Taqi al-Din ibn Ma'ruf (Ottoman: تقي الدين محمد بن معروف الشامي السعدي; English: Taqi al-Din) (14 June 1521 – 18 February 1585), an Ottoman Turkish polymath (hezarfen), astronomer, engineer, mathematician, and mechanical scientist.
One of the Ottomans' most important astronomers, Taqi al-Din was born on 14 June 1526 in Damascus and was raised in Egypt and Damascus. Taqi al-Din, who came to Istanbul in 1550, founded an observatory on the heights of Tophane in 1577 by the decree of Murad III. He made sine/tangent calculations available in the form of tables and produced 1,337 works, 841 of them in Turkish. As a result of irrational rumors, the observatory on the heights of Tophane was demolished by order of the Sultan (Murad III). A new observatory was founded only 300 years later, but this time too it fell victim to the 31 March uprising.
He lived at the same time as Kepler's teacher Tycho Brahe and made approximately the same observations. Because the observatory was demolished, his work came to an end. Kepler, on the other hand, using Brahe's observations, discovered the laws concerning the revolutions of the planets known as Kepler's laws.
Life
He was born in 1526 in Damascus as a member of a family of Turkic origin. The information that he was born in 1521 is incorrect. After his education he was appointed qadi of Tinnis. He gained fame through the observations he made during his qadiship. In 1571, after the death of Mustafa Çelebi, he was appointed chief astronomer of the court by Selim II. In 1574 he began observational work in the Galata Tower. With the support of Hoca Saadettin and Sokullu Mehmed Pasha and by the decree of Sultan Murad III, Taqi al-Din's Observatory, an observatory under the direction of Taqi al-Din, was founded on the heights of Tophane in 1577. In 1580 it was demolished by cannon fire.
Mathematics, astronomy, and trigonometric values
Taqi al-Din gave the definitions of sine, cosine, tangent, and cotangent, presented their proofs, and prepared their tables. By finding the angle of 23° 27' between the ecliptic and the equator as 23° 28' 40", with a difference of 1 minute 40 seconds, he calculated for the first time at that date the degree closest to reality and most accurate. Moreover, he began for the first time to use decimal fractions in astronomy in place of the sexagesimal fractions that had long been in use.
Optics
As an astronomer, Taqi al-Din was very familiar with optics and the study of the nature of light. From this work a book was born, the Kitab (Taqi al-Din's Book of Optics). He recorded that his work was based on experimental evidence and had no connection with the conclusions of earlier literary works, and he underlined that in each of the phenomena he investigated, light was the same.
Vision
In the earliest studies conducted on the Greeks in antiquity, different views about the nature of vision were opposed to one another. One spoke of rays emanating from the eye toward an object, while another stated that light emanated from objects and the eye merely observed. Both theories boasted of their supporters, but Taqi al-Din was able to observe experimentally that light comes from a body and is perceived by our eye. "Since we can see the stars at night without delay, it is clear that light comes from them and is not something we produce." From this he concluded that the color of light is therefore contained in the light of the object. He also claimed that light coming from a single point could move outward within a sphere, while individual light rays travel in straight lines. Finally, he showed that the color of an object results from the object's reflection and refraction properties.
Reflection
Although the concept of reflection was already known in the Arab world, Taqi al-Din investigated the subject a little further and noticed that light rays reflected from a mirror spread in different directions, taking a spherical shape. He also discovered that the incident ray, the reflected ray, and the normal ray are in the same plane. Furthermore, since the angle of incidence and the angle of reflection are the same, he provided demonstrative proof concerning the law of observation and the law of reflection. In the end he discovered that even emanating light rays have the same color as the reflecting surface.
Refraction
Like reflection, which had been discovered some time earlier, refraction had also been known for some time, and refracted light, just like reflected light, spreads within a spherical shell and takes on the color of the material through which it passes. It was also known that if a light ray goes back and forth from one medium to another, its angle would bend depending on the density of the two substances. As with reflections, the incident ray, the refracted ray, and the normal ray are in the same place, but the angle of refraction is always smaller than the angle of incidence. The only exception to this is vertical rays, which are not actually refracted. Nevertheless, Taqi al-Din discovered that "the difference between the refraction angles of different incident rays is less than the difference between their angles of incidence." He also noticed that the ratio of the angle of incidence to the angle of refraction for a large incidence is greater than the same ratio for a small incidence. These are almost our modern rules of optics, and although Taqi al-Din did not succeed, he even attempted to pioneer Snell's law.
Clock mechanics
Because of this intense demand for mechanical clocks, the Grand Vizier asked Taqi al-Din to make a clock that would show exactly when the call to prayer was recited. This would lead him to write, in 1563 CE, his first book on the making of mechanical clocks, titled "al-Kawakib al-Durriya fi Bengamat al-Dawriyya," which he used throughout his research at the short-lived observatory. He believed it would be advantageous to bring "a truly hermetic and distilled perception of the movement of the celestial bodies." To better understand how clocks work, Taqi al-Din, in addition to gaining access to the treasury of Semiz Ali Pasha, took the time to obtain information from many European clockmakers and to learn everything he could from the many clocks he possessed.
Types of clocks examined
Taqi al-Din examined three different types of the clocks in his Grand Vizier's treasury. These three were weight-driven, spring-driven, and driven by a lever escapement. He wrote about these three types of clocks, but he also made comments about pocket watches and astronomical ones. As Chief Astronomer, Taqi al-Din created a mechanical astronomical clock. This clock was made to allow more precise measurements at the Constantinople observatory. As stated above, the creation of this clock was considered one of the most important astronomical discoveries of the sixteenth century. Taqi al-Din made a mechanical clock with three dials showing the hours, minutes, and seconds, with each minute consisting of five seconds. After this clock, given that a large part of clockmaking in the Ottoman Empire was taken over by Europeans, it is not known whether Taqi al-Din's work on mechanical clocks continued.
Sources
- Turkish Wikipedia: tr.wikipedia.org
- English Wikipedia: en.wikipedia.org