The constructal law of "designedness" in nature
The laws of classical thermodynamics refer to systems as black boxes, without configuration. Nature is different: it has "designedness" everywhere and at all scales (pattern, configuration, rhythm). The generation of configuration is a phenomenon of all physics, and it is covered by the constructal law: for a finite-size flow system to persist in time (to live) it must evolve such that it provides easier access to its currents. The constructal law is predictive across the board, in inanimate, animate and human flow systems. Examples are the scaling laws of all river basins, the speeds and frequencies of all kinds of animal locomotion, and the zipfian distribution of hierarchical city sizes and numbers on the globe. The constructal law accounts for the numerous and often contradictory ad-hoc statements of self-optimization, e.g. minimization and maximization of entropy generation, minimization and maximization of flow resistance, minimization of time and cost, maximization of utility, and the axiom of uniform stresses in animal bones and botanical trees. © 2008 American Institute of Physics.
