Ptolemy was the most important physical scientist of the Roman Empire, and for a millennium and a half his writings on astronomy, astrology, and geography were models for imitation, resources for new work, and targets of criticism. Ptolemy in Perspective traces reactions to Ptolemy from his own times to ours. The nine studies show the complex processes by which an ancient scientist and his work gained and subsequently lost an overreaching reputation and authority.

Viewed as a flashpoint of the Scientific Revolution, early modern astronomy witnessed a virtual explosion of ideas about the nature and structure of the world. This study explores these theories in a variety of intellectual settings, challenging our view of modern science as a straightforward successor to Aristotelian natural philosophy. It shows how astronomers dealt with celestial novelties by deploying old ideas in new ways and identifying more subtle notions of cosmic rationality. Beginning with the celestial spheres of Peurbach and ending with the evolutionary implications of the new star Mira Ceti, it surveys a pivotal phase in our understanding of the universe as a place of constant change that confirmed deeper patterns of cosmic order and stability.

The physical processes driving the different manifestations of the phe nomenon of active galactic nuclei have been studied extensively during the last decade. A major obstacle in all attempts to understand the relevant pro cesses has always been the wide range of frequencies over which significant fractions of the total power are emitted. During the last decade, orbiting telescopes and instrumental improvements for ground-based instrumenta tion provided the means for major advancements on the observational side. The organizers felt that it was timely to organize a meeting to discuss the impact of this new situation on the understanding of the relevant physical processes. More then 400 astrophysicists were interested in participating in the meeting, in spite of the constraints on overseas travel which were imposed in early 1991. Unfortunately only 220 participants could be hosted by the Max-Planck-Haus, the site of the 1991 Heidelberg conference. The meet ing was organized by Sonderforschungsbereich 328 "Evolution of Galaxies". During 5 sessions, most of which lasted for one day each, 47 invited and con tributed talks and 150 poster papers were given, most, but not all, of which are included in these proceedings. With a few exceptions the order of the written texts follows that of the oral contributions during the meeting. The arrangement of posters into the five sections was not always unambiguous. We hope to have placed them in the most appropriate sections, in which they are listed in alphabetical order.

Because of recent progress in the development of quasistationary toroidal mag- netic confinement systems, especially tokamaks, these systems are at the center of research on controlled thermonuclear fusion. Tokamaks were proposed and first built at the Kurchatov Institute of Atomic Energy. In the 1960s the basic features of plasma behavior in toroidal magnetic confinement systems were investigated in ex- periments on the first tokamaks and the possibility of obtaining effective confine- ment in them was demonstrated. The successes of this first stage led to a rapid ex- pansion in tokamak research around the world. The development of a thermonu- clear power reactor based on the tokamak is now actively under way. During the earliest phase of research on tokamaks, it was already clear that the ohmic heating used in them was not sufficient to obtain the temperatures needed for initiation of a self-sustaining thermonuclear reaction. At the beginning of the 1970s, therefore, a search was begun for methods of heating which could supple- ment ohmic heating. The best of these auxiliary heating techniques are neutral beam injection, various methods based on the collisionless absorption of rf (radio fre- quency) waves, and adiabatic compression of the plasma by a rising magnetic field.

Ram accelerators are among the most advanced tools for generating fluid dynamcis data in supersonic reacting systems. They require the combined action of combustion, wave systems and turbulence and are still a serious challenge for physicists and engineers. This book will serve as an introductionary textbook on ram accelerators and gives a thorough overview on research activities, performance modeling and high-pressure detonation dynamics.

This volume of Astrophysical Data deals with Planets and Stars; a second volume, Part II, will give data for Galaxies and the Universe. They both pro vide basic data for use by all scientists, from the amateur astronomer to the professional astrophysicist. In this first volume, we not only provide physical parameters of planets, stars and their environment, but we also provide the celestial coordinates required to observe them. Here we use c.g.s. units, for they are the most commonly used in astron omy and astrophysics; but our volume begins with astronomical and physical constants and the conversion factors needed for other units. The next section concerns the planets and their satellites; it singles out the Earth and Moon for special treatment. Spacecraft rendezvous with the planets and satellites have led to improved values for their atmospheric compositions, orbital parameters, magnetic fields, masses, radii, rotation periods, and surface pressures and temperatures. This section also contains data for the asteroids, comets and their debris. We then discuss everyday stars, beginning with the Sun, and continuing with basic stellar data, the brightest stars and nearby stars. Special categories of stars, such as the Wolf-Rayet stars, magnetic stars, flare stars, and RS CVn binary stars, are included.

After the launching of the first artificial satellites preceding interplanetary vehicles, celestial mechanics is no longer a science of interest confined to a small group of astronomers and mathematicians; it becomes a special engineering technique. I have tried to set this book in this new perspective, by severely limiting the choice of examples from classical celestial mechanics and by retaining only those useful in calculating the trajectory of a body in space. The main chapter in this book is the fifth, where a detailed solution is given of the problem of motion of an artificial satellite in the Earth's gravitational field, using the methods of Von Zeipel and of Brouwer. It is shown how Lagrange's equations can be applied to this problem. The first four chapters contain proofs of the main results useful for these two methods: the elliptical solution of the two-body problem and the basic algebra of celestial mechanics; some theorems of analytical mechanics; the Delaunay variables and the Lagrangian equations of variation of elements; the expansion of the disturbing function and the Bessel functions necessary for this expansion. The last two chapters are more descriptive in character. In them I have summarized briefly some of the classical theories of celestial mechanics, and have tried to show their distinctive characteristics without going into details.

The Ionospheric Institute of the National Observatory of Athens has had two interests in recent years: the study of the ionosphere and the study of the sun. In our previous Advanced Study Institutes in 1960, 1961, and 1962, we have em phasized the ionosphere. For the Advanced Study Institute of 1964, however, we invited Dr. Jules Aarons of the Air Force Cambridge Research Laboratories to collaborate in preparing and directing a program of studies of the sun, the moon, the planets, and the interplanetary medium. The lectures of this Advanced Study Institute form essentially an advanced course in radio astronomy. Without being a textbook on the matter, we feel that the present book can be considered as an excellent reference for those students starting their research work in the field of solar system radio astronomy. All lecturers tried to present their subjects in a simple form based upon their exten sive personal experience, but without emphasizing their personal research. We must recognize that it was an excellent achievement for them to keep their text exactly at the level indicated by the Program Director, and outlined by the gen eral program of Advanced Study Institutes of NATO. We are deeply grateful to all the invited scientists for their outstanding contributions in lecturing on their subjects in a clear and authoritative manner. The Scientific Affairs Division of NATO, in its aid to basic research, spon sors various programs. Among them is the Program of Advanced Study Institutes."

For this set of lectures we assumed that the reader has a reasonable back ground in physics and some knowledge of general relativity, the modern theory of gravity in macrophysics, and cosmology. Computer methods are present ed by leading experts in the three main domains: in numerics, in computer algebra, and in visualization. The idea was that each of these subdisciplines is introduced by an extended set of main lectures and that each is conceived as being of comparable 'importance. Therefpre we believe that the book represents a good introduction into scientific I computing for any student who wants to specialize in relativity, gravitation, and/or astrophysics. We took great care to select lecturers who teach in a comprehensible way and who are, at the same time, at the research front of their respective field. In numerics we had the privilege of having a lecturer from the National Center for Supercomputing Applications (NCSA, Champaign, IL, USA) and some from other leading institutions of the world; visualization was taught by a visualization expert from Boeing; and in com puter algebra we took recourse to practitioners of different computer algebra systems as applied to classical general relativity up to quantum gravity and differential geometry.

The present NATO Advanced Study Institute held in CARGESE (Corsica) from Au- gust 8th to August 18th, 1989 was devoted to Hadronic Physics. We tried to give this school a key educational role in this new and rapidly developing interdisciplinary field. We hope that the combination of the lectures and the open atmosphere of scientific exchange and inquiry afforded by the Cargese format has provided a unique educational and scien- tific opportunity for students and has brought together all the relevant concepts and issues for frontier research in this field. We would like to express our gratitude to NATO for its generous financial support which made this Institute possible. We also wish to thank Dr. Luis V. Da Cunha, Director of the Scientific Affairs Division, for his valuable comments and advice. We acknowledge the support of the Institut de Physique Nucleaire et de Physique des Particules (France), the Commissariat a l'Energie Atomique (France), and the U.S. National Science Fundation, for the attribution of travel grants. Our special appreciation is due to Frederique Dykstra for her oustanding organiza- tional work throughout the preparation and duration of this conference It is also a pleasure to thank the Universite de Nice for making available the facilities of the Cargese Scientific Institute. The pictures of the lecturers included in the present volume were kindly provided by one of the participants, Dr.R.Janner.

Light scattering and absorption by small homogeneous particles can be worked-out exactly for spheres and infinite cylinders. Homogeneous particles of irregular shapes, when averaged with respect to rotation, have effects that can in general be well-approximated by reference to results for these two idealised cases. Likewise, small inhomogeneous particles have effects similar to homogeneous particles of the same average refractive index. Thus most problems can be solved to a satisfactory approximation by reference to the exact solutions for spheres and cylinders, which are fully stated here in the early part of the book. The sum of scattering and absorption, the extinction, is too large to be explained by inorganic materials, provided element abundances in the interstellar medium are not appreciably greater than solar, H 0 and NH3 being essentially excluded in the 2 general medium, otherwise very strong absorptions near 3p, m would be observed which they are not. A well-marked extinction maximum in the ultraviolet near 2200A has also not been explained satisfactorily by inorganic materials. Accurately formed graphite spheres with radii close to O.02p, m could conceivably provide an explanation of this ultraviolet feature but no convincing laboratory preparation of such spheres has ever been achieve

This volume is a collection of experimental and theoretical papers presented at the international "Topical Meeting on Optical Bistability," held at the University of Rochester, June 15-17, 1983, sponsored jointly by the Air Force Office of Scientific Re search; the Army Research Office; and the Optical Society of America. The Conference, which had 150 attendees, overlapped (on June 15) with the Fifth Rochester Conference on Coherence and Quantum Optics with two joint sessions. Some of the topics cover ed in this volume are also treated io the Proceedings of that Conference. Since the last international conference on Optical Bistability, held in Asheville, North Carolina, June 3-5, 1980, there have been new and important fundamental advances in the field. This is borne out in papers in this volume dealing with optical chaos and period doubling bifurcations leading to chaos as well as the report of results of an experiment using a very simple system exhibiting ab sorptive optical bistability in a ring cavity using optically pump ed sodium atoms, which was successfully analyzed quantitatively by a simple theory. Other advances discussed here include the ob servation of optical bistability due to the effect of radiation pressure on one mirror of a fabry-Perot cavity. and the prediction of mirrorless intrinsic opittal bistability due to the local field correction incorporated into the Maxwell-Bloch formulation. Advances in optical bistability in semiconductors relate closer to actual device applications."

This book deals with the fundamentals of stellar interferometry with emphasis on aperture synthesis using sparse array of telescopes particularly at optical/IR wavelengths, the origin, properties, and optical effects of turbulence in the Earth's atmosphere, techniques developed to overcome image degradation. Studded with more than one hundred and fifty illustrations and tens of footnotes, it addresses the basic tricks of trade, current trend, motivation, methods, and path to future promise of true interferometry both from the ground and space. Also discussed are the technical challenge involved, such as beam transportation and recombination, detecting fringes using modern sensors, and image synthesis. Astronomical science that benefits from aperture synthesis imaging are highlighted as well.

The General Assemblies of the International Astronomical Union are landmarks in the life of the world-wide astronomical community, as they review, at triennial intervals, the progress made in this scientific field, promulgate the most spect acular astronomical achievements, formulate scientific programmes for the years to come and, last but not least, deal with the administration and finances of the IAU. The Reports on Astronomy 1976, published as Transactions XVIA (in 3 volumes) before the XVlth General Assembly, are a synopsis of the work done in astronomy from 1973 to 1975. The volume "Highlights of Astronomy, as presented at the XVlth General As sembly of the IAU in Grenoble, 1976" includes some selected scientific topics, and will appear in the first half of 1977. Apart from the Invited Discourses and the Proceedings of the seven Joint Discussions, the Highlights volume No.4 con tairsthe proceedings of two Joint Commissions Meetings."

These proceedings are the result of a three-day meeting held in Oogliani (Italy), on October 2-4 2003, whose title was "VIrtual Astrophysical Jets 2003". Our goal in convening this meeting was to gather some of the scientists among the most active in the field of numerical simulations and modelling of astrophysi cal jets. For keeping the participants close to the "real world", we also invited a few observers to give up-to-date reviews outlining the state-of-the-art of jet observations. The principal aim of the meeting was thus to present and critically discuss the state-of-the-art numerical simulations, analytical models and laboratory ex periments for reproducing the main aspects of astrophysical jets and compar ing them with observations. The discussion has been focused on the following topics: * Observations and intepretions of jets from young stars and AGNs, comparisons of models with observations; * MHO accelerations of jets: steady self-similar models, MHO numerical simula tions of time-dependent accelerations mechanisms; * Jet stability and interaction with the ambient: formation of knots in YSO jets, jet survival to instabilities, deceleration of relativistic jets in FRI sources, simulations of jets-IGM interactions, jets propagation and galaxy formation; * Numerical codes and their validation: relativistic MHO codes, comparisons among different numerical schemes, jets in the laboratory and code validation. These topics have been discussed intensively during the meeting, and the out come of these discussions is presented in this volume. The contributions have been divided in five sections.

The last decades have marked the beginning of a new era in Celestial Mech- ics. The challenges came from several di?erent directions. The stability theory of nearly-integrable systems (a class of problems which includes many models of - lestial Mechanics) pro?ted from the breakthrough represented by the Kolmogorov- Arnold-Moser theory, which also provides tools for determining explicitly the - rameter values allowing for stability. A con?nement of the actions for exponential times was guaranteed by Nekhoroshev's theorem, which gives much information about the geography of the resonances. Performing ever-faster computer simu- tionsallowedustohavedeeperinsightsintomanyquestionsofDynamicalSystems, most notably chaos theory. In this context several techniques have been developed to distinguish between ordered and chaotic behaviors. Modern tools for computing spacecraft trajectories made possible the realization of many space missions, es- cially the interplanetary tours, which gave a new shape to the solar system with a lot of new satellites and small bodies. Finally, the improvement of observational techniques allowed us to make two revolutions in the sky: the solar system does not end with Pluto, but it extends to the Kuiper belt, and the solar system is not unique, but the universe has plenty of extrasolar planetary systems. Cookingalltheseingredientstogetherwiththeclassicaltheoriesdevelopedfrom the 17th to the 19th centuries, one obtains themodern Celestial Mechanics.

decision and investigative process of the scientist, they can also wri te the paragra}ils of scientific resul ts. Once a canputer research activity progresses from intuitive guesses to a systematic study, the canputer program can free the scientist to pursue new original ideas. '!his concept is illustrated in the ptper by Hut. Sussnan says "Knowledge" is knowing what not to canpute. His main message is that we must change from trying to maximize the efficiency of the canputer to maximizing the effectiveness of the scientist. The canputer is relatively cheap, it is the trained scientist who is most valuable. In the second keynote address, R. L. Duncombe (University of Texas) described the "Early Applications of Canputer Technology to Dynamical Astronany. " His talk traced the worldwide introduction of punched card equipnent and their applications through the use of the first electronic canputers. Sussman and Duncombe, therefore, provided a forecast and review of the use of computers in dynamical astronany. This proceedings is intended to provide a consolidated general view of the ptst, present, and future of the Applications of Canputer Technology to Dynamical Astronany. Of necessity this requires that the ptpers be rela ti vely short and provide references to the more canplete discussions. Thanks to the representa tion from so many different countries the proceedings give a picture of the activities worldwide. The Scientific Organizing Comnittee included K. B. IIlatnagar, V. A. Brtmberg, G. Contopoulos, A. Depri t , J. Henrard, J. Kovalevsky, Y.

Neutrinos play an intriguing role in modern physics linking central questions of particle physics, cosmology and astrophysics. The contributions in this book reflect the present status of neutrino physics with emphasis on non-accelerator or beyond-accelerator experiments. Since a nonvanishing neutrino mass would yield an important boundary condition for GUT, SUSY or Superstring models and since neutrinos are the best candidates for dark matter in the universe, the many efforts to look for a neutrino mass, ranging from neutrino oscillation experiments using reactors, accelerators or the sun as neutrino sources, to tritium decay experiments and the search for neutrinoless double beta decay, are described in some detail. One of the sections is devoted to neutrinos from collapsing stars, including the supernova SN 1987 A. Possibilities for detecting cosmological neutrinos are discussed and an outlook to future experiments is given.

The 2nd International Conference on Space Engineering took place May 7-10, 1969, at Venice, Italy, under the organization of the Centro Studi Trasporti Missilistici and the Association pour l'Etude et la Recherche Astronautique et Cosmique. Its purpose was to bring together those interested in the technological development of space components, to exchange information by the presentation of papers and to discuss present problems and future trends, and to this end forty-eight papers were presented by distinguished experts from all over the world. The papers were selected from as wide a background as possible, approximately an equal number coming from the academic and research establishments as from industry. The principal criterion for their selection was that they should contribute to the knowledge of Space Engineering, and have application either to the improve ment of current technologies or to the design of more advanced systems for the future. Six pertinent sessions were planned which covered the major areas of interest: (1) Structures and Materials, where three important papers were presented; (2) Guidance and Control Systems, in which six valuable papers were presented, in cluding problems of controlling space ships, details of the inertial guidance system of the ELDO launch vehicle, the attitude control system of the "Europa 2"; (3) Propellants and Combustion, where eleven papers described recent work on solid and liquid rocket engines, advanced fuels and oxidizers, effects of additives, propellant injection, propellant expulsion techniques; (4) Propulsion, in which session ten papers"

IAU Transactions are published as a volume corresponding to each General Assembly. Volume A is produced prior to the Assembly and contains Reports on Astronomy, prepared by each Commission President. The intention is to summarize the astronomical results that have affected the work of the Commission since the production of the previous Reports up to a time which is about one year prior to the General Assembly. Volume B is produced after the Assembly and contains accounts of Commission Meetings which were held, together with other material. The reports included in the present volume range from outline summaries to lengthy compilations and references. Most reports are in English.

The second workshop on High Energy Astrophysics of the Ma..x-Planck-Society and the Academia Sinica was held at Ringberg Castle near Tegernsee during the week July 12-July 17, 1987. It is the purpose of these workshops to en courage the exchange of ideas between German and Chinese astrophysicists (scientists from other countries are also welcome, of course), and the pleas ant atmosphere and surroundings of Ringberg Castle certainly helped the development of relaxed and stimulating discussions. In addition, we seemed to have picked out the one week of perfect weather during a rainy summer. Thanks are due to Mr. Hormann and his staff for creating a perfect infra structure. The proceedings have required a considerable amount of editing, and I hope that all the papers are comprehensible. Thanks are due to Miss Petra Berkemeyer and Miss Hannelore Muller, who patiently retyped several manu scripts and helped with other editing jobs. I did not feel that a sharp refer eeing procedure should be done, although I do not agree with all the papers in this volume. The interested reader will find that this book gives a fair account of the present status of Chinese activities in the field of high energy astrophysics, i.e. in supernova physics, accretion onto compact objects, active galaxies, and cosmology."

The last two subjects mentioned in the title "Wavelets" are so well established that they do not need any explanations. The first is related to them, but a short introduction is appropriate since the concept of wavelets emerged fairly recently. Roughly speaking, a wavelet decomposition is an expansion of an arbitrary function into smooth localized contributions labeled by a scale and a position pa rameter. Many of the ideas and techniques related to such expansions have existed for a long time and are widely used in mathematical analysis, theoretical physics and engineering. However, the rate of progress increased significantly when it was realized that these ideas could give rise to straightforward calculational methods applicable to different fields. The interdisciplinary structure (R.c.P. "Ondelettes") of the C.N .R.S. and help from the Societe Nationale Elf-Aquitaine greatly fostered these developments. This conference was held at the Centre National de Rencontres Mathematiques (C.I.R.M) in Marseille from December 14 to 18, 1987 and brought together an interdisciplinary mix of participants. We hope that these proceedings will convey to the reader some of the excitement and flavor of the meeting.

In the 18th century, purely scientific interests as well as the practical necessities of navigation motivated the development of new theories and techniques to accurately describe celestial and lunar motion. "Between Theory and Observations" presents a detailed and accurate account, not to be found elsewhere in the literature, of Tobias Mayer's important contributions to the study of lunar motion-including the creation of his famous set of lunar tables, which were the most accurate of their time.

Modern observations, including recent ones with the Hubble Space Telescope, have revealed that the Universe is replete with plasma outflows from all kinds of objects, ranging from stars in all their variety to galaxies. In this masterly survey of plasma astrophysics, written by leading practitioners, the first 15 articles in Part I deal with the use of the MHD approach in several key problems of solar plasma, such as magnetoconvection and magnetic field generation, sunspots and coronal loops, magnetic nonequilibrium and coronal heating, coronal mass ejections, the acceleration of the solar wind, and stellar winds across the Main Sequence. The following 16 articles of Part II deal with the use of the same MHD approach in several central and puzzling aspects of more distant astrophysical plasmas, such as the dynamics of the interstellar medium, collimated outflows from young stellar objects and accretion disks, molecular outflows and jets associated with enigmatic binaries and symbiotic stars, relativistic flows associated with superluminal microquasars in our own galaxy, astrophysical jets from nearby galaxies, or remote active galactic nuclei and quasars, probably fuelled by supermassive black holes. The emphasis throughout is on the striking underlying similarities in the physics of all these problems. Audience: Indispensable for solar physicists and astrophysics alike. An ideal textbook for graduate students in physics and astrophysics.