The Problem of Time: Quantum Mechanics Versus General Relativity

The Problem of Time is a comprehensive exploration of how time is perceived across different paradigms of physics, including Newtonian mechanics, special relativity, quantum mechanics, and general relativity. The book reveals substantial differences between the concepts of time in quantum mechanics and general relativity, which together give rise to the Problem of Time. This problem encompasses nine interlinked facets that emerge when attempting to reconcile these two paradigms, particularly in the context of developing a background-independent theory of quantum gravity. The book also demonstrates the practical relevance of its foundational topic to ongoing quantum gravity programs, such as geometrodynamical and loop quantum gravity approaches, quantum cosmology, supergravity, and M-theory. By examining background independence in both classical and quantum physics, the book establishes background independence as a distinct field of study and offers a local resolution to the Problem of Time through various reconceptualizations and mathematical reformulations. Self-contained appendices on mathematical methods for basic and foundational quantum gravity are included, and the book concludes by exploring how supergravity differs from general relativity in its realization of background independence.