Two Rival Approaches to Problem of Irreversibility

With the discovery of second law of thermodynamics and the attemptto supervene it on the classical dynamics, the paradox of irreversibilityshowed up for the first time, as the laws of classical dynamics, incontrast to the second law of thermodynamics, were reversible andsymmetric with respect to time. In this paper, after reviewing theproblem of irreversibility, we pin down two rival approaches to theproblem. The first approach whose pioneer is Ilya Prigogine claims thatirreversibility arises out of dynamical instabilities defined as “disorder”at microscopic level. However, according to the rival theory, which isadvocated by Price and Bricmont, irreversibility at macroscopic levelarises out of specific initial conditions of the world. This is notcontrasted with the notion of irreversibility at microscopic level.Although the two rival theories are completely different with respect totheir theoretical foundations, I will show that one can trace a consensusin a view that reversibility is “practically in principle” impossible. Thisis the term I have coined for the commonality between the two opposedtheories