Thomas Durt, Postdoc Researcher, TONA, Free University Brussels (VUB), Brussels, Belgium
Durt, Thomas. 2009. Anthropomorphic Quantum Darwinism as an explanation for Classicality. Foundations of Science, no. Special Issue of the Conference on the Evolution and Development of the Universe (EDU-2008). In press. http://evodevouniverse.com/EDU2008Papers/DurtAnthropomorphicQuantumDarwinismEDU2008.pdf.
The term entanglement was first introduced by Schroedinger who described this as the characteristic trait of quantum mechanics, "the one that enforces its entire departure from classical lines of thought". Bell's inequalities show that when two systems are prepared in an entangled state, the knowledge of the whole cannot be reduced to the knowledge of the parts, and that to some extent the systems lose their individuality. It is only when their joint wave-function is factorisable that they are separable. So, entanglement reintroduces holism and interdependence at a fundamental level and raises the following question: is it legitimate to believe in the Cartesian paradigm (the whole is the sum of its parts, the description of the whole reduces to the description of its parts), when we know that entangled objects (the majority of quantum systems) are entangled?
In order to solve this apparent contradiction, Zurek and coworkers developed, in the framework of the decoherence approach, the idea that maybe if we think classically, this is because during the evolution, our brain selected in the external (supposedly quantum) world the islands of stability that correspond to the maximal quantum (Shannon-von Neumann) information. These ‘classical islands’ would correspond to the structures that our brain naturally recognizes and identifies, and this is why the way we think is classical.