Physics theory suggests everything that moves is based on a 'flow system' | PRI.ORG

# Physics theory suggests everything that moves is based on a 'flow system'

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Constructal law suggests that everything which moves is based on a flow system that is tree shaped. The flow connects one point with a larger area with infinite points. (Photo by Flickr user Kerry Woo.)

Constructal law, designed by Duke University professor Adrian Bejan, is a new way of looking at how the world works. According to the law, everything that moves, whether animate or inanimate, is based on a flow system, which is tree shaped.

Mechanical engineer Adrian Bejan, a professor at Duke University, has spent the last 16 years working on a theory on how the world works. He calls it constructal law.

Contructal law says that flow systems will shape themselves to flow more easily over time, eventually making a tree shape. One example Bejan gives is the representation of the Mississippi River basin.

"In reality, that is not a static drawing. That is a dynamic, a morphing animal, which is called a Mississippi flow, which is from an area, a huge area, to one point," Bejan said.

The design of tree branches, rivers, the air passages in the human lung and even man-made products, like highways, make a similar flow, according to Bejan's theory. But the theory doesn't just describe the flow of corporeal beings. The flow of an idea is also tree shaped.

"Anything that flows, the animate, the inanimate and our social dynamics is subject to this law and, for that matter, to any other law of physics," Bejan said.

But not everything grows and branches out. It is here that constructal law makes the distinction between what is "alive" and what is "dead."

"To be alive means to be a flow system that is free to change its configuration over time," Bejan said. "Dead are samples of, say, crystals or solid. Dead is anything that shows absolutely no movement."

However, a dead flow is not irreversible. Bejan said a glass of water is dead, but if the water is exposed to air and thus evaporated, it would re-enter a flow system.

Bejan's idea of constructal law came about in contention to a speech given by Ilya Prigogine, a Nobel Prize laureate for chemistry and proponent of chaos theory, at a 1995 science conference in France. According to Bejan, Prigogine said similar branching shapes in nature were coincidental.

Chaos theory holds that small changes in initial condition end in widely diverse results and makes them unpredictable, despite being deterministic in nature. Constructal law directly conflicts with this notion.

He is currently trying to change the way people think about the universe with his new book Design in Nature: How the Constructal Law Governs Evolution in Biology, Physics, Technology, and Social Organization.

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#### Comments (3 posted)

Sean 01 May, 2012 11:16:32
Granted, I have only a naive understanding of the theory, but From what's said about constructual law, here, I don't see how it conflicts with nonlinear dynamics - I would think that nonlinear dynamics would rather compliment it. For example - in keeping with the example of the Mississippi - a small change in a small stream in the collective headwaters may nonetheless have an affect on the broader Mississippi itself, all the way from that stream, on to where it meets the river, then through the delta and into the ocean. Perhaps the most negative example of that would be: A case of wate pollution. A polluted headwaters pollutes the whole river with same toxic elements in the headwaters.

In the case of non-toxiFrom what they say about constructual law, I don't see how it conflicts with nonlinear dynamics - I would think that nonlinear dynamics would rather compliment the tree model of flows. For example, a small change in a small stream in the collective headwaters on the Mississippi may nonetheless have an affect on the Mississippi itself, all the way from that stream, on to where it meets the river, then through the delta and into the ocean. Perhaps the most negative example of that would be: A case of wate pollution. A polluted headwaters pollutes the whole river with same toxic elements in the headwaters. This could alternately be demonstrated with a matter of natural, non-toxic mineral content.

An affect on one headwaters stream may appear to be subtle, in the waters of the whole river, but there would nonetheless be an effect taking place, there.

From that admittedly naive illustration, then, I think it stands to hypothesize that nonlinear dynamics - chaos theory - could compliment constructural law.

What a nice item to find in the news, by the way! Thanks, PRI!
Sean 01 May, 2012 11:47:34
I regret making that bad cut-and-paste job, there. I would say that it could be a matter of netiquette - at which, I apologize. I would like to revise that comment, then, if I may:

Granted, I have only a naive understanding of the theory, but From what's said about constructual law, here, I don't see how it conflicts with nonlinear dynamics - I would think that nonlinear dynamics would rather compliment it. For example - in keeping with the example of the Mississippi - a small change in a small stream in the collective headwaters may nonetheless have an affect on the broader Mississippi itself, all the way from that stream, on to where it meets the river, then through the delta and into the ocean. Perhaps the most negative example of that would be: A case of water pollution. A polluted headwaters pollutes the whole river with the same toxic elements in the headwaters.

Adding, then: A more naturalistic illustration could be made, in regards to mineral content in the body of water. A change in a proportion of Zinc, for example - or any other mineral or element - in the headwaters, it would ultimately affect the river, such that we may not be able to predict every possible result of - with existing knowledge, if ever - even so far as any affects the change would have on any organisms living in the downflow sections of the river and/or in the broader riparian ecosystems along the same. Perhaps it could result in a population growth, somewhere in the downflow ecosystem. Perhaps not. Perhaps it may have effects we cannot predict.

I realize that for the purpose of illustration, the river would be an isolated entity. In the real world, however, a river is no isolated thing. I would suggest, inasmuch, that no flow exists separate to its natural, innate environment. I think that nonlinear dynamics may be introduced as to compliment the theory, at that.

I suppose I should stop conjecturing, though, and read more about it ;)
Carine 29 January, 2013 05:41:10
Dear Craig,Thanks for your kind words. It's true this is a generative prseocs which does have a relation with the way infrastructural networks are formed, as opposed to voronoi or other variations. I'm glad I'm not the only one seeing this. Regarding the errors, there's plenty of places they can come from. First off, try to see if you have all the libraries that the sketches are using (they're at the top, the import bla.bla.*; statements) and if not, head over to the prseocsing website and download&install them (there's instructions there on how to do that). If this is not the case, then something might be more seriously wrong so if you hit me (preferably in an email) with the specific errors it would be great. Cheers!
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