Time in Science: Reversibility vs. Irreversibility

  • Yves Pomeau
Part of the Lecture Notes in Physics book series (LNP, volume 644)


To discuss properly the question of irreversibility one needs to make a careful distinction between reversibility of the equations of motion and the ‘choice’ of the initial conditions. This is also relevant for the rather confuse philosophy of the ‘wave packet reduction’ in quantum mechanics. The explanation of this reduction requires also to make precise assumptions on what initial data are accessible in our world. Finally I discuss how a given (and long) time record can be shown in an objective way to record an irreversible or reversible process. Or: can a direction of time be derived from its analysis? This leads quite naturally to examine if there is a possible spontaneous breaking of the time reversal symmetry in many body systems, a symmetry breaking that would be put in evidence objectively by looking at certain specific time correlations.


Wave Packet Cellular Automaton Cellular Automaton Time Reversal Symmetry Quantum Chaos 
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  1. 1. Y. Pomeau, J. de Physique (Paris), 43, (1982) 859.Google Scholar
  2. 2. Y. Pomeau, Phys. Letters 26A, (1968) 34.Google Scholar
  3. 3. J. Hardy, de Pazzis O. and Pomeau Y., Phys. Rev. Letters 31, (1973) 276; D. d’Humières, Lallemand P. and Pomeau Y., C. R. Ac. Sci. 301, (1985) 1391; U. Frisch, Hasslacher B. and Pomeau Y., Phys. Rev. Lett. 56, (1986) 1505; Y. Pomeau, J. of Phys. A17(1984) L415; Y. Pomeau, Vichniac G., Comment, J. of Physics A21, (1988) 3297. Google Scholar

Authors and Affiliations

  • Yves Pomeau
    • 1
  1. 1.Laboratoire de Physique Statistique de l’Ecole normale supérieure, 24 Rue Lhomond, 75231 Paris Cedex 05France

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