Over the course of history, materials such as concrete and steel changed the thinking process of architects. Immaterial / Ultramaterial, the second volume in the Millennium Matters series, investigates today's revolutionary new materials and methods of fabrication, and the profound impact they are having on the continuing evolution of architecture. The impact is felt in many areas, including architects' design methods, the conception of form, and modes of production. From the use of immaterial elements such as light, sound, and smell, to the implications of invincible materials ("ultramaterials"), which technological developments may soon place within our reach, this book envisions the future direction of architecture.