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

One of them, Jamie Klair, unexpectedly spotted a passage in Greek often attributed to the astronomer Eratosthenes.

From Scientific American • Oct. 20, 2022

Hellenistic astronomers also refined the calculations associated with the size of the Earth; one astronomer named Eratosthenes calculated the circumference of the Earth that was only off by 200 miles.

From Textbooks • Jan. 1, 2020

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

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 most pedantic difficulty—and the one that has undoubtedly spilled the most scholarly ink—is the question of which version of the stade Eratosthenes used in his work.

From "Circumference" by Nicholas Nicastro