Tolong jelaskan mengenai abad ke-9 dari Daftar penemuan di dunia Islam pertengahan

Algebra discipline: Al-Khwarizmi is considered the father of the algebra discipline. The word Algebra comes from the Arabic الجبر (al-jabr) in the title of his book Ilm al-jabr wa'l-muḳābala. He was the first to treat algebra as an independent discipline in its own right.

Algebraic reduction and balancing, cancellation, and like terms: Al-Khwarizmi introduced reduction and balancing in algebra. It refers to the transposition of subtracted terms to the other side of an equation, that is, the cancellation of like terms on opposite sides of the equation, which the term al-jabr (algebra) originally referred to.

Automatic controls: The Banu Musa's preoccupation with automatic controls distinguishes them from their Greek predecessors, including the Banu Musa's "use of self-operating valves, timing devices, delay systems and other concepts of great ingenuity."

Chemical synthesis of a naturally occurring compound: The oldest known instructions for deriving an inorganic compound (sal ammoniac or ammonium chloride) from organic substances (such as plants, blood, and hair) by chemical means appear in the works attributed to Jabir ibn Hayyan (written c. 850–950).

Chess manual: The oldest known chess manual was in Arabic and dates to 840–850, written by Al-Adli ar-Rumi (800–870), a renowned Arab chess player, titled Kitab ash-shatranj (Book of Chess). During the Islamic Golden Age, many works on shatranj were written, recording for the first time the analysis of opening moves, game problems, the knight's tour, and many more subjects common in modern chess books.

Automatic crank: The non-manual crank appears in several of the hydraulic devices described by the Banū Mūsā brothers in their Book of Ingenious Devices. These automatically operated cranks appear in several devices, two of which contain an action which approximates to that of a crankshaft, anticipating Al-Jazari's invention by several centuries and its first appearance in Europe by over five centuries. However, the automatic crank described by the Banu Musa would not have allowed a full rotation, but only a small modification was required to convert it to a crankshaft.

Conical valve: A mechanism developed by the Banu Musa, of particular importance for future developments, was the conical valve, which was used in a variety of different applications.

Control valve: The Banu Musa brothers are credited with the first known use of conical valves as automatic controllers.

Cryptanalysis and frequency analysis: In cryptology, the first known recorded explanation of cryptanalysis was given by Al-Kindi (also known as "Alkindus" in Europe), in A Manuscript on Deciphering Cryptographic Messages. This treatise includes the first description of the method of frequency analysis.

Double-seat valve: It was invented by the Banu Musa, and has a modern appearance in their Book of Ingenious Devices.

Farabian theories: three philosophical theories of al-Farabi: the theory of ten intelligences, theory of the intellect and theory of prophecy.

Food chains: This was identified by al-Jahiz.

Glass manufacturing: Abbas ibn Firnas developed the process of creating glass from stones.

Lusterware: Lustre glazes were applied to pottery in Mesopotamia in the 9th century; the technique soon became popular in Persia and Syria. Earlier uses of lustre are known.

Hard soap: Hard toilet soap with a pleasant smell was produced in the Middle East during the Islamic Golden Age, when soap-making became an established industry. Recipes for soap-making are described by Muhammad ibn Zakariya al-Razi (c. 865–925), who also gave a recipe for producing glycerine from olive oil. In the Middle East, soap was produced from the interaction of fatty oils and fats with alkali. In Syria, soap was produced using olive oil together with alkali and lime. Soap was exported from Syria to other parts of the Muslim world and to Europe.

Mental institute: In 872, Ahmad ibn Tulun built a hospital in Cairo that provided care to the insane, which included music therapy.

Kerosene distillation: Although the Chinese made use of kerosene through extracting and purifying petroleum, the process of distilling crude oil/petroleum into kerosene, as well as other hydrocarbon compounds, was first written about in the 9th century by the Persian scholar Rāzi (or Rhazes). In his Kitab al-Asrar (Book of Secrets), the physician and chemist Razi described two methods for the production of kerosene, termed naft abyad ("white naphtha"), using an apparatus called an alembic.

Kerosene lamp: The first description of a simple lamp using crude mineral oil was provided by Persian alchemist al-Razi (Rhazes) in 9th century Baghdad, who referred to it as the "naffatah" in his Kitab al-Asrar (Book of Secrets).

Minaret: The first known minarets appeared in the early 9th century under Abbasid rule.

Music sequencer and mechanical musical instrument: The origin of automatic musical instruments dates back to the 9th century, when Persian inventors Banū Mūsā brothers invented a hydropowered organ using exchangeable cylinders with pins, and also an automatic flute playing machine using steam power. These were the earliest mechanical musical instruments, and the first programmable music sequencers.

Kamal: The kamal originated with Arab navigators of the late 9th century. The invention of the kamal allowed for the earliest known latitude sailing, and was thus the earliest step towards the use of quantitative methods in navigation.

Observatory and research institute: The oldest true observatory, in the sense of a specialized research institute, was built in 825, the Al-Shammisiyyah observatory, in Baghdad, Iraq.

Petroleum distillation: Crude oil was often distilled by Arabic chemists, with clear descriptions given in Arabic handbooks such as those of Muhammad ibn Zakarīya Rāzi (Rhazes).

Programmable machine and automatic flute player: The Banū Mūsā brothers invented a programmable automatic flute player and which they described in their Book of Ingenious Devices. It was the earliest programmable machine.

Sharbat and soft drink: In the medieval Middle East, a variety of fruit-flavoured soft drinks were widely drunk, such as sharbat, and were often sweetened with ingredients such as sugar, syrup and honey. Other common ingredients included lemon, apple, pomegranate, tamarind, jujube, sumac, musk, mint and ice. Middle Eastern drinks later became popular in medieval Europe, where the word "syrup" was derived from Arabic.

Sine quadrant: A type of quadrant used by medieval Arabic astronomers, it was described by Muhammad ibn Mūsā al-Khwārizmī in 9th century Baghdad.

Scimitar: The curved sword or "scimitar" was widespread throughout the Middle East from at least the Ottoman period, with early examples dating to Abbasid era (9th century) Khurasan.

Sugar mill: Sugar mills first appeared in the medieval Islamic world. They were first driven by watermills, and then windmills from the 9th and 10th centuries in what are today Afghanistan, Pakistan and Iran.

Early syringe: The Iraqi/Egyptian surgeon Ammar ibn Ali al-Mawsili invented an early syringe in the 9th century using a hollow glass tube, providing suction to remove cataracts from patients' eyes.

Systemic algebraic solution and completing the square: Al-Khwarizmi's popularizing treatise on algebra (The Compendious Book on Calculation by Completion and Balancing, c. 813–833 CE) presented the first systematic solution of linear and quadratic equations. One of his principal achievements in algebra was his demonstration of how to solve quadratic equations by completing the square, for which he provided geometric justifications.

Thabit numbers: Named after Thabit ibn Qurra

Throttling valve: It appears for the first time in the Banu Musa's Book of Ingenious Devices.

Variable structure control: Two-step level controls for fluids, a form of discontinuous variable structure controls, was developed by the Banu Musa brothers.

Wind-powered gristmill: The first wind-powered gristmills were built in the 9th and 10th centuries in what are now Afghanistan, Pakistan and Iran.

Windpump: Windpumps were used to pump water since at least the 9th century in what is now Afghanistan, Iran and Pakistan.