Medieval Islamic scientific achievements encompassed a wide range of subject areas, especially
mathematics,
astronomy, and
medicine.
Alchemy and chemistry The early Islamic period saw the development of theoretical frameworks in
alchemy and
chemistry, laying the foundation for later advancements in both fields. The
sulfur-mercury theory of metals, first found in
Sirr al-khalīqa ("The Secret of Creation", c. 750–850,
falsely attributed to
Apollonius of Tyana), and in the writings attributed to
Jabir ibn Hayyan (written c. 850–950), remained the basis of theories of metallic composition until the 18th century. The
Emerald Tablet, a cryptic text that all later alchemists up to and including
Isaac Newton saw as the foundation of their art, first occurs in the
Sirr al-khalīqa and in one of the works attributed to Jabir. In practical chemistry, the works of Jabir, and those of the Persian alchemist and physician
Abu Bakr al-Razi (c. 865–925), contain the earliest systematic classifications of chemical substances. Alchemists were also interested in artificially creating such substances. Jabir describes the synthesis of
ammonium chloride (
sal ammoniac) from
organic substances,
Al-Battani (850–922) accurately determined the length of the
solar year. He contributed to the
Tables of Toledo, used by astronomers to predict the movements of the sun, moon and planets across the sky.
Copernicus (1473–1543) later used some of Al-Battani's astronomic tables.
Al-Zarqali (1028–1087) developed a more accurate
astrolabe, used for centuries afterwards. He constructed a
water clock in
Toledo, discovered that the Sun's
apogee moves slowly relative to the fixed stars, and obtained a good estimate of its motion for its rate of change.
Nasir al-Din al-Tusi (1201–1274) 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, and compiled the most
accurate astronomical tables available up to that time.
Botany and agronomy ,
cypress, and
sumac trees, in
Zakariya al-Qazwini's 13th century
Wonders of Creation The study of the natural world extended to a detailed examination of plants. The work done proved directly useful in the unprecedented growth of
pharmacology across the Islamic world. The use and cultivation of plants was documented in the 11th century by
Muhammad bin Ibrāhīm Ibn Bassāl of
Toledo in his book
Dīwān al-filāha (The Court of Agriculture), and by
Ibn al-'Awwam al-Ishbīlī (also called Abū l-Khayr al-Ishbīlī) of
Seville in his 12th century book
Kitāb al-Filāha (Treatise on Agriculture). Ibn Bassāl had travelled widely across the Islamic world, returning with a detailed knowledge of
agronomy that fed into the
Arab Agricultural Revolution. His practical and systematic book describes over 180 plants and how to propagate and care for them. It covered leaf- and root-vegetables, herbs, spices and trees.
Geography and cartography of
Piri Reis (1513) The spread of Islam across Western Asia and North Africa encouraged an unprecedented growth in trade and travel by land and sea as far away as Southeast Asia, China, much of Africa, Scandinavia and even Iceland. Geographers worked to compile increasingly accurate maps of the known world, starting from many existing but fragmentary sources.
Abu Zayd al-Balkhi (850–934), founder of the Balkhī school of cartography in Baghdad, wrote an atlas called
Figures of the Regions (Suwar al-aqalim).
Al-Biruni (973–1048) measured the radius of the Earth using a new method. It involved observing the height of a mountain at
Nandana (now in Pakistan).
Al-Idrisi (1100–1166) drew a map of the world for
Roger, the Norman King of Sicily (ruled 1105–1154). He also wrote the
Tabula Rogeriana (Book of Roger), a geographic study of the peoples, climates, resources and industries of the whole of the world known at that time. The
Ottoman admiral Piri Reis ( 1470–1553) made a map of the New World and West Africa in 1513. He made use of maps from Greece, Portugal, Muslim sources, and perhaps one made by
Christopher Columbus. He represented a part of a major tradition of Ottoman cartography. File:TabulaRogeriana upside-down.jpg| Modern copy of
al-Idrisi's 1154
Tabula Rogeriana, upside-down, north at top
Mathematics 's
Algebra Islamic mathematicians gathered, organised and clarified the mathematics they inherited from ancient Egypt, Greece, India, Mesopotamia and Persia, and went on to make innovations of their own. Islamic mathematics covered
algebra,
geometry and
arithmetic. Algebra was mainly used for recreation: it had few practical applications at that time. Geometry was studied at different levels. Some texts contain practical geometrical rules for surveying and for measuring figures. Theoretical geometry was a necessary prerequisite for understanding astronomy and optics, and it required years of concentrated work. Early in the Abbasid caliphate (founded 750), soon after the foundation of Baghdad in 762, some mathematical knowledge was assimilated by
al-Mansur's group of scientists from the pre-Islamic Persian tradition in astronomy. Astronomers from India were invited to the court of the caliph in the late eighth century; they explained the rudimentary
trigonometrical techniques used in Indian astronomy. Ancient Greek works such as
Ptolemy's
Almagest and
Euclid's Elements were translated into Arabic. By the second half of the ninth century, Islamic mathematicians were already making contributions to the most sophisticated parts of Greek geometry. Islamic mathematics reached its apogee in the Eastern part of the Islamic world between the tenth and twelfth centuries. Most medieval Islamic mathematicians wrote in Arabic, others in Persian. 's "Cubic equation and intersection of
conic sections"
Al-Khwarizmi (8th–9th centuries) was instrumental in the adoption of the
Hindu–Arabic numeral system and the development of
algebra, introduced methods of simplifying equations, and used
Euclidean geometry in his proofs. He was the first to treat algebra as an independent discipline in its own right, and presented the first systematic solution of
linear and
quadratic equations.
Ibn Ishaq al-Kindi (801–873) worked on cryptography for the
Abbasid Caliphate, and gave the first known recorded explanation of
cryptanalysis and the first description of the method of
frequency analysis.
Avicenna ( 980–1037) contributed to mathematical techniques such as
casting out nines.
Thābit ibn Qurra (835–901) calculated the solution to a
chessboard problem involving an exponential series.
Al-Farabi ( 870–950) attempted to describe, geometrically, the
repeating patterns popular in Islamic decorative motifs in his book
Spiritual Crafts and Natural Secrets in the Details of Geometrical Figures.
Omar Khayyam (1048–1131), known in the West as a poet, calculated the length of the year to within 5 decimal places, and found geometric solutions to all 13 forms of cubic equations, developing some
quadratic equations still in use.
Jamshīd al-Kāshī (c. 1380–1429) is credited with several theorems of trigonometry, including the
law of cosines, also known as Al-Kashi's Theorem. He has been credited with the invention of
decimal fractions, and with a
method like Horner's to calculate roots. He calculated
π correctly to 17 significant figures. Sometime around the seventh century, Islamic scholars adopted the
Hindu–Arabic numeral system, describing their use in a standard type of text
fī l-ḥisāb al hindī, (On the numbers of the Indians). A distinctive Western Arabic variant of the
Eastern Arabic numerals began to emerge around the 10th century in the
Maghreb and
Al-Andalus (sometimes called
ghubar numerals, though the term is not always accepted), which are the direct ancestor of the modern
Arabic numerals used throughout the world.
Medicine 's
Anatomy, Islamic society paid careful attention to medicine, following a
hadith enjoining the preservation of good health. Its physicians inherited knowledge and traditional medical beliefs from the civilisations of classical Greece, Rome, Syria, Persia and India. These included the writings of
Hippocrates such as on the theory of the
four humours, and the theories of
Galen.
al-Razi ( 865–925) identified smallpox and measles, and recognized fever as a part of the body's defenses. He wrote a 23-volume compendium of Chinese, Indian, Persian, Syriac and Greek medicine. al-Razi questioned the classical Greek medical theory of how the four humours regulate
life processes. He challenged Galen's work on several fronts, including the treatment of
bloodletting, arguing that it was effective.
al-Zahrawi (936–1013) was a surgeon whose most important surviving work is referred to as
al-Tasrif (Medical Knowledge). It is a 30-volume set mainly discussing medical symptoms, treatments, and pharmacology. The last volume, on surgery, describes surgical instruments, supplies, and pioneering procedures. Avicenna (c. 980–1037) wrote the major medical textbook,
The Canon of Medicine.
Optics and ophthalmology , Optics developed rapidly in this period. By the ninth century, there were works on physiological, geometrical and physical optics. Topics covered included mirror reflection.
Hunayn ibn Ishaq (809–873) wrote the book
Ten Treatises on the Eye; this remained influential in the West until the 17th century.
Abbas ibn Firnas (810–887) developed lenses for magnification and the improvement of vision.
Ibn Sahl ( 940–1000) discovered the law of refraction known as
Snell's law. He used the law to produce the first
Aspheric lenses that focused light without geometric aberrations. In the eleventh century
Ibn al-Haytham (Alhazen, 965–1040) rejected the Greek ideas about vision, whether the Aristotelian tradition that held that the form of the perceived object entered the eye (but not its matter), or that of Euclid and Ptolemy which held that the eye emitted a ray. Al-Haytham 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 suggested that light was reflected from different surfaces in different directions, thus causing objects to look different. He argued further that the 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, the concept that a hypothesis must be proved by experiments based on confirmable procedures or mathematical evidence, five centuries before
Renaissance scientists.
Pharmacology teaching the use of drugs. 15th-century
Great Canon of Avicenna Advances in
botany and
chemistry in the Islamic world encouraged developments in
pharmacology.
Muhammad ibn Zakarīya Rāzi (Rhazes) (865–915) promoted the medical uses of chemical compounds.
Abu al-Qasim al-Zahrawi (Abulcasis) (936–1013) pioneered the preparation of medicines by
sublimation and
distillation. His
Liber servitoris provides instructions for preparing
"simples" from which were
compounded the complex drugs then used. Sabur Ibn Sahl (died 869) was the first physician to describe a large variety of drugs and remedies for ailments.
Al-Muwaffaq, in the 10th century, wrote
The foundations of the true properties of Remedies, describing chemicals such as
arsenious oxide and
silicic acid. He distinguished between
sodium carbonate and
potassium carbonate, and drew attention to the poisonous nature of
copper compounds, especially copper
vitriol, and also of
lead compounds.
Al-Biruni (973–1050) wrote the
Kitab al-Saydalah (
The Book of Drugs), describing in detail the properties of drugs, the role of pharmacy and the duties of the pharmacist.
Ibn Sina (Avicenna) described 700 preparations, their properties, their mode of action and their indications. He devoted a whole volume to simples in
The Canon of Medicine. Works by
Masawaih al-Mardini ( 925–1015) and by
Ibn al-Wafid (1008–1074) were printed in
Latin more than fifty times, appearing as
De Medicinis universalibus et particularibus by
Mesue the Younger (died 1015) and as the
Medicamentis simplicibus by
Abenguefit (c. 997 – 1074) respectively.
Peter of Abano (1250–1316) translated and added a supplement to the work of al-Mardini under the title
De Veneris.
Ibn al-Baytar (1197–1248), in his
Al-Jami fi al-Tibb, described a thousand simples and drugs based directly on Mediterranean plants collected along the entire coast between Syria and Spain, for the first time exceeding the coverage provided by
Dioscorides in classical times.
Physics 's treatise on mechanical devices, c. 850 The fields of physics studied in this period, apart from optics and astronomy which are described separately, are aspects of
mechanics:
statics,
dynamics,
kinematics and
motion. In the sixth century
John Philoponus () rejected the
Aristotelian view of motion. He argued instead that an object acquires an inclination to move when it has a motive power impressed on it. In the eleventh century Ibn Sina adopted roughly the same idea, namely that a moving object has force which is dissipated by external agents like air resistance. Ibn Sina distinguished between "force" and "inclination" (
mayl); he claimed that an object gained
mayl when the object is in opposition to its natural motion. He concluded that continuation of motion depends on the inclination that is transferred to the object, and that the object remains in motion until the
mayl is spent. He also claimed that a projectile in a vacuum would not stop unless it is acted upon. That view accords with
Newton's first law of motion, on inertia. As a non-Aristotelian suggestion, it was essentially abandoned until it was described as "impetus" by
Jean Buridan (c. 1295–1363), who was likely influenced by Ibn Sina's
Book of Healing. Ibn-Sina's theory of
mayl tried to relate the velocity and weight of a moving object, a precursor of the concept of
momentum. Aristotle's theory of motion stated that a constant force produces a uniform motion;
Abu'l-Barakāt al-Baghdādī (c. 1080 – 1164/5) disagreed, arguing that velocity and acceleration are two different things, and that force is proportional to acceleration, not to velocity.
The Banu Musa brothers, Jafar-Muhammad, Ahmad and al-Hasan (c. early 9th century) invented automated devices described in their
Book of Ingenious Devices.
Zoology . Ninth century Many
classical works, including those of Aristotle, were transmitted from Greek to Syriac, then to Arabic, then to Latin in the Middle Ages.
Aristotle's zoology remained dominant in its field for two thousand years. The
Kitāb al-Hayawān (كتاب الحيوان, English:
Book of Animals) is a 9th-century
Arabic translation of
History of Animals: 1–10,
On the Parts of Animals: 11–14, and
Generation of Animals: 15–19. The book was mentioned by
Al-Kindī (died 850), and commented on by
Avicenna (Ibn Sīnā) in his
The Book of Healing.
Avempace (Ibn Bājja) and
Averroes (Ibn Rushd) commented on and criticised
On the Parts of Animals and
Generation of Animals. ==Significance==