2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228243The energy dissipation in a gas of structured objects, e.g. molecules, is considered in density matrix formalism. It is shown that the macroscopic irreversibility of the kinetic processes can be considered as a consequence of the microscopic operator ordering. Our approach is free of any special assumptions on the space-time geometry, except for the general causality assumptions, so it can be applied to a wide variety of processes, from the cosmological processes at Big Bang stage till the energy dissipation in molecular gases.LaTeX, 15 pages, 5 eps figureQuantum Physicstext