Eratosthenes (276 BC - 194 BC ) | Biography , Discoveries , Sieve , Facts [ EDU Science ]

Eratosthenes (276 BC - 194 BC ) | Biography, Discoveries, Sieve, Facts 

Eratosthenes in full  Eratosthenes of Cyrene was an ancient Greek scientist. He was born in the city of Cyrene; which is located in present-day Libya but used to be a part of the Greek empire. He was also classified as being poet, astronomer, geographer, athlete, and music theorist.

 Eratosthenes was educated in philosophy and mathematics. He was learning in Athens for his education and was taught by the best teacher of the day. His teachers included the famous philosophers Ariston of Chios and Arcesilaus of  Pitane who also the principal at the celebrated 'Platonic Academy '.

 Eratosthenes's greatest achievements are he produced a reliable, logical method to discover prime numbers. He invented geography. He was regarded as the father of  Geography'.In about 240 Bc  Eratosthenes was the first person to have measured and calculated Earth's size with good accuracy.  Eratosthenes saw that the heavens seemed to rotate once a day around Earth. The axis of rotation formed an imaginary line from the north pole to the south pole through Earth's center.  Eratosthenes calculated the tilt of Earth's axis relative to the plane equator with good accuracy. He produced the first map of the world featuring meridian lines and parallel lines. These were similar to our modern lines of latitude and longitude. He invented the armillary sphere, for 1800 years the most important instrument in Astronomy for determining the position of celestial objects.