Vascular Societies

Hustle, bustle, and wealth is where you'll find the flow.

Yesterday, we discussed the genesis of constructal theory for Adrian Bejan. Today, we’re going to click out a bit to survey the macro processes of human societies through the lens of the Law of Flow.

Everything that moves is a flow system. Whether animate or inanimate, says Adrian Bejan, all flow systems generate their structures based on the currents they encounter in the wider environment. So evolution applies beyond the realm of biology: 

Flow systems have two basic features (properties). There is the current that is flowing (for example, fluid heat, mass or information) and the design through which it flows. A lightning bolt, for example, is a flow system for discharging electricity from a cloud. In a flash it creates a brilliant branched structure because this is a very efficient way to move a current (electricity) from a volume (the cloud) to a point (the church steeple). A river basin’s evolution produces a similar architecture because it, too, is moving water from an area (the plain) to a point (the river mouth). We also find a treelike structure in the air passes in lungs (a flow system for oxygen), in the capillaries (a flow system for blood), and the dendrites of neurons in our brains (a flow system for electrical signals and images). This treelike pattern emerges throughout nature because it is an effective design.

Look for the treelike structures. That’s where you’ll find the flow Lao-Tsu cautions us not to resist. 

I had come across an article about Bejan and his work online. Some egghead from Duke had reportedly explained everything in the world with a single principle: swimming fish, running mammals, and branching trees. I didn’t pay it much attention at the time. I was still synthesizing the insights of complexity—the study of emergence and the relationships among parts, wholes, and the rules they live by. Little did I realize there were more intimate connections between emergent complexity and what Bejan was saying.

I would have passed over it had I not encountered a journalist named J. Peder Zane at an event. Zane had been working with Professor Bejan on a book (in which the passage above appears). We got to talking and eventually had lunch together to share interests. Before I knew it, I was searching constructal law online back at my house.

I soon began to turn this new lens onto my own interests.

Channels and Rules

In September 2010, I called Professor Bejan for the first time. Because my background lies primarily in political and economic theory, I wanted to see how far he’d extended constructal theory to these subjects. I asked him about the relationship between the constructal law and legal rules (institutions). After all, if the constructal law is a law of nature that extends to animate and inanimate systems alike, might it not also extend to human social arrangements?

Wearily, he told me of his recent trip to Edinburgh. Bejan had been on foot, on his way to give a talk on an academic paper, but in a flash of insight, he got his own lesson that day. As he began to explain, he shed some of his weariness.

“I kept bumping into people,” he said, with the softest Romanian accent. “Why was this happening? Then it occurred to me: people in the UK drive on the left.”

The natural inclination of Scots is to mimic the rules of the road in the relative anarchy of the pedestrian thoroughfare. Bejan had been breaking an informal rule. In order to find flow, he had to adapt to the channels local to Edinburghers.

“Channels are analogous to rules,” Bejan said.

I wondered if Bejan had read the work of new institutional economist Douglass North, who speaks of the tendency of certain institutions (rules) to “lower transaction costs.” This, after all, is econ-speak for “flow.”

In his Nobel Prize lecture, North said:

Institutions are the humanly devised constraints that structure human interaction. They are made up of formal constraints [rules, laws, constitutions], informal constraints [norms of behavior, conventions, and self-imposed codes of conduct], and their enforcement characteristics.

But how much do institutions—formal and informal—matter to the success of societies?

Together they define the incentive structure of societies and specifically economies. … Only under the conditions of costless bargaining will the actors reach the solution that maximizes aggregate income regardless of the institutional arrangements. When it is costly to transact, then institutions matter. And it is costly to transact.

It’s costly to transact, indeed.

You must trust that people will come through on their end of a bargain. You have to be able to find those you want to transact with. You have to be able to count on a wider business environment that doesn’t include too many third-party intermediaries, such as regulators, tax men, or strongmen collecting bribes. The rules of the game are critical to economic prosperity over time. Likewise, channels within systems form over time to improve flow. 

Vascularization

Just like the fractals I used to see everywhere, I began to see the constructal principle working everywhere. Bejan calls it “vascularization.” The big difference is fractals only describe; the constructal law explains. Bejan writes:

The constructal law does much more than explain the designs we see in nature. It articulates a law we can use to understand why designs emerge and predict how they will evolve in the future.

To get our heads around vascularization, think about trees in terms of their form and function. In the air, why do they branch so? To ensure the inflow of carbon dioxide. In the soil, why do the roots fork the way they do? To optimize the inflow of nutrients and water to the tree. Outflows of waste (oxygen) by trees ensure we get fresh air, which we need in our human cardiovascular systems. Our vascular systems have co-evolved with that of the plants, so it’s no wonder the plant and human systems resemble tree branches.

In order to accommodate currents in the world, vascularization abounds. Tree-like configurations in everything, from river basins to the transportation networks that deliver your milk, are instances of Bejan’s principle at work. For any such system to persist in time, it must continuously provide better flow.

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Phenomena Explained or Predicted by the Constructal Law

1. The shape and distribution of trees in forests

2. The form and function of river basins

3. The form and function of circulatory systems

4. The physics of flight in animals

5. The physics of running animals

6. The physics of swimming animals

7. The size, shape, and race of Olympic runners

8. The size, shape, and race of Olympic swimmers

9. University rankings

10. College basketball rankings

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Few Large and Many Small

Finally, we arrive at the question of wealth: How do the tree-like/vascular designs we see everywhere in nature extend to economies, corporations, companies, CEOs, employees, investors, and consumers?

“Constructal theory,” says Bejan, “is the view that the generation of design in nature is a phenomenon of all physics.” All physics includes “everything, animate or inanimate, geophysical and societal.” That’s a powerful, sweeping claim, but Bejan is confident. His law has been so fruitful in its ability to explain so much.

Can it explain the rich-poor gap?

Bejan’s French collaborator Sylvie Lorente argues that constructal designs exhibit the property “few large and many small.” That is, flow systems normally organize like vascular systems in which big currents are connected to ever-smaller streams. If the law stands up across multiple areas, the distributions of resources will exhibit a similar pattern, whether in college rankings, well-paid jobs, or wealth. In the case of income, the constructal law explains why we have a few people with large net worth and many people with small net worth. Wealth is distributed naturally this way, like a scaling law. But the distribution is no cosmic accident—no aléatoires. The evolved distribution is functional.

Function gives rise to form, and form is about flow.

Constructal logic explains the strong relationship between energy use and GDP. Advanced nations are wealthy because they can move stuff more efficiently than developing countries. Energy consumption is, simply said, a measure of moving stuff where it needs to go. Is it any wonder, then, that some of the biggest companies in the world have to do with energy and flow?

• ExxonMobil (energy),

• Wal-Mart (logistics and retail) and

• Google (information).

The extent to which an entrepreneur, say, can make and move valued products, services, or information is the extent to which he’ll be rewarded. Think J.P. Morgan and Henry Ford; in the information space, there were Gutenberg, Morse, and Bell before Jobs, Metcalfe, and Berners-Lee.

“Wealth is physics,” Bejan says, “because wealth is in some sense flow and movement. And that is measurable. Wealth is not abstract.”

Because wealth is connected to the physical world, Bejan thinks it underpins the evolved design of flowing economies.

The foregoing was the second in a series on the constructal law. Read the first here. Next time, we’ll discuss the relationship between wealth and flow.