3rd century BCE In a work called The Sand Reckoner, Archimedes reports the ideas of Aristarchus of Samos, who proposed that the universe was much larger than commonly believed, and that the Sun was at its center.
150 CE Ptolemy of Alexandria uses mathematics to describe a geocentric (Earth-centered) model of the universe.
1609 Johannes Kepler resolves the outstanding conflicts in the heliocentric (Sun-centered) model of the solar system by proposing elliptical orbits.
1610 After observing the moons of Jupiter, Galileo becomes convinced that Copernicus was right.
Throughout its early history, Western thought was shaped ...