Alhazen pretended madness to escape from Egypt Ruler
Ibn al-Haytham (Alhazen)
Alhazen is known as the "Father of Modern Optics, Experimental physics and scientific methodology" According to one version of his biography, overconfident about practical application of his mathematical knowledge, he assumed that he could regulate the floods of the Nile, a task requiring an early attempt at building a dam at the present site of the Aswan High Dam.
After being ordered by Al-Hakim bi-Amr Allah, the sixth ruler of the Fatimid caliphate, to carry out this operation, he quickly perceived the impossibility of what he was attempting to do. Soon he decided that the scheme was impractical and he feared the caliph's anger.
Fearing for his life, he feigned (pretended) madness. He was kept under house arrest from 1011 until al-Hakim's death in 1021. During this time, he wrote his most influential Book of Optics. After the death of Al-Hakim he was able to prove that he was not mad. After his house arrest ended, he wrote scores of other treatises on physics, astronomy and mathematics.
Alhazen
Alhazen (965 – 1040) was an Iraqi Muslim scientist, polymath, mathematician, astronomer and philosopher. He made significant contributions to the principles of optics, as well as to astronomy and mathematics.
Isis's tears of sorrow
Ancient Egyptians believed that the Nile flooded every year because of Isis's tears of sorrow for her dead husband, Osiris. Isis is an ancient Egyptian goddess and she was worshiped as the ideal mother and wife as well as the patroness of nature and magic. Osiris is an Egyptian god, usually identified as the god of the afterlife, the underworld and the dead.
Aswan High Dam in Nile – 3rd biggest in World
The Aswan High Dam is 3,830 metres (12,570 ft) long, 980 metres (3,220 ft) wide at the base, 40 metres (130 ft) wide at the crest and 111 metres (364 ft) tall. It contains 43,000,000 cubic metres (56,000,000 cu yd) of material. At maximum, 11,000 cubic metres per second (390,000 cu ft/s) of water can pass through the dam. There are further emergency spillways for an extra 5,000 cubic metres per second (180,000 cu ft/s). The reservoir, named Lake Nasser, is 550 kilometres (340 miles) long and 35 kilometres (22 miles) at its widest with a surface area of 5,250 square kilometres (2,030 sq miles). It holds 132 cubic kilometres of water.