Conversations on the Plurality of Worlds Conversations on the Plurality of Worlds Conversations on the Plurality of Worlds () is a popular science book by French author Bernard le Bovier de Fontenelle, published in 1686. It offered an explanation of the heliocentric model of the Universe, suggested by Nicolaus Copernicus in his 1543 work "De revolutionibus orbium coelestium". The book is Fontenelle's most famous work and is considered to be one of the first major works of the Age of Enlightenment. Unlike many scientific works of its time, "Conversations on the Plurality of Worlds" was written not in Latin, but in French and is notable as
History of the center of the Universe the Sun" from the centre of gravity of the solar system. For Newton, it was not precisely the centre of the Sun or any other body that could be considered at rest, but rather "the common centre of gravity of the Earth, the Sun and all the Planets is to be esteem'd the Centre of the World", and this centre of gravity "either is at rest or moves uniformly forward in a right line" (Newton adopted the "at rest" alternative in view of common consent that the centre, wherever it was, was at rest). Before the 1920s, it was generally