'The constructal law was stated by Adrian Bejan in 1996 as follows: "For a finite-size system to persist in time (to live), it must evolve in such a way that it provides easier access to the imposed currents that flow through it." - Bejan, Adrian (1997). Advanced Engineering Thermodynamics, (2nd ed.). New York: Wiley'
"The constructal law is a first principle of physics that accounts for all design and evolution in nature. It holds that shape and structure arises to facilitate flow. The designs that arise spontaneously in nature reflect this tendency: they allow entities to flow more easily – to measurably move more current farther and faster for less unit of useful energy consumed. - Bejan, A; Lorente, S (2006). Constructal Theory of Generation of Configuration in Nature and Engineering, Journal of Applied Physics. Vol. 100: 041301.'
According to Bejan the constructal law deals with nature's propensity to evolve designs that facilitate flow. Designs that move currents from an area to a point and/or from a point to an area (tree-like designs, circulatory and nervous systems are examples).
As I was reading about this an image of an Aikido encounter arose in my mind. The image conveyed that as the encounter begins uke and I are area bound. As we come together along the paths of our motion we proceed from an area bound configuration to one that is increasingly point bound. The technique executed will take us through the point bound state back to an area bound state as we disengage. The totality of our interaction forms a tree-like structure and its mirror image, as though reflected in a still pond.
Within the context of Aikido, the shape and structure we form facilitates the flow of Ki. As I continue to practice I am better able to shape and structure my movements in order to move more Ki through our connection using less energy. My goal is to ultimately be able to merge my motion with my uke to such a fine degree that our energies become completely additive. Growth via Aikido training is an excellent example of the constructal law in action. Growing more coordinated in mind and body I am able to more efficiently move greater and greater amounts of Ki using less and less energy. In addition, the changes wrought in me provide me with easier access to the Ki that is the result of a coordinated mind and body.