De revolutionibus orbium coelestium divided into six "books" (sections or parts), following closely the layout of Ptolemy's "Almagest" which it updated and replaced: Copernicus argued that the universe comprised eight spheres. The outermost consisted of motionless, fixed stars, with the Sun motionless at the center. The known planets revolved about the Sun, each in its own sphere, in the order: Mercury, Venus, Earth, Mars, Jupiter, Saturn. The Moon, however, revolved in its sphere around the Earth. What appeared to be the daily revolution of the Sun and fixed stars around the Earth was actually the Earth's daily rotation on its own axis. Copernicus adhered
The Fate of the Earth wonder, our wonder should make us humble, our humility should inspire us to reverence and caution, and our reverence and caution should lead us to act without delay to withdraw the threat we now pose to the earth and to ourselves." (p.95) The Fate of the Earth The Fate of the Earth is a 1982 book by Jonathan Schell. This "seminal" description of the consequences of nuclear war "forces even the most reluctant person to confront the unthinkable: the destruction of humanity and possibly most life on Earth". The book is regarded as a key document in the nuclear disarmament