The ‘mad’ Egyptian scholar who proved Aristotle wrong
6 January 2011 | Source: Physics World
Ibn al-Haytham’s 11th-century Book of Optics, which was published exactly 1000 years ago, is often cited alongside Newton’s Principia as one of the most influential books in physics. Yet very little is known about the writer, considered by many to be the father of modern optics.
January’s Physics World features a fanciful re-imagining of the 10-year period in the life of the medieval Muslim polymath, written by Los Angeles-based science writer Jennifer Ouellette.
The feature covers the time when al-Haytham -- banished from society and deprived of books -- came up with his revolutionary theories about the form and passage of light.
Ouellette brings detail to the skeletal plot of al-Haytham’s life, from the awe and intimidation felt when he was summoned by the Caliph to use his engineering prowess to overcome the annual flooding of the Nile, to his fear of punishment when he realised he had failed in his task.
Al-Haytham was only able to escape a death sentence from the notoriously brutal Caliph by pretending he had gone mad. The Caliph instead incarcerated al-Haytham, imprisoning him under house arrest to a cell. Confined and alone, it was here that al-Haytham carried out the work that was to make him famous.
In 11th-century Egypt, Aristotle’s ancient thought that visible objects and our own eyes emit rays of light to enable our vision still held.
Ouellette imagines al-Haytham lying alone in his darkened room questioning why the objects in the room are not emitting light and asking ‘Is it possible that the ancients were mistaken?’
The question providing the crux, al-Haytham was spurred into experimental action with the candles and copper in his bare room to conclude that there is no mysterious “form” that all objects emit; rather there are sources of primary light that are reflected by other objects.
As Ouellette writes, “This is a work of fiction – a fanciful re-imagining of a 10-year period in the life of Ibn al-Haytham, considered by many historians to be the father of modern optics. Living at the height of the golden age of Arabic science, al-Haytham developed an early version of the scientific method 200 years before scholars in Western Europe.”
Released from prison after the Caliph's death, al-Haytham (AD 965-1040) went on to make contributions to astronomy, mathematics, engineering and medicine, as well as physics. But it his seven-volume Book of Optics, which he wrote while imprisoned, that remain his most famous contributions to science, covering visual perception, psychology and physical optics.
Also in the January edition:
- Condensed-matter analogues of black holes and other cosmic phenomena may allow physicists to test ideas about quantum gravity and the early universe, as Ralf Schützhold, theoretical physicist at the University of Duisburg-Essen, and Bill Unruh, theoretical physicist at the University of British Columbia, explain.
- Classical physics is usually enough to be able to understand the behaviour of biological molecules. But as Seth Lloyd, from the Department of Quantum Mechanical Engineering at the Massachusetts Institute of Technology, describes, some photosynthetic bacteria exploit weird quantum-mechanical effects to convert harvested light into chemical energy.