# Abu Ali Hasan Ibn al-Haitham

Essay by rcboy93Junior High, 7th gradeA+, January 2007

Abu Ali Hasan Ibn al-Haitham was a great popular physicist. He was born in 965 C.E. in Basrah. He was educated in Basrah and Baghdad. Abu went to Egypt. He was hired to figure out how to control the flood of the Nile but he failed. He was afraid that he would be punished for this failure so he pretended to be insane until the Muslim ruler, Caliph al-Hakim died. Abu Ali Hasan Ibn al-Haitham then went to Spain. At this time he had a lot of time for scientific studies and he wrote many outstanding books on them. These studies included optics, mathematics, physics, and medicine.

His book "Kitab-al-Manadhir" was very famous. It was translated in Latin in the middle ages. The book was about his examination of the passage of light. While he was studying the passage of light he discovered the laws of refraction. Laws of Refraction is the constant for light of a given color crossing the boundary of two given conditions; such as air.

Refraction describes the way light rays are bent when they travel through a clear substance. His book helped others such as Roger Bacon and Kepler to do more experiments on the subject. Abu wrote another book about the colors of the sunset, which was also translated in Latin.

He was the first to correctly explain the parts of the eyes. He achieved this by studying shadows, eclipses, and the rainbow. He researched the physical nature of light. Abu tried to explain binocular vision and was also known for his studies of the use of the camera obscua. Camera obscua is comparing how the eye works to a camera. Abu also wrote a book called "Mizan al-Hikmah". He talked about the atmosphere and the thickness of it and compared the thickness to the height.

Abu's greatest contribution was in mathematics and physics. He developed detailed geometry by linking algebra and geometry together. He also studied the way the body moved. He said that the body remains upward unless an outer force makes it stop or changes its direction. An example of an outer force is someone pushing another.

Abu wrote over two hundred books. The subjects were science, vision, light, motion of the body and a book on evolution. No one knows how Abu died but they think he probably died in Cairo, Egypt in 1040 C.E.

Bibliography:

Wikipedia. October 25, 2006. http://en.wikipedia.org/wiki/Ibn_al-Haitham. October 25, 2006.

Famous Muslims. 2003. http://www.famousmuslims.com/ABU%20ALI%20HASAN%20IBN%20AL-HAITHAM.htm. October 25, 2006.