Constructal Theory

Constructal theory is this mental viewing:

(i) The generation of design (configuration, pattern, geometry) in nature is a physics phenomenon that unites all animate and inanimate systems, and

(ii) This phenomenon is covered by the Constructal Law: "For a finite-size (flow) system to persist in time (to live), its configuration must evolve such that it provides easier and easier access to its currents." (Bejan, 1996)

The Constructal Law is about the time direction of the "movie" of design generation and evolution. It is not about optimality (min, max), end design, destiny or entropy.
The concept that the Constructal Law defines in Physics is "design" (configuration) as a phenomenon in time.


The constructal theory was developed by Adrian Bejan, Ph. D. MIT (1975) in the late 90's.

Professor Bejan taught at MIT until 1976 and is now J.A. Jones Distinguished Professor at Duke University, Durham.

Bejan's research areas cover: thermodynamics, heat transfer, design in nature, convection in porous media, transition to turbulence,

"Constructal" is a word created by Bejan, coming from the Latin verb construere, to construct, in order to designate the natural tendency of all flow systems to construct flow configurations, such as rivers, trees and branches, lungs and also the engineered forms coming from the constructal design-generation.

Because Bejan has identified a basic Law of Physics that describes and predicts how design patterns emerge over time, he contends that one can construct a “constructal theory” about any system, animate, inanimate or technological (see more about this at Constructal Theory Web Portal). This last one of course got my attention and I have been peppering my posts with little constructal tidbits ever since. Anybody who has participated in the phenomenon of viral social media understands, intuitively, what Bejan is describing mathematically. There are characteristic ways that flows change their configuration over time to flow more (and more!).

In many parts of science, and in life, we have “black boxed” the processes through which things change. We put energy into a box called entropy and note that it dissipates. We are born and then we die—but in between something happens, we live. The Constructal Law is important because it not only describes the patterns of change in the world within and around us, but it allows us to predict how the configuration of those patterns will evolve over time.

The verb “to design” is the human urge of contriving and extending the reach and power of each individual. Those who design are designers. The Constructal Law of design in nature is not about the designer. It has nothing to do with “intelligent design.”

Science is the search for the laws that govern natural phenomena. Science is not the search for the designer, one or many. The latter is a much older search called religion.

The Constructal Law defines in physics terms what it means to be “fit”. It defines in physics terms what it means to be “alive”, and why the “adaptable” is more likely to survive. “Freedom is good for design”, is one of my favorite lines in the book and the class room.

The Constructal Law has countless applications because it puts biological design and evolution within the realm of physics, along with everything else that did not have a home in “hard science” until now : economics, social dynamics, business, and government.

Posted on Friday, August 17, 2012 at 07:40:11 PM in Nemetics
Dan RD

By Dan RD

Yo! I'm mulling the future of everything.  My interests are so diverse I've decided to collapse them into the study of Nemetics -- an ongoing collaborative inquiry.

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