NASA's Advanced Composition Explorer (ACE) was launched on August 25, 1997, carrying six high-resolution spectrometers that measure the abundances of the elements, isotopes, and ionic charge states of energetic nuclei in space. Data from these instruments is being used to measure and compare the composition of the solar corona, the nearby interstellar medium, and cosmic-ray sources in the Galaxy, and to study particle acceleration processes in a variety of environments. ACE also includes three instruments that monitor solar wind and energetic particle activity near the inner Lagrangian point, "1.5 million kilometers sunward of Earth, and provide continuous, real-time data to NOAA for use in forecasting space weather. Eleven of the articles in this volume review scientific progress and outline questions that ACE will address in solar, space-plasma, and cosmic-ray physics. Other articles describe the ACE spacecraft, the real-time solar-wind system, and the instruments used to measure energetic particle composition.

This unique volume contains the proceedings of two "Non-Sleeping Universe" conferences: "Stars and the ISM" and "From Galaxies to the Horizon." The book provides an overview of recent developments in a variety of areas, covering a very wide range of spatial and temporal scales.

Radio surveys play an important role in observational cosmology. However, until recently the surveys have been either of wide area but with low sensitivity or of small area with high sensitivity. Both limit the kinds of cosmology that can be carried out with radio surveys. This situation has been revolutionised in the past few years by the availability of new, large-area, high-sensitivity radio surveys at both low and high radio frequencies. These significant improvements allow studies based on both the statistics of the surveys themselves and multiwavelength follow-up of the galaxies and AGN responsible for the radio emission. It is therefore an opportune time to summarise progress in this field with a workshop. This book comprises the proceedings of the `Observational Cosmology with the New Radio Surveys' workshop, held on Tenerife, January 13-15, 1997. Topics covered include: lessons learned and important results from earlier surveys, descriptions of some of the new surveys, clusters of galaxies and large-scale structure, radio source evolution, CMB studies, gravitational lensing and multiwavelength studies of distant radio sources.

The last decade has been witness to many exciting and rapid developments in the fields of Nuclear Physics and Intermediate Energy Physics, the interface between Nuclear and Elementary Particle Physics. These developments involved to a large extent the sub nucleonic degrees of freedom in nuclei. In deep inelastic lepton scattering from nuclei, for example, it was observed that the quark structure of the nucleon is influenced by the nuclear medium. Also, the spin-dependent structure function of the nucleon was found to differ from sum rules based on SU(3) symmetry, a discrepancy referred to as the "spin crisis". In pion electroproduction at threshold and in the production of pions and other mesons in heavy ion collisions at intermediate energies interesting experimental results have been obtained, which triggered lively theoretical discussions. Furthermore, the search for the quark-gluon plasma phase of hadronic matter, a phase that is supposed to have existed in the first few seconds of the Big Bang, has been intensified. Not only were these developments accompanied by technical developments, such as the building of new experimental facilities, but also extensive theoretical efforts have been directed towards understanding these phenomena. These concerted efforts will hopefully lead to an understanding of the transition from the non-perturbative QCD regime to the perturbative one, in which the quark structure of nucleons is better understood. All of the aforementioned developments occur at a high pace, making it difficult to incorporate them into the courses offered to advanced students.

The twenty-second Coral Gables conference "UNIFIED SYMMETRY: In the Small and In the Large" continued with the efforts to unify the small and the large. The information gathered with the Huble telescope has in part, in the absence of the SCC , provided a basis for the physicists to unify cosmology and elementary particle physics. The congressional cancellation of the biggest experimental project on the frontiers of physics should not be regarded as an insurmountable obstacle to progress in theoretical physics. The physicists' rise to prominence was mostly reached through their creation of the nuclear era. The post cold war era has somewhat reduced the political, military, and, in part, the social role of the physicist. Some in the administration and the Congress would like physicists to focus on the directly utilitarian aspects of science. Thus, some people do not realize that this regimentation of science would inhibit the creativity. The contributions of solid state physics research to the advancement of technology is the result of physics freely pursued independently of its applications. Modern Physics beginning with Newton's theory of gravity has enabled us to create the space age, to contribute to various technologies, and to impact on our technological modus vivendi.

The nature of time has long puzzled physicists and philosophers. Time potentially has very fundamental yet unknown properties. In 1993 a new model of multi-dimensional time was found to relate closely to properties of the cosmological redshift. An international conference was subsequently convened in April 1996 to examine past, current and new concepts of time as they relate to physics and cosmology. These proceedings incorporate 34 reviews and contributed papers from the conference. The major reviews include observational properties of the redshift, alternative cosmologies, critical problems in cosmology, alternative viewpoints and problems in gravitation theory and particle physics, and new approaches to mathematical models of time. Professionals and students with an interest in cosmology and the structure of the universe will find that this book raises critical problems and explores challenging alternatives to classical viewpoints.

The International Conference "Primordial Nucleosynthesis and Evolution of Early Universe" was held in the presence of Prof. William Fowler on 4 - 8 September 1990 at the Sanjo Conference Hall, the University of Tokyo. This conference was co-sponsored by IUPAP, the International Union of Pure and Applied Physics, and by the University of Tokyo. The number of participants was 156, 58 from 15 foreign countries and 98 from Japan. About 120 contributions were submitted orally or as posters. Originally this conference was planned as a small gathering on Primordial Nucleosynthesis as indicated in the title, since primordial nucleosynthesis is the most important probe of the early stage of the universe. As is well known, light element abundances strongly depend on the time evolution of temperature and density. In this sense we can say that primordial nucleosynthesis is both the thermometer and speedometer of the early universe. Moreover, recently it has been claimed that primordial nucleosynthesis is an indicator of inhomogeneity of the early universe too. Now research of the primordial nucleosynthesis is in a boom. We, however, decided to include observational cosmology, of observations. taking into account the recent remarkable results Nowadays, to reveal the large scale structure of the universe and discover its origin is a main subject in cosmology. We invited distinguished scientists from all over the world, and very fortunately almost all these people accepted to attend this conference.

This volume consists of invited lectures and seminars presented at the NATO Advanced Study Institute "The Infrared and Submillimetre Sky after COBE", which was held at the Centre de Physique Theorique of Les Houches (France) in March 1991. The school has been planned by a Scientific Organizing Committee. It was organized with the aim of providing students and young researchers with an up-to-date account of the Cosmic Microwave Background, the Cosmic Infrared Background (if any), and the infrared emission of the Galaxy, after the early results from COBE (Cosmic Background Explo- rer). It was attended by about sixty researchers from many countries. The lectures and seminars represent a complete coverage of our present knowledge and understanding of: the Early Universe, Large-Scale Structure, Dust in Galaxies, Infrared to Submillimetre Backgrounds, CMB Anisotropies, complementary observations and instrumentation problems, etc. Most of these lectures are reproduced in this volume. Unfortunately, a few lecturers have chosen not to submit their manuscript. I would like to express my gratitude to the Scientific Affairs Division of NATO (North Atlantic Treaty Organization) and to the Theoretical Physics and Astrophysics Sections of the CNRS (Centre National de la Re- cherche Scientifique) for their generous support. Further help was obtain- ed from the DRET (Direction des Recherches, Etudes et Techniques), the CNES (Centre National d'Etudes Spatiales) and the IN2P3 (Institut Natio- nal de Physique Nuc1eaire et de Physique des Particules), which I hereby gratefully acknowledge.

Scheibe is one of the most important philosophers of science in Germany. He has written extensively on all the problems that confront the philosophy of physics: rationalism vs. empiricism; reductionism; the foundations of quantum mechanics; space-time, and much more. Since little of his work has been translated into English, he is not yet well known internationally. However, this collection of some 40 of his papers will remedy this unfortunate situation.

Clusters and superclusters of galaxies are the largest objects in the Universe. They have been the subject of intense observational studies at a variety of wavelengths, from radio to X-ray which has provoked much theoretical debate and advanced our understanding of the recent evolution of the large-scale structure of the Universe. The current status of the subject is reviewed in this volume by active researchers who lectured at a NATO Advanced Study Institute held in Cambridge, England in July 1991. Much of the material is presented in a pedagogical manner and will appeal to scientists, astronomers and graduate students interested in extragalactic astronomy.

The aim of this book is to present the theory and applications of the relativistic Boltzmann equation in a self-contained manner, even for those readers who have no familiarity with special and general relativity. Though an attempt is made to present the basic concepts in a complete fashion, the style of presentation is chosen to be appealing to readers who want to understand how kinetic theory is used for explicit calculations. The book will be helpful not only as a textbook for an advanced course on relativistic kinetic theory but also as a reference for physicists, astrophysicists and applied mathematicians who are interested in the theory and applications of the relativistic Boltzmann equation.

For the Sixth Course of the International School of Cosmology and Gravitation of the "Ettore Maj orana" Centre for Scientific Cul- ture we choose as the principal topics torsion and supergravity, because in our opinion it is one of the principal tasks of today's theoretical physics to attempt to link together the theory of ele- mentary particles and general relativity. Our aim was to delineate the present status of the principal efforts directed toward this end, and to explore possible directions of work in the near future. Efforts to incorporate spin as a dynamic variable into the foundations of the theory of gravitation were poineered by E. Cartan, whose contributions to this problem go back half a century. Accord- ing to A. Trautman this so-called Einstein-Cartan theory is the sim- plest and most natural modification of Einstein's 1916 theory. F. Hehl has contributed a very detailed and comprehensive analysis of this topic, original view of non-Riemannian space-time. Characteristic of Einstein-Cartan theories is the enrichment of Riemannian geometry by torsion, the non-symmetric part of the otherwise metric-compatible affine connection. Torsion has a impact on the theory of elementary particles. According to V. de Sabbata, weak interactions can be based on the Einstein-Cartan geometry, in that the Lagrangian describing weak interactions and torsion inter-- action possess analogous structures, leading to a unification of weak and gravitational forces.

This volume comprises selected lectures presented in the Ninth Course of the International School ofCosmic-Ray Astrophysics held at the Ettore Majorana Centre in Erice, Sicily, May 7-18,1994. Director ofthe Centre is A. Zichichi, assisted by M. Zaini. Director ofthe School is M. M. Shapiro. 1. P. Wefel was co-director of the Ninth Course, which was also a NATO Advanced Study Institute (ASI), and NATO support is gratefully acknowledged. Devoted to problems and prospects in high-energy astrophysics and cosmology, the major areas explored in this course were: gamma-ray, X-ray, and neutrino astronomies; cosmic rays; pulsars and supernova remnants; and cosmology, as well as cosmogony. Among the principal developments in gamma-ray astrophysics were those generated by the Compton Gamma Ray Observatory. Cosmic neutrinos at MeV energies, i.e., those from the sun and from Supernova 1987a, were discussed, as well as neutrino masses in astrophysics. The source composition ofcosmic rays, and extensive air shower experiments, received special attention. The early universe according to COBE data, and as viewed by theorists ofcosmology, was reviewed. Finally, the connections with particle physics occasioned a timely description ofthe Standard Model ofelementary particles.

The first Asia-Pacific Conference on Few-Body Problems in Physics took place from August 23 to August 28, 1999, at the Noda campus of the Sci ence University of Tokyo in Noda-city and Sawayaka Chiba Kenmin Plaza in Kashiwa-city, a suburb of Tokyo close to the Narita-Tokyo International Air port, with the Frontier Research Center for Computation Sciences (FRCCS) of the Science University of Tokyo as the host institute. The High Energy Accel erator Research Organization (KEK), the Institute of Physical and Chemical Research (RIKEN), the Research Center for Nuclear Physics (RCNP)-Osaka University, the Physical Society of Japan, and the Association of Asia Pacific Physical Societies (AAPPS) supported this conference. The conference was initiated in the Asia Pacific area as a counterpart to the successful European Conference on Few-Body Problems in Physics (APFB99), in addition to the International Few-Body Conference Series and the Few Body Gordon Conference series in North America. The Physics of Few-Body Problems covers, as is well known, systems with finite numbers of particles in contrast to many-body systems with very large numbers of particles. Therefore, it covers such wide fields as mesoscopic, atom-molecular, exotic atom, nucleon, hyperon, and quark-gluon physics, plus their applications."

The Olympia conference Frontiers of Fundamental Physics was a gathering of about hundred scientists who carryon their research in conceptually important areas of physical science (they do "fundamental physics"). Most of them were physicists, but also historians and philosophers of science were well represented. An important fraction of the participants could be considered "heretical" because they disagreed with the validity of one or several fundamental assumptions of modern physics. Common to all participants was an excellent scientific level coupled with a remarkable intellectual honesty: we are proud to present to the readers this certainly unique book. Alternative ways of considering fundamental matters should of course be vitally important for the progress of science, unless one wanted to admit that physics at the end of the XXth century has already obtained the final truth, a very unlikely possibility even if one accepted the doubtful idea of the existence of a "final" truth. The merits of the Olympia conference should therefore not be judged a priori in a positive or in a negative way depending on one's refusal or acceptance, respectively, but considered after reading the actual of basic principles of contemporary science, new proposals and evidences there presented. They seem very important to us.

The NATO Advanced Study Institute "Cosmological Aspects of X-Ray Clus ters of Galaxies" took place in Vel en, Westphalia, Germany, from June 6 to June 18, 1993. It addressed the fruitful union of two topics, cosmology and X-ray clus ters, both of which carry substantial scientific weight at the beginning of the last decenium of the last century in the second millenium of our era. The so far largest X-ray "All-Sky Survey," observed by the ROSAT X-ray satel lite, and ROSAT's deep pointed observations, have considerably enlarged the base of X-ray astronomy, particularly concerning extragalactic sources. Cosmology has gained significant impetus from the large optical direct and spectroscopic surveys, based on high quality 2-dimensional receivers at large telescopes and powerful scan ning devices, harvesting the full information 1 content from the older technique of employing photographic plates. Radioastronomy and IR-astronomy with IRAS, as well as r-astronomy with GRO, continue and strengthen the role of extragalactic research. The rapidly growing computer power in data reduction and data storage facilities support the evolution towards large-number statistics. A most significant push was given to early cosmology by the needs of physics in trying to unravel the nature of forces which govern our material world. The topic of the ASI was chosen because it opens new vistas on this for ever new problem: the universe. Clusters of galaxies probe large-scale matter distributions and the structure of space-time."

In this book are reported the main results presented at the "Fourth International Workshop on Data Analysis in Astronomy," held at the Ettore Majorana Center for Scientific Culture, Erice, Sicily, Italy, on April 12-19, 1991. The Workshop was preceded by three workshops on the same subject held in Erice in 1984, 1986 and 1988. The frrst workshop (Erice 1984) was dominated by presentations of "Systems for Data Analysis"; the main systems proposed were MIDAS, AlPS, RIAIP, and SAIA. Methodologies and image analysis topics were also presented with the emphasis on cluster analysis, multivariate analysis, bootstrap methods, time analysis, periodicity, 2D photometry, spectrometry, and data compression. A general presentation on "Parallel Processing" was made which encompassed new architectures, data structures and languages. The second workshop (Erice 1986) reviewed the "Data Handling Systems" planned for large major satellites and ground experiments (VLA, HST, ROSAT, COMPASS-COMPTEL). Data analysis methods applied to physical interpretation were mainly considered (cluster photometry, astronomical optical data compression, cluster analysis for pulsar light curves, coded aperture imaging). New parallel and vectorial machines were presented (cellular machines, PAPIA-machine, MPP-machine, vector computers in astronomy). Contributions in the field of artificial intelligence and planned applications to astronomy were also considered (expert systems, artificial intelligence in computer vision).

I have been asked by Professor Kikuchi to write a foreword for this interesting book on Dusty Plasmas and other electrical phenomena. This was a somewhat daunting task due to the wide range of topics covered. In what follows I have attempted to summarize most of these topics; for this purpose I have divided them into four groups, namely (a) Dusty Plasmas, (b) The Electrical Environment, (c) Lightning and (d) The Noise Environment. I hope that I have succeeded. in indicating that each section contains much that is of great interest. It is perhaps unnecessary for me to point out that the book contains subjects which are at an exciting and important stage in their development. (a) Dusty Plasmas The subject of dusty plasmas is one of great interest. Dust particles in interplanetary space, within comets, in inter-stellar space and at ever greater distances will in general be charged. The plasma environment will ensure this, bombarding electrons will charge up the particle until it assumes a "floating potential," although time variation can occur. Ultra violet radiation can cause photoemission and in certain cases field emission is a possibility. The motion of the particles will be determined by electric and magnetic fields together with gravity. If the density of charged grains becomes sufficiently high the grains will interact with each other and collective behaviour will ensue. This newly evolving subject entails the study of all kinds of plasma waves.

ROSAT Observations G. HASINGER Max-Planck-Institut flir extraterrestrische Physik, D-85740 Garching, Germany Abstract. This review describes the most recent advances in the study of the extragalactic soft X-ray background and what we can learn about its constituents. The deepest pointed observations with the ROSAT PSPC are discussed. The logN-logS relation is presented, which reaches to the faintest X-ray fluxes and to the highest AGN surface densities ever achieved. The N(>S) relation shows a 2 density in excess of 400 deg- at the faintest fluxes and a flattening below the Einstein Deep Survey limit. About 60% of the extragalactic background has been resolved in the deepest field. Detailed source spectra and first optical and radio identifications will be discussed. The results are put into perspective of the higher energy X -ray background. Key words: X-rays, background radiations, active galactic nuclei. 1. Introduction The extragalactic X-ray background (XRB), discovered about 30 years ago, has been studied extensively with many X-ray experiments, in particular with the satel lites HEAO I and II (see ego Boldt 1987) and with ROSAT (e. g. Hasinger et aI. , 1993). Figure 1 shows a compilation of some of the most recent spectral measure ments for the X-ray background. Over the energy range from 3 to about 100 keY its spectrum can be well approximated by an optically thin thermal bremsstrahlung model with kT ~ 40 keY, while at lower X-ray energies a steepening into a new component has been observed observed (e. g.

This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves near a target edge at a distance ( - Lorentz factor, - wave length). Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results.

In June of 1996, at the idyllic seaside resort of Guaruja, Brazil, a renowned group of researchers in space and astrophysical plasmas met to provide a forum on Advanced Topics on Astrophysical and Space Plasmas at a school consisting of some 60 students and teachers, mainly from Brazil and Argentina, but also from all the other parts of the globe. The purpose was to provide an update on the latest theories, observations, and simulations of space-astrophysical plasma phenomena. The topics covered included space plasma mechanisms for particle acceleration, nonthermal emission in cosmic plasma, magnetohydrodynamic instabilities in solar, interstellar, and other cosmic objects, magnetic field line reconnection and merging, the nonlinear and often chaotic structure of astrophysical plasmas, and the advances in high performance supercomputing resources to replicate the observed phenomena. The lectures were presented by Professor Mark Birkinshaw of the Harvard-Smithsonian Center for Astrophysics and the University of Bristol; Dr Anthony Peratt, Los Alamos National Laboratory Scientific Advisor to the United States Department of Energy; Dr Dieter Biskamp of the Max Planck Institute for Plasma Physics, Garching, Germany; Professor Donald Melrose, Director, Centre for Theoretical Astrophysics, University of Sydney, Australia; Professor Abraham Chian of the National Institute for Space Research, Brazil; and Professor Nelson Fiedler-Ferrara of the University of Sao Paulo, Brazil. As summarized by Professor Reuven Opher, Institute of Astronomy and Geophysics, University of Sao Paulo, the advanced or interested student of space and astrophysical plasmas will find reference to nearly all modern aspects in the field of Plasma Astrophysics and Cosmology in the presented lectures.

It is with great joy that we present a collection of essays written in honour of Jayant Vishnu Narlikar, who completed 60 years of age on July 19, 1998, by his friends and colleagues, including several of his for mer students. Jayant has had a long research career in astrophysics and cosmology, which he began at Cambridge in 1960, as a student of Sir Fred Hoyle. He started his work with a big bang, expounding on the steady state theory of the Universe and creating a new theory of gravity inspired by Mach's principle. He also worked on action-at-a-distance electrodynamics, inspired by the explorations of Wheeler, Feynman and Hogarth in that direction. This body of work established Jayant's rep utation as a bold and imaginative physicist who was ever willing to take a fresh look at fundamental issues, undeterred by conventional wis dom. This trait, undoubtedly inherited from his teacher and mentor, has always remained with Jayant. It is now most evident in his untir ing efforts to understand anomalies in quasar astronomy, and to develop the quasi-steady state cosmology, along with a group of highly distin guished astronomers including Halton Arp, Geoffrey Burbidge and Fred Hoyle. In spite of all this iconoclastic activity, Jayant remains a part of the mainstream; he appreciates as well as encourages good work along conventional lines by his students and colleagues. This is clear from the range of essays included in this volume, and the variety and distribution of the essayists.

Today many scientists recognize plasma as the key element in understanding new observations in interplanetary and interstellar space, in stars, galaxies, and clusters of galaxies, and throughout the observable universe. Plasma astrophysics and cosmology, as a unified discipline, cover topics such as the large scale structure and filamentation of the universe; the microwave background; the formation of galaxies and magnetic fields; active galactic nuclei and quasars; the origin and abundance of light elements; star formation and the evolution of solar systems; redshift periodicities and anomalous redshifts; general relativity; electric fields; the acceleration of charged particles to high energies; and cosmic rays. Plasma Astrophysics and Cosmology is an update on the observations made in radio, optical, and high-energy astrophysics, especially over the last decade, and addresses the paradigm changing discoveries made by the planetary probes and satellites, radio telescopes, and the Hubble space telescope. Over twenty contributors, all distinguished plasma scientists, present an entirely new picture of the nature of our plasma universe with articles ranging from the popular level to advanced topics in plasma cosmology.

This volume contains the proceedings of the meeting entitled, "The IGM/Galaxy Connection: The Distribution of Baryons at z = 0. " The meeting was held August 8 -10 at the National Center for Atmospheric Research (NCAR) located in Boulder, Colorado on the foothills of the Rocky Mountains (see conference photo). We organized this meeting because we felt it was time to address the link between galaxies and the intergalactic medium at low redshift. In this vein, we posed several questions to the conference participants: Where are the baryons in the local universe and in what phase do they reside? What signatures of galaxy evolution have been imprinted on the IGM? What percentage of intergalactic gas is left from the galaxy formation process? What does the distribution of baryons at z = 0 tell us about the early universe? The conference was an overwhelming success with lots of friendly interaction and discussion among the participants. At lunch we were treated to splendid views from the NCAR terrace and discussions rang ing from the importance of the LSR, GSR, and LGSR velocity frames to how long the desserts would last with 90 astronomers and the hot Boul der sun. From an inventory of the baryons, to the associations between galaxies and Lya absorbers, to the mechanisms by which galaxies obtain and lose gas, the conference covered many topics. The results of these endeavors are contained in these pages and eloquently summarized by Chris Impey.

In recent years there has been a steadily increasing cross-fertilization between cosmology and particle physics, on both the theoretical and experimental levels. Particle physics has provided new experimental data from the big accelerators in operation, and data from space satellites are accumulating rapidly. Cosmology is still one of the best laboratories for testing particle theory. The present work discusses such matters in the context of inflation, strings, dark matter, neutrinos and gravitational wave physics in the very early universe, field theory at the Planck scale, and high energy physics. A particular emphasis has been placed on a new topology for spatial infinity, on the relation between temperature and gravitational potential, a canonical formulation of general relativity, the neutrino mass, spin in the early universe, the measurement of gravity in the 10--100 m range, galaxy--galaxy and cluster--cluster correlation, black holes, string theory and string/string duality. The work also presents a beautiful review of high energy elementary particle physics, treating the meaning, status and perspectives of unification and standard model gauge couplings.