Along a typical river in Bali, small groups of farmers meet regularly in water temples to manage their irrigation systems.They have done so for a thousand years. Over the centuries, water temple networks have expanded to manage the ecology of rice terraces at the scale of whole watersheds. Although each group focuses on its own problems, somehow everything works out in a way that optimises rice harvests for the farmers in dozens of villages. How is this possible? Google Earth reveals transitory patterns in the rice paddies that closely resemble phase transitions in physics, like the onset of magnetism.This unlocks a story of hidden order that charms the physics community, perplexes economists and offers everyone a startlingly new way to think about how people interact with nature.J. STEPHEN LANSING is the Director of the Complexity Institute, Professor in the Asian School of the Environment, Nanyang Technological University, and external Professor, Santa Fe Institute and Vienna Complexity Hub. He is anemeritus professor of anthropology at the University of Arizona, a senior research fellow at the Stockholm Resilience Centre, and president of the Anthropology and Environment Society of the American Anthropological Association. His recent research has to do with adaptive self-organised criticality and the long-term dynamics of coupled social-ecological systems. Before moving to Arizona in 1998, Lansingheld joint appointments at the University of Michigan in the School of Natural Resources & Environment and the Department of Anthropology, and earlier chaired the anthropology department of the University of Southern California. He has been a Fellow at the Institute for Advanced Study at Princeton, the Center for Advanced Study in the Behavioral Sciences at Stanford, the Institute of Advanced Study at Durham University and the Eijkman Institute for Molecular Biology in Jakarta.

Publications and films areavailable at www.slansing.org