Editing Abbasid Caliphate (section)

===Science===
{{Main |Science in the medieval Islamic world}}
{{Further |Alchemy (Islam)|Islamic astronomy|Islamic mathematics|Islamic medicine|Timeline of science and technology in the Islamic world}}
[[File:Al-Mustansriah School - Main door.jpg|thumb|The [[Mustansiriyya Madrasa]] in [[Baghdad]], established in 1227, one of the few Abbasid-era [[madrasa]]s remaining today]]

[[File:Al-Jaahith - African Arab Naturalist - Basra - al jahiz.jpg|thumb|[[Jabir ibn Hayyan]], a pioneer in [[organic chemistry]].
The reigns of [[Harun al-Rashid]] (786–809) and his successors fostered an age of great intellectual achievement. In large part, this was the result of the schismatic forces that had undermined the Umayyad regime, which relied on the assertion of the superiority of [[Arab culture]] as part of its claim to legitimacy, and the Abbasids' welcoming of support from non-Arab Muslims.<ref>{{harvnb|Stapleton|Azo|Hidayat Husain|1927|pp=338–340}}; {{harvnb|Kraus|1942–1943|loc=vol. II, pp. 41–42}}</ref>]]
A number of medieval thinkers and scientists living under Islamic rule played a role in transmitting [[Islamic science]] to the Christian West. In addition, the period saw the recovery of much of the [[Alexandria]]n mathematical, geometric and astronomical knowledge, such as that of [[Euclid]] and Claudius [[Ptolemy]]. These recovered mathematical methods were later enhanced and developed by other Islamic scholars, notably by Persian scientists [[Al-Biruni]] and [[Abu Nasr Mansur]].

[[Christians]] (particularly [[Nestorianism|Nestorian]] Christians) contributed to the Arab Islamic Civilization during the Umayyads and the Abbasids by translating works of [[Greek philosophers]] to [[Syriac Language|Syriac]] and afterwards to [[Arabic Language|Arabic]].<ref>{{harvnb|Hill|1993|p=4}}</ref><ref>{{harvnb|Brague|2009|p=164}}</ref> Nestorians played a prominent role in the formation of Arab culture,<ref>{{Cite book |last= |chapter-url=https://archive.org/details/newencyclopaedia08chic/page/612/mode/2up |title=The New Encyclopaedia Britannica |publisher=Encyclopaedia Britannica |year=1985 |isbn=978-0-85229-423-9 |editor-last=Goetz |editor-first=Philip W. |edition=15th |volume=8 |location=Chicago |pages=612–613 |language=en |chapter=Nestorian |orig-year=1974}}</ref> with the [[Academy of Gondishapur]] being prominent in the late [[Sassanid]], [[Umayyad]] and early Abbasid periods.<ref>{{harvnb|Söylemez|2005|p=3}}</ref> Notably, eight generations of the Nestorian [[Bukhtishu]] family served as private doctors to caliphs and sultans between the eighth and eleventh centuries.<ref>{{harvnb|Bonner|Ener|Singer|2003|p=97}}</ref><ref>{{harvnb|Ruano|Burgos|1992|p=527}}</ref>

[[Algebra]] was significantly developed by Persian scientist [[Muhammad ibn Mūsā al-Khwārizmī]] during this time in his landmark text, ''[[The Compendious Book on Calculation by Completion and Balancing|Kitab al-Jabr wa-l-Muqabala]]'', from which the term ''algebra'' is derived. He is thus considered to be the father of algebra by some,<ref>{{harvnb|Eglash|1999|p=61}}</ref> although the Greek mathematician [[Diophantus]] has also been given this title. The terms ''[[algorism]]'' and ''[[algorithm]]'' are derived from the name of al-Khwarizmi, who was also responsible for introducing the [[Arabic numerals]] and [[Hindu–Arabic numeral system]] beyond the [[Indian subcontinent]].
[[File:Ibn al-Haytham crop.jpg|thumb|[[Alhazen|Ibn al-Haytham]], "the father of [[Optics]]".<ref>{{harvnb|Verma|1969}}{{full citation needed|date=May 2015}}</ref>]]

Arab scientist [[Ibn al-Haytham]] (Alhazen) developed an early [[scientific method]] in his ''[[Book of Optics]]'' (1021). The most important development of the scientific method was the use of experiments to distinguish between competing scientific theories set within a generally [[empiricism|empirical]] orientation, which began among Muslim scientists. Ibn al-Haytham's empirical proof of the intromission theory of light (that is, that light rays entered the eyes rather than being [[emission theory (vision)|emitted by them]]) was particularly important. Ibn al-Haytham was significant in the [[history of scientific method]], particularly in his approach to experimentation,<ref>{{harvnb|Toomer|1964}}</ref> and has been referred to as the "world's first true scientist".<ref>{{harvnb|Al-Khalili|2009}}</ref>

[[Medicine in medieval Islam]] was an area of science that advanced particularly during the Abbasids' reign. During the 9th century, Baghdad contained over 800 doctors, and great discoveries in the understanding of anatomy and diseases were made. The clinical distinction between [[measles]] and [[smallpox]] was described during this time. Famous Persian scientist [[Ibn Sina]] (known to the West as [[Avicenna]]) produced treatises and works that summarized the vast amount of knowledge that scientists had accumulated, and was very influential through his encyclopedias, ''[[The Canon of Medicine]]'' and ''[[The Book of Healing]]''. The work of him and many others directly influenced the research of European scientists during the [[Renaissance]].

[[Astronomy in medieval Islam]] was advanced by [[Al-Battani]], who improved the precision of the measurement of the [[precession]] of the Earth's axis. The corrections made to the [[geocentric model]] by al-Battani,{{Citation needed|date=August 2011}} [[Averroes]],{{Citation needed|date=August 2011}} [[Nasir al-Din al-Tusi]], [[Mo'ayyeduddin Urdi]] and [[Ibn al-Shatir]] were later incorporated into the [[Copernican heliocentrism|Copernican heliocentric]] model.<ref>{{harvnb|Rabin|2015}}</ref> The [[astrolabe]], though originally developed by the Greeks, was developed further by Islamic astronomers and engineers, and subsequently brought to medieval Europe.

[[Alchemy and chemistry in medieval Islam|Muslim alchemists]] influenced medieval European alchemists, particularly the writings attributed to [[Jābir ibn Hayyān]] (Geber).