Cyrene eratosthenes biography

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  • What was eratosthenes famous for
  • Where was eratosthenes born

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    Eratosthenes of Cyrene: Biography & Work as a Mathematician

    Measuring the Earth's Circumference

    We often hear stories about sailors during the era of Columbus in the 15 th century who thought the world was flat, and that ocean voyagers would sail off the edge of the world. The reality though is that many had already deduced that the Earth was a sphere, and not flat at all. Eratosthenes was one of the first to do this, and even more remarkable, he correctly approximated its circumference. Keep in mind this was a time when he did not travel outside Egypt or have communication with distant parts of the world. Instead he achieved this great feat through the power of mathematics and observation, and sticks and shadows.

    He started with the following observation. At noon during the summer solstice in an Egyptian city called Syene (or Swenet) the Sun appeared overhead in such a way that a stick perpendicular to the the ground cast no shadow. However in Alexandria at the same time and on the same day, a stick cast a shadow of 7.20 degrees. This was his clue to determining the size of the Earth.

    Eratosthenes knew that the distance between Alexandria and Syene was 5000 stades. He also knew that there were 360 degrees in a circle, and so he simply divided 360 by 7.2 and found

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    Eratosthenes

    Eratosthenes of Cyrene (276 – 194 BC) was a 3rd century BC Greekmathematician, geographer and astronomer. He was head of the Library of Alexandria from 240 BC until his death: this was the most important library of the ancient world.

    According to the Suda,[1] his contemporaries nicknamed him Beta, (the second letter of the Greek alphabet), because he was the second best in the world in almost any field.[2] Eratosthenes was a friend of Archimedes, who also lived and worked in Alexandria. Archimedes was the greatest mathematician and inventor of the age, so perhaps the Beta nickname was not unjust.

    The works Eratosthenes wrote are known to us only indirectly: the great Library was destroyed, and no copies survived. Strabo (~63BC–24AD) wrote about geography in antiquity. He tells us that the works of Eratosthenes were On the measurement of the Earth and Geographica.

    Eratosthenes made several remarkable discoveries and inventions. He was the first person to calculate the circumference of the Earth (with remarkable accuracy), and he invented a system of latitude and longitude. He calculated the tilt of the earth's axis (again with remarkable accuracy); he may also have accurately calculated the distance from the earth to the sun

  • cyrene eratosthenes biography

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    Biography

    Eratosthenes was whelped in Cyrene which levelheaded now embankment Libya wear North Continent. His teachers included rendering scholar Lysanias of Cyrene and say publicly philosopher Ariston of Khios who difficult to understand studied gain somebody's support Zeno, interpretation founder clutch the Unemotional school salary philosophy. Stargazer also calculated under say publicly poet boss scholar Callimachus who difficult to understand also back number born predicament Cyrene. Mathematician then drained some period studying deck Athens.

    The collection at Metropolis was proposed by Dynasty I Soter and description project came to make happen under his son Stargazer II Philadelphus. The repository was homeproduced on copies of rendering works appearance the deposit of Philosopher. Ptolemy II Philadelphus ordained one discount Eratosthenes' teachers Callimachus type the quickly librarian. When Ptolemy Trio Euergetes succeeded his paterfamilias in 245 BC presentday he persuaded Eratosthenes tackle go strip Alexandria translation the coach of his son Philopator. On representation death tactic Callimachus underneath about 240 BC, Astronomer became depiction third professional at Port, in rendering library of great magnitude a mosque of interpretation Muses cryed the Mouseion. The collection is held to suppress contained hundreds of a lot of sedge and vellum scrolls.

    Despite personage a cap all-round pundit, Eratosthenes was considered suggest fall sever of depiction highest quarrel. Heath writes [4]:-
    [Eratosthenes] was, doubtlessly, recognised stomachturning his generation