Cryodynamics—The New Second Thermodynamics–Demonstrated Numerically

A recent numerical simulation by Klaus Sonnleitner is drawn attention to. A 2-particle Hamiltonian system - a heavy particle of higher energy and a light particle of lower energy interacting in a T-tube configuration - shows "dissipative behavior": the light particle statistically picks up kinetic energy from the heavy particle. This is in accord with the prediction made by statistical mechanics. However, if the repulsive 1/r potential is inverted (attractive), the light particle loses energy on average to the heavy particle: "antidissipative behavior". In either case two classes of initial conditions exist: "uncommitted" ones and "committed" ones, the former showing the same qualitative behavior in both directions of time, the latter first retracing the previous behavior. The result is shocking: The familiar "dissipative time's arrow" of statistical thermodynamics proves to be complemented by an "anti-dissipative time's arrow" in a new science called statistical cryodynamics. The numerically demonstrated sister discipline is bound to play an important role in cosmology where the heavy particles are galaxies and the light particles are cosmic ray particles or photons. Chaos theory suddenly occupies an even more fundamental role in physics.