He did the measurement in Alexandria and timed it to coincidence when the Sun is directly overhead Syene. He did the measurement in Alexandria and timed it to coincidence when the Sun is directly overhead Syene. Eratosthenes was a Greek astronomer in ancient times. The astronomer Eratosthenes is believed to be one of the first to determine the globe's shape. As an intelligent astronomer, privy to the advanced astronomical knowledge that seems to have been handed down since the dawn of civilization in Sumer and of recorded history (indeed, astronomical texts where some of the first written down), Eratosthenes knew that on the summer solstice in Syene, Egypt (modern-day Aswan) the sun would be directly overhead. Eratosthenes of Cyrene (276 b.c.-194 b.c.). C) He discovered his Three Laws (of Planetary Motion). What are the release dates for The Wonder Pets - 2006 Save the Ladybug? plataea. in, "June 19, 240 B.C. Eratosthenes determined the angular distance from the equator to the tropic: he found it equal to 11/83 of 180 °. [4] He created the first global projection of the world, incorporating parallels and meridians based on the available geographic knowledge of his era. Who is the divisor of centigrade thermomoter? 2006. Eratosthenes’ method to calculate the Earth’s circumference Eratosthenes knew that at local noon on the summer solstice (at the time of the longest day, about 21 June in the northern hemisphere) in Syene (modern Aswan, Egypt), the Sun was directly overhead – Syene was in fact slightly north of the tropic, though (see notes 1). 276–195 B.C. How do you correct too much worcestershire sauce in gravy? Archimedes. For the crater named after him, see. He was also the chief librarian of the great Library of Alexandria. Since the Sun was directly overhead, a well situated in that town didn’t cast a shadow at its bottom. ", "Eratosthenes on the "measurement" of the Earth", "The origin and value of the stadion unit used by Eratosthenes in the third century B.C", "Eratosthenes's large Earth and tiny universe", "Eratosthenes' Parallel of Rhodes and the History of the System of Climata", English translation of the primary source for Eratosthenes and the size of the Earth, About Eratosthenes' methods, including a Java applet, How the Greeks estimated the distances to the Moon and Sun, Measuring the Earth with Eratosthenes' method, List of ancient Greek mathematicians and contemporaries of Eratosthenes, New Advent Encyclopedia article on the Library of Alexandria, Eratosthenes' sieve in classic BASIC all-web based interactive programming environment, Open source Physics Computer Model about Eratosthenes estimation of radius and circumference of Earth, Eratosthenes, Katasterismoi (or Astrothesiae), original text, Ancient Greek and Hellenistic mathematics, https://en.wikipedia.org/w/index.php?title=Eratosthenes&oldid=993238914, Articles containing Ancient Greek (to 1453)-language text, CS1 maint: DOI inactive as of October 2020, Short description is different from Wikidata, Wikipedia articles with BIBSYS identifiers, Wikipedia articles with CANTIC identifiers, Wikipedia articles with CINII identifiers, Wikipedia articles with SELIBR identifiers, Wikipedia articles with SUDOC identifiers, Wikipedia articles with Trove identifiers, Wikipedia articles with WORLDCATID identifiers, Creative Commons Attribution-ShareAlike License, Cleomedes assumes that the distance between Syene and Alexandria was 5,000, he assumes the simplified (but false) hypothesis that Syene was precisely on the, he assumes the simplified (but false) hypothesis that Syene and Alexandria are on the same, The first book was something of an introduction and gave a review of his predecessors, recognizing their contributions that he compiled in the library. 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