How Nature Works

First proposed by physicists Per Bak, Chao Tang and Kurt Wiesenfeld in 1993, self-organized criticality is a theory that seeks to explain the way complex systems—such as stock markets, natural disasters and mass extinctions—evolve over time. The theory holds that the behaviors of these systems are governed by a small number of simple rules. It is commonly observed that many of these systems exist in a critical state, in which small changes can lead to drastic consequences. This is sometimes referred to as “the edge of chaos” and "tipping points" or "phase transitions. "