The International Astronomical Union (IAU) was founded in 1919, in the wake of the First World War, together with its sister Unions in related natural sciences. It will thus turn 100 years in 2019. Written by a mixed team of insiders and outsiders, this book presents the IAU in the changing context of the historical, scientific and technological development of astronomy during the past 100 years. While much important scientific progress took place already before 1945, the book naturally focuses on the accelerating evolution during the second half of the century. In the past few decades, the previously narrow IAU focus on organising professional astronomy has broadened to include societally relevant activities such as addressing the hazard of asteroid impacts, the planetary status of Pluto in the Solar System, and the hugely successful International Year of Astronomy. Most recently, it is spearheading a combination of science literacy and public outreach. The book will be of interest to professional astronomers as well as an astronomically interested general audience. The book features live personal interviews with as many of the key actors as still possible.

This History has its origin in a suggestion, made in September 1990 by former IAU General Secretary Derek McNally, who felt "that a 75 year history of the Union was needed before the col lective memory of those who knew the Union before the Second World War vanished. It would then be a preparatory volume to a centennial history in 2019. " Indeed, of those who knew the Union that long ago, few are still with us. Six years ago, at Baltimore on August 2, 1988, listening and reminiscing at the Inaugural Ceremonies of the Union's 20th General Assembly, I realized that it was almost exactly half a century ago that, at the age of 24, I attended the Inaugurations at my "first" Assembly: on August 3, 1938 in Stockholm. Now, in 1994, this is almost 56 years ago, three quarters of the Union's age. Only vague recollections - no better than that -lead me back to this event, just before World War II. And so, this is not a history based on recollection, far from it. Recollection was helpful in that it allowed me, better perhaps than a younger author, to appreciate circumstances under which the letters and reports which form the basis for this History were written. The account is largely based on archival documents, collected from a wide variety of sources.

Seen from “inside the IAU,” this book tells the in-depth story of a major crisis in which China “divorced” from the International Astronomical Union in 1960 as a protest against the admission of Taiwan. This happened to all the scientific unions at the same time, and to the Olympic Games, which, unexpectedly, would serve as a laboratory for the “reconciliation” which took place following the re-opening of China to the world 20 years later. The so-called “China conflict” is the most important crisis in the post-WWII history of the IAU. Yet, many details about this conflict and its links to broader geopolitical events have long remained unsettled, obscure, or altogether absent. In particular, the book describes for the first time the “separation” period, which covered the Cultural Revolution, and in which the IAU made desperate official efforts to reach out to China, while some groups of Western and Chinese astronomers managed to keep contact at times. On the occasion of the IAU Centenary celebrations in 2019, the book revisits this painful succession of events using unpublished documents from the IAU Archives and the International Council of Scientific Unions. The book also contains supplementary typescripts of selected handwritten correspondences and the full translation of key original Chinese documents unknown to readers outside China. What emerges is a complex and fascinating story of human relations and science diplomacy under the shadow of the Cold War. Readers will learn how the 20-year “China conflict” as lived by astronomers and scientists is important not only for the history of the IAU, but also for the history of contemporary China. “This book is full of so many original documents of the IAU office, very reliable and good to open to the public readers.” Shuhua Ye, Shanghai Observatory (IAU Vice-President, 1988-1994) This book is a companion book to "Astronomers as Diplomats," published at the same time in the same series.

Ptolemy's Almagest is one of the most influential scientific works in history. A masterpiece of technical exposition, it was the basic textbook of astronomy for more than a thousand years, and still is the main source for our knowledge of ancient astronomy. This translation, based on the standard Greek text of Heiberg, makes the work accessible to English readers in an intelligible and reliable form. It contains numerous corrections derived from medieval Arabic translations and extensive footnotes that take account of the great progress in understanding the work made in this century, due to the discovery of Babylonian records and other researches. It is designed to stand by itself as an interpretation of the original, but it will also be useful as an aid to reading the Greek text.

A reconstruction of the Chinese sky of two thousand years ago, based on analysis of the first star catalogue in China and other sources. Presented in six well-sized star maps for 100 BC, it is especially important for the history of astronomy. The Han sky, with five times more constellations than Ptolemy knew, reflects diverse human activities. The way in which constellations were grouped discloses a systematic cosmology, uniting universe and the state. The work of the three Han schools is comparable to Ptolemy's Almagest. With three detailed Appendices on the constellations of the three schools, well illustrated to demonstrate the relation between sky and human society, this book is valuable not only for astronomy historians and sinologists, but in general for scholars interested in the ancient cultures of Asia.

An award-winning science journalist details the quest to isolate and understand dark matter--and shows how that search has helped us to understand the universe we inhabit. When you train a telescope on outer space, you can see luminous galaxies, nebulae, stars, and planets. But if you add all that together, it constitutes only 15 percent of the matter in the universe. Despite decades of research, the nature of the remaining 85 percent is unknown. We call it dark matter. In The Elephant in the Universe, Govert Schilling explores the fascinating history of the search for dark matter. Evidence for its existence comes from a wealth of astronomical observations. Theories and computer simulations of the evolution of the universe are also suggestive: they can be reconciled with astronomical measurements only if dark matter is a dominant component of nature. Physicists have devised huge, sensitive instruments to search for dark matter, which may be unlike anything else in the cosmos--some unknown elementary particle. Yet so far dark matter has escaped every experiment. Indeed, dark matter is so elusive that some scientists are beginning to suspect there might be something wrong with our theories about gravity or with the current paradigms of cosmology. Schilling interviews both believers and heretics and paints a colorful picture of the history and current status of dark matter research, with astronomers and physicists alike trying to make sense of theory and observation. Taking a holistic view of dark matter as a problem, an opportunity, and an example of science in action, The Elephant in the Universe is a vivid tale of scientists puzzling their way toward the true nature of the universe.

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.

IAU Transactions XXIIB summarizes the work of the XXIInd General Assembly. The discourses given during the Inaugural and Closing Ceremonies are reproduced in Chapters I and III, respectively. The proceedings of the two sessions of the General Assembly will be found in Chapter II, which includes the Resolutions and the report of the Finance Committee. The Statutes, Bye-Laws and a few working rules of the Union are published in Chapter IV. The Accounts and other aspects of the administration of the Union are recorded in Chapter V, together with the report of the Executive Committee for this last triennium, and provide the permanent record for the Union in the period 1991-1994. This volume also contains the Commission reports from The Hague compiled by the Presidents of the Commissions (Chapter VI). Finally, Chapter VII contains the list of countries adhering to the Union and the alphabetical, geographical and commission membership lists of about 8000 individual members. The IAU still appears to be unique among the scientific Unions in maintaining this category of individual membership which contributes in a crucial way to the spirit and the aims of the Union.