Calculating the Radius of the Earth Using Sunset Method: Comparison with al-Bīrūni Method

Authors

Jana Kamal, effat universityFollow
Tayeb Brahimi

Abstract

This paper attempts to compare the earth's radius calculation based on the sunset or sunrise (moonset or moonrise) with the Method developed by the scientist Al-Bīrūni. The sunset sunrise method is used to calculate the earth radius by standing in front of a flat horizontal plane. In addition, the authors have use Al-Bīrūni's rule to calculate the radius. Furthermore, the error percent of both Al-Bīrūni and the sunset sunrise method were calculated as well. The results showed that the earth actual radius is 6371 km. Eratosthenes radius which is 6366 km is the closest to the actual earth radius, then comes Al-Bīrūni’s radius 6336 km and last but not least the Sunrise or Sunset (moonrise or moonset) radius 6316 km. Furthermore, the radius of Eratosthenes method has the least percent error which is 0.08%. The radius of Al-Bīrūni’s Method comes in second with 0.6% and the radius of the Sunrise or Sunset (moonrise or moonset) method radius has 0.9% which is the highest percent error.

Recommended Citation

Kamal, Jana and Brahimi, Tayeb (2021) "Calculating the Radius of the Earth Using Sunset Method: Comparison with al-Bīrūni Method," Effat Undergraduate Research Journal: Vol. 2: Iss. 1, Article 6.
Available at: https://digitalcommons.aaru.edu.jo/eurj/vol2/iss1/6