Excerpts from "Freedom Is Good for Design: An Interview with Adrian Bejan"

Adrian Bejan is a professor of mechanical engineering at Duke University. So why on earth are we talking to him? Bejan is the first person to articulate what could be one of the most important ideas since Darwin’s theory of evolution. He calls it the Constructal Law. It goes like this:

For a finite-size system to persist in time (to live), it must evolve in such a way that it provides easier access to the imposed currents that flow through it.

All this may sound highfalutin. But the idea is this: Systems survive when things flow better over time—all kinds of systems. In fact, this is what “life” is: flowing  and changing  (morphing) freely to flow/move more easily. From natural systems to human systems, when things low better, we start to notice patterns in nature that are products of good flow. And if Adrian Bejan is right, this is one of the most important—and underappreciated—aspects of our world. Combine the insights of Hayek, the
mathematics of Mandelbrot, and the biology of Darwin and you get something that might transform the way you see the world.

Adrian Bejan: Put another way, a rigid flow system (dammed river, rigid society) is not natural and is destined to be replaced by one that is free to morph, because the future points toward configurations with greater and greater low access. This is why freedom is good for design.

The Freeman: You have discovered an important relationship using constructal thinking: the relationship between energy and the wealth of nations. Can you help us understand this in layman’s terms?

Adrian Bejan: Look, everything that moves does so because it is being pushed or pulled. Nothing is moving by itself. The river water is pushed by the earth heat engine, which drives the climate (winds, oceans, and so on), the animal is moved by the work derived from food, and we are pushed by our engines—by the work derived from fuel. All this work is destroyed (dissipated), and the visible phenomenon is movement with evolving design.

With the Constructal Law, we had predicted that our movement on the globe should be hierarchical, with few large and many small (as in the mass traffic of airways), and that it should be increasing over time, to spread more, to bathe the world map more.

The Freeman: With a few major arteries and many minor streets and roads, for example.

Adrian Bejan: Exactly. Then we discovered that the big channels (the few large) in this global basin of human flow are the inhabitants of the affluent countries. So, because more flow means more fuel spent, we made an x-y plot with all the countries, showing (x) the annual fuel  consumed, versus (y) the annual wealth—i.e., the gross domestic product (GDP). We found that the intangible “wealth” is proportional to the fuel spent, which means
that wealth is movement, and wealth is physics.

The Constructal Law governs not only the hierarchical, vascular designs—i.e., few large and many small movers—but the future design, which consists of more movement over time and greater wealth and fuel consumption for every group on earth. This is why every group is racing upward on the line indicating the proportionality between energy use and wealth.

The urge to have wealth is a manifestation of the Constructal Law. It is the urge to have more movement, fewer obstacles, and more freedom.

Source: “Freedom is Good for Design. Freedom Is Good for Design: An Interview with Adrian Bejan” The Freemen. Volume 63, No. 4. May 2013.