First Islamic observatory was Semmâsa in Baghdad built by Abbasid Caliph Me'mun. About fifty observatories were established across Islamic geography until Ottoman period. Semmâsa and Qasiyûn Observatories were first to make extensive moon and sun observations
Project initiated at 1939 Turkish Publications Congress. First fascicle published in December 1940. Completed in 1987 under leadership of Abdülhak Adnan Adıvar. Initially planned as translation of Encyclopaedia of Islam
Byzantine Empire experienced sudden decline, Normans gained European dominance. Roman Catholicism and Eastern Orthodoxy split within Christendom. William the Conqueror became King of England after Battle of Hastings. First Crusade occurred from 1096 to 1099, capturing Jerusalem
Astrology began with seasonal changes and lunar cycle observations 25,000 years ago. Oldest known astrological references found in Mesopotamian texts from 1700 BC. Babylonian astrology emerged in 2nd millennium BC as first organized system. Babylonian astrology combined celestial omens with divination practices
Gnomon, first timekeeping device, appeared around 3500 BCE. Egyptian shadow clock from 8th century BCE used east-west direction. Aristarchus's hemicycle sundial (280 BCE) featured 12 equal seasonal hours
Al-Jazari was a prominent mechanical engineer from Diyar-Bakir during the 12th-13th centuries CE. He served the Artuqid kings of Diyar-Bakir between 1174 and 1200 CE. His full name was Badi' al-Zaman Abu-'l-'Izz Ibn Isma'il Ibn al-Razzaz al-Jazari