Science in the medieval Islamic world
In 762, the Abbasid caliph Al-Mansur founded Baghdad as a new capital for his empire. This city became the center of a massive translation movement that began in the late eighth century. Scholars gathered there to translate works from Greek, Persian, Indian, and Assyrian traditions into Arabic. The period known as the Islamic Golden Age lasted roughly between 786 and 1258. During these centuries, stable political structures allowed trade and culture to flourish across a vast region stretching from Portugal to Central Asia. An Arab Agricultural Revolution improved irrigation systems and increased crop yields. This agricultural growth supported larger populations and enabled cities to expand rapidly. The resulting environment fostered an era of high culture and innovation. Religious and cultural works were translated into both Arabic and occasionally Persian. A new common civilization formed based on Islam, integrating diverse influences.
Islamic mathematicians adopted the Hindu-Arabic numeral system around the seventh century. They described this adoption in texts titled fī l-ħisāb al hindī, meaning On the numbers of the Indians. Al-Khwarizmi lived during the eighth and ninth centuries and was instrumental in developing algebra as an independent discipline. He presented the first systematic solution of linear and quadratic equations. His work introduced methods for simplifying equations using Euclidean geometry. Omar Khayyam calculated the length of the year to within five decimal places. He found geometric solutions to all thirteen forms of cubic equations. Jamshīd al-Kāshī calculated pi correctly to seventeen significant figures. He is credited with inventing decimal fractions and a method similar to Horner's rule for calculating roots. A distinctive Western Arabic variant of numerals emerged around the tenth century in the Maghreb and Al-Andalus region. These numerals are the direct ancestors of modern Arabic numerals used worldwide today.
Astronomers devoted effort toward understanding the nature of the cosmos and practical purposes like determining prayer directions. Al-Battani lived between 850 and 922 and accurately determined the length of the solar year. He contributed to the Tables of Toledo which were later used by Copernicus. Al-Zarqali lived from 1028 to 1087 and developed a more accurate astrolabe used for centuries afterwards. He constructed a water clock in Toledo and discovered that the Sun's apogee moves slowly relative to fixed stars. Nasir al-Din al-Tusi lived from 1201 to 1274 and wrote an important revision to Ptolemy's second-century celestial model. When Tusi became Helagu's astrologer, he was given an observatory and gained access to Chinese techniques. He developed trigonometry as a separate field and compiled the most accurate astronomical tables available up to that time. The Tusi couple was a mathematical device invented by him to model not perfectly circular motions of planets.
Islamic society paid careful attention to medicine following a hadith enjoining the preservation of good health. Physicians inherited knowledge from classical Greece, Rome, Syria, Persia, and India including writings of Hippocrates and Galen. Al-Razi lived between 865 and 925 and identified smallpox and measles while recognizing fever as part of the body's defenses. He wrote a twenty-three-volume compendium of Chinese, Indian, Persian, Syriac, and Greek medicine. Al-Zahrawi lived from 936 to 1013 and his most important surviving work is referred to as al-Tasrif. This thirty-volume set discusses medical symptoms, treatments, and pharmacology with the last volume focusing on surgery. Avicenna lived from 980 to 1037 and wrote the major medical textbook known as The Canon of Medicine. Ibn al-Nafis lived from 1213 to 1288 and wrote an influential book largely replacing Avicenna's Canon in the Islamic world. One commentary discovered in 1924 described the circulation of blood through the lungs. Sabur Ibn Sahl died in 869 and was the first physician to describe a large variety of drugs and remedies for ailments.
Optics developed rapidly during this period with works covering physiological, geometrical, and physical optics by the ninth century. Hunayn ibn Ishaq lived from 809 to 873 and wrote Ten Treatises on the Eye which remained influential in the West until the seventeenth century. Abbas ibn Firnas lived from 810 to 887 and developed lenses for magnification and vision improvement. Ibn Sahl lived from 940 to 1000 and discovered the law of refraction now known as Snell's law. He used this law to produce the first aspheric lenses that focused light without geometric aberrations. Ibn al-Haytham lived from 965 to 1040 and rejected Greek ideas about vision whether Aristotelian or Euclidean. He proposed in his Book of Optics that vision occurs by way of light rays forming a cone with its vertex at the center of the eye. He argued further that mathematics of reflection and refraction needed to be consistent with the anatomy of the eye. He was also an early proponent of the scientific method requiring hypotheses proved by experiments based on confirmable procedures or mathematical evidence.
The spread of Islam across Western Asia and North Africa encouraged unprecedented growth in trade and travel by land and sea. Geographers worked to compile increasingly accurate maps starting from many existing but fragmentary sources. Abu Zayd al-Balkhi lived between 850 and 934 and founded the Balkhī school of cartography in Baghdad. He wrote an atlas called Figures of the Regions. Al-Biruni lived from 973 to 1048 and measured the radius of the Earth using a new method involving observation of a mountain height at Nandana now located in Pakistan. Al-Idrisi lived from 1100 to 1166 and drew a map of the world for Roger, the Norman King of Sicily who ruled from 1105 to 1154. He also wrote the Tabula Rogeriana describing peoples, climates, resources, and industries of the whole known world. The Ottoman admiral Piri Reis lived from 1470 to 1553 and made a map of the New World and West Africa in 1513. He used maps from Greece, Portugal, Muslim sources, and perhaps one made by Christopher Columbus.
Muslim scientists helped lay foundations for experimental science with contributions to the scientific method and empirical approaches. Their positive achievement was simply to flourish for centuries in wide-ranging institutions from observatories to libraries. These institutions included madrasas, hospitals, and courts both during the Islamic Golden Age and for some centuries afterwards. It did not lead to a Scientific Revolution like that in Early modern Europe but such external comparisons are probably to be rejected as imposing chronologically and culturally alien standards on a successful medieval culture. The fields studied included mechanics aspects like statics, dynamics, kinematics, and motion alongside optics and astronomy. Ibn Sina adopted ideas about force and inclination similar to those later described as impetus by Jean Buridan. The Banu Musa brothers invented automated devices described in their Book of Ingenious Devices around the early ninth century. Zoology remained dominant for two thousand years with works transmitted from Greek to Syriac then to Arabic before Latin translation.
Common questions
When did the Islamic Golden Age last and what was its duration?
The Islamic Golden Age lasted roughly between 786 and 1258. This period saw stable political structures that allowed trade and culture to flourish across a vast region stretching from Portugal to Central Asia.
Who invented algebra and when did Al-Khwarizmi live?
Al-Khwarizmi lived during the eighth and ninth centuries and was instrumental in developing algebra as an independent discipline. He presented the first systematic solution of linear and quadratic equations using methods for simplifying equations based on Euclidean geometry.
What medical discoveries did Al-Razi make between 865 and 925?
Al-Razi lived between 865 and 925 and identified smallpox and measles while recognizing fever as part of the body's defenses. He wrote a twenty-three-volume compendium of Chinese, Indian, Persian, Syriac, and Greek medicine.
How did Ibn al-Haytham contribute to the field of optics between 965 and 1040?
Ibn al-Haytham lived from 965 to 1040 and proposed in his Book of Optics that vision occurs by way of light rays forming a cone with its vertex at the center of the eye. He argued further that mathematics of reflection and refraction needed to be consistent with the anatomy of the eye and was an early proponent of the scientific method requiring hypotheses proved by experiments.
When did Piri Reis create his map of the New World and West Africa?
The Ottoman admiral Piri Reis lived from 1470 to 1553 and made a map of the New World and West Africa in 1513. He used maps from Greece, Portugal, Muslim sources, and perhaps one made by Christopher Columbus.