Ancient astronomy

• Geocentric


  • Earth was the center of the universe
  • Motionless sphere
  • The sun, moon, and other planets orbit the earth
• Celestial sphere


  A transparent hollow sphere located beyond the planets
• The greeks believed that the earth was flat
• "On the Heavens" by Aristotle


  1. Due to the position of the stars and constellations seeming to change as a person travelled north or south
  2. Pointed out that the shape of the earth's shadow outline is always curved during eclipse
• Alexander the great


  • Alexander helps spread the theory of aristotle as far east india conquered the world
  • "Hellenistic" period in history because of the Greek influence across the globe where the world was thought to be flat among the philosophers in Mesopotamia under Greek Seleucids and Egyptian philosophers under Greek Ptolomies
• Seleucus of Seleucia 


  Lived in the 2nd century who proposed that not only is the earth round but it also revolves around the sun
• Eratosthenes


  A greek philosopher in egypt who use the round earth theory and shadows to measure the circumference of the earth
• Claudius Ptolemy


  In the 2nd Century AD he created a map that shows the earth has been round which was held as the most popular map in the Middle Ages