By Neenah Payne
Ibn al-Haytham (Alhazen) (965-1039) was the founder of the scientific method, the founder of modern optics, a pioneer in astronomy, and invented analytic geometry.
Under house arrest in Cairo, Egypt, between 1011 and 1021, Iraqi Muslim scientist Ibn al-Haytham (Latinized as Alhacen or Alhazen) wrote The Book of Optics (Arabic: Kitab al-Manazir; Latin: De aspectibus or Opticae Thesaurus: Alhazeni Arabis,) a seven-volume treatise on optics, physics, mathematics, anatomy and psychology.
The book had an important influence on the development of optics, as it laid the foundations for modern physical optics after drastically transforming the way in which light and vision had been understood, and on science in general with its introduction of the experimental scientific method. Ibn al-Haytham has been called the ‘father of modern optics’, the ‘pioneer of the modern scientific method, and the founder of experimental physics, and for these reasons he has been described as the ‘first scientist’.
The Book of Optics has been ranked alongside Isaac Newton’s Philosophiae Naturalis Principia Mathematica as one of the most influential books in the history of physics, as it is widely considered to have initiated a revolution in the fields of optics and visual perception. It established experimentation as the norm of proof in optics, and gave optics a physico-mathematical conception at a much earlier date than the other mathematical disciplines of astronomy and mechanics.
The Book of Optics also contains the earliest discussions and descriptions of the psychology of visual perception and optical illusions, as well as experimental psychology, and the first accurate descriptions of the camera obscura, a precursor to the modern camera. In medicine and ophthalmology, the book also made important advances in eye surgery, as it correctly explained the process of sight for the first time.
Birth of the Scientific Method
Ibn al-Haytham (Alhazen) – World’s First True Scientist, a very long article, discusses Alhazen’s many contributions. It says:
His optical writings influenced many Western intellectuals such as Roger Bacon, John Pecham, Witelo, Johannes Kepler. His pioneering work on number theory, analytic geometry, and the link between algebra and geometry, also had an influence on René Descartes’s geometric analysis and Isaac Newton’s calculus.
According to medieval biographers, Ibn al-Haytham wrote more than 200 works on a wide range of subjects, of which at least 96 of his scientific works are known. 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 subjects…. Ibn al-Haytham also discovered the concept of momentum (now part of Newton’s second law of motion) around the same time as his contemporary, Avicenna (Ibn Sina).
500 years before the Scientific Revolution, the mathematician Al-Hassan Ibn al-Haytham spent hours in a dark room studying the light that filtered in. Not only did he revolutionize how we literally see the world, he pioneered the scientific method that is now the backbone of modern science.
If asked who gave birth to the modern scientific method, how might you respond? Isaac Newton, maybe? Galileo? Aristotle? A great many students of science history would probably respond, “Roger Bacon.” An English scholar and friar, and a 13th century pioneer in the field of optics, he described, in exquisite detail, a repeating cycle of observation, hypothesis, and experimentation in his writings, as well as the need for independent verification of his work.
But dig a little deeper into the past, and you’ll unearth something that may surprise you: The origins of the scientific method hearken back to the Islamic World, not the Western one. Around 250 years before Roger Bacon expounded on the need for experimental confirmation of his findings, an Arab scientist named Ibn al-Haytham was saying the exact same thing.
Little is known about Ibn al-Haytham’s life, but historians believe he was born around the year 965, during a period marked as the Golden Age of Arabic science. His father was a civil servant, so the young Ibn al-Haytham received a strong education, which assuredly seeded his passion for science. He was also a devout Muslim, believing that an endless quest for truth about the natural world brought him closer to God. Sometime around the dawn of the 11th Century, he moved to Cairo in Egypt. It was here that he would complete his most influential work.
The prevailing wisdom at the time was that we saw what our eyes, themselves, illuminated. Supported by revered thinkers like Euclid and Ptolemy, emission theory stated that sight worked because our eyes emitted rays of light — like flashlights. But this didn’t make sense to Ibn al-Haytham. If light comes from our eyes, why, he wondered, is it painful to look at the sun? This simple realization catapulted him into researching the behavior and properties of light: optics.
In 1011, Ibn al-Haytham was placed under house arrest by a powerful caliph in Cairo. Though unwelcome, the seclusion was just what he needed to explore the nature of light. Over the next decade, Ibn al-Haytham proved that light only travels in straight lines, explained how mirrors work, and argued that light rays can bend when moving through different mediums, like water, for example.
But Ibn al-Haytham wasn’t satisfied with elucidating these theories only to himself, he wanted others to see what he had done. The years of solitary work culminated in his Book of Optics, which expounded just as much upon his methods as it did his actual ideas. Anyone who read the book would have instructions on how to repeat every single one of Ibn al-Haytham’s experiments.
“His message is, ‘Don’t take my word for it. See for yourself,'” Jim Al-Khalili, a professor of theoretical physics at the University of Surrey noted in a BBC4 Special. “This, for me, is the moment that Science, itself is summoned into existence and becomes a discipline in its own right,” he added.
Apart from being one of the first to operate on the scientific method, Ibn al-Haytham was also a progenitor of critical thinking and skepticism. “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… attack it from every side,” he wrote. “He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.”
It is the nature of the scientific enterprise to creep ahead, slowly but surely. In the same way, the scientific method that guides it was not birthed in a grand eureka moment, but slowly tinkered with and notched together over generations, until it resembled the machine of discovery that we use today. Ibn al-Haytham may very well have been the first to lay out the cogs and gears. Hundreds of years later, other great thinkers would assemble them into a finished product.
A very brief history of Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham known to the West as Alhazen, the Father of Optics and arguably the first modern scientist.
Father of Modern Optics
In addition to creating the scientific method, Alhazen was a pioneer in optics.
Ibn al-Haytham (Alhazen) – World’s First True Scientist is a very long article that discussed the many contributions of Alhazen including his work on optics:
Ibn al-Haythem made significant improvements in optics, physical science, and the scientific method which influenced the development of science for over five hundred years after his death. Ibn al-Haytham’s work on optics is credited with contributing a new emphasis on experiment. His influence on physical sciences in general, and on optics in particular, has been held in high esteem and, in fact, 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 practising scientists—consider earlier inquiries into nature to be pre-scientific.
Richard Powers nominated Ibn al-Haytham’s scientific method and scientific skepticism as the most influential idea of the second millennium. George Sarton, the father of the history of science, wrote that “Ibn Haytham’s writings reveal his fine development of the experimental faculty” and considered him “not only the greatest Muslim physicist, but by all means the greatest of mediaeval times.”
Robert S. Elliot considers Ibn al-Haytham to be “one of the ablest students of optics of all times.” Professor Jim Al-Khalili also considers him the “world’s first true scientist”. The Biographical Dictionary of Scientists wrote that Ibn al-Haytham was “probably the greatest scientist of the Middle Ages” and that “his work remained unsurpassed for nearly 600 years until the time of Johannes Kepler.”
At a scientific conference in February 2007 as a part of the Hockney-Falco thesis, 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 circa 1430, arguably initiated as a result of Ibn al-Haytham’s influence, until today.”
The Latin translation of his main work, Kitab al-Manazir (Book of Optics), exerted a great influence on Western science: for example, on the work of Roger Bacon, who cites him by name, and on Johannes Kepler. It brought about a great progress in experimental methods. His research in catoptrics (the study of optical systems using mirrors) centred on spherical and parabolic mirrors and spherical aberration. He made the 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 problem known as “Alhazen’s problem”.
Meanwhile in the Islamic world, Ibn al-Haytham’s work influenced Averroes’ writings on optics, and his legacy was further advanced through the ‘reforming’ of his Optics by Persian scientist Kamal al-Din al-Farisi (d. ca. 1320) in the latter’s Kitab Tanqih al-Manazir (The Revision of [Ibn al-Haytham’s] Optics).
The correct explanations of the rainbow phenomenon given by al-Farisi and Theodoric of Freiberg in the 14th century depended on Ibn al-Haytham’s Book of Optics. The work of Ibn al-Haytham and al-Farisi was also further advanced in the Ottoman Empire by polymath Taqi al-Din in his Book of the Light of the Pupil of Vision and the Light of the Truth of the Sights (1574).
He wrote as many as 200 books, although only 55 have survived, and many of those have not yet been translated from Arabic. Even some of his treatises on optics survived only through Latin translation.
During the Middle Ages his books on cosmology were translated into Latin, Hebrew, and other languages.
The crater Alhazen on the Moon is named in his honour, as was the asteroid “59239 Alhazen”. In honour of Ibn al-Haytham, the Aga Khan University (Pakistan) named its Ophthalmology endowed chair as “The Ibn-e-Haitham Associate Professor and Chief of Ophthalmology”. Ibn al-Haytham is featured on the obverse of the Iraqi 10,000 dinars banknote issued in 2003, and on 10 dinar notes from 1982. A research facility that UN weapons inspectors suspected of conducting chemical and biological weapons research in Saddam Hussein’s Iraq was also named after him.
Book of Optics:
Ibn al-Haytham’s most famous work is his seven volume Arabic treatise on optics, Kitab al-Manazir (Book of Optics), written from 1011 to 1021. It has been ranked alongside Isaac Newton’s Philosophiae Naturalis Principia Mathematica as one of the most influential books in physics for introducing an early scientific method, and for initiating a revolution in optics and visual perception.
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 Risner he was known in the west as Alhacen, which is the correct transcription of the Arabic name. This work enjoyed a great reputation during the Middle Ages. Works by Ibn al-Haytham on geometric 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.
Theory of Vision:
Ibn al-Haytham proved that light travels in straight lines using the scientific method in his Book of Optics (1021).Two major theories on vision prevailed in classical antiquity. 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.
Ibn al-Haytham argued that the process of vision occurs neither by rays emitted from the eye, nor through physical forms entering it. He reasoned that a ray could not proceed from the eyes and reach the distant stars the instant after we open our eyes. He also appealed to common observations such as the eye being dazzled or even injured if we look at a very bright light. He instead developed a highly successful theory which explained the process of vision as rays of light proceeding to the eye from each point on an object, which he proved through the use of experimentation.
His unification of geometrical optics with philosophical physics forms the basis of modern physical optics. Ibn al-Haytham proved that rays of light travel in straight lines, and carried out various experiments 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 also gave the first clear description and correct analysis of the camera obscura and pinhole camera. While Aristotle, Theon of Alexandria, Al-Kindi (Alkindus), and Chinese philosopher Mozi had earlier described the effects of a single light passing through a pinhole, none of them suggested that what is being projected onto the screen is an image of everything on the other side of the aperture. Ibn al-Haytham was the first to demonstrate this with his lamp experiment where several different light sources are arranged across a large area. He was thus the first to successfully project an entire image from outdoors onto a screen indoors with the camera obscura.
In addition to physical optics, The Book of Optics also gave rise to the field of “physiological optics”. Ibn al-Haytham discussed the topics of medicine, ophthalmology, anatomy, and physiology, which included commentaries on Galenic works. He described the process of sight, the structure of the eye, image formation in the eye, and the visual system. He also described what became known as Hering’s law of equal innervation, vertical horopters, and binocular disparity, and improved on the theories of binocular vision, motion perception and horopters previously discussed by Aristotle, Euclid, and Ptolemy.
His most original anatomical contribution was his description of the functional anatomy of the eye as an optical system, or optical instrument. His experiments with the camera obscura provided sufficient empirical grounds for him to develop his theory of corresponding point projection of light from the surface of an object to form an image on a screen.
It was his comparison between the eye and the camera obscura which brought about his synthesis of anatomy and optics, which forms the basis of physiological optics. As he conceptualized the essential principles of pinhole projection from his experiments with the pinhole camera, he considered image inversion to also occur in the eye, and viewed the pupil as being similar to an aperture. Regarding the process of image formation, he incorrectly agreed with Avicenna that the lens was the receptive organ of sight, but correctly hinted at the retina being involved in the process.
The Father Of Modern Optics – Ibn Al Haytham | Muslim Pioneers 9/16/21
Ibn Al Haytham was one of the earliest scientists to study the characteristics of light and the mechanism of vision. Referred to as “the father of modern optics”, he made significant contributions to the principles of optics and visual perception in particular. His most influential work is titled Kitāb al-Manāẓir, whose title is commonly translated into English as Book of Optics but more properly has the broader meaning Book of Vision.
Vision and Cameras – Ibn al-Haytham 4/13/18
For a long time, scholars could not agree on how vision worked, and could not derive suitable evidence to support their work. 3 Muslim scholars discovered the secrets of vision, light and optics. Read below to find out the story of how these scholars literally revolutionised the world.
The video below says Muslim names were Westernized to erase Muslim contributions to Europe. However, the names were shortened and Anglicized because Arabic names are often very long and difficult for non-Muslims to pronounce or remember. Nevertheless, “Humanists” did steal all credit during the Renaissance. That’s why few Americans or Europeans know about these giants today.
Watch the short film ‘1001 Inventions and the World of Ibn Al-Haytham’. From director and producer Ahmed Salim, starring legendary actor Omar Sharif, voice by Khalid Abdalla and music composed by Sami Yusuf. The creators of ‘1001 Inventions and the Library of Secrets’ bring you this short film on the 11th century scientist Ibn Al-Haytham. The film was launched during the United Nations proclaimed International Year of Light and is produced by 1001 Inventions in partnership with UNESCO.
The Optics of Ibn Al-Haytham
by Charles Burnett 9/4/423
The Optics (kitāb al-Manāzir or Perspectiva/De aspectibus of Abū ʿAlī ibn al-Haytham al-Ḥasan ibn al-Ḥasan (ca. 965-1040) is one of the foundational works in the history of science. It was written between 1028 and 1038 in Cairo and had a distribution in the Islamicate world, and even more so in Western Christendom, after its translation into Latin in the late 12th or early 13th century under the name ‘Alhazen’ or ‘Alhacen’.
Its seven books treat of the function of the eye, direct vision, reflection, and images seen by reflection, refracted light and false images. It is known for its description and demonstration of the scientific method – principles on which all reliable scientific experimentation should be based; for its establishment of the intromission theory of vision, whereby the eye receives rays directly from the object of sight, rather than sending out a spirit to retrieve the image of the object; and its account of the camera obscura whose concept was eventually realised in photography; as well as many other aspects.
In the East, it was revised by Kamāl al-Dīn al-Fārisī (1267-1319) in his Tanqīḥ al-Manāzir (‘Revision of the Optics’). In the West, it was influential on the optical writings of Roger Bacon (ca.1220-ca.1292), John Pecham (ca. 1230-1292), and Erazmus Ciolek Witelo (Vitello; ca. 1230 – ca. 1280), who in turn wrote a revision. Apparently, it suffered a decline in the fourteenth and fifteenth centuries (though it was translated into Italian in the late fourteenth century). But it was revived by Friedrich Risner (ca. 1533-1580), who published the medieval Latin translation for the first time in 1572.
This enabled Johannes Kepler (1571-1630) and René Descartes (1596-1650) to use it extensively in their own works on optics.….
Note: The word “camera” comes from the Arabic word “kamra” which means “dark room” and was translated into Latin as “camera obscura”.
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Neenah Payne writes for Activist Post
Top image credit: Science of Faith
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