Timeline of Discoveries of Models of the Universe

By KELISEB24
  • 500 BCE

    Eudoxus and a geocentric universe

    Eudoxus and a geocentric universe
    The ancient Greek mathematician Pythagoras suggested that the Earth is spherical
  • 150 BCE

    Ptolemy and epicycles

    Ptolemy and epicycles
    Ptolemy developed Aristotle’s geocentric theory of the universe in about 150 CE. Ptolemy knew that the planets don’t appear to orbit in perfect circles around the Earth.[
  • 4 BCE

    Aristotle and a finite, eternal, and geocentric universe

    Aristotle and a finite, eternal, and geocentric universe
    The ancient Greek philosopher Aristotle extended Eudoxus’ model of the universe in the 4th century BCE. Aristotle’s model of the universe was also geocentric, with the Sun, Moon, planets, and stars all orbiting the Earth inside of Eudoxus’ spheres.
  • 1543

    A heliocentric universe

    A heliocentric universe
    The Polish astronomer Nicolaus Copernicus reintroduced the idea of a heliocentric universe in On the Revolutions of the Celestial Spheres, first published in 1543.