Ludvig Bertalanfy
Karl Ludwig von Bertalanffy
 (September 19, 1901, Atzgersdorf near Vienna – June 12, 1972, Buffalo, New York) was an Austrian-born biologist known as one of the founders of general systems theory (GST). GST is an interdisciplinary practice

that describes systems with interacting components, applicable to biology, cybernetics, and other fields. Bertalanffy proposed that the classical laws of thermodynamics applied to closed systems, but not necessarily to "open systems," such as living things. His mathematical model of an organism's growth over time, published in 1934,[1] is still in use today.