Presentation on theme: "The History of Astronomy Part One The Ancients Astronomy “BC”"— Presentation transcript:
The History of Astronomy Part One The Ancients Astronomy “BC”
Eudoxus (400-347 BC) first known Geocentric (Earth-centered) model It was (from Earth out): The Moon, Inferior Planets, Sun, Superior Planets & stars all orbiting in circles… On nested Spheres It explained: – the phases of the Moon, – Eclipses, – why Inferior Planets are always near the Sun.
Aristotle (383-322BC) The Ancient Greeks believed the Earth was a sphere. As early as 500 BC Pythagoras suggested that the Earth was a sphere as it was the ‘perfect shape.’ Later Aristotle gave two reasons to believe the Earth was round: 1.The shape of Earth’s shadow on the moon during an Eclipse is always curved, only a sphere can do this. 2.Some stars are only visible from certain places on Earth
Aristotle’s Physics Everything is made of the 4 Elements Which of these an object is made of determines…. where in the universe the object belongs Fire at the highest levelAir next level down Water below the AirEarth lowest level The natural state of an object at rest at its proper level. Objects move in two ways Naturally seeking to return to its proper level Unaturally or Violently when it is forced to move. Unless forced to move all objects come to rest at their proper level