The 1000s (pronounced "one-thousands") was a decade of the Julian Calendar which began on January 1, 1000, and ended on December 31, 1009. Science and technology The scientific achievements of the Islamic civilization reach their zenith. Major works from this decade include Ibn al-Haytham (Alhacen)'s Book of Optics, Abu al-Qasim al-Zahrawi (Abulcasis)'s 30-volume medical encyclopedia, the Al-Tasrif. Other significant contributions to scientific and mathematical understanding were made by Avicenna, who would later publish influential works on medicine, Persian Muslim polymath and scientist Abu Rayhan al-Biruni, Arab Egyptian Muslim mathematician and astronomer Ibn Yunus, Persian Muslim physicist and mathematician Abu Sahl al-Quhi (Kuhi) and Persian Muslim astronomer and mathematician, Abu-Mahmud al-Khujandi. The Law of sines is discovered by Muslim mathematicians. Bell foundry is founded in Italy. Gunpowder is invented in China. Significant people Abd al-Rahman Ibn Yunus Al-Qadir caliph of Baghdad Abu al-Qasim al-Zahrawi (Abulcasis) Abu-Mahmud al-Khujandi Abu Nasr Mansur Abu Rayhan al-Biruni Alhacen (Ibn al-Haytham) Avicenna (Ibn Sina) Basil II Boleslaus I of Poland Brian Boru Bruno of Querfurt Robert II of France Robert Guiscard Roger I of Sicily Sancho III of Navarre Stephen I of Hungary Sweyn I of Denmark Tsar Samuil of Bulgaria References