Il quaderno di appunti zurighese di Einstein e la scoperta delle equazioni del campo della gravitazione nell’anno 1912

Einstein worked eight years (from 1907 to 1915) to obtain an extension of special relativity to accelerated frames and to develop a relativistic theory of gravitation. Although the field equations of the theory of general relativity appeared at the end as a full realization of the heuristic assumptions he had formulated at an early stage of his investigations, the process that led to the final result was far from being straightforward. As shown by an analysis of an Einstein’s manuscript that until now had been only partially examined, those heuristic assumptions had almost led him in 1912 to the 1915 equations, but, at the same time, had hindered a meaningful physical interpretation of them. A reconstruction of Einstein’s ideas, as drawn up in the manuscript, allows a better interpretation of the history of the discovery of general relativity, and, in particular. a perception of the conceptual difficulties that Einstein had to overcome.