Z. Naturforsch. 55a, 405-411(2000)
The concept of the time dependent instantaneously occupied phase space volume is applied to multi-component systems. It allows for the investigation of entropy flows betweeen the components of the system and the evaluation of partial entropies assigned to the subsystems. We give numerical examples by means of molecular dynamics simulations of a 100-particle gas. Using a symplectic exactly reversible algorithm a consistent and reliable evalutation of energy and entropy exchanges as well as the intake of work is achieved. The entropy flow which is related to an information flow is linked to an observational situation. This yields a further indication for the necessity of an intrinsic observer for a better understanding of the physical world. In addition, it indicates the Gödelian structure of cognition in a most serious way because only "first-principle" assumptions are made. Thereby, the paradoxical situation which is created by Jaynes' concept of an "anthropomorphic entropy" can be resolved by putting the anthropomorphic contents of thermodynamics down to an ontological basis. This is a straightforward extension of Szilard's and Brillouin's information theoretical treatment of cognition.