
easuring a quantum state causes it to interact with the environment and jump to a particular outcome. This leads to some of the stranger results in quantum theory. This book is a wellwritten and up to date account of recent theoretical developments in this exciting aspect of quantum physics by leading researchers in the field. Decoherence, superposition, and wavefunction collapse are described in terms of Schrodinger equations with a brief section on the Wigner function. Other chapters discuss implications for quantum gravity, field theory, and superselection rules and symmetries.