Whether TV shows or cell phone and internet traffic, whether encoded in the radio waves that fill the atmosphere or coursing through wires of copper and glass, information, in its electronic form, surrounds us. And equally copious to this is the realm of physical information, that which mediates between reality and our understanding of it. Our senses record and interpret it; our brains manipulate and process it; our genes pass it from one generation to the next; and the need to share it is an attribute common to every member of the animal kingdom.But what actually is information? Can it be analyzed and measured? Why, if information is such an essential ingredient of the world around us, is it not yet part of the vocabulary of physical science? In this exciting, enlightening, and extraordinary book, Hans Christian von Baeyer addresses these and many other questions, revealing how the concept of information can cast light on principles as diverse as thermodynamics in physics and heredity in biology. For, despite its shadowy, paradoxical, and subjective nature, this is a concept of unarguable importance and power, one that could soon become just as central to science as space, time, mass, or energy - if not more so.With a narrative marked out by its clarity and sheer readability, von Baeyer takes us from the roots of the theory through to the coal-face of modern physics and beyond, deftly unpicking the many strands that knit information so tightly into the fabric of the universe. Along the way, he illuminates topics from gaming theory and probability through to black holes, the history of Morse Code, the future of computing and the role of philosophy in contemporary physics - all whileunderlining this emergent and rapidly developing field as the key to a fundamental new scientific language.