Eratosthenes

American  

[er-uh-tos-thuh-neez] / ˌɛr əˈtɒs θəˌniz /

noun

1. 276?–195? b.c., Greek mathematician and astronomer at Alexandria.

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Eratosthenes British  

/ ˌɛrəˈtɒsθɪˌniːz /

noun

1. ?276–?194 _bc , Greek mathematician and astronomer, who calculated the circumference of the earth by observing the angle of the sun's rays at different places

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Eratosthenes Scientific  

/ ĕr′ə-tŏs′thə-nēz′ /

1. Greek mathematician and astronomer who is best known for making an accurate estimate of the circumference of the Earth by measuring the angle of the Sun's rays at two different locations at the same time. He also invented a method for listing the prime numbers that are less than any given number.

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Example Sentences

It includes star-origin myths by Eratosthenes and parts of a famous third-century-BC poem called Phaenomena, which describes the constellations.

From Scientific American • Oct. 20, 2022

So did Pythagoras, Archimedes and later, in 240BC, the astronomer Eratosthenes, who was among the first to estimate the Earth’s circumference.

From The Guardian • May 27, 2018

It is not possible to evaluate precisely the accuracy of Eratosthenes solution because there is doubt about which of the various kinds of Greek stadia he used as his unit of distance.

From Textbooks • Oct. 13, 2016

Just as a chess player might examine variations of the Ruy Lopez and King’s Indian Defense, a mathematician might study particularly clever applications of the Chinese remainder theorem or the sieve of Eratosthenes.

From New York Times • Jul. 24, 2015

The pertinent point is worth emphasizing: though the Alexandrian Greeks such as Eratosthenes worked within the geographical confines of Egypt, they were not drawing from some deep well of native wisdom.

From "Circumference" by Nicholas Nicastro