astro 1

• pythagoras - influenced by thales and anaximander and said sphere is the perfect shape.
• plato - my conviction is that the earth is a round body in the centerof the heavens
• aristotle - experiment length of the shadow casted by vertical stick
• eratosthenes - there are stars that were seen in Egypt and Cyprus that is not visible in the northern region.
• 2 model:

  • Geocentric model
  • Heliocentric model
• Plato and Pythagoras - entertained the 2 models
• pythagoreans - developed spherical model since fifth century BC, also non-geocentric
• aristotle - student of plato, 320 BC - concluded eclipse the moon it always casts a curved shadow
• navigation - gradually disappear behind the horizon
• eratosthenes - TO approximate the circumference - 235 BC
• eratosthenes - approximated the circumference - 276 to 194 BC
• 40,075 km - circumference of the earth.
• eclipse - cover object