Early Developments

The main aim of differential calculus is to break a quantity into infinitesimally small parts to study how it changes -- which is why it was originally called infinitesimal calculus. Its applications to physics and astronomy go back to the very origins of modern science. Through the 18th century these applications multiplied, until Laplace and Lagrange brought the entire study of forces within the reach of analysis. Later contributions came from Dirichlet, Riemann, von Neumann, Heine, Kronecker, Lipschitz, Christoffel, Kirchhoff, Beltrami and many of the leading physicists of the century. …