Gibbs is perhaps the most brilliant person that most people have never heard of. Modest to the point of near invisibility, he passed virtually the whole of his life, apart from three years spent studying in Europe, within a three-block area bounded by his house and the Yale campus in New Haven, Connecticut. For his first ten years at Yale he didn’t even bother to draw a salary. (He had independent means.) From 1871, when he joined the university as a professor, to his death in 1903, his courses attracted an average of slightly over one student a semester. His written work was difficult to follow and employed a private form of notation that many found incomprehensible. But buried among his arcane formulations were insights of the loftiest brilliance.

In 1875–78, Gibbs produced a series of papers, collectively titled On the Equilibrium of Heterogeneous Substances, that dazzlingly elucidated the thermodynamic principles of, well, nearly everything—“gases, mixtures, surfaces, solids, phase changes ... chemical reactions, electrochemical cells, sedimentation, and osmosis,” to quote William H. Cropper. In essence what Gibbs did was show that thermodynamics didn’t apply simply to heat and energy at the sort of large and noisy scale of the steam engine, but was also present and influential at the atomic level of chemical reactions. Gibbs’s Equilibrium has been called “the Principia of thermodynamics,” but for reasons that defy speculation Gibbs chose to publish these landmark observations in the Transactions of the Connecticut Academy of Arts and Sciences, a journal that managed to be obscure even in Connecticut, which is why Planck did not hear of him until too late.