Who discovered that light travels in straight line?

Answer 1

Ibn al-Haytham (965 in Basra - c. 1040 in Cairo) a Muslim scientist, proved that rays of light travel in straight lines, and carried out various experiments with lenses, mirrors,refraction, and reflection. He was also the first to reduce reflected and refracted light rays into vertical and horizontal components, which was a fundamental development in geometric optics.Book of Optics.(Ibn al-Haytham)

Answer 2

The principle that light travels in straight lines was first proposed by the ancient Greek philosopher Euclid in his work "Optics." Euclid's ideas were further developed by Islamic scientist Ibn al-Haytham in the 11th century, who is often credited with the discovery that light travels in straight lines.