Design in Nature

November 7, 2011
The constructal law, as articulated by Duke engineering professor Bejan is relatively simple: systems change over time to maximize the rate of flow through the system. And this high level of efficiency is achieved in similar ways in any dynamic system, whether water flowing through an ecosystem or blood through a body’s circulatory system. Bejan makes the controversial claim that the constructal law explains everything in the world, from the evolution of life to the development of human culture, and can predict how things will evolve—toward the ability to move more freely on Earth. But this tediously repetitious book fails to live up to its predictive promise. Nor can Bejan’s application of his theory to biology be taken seriously when he says, for instance, that biologists claim that evolution cannot be tested or when he conflates “evolving” and “morphing.” Bejan’s reductionism achieves a level of grandiosity when he asserts that constructal theory explains all of human history as a movement toward human freedom and the free flow of ideas. His conclusion is strangely Panglossian: “we can witness many entities morphing—becoming better and better” in this best-designed of all possible worlds. Illus.

November 1, 2011
Thermodynamics expert Bejan (Engineering/Duke Univ.; Porous and Complex Flow Structures in Modern Technologies, 2011 etc.) claims to have discovered a new scientific principle called the "constructal law." With the assistance of columnist Zane, Bejan takes the evolution of "finite-size flow system[s]" as a model to exemplify his unifying principle that allegedly explains the design of all natural systems—both inanimate and animate, biological or social. The author conflates life and motion, writing that "anything that flows… is 'alive' because it evolves"—whether it be a river or a human being—and that the "hydrosphere, atmosphere, lithosphere, and biosphere are a tapestry of engines attached to brakes." Bejan compares himself favorably to Newton and Darwin, and he suggests that a law similar to the constructal law applies to the way that tributaries flow into rivers, increasing the speed of the flowing water; to highway systems and athletic competitions, in which athletes achieve record-breaking performances; and to the military, which channels soldiers, supplies, vehicles, strategies, etc. Lest the title suggest that he is a supporter of theories of Intelligent Design, the author explicitly rejects the existence of a designer. He also opts for hierarchical social systems and the concentration of power and wealth. Bejan provides clear explanations of basic design principles as they apply to fluid flow, the design of computer chips and the function of animal circulatory systems, but his broader claim to have discovered an umbrella theory about the universe is unconvincing.

(COPYRIGHT (2011) KIRKUS REVIEWS/NIELSEN BUSINESS MEDIA, INC. ALL RIGHTS RESERVED.)

Starred review from February 15, 2012

Bejan (J.A. Jones Distinguished Professor of Mechanical Engineering, Duke Univ.), with the editorial assistance of Zane (journalism, St. Augustine's Coll., Raleigh), has written a book that should be in every academic library. In 1995, Bejan first outlined the concept of constructal law, a theory of organization that studies the thermodynamics, shape, structure, and patterns of flow systems. This emergent body of knowledge has quickly developed into a new extension of physics, with applications in fields including evolution, predictability, engineering, biology, and intelligent design. Constructal first principles are a new way of investigating the world to better predict patterns and structures in systems small (e.g., the flow of water, blood, and electricity) and large (e.g., river patterns, social organizations). VERDICT Bejan's writing is brilliant. He effectively illustrates complex ideas for a general audience, provides real-world examples, and includes scholarly notes and references. A landmark publication.--Ian D. Gordon, Brock Univ. Lib., St. Catharines, Ont.

Copyright 2012 Library Journal, LLC Used with permission.

December 15, 2011
When lightning flashes in the sky, showing off its characteristic pattern of zigzagging veins, it's not hard to see its resemblance to branching trees or waterway tributaries. It's also easy to assume those similarities are purely visual because these patterns occur in such different realms of nature. Yet according to veteran mechanical engineer and Duke University professor Bejan, these recurring shapes and structures obey a fundamental principle of physics known as the constructal law. Put simply, this law asserts that all things that live or move, from ants and animal herds to rivers and electric currents, persist and evolve according to their ability to facilitate flow. In this lucidly written overview of the constructal law, Bejan, with journalist Zane, describes all the circumstances and ways this law operates in the world, including blood vessels and man-made cooling systems. The authors' language is never too abstract for the lay reader to easily grasp, and the insights offered here present a revolutionary, unifying vision of nature that could impact all branches of science.(Reprinted with permission of Booklist, copyright 2011, American Library Association.)