When I wasa child, growing up in South America,I often went camping in the wild and hence had direct access to the wondrous Southern sky; the Southern Cross was all mine at the time. Little did I know then that the study of the sky would take such a huge importance in my life, and that in the end astronomy and astrophysics would in many ways become my country and my religion. I have lived in several di?erent countries, and when asked my nationality, I am always very tempted to reply: astronomer. I started as a theorist, and my only dream in my youth was to spend nights thinking and calculating, with paper and pencil, and to have the impression by dawn that I had understood something new. So at the time astronomy was seen or dreamt by me as a solitary endeavour, with periodic encounters with my wise adviser and professors; it is this model that I adopted when doing my PhD work. My generation has lived through many revolutions of all kinds. Those in astronomy, I believe, remain particularly remarkable, and I am a true product of them. Now, I elect to live and work in large organizations, and to share my endeavours with many people. And I relish the series of Andr ́ e Heck on Organizations and Strategies in Astronomy, which help us recover our memories, reconstitute our own story, and read with glee about our neighbouring or far-away colleagues.

Research and publications in the field of Astronomy have undergone dramatic changes in the last half-century. While activities just slowed down during World War II in the US and in Latin America, they were very strongly affected by the difficult conditions prevailing among the European belligerent nations. Half a century ago, re search activities were mostly confined to observatories (linked or not to universities) and usually separated from the teaching of physical sciences. Hence, directors of observatories played an important role in the choice of the research fields, and "schools" of research appeared at various places, de veloping specific instrumentation, reduction techniques and mathematical methods to achieve their scientific goals. Reorganising the research activities after the war was no minor under taking, specially because communications were interrupted for over five years and isolated continental Europe from overseas activities. Scarcity of observing instruments (some of them being requisitioned by occupy ing armies) , enormous gaps in the available litterature led to local research activities, conducted independently of similar efforts undertaken elsewhere.

Astronomy isthemostancientsciencehumanshavepracticedonEarth. Itisascienceofextremesandoflargenumbers:extremesoftime–fromthe big bang to in?nity –, of distances, of temperatures, of density and masses, ofmagnetic?eld,etc.Itisasciencewhichishighlyvisible,notonlybecause stars and planets are accessible in the sky to the multitude, but also - cause the telescopes themselves are easily distinguishable, usually on top of scenic mountains, and also because their cost usually represent a subst- tialproportionofthenation’sbudgetandofthetaxpayerscontributionsto that budget. As such, astronomy cannot pass unnoticed. It touches on the origins of matter, of the Universe where we live, on life and on our destiny. It touches on philosophy as well as on religion. Astronomy is the direct c- tactofhumankindwithitsoriginsandtheimmensityofuniversalnature.It is indeed a science of observation where experimentation is practically - possible and which is ruled by mathematics, physics, chemistry, statistical analysis and modelling, while o?ering the largest number of veri?cations of the most advanced theories of fundamental physics such as general r- st ativity and gravitation. At the beginning of the 21 century astronomy is clearly a multidisciplinary activity touching on all aspects of science. It is therefore logical that in the past and still now, astronomy has attracted the most famous scientists, be they pure observers, mathematicians, physicists, biologists, experimentalists, and even politicians.

This book deals with collective and stochastic processes in astrophysical disks involving theory, observations, and the results of modelling. It examines the spiral-vortex structure in galactic and accretion disks, and stochastic and ordered structures in developed turbulence. The book advances the study in this important branch of astrophysics and will benefit professional researchers, lecturers, and graduate students.

This detailed examination of our steps into space is viewed from our potential future there – on Mars to be exact – and considers how we will reach that point.

This book offers a unique review of how astronomical information handling (in the broad sense) evolved in the course of the 20th century, and especially during its second half. It will be very useful for researchers, teachers, editors, publishers, librarians, computer scientists, sociologists of science, research planners and strategists, project managers, public-relations officers, plus those in charge of astronomy-related organizations, as well as by students aiming at a career in astronomy or related space science.