Symmetry and the order of events in time: description of a reversible thermal energy converter composed of negative mass

Abstract

In a previous paper [1], we analyzed the sequence of events that occurs in the time domain of a reversible cyclical thermal energy converter using the Gibbs equation and showed that even when there is no net change of entropy there is an asymmetrical order of quasi-static states along the time axis, when thermal energy is converted into mechanical pressure-volume work. The spontaneous evolution towards an equilibrium state, which is characterized by the unidirectional transport of entropy from the hot reservoir to the cold reservoir, is coincident with this asymmetrical order of events. In this paper, we \"mend\" the above mentioned asymmetry by writing the Gibbs equation for a class of substances that have negative mass. Such extraordinary substances would allow a reversible cyclical energy converter to proceed in the reverse order coincident with a unidirectional transport of entropy from the cold reservoir to the hot reservoir and a spontaneous evolution away from equilibrium. By taking into consideration thermodynamic systems composed of positive or negative mass, we have made the Second Law of Thermodynamics symmetrical in terms of entropy flow. The symmetrical Second Law of Thermodynamics states that, for reversible thermodynamic systems composed of positive mass, entropy flows from the hot reservoir to the cold reservoir and for reversible thermodynamic systems composed of negative mass, entropy flows from the cold reservoir to the hot reservoir. Consequently, systems of positive mass evolve towards equilibrium while systems of negative mass evolve away from equilibrium. This is reminiscent of Feynman's definition of antimatter as matter going backward in time. In another paper in this series [2], we suggested that substances with negative mass are real and synonymous with antimatter.