Battani (Abu-Abdullah Muhammad ibn Jabir al-Battani) (Abu ‘Abd Allah Muhammad al-Battani (al-Battani) (Albategnius) (Albatenius) (c.858-929). Astronomer who examined and corrected, through application of trigonometry, astronomical theories first put forward by the second century Alexandrian Ptolemy.
Born near Haran in north-central Syria in 858, the young Abu ‘Abd Allah Muhammad ibn Jabir ibn Sinan al-Battani al-Harrani al-Sabi’ moved with his and several other families to Rakka on the Euphrates River midway on the caravan route between Aleppo and the Upper Mesopotamian city of Mosul. This migration may be explained in part by the nisba, or nickname, retained by the future Islamic astronomer. “Al-Sabi” may refer to his family’s earlier adherence to the so-called Sabian sect, which was reputed to follow a mixture of Christian and Islamic principles. Whatever the family’s original religious orientation, Abu ‘Abd Allah’s later fame was won under the banner of Islam, the faith he ultimately followed. After his move to Rakka as a youth, al-Battani spent the remainder of his life in the same geographical and cultural environment.
No specific information is available on al-Battani’s formal education. It is not known, for example, whether his original training was obtained in a fully secular “scientific” or in a religious setting. It was as a youth in Rakka, however, that al-Battani decided to devote himself to careful study of ancient texts, especially those of Ptolemy, which provided him with the knowledge needed to carry out the series of astronomical observations which would make him famous, not only in the Islamic world but in the medieval European West as well.
Al-Battani, known to the West as Albatenius, contributed greatly to advances in the field of trignometry. To carry out key calculations, he relied on algebraic rather than geometric methods. Like his somewhat lesser known follower Abul Wefa (940-998), al-Battani focused much of his attention on the theories of the second century Alexandrian astronomer Ptolemy. Several Islamic scholars before him had been intrigued by Ptolemy’s approach to the phenomenon of the oscillatory motion of the equinoxes. Al-Battani’s contemporary Thabit ibn Qurrah tried to account for this by supplementing Ptolemy’s theory, merely adding a ninth sphere to the Greek scientist’s assumption of eight spheres. Al-Battani, however, remained doubtful. He was convinced that trigonometry should be developed more effectively for the purpose of achieving greater precision in already known methods of making these and other astronomical calculations. This goal led him to explore and expand the relevance of sines. His use of the Indian sines, or half chords, enabled him to criticize Ptolemy’s conclusions in several areas.
For example, Ptolemy had insisted that the solar apogee was a fully immobile phenomenon. Al-Battani, however, was able to observe that in the seven centuries since Ptolemy’s time there had been a notable increase in the sun’s apogee. His further observations suggested that the apogee was affected by the precession of the equinoxes. To explore this theory required a substantial revision of methods of proposing equations to represent the passage of time in accurate astronomical terms. Room had to be made for accommodating slow secular variations. As part of this process, al-Battani set out to correct Ptolemy’s theory of the precession of the equinoxes.
The phenomenon of eclipses was also a field incompletely pioneered by Ptolemy. Interest in this subject motivated al-Battani to make a variety of studies that aided subsequent astronomers in their calculations to determine the time of the visibility of the new moon. His treatment of the phenomena of lunar and solar eclipses provided the basic information that would be used by European astronomers as late as the eighteenth century.
In a somewhat more practical vein easily appreciated by the layman, al-Battani’s observations allowed him to determine the length of the tropic year and, significantly, the precise duration of the four seasons of the year.
One of the most original areas of al-Battani’s work involved the use of horizontal and vertical sundials. Through their use, he was able to denote the characteristics of a so-called “horizontal shadow” (umbra extensa). These he used to reveal cotangents, for which he prepared the first known systematic tables. Similarly, his study of “vertical shadows” (umbra versa) provided pioneer data for calculating tangents.
Most of al-Battani’s important findings in the field of astronomy were contained in his major work, Kitab al-zij (De scientia stellarum or De motu stellarum -- c.900-901). As the Latin titles suggest, this magnum opus was first circulated widely among scholars of the early period of the European Renaissance.
Unfortunately, modern scholars’ familiarity with other important writings by al-Battani is limited to what can be gleaned from references to them in other Islamic authors’ works. A “Book of the Science of Ascensions of the Signs of the Zodiac,” a commentary on Ptolemy’s Apotelesmatika tetrabiblos, and a third work on trigonometry, for example, are all lost in their original versions.
The scholarly career of al-Battani provides an example of the diversity of pre-Islamic sources that contributed to the rise of Islamic science. It also illustrates the importance of such scientists’ work in saving traces of pre-Islamic contributions to knowledge during the Dark Ages of European history, when much of the classical heritage of Western civilization was lost. To speak of al-Battani’s role as that of an interim transmitter of knowledge, however, would be to miss the essential importance of scientific endeavors in his era. It is clear, for example, that al-Battani was dissatisified with interpretations offered by his classical and Indian forerunners. By the time his work of reinterpretation was translated for transmission to the European world, it reflected numerous original contributions. Thus, in regard to the re-emergence of Western science during the classical revival period of the Renaissance, it can be said that many of the principles upon which it was based came from Islamic sources.
The fact that such advances in several fields of “pure” science were actively sponsored by the early Islamic caliphs -- themselves assumed to be primary guardians of the religious interests of their realm -- is of major significance. In al-Battani’s age, knowledge was still recognized as something necessarily derived from syncretic sources. Tolerance for the exploration of different secular scientific traditions did not, however, survive too many successive generations. Narrowness of views in the eastern Islamic world a mere century and a half after al-Battani’s contributions would make the role of Western translators of Arabic scientific works just as vital to the conservation of cumulative knowledge in world culture as the work of Islamic translators and commentators had been after the end of the classical era. Outstanding figures such as al-Battani, therefore, definitely span world civilizations and reflect values that are universal. These are easily recognized as such beyond the borders of their chronological time or geographic zone.
Al-Battani was the leading Arab astronomer and mathematician of his time. His astronomical observations at ar-Raqqah, Syria, extended for a period of more than forty years.
Al-Battani has been recognized as the greatest astronomer of his time and one of the greatest of the Middle Ages. Abu Abdullah Muhammad ibn Jabir ibn Sin'an al-Battani was born around 858 in or near Battan, a state of Harran. He belonged to the princely Sa’bi family of Harran and he was a Muslim. Al-Battani was first educated by his father Jabir ibn Sin’an al-Battani, who was also a well-known scientist. He then moved to Raqqa, situated on the bank of the Euphrates, where he received advanced education in sciences. At the end of the ninth century, he migrated to Samarra, where he worked until his death in 929.
Al-Battani made his observations and studies in al-Raqqah from 877 to 929 and made many important discoveries in astronomy. He made several corrections to Ptolemy’s work and rectified the calculations for the orbits of the moon and certain planets. He proved the possibility of annular eclipses of the sun and determined with greater accuracy the obliquity of the seasons and the true and mean orbit of the ecliptic, the length of the tropical year and the seasons and the true and mean orbit of the sun. Al-Battani’s remarkably accurate calculation of the solar year as 365 days, 5 hours, 46 minutes and 24 seconds is very close to the latest estimates. He found that the longitude of the Sun’s apogee had increased by sixteen degrees since Ptolemy. If inferred the important discovery of the motion of solar apsides and of a slow variation in the equation of time. He did not believe in the trepidation of the equinoxes, although Copernicus, several centuries later, held that erroneous notion.
In a sharp contrast to Ptolemy, al-Battani proved the variation of the apparent angular diameter of the sun and the possibility of annular eclipses. He revised orbits of the Moon and the planets and proposed a new and very ingenious theory to determine the conditions of visibility of the new moon. Eighteenth century scientists used al-Battani’s excellent observations of the lunar and solar eclipses to determine the acceleration of motion of the moon. He determine many astronomical coefficients with great accuracy. Al-Battani also provided very ingenious solutions for some problems of spherical trigonometry using the methods of orthographic projection. It was from a perusal of al-Battani’s work on apparent motion of fixed stars that Hevilius discovered the circular variation of the moon.
Al-Battani’s greatest fame came in mathematics with the use of trigonometric ratios as we used them today. He was the first to replace the use of Greek chords by Sines, with a clear understanding of their superiority. He also developed the concept of cotangent and furnished their tables in degrees.
Al-Battani wrote many books on astronomy and trigonometry. His most famous book was an astronomical treatise with tables, which was translated into Latin in the twelfth century and is known by the title De Scienta Stellarum - De Numeris Stellarum et motibus. The third chapter of al-Battani’s book on astronomy is devoted to trigonometry. His treatise on astronomy was extremely influential in Europe until the Renaissance and was translated in several languages.
The work of such Muslim scholars as al-Battani paved the way for the great advances in science that we enjoy today. It is no overstatement to say that in the domain of trigonometry the theory of sine, cosine and tangent is directly attributable to the mathematical genius of al-Battani. Al-Battani’s original discoveries both in astronomy and trigonometry were of great consequence to the development of the sciences, particularly during the Renaissance. Copernicus in his trailblazing (and revolutionary) book De Revolutionibus Orbium Celestium pays tribute to al-Battani and acknowledges his indebtedness to al-Battani.
Indeed, from a more global perspective, the brilliant advances of not only Copernicus, but also Tycho Brahe, Kepler, Galileo, Descartes and Newton cannot be, and should not be, recalled without paying tribute to the fundamental and preparatory labor of such Arab mathematicians as al-Khwarizmi, Thabit ibn Qurrah, al-Biruni, Ulugh Beg and al-Battani.
In small recognition of al-Battani’s contributions to the advancement of mankind, one of the surface features of the moon (a plain eighty miles in diameter) was named after al- Battani, or as he is known in the West --Albategnius.
Abu-Abdullah Muhammad ibn Jabir al-Battani see Battani
Abu ‘Abd Allah Muhammad al-Battanisee Battani
Albategnius see Battani
Albatenius see Battani
Abu ‘Abd Allah Muhammad ibn Jabir ibn Sinan al-Battani al-Harrani al-Sabi’ see Battani
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