In this paper we consider the prehistory of quantum gravity (1916–1930) from two perspectives. First, we investigate how this research field constituted itself and we propose for the first time a red thread to trace its evolution in this earliest period. Second, we focus on a case study: the earliest work of Léon Rosenfeld. In 1927 he tried to merge wave mechanics with general relativity in the context of a five‐dimensional universe. We describe how Oskar Klein, Louis de Broglie, and (...) Théophile De Donder influenced Rosenfeld's work and analyze how and why Rosenfeld attempted to reconcile Einstein's theory with quantum phenomena. We argue that Rosenfeld investigated for the first time the corrections to a classical space‐time metric generated by a quantum source. As far as we know, Rosenfeld's approach has been largely ignored until today: he himself considered it “an accident.” After having reconsidered its connection with de Broglie's ideas and Rosenfeld's interpretation of the wave function in 1927, we argue that Rosenfeld's work can be interpreted as a first attempt to introduce the pilot‐wave theory in the context of quantum gravity and we infer that this was one of the reasons that ruled it out. (shrink)

Théophile De Donder, a Belgian mathematician born in Brussels, elaborated two important ideas that created a bridge between thermodynamics and chemical kinetics. He invented the concept of the degree of advancement of a reaction, and, in 1922, he provided a precise mathematical form to the already known chemical affinity by translating Clausius’s uncompensated heat into formal language. These concepts merge in an important inequality that was the starting point for the formalization of non-equilibrium thermodynamics. The present article aims to reconstruct (...) how De Donder elaborated his ideas and developed them by exploring his teaching activity and its connection with his scientific production. Furthermore, it emphasizes the role played by the discussions with his disciples who became his collaborators. The paper analyzes De Donder’s efforts in participating in the second Solvay Chemistry Council in 1925 to call the attention of chemists to his mathematical approach. We explain why his work did not receive much attention at the time, and how, despite this, his formalization of chemical affinity became the basis for the birth of the so-called Brussels school of thermodynamics. (shrink)

In June 1888, Oliver Heaviside received by mail an officially unpublished pamphlet, which was written and printed by the American author Willard J. Gibbs around 1881–1884. This original document is preserved in the Dibner Library of the History of Science and Technology at the Smithsonian Institute in Washington DC. Heaviside studied Gibbs’s work very carefully and wrote some annotations in the margins of the booklet. He was a strong defender of Gibbs’s work on vector analysis against quaternionists, even if he (...) criticised Gibbs’s notation system. The aim of our paper is to analyse Heaviside’s annotations and to investigate the role played by the American physicist in the development of Heaviside’s work. (shrink)