Stephen Webb, author of WHERE IS EVERYBODY?, takes the interested amateur on a thrilling and enlightening tour of the amazing, even bizarre, new ideas of modern physics, including alternatives to the Big Bang, parallel universes, and an imaginary trip to the other side of the black hole.

Quantum gravity is perhaps the most important open problem in fundamental physics. It is 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 2004 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.

This 2004 textbook fills a gap in the literature on general relativity by providing the advanced student with practical tools for the computation of many physically interesting quantities. The context is provided by the mathematical theory of black holes, one of the most elegant, successful, and relevant applications of general relativity. Among the topics discussed are congruencies of timelike and null geodesics, the embedding of spacelike, timelike and null hypersurfaces in spacetime, and the Lagrangian and Hamiltonian formulations of general relativity. Although the book is self-contained, it is not meant to serve as an introduction to general relativity. Instead, it is meant to help the reader acquire advanced skills and become a competent researcher in relativity and gravitational physics. The primary readership consists of graduate students in gravitational physics. It will also be a useful reference for more seasoned researchers working in this field.

The theory, observations, and applications ofgravitational lensingconstitute one ofthe most rapidly growing branches ofextragalactic astrophysics. The deflection of light from very distant sources by intervening masses provides a unique possibility for the investigation of both background sources and lens mass distributions. Gravitational lensing manifestsitselfmost distinctly through multiply imaged QSOs and the formation of highly elongated im ages of distant galaxies ('arcs') and spectacular ring-like images of extra galactic radio sources. But the effects of gravitational light deflection are not limited to these prominent image configurations; more subtle, since not directly observable, consequences of lensing are the, possibly strong, mag nification of sources, which may permit observation of intrinsically fainter, or more distant, sources than would be visible without these natural tele scopes. Such light deflection can also affect the source counts of QSOs and of other compact extragalactic sources, and can lead to flux variability of sources owing to propagation effects. Trying to summarizethe theory and observationalstatus ofgravitational lensing in a monograph turned out to be a bigger problem than any of the authors anticipated when we started this project at the end of 1987, encour aged by Martin Harwit, who originally approached us. The development in the field has been very rapid during the last four years, both through the ory and through observation, and many sections have been rewritten several times, as the previous versions became out of date.

Like a river, the progress of science has a tendency to run tast or slow. Once the water meets a dam, it may stop for a while, but eventually it will flow over the top and run fast again. In scientific research, a breakthrough to overcome a simile>r barrier is often made by a small number of scientists, or perhaps by a single person of special creativity, extraordinary talent and unusual perseverance. Through such individuals science can proceed in great strides. No one can deny that Professor Kazuo Takayanagi is one of these special individuals who have played a leading role in the field of atomic and molecular physics, as well as space physics. This book is dedicated to Professor Takayanagi on the occasion of his retirement from the Institute of Space and Astronautical Science. Professor Takayanagi was born in 1926 and grew up in Tomakomai in Hokkaido, the northern island of Japan. In his boyhood, he was interested in natural sciences, particularly astronomy. On 5th February, 1943, when he was attending secondary school, a solar eclipse was seen in his town. He organized a group of students from his school to observe the eclipse. He still remembers the scene: it grew so dark during the eclipse that two stars, Vega and Arcturus, could be seen. After graduation from the University of Tokyo in 1948, he entered the graduate school there.

The second Erice course in the school of Particle-Astrophysics was held in May, 1988. The topic choosen was Dark Matter. This is one of the most exciting top ics at the interface of particle physics and astrophysics. It is developing rapidly now due to a coming together not only of the theoretical concepts from the early universe with the theoretical concepts of galaxy formation, but also the coming to gether of the theorists, experimentalists and observers. It is with Dark Matter, the combined interrelated topics of galaxy formation and the generation of large scale structure that we see a confrontation of the exotic ideas from the early universe, such as phase transitions and unification, coming face to face with the realities of traditional observational cosmology. These realities have recently been heightened by the tremendous number of new observations, demonstrating that large scale structure of the universe is far more complex than anybody had suspected. In particular, we now see large scale foam, apparent large scale velocity fields, indicating devations from the Hubble flow, large scales of the order 100 Mpc, and galaxy formation occurring at high red shifts much greater than unity. We also see an apparent correlation of clusters of galaxies that may even exceed the c- relation of galaxies despite their being on much larger scales with lower average densities."

The scalar-tensor theory of gravitation is one of the most popular alternatives to Einstein's theory of gravitation. This book provides a clear and concise introduction to the theoretical ideas and developments, exploring scalar fields and placing them in context with a discussion of Brans-Dicke theory. Topics covered include the cosmological constant problem, time variability of coupling constants, higher dimensional space-time, branes and conformal transformations. The authors emphasize the physical applications of the scalar-tensor theory and thus provide a pedagogical overview of the subject, keeping more mathematically detailed sections for the appendices. This book is suitable for graduate courses in cosmology, gravitation and relativity. It will also provide a valuable reference for researchers.

This monograph presents a self contained mathematical treatment of the initial value problem for shock wave solutions of the Einstein equations in General Relativity. It has a clearly outlined goal: proving a certain local existence theorem. Concluding remarks are added and commentary is provided throughout. The author is a well regarded expert in this area.

This is a book about physics, written for mathematicians. The readers we have in mind can be roughly described as those who: I. are mathematics graduate students with some knowledge of global differential geometry 2. have had the equivalent of freshman physics, and find popular accounts of astrophysics and cosmology interesting 3. appreciate mathematical elarity, but are willing to accept physical motiva tions for the mathematics in place of mathematical ones 4. are willing to spend time and effort mastering certain technical details, such as those in Section 1. 1. Each book disappoints so me readers. This one will disappoint: 1. physicists who want to use this book as a first course on differential geometry 2. mathematicians who think Lorentzian manifolds are wholly similar to Riemannian ones, or that, given a sufficiently good mathematical back ground, the essentials of a subject !ike cosmology can be learned without so me hard work on boring detaiis 3. those who believe vague philosophical arguments have more than historical and heuristic significance, that general relativity should somehow be "proved," or that axiomatization of this subject is useful 4. those who want an encyclopedic treatment (the books by Hawking-Ellis [1], Penrose [1], Weinberg [1], and Misner-Thorne-Wheeler [I] go further into the subject than we do; see also the survey article, Sachs-Wu [1]). 5. mathematicians who want to learn quantum physics or unified fieId theory (unfortunateIy, quantum physics texts all seem either to be for physicists, or merely concerned with formaI mathematics).

The accretion process is thought to play a key role in the Universe. This book explains, in a form intelligible to graduate students, its relation to the formation of new stars, to the energy release in compact objects and to the formation of black holes. The monograph describes how accretion processes are related to the presence of jets in stellar objects and active galactic nuclei and to jet formation. The authors treat theoretical work as well as current observational facts. This volume of the highly esteemed Les Houches series is meant as an advanced text that can serve to attract students to exciting new research work in astrophysics.

This volume consists of papers developed from a joint ACE/ISSI symposium at the occasion of the eightieth birthday of Johannes Geiss. The symposium explored insights into the composition of solar-system and galactic matter that have been brought about by recent space missions, ground-based studies, and theoretical advances. Coverage includes linking primordial to solar composition, planetary samples, solar sources and fractionation processes, and interstellar gas and Cosmic rays.

Modern cosmology is a quickly developing ?eld of research. New technical devices and tools supply the community with new experimental data measured with high accuracy. The self-consistent explanation of these data needs t- oretical models that are based on hypothetical predictions of particle theory. In their turn, such predictions imply cosmology for their probe. Speci?c st- ies of the cosmological consequences of particle theory, linking them to their observable signatures, are actual. This boiling kettle of theoretical research and experimental efforts produces ideas that will be preserved for following generations. The aim of this book is to acquaint the reader with some of these ideas, - fering nontrivial ways to probe the physical basis of modern cosmology. An extensive review of the newest ideas in modern cosmology, e. g. , related with the development of the M-brane theory, lies beyond the scope of our book, which is aimed at providing a ?rmly established system of probes for these ideas, linking their predictions to their possible experimental test. We use the framework of in?ationary paradigm to reveal the phenomena that can shed light on the physical origin of the observed Universe, of its matter content and large-scale structure. The crucial role of quantum ?uctuations in creation of our Universe and in possible features, re?ecting cosmological impact of microphysics, is discussed. These features are shown to be accessible to - perimental test in the near future.

REFLECTIONS ON SPACETIME - FOUNDATIONS, PHILOSOPHY AND HISTORY During the academic year 1992/93, an interdisciplinary research group constituted itself at the Zentrum fUr interdisziplinare Forschung (ZiF) in Bielefeld, Germany, under the title 'Semantical Aspects of Spacetime Theories', in which philosophers and physicists worked on topics in the interpretation and history of relativity theory. The present issue consists of contributions resulting from material presented and discussed in the group during the course of that year. The scope of the papers ranges from rather specialised issues arising from general relativity such as the problem of referential indeterminacy, to foundational questions regarding spacetime in the work of Carnap, Weyl and Hilbert. It is well known that the General Theory of Relativity (GTR) admits spacetime models which are 'exotic' in the sense that observers could travel into their own past. This poses a number of problems for the physical interpretation of GTR which are also relevant in the philosophy of spacetime. It is not enough to exclude these exotic models simply by stating that we live in a non-exotic universe, because it might be possible to "operate time machines" by actively changing the topology of the future part of spacetime. In his contribution, Earman first reviews the attempts of physicists to prove "chronology protection theorems" (CPTs) which exclude the operation of time machines under reasonable assumptions.

Sponsored by the Global Foundation, Inc., these proceedings are derived from the International Conference on Orbis Scientiae II. Topics covered include: gravitational mass, neutrino mass, particle masses, cosmological masses, susy masses, and big bang creation of mass.

This volume contains papers presented at an international conference to celebrate Fred Hoyle's monumental contributions to astronomy, astrophysics and astrobiology and more generally to humanity and culture. The contributed articles highlight the important aspects of his scientific life and show how much of an example and inspiration he has been for over three generations in the 20th century.
There are a few people of whom it could be said they changed the way we perceive the world. Galileo Galilei, Nicholas Copernicus and Isaac Newton were amongst these. The inclusion of Fred Hoyle in this elite group may be contentious at the moment for the reason that in challenging the most cherished of Holy Grails in science he unwittingly offended many. But once the dust has settled over the many disputes that were raised and in the fullness of time there can be little doubt that Fred Hoyle will be ranked alongside these figures of history.
Hoyle perceived science with an indomitable passion and an obsessive desire to find the truth wherever it lay. His singleness of purpose in this great mission and his deep suspicion of orthodoxy, his powerful intellect and imagination set him apart from most of his contemporaries in the last century.
This volume includes papers presented at a commemorative conference held in Cardiff in June 2002. The material divides naturally into several sections: Personal Reminiscences, Stellar Structure and Evolution, Cosmology, Interstellar Matter, Comets and finally Panspermia. Each article pays its own tribute to Fred Hoyle for his inspiration and guidance that led to major breakthroughs in astrophysics and space science throughout the 20th century.

This book is written for theoretical and mathematical physicists and mat- maticians interested in recent developments in complex general relativity and their application to classical and quantum gravity. Calculations are presented by paying attention to those details normally omitted in research papers, for pedagogical r- sons. Familiarity with fibre-bundle theory is certainly helpful, but in many cases I only rely on two-spinor calculus and conformally invariant concepts in gravitational physics. The key concepts the book is devoted to are complex manifolds, spinor techniques, conformal gravity, ?-planes, ?-surfaces, Penrose transform, complex 3 1 - - space-time models with non-vanishing torsion, spin- fields and spin- potentials. 2 2 Problems have been inserted at the end, to help the reader to check his und- standing of these topics. Thus, I can find at least four reasons for writing yet another book on spinor and twistor methods in general relativity: (i) to write a textbook useful to - ginning graduate students and research workers, where two-component spinor c- culus is the unifying mathematical language.

Soliton theory is an important branch of applied mathematics and mathematical physics. An active and productive field of research, it has important applications in fluid mechanics, nonlinear optics, classical and quantum fields theories etc. This book presents a broad view of soliton theory. It gives an expository survey of the most basic ideas and methods, such as physical background, inverse scattering, Backl nd transformations, finite-dimensional completely integrable systems, symmetry, Kac-moody algebra, solitons and differential geometry, numerical analysis for nonlinear waves, and gravitational solitons. Besides the essential points of the theory, several applications are sketched and some recent developments, partly by the authors and their collaborators, are presented.

The Joint European and National Astronomical Meeting (JENAM) of 2002, was held in Porto - Portugal (2-7 September 2002), corresponding to the I ph Meeting of the European Astronomical Society (EAS) and the IJ! En- contra Nacional de Astronomia e Astroftsica (12ENAA) of the Sociedade Portuguesa de Astronomia (SPA). Portugal has a small and young community of researchers in Astronomy. This meeting have had an important role in marking the beginning of what we expect to be a new phase for Astronomy in Portugal. The fact that we have chosen to address '"the future" reflects this will of the Portuguese com- munity to share and discuss our commitment for the next decades with our colleagues. The meeting, titled "The Unsolved Universe: Challenges for the Fu- ture", aimed at discussing some of the major research programmes and objec- tives for the next decades. The scientific programme included the plenary ses- sions (invited reviews and highlight talks), whose contributions are published in this book, and several workshops on more specific topics.

This book is a comprehensive reference on differential geometry. It shows that Maxwell, Dirac and Einstein fields, which were originally considered objects of a very different mathematical nature, have representatives as objects of the same mathematical nature. The book also analyzes some foundational issues of relativistic field theories. All calculation procedures are illustrated by many exercises that are solved in detail.

Relativistic quantum electrodynamics, which describes the electromagneticinteractions of electrons and atomic nuclei, provides the basis for modeling the electronic structure of atoms, molecules and solids and of their interactions with photons and other projectiles. The theory underlying the widely used GRASP relativistic atomic structure program, the DARC electron-atom scattering code and the new BERTHA relativistic molecular structure program is presented in depth, together with computational aspects relevant to practical calculations. Along with an understanding of the physics and mathematics, the reader will gain some idea of how to use these programs to predict energy levels, ionization energies, electron affinities, transition probabilities, hyperfine effects and other properties of atoms and molecules.

This Brief presents a new way of introducing relativity theory, in which perplexing relativistic effects such as time dilation and Lorentz contraction are explained prior to the discussion of Lorentz-transformation. The notion of relativistic mass is shown to contradict the spirit of relativity theory and the true significance of the mass-energy relation is contrasted with the popular view of it. The author discusses the twin paradox from the point of view of both siblings. Last but not least, the fundamentals of general relativity are described, including the recent Gravity Probe B experiment.

This volume is composed of extensive and detailed notes from the lectures given at the 40th Karpacz Winter School. This school focussed on quantum gravity phenomenology with emphasis on its relation to observational astrophysics and cosmology. These notes have been carefully edited with the aim to give advanced students and young researchers a balanced and accessible introduction to a rather heavily mathematical subject.

Each contribution is an article in itself, and great effort has been made by the authors to be lucid and not too technical. A few brief highlights of the round-table discussions are given between the chapters.

Topics include: Quantum non-locality, the measurement problem, quantum insights into relativity, cosmology and thermodynamics, and possible bearings of quantum mechanics to biology and consciousness. Authors include Yakir Aharanov and Anton Zeilinger, plus Nobel laureates Anthony J. Leggett (2003) and Gerardus t Hooft (1999).

Foreword written by Sir Roger Penrose, best-selling author (The Emperor's New Mind) and world-renowned mathematical physicist.

Back in1954,a paper[2] by Bondi and Gold was to pick upona much olderqu- tion and raise anew one that would trigger another longdebate. The old question hadbeenaroundsince the beginning of the twentiethcentury, whenBorn?rstraised it[1] and others followed suit. This was the question of whethera uniformly acc- erated charge (in?at spacetime) would radiateelectromagnetic energy. The new question arose from the claim by Bondi and Gold that (inthe contextof general relativity now)a static charge ina static gravitational ?eld cannot radiateenergy. If this were the case,thenaparticular version of the equivalence principle would thereby be contradicted. This book reviews the problem discovered by Bondi and Gold and discusses the ensuingdebate ascarried on by Fulton and Rohrlich [3], DeWitt and Brehme [4], Mould [5], Boulware [6], andParrott [7].Various solutionshave been proposed by the above (and otherswhoare not discussed here). One of the aims here will be to putforward arather different solution to Bondi and Gold's radiation problem. So eventhough the paperscited are discussed to a large extent in chronological order, the reason for writing this is not justto produce an historical reference. Andeven though the version of general relativity applied hereis entirely consensual, every one of these papersis criticised on at leastoneimportant count, soI suspectthat the resultas a whole should not be described asconsensual.

This thoroughly revised 5th edition of Zeh's classic text investigates irreversible phenomena and their foundation in classical, quantum and cosmological settings. It includes new sections on the meaning of probabilities in a cosmological context, irreversible aspects of quantum computers, and various consequences of the expansion of the Universe. In particular, the book offers an analysis of the physical concept of time.