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🔗 Physics

Wigner's friend is a thought experiment in theoretical quantum physics, first conceived by the physicist Eugene Wigner in 1961., and developed into a thought experiment by David Deutsch in 1985. The scenario involves an indirect observation of a quantum measurement: An observer W observes another observer F who performs a quantum measurement on a physical system. The two observers then formulate a statement about the physical system's state after the measurement according to the laws of quantum theory. However, in most of the interpretations of quantum theory, the resulting statements of the two observers contradict each other. This reflects a seeming incompatibility of two laws in quantum theory: the deterministic and continuous time evolution of the state of a closed system and the probabilistic, discontinuous collapse of the state of a system upon measurement. Wigner's friend is therefore directly linked to the measurement problem in quantum mechanics with its famous Schrödinger's cat paradox.

🔗 International relations 🔗 History 🔗 Military history 🔗 Africa 🔗 Europe 🔗 Military history/African military history 🔗 British Empire 🔗 Military history/World War II 🔗 Colonialism 🔗 Countering systemic bias

The Scramble for Africa, also called the Partition of Africa or the Conquest of Africa, was the invasion, occupation, division, and colonisation of African territory by European powers during a short period known to historians as the New Imperialism (between 1881 and 1914). In 1870, only 10 percent of Africa was under formal European control; by 1914 this had increased to almost 90 percent of the continent, with only Ethiopia (Abyssinia), the Dervish state (a portion of present-day Somalia) and Liberia still being independent. There were multiple motivations for European colonizers, including desire for valuable resources available throughout the continent, the quest for national prestige, tensions between pairs of European powers, religious missionary zeal and internal African native politics.

The Berlin Conference of 1884, which regulated European colonisation and trade in Africa, is usually referred to as the ultimate point of the Scramble for Africa. Consequent to the political and economic rivalries among the European empires in the last quarter of the 19th century, the partitioning, or splitting up of Africa was how the Europeans avoided warring amongst themselves over Africa. The later years of the 19th century saw the transition from "informal imperialism" by military influence and economic dominance, to direct rule, bringing about colonial imperialism.

🔗 Economics

A job guarantee (JG) is an economic policy proposal aimed at providing a sustainable solution to the dual problems of inflation and unemployment. Its aim is to create full employment and price stability, by having the state promise to hire unemployed workers as an employer of last resort (ELR).

The economic policy stance currently dominant around the world uses unemployment as a policy tool to control inflation; when inflation rises, the government pursues contractionary fiscal or monetary policy, creating a buffer stock of unemployed people, reducing wage demands, and ultimately inflation. When inflationary expectations subside, expansionary policy aims to produce the opposite effect. In Marxian terms, the unemployed serve as a reserve army of labor. By contrast, in a job guarantee program, a buffer stock of employed people (employed in the job guarantee program) provides the same protection against inflation without the social costs of unemployment, hence potentially fulfilling the dual mandate of full employment and price stability.

🔗 United States 🔗 Biography 🔗 Computing 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 Chicago 🔗 Catholicism 🔗 United States/Iowa

Mary Kenneth Keller, B.V.M. (December 17, 1913 – January 10, 1985) was an American Roman Catholic religious sister, educator and pioneer in computer science. She and Irving C. Tang were the first two people to earn a doctorate in computer science in the United States.

🔗 Iran 🔗 Architecture 🔗 Food and drink

Yakhchāl (Persian: یخچال‎ "ice pit"; yakh meaning "ice" and chāl meaning "pit") is an ancient type of evaporative cooler. Above ground, the structure had a domed shape, but had a subterranean storage space. It was often used to store ice, but sometimes was used to store food as well. The subterranean space coupled with the thick heat-resistant construction material insulated the storage space year round. These structures were mainly built and used in Persia. Many that were built hundreds of years ago remain standing.

🔗 Biography 🔗 Aviation 🔗 France 🔗 Biography/science and academia 🔗 Brazil 🔗 Aviation/aerospace biography 🔗 Brazil/Education and Science in Brazil

Alberto Santos-Dumont (Brazilian Portuguese: [awˈbɛɾtu ˈsɐ̃tus duˈmõ]; 20 July 1873 – 23 July 1932) was a Brazilian inventor and aviation pioneer, one of the very few people to have contributed significantly to the development of both lighter-than-air and heavier-than-air aircraft.

The heir of a wealthy family of coffee producers, Santos-Dumont dedicated himself to aeronautical study and experimentation in Paris, where he spent most of his adult life. In his early career he designed, built, and flew hot air balloons and early dirigibles, culminating in his winning the Deutsch de la Meurthe prize on 19 October 1901 for a flight that rounded the Eiffel Tower. He then turned to heavier-than-air machines, and on 23 October 1906 his 14-bis made the first powered heavier-than-air flight in Europe to be certified by the Aéro-Club de France and the Fédération Aéronautique Internationale. His conviction that aviation would usher in an era of worldwide peace and prosperity led him to freely publish his designs and forego patenting his various innovations.

Santos-Dumont is a national hero in Brazil, where it is popularly held that he preceded the Wright brothers in demonstrating a practical airplane. Countless roads, plazas, schools, monuments, and airports there are dedicated to him, and his name is inscribed on the Tancredo Neves Pantheon of the Fatherland and Freedom. He was a member of the Brazilian Academy of Letters from 1931 until his suicide in 1932.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Free and open-source software 🔗 Plan 9

Plan 9 from Bell Labs is a distributed operating system, originating in the Computing Science Research Center (CSRC) at Bell Labs in the mid-1980s, and building on UNIX concepts first developed there in the late 1960s. The final official release was in early 2015.

Under Plan 9, UNIX's everything is a file metaphor is extended via a pervasive network-centric filesystem, and graphical user interface is assumed as a basis for almost all functionality, though it retains a heavily text-centric ideology.

The name Plan 9 from Bell Labs is a reference to the Ed Wood 1959 cult science fiction Z-movie Plan 9 from Outer Space. The name of the project's mascot is "Glenda, the Plan 9 Bunny". The system continues to be used and developed by operating system researchers and hobbyists.

🔗 Mathematics 🔗 Statistics 🔗 History of Science

Stigler's law of eponymy, proposed by University of Chicago statistics professor Stephen Stigler in his 1980 publication Stigler’s law of eponymy, states that no scientific discovery is named after its original discoverer. Examples include Hubble's law, which was derived by Georges Lemaître two years before Edwin Hubble, the Pythagorean theorem, which was known to Babylonian mathematicians before Pythagoras, and Halley's Comet, which was observed by astronomers since at least 240 BC (although its official designation is due to the first ever mathematical prediction of such astronomical phenomenon in the sky, not to its discovery). Stigler himself named the sociologist Robert K. Merton as the discoverer of "Stigler's law" to show that it follows its own decree, though the phenomenon had previously been noted by others.

🔗 Law 🔗 England

The man on the Clapham omnibus is a hypothetical ordinary and reasonable person, used by the courts in English law where it is necessary to decide whether a party has acted as a reasonable person would – for example, in a civil action for negligence. The character is a reasonably educated, intelligent but nondescript person, against whom the defendant's conduct can be measured.

The term was introduced into English law during the Victorian era, and is still an important concept in British law. It is also used in other Commonwealth common law jurisdictions, sometimes with suitable modifications to the phrase as an aid to local comprehension. The route of the original "Clapham omnibus" is unknown but London Buses route 88 was briefly branded as "the Clapham Omnibus" in the 1990s and is sometimes associated with the term.