An eminently readable overview of the history and physics of galaxies.

In Galaxies, Or Graur offers a brief and fascinating overview of the history, physics, and astrophysical uses of galaxies. Starting with the history of the last two thousand years of galaxy studies, Graur discusses the types of galaxies we observe and the physics that drive them; the myths and physical structure of the Milky Way; how galaxies were used to discover and study the mysterious phenomena of dark matter and dark energy; and how scientists think galaxies formed shortly after the Big Bang and evolved to their present forms.

Tracing galaxy studies back thousands of years ago to their beginnings, Graur describes their origin in Ptolemy’s book Almagest, which was written in the first century CE. Almagest catalogued hundreds of stars and a few hazy cloud-like objects, one of which was the Andromeda galaxy. The reader will also encounter in this book well-known figures such as William Herschel, who, along with his sister Caroline (the first professional female astronomer), discovered hundreds of galaxies and lay the foundations for modern galaxy studies, as well as lesser-known astronomers, including tenth-century Persian astronomer Abd al-Rahman al-Sufi, twentieth-century American astronomer Vesto Melvin Slipher, and others. Galaxies concludes by showing readers how they can get involved in galaxy studies themselves and do their part to fight the light pollution that today obscures the Milky Way and all but the brightest of stars.

Providing a brief but broad overview of galaxies for the nonspecialist, Galaxies shows just how modern science is done and what the future holds for this specific field of astronomy.

Series Overview: The MIT Press Essential Knowledge series offers accessible, concise, beautifully produced books on topics of current interest. Written by leading thinkers, the books in this series deliver expert overviews of subjects that range from the cultural and the historical to the scientific and the technical. In today’s era of instant information gratification, we have ready access to opinions, rationalizations, and superficial descriptions. Much harder to come by is the foundational knowledge that informs a principled understanding of the world. Essential Knowledge books fill that need. Synthesizing specialized subject matter for nonspecialists and engaging critical topics through fundamentals, each of these compact volumes offers readers a point of access to complex ideas.