Time asymmetry or T-noninvariance. Its acceptance is the main point of departure of causal mechanics. In this case irreversibility of the processes (second principle of thermodynamics) is the property of time itself, but not the systems. According to CPT-theorem, T-noninvariance is necessary and sufficient for CP-noninvariantness. The last one is the proved fact for week interaction. Causal mechanics asserts the same and for other (at least for electromagnetic) interactions. Time asymmetry by force of Noether's theorem and its quantum-mechanical analog involves violation of energy conservation in usual understanding, which can be avoided only considering that time itself posses an energy. Hence a possibility of transaction of the irreversible (dissipative) processes arises. Time asymmetry is taken into account in classical and quantum electrodynamics by man-made way - by discarding the advanced solutions as non-physical. In action-at-a-distance electrodynamics the retarded and advanced solution are considered as equal in rights, time asymmetry arises by indirect, but natural way - efficiency of absorption of retarded field by the matter is a = 1 (perfect absorption), efficiency of absorption of advanced field is 0 ≤ b < 1 (imperfect absorption).

S.M.Korotaev