Participación invitada: Multiple realizability: comparing classical irreversibility and decoherence

OLIMPIA LOMBARDI; SEBASTIAN FORTIN

Valparaíso

Workshop; Workshop Multiple Realizability, Causation and Reductive Explanation in Science; 2018

Universidad de Valparaíso

Originally,multiple realizability was proposed in the philosophy of mind as anon-reductionist position. Nevertheless, it was immediately extrapolated to therelation between thermodynamics and mechanics: a single thermodynamic state isrealized by many different mechanical states. This many-to-one relationship hasbeen viewed as supporting the idea of the emergence of thermodynamicirreversibility from the time behavior of the underlying mechanical states.In this talk we will compare the case of the emergence of classicalirreversibility with the case of the irreversibility involved in quantum decoherence.In particular, we will show that the quantum case cannot be easily understoodin terms of a many-to-one relationship: the reduced state that evolvesirreversibly is not a mere disjunction of underlying quantum states. On thisbasis, we will give a unified view of the emergence of irreversibility,applicable both to the classical and to the quantum case. According to thisunified view, the relation between the macro-emergent level and the micro-basallevel is a generalized coarse-graining, mathematically defined as a projection.It is this generalized-coarse graining, and not multiple realizability, theessential feature of this kind of emergence: multiple realizability is only aparticular case of generalized-coarse graining.