Everything about Ibn Al-haytham totally explained
or (
Latinized:
Alhacen or (deprecated)
Alhazen) (965 – 1039), was an
Arab or
Persian Muslim polymath
who made significant contributions to the principles of
optics, as well as to
anatomy,
astronomy,
engineering,
mathematics,
medicine,
ophthalmology,
philosophy,
physics,
psychology,
Ash'ari theology,
visual perception, and to
science in general with his introduction of the
scientific method. He is sometimes called
al-Basri (Arabic: البصري), after his birthplace in the city of
Basra,
Iraq then ruled by the
Buyid dynasty of
Persia.
Ibn al-Haytham is regarded as the father of
optics for his influential
Book of Optics, which correctly explained and proved the modern intromission theory of
vision, and for his
experiments on optics, including experiments on
lenses,
mirrors,
refraction,
reflection, and the dispersion of
light into its constituent
colours. and argued for the
corpuscular theory.
Due to his formulation of a modern
quantitative,
empirical and
experimental approach to
physics and
science, he's considered the pioneer of the modern
scientific method and the originator of
experimental science and
experimental physics, and some have described him as the "first
scientist" for these reasons.
He is also considered by some to be the founder of
experimental psychology for his experimental approach to the
psychology of
visual perception and
optical illusions, and a pioneer of the philosophical field of
phenomenology.
His
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, for initiating a
revolution in
optics discovered that the
heavenly bodies were accountable to the
laws of physics, presented a critique and reform of
Ptolemaic astronomy, first stated
Wilson's theorem in
number theory, formulated and solved
Alhazen's problem geometrically using early ideas related to
calculus and
mathematical induction, as well as for the
microscope and the use of optical aids in
Renaissance art. 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 his influential
Book of Optics and scores of other important treatises on
physics and
mathematics. He later traveled to
Spain and, during this period, he'd ample time for his scientific pursuits, which included
optics, mathematics, physics,
medicine, and the development of scientific methods — on all of which he's left several outstanding books.
Works
Ibn al-Haytham was a pioneer in
optics,
astronomy,
engineering,
mathematics,
physics, and
psychology. 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 areas of science. Not all of his surviving works have yet been studied, but some of his most important ones are described below. These include:
- Book of Optics (1021)
- Analysis and Synthesis
- Balance of Wisdom
- Discourse on Place
- Maqala fi'l-qarastun
- Doubts Concerning Ptolemy (1028)
- On the Configuration of the World
- Opuscula
- The Model of the Motions of Each of the Seven Planets (1038)
- The Resolution of Doubts
- Treatise on Light
- Treatise on Place
Legacy
Ibn al-Haytham was one of the most eminent
physicists, whose developments in
optics and the
scientific method were particularly 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 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.
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 millennium.
Nobel Prize winning physicist
Abdus Salam considered Ibn-al-Haitham "one of the greatest physicists of all time."
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 considered Ibn al-Haytham to be "one of the ablest students of optics of all times." 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."
The Latin translation of his main work,
Kitab al-Manazir, exerted a great influence upon Western science: for example, on the work of
Roger Bacon, who cites him by name, and on
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 doesn't 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. Ibn al-Haytham 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 him as well.
Book of Optics
Ibn al-Haytham's most famous work is his seven volume treatise on
optics,
Kitab al-Manazir (
Book of Optics) (written from 1011 to 1021), which has been ranked alongside
Isaac Newton's
Philosophiae Naturalis Principia Mathematica as one of the most influential books in
physics, 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 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,
Ibn al-Haytham proved that rays of light travel in straight lines, and carried out a number of experiments with
lenses,
mirrors,
refraction, and
reflection. He also discovered a result similar to
Snell's law of sines, but didn't quantify it and derive the law mathematically. Ibn al-Haytham also gave the first clear description and correct analysis of the
camera obscura, though the underlying principles of the
camera oscura or
pinhole camera were earlier known to
Mozi and
Aristotle. Ibn al-Haytham developed rigorous
experimental methods of controlled
scientific testing in order to verify theoretical
hypotheses and substantiate
inductive conjectures. Ibn al-Haytham eventually solved the problem using
conic sections and a geometric proof, though many after him attempted to find an algebraic solution to the problem,
Other contributions
Chapters 15–16 of the
Book of Optics dealt with
astronomy. Ibn al-Haytham was the first to discover that the
celestial spheres don't consist of
solid matter, and he also discovered that the heavens are less dense than the air. These views were later repeated by
Witelo and had a significant influence on the
Copernican and
Tychonic systems of astronomy.
Ibn al-Haytham discussed the topics of
medicine,
ophthalmology and
eye surgery in the
anatomical and
physiological portions of the
Book of Optics and in his commentaries on
Galenic works. He also made several improvements to
eye surgery and described the process of sight.
In
philosophy, Ibn al-Haytham is considered a pioneer of
phenomenology. He articulated a relationship between the physical and observable
world and that of
intuition,
psychology and
mental functions. His theories regarding
knowledge and
perception, linking the domains of science and religion, led to a philosophy of
existence based on the direct observation of
reality from the observer's point of view.
In
Islamic psychology, Ibn al-Haytham is considered the founder of
experimental psychology,
Astrophysics
In
astrophysics and the
celestial mechanics field of
physics, Ibn al-Haytham, in his
Epitome of Astronomy, discovered that the
heavenly bodies "were accountable to the
laws of physics".
Ibn al-Haytham's
Mizan al-Hikmah (
Balance of Wisdom) dealt with
statics, astrophysics, and celestial mechanics. He discussed the theory of
attraction between
masses, and it seems that he was also aware of the
magnitude of
acceleration due to
gravity at a distance.
Mechanics
In the
dynamics and
kinematics fields of
mechanics, Ibn al-Haytham's
Risala fi’l-makan (
Treatise on Place) discussed theories on the
motion of a body. He maintained that a body moves
perpetually unless an external force stops it or changes its direction of motion.
Astronomical works
Doubts Concerning Ptolemy
In his
Al-Shukūk ‛alā Batlamyūs, variously translated as
Doubts Concerning Ptolemy or
Aporias against Ptolemy, written between 1025 and 1028, Ibn al-Haytham criticized many of
Ptolemy's works, including the
Almagest,
Planetary Hypotheses, and
Optics, pointing out various contradictions he found 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:
empirical,
observational and
experimental grounds, such as Ptolemy's use of
conjectural undemonstrated theories in order to "save appearances" of certain
phenomena, which Ibn al-Haytham didn't approve of due to his insistence on
scientific demonstration. Unlike some later astronomers who criticized the Ptolemaic model on the grounds of being incompatible with
Aristotelian natural philosophy, Ibn al-Haytham was mainly concerned with empirical observation and the internal contradictions in Ptolemy's works.
In his
Aporias against Ptolemy, Ibn al-Haytham commented on the difficulty of attaining scientific knowledge:
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 Model of the Motions
Ibn al-Haytham's
The Model of the Motions of Each of the Seven Planets, written in 1038, was an important book on astronomy. The surviving manuscript of this work has only recently been discovered, with much of it still missing, hence the work hasn't yet been published in modern times. Following on from his
Doubts on Ptolemy and
The Resolution of Doubts, Ibn al-Haytham described the first non-Ptolemaic model in
The Model of the Motions. His reform wasn't concerned with
cosmology, as he developed a systematic study of
celestial kinematics that was completely
geometric. This in turn led to innovative developments in
infinitesimal geometry.
His reformed
empirical model was the first to reject the
equant and
eccentrics, separate
natural philosophy from astronomy, free celestial kinematics from cosmology, and reduce physical entities to geometrical entities. The model also propounded the
Earth's rotation about its axis, and the centres of motion were geometrical points without any physical significance, like
Johannes Kepler's model centuries later.
In the text, Ibn al-Haytham also describes an early version of
Occam's razor, where he employs only minimal hypotheses regarding the properties that characterize astronomical motions, as he attempts to eliminate from his planetary model the cosmological hypotheses that can't be observed from the
Earth.
Refutation of astrology
Ibn al-Haytham distinguished
astrology from astronomy, and he refuted the study of astrology, due to the methods used by astrologers being
conjectural rather than
empirical, and also due to the views of astrologers conflicting with orthodox
Islam.
Mathematical works
In
mathematics, Ibn al-Haytham builds on the mathematical works of
Euclid and
Thabit ibn Qurra. He goes on to systemize
conic sections and
number theory, carries out some early work on
analytic geometry, and works on "the beginnings of the link between
algebra and
geometry." This in turn had an influence on the development of
René Descartes's
geometric analysis and
Isaac Newton's
calculus.
Ibn al-Haytham made the first attempt at proving the
Euclidean parallel postulate using a
proof by contradiction, where he introduced the concept of
motion and
transformation into geometry. His proof was also the first to employ the
Lambert quadrilateral and
Playfair's axiom, both of which were not known in Europe until the 18th century. Some have referred to the Lambert quadrilateral as the "Ibn al-Haytham–Lambert quadrilateral" as a result. His theorems on
quadrilaterals, including the Lambert quadrilateral, were the first theorems on
elliptical geometry and
hyperbolic geometry, and along with his alternative postulates, such as Playfair's axiom, his work marked the beginning of
non-Euclidean geometry and had a considerable influence on its development among later Muslim geometers such as
Omar Khayyám and
Nasīr al-Dīn al-Tūsī and European geometers such as
Witelo,
Gersonides,
Alfonso,
John Wallis and
Giovanni Girolamo Saccheri.
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.
According to
al-Khazini, Ibn al-Haytham also wrote a treatise providing a description on the
construction of a
water clock.
Philosophy
In
early Islamic philosophy, 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's 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
René Descartes's concept of place in the
Extensio in the 17th century.
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.
Theology
Ibn al-Haytham was a devout
Muslim, who is said to have been a follower of the orthodox
Ash'ari school of
Sunni Islamic theology, and opposed to the views of the
Mu'tazili school, though he may have been a supporter of Mu'tazili theology or
Shia Islam at some point in his life.
Ibn al-Haytham also wrote a work on Islamic theology, in which he discusses
prophethood and develops a system of philosophical criteria to discern true prophethood from false claimants in his time.
Ibn al-Haytham attributed his
experimental
scientific method and
scientific skepticism to his
Islamic faith. The
Qur'an, for example, placed a strong emphasis on
empiricism. He also believed that
human beings are inherently flawed and that only
God is perfect. He
reasoned that to discover the
truth about
nature, it's necessary to eliminate human
opinion and
error, and allow the
universe to speak for itself.}}
Ibn al-Haytham described his search for truth and
knowledge as a way of leading him closer to God:
Further Information
Get more info on 'Ibn Al-haytham'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://ibn_al-haytham.totallyexplained.com">Ibn al-Haytham Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
