Physicist understanding of the essential nature of reality changed radically over the past quarter century. Frank Wilczek has played a lead role in establishing the new paradigms. Transcending the clash and mismatch of older ideas about what matter is, and what space is, Wilczek presents here some brilliant and clear syntheses. Space is a dynamic material, the engine of reality; matter is a subtle pattern of disturbance in that material. Extraordinarily readable and authoritative, The Lightness of Being is the first book to unwrap these exciting new ideas for the general public. It explores their implications for basic questions about space, mass, energy, and the longed-for possibility of a fully unified theory of Nature. Along the way, Wilczek presents new perspectives on many strange aspects of our fantastic universe. Pointing toward new directions where the great discoveries in fundamental physics are likely to come, he envisions a new Golden Age in physics.