Islamic Thinkers In Physics
Ibn al-Haytham
A man whom Archbishop John Peckham referred to as 'The Physicist', and often called the father of optics, Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham was a pioneer in the fields of Optics, Astronomy and Theology who inspired many of Europe's greatest thinkers, such as Witelo, an inspiration of Galileo, and Bacon, whose work amongst other things introduced the western world to gunpowder.
Biography
Ibn al-Haytham, often Romanised as Alhazen, was born in 965 CE in Basra, modern day Iraq. He was educated in a civil capacity, and served as a judge, before becoming disillusioned with the study of religious law due to the conflicting views on religion and its laws at the time. He subsequently studied Mathematics, Physics and Engineering, and claimed to be able to control the flooding of the Nile. Having been invited to the court of the Fatimid Dynasty, but finding his concept of a dam at Aswan to be impractical with the technology of the time, he feigned insanity and was placed under house arrest for ten years until the death of the Caliph. It was at this time al-Haytham published his most influential work, Kitab Al Manazer (the book of optics), and established himself as a revolutionary thinker in how light interacts with the world, and about how science should be performed. He died around 1040 CE, with a legacy that shaped much of modern scientific thought.
Kitab Al Manazer
The 'Kitab Al Manazer', or 'Book of Optics', was Ibn al-Haytham's most famous work, and defined him as a scientist. In it, he discussed topics such as the ways in which sight works, namely that light enters, rather than leaves, the eye (contrary to Greek thought). Also discussed were the properties of light and vision, and detailed certain experiments, including one proving the motion of light is straight, as well as describing prism light separation and the camera obscura (pinhole camera).
The book includes experiments, theory, and discussion, but the key point of the book, in my opinion, his emphasis on experimentation. His points are routinely backed up with experiments. Take, for instance, the assertion that light travels in straight lines. Al-Haytham proves this by lighting a candle, and observing it through a tube. He then covers the tube, and determines that, as he can no longer observe the candle, that the light must have to travel in straight lines, else it would be able to bend around the tube. Whilst rudimentary, it is still revolutionary, as much of the 'science' that was performed at the time, and indeed for a time after, was more philosophical, posing questions and theories based on data, but not often supporting them with mathematical laws or experimentation.
Al-Haytham's experiment with camera obscura, proving that light rays don't mix
Other Works
Al-Haytham also worked on fields outside of optics, namely astronomy and mechanics. His 'Doubts Concerning Ptolemy' sought to challenge the Greek thinker on many astronomical topics, whose beliefs were commonplace across Europe. This includes criticising Ptolemy's order of the planets, arguing that the order he had posed did not agree with data, and arguing that elliptical orbits could exist, that it would not cause a vacuum. He also disagreed with Aristotle, saying that vacuums were perfectly acceptable in nature. Importantly, in his mind the heavens were, as Pierre Duhem puts it, "accountable to the laws of physics". This was a big step in astronomy, as Greek and Christian scholars had often seen the heavens as separate from the natural processes of the earth, ideas not really seen in Europe until Copernicus, Galileo, and Newton.
The above sections gives insight into why he could be considered the 'first scientist', as his experimentalism and insistence on theory consistent with data was far more in line with the thinkers of the scientific revolution (think Newton and Boyle) than that of his European contemporaries. Yet, his name is often left off of lists of influential thinkers, especially in the classroom.
"The Latin translation of Alhazen's work influenced scientists and philosophers such as (Roger) Bacon and da Vinci, and formed the foundation for the work by mathematicians like Kepler, Descartes and Huygens..."
(Zewail, Ahmed H.; Thomas, John Meurig (2010), 4D Electron Microscopy: Imaging in Space and Time)
Ibn al-Haytham was well known to scientists of the enlightenment and before, being a source of knowledge for Bacon and Descartes, as they had translated his works. Newton was said to have kept Kitab Al Manazer in his personal library, which is unsurprising given optics and prisms as a shared field of study. The work of these men is clearly influential and much of it is taught today, from Newton's work on prisms and optics to Kepler's laws of planetary motion. As a key stepping stone in the field of optics, it is important, in my eyes, that his name at least be mentioned in curricula as a bridge between the work of these enlightenment thinkers and the Greeks, given his influence in the research of later scholars.