Eratosthenes

Forfatter/Opretter:

Lookang many thanks to author of original simulation = Todd K. Timberlake author of Easy Java Simulation = Francisco Esquembre

Attribution:

Billedet er tagget "Attribution Required", men der blev ikke angivet nogen tilskrivningsoplysninger. Attributionsparameteren blev sandsynligvis udeladt ved brug af MediaWiki-skabelonen til CC-BY-licenserne. Forfattere og ophavsmænd finder et eksempel på korrekt brug af eksempel her. her.

Kredit:

Eget arbejde http://weelookang.blogspot.sg/2012/06/ejs-open-source-eratosthenes-measures.html
Picture is from http://www.shadedrelief.com/natural3/pages/textures.html // who release it to the public domain by Tom Patterson, www.shadedrelief.com.

Shortlink:

https://dkwiki.dk/b/2513a

kilde:

Wikimedia Commons

størrelse:

701 x 542 Pixel (138909 Bytes)

beskrivelse:

Measurements taken at Alexandria and Syene. Eratosthenes calculated the circumference of the Earth without leaving Egypt. Eratosthenes knew that on the summer solstice at local noon in the Ancient Egyptian city of Swenet (known in Greek as Syene, and in the modern day as Aswan) on the Tropic of Cancer, the sun would appear at the zenith, directly overhead (he had been told that the shadow of someone looking down a deep well would block the reflection of the Sun at noon). He also knew, from measurement, that in his hometown of Alexandria, the angle of elevation of the sun was 1/50th of a circle (7°12') south of the zenith on the solstice noon. Assuming that the Earth was spherical (360°), and that Alexandria was due north of Syene, he concluded that the meridian arc distance from Alexandria to Syene must therefore be 1/50 = 7°12'/360°, and was therefore 1/50 of the total circumference of the Earth.

Licens:

CC BY-SA 3.0

Licensbetingelser:

Creative Commons Attribution-Share Alike 3.0