Summary
The book begins by asserting the importance of the role of time in newly emerging sciences. The time paradox, within the confines of classical Newtonian dynamics, relativity and quantum physics, led Einstein to claim that time is an illusion. In deterministic physics, all processes are time-reversible, meaning that they can proceed backward as well as forward through time. Time is simply a given; thus, according to Prigogine, determinism is fundamentally a denial of the “arrow of time”. Prigogine believes that the paradox has been solved by two recent developments in physics: the the study of non-equilibrium processes and of the dynamics of unstable systems, beginning with the idea of chaos, which has led to concepts such as self-organization and dissipative structures. The discovery of dissapative structures and their role in thermodynamic systems far from equilibrium won him the 1977 Nobel Prize in Chemistry. Essentially, Prigogine discovered that the dissipation of energy into chemical systems can bring about the emergence of new structures through internal self reorganization. These structures, whose dynamical regimes can be regarded as thermodynamic steady states, arise as the result of irreversible processes. A dissipative structure is characterized by spontaneous symmetry-breaking and the formation of complex, sometimes chaotic structures whose interacting particles show long range correlations. Examples in everyday life include both hurricanes and living organisms. Dissipative structure theory triggered revolutionary findings on self-organizing systems and complexity in the natural sciences, as well as philosophical quandries on life itself. Essentially, there are two important take-away messages that can be understood and applied today to a variety of interdisciplinary fields:
• The maintenance of order in nature is maintained by self-organization.
• Dissipative structures require an arrow of time.
Classical science emphasized order and stability; today, in contrast, we see fluctuations, instability, and unpredictability at all levels of observation. In Prigogine’s words, “The more we know about our universe, the more difficult it becomes to believe in determinism." This is a major departure from the approach of Newton, Einstein and Schrödinger, all of whom expressed their theories in terms of deterministic equations. Yet, Prigogine says, in the late 1850s Darwin had already given a great shake to the idea of determinism, just a few years before the scientist Ludwig Boltzmann discovered that gasses undergo irreversible processes. Probability was thus introduced as an empirical tool, paving the way to the future science of non-equilibrium physics, which has given scientists the possibility to extend classical and quantum physics to include instability and chaos. According to Prigogine, in fact, determinism loses its explanatory power in the face of irreversibility and instability. Once instability is included, the meaning of the laws of nature changes radically, and they now express possibilities or probabilities. These non-equilibrium processes illustrate the constructive role of time. Entropy itself, based on the second law of thermodynamics, which had been formulated just nine years before Darwin published his theory of evolution, is often called “the arrow of time.”
Relevance for Complex Systems Knowledge
In his own words, “I believe that we are at an important point in the history of science. We have come to the end of the road paved by Galileo and Newton, which presented us with an image of a time-reversible, deterministic universe. We now see the erosion of determinism and the emergence of a new formulation of the laws of physics“. Prigogine insists on the necessity of an arrow of time to account for the time-irreversible processes studied in thermodynamics. Far-from-equilibrium processes and chaotic systems provide the examples, and as he points out, these are the most common things found in nature; phenomena described as time-reversible is generally a simplification of what actually occurs in nature.
