This theory Odum called maximum power theory. In order to formulate maximum power theory Gilliland observed that Odum had added another law (the maximum power principle) to the already well established laws of thermodynamics. In 1978 Gilliland wrote that Odum's new law had not yet been validated (Gilliland 1978, p. 101). Gilliland stated that in maximum power theory the second law efficiency of thermodynamics required an additional physical concept: "the concept of second law efficiency under maximum power" (Gilliland 1978, p. 101):