<P> The biologist Ludwig von Bertalanffy (1901--1972) became one of the pioneers of the general systems theory . In 1945 he introduced models, principles, and laws that apply to generalized systems or their subclasses, irrespective of their particular kind, the nature of their component elements, and the relation or' forces' between them . </P> <P> Norbert Wiener (1894--1964) and Ross Ashby (1903--1972), who pioneered the use of mathematics to study systems, carried out significant development in the concept of a system . </P> <P> In the 1980s John Henry Holland (1929--), Murray Gell - Mann (1929--) and others coined the term "complex adaptive system" at the interdisciplinary Santa Fe Institute . </P> <Dl> <Dt> Environment and boundaries </Dt> <Dd> Systems theory views the world as a complex system of interconnected parts . One scopes a system by defining its boundary; this means choosing which entities are inside the system and which are outside--part of the environment . One can make simplified representations (models) of the system in order to understand it and to predict or impact its future behavior . These models may define the structure and behavior of the system . </Dd> </Dl>

What do physical systems and social systems have in difference