لنستخرج كنوزا من المعرفة و الإبداع و العلم و الأفكار
Introduction The works of art featured in this unit were created with a practical purpose in mind. Together, they highlight achievements in three of the most developed scientific disciplines in the Islamic world: astronomy, astrology, and medicine. Scientists in the Islamic world drew on Greco-Roman, Indian, Persian, Egyptian, and Chinese traditions to formulate many of the principles that today are recognized as the foundation of modern science. One of the Islamic world’s most significant contributions to modern science was the translation of mathematical, medical, and astronomical texts from their original languages into Arabic. These texts, along with many other Greek and Roman writings, had long been forgotten in the West, and their translation into Arabic ensured their survival and transmission across the globe and through the centuries.
The Islamic scientific community was united by the Arabic language, but was religiously, ethnically, and geographically diverse. It included Muslims, Christians, Jews, Arabs, Persians, Indians, Turks, and Berbers. The so-called golden age of Islamic science (from the eighth to the fifteenth century) took place in regions and centers throughout the Islamic world, such as al-Andalus in Spain, the Near East, Central and West Asia, Ottoman Turkey, and India. The impact of Arab math and science on Western civilization is evident in the scientific and mathematical language we use today. Many scientific words in English derive from Arabic: alchemy, algebra, alkaline, antimony, chemistry, elixir, zero, alcohol, algorithm, almanac, azimuth, cipher, sine, zenith. In addition, many stars discovered by Arab astronomers still bear Arabic names. For instance, the star that comprises the tail of the constellation Cygnus is called Deneb, the Arabic word for tail. Astronomy and Astrology By the ninth century, Islam had expanded into regions where a knowledge of the stars and their movements had long helped in the calculation of time, the prediction of weather and river floodings, and navigation across trackless deserts. During the eighth and ninth centuries, under the rule of the first Islamic dynasties (the Umayyads and Abbasids), scientists built upon this knowledge to develop new theories and instruments. Court patronage also supported an intensive program of translation of Greek, Sanskrit, and Pahlavi (early Persian) astronomical texts into Arabic, a practice that was instrumental in preserving this important body of knowledge. One of the most influential of these translated works was Ptolemy’s Almagest (the Latinized version of the Arabic title al-Majisti, or “Great Compilation”). The treatise, which describes the circular motion of the sun and the planets around a fixed earth, became the most important point of departure for astronomers working in the Islamic world. Supported by their own observational records, they identified discrepancies between scientific models and reality and set out to create theories regarding the celestial bodies that would address these inconsistencies. Significantly, astronomical knowledge fulfilled a utilitarian function in the Muslim world by facilitating the proper ritual practice of Islam. Daily prayers occur at times determined by the sun’s position and are always performed facing the direction of the holy city of Mecca, where the Ka‘ba, Islam’s holiest shrine, is situated. The Islamic calendar is a lunar one, which means that every month starts when the new moon first becomes visible.
Precise observation of the moon is crucial to determine holidays and other key dates, such as the start of the month of Ramadan, when Muslims are required to fast during daylight hours. Though not considered a science today, astrology used to be regarded as a branch of astronomy. In practice, astrology is largely concerned with understanding the influence of the stars on earthly events. Astrologers therefore needed an in-depth understanding of the movement of the planets and the locations of the stars. Serious scientists such as Abu Ma‘shar al-Balkhi (787–886), al-Biruni (973–1048), and Nasir al-Din al-Tusi (1201–1274) all wrote astrological treatises. Observatories Observational astronomy flourished in the Islamic world, where sophisticated observatories and instruments were developed. Observatories were centers of learning and research that also housed libraries containing thousands of books. The Caliph al-Ma’mun (reigned 813–33) built the first observatory in Baghdad in the ninth century. His patronage enabled astronomers to prepare tables describing the motions of the sun and moon, star catalogues, and descriptions of the instruments used. The accuracy of medieval Islamic observatories and astronomical instruments was remarkable. In fact, the calculations of famous observatories in Samarqand (in present-day Uzbekistan) and Maragha (in present-day Iran) differ from contemporary calculations by only a fraction of a percent. In addition to the large stationary instruments at observatories, scientists working under Islamic patronage were also successful in developing smaller portable tools such as the astrolabe (used for mapping and astronomical calculations), the astrolabic quadrant, and the celestial globe. The astrolabic quadrant, shaped like a 90-degree pie segment, was used to record the location of stars and planets in the celestial sphere, the domelike shape the skies take when observed from the earth. The celestial globe (see the Austrian example from 1579 in the Museum’s collection, 17.190.636) was used for teaching and illustrative purposes, and for many was also a desirable decorative object. Over time, these portable tools made their way into Renaissance Europe, aiding in the development of similar astronomic instruments by European scientists. This is clearly seen in the astrolabes produced by sixteenth-century Italian and Flemish scholars, which are decorated with motifs and inscriptions similar to those on Islamic instruments. Moreover, Italian and Flemish scientists and architects produced detailed drawings of Near Eastern astrolabes, including refined reproductions of the engraved Arabic inscriptions. These drawings and astrolabes demonstrate knowledge of Arabic and an avid interest in Islamic instruments in sixteenth-century Europe.
Planispheric astrolabe
Link to the Theme of This Chapter Astrolabes were the most important astronomical instruments in the Islamic world and Europe until the early Renaissance. Astrolabes created in the Islamic world made their way to the West and shaped the production of these scientific tools in Europe. Function An astrolabe maps the spherical universe on a flat surface without compromising the exact angles between the celestial bodies. Thus, it can show the position of the stars and planets in the sky at a particular location and time. When given certain initial values, astrolabes can do a range of astronomical, astrological, and topographical calculations, such as measuring latitudes, telling time, and determining hours of daylight. They were also used to determine prayer times and the direction of Mecca. Description/Visual Analysis An astrolabe consists of a number of stacked circular plates, which rotate around the axis of a central pin (fig. 19). The topmost plate, the rete, was often decorated. In this example, an elegant cut-brass lattice forms the bismillah, the opening phrase of most chapters (suras) of the Qur’an. The degrees of latitude and geographical locations are engraved on the topmost plate. The name of the maker is on the back.
Context The earliest examples of Persian astrolabes date from the ninth and tenth centuries. This particular one was made in seventeenth-century Iran, a flourishing center of astrolabe production. Scientists and artisans in the Islamic world embellished and refined the astrolabe, which was originally an ancient Greek invention. Astrolabes produced in the Islamic world inspired those made in Europe. For example, this astrolabe and another by a Flemish maker, Arsenius, with a similar calligraphic design, were both based upon earlier Islamic prototypes.
