Muslim Scientists and Thinkers–Abu Ali al Hasan ibn al-Haytham

By Syed Aslam

Abu Ali al Hasan ibn al-Haytham also known in the West as Alhazen, was born in Basra, Iraq in the year 965 CE and received his education in Baghdad. Khalifa Hakim summand him to Egypt to work on a project to control the flood of the river Nile. After doing some field work he informed the Khalifa about the impracticality of the project. The mercurial Khalifa became mad at his assessment of the project and put him under house arrest for ten years. It is said that during this period he did a lot of work in optics, physics and mathematics. He became a free man when the Khalifa died in 1021 CE. He traveled to Spain and other places but came back to Cairo Egypt where he died in year 1039 CE.

Al-Haytham was a polymath who made significant contributions to the principles of optics, as well as to astronomy, engineering, mathematics, medicine, ophthalmology, philosophy, physics and theology. He is considered as the first scientist, a pioneer of the modern scientific method and the originator of experimental science, especially Physics. He was the author of more than two hundred books on wide range of subjects. Most of his works are lost but about sixty five of his precious work have still survived in which 25 is on mathematics, 20 on astronomy, 14 on optics, and five on different science subjects. He is also considered to be the founder of experimental psychology for his experimental approach to the psychology of visual perception.

Al-Haytham is regarded as the father of optics for his extensive contribution in this field. In the book of optics (Kitab al Manazir) he explained the modern intromission theory of vision, other experiments on optics, including experiments on lenses, mirrors, refraction, reflection, and the dispersion of light. He discovered the laws refraction and carried out the first experiment of dispersing the light into seven constituent colors by passing the light through a prism. This was rediscovered six century later by Isaac Newton who claimed all the credit for this magnificent discovery. He speculated on the finite speed of light and its electromagnetic aspects. He argued that rays of light are streams of energy particles traveling in straight lines, an idea so close to the modern concept of propagation of light. He invented the artificial lenses and conducted many experiments with them. His research in optics laid the foundation of telescopic astronomy as well as the later development of microscope. Al-Haytham was the first scientist who accurately explained how the eyes functions, its process of vision through the lenses and the binocular vision. His book on Optics has been ranked alongside Isaac Newton’s book Principia Mathematica as one of the most important book in the history of physics.

Al-Haytham described the pinhole camera and invented the camera obscure, a precursor to the modern camera. He discovered Fermat’s principle of least time, the law of inertia and gave the concept of momentum which was very close to the Newton’s Laws of Motion.

He also gave an idea that masses attracts each other and was aware of the magnitude of acceleration due to gravity. He discovered that the heavenly bodies were accountable to the laws of physics and presented the earliest reform of the Ptolemaic model including Planetary hypotheses and optics, pointing out various contradictions in his work.

Al-Haytham pioneered analytical geometry and the first theorems on non-Euclidean geometry, formulated and solved Alhazen’s problem geometrically, developed and proved the earliest general formula for infinitesimal and integral calculus using mathematical induction. Al-Haytham’s contributions to geometry and number theory went well beyond the Archimedean tradition. He also worked on analytical geometry and the beginnings of the link between algebra and geometry. Subsequently, this work led in pure mathematics and the harmonious fusion of algebra and geometry which was epitomized by Rene Descartes in geometric analysis and by Newton in the integral calculus.

Al-Haytham discussed in his book Mizan al-Hikmah the density of the atmosphere and developed a relation between it and the altitude. He also discussed about the atmospheric refraction and explained why the sun and the moon apparently seem increased in size near the horizon.

Al-Haytham developed rigorous experimental methods of controlled scientific testing in order to verify theoretical hypotheses and substantiate inductive conjectures. His scientific method was very similar to the modern scientific method. He attributed his scientific experiment to his faith in Islam, because he argued that Qur’an placed a very strong emphasis on empiricism (Seek knowledge by observation). He believed that truth and knowledge is the only way of attaining the closeness to God. His book on optics and other subjects has been translated in to Latin and other European languages by the twelfth and thirteenth century. His work remained unsurpassed for nearly 600 years until the time of Keplar.

Al-Haytham is regarded as a pioneer of Phenomenology a branch of philosophy. He articulated a relationship between the physical and observable world to that of intuition and mental functions. He linked the knowledge and perception to the domain of science and religion which led to a philosophy of existence. His thought on phenomenology was not developed further until the twentieth century.

There is no doubt that al- Haytham was one of the versatile universal genius of the Middle Ages, but it is sad to say none of his work survived in original Arabic text. His monumental treatise on optics and other subjects survived only through its Latin translation. We Muslims long neglected him and did not pay any attention to these gems among us. The Alhazen crater on the Moon and the asteroid 59239 are named in his honor by the west.



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