In this groundbreaking book, Adrian Bejan takes the recurring patterns in nature-trees, tributaries, air passages, neural networks, and lightning bolts- and reveals how a single principle of physics, the constructal law, accounts for the evolution of these and many other designs in our world. Everything- from biological life to inanimate systems-generates shape and structure and evolves in a sequence of ever-improving designs in order to facilitate flow. River basins, cardiovascular systems, and bolts of lightning are very efficient flow systems to move a current-of water, blood, or electricity. Likewise, the more complex architecture of animals evolve to cover greater distance per unit of useful energy, or