April 07, 2010

Turtles all the way


...the non-fundamental ontology of everyday life (solids and fluids) can seem as a kind of "coarse-grained" macroscopic approximation to the more fundamental microscopic ontology of quarks and electrons; indeed, the former should be (at least in principle) derivable as a logical consequence of the underlying fundamental theory.
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...it means that what appear in the older theory to be a fundamental entity is, in reality, a non-fundamental entity derivable as a "coarse-grained: version of something deeper.
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In this view, reality is composed of a hierarchy of "scales"... The theory on each scale emerges from the theory on the next finer-scale by ignoring some of the (irrelevant) details of the latter. And the ontology of the theory on each scale - in particular, its "unobservable" theoretical entities - can be understood, at least in principle, as arising from the "collective" or "emergent" effects of a more fundamental theory at a finer scale.

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