theories include geomorphology and climate variability, while he improves Chinese astronomy, by fixing the position of the pole star and correcting the lunar error, by plotting its orbital course every night for a continuum of five years. Shen's book is also the first to describe the drydock in China – and discusses the advantages of the recent invention of the canal pound lock, over the old flash lock. Su Song, Chinese polymath scientist and statesman, invents the pilot model for his astronomical clock tower constructed in Kaifeng. It features an escapement mechanism – and the world's oldest known power-transmitting chain drive to operate the armillary sphere, opening doors, and mechanical-driven mannequins, that would rotate in shifts to announce the time on plaques. Education The oldest extant university, the University of Bologna, is founded in Italy (approximate date). Geology April 16 – The 6.5 Tmogvi earthquake affects the southern provinces of Georgia, which causes the destruction of the castle of Tmogvi and many deaths. Religion March 12 – Pope Urban II (or Urbanus) succeeds Victor III as the 159th pope of the Catholic Church in Rome. Births January 31 – Ja'far ibn Abdallah al-Muqtadi, was the son of caliph al-Muqtadi and Mah-i Mulk. July 24 – Ibn al-Arif, Moorish Sufi scholar and writer (d. 1141) Bermudo Pérez de Traba, Spanish nobleman (d. 1168) Hemachandra, Indian Jain poet and polymath (d. 1173) Irene of Hungary, Byzantine empress consort (d. 1134) John IV, Byzantine prince and archbishop (approximate date) Lucienne de Rochefort, French crown princess (d. 1137) Tairrdelbach Ua Conchobair, king of Connacht (d. 1156) William III (or William IV), French nobleman (d. 1156) Zhenxie Qingliao, Chinese Zen Buddhist monk (d. 1151) Deaths January 6 – Berengar of Tours, French theologian April 7 – Burchard II (or Bucco), German bishop June 15 – Gebhard of Salzburg, German archbishop June 24 – William de Warenne, Norman nobleman July 27 – Benno II, German bishop and architect September 25 – Godfrey, bishop of Chichester September 28 – Hermann of Salm, German nobleman Alberic of Monte Cassino, German Benedictine cardinal Berthold of Reichenau, German chronicler and writer Dubh Chablaigh ingen Áed, Irish queen of Munster Hugh de Montfort, Norman nobleman (approximate date) John Doukas, Byzantine usurper (approximate date) Khwaja Abdullah Ansari, Persian Sufi poet (b. 1006) Mael Isa ua Máilgiric, Irish Chief Ollam and writer Marianus Scotus of Regensburg, Irish abbot Naser Khosrow, Persian poet and