Contributions of Historical Arabian and Egyptian Scientists on Astronomy

Contributions of Historic Arabian and Egyptian Scientists on Astronomy

Md. Wasim Aktar

Deptt. of Agril. Chemical substances, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, India.

Astronomy (‘Ilm al-Hay’ah) or the science of formation (i.e. of the heavens) deals with these kinds of items as the construction of the heavens, the range and configuration of the stars, the indicators of the zodiac, the distances of the stars, their size and their motions. It also specials with the compilation of planetary tables, the catalogue of stars for the making of calendars and equivalent tasks.

The Arabs took a keen interest in the review of heavens. They created this interest firstly, because they had once worshipped heavenly bodies, (one) and secondly, for the reason that the dwellers of the desert who often traveled at night in connection with trade, war and migration from a single put to another, uncovered the course of their journey with the support of the stars. The clear sky of the desert gave them a likelihood of producing exact observations. As a result there was some locally acquired knowledge of the fixed stars, the movements of the planets and the changes of the weather.

Right after the advent of Islam, the Muslims had to figure out the time of the prayers and the route of the Ka�bah to turn their faces in direction of it at the time of prayers. For this purpose it was essential to know the altitude of the sun and the latitudes and longitudes of all the areas the place the Muslims lived. The very same want arose for the orientation of the mosque. This gave a religious impetus to the study of astronomy and the allied subjects like as astronomical geography and mathematics. On the other hand, the Muslims, who the moment carried on flourishing trade all over the globe and occasionally launched Jihad, had to journey on the land and the sea. As an support to journey, navigation and meteorology, a by merchandise of navigation, they necessary star maps. The necessity of this sort of maps was also a bring about of their curiosity in astronomy.

There was a group of astronomers who believed in the affect of heavenly bodies on the terrestrial affairs, and the fate and future of human beings. According to them, the prognostication of sub-lunar events from the revolution of the heavens, the indicators of the zodiac in the ascendant and the movement of the planets was achievable. The science dealing with this sort of influences was termed as Astrology (’Ilm-Ahkam al-Nujum). Astrology, as a portion of astronomy, was studied and designed by ancient Babylonians. The research of this art or science was then created in Greece and Rome, a handful of centuries previously the opening of the Christian era. It was also cultivated in India, China and Egypt. From the 7th to the 13th century it was even more created by the Muslims and later on by the Europeans. In the 14th and the 15th centuries, the astrologers had great affect on the kings of the European countries. (2) The orthodox Muslims did not believe that in the impact of the heavenly bodies on fate or the future of human beings.

The regular study of astronomy and mathematics was begun at Baghdad in the 2nd half of the 8th century all through the reign of the 2nd ‘Abbasi Caliph Al-Mans�¼r. Just after that the patronage and generosity of other Muslim rulers, specifically of the seventh ��Abbasi Caliph Al-Ma’mun, furnished stimulation to the astronomical and mathematical researches of every type. Indian, Persian and Greek astronomical functions were translated into Arabic, and for creating the astronomical observations the observatories were established by the caliphs and personal persons at many places in the Muslim world. Astronomy was studied with terrific curiosity with the consequence that the quantity of Muslim astronomers raised surprisingly in a brief period of time, and by the end of the 10th century, a substantial selection of eminent Muslim astronomers gathered in Baghdad. In the 11th and the 12th centuries astronomy flourished in Muslim Spain exactly where a very good deal of artistic and authentic do the job on this branch of science was performed.

The Muslim scientists connected utmost significance to accuracy in observations and calculations, with out caring for the length of time required for it. Thus from time to time their astronomical researches prolonged for far more than forty years. Due to this want of accuracy the Muslims did not accept as these kinds of the astronomical tables or measurements of Ptolemy, a great Greek astronomer and mathematician. They only accepted his planetary concept just to give a foundation for astronomical exploration. They by themselves performed astronomical researches in Baghdad, Samarqand, Nishapur, Cordova, Damascus and Ray, and after creating a careful review of the heavens they not only corrected and amplified Ptolemy’s astronomical tables, but also compiled a range of new ones and drew up new star catalogues. On the foundation of clean observations, the Ptolemaic process was repeatedly criticized by the Muslim astronomers, particularly people of Spain.

The investigations on astronomy have been continued, and till the stop of the 11th century, nearly all the original and imaginative perform was performed by Muslims, and even the functions of non-Muslims were published in Arabic. Astronomy attained its highest in the 13th and 14th centuries. In the 12th century, the Christians and Jews started out the do the job of translation from Arabic into Latin and Hebrew, and commenced to conduct research in this subject. But till the end of the 13th century, no mathematical and astronomical function similar to that of the Muslims could be developed by the Christians or Jews. It is intriguing to note that in the 12th century, whilst Ptolemy’s astronomical work, Almagest, just after a thorough research and exploration, was subjected to serious criticism by Muslims especially those of Spain, the study of this work was begun in the Latin entire world.

Besides compiling the astronomical tables, the Muslims ready celestial globes on which the positions and magnitudes of the stars have been represented. The globe is of Greek origin, but because Ptolemy’s time there has been a steady enhancement on it. The Muslim scientists also wrote thorough books on astronomy and mathematics, and also composed treatises on numerous branches of this science.

The Muslim astronomers also prepared the star maps to protect the aged astronomical know-how, and to use them as an aid to journey, navigation and meteorology.

A good incentive for the research of astronomy arrived from an Indian astronomical get the job done referred to as Siddhanta which was introduced to the court of Baghdad by a Hindu named Kanka. Kanka met Yaâ€�qüb Ibn Tãriq in 767 who was a person of the biggest astronomers of his time. Ya’qüb Ibn Tãriq released him to the Caliph Al-Mansür.(3) Kanka showed the guide to the Caliph who ordered Muhammad Ibn Ibrahim Al-Fazãri to translate it into Arabic.(4) He also ordered that a perform based on Siddhanta must be composed, which could serve as a reference guide for the Arabs. Muhammad Ibn Ibrahim took this obligation and prepared a guide which was identified as by the astronomers as Sind Hind al-Kabir (the excellent Siddhanta). (5) It was utilized till the time of the Caliph Al-Ma’mun. Then Al-Khwãrizmi, who was a single of the biggest scientists, prepared a summary of this guide. He also compiled astronomical and trigonometrical tables according to the combined procedures of Indians, Persians and Greeks. These tables were revised by Maslamah al-Majriti (c. the 2nd fifty percent of the 10th century). They acquired so substantially recognition that they were used even in China. In the 12th century, the translation of these tables was manufactured into Latin. (five) Al-Khawarizmi glimpsed in his functions on astral motion and the force of attraction the law of universal gravitation.

The astronomer Ibrahim Ibn Habib al-Fazãri was the first Muslim who produced astrolabes. He composed a poem on astrology, and compiled a Zij (calendar) according to the Arab strategy. He also wrote on the use of astrolabes and on the armillary spheres. (six)

In 762-63 the Persian astronomer and engineer, Naubakht, collectively with Masha’ Allah (Latin Macellama, Macelarama, Messahala), built a survey ahead of the building of Baghdad. Masha’ Allah (d. 815 or 820) was one particular of the earliest astronomers and astrologers, who flourished underneath the Caliph Al-Mansür. (7) Naubakht (d. 776-77) was the author of a guide on astrological judgments entitled Kitäb al-Ahkam. (8)

Through the reign of the Caliph al-Ma’mun, the crucial function of translation of Ptolemy’s Almagest from Greek into Arabic was completed. The Caliph was incredibly anxious to get it translated accurately. It was translated a number of timed. Quite a few commentaries on it were created. Its summaries were also produced. The Minister Yahya Ibn Khalid Barmaki was the 1st to get it translated. A group of scholars wrote for him a commentary on this e-book, but he did not like it. He appointed Abu Hasan and Salman who had been attached to the scientific academy termed Bait al-Hikmah (The home of wisdom) to compose a commentary on it.(9) The Almagest represents the finest example of Greek classical works on astronomy. It served as a basis for the later astronomical performs. Al-Hajjaj Ibn-Yusuf was one of the first translators of the Almagest. He made this translation on the foundation of a Syriac edition. (ten)

The Caliph al-Ma’mun (169-218 / 786-833) was very fond of philosophy and science. The far more he received acquainted with the captivating troubles of science, the additional his curiosity grew in the practical operate. He constructed an observatory at Baghdad in his Bait al-Hikmah and yet another in the plain of Tadmor (Palmyra). In these observatories the fundamental elements of the Almagest like the inclination of the ecliptic, the length of the photo voltaic year, and the precession of the equinoxes had been verified. Observations on the celestial motions were carried out and geodetic measurements were made. (eleven)

Al-Ma�€™mun ordered Ahmed, Muhammad and Hasan, who have been eminent scientists and his courtiers, to measure in collaboration with other court scientists the duration of the terrestrial degree and the circumference’ of the earth in some huge planes. The planes of Sinjar and Tadmor had been selected for this intent. The astronomers stayed at a destination and mentioned with the guide of instruments the altitude of the North. Pole, and pitched a nail there. Then tying a lengthy rope with the nail, they carried the rope in the path of the North. Wherever the rope ended they pitched one more nail and tied an additional rope with it, and proceeded in the exact course. They continued this course of action as well as observations on the altitude of the North Pole, right until on reaching a distinct spot they noticed that the altitude of this Pole had enhanced by a single degree. The distance they covered was also measured, which was observed to be 56 2Ǚ miles. From, these observations it was inferred that for just about every terrestrial diploma the distance covered on the earth amounts to 56 2/3 miles. The exact same operation was repeated in the route of the South in which at one particular spot they discovered that the altitude had reduced by, one diploma. The distance covered was the exact same as in the first scenario. Now on multiplying this distance by 360 which is the total quantity of terrestrial degrees, the circumference of the earth was discovered to be equal to twenty,400 miles, and the diameter equal to 6,500 miles. (12)

The chief of astronomers who carried observations beneath al-Ma’mun was Sanad Ibn ‘Ali. He was a Jewish convert to Islam. He constructed an observatory (Kanisah) at the back again of the Shamãsiah Gate at the palace of Mu�€™izz al-Dawlah in Baghdad. An astronomical table and some writings on astronomy and mathematics, such as a guide on Arabic numerals, are ascribed to him. (13)

‘Ali Ibn ‘Isa al-Astur1ãbi who flourished in Baghdad and Damascus in the initial half of the 9th century, took portion in the measurement of the length of the terrestrial degree ordered by al-Ma’mun. He designed astronomical observations at Baghdad and Damascus from 829 to 833. He was the popular constructor of astrolabes; hence the nickname al-Asturlãbi (maker of astrolabe). He wrote a treatise on astrolabes, which is one particular of the earliest functions on this instrument. (14)

Yahya Ibn Abi Mansür also took element in the observations created at Baghdad in 829-30, and compiled the astronomical tables referred to as Ma’munic tables. Like the tables of Habash these, too, are a collective work of ‘various astronomers. Al-Marwarudhi, who also flourished below al-Ma���mun, created photo voltaic observations. (15)

In the 9th century astronomy flourished in the East, Astronomical researches had been performed in the observatories of Baghdad, Damascus and other spots. Much more unique and enhanced function was carried out in thełnd half of the 10th century. The elaboration of trigonometry, which was considered to be a branch of astronomy at that time, was also continued. A fantastic consideration was compensated to the construction of good astronomical instruments, especially to the spherical astrolabe which was freshly introduced at that time. Hamid Ibn ‘Ali was a famed constructor of spherical astrolabes. Jãbir Ibn Sinan was also a maker of this as nicely as of other astronomical instruments. According to al-Biruni, he was the first to make a spherical astrolabe. Al-Nairizi wrote on this instrument an elaborate treatise which represents the best Arabic work on this topic. In this treatise the writer, soon after giving the introduction, describes the instruments, and presents its applications. Beside this operate, al-Nairizi compiled astronomical tables. A excellent scientist al-Mähani made for 33 many years (833—886), a series of observations on lunar and photo voltaic eclipses and planetary conjunctions. Another astronomer of this time Ahmad al- Nahâwandi, who flourished at the time of Yahya Ibn Khalid Ibn Barmak, built astronomical observations at Jundishapur and compiled tables called Mushtamil. (16)

After carrying out astronomical observations for ten years (825 to 835) Habash al-Hãsib compiled three astronomical tables. The primary have been in accordance to the Hindu approach (centered on Siddhanta). The 2nd termed Al-Zij al-Mumtahan (the �€œtested Tables”) were in accordance to the Arab method. They were really crucial and had been likely due to the co-operative efforts of al-Ma’mun’s astronomers. The third named Al-Zij Al-Saghir (the tiny tables) was frequently known as the Tables of Shah. Habash al-Hãsib established the time of the photo voltaic eclipse of the yr 829. He was the very first to identify time by an altitude (in this case, of the sun). This technique was commonly accepted and adopted by Muslim astronomers. (17)

The most illustrious scholar of this age, and a person of the best astronomers of Islam, was ‘Abd Allah Muhammad Ibn Jãbir Ibn Sinan al-Battãni (Latin; Albategnius, Albatenius). His ancestors had been Sabeans of Harran, but he himself was a Muslim. He carried out astronomical observations of a huge range and with amazing accuracy for about 41 a long time (877—918). He decided several astronomical co-efficients, like the precession 54.5” a yr, inclination of the ecliptic 23° 35’, with terrific accuracy. He noticed an improve of 16° 47’ in the longitude of the sun’s apogee considering Ptolemy’s time. This led to the discovery of the motion of the solar apsides and of slow variation in the equation of time. Al-Battãni proved the likelihood of the annular eclipses of the sun. He also wrote several astrological works. His most important do the job is a huge astronomical treatise which include the astronomical tables. His tables include a catalogue of fixed stars for the year 880—81. His operate is an advance on that of al-Khwãrizmi, and exhibits additional divergence from Indian approaches. Observations about the initially physical appearance of the new moon, the length of the tropic and sidereal 12 months, the obliquity of the ecliptic, the lunar anomalies, the parallaxes, etc., are a lot more complicated and more accurately created by al-Battãni than by al-Khwãrizmi

Al-BattÃ�ni’s astronomical treatise was translated into Latin and Spanish in the 12th and 13th centuries respectively. It exerted a great influence on the European scholars of the middle Ages and Renaissance. (l8)

Thãbit Ibn Qurrah (d. 901) who was a physician, mathematician, astronomer and translator from Greek and Syriac into Arabic published his solar observations designed at Baghdad. He specially decided the altitude of the sun and the length of the solar year. (19)

The astronomer and mathematician Wijan Ibn Rustam al-Kühi wrote many astronomical and mathematical functions, such as a treatise on the development of the astrolabe. He was the head of the astronomers doing work in 988 at the Buwayhid Sharaf al-Dawlah’s observatory. (twenty) His co-employee Ahmad Ibn Muhammad al-Saghâni was the inventor and maker of astronomical instruments. Abu��l-Wafã is stated to be the discoverer of the variation, the third inequality of the moon; a discovery which was later ascribed to Tycho Brahe. (21)

‘Ali Ibn al-Husain al-’Alawi (d. 985) showed a impressive accuracy in observations. He compiled astronomical tables which remained incredibly well-liked for at least two centuries. (22)

Now we come to a renowned astronomer of the 10th century, named Abu’l-Husain ‘Abd al-Rahman al-Sufi. He was born in Ray (Persia) in 903, and died in 966. He was a notable astronomer of the medieval instances. His knowledge of both equally the Islamic and Greek astronomy, especially uranometry, was complete. He was the 1st to observe the switch of the colour of stars, the switch in the magnitude of stars, the proper motion of stars, the very long period variable stars and the Southern constellations which have been wrongly ascribed by modern day astronomers to some later ones.

Abd al-Rahman al-Sufi was patronized by the Buwayhid ruler Adud al-Dawlah (949—982) who was a terrific patron of astronomy, and had constructed an observatory at Shiraz. Al-Sufi wrote for the ruler a guide on uranometry, entitled Suwar al-Kawàkib (The book of the fixed stars). In this e-book he presents a full description of the constellations of the heavens. He also presents the placement of each and every star of the constellations, illustrating with photographs. The book includes 55 astronomical tables along with illustrations of 48 constellations in 96 diagrams as seen in the heavens. The creative worth of the pictorial illustrations in the Mss. of this do the job is incredibly good, and represents a single of the greatest examples of the Persian miniature paintings. Al-Sufi has not only corrected the errors of observations in the get the job done of his predecessors like al-Battãni, but also, pointed out quite a few faulty observations observed in Ptolemy’s Almagest. He defined very carefully the boundaries of every single constellation, and recorded the magnitudes and positions of stars immediately after producing new observations.

The Suwar al-Kawàkib is a person of the three masterpieces of observational astronomy of the medieval instances; the other two getting the catalogues of Ibn Yünus and Ulugh Beg prepared in the 12th and 15th centuries respectively. It is an addition to the Muslims’ knowledge on uranometry. The later astronomers, like al-Biruni, Alfonso, Prince of Castile, Khwãjah Näsir al-Din Tusi, Prince Ulugh Beg and Jai Singh II, centered their catalogues of stars on this authentic catalogue. This get the job done was translated into Latin, French and Persian, and a commentary on it was created in Spanish.

It served as a foundation for later functions in Western Europe. The contemporary astronomers like Hauber, Down, Argelander, Ideler, Schellerup and Knobel had produced an comprehensive use of it.

Al-Sufi ready a very good celestial globe. A number of celestial globes which cover the period from the 11th to the 18th century display the star positions and magnitudes according to al-Sufi. He showed a impressive accuracy in the design and style of the astrolabes. He wrote a treatise on this instrument. In this treatise he throws light on the astronomical tactics as practiced it that time. (23)

Yet another wonderful astronomer and one of the best Muslim astronomers was Abu’l-Hasan Ali Ibn Abi Mentioned ‘Abd al-Rahman Ibn Ahmad Ibn Yünus al-Sadafi, usually regarded as Ibn Yünus. He was very well versed in Arabic literature, poetry and background, and had understanding of many other subjects. He belonged to Egypt where by he died in 1009. He was a courtier of the Fatimi Caliph al-‘Aziz Billah (ᚏ—996). He obtained a opportunity of doing work in a effectively-outfitted observatory which was the aspect of a Muslim academy of science, named Dar al-Hikmah (the home of wisdom) founded in Cairo by the Fatimi rulers. He manufactured astronomical observations, and by the buy of the Caliph al-‘Aziz he compiled the astronomical tables. The get the job done of compilation of these tables was started in 990 through the lifetime of the Caliph, but it was completed right after his death underneath his son al- Hakim (966�€”뽼). Consequently they were named after him Al-Zij al-Kabir al-Hakimi. In these tables he entered his observations about the eclipses and conjunctions, aged and new, improved values of astronomical constants (inclination of the ecliptic, 23° 35’; longitude of the sun�€™s apogee, 86° 10’; solar parallax reduced from 3’ to 2�™ precession, 51.2�� a yr). He gave an account of the geodetic measurements which were carried on by the buy of the Caliph al-Ma’mun in the ninth century.

Ibn Yünus in his astronomical tables (written in four volumes) corrected the mistakes of observations in the astronomical tables of his predecessors. The folks of Egypt relied on these tables. It is explained that immediately after their compilation the use of all the preceding tables in the globe was given up. Even the astronomers of China considerably utilized them. The translation of a massive aspect of the tables, except the chronological part, has been built in French in 1804.

Beside these-tables, Ibn Yünus has composed a lot of books. One particular of these is Jadawil al-Samt (the tables of direction), and the other is the Jadawil al-Shams wa’l-Qamar (the tables of the sun and the moon). (24)

A well known astronomer of the 11th century, who belonged to Cordova (Spain), was Abu Ishaq Ibrahim Ibn Yahya al-Naqqàsh, generally recognized as Ibn al-Zarqàli or al-Zarqàli (Latin: Arzachel). He was also an eminent astronomer of this century. He lived from 1029 to 1087. He was the most effective observer of his time, who made astronomical observations for about 19 many years (1061—1080). He invented an improved astrolabe identified as Safihah (Saphaea Arzachelis) on which he also wrote a treatise. It was translated into Latin, Hebrew and many vernaculars. Al-Zarqàli was the first to show explicitly the movement of the photo voltaic apogee with reference to the stars. In accordance to his calculations it was equal to twelve.04” per year (the real value being 11.8”). He edited the planetary tables identified as Toledan Tables. These tables have been probably the end result of the observations built in Toledo by him and by a great observer Ibn Said in collaboration with other Muslim and Jewish astronomers. They had been translated into Latin and appreciated substantially fame. (25)

A renowned astronomer, mathematician and poet, ‘Umar Ibn al-Khayyãm, reformed the old Persian calendar which had been changed by the Islamic calendar immediately after the Muslim conquest of Persia. This reformed calendar was known as Al-Tàrikh al-Jalãli soon after the name of the Saljuq Sultan Malik Shah Jalal al-Din who in 1074-seventy five known as ‘Umar Ibn al-Khayyãm to his observatory for generating this reform. Many interpretations have been given to it. Every interpretation is exact to a sure degree, but at any price ‘Umar’s calendar was possibly much more precise than the Gregorian (Christian) calendar. Three interpretations, the second of which looks to be the most accurate, are currently being quoted here along with the authority giving the interpretation and the resulting error.

one. Al-Shirãzi’s interpretation: 17 intercalary days in 70 many years;’ error. one day in about 1540 years.

two. Ulugh Beg’s interpretation: 15 intercalary days in 62 a long time; error, 1 day in about 3770 years.

3. Modern interpretation: 8 intercalary days in 33 years: error, 1 day in about 5,000

(in the Gregorian calendar there is an error of one day in 3330 years). (26)

The greatest astronomer of the 12th century, who also belonged to Spain, was Abu Muhammad Jãbir Ibn Aflah. He was born or lived in Seville. He vigorously criticized the Ptolemaic concept of planets, and wrote a book on astronomy entitled Islah al-Majisti (the correction of the Almagest). He was of the see that the reduced planets Mercury and Venus), at least, will need to have visible parallaxes. Venus may possibly come about to be precisely on the line joining the sun and the earth. The most essential component of his guide is the introduction on trigonometry. The guide was quickly translated into Latin and Hebrew. Jãbir Ibn Aflah is said to be the inventor of the astronomical instrument identified as turquet (torquetum) which contains two graduated circles in two perpendicular planes. The identical invention has also been ascribed to two other individuals, namely, Frances of Leige (11th century) and Näsir al-Din Tusi (13th century). The turquet was introduced into the Latin West by Regionomentus. It obtained a great recognition in the 15th and 17th centuries. (27)

One more astronomer of the time was Abu’l Qãsim Hibat Allah Ibn Husain al-Badi’ al-Asturlãbi. He was also a physician, mathematician, poet and litterateur. He was the greatest specialist of his time in the expertise and building of astrolabes; consequently his nickname al-Asturlãbi. In 1120—30 astronomical observations were designed beneath his path, and astronomical tables had been compiled. The observations had been carried out in the palace of the Saljuq Sultan of Iran, Mughith al-Din Mahmud (1117—1131). The tables were devoted to the Sultan, and had been called just after him the Mahmudic tables. Al-Asturlãbi was extremely significantly praised by Muslim biographers. He died in Baghdad in 1139-forty. (28)

In the 13th century there flourished in the East a good scholar of Persian origin, named Abu Ja’far Muhammad Ibn Muhammad Ibn al-Hasan, Näsir al-Din al-Tusi al-Muhaqqiq, (the researcher). He was born in Tus (Khurasan) in 1201, and died in Baghdad in 1274. He was a philosopher, mathematician, astronomer and physician. He was a single of the biggest Muslim mathematicians and scientists. He wrote the two in Arabic and Persian. It is explained that he knew Greek as properly. He joined the Mongol service, and was later produced administrator of the Waqf revenues.

Though he was administrator he resided at Maragha in Asia Small (1259—1274). Right here he built astronomical observations in an observatory established by the Mongol ruler Hulagu Khan II right after he had defeated the previous ‘Abbasi Caliph, al-Mu’tasim, in 1258. A library was connected to it. It is said to have contained 4, 00,000 volumes which the Mongol armies had collected in Syria, Mesopotamia and Persia. Näsir al-Din was the primary director of this observatory. He was succeeded by two of his sons.

Näsir al-Din was well acquainted with the information of the Greeks. He wrote about 64 performs on quite a few topics. Here we shall, take into account only some of his astronomical and astrological performs. The most significant astronomical work of Näsir al-Din is the Tadhkirah fi â€�Ilm al-Hay’ah (The description of astronomy) which is a condensed summary of astronomy. To make clear it numerous commentaries and super commentaries have been written. The do the job loved a lot reputation, it is made up of four chapters. The 2nd chapter, beside other points, incorporates interesting criticism of the Ptolemy’s Almagest in which he showed a fantastic ingenuity. The criticism chiefly considerations the anomalies of the moon, and the movement in the latitude of the planets (especially Mercury and Venus) also the proposition of a new system to change the complex Ptolemaic machinery of deferents and epicycles. His new and forceful criticism of astronomy as properly as of other Muslim astronomers assisted Copernicus in producing his reform’. Näsir al-Din wrote one particular treatise on the five quadrants and two treatises on astrolabe. He also wrote two treatises on calendar.

Näsir al-Din created observations in the observatory at Maragha which was nicely outfitted with fantastic astronomical instruments. He prepared new astronomical tables called immediately after the Mongol ruler, Al-Zij al-Ilkhäni. Nasir al-Din asked the ruler to give him a period of 30 years to compile the tables, for the reason that it was the shortest period during which the planetary cycles have been finished. But the ruler refused, and gave him only twelve many years to accomplish this project. Nasir al-Din tried a succeeded in completing the tables within this time. They had been primarily based upon new observations. But the use of the earlier ones had also been manufactured.

The Zij-i- Ilkhäni was originally published in Persian. It is made up of four books dealing respectively with (a) Chinese, Greek, Arabic and Persian Chronology; (b) motions of the planets; (c) ephemeredes and (d) astrological operations. The translation of the Zij was created into Arabic, and commentaries on it had been written. Last but not least, a type of supplement to it was compiled by Jamshed Ibn Mas’üd al-Käshi (d. 840񳆌), the 1st director of Ulugh Beg’s observatory in Samarqand. These tables enjoyed a great popularity in the East such as China, and were, continued to be used even just after the compilation of new tables by Ulugh Beg in 1437. (29)

A modern of Nasir al-Din, Mu’ayyid al-Din al-Urdi al-Dimashqi also took part with him in compiling the tables. He was a Syrian astronomer, architect and engineer. He started off his career as a technician in Syria. He did some hydraulic function in Damascus, and also built there an astronomical instrument for al-Mansür Ibrahim (King of Hims, 1239—1245). In about 1259 he went to Maragha, and assisted Nasir al-Din in organizing the observatory and compiling the tables. It appears that the instruments, remarkably precise, have been built underneath his supervision in the foundry attached to the observatory.

Al-Urdi was the author of a treatise in which he also described the instruments put to use in the observatory of Maragha, and explained their use and construction. The instruments are as follows:�€”

(1) mural quadrant (two) armillary sphere (three) solstitial armil (four) equinoctial armil (five) Hipparch’s diopter (alidade); (six) instrument with two quadrants (7) instrument with two limbs (eight) instruments to figure out sines and azimuths (9) instruments to ascertain sines and versed sines, (ten) the perfect instrument (a universal instrument) (eleven) parallactic ruler (soon after Ptolemy).

Al-Urdi was also the writer of two other treatises; one on the building of a excellent sphere and an additional on the dedication of the distance in between the centre of the sun and the apogee. He compiled astronomical tables, and wrote on Ptolemaic astronomy.

In 1279 or 1289 al-Urdi’s son Muhammad built a celestial globe. It consisted of two brass hemispheres separated by the ecliptic. Its diameter was 140 mm. It had a horizon circle. Two movable 50 percent circles had been connected to the zenith level by a pivot. These circles are graduated and are employed to ascertain the declination and appropriate ascension of any star. Forty-8 constellations, the equator and the ecliptic are inlaid with silver or gold. It is preserved in the mathematical salon of Dresden. (30)

The functions of Muslim astronomers had been later translated into Latin, Hebrew and vernaculars by the Christian and Jewish scholars, some of the technical terms including azimuth (al-Samt), Algol (Alfol), Achernar (Akhir al-Nahr), passed into the European languages. The names of a lot of stars these as akrab (Aqrab), Algedi (al-Jadi, the kid), Altair (al-ta’ir ,the player), Denab (dhanb, tail), Pherkad (Farqad, calf), Adara (‘Adhrah) Aldebaran (al-dibràn), which are of Arabic origin, also handed into these languages. The stars currently being numerous in number, their separate examine is not probable. They were, for that reason, divided into a variety of groups, and the groups were named just after the factors and animals with which they resembled.

REFERENCES :-

one. Briffault, Robert , The Making of’ Humanity, Lahore, 1980, p. 1ȷ.

two. Encyclopedia Britannica, London, Vol. II, p.575.

3. Abu’l Hasan Ali Ibn Yusuf , Al-Qifti , Tàrikh al-Hikmah,’ Leipzig, 1ᙇ, p. 265.

Sarton, George, Introduction to the Background of Science, Washington 1927, vol. I. p. 530.

four. Ibid.

5. Ibid, p. 563.

six. Al-Qifti, op. cit.,ಹ.

7. Ibid., p. 327.

Sarton, op. cit. p. 531.

eight. Ibid.

9. Ibid. p. 557.

Haji Khalifah, Kashf al-Zunün, Istanbul, 1943, vol. II, p. 1594.

10. Sarton, op. cit., p. 562.

11. Ibid, p. 558.

12. Shibli Nu’mani, Al-Ma’mun, Agra, 1894, pp. 49— 50,

13. Ibn Nadeem, Al-Fehrist, Matba’ah al-Rahmaniyah, Cairo, n.d.. p. 383.

14. Shibli Nu�™mani, op. cit. pp. 49—50

Sarton, op. cit. p. 566.

15. Ibid.

sixteen. Sarton, op. cit.. p.罉.

17. Al-Qifti, op. cit. p. 170.

18. Ibid, p. 280.

Sarton, op. cit. p. 5858.

19. Ibid., p. 599.

twenty. Al-Qifti, op. cit. p. 351.

21. Sarton, op. cit. p. 666.

22. Ibid.

23. A1-Süfi, ‘Abd al-Rahman, Swar al-Kawàkib, Hyderabad, preface by M. Nizamuddin, and J.J. Winter, pp. 1-7.

24. Al-Qifti, op. cit., p. 226.

25. A1-Qifti, op. cit., p. 2Ǿ.

26. Sarton, op. cit., p. 758,

27 Ibid., p.759

28. Ibid, vol. II, component I, p. 206.

29. Ibid., portion I, p. 204.

30. Al-Baghdadi, Isma’il Bãshã, Hadiyyat al-‘Arifin, Istanbul, 1951, vol. II, p. 131.

31. Sarton, op. cit. vol. II, portion II, p. 1005.

32. Ibid., pp. 1013-1014.

Related posts

• What sensible value did astronomy give to historical civilizations? It helped them uncover employs for historic stru? (7)
• how would i submit a concept to an astronomy researchers community ? (14)
• How is our astronomy that we know right now related to the ancient greek a person (with gods and rulers)? (5)
• Historic Astronomy – where on the World wide web can I locate out the names,mythology,and skymaps of historic Egypt? (11)
• You Can Foster a Like of Astronomy (0)

This entry was posted on Monday, January 24th, 2011 at 2:00 am and is filed under About Astronomy. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.