I.A.U. symposium No. 110 on VLBI and Compact Radio Sources was held in Bologna, Italy from June 27 to July 1, 1983. 166 participants from 19 countries were registered and 106 invited and contributed papers were registered. The scientific presentations and discussion concentrated on VLBI observation and interpretation of galactic and extragalactic radio sour ces, including topics as diverse as quasars and galactic nuclei, inter stellar masers, pulsars, and astrometry. Geodetic applications and tech nical development were treated only briefly, as these topics have been the subject of other recent international symposia. Since the first VLBI observations in 1967, sensitivity, resolution, and image quality have improved dramatically. Radio maps shown at the symposium were of comparable quality to conventional synthesis maps be ing made at the time of the first VLBI experiments 15 years ago, but with a resolution more than a factor of 1000 better. We wanted to accommodate the large number of contributed papers in this rapidly developing field, but there was inadequate time for normal oral presentations and discussion. We therefore asked that all contrib uted papers be put on display for at least 24 hours prior to a brief oral summary. A question and discussion period followed groups of oral pres entations on the same or similar topic. In this way the opportunity for interactive discussion, not available in conventional poster displays, was preserved.

This open access book on the history of the National Radio Astronomy Observatory covers the scientific discoveries and technical innovations of late 20th century radio astronomy with particular attention to the people and institutions involved. The authors have made extensive use of the NRAO Archives, which contain an unparalleled collection of documents pertaining to the history of radio astronomy, including the institutional records of NRAO as well as the personal papers of many of the pioneers of U.S. radio astronomy. Technical details and extensive citations to original sources are given in notes for the more technical readers, but are not required for an understanding of the body of the book. This book is intended for an audience ranging from interested lay readers to professional researchers studying the scientific, technical, political, and cultural development of a new science, and how it changed the course of 20th century astronomy.

I.A.U. symposium No. 110 on VLBI and Compact Radio Sources was held in Bologna, Italy from June 27 to July 1, 1983. 166 participants from 19 countries were registered and 106 invited and contributed papers were registered. The scientific presentations and discussion concentrated on VLBI observation and interpretation of galactic and extragalactic radio sour ces, including topics as diverse as quasars and galactic nuclei, inter stellar masers, pulsars, and astrometry. Geodetic applications and tech nical development were treated only briefly, as these topics have been the subject of other recent international symposia. Since the first VLBI observations in 1967, sensitivity, resolution, and image quality have improved dramatically. Radio maps shown at the symposium were of comparable quality to conventional synthesis maps be ing made at the time of the first VLBI experiments 15 years ago, but with a resolution more than a factor of 1000 better. We wanted to accommodate the large number of contributed papers in this rapidly developing field, but there was inadequate time for normal oral presentations and discussion. We therefore asked that all contrib uted papers be put on display for at least 24 hours prior to a brief oral summary. A question and discussion period followed groups of oral pres entations on the same or similar topic. In this way the opportunity for interactive discussion, not available in conventional poster displays, was preserved.

On the 100th anniversary of Marconi's successful experiment on radio broadcasting, 250 astronomers from all over the world met in Bologna (Italy) for five days, to update their knowledge of the physics and statistical properties of powerful extragalactic radio sources. Since their discovery in the fifties enormous progress has been made. The existence of superluminal motions in the cores of radio sources, the presence there of a black hole surrounded by an absorbing dust torus, as inferred mostly from studies at other wavelengths, are now accepted ideas. Nevertheless, in spite of these efforts, there are many questions still unanswered. For instance we do not know which mechanism produces the huge amount of energy supplied to radio sources, how the jets connecting the `engine' to the lobes are formed and collimated, which of the differences observed among the various classes of radio sources are apparent and which are real. These and other related topics are discussed in this book.

The physics of active galactic nuclei, the origin of extragalactic jets and the formation of extended extragalactic radio sources are among the most interesting challenges of modern astrophysics. This book contains the proceedings of the 7th meeting of the Institut d'Astrophysique de Paris, which drew together both theorists and observers in this exciting field. Recent observational data at X-ray, optical and radio wavelengths is discussed, and new theoretical developments concerning beam and jet formation models are considered. Special treatment is given to plasma physics problems related to particle acceleration, magnetic reconnection, beam-plasma interaction and coherent emission. The volume will be of use to all students and researchers who are working in this field.

The quest for high resolution has preoccupied radio astronomers ever since radio waves were first detected from space fifty years ago. This venture was par ticularly stimulated by the discovery of quasars, and led to the development of interferometer techniques using baselines of transglobal dimensions. These meth ods have become known as Very Long Baseline Interferometry (VLBI). Arrays of radio telescopes situated all over the Earth (or even in space) are regularly used for researches in radio astronomy, reaching resolutions as small as a fraction of a milli arcsecond. The technique also allows the measurement of the positions of the radio telescopes to a few millimeters and so VLBI has become a major tool in geodesy and the study of the rotation of the Earth. VLBI has now passed the pioneer stage and is becoming a standard facility available to astronomers and geodesists, requiring the coordination of the operations of indpendently owned radio telescopes around the world. In Europe observatories from England, Federal Republic of Germany, France, Italy, Poland, Sweden and The Netherlands are coordinated in their VLBI activity by the European VLBI Network Consortium (EVN). The Programme Committee of the EVN allocates time to scientific projects on a routine basis three times a year. The Unites States has a similar arrangement of a network of independent radio observatories, and joint experiments using 'Global Network' are often made.