Causal Modeling and Thermodynamics: Towards a New Convergence of the Two Fields.

In 1824, Nicolas Léonard Sadi Carnot paid for the publication of his first book. Unfortunately, it sparked little interest, and the young engineer never published another. In quick succession, Carnot served in the military, suffered from scarlet fever, mania, and cholera, passing away in obscurity at age 36. Two centuries have passed since Carnot published his only book. Recognition has come later. In particular, Carnot's reasoning spearheaded the development of the first and second laws of Thermodynamics. The new science that has emerged around these physical laws is nothing short of breathtaking, providing a stunning testimony to human creativity. Yet success and growth have also brought critical attention and doubts. In 1924, Louis de Broglie lauded the first law of Thermodynamics more than the second. The first law builds on a long history rooted in Causal Modeling, the second does less so. Today, physicists such as Adrian Bejan specialize in Thermodynamics but contend that some formulations of the second law may have attracted broken science. The present article revisits this history in an attempt to cut through some of the fog. As outcome of this re-evaluation, the article outlines a new convergence of Thermodynamics and Causal Modeling.