The ongoing paradigm change in regard to the use of energy, its efficient usage and the consumption of resources is giving rise to new light systems and lighting appliances. This development might also lead to the use of light as a building material in its own right, comparable to traditional building materials, making it possible to create light space productions – something that did not seem feasible up to now due to the high cost of energy and of light systems. The goal of this book is to develop temporary light spaces that re-interpret the existing urban environment on a seasonal basis or over a cycle of several years. As a result, the city will literally appear in a new light. Strollers in the city streets will experience their familiar environment in a new way. Illuminated planes interlacing with planes made by linear fields of light beams will create immaterial material space experiences: still lifes of light within which one can move about and light choreographies that move barely noticeably, creating still lifes in motion. Current research aims at exploring, imagining and inventing stand-alone spatial structures of light, adding on to and transforming existing spaces, creating a new spatial awareness that may enable people to experience urban space in a different way. Similar to the process of architectural design, where haptic built volumes create interspaces, the light spaces that are presently being designed make these interspaces visible and allow urban dwellers to experience unexpected spatial constellations. The discourse in this book starts with essays introducing aspects of light spaces, including the following: Christian Bartenbach on the perception of light as something that creates space; Niels Gutschow on the ritual dimension of light, an element in the history of creation; Samuel Widmer on light in near-death experiences; Aldous Huxley on light as the messenger from a world we perceive on an unconscious level; Jun'ichiro Tanizaki on the world of the shadow and Tadashi Endo on movement as a relation between time and space in Butoh, the Japanese dance of darkness. The discourse concludes with documents on light spaces by Wolfgang Rang collected over a period of 30 years showing how these light spaces were regarded in the writings of con-temporaries, including Max Bächer on the dawn of a new era; Hans-Peter Schwarz on the deconstruction of space by light; Jürgen Hasse on light as a discourse fragment of public space; Manuel Cuadra on red luminescence; and Antonio de Campos on shadow as an expression of light.