Models of the universe

• The universe has been modeled through the years as

  • Pyrocentric
  • Tychonic
  • Geocentric
  • Heliocentric
• Pyrocentric - fire is the center of the universe proposed by philolaus
• Tychonic - a comprised between the heliocentric and geocentric models was proposed by brahe
• Geocentric - suggested that earth is the center of the universe
• Pythagoren model - earth is at rest at the center of the universe and everything rotates around it
• Eudoxus‘ model - he was the first to “save the appearances” that Plato referred to, using a series of 27 concentric spheres on which the Sun, the moon, and the planes moved in perfect circular motion
• Aristotle model - Aristotle used 27 ”buffering” spheres between the celestial spheres of eudoxus and an outermost sphere that was the domain of what he called the prime mover
• Ptolemy’s model - an epicycle is a circle on which planet moves. The center of the small Circle turn moves around the earth along a bigger circular path called the deferent
• GEOCENTRIC MODELS

  • Pythagoras
  • plato
  • eudoxus
  • aristotle
  • apollonius
  • ptolomy
• heliocentric - suggested that the Sun is the center of the universe