What if energy flowed from cold to hot regions? How would thermodynamics be different? We examine such an imagined cold-to-hot world, abbreviated here as a C2H world, and show that the unfamiliar direction of energy flow implies that two thermally interacting objects at different temperatures will not equilibrate. We find that there is no…

To most students today the mechanical equivalent of heat, called the Mayer-Joule principle, is simply a way to convert from calories to joules and vice versa. However, in linking work and heat--once thought to be disjointed concepts--it goes far beyond unit conversion. Heat had eluded understanding for two centuries after Galileo Galilei…

Describes the relationship existing between coefficient of performance (COP) and energy efficiency ratio (EER) in air conditioning units and introduces new efficiency parameters measured relative to the energy extracted from the primary energy source. (SL)

Presents a simple model whereby the work per cycle done on an external agent, and a sand reservoir, by a reversible heat engine can be analyzed explicitly. (Author/SL)