(treated as sing. or pl) the branch of physics dealing with the mechanical action of, or relations between, heat and other forms of energy, or the branch of physics that deals with this
Thermodynamics is used to assess the efficiency of thermal processes and to discuss the equilibrium composition of chemical reactions. There are three laws of thermodynamics. The first law expresses the conservation of energy and the equivalence of heat and work. The second law introduces the concept of increasing entropy as the signpost of spontaneous change. The third law expresses the unattainability of absolute zero — Professor Peter Atkins
thermodynamic adj
thermodynamically adv
thermodynamicist /-ʹnaməsist/ noun