 However, such models are no longer regarded as viable theories within the mainstream scientific community and general relativity is now the standard model to describe gravitation without the use of actions at a distance.Modern "quantum gravity" hypotheses also attempt to describe gravity by more fundamental processes such as particle fields, but they are not based on classical mechanics.This theory is probably the best-known mechanical explanation, and was developed for the first time by Nicolas Fatio de Duillier in 1690, and re-invented, among others, by Georges-Louis Le Sage (1748), Lord Kelvin (1872), and Hendrik Lorentz (1900), and criticized by James Clerk Maxwell (1875), and Henri Poincaré (1908).