The book is divided into sections, each dealing with one of the main physical processes in photosynthetic energy conversion. Each section has several chapters each describing the role that a basic physical property, such as charge or spin, plays in governing the process being discussed. The chapters proceed in an orderly fashion from a quantum mechanical description of early processes on an ultrafast timescale to a classical treatment of electron transfer and catalysis on a biochemical timescale culminating in evolutionary principles on a geological timescale.