“Hierarchy is not imposed, it is natural,” Duke professor Adrian Bejan told J. Peder Zane in a recent interview. “Equality, however, is artificial, because it violates the law of evolution in nature.” Bejan comes to this conclusion because “physics and economics are two sides of the same coin,” and physics governs the structure of everything that moves, whether water,  air, blood, people, goods, ideas, or money.

Because everything is about flows, he adds, no snapshot ever captures the full truth. In economics, supply and demand may move toward equilibrium, but never rest there. “Everywhere,” Mr. Bejan says, “we see this phenomenon: a few large movers and many smaller ones, all working together for the good of the whole. The large channels are not robbing the smaller ones; both are serving each other.”

This has design implications in nature, in engineering, and in policy. It takes energy to redirect a natural outcome, whether damming or channeling a river, or promoting more equitable economic outcomes. Those, like Anand Giridharadas, who complain about “an economic order, a set of social arrangements, that is guaranteed to shut most Americans out of the so-called American dream” and those who pine for a socialist utopia, ignore the physical and human fundamentals that bring about inequality in any social system.

Zane and Bejan collaborated a fews ago to explain the constructal law to a broader audience.