Constructal Theory: Sustainability
by Tim McGee, Helena, MT, USA on 12.21.06
Sustainability has become a key concept to solving global resource and environmental issues. Several concepts have emerged in the past few decades that appear to provide a path towards a sustainable future. Biomimicry inspires and provides a way for us to adopt examples of evolved sustainable design and systems. Cradle-to-Cradle design provides a goal for enriching our industrial systems. Constructal theory provides the instructions for creating the optimized systems needed, and further, gives us the key for understanding the nature of sustainable technology. These ideas have come at a unique time in our history when, as a society, we are looking at all scales of systems to determine how we might be able to better manage our impact on Earth. Read on to see how constructal theory fits into the new paradigm.
North American native prairie grass is a good example to consider when trying to understand Constructal theory (CT).The prairie is a system of individual plants that grow and change through time, it is resistant to pests, recovers from extreme weather, and enriches the surroundings. By most standards, the native grass prairie is a sustainable system. A recent article stated that the native grass prairie packs 283% more potential bioenergy then a simple monoculture.
- Constructal theory (CT) points out that systems must 'evolve' through time, no single structural design will be sustainable forever. Instead, we must recognize changes within the system and give ourselves the freedom to redraw our design. The native grass prairie does this though more then 100 species of grasses, each with their own unique character. During a drought year, one species may dominate but during a wet year, another will take over. The multiple species can 'redraw' the system to accommodate changes. CT gives us the mathematical concepts needed to determine if a system is optimal for specific conditions, and guide our design options in sustainable directions.
- CT states that for sustainable design, system architecture depends on (and in a sustainable system - is shaped by) the currents that flow through it. This idea echoes what we have learned in biomimicry and Cradle-to-Cradle. Local solutions only make sense locally, because the currents that flow through the system are unique. Just as the native grass prairie changes from shade to full sun, CT provides for us the reason why architectures must be unique to place and circumstance. Further, a CT analysis gives us an optimal architecture that fits to that place.
- It is often problematic for us to determine not only the optimized architecture, but the optimal complexity of a system. CT provides us with the method for determining a level of complexity that fits the system. Although as far as I can tell, nobody has yet used constructal theory to determine the necessary minimal complexity of a prairie, it could potentially provide a guide for developing an optimally complex polyculture (The Land Institute may enjoy this analysis). Given our previous two observations, it is likely that the optimal complexity changes depending on conditions, again increasing our understanding why there is such complexity in the prairie.
- Lastly, it is important to realize that CT echoes biomimicry, cradle-to-cradle, and many other natural observations because it is a fundamental law of physics. CT provides a unified theory for understanding these phenomenon, and gives us a tool to design within the threshold of nature itself. All we need is the wisdom to follow it.
Constructal Theory: Introduction to the Inverse of Biomimicry
Constructal Theory: Sustainability
Constructal Theory: The Science
Constructal Theory: The Applications
Images used with permission from author::Constructal Theory Web Portal::Shape and Structure, From Engineering to Nature
I know that you have an outline that you're going through, but I'm having a hard time grasping how this comes together. Maybe you could work through an example that shows off what constructal theory offers. So far, it seems like a hodgepodge of existing ideas (which isn't bad if it nicely unifies them, but I get the impression that's not the intention).
Maybe I read the env-econ blog too much, but when I try to imagine what you mean, in this post and your previous one, I come up with something that looks like neoclassical economics, with technological change lowering prices and then pushing the discovery of alternatives.
In Adrian Bejan's books he works through several examples of constructal theory- But the thing to remember is that it is a law of physics. All things in the universe that flow acquire architecture.
This simple law unites multiple examples of what people have been looking at in different fields. It might work better to see the entire series as a whole, but that is also too long for this format. Adrian's books perform this feat in great detail. I hope the full series will help, or at least make people aware this unified theory of natural architecture can help us design sustainable technology.
In Adrian Bejan's books he works through several examples of constructal theory- But the thing to remember is that it is a law of physics. All things in the universe that flow acquire architecture.
This simple law unites multiple examples of what people have been looking at in different fields. It might work better to see the entire series as a whole, but that is also too long for this format. Adrian's books perform this feat in great detail.
Can someone show me the math, or at least the methodology? I've made an exhaustive search of the online material, and can only find theory and generalities, but no techniques for application. Anyone know where to find the meaty stuff?