Quasiclassical Domains in a Quantum Universe

摘要: In this universe, governed fundamentally by quantum mechanical laws, characterized indeterminism and distributed probabilities, classical deterministic laws are applicable over a wide range of time, place, scale. We review the origin these in context mechanics closed systems, most generally, universe as whole. There probabilities predicted for members decoherent sets alternative histories ie ones which interference between pairs set is negligible measured decoherence functional. An expansion functional separation allows form equations motion to be derived suitable coarse grainings class non-relativistic including with general non-linear interactions. More graining needed achieve predictability than naive arguments based on uncertainty principle would suggest. Coarse decoherence, beyond that inertia necessary resist noise mechanisms produce. Sets largely constitute quasiclassical realm everyday experience an emergent feature system's initial condition Hamiltonian. analyse sensitivity existence particular condition. find almost any will exhibit some sort, but only small fraction total number possible states could reproduce our universe. (Talk given at Lanczos Centenary Conference, North Carolina State University, December 15, 1993.)