Artists play several roles in recording and shaping our understanding of the world: 1) They record and document the places, ideas, and experiences around them, such as Albert Bierstadt's paintings of the Rocky Mountains and Georgia O'Keeffe's landscapes. 2) Artists give tangible form to intangible concepts and philosophies, like Wu Chen's painting representing Taoist ideals. 3) They provide new perspectives and ways of seeing, exemplified by Robert Smithson's Spiral Jetty earthwork and Christo and Jeanne-Claude's large-scale Umbrellas installation.