This book on space geodesy presents pioneering geometrical approaches in the modelling of satellite orbits and gravity field of the Earth, based on the gravity field missions CHAMP, GRACE and GOCE in the LEO orbit. Geometrical approach is also extended to precise positioning in space using multi-GNSS constellations and space geodesy techniques in the realization of the terrestrial and celestial reference frame of the Earth. This book addresses major new developments that were taking place in space geodesy in the last decade, namely the availability of GPS receivers onboard LEO satellites, the multitude of the new GNSS satellite navigation systems, the huge improvement in the accuracy of satellite clocks and the revolution in the determination of the Earth's gravity field with dedicated satellite missions.

This thesis focuses on the very high Mach number shock wave that is located sunward of Saturn's strong magnetic field in the continuous high-speed flow of charged particles from the Sun (the solar wind). The author exploits the fact that the Cassini spacecraft is the only orbiter in a unique parameter regime, far different from the more familiar near-Earth space, to provide in-situ insights into the unreachable exotic regime of supernova remnants. This thesis bridges the gap between shock physics in the Solar System and the physics of ultra-high Mach number shocks around the remnants of supernova explosions, since to date research into the latter has been restricted to theory, remote observations, and simulations.

Of Clocks and Time takes readers on a five-stop journey through the physics and technology (and occasional bits of applications and history) of timekeeping. On the way, conceptual vistas and qualitative images abound, but since mathematics is spoken everywhere the book visits equations, quantitative relations, and rigorous definitions are offered as well. The expedition begins with a discussion of the rhythms produced by the daily and annual motion of sun, moon, planets, and stars. Centuries worth of observation and thinking culminate in Newton's penetrating theoretical insights since his notion of space and time are still influential today. During the following two legs of the trip, tools are being examined that allow us to measure hours and minutes and then, with ever growing precision, the tiniest fractions of a second. When the pace of travel approaches the ultimate speed limit, the speed of light, time and space exhibit strange and counter-intuitive traits. On this fourth stage of the journey, Einstein is the local tour guide whose special and general theories of relativity explain the behavior of clocks under these circumstances. Finally, the last part of the voyage reverses direction, moving ever deeper into the past to explore how we can tell the age of "things" - including that of the universe itself.

This book develops a general approach that can be systematically refined to investigate the statics and dynamics of deformable solid bodies. These methods are then employed to small bodies in the Solar System. With several space missions underway and more being planned, interest in our immediate neighbourhood is growing. In this spirit, this book investigates various phenomena encountered in planetary science, including disruptions during planetary fly-bys, equilibrium shapes and stability of small rubble bodies, and spin-driven shape changes. The flexible procedure proposed here will help readers gain valuable insights into the mechanics of solar system bodies, while at the same time complementing numerical investigations. The technique itself is built upon the virial method successfully employed by Chandrasekhar (1969) to study the equilibrium shapes of spinning fluid objects. However, here Chandrasekhar's approach is modified in order to study more complex dynamical situations and include objects of different rheologies, e.g., granular aggregates, or "rubble piles". The book is largely self-contained, though some basic familiarity with continuum mechanics will be beneficial.

This book is the fruit of the first ever interdisciplinary international scientific conference on Matthew's story of the Star of Bethlehem and the Magi, held in 2014 at the University of Groningen, and attended by world-leading specialists in all relevant fields: modern astronomy, the ancient near-eastern and Greco-Roman worlds, the history of science, and religion. The scholarly discussions and the exchange of the interdisciplinary views proved to be immensely fruitful and resulted in the present book. Its twenty chapters describe the various aspects of The Star: the history of its interpretation, ancient near-eastern astronomy and astrology and the Magi, astrology in the Greco-Roman and the Jewish worlds, and the early Christian world - at a generally accessible level. An epilogue summarizes the fact-fiction balance of the most famous star which has ever shone. Cover illustration: (c) Michael Farrell

In his PhD dissertation Martin Bo Nielsen performs observational studies of rotation in stars like the Sun. The interior rotation in stars is thought to be one of the driving mechanisms of stellar magnetic activity, but until now this mechanism was unconstrained by observational data. NASA's Kepler space mission provides high-precision observations of Sun-like stars which allow rotation to be inferred using two independent methods: asteroseismology measures the rotation of the stellar interior, while the brightness variability caused by features on the stellar surface trace the rotation of its outermost layers. By combining these two techniques Martin Bo Nielsen was able to place upper limits on the variation of rotation with depth in five Sun-like stars. These results suggest that the interior of other Sun-like stars also rotate in much the same way as our own Sun.

This book comprises a fascinating collection of contributions on the Merz telescopes in Italy that collectively offer the first survey on historical large refracting telescopes in the country, drawing on original documents and photographs. It opens with a general introduction on the importance of Merz telescopes in the history of astronomy and analyses of the local and international contexts in which the telescopes were made. After examination of an example of the interaction between the maker and the astronomer in the construction and maintenance of these refractors, the history of the Merz telescopes at the main Italian observatories in the nineteenth century is described in detail. Expert testimony is also provided on how these telescopes were successfully used until the second half of the twentieth century for research purposes, thus proving their excellent optical qualities.

A Survey of the Status of the Determination of the General Perturbations of the Minor Planets (Asteroids).

This work discusses the problem of physical meaning of the three main dynamical properties of matter motion, namely gravitation, inertia and weightlessness. It considers that Newtonian gravitation and Galileo's inertia are the centrifugal effects of interaction energy of a self-gravitating n-body system and its potential field. A self-gravitating celestial body appears to be an excellent natural centrifuge that is rotated by the energy of interacting elementary particles. Weightlessness is a consequence of the centrifugal effect of elementary particles interaction that appears at differentiation of a body matter with respect to density. The author analyzes the problem of creation of mass particles and elements from the elementary particles of "dark matter", and discusses the basic physics of the Jacobi dynamics from the viewpoint of quantum gravitation. Chapters assert that the fundamentals of Jacobi dynamics completely correspond to conditions of natural centrifuges. The centrifuge is an excellent experimental model for the study of dynamical effects in solving the many body problem. In this book, readers may follow the demonstration of some of those studies and follow derivations, solutions and conclusions that provide a solid basis for further research in celestial mechanics, geophysics, astrophysics, geo- and planetary sciences.

This book provides the only critical edition and English translation of Mahmud al-Jaghmini's al-Mulakhkhas fi al-hay'a al-basita, the most widely circulated Arabic treatise on Ptolemaic astronomy ever written. Composed in the early 13th century, this introductory textbook played a crucial role in the teaching, dissemination, and institutional instruction of Islamic astronomy well into the 19th century (and beyond). Establishing the base text is a fundamental prerequisite for gaining insights into what was considered an elementary astronomical textbook in Islam and also for understanding the extensive commentary tradition that built upon it. Within this volume, the Mulakhkhas is situated within the broader context of the genre of literature termed 'ilm al-hay'a, which has become the subject of intensive research over the past 25 years. In so doing, it provides a survey of summary accounts of theoretical astronomy of Jaghmini's predecessors, both Ancient and Islamic, which could have served as potential sources for the Mulakhkhas. Jaghmini's dates (which until now remained unsettled) are established, and it is definitively shown that he composed not only the Mulakhkhas but also other scientific treatises, including the popular medical treatise al-Qanunca, during a period that has been deemed one of scientific decline and stagnation in Islamic lands. The book will be of particular interest to scholars engaged in the study of Islamic theoretical astronomy, but is accessible to a general readership interested in learning what constituted an introduction to Ptolemaic astronomy in Islamic lands.

How is it possible to imagine what is unknown and therefore unimaginable? How can the unimaginable be represented? On what materials do such representations rely? These questions lie at the heart of this book. Copernican theory redefined the role and importance of the imagination even as it implied the moment of its crisis. Based on this claim, Ladina Bezzola Lambert analyzes seventeenth-century astronomical texts - particularly descriptions of the moon and treatises written in support of the theory of the plurality of worlds - to show how early modern astronomers questioned the role of the imagination as a tool to visualize the unknown, but also how, pressed by the need to support their theories with convincing descriptions of other potential worlds, they sought to overcome the limitations of the imagination with a sophisticated rhetoric and techniques more commonly associated with poetic writing. The limitations of the imagination are at once a problem that all of the texts discussed struggle with and their recurrent theme. In the first and last chapter, the focus shifts to a more explicitly literary context: Ariosto's Orlando furioso and the work of Italo Calvino. The change of focus from science to literature and from the narratives of the past to contemporary ones serves to emphasize that the issues relating to the imagination, its limitations and creative means, are basically the same both in science and literature and that they are still relevant today.

This book deals with a topic that has been largely neglected by philosophers of science to date: the ability to refer and analyze in tandem. On the basis of a set of philosophical case studies involving both problems in number theory and issues concerning time and cosmology from the era of Galileo, Newton and Leibniz up through the present day, the author argues that scientific knowledge is a combination of accurate reference and analytical interpretation. In order to think well, we must be able to refer successfully, so that we can show publicly and clearly what we are talking about. And we must be able to analyze well, that is, to discover productive and explanatory conditions of intelligibility for the things we are thinking about. The book's central claim is that the kinds of representations that make successful reference possible and those that make successful analysis possible are not the same, so that significant scientific and mathematical work typically proceeds by means of a heterogeneous discourse that juxtaposes and often superimposes a variety of kinds of representation, including formal and natural languages as well as more iconic modes. It demonstrates the virtues and necessity of heterogeneity in historically central reasoning, thus filling an important gap in the literature and fostering a new, timely discussion on the epistemology of science and mathematics.

This interdisciplinary volume of essays explores how the notion of time varies across disciplines by examining variance as a defining feature of temporalities in cultural, creative, and scholarly contexts. Featuring a President's Address by philosopher David Wood, it begins with critical reassessments of J.T. Fraser's hierarchical theory of time through the lens of Anthropocene studies, philosophy, ecological theory, and ecological literature; proceeds to variant narratives in fiction, video games, film, and graphic novels; and concludes by measuring time's variance with tools as different as incense clocks and computers, and by marking variance in music, film, and performance art.

Robert Grosseteste (1168/75-1253), Bishop of Lincoln from 1235-1253, is widely recognized as one of the key intellectual figures of medieval England and as a trailblazer in the history of scientific methodology. Few of his numerous philosophical and scientific writings circulated as widely as the Compotus, a treatise on time reckoning and calendrical astronomy apparently written during a period of study in Paris in the 1220s. Besides its strong and long-lasting influence on later writers, Grossteste's Compotus is particularly noteworthy for its innovatory approach to the theory and practice of the ecclesiastical calendar-a subject of essential importance to the life of the Latin Church. Confronting traditional computistical doctrines with the lessons learned from Graeco-Arabic astronomy, Grosseteste offered his readers a critical and reform-oriented take on the discipline, in which he proposed a specific version of the Islamic lunar as a substitute for the failing nineteen-year cycle the Church still employed to calculate the date of Easter. This new critical edition of Grosseteste's Compotus contains the Latin text with an en-face English translation. It is flanked by an extensive introduction and chapter commentary, which will provide valuable new insights into the text's purpose and disciplinary background, its date and biographical context, its sources, as well as its reception in later centuries.

This new text looks at Quantum Chromodynamics, the theory of the strong force between quarks, which form the fundamental building blocks of nuclear matter. With a primary focus on experiments, the authors also include an extensive theoretical introduction to the field, as well as many exercises with solutions explained in detail.

The thesis presents a tool to create rubble pile asteroid simulants for use in numerical impact experiments, and provides evidence that the asteroid disruption threshold and the resultant fragment size distribution are sensitive to the distribution of internal voids. This thesis represents an important step towards a deeper understanding of fragmentation processes in the asteroid belt, and provides a tool to infer the interior structure of rubble pile asteroids. Most small asteroids are 'rubble piles' - re-accumulated fragments of debris from earlier disruptive collisions. The study of fragmentation processes for rubble pile asteroids plays an essential part in understanding their collisional evolution. An important unanswered question is "what is the distribution of void space inside rubble pile asteroids?" As a result from this thesis, numerical impact experiments can now be used to link surface features to the internal structure and therefore help to answer this question. Applying this model to asteroid Steins, which was imaged from close range by the Rosetta spacecraft, a large hill-like structure is shown to be most likely primordial, while a catena of pits can be interpreted as evidence for the existence of fracturing of pre-existing internal voids.

Published over a period of 20 years the essays collected together in this volume all relate to the lasting human preoccupation with cosmological matters and modern responses to them. The eclecticism of the typical medieval scholar might now seem astonishing, regrettable, amusing, or derisory, according to one's view of how rigid intellectual barriers should be. In Stars, Fate & Mind North argues that we will seriously misunderstand ancient and medieval thought if we are not prepared to share a willingness to look across such frontiers as those dividing astrology from ecclesiastical history, biblical chronology from astronomy, and angelic hierarchies from the planetary spheres, theology from the theory of the continuum, celestial laws from terrestrial, or the work of the clockmaker from the work of God himself, namely the universe. Surveying the work of such controversial scholars as Alexander Thom and Immanuel Velikovsky this varied volume brings together current scholarship on cosmology, and as the title suggest considers the confluence of matters of the stars, fate and the mind. The collection is accompanied by further commentary from the author and new illustrations.

Recent discoveries of planet-like objects circling other sun-like stars have stirred enormous interest in what other planets may exist in the universe, and whether they could support intelligent life. This book takes us into the midst of this search for extrasolar planets. Unlike other books, it focuses on the people behind the searches -- many known personally by the author -- and the extraordinary technology that is currently on the drawing boards. The author is an experienced, award-winning science journalist who was previously technology correspondent for the Financial Times of London. He has written on many topics in astronomy and astrobiology in over 35 different newspapers and magazines worldwide.

This thesis describes the studies on the solar interior where turbulent thermal convection plays an important role. The author solved, for the first time, one of the long-standing issues in solar physics, i.e., the maintenance mechanism of the solar differential rotation in the near-surface shear layer. The author attacked this problem with a newly developed approach, the reduced speed of sound technique, which enabled him to investigate the surface and deep solar layers in a self-consistent manner. This technique also made it possible to achieve an unprecedented performance in the solar convection simulations for the usage of the massively parallel supercomputers such as the RIKEN K system. It was found that the turbulence and the mean flows such as the differential rotation and the meridional circulation mutually interact with each other to maintain the flow structures in the Sun. Recent observations by helioseismology support the author's proposed theoretical mechanism. The book also addresses the generation of the magnetic field in such turbulent convective motions, which is an important step forward for solar cyclic dynamo research.

This book contains the elaborated and updated versions of the 24 lectures given at the 43rd Saas-Fee Advanced Course. Written by four eminent scientists in the field, the book reviews the physical processes related to star formation, starting from cosmological down to galactic scales. It presents a detailed description of the interstellar medium and its link with the star formation. And it describes the main numerical computational techniques designed to solve the equations governing self-gravitating fluids used for modelling of galactic and extra-galactic systems. This book provides a unique framework which is needed to develop and improve the simulation techniques designed for understanding the formation and evolution of galaxies. Presented in an accessible manner it contains the present day state of knowledge of the field. It serves as an entry point and key reference to students and researchers in astronomy, cosmology, and physics.