BBC - History - Alhazen (c.965 - 1039) alhazen (full name Abu Ali alHasan Ibn al-Haitham) was the son of a civil servant and consequently relatively well http://www.bbc.co.uk/history/historic_figures/alhazen.shtml
Extractions: Send it to a friend! Alhazen (full name Abu Ali al-Hasan Ibn al-Haitham) was the son of a civil servant and consequently relatively well educated. In the course of his reading he became fascinated by the flooding of the River Nile. He reasoned that constructing a dam would enable water to be stored for irrigation in the dry season, and flooding could be prevented at other times. He pitched his idea to the ruler of Egypt, Caliph al-Hakim. The Caliph was intrigued, and provided financial backing and workmen. On arrival at the dam's proposed site at Aswan, Alhazen realised that he had insufficient money, materials or labour to complete the project successfully. Not wanting to waste money, but concerned at the price he might have to pay for failure, he pretended to be insane, a pretence he was required to keep up until the Caliph died twelve years later. By the time the Caliph had died, in 1021, Alhazen was teaching in Cairo, where he lived out his life. He spent much of his time conducting experiments, of which many involved a dark room with a hole in it. He hung five lanterns outside the room, adjacent to the wall with the hole, and noticed that there were five 'lights' on the wall inside his dark room. He would then place an obstruction between one of the lanterns and the hole, and observed one of the 'lights' on the wall disappear. Furthermore the lantern, the obstruction and the hole were in a straight line.
ALHAZEN alhazen (Asu ALI ALHASAN IBN ALHASAN), Arabian mathematician of the nth century, was born at Basra and died at Cairo in 1038 http://22.1911encyclopedia.org/A/AL/ALHAZEN.htm
Alhazen, The Islamic Scholar Bibliography p. 290297. Subjects alhazen, 965-1039. Optics. Series Entry Boethius (Series) ; Bd. http://www2.potsdam.edu/PHYS/islamma/phys111_alhazen.htm
Extractions: ABU ALI HASAN IBN AL-HAITHAM ( 965 - 1040 A.D.) Abu Ali Hasan Ibn al-Haitham was one of the most eminent physicists, whose contributions to optics and the scientific methods areoutstanding. Known in the West as Alhazen, Ibn aI-Hautham was born in965 A. D. in Basrah, and was educated in Basrah and Baghdad. Thereafter, he went to Egypt, where he was asked to find ways of controlling the flood of the Nile. Being unsuccessful in this, he feigned madness until the death of Caliph al-Hakim. He also 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. The Latin translation of his main work, Kitab-at-Manazir, exerted a great influence upon Western science e.g. on the work of Roger Bacon 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 radio between the angle of incidence and refraction does not remain constant and investigated the magnifying power of a lens. His catoptrics contain 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.
[ Burburinho - Eu Queria Ser Alhazen ] eu queria ser alhazen por Nemo Nox lgumas vezes tenho vontade de ser o alhazen, me fingir de louco e ficar fazendo as minhas coisinhas sem ninguém me incomodando. http://www.burburinho.com/nn010712.html
Extractions: lgumas vezes tenho vontade de ser o Alhazen, me fingir de louco e ficar fazendo as minhas coisinhas sem ninguém me incomodando. Abu Ali Hasan Ibn al-Haitham, mais conhecido como Alhazen, foi um cientista árabe da virada do milênio passado (965-1039) que passou a maior parte da sua vida no Egito, naquela época governado pelo todo-poderoso e também muito temperamental califa Al-Hakim. Pois o soberano o contratou para um projeto grandioso, desviar o curso do rio Nilo para controlar as cheias. Percebendo que se tratava de uma tarefa impossível, e temeroso da fúria do califa, Alhazen passou a se fingir de louco, e assim viveu por cerca de vinte anos sem ter que dar satisfações de seus atos. Sem pressões exteriores e com o sustento garantido, o cientista árabe foi então capaz de avançar em seus estudos de física e matemática, e acabou por se tornar uma figura importantíssima na história da ciência. Foi ele, por exemplo, que provou que Aristóteles estava errado ao afirmar que um arco-íris se formava pelo reflexo do sol nas gotas de chuva. Depois de experiências com garrafas cheias d'água (imagino os empregados se perguntando "o que esse louco estará fazendo com as garrafas?"), Alhazen descobriu que o arco-íris é na verdade fruto da refração da luz, cada cor com seu ângulo diferente. Hoje isso pode parecer brincadeira de criança (ou passatempo de loucos) mas foi uma descoberta importante, que precedeu em muito tempo trabalhos semelhantes de cientistas europeus.
Haupttext Geometry. Transformations. Reflections. alhazen's Billiard Problem http://www.rudiviertel.de/avicenna.htm
Extractions: Rudi.Viertel@ t-online.de Avicenna und Alhazen Avicenna (Ibn Sina, 980 Provinz Buchara, Persien; Avicenna hatte erkannt, dass jeder einzelne Farbton eine Vielzahl von Abstufungen umfaßt, die sich nur in der Helligkeit unterscheiden. Er kannte auch bereits eine Abfolge vom Weiß über alle Grauwerte zum Schwarz. In der aus dem 12. Jh. stammenden lateinischen Übersetzung seiner Werke werden drei Farbreihen herausgestellt: "Die erste ‘reine’ Skala der Unbuntarten, die über ‘subpallidum’ und ‘pallidum’, eine zweite die über Fahlrot (‘sunrubeus’) und Rot, und eine dritte, die über Grün und Indigo führte." Diese Farbreihen wurden von Vinzenz von Beauvais in seine Enzyklopädie aufgenommen (Speculum naturae II, Kap. lxviii) und von
Al-Haitham (Alhazen), 965-1040 C.E. ABU ALI HASAN IBN ALHAITHAM (alhazen) (965 - 1040CE), by Dr. A. Zahoor. Click here to proceed. http://salam.muslimsonline.com/~azahoor/haitham.html
Al-Haytham He is often known as alhazen which is the Latinised version of hisfirst name alHasan . In Lunar features, Crater alhazen. Other http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Al-Haytham.html
Extractions: In particular this name occurs in the naming of the problem for which he is best remembered, namely Alhazen's problem: Given a light source and a spherical mirror, find the point on the mirror were the light will be reflected to the eye of an observer. We shall discuss this problem, and ibn al-Haytham's other work, after giving some biographical details. In contrast to our lack of knowledge of the lives of many of the Arabic mathematicians, we have quite a number of details of ibn al-Haytham's life. However, although these details are in broad agreement with each other, they do contradict each other in several ways. We must therefore try to determine which are more likely to be accurate. It is worth commenting that an autobiography written by ibn al-Haytham in 1027 survives, but it says nothing of the events his life and concentrates on his intellectual development. Since the main events that we know of in ibn al-Haytham's life involve his time in Egypt, we should set the scene regarding that country. The Fatimid political and religious dynasty took its name from Fatimah, the daughter of the Prophet Muhammad. The Fatimids headed a religious movement dedicated to taking over the whole of the political and religious world of Islam. As a consequence they refused to recognise the 'Abbasid caliphs. The Fatimid caliphs ruled North Africa and Sicily during the first half of the 10th century, but after a number of unsuccessful attempts to defeat Egypt, they began a major advance into that country in 969 conquering the Nile Valley. They founded the city of Cairo as the capital of their new empire. These events were happening while ibn al-Haytham was a young boy growing up in Basra.
References For Al-Haytham Internat. Hist. Sci. 32 (108) (1982), 112113. D Lindberg, alhazen,'s theoryof vision and its reception in the west, Isis 58 (1968), 321-341. http://www-gap.dcs.st-and.ac.uk/~history/References/Al-Haytham.html
Extractions: A I Abdul-Latif, Ibn al-Haytham : The geometer (Arabic) (Amman, 1993). J P Hogendijk, ibn al-Haytham's 'Completion of the conics' (New York-Berlin, 1985). Y T Langermann, ibn al-Haytham's "On the configuration of the world" (New York, 1990). M Nazif, Al-Hasan ibn al-Haytham, his optical researchs and discoveries (2 Vols.) (Cairo, 1942-43). R Rashed, The development of Arabic mathematics : between arithmetic and algebra (London, 1994). R Rashed, (Paris, 1984). A I Sabra, The optics of ibn al-Haytham (2 Vols.) (London, 1989). Articles: A I Abd al-Latif, A detailed article on ibn al-Haytham's lunules (Arabic), in (Tunis, 1990), A40-A67, 195. A Abdukabirov, Some problems from ibn al-Haytham's completion of the reconstruction of the eighth book of 'Conics' of Apollonios of Perga (Russian), in Mathematics and astronomy in the works of Ibn Sina, his contemporaries and successors (Tashkent, 1981), 80-94.
Al-Haitham (Alhazen), 965-1040 C.E. ABU ALI HASAN IBN ALHAITHAM (alhazen) (965 - 1040 CE),by Dr. A. Zahoor. Biography Available in the E-Book. http://cyberistan.org/islamic/haitham.html
Al-Haytham Biography of Ibn alHaytham (965-1039) He is often known as alhazen which is the Latinised version of his first name "al-Hasan". http://www-history.mcs.st-and.ac.uk/history/Mathematicians/Al-Haytham.html
Extractions: In particular this name occurs in the naming of the problem for which he is best remembered, namely Alhazen's problem: Given a light source and a spherical mirror, find the point on the mirror were the light will be reflected to the eye of an observer. We shall discuss this problem, and ibn al-Haytham's other work, after giving some biographical details. In contrast to our lack of knowledge of the lives of many of the Arabic mathematicians, we have quite a number of details of ibn al-Haytham's life. However, although these details are in broad agreement with each other, they do contradict each other in several ways. We must therefore try to determine which are more likely to be accurate. It is worth commenting that an autobiography written by ibn al-Haytham in 1027 survives, but it says nothing of the events his life and concentrates on his intellectual development. Since the main events that we know of in ibn al-Haytham's life involve his time in Egypt, we should set the scene regarding that country. The Fatimid political and religious dynasty took its name from Fatimah, the daughter of the Prophet Muhammad. The Fatimids headed a religious movement dedicated to taking over the whole of the political and religious world of Islam. As a consequence they refused to recognise the 'Abbasid caliphs. The Fatimid caliphs ruled North Africa and Sicily during the first half of the 10th century, but after a number of unsuccessful attempts to defeat Egypt, they began a major advance into that country in 969 conquering the Nile Valley. They founded the city of Cairo as the capital of their new empire. These events were happening while ibn al-Haytham was a young boy growing up in Basra.
- Great Books - alhazen (9651040), Biography 1038. He is to be distinguished from anotheralhazen who translated Ptolemy's Almagest in the 10th century. http://www.malaspina.com/site/person_69.asp
Extractions: Arabian mathematician of the 11th century, was born at Basra and died at Cairo in 1038. He is to be distinguished from another Alhazen who translated Ptolemy 's Almagest in the 10th century. Having boasted that he could construct a machine for regulating the inundations of the Nile, he was summoned to Egypt by the caliph Hakim; but, aware of the impracticability of his scheme, and fearing the caliph's anger, he feigned madness until Hakim's death in 1021. Alhazen was, nevertheless, a diligent and successful student, being the first great discoverer in optics after the time of Ptolemy . According to Giovanni Battista della Porta, he first explained the apparent increase of heavenly bodies near the horizon, although Bacon gives the credit of this discovery to Ptolemy Wikipedia
Alhazen Translate this page Ibn al HAYTHAM al Hassan (alhazen) arabe, 965-1039 Astronome, médecin,philosophe et physicien. Ses travaux portent essentiellement http://www.sciences-en-ligne.com/momo/chronomath/chrono1/Alhazen.html
ALHAZEN outstanding. Known in the West as alhazen, Ibn alHaitham was bornin 965 AD in Basrah, and was educated in Basrah and Baghdad. http://home.att.net/~mleary/alhazen.htm
Extractions: (965-1040 A.D.) Abu Ali Hasan Ibn al-Haitham was one of the most eminent physicists, whose contributions to optics and the scientific methods are outstanding. Known in the West as Alhazen, Ibn al-Haitham was born in 965 A.D. in Basrah, and was educated in Basrah and Baghdad. Thereafter, he went to Egypt, where he was asked to find ways of controlling the flood of the Nile. Being unsuccessful in this, he feigned madness until the death of Caliph al-Hakim. He also travelled 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. The Latin translation of his main work, Kitabal Manadhir, exerted a great influence upon Western science e.g. on the work of Roger Bacon and Kepler. It brought about a great progress in experimental methods. His research in catoptrics centred 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 catoptrics contain 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.
Alhazen Alhazan. alhazen 965 1039 BCE. In Umberto Eco's The Name of theRose, alhazen is mentioned briefly on pages 172 and 315. alhazen http://www.louisville.edu/~d0hess01/alhazen.html
Extractions: mentioned briefly on pages 172 and 315. Alhazen (the Arabic name is Abu Ali Hasan Ibn al-Haitham) was born and educated in Barash. He was one of the most exalted physicists in the Middle East and North Africa. His scientific methodology and contributions to optics were unparalleled. In fact, his knowledge led to his being asked to Egypt to help find a way to control the flood of the Nile. However, he was unsuccessful. Later, he moved to Spain, were he wrote treatises on optics, physics, medicine, mathematics, and the scientific method. In his book Kitab-at-Manazir, he examined the passage of light, laws of refraction, and the role of the dispersion light in the determination of colors. He also studied the phenomena of eclipses, shadows, and rainbows. Alhazen also studied the procedure of vision, and he was the first to correctly describe the different parts of the eye. In his attempts to explain binocular vision, his use of the camera obscura, and correctly speculating that light emanates from the object that we are seeing and not the eye, led to him being christened the father of modern optics. Alhazen's book, Mizan al-Hikmah Ibn al-Haitham, examines the density of the atmosphere, atmospheric refraction, and why twilight begins or ends only when the sun is 19? below the horizon. Ultimately, his desire was to use all of these aspects to determine the height of the atmosphere.
Alhazen's Billiard Problem -- From MathWorld alhazen's Billiard Problem, Dörrie, H. alhazen's Billiard Problem. §41 in100 Great Problems of Elementary Mathematics Their History and Solutions. http://mathworld.wolfram.com/AlhazensBilliardProblem.html
Extractions: In a given circle , find an isosceles triangle whose legs pass through two given points inside the circle . This can be restated as: from two points in the plane of a circle , draw lines meeting at the point of the circumference and making equal angles with the normal at that point The problem is called the billiard problem because it corresponds to finding the point on the edge of a circular " billiard " table at which a cue ball at a given point must be aimed in order to carom once off the edge of the table and strike another ball at a second given point . The solution leads to a biquadratic equation of the form The problem is equivalent to the determination of the point on a spherical mirror where a ray of light will reflect in order to pass from a given source to an observer. It is also equivalent to the problem of finding, given two points and a circle such that the points are both inside or outside the circle , the ellipse whose foci are the two points and which is tangent to the given circle The problem was first formulated by Ptolemy in 150 AD and was named after the Arab scholar Alhazen who discussed it in his work on optics. The problem is insoluble using a
Philosophers : Alhazen alhazen. Iranian Muslim Philosopher. 9651040. Known in the West as alhazen, Ibn al-Haithamwas born in 965 AD in Basrah, and was educated in Basrah and Baghdad. http://www.trincoll.edu/depts/phil/philo/phils/muslim/alhazen.html
Extractions: Abu Ali Hasan Ibn al-Haitham was one of the most eminent physicists, whose contributions to optics and the scientific methods are outstanding. Known in the West as Alhazen, Ibn al-Haitham was born in 965 A.D. in Basrah, and was educated in Basrah and Baghdad. Thereafter, he went to Egypt, where he was asked to find ways of controlling the flood of the Nile. Being unsuccessful in this, he feigned madness until the death of Caliph al-Hakim. He also travelled 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. He 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-Manadhir was translated into Latin in the Middle Ages, as also his book dealing with the colours of sunset. He dealt at length with the theory of various physical phenomena like shadows, eclipses, 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 gave a correct explanation of 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.
