E C George Sudarshan – författare

Robert Eugene Marshak (1916-92) devoted much of his life to helping other people carry out scientific research and gather to discuss their work. In addition to his scientific statesmanship, he was an extraordinarily gifted research scientist, and many of his scientific contributions have been prophetic. This book pays homage to his creativity and continuing work, with contributions from many of the people whose lives have been influenced by him.

This book makes broadly accessible an understandable proof of the infamous spin-statistics theorem. This widely known but little-understood theorem is intended to explain the fact that electrons obey the Pauli exclusion principle. This fact, in turn, explains the periodic table of the elements and their chemical properties. Therefore, this one simply stated fact is responsible for many of the principal features of our universe, from chemistry to solid state physics to nuclear physics to the life cycle of stars.In spite of its fundamental importance, it is only a slight exaggeration to say that “everyone knows the spin-statistics theorem, but no one understands it”. This book simplifies and clarifies the formal statements of the theorem, and also corrects the invariably flawed intuitive explanations which are frequently put forward.The book will be of interest to many practising physicists in all fields who have long been frustrated by the impenetrable discussions on the subject which have been available until now. It will also be accessible to students at an advanced undergraduate level as an introduction to modern physics based directly on the classical writings of the founders, including Pauli, Dirac, Heisenberg, Einstein and many others.

This invaluable book takes the reader from Planck's discovery of the quantum in 1900 to the most recent interpretations and applications of nonrelativistic quantum mechanics.The introduction of the quantum idea leads off the prehistory of quantum mechanics, featuring Planck, Einstein, Bohr, Compton, and de Broglie's immortal contributions. Their original discovery papers are featured with explanatory notes and developments in Part 1.The invention of matrix mechanics and quantum mechanics by Heisenberg, Born, Jordan, Dirac, and Schrödinger is presented next, in Part 2.Following that, in Part 3, are the Einstein-Bohr debates on the interpretation of quantum mechanics culminating in Bell's inequality and Aspect's experiment demonstrating the actuality of the long range quantum correlations to which Einstein, Podolsky, and Rosen took great exception. Resolutions of quantum paradoxes and the current state of such debates are summarized.Part 4 presents a selection of the most dramatic modern developments, both theoretical and experimental. These include Feynman path integrals, the modern interpretation based on decoherence, quantum optics experiments leading to teleportation, DeWitt's wave function of the universe, and a brief introduction to the end-of-the-millennium prospects of quantum computation. A concluding chapter presents the authors' conjectures for the next 100 years of the quantum.This book is ideally suited to anyone with a junior level background in modern physics and quantum mechanics, and a cultural interest in the original sources of the greatest ideas of the greatest founders of this subject as derived from their first discovery papers. These papers have led, in giant strides across the whole of the twentieth century, to the revolutionary experimental advances of the last decade. The book makes accessible — physically and intellectually — both the deepest roots and the highest branches of nonrelativistic quantum physics.

Classical dynamics is traditionally treated as an early stage in the development of physics, a stage that has long been superseded by more ambitious theories. Here, in this book, classical dynamics is treated as a subject on its own as well as a research frontier. Incorporating insights gained over the past several decades, the essential principles of classical dynamics are presented, while demonstrating that a number of key results originally considered only in the context of quantum theory and particle physics, have their foundations in classical dynamics.Graduate students in physics and practicing physicists will welcome the present approach to classical dynamics that encompasses systems of particles, free and interacting fields, and coupled systems. Lie groups and Lie algebras are incorporated at a basic level and are used in describing space-time symmetry groups. There is an extensive discussion on constrained systems, Dirac brackets and their geometrical interpretation. The Lie-algebraic description of dynamical systems is discussed in detail, and Poisson brackets are developed as a realization of Lie brackets. Other topics include treatments of classical spin, elementary relativistic systems in the classical context, irreducible realizations of the Galileo and Poincaré groups, and hydrodynamics as a Galilean field theory. Students will also find that this approach that deals with problems of manifest covariance, the no-interaction theorem in Hamiltonian mechanics and the structure of action-at-a-distance theories provides all the essential preparatory groundwork for a passage to quantum field theory.This reprinting of the original text published in 1974 is a testimony to the vitality of the contents that has remained relevant over nearly half a century.

Classical dynamics is traditionally treated as an early stage in the development of physics, a stage that has long been superseded by more ambitious theories. Here, in this book, classical dynamics is treated as a subject on its own as well as a research frontier. Incorporating insights gained over the past several decades, the essential principles of classical dynamics are presented, while demonstrating that a number of key results originally considered only in the context of quantum theory and particle physics, have their foundations in classical dynamics.Graduate students in physics and practicing physicists will welcome the present approach to classical dynamics that encompasses systems of particles, free and interacting fields, and coupled systems. Lie groups and Lie algebras are incorporated at a basic level and are used in describing space-time symmetry groups. There is an extensive discussion on constrained systems, Dirac brackets and their geometrical interpretation. The Lie-algebraic description of dynamical systems is discussed in detail, and Poisson brackets are developed as a realization of Lie brackets. Other topics include treatments of classical spin, elementary relativistic systems in the classical context, irreducible realizations of the Galileo and Poincaré groups, and hydrodynamics as a Galilean field theory. Students will also find that this approach that deals with problems of manifest covariance, the no-interaction theorem in Hamiltonian mechanics and the structure of action-at-a-distance theories provides all the essential preparatory groundwork for a passage to quantum field theory.This reprinting of the original text published in 1974 is a testimony to the vitality of the contents that has remained relevant over nearly half a century.