There is at present in the material world a universal tendency to the dissipation of mechanical energy.Ģ. From the newly refounded dynamic theory of heat (heat as motion) on the one hand, which said you cannot recover spent mechanical energy from the heat of something no warmer than its surroundings, and from the conservation of energy principle on the other, which allowed of no additions to the existing store, Thomson thought to extrapolate to the largest of systems, the “thermo-dynamic engine” of the whole physical world. In 1852, William Thomson, later Lord Kelvin, delivered a short, startling paper to the Royal Society of Edinburgh called, “On a Universal Tendency in Nature to the Dissipation of Mechanical Energy.” Its object, he said, was “to call attention to the remarkable consequences which follow from Carnot’s proposition, that there is an absolute waste of mechanical energy available to man when heat is allowed to pass from one body to another at a lower temperature by any means not fulfilling his criterion of a ‘perfect thermo-dynamic engine’“ (510), that is, in all actual circumstances. And its content laid some of the groundwork for the pessimism that qualified the cult of progress and the whiggish habits of cultural and material complacency towards the end of the century.

The argument-resolved only in the next century-has exemplary value as an intractable dissonance between two vigorous and well established, but not entirely secure scientific disciplines.

The leading voices in the debate were William Thomson, later Lord Kelvin, and Thomas Henry Huxley, Darwin’s most able champion. The Charles Darwin-inspired debate over the Age of the Earth that pitted contemporary Physics against the theory and practice of contemporary Geology was intimately tied to recent unsettling projections on the thermodynamic fate of the universe.

Endless space 2 depletion points