20. ALHAZEN IBN al-HAYTHAM

(July 1, 965 – March 6, 1040)

Alhazen Ibn al-Haytham was a superb polymath: an illustrious pacesetter who illuminated the paths of those who came after him. He is regarded as an ingenious icon across the Islamic world. Medieval Europeans nicknamed him Ptolemaeus Secundus (which literally translates to “Second Ptolemy”). Nonetheless, he was Ptolemy’s superior in every aspect of science and mathematics. His works spanned across a wide range of maths and mathematical physics. And they influenced lots of notable scientists such as Regiomontanus, Nicolaus Copernicus, Johannes Kepler, Isaac Newton, and many others. Alhazen is without question, the greatest and the most influential scientist of the Middle Ages. His Book of Optics was hailed as the most important work on mathematical physics before Newton’s Principia Mathematica emerged (more than half a millennium later). He also advanced other areas such as: arithmetic, geometry and astronomy. Galileo Galilei, René Descartes and Leonardo da Vinci all borrowed ideas from his works. The same is true for Omar Khayyam and his protégé: Abu al-Fath al-Khazini. As an engineer, Alhazen was entrusted with the task of remedying the overflowing River Nile in Egypt: during the reign of Fatimid Caliph, Al-Hakim bi-Amr Allah. Although most of his works were lost over the centuries, those that survived indicated that he foraged into fields as diverse as literature, biology, theology, psychology, philosophy, mechanics and medicine. For his role in consolidating science, the 59239 Alhazen asteroid and the Alhazen lunar crater were named after him. In 2015, the UNESCO commemorated him as the “Father of Optics”.