Edge corrugated, 10 corrugation sectors.
Abū Naṣr al-Fārābi (أبو نصر محمد الفارابي - Abū Naṣr Muḥammad al-Fārābi; in some sources also mentioned as محمد بن محمد بن أوزلغ الفارابي - Muḥammad ibn Muḥammad (ibn Tarḫān) ibn Awzlaġ al-Fārābi), known in the West as Alpharabius (c. 872 – between 14 December 950 and 12 January 951), was a Persian polymath and one of the greatest scientists and philosophers of Persia and the Islamic world in his time. He was also a cosmologist, logician, musician, psychologist and sociologist.