Network theory and its relation to the theory of linear systems

Some general theorems of network theory are studied in their relation to other fields of linear physics. It is pointed out that general laws of the same character hold for the dissipative linear systems (thermodynamic systems with small departures from equilibrium). Another class of linear systems which one meets in scattering problems can also be related to network theory, but in a different way. For an example in which both the theory of dissipative and of scattering systems applies, the results of the two approaches are compared. Finally, results are mentioned on almost equivalent networks which have a bearing on the transition from the reversible behavior of the atomistic constituents of matter to the irreversible behavior of matter in bulk.