Post-Newtonian and pre-Kantian theory of space and time: Euler, Du Chatelet, Lambert

Dieter Suisky, Ph.D. Professor
Humboldt University Berlin, Germany

In the beginning of the 18th century, the Leibniz-Clarke Correspondence provided contemporaries with an appropriate presentation and summary of the actual state of the physical theory and the philosophical interpretation of Newton's and Leibniz's life-long contributions to the space-time theory. Far from being an exhaustive examination it was rather the outset of a further fruitful development in the next decades after 1716 superimposed and promoted by the transition from Cartesianism to Newtonianism on the continent. Among the main figures who were involved in the debates were first of all Leonhard Euler, Emilie Du Chatelet and Johann Heinrich Lambert. Euler reconciled Newton's idea of absolute space with Leibniz's model of relative motion. His theory was later surpassed partially by Mach and finally only by Einstein. Du Chatelet discussed the epistemological background of the formation of the concepts of space and time and adapted Leibniz's idea of a space-time related order to Newton's dynamics. Lambert did first steps towards a non-Euclidean geometry. Furthermore, Euler paved the path for methodological and epistemological consequences which follow from the properties of light, especially in view of the origin of colours and the time delay caused by the propagation of light for the visibility of remote stars in the universe.