Cybernetics started by being closely associated in many ways with physics, but it depends in no essential way on the laws of physics or on the properties of matter. Cybernetics deals with all forms of behaviour in so far as they are regular, or determinate, or reproducible. The materiality is irrelevant, and so is the holding or not of the ordinary laws of physics... The truths of cybernetics are not conditional on their being derived from some other branch of science. Cybernetics has its own foundations...
In this discussion, questions of energy play almost no part-the energy is simply taken for granted. Even whether the system is closed to energy or open is often irrelevant; what is important is the extent to which the system is subject to determining and controlling factors. So no information or signal or determining factor may pass from part to part without its being recorded as a significant event. Cybernetics might, in fact, be defined as the study of systems that are open to energy but closed to information and control-systems that are "information-tight".
Ashby, W R. An introduction to cybernetics. London: Chapman & Hall, 1956.