Artist Robert Irwin. He's been a pivotal figure in American Art for over 30 years. He was one of the creators in the late 60s of the "light and space" movement, using unobtrusive objects, such as light, tape, and string to alter the viewers perception of the space in which the work is found. His work can be found in public spaces throughout the country, often using material natural to that environment, and delving into the "character" of the place. A new book, encompassing his work, has been published, "Robert Irwin" (published by the Museum of Contemporary Art, Los Angeles).