Monday, April 19, 2010

The Great Astronomer - Muhammad Taragay Ulugbek

The post office of Uzbekistan has issued two stamps celebrating the 615th anniversary of Ulubek's birth to coincide with the International Year of Astronomy.The two stamps are separated by a label featuring the IYA 2009 logo. The 350 Soum  stamp features the Ulugbek Observatory in Samarkand while the 750 Soum stamp has a statue depicting the great astronomer, mathematician and statesmen Muhammad Taragay Ulugbek.

Stamps commemorating the
Ulugbek Observatory in Samarkand.
Among his many accomplishments, he was the creator of a number of astronomical catalogues and tables, defining the location of thousands of planets and stars, which even today astound scientists with their accuracy.

Ulugbek was an outstanding scholar of his time and a grandson of the great Аmir Timur. He was born on March 22, 1394 in Sultania, in today's Azerbaijan. The young scholar was brought up by his grandmother, the first wife of Timur, Saray Mulkkhanim and from an early age he displayed a great thirst for knowledge. He was also tutored in theory of music and poetry and had an exceptional memory.

After the Great Amir Timur’s death in February 1405, a struggle for power started among his sons that lasted almost for 5 years. Eventually Ulubek's father, Shahrukh gained power. He made Herat his residence and gave his eldest son Ulugbek Samarkand in 1409 and then the whole of Maveraunnakhr in 1411 to govern.

With an advent of a clever and educated ruler rising to power, Samarkand soon became a major centre for scholarship and intellectual pursuit. During the years 1417-1420 he erected the first madrasah in the Registan (square) where many great oriental scholars of the age lectured. He also built two other important madrasah’s in Gijduvan and Bukhara. The inscription on the entrance portal of Ulugbek’s madrasah in Bukhara proclaims: “It is the sacred duty of every Muslim man and woman to seek after knowledge”

His major passion was for astronomy and he made the construction of a great observatory in Samarkand a key priority. His magnificent three-level observatory was completed by 1428-1429. It was a unique building of its time, built in the stony foothills of the Kuhak hills as they were believed to be more earthquake resistant. The observatory was a round three-storey building with a height of 30.4 m. At the base of the observatory was set in place the azimuth quadrant with a radius of 40.212 meters and arc length of 63 meters. The main instrument its massive sextant was orientated to the meridian line from the south to the north. Other astronomical instruments were also kept in the top levels of the observatory. The size of the sextant, its almost perfect construction and the scientific knowledge of Ulugbek and his fellow scientist-astronomers Qazi-Zadeh Rumi, Djemsnid Giyas ad-Din Kashi, Giyasaddin Jamshid, Ali Kushji, Muhhamad Havofi and others made for much more accurate astronomical observations than any until that time been performed.

The Samarkand observatory became famous after it published the "Ulugbeg Zidj" (Catalogue of the Stars) containing a theoretical introduction and astronomical charts describing 1,018 stars. This was the first such major publication since that of the ancient Greek astronomer Gipparkh (190-126 BC).

This astronomical catalogue of the celestial sky is still considered as one of the greatest historical contributions to the science of astronomy. Besides this, he wrote two other great works, one on the definition of ecliptic movement to the equator and the other on the measurements of the stellar year carried out in the observatory. He determined that the length of the stellar year to be equal to 365 days 6 hours 10 minutes and 8 seconds. Today with all our advanced technology we now known that the star year is equal to 365 days, 6 hours, 9 minutes and 9.6 seconds. Amazingly only a 61.6 seconds difference.

Ulugbek as he got older spent more and more of his time in the observatory and paid less and less attention to government affairs. His eldest son, Abd al-Latif, fell under the influence of a radical religious group (ED: nothing is new sadly) and on a pilgrimage to Mecca, Ulugbek was deceitfully beheaded with Abd-al-Latif’s connivance.After the tragic death of Ulugbek, these same religious fanatics provoked the destruction of his great observatory. The scholars, who worked in this famous scientific centre fled or were killed and the valuable library was plundered. The main building housing the observatory was also destroyed and by the end of the XVII century very little remained of the observatory.

Its location stayed unknown for a long time and it was only in 1908, did the famous Samarkand archaeologist V.L.Vyatkin find the ruins by studying old documents. He excavated the underground remains of the huge quadrant (40m in radius) which was used for the observation of the Sun, Moon and other celestial bodies and restored it to allow people to see this a great achievement of Ulugbeg.

Though he was unable to complete his work, Ali Kushji, a devoted follower of Ulugbek was able to escape Samarkand in time and took his famous catalogue of the stars to Europe where upon  Ulugbek’s name and his scientific achievements became well known. His catalogue of the stars became the most accurate astronomical guide right up until the invention of telescope. The important astronomical tome “The Catalogue of stellar sky” was published during the XVII century in Europe by the Dutchman Jan Geveliy was decorated with beautiful engravings, one of which depicts a symbolic meeting of the greatest astronomers who lived in different countries at different times Ulugbek among them. The inscription over the image of Ulugbek states "I have presented my case seriously" - where Ulugbek stands on the right arm of the goddess of astronomy, Urania.


1 comment:

  1. Ulugh Beg (Chaghatay/Persian: (میرزا محمد طارق بن شاهرخ (الغبیگ Mīrzā Muhammad Tāriq ibn Shāhrukh (Ulugh Beg) - also Uluğ Bey, Ulugh Bek and Ulug Bek) (c. 1393 or 1394 in Sultaniyeh – October 27, 1449).

    His commonly-known name is not truly a personal name, but rather a moniker, which can be loosely translated as "Great Ruler" or "Patriarch Ruler" and was the Turkic equivalent of Timur's Perso-Arabic title Amīr-e Kabīr. His real name was Mīrzā Mohammad Tāregh bin Shāhrokh.

    Ulugh Beg was a Timurid ruler as well as one of Islam's greatest astronomers during the Middle Ages. He was also notable for his work in astronomy-related mathematics, such as trigonometry and spherical geometry. He built the great observatory in Samarkand between 1424 and 1429.

    At sixteen-year-old Ulugh Beg became the shah's governor in Samarkand in 1409. In 1411, he became the sovereign ruler of the whole Mavarannahr khanate. The teenaged ruler set out to turn the city into an intellectual center for the empire. Between 1417 and 1420, he built a madrasa ("university" or "institute") on Registan Square in Samarkand, and he invited numerous Islamic astronomers and mathematicians to study there. The madrasa building still survives. Ulugh Beg's most famous pupil in mathematics was Ghiyath al-Kashi (approximately 1370-1429).

    His own particular interests concentrated on astronomy, and, in 1428, he built an enormous observatory, called the Gurkhani Zij, similar to Tycho Brahe's later Uraniborg as well as Taqi al-Din's observatory in Constantinople. Lacking telescopes to work with, he increased his accuracy by increasing the length of his sextant; the so-called Fakhri sextant had a radius of about 36 meters (118 ft) and the optical separability of 180" (seconds of arc).

    Using it, he compiled the 1437 Zij-i-Sultani of 994 stars, generally considered[who?] the greatest star catalogue between those of Ptolemy and Brahe, a work that stands alongside Abd al-Rahman al-Sufi's Book of Fixed Stars. The serious errors which he found in previous Arabian star catalogues (many of which had simply updated Ptolemy's work, adding the effect of precession to the longitudes) induced him to re-determine the positions of 992 fixed stars, to which he added 27 stars from Abd al-Rahman al-Sufi's catalogue Book of Fixed Stars from the year 964, which were too far south for observation from Samarkand.

    This catalogue, one of the most original of the Middle Ages, was first edited by Thomas Hyde at Oxford in 1665 under the title Tabulae longitudinis et latitudinis stellarum fixarum ex observatione Ulugbeighi and reprinted in 1767 by G. Sharpe. More recent editions are those by Francis Baily in 1843 in vol. xiii of the Memoirs of the Royal Astronomical Society and by Edward Ball Knobel in Ulugh Beg's Catalogue of Stars, Revised from all Persian Manuscripts Existing in Great Britain, with a Vocabulary of Persian and Arabic Words (1917).

    In 1437, Ulugh Beg determined the length of the sidereal year as 365.2570370...d = 365d 6h 10m 8s (an error +58s). In his measurements within many years he used a 50 m high gnomon. This value was improved by 28s in 1525 by Nicolaus Copernicus, who appealed to the estimation of Thabit ibn Qurra (826-901), which was accurate to +2s. However, Beg later measured another more precise value as 365d 5h 49m 15s, which has an error of +25s, making it more accurate than Copernicus' estimate which had an error of +30s. Beg also determined the Earth's axial tilt as 23.52 degrees, which remains the most accurate measurement to date. It was more accurate than later measurements by Copernicus and Tycho Brahe, and matches the currently accepted value precisely.

    Ulugh Beg also was a fine mathematician he wrote accurate trigonometric tables of sine and tangent values correct to at least eight decimal places.

    From Wikipedia