Along rivers 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, a global solution nonetheless emerges that optimizes irrigation flows for everyone. Did someone have to design Bali's water temple networks, or could they have emerged from a self-organizing process?

Perfect Order--a groundbreaking work at...