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
Earth in the Balance to react in time to save our skins”. Earth in the Balance Earth in the Balance: Ecology and the Human Spirit (, paperback ) is a 1992 book written by Al Gore, published in June 1992, shortly before he was elected Vice President in the 1992 presidential election. Known by the short title "Earth in the Balance", the book explains the world's ecological predicament and describes a range of policies to deal with the most pressing problems. It includes a proposed "Global Marshall Plan" to address current ecological issues. Written while his son was recovering from a serious accident, "Earth