Thermodynamic cosmology

The universe is an isolated system with constant mass-energy. The second la w of thermodynamics requires that its entropy must increase over time-that is, the universe is irreversible-yet modern cosmological models presume ise ntropy. Entropy production due to expansion of the universe is calculable a nd negligible, but enormous entropy is created as matter is converted to en ergy and irreversibly transferred from hot stellar interiors to cold dark m atter. Although the rate of entropy increase must eventually diminish, entr opy production may be nearly linear at this time. Previous omission of entr opy production from the cosmological equations is the source of "reversible " time and has led to the misconceptions that the universe is expanding and that a big bang is necessary. Instead, the evolution of the universe is gu ided by irreversible mass loss through stellar burning, which requires cont raction, as is observed among our local group of galaxies. A new equation for the mass of the universe gives a result that is in good agreement with previous equations and with extrapolated densities and that leads to the conclusion that the binding energy of matter to the universe i s equal to its rest energy. The microwave background radiation does not req uire a big bang but instead is consistent with blackbody emissions from dar k matter (cavity radiation) that is warmed to 2.7 K by radiative transfer f rom the stars; such a balance of flux is required by the zeroth law. The ev olution of the universe, being irreversible, is best described as the self- organization of a nonequilibrium system with ordering through fluctuations and dissipative structures. Complexity behavior is implicit in the dominanc e of matter over antimatter, the archetypical birfurcation, and in the spir al forms of the galaxies, a pattern expected for asymptotic stability. Copy right (C) 2001 Elsevier Science Ltd.