In addition to confusion with regard to exactly what entropy is, current scientific explanations of the associated irreversibility and the ineluctable increases in entropy are complicated, unsatisfactory, and completely incorrect. This problem is so impenetrable in fact that in over two centuries of notable attempts by the greatest scientific minds there has still been no explanation that is credible. The ubiquitous increases in entropy seem, however, to only affect the happenings at the macroscopic level of our everyday existence for which no process is completely reversible. Processes that are irreversible like those we witness every day with the naked eye are ipso facto those for which entropy is increased. But there has seemed to be no origin of this dire trend at the submicroscopic level where the answers to virtually all of the difficult problems of physics have been resolved.In resolving irreversibility at the submicroscopic level it has been necessary to augment Boltzmann's kinetic theory beyond two types of interaction and to more fully elaborate necessary constraints on the emission and absorption of radiation in Einstein's quantum theory of radiation. It is in the interactions between these domains where irreversibility enters. It has been incumbent upon us to close major loops left open by the scope of their analyses. Boltzmann could not have foreseen the impact of mediated interactions involving quantized photons, nor certainly relativistic effects. A comprehensive model has had to be developed to incorporate complimentary mechanical and radiational aspects of a thermodynamic system. The mediated interactions between molecules that do not involve direct collisions always reduce the relative velocity of the interacting molecules, which is very entropic behavior. In this way, individual submicroscopic processes 'use up' otherwise useful energy and increase entropy even at the submicroscopic level.Yet another form of interaction involving both radiational and particulate dynamics is the scattering of radiation by arrays of charges within a thermodynamic system. 'Forward' scattering in particular has traditionally been considered to involve conservative forces that do not alter the energetics of either the ensemble of particles or the radiation field. We show that this too is an over simplification whose correction has profound consequences of irreversible behavior, producing what have been considered 'cosmological' effects. The major loops that must be closed in this regard involve the origin of the ubiquitous hydrogenous intergalactic plasma with 24% helium by weight and the supposed disappearance of mass (and information) in black holes. There is increasing evidence that black holes do indeed errupt spewing forth hydrogenous plasma to again produce the 24% helium in generating the gamma radiation that after prolonged redshifting caused by irreversible scattering becomes the microwave background radiation. The blackbody temperature of a redshifting medium does not reflect the kinetic temperature of the particulate matter by which that radiation is scattered.