Gravitationally-Induced, Dynamically-Maintained, Steady-State Pressure Gradients

Abstract

Under sealed blackbody cavity conditions, pressure gradients typically take three forms: (a) statistical fluctuations, (b) transients associated with the system relaxing toward equilibrium, and (c) equilibrium pressure gradients, such as those associated with static gravitational potentials. In this paper a new type of pressure gradient is introduced, one which arises if a gravitator has surfaces with different trapping probabilities for suprathermal gas collisions. Three-dimensional test particle simulations of this system using realistic physical parameters support this hypothesis. This gas phase is inherently nonequilibrium in character and represents an unstudied thermodynamic regime involving low-density gas-surface interactions. This is the gravitational analog of a previously studied, chemically-induced pressure gradient (D P Sheehan 1998 Phys. Rev. E 57 6660).