During the 12th and 13th centuries, Persia witnessed significant advancements in the development of timekeeping instruments. The specialized field associated with this knowledge was known as Ilm al-Miqat, the science of time measurement, which played a crucial role in determining accurate prayer times. Given that Muslims are obligated to perform the five daily prayers at specific times, this discipline became an essential aspect of Islamic astronomy.

Scholars who mastered this field, known as Muwaqqits, were responsible for preparing mathematical tables that provided precise prayer timings for different regions. These tables were carefully calculated based on solar and lunar positions, ensuring that the prayer schedules were accurate according to the geographical location of each community. The development of astronomical instruments and tables for timekeeping in Persia not only enhanced religious observances but also contributed to the broader advancements in Islamic astronomy and mathematics.

Nasir al-Din al-Tusi and His Astronomical Research

One of the most significant astronomical research centers in the Eurasian world during the medieval period was the Maragheh Observatory, established in the 13th century in Iran. This institution was led by the renowned astronomer, mathematician, and philosopher Nasir al-Din al-Tusi (1201–1274 CE).

Al-Tusi was a polymath with expertise in astronomy, medicine, philosophy, logic, and mathematics. He wrote over 150 books in both Persian and Arabic, integrating new discoveries with classical Greek works on mathematics, astronomy, and philosophy. He gained widespread fame under the title of “Khajeh” (Master), and his reputation quickly spread from Baghdad to China. The famous historian Ibn Khaldun later recognized him as one of the greatest Persian scholars of all time.

For twenty-five years, Al-Tusi was actively engaged in scientific research and writing under the rule of Nasir al-Din Mu‘attasim, the leader of the Nizari Ismaili state in Alamut. His life coincided with the Mongol invasions, which were reshaping the political and intellectual landscape of the region. When Hulagu Khan, the grandson of Genghis Khan, led the Mongol conquest of Persia and Mesopotamia, he spared Al-Tusi due to his deep interest in astronomy. Recognizing his intellectual capabilities, Hulagu appointed him as the chief astronomer of his court and granted him patronage to establish an advanced observatory and research center in Maragheh.

Al-Tusi wrote his first astronomical treatise, Risalat al-Mu‘iniyya, in 1235 CE, designed as an introductory textbook for students of astronomy. In 1247 CE, he completed Tahrir al-Majisti, a detailed revision of Ptolemy’s Almagest, in which he corrected earlier errors and refined astronomical theories. His most significant astronomical work, completed in 1261 CE, was a comprehensive treatise on astronomy, which introduced a revolutionary concept later known as the Tusi Couple. This theory was later adopted and influenced European astronomers such as Copernicus and Regiomontanus.

Beyond theoretical investigations, Al-Tusi was deeply involved in observational astronomy. His work, A Brief Description of Star Distances, systematically documented stellar motions, celestial transformations, and planetary movements. The book contained thirty chapters, offering highly detailed insights into the structure of the Milky Way. It was only 350 years later, when Galileo made new observations of the Milky Way, that scholars fully recognized the depth and accuracy of Al-Tusi’s findings.

The Maragheh Observatory, under Al-Tusi’s leadership, became a world-renowned center for astronomical research. Equipped with a vast library housing over 40,000 books, it played a crucial role in preserving scientific knowledge following the Mongol destruction of Baghdad and Damascus. Under Hulagu Khan’s patronage, the Mongols invested heavily in the development of this scientific institution, making it one of the most advanced observatories of its time.

Al-Tusi’s contributions extended beyond astronomy. He wrote extensively on trigonometry, geometry, and arithmetic, making significant advancements in spherical and plane trigonometry. His work on mineralogy, titled Precious Minerals, also demonstrated his broad scientific curiosity, further cementing his legacy as one of the most influential scholars of the Islamic Golden Age.

The Golden Age of Islam: A Harbinger of European Renaissance

From the 5th century onward, Europe entered a period of intellectual decline, often referred to as the Dark Ages. The rediscovery of scientific knowledge and intellectual progress in the later centuries was largely catalyzed by the unparalleled scholarly endeavors of the Muslim world, spanning from the 7th to the 13th century. In the pre-Islamic era, astronomical knowledge remained fragmented across different civilizations. However, under the Abbasid Caliphs in Baghdad, this scattered knowledge was systematically compiled, translated into Arabic, critically analyzed, and expanded through new research. This intellectual revival led to groundbreaking discoveries in astronomy and the natural sciences.

A defining characteristic of Muslim scientific progress was its inclusive approach, embracing beneficial knowledge from all traditions while ensuring participation from scholars of diverse backgrounds. A study of Al-Andalus (Muslim Spain) reveals that Muslim, Christian, and Jewish scholars worked together in pursuit of knowledge, fostering an intellectual environment that transcended religious and cultural divisions. This period saw unprecedented advancements in astronomy, mathematics, medicine, and philosophy, contributing to the universalization of knowledge.

A major figure in the later development of astronomy was Nicolaus Copernicus (1473–1543 CE), whose seminal work De Revolutionibus directly acknowledged the influence of five Muslim scientists who shaped his understanding of celestial mechanics. These scholars—Al-Battani, Al-Zarqali, Ibn Rushd, Al-Bitruji, and Thabit ibn Qurra—played a crucial role in shaping the scientific revolution of early modern Europe.

Even today, the study of Islamic contributions to astronomy remains an active area of research in various Western universities. Understanding the origins of past intellectual advancements is essential for enabling future progress. By studying the light of knowledge that illuminated past civilizations, new scientific breakthroughs can continue to shape the intellectual landscape of the modern world.