This is the second of two volumes on the genesis of quantum mechanics in the first quarter of the 20th century. It covers the period 1923-1927. After covering some of the difficulties the old quantum theory had run into by the early 1920s as well as the discovery of the exclusion principle and electron spin, it traces the emergence of two forms of the new quantum mechanics, matrix mechanics and wave mechanics, in the years 1923-27. It then shows how the new theory took care of some of the failures of the old theory and put its successes on a more solid basis. Finally, it shows how in 1927 the two forms of the new theory were unified, first through statistical transformation theory, then through the Hilbert space formalism. This volume provides a detailed analysis of the classic papers by Heisenberg, Born, Jordan, Dirac, De Broglie, Einstein, Schrödinger, von Neumann and other authors. Drawing on the correspondence of these and other physicists, their later reminiscences and the extensive secondary literature on the “quantum revolution”, this volume places these papers in the context of the discussions out of which modern quantum mechanics emerged. It argues that the genesis of modern quantum mechanics can be seen as the construction of an arch on a scaffold provided by the old quantum theory, discarded once the arch could support itself.

The book attempts to provide an introduction to quantum field theory emphasizing conceptual issues frequently neglected in more "utilitarian" treatments of the subject. The book is divided into four parts, entitled respectively "Origins", "Dynamics", "Symmetries", and "Scales". The emphasis is conceptual - the aim is to build the theory up systematically from some clearly stated foundational concepts - and therefore to a large extent anti-historical, but two historical Chapters ("Origins") are included to situate quantum field theory in the larger context of modern physical theories. The three remaining sections of the book follow a step by step reconstruction of this framework beginning with just a few basic assumptions: relativistic invariance, the basic principles of quantum mechanics, and the prohibition of physical action at a distance embodied in the clustering principle. The "Dynamics" section of the book lays out the basic structure of quantum field theory arising from the sequential insertion of quantum-mechanical, relativistic and locality constraints. The central role of symmetries in relativistic quantum field theories is explored in the third section of the book, while in the final section, entitled "Scales", we explore in detail the feature of quantum field theories most critical for their enormous phenomenological success - the scale separation property embodied by the renormalization group properties of a theory defined by an effective local Lagrangian.

The book attempts to provide an introduction to quantum field theory emphasizing conceptual issues frequently neglected in more "utilitarian" treatments of the subject. The book is divided into four parts, entitled respectively "Origins", "Dynamics", "Symmetries", and "Scales". The emphasis is conceptual - the aim is to build the theory up systematically from some clearly stated foundational concepts - and therefore to a large extent anti-historical, but two historical Chapters ("Origins") are included to situate quantum field theory in the larger context of modern physical theories. The three remaining sections of the book follow a step by step reconstruction of this framework beginning with just a few basic assumptions: relativistic invariance, the basic principles of quantum mechanics, and the prohibition of physical action at a distance embodied in the clustering principle. The ``Dynamics" section of the book lays out the basic structure of quantum field theory arising from the sequential insertion of quantum-mechanical, relativistic and locality constraints. The central role of symmetries in relativistic quantum field theories is explored in the third section of the book, while in the final section, entitled "Scales", we explore in detail the feature of quantum field theories most critical for their enormous phenomenological success - the scale separation property embodied by the renormalization group properties of a theory defined by an effective local Lagrangian.The book includes a wide range of problems at chapter ends. Solutions can be requested via the publisher's web site.

This two-volume book is on the genesis of quantum mechanics. The first volume covers the key developments in the period 1900-1923, which provided the scaffold on which the arch of modern quantum mechanics was built. This volume traces the early contributions by Planck, Einstein, and Bohr to the theories of black-body radiation, specific heats, and spectroscopy, all showing the need for drastic changes to the physics of their day. It examines the efforts by Sommerfeld and others to provide a new theory, now known as the old quantum theory. After some striking initial successes (explaining the fine structure of hydrogen, X-ray spectra, and the Stark effect), the old quantum theory ran into serious difficulties (failing to provide consistent models for helium and the Zeeman effect) and eventually gave way to matrix and wave mechanics. The second volume provides detailed analysis of the classic papers by Heisenberg, Born, Jordan, Dirac, De Broglie, Einstein, Schrödinger, von Neumann and other authors. Drawing on the correspondence of these and other physicists, their later reminiscences and the extensive secondary literature on the "quantum revolution," this volume places these papers in the context of the discussions out of which modern quantum mechanics emerged. It argues that the genesis of modern quantum mechanics can be seen as the construction of an arch on a scaffold provided by the old quantum theory, discarded once the arch could support itself.

"By the time we met, he was a newly ordained curate and I was scratching a living in the esoteric world, had written a book on the Qabalah and ran an occult magazine. We were thus inhabitants of two worlds that were never supposed to meet - at least by popular convention - or if they did, to be diametrically opposed to each other." The catalyst for such a meeting of the minds was the provocative poetry of Anthony Duncan, hitherto little known to the world but privately praised by Kathleen Raine. Following on from the "Lord of the Dance" chapter in his recent autobiography, I Called it Magic, and various entries in his book of collected letters, Yours Very Truly, Gareth Knight muses on the esoteric resonances resulting from his unlikely friendship with the Reverend Anthony Duncan. Their intellectual sharing of ideas led to Duncan's The Christ, Psychotherapy and Magic and Knight's Experience of the Inner Worlds, which have become companion texts of esoteric Christianity often read and taught together. The pair had planned to co-author a book before Duncan's untimely passing in 2003 so Christ & Qabalah comes as a fulfilment of a long-held promise. The book will delight admirers of both authors with its intertextual interplay as well as a fresh exploration of the differences and similarities between a cleric and an occultist. Knight has described the book as an "organic process, almost an initiation, that has left me with a somewhat expanded consciousness." Readers are invited to share in the various machinations that sparked this dynamic relationship - one that keeps on giving.

Constructing Quantum Mechanics is the first of two volumes on the genesis of quantum mechanics. This volume traces the early contributions by Planck, Einstein, and Bohr, all showing the need for drastic changes to the physics of their day. It examines the efforts by Sommerfeld and others to develop a new theory, now known as the old quantum theory. After some striking successes, this theory ran into serious difficulties and ended up serving as the scaffold on which the arch of modern quantum mechanics was built. This volume breaks new ground, both in its treatment of the work of Sommerfeld and his associates, and by offering new perspectives on classic papers by Planck, Einstein, Bohr, and others. Paying close attention to both primary and secondary sources, Constructing Quantum Mechanics provides an in-depth analysis of the heroic struggle to come to terms with the wealth of mostly spectroscopic data that eventually gave us modern quantum mechanics.

Anthony Duncan, author of "The Christ, Psychotherapy and Magic", openly and frankly examines the experience of communication with "extra-terrestrial" contacts, and the leaps of faith and mutual acceptance on which such contact depends. He considers that experiences of the extra-terrestrial are essentially objective and real, and that there is a common, underlying dynamic which is prompting an increasing - and increasingly varied - pattern of visitations. But who or what are these visitors? Do they come from elsewhere in our Universe or from another Universe altogether? Do they travel here across space or by a shift of wavelength? And how do they fit into the pattern set by the Incarnation of Christ? Duncan suggests that the first step towards an answer is to let go of our fear. Also included is a previously unpublished essay, The Liberation of the Imagination, and a personal account of the experiences with extra-terrestrial contacts which led Duncan to write the book. Presented from a Christian perspective, the book offers a sane and sensible discussion of a controversial subject by a priest and mystic who has never been afraid to think and minister beyond conventional boundaries.

Celtic spirituality is the "forgotten faith" of the West. It is essentially joyful and holistic and holds together the two human faculties of reason and intuition, taking joy in the beauty of the created world. The Celtic saints were intuitives whose feet were very firmly planted on the ground. It is their equilibrium as human beings that gives much of their appeal, and in this, as in the holiness their lives display, they are Christlike. This book by Anglican cleric Anthony Duncan examines the lives of the Celtic saints in the context of their time, along with the sacred places in the landscape that have become associated with them.