Relativity Reexamined examines relativity from a new angle and with an unconventional perspective. Topics covered range from quantum theory and relativity to gravitation and relativity quantized atomic clocks, as well as special relativity Doppler effect and spherical symmetry. A distinction is also made between mathematical coordinates and physical frames of reference. This book is comprised of eight chapters and begins by considering the development of scientific theories in general, citing examples to show how scientists’ viewpoints have progressively changed. Some of the problems that have emerged, and which even Albert Einstein was unable to foresee, are highlighted. The first chapter reviews the historical sequence of events that led to quantum theory and relativity, while the second chapter focuses on some problems about restricted relativity, paying particular attention to the meaning of potential energy and the importance of field theory in relativistic theories. The following chapters analyze a variety of experimental evidences that challenge many basic assumptions in theoretical physics, focusing on the fundamental importance of the Mossbauer effect and of atomic clocks; the link between gravitation and relativity; classical problems of theoretical mechanics; and special relativity Doppler effect. A gravistatic problem with spherical symmetry is also described. This monograph will be of interest to physicists and students of physics.