Dynamics of a system of particles in the framework of the field theory of interactions between them. Elimination of field variables and non-Hamiltonian character of the equations of motion for a system of particles with excluded field variables. Non-existence of integral invariants, violation of the conditions of applicability of Liouville’s theorem and Poincare’s recurrence theorem. Non-invariance of the equations of dynamics with respect to time reversal. Dynamic irreversibility of the evolution of a system of particles. Eliminate the unnecessary concept of probability. Electromagnetic origin of interatomic interactions and construction of model potentials for atoms at rest. Dynamics of the process of establishing thermodynamic equilibrium: necessary and sufficient conditions. Hierarchy of scales in the dynamics of equilibration processes. Limits of applicability of relativistic thermodynamics. Towards thermodynamics of small systems. Perspective: from relativistic dynamics to thermodynamics and to synergetics.