History of physics to simplify their production. In heliocentric models of the Solar system, the Earth orbits the Sun along with other bodies in Earth's galaxy, a contradiction according to the Greek-Egyptian astronomer Ptolemy (2nd century CE; see above), whose system placed the Earth at the center of the Universe and had been accepted for over 1,400 years. The Greek astronomer Aristarchus of Samos (c.310 – c.230 BCE) had suggested that the Earth revolves around the Sun, but Copernicus' reasoning led to lasting general acceptance of this "revolutionary" idea. Copernicus' book presenting the theory ("De revolutionibus orbium coelestium", "On the Revolutions of the
The Sun in culture The Sun in culture The Sun, as the source of energy and light for life on earth has been a central object in culture and religion since prehistory. Ritual solar worship has given rise to solar deities in theistic traditions throughout the world, and solar symbolism is ubiquitous. Apart from its immediate connection to light and warmth, the sun is also important in timekeeping as the main indicator of the day and the year. The earliest understanding of the Sun was that of a disk in the sky, whose presence above the horizon creates day and whose absence causes night.