All articles starting with O
9,097 articles
Orders of magnitude (mass)
Orders of magnitude survey the masses of physical objects across known physics, from the neutrino mass limit near 8 × 10⁻³⁷ kg to a critical-density Universe's 6 × 10⁵² kg.
Orders of magnitude (numbers)
Orders of magnitude express a number's approximate size as the nearest power of ten, and two quantities differ by one order when one is about 10 times the other.
Orders of magnitude (time)
Orders of magnitude (time) are the successive powers of ten used to describe durations, from the Planck time of about 5.4 × 10⁻⁴⁴ seconds up to cosmic timescales.
Orders of precedence in the United Kingdom
Orders of precedence in the United Kingdom: official rankings of royals, clergy, peers, officers of state, honours holders and professionals, based on the 1539 Precedence Act and 1595 ordinance, used at state banquets and ceremonies.
Orders, decorations, and medals of Canada
Canadian Honours System: national orders, decorations, and medals created by the Sovereign and administered by the Governor General's Chancellery, founded on the 1967 Order of Canada, with valour, bravery, merit, and service awards.
Orders, decorations, and medals of China
Orders, decorations, and medals of China covers the PRC honor system created by the 2015 National Medals Law (Medal of the Republic, Friendship Medal, national honorary titles) and PLA military decorations, alongside the separate ROC (Taiwan) orders such as the Order of Brilliant Jade.
Orders, decorations, and medals of India
Orders, decorations, and medals of India: the President's honors system, covering gallantry awards (Param Vir Chakra through Shaurya Chakra), Yudh Seva and Vishisht Seva service medals, the Bharat Ratna and Padma civilian awards, police medals, and Jeevan Raksha Padak.
Orders, decorations, and medals of Nazi Germany
Orders, decorations, and medals of Nazi Germany: military, political, and civilian awards bestowed 1923–1945, from the Iron Cross and Knight's Cross to the Mother's Cross, denazified under the 1957 Federal Republic law.
Orders, decorations, and medals of Nigeria
Nigeria's national honours system: the Order of the Federal Republic and Order of the Niger (GCFR to MON), Federal Republic Medals, the separate NNOM merit award, 1979 quotas, and 2025 reform efforts.
Orders, decorations, and medals of Romania
Orders, decorations, and medals of Romania: national honours begun under Cuza (1860–1864), formalized with the 1877 Order of the Star of Romania, abolished in 1948 for Soviet-pattern awards, and rebuilt by Law 29/2000.
Orders, decorations, and medals of Samoa
Samoa's national honours system, based on the Merit Act 1992/1993 and Honours and Awards Act 1999, ranks civil and bravery awards, with the Order of Samoa (Poloaiga Sili a Samoa) as highest merit award and the Malietoa Cross as top bravery award.
Orders, decorations, and medals of the United Kingdom
Orders, decorations, and medals of the United Kingdom: the British honours system's state awards, including the Garter, Bath, St Michael and St George, Royal Victorian Order, Order of Merit, Order of the British Empire, gallantry awards, forfeiture, and foreign-award rules.
Ordesa-Viñamala Biosphere Reserve
Ordesa-Viñamala Biosphere Reserve, a UNESCO MaB site in Huesca, Aragon, Spanish Pyrenees; designated 1977 with Sierra de Grazalema as Spain's first biosphere reserves, expanded 2013 to 117,264.99 ha around Ordesa y Monte Perdido National Park.
Ordet
Ordet (The Word) is Carl Theodor Dreyer's 1955 Danish drama, adapted from Kaj Munk's 1932 play, about a West Jutland farming family divided by faith, ending in a resurrection miracle; Golden Lion winner.
Ordinal analysis
Ordinal analysis, also known as proof theoretic ordinal, is a proof theory research program assigning each formal theory a characteristic ordinal, begun with Gentzen's 1936 consistency proof of Peano arithmetic.
Ordinal collapsing function
An ordinal collapsing function is a proof theory function that assigns large uncountable ordinals smaller countable ones, introduced by Heinz Bachmann and central to analyzing impredicative theories via the Bachmann–Howard ordinal.
Ordinal data
Ordinal data are categorical data whose values can be logically ordered or ranked, such as grades, clothing sizes, and Likert responses, while the spacing between categories is unknown or unequal.
Ordinal indicator
Ordinal indicator: the raised º (U+00BA) and ª (U+00AA) signs marking gendered ordinal numbers in Spanish, Portuguese, and Italian; distinct from the degree sign, rooted in Latin ablative scribal practice.
Ordinal notation
An ordinal notation is a formal system of finite expressions with a computable ordering that names ordinals, central to ordinal analysis in proof theory and to proving program termination.
Ordinal number
An ordinal number (or ordinal) is the order type of a well-ordered set, introduced by Georg Cantor in 1883 to extend natural numbers to infinite positions.
Ordinance 50
Ordinance 50 was a Cape Colony law of 1828 granting Khoikhoi and other free people of color freedom of movement, land ownership, and equality before the law.
Ordinance on Dajōkan System
The Ordinance on Dajōkan System (太政官職制) was Meiji-era legislation prescribing the organization of the Dajōkan, Japan's Grand Council of State, which governed until the cabinet system replaced it in 1885.
Ordinance on the High Treason Incident prosecutions
The Ordinance on the High Treason Incident prosecutions (大逆事件関連法令) is the Japanese law, chiefly Article 73 of the 1907 Criminal Code, under which the 1910 High Treason Incident was prosecuted.
Ordinance on the Privy Council
The Ordinance on the Privy Council (枢密院官制) was an 1888 Japanese imperial ordinance that created the Privy Council, the emperor's supreme advisory body, which was abolished in 1947.
Ordinance on the Shizoku
The Ordinance on the Shizoku (士族の職業許可) was a set of Meiji edicts of 1869 to 1871 permitting the former samurai class to take up agriculture, commerce, and industry.
Ordinances of Discovery and New Settlements
The Ordinances of Discovery and New Settlements (Ordenanzas de descubrimiento, nueva población y pacificación de 1573) were issued by Philip II in 1573, replacing conquest with pacification in the Indies.
Ordinances of Jin (Jin ling)
The Ordinances of Jin (晋令) were the administrative ordinances of China's Western Jin dynasty, a 40-juan code of 2,306 articles whose original text is now lost.
Ordinances of Viceroy Toledo
The Ordinances of Viceroy Toledo (Ordenanzas del virrey Toledo) are the laws issued by Francisco de Toledo, viceroy of Peru from 1569 to 1581, governing the Andes.
Ordinary (Alex Warren song)
"Ordinary" is a 2025 love ballad by American singer-songwriter Alex Warren, released February 7, 2025 as the lead single from his debut album You'll Be Alright, Kid.
Ordinary (heraldry)
Ordinary (heraldry): a simple geometric charge such as the pale, fess, bend, chevron, cross, or saltire; also a reference book of coats of arms organized by blazon for conflict checking.