The authors and editors of Spectroscopy of Astrophysical Plasmas dedicate this book to Leo Goldberg, who, fifty years ago, recognized both the fundamental role of spectroscopy in the observation and interpretation of astrophysical objects and the essential supporting role of basic laboratory and theoretical studies of atomic and molecular spectra. Leo recognized the importance of all regions of the electromagnetic spectrum from radio waves to gamma rays and he made unique original contributions in ultraviolet, visible, infrared, millimeter and radio astronomy. He fostered the careers of many astronomers, several of whom are authors of this book. His understanding of the value of observations at all wavelengths led him to become a persuasive and influential advocate of space astronomy. At Harvard University he created a research group that was at the forefront of ultraviolet observations, particularly of the Sun.

Atoms, Stars and Nebulae, the title of Leo's first book, written with Lawrence Aller, sums up the main themes of Leo Goldberg's remarkable and still flourishing scientific career. In the early 1930s, when Leo embarked on that career, the ‘new physics’ – quantum mechanics – was still terra incognita for most astronomers. A few, however, had recognized its possibilities years earlier. They saw that quantum mechanics could make possible a quantitative understanding of the structure, composition, and physical conditions of stellar atmospheres and interiors, planetary nebulae, and the interstellar medium; and they set out to do something about it. One of these far-sighted and energetic people was Donald H. Menzel, and Leo Goldberg was a member of the first generation of Menzel's students at Harvard.