127,669 articles
Rating of perceived exertion
Rating of perceived exertion (RPE) is a psychometric scale on which a person rates how hard their physical exertion feels, used to monitor and prescribe exercise intensity.
Ratio analysis
Ratio analysis is a financial analysis method that computes ratios from a firm's balance sheet and income statement to assess profitability, liquidity, solvency, efficiency, and market valuation.
Ratio Educationis
Ratio Educationis was a royal decree issued by Queen Maria Theresa in 1777, the first comprehensive state regulation of public education in the Kingdom of Hungary.
Ration card (India)
A ration card in India is a state-issued document letting households buy subsidized rice and wheat from fair price shops under the Public Distribution System.
Rational choice model
Rational choice model (rational choice theory): formal social-science framework modeling choice as axiomatic utility maximization, foundational to neoclassical microeconomics, critiqued by bounded rationality and behavioral economics.
Rational expectations
Rational expectations, also called the rational expectations hypothesis, is an economic theory proposed by John Muth in 1961 and applied to macroeconomics by Robert Lucas in 1972.
Rational ignorance
Rational ignorance, from Anthony Downs's 1957 An Economic Theory of Democracy: voters stay uninformed because information costs exceed the negligible benefit of a non-decisive vote; studied via cue-taking, motivated ignorance, and electoral models.
Rational irrationality
Rational irrationality, coined by economist Bryan Caplan (Eastern Economic Journal 2000; Kyklos 2001), explains systematically biased, high-certitude political and religious beliefs as privately cheap consumption of pleasing false beliefs, extending rational ignorance and expressive voting.
Rationale for the 2026 Iran war
Rationale for the 2026 Iran war: the US and Israeli justifications for Operation Epic Fury, launched February 28, 2026, targeting Iran's missiles, navy, proxies, and nuclear program, and the intelligence, legal, and diplomatic disputes over those aims.
Rationale for the Iraq War
Rationale for the Iraq War: the US and UK justifications for the March 2003 invasion, chiefly Iraqi WMD, terrorism links, and democratization; later inquiries found the intelligence flawed and no stockpiles existed.
Rationalism
Rationalism, or epistemological rationalism, is the philosophical view that some knowledge comes from reason alone, independent of sense experience, classically represented by Descartes, Spinoza, and Leibniz.
Rationalist community
Rationalist community, also rationality community or rationalsphere: social movement formed around Overcoming Bias and LessWrong (Eliezer Yudkowsky, Robin Hanson) from 2006-2009, centered on Bayesian reasoning, cognitive bias, and AI risk, overlapping with effective altruism.
Rationality
Rationality: the property of conforming to standards of good cognition, divided into epistemic rationality of belief and instrumental rationality of means to ends; includes Herbert Simon's 1957 bounded rationality, satisficing, and the rationality wars.
Rationalization (psychology)
Rationalization (psychology): an unconscious defense mechanism, named by Ernest Jones in 1908, in which plausible false reasons justify intolerable motives; linked to Festinger's cognitive dissonance theory and rated a disavowal-level defense in the DMRS hierarchy.
Rationing
Rationing is the allocation of a scarce good by a rule other than price, such as queues or coupons, when price is held below its market-clearing level.
Rationing in the United Kingdom
Rationing in the United Kingdom: British WWII and postwar controls on food, clothing, petrol, and furniture, from petrol rationing in 1939 and food rationing on 8 January 1940 to the end of meat rationing in July 1954.
Ratko Mladić
Ratko Mladić, 'Butcher of Bosnia', Bosnian Serb VRS Main Staff commander (1992-1995) during the Sarajevo siege and Srebrenica genocide; convicted by the ICTY in 2017, life sentence upheld 2021, died in The Hague 27 August 2026.
Ratlines (World War II)
The Ratlines, also called the Vatican Ratlines, were clandestine escape routes that helped Nazi war criminals flee Europe after World War II, chiefly through Spain and Italy to Argentina.
Ratna Debnath
Ratna Debnath is an Indian politician who won the Panihati seat in 2026. Her career began after her daughter's death in 2024.
Ratna Manikya
Ratna Manikya (রত্ন মাণিক্য) was a ruler of Tripura in northeast India who reigned from 1464 to 1489, taking the throne with the Sultan of Bengal's help.
Ratnakara
Ratnakara (रत्नाकर), also called Rajanaka Ratnakara Vagisvara, was a ninth-century Sanskrit poet of Kashmir, best known for the Haravijaya, the longest extant Sanskrit court epic.
Ratnakirti
Ratnakirti (रत्नकीर्ति) was an Indian Buddhist scholar at the Vikramasila monastery-university, active in the first half of the eleventh century, a pupil of Jnanasrimitra best known for ten Sanskrit works on logic, epistemology, and metaphysics.
Ratnasimha (रत्नसिंह)
Ratnasimha (Ratan Singh, Rawal Ratan Singh), last Rawal-branch Guhila ruler of Mewar at Chittor, reigned 1302–1303, attested by the 1302 Dariba inscription; defeated in Alauddin Khalji's 1303 siege of Chittor.
Ratnavali
Ratnavali (रत्नावली) is a four-act Sanskrit natika, or court romance drama, attributed to King Harsha of Kanauj, telling of the Simhala princess Ratnavali and King Udayana.
Ratnesh Sada
Ratnesh Sada is an Indian Janata Dal (United) politician who has represented Sonbarsa in the Bihar assembly since 2010 and serves as Bihar's Disaster Management minister.
Ratnik (Ратник) (program)
Ratnik (Ратник, Warrior) is Russia's modular future infantry combat system: 6B47 helmet, 6B45 body armor, Strelets communications, fielded from 2014–2015 with about 300,000 sets delivered; its announced Sotnik successor stalled.
Ratnins
The Ratnins (रत्निन्, "jewel-bearers") were the high functionaries of the later Vedic royal household, including the royal priest, chief queen, and commander-in-chief, at whose houses the consecrated king offered sacrifices during the Rajasuya ceremony.
Ratramnus
Ratramnus, also recorded as Rotramus, was a ninth-century Benedictine monk of Corbie whose Eucharist treatise, burned in 1050 and misattributed for centuries, was consulted by King Charles the Bald.
Rattanakosin Kingdom
The Rattanakosin Kingdom (อาณาจักรรัตนโกสินทร์) was the Siamese kingdom founded in 1782 when King Rama I moved the capital to Bangkok, ending absolute Chakri rule in 1932.
Rattanakosin Kingdom (อาณาจักรรัตนโกสินทร์) (1782–1932)
Rattanakosin Kingdom (อาณาจักรรัตนโกสินทร์), 1782–1932, the Bangkok era of Siam under the Chakri dynasty, founded by Rama I; marked by the Nine Armies War, the 1855 Bowring-era trade treaty, reforms under Mongkut and Chulalongkorn, and the 1932 end of absolute monarchy.