In trying to understand the atom, physicists built quantum mechanics, the most successful theory in science and the basis of one-third of our economy. They found, to their embarrassment, that with their theory, physics encounters consciousness. Authors Bruce Rosenblum and Fred Kuttner explain all this in non-technical terms with help from some fanciful stories and anecdotes about the theory's developers. They present the quantum mystery honestly, emphasizing what is and what is not speculation. Quantum Enigma's description of the experimental quantum facts, and the quantum theory explaining them, is undisputed. Interpreting what it all means, however, is heatedly controversial. But every interpretation of quantum physics involves consciousness. Rosenblum and Kuttner therefore turn to exploring consciousness itself--and encounter quantum mechanics. Free will and anthropic principles become crucial issues, and the connection of consciousness with the cosmos suggested by some leading quantum cosmologists is mind-blowing. Readers are brought to a boundary where the particular expertise of physicists is no longer the only sure guide. They will find, instead, the facts and hints provided by quantum mechanics and the ability to speculate for themselves. In the few decades since the Bell's theorem experiments established the existence of entanglement (Einstein's "spooky action"), interest in the foundations, and the mysteries, of quantum mechanics has accelerated. In recent years, physicists, philosophers, computer engineers, and even biologists have expanded our realization of the significance of quantum phenomena. This second edition includes such advances. The authors have also drawn on many responses from readers and instructors to improve the clarity of the book's explanations.

Quantum mechanics is one of mankind's most remarkable intellectual achievements. Stunningly successful and elegant, it challenges our deepest intuitions about the world. In this book, seventeen physicists and philosophers, all deeply concerned with understanding quantum mechanics, reply to Schlosshauer's penetrating questions about the central issues. They grant us an intimate look at their radically different ways of making sense of the theory's strangeness. What is quantum mechanics about? What is it telling us about nature? Can quantum information or new experiments help lift the fog? And where are we headed next? Everyone interested in the contemporary but often longstanding conundrums of quantum theory, whether lay reader or expert, will find much food for thought in these pages. A wealth of personal reflections and anecdotes guarantee an engaging read. Participants: Guido Bacciagaluppi, Caslav Brukner, Jeffrey Bub, Arthur Fine, Christopher Fuchs, GianCarlo Ghirardi, Shelly Goldstein, Daniel Greenberger, Lucien Hardy, Anthony Leggett, Tim Maudlin, David Mermin, Lee Smolin, Antony Valentini, David Wallace, Anton Zeilinger, and Wojciech Zurek.

Following upon the overthrow of the classical world picture by the findings of quantum mechanics, physicists have proposed a broad gamut of alternative world views. The present book begins with the major recognition that each of these suffers from a certain "residual Cartesianism" that has been smuggled in, as it were, unconsciously. It turns out, moreover, that the moment one discards this hidden and problematic premise, quantum theory begins to "make sense" in a way that it never has before. As the author goes on to show, it now becomes possible, for the first time, to integrate the findings of quantum physics into a world view that is neither forced nor ad hoc, but conforms to the permanent intuitions of mankind. Surprisingly, this treatise can be read with pleasure and profit, not only by scientists, but also by readers previously unacquainted with the technical conceptions of physics or the quantum-reality literature.

In this ground-breaking work the authors show how quantum properties are being observed in larger and larger objects and argue that explanations about quantum physics may lie in the field cognitive neuro-science.

The intellectual adventure story of the "double-slit" experiment, showing how a sunbeam split into two paths first challenged our understanding of light and then the nature of reality itself--and continues to almost two hundred years later. Many of science's greatest minds have grappled with the simple yet elusive "double-slit" experiment. Thomas Young devised it in the early 1800s to show that light behaves like a wave, and in doing so opposed Isaac Newton. Nearly a century later, Albert Einstein showed that light comes in quanta, or particles, and the experiment became key to a fierce debate between Einstein and Niels Bohr over the nature of reality. Richard Feynman held that the double slit embodies the central mystery of the quantum world. Decade after decade, hypothesis after hypothesis, scientists have returned to this ingenious experiment to help them answer deeper and deeper questions about the fabric of the universe. How can a single particle behave both like a particle and a wave? Does a particle exist before we look at it, or does the very act of looking create reality? Are there hidden aspects to reality missing from the orthodox view of quantum physics? Is there a place where the quantum world ends and the familiar classical world of our daily lives begins, and if so, can we find it? And if there's no such place, then does the universe split into two each time a particle goes through the double slit? With his extraordinarily gifted eloquence, Anil Ananthaswamy travels around the world and through history, down to the smallest scales of physical reality we have yet fathomed. Through Two Doors at Once is the most fantastic voyage you can take.

A physicist's efforts to understand the enigma that is quantum mechanics. Quantum mechanics is one of the glories of our age. The theory lies at the heart of modern society. Quantum mechanics is one of our most valuable forecasters—a “great predictor.” It has immeasurably altered our conception of the natural world. Its philosophical implications are earthshaking. But quantum mechanics steadfastly refuses to speak of many things; it deals in probabilities rather than giving explicit descriptions. It never explains. Einstein, one of its creators, considered the theory incomplete. Even now, many years after the creation of quantum mechanics, physicists continue to argue about it. Astrophysicist George Greenstein has been both fascinated and confused by quantum mechanics for his entire career. In this book, he describes, engagingly and accessibly, his efforts to understand the enigma that is quantum mechanics. The fastest route to the insight into the ultimate nature of reality revealed by quantum mechanics, Greenstein writes, is through Bell's Theorem, which concerns reality at the quantum level; and Bell's 1964 discovery drives Greenstein's quest. Greenstein recounts a scientific odyssey that begins with Einstein, continues with Bell, and culminates with today's push to develop an industry of quantum machines. Along the way, he discusses spin, entanglement, experimental metaphysics, and quantum teleportation, often with easy-to-grasp analogies. We have known for decades that the world of the quantum was strange, but, Greenstein says, not until John Bell came along did we know just how strange.