of books by Adrian Bejan
ADRIAN BEJAN (b. 1948) is J. A. Jones Distinguished Professor of Mechanical Engineering at Duke University. He has devised the constructal law of design and evolution in nature.
Design by Nature is about a first principle explanation of natural forms and the evolution of both living and non-living things that depend on movement. Bejan explicitly introduces the term 'design' as a feature of dynamic physical systems that depend on or show movement. The form of these objects evolves such that it finds the easiest path to move things (like heat out of a body, liquid through a distribution system, information through a population of organisms). The central idea to the constructal law is that natural patterns like branching, cracking and turbulence are the result of finding the most frictionless way of moving things through the structure. The constructal law explicitly explains why these natural forms evolve, and is not just another mathematical model of fractals, complexity or networks that describe their shape or function.
In his newest book, Adrian Bejan explains his Constructal law as universal and applicable to biology, science, culture and inanimate systems in the Universe. Anything that has the ability to change will do so, and will change in ways that improves flow and efficiency of moving matter or information through the system. Each chapter repeats these talking points again and again, and in my view very convincingly, maybe not in the easiest way possible. He explains both growth and evolution and makes sure we understand the difference. In all systems that evolve, the participating entitites grow, first slow, then fast, then slow again. Any a new system that evolves does so first slowly, then fast, then slowly again. Growth and movement are necessary for change. It seems repeptitive, but in a sense that is exactly how life is as well. As an engineer, he has several well developed chapters on sports and development of airplains, the design of cities and dissimination of scientific knwolede, where he provides equations to capture an essential core of the constructal law that applies. Large objects move faster and farther, and do so by using less energy per unit mass moved. He uses the engineering solutions in heat dissipation and growth of snowflakes to that all evolvable systems are hierarchical, trending to form dissipative systems with a few large dissipative channels and many smaller tributaries (also for tributaries of rivers and river deltas, the design of streets of ancient on modern cities etc.). In evolution as in engineering, there is ways something that works better - a better organization for better flow and more efficient energy use. This is also remarkably well described by Henri Petroski in his 1994 book The Evolution of Useful Things.
January 23, 2013, updated July 2018/ © 2013 Lukas K. Buehler / go back to Book Review Home