RT @hist_astro: Concentric planetary orbs. From commentary on handbook of astronomy of al-Jighmīnī, 16thc.? brbl-dl.library.yale.edu/vufind/Record/… http://t.co/vJtU4d5qiD
RT @hist_astro: Concentric planetary orbs. From commentary on handbook of astronomy of al-Jighmīnī, 16thc.? brbl-dl.library.yale.edu/vufind/Record/… http://t.co/vJtU4d5qiD