Monday, April 2, 2012

Should the 'constructal law' restore our faith in progress?

‘Everything that moves, whether animate or inanimate, is a flow system. All flow systems generate shape and structure in time to facilitate this movement across a landscape filled with resistance (for example, friction). The designs we see in nature are not the result of chance. They arise naturally, spontaneously, because they enhance access to flow in time.’

Cover art for DESIGN IN NATUREThe quote is a statement of Adrian Bejan’s ‘constructal law’ and is from ‘Design in Nature, How the constructal law governs evolution in biology, physics, technology and social organization’ (2012, p 3). Bejan, a professor of mechanical engineering, has co-authored the book with Peder Zane, an assistant professor of communications.

A basic point that the authors are making is that it is no accident that treelike patterns emerge throughout nature, e.g. trees, river systems, lightning bolts, blood capillaries and dendrites of neurons in brains. The treelike pattern is an effective design for facilitating flows – both from areas to points (as in the flow of water through the root system of a tree to its trunk) and from points to areas (as in the flow of water from the trunk of a tree to its leaves).

When I began to read the book I felt as though I had always believed that the design of flow systems in nature would evolve to facilitate the flow of the stuff that is flowing through them. It seemed intuitively obvious that that should be so, even though I could not claim to have thought much about the matter previously. (In fact, insofar as I had previously thought about it I would probably have been inclined to the view that the evolution of design in nature must be largely random because it is largely a consequence of random events.) After reading a few pages of the book, the main question in my mind was how the authors would justify the claim in the sub-title that the constructal law governs the evolution of technology and social organization as well as natural phenomena.

It seems to me that the authors’ application of the constructal law to technology and social organization is analogous to the application of the theory of evolution to economics (evolutionary economics) and culture (e.g. Hayek’s theory of group selection). The flow perspective actually helps to promote an understanding of social evolutionary processes as being about much more than just survival of the fittest – whether in terms of crude social Darwinism, or more sophisticated concepts relating to survival of ideas, firms, forms of economic and social organization, and social norms.

In my view the authors make a strong case that the accumulation of scientific knowledge can be viewed as a process in which the stuff that is flowing (new ideas) determines design (the organization of knowledge). In their words:
‘Indeed, all the great discoveries, from Newton’s laws of motion to the laws of thermodynamics, didn’t just tell us something new, they organized and streamlined our knowledge’.
The authors explain that scientific discoveries allow disorganized pieces of empirical information to be replaced by summarizing statements (laws). They suggest:
‘A hierarchy of statements emerges naturally because it facilitates the flow of information. It is an expression of the never-ending struggle of all flow systems to design and re-design themselves’ (p 163).

The application of the constructal law to social organization provides insights similar to those provides by the ‘new institutional economics’.  Institutional designs tend to evolve to facilitate transactions – i.e. to reduce transactions costs (which are analogous to friction in physical systems). Unfortunately, the authors don’t provide an explicit discussion of path dependency – in particular the potential for some societies to remain locked in to inferior institutions involving high transactions costs and poor social outcomes. Perhaps a flow perspective provides us with greater grounds for optimism that all people suffering under inferior institutions will eventually obtain the freedom they need to better their condition.

So, should the constructal law restore our faith in progress? The constructal law has not changed my view that it is better to think in terms of conditions for progress than faith in progress (see my last post). We can only be optimistic about progress if conditions are favourable. It makes more sense to ask whether the constructal law provides grounds for greater optimism than to ask whether it should restore our faith in progress. It seems to me that the constructal law provides an appropriately optimistic frame of reference for thinking about progress. Progress isn’t inevitable, but we have strong grounds to view it as a natural or normal phenomenon.

Adrian Bejan has responded as follows:

'Thank you very much for reading our book Design in Nature and writing about it.

I can respond to your call for "how the authors would justify the claim in the sub-title that the constructal law governs the evolution of technology and social organization as well as natural phenomena".

This is actually discussed in ch. 10, and it pivots on Fig. 57. The long version of this response is in the review article published last fall in Physics of Life Reviews (read the comments on Figs. 1, 5, and 20-24.

In our book Design in Nature, the justification is best illustrated by the story of how nature (not man) invented the wheel (Ch.4). Technology is all the contrivances that we make and attach to ourselves to in order to move farther, faster, more efficiently, and for longer (i.e. to live longer). This is no different than the morphological changes that stick as the river basin evolves

So, everything that looks good and we adopt and we acquire is helpful in this constructal flow direction, which is for the whole to flow more easily.. It sounds simple, and it is. Think about the evolution of the technology for power generation, for example. The same with transportation technology, science, language, communications, and currency, and bank tellers, and English as the global language. They all help us go with the flow.'

The article to which Professor Bejan refers in Physics of Life Reviews is also available at the constructal theory web site.


Troy Camplin said...

Very cool he responded to you. I talked about constructal law here and here, though in many ways, I was talking about it even before I knew of it. It is ultimately what network theory is about.

Winton Bates said...

I am still getting my head around Adrian Bejan's response. He clearly wants the constructal law to be viewed as a physical law rather than just a beautiful metaphor - one that we find beautiful because of evolution and our cultural history.
I accept the points he is making about moving further, faster and more efficiently, but human flourishing involves more than that.
Perhaps the issue turns on the extent to which cultural evolution reflects some degree of brain plasticity. I am currently reading Steven Pinker's 'Better angels ...' book, which might help my understanding.