Abstract

LABARCA, Martín  and  LOMBARDI, Olimpia. Irreversibility and ontological pluralism. Sci. stud. [online]. 2007, vol.5, n.2, pp. 139-167. ISSN 1678-3166.  http://dx.doi.org/10.1590/S1678-31662007000200002.

The problem of irreversibility finds its roots at the end of 19th century and the beginning of 20th century with the works of Maxwell, Boltzmann and Gibbs. The controversy arises when trying to make compatible the irreversible macroscopic evolution of thermodynamics systems with t-invariant dynamics of its microscopic components. In the traditional approach of statistical mechanics, the irreversible evolution is explained by introducing a coarse grain on the underlying microscopic dynamics. For this reason, it is generally accepted that statistical mechanics offers a subjective description of irreversibility. The purpose of this work is to reject the traditional approaches of the problem by stressing that its only foundation is the implicit adoption of metaphysical realism that adjudges ontological priority to the microscopic world. We will argue that the problem can be addressed on the basis of an ontological pluralism of kantian roots, inspired by Putnam's internalist realism. From this philosophical framework, macroscopic irreversibility is an objective property that has not need to be explained in microscopic terms to acquire ontological legitimacy: the coarse grain is the relationship between two equally objective descriptions.

Keywords : Irreversibility; Statistical mechanics; Gibbs; Ontological pluralism; Coarse grain.