This book is the first of its kind devoted to the key role played by light and electromagnetic radiation in the universe. Readers are introduced to philosophical hypotheses such as the economy, symmetry and the universality of natural laws, and are then guided to practical consequences such as the rules of geometrical optics and even Einstein's well-known but mysterious relationship, E = mc2. Most chapters feature a pen picture of the life and character of a relevant scientific figure. These ‘Historical Interludes’ include, among others, Galileo's conflicts with the Inquisition, Fourier's taunting of the guillotine, Neils Bohr and World War II, and the unique character of Richard Feynman.This second edition has been revised to present information in a more accessible style. Most of the mathematical jargon and equations from the first edition have been transformed into layman's terms. More historical materials have been included to account for the application and understanding of the phenomena of light from pre-historic to present times.The book will be of interest to students and teachers, as well as general readers interested in physics.