Central Asia and Iran were renowned centres of advances in science and technology.

The field we are discussing today is astronomy.

As early as the 13th century an observatory was established in Maragheh  (Iran) by Nasir al-Din al-Tusi. This observatory was known for its innovative instruments and research in both astronomy and mathematics. It played a crucial role in advancing our understanding of planetary motion.

Ulugh Beg’s Observatory, was the next significant step. This astronomical observatory built in the 15th century in Samarqand, Uzbekistan. It was established by the Timurid ruler and astronomer Ulugh Beg (1394-1449) who ruled from 1411-49).

The observatory’s advancements in observational astronomy contributed to the understanding of celestial movements during that era.

Babur has commented on the observatory in his memoirs: “Another of Aūlūgh Beg Mīrzā’s fine buildings is an observatory, that is, an instrument for writing Astronomical Tables. This stands three storeys high, on the skirt of the Kohik upland. By its means the Mīrzā worked out the Kūrkāni Tables, now used all over the world.”

This observatory is now in ruins only one instrument remains.

This is the large marble sextant, also known as the “Fakhri Sextant.” This impressive instrument was used to observe celestial objects and make accurate measurements in astronomy. It had radius of 40 meters used to measure the elevation of the Sun, Moon and stars.

It was used to make precise measurements of star positions and compile a comprehensive star catalog. This catalog, known as the “Zij-i Sultani,” contained the positions of over 1,000 stars and remained a vital astronomical reference for centuries. it was copied more than a hundred times, translated into Arabic and Turkish, and parts of it were translated into Latin and published in Oxford and London in the mid 17th century.

“The basis of the trigonometric tables of the Sultānī Zīj is the very accurate calculation of the sine of 1°, which Ulugh Beg Ghiyāth al-Dīn Jamshid al-Kāshī, the senior astronomer of the observatory, calculated using new procedures to sixteen decimal places. His work the Key to Arithmetic is one of the best treatises written about arithmetic in the Middle Ages.”

https://www3.astronomicalheritage.net/index.php/show-entity?idunescowhc=603

The three astronomers  responsible for creating the  Zij were al-Rumi, al-Kashi, and Ali al-Qushji (1403-1474).

al-Qushji was born in Samarkand and was initially a student at the madrassa. After completing his studies, he moved to Persia for research purposes and produced his treatise Explanations of the Periods of the Moon. Ulugh Beg immediately appointed him as an astronomer at the observatory after reading his work. After Ulugh Beg’s death, al-Qushji left Samarqand for Tabriz where he worked under the Akkoyunlu Ruler Uzun Hasan. He spent the last two years of his life working for the Ottoman emperor Sultan Muhammad II in Istanbul. The preface of Zij-i Sultani also highlights the contributions of these three astronomers:

The work was started jointly with the aid of Qadizada-i Rumi . . . and Giyath al Din Jamshid . . . At the initial stage of the work . . . Giyath al Din Jamshid . . . passed away . . Thereafter the work was completed by Ali ibn Muhammad Qushji.”

1. Ali Qushji (Turkey): An Ottoman-Turkish astronomer, Qushji studied under Ulugh Beg and later worked at the Samarkand Observatory. He made contributions to planetary theory and Islamic mathematics.
2. Al-Kashi, whose full name was Ghiyath al-Din Jamshid Mas’ud al-Kashi, was a prominent Uzbek astronomer and mathematician from the 15th century. He made significant contributions to various fields, including trigonometry and astronomy. Al-Kashi is best known for his accurate calculations of trigonometric values and his work on spherical geometry. His most notable work, “Zij-i Ilkhani,” was a comprehensive astronomical tables that included detailed calculations of planetary positions and eclipses. His contributions played a vital role in advancing the understanding of astronomy during his time.
3. Al Rumi was a Turkish astronomer and mathematician who  computed sin 1° to an accuracy of 10is to the power of 12

The sextant

The sextant “Samrat Yantra” in Jantar Mantar Delhi built between 1724 and 1730 A.D. ,  a massive sundial that was used to measure the time of day with high accuracy is similar to it. Sawai Raja Jai Singh II had got Ulugh Beg’s Zij e Sultani/ Ulugh Begi,  translated into Sanskrit along with other astronomical works while building his 5 observatories in India.

Sawai Raja Jai Singh II also prepared tables called Zij e Mohammad Shahi to bring Zij e Sultani   up to date, for in the 297 hijri years that separated the two rulers the observed position of the “fixed” stars had changed.

Both the observatories had some similarities but it’s important to note that there are also significant differences between the two observatories in terms of their specific instruments, architectural styles, and historical contexts.

Apart from the  suds-i fakhri , the colossal meridian arc or sextant that ran through the observatory’s center, and was   placed on a north-south axis, the other instruments now lost to us would have been the I’tidal, or solar clock, made up of a wall with a concave profile. It was built on an east-west axis, perpendicular to the suds-i Fakhri so that the sextant functioned as the clock’s gnomon. The third instrument was the ustuvan, which was a rotating quadrant sector.

The decline of Ulugh Beg’s Observatory can be attributed to several factors: mainly the political instability that followed his assassination by his son. The observatory was destroyed and talented scientests and astronomers driven away.

It lay in oblivion till 1908 and no one knew its exact location till it  was rediscovered by the Russian archaeologist Vassily Vyatkin. Only its foundations and bits of the suds-i Fakhri (more specifically, the underground part of the instrument), remained. 

Vyatkin is buried at the site, according to his wishes.

Some instruments and books that would have been used in the observatory.

Ulugh Beg’s astronomical knowledge had a lasting impact on modern science in several ways:

1. Star Catalog: Ulugh Beg’s observatory produced a comprehensive star catalog known as the “Zij-i Sultani.” This catalog contained accurate positions of over 1,000 stars. Although not perfect by today’s standards, it was an impressive achievement for its time and served as a reference for later astronomers.

2. Advancements in Observational Techniques: Ulugh Beg’s observatory pioneered advanced observational techniques and instruments. His large marble sextant allowed for precise measurements of star positions. These techniques laid the foundation for modern methods of celestial observation.

3. Data Preservation: The star catalog and observations made at the observatory contributed to the preservation of astronomical knowledge. Even though the observatory’s activities declined, its records continued to be studied and referenced by later generations of astronomers.

4. Inspiration for Future Astronomers: Ulugh Beg’s observatory inspired subsequent generations of astronomers to explore the skies. The observatory’s legacy encouraged the pursuit of observational and mathematical astronomy.

5. Historical Context: The observatory’s existence highlighted the scientific achievements of the Timurid Empire and the importance of astronomy in their culture. It offers valuable insights into the history of science and its connections to different cultures and civilizations.

6. Comparison with Modern Data: While the observational data collected by Ulugh Beg is not directly comparable to modern astronomical data, it can still provide valuable insights into the changes in celestial positions and movements over time. This aids in understanding long-term cosmic patterns.

7. Cultural and Educational Impact: The observatory’s legacy contributes to cultural and educational initiatives that emphasize the historical importance of astronomy. It serves as a reminder of the contributions of past civilizations to scientific progress.

Ulugh Beg, wrote several books. Some of his notable works include:

1. “Zij-i Sultani”: This is Ulugh Beg’s most famous work, often referred to as his magnum opus. It is an astronomical treatise and star catalog that contains precise measurements of the positions of over 1,000 stars. The catalog was used for centuries as a reference by astronomers.

2. “Zij-i Gurkani”: Also known as the “Tables of the Khan,” this work is an expanded version of the “Zij-i Sultani.” It includes additional calculations and data, covering topics like planetary motion and eclipses.

The front of the museum in the observatory

What the observatory would have looked like

The back of the museum building