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ERIC Number: EJ943474
Record Type: Journal
Publication Date: 2011-Oct
Pages: 3
Abstractor: As Provided
Reference Count: 10
ISSN: ISSN-0031-921X
A New Perspective on Eratosthenes' Measurement of the Earth
Brown, Ronald A.; Kumar, Alok
Physics Teacher, v49 n7 p445-447 Oct 2011
Around 240 B.C., Eratosthenes made what is considered to be the most famous and accurate of the ancient measurements of the circumference of the Earth. It was accomplished by making "presumably simultaneous" measurements of the angles of the shadows cast by a vertical stick at Syene (today known as Aswan) and another at Alexandria, at noon on the day of the summer solstice (about June 21 every year). From these measurements, and knowing the distance from Syene to Alexandria along the assumed same meridian of longitude, Eratosthenes was able to provide a remarkably accurate estimate of the radius of the Earth.
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Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A