Concept
Eratosthenes
Overview
Eratosthenes of Cyrene ( err-ə-TOSS-thə-NEEZ; Ancient Greek: Ἐρατοσθένης [eratostʰénɛːs]; c. 276 BC – c. 195/194 BC) was an Ancient Greek polymath: a philosopher, scholar, mathematician, geographer, poet, astronomer, and music theorist. Eratosthenes eventually became the chief librarian at the Library of Alexandria. His work was the precursor to the modern discipline of geography, and he introduced some of its terminology, coining the terms geography and geographer.
He is best remembered as the first known person to calculate the Earth's circumference. He was also the first to calculate Earth's axial tilt, which similarly proved to have remarkable accuracy. He created the first global projection of the world incorporating parallels and meridians based on the geographic knowledge of his era. Eratosthenes was the founder of scientific chronology; he used Egyptian and Persian records to estimate the dates of the main events of the Trojan War, dating the sack of Troy to 1184 BC. In number theory, he introduced the sieve of Eratosthenes, an efficient method of identifying prime numbers and composite numbers.
His devotees nicknamed him Pentathlos after the Olympians who were well-rounded competitors, for he had proven himself to be knowledgeable in every area of learning. Yet, according to an entry in the Suda (a 10th-century Byzantine encyclopedia), some critics scorned him, calling him Beta (Second, or Number 2) because he always came in second in all his endeavors.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
Found by search and not yet checked by a person; they may only mention the idea in passing.
The length of the schœnus, according to the estimate of Eratosthenes, is forty stadia, or, in other words, five miles; some persons, however, have estimated the schœnus at no more than thirty-two stadia. In this district some lofty hills take their rise, and the trees, which spring up spontaneously, run downwards along the declivities to the plains.
the Elder Pliny, The Natural History of Pliny, Volume 3
States what Eratosthenes is; opens on Eratosthenes.
On one occasion, wishing to draw them on to speak of antiquity, he began to tell about the most ancient things in our part of the world—about Phoroneus, who is called ‘the first man,’ and about Niobe; and after the Deluge, of the survival of Deucalion and Pyrrha; and he traced the genealogy of their descendants, and reckoning up the dates, tried to compute how many years ago the events of which he was speaking…
Plato, Timaeus
States what Eratosthenes is; the author is tied to Eratosthenes in the knowledge graph.
Pythagoras, that the world was formed of five solid figures which are called mathematical; the earth was produced by the cube, the fire by the pyramid, the air by the octahedron, the water by the icosahedron, and the globe of the universe by the dodecahedron. In all these Plato hath the same sentiments with Pythagoras.
Plutarch, Complete Works of Plutarch — Volume 3
States what Eratosthenes is.
Philosophers who discussed Eratosthenes
Related ideas
- Eusebius
- Athens
- Harvard University Press
- Princeton University Press
- Grammar
- Herodotus
- Homer
- Philosophy
- Julius Caesar
- Athenaeus
- Chios
- Libya
- Library of Alexandria
- Sextus Empiricus
- Archimedes
- Geography
- Geometry
- Mediterranean Sea
- Cynicism (philosophy)
- Stoicism
- Aeschylus
- Number theory
- Platonism
- Plato
Place in the tradition
Part of Anaximander.