Based on a course taught at the University of Rochester, this volume describes the physical principles on which modern technology is based. Four primary areas are discussed; computers and microelectronics, communications, nuclear energy and space flight. Each topic is treated in a manner that provides the reader with insight into the underlying physics that makes the technology possible as well as the orders of magnitude involved. The book will appeal to anyone interested in modern technology and will serve as a reference book and a textbook for courses in applied physics, and engineering.