Quantum gravity poses the problem of merging quantum mechanics and general relativity, the two great conceptual revolutions in the physics of the twentieth century. The loop and spinfoam approach, presented in this book, is one of the leading research programs in the field. The first part of the book discusses the reformulation of the basis of classical and quantum Hamiltonian physics required by general relativity. The second part covers the basic technical research directions. Appendices include a detailed history of the (...) subject of quantum gravity, hard-to-find mathematical material, and a discussion of some philosophical issues raised by the subject. This fascinating text is ideal for graduate students entering the field, as well as researchers already working in quantum gravity. It will also appeal to philosophers and other scholars interested in the nature of space and time. (shrink)

In earlier writings, I argued that neither of the two major physical cosmologies of the twentieth century support divine creation, so that atheism has nothing to fear from the explanations required by these cosmologies. Yet theists ranging from Augustine, Aquinas, Descartes, and Leibniz to Richard Swinburne and Philip Quinn have maintained that, at every instant anew, the existence of the world requires divine creation ex nihilo as its cause. Indeed, according to some such theists, for any given moment t, God’s (...) volition thatthe-world-should-exist-at-t supposedly brings about its actual existence at t.In an effort to establish the current viability of this doctrine of perpetual divine conservation. Philip Quinn I argued that it is entirely compatible with physical energy-conservation in the Big Rang cosmology, as well as with the physics of the steady-state theories.But I now contend that instead, there is a logical incompatibility on both counts. Resides, the stated tenet of divine conservation has an additional defect: It speciously purchases plausibility by trading on the multiply disanalogous volitional explanations of human actions. (shrink)

Ever since Copernicus, scientists have continually adjusted their view of human nature, moving it further and further from its ancient position at the center of Creation. But in recent years, a startling new concept has evolved that places it more firmly than ever in a special position. Known as the Anthropic Cosmological Principle, this collection of ideas holds that the existence of intelligent observers determines the fundamental structure of the Universe. In its most radical version, the Anthropic Principle asserts that (...) "intelligent information-processing must come into existence in the Universe, and once it comes into existence, it will never die out." This wide-ranging and detailed book explores the many ramifications of the Anthropic Cosmological Principle, covering the whole spectrum of human inquiry from Aristotle to Z bosons. Bringing a unique combination of skills and knowledge to the subject, John D. Barrow and Frank J. Tipler--two of the world's leading cosmologists--cover the definition and nature of life, the search for extraterrestrial intelligence, and the interpretation of the quantum theory in relation to the existence of observers. The book will be of vital interest to philosophers, theologians, mathematicians, scientists, and historians, as well as to anyone concerned with the connection between the vastness of the universe of stars and galaxies and the existence of life within it on a small planet out in the suburbs of the Milky Way. (shrink)

This chapter contains sections titled: * 1 God’s Love for All Humans * 2 Parallels Between Evolution and Multiverse Ideas * 3 Fine-Tuning in Our Universe * 4 Explanations for Fine-Tuning * 5 Applying Bayes’ Theorem * 6 Toy Multiverse Model from Arithmetic * 7 The Growth of Our Knowledge of the Universe * 8 Objections to Multiverse Ideas * 9 Conclusions * Note * Acknowledgments * References.