Medicine in the medieval Islamic world
In the history of medicine, Islamic medicine is the science of medicine developed in the Islamic Golden Age, written in Arabic, the lingua franca of Islamic civilization. Islamic medicine preserved and developed the medical knowledge of classical antiquity, including the major traditions of Hippocrates and Dioscorides. During the post-classical era, Islamic medicine was the most advanced in the world, integrating concepts of ancient Greek and Persian medicine as well as the ancient Indian tradition of Ayurveda, while making numerous advances and innovations. Islamic medicine, along with knowledge of classical medicine, was adopted in the medieval medicine of Western Europe, after European physicians became familiar with Islamic medical authors during the Renaissance of the 12th century. Medieval Islamic physicians retained their authority until the rise of medicine as a part of the natural sciences, beginning with the Age of Enlightenment, nearly six hundred years after their textbooks were opened by many people.
Aspects of their writings remain of interest to physicians today. Medicine was a central part of medieval Islamic culture. Responding to circumstances of time and place/location, Islamic physicians and scholars developed a large and complex medical literature exploring and synthesizing the theory and practice of medicine Islamic medicine was built on tradition, chiefly the theoretical and practical knowledge developed in Arabia and was known at Muhammad's time, ancient Hellenistic medicine such as Unani, ancient Indian medicine such as Ayurveda, the ancient Iranian Medicine of the Academy of Gundishapur; the works of ancient Greek and Roman physicians Hippocrates and Dioscorides had a lasting impact on Islamic medicine. Ophthalmology has been described as the most successful branch of medicine researched at the time, with the works of Ibn al-Haytham remaining an authority in the field until early modern times; the adoption by the newly forming Islamic society of the medical knowledge of the surrounding, or newly conquered, "heathen" civilizations had to be justified as being in accordance with the beliefs of Islam.
Early on, the study and practice of medicine was understood as an act of piety, founded on the principles of Imaan and Tawakkul. The Prophet not only instructed sick people to take medicine, but he himself invited expert physicians for this purpose. Muhammad's opinions on health issues, habits with regard to leading a healthy life, were collected early on, edited as a separate corpus of writings under the title Ṭibb an-Nabī. In the 14th century, Ibn Khaldun, in his work Muqaddimah provides a brief overview over what he called "the art and craft of medicine", separating the science of medicine from religion: You'll have to know that the origin of all maladies goes back to nutrition, as the Prophet – God bless him! – says with regard to the entire medical tradition, as known by all physicians if this is contested by the religious scholars. These are his words: "The stomach is the House of Illness, abstinence is the most important medicine; the cause of every illness is a poor digestion." The Sahih al-Bukhari, a collection of prophetic traditions, or hadith by Muhammad al-Bukhari refers to a collection of Muhammad's opinions on medicine, by his younger contemporary Anas bin-Malik.
Anas writes about two physicians who had treated him by cauterization and mentions that the prophet wanted to avoid this treatment and had asked for alternative treatments. On, there are reports of the caliph ʿUthmān ibn ʿAffān fixing his teeth with a wire made of gold, he mentions that the habit of cleaning one's teeth with a small wooden toothpick dates back to pre-islamic times. The "Prophetic medicine" was mentioned by the classical authors of Islamic medicine, but lived on in the materia medica for some centuries. In his Kitab as-Ṣaidana from the 10./11. Century, Al-Biruni refers to collected poems and other works dealing with, commenting on, the materia medica of the old Arabs; the most famous physician was Al-Ḥariṯ ben-Kalada aṯ-Ṯaqafī, who lived at the same time as the prophet. He is supposed to have been in touch with the Academy of Gondishapur he was trained there, he had a conversation once with Khosrow I Anushirvan about medical topics. Most the Arabian physicians became familiar with the Graeco-Roman and late Hellenistic medicine through direct contact with physicians who were practicing in the newly conquered regions rather than by reading the original or translated works.
The translation of the capital of the emerging Islamic world to Damascus may have facilitated this contact, as Syrian medicine was part of that ancient tradition. The names of two Christian physicians are known: Ibn Aṯāl worked at the court of Muawiyah I, the founder of the Umayyad dynasty; the caliph abused his knowledge. Abu l-Ḥakam, responsible for the preparation of drugs, was employed by Muawiah, his son and great-grandson were serving the Umayyad and Abbasid caliphate. These sources testify to the fact that the physicians of the emerging islamic society were familiar with the classical medical traditions at the times of the Umayyads; the medical knowledge arrived from Alexandria, was transferred by Syrian scholars, or translators, finding its way into the Islamic world. Few sources provide information about how the expanding Islamic society received any medical knowledge. A physician called Abdalmalik ben Abgar al-Kinānī from Kufa in Iraq is supposed to have worked at the medical school of Alexandria before he joined ʿUmar ibn ʿAbd al-ʿAzīz's court
The Renaissance is a period in European history, covering the span between the 14th and 17th centuries and marking the transition from the Middle Ages to modernity. The traditional view focuses more on the early modern aspects of the Renaissance and argues that it was a break from the past, but many historians today focus more on its medieval aspects and argue that it was an extension of the middle ages; the intellectual basis of the Renaissance was its version of humanism, derived from the concept of Roman Humanitas and the rediscovery of classical Greek philosophy, such as that of Protagoras, who said that "Man is the measure of all things." This new thinking became manifest in art, politics and literature. Early examples were the development of perspective in oil painting and the recycled knowledge of how to make concrete. Although the invention of metal movable type sped the dissemination of ideas from the 15th century, the changes of the Renaissance were not uniformly experienced across Europe: the first traces appear in Italy as early as the late 13th century, in particular with the writings of Dante and the paintings of Giotto.
As a cultural movement, the Renaissance encompassed innovative flowering of Latin and vernacular literatures, beginning with the 14th-century resurgence of learning based on classical sources, which contemporaries credited to Petrarch. In politics, the Renaissance contributed to the development of the customs and conventions of diplomacy, in science to an increased reliance on observation and inductive reasoning. Although the Renaissance saw revolutions in many intellectual pursuits, as well as social and political upheaval, it is best known for its artistic developments and the contributions of such polymaths as Leonardo da Vinci and Michelangelo, who inspired the term "Renaissance man"; the Renaissance began in the 14th century in Italy. Various theories have been proposed to account for its origins and characteristics, focusing on a variety of factors including the social and civic peculiarities of Florence at the time: its political structure, the patronage of its dominant family, the Medici, the migration of Greek scholars and texts to Italy following the Fall of Constantinople to the Ottoman Turks.
Other major centres were northern Italian city-states such as Venice, Milan and Rome during the Renaissance Papacy. The Renaissance has a long and complex historiography, and, in line with general scepticism of discrete periodizations, there has been much debate among historians reacting to the 19th-century glorification of the "Renaissance" and individual culture heroes as "Renaissance men", questioning the usefulness of Renaissance as a term and as a historical delineation; the art historian Erwin Panofsky observed of this resistance to the concept of "Renaissance": It is no accident that the factuality of the Italian Renaissance has been most vigorously questioned by those who are not obliged to take a professional interest in the aesthetic aspects of civilization – historians of economic and social developments and religious situations, most natural science – but only exceptionally by students of literature and hardly by historians of Art. Some observers have called into question whether the Renaissance was a cultural "advance" from the Middle Ages, instead seeing it as a period of pessimism and nostalgia for classical antiquity, while social and economic historians of the longue durée, have instead focused on the continuity between the two eras, which are linked, as Panofsky observed, "by a thousand ties".
The word Renaissance meaning "Rebirth", first appeared in English in the 1830s. The word occurs in Jules Michelet's 1855 work, Histoire de France; the word Renaissance has been extended to other historical and cultural movements, such as the Carolingian Renaissance and the Renaissance of the 12th century. The Renaissance was a cultural movement that profoundly affected European intellectual life in the early modern period. Beginning in Italy, spreading to the rest of Europe by the 16th century, its influence was felt in literature, art, politics, science and other aspects of intellectual inquiry. Renaissance scholars employed the humanist method in study, searched for realism and human emotion in art. Renaissance humanists such as Poggio Bracciolini sought out in Europe's monastic libraries the Latin literary and oratorical texts of Antiquity, while the Fall of Constantinople generated a wave of émigré Greek scholars bringing precious manuscripts in ancient Greek, many of which had fallen into obscurity in the West.
It is in their new focus on literary and historical texts that Renaissance scholars differed so markedly from the medieval scholars of the Renaissance of the 12th century, who had focused on studying Greek and Arabic works of natural sciences and mathematics, rather than on such cultural texts. In the revival of neo-Platonism Renaissance humanists did not reject Christianity. However, a subtle shift took place in the way that intellectuals approached religion, reflected in many other areas of cultural life. In addition, many Greek Christian works, including the Greek New Testament, were brought back from Byzantium to Western Europe and engaged Western scholars for the first time since late antiquity; this new engagement with Greek Christian works, the return to the original Greek of the Ne
Thomas the Slav
Thomas the Slav was a 9th-century Byzantine military commander, most notable for leading a wide-scale revolt in 821–23 against Emperor Michael II the Amorian. An army officer of Slavic origin from the Pontus region, Thomas rose to prominence, along with the future emperors Michael II and Leo V the Armenian, under the protection of general Bardanes Tourkos. After Bardanes' failed rebellion in 803, Thomas fell into obscurity until Leo V's rise to the throne, when Thomas was raised to a senior military command in central Asia Minor. After the murder of Leo and usurpation of the throne by Michael the Amorian, Thomas revolted, claiming the throne for himself. Thomas secured support from most of the themes and troops in Asia Minor, defeated Michael's initial counter-attack and concluded an alliance with the Abbasid Caliphate. After winning over the maritime themes and their ships as well, he crossed with his army to Europe and laid siege to Constantinople; the imperial capital withstood Thomas's attacks by land and sea, while Michael II called for help from the Bulgarian ruler khan Omurtag.
Omurtag attacked Thomas's army, but although repelled, the Bulgarians inflicted heavy casualties on Thomas's men, who broke and fled when Michael took to the field a few months later. Thomas and his supporters sought refuge in Arcadiopolis, where he was soon blockaded by Michael's troops. In the end, Thomas's supporters surrendered him in exchange for a pardon, he was executed. Thomas's rebellion was one of the largest in the Byzantine Empire's history, but its precise circumstances are unclear due to competing historical narratives, which have come to include claims fabricated by Michael to blacken his opponent's name. Various motives and driving forces have been attributed to Thomas and his followers; as summarized by the Oxford Dictionary of Byzantium, "Thomas's revolt has been variously attributed to a reaction against Iconoclasm, a social revolution and popular uprising, a revolt by the Empire's non-Greek ethnic groups, Thomas's personal ambitions, his desire to avenge Leo V." Its effects on the military position of the Empire vis-à-vis the Arabs, are disputed.
The 11th-century Theophanes Continuatus states that Thomas was descended from South Slavs resettled in Asia Minor by successive Byzantine emperors, while the 10th-century chronicler Genesios calls him "Thomas from Lake Gouzourou, of Armenian race". Most modern scholars support his Slavic descent and believe his birthplace to have been near Gaziura in the Pontus. Hence his epithet of "the Slav", applied to him only in modern times. Nothing is known about his family and early life, except that his parents were poor and that Thomas himself had received no education. Given that he was between 50 and 60 years old at the time of the rebellion, he was born around 760. Two different accounts of Thomas's life are recounted in both Genesios and Theophanes Continuatus. According to the first account, Thomas first appeared in 803 accompanying general Bardanes Tourkos, pursued a military career until launching his revolt in late 820. In the second version, he came to Constantinople as a poor youth and entered the service of a man with the high court rank of patrikios.
Discovered trying to commit adultery with his master's wife, Thomas fled to the Arabs in Syria, where he remained for 25 years. Pretending to be the murdered emperor Constantine VI, he led an Arab-sponsored invasion of Asia Minor, but was defeated and punished. Classical and Byzantine scholar J. B. Bury tried to reconcile the two narratives, placing Thomas's flight to the Abbasid Caliphate at around 788 and having him return to Byzantine service before 803, while the Russian scholar Alexander Vasiliev interpreted the sources as implying that Thomas fled to the Caliphate at Constantine VI's deposition in 797, that his participation in Bardanes's revolt must be discounted entirely; the second version of Thomas's story is explicitly preferred by Genesios and Theophanes Continuatus, is the only one recorded in 9th-century sources, namely the chronicle of George the Monk and the Life of Saints David and George of Lesbos. The French Byzantinist Paul Lemerle came to consider it an unreliable tradition created by his rival Michael II to discredit Thomas, rejected it altogether, preferring to rely on the first account alone.
Most modern scholars follow him in this interpretation. The first tradition relates that Thomas served as a spatharios to Bardanes Tourkos, the monostrategos of the eastern themes, who in 803 rose in rebellion against Emperor Nikephoros I. Alongside Thomas were two other young spatharioi in Bardanes's retinue, who formed a fraternal association: Leo the Armenian, the future Leo V, Michael the Amorian, the future Michael II. According to a hagiographic tradition, before launching his revolt, Bardanes, in the company of his three young protégés, is said to have visited a monk near Philomelion, reputed to foresee the future; the monk predicted what would indeed happen: that Bardanes's revolt would fail, that Leo and Michael would both become emperors, that Thomas would be acclaimed emperor and killed. When Bardanes did in fact rise up, he failed to win any widespread support. Leo and Michael soon abandoned him and defected to the imperial camp and were rewarded with senior military posts. Thomas alone remained loyal to Bardanes until his surrender.
In the aftermath of Bardanes's failure, Thomas disappears from the sources for ten years. Bury suggests that he fled
The Madrid Skylitzes is a richly illustrated illuminated manuscript of the Synopsis of Histories, by John Skylitzes, which covers the reigns of the Byzantine emperors from the death of Nicephorus I in 811 to the deposition of Michael VI in 1057. The manuscript was produced in Sicily in the 12th century, is now at the Biblioteca Nacional de España in Madrid, with the shelfmark MS Graecus Vitr. 26-2. It is the only surviving illustrated manuscript of a Greek chronicle, includes 574 miniatures, it is unclear whether these illustrations are copies of earlier Byzantine images or were newly created for this copy. Color facsimile edition by Militos Publishers, ISBN 960-8460-16-6. Vasiliki Tsamakda, The Illustrated Chronicle of Ioannes Skylitzes, Leiden 2002. Bente Bjørnholt and J. Burke, eds. "The Cultures and Contexts of the Madrid Skylitzes" International Medieval Congress, University of Leeds, 13 July 2004. Images from the Madrid Skylitzes World Digital Library page, PDF download of the Madrid Skylitzes Evans, Helen C.
& Wixom, William D. The glory of Byzantium: art and culture of the Middle Byzantine era, A. D. 843-1261, no. 338, 1997, The Metropolitan Museum of Art, New York, ISBN 9780810965072.
Architecture is both the process and the product of planning and constructing buildings or any other structures. Architectural works, in the material form of buildings, are perceived as cultural symbols and as works of art. Historical civilizations are identified with their surviving architectural achievements. Architecture is both the process and the product of planning and constructing buildings and other physical structures. Architecture can mean: A general term to describe other physical structures; the art and science of designing buildings and nonbuilding structures. The style of design and method of construction of buildings and other physical structures. A unifying or coherent form or structure. Knowledge of art, science and humanity; the design activity of the architect, from the macro-level to the micro-level. The practice of the architect, where architecture means offering or rendering professional services in connection with the design and construction of buildings, or built environments.
The earliest surviving written work on the subject of architecture is De architectura, by the Roman architect Vitruvius in the early 1st century AD. According to Vitruvius, a good building should satisfy the three principles of firmitas, venustas known by the original translation – firmness and delight. An equivalent in modern English would be: Durability – a building should stand up robustly and remain in good condition. Utility – it should be suitable for the purposes for which it is used. Beauty – it should be aesthetically pleasing. According to Vitruvius, the architect should strive to fulfill each of these three attributes as well as possible. Leon Battista Alberti, who elaborates on the ideas of Vitruvius in his treatise, De Re Aedificatoria, saw beauty as a matter of proportion, although ornament played a part. For Alberti, the rules of proportion were those that governed the idealised human figure, the Golden mean; the most important aspect of beauty was, therefore, an inherent part of an object, rather than something applied superficially, was based on universal, recognisable truths.
The notion of style in the arts was not developed until the 16th century, with the writing of Vasari: by the 18th century, his Lives of the Most Excellent Painters and Architects had been translated into Italian, French and English. In the early 19th century, Augustus Welby Northmore Pugin wrote Contrasts that, as the titled suggested, contrasted the modern, industrial world, which he disparaged, with an idealized image of neo-medieval world. Gothic architecture, Pugin believed, was the only "true Christian form of architecture." The 19th-century English art critic, John Ruskin, in his Seven Lamps of Architecture, published 1849, was much narrower in his view of what constituted architecture. Architecture was the "art which so disposes and adorns the edifices raised by men... that the sight of them" contributes "to his mental health and pleasure". For Ruskin, the aesthetic was of overriding significance, his work goes on to state that a building is not a work of architecture unless it is in some way "adorned".
For Ruskin, a well-constructed, well-proportioned, functional building needed string courses or rustication, at the least. On the difference between the ideals of architecture and mere construction, the renowned 20th-century architect Le Corbusier wrote: "You employ stone and concrete, with these materials you build houses and palaces:, construction. Ingenuity is at work, but you touch my heart, you do me good. I am happy and I say: This is beautiful; that is Architecture". Le Corbusier's contemporary Ludwig Mies van der Rohe said "Architecture starts when you put two bricks together. There it begins." The notable 19th-century architect of skyscrapers, Louis Sullivan, promoted an overriding precept to architectural design: "Form follows function". While the notion that structural and aesthetic considerations should be subject to functionality was met with both popularity and skepticism, it had the effect of introducing the concept of "function" in place of Vitruvius' "utility". "Function" came to be seen as encompassing all criteria of the use and enjoyment of a building, not only practical but aesthetic and cultural.
Nunzia Rondanini stated, "Through its aesthetic dimension architecture goes beyond the functional aspects that it has in common with other human sciences. Through its own particular way of expressing values, architecture can stimulate and influence social life without presuming that, in and of itself, it will promote social development.' To restrict the meaning of formalism to art for art's sake is not only reactionary. Among the philosophies that have influenced modern architects and their approach to building design are rationalism, structuralism, poststructuralism, phenomenology. In the late 20th century a new concept was added to those included in the compass of both structure and function, the consideration of sustainability, hence sustainable architecture. To satisfy the contemporary ethos a building should be constructed in a manner, environmentally friendly in terms of the production of its materials, its impact upon the natural and built environment of its surrounding area and the demands that it makes upon non-sustainable power sources for heating, cooling and waste management and lighting
A grenade is an explosive weapon thrown by hand, but can refer to projectiles shot out of grenade launchers. A grenade consists of an explosive charge, a detonating mechanism, firing pin inside the grenade to trigger the detonating mechanism. Once the soldier throws the grenade, the safety lever releases, the striker throws the safety lever away from the grenade body as it rotates to detonate the primer; the primer ignites the fuze. The fuze burns down to the detonator. There are several types of grenades like the fragmentation, high explosive concussion and smoke grenades. Fragmentation grenades are the most common in modern armies, they are missiles designed to disperse shrapnel on detonation. The body is made of a hard synthetic material or steel, which will provide limited fragmentation through sharding and splintering, though in modern grenades a pre-formed fragmentation matrix inside the grenade is used; the pre-formed fragmentation may be spherical, wire or notched wire. Most anti-personnel grenades are designed to detonate either on impact.
When the word grenade is used colloquially, it is assumed to refer to a fragmentation grenade. Stick grenades have a long handle attached to the grenade directly, providing leverage for longer throwing distance, at the cost of additional weight and length; the term "stick grenade" refers to the German Stielhandgranate style stick grenade introduced in 1915 and developed throughout World War I. A friction igniter was used. Grenades are round-shaped with a "pineapple" or "baseball"-style design, or an explosive charge on a handle, referred to as a "stick grenade"; the stick grenade design has been considered obsolete since the Cold War period. They saw extensive use in World War I and in World War II; the WWI and WWII era "stick grenade" was used in trench and built-up warfare by the Central Powers and Nazi Germany, while the Triple Entente and Allied powers would use some improvised earlier grenades or round-shaped fragmentation grenades. The word "grenade" is derived from Old French pomegranate and influenced by Spanish granada, as the bomb is reminiscent of the many-seeded fruit, together with its size and shape.
Its first use in English dates from the 1590s. Rudimentary incendiary grenades appeared in the Eastern Roman Empire, not long after the reign of Leo III. Byzantine soldiers learned that Greek fire, a Byzantine invention of the previous century, could not only be thrown by flamethrowers at the enemy but in stone and ceramic jars. Glass containers were employed; the use of Greek fire spread to Muslim armies in the Near East, from where it reached China by the 10th century. In China, during the Song Dynasty, weapons known as Zhen Tian Lei were created when Chinese soldiers packed gunpowder into ceramic or metal containers. In 1044, a military book Wujing Zongyao described various gunpowder recipes in which one can find, according to Joseph Needham, the prototype of the modern hand grenade; the mid-14th-century book Huolongjing, written by Jiao Yu, recorded an earlier Song-era cast iron cannon known as the "flying-cloud thunderclap cannon". The manuscript stated that: The shells are made of cast iron, as large as a bowl and shaped like a ball.
Inside they contain half a pound of'divine fire'. They are sent flying towards the enemy camp from an eruptor, when they get there a sound like a thunder-clap is heard, flashes of light appear. If ten of these shells are fired into the enemy camp, the whole place will be set ablaze... The first cast iron bombshells and grenades did not appear in Europe until 1467. A hoard of several hundred ceramic hand grenades was discovered during construction in front of a bastion of the Bavarian city of Ingolstadt, Germany dated to the 17th century. Many of the grenades igniters. Most the grenades were intentionally dumped in the moat of the bastion prior to 1723. In 1643, it is possible that "Grenados" were thrown amongst the Welsh at Holt Bridge during the English Civil War; the word "grenade" originated during the events surrounding the Glorious Revolution in 1688, where cricket ball-sized iron spheres packed with gunpowder and fitted with slow-burning wicks were first used against the Jacobites in the battles of Killiecrankie and Glen Shiel.
These grenades were not effective and, as a result, saw little use. Grenades were used during the Golden Age of Piracy: pirate Captain Thompson used "vast numbers of powder flasks, grenade shells, stinkpots" to defeat two pirate-hunters sent by the Governor of Jamaica in 1721. Improvised grenades were used from the mid-19th century, being useful in trench warfare. In a letter to his sister, Colonel Hugh Robert Hibbert described an improvised grenade, employed by British troops during the Crimean War: We have a new invention to annoy our friends in their pits, it consists in filling empty soda water bottles full of powder, old twisted nails and any other sharp or cutting thing we can find at the time, sticking a bit of tow-in for a fuse lighting it and throwing it into our neighbors’ pit where it bursts, to their great annoyance. You may
Science in the medieval Islamic world
Science in the medieval Islamic world was the science developed and practised during the Islamic Golden Age under the Umayyads of Córdoba, the Abbadids of Seville, the Samanids, the Ziyarids, the Buyids in Persia, the Abbasid Caliphate and beyond, spanning the period c. 800 to 1250. Islamic scientific achievements encompassed a wide range of subject areas astronomy and medicine. Other subjects of scientific inquiry included alchemy and chemistry, botany and cartography, pharmacology and zoology. Medieval Islamic science had practical purposes as well as the goal of understanding. For example, astronomy was useful for determining the Qibla, the direction in which to pray, botany had practical application in agriculture, as in the works of Ibn Bassal and Ibn al-'Awwam, geography enabled Abu Zayd al-Balkhi to make accurate maps. Islamic mathematicians such as Al-Khwarizmi and Jamshīd al-Kāshī made advances in algebra, trigonometry and Arabic numerals. Islamic doctors described diseases like smallpox and measles, challenged classical Greek medical theory.
Al-Biruni and others described the preparation of hundreds of drugs made from medicinal plants and chemical compounds. Islamic physicists such as Ibn Al-Haytham, Al-Bīrūnī and others studied optics and mechanics as well as astronomy, criticised Aristotle's view of motion; the significance of medieval Islamic science has been debated by historians. The traditionalist view holds that it lacked innovation, was important for handing on ancient knowledge to medieval Europe; the revisionist view holds. Whatever the case, science flourished across a wide area around the Mediterranean and further afield, for several centuries, in a wide range of institutions; the Islamic era began in 622. Islamic armies conquered Arabia and Mesopotamia displacing the Persian and Byzantine Empires from the region. Within a century, Islam had reached the area of present-day Portugal in the west and Central Asia in the east; the Islamic Golden Age spanned the periods of the Umayyad Caliphate and, in particular, the early phase of the succeeding Abbasid Caliphate, with stable political structures and flourishing trade.
Major religious and cultural works of the Islamic empire were translated into Arabic. Islamic culture inherited Greek, Indic and Persian influences. A new common civilisation formed, based on Islam. An era of high culture and innovation ensued, with rapid growth in population and cities; the Arab Agricultural Revolution in the countryside brought more crops and improved agricultural technology irrigation. This enabled culture to flourish. From the 8th century onwards, scholars such as Al-Kindi translated Indian, Assyrian and Greek knowledge, including the works of Aristotle, into Arabic; these translations supported advances by scientists across the Islamic world. Islamic science survived the initial Christian reconquest of Spain, including the fall of Seville in 1248, as work continued in the eastern centres. After the completion of the Spanish reconquest in 1492, the Islamic world went into an economic and cultural decline; the Abbasid caliphate was followed by the Ottoman Empire, centred in Turkey, the Safavid Empire, centred in Persia, where work in the arts and sciences continued.
Medieval Islamic scientific achievements encompassed a wide range of subject areas mathematics and medicine. Other subjects of scientific inquiry included physics and chemistry, geography and cartography. Alchemy well established before the rise of Islam, stemmed from the belief that substances comprised mixtures of the four Aristotelian elements in different proportions. Alchemists regarded gold as the noblest metal, held that other metals formed a series down to the basest, such as lead, they believed, that a fifth element, the elixir, could transform a base metal into gold. Jabir ibn Hayyan wrote based on his own experiments, he described laboratory techniques and experimental methods that would continue in use when alchemy had transformed into chemistry. Ibn Hayyan identified many substances, including nitric acids, he described processes such as sublimation and distillation. He made use of equipment such as the retort stand. Astronomy became a major discipline within Islamic science. Astronomers devoted effort both towards understanding the nature of the cosmos and to practical purposes.
One application involved the direction to face during prayer. Another was astrology, predicting events affecting human life and selecting suitable times for actions such as going to war or founding a city. Al-Battani determined the length of the solar year, he contributed to the Tables of Toledo, used by astronomers to predict the movements of the sun and planets across the sky. Copernicus used some of Al-Battani's astronomic tables. Al-Zarqali developed a more accurate astrolabe, used for centuries afterwards, he constructed a water clock in Toledo, discovered that the Sun's apogee moves relative to the fixed stars, obtained a good estimate of its motion for its rate of change. Nasir al-Din al-Tusi wrote an important revision to Ptolemy's 2nd-century celestial model; when Tusi became Helagu's astrologer, he was given an observatory and gained access to Chinese techniques and observations. He developed trigonometry as a separate field, compiled the