Constructing a Theory for Scaling and More

Abstract

Adrian Bejan, in his book, Shape and Structure: From Engineering to Nature (Cambridge University Press, 2000), sums up work that started well before Geoffrey West and James Brown’s early paper in 1997. Bejan discusses the emergence of shape and structure that derive from the purposes of animate and inanimate systems, which must deal with limited resources and other constraints. Animate systems must survive; inanimate systems—for example, engineered ones—must meet specific objectives.In particular, the 3/4 exponent in the relationship between metabolic rate and body size is proven on the basis of pure constructal theory (see section 10.6 of Bejan’s book), which avoids the ad-hoc assumption of the tree architecture. Logically, any animal correlation that West and Brown derived in 1997 is evidence that the constructal law is valid.© 2005 American Institute of Physics.