Archive for August, 2011
Contributions Of Ancient Arabian And Egyptian Scientists On Astronomy
Md. Wasim Aktar
Deptt. of Agril. Chemicals Bidhan Chandra Krishi Viswavidyalaya Mohanpur Nadia West Bengal India.
Astronomy Ilm alHayah or the science of formation i.e. of the heavens deals with such things as the structure of the heavens the number and configuration of the stars the signs of the zodiac the distances of the stars their size and their motions. It also deals with the compilation of planetary tables the catalogue of stars for the making of calendars and similar tasks.
The Arabs took a keen interest in the study of heavens. They developed this interest firstly because they had once worshipped heavenly bodies 1 and secondly because the dwellers of the desert who usually traveled at night in connection with trade war and migration from one place to another found the direction of their journey with the help of the stars. The clear sky of the desert gave them a chance of making precise observations. Thus there was some locally acquired knowledge of the fixed stars the movements of the planets and the changes of the weather.
After the advent of Islam the Muslims had to determine the time of the prayers and the direction of the Kabah to turn their faces towards it at the time of prayers. For this purpose it was necessary to know the altitude of the sun and the latitudes and longitudes of all the places where the Muslims lived. The same need arose for the orientation of the mosque. This gave a religious impetus to the study of astronomy and the allied subjects such as astronomical geography and mathematics. On the other hand the Muslims who once carried on flourishing trade all over the world and occasionally launched Jihad had to travel on the land and the sea. As an aid to travel navigation and meteorology a by product of navigation they needed star maps. The necessity of such maps was also a cause of their interest in astronomy.
There was a group of astronomers who believed in the influence of heavenly bodies on the terrestrial affairs and the fate and future of human beings. According to them the prognostication of sublunar events from the revolution of the heavens the signs of the zodiac in the ascendant and the motion of the planets was possible. The science dealing with such influences was termed as Astrology IlmAhkam alNujum. Astrology as a part of astronomy was studied and developed by ancient Babylonians. The study of this art or science was then made in Greece and Rome a few centuries before the opening of the Christian era. It was also cultivated in India China and Egypt. From the 7th to the 13th century it was further developed by the Muslims and later on by the Europeans. In the 14th and the 15th centuries the astrologers had great influence on the kings of the European countries. 2 The orthodox Muslims did not believe in the influence 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 second half of the 8th century during the reign of the second Abbasi Caliph AlMansr. After that the patronage and generosity of other Muslim rulers particularly of the seventh Abbasi Caliph AlMamun provided stimulation to the astronomical and mathematical researches of every kind. Indian Persian and Greek astronomical works were translated into Arabic and for making the astronomical observations the observatories were established by the caliphs and private persons at various places in the Muslim world. Astronomy was studied with great interest with the result that the number of Muslim astronomers raised surprisingly in a short period of time and by the end of the 10th century a large number of eminent Muslim astronomers gathered in Baghdad. In the 11th and the 12th centuries astronomy flourished in Muslim Spain where a good deal of creative and original work on this branch of science was done.
The Muslim scientists attached utmost importance to accuracy in observations and calculations without caring for the length of time needed for it. Thus sometimes their astronomical researches extended for more than forty years. Due to this desire of accuracy the Muslims did not accept as such the astronomical tables or measurements of Ptolemy a great Greek astronomer and mathematician. They only accepted his planetary theory just to provide a basis for astronomical research. They themselves conducted astronomical researches in Baghdad Samarqand Nishapur Cordova Damascus and Ray and after making a careful study of the heavens they not only corrected and amplified Ptolemys astronomical tables but also compiled a number of new ones and drew up new star catalogues. On the basis of fresh observations the Ptolemaic system was repeatedly criticized by the Muslim astronomers particularly those of Spain.
The investigations on astronomy were continued and till the end of the 11th century nearly all the original and creative work was done by Muslims and even the works of nonMuslims were written in Arabic. Astronomy reached its highest in the 13th and 14th centuries. In the 12th century the Christians and Jews started the work of translation from Arabic into Latin and Hebrew and began to conduct research in this field. But until the end of the 13th century no mathematical and astronomical work comparable to that of the Muslims could be produced by the Christians or Jews. It is interesting to note that in the 12th century while Ptolemys astronomical work Almagest after a thorough study and research was subjected to severe criticism by Muslims particularly those of Spain the study of this work was begun in the Latin world.
Besides compiling the astronomical tables the Muslims prepared celestial globes on which the positions and magnitudes of the stars were represented. The globe is of Greek origin but since Ptolemys time there has been a continuous improvement on it. The Muslim scientists also wrote comprehensive books on astronomy and mathematics and also composed treatises on various branches of this science.
The Muslim astronomers also prepared the star maps to preserve the old astronomical knowledge and to use them as an aid to travel navigation and meteorology.
A great incentive for the study of astronomy came from an Indian astronomical work called Siddhanta which was brought to the court of Baghdad by a Hindu named Kanka. Kanka met Yaqb Ibn Triq in 767 who was one of the greatest astronomers of his time. Yaqb Ibn Triq introduced him to the Caliph AlMansr.3 Kanka showed the book to the Caliph who ordered Muhammad Ibn Ibrahim AlFazri to translate it into Arabic.4 He also ordered that a work based on Siddhanta should be composed which could serve as a reference book for the Arabs. Muhammad Ibn Ibrahim took this responsibility and prepared a book which was called by the astronomers as Sind Hind alKabir the great Siddhanta. 5 It was used until the time of the Caliph AlMamun. Then AlKhwrizmi who was one of the greatest scientists prepared a summary of this book. He also compiled astronomical and trigonometrical tables according to the combined methods of Indians Persians and Greeks. These tables were revised by Maslamah alMajriti c. the second half of the 10th century. They gained so much popularity that they were used even in China. In the 12th century the translation of these tables was made into Latin. 5 AlKhawarizmi glimpsed in his works on astral motion and the force of attraction the law of universal gravitation.
The astronomer Ibrahim Ibn Habib alFazri was the first Muslim who constructed astrolabes. He composed a poem on astrology and compiled a Zij calendar according to the Arab method. He also wrote on the use of astrolabes and on the armillary spheres. 6
In 76263 the Persian astronomer and engineer Naubakht together with Masha Allah Latin Macellama Macelarama Messahala made a survey before the building of Baghdad. Masha Allah d. 815 or 820 was one of the earliest astronomers and astrologers who flourished under the Caliph AlMansr. 7 Naubakht d. 77677 was the author of a book on astrological judgments entitled Kitb alAhkam. 8
During the reign of the Caliph alMamun the important work of translation of Ptolemys Almagest from Greek into Arabic was completed. The Caliph was very anxious to get it translated correctly. It was translated several timed. Many commentaries on it were written. Its summaries were also made. The Minister Yahya Ibn Khalid Barmaki was the first to get it translated. A group of scholars wrote for him a commentary on this book but he did not like it. He appointed Abu Hasan and Salman who were attached to the scientific academy called Bait alHikmah The house of wisdom to write a commentary on it.9 The Almagest represents the best example of Greek classical works on astronomy. It served as a basis for the later astronomical works. AlHajjaj IbnYusuf was one of the first translators of the Almagest. He made this translation on the basis of a Syriac version. 10
The Caliph alMamun 169218 / 786833 was very fond of philosophy and science. The more he got acquainted with the interesting problems of science the more his interest grew in the practical work. He built an observatory at Baghdad in his Bait alHikmah and 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 solar year and the precession of the equinoxes were verified. Observations on the celestial motions were carried out and geodetic measurements were made. 11
AlMamun ordered Ahmed Muhammad and Hasan who were eminent scientists and his courtiers to measure in collaboration with other court scientists the length of the terrestrial degree and the circumference of the earth in some vast planes. The planes of Sinjar and Tadmor were selected for this purpose. The astronomers stayed at a place and noted with the help of instruments the altitude of the North. Pole and pitched a nail there. Then tying a long rope with the nail they carried the rope in the direction of the North. Where the rope ended they pitched another nail and tied another rope with it and proceeded in the same direction. They continued this process as well as observations on the altitude of the North Pole until on reaching a particular spot they noticed that the altitude of this Pole had increased by one degree. The distance they covered was also measured which was found to be 56 2/3 miles. From these observations it was inferred that for each terrestrial degree the distance covered on the earth amounts to 56 2/3 miles. The same operation was repeated in the direction of the South where at one spot they noticed that the altitude had decreased by one degree. The distance covered was the same as in the first case. Now on multiplying this distance by 360 which is the total number of terrestrial degrees the circumference of the earth was found to be equal to 20400 miles and the diameter equal to 6500 miles. 12
The chief of astronomers who carried observations under alMamun was Sanad Ibn Ali. He was a Jewish convert to Islam. He constructed an observatory Kanisah at the back of the Shamsiah Gate at the palace of Muizz alDawlah in Baghdad. An astronomical table and some writings on astronomy and mathematics including a book on Arabic numerals are ascribed to him. 13
Ali Ibn Isa alAstur1bi who flourished in Baghdad and Damascus in the first half of the 9th century took part in the measurement of the length of the terrestrial degree ordered by alMamun. He made astronomical observations at Baghdad and Damascus from 829 to 833. He was the famous constructor of astrolabes; hence the nickname alAsturlbi maker of astrolabe. He wrote a treatise on astrolabes which is one of the earliest works on this instrument. 14
Yahya Ibn Abi Mansr also took part in the observations made at Baghdad in 82930 and compiled the astronomical tables called Mamunic tables. Like the tables of Habash these too are a collective work of various astronomers. AlMarwarudhi who also flourished under alMamun made solar observations. 15
In the 9th century astronomy flourished in the East Astronomical researches were conducted in the observatories of Baghdad Damascus and other places. More original and improved work was done in the second 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 great attention was paid to the construction of good astronomical instruments especially to the spherical astrolabe which was newly introduced at that time. Hamid Ibn Ali was a famous constructor of spherical astrolabes. Jbir Ibn Sinan was also a maker of this as well as of other astronomical instruments. According to alBiruni he was the first to make a spherical astrolabe. AlNairizi wrote on this instrument an elaborate treatise which represents the best Arabic work on this topic. In this treatise the author after giving the introduction describes the instruments and gives its applications. Beside this work alNairizi compiled astronomical tables. A great scientist alMhani made for 33 years 833886 a series of observations on lunar and solar eclipses and planetary conjunctions. Another astronomer of this time Ahmad al Nahwandi who flourished at the time of Yahya Ibn Khalid Ibn Barmak made astronomical observations at Jundishapur and compiled tables called Mushtamil. 16
After carrying out astronomical observations for ten years 825 to 835 Habash alHsib compiled three astronomical tables. The first were according to the Hindu method based on Siddhanta. The second called AlZij alMumtahan the tested Tables were according to the Arab method. They were very important and were probably due to the cooperative efforts of alMamuns astronomers. The third called AlZij AlSaghir the small tables was commonly known as the Tables of Shah. Habash alHsib determined the time of the solar eclipse of the year 829. He was the first to determine time by an altitude in this case of the sun. This method was generally accepted and adopted by Muslim astronomers. 17
The most illustrious scholar of this age and one of the greatest astronomers of Islam was Abd Allah Muhammad Ibn Jbir Ibn Sinan alBattni Latin; Albategnius Albatenius. His ancestors were Sabeans of Harran but he himself was a Muslim. He carried out astronomical observations of a wide range and with remarkable accuracy for about 41 years 877918. He determined many astronomical coefficients like the precession 54.5 a year inclination of the ecliptic 23 35 with great accuracy. He noticed an increase of 16 47 in the longitude of the suns apogee since Ptolemys time. This led to the discovery of the motion of the solar apsides and of slow variation in the equation of time. AlBattni proved the possibility of the annular eclipses of the sun. He also wrote many astrological works. His main work is a large astronomical treatise including the astronomical tables. His tables contain a catalogue of fixed stars for the year 88081. His work is an advance on that of alKhwrizmi and shows more divergence from Indian methods. Observations regarding the first appearance of the new moon the length of the tropic and sidereal year the obliquity of the ecliptic the lunar anomalies the parallaxes etc. are more complicated and more accurately made by alBattni than by alKhwrizmi
AlBattnis 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
Thbit Ibn Qurrah d. 901 who was a physician mathematician astronomer and translator from Greek and Syriac into Arabic published his solar observations made at Baghdad. He particularly determined the altitude of the sun and the length of the solar year. 19
The astronomer and mathematician Wijan Ibn Rustam alKhi wrote many astronomical and mathematical works including a treatise on the construction of the astrolabe. He was the head of the astronomers working in 988 at the Buwayhid Sharaf alDawlahs observatory. 20 His coworker Ahmad Ibn Muhammad alSaghni was the inventor and maker of astronomical instruments. AbulWaf is said 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 alHusain alAlawi d. 985 showed a remarkable accuracy in observations. He compiled astronomical tables which remained very popular for at least two centuries. 22
Now we come to a famous astronomer of the 10th century named AbulHusain Abd alRahman alSufi. He was born in Ray Persia in 903 and died in 966. He was a prominent astronomer of the medieval times. His knowledge of both the Islamic and Greek astronomy particularly uranometry was comprehensive. He was the first to observe the change of the colour of stars the change in the magnitude of stars the proper motion of stars the long period variable stars and the Southern constellations which have been wrongly ascribed by modern astronomers to some later ones.
Abd alRahman alSufi was patronized by the Buwayhid ruler Adud alDawlah 949982 who was a great patron of astronomy and had built an observatory at Shiraz. AlSufi wrote for the ruler a book on uranometry entitled Suwar alKawkib The book of the fixed stars. In this book he gives a complete description of the constellations of the heavens. He also gives the position of each star of the constellations illustrating with pictures. The book contains 55 astronomical tables along with illustrations of 48 constellations in 96 diagrams as seen in the heavens. The artistic value of the pictorial illustrations in the Mss. of this work is very great and represents one of the best examples of the Persian miniature paintings. AlSufi has not only corrected the errors of observations in the work of his predecessors like alBattni but also pointed out many faulty observations found in Ptolemys Almagest. He defined carefully the boundaries of each constellation and recorded the magnitudes and positions of stars after making new observations.
The Suwar alKawkib is one of the three masterpieces of observational astronomy of the medieval times; the other two being the catalogues of Ibn Ynus 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 alBiruni Alfonso Prince of Castile Khwjah Nsir alDin Tusi Prince Ulugh Beg and Jai Singh II based their catalogues of stars on this authentic catalogue. This work was translated into Latin French and Persian and a commentary on it was written in Spanish.
It served as a basis for later works in Western Europe. The modern astronomers like Hauber Down Argelander Ideler Schellerup and Knobel had made an extensive use of it.
AlSufi prepared a fine celestial globe. Several celestial globes which cover the period from the 11th to the 18th century show the star positions and magnitudes according to alSufi. He showed a remarkable accuracy in the design of the astrolabes. He wrote a treatise on this instrument. In this treatise he throws light on the astronomical techniques as practiced it that time. 23
Another great astronomer and one of the greatest Muslim astronomers was AbulHasan Ali Ibn Abi Said Abd alRahman Ibn Ahmad Ibn Ynus alSadafi generally known as Ibn Ynus. He was well versed in Arabic literature poetry and history and had knowledge of many other subjects. He belonged to Egypt where he died in 1009. He was a courtier of the Fatimi Caliph alAziz Billah 975996. He got a chance of working in a wellequipped observatory which was the part of a Muslim academy of science named Dar alHikmah the house of wisdom founded in Cairo by the Fatimi rulers. He made astronomical observations and by the order of the Caliph alAziz he compiled the astronomical tables. The work of compilation of these tables was begun in 990 during the lifetime of the Caliph but it was completed after his death under his son al Hakim 9661020. Hence they were named after him AlZij alKabir alHakimi. In these tables he entered his observations about the eclipses and conjunctions old and new improved values of astronomical constants inclination of the ecliptic 23 35; longitude of the suns apogee 86 10; solar parallax reduced from 3 to 2; precession 51.2 a year. He gave an account of the geodetic measurements which were carried on by the order of the Caliph alMamun in the ninth century.
Ibn Ynus in his astronomical tables written in 4 volumes corrected the errors of observations in the astronomical tables of his predecessors. The people of Egypt relied on these tables. It is said that after their compilation the use of all the previous tables in the world was given up. Even the astronomers of China greatly utilized them. The translation of a large part of the tables except the chronological section has been made in French in 1804.
Beside thesetables Ibn Ynus has composed many books. One of these is Jadawil alSamt the tables of direction and the other is the Jadawil alShams walQamar the tables of the sun and the moon. 24
A famous astronomer of the 11th century who belonged to Cordova Spain was Abu Ishaq Ibrahim Ibn Yahya alNaqqsh commonly known as Ibn alZarqli or alZarqli Latin: Arzachel. He was also an eminent astronomer of this century. He lived from 1029 to 1087. He was the best observer of his time who made astronomical observations for about 19 years 10611080. He invented an improved astrolabe called Safihah Saphaea Arzachelis on which he also wrote a treatise. It was translated into Latin Hebrew and many vernaculars. AlZarqli was the first to prove explicitly the motion of the solar apogee with reference to the stars. According to his calculations it was equal to 12.04 per year the real value being 11.8. He edited the planetary tables called Toledan Tables. These tables were probably the result of the observations made in Toledo by him and by a great observer Ibn Said in collaboration with other Muslim and Jewish astronomers. They were translated into Latin and enjoyed much fame. 25
A famous astronomer mathematician and poet Umar Ibn alKhayym reformed the old Persian calendar which had been replaced by the Islamic calendar after the Muslim conquest of Persia. This reformed calendar was called AlTrikh alJalli after the name of the Saljuq Sultan Malik Shah Jalal alDin who in 107475 called Umar Ibn alKhayym to his observatory for making this reform. Many interpretations have been given to it. Each interpretation is accurate to a certain degree but at any rate Umars calendar was probably more accurate than the Gregorian Christian calendar. Three interpretations the second of which seems to be the most accurate are being quoted here along with the authority giving the interpretation and the resulting error.
1. AlShirzis interpretation: 17 intercalary days in 70 years; error. 1 day in about 1540 years.
2. Ulugh Begs interpretation: 15 intercalary days in 62 years; error 1 day in about 3770 years.
3. Modern interpretation: 8 intercalary days in 33 years: error 1 day in about 5000
in the Gregorian calendar there is an error of 1 day in 3330 years. 26
The greatest astronomer of the 12th century who also belonged to Spain was Abu Muhammad Jbir Ibn Aflah. He was born or lived in Seville. He vigorously criticized the Ptolemaic theory of planets and wrote a book on astronomy entitled Islah alMajisti the correction of the Almagest. He was of the view that the lower planets Mercury and Venus at least must have visible parallaxes. Venus may happen to be exactly on the line joining the sun and the earth. The most important part of his book is the introduction on trigonometry. The book was soon translated into Latin and Hebrew. Jbir Ibn Aflah is said to be the inventor of the astronomical instrument called turquet torquetum which contains two graduated circles in two perpendicular planes. The same invention has also been ascribed to two other persons namely Frances of Leige 11th century and Nsir alDin Tusi 13th century. The turquet was introduced into the Latin West by Regionomentus. It gained a great popularity in the 15th and 17th centuries. 27
Another astronomer of the time was Abul Qsim Hibat Allah Ibn Husain alBadi alAsturlbi. He was also a physician mathematician poet and litterateur. He was the greatest expert of his time in the knowledge and construction of astrolabes; hence his nickname alAsturlbi. In 112030 astronomical observations were made under his direction and astronomical tables were compiled. The observations were carried out in the palace of the Saljuq Sultan of Iran Mughith alDin Mahmud 11171131. The tables were dedicated to the Sultan and were called after him the Mahmudic tables. AlAsturlbi was very much praised by Muslim biographers. He died in Baghdad in 113940. 28
In the 13th century there flourished in the East a great scholar of Persian origin named Abu Jafar Muhammad Ibn Muhammad Ibn alHasan Nsir alDin alTusi alMuhaqqiq 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 one of the greatest Muslim mathematicians and scientists. He wrote both in Arabic and Persian. It is said that he knew Greek as well. He joined the Mongol service and was later made administrator of the Waqf revenues.
While he was administrator he resided at Maragha in Asia Minor 12591274. Here he made astronomical observations in an observatory established by the Mongol ruler Hulagu Khan II after he had defeated the last Abbasi Caliph alMutasim in 1258. A library was attached to it. It is said to have contained 4 00000 volumes which the Mongol armies had collected in Syria Mesopotamia and Persia. Nsir alDin was the first director of this observatory. He was succeeded by two of his sons.
Nsir alDin was well acquainted with the knowledge of the Greeks. He wrote about 64 works on many subjects. Here we shall consider only some of his astronomical and astrological works. The most important astronomical work of Nsir alDin is the Tadhkirah fi Ilm alHayah The description of astronomy which is a condensed summary of astronomy. To explain it many commentaries and super commentaries have been written. The work enjoyed much popularity it consists of four chapters. The second chapter beside other things contains interesting criticism of the Ptolemys Almagest in which he showed a great ingenuity. The criticism chiefly concerns the anomalies of the moon and the motion in the latitude of the planets particularly Mercury and Venus ; also the proposition of a new system to replace the complicated Ptolemaic machinery of deferents and epicycles. His new and forceful criticism of astronomy as well as of other Muslim astronomers helped Copernicus in making his reform. Nsir alDin wrote one treatise on the five quadrants and two treatises on astrolabe. He also wrote two treatises on calendar.
Nsir alDin made observations in the observatory at Maragha which was well equipped with good astronomical instruments. He prepared new astronomical tables called after the Mongol ruler AlZij alIlkhni. Nasir alDin asked the ruler to give him a period of 30 years to compile the tables because it was the shortest period during which the planetary cycles were completed. But the ruler refused and gave him only 12 years to accomplish this task. Nasir alDin tried a succeeded in completing the tables within this time. They were based upon new observations. But the use of the earlier ones had also been made.
The Ziji Ilkhni was originally written in Persian. It consists 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 made into Arabic and commentaries on it were written. Finally a sort of supplement to it was compiled by Jamshed Ibn Masd alKshi d. 840/1436 the first director of Ulugh Begs observatory in Samarqand. These tables enjoyed a great popularity in the East including China and were continued to be used even after the compilation of new tables by Ulugh Beg in 1437. 29
A contemporary of Nasir alDin Muayyid alDin alUrdi alDimashqi also took part with him in compiling the tables. He was a Syrian astronomer architect and engineer. He started his career as a technician in Syria. He did some hydraulic work in Damascus and also constructed there an astronomical instrument for alMansr Ibrahim King of Hims 12391245. In about 1259 he went to Maragha and helped Nasir alDin in organizing the observatory and compiling the tables. It seems that the instruments remarkably precise were constructed under his supervision in the foundry attached to the observatory.
AlUrdi was the author of a treatise in which he also described the instruments used in the observatory of Maragha and explained their use and construction. The instruments are as follows:
1 mural quadrant 2 armillary sphere 3 solstitial armil 4 equinoctial armil 5 Hipparchs diopter alidade; 6 instrument with two quadrants 7 instrument with two limbs 8 instruments to determine sines and azimuths 9 instruments to determine sines and versed sines 10 the perfect instrument a universal instrument 11 parallactic ruler after Ptolemy.
AlUrdi was also the author of two other treatises; one on the construction of a perfect sphere and another on the determination of the distance between the centre of the sun and the apogee. He compiled astronomical tables and wrote on Ptolemaic astronomy.
In 1279 or 1289 alUrdis son Muhammad made 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 half circles were attached to the zenith point by a pivot. These circles are graduated and are used to determine the declination and right ascension of any star. Fortyeight constellations the equator and the ecliptic are inlaid with silver or gold. It is preserved in the mathematical salon of Dresden. 30
The works of Muslim astronomers were later translated into Latin Hebrew and vernaculars by the Christian and Jewish scholars some of the technical terms including azimuth alSamt Algol Alfol Achernar Akhir alNahr passed into the European languages. The names of many stars such as akrab Aqrab Algedi alJadi the kid Altair altair the player Denab dhanb tail Pherkad Farqad calf Adara Adhrah Aldebaran aldibrn which are of Arabic origin also passed into these languages. The stars being countless in number their separate study is not possible. They were therefore divided into various groups and the groups were named after the things and animals with which they resembled.
REFERENCES :
1. Briffault Robert The Making of Humanity Lahore 1980 p. 187.
2. Encyclopedia Britannica London Vol. II p.575.
3. Abul Hasan Ali Ibn Yusuf AlQifti Trikh alHikmah Leipzig 1903 p. 265.
Sarton George Introduction to the History of Science Washington 1927 vol. I. p. 530.
4. Ibid.
5. Ibid p. 563.
6. AlQifti op. cit. 57.
7. Ibid. p. 327.
Sarton op. cit. p. 531.
8. Ibid.
9. Ibid. p. 557.
Haji Khalifah Kashf alZunn Istanbul 1943 vol. II p. 1594.
10. Sarton op. cit. p. 562.
11. Ibid p. 558.
12. Shibli Numani AlMamun Agra 1894 pp. 49 50
13. Ibn Nadeem AlFehrist Matbaah alRahmaniyah Cairo n.d.. p. 383.
14. Shibli Numani op. cit. pp. 4950
Sarton op. cit. p. 566.
15. Ibid.
16. Sarton op. cit.. p. 585.
17. AlQifti op. cit. p. 170.
18. Ibid p. 280.
Sarton op. cit. p. 5858.
19. Ibid. p. 599.
20. AlQifti op. cit. p. 351.
21. Sarton op. cit. p. 666.
22. Ibid.
23. A1Sfi Abd alRahman Swar alKawkib Hyderabad preface by M. Nizamuddin and J.J. Winter pp. 17.
24. AlQifti op. cit. p. 226.
25. A1Qifti op. cit. p. 230.
26. Sarton op. cit. p. 758
27 Ibid. p.759
28. Ibid vol. II part I p. 206.
29. Ibid. part I p. 204.
30. AlBaghdadi Ismail Bsh Hadiyyat alArifin Istanbul 1951 vol. II p. 131.
31. Sarton op. cit. vol. II part II p. 1005.
32. Ibid. pp. 10131014.
About the writer:nbsp;nbsp;Professor Ghulam Mohyuddin Wani did his Ph.D from IVRI Izatnagar in 1985 in Animal Reproduction / Gynaecology and got Dr. Med. Vet.**Additional Doc. Degree from Veterinary Institute Deemed Univ. Hannover Germany in 1984 in the field of Animal Reproduction/ Production. He also earned DAAD FellowshipPost Doc. from German Academic Exchange Hannover Germany in Animal Breeding institute Buetweg HannoverGermany and is currently Director Extension Education and Director SAMETI in the S.K. University of Agricultural Sciences and Technology of Kashmir Shalimar ndash; Srinagar.
The author can be contacted at: P.O.Box: 461 GPO Srinagar by post or mailed at wanimohyuddinyahoo.com
Common Fish Species Has Human Ability To Learn
ScienceDaily June 17 2009 Although worlds apart the way fish learn could be closer to humans’ way of thinking than previously believed suggests a new research study.
A common species of fish which is found across Europe including the UK called the ninespined stickleback could be the first animal shown to exhibit an important human social learning strategy. The sticklebacks can compare the behaviour of other sticklebacks with their own experience and make choices that lead to better food supplies according to the study by St Andrews and Durham universities.
The researchers suggest these fish might have an unusually sophisticated social learning capability not yet found in other animals called a ‘hillclimbing’ strategy.
This ability of picking the best quality food patch by comparing how successful others are at getting food from it against their personal experience has not been shown before in animals say the scientists.
The team of researchers suggests that in the case of the ninespined stickleback it is likely to be a case of ‘needs must’ as the anatomy of this particular species of fish does not offer significant protection from predators to forage alone safely. They may have been ‘forced’ to learn from others about where to feed while hiding from predators as they themselves cannot risk looking for food sites in the open.
The scientists say the findings published in the academic journal Behavioral Ecology show that the cognitive mechanisms underlying cumulative cultural evolution may be more prevalent in nonhuman animals than currently believed. The findings show that big brains like those in humans are not necessarily needed as a prerequisite for cumulative culture.
The researchers say the findings contribute to the understanding of brain evolution and the types of brain required for certain cognitive functions both in humans and animals.
Lead author Dr Jeremy Kendal from Durham University’s Anthropology Department and a Research Council UK Fellow said: “Small fish may have small brains but they still have some surprising cognitive abilities.
“‘Hillclimbing’ strategies are widely seen in human society whereby advances in technology are down to people choosing the best technique through social learning and improving on it resulting in cumulative culture.
“But our results suggest brain size isn’t everything when it comes to the capacity for social learning.”
Around 270 fish were caught using dip nets from Melton Brook in Leicester and housed in aquariums in a laboratory. The fish were split into three experimental groups and one control group. The fish in the experimental groups were given two different learning experiences and two preference tests in a tank with a feeder at each end.
First they were free to explore the feeder at each end during a number of training trials where one feeder supplied more worms than the other called the rich feeder. They were then tested to see which feeder they preferred. In the second training trial those fish that had learned a preference for the rich feeder observed other fish feeding but this time the rich and poor feeders were swapped round with the rich feeder either giving even more worms than the one the fish previously got their food from or giving roughly the same or less. In the second test the fish were again free to swim around and choose their feeder.
Around 75 per cent of fish were ‘clever’ enough to know from watching the other fish that the rich feeder previously experienced first hand themselves as the poor feeder gave them the better pay off. In comparison significantly fewer fish preferred the feeder that appeared to be rich from watching others if they themselves had experience that the alternative feeder would give roughly the same or more food.
The team’s further studies have found that the likelihood of copying the behaviour of others increased with the rate at which the others fed.
Dr Kendal said: “Lots of animals observe more experienced peers and that way gain foraging skills develop food preferences and learn how to evade predators. But it is not always a recipe for success to simply copy someone. Animals are often better off being selective about when and who they copy.
“These fish are obviously not at all closely related to humans yet they have this human ability to only copy when the pay off is better than their own. You might expect this ability in animals who are closely related to humans. In the case of the ninespined stickleback they have most likely adapted to their local ecology.”
Coauthor Professor Kevin Laland from the School of Biology at St Andrews University added: “Ninespined sticklebacks may be the geniuses of the fish world. It’s remarkable that a form of learning found to be optimal in humans is exactly what these fish do.”
The research was carried out at St Andrews University where Dr Kendal was employed before joining Durham University in 2007.
It was funded by the Biotechnology and Biological Sciences Research Council.
Facts about ninespined sticklebacks
Stickleback species are found in fresh and marine water environments in Europe Asia and North America including in weedy ditches and rivers.
They feed on small crustaceans and fish larvae.
In breeding season the male builds a nest suspended on a piece of waterweed. The female is attracted over by the male and she lays eggs inside the nest. The male guards these eggs and the young fry when they hatch. When the young have their spines he drives them away to look after themselves.
Journal reference:
1. Jeremy R. Kendal Luke Rendell Thomas W. Pike and Kevin N. Laland. Ninespined sticklebacks deploy a hillclimbing social learning strategy. Behavioral Ecology 2009; 20 2: 238 DOI: 10.1093/beheco/arp016
Adapted from materials provided by Durham University via EurekAlert! a service of AAAS.
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Cervical Alterations During Pregnancy In Small Ruminants
Cervical alterations during pregnancy in Small Ruminants
P. Goswami and G. M. Wani
Directorate of Extension Education
SKUASTK Shalimar Srinagar
The cervix uteri is a thick walled fibromascular tube connecting the body of the uterus and vagina. It a muscular organ composed of connective tissues predominantly elastic fibres. In the non pregnant ewes the cervical canal is impassable except during oestrous. Five or six hard prominences within the canal assist the sphincter effect of the cervix Nickel Schummer Seiferle 1973. During the course of gestration the length of cervix increases and in late pregnancy the wall becomes thicker with an overall increase in the compliances of the tissues Cloete 1939; Abusineina 1969. This may be related to disaggregation of densely packed collagen fibre in the cervix of prepartum ewe. This paper will focus some of the important physical and microscopical changes occurred in the cervix of small ruminants during pregnancy
Anatomy of the cervix:
The cervix separates the uterus from the vagina. During pregnancy it seals and protects the embryo and fetus from the external environment. The gross and microscopic anatomy of the cervix has been studied by various workers. The casts of the inside of the cervical lumen shows its convulated structure consisting five to six circular folds and the second fold being eccentric to the other concentric folds and acting as physiological barrier. The cervical fold in small ruminants varies from five to six folds. In cow four large circular and 1525 longitudinal primary folds each with many secondary and tertiary folds are present. Cervical mucosa is generally characterized by longitudinal primary fold and most of which maintained continuity throughout the cervix. Superimposed on these secondary folds which is varied in length and depth. Abundant shallow uniformity and parallel longitudinal grooves covers all surface.
Morphological changes in the cervix:
Three major changes generally observe in cervix during pregnancy. These are described as growth physical increase in length and breadth. Softening changes in tensile properties and dilation to allow passage of the foetus. The study carried out by different workers showed that ovine cervix shows an increase in width and length in the later stages of pregnancy. The analysis of the constituency of cervices shows increase softening from the mid pregnancy and there after firmness of cervix losses.
A small increase in the degree of hydration of the cervix or dry weight at different gestrational stages has been reported by Fosang et. al. 1994 ward 1968. This may be due to increased tissue mass rather than increase in size of water content. However some author reported no significant changes/differences in water content of the cervices from non pregnant to pregnant animals. The physical chemical and histological properties of cervix are constant throughout the length of cervix. However Basset 1958 reported morphological changes in the fibroblast of the broad and sacroiliac ligament by the 60th day of pregnancy but this information is not supported on ultrastructural studies.
Light Microscopical changes:
Morphologically the most prominent feature of non pregnant cervix is heavy densely packed collagen fibre interspersed with fibroblast fig.3 . Small blood vessels are present throughout the depth of the tissue but most numerous in deepest layer. Smooth muscle bundle are running both longitudinally and transversely in the middle and deeper layer. The figure represents a wall of non pregnant cervix. The lining epithelium is low columnar and secrets neutral mucin. The sub epithelial connective tissue is vascular and contains variety of cells including eosinophil macrophages mast cells and plasma cells. The greater proportion of cervical wall is composed of dense fibrous connective tissue consisting of compactly arranged collagen fibre with some fibrocytes and occasional fibroblast embeds in sparse ground substance. The individually arranged smooth muscle fibre forms an incomplete muscularies of which the outer fibre is longer and more prominent than inner fibre. The electron microscopically the collagen fibre shows very compact in arrangement and the scarcity of the ground substance and the presence of fibrocytes. Fosang et. al . opined that there is no significant changes observe between proximal middle and distal portion of cervix irrespective of stain used. The best stain normally use for differentiation between collagen fibre and the smooth muscle bundle are Massons Trichrome stain where the alignment of the collagen fibre along with villi shows projecting towards lumen. In general collagen fibre are large and closely spaced and are organized either longitudinally or obliquely. Section stained with Toludine Blue stain revels metachromatic staining along the collagen fibrils with strong staining of epithelial cells associated mucus. The morphological changes donot become apparent until quite late in the gestration period. The description of non pregnant cervix applied equally to the connective tissues observed in the early stages of pregnancy even to 100 days.
Fig. Pregnant cervix showing
Fig: Dense Collagen fibre inner circular longitudinal muscular layer with epithelium HE 4X
Fig. Central cervix Transverse section Loosening of epithelium and collagens layer HE pregnant
The histological section at 100 days of pregnancy revels no virtually distinguish alteration from that of non pregnant cervix Calder et. al. The tall columnar cervical epitheliums are the only changes represents in pregnancy and the secretions are a mixture of acid and neutral mucin. Acidity increases with the pregnancy age. Tissue breakdown and destruction of collagen networks is evident at 140 days of pregnancy. The cells are more widely spaced empty area and the collagen fibre losing their organization exposing smooth muscle cells. This can be best seen with Massons Trichrome. The infiltrating cell at this stage are lymphocytes and monocytes and few eosinophils. In late gestration increased fibroblast activity smooth muscle hypertrophy vascular edema and dissolution of collagen fibre bundle are reported by various worker. These findings contrasted with the rigid fibromuscular tissue observe in the non pregnant animals. The appearance of thinner fibre and empty areas between fibres in late pregnancy is lead to decrease concentrations of hydroxyproline in tissue. Collagen fibre dissolution in pregnant cervix has been extensively reported in several species and many authors have reported that active collagenolysis occurring during pregnancy may be the underlying mechanism of cervical softening. Ellowed et al 1981 have shown that ovine cervical explants produce both latent and active collagenase activity with greater yields of activity in parturient tissue compared with the late pregnancy after 35 days in culture. Inflammatory cells invading cervix towards late gestration provide a potential source of collagenase and neutral protinease activity. Eosinophils also have been described as potential bearer of specific collagenase which may be responsible for collagen catabolism Basset 1972. At the term the disruption of collagen fibre are more even pronounced with virtually no large fibre remaining. In Haematoxyline Eosin stain sectioned it sometimes appears very little or no collagen at all. But very little and small fibrils arranging random pattern are seen in Massons Trichrome stains. In this stage there is heavy infiltration of inflammatory cells among which eosinophils predominant. An area of haemorrhage is also a constant finding along with infiltrating cells. In late pregnancy there is complete network of subepithelial capillaries with a marked increase in the size of the vessels in the outer part of the cervical wall.
Ultrastructure feature:
Ultrastructuraly non pregnant cervix reveals the typical dense connective tissue with collagen aggravated in closely packed fascicles and fibrocytes embedded in sparse ground substance. The ultrastructural characteristic in late pregnancy are presence of rough endoplasmic reticulum mitochondriaplasmalemmal vesicle and extensive branching of individual fibres in contrast to the absence of these feature in muscle fibres of the nonpregnant cervix. This description is also similar to early pregnancy stage. The ultrastructural analyses of the cervical connective tissue reflects active changes in tissues with a reorganization of the cervix prior to the functional changes at parturition.
Changes in collagen concentration:
The biochemical analysis of hydroxyproline in tissue can be used for collagen concentrations. Study carried out by Regassa et al. 1983 shows the total collagen content of cervix at all stages of pregnancy is significantly greater than that of caruncular mean and the intercaruncular areas. The concentration of hydroxyproline is not changed in cervix during Ist trimester of pregnancy. However the concentration of hydroxyproline progressively decreases at days 100 140 days and in post partum tissues as compared to the non pregnant tissueFosang et. al 1984. The concentration is same between proximal middle or distal region of the pregnant and non pregnant cervix.
In conclusion it is summarized that uterine cervix of small ruminants became softer during the pregnancy and that some associated changes first appear in early gestartion. There is no significant changes in water content through pregnancy although light increases is associated with cervical size and softening of the tissue. Physical and histological properties are identical in all section along the length of cervix. The changes associated with increasing length of gestration are absolute increase in width and length relative increases in fibroblasts smooth muscle and softening; relative decreases in collagen and fibrocytes. But increased vascularisation without any white cell infiltration of the tissue is specifically associated with late gestration.
REFERENCES
Abusineina M.E. 1969 Effect of pregnancy on the dimendions and weight of the cervix uteri of sheep. British Vet. J 125 2124
Amanda J. Fosang Christopher J. H. Vivien S. Dennis A. L. and Geoffery D. T. 1984 pregnancy related changes in connective tissue of ovine cervix. Biology of reproduction 30 12231225
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Hollingsworth M. 1981 Softening of rat cervix during pregnancy. In the cervix in pregnancy and labour clinical and biochemical investigations ed. D. A. Ellwood A.B.M. Anderson pp.1333 Edinburg
K. June Mullins R. G. Saacke 1988 Study of the functional anatomy of bovine cervical mucosa with special reference to mucus secretion and sperm transport Journal of Reproduction and Fertility 1979 57 261266
Karen Sohan Rebecca Wiggins and Peter Soothill 1999 Cervical Physiology in pregnancy and labour. Foetal and Maternal Medicine review 11: 135141 Cambridge
More J 1984 Anatomy and Histology of the cervix uteri of ewe: A new insight Acta. Anat basal 120 3. 1569
Nickel R. Schummer A. Seiferle E. 1981 The viscera of domestic animals pp.358 and 361 berlin verlag Paul Pavey.
Regassa F. and Noakes D. E.1983 Changes in the weight collagen concentration and content of the uterus and cervix of ewe during pregnancy. J Biology 73 22125
About the writer:nbsp;nbsp;Assistant Professor Veterinar Pathology
SKUASTK Shalimar Srinagar
