HOME



picture info

Al-Sufi
ʿAbd al-Raḥmān al-Ṣūfī (; 7 December 90325 May 986) was a Persian astronomer. His work '' '' ("''The Book of Fixed Stars''"), written in 964, included both textual descriptions and illustrations. The Persian polymath Al-Biruni wrote that al-Ṣūfī's work on the ecliptic was carried out in Shiraz. Al-Ṣūfī lived at the Buyid court in Isfahan. Biography ʿAbd al-Rahmān al-Ṣūfī (full name: Abū’l-Ḥusayn ʿAbd al-Raḥmān ibn ʿUmar ibn Sahl al-Ṣūfī al-Rāzī) was one of the nine famous Muslim astronomers. He lived at the court of Emir 'Adud al-Dawla in Isfahan, and worked on translating and expanding ancient Greek astronomical works, especially the '' Almagest'' of Ptolemy. He made corrections to Ptolemy's star list, and his estimations of star brightness and magnitude deviated from those by Ptolemy; just over half of al-Ṣūfī's magnitudes being identical to Ptolemy's. A Persian, al-Ṣūfī wrote in Arabic, the lingua franca of the scientific Mu ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

The Book Of Fixed Stars
''The Book of Fixed Stars'' ( ', literally ''The Book of the Shapes of Stars'') is an astronomical text written by Abd al-Rahman al-Sufi (Azophi) around 964. Following the translation movement in the 9th century AD, the book was written in Arabic, the common language for scholars across the vast Islamic territories, although the author himself was Persian. It was an attempt to create a synthesis of the comprehensive star catalogue in Ptolemy's ''Almagest'' (books VII and VIII) with the indigenous Arabic astronomical traditions on the constellations (notably the Arabic constellation system of the ''Anwā). The original manuscript no longer survives as an autograph; however, the importance of tradition and the practice of diligence central to Islamic manuscript tradition have ensured the survival of the ''Book of Stars'' in later-made copies. Historical context The treatise was written in the Persian city of Shiraz, for the patron and Buyid emir 'Adud al-Dawla. Although al-Suf ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Islamic Golden Age
The Islamic Golden Age was a period of scientific, economic, and cultural flourishing in the history of Islam, traditionally dated from the 8th century to the 13th century. This period is traditionally understood to have begun during the reign of the Abbasid Caliphate, Abbasid caliph Harun al-Rashid (786 to 809) with the inauguration of the House of Wisdom, which saw Ulama, scholars from all over the Muslim world flock to Baghdad, the world's largest city at the time, to translate the known world's classical knowledge into Arabic and Persian language, Persian. The period is traditionally said to have ended with the collapse of the Abbasid caliphate due to Mongol invasions and conquests, Mongol invasions and the Siege of Baghdad (1258), Siege of Baghdad in 1258. There are a few alternative timelines. Some scholars extend the end date of the golden age to around 1350, including the Timurid Renaissance within it, while others place the end of the Islamic Golden Age as late as the en ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

'Adud Al-Dawla
Fannā (Panāh) Khusraw (), better known by his laqab of ʿAḍud al-Dawla (; 24 September 936 – 26 March 983) was an emir of the Buyid dynasty, ruling from 949 to 983. At the height of his power, he ruled an empire stretching from Makran to Yemen and the shores of the Mediterranean Sea. He is widely regarded as the greatest monarch of the Buyid dynasty, and by the end of his reign he was the most powerful ruler in the Middle East. Early life Fanna Khusraw was born in Isfahan on 24 September 936. He was the son of Rukn al-Dawla, the brother of Imad al-Dawla and Mu'izz al-Dawla. According to Ibn Isfandiyar, Fanna Khusraw's mother was the daughter of the Daylamites, Daylamite Firuzanids, Firuzanid nobleman al-Hasan ibn al-Fairuzan, who was the cousin of the prominent Daylamite military leader Makan ibn Kaki. In 948, Fanna Khusraw was chosen by his uncle Imad al-Dawla as his successor because he had no heir. Imad al-Dawla died in December 949, and thus Fanna Khusraw became th ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Albrecht Dürer
Albrecht Dürer ( , ;; 21 May 1471 – 6 April 1528),Müller, Peter O. (1993) ''Substantiv-Derivation in Den Schriften Albrecht Dürers'', Walter de Gruyter. . sometimes spelled in English as Durer or Duerer, was a German painter, Old master prints, printmaker, and history of geometry#Renaissance, theorist of the German Renaissance. Born in Free Imperial City of Nuremberg, Nuremberg, Dürer established his reputation and influence across Europe in his twenties due to his high-quality List of woodcuts by Dürer, woodcut prints. He was in contact with the major Italian artists of his time, including Raphael, Giovanni Bellini and Leonardo da Vinci, and from 1512 was patronized by Holy Roman Emperor, Emperor Maximilian I, Holy Roman Emperor, Maximilian I. Dürer's vast body of work includes List of engravings by Dürer, engravings, his preferred technique in his later prints, Altarpiece, altarpieces, portraits and self-portraits, watercolours and books. The woodcuts series are stylist ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Amir Al-umara
The office of (), variously rendered in English as emir of emirs, prince of princes, chief emir, and commander of commanders, was a senior military position in the 10th-century Abbasid Caliphate, whose holders in the decade after 936 came to supersede the civilian bureaucracy under the vizier and become effective regents, relegating the Abbasid caliphs to a purely ceremonial role. The office then formed the basis for the Buyid dynasty, Buyid control over the Abbasid caliphs and over Iraq until the mid-11th century. The title continued in use by Muslim states in the Middle East, but was mostly restricted to senior military leaders. It was also used in Norman Sicily for a few of the king's chief ministers. In the Abbasid Caliphate Background The first person to be titled was the commander Harun ibn Gharib, a cousin of the Caliph al-Muqtadir (), in 928. He was followed soon after by his rival, the eunuch Mu'nis al-Muzaffar (845–933), who served as commander-in-chief of the cal ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Egypt
Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northern coast of Egypt, the north, the Gaza Strip of Palestine and Israel to Egypt–Israel barrier, the northeast, the Red Sea to the east, Sudan to Egypt–Sudan border, the south, and Libya to Egypt–Libya border, the west; the Gulf of Aqaba in the northeast separates Egypt from Jordan and Saudi Arabia. Cairo is the capital, list of cities and towns in Egypt, largest city, and leading cultural center, while Alexandria is the second-largest city and an important hub of industry and tourism. With over 109 million inhabitants, Egypt is the List of African countries by population, third-most populous country in Africa and List of countries and dependencies by population, 15th-most populated in the world. Egypt has one of the longest histories o ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Alexandria
Alexandria ( ; ) is the List of cities and towns in Egypt#Largest cities, second largest city in Egypt and the List of coastal settlements of the Mediterranean Sea, largest city on the Mediterranean coast. It lies at the western edge of the Nile Delta, Nile River delta. Founded in 331 BC by Alexander the Great, Alexandria grew rapidly and became a major centre of Hellenic civilisation, eventually replacing Memphis, Egypt, Memphis, in present-day Greater Cairo, as Egypt's capital. Called the "Bride of the Mediterranean" and "Pearl of the Mediterranean Coast" internationally, Alexandria is a popular tourist destination and an important industrial centre due to its natural gas and petroleum, oil pipeline transport, pipelines from Suez. The city extends about along the northern coast of Egypt and is the largest city on the Mediterranean, the List of cities and towns in Egypt#Largest cities, second-largest in Egypt (after Cairo), the List of largest cities in the Arab world, fourth- ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Hellenistic
In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the Roman Empire, as signified by the Battle of Actium in 31 BC and the Roman conquest of Ptolemaic Egypt the following year, which eliminated the last major Hellenistic kingdom. Its name stems from the Ancient Greek word ''Hellas'' (, ''Hellás''), which was gradually recognized as the name for Greece, from which the modern historiographical term ''Hellenistic'' was derived. The term "Hellenistic" is to be distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all the ancient territories of the period that had come under significant Greek influence, particularly the Hellenized Middle East, after the conquests of Alexander the Great. After the Macedonian conquest of the Achaemenid Empire in ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Lingua Franca
A lingua franca (; ; for plurals see ), also known as a bridge language, common language, trade language, auxiliary language, link language or language of wider communication (LWC), is a Natural language, language systematically used to make communication possible between groups of people who do not share a First language, native language or dialect, particularly when it is a third language that is distinct from both of the speakers' native languages. Linguae francae have developed around the world throughout human history, sometimes for commercial reasons (so-called "trade languages" facilitated trade), but also for cultural, religious, diplomatic and administrative convenience, and as a means of exchanging information between scientists and other scholars of different nationalities. The term is taken from the medieval Mediterranean Lingua Franca, a Romance languages, Romance-based pidgin language used especially by traders in the Mediterranean Basin from the 11th to the 19th c ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Arabic
Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns language codes to 32 varieties of Arabic, including its standard form of Literary Arabic, known as Modern Standard Arabic, which is derived from Classical Arabic. This distinction exists primarily among Western linguists; Arabic speakers themselves generally do not distinguish between Modern Standard Arabic and Classical Arabic, but rather refer to both as ( "the eloquent Arabic") or simply ' (). Arabic is the List of languages by the number of countries in which they are recognized as an official language, third most widespread official language after English and French, one of six official languages of the United Nations, and the Sacred language, liturgical language of Islam. Arabic is widely taught in schools and universities around the wo ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Brightness
Brightness is an attribute of visual perception in which a source appears to be radiating/reflecting light. In other words, brightness is the perception dictated by the luminance of a visual target. The perception is not linear to luminance, and relies on the context of the viewing environment (for example, see White's illusion). Brightness is a subjective sensation of an object being observed and one of the color appearance parameters of many color appearance models, typically denoted as Q. Brightness refers to how much light ''appears to shine'' from something. This is a different perception than lightness, which is how light something appears ''compared to'' a similarly lit white object. The adjective '' bright'' derives from an Old English '' beorht'' with the same meaning via metathesis giving Middle English ''briht''. The word is from a Proto-Germanic ', ultimately from a PIE root with a closely related meaning, *' "white, bright". "Brightness" was formerly used as a ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]