THE PRESENT STATUS OF THE QUANTUM THEORY OF LIGHT In August of 1995, a group of over 70 physicists met at York University for a three-day symposium in honour of Professor Jean-Pierre Vigier. The attendance included theoretical and experimental physicists, mathematicians, astronomers and colleagues concerned with issues in the philosophy of science. The symposium was entitled "The Present Status of the Quantum Theory of Light" in accordance with Professor Vigier's wishes but in fact encompassed many of the areas to which Professor Vigier has contributed over his long and distinguished career. These include stochastic interpretations of quantum mechanics, particle physics, and electromagnetic theory. The papers presented at the symposium have been arranged in this proceedings in the following approximate order: ideas about the nature of light and photons, electrodynamiCS, the formulation and interpretation of quantum mechanics, and aspects of relativity theory. Some of the papers presented deal with alternate interpretations of quantum phenomena in the tradition of Vigier, Bohm et al. These interpretations reject the account given in purely probabilistic terms and which deems individual quantum events to be acausal and not amenable to any analysis in space-time terms. As is well known, Einstein and others also rejected the purely statistical account of quantum mechanics. As stressed by Professor Vigier at the symposium, the current experimental situation now allows for the first time for individual quantum events to be studied, e. g.

"A thorough, illuminating exploration of the most consequential controversy raging in modern science." --New York Times Book Review An Editor's Choice, New York Times Book Review Longlisted for PEN/E.O. Wilson Prize for Literary Science Writing Longlisted for Goodreads Choice Award Every physicist agrees quantum mechanics is among humanity's finest scientific achievements. But ask what it means, and the result will be a brawl. For a century, most physicists have followed Niels Bohr's solipsistic and poorly reasoned Copenhagen interpretation. Indeed, questioning it has long meant professional ruin, yet some daring physicists, such as John Bell, David Bohm, and Hugh Everett, persisted in seeking the true meaning of quantum mechanics. What Is Real? is the gripping story of this battle of ideas and the courageous scientists who dared to stand up for truth. "An excellent, accessible account." --Wall Street Journal "Splendid. . . . Deeply detailed research, accompanied by charming anecdotes about the scientists." --Washington Post

Named a Best Book of 2021 by the Financial Times and a Best Science Book of 2021 by The Guardian “Rovelli is a genius and an amazing communicator… This is the place where science comes to life.” ―Neil Gaiman “One of the warmest, most elegant and most lucid interpreters to the laity of the dazzling enigmas of his discipline...[a] momentous book” ―John Banville, The Wall Street Journal A startling new look at quantum theory, from the New York Times bestselling author of Seven Brief Lessons on Physics, The Order of Time, and Anaximander. One of the world's most renowned theoretical physicists, Carlo Rovelli has entranced millions of readers with his singular perspective on the cosmos. In Helgoland, he examines the enduring enigma of quantum theory. The quantum world Rovelli describes is as beautiful as it is unnerving. Helgoland is a treeless island in the North Sea where the twenty-three-year-old Werner Heisenberg made the crucial breakthrough for the creation of quantum mechanics, setting off a century of scientific revolution. Full of alarming ideas (ghost waves, distant objects that seem to be magically connected, cats that appear both dead and alive), quantum physics has led to countless discoveries and technological advancements. Today our understanding of the world is based on this theory, yet it is still profoundly mysterious. As scientists and philosophers continue to fiercely debate the meaning of the theory, Rovelli argues that its most unsettling contradictions can be explained by seeing the world as fundamentally made of relationships rather than substances. We and everything around us exist only in our interactions with one another. This bold idea suggests new directions for thinking about the structure of reality and even the nature of consciousness. Rovelli makes learning about quantum mechanics an almost psychedelic experience. Shifting our perspective once again, he takes us on a riveting journey through the universe so we can better comprehend our place in it.

A quantum origin of life? -- Quantum mechanics and emergence -- Quantum coherence and the search for the first replicator -- Ultrafast quantum dynamics in photosynthesis -- Modelling quantum decoherence in biomolecules -- Molecular evolution -- Memory depends on the cytoskeleton, but is it quantum? -- Quantum metabolism and allometric scaling relations in biology -- Spectroscopy of the genetic code -- Towards understanding the origin of genetic languages -- Can arbitrary quantum systems undergo self-replication? -- A semi-quantum version of the game of life -- Evolutionary stability in quantum games -- Quantum transmemetic intelligence -- Dreams versus reality : plenary debate session on quantum computing -- Plenary debate: quantum effects in biology : trivial or not? -- Nontrivial quantum effects in biology : a skeptical physicists' view -- That's life! : the geometry of p electron clouds.

This third edition, like its two predecessors, provides a detailed account of the basic theory needed to understand the properties of light and its interactions with atoms, in particular the many nonclassical effects that have now been observed in quantum-optical experiments. The earlier chapters describe the quantum mechanics of various optical processes, leading from the classical representation of the electromagnetic field to the quantum theory of light. The later chapters develop the theoretical descriptions of some of the key experiments in quantum optics. Over half of the material in this third edition is new. It includes topics that have come into prominence over the last two decades, such as the beamsplitter theory, squeezed light, two-photon interference, balanced homodyne detection, travelling-wave attenuation and amplification, quantum jumps, and the ranges of nonliner optical processes important in the generation of nonclassical light. The book is written as a textbook, with the treatment as a whole appropriate for graduate or postgraduate students, while earlier chapters are also suitable for final- year undergraduates. Over 100 problems help to intensify the understanding of the material presented.

Bell anchored the logic chain begun by Einstein, Rosen, and Podolskyand tested by Aspect "et al.," showing that entangled electronsare nonlocal. Feynman showed that free electrons are nonlocal in thatthey travel between any two points using all possible paths.