Piero Scaruffi

These are excerpts and elaborations from my book "The Nature of Consciousness"

Einselection: Darwinian Collapse One man who has been studying the problem of how classical Physics emerges from Quantum Physics (how objects that behave deterministically emerge from particles that behave probabilistically, how coherent states of Quantum Mechanics become classical ones) is the Polish-born Wojciech Zurek. He does not believe that consciousness has anything to do with it: it is rather the environment that determines the emergence of reality. Since 1991, experiments have been performed to show the progressive evolution of a system from quantum to classical behavior. The goal is to observe the progressive collapse of the wave function, the progressive disappearance of quantum weirdness, and the progressive emergence of reality from probability. Zurek ("Environment-induced superselection rules", 1982) has proposed a different twist to the debate on the "collapse of the wave". It doesn't necessarily take an observer. Zurek thinks that the environment destroys quantum "coherence" (superposition). The environment includes anything that may interact with the quantum system, from a single photon to a microscope. The environment causes "decoherence" (the choice of one or some of the possible outcomes) and decoherence causes selection (or "einselection") of which possibilities will become reality. The "best fit" states turn out to be the classical states. Systems collapse to classical states because classical states are the ones that best "fit" the environment. The environment causes the collapse of the wave just like an observer. Decoherence occurs to any system that interacts with other systems. Large objects are classical and not quantum objects because they are inherently "decohered" by being a collection of interacting parts. Small objects are isolated to some extent and therefore exhibit quantum behavior. Quantum Darwinism explains how quantum possibilities can give rise to objective, classical reality. What is objective reality? It is a measurement that is the same for all observers. The size and position of this desk are the same for all observers, therefore this is objective reality. Quantum Darwinism is the theory that this objective reality is the result of a process analogous to natural selection in evolution: what we call "objective" is the "fittest", the survivor. The fittest property makes copies of itself and spreads from observer to observer, whereas the properties that are not fit do not make copies and quickly disappear. The US physicist James Anglin, a close associate of Zurek, studied the evolution of "open quantum systems" far from equilibrium, which resemble Prigogine's studies on open classical systems (“Decoherence of Quantum Fields”, 1997). This line of research was, indirectly, establishing intriguing similarities between the emergence of classical systems from quantum systems and the emergence of living systems from non-living systems.   Back to the beginning of the chapter "The New Physics" | Back to the index of all chapters