The story
Developed by German physicist and mathematician Rudolf Clausius.
Etymology from Wiktionary, CC BY-SA 4.0.
Clausius theorem
Today it means: A theorem stating that, for a thermodynamic system exchanging heat with external reservoirs and undergoing a thermodynamic cycle, ∮(δQ)/(T_surr)≤0,, where δQ is the infinitesimal amount of heat absorbed by the system from the reservoir, and T_surr is the temperature of the external reservoir (surroundings) at a particular instant in time. Full definition →