"Dan Siegel has a special gift for clear and vivid exposition, and he conveys difficult issues and concepts with a minimum of technicalities. He tells the story of relativity in a novel way, with useful insights into the process of theory making in general." 

-Olivier Darrigol, Centre National de la Recherche Scientifique

"Dan Siegel has written the book the relativity revolution deserved but never had. By taking the protorelativity period seriously—the quarter-century of work by Lorentz, Poincaré, and others that established the building blocks Einstein would radically restructure—Siegel shows that even the most celebrated breakthrough in modern physics was a two-phase transformation, not a single stroke of genius. His vivid mountain-climbing metaphor captures what linear narratives miss: While the protorelativists pushed straight up from base camp, battling unresolved puzzles about the structure of the electron, Einstein found a completely different route around the mountain—reaching a higher summit by asking different questions rather than by solving the old ones. What makes this book exceptional is the way it integrates history with pedagogy. The protorelativity material does not merely credit Einstein’s predecessors; it provides the concrete, pictorial entry point that makes Einstein’s abstract reasoning genuinely accessible. And by tracing the long road to acceptance—thirty years in which protorelativistic and relativistic approaches coexisted, competed, and cooperated—Siegel dismantles the myth of instant paradigm shifts. This is a book that deepens our understanding of both the physics and the process by which scientific revolutions actually unfold." 

-Jürgen Renn, Max Planck Institute of Geoanthropology, author of The Evolution of Knowledge

"A well written, comprehensive, detailed, yet broadly accessible account of one of the most significant scientific revolutions of recent times initiated by one of the greatest scientists of all time. Dan Siegel enhances our understanding of how this revolution arose and influenced the sciences and other facets of culture far beyond its sphere. He also offers a new perspective on the relationship of a transformative scientist such as Einstein to his scientific community."

-David Cassidy, Hofstra University

Dan Siegel is emeritus professor of the history of science at the University of Wisconsin–Madison.