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

See Examples For:

Eratosthenes

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

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

Eratosthenes reasoned that the curvature of the round Earth meant that “straight up” was not the same in the two cities.

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 results were amazing: Eratosthenes accurately calculated the size of the Earth, mapped it, and argued that India could be reached by sailing westward from Spain.

From "Cosmos" by Carl Sagan