Generally speaking, virtual displacement or work concerns to a timely idea according to which a motion of a certain body is not the unique possible motion. The process of reducing this motion to a particular magnitude and concept, eventually minimizing as a hypothesis, can be traced back to the Aristotelian school. In the history and philosophy of science one finds various enunciations of the Principle of Virtual Laws and its virtual displacement or work applications, i.e., from Aristotle to Leibniz’s vis (...) viva, from Maupertuis’ least action to Euler and Lagrange with calculus of variations to Lazare Carnot’s mechanics. In this case study, I will demonstrate that a particular approach used by Lazare Carnot is original by explaining within the historical context of rival approaches such as the development of the Principle of virtual Laws. I will also discuss Carnot’s geometric motion as one of the possible but invertible movements applied to virtual displacement as employed in his theories of machines and collisions. I will then go on to explore how the originality of an invertible motion within his mechanical and, in general, mathematical research program permitted Carnot to introduce a new way of structuring a scientific theory and making mechanics, with respect to the Newtonian paradigm, to scholars and his students of the École polytechnique de Paris. (shrink)

Forums, I extensively analysed Tartaglia’s corpus: science of weights, geometry, arithmetic, mathematics and physics–trajectories of the projectiles, fortifications, included its intelligibility science in the military architecture. The latter is exposed in Book VI of the Quesiti et invention diverse. In Quesiti there is La Gionta del sesto libro—a kind of appendix to the Book VI containing drawings of the geometric shape of the Italian fortifications. It is based on Euclidean geometry and other figures where a scale is displayed. The interest—included (...) intellectual history and cultural foundations of science—is: what is the role–played by La Gionta del sesto libro in the Quesiti? Is it independent booklet/speeches? If yes, when Tartaglia did write it? In this paper, I present an historical–philological–foundational hypothesis on the Tartaglia’s fortifications corpus, as exposed in the Book VI and La Gionta del sesto libro; with respect to dates of editions of Quesiti. This goal is important to make historically clear both the editorial role–played by Curzio Troiano Navò in the Tartaglia’s corpus before—after Tartaglia’s death and the particular interest and development of subject of fortifications by Tartaglia between 1537–1546 and 1554. (shrink)