Speaker: Steven N. Shore Dipartimento di Fisica (Pisa) "The Space Between the Stars: the Interstellar Medium" The talk will provide an overview of the original "dark matter" problem, how this diffuse medium was discovered, what multispectral techniques are required to study it, and how our understanding has developed of its present state and its evolution through the history of galactic star formation and death through the combined advances of theory, modeling, and technology during the past 50 years.