900

Astronomy

Arabian astronomer Albategnius (Abu-'Abdullah Muhammad ibn Jabir Al-Battani) [b. Haran (Turkey), 858, d. Samarra (Iraq), 929] refines Ptolemy's work by making more careful measurements and introduces the use of trigonometry to Arabic astronomy. He calculates the length of the year and determines more accurately than his predecessors the precession of the equinoxes. See also 850 Astronomy.

The Persian physician and alchemist al-Razi, best known by his Latinized name of Rhazes, is the first to classify chemical substances into mineral, vegetable, animal, and derivative. He further classifies minerals into metals, spirits, salts, and stones and describes how to make plaster of Paris and metallic antimony. See also 750 Chemistry; 1250 Chemistry. (See biography.)

The Mississippian city now called Cahokia, near the confluence of the Mississippi and Ohio rivers, features a shrine atop a 6 hectare (15 acre), 30-m- (100-ft-) high temple mound and a local population of about 10,000. The temple mound is at this time the third largest structure of any kind in the Americas (after two pyramids in what is now Mexico). See also 700 Construction.

Arab chemists and physicians prepare alcohol by distilling wine. See also 3500 bce Food & agriculture; 1100 Food & agriculture; 1100 Food & agriculture.

The art of paper manufacture spreads from Baghdad to Cairo. See also 793 Materials; 1100 Materials.

Around this time real paper money -- that is, printed paper used as a medium of exchange -- is in use in Szechwan Province in China. See also 800 Materials; 1107 Materials.

The astronomy books of Albategnius offer the main means for European scholars to learn of trigonometry. The version in Albategnius's work is built mainly on use of the sine function. See also 628 Mathematics; 980 Mathematics.

Al-Razi (Rhazes) writes the first scientific paper on infectious diseases, describing smallpox and measles. His multivolume al-Hawi ("comprehensive book") includes all medical knowledge of the time and is used in training physicians until the 1600s. See also 400 bce Medicine & health; 1000 Medicine & health.

A school of medicine is founded in Salerno (Italy). It flourishes for centuries, becoming the University of Salerno in the twelfth century. See also 1150 Medicine & health.

This article is about year. For the number, see 900 (number). For the skateboarding trick, see 900 (skateboarding trick).

Eastern Hemisphere in 900 AD.

Millennium:	1st millennium
Centuries:	8th century - 9th century - 10th century
Decades:	870s  880s  890s  - 900s -  910s  920s  930s
Years:	897 898 899 - 900 - 901 902 903

900 by topic v • d • e

Politics

State leaders - Sovereign states

Birth and death categories

Births - Deaths

Establishment and disestablishment categories

Establishments - Disestablishments

900 in other calendars

Gregorian calendar	900 CM
Ab urbe condita	1653
Armenian calendar	349 ԹՎ ՅԽԹ
Bahá'í calendar	-944 – -943
Berber calendar	1850
Buddhist calendar	1444
Burmese calendar	262
Byzantine calendar	6408 – 6409
Chinese calendar	己未年十一月廿六日 (3536/3596-11-26) — to — 庚申年十二月初七日 (3537/3597-12-7)
Coptic calendar	616 – 617
Ethiopian calendar	892 – 893
Hebrew calendar	4660 – 4661
Hindu calendars
- Vikram Samvat	955 – 956
- Shaka Samvat	822 – 823
- Kali Yuga	4001 – 4002
Holocene calendar	10900
Iranian calendar	278 – 279
Islamic calendar	286 – 288
Japanese calendar
Korean calendar	3233
Thai solar calendar	1443
v • d • e

Year 900 (CM) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.

Events

By place

Asia

• Gyeonhwon formally establishes the kingdom of Hubaekje in southwestern Korea.
• Namwaran and his children, Lady Angkatan and Bukah, are granted pardon by the Datu of Tondo, as represented Jayadewa, Lord Minister of Pila, which released them of all their debts as inscribed in the Laguna Copperplate Inscription, Philippines.

Europe

• Harald Fairhair (of the Yngling or Scilfing Dynasty) subdues the petty kings of Norway and conquers the Orkney and Shetland Islands.

By topic

Religion

• February — Pope Benedict IV succeeds Pope John IX as the 117th pope.

Medicine

• The Persian scientist Rhazes distinguishes smallpox from measles in the course of his writings. Holding against any sort of orthodoxy, particularly Aristotle's physics, he maintains "the conception of an 'absolute' time, regarded by him as a never-ending flow".

Births

• Abu Jafar Khazeni, Persian astronomer and mathematician

Deaths

• August 13 — Zwentibold, last King of Lotharingia (b. 870)
• Domnall II, King of the Picts
• Fulk the Venerable, Archbishop of Rheims (assassinated by Count Baldwin II of Flanders)

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)