Biruni's Measurement of the Earth

Alberto Gomez Gomez

Abstract: The peak from which Biruni measured the Earth is pinpointed; his measurements are shown to tally with the geographical features of the landscape around the peak. Mathematics shows what measurements he is likely to have taken, and his famous formula is fully derived. Also, an appendix is given for those who wish to measure mountains by themselves and follow in Biruni's footsteps.

Keywords: Biruni, Nandana, Earth's radius, Baghanwala, India