This interesting compilation of essays written over a period of thirty years by the author addresses issues that arise frequently in physics — for example, those connected with the understanding of quantum mechanics. While some essays deal with physical theories in general, those categorized in quantum mechanics include topics in closed systems, and spacetime approach. Quantum universe is explained through the generalization of standard quantum mechanics that is necessary for quantum spacetime geometry and quantum cosmology. Some personal recollections of distinguished collaborators are also appended in this volume. The essays may vary in length, style or level but are certainly accessible to most physicists.
James B Hartle is Research Professor and Professor of Physics Emeritus at the University of California, Santa Barbara. His scientific work is concerned with the application of Einstein's relativistic theory of gravitation general relativity to realistic astrophysical situations, especially cosmology. He has contributed usefully to the understanding of gravitational waves, relativistic stars, black holes, and the theory of the wave function of the universe. He is currently interested in the earliest moments of the big bang where the subjects of quantum mechanics, quantum gravity, and cosmology overlap. Much of his recent work is concerned with the generalizations of usual quantum mechanics that are necessary for cosmology and quantum gravity. He is a member of the US National Academy of Sciences, a fellow of the American Academy of Arts and Sciences, and is a founder and past director of the Institute for Theoretical Physics at Santa Barbara.