This book explores the debate between Einstein and Bohr in the 1920s and 1930s about their interpretations of the quantum theory.

"Quantum theory, the most successful physical theory of all time, provoked intense debate between the twentieth century's two greatest physicists, Niels Bohr and Albert Einstein. The debate concerned the nature of quantum theory, and the major contradictions and conceptual problems at its heart." "This second edition contains sympathetic accounts of the views of both Bohr and Einstein, and a thorough study of the argument between them. It includes non-technical and non-mathematical accounts of the development of quantum theory and relativity, and also the work of David Bohm and John Bell that restored interest in Einstein's views. It has been extensively revised and updated to cover recent developments, and the account of ongoing work has been brought up to date. A new chapter is devoted to describing the whole area of quantum information theory, from the work of Richard Feynman and David Deutsch that initiated the study of quantum computation to the theoretical and experimental approach to quantum cryptography." "This book provides an account of the development of quantum theory, which will appeal to anyone with an interest in the fundamental questions of physics, its philosophy and its history."--BOOK JACKET.

'This is about gob-smacking science at the far end of reason ... Take it nice and easy and savour the experience of your mind being blown without recourse to hallucinogens' Nicholas Lezard, Guardian For most people, quantum theory is a byword for mysterious, impenetrable science. And yet for many years it was equally baffling for scientists themselves. In this magisterial book, Manjit Kumar gives a dramatic and superbly-written history of this fundamental scientific revolution, and the divisive debate at its core. Quantum theory looks at the very building blocks of our world, the particles and processes without which it could not exist. Yet for 60 years most physicists believed that quantum theory denied the very existence of reality itself. In this tour de force of science history, Manjit Kumar shows how the golden age of physics ignited the greatest intellectual debate of the twentieth century. Quantum theory is weird. In 1905, Albert Einstein suggested that light was a particle, not a wave, defying a century of experiments. Werner Heisenberg's uncertainty principle and Erwin Schrodinger's famous dead-and-alive cat are similarly strange. As Niels Bohr said, if you weren't shocked by quantum theory, you didn't really understand it. While "Quantum" sets the science in the context of the great upheavals of the modern age, Kumar's centrepiece is the conflict between Einstein and Bohr over the nature of reality and the soul of science. 'Bohr brainwashed a whole generation of physicists into believing that the problem had been solved', lamented the Nobel Prize-winning physicist Murray Gell-Mann. But in "Quantum", Kumar brings Einstein back to the centre of the quantum debate. "Quantum" is the essential read for anyone fascinated by this complex and thrilling story and by the band of brilliant men at its heart.

"I find the idea quite intolerable that an electron exposed to radiation should choose of its own free will, not only its moment to jump off, but also its direction. In that case, I would rather be a cobbler, or even an employee in a gaming house, than a physicist." -Albert Einstein A scandal hovers over the history of 20th century physics. Albert Einstein-the century's greatest physicist-was never able to come to terms with quantum mechanics, the century's greatest theoretical achievement. For physicists who routinely use both quantum laws and Einstein's ideas, this contradiction can be almost too embarrassing to dwell on. Yet Einstein was one of the founders of quantum physics and he spent many years preaching the quantum's importance and its revolutionary nature. The Danish genius Neils Bohr was another founder of quantum physics. He had managed to solve one of the few physics problems that Einstein ever shied away from, linking quantum mathematics with a new model of the atom. This leap immediately yielded results that explained electron behavior and the periodic table of the elements. Despite their mutual appreciation of the quantum's importance, these two giants of modern physics never agreed on the fundamentals of their work. In fact, they clashed repeatedly throughout the 1920s, arguing first over Einstein's theory of "light quanta"(photons), then over Niels Bohr's short-lived theory that denied the conservation of energy at the quantum level, and climactically over the new quantum mechanics that Bohr enthusiastically embraced and Einstein stubbornly defied. This contest of visions stripped the scientific imagination naked. Einstein was a staunch realist, demanding to know the physical reasons behind physical events. At odds with this approach was Bohr's more pragmatic perspective that favored theories that worked, even if he might not have a corresponding explanation of the underlying reality. Powerful and illuminating, Einstein Defiant is the first book to capture the soul and the science that inspired this dramatic duel, revealing the personalities and the passions-and, in the end, what was at stake for the world.

Galileo Unbound traces the journey that brought us from Galileo's law of free fall to today's geneticists measuring evolutionary drift, entangled quantum particles moving among many worlds, and our lives as trajectories traversing a health space with thousands of dimensions. Remarkably, common themes persist that predict the evolution of species as readily as the orbits of planets or the collapse of stars into black holes. This book tells the history of spaces of expanding dimension and increasing abstraction and how they continue today to give new insight into the physics of complex systems. Galileo published the first modern law of motion, the Law of Fall, that was ideal and simple, laying the foundation upon which Newton built the first theory of dynamics. Early in the twentieth century, geometry became the cause of motion rather than the result when Einstein envisioned the fabric of space-time warped by mass and energy, forcing light rays to bend past the Sun. Possibly more radical was Feynman's dilemma of quantum particles taking all paths at once — setting the stage for the modern fields of quantum field theory and quantum computing. Yet as concepts of motion have evolved, one thing has remained constant, the need to track ever more complex changes and to capture their essence, to find patterns in the chaos as we try to predict and control our world.

The gripping, entertaining, and vividly-told narrative of a radical discovery that sent shockwaves through the scientific community and forever changed the way we understand the world. Werner Heisenberg’s “uncertainty principle” challenged centuries of scientific understanding, placed him in direct opposition to Albert Einstein, and put Niels Bohr in the middle of one of the most heated debates in scientific history. Heisenberg’s theorem stated that there were physical limits to what we could know about sub-atomic particles; this “uncertainty” would have shocking implications. In a riveting and lively account, David Lindley captures this critical episode and explains one of the most important scientific discoveries in history, which has since transcended the boundaries of science and influenced everything from literary theory to television.

"Niels Bohr was a central figure in quantum physics, well-known for his work on atomic structure and his contributions to the Copenhagen interpretation of quantum mechanics. In this book, philosopher Slobodan Perović explores the way Bohr practiced and understood physics, and the implications of this for our understanding of modern science, especially contemporary quantum experimental physics. Perović's method of studying Bohr is philosophical-historical, and his aim is to make sense of both Bohr's understanding of physics and his method of inquiry. He argues that in several important respects, Bohr's vision of physics was driven by his desire to develop a comprehensive perspective on key features of experimental observation as well as emerging experimental work. Perović uncovers how Bohr's distinctive breakthrough contributions are characterized by a multi-layered, phased approach of building on basic experimental insights inductively to develop intermediary and overarching hypotheses. The strengths and limitations of this approach, in contrast to the mathematically or metaphysically driven approaches of other physicists at the time, made him a thoroughly distinctive kind of theorist and scientific leader. Once we see that Bohr played the typical role of a laboratory mediator, and excelled in the inductive process this required, we can fully understand the way his work was generated, the role it played in developing novel quantum concepts, and its true limitations, as well as current adherence to and use of Bohr's complementarity approach among contemporary experimentalists"--

This book presents unpublished excerpts from extensive correspondence between Niels Bohr and his immediate family, and uses it to describe and analyze the psychological and cultural background to his invention of the quantum theory of the atom.

These fourteen essays by leading historians and philosophers of science introduce the reader to the work of Albert Einstein. Following an introduction that places Einstein's work in the context of his life and times, the essays explain his main contributions to physics in terms that are accessible to a general audience, including special and general relativity, quantum physics, statistical physics, and unified field theory. The closing essays explore the relation between Einstein's work and twentieth-century philosophy, as well as his political writings.

Authored by an acclaimed teacher of quantum physics and philosophy, this textbook pays special attention to the aspects that many courses sweep under the carpet. Traditional courses in quantum mechanics teach students how to use the quantum formalism to make calculations. But even the best students - indeed, especially the best students - emerge rather confused about what, exactly, the theory says is going on, physically, in microscopic systems. This supplementary textbook is designed to help such students understand that they are not alone in their confusions (luminaries such as Albert Einstein, Erwin Schroedinger, and John Stewart Bell having shared them), to sharpen their understanding of the most important difficulties associated with interpreting quantum theory in a realistic manner, and to introduce them to the most promising attempts to formulate the theory in a way that is physically clear and coherent. The text is accessible to students with at least one semester of prior exposure to quantum (or "modern") physics and includes over a hundred engaging end-of-chapter "Projects" that make the book suitable for either a traditional classroom or for self-study.