Many of the ISO observers who assembled for this workshop at Ringberg c- tle met for the third time in the Bavarian Alps. At two previous meetings in 1989 and 1990 surveys were only a minor topic. At that time we were excited by the discoveries of the IRAS survey mission and wanted to follow it up with pointed observations using an observatory telescope equipped with versatile instruments. With the rapid development of detector arrays and stimulated by ISO’s Observing Time Allocation Committee, however, surveys eventually became an issue for the upcoming mission. In a review paper on “Infrared S- veys - the Golden Age of Exploration” given at an IAU meeting in 1996, Chas Beichman already mentioned that there are ISO surveys. They were at the bottom of his hit list, while the winners were future space missions (Planck, SIRTF, etc. ) and ground-based surveys in preparation (Sloan, 2MASS, DE- NIS, etc. ). He organized his table according to the relative explorable volume, calculated from the solid angle covered on the sky and the maximum distance derived from the detection sensitivity. Clearly, with this ?gure of merit, ISO, as a pointed observatory, is rated low. Applying the classical de?nition of a survey, i. e. to search in as large a volume as possible for new or rare objects and/or study large numbers of objects of various classes in order to obtain statistical properties, ISO was indeed limited.

The arrival of large submillimeter and millimeter-wave detector arrays opened a new window on galaxy formation and evolution. The major new facilities now being designed or constructed, such as ALMA (MMA) and the Large Millimeter Telescope (LMT), will soon be expanding the horizons even farther.The Conference on “Deep Millimeter Surveys: Implications for Galaxy Formation and Evolution” drew together the major international groups working on submillimeter and millimeter-wave galaxies to discuss their relation to other galaxies both near by and in the early Universe, the role of the LMT and other new facilities in advancing the new field, and the implications of the new results and models for our understanding of galaxy formation and evolution. The resulting compendium of reports on observations, simulations, theory and interpretation, and instrumentation is the first book to present the new millimeter view of the early Universe thoroughly in a single volume.

This book recounts results obtained via the Infrared Space Observatory (ISO) on comets, in the close environment of pre-main sequence stars, in the interstellar medium, and in the final stages of stellar life, using molecular hydrogen, ubiquitous crystalline silicates, water and ices. ISO has enabled investigation of the fuelling mechanism of galaxies, and new understanding of luminous infrared galaxies and their role in shaping present galaxies and in producing the cosmic infrared background.

Quasars, and the menagerie of other galaxies with "unusual nuclei", now collectively known as Active Galactic Nuclei or AGN, have, in one form or another, sparked the interest of astronomers for over 60 years. The only known mechanism that can explain the staggering amounts of energy emitted by the innermost regions of these systems is gravitational energy release by matter falling towards a supermassive black hole --- a black hole whose mass is millions to billions of times the mass of our Sun. AGN emit radiation at all wavelengths. X-rays originating at a distance of a few times the event horizon of the black hole are the emissions closest to the black hole that we can detect; thus, X-rays directly reveal the presence of active supermassive black holes. Oftentimes, however, the supermassive black holes that lie at the centers of AGN are cocooned in gas and dust that absorb the emitted low energy X-rays and the optical and ultraviolet light, hiding the black hole from view at these wavelengths. Until recently, this low-energy absorption presented a major obstacle in observational efforts to map the accretion history of the universe. In 1999 and 2000, the launches of the Chandra and XMM-Newton X-ray Observatories finally broke the impasse. The impact of these observatories on X-ray astronomy is similar to the impact that the Hubble Space Telescope had on optical astronomy. The astounding new data from these observatories have enabled astronomers to make enormous advances in their understanding of when accretion occurs.

Martin Harwit, author of the influential book Cosmic Discovery, asks key questions about the scope of observational astronomy. Humans have long sought to understand the world we inhabit. Recent realization of how our unruly Universe distorts information before it ever reaches us reveals distinct limits on how well we will ultimately understand the Cosmos. Even the best instruments we might conceive will inevitably be thwarted by ever more complex distortions and will never untangle the data completely. Observational astronomy, and the cost of pursuing it, will then have reached an inherent end. Only some totally different lines of approach, as yet unknown and potentially far more costly, might then need to emerge if we wish to learn more. This accessible book is written for all astronomers, astrophysicists, and those curious about how well we will ever understand the Universe and the potential costs of pushing those limits.

Many important observational clues about our understanding of how stars and planets form in the interior of molecular clouds have been amassed using recent technological developments. ESO's Very Large Telescope promises to be a major step forward in the investigation of stellar nurseries and infant stars. This volume collects papers from the leaders in this very timely field of astrophysical research. It presents theoretical and a host of observational results and many papers show the plans for future observations.