Radio de la tierra eratosthenes biography en

He was a man of learning, becoming the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography , and he introduced some of the terminology still used today. He is best known for being the first person known to calculate the Earth's circumference , which he did by using the extensive survey results he could access in his role at the Library.

Eratosthenes was the founder of scientific chronology ; [ 5 ] he used Egyptian and Persian records to estimate the dates of the main events of the Trojan War , dating the sack of Troy to BC. In number theory , he introduced the sieve of Eratosthenes , an efficient method of identifying prime numbers and composite numbers.

He was a figure of influence in many fields who yearned to understand the complexities of the entire world. Yet, according to an entry [ 7 ] in the Suda a 10th-century encyclopedia , some critics scorned him, calling him Number 2 because he always came in second in all his endeavours. Now part of modern-day Libya , Cyrene had been founded by Greeks centuries earlier and became the capital of Pentapolis North Africa , a country of five cities: Cyrene, Arsinoe , Berenice , Ptolemias , and Apollonia.

Under Ptolemaic rule the economy prospered, based largely on the export of horses and silphium , a plant used for rich seasoning and medicine. Like any young Greek at the time, Eratosthenes would have studied in the local gymnasium , where he would have learned physical skills and social discourse as well as reading, writing, arithmetic, poetry, and music.

Eratosthenes went to Athens to further his studies. There he was taught Stoicism by its founder, Zeno of Citium , in philosophical lectures on living a virtuous life. He also studied under the head of the Platonic Academy , who was Arcesilaus of Pitane. His interest in Plato led him to write his first work at a scholarly level, Platonikos , inquiring into the mathematical foundation of Plato's philosophies.

Shape of the earth geography

This work was highly esteemed for its accuracy. George Syncellus was later able to preserve from Chronographies a list of 38 kings of the Egyptian Thebes. Eratosthenes also wrote Olympic Victors , a chronology of the winners of the Olympic Games.