Stellar accretion and associated processes: Perspectives from kinetic theory and thermodynamics

Temperature and the laws of thermodynamics are central to physics. They serve to guide all theory that involves thermodynamic relations. Temperature, irrespective of global or local equilibrium conditions, must always be intensive to satisfy the zeroth and second laws of thermodynamics. At the same time, if the laws of thermodynamics are to be followed, not only must the units balance on each side of a thermodynamic equation but so too must thermodynamic character. The theory of protostar formation by gravitational collapse is constructed from the kinetic theory of an ideal gas. In this instance, temperature is introduced in combination with gravitation via the virial theorem. Such an approach assumes that an uncontained cloud of gas in interstellar space will gravitationally collapse, or self-compress, when sufficiently massive. Yet, experiments demonstrate that uncontained gases, irrespective of bulk mass, always expand into their surroundings. The critical mass for initiation of self-compression of a gas is the Jeans mass, which depends on the gas temperature. Similarly, stellar accretion and accretion disk relations involve temperature. All these expressions assign temperature a nonintensive character, in violation of the laws of thermodynamics. Consequently, the relations and the theories from which they are derived are invalid.