a condition characterized by a balance of forces. (
Umpleby )
Literally, "balance", here balance of forces acting on each other. In a static equilibrium forces compensate each other so that the
system is motionless, e.g., a scale at rest. If forces do not compensate each other fully at one instant in time, a system moves until it encounters higher-order
constraints, e.g., after starting an engine, it accelerates to a point at which energy supply and work load plus friction are again in balance. In such a
dynamic equilibrium, forces complement each other dynamically so that the system's
behavior is repetitive, predictable, does not generate new
states and the trajectory follows a regular cycle. E.g., mass production at a well-worked out assembly line, stereotypical conversation within a family, routine administrative procedures. A system may have several distinct equilibria (
see polystability ). A system in equilibrium conveys no
information. One important equilibrium property is
stability. homeostasis is a process of interaction favoring an equilibrium. (
Krippendorff )
