Ibn al-Haytham

[[File:Alhazen,_the_Persian.gif|thumb|165px|Ibn al-Haytham 
has given permission for future generations to depict him
 in all his glory.]]
{{sciencenav}}
{{cquote|Ibn al-Haytham was the first person ever to set down the rules of [[science]].|4=[[Neil deGrasse Tyson]]<ref>"Hiding in the Light", the fifth episode of the American documentary television series Cosmos: A Spacetime Odyssey</ref>}}
'''Ibn al-Haytham''' (full name '''Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham'''; commonly known as '''ibn al-Haytham''', '''Ali al-Hasan''', '''al-Basri''',<ref>Smith AM. ''Alhacen’s theory of visual perception: a critical edition, with English translation and commentary, of the first three books of Alhacen’s De aspectibus, the medieval Latin version of Ibn al-Haytham’s Kitab al-Manazir.'' Vol. 1. Philadelphia: American Philosophical Society</ref> or in older texts as the [[Latin]]ized "'''Alhazen'''"; Arabic: أبو علي، الحسن بن الحسن بن الهيثم‎‎) {{lived|c. 965|c. 1040}}<ref>{{cite web|url=https://www.britannica.com/biography/Ibn-al-Haytham|title=Ibn al-Haytham|last=Lorch|first=Richard|date=October 5, 2024|publisher=''Britannica Encyclopedia''}}</ref> was a [[scientist]] from the [[Islam]]ic Golden Age.  Despite being virtually unknown in the modern [[West]], he was an ''extremely'' important figure in the history and [[philosophy of science]], as his [[experiment]]s in optics were essentially the first step in the development of what would one day be called the [[scientific method]].<ref name="ElBizri2005a>El-Bizri, Nader, "A Philosophical Perspective on Ibn al-Haytham's Optics", ''Arabic Sciences and Philosophy'' '''15''' (2005-08-05), 189–218 </ref><ref name="Malik">Malik, Kenan (2010-10-22). "Pathfinders: The Golden Age of Arabic Science, By Jim Al-Khalili". The Independent. Retrieved 2014-10-22.</ref><ref name="Haq">Nomanul Haq|Haq, Syed (2009). "Science in Islam". Oxford Dictionary of the Middle Ages. ISSN 1703-7603. Retrieved 2014-10-22.</ref><ref name="Sabra">Sabra, A. I. (1989). The Optics of Ibn al-Haytham. Books I–II–III: On Direct Vision. London: The Warburg Institute, University of London. pp. 25–29. ISBN 0-85481-072-2.</ref>

==Biography==
===Obligatory disclaimer===
Many of the details of Alhazen's life have been lost to time, with the [[anecdotes]] we have available to us being often contradictory, depending on which historian is relating the information.<ref name="father">Tbakhi A, Amr SS. Ibn Al-Haytham: father of modern optics. Ann Saudi Med. 2007 Nov-Dec;27(6):464-7. doi: 10.5144/0256-4947.2007.464. PMID: 18059131; PMCID: PMC6074172.</ref> The primary source of biographical information about Alhazen is related to us by the 13th century historian Ibn al-Qifti, who was born over a century after the death of Alhazen.<ref name="father"/>

===Alhazen's life===
Alhazen was born in the city of Basra in what is now modern day [[Iraq]]{{efn|Hence the name "al-Basri".}} in about the year 965 CE.<ref name="father"/> Initially Alhazen was trained for the judiciary, and was appointed a judge for Basra. Alhazen became disillusioned with the diverse religious movements of the time, which proved incredibly contradictory, and so he turned to the scientific endeavor instead.<ref name="father"/>

Alhazen quickly became famous for his knowledge of science and mathematics, and so was invited by the [[Shia]] {{wpl|Fatimid}} [[caliph]] of [[Egypt]] {{wpl|Al-Hakim bi-Amr Allah}} to help "regulate the flow of the {{wpl|Nile|}} during floods."<ref name="father"/> Al-Hakim had a reputation as an unstable tyrant, and so when Alhazen realized that regulating the flow of the Nile by building a dam "south of Amwan" was a futile endeavor, he faked [[insanity]] to avoid [[capital punishment]].<ref name="father"/> Instead of being sentenced to [[death]], Alhazen was sentenced to house arrest, with his possessions seized by the state.<ref name="father"/> He remained in house arrest for a decade, until al-Hakim's assassination in 1021.<ref name="father"/>

It was during this ten year period of house arrest that Alhazen wrote his magnum opus the ''Book of Optics''.<ref name="father"/> He also wrote his introduction to the scientific method during this time.<ref name="father"/> Alhazen was a prolific writer, having written over two hundred works. Fifty of those works are extant.<ref name="father"/>

Following his release from house arrest, Alhazen moved into a domed building close to the Grand Mosque of Cairo, where he taught mathematics and physics, and copied texts for a living.<ref name="father"/> He continued to live in Cairo until his death in the year 1040 CE.<ref>Corbin, Henry (1993) [Original French 1964], ''History of Islamic Philosophy'', translated by Sherrard, Liadain; Sherrard, Philip, London: Kegan Paul International in association with Islamic Publications for The Institute of Ismaili Studies, {{isbn|0-7103-0416-1}}, OCLC 22109949</ref>{{rp|149}}

==Book of Optics==
His ''magnum opus'' was the ''Book of Optics'' (''Kitab al-Manazir''; Arabic: كتاب المناظر), a compendium of optical [[knowledge]] famous for, among other things, disproving the {{wpl|emission theory (vision)|emission theory of vision}} (the idea that our [[eyes]] project [[light]] onto objects rather than receive it, which was considered possible at the time).  What is most impressive about this was his emphasis on rigorous [[experiment]], rather than appeals to [[argument]]ation or reason. Al-Haytham was the first to describe a [[theory]], make a [[prediction]] based on that theory, design an experiment which could refute it, and then carry out the experiment and successfully disprove it. In other words, he was essentially the first known user of the scientific method, although the particulars would not be laid out until [[Francis Bacon]] some centuries later.

==Scientific views==
The following quote from his work ''Doubts Concerning Ptolemy'' illustrates this perspective nicely:<ref>Sobhi Rayan. [http://bioinfo.aizeonpublishers.net/content/2014/1/bioinfo321-326.pdf Analogical reasoning roots in Ibn al-Haytham's scientific method of research.] ''International Journal of Computational Bioinformatics and In Silico Modeling'', 2014.</ref>

{{quotebox|[[Truth]] is sought for its own sake … Finding the truth is difficult, and the road to it is rough. For the truths are plunged in obscurity … God, however, has not preserved the scientist from error and has not safeguarded science from shortcomings and faults. If this had been the case, scientists would not have disagreed upon any point of science… Therefore, the seeker after the truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration, and not to the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency. Thus the duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and, applying his mind to the core and margins of its content, attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.}}

==External links==
*{{wpa|Ibn al-Haytham}}
*[https://www.youtube.com/watch?v=kN8Bv3x1o4M Ibn Al-Haytham: The First Scientist] on [[YouTube]]

==Notes==
{{notelist}}

==References==
{{reflist|2|80%}}

{{DEFAULTSORT:al-Haytham, Ibn}}
[[Category:Muslims]]
[[Category:Physicists]]
[[Category:Mathematicians]]
[[Category:Philosophy of science]]

Categories: Muslims, Physicists, Mathematicians, Philosophy of science