Starting in 1995 numerical modeling of the Earth's dynamo has ourished with remarkable success. Direct numerical simulation of convection-driven MHD- ow in a rotating spherical shell show magnetic elds that resemble the geomagnetic eld in many respects: they are dominated by the axial dipole of approximately the right strength, they show spatial power spectra similar to that of Earth, and the magnetic eld morphology and the temporal var- tion of the eld resembles that of the geomagnetic eld (Christensen and Wicht 2007). Some models show stochastic dipole reversals whose details agree with what has been inferred from paleomagnetic data (Glatzmaier and Roberts 1995; Kutzner and Christensen 2002; Wicht 2005). While these models represent direct numerical simulations of the fundamental MHD equations without parameterized induction effects, they do not match actual pla- tary conditions in a number of respects. Speci cally, they rotate too slowly, are much less turbulent, and use a viscosity and thermal diffusivity that is far too large in comparison to magnetic diffusivity. Because of these discrepancies, the success of geodynamo models may seem surprising. In order to better understand the extent to which the models are applicable to planetary dynamos, scaling laws that relate basic properties of the dynamo to the fundamental control parameters play an important role. In recent years rst attempts have been made to derive such scaling laws from a set of numerical simulations that span the accessible parameter space (Christensen and Tilgner 2004; Christensen and Aubert 2006).

It is this editor's distinct pleasure to offer to the readership the text of the lectures presented at our recent NATO Advanced Study Institute held in Cortina d'Ampezzo, Italy between August 6 and August 17, 1984. The invited lectures are printed in their entirety while the seminar contributions are presented as abstracts. Our Advanced Study Institutes were originated in 1972 and the reader, familiar with periodic phenomena, so important in Celestial Mechanics, will easily establish the fact that this Institute was our fifth one in the series. We dedicated the Institute to the subject of stability which itself is a humbling experience since it encompasses all fields of sciences and it is a basic element of human culture. The many definitions in existence and their practical applications could easily fill another volume. It is known in this field that it is easy to deliver lectures or write papers on stability as long as the definition of stability is carefully avoided. On the other hand, if one selects a definition, he might be criticized for using that definition and not another one. In this volume we carefully defined the specific concept of stability used in every lecture. If the reader wishes to introduce other definitions we feel that he should be entirely free and we encourage him to do so. It is also known that certain sta bility definitions and concepts are more applicable to certain given fields than to others."

On the 6th, 7th' and 8th April 1983, a conference entitled "Magnetism, planetary rotation and convection in the Solar System" was held in the School of Physics at the University of Newcastle upon Tyne. The purpose of the meeting was to celebrate the 60th birthday of Prof. Stanley Keith Runcorn and his, and his students' and associates', several decades of scientific achievement. The social programme, which consisted of excursions in Northumberland and Durham with visits to ancient castles and churches, to Hexham Abbey and Durham Cathedral, and dinners in Newcastle and Durham, was greatly enjoyed by those attending the meeting and by their guests. The success ofthe scientific programme can be judged by this special edition of Geophysical Surveys which is derived mainly from the papers given at the meeting. The story starts in the late 1940s when the question of the origin of the magnetic field of the Earth and such other heavenly bodies as had at that time been discovered as having a magnetic field, was exercising the minds of several scientists; notably P. M. S. Blackett at Manchester, W. M. Elsasser at the University of Pennsylvania and E. C. Bullard at Cambridge. Two alternative mechanisms were proposed. In one the magnetic field was in some way connected with the distributed angular momentum of a rotating body; in the other, electric currents in conducting parts within the body were proposed as the source of magnetic field.

This 1986 book presents a series of computer-drawn maps and tables for all total and annular eclipses of the Sun calculated to have been observable in East Asia in the 3400 years from 1500 BC to AD 1900. The study of past eclipses is a useful tool in both geophysics and chronology, for example in determining the long-term behaviour of the Earth's rate of rotation. The eclipses of the Sun that occurred in East Asia - notably in China, Korea and Japan - are particularly useful because numerous reliable written records of them are extant. The book will be of interest to professional astronomers whose work can benefit from long-term historical data, especially those interested in studying the Earth's rotation and to historians of Chinese astronomy. It will be an essential reference work for research libraries.

Plant hormone research is the favorite topic of physiologists. Past three decades have witnessed that this subject has received much attention. The inquisitive nature of human mind has pumped much in literature on this subject and this volume is the product of such minds. In the following pages various hormonal-controlled physiological processes like, flowering, seed dormancy and germination, enzyme secretion, senes cence, ion transport, fruit ripening, root growth and development, thig momorphogenesis and tendril thigmonasty have been included. The volume also contains a review paper on 'Growth Regulating Activity of Penicillin in Higher Plants' and has been presented for the first time. The vast contents of each review paper have been written by erudite scholars who have admirably carried out their evangelic task to make the text up TO date. This volume, I am sure, would stimulate the appetite of researchers of peripheral disciplines of botany and agricultural sciences and they will continue to enjoy the fun and adventures of plant hormone research. Save one. my most outstanding debts are due to the rich array of the contributors and other plant physiologists specially to Prof. Thomas Gaspar (Belgium), Prof. E. E. Goldschmidt (Isreal), Prof. H. Greppin (Switzerland), Dr. K. Gurumurti (India), Prof. M. A. Hall (U. K. ), Prof. H. Harada (Japan), Dr. M. Kaminek (Czechoslovakia), Dr. J. L. Karm oker (BangIa Desh), Prof. Peter B. Kaufman (U. S. A. ), Dr. V. I. Kefeli . / (U. S. S. R. ), Dr. M. Kutaoek (Czechoslovakia), Prof. S."

In this volume we compare modem observations of solar flares with results from recent theoretical research and simulation studies on current-carrying loops and their interaction. These topics have undergone rapid developments in the course of recent years. Observational results by X-ray monitoring and imaging spacecraft in the seventies and by dedicated imaging instrumentation in the satellites Solar Max imum Mission and Hinotori, launched 1980 and 1981, have shown the importance of X-ray imaging for understanding the ignition processes of solar flares. Such observations, in tum, stimulated theoretical studies, centered around the flux-tube concept. The classical idea that flares originate by interaction of current-carrying loops was developed and proved to be promising. Concepts on reconnection and coalescence of flux tubes were developed, and their consequences studied. The Yohkoh spacecraft, launched 1991, showed the overwhelming importance of coro nal flux tubes and their many possible ways of interaction. Subsequent and parallel theoretical studies and simulations, differentiating between the topology of interact ing fluxtubes, demonstrated that the mutual positioning and the way of interaction are important for the subsequent processes of energy release in flares and the many associated phenomena such as the expUlsion of jets and the emission of X -ray and microwave radiation. The new developments now enable researchers to understand and classify flares in a physically significant way. Various processes of accelera tion are active in and after flares on greatly varying timescales; these can now be distinguished and explained.

The many papers by Soviet authors have been translated into English by A. P. Kirillov, N. A. Nikiforova, E. A. Voronov, and others. Some of the papers were trans lated by the authors themselves. The discussion records have been prepared at the Institute for Theoretical Astronomy by V. K. Abalakin, N. A. Belyaev, A. P. Kirillov, V. A. Shor, E. A. Voronov, N. S. Yakhontova, and others. The three papers published in French have been carefully checked by B. Milet. The final editing has been done at the Smithsonian Astrophysical Observatory, and we thank J. H. Clark, P. D. Gregory, J. E. Kervick, and G. Warren for retyping much of the material. Our special thanks are due to the D. Reidel Publishing Company for the excellent care they have taken in printing these proceedings of IAU Symposium No. 45. G. A. CHEBOT AREV E. I. KAZIMIRCHAK-POLONSKA Y A B. G. MARSDEN INTRODUCTION The idea to organize a Symposium on 'The Motion, Evolution of Orbits, and Origin of Comets' dates back to the IAU thirteenth General Assembly, held in 1967 in Prague. Owing to the impossibility of completing during the General Assembly the discussion on the problem of orbital evolution of comets Professor G. A. Chebotarev, then the newly elected President of IAU Commission 20, initiated the organization of the international symposium in Leningrad where the full scope of cometary problems might be considered from the viewpoint of celestial mechanics."

At the XV. General Assembly of the International Astronomical Union in Sydney 1973, Commission 10 for Solar Activity requested the incoming Organising Committee to establish a small group to recommend a standard nomenclature for solar features and to prepare an illustrated text which would clear the jungle of terms for the benefit of solar physicists as well as of theoreticians and research workers in related fields. The challenge was taken up by the president of Commission 10, Prof. K. O. Kiepenheuer, and his persuasive advocacy has led eventually to the present book. In the course of the work, the declared aim but not the basic purpose was revised. Rather than prepare a list of standard terms, we have preferred to collect together all the terms that appear in current English-language literature. Synonyms and partially overlapping terms are all recorded for the most part without prejudice. Each has been defined as exactly as possible with the hope that in the future they may be used and understood without ambiguity. It would be a step on the road to standardisation if these terms were not re-used for new phenomena. New observations and new theories will lead to reappraisals and redefinitions so the Glossary is intended more as a guide to the present situation than as a rule-book.

A favourable reception of the first edition of this book - due no doubt to the nature of its subject - which went out of print in 2 years, gave its author a welcome oppor tunity to update at present its contents. This was all the more necessary, as seldom in the annals of science has our knowledge of the physics and astronomy of the Moon made greater progress than during this time. The real heroes of this advance have, of course, been the spacecraft - 33 of which have now been sent out since 1959 to reconnoiter our satellite at a close range. The hard-landers among them just about delivered their message by the time when the first edition of this book went to the press; but it was the soft-landers and orbiters, which followed in their wake between 1966-67, that became really the principal contributors to lunar research. By now that it may be both timely and their programmes have likewise been completed; so opportune to take stock of the present state of our subject now - on the eve of the next stage of lunar exploration by manned landings on the surface of our satellit- which can be expected to take place in the very near future. * The aim of the second edition of this book will be to provide the requisite infor mation, brought up to date in an organized manner."

These are the Proceedings of Colloquium No. 153 of the International Astro nomical Union, held at Makuhari near Tokyo on May 22 - 26, 1995, and hosted by the National Astronomical Observatory. This meeting was intended to be an interdisciplinary meeting between re searchers of solar and stellar activity, in order for them to exchange the newest information in each field. While each of these areas has seen remarkable advances in recent years, and while the researchers in each field have felt that information from the other's domain would be extremely useful in their own work, there have not been very many opportunities for intensive exchanges of information between these closely related fields. We therefore expected much from this meeting in pro viding stellar researchers with new results of research on the counterparts of their targets of research, spatially and temporarily resolved, as observed on the Sun. Likewise we hoped to provide solar researchers with new results on gigantic ver sions of their targets of research under the very different physical circumstances on other active stars. It was our greatest pleasure that we had wide attendance of experts and active researchers of both research fields from all over the world. This led to extremely interesting talks and very lively discussions, thereby stimulating the exchange of ideas across the fields.

Leading researchers in the area of the origin and evolution of life in the universe contributed to Chemical Evolution: Physics of the Origin and Evolution of Life. This volume provides a review of this interdisciplinary field. In 35 chapters many aspects of the origin of life are discussed by 90 authors, with particular emphasis on the early paleontological record: physical, chemical, biological, and informational aspects of life's origin, instrumentation in exobiology and system exploration; the search for habitable planets and extraterrestrial intelligent radio signals. This book contains the proceedings of the Fourth Trieste Conference on Chemical Evolution that took place in September 1995, in which scientists from a wide geographical distribution joined in a Memorial to Cyril Ponnamperuma, who was a pioneer in the field of chemical evolution, the origin of life, and exobiology, and also initiated the Trieste Conferences on Chemical Evolution and the Origin of Life. This fourth Conference was therefore dedicated to his memory. Audience: Graduate students and researchers in the many areas of basic, earth, and life sciences that contribute to the study of chemical evolution and the origin of life.

TECTONlCS AND PHYSICS Geology, although rooted in the laws of physics, rarely has been taught in a manner designed to stress the relations between the laws and theorems of physics and the postulates of geology. The same is true of geophysics, whose specialties (seismology, gravimetIy, magnetics, magnetotellurics) deal only with the laws that govern them, and not with those that govern geology's postulates. The branch of geology and geophysics called tectonophysics is not a formalized discipline or subdiscipline, and, therefore, has no formal laws or theorems of its own. Although many recent books claim to be textbooks in tectonophysics, they are not; they are books designed to explain one hypothesis, just as the present book is designed to explain one hypothesis. The textbook that comes closest to being a textbook of tectonophysics is Peter 1. Wyllie's (1971) book, The Dynamic Earth. Teachers, students, and practitioners of geology since the very beginning of earth science teaching have avoided the development of a rigorous (but not rigid) scientific approach to tectonics, largely because we earth scientists have not fully understood the origin of the features with which we are dealing. This fact is not at all surprising when one considers that the database for hypotheses and theories of tectonics, particularly before 1960, has been limited to a small part of the exposed land area on the Earth's surface.

Planetary Crusts explains how and why solid planets and satellites develop crusts. Extensively referenced and annotated, it presents a geochemical and geological survey of the crusts of the Moon, Mercury, Venus, Earth and Mars, the asteroid Vesta, and several satellites like Io, Europa, Ganymede, Titan and Callisto. After describing the nature and formation of solar system bodies, the book presents a comparative investigation of different planetary crusts and discusses many crustal controversies. The authors propose the theory of stochastic processes dominating crustal development, and debate the possibility of Earth-like planets existing elsewhere in the cosmos. Written by two leading authorities on the subject, this book presents an extensive survey of the scientific problems of crustal development, and is a key reference for researchers and students in geology, geochemistry, planetary science, astrobiology and astronomy.

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.

The proposal of the School was made in 1998 to three institutions, which responded enthusiastically: The Abdus Salam International Centre for Theoretical Physics (ICTP), its main co-sponsor, the International Centre for Genetic Engineering and Biotechnology, both in Trieste, Italy, and the Chancellor's Office, Universidad Simon Bolfvar (USB). The secretarial and logistic support was provided in Trieste by the ICTP and in Caracas by USB and the IDEA Convention Center. In addition the event was generously supported by the following institutes, agencies, foundations and academies: NASA Headquarters, European Space Agency, TALVEN Programme, (Delegacion Permanente de Venezuela ante la UNESCO), The SETI Institute, Centro Latinoamericano .de Ffsica, The Third World Academy of Sciences, Academia de Ciencias Ffsicas, Matematicas y Naturales, Red Latinoamericana de Biologfa, The Planetary Society, The Latin American Academy of Sciences (Fondo ACAL), Alberto Vollmer Foundation, Inc, Fundacion J. Oro, Associated to the Catalonian Research Foundation, Red Latinoamericana de Astronomfa and Colegio Emil Friedman. A total of 36 lectures were delivered by 20 lecturers, of which 14 were from the following countries: Argentina, Mexico, Italy, Spain and the USA. Six lecturers were from the host country. In addition there were 5 chairpersons from the host country that were not participants; two participants acted as chairpersons (Pedro Benitez and Tomas Revilla).

Beyond the four centuries of sunspot observation and the five decades during which artificial satellites have monitored the Sun that is to say for 99.99999% of the Sun 's existence our knowledge of solar history depends largely on analogy with kindred main sequence stars, on the outcome of various kinds of modelling, and on indirect measures of solar activity. They include the analysis of lunar rocks and meteorites for evidence of solar flares and other components of the solar cosmic-ray (SCR) flux, and the measurement of cosmogenic isotopes in wood, stratified ice and marine sediments to evaluate changes in the galactic cosmic-ray (GCR) flux and thus infer changes in the sheltering magnetic fields of the solar wind. In addition, shifts in the global atmospheric circulation which appear to result from cyclic fluctuations in solar irradiance have left their mark in river sediments and in the isotopic composition of cave deposits. In this volume the results these sources have already produced have been summarised, paying special attention to those that reflect processes in different parts of the Sun 's interior and that display periodicities and trends which may enable us to forecast future large-scale environmental changes.

Based on lectures given at a CNRS summer school in France, this book covers many aspects of stellar environments (both observational and theoretical) and offers a broad overview of the field. More specifically, Part I of the book focuses on the Sun, the properties of the ejected plasma, of the solar wind and on space weather. The second part deals with tides in planetary systems and in binary stellar systems, as well as with interactions in massive binary stars as seen by interferometry. Finally the chapters of Part III discuss the very close environments of young stars; Stellar Winds, Magnetic Fields and Disks; Magnetic field and convection in the cool supergiant Betelgeuse; The formation of circumstellar disks around evolved stars; and an introduction to accretion disks is given. With its broad approach the book will provide graduate students with a good overview of the environments of the Sun and stars.

Luminous hot stars represent the extreme upper mass end of normal stellar evolution. Before exploding as supernovae, they live out their lives of a few million years with prodigious outputs of radiation and stellar winds, dramatically affecting both their evolution and environments. A detailed introduction to the topic, this book connects the astrophysics of massive stars with the extremes of galaxy evolution represented by starburst phenomena. A thorough discussion of the physical and wind parameters of massive stars is presented. HII galaxies, their connection to starburst galaxies, and the contribution of starburst phenomena to galaxy evolution through superwinds, are explored. The book concludes with the wider cosmological implications, including Population III stars, Lyman break galaxies and gamma-ray bursts, for each of which massive stars are believed to play a crucial role. This book is ideal for graduate students and researchers in astrophysics interested in luminous hot stars and galaxy evolution.

The past two decades have seen remarkable advances in observations of sunspots and their magnetic fields, in imaging of spots and fields in distant stars and in associated theoretical models and numerical simulations. This book provides a comprehensive combined account of the properties of sunspots and starspots. It covers both observations and theory, and describes the intricate fine structure of a sunspot's magnetic field and the prevalence of polar spots on stars. The book includes a substantial historical introduction and treats solar and stellar magnetic activity, dynamo models of magnetic cycles, and the influence of solar variability on the Earth's magnetosphere and climate. This volume is a valuable reference for graduate students and specialists in solar and stellar physics, astronomers, geophysicists, space physicists and experts in fluid dynamics and plasma physics.

The articles in this volume cover, for the first time, all aspects of planetary magnetism, from the observations made by space missions to their interpretation in terms of the properties of all the planets in the solar system. Studies of dynamo-generated magnetic fields in Mercury, the Earth, the giant planets, as well as in Ganymede, one of Jupiter s moons, are presented. Crustal magnetic field in Mars, the Mon and the Earth are described as well as magnetic fields induced in the solar system bodies. There are several articles dealing with dynamo theory and modelling and applications to the different planets."

As in the days following Skylab, solar physics came to the end of an era when the So lar Maximum Mission re-entered the earth's atmosphere in December 1989. The 1980s had been a pioneering decade not only in space- and ground-based studies of the solar atmosphere (Solar Maximum Mission, Hinotori, VLA, Big Bear, Nanc;ay, etc.) but also in solar-terrestrial relations (ISEE, AMPTE), and solar interior neutrino and helioseismol ogy studies. The pace of development in related areas of theory (nuclear, atomic, MHD, beam-plasma) has been equally impressive. All of these raised tantalizing further questions about the structure and dynamics of the Sun as the prototypical and best observed star. This Advanced Study Institute was timed at a pivotal point between that decade and the realisation of Yohkoh, Ulysses, SOHO, GRANAT, Coronas, and new ground-based optical facilities such as LEST and GONG, so as to teach and inspire the up and coming young solar researchers of the 1990s. The topics, lecturers, and students were all chosen with this goal in mind, and the result seems to have been highly successful by all reports."

Magnetism is one of the basic properties of matter. Mankind has trav elled a long road in discovering and utilizing magnetism, and in this respect the ancient Chinese people have made outstanding contribu tions. In the book 'Lu's Spring and Autumn', written near the end of the Warring States Period, i. e. in the third century B. C. , there is a statement on the "attraction of iron by lodestones". So at that time it was known that magnets can attract ferromagnetic material. At the be ginning ofthe first century A. D. , viz. in the early years ofthe East Hang Dynasty, the famous scholar Wang Chong wrote in his masterpiece 'Len Hen' that the handle of a magnetic dipper pointed to the south. It was thus discovered at the time that magnets can point to the poles of the geomagnetic field. At the beginning of the twelfth century, during the reign of Emperor Hui of the Sung Dynasty, in the two books written by Zhu Yo and Xu Jin, respectively, there are descriptions of the com pass used in navigation. This tells us that the application of compasses was rather widespread at that time. The distinguished scientist Sen Go (1031-1085) discovered the declination of the terrestrial magnetic field. This is four hundred and more years earlier than its discovery by Christopher Columbus in 1492 during his voyage across the Atlantic Ocean. Such facts as these manifest the important contributions of ancient China to global civilization.

Astronomical jets are key astrophysical phenomena observed in gamma-ray bursts, active galactic nuclei or young stars. Research on them has largely occurred within the domains of astronomical observations, astrophysical modeling and numerical simulations, but the recent advent of high energy density facilities has added experimental control to jet studies. Front-line research on jet launching and collimation requires a highly interdisciplinary approach and an elevated level of sophistication. Bridging the gaps between pure magnetohydrodynamics, thermo-chemical evolution, high angular resolution spectro-imaging and laboratory experiments is no small matter. This volume strives to bridge those very gaps. It offers a series of lectures which, taken as whole, act as a thorough reference for the foundations of this discipline. These lectures address the following: * laboratory jets physics from laser and z-pinch plasma experiments, * the magnetohydrodynamic theory of relativistic and non-relativistic stationary jets, * heating mechanisms in magnetohydrodynamic jets, from the solar magnetic reconnection to the molecular shock heating perspectives, * atomic and molecular microphysics of jet shocked material. In addition to the lectures, the book offers, in closing, a presentation of a series of observational diagnostics, thus allowing for the recovery of basic physical quantities from jet emission lines.

Given the past decade's explosion of neurobiological and paleontologi cal data and their increasingly sophisticated analyses, interdisciplinary syntheses between these two broad disciplines are of value and interest to many different scientists. The collected papers of this volume will appeal to students of primate and hominid evolution, neuroscientists, sociobiolo gists, and other behaviorists who seek a better understanding of the substrates of primate, including human, behavior. Each species of living primates represents an endpoint in evolution, but comparative neurologists can produce approximate evolutionary se quences by careful analyses of representative series. Because nervous tissue does not fossilize, only a comparison of structures and functions among extant primates can be used to investigate the fine details of primate bra~n evolution. Paleoneurologists, who directly examine the fossil record via endocasts or cranial capacities of fossil skulls, can best provide information about gross details, such as changes in brain size or sulcal patterns, and determine when they occurred. Physical anthropologists and paleontologists have traditionally relied more on paleoneurology, whereas neuroscientists and psychologists have relied more on comparative neurology. This division has been a detriment to the advancement of these fields and to the conceptual bases of primate brain evolution. Both methods are important and a synthesis is desirable. To this end, two symposia were held in 1980--one at the meeting of the American Association of Physical Anthro pologists in Niagara Falls, U. S. A. , and one at the precongressional meeting of the International Primatological Society in Torino, Italy.

Meteor Showers and their Parent Comets is a unique handbook for astronomers interested in observing meteor storms and outbursts. Spectacular displays of 'shooting stars' are created when the Earth's orbit crosses a meteoroid stream, as each meteoroid causes a bright light when it enters our atmosphere at high speed. Jenniskens, an active meteor storm chaser, explains how meteoroid streams originate from the decay of meteoroids, comets and asteroids, and how they cause meteor showers on Earth. He includes the findings of recent space missions to comets and asteroids, the risk of meteor impacts on Earth, and how meteor showers may have seeded the Earth with ingredients that made life possible. All known meteor showers are identified, accompanied by fascinating details on the most important showers and their parent comets. The book predicts when exceptional meteor showers will occur over the next fifty years, making it a valuable resource for both amateur and professional astronomers.