History's Most Productive Imprisonment
Ibn al-Haytham wrote the scientific method under house arrest, 550 years before Bacon was born. He managed it because he had ten years in which nobody could ask him for anything.
Around 1011, in Cairo, a scholar realised he had made a serious mistake with his career.
Ibn al-Haytham had proposed to the Fatimid caliph al-Hakim that the annual flooding of the Nile could be regulated by a dam near Aswan. He travelled south to survey the site, looked at the scale of what he had promised, and understood that with the engineering available to him it could not be done.
Al-Hakim was not a man to whom one delivered that news. He had a documented record of executing people for less.
So Ibn al-Haytham feigned madness, which in that court was one of the few reliable ways to become uninteresting, and was placed under house arrest.
He stayed there about ten years, until al-Hakim died in 1021.
During those ten years he wrote the Kitab al-Manazir, the Book of Optics.
It is one of the most consequential scientific works ever produced, and the argument for that is not sentimental.
Since Euclid and Ptolemy, optics had rested on the emission theory: the eye sees by sending out rays that strike objects. Ibn al-Haytham demolished it and replaced it with intromission, that vision happens when light reflected from an object enters the eye. This is correct, and it had been wrong for thirteen hundred years.