From computers to optical communications, this textbook explores the core principles of physics that underlie those technologies that are revolutionizing our everyday lives. The text first provides an introduction to physics, silicon, and the Internet. The second part of the text establishes the basic physics principles at the core of the information technology revolution. A third part examines the quantum era, with in-depth discussion of digital memory and computers. The final part moves onto the Internet era, covering lasers, optical fibers, light amplification, and fiber-optic and wireless communication technologies. Designed for the nonscientist, this text requires no higher math or prior experience with physics.