Multidisciplinary Applications of State-Selected Atoms Ron Walsworth Harvard-Smithsonian Center for Astrophysics Cambridge, MA   State-selected atoms provide powerful tools to attack a wide range of problems. Examples I will discuss include: atomic population inversion, which enables masers that can be used as high-stability clocks and for precision tests of Lorentz and CPT symmetry; spin polarization of noble gases, which enables high-sensitivity gas-phase NMR, with applications in biomedical imaging and materials science; (and if time permits) coherent superposition of atomic states, which can be crafted to enable "slow" and "stored" light, with potential applications in quantum information processing and elsewhere.