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works = '']'', ''Analysis and Synthesis'', ''Aporias (or Doubts) against Ptolemy'', ''Balance of Wisdom'', ''Discourse on Place'', ''Maqala fi'l-qarastun'', ''On the Configuration of the World'', ''Opuscula'', ''The Resolution of Doubts'', ''Treatise on Light'', ''Treatise on Place'' | | works = '']'', ''Analysis and Synthesis'', ''Aporias (or Doubts) against Ptolemy'', ''Balance of Wisdom'', ''Discourse on Place'', ''Maqala fi'l-qarastun'', ''On the Configuration of the World'', ''Opuscula'', ''The Resolution of Doubts'', ''Treatise on Light'', ''Treatise on Place'' | | ||
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'''Abū ‘Alī al-Ha{{Unicode|ṣ}}an ibn al-Ha{{Unicode|ṣ}}an ibn al-Haytham''' (]: أبو علي الحسن بن الحسن بن الهيثم, ]ized: '''Alhacen''' or (deprecated) '''Alhazen''') (]–]), was a ] ], ], ], ], ], ], ], ], ], ], and ], who made significant contributions to the principles of ], as well as ], ], ] and ] ], ], ], ], and ], and pioneered the use of the ]. He is sometimes called '''al-Basri''' (Arabic: البصري), after his birthplace of ] in ] (]), then part of the ] of ].<ref name=Persia></ref> | '''Abū ‘Alī al-Ha{{Unicode|ṣ}}an ibn al-Ha{{Unicode|ṣ}}an ibn al-Haytham''' (]: أبو علي الحسن بن الحسن بن الهيثم, ]ized: '''Alhacen''' or (deprecated) '''Alhazen''') (]–]), was a ] ], ], ], ], ], ], ], ], ], ], ], and ], who made significant contributions to the principles of ], as well as ], ], ] and ] ], ], ], ], and ], and pioneered the use of the ]. He is sometimes called '''al-Basri''' (Arabic: البصري), after his birthplace of ] in ] (]), then part of the ] of ].<ref name=Persia></ref> | ||
Ibn al-Haytham is considered the |
Ibn al-Haytham is considered the ] for correctly explaining and proving the modern intromission theory of ] in his influential '']'', and for his ]s on ], including experiments on ], ]s, ], ], and the dispersion of ] into its constituent ].<ref name=Deek/> He also explained ], speculated on the ], ] and ] aspects of light,<ref>Sami Hamarneh (March 1972). Review of Hakim Mohammed Said, ''Ibn al-Haitham'', '']'' '''63''' (1), p. 119.</ref> and argued that ] of light are streams of ]<ref>Roshdi Rashed (2007). "The Celestial Kinematics of Ibn al-Haytham", ''Arabic Sciences and Philosophy'' '''17''', p. 19. ].</ref> travelling in straight lines.<ref>J. J. O'Connor and E. F. Robertson (2002). , '']''.</ref> Due to his ] and ]al approach to ], he is also considered the pioneer of the modern ],<ref name=Agar>David Agar (2001). . ].</ref><ref name=Gorini/> and some have described him as the "first ]" for this reason.<ref>Bradley Steffens (2006). ''Ibn al-Haytham: First Scientist'', Morgan Reynolds Publishing, ISBN 1599350246.</ref> | ||
Among his other achievements, Ibn al-Haytham described the ] and invented the ] (a precursor to the modern ]),<ref name=Wade/> discovered ] and ],<ref name=Salam/> described the ] between ]es and was aware of the ] of ] due to ],<ref name=Bizri/> |
Among his other achievements, Ibn al-Haytham described the ] and invented the ] (a precursor to the modern ]),<ref name=Wade/> discovered ] and ],<ref name=Salam/> described the ] between ]es and was aware of the ] of ] due to ],<ref name=Bizri/> presented the earliest critique and reform of the ], first stated ], formulated and solved ] geometrically, developed and proved the earliest general formula for ] ] using ],<ref name=Katz/> discussed the earliest theories on the ] of ],<ref name=Steffens/> and in his optical research, laid the foundations for the later development of ] astronomy,<ref name=Marshall/> as well as the ] and the use of optical aids in ].<ref name=Power/> | ||
== Biography == | == Biography == | ||
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{{quote|"Alhazen was one of the ablest students of optics of all times and published a seven-volume treatise on this subject which had great celebrity throughout the medieval period and strongly influenced Western thought, notably that of Roger Bacon and Kepler. This treatise discussed ] and ] ]s in both ] and ] geometries, anticipated ], and considered refraction and the magnifying power of lenses. It contained a remarkably lucid description of the optical system of the eye, which study led Alhazen to the belief that light consists of rays which originate in the object seen, and not in the eye, a view contrary to that of Euclid and Ptolemy."<ref>R. S. Elliott (1966). ''Electromagnetics'', Chapter 1. ].</ref>}} | {{quote|"Alhazen was one of the ablest students of optics of all times and published a seven-volume treatise on this subject which had great celebrity throughout the medieval period and strongly influenced Western thought, notably that of Roger Bacon and Kepler. This treatise discussed ] and ] ]s in both ] and ] geometries, anticipated ], and considered refraction and the magnifying power of lenses. It contained a remarkably lucid description of the optical system of the eye, which study led Alhazen to the belief that light consists of rays which originate in the object seen, and not in the eye, a view contrary to that of Euclid and Ptolemy."<ref>R. S. Elliott (1966). ''Electromagnetics'', Chapter 1. ].</ref>}} | ||
The ''Biographical Dictionary of Scientists'' wrote the following on Ibn al-Haytham:: | |||
{{quote|"He was probably the greatest scientist of the Middle Ages and his work remained unsurpassed for nearly 600 years until the time of Johannes Kepler."<ref>"Alhazen", ''Biographical Dictionary of Scientists'', Vol. I, p. 75.</ref>}} | |||
Ibn al-Haytham made a thorough examination of the passage of ] through various media and discovered the laws of ]. He also carried out the first experiments on the dispersion of light into its constituent ].<ref name=Deek/> His book ''Kitab al-Manazir'' (''Book of Optics'') was translated into ] in the ], as also was his book dealing with the colours of sunset. He dealt at length with the theory of various physical phenomena such as ], ]s, and the ], and speculated on the physical nature of light. He is the first to describe accurately the various parts of the ] and give a scientific explanation of the process of ]. He also attempted to explain ] and the ] of the ] and the ] when near the ]. He is known for the earliest use of the ]. He contradicted ]'s and ]'s theory of vision that objects are seen by rays of light emanating from the eyes; according to him the rays originate in the object of vision and not in the eye. Through these extensive researches on optics, he has been considered as the ]. | Ibn al-Haytham made a thorough examination of the passage of ] through various media and discovered the laws of ]. He also carried out the first experiments on the dispersion of light into its constituent ].<ref name=Deek/> His book ''Kitab al-Manazir'' (''Book of Optics'') was translated into ] in the ], as also was his book dealing with the colours of sunset. He dealt at length with the theory of various physical phenomena such as ], ]s, and the ], and speculated on the physical nature of light. He is the first to describe accurately the various parts of the ] and give a scientific explanation of the process of ]. He also attempted to explain ] and the ] of the ] and the ] when near the ]. He is known for the earliest use of the ]. He contradicted ]'s and ]'s theory of vision that objects are seen by rays of light emanating from the eyes; according to him the rays originate in the object of vision and not in the eye. Through these extensive researches on optics, he has been considered as the ]. | ||
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According to medieval biographers, Ibn al-Haytham wrote at least 96 scientific works. Most of his works are now lost, but more than 50 of them have survived to some extent. Nearly half of his surviving works are on mathematics, 23 of them are on astronomy, and 14 of them are on optics, with a few on other areas of science.<ref name=Rashed>Roshdi Rashed (August 2002). "A Polymath in the 10th Century", ''Science'' '''297''' (5582), p. 773.</ref> Not all of his surviving works have yet been studied, but some of his most important ones are described below. | According to medieval biographers, Ibn al-Haytham wrote at least 96 scientific works. Most of his works are now lost, but more than 50 of them have survived to some extent. Nearly half of his surviving works are on mathematics, 23 of them are on astronomy, and 14 of them are on optics, with a few on other areas of science.<ref name=Rashed>Roshdi Rashed (August 2002). "A Polymath in the 10th Century", ''Science'' '''297''' (5582), p. 773.</ref> Not all of his surviving works have yet been studied, but some of his most important ones are described below. | ||
===''Treatise on Light''=== | |||
His ''Risala fi l-Daw’'' (''Treatise on Light'') is a supplement to his ''Kitab al-Manazir'' (''Book of Optics''). The text contained further investigations on the properties of ] and its ] dispersion through various ] media. He also carried out further observations, investigations and examinations on the ] of the ], the ] and ], the illusions in ], the ] of the ] and the ] of the ], various ] phenomena (including the ], ], and ]), ], ], ], ] and ] mirrors, and ].<ref name=Bizri/> | |||
According to ], Alhacen was the first to give a correct explanation of the apparent increase in the size of the ] and ] when near ]'s ].<ref>Vernon O. Georgia (2003). ''A History of the Muslim World to 1405: The Making of a Civilization'', p. 200. Prentice Hall. ISBN 0-13-098389-6.</ref> (] made earlier attempts at explaining it, according to ].) | |||
===''Analysis and Synthesis''=== | ===''Analysis and Synthesis''=== | ||
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===''Doubts concerning Ptolemy''=== | ===''Doubts concerning Ptolemy''=== | ||
⚫ | In his ''Al-Shukūk ‛alā Batlamyūs'', variously translated as ''Doubts concerning Ptolemy'' or ''Aporias against Ptolemy'', Ibn al-Haytham criticized many of ]'s works, including the '']'', ''Planetary Hypotheses'', and ''Optics'', pointing out various contradictions he finds in these works. He considered that some of the mathematical devices Ptolemy introduced into astronomy, especially the ], failed to satisfy the physical requirement of uniform circular motion, and wrote a scathing critique of the physical reality of Ptolemy's astronomical system, noting the absurdity of relating actual physical motions to imaginary mathematical points, lines, and circles:<ref>Y. Tzvi Langerman, ''Ibn al Haytham's On the Configuration of the World'', p. 8-10</ref> | ||
⚫ | In his ''Al-Shukūk ‛alā Batlamyūs'', variously translated as ''Doubts concerning Ptolemy'' or ''Aporias against Ptolemy'', Ibn al-Haytham criticized many of ]'s works, including |
||
{{quote|"Ptolemy assumed an arrangement (''hay'a'') that cannot exist, and the fact that this arrangement produces in his imagination the motions that belong to the planets does not free him from the error he committed in his assumed arrangement, for the existing motions of the planets cannot be the result of an arrangement that is impossible to exist.... or a man to imagine a circle in the heavens, and to imagine the planet moving in it does not bring about the planet's motion."<ref>A. I. Sabra, "An Eleventh-Century Refutation of Ptolemy's Planetary Theory," pp. 117-131 in Erna Hilfstein, Paweł Czartoryski, Frank D. Grande, ed., ''Science and History: Studies in Honor of Edward Rosen,'' Studia Copernicana XVI, (Wrocław: Ossolineum, 1978), p. 121, n. 13</ref><ref>. ] (2004).</ref>}} | {{quote|"Ptolemy assumed an arrangement (''hay'a'') that cannot exist, and the fact that this arrangement produces in his imagination the motions that belong to the planets does not free him from the error he committed in his assumed arrangement, for the existing motions of the planets cannot be the result of an arrangement that is impossible to exist.... or a man to imagine a circle in the heavens, and to imagine the planet moving in it does not bring about the planet's motion."<ref>A. I. Sabra, "An Eleventh-Century Refutation of Ptolemy's Planetary Theory," pp. 117-131 in Erna Hilfstein, Paweł Czartoryski, Frank D. Grande, ed., ''Science and History: Studies in Honor of Edward Rosen,'' Studia Copernicana XVI, (Wrocław: Ossolineum, 1978), p. 121, n. 13</ref><ref>. ] (2004).</ref>}} | ||
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{{quote|"Truth is sought for itself the truths, are immersed in uncertainties not immune from error..."<ref name=Sabra>], , '']'', October-December 2003.</ref>}} | {{quote|"Truth is sought for itself the truths, are immersed in uncertainties not immune from error..."<ref name=Sabra>], , '']'', October-December 2003.</ref>}} | ||
He held that the criticism of existing theories, which dominated this book, a special place in the growth of scientific knowledge: | He held that the criticism of existing theories, which dominated this book, hold a special place in the growth of scientific knowledge: | ||
{{quote|"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."<ref name=Sabra/>}} | {{quote|"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."<ref name=Sabra/>}} |
Revision as of 17:14, 26 June 2007
- This article is about the scientist. For the crater on the Moon named after him, see Alhazen (crater).
Abū ‘Alī al-Haṣan ibn al-Haṣan ibn al-Haytham | |
---|---|
Title | Ibn al-Haytham and Alhacen |
Personal life | |
Era | Islamic Golden Age |
Region | Muslim scientist |
Main interest(s) | Anatomy, Astronomy, Engineering, Mathematics, Mechanics, Medicine, Optics, Ophthalmology, Philosophy, Physics, Psychology, Science |
Notable work(s) | Book of Optics, Analysis and Synthesis, Aporias (or Doubts) against Ptolemy, Balance of Wisdom, Discourse on Place, Maqala fi'l-qarastun, On the Configuration of the World, Opuscula, The Resolution of Doubts, Treatise on Light, Treatise on Place |
Senior posting | |
Influenced by | |
Influenced |
Abū ‘Alī al-Haṣan ibn al-Haṣan ibn al-Haytham (Arabic: أبو علي الحسن بن الحسن بن الهيثم, Latinized: Alhacen or (deprecated) Alhazen) (965–1039), was a Muslim polymath, anatomist, astronomer, engineer, mathematician, mechanician, ophthalmologist, philosopher, physician, physicist, psychologist, and scientist, who made significant contributions to the principles of optics, as well as astronomy, analytic geometry, infinitesimal and integral calculus, mechanics, motion, number theory, and visual perception, and pioneered the use of the scientific method. He is sometimes called al-Basri (Arabic: البصري), after his birthplace of Basra in Iraq (Mesopotamia), then part of the Buyid dynasty of Persia.
Ibn al-Haytham is considered the father of optics for correctly explaining and proving the modern intromission theory of vision in his influential Book of Optics, and for his experiments on optics, including experiments on lenses, mirrors, refraction, reflection, and the dispersion of light into its constituent colours. He also explained binocular vision, speculated on the finite speed, rectilinear propagation and electromagnetic aspects of light, and argued that rays of light are streams of energy particles travelling in straight lines. Due to his empirical and experimental approach to science, he is also considered the pioneer of the modern scientific method, and some have described him as the "first scientist" for this reason.
Among his other achievements, Ibn al-Haytham described the pinhole camera and invented the camera obscura (a precursor to the modern camera), discovered Fermat's principle of least time and Newton's first law of motion, described the attraction between masses and was aware of the magnitude of acceleration due to gravity, presented the earliest critique and reform of the Ptolemaic model, first stated Wilson's theorem, formulated and solved Alhazen's problem geometrically, developed and proved the earliest general formula for integral calculus using mathematical induction, discussed the earliest theories on the psychology of visual perception, and in his optical research, laid the foundations for the later development of telescopic astronomy, as well as the microscope and the use of optical aids in Renaissance art.
Biography
Abū ‘Alī al-Hasan ibn al-Hasan ibn al-Haytham was born in the Arab city of Basra, Iraq (Mesopotamia), then part of the Shia Muslim Buyid dynasty of Persia, and he probably died in Cairo, Egypt. Known in the West as Alhacen or Alhazen, Ibn al-Haytham was born in 965 in Basra, and was educated there and in Baghdad.
One account of his career has him summoned to Egypt by the mercurial caliph Hakim to regulate the flooding of the Nile. After his field work made him aware of the impracticality of this scheme, and fearing the caliph's anger, he feigned madness. He was kept under house arrest until Hakim's death in 1021. During this time he wrote scores of important mathematical treatises. He later traveled to Spain and, during this period, he had ample time for his scientific pursuits, which included optics, mathematics, physics, medicine and development of scientific methods on each of which he has left several outstanding books.
Legacy
Ibn al-Haytham was one of the most eminent physicists, whose development of optics and the scientific method are outstanding. Ibn al-Haytham's work on optics is credited with contributing a new emphasis on experiment. His influence on physical sciences in general, and optics in particular, has been held in high esteem and, in fact, it ushered in a new era in optical research, both in theory and practice. The scientific method is considered to be so fundamental to modern science that some — especially philosophers of science and practicing scientists — consider earlier inquiries into nature to be pre-scientific. Due to its importance in the history of science, some have considered his development of the scientific method to be the most important scientific development of the second millenium.
Rosanna Gorini wrote the following on Ibn al-Haytham's development of the scientific method:
"According to the majority of the historians al-Haytham was the pioneer of the modern scientific method. With his book he changed the meaning of the term optics and established experiments as the norm of proof in the field. His investigations are based not on abstract theories, but on experimental evidences and his experiments were systematic and repeatable."
Roshdi Rashed wrote the following on Ibn al-Haytham:
"His work on optics, which includes a theory of vision and a theory of light, is considered by many to be his most important contribution, setting the scene for developments well into the 17th century. His contributions to geometry and number theory go well beyond the archimedean tradition. And by promoting the use of experiments in scientific research, al-Haytham played an important part in setting the scene for modern science."
Nobel Prize winning physicist Abdus Salam wrote:
"Ibn-al-Haitham (Alhazen, 965-1039 CE) was one of the greatest physicists of all time. He made experimental contributions of the highest order in optics. He enunciated that a ray of light, in passing through a medium, takes the path which is the easier and 'quicker'. In this he was anticipating Fermat's Principle of Least Time by many centuries. He enunciated the law of inertia, later to become Newton's first law of motion. Part V of Roger Bacon's "Opus Majus" is practically an annotation to Ibn al Haitham's Optics."
George Sarton, the "father of the history of science", wrote in the Introduction to the History of Science:
" the greatest Muslim physicist and student of optics of all times."
"Ibn Haytham's writings reveal his fine development of the experimental faculty. His tables of corresponding angles of incidence and refraction of light passing from one medium to another show how closely he had approached discovering the law of constancy of ratio of sines, later attributed to Snell. He accounted correctly for twilight as due to atmospheric refraction, estimating the sun's depression to be 19 degrees below the horizon, at the commencement of the phenomenon in the mornings or at its termination in the evenings."
Robert S. Elliot wrote the following on the Book of Optics:
"Alhazen was one of the ablest students of optics of all times and published a seven-volume treatise on this subject which had great celebrity throughout the medieval period and strongly influenced Western thought, notably that of Roger Bacon and Kepler. This treatise discussed concave and convex mirrors in both cylindrical and spherical geometries, anticipated Fermat's law of least time, and considered refraction and the magnifying power of lenses. It contained a remarkably lucid description of the optical system of the eye, which study led Alhazen to the belief that light consists of rays which originate in the object seen, and not in the eye, a view contrary to that of Euclid and Ptolemy."
The Biographical Dictionary of Scientists wrote the following on Ibn al-Haytham::
"He was probably the greatest scientist of the Middle Ages and his work remained unsurpassed for nearly 600 years until the time of Johannes Kepler."
Ibn al-Haytham made a thorough examination of the passage of light through various media and discovered the laws of refraction. He also carried out the first experiments on the dispersion of light into its constituent colours. His book Kitab al-Manazir (Book of Optics) was translated into Latin in the Middle Ages, as also was his book dealing with the colours of sunset. He dealt at length with the theory of various physical phenomena such as shadows, eclipses, and the rainbow, and speculated on the physical nature of light. He is the first to describe accurately the various parts of the eye and give a scientific explanation of the process of vision. He also attempted to explain binocular vision and the apparent increase in size of the Sun and the Moon when near the horizon. He is known for the earliest use of the camera obscura. He contradicted Ptolemy's and Euclid's theory of vision that objects are seen by rays of light emanating from the eyes; according to him the rays originate in the object of vision and not in the eye. Through these extensive researches on optics, he has been considered as the father of modern optics.
The Latin translation of his main work, Kitab al-Manazir, exerted a great influence upon Western science e.g. on the work of Roger Bacon who cites him by name and Kepler. It brought about a great progress in experimental methods. His research in catoptrics centered on spherical and parabolic mirrors and spherical aberration. He made the important observation that the ratio between the angle of incidence and refraction does not remain constant and investigated the magnifying power of a lens. His work on catoptrics also contains the important problem known as Alhazen's problem.
The list of his books runs to 200 or so, yet very few of the books have survived. Even his monumental treatise on optics survived only through its Latin translation. During the Middle Ages his books on cosmology were translated into Latin, Hebrew and other languages.
The Alhazen crater on the Moon was named in his honour. Alhacen is also featured on the obverse of the Iraqi 10,000 dinars banknote issued in 2003. The asteroid "59239 Alhazen" was also named in his honour, while Iran's largest laser research facility, located in the Atomic Energy Organization of Iran headquarters in Tehran, is named after Alhazen as well.
Book of Optics
Main article: Book of OpticsHis seven volume treatise on optics, Kitab al-Manazir (Book of Optics) (written from 1011 to 1021), drastically transformed the understanding of light and vision. In classical antiquity, there were two major theories on vision. The first theory, the emission theory, was supported by such thinkers as Euclid and Ptolemy, who believed that sight worked by the eye emitting rays of light. The second theory, the intromission theory, supported by Aristotle and his followers, had physical forms entering the eye from an object. Alhacen argued on the basis of common observations (such as the eye being dazzled or even injured if we look at a very bright light) and logical arguments (such as how a ray could proceeding from the eyes reach the distant stars the instant after we open our eye) to maintain that we cannot see by rays being emitted from the eye nor through physical forms entering the eye. Alhacen instead developed a highly successful theory which explained the process of vision by rays of light proceeding to the eye from each point on an object, which he proved through the use of experimentation.
Ibn al-Haytham proved that rays of light travel in straight lines, and carried out a number of experimnts with lenses, mirrors, refraction, and reflection. He was also the first to reduce reflected and refracted light rays into vertical and horizontal components, which was a fundamental development in geometric optics. He also discovered a result similar to Snell's law of sines, but did not quantify it and derive the law mathematically. Ibn al-Haytham is also credited with the invention of the camera obscura and pinhole camera.
The book also pioneered the psychology of visual perception, in which Ibn al-Haytham was the first scientist to argue that vision occurs in the brain, rather than the eyes. He pointed out that personal experience has an affect on what people see and how they see, and that vision and perception are subjective. He explained possible errors in vision in detail, and as an example, describes how a small child with less experience may have more difficulty interpreting what he/she sees. He also gives an example of an adult that can make mistakes in vision because of how one's experience suggests that he/she is seeing one thing, when he/she is really seeing something else.
Optics was translated into Latin by an unknown scholar at the end of the 12th century or the beginning of the 13th century. It was printed by Friedrich Risner in 1572, with the title Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus . Risner is also the author of the name variant "Alhazen", before him he was known in the west as Alhacen, which is correct transcription of the Arabic name. This work enjoyed a great reputation during the Middle Ages. Works by Alhacen on geometrical subjects were discovered in the Bibliothèque nationale in Paris in 1834 by E. A. Sedillot. Other manuscripts are preserved in the Bodleian Library at Oxford and in the library of Leiden. Ibn al-Haytham's optical studies were influential in a number of later developments, including the telescope, which laid the foundations of telescopic astronomy, as well as the modern camera, the microscope, and the use of optical aids in Renaissance art.
Other works
Alhacen was a pioneer in optics, astronomy, engineering, mathematics and physics. Alhacen's optical writings influenced many Western intellectuals such as Roger Bacon, John Pecham, Witelo, and Johannes Kepler.
According to medieval biographers, Ibn al-Haytham wrote at least 96 scientific works. Most of his works are now lost, but more than 50 of them have survived to some extent. Nearly half of his surviving works are on mathematics, 23 of them are on astronomy, and 14 of them are on optics, with a few on other areas of science. Not all of his surviving works have yet been studied, but some of his most important ones are described below.
Analysis and Synthesis
His contributions to number theory includes his work on perfect numbers. In his Analysis and Synthesis, Ibn al-Haytham was the first to realize that every even perfect number is of the form 2(2 − 1) where 2 − 1 is prime, but he was not able to prove this result successfully (Euler later proved it in the 18th century).
Opuscula
In number theory, Ibn al-Haytham solved problems involving congruences using what is now called Wilson's theorem. In his Opuscula, Ibn al-Haytham considers the solution of a system of congruences, and gives two general methods of solution. His first method, the canonical method, involved Wilson's theorem, while his second method involved a version of the Chinese remainder theorem.
Doubts concerning Ptolemy
In his Al-Shukūk ‛alā Batlamyūs, variously translated as Doubts concerning Ptolemy or Aporias against Ptolemy, Ibn al-Haytham criticized many of Ptolemy's works, including the Almagest, Planetary Hypotheses, and Optics, pointing out various contradictions he finds in these works. He considered that some of the mathematical devices Ptolemy introduced into astronomy, especially the equant, failed to satisfy the physical requirement of uniform circular motion, and wrote a scathing critique of the physical reality of Ptolemy's astronomical system, noting the absurdity of relating actual physical motions to imaginary mathematical points, lines, and circles:
"Ptolemy assumed an arrangement (hay'a) that cannot exist, and the fact that this arrangement produces in his imagination the motions that belong to the planets does not free him from the error he committed in his assumed arrangement, for the existing motions of the planets cannot be the result of an arrangement that is impossible to exist.... or a man to imagine a circle in the heavens, and to imagine the planet moving in it does not bring about the planet's motion."
In his Aporias against Ptolemy Ibn al-Haytham also commented on the difficulty of attaining scientific knowledge:
"Truth is sought for itself the truths, are immersed in uncertainties not immune from error..."
He held that the criticism of existing theories, which dominated this book, hold a special place in the growth of scientific knowledge:
"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."
On the Configuration of the World
In his On the Configuration of the World, despite his criticisms directed towards Ptolemy, Ibn al-Haytham continued to accept the physical reality of the geocentric model of the universe, presenting a detailed description of the physical structure of the celestial spheres in his On the Configuration of the World:
"The earth as a whole is a round sphere whose center is the center of the world. It is stationary in its middle, fixed in it and not moving in any direction nor moving with any of the varieties of motion, but always at rest."
While he attempted to discover the physical reality behind Ptolemy's mathematical model, he developed the concept of a single orb (falak) for each component of Ptolemy's planetary motions. This work was eventually translated into Hebrew and Latin in the 13th and 14th centuries and subsequently had an important influence during the European Middle Ages and Renaissance.
The Resolution of Doubts
Ibn al-Haytham's The Resolution of Doubts, written in 1029, was an important book on astronomy, which has not yet been published. Following on from his Doubts on Ptolemy, The Resolution of Doubts contains Ibn al-Haytham's reform of the Ptolemaic model. His reform excluded cosmology, as he developed a systematic study of celestial kinematics that was completely geometric. This in turn led to innovative developments in infinitesimal geometry.
Balance of Wisdom
In his book, Mizan al-Hikmah (Balance of Wisdom), Ibn al-Haytham has discussed the density of the atmosphere and related it to altitude. He also studied atmospheric refraction. He discovered that the twilight only ceases or begins when the Sun is 19° below the horizon and attempted to measure the height of the atmosphere on that basis.
He also discussed the theory of attraction between masses. It seems that he was also aware of the magnitude of acceleration due to gravity.
Maqala fi'l-qarastun
The Maqala fi'l-qarastun is a treatise on centers of gravity. Little is currently known about the work, except for what is known through the later works of al-Khazini in the 12th century. In this treatise, Ibn al-Haytham formulated the theory that the heaviness of bodies vary with their distance from the center of the Earth.
Treatise on Place
Ibn al-Haytham's Risala fi’l-makan (Treatise on Place) presents a critique of Aristotle's concept of place (topos). Aristotle's Physics stated that the place of something is the two-dimensional boundary of the containing body that is at rest and is in contact with what it contains. Ibn al-Haytham disagreed and demonstrated that place (al-makan) is the imagined three-dimensional void between the inner surfaces of the containing body. He showed that place was akin to space, foreshadowing Rene Descartes’ concept of place in the Extensio in the 17th century. Ibn al-Haytham also builds on the mathematical works of Euclid and Thabit ibn Qurra, and goes on to systemize infinitesimal calculus, conic sections, number theory, and analytic geometry after linking algebra to geometry. Ibn al-Haytham also studied the mechanics of the motion of a body and maintained that a body moves perpetually unless an external force stops it or changes its direction of motion. This was similar to the law of inertia later stated by Galileo Galilei in the 16th century and now known as Newton's first law of motion.
Discourse on Place
Following on from his Treatise on Place, Ibn al-Haytham's Qawl fi al-Makan (Discourse on Place) was an important treatise which presents geometrical demonstrations for his geometrization of place, in opposition to Aristotle's philosophical concept of place, which Ibn al-Haytham rejected on mathematical grounds. Abd-el-latif, a supporter of Aristotle's philosophical view of place, later criticized the work in Fi al-Radd ‘ala Ibn al-Haytham fi al-makan (A refutation of Ibn al-Haytham’s place) for its geometrization of place.
Other contributions
Yasmeen M. Faruqi writes:
"In seventeenth century Europe the problems formulated by Ibn al-Haytham (965-1041) became known as “Alhazen’s problem”. Al-Haytham’s contributions to geometry and number theory went well beyond the Archimedean tradition. Al-Haytham also worked on analytical geometry and the beginnings of the link between algebra and geometry. Subsequently, this work led in pure mathematics to the harmonious fusion of algebra and geometry that was epitomised by Descartes in geometric analysis and by Newton in the calculus. Al-Haytham was a scientist who made major contributions to the fields of mathematics, physics and astronomy during the latter half of the tenth century."
Alhazen's problem
His work on catoptrics in Book V of the Book of Optics contains the important problem known as Alhazen's problem. It comprises drawing lines from two points in the plane of a circle meeting at a point on the circumference and making equal angles with the normal at that point. This leads to an equation of the fourth degree. This eventually led Ibn al-Haytham to derive the earliest formula for the sum of the fourth powers, and using an early proof by mathematical induction, he developed a method for determining the general formula for the sum of any integral powers, which was fundamental to the development of infinitesimal and integral calculus.
Ibn al-Haytham solved the problem using conic sections and a geometric proof, but Alhazen's problem remained influential in Europe, when later mathematicians such as Christiaan Huygens, James Gregory, Guillaume de l'Hôpital, Isaac Barrow, and many others, attempted to find an algebraic solution to the problem, using various methods, including analytic methods of geometry and derivation by complex numbers. Mathematicians were not able to find an algebraic solution to the problem until the end of the 20th century.
Geometry
In mathematics, Ibn al-Haytham developed analytical geometry by establishing linkage between algebra and geometry. Ibn al-Haytham also discovered a formula for adding the first 100 natural numbers, which was later often attributed to Carl Friedrich Gauss. Ibn al-Haytham had used a geometric proof to prove the formula. His attempted proof of the parallel postulate was also similar to the Lambert quadrilateral and Playfair's axiom in the 18th century.
In elementary geometry, Ibn al-Haytham attempted to solve the problem of squaring the circle using the area of lunes, but later gave up on the impossible task. Ibn al-Haytham also tackled other problems in elementary (Euclidean) and advanced (Apollonian and Archimedean) geometry, some of which he was the first to solve.
Hockney-Falco thesis
Main article: Hockney-Falco thesisAt a scientific conference in February 2007, Charles M. Falco argued that Ibn al-Haytham's work on optics may have influenced the use of optical aids by Renaissance artists. Falco said that his and David Hockney's examples of Renaissance art "demonstrate a continuum in the use of optics by artists from c. 1430, arguably initiated as a result of Ibn al-Haytham's influence, until today."
See also
Notes
- ^ Electromagnetic Theory and Light
- ^ Dr. Mahmoud Al Deek. "Ibn Al-Haitham: Master of Optics, Mathematics, Physics and Medicine", Al Shindagah, November-December 2004.
- Sami Hamarneh (March 1972). Review of Hakim Mohammed Said, Ibn al-Haitham, Isis 63 (1), p. 119.
- Roshdi Rashed (2007). "The Celestial Kinematics of Ibn al-Haytham", Arabic Sciences and Philosophy 17, p. 19. Cambridge University Press.
- J. J. O'Connor and E. F. Robertson (2002). Light through the ages: Ancient Greece to Maxwell, MacTutor History of Mathematics archive.
- David Agar (2001). Arabic Studies in Physics and Astronomy During 800 - 1400 AD. University of Jyväskylä.
- ^ Rosanna Gorini (2003). "Al-Haytham the Man of Experience. First Steps in the Science of Vision", International Society for the History of Islamic Medicine. Institute of Neurosciences, Laboratory of Psychobiology and Psychopharmacology, Rome, Italy.
- Bradley Steffens (2006). Ibn al-Haytham: First Scientist, Morgan Reynolds Publishing, ISBN 1599350246.
- ^ Nicholas J. Wade, Stanley Finger (2001), "The eye as an optical instrument: from camera obscura to Helmholtz's perspective", Perception 30 (10), p. 1157-1177.
- ^ Abdus Salam (1984), "Islam and Science". In C. H. Lai (1987), Ideals and Realities: Selected Essays of Abdus Salam, 2nd ed., World Scientific, Singapore, p. 179-213.
- ^ Dr. Nader El-Bizri, "Ibn al-Haytham or Alhazen", in Josef W. Meri (2006), Medieval Islamic Civilization: An Encyclopaedia, Vol. II, p. 343-345, Routledge, New York, London.
- ^ Victor J. Katz (1995). "Ideas of Calculus in Islam and India", Mathematics Magazine 68 (3), p. 163-174.
- ^ Bradley Steffens (2006). Ibn al-Haytham: First Scientist, Chapter 5. Morgan Reynolds Publishing. ISBN 1599350246.
- ^ O. S. Marshall (1950). "Alhazen and the Telescope", Astronomical Society of the Pacific Leaflets 6, p. 4.
- ^ Richard Power (University of Illinois), Best Idea; Eyes Wide Open, New York Times, April 18, 1999.
- ^ O'Connor, John J.; Robertson, Edmund F., "Abu Ali al-Hasan ibn al-Haytham", MacTutor History of Mathematics Archive, University of St Andrews
- Robert Briffault (1928), The Making of Humanity, p. 190-202, G. Allen & Unwin Ltd:
"What we call science arose as a result of new methods of experiment, observation, and measurement, which were introduced into Europe by the Arabs. Science is the most momentous contribution of Arab civilization to the modern world, but its fruits were slow in ripening. Not until long after Moorish culture had sunk back into darkness did the giant to which it had given birth, rise in his might. It was not science only which brought Europe back to life. Other and manifold influences from the civilization of Islam communicated its first glow to European life. The debt of our science to that of the Arabs does not consist in startling discoveries or revolutionary theories; science owes a great deal more to Arab culture, it owes its existence....The ancient world was, as we saw, pre-scientific. The astronomy and mathematics of Greeks were a foreign importation never thoroughly acclimatized in Greek culture. The Greeks systematized, generalized and theorized, but the patient ways of investigations, the accumulation of positive knowledge, the minute methods of science, detailed and prolonged observation and experimental inquiry were altogether alien to the Greek temperament. What we call science arose in Europe as a result of new spirit of enquiry, of new methods of experiment, observation, measurement, of the development of mathematics, in a form unknown to the Greeks. That spirit and those methods were introduced into the European world by the Arabs."
- ^ Roshdi Rashed (August 2002). "A Polymath in the 10th Century", Science 297 (5582), p. 773.
- Dr. A. Zahoor and Dr. Z. Haq (1997). Quotations from Famous Historians of Science, Cyberistan.
- R. S. Elliott (1966). Electromagnetics, Chapter 1. McGraw-Hill.
- "Alhazen", Biographical Dictionary of Scientists, Vol. I, p. 75.
- David C. Lindberg. Roger Bacon and the Origins of Perspectiva in the Middle Ages. Clarendon Press 1996, p. 11, passim.
- Bradley Steffens (2006), Ibn al-Haytham: First Scientist, Morgan Reynolds Publishing, ISBN 1599350246. (cf. Reviews of Ibn al-Haytham: First Scientist, The Critics, Barnes & Noble.)
- D. C. Lindberg, Theories of Vision from al-Kindi to Kepler, (Chicago, Univ. of Chicago Pr., 1976), pp. 60-7.
- Albrecht Heeffer. Kepler’s near discovery of the sine law: A qualitative computational model, Ghent University, Belgium.
- A. I. Sabra (1981), Theories of Light from Descartes to Newton, Cambridge University Press. (cf. Pavlos Mihas, Use of History in Developing ideas of refraction, lenses and rainbow, p. 5, Demokritus University, Thrace, Greece.)
- A. C. Crombie, Robert Grosseteste and the Origins of Experimental Science, 1100 - 1700, (Oxford: Clarendon Press, 1971), p. 147, n. 2.
- Smith, A Mark (2001). 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. pp. xxi. ISBN 9780871699145..
- David C. Lindberg, "Alhazen's Theory of Vision and Its Reception in the West", Isis, 58 (1967): 321-341.
- Y. Tzvi Langerman, Ibn al Haytham's On the Configuration of the World, p. 8-10
- A. I. Sabra, "An Eleventh-Century Refutation of Ptolemy's Planetary Theory," pp. 117-131 in Erna Hilfstein, Paweł Czartoryski, Frank D. Grande, ed., Science and History: Studies in Honor of Edward Rosen, Studia Copernicana XVI, (Wrocław: Ossolineum, 1978), p. 121, n. 13
- Nicolaus Copernicus. Stanford Encyclopedia of Philosophy (2004).
- ^ A. I. Sabra, Ibn al-Haytham: Brief life of an Arab mathematician, Harvard Magazine, October-December 2003.
- Some writers, however, argue that Alhazen's critique constituted a form of heliocentricity. (See Asghar Qadir, Relativity: An Introduction to the Special Theory, Singapore: World Scientific Publishing Co., 1989, pp. 5-6, 10.)
- Y. Tzvi Langerman, ed. and tr., Ibn al Haytham's On the Configuration of the World, chap. 2, sect.22, p. 61.
- Y. Tzvi Langerman, ed. and tr., Ibn al Haytham's On the Configuration of the World, pp. 34-41.
- Prabhakar M. Gondhalekar (2001). The Grip of Gravity: The Quest to Understand the Laws of Motion and Gravitation, p. 21. Cambridge University Press. ISBN 0521803160.
- Roshdi Rashed (2007). "The Celestial Kinematics of Ibn al-Haytham", Arabic Sciences and Philosophy 17, p. 7-55. Cambridge University Press.
- Professor Mohammed Abattouy (2002). "The Arabic Science of weights: A Report on an Ongoing Research Project", The Bulletin of the Royal Institute for Inter-Faith Studies 4, p. 109-130.
- Nader el-Bizri (2007). "In Defence of the Sovereignty of Philosophy: Al-Baghdadi's Critique of Ibn al-Haytham's Geometrisation of Place", Arabic Sciences and Philosophy 17, p. 57-80. Cambridge University Press.
- Y. M. Faruqi (2006). "Contributions of Islamic scholars to the scientific enterprise", International Education Journal 7 (4), p. 395-396.
- ^ John D. Smith (1992). "The Remarkable Ibn al-Haytham", The Mathematical Gazette 76 (475), p. 189-198.
- J. Rottman. A first course in Abstract Algebra, Chapter 1.
- Falco, Charles M. "Ibn al-Haytham and the Origins of Modern Image Analysis", presented at a plenary session at the International Conference on Information Sciences, Signal Processing and its Applications, 12–15 February 2007. Sharjah, United Arab Emirates (U.A.E.).
References
- Lindberg, David C. Theories of Vision from al-Kindi to Kepler. Chicago: Univ. of Chicago Press, 1976. ISBN 0-226-48234-0
- Sabra, A. I., "The astronomical origin of Ibn al-Haytham’s concept of experiment," pp. 133-136 in Actes du XIIe congrès international d’histoire des sciences, vol. 3. Paris: Albert Blanchard, 1971; reprinted in A. I. Sabra, Optics, Astronomy and Logic: Studies in Arabic Science and Philosophy. Collected Studies Series, 444. Aldershot: Variorum, 1994 ISBN 0-86078-435-5
- Omar, Saleh Beshara. Ibn al-Haytham's Optics: A Study of the Origins of Experimental Science. Minneapolis: Bibliotheca Islamica, 1977. ISBN 0-88297-015-1
Further reading
Primary sources
- Langermann, Y. Tzvi, ed. and trans. Ibn al-Haytham's On the Configuration of the World, Harvard Dissertations in the History of Science. New York: Garland, 1990. ISBN 0824000412
- Sabra, A. I., ed. The Optics of Ibn al-Haytham, Books I-II-III: On Direct Vision. The Arabic text, edited and with Introduction, Arabic-Latin Glossaries and Concordance Tables. Kuwait: National Council for Culture, Arts and Letters, 1983.
- Sabra, A. I., ed. The Optics of Ibn al-Haytham. Edition of the Arabic Text of Books IV-V: On Reflection and Images Seen by Reflection. 2 vols., Kuwait: The National Council for Culture, Arts and Letters, 2002.
- Sabra, A. I., trans. The Optics of Ibn al-Haytham. Books I-II-III: On Direct Vision. English Translation and Commentary. 2 vols. Studies of the Warburg Institute, vol. 40. London: The Warburg Institute, University of London, 1989. ISBN 0-85481-072-2
- Smith, A. Mark, ed. and trans. 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 Kitāb al-Manāzir, 2 vols. Transactions of the American Philosophical Society, 91.4-5, Philadelphia, 2001. ISBN 0-87169-914-1
- Smith, A. Mark, ed. and trans. Alhacen on the Principles of Reflection: A Critical Edition, with English Translation and Commentary, of Books 4 and 5 of Alhacen's De Aspectibus, the Medieval Latin version of Ibn-al-Haytham's Kitāb al-Manāzir, 2 vols. Transactions of the American Philosophical Society, 96.2-3, Philadelphia, 2006. ISBN 0-87169-962-1
Secondary literature
- Falco, Charles M. "Ibn al-Haytham and the Origins of Modern Image Analysis" presented at a plenary session at the International Conference on Information Sciences, Signal Processing and its Applications, 12–15 February 2007. Sharjah, United Arab Emirates (U.A.E.). In this lecture, Falco speculates that Ibn al-Haytham may have influenced the use of optical aids in Renaissance art. (See Hockney-Falco thesis.}
- Omar, Saleh Beshara. Ibn al-Haytham and Greek optics: a comparative study in scientific methodology. PhD Dissertation, Univ. of Chicago, Dept. of Near Eastern Languages and Civilizations, June 1975.
External links
- O'Connor, John J.; Robertson, Edmund F., "Abu Ali al-Hasan ibn al-Haytham", MacTutor History of Mathematics Archive, University of St Andrews
- Weisstein, Eric Wolfgang (ed.). "Alhazen (ca. 965-1039)". ScienceWorld.
- Ibn al-Haitham on two Iraqi banknotes
- http://www.daviddarling.info/encyclopedia/A/Alhazen.html
- Alhazen Master of Optics
- The Miracle of Light - a UNESCO article on Ibn Haitham
- Roshdi Rashed. "A Polymath in the 10th Century", Science, 297 (2002): 773
- A. I. Sabra, "Ibn al-Haytham: Brief life of an Arab mathematician"
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