Tiny errors in one system component will translate linearly into tiny errors in later system measurements. During the 19th Century, linear systems and careful measurements gave the impression that we could predict the future - scientific determinism. Linear equations should always be able to give an exact and predictable answer. Problems of friction, air resistence, and fluid motion were ignored or treated as problems that have average linear behavior. This is referred to as feedback.
Negative feedback means the opposite.
Edward Lorentz was one of the first to systematically investigate nonlinear systems and their feedback. He was particularily interested in climate and its predictability. He used computers and simple models to try and predict weather. When he made small changes in theinput parameters of his model, the results would quickly diverge from previous values. Nonlinear dynamical sytems are groups of equations that encompass chaos.