User:Rarrell/sandbox/Taqi al-Din

Taqi ad-Din Muhammad ibn Ma'ruf ash-Shami al-Asadi (Arabic: تقي الدين محمد بن معروف الشامي, Turkish: Takiyüddin or Taki) (1526–1585) was a Ottoman era polymath active in Constantinople. He was the author of more than ninety books on a wide variety of subjects, including astronomy, clocks, engineering, mathematics, mechanics, optics and natural philosophy. In 1574 the Ottoman Sultan Murad III invited Taqī al-Dīn to build the Constantinople observatory. Using his exceptional knowledge in the mechanical arts, Taqī al-Dīn constructed instruments like huge armillary and mechanical clocks that he used in his observations of the Great Comet of 1577. He also used European celestial and terrestrial globes that were delivered to Istanbul in gift-exchange. The major work that resulted from his work in the observatory is titled The tree of ultimate knowledge [in the end of time or the world] in the Kingdom of the Revolving Spheres: The astronomical tables of the King of Kings [Murād III](Sidrat al-muntah al-afkar fi malkūt al-falak al-dawār– al-zij al-Shāhinshāhi). The work was prepared according to the results of the observations carried out in Egypt and Istanbul in order to correct and complete Ulugh Beg’s Zij as-Sultani. The first 40 pages of the work deal with calculations, followed by discussions of astronomical clocks, heavenly circles, and information about three eclipses which he observed at Cairo and Istanbul. For corroborating data of other observations of eclipses in other locale like Daud ar-Riyyadi (David the Mathematician), David Ben-Shushan of Salonika. According to Salomon Schweigger, the chaplain of Habsburg ambassador Johann Joachim von Sinzendorf, Taqi ad-Din was a charlatan who deceived Sultan Murad III and had him spent enormous resources.

As a polymath, Taqī al-Dīn wrote numerous books on astronomy, mathematics, mechanics, and theology. His method of finding coordinates of stars were reportedly so precise that he got better measurements than of his contemporaries, Tycho Brahe and Nicolas Copernicus. Brahe is also thought to have been aware of al-Dīn's work. Al-Dīn also described a steam turbine with the practical application of rotating a spit in 1551. He worked on and created astronomical clocks for his observatory. Al-Dīn also wrote a book on optics, in which he determined the light emitted from objects, proved the Law of Reflection observationally, and worked on refraction.

Water Power
In 1551 Taqī al-Dīn described a self-rotating spit that is important in the history of the steam turbine. In Al-Turuq al-samiyya fi al-alat al-ruhaniyya (The Sublime Methods of Spiritual Machines) al-Dīn describes this machine as well as some practical applications for it. The spit is rotated by directing steam into the vanes which then turns the wheel at the end of the axel. Al-Dīn also described four water raising machines. The first two are animal driven water pumps. The third and fourth are both driven by a paddle wheel. The third is a slot-rod pump while the fourth is a six-cylinder pump. The vertical pistons of the final machine are operated by cams and trip-hammers, run by the paddle wheel. The descriptions of these machines predates many of the more modern engines. The screw pump, for example, that al-Dīn describes predates Agricola, whose description of the rag and chain pump was published in 1556. The two pump engine, which was first described by al-Jazarī, was also the basis of the steam engine.

Optics
Taqī al-Dīn, being an astronomer, was very familiar with optics and the behavior of light. From this he wrote a book called Takîyüddîn'in Optik Kitabi or Taqī al-Dīn's Book of Optics. This book is written in three chapters. The first deals with the nature of vision, the second with reflection and then concludes with an understanding of refraction. He made a special note that his book was based on experimental evidence rather than being a conclusion drawn of previous works of literature. He also made a note that light is the same from all sources, contradicting Ibn al-Haytham.

Sight
In the early Greek world there were two competing ideas of sight. One that rays emanated from the eyes onto an object and another that and object emanated light and our eyes only observed it. Both sides had their champions, however Taqī al-Dīn was able to show experimentally that light emanates from an object and is then collected by our eyes. Al-Dīn argued that light would take too long to travel between us and the heavens to see the sphere that held the stars. Since we can see the stars at night without any delay it is clear that light comes from them and not from something we produce. From this he also argued that the color of the light is thus contained within the light of the object. He also argued that while light, emanating from a single point, may travel outward in a sphere the individual rays of light travel in straight lines. Finally he showed that the color of an object was produced by the reflection and refraction properties of an object.

Reflection
Reflection itself was nothing new to the Islamic world and had been figured out for quite some time. However, any optics book that left out a section of reflective surfaces would be considered lacking. To this effect al-Dīn included a section on it. He noted that rays of light being reflected off a mirror will propagate is a spherical form. As such, reflections of rays are a geometrical problem. He also found that the incident ray, the reflected ray and the normal all lie in the same plane. Al-Dīn also provided observational evidence to the Law of Reflection, that is the angle of incidence and the angle of reflection are the same. The rays of light being emitted were also found to have the same color as the reflective surface.

Refraction
Like reflection, refraction had been known about for some time. It was, however, a much more complicated problem that required further work. It was known that refracted light propagates in a spherical shell as much as reflected light does and that it also takes on the color of the material through which it is traveling. It was also known that if a ray of light is traveling and goes from one medium to another that its angle will bend in a manner related to the density of the two materials. Like reflections the incident ray, the refracted ray and the normal all lie in the same place however the angle of refraction is always less than the angle of incidence. The only exceptions to this are perpendicular rays which do not refract. Taqī al-Dīn did discover though that “the difference between the refraction angles of different incident rays is less than the difference between the angles of incidence.” He also noted that the ratio of incident angle to refraction angle of the larger incident is greater than the same ratio for the smaller incident. These are pretty much still our modern rules for optics and Taqī al-Dīn even tried to formulate Snell’s law although he was unsuccessful.