  It is shown that the irreversible behavior of classical systems of
interacting particles is a common property for both few-body and many-body
systems. It is due to the delay in the interactions between the particles.
  PACS: 45.50.Jf Few- and many-body systems; 82.40.Bj Oscillations, chaos, and
bifurcations; 05.70.-a Thermodynamics.
  Keywords: irreversibility, interactions retardation.
