"Version: 20250901"--Title page verso.Includes bibliographical references.The drunkard and the policeman -- part I. Theoretical background. 1. The ISM and star formation -- 1.1. The ISM as a Flowing continuum -- 1.2. the components of the ISM2. The hydrodynamic equations -- 2.1. The fluid approach -- 2.2. The conservation equations -- 2.3. Constitutive relations -- 2.4. The fluid equations from…
"Version: 20190901"--Title page verso.Includes bibliographical references.part I. Foundations. 1. The early history of the transient sky -- 1.1. The nebulae -- 1.2. Novae in nebulae!2. Novae and the nature of spiral nebulae -- 2.1. Proper motions and spiral nebulae -- 2.2. Novae and nebulae -- 2.3. The great debate -- 2.4. The birth of extragalactic astronomy -- 2.5. Hubble's survey: the Mount …