Planetary system BC by Aristarchus of Samos, but received no support from most other ancient astronomers. "De revolutionibus orbium coelestium" by Nicolaus Copernicus, published in 1543, was the first mathematically predictive heliocentric model of a planetary system. 17th-century successors Galileo Galilei, Johannes Kepler, and Isaac Newton developed an understanding of physics which led to the gradual acceptance of the idea that the Earth moves round the Sun and that the planets are governed by the same physical laws that governed the Earth. In the 16th century the Italian philosopher Giordano Bruno, an early supporter of the Copernican theory that the Earth and
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