge National Laboratory.