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🔗 Philosophy 🔗 Philosophy/Logic 🔗 Game theory

In philosophy and mathematics, Newcomb's paradox, also referred to as Newcomb's problem, is a thought experiment involving a game between two players, one of whom is able to be able to predict the future.

Newcomb's paradox was created by William Newcomb of the University of California's Lawrence Livermore Laboratory. However, it was first analyzed in a philosophy paper by Robert Nozick in 1969, and appeared in the March 1973 issue of Scientific American, in Martin Gardner's "Mathematical Games." Today it is a much debated problem in the philosophical branch of decision theory.

🔗 Statistics 🔗 Futures studies

The Delphi method or Delphi technique ( DEL-fy; also known as Estimate-Talk-Estimate or ETE) is a structured communication technique or method, originally developed as a systematic, interactive forecasting method which relies on a panel of experts. The technique can also be adapted for use in face-to-face meetings, and is then called mini-Delphi or Estimate-Talk-Estimate (ETE). Delphi has been widely used for business forecasting and has certain advantages over another structured forecasting approach, prediction markets.

Delphi is based on the principle that forecasts (or decisions) from a structured group of individuals are more accurate than those from unstructured groups. The experts answer questionnaires in two or more rounds. After each round, a facilitator or change agent provides an anonymised summary of the experts' forecasts from the previous round as well as the reasons they provided for their judgments. Thus, experts are encouraged to revise their earlier answers in light of the replies of other members of their panel. It is believed that during this process the range of the answers will decrease and the group will converge towards the "correct" answer. Finally, the process is stopped after a predefined stop criterion (e.g., number of rounds, achievement of consensus, stability of results), and the mean or median scores of the final rounds determine the results.

Special attention has to be paid to the formulation of the Delphi theses and the definition and selection of the experts in order to avoid methodological weaknesses that severely threaten the validity and reliability of the results.

🔗 Lists 🔗 Brands

The following three lists of generic and genericized trademarks are:

• marks which were originally legally protected trademarks, but have been genericized and have lost their legal status due to becoming generic terms,
• marks which have been abandoned and are now generic terms
• marks which are still legally protected as trademarks, at least in some jurisdictions

🔗 Mathematics

In mathematics and computing, Fibonacci coding is a universal code which encodes positive integers into binary code words. It is one example of representations of integers based on Fibonacci numbers. Each code word ends with "11" and contains no other instances of "11" before the end.

The Fibonacci code is closely related to the Zeckendorf representation, a positional numeral system that uses Zeckendorf's theorem and has the property that no number has a representation with consecutive 1s. The Fibonacci code word for a particular integer is exactly the integer's Zeckendorf representation with the order of its digits reversed and an additional "1" appended to the end.

🔗 United States 🔗 Biography 🔗 Chicago 🔗 African diaspora 🔗 United States/FBI 🔗 Civil Rights Movement 🔗 Illinois 🔗 Biography/Actors and Filmmakers

Fredrick Allen Hampton (August 30, 1948 – December 4, 1969) was an American activist and revolutionary socialist. He came to prominence in Chicago as chairman of the Illinois chapter of the Black Panther Party (BPP), and deputy chairman of the national BPP. In this capacity, he founded a prominent multicultural political organization, the Rainbow Coalition that initially included the Black Panthers, Young Patriots and the Young Lords, and an alliance among major Chicago street gangs to help them end infighting, and work for social change.

In 1967, Hampton was identified by the Federal Bureau of Investigation as a radical threat. The FBI tried to subvert his activities in Chicago, sowing disinformation among these groups and placing a counterintelligence operative in the local Panthers. In December 1969, Hampton was shot and killed in his bed during a predawn raid at his Chicago apartment by a tactical unit of the Cook County State's Attorney's Office in conjunction with the Chicago Police Department and the Federal Bureau of Investigation; during the raid, another Panther was killed and several seriously wounded. In January 1970, a coroner's jury held an inquest and ruled the deaths of Hampton and Mark Clark to be justifiable homicide.

A civil lawsuit was later filed on behalf of the survivors and the relatives of Hampton and Clark. It was resolved in 1982 by a settlement of $1.85 million; the City of Chicago, Cook County, and the federal government each paid one-third to a group of nine plaintiffs. Given revelations about the illegal COINTELPRO program and documents associated with the killings, scholars now widely consider Hampton's death an assassination under the FBI's initiative.

🔗 Aviation 🔗 Disaster management 🔗 Aviation/Aviation accident 🔗 Occupational Safety and Health

Aviation safety means the state of an aviation system or organization in which risks associated with aviation activities, related to, or in direct support of the operation of aircraft, are reduced and controlled to an acceptable level. It encompasses the theory, practice, investigation, and categorization of flight failures, and the prevention of such failures through regulation, education, and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.

Aviation safety should not be confused with airport security which includes all of the measures taken to combat intentional malicious acts.

🔗 United States 🔗 Biography 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 History of Science 🔗 Austria 🔗 Jewish Women 🔗 Biography/Actors and Filmmakers

Hedy Lamarr (), born Hedwig Eva Maria Kiesler (November 9, 1914 – January 19, 2000), was an Austrian-born American actress, inventor and film producer. She was part of 30 films in an acting career spanning 28 years, and co-invented an early version of frequency-hopping spread spectrum.

After a brief early film career in Czechoslovakia, including the controversial Ecstasy (1933), she fled from her husband, a wealthy Austrian ammunition manufacturer, and secretly moved to Paris. Traveling to London, she met Louis B. Mayer, head of Metro-Goldwyn-Mayer (MGM) studio, who offered her a movie contract in Hollywood, where he began promoting her as the "world's most beautiful woman".

She became a star with her performance in Algiers (1938), her first film made in the United States. Her MGM films include Lady of the Tropics (1939), Boom Town (1940), H.M. Pulham, Esq. (1941), and White Cargo (1942). Dismayed with her MGM contract, Lamarr co-founded a new production studio and starred in its films including The Strange Woman (1946), and Dishonored Lady (1947). Her greatest success was as Delilah in Cecil B. DeMille's Samson and Delilah (1949). She also acted on television before the release of her final film, The Female Animal (1958). She was honored with a star on the Hollywood Walk of Fame in 1960.

At the beginning of World War II, Lamarr and composer George Antheil developed a radio guidance system for Allied torpedoes, intended to use frequency-hopping spread spectrum technology to defeat the threat of jamming by the Axis powers. She also helped to improve aviation designs for Howard Hughes while they dated during the war. Although the US Navy did not adopt Lamarr and Antheil's invention until 1957, various spread-spectrum techniques are incorporated into Bluetooth technology and are similar to methods used in legacy versions of Wi-Fi. Recognition of the value of their work resulted in the pair being posthumously inducted into the National Inventors Hall of Fame in 2014.

🔗 Finance & Investment 🔗 Economics 🔗 India 🔗 Arab world

Hawala or hewala (Arabic: حِوالة‎ ḥawāla, meaning transfer or sometimes trust), also known as havaleh in Persian, and xawala or xawilaad in Somali, is a popular and informal value transfer system based not on the movement of cash, or on telegraph or computer network wire transfers between banks, but instead on the performance and honour of a huge network of money brokers (known as hawaladars). While hawaladars are spread throughout the world, they are primarily located in the Middle East, North Africa, the Horn of Africa, and the Indian subcontinent, operating outside of, or parallel to, traditional banking, financial channels, and remittance systems. Hawala follows Islamic traditions but its use is not limited to Muslims.

🔗 International relations 🔗 Human rights 🔗 History 🔗 Islam 🔗 International relations/International law 🔗 Sociology 🔗 Discrimination 🔗 International relations/United Nations

The history of slavery in the Muslim world began with institutions inherited from pre-Islamic Arabia; and the practice of keeping slaves subsequently developed in radically different ways, depending on social-political factors such as the Arab slave trade. Any non-Muslim could be enslaved. Throughout Islamic history, slaves served in various social and economic roles, from powerful emirs to harshly treated manual laborers. Early on in Muslim history slaves provided plantation labor similar to that in the early-modern Americas, but this practice was abandoned after harsh treatment led to destructive slave revolts, the most notable being the Zanj Rebellion of 869–883. Slaves were widely employed in irrigation, mining, and animal husbandry, but most commonly as soldiers, guards, domestic workers, concubines and sex slaves. Many rulers relied on military slaves (often in huge standing armies) and on slaves in administration - to such a degree that the slaves could sometimes seize power. Among black slaves, there were roughly two females to every one male. Two rough estimates by scholars of the numbers of just one group - black slaves held over twelve centuries in the Muslim world - are 11.5 million and 14 million, while other estimates indicate a number between 12 and 15 million African slaves prior to the 20th century.

Islam encouraged the manumission of Muslim slaves as a way of expiating sins. Many early converts to Islam, such as Bilal, were former slaves. In theory, slavery in Islamic law does not have a racial or color basis, although this has not always been the case in practice. In 1990 the Cairo Declaration on Human Rights in Islam declared that "no one has the right to enslave" another human being. Many slaves were imported from outside the Muslim world.

The Arab slave trade was most active in West Asia, North Africa, and Southeast Africa. The Ottoman slave trade exploited the human resources of eastern and central Europe and the Caucasus; the Barbary Coast slave traders raided the Mediterranean coasts of Europe and as far afield as the British Isles and Iceland. In the early 20th century (post-World War I), authorities gradually outlawed and suppressed slavery in Muslim lands, largely due to pressure exerted by Western nations such as Britain and France. Slavery in the Ottoman Empire was abolished in 1924 when the new Turkish Constitution disbanded the Imperial Harem and made the last concubines and eunuchs free citizens of the newly proclaimed republic. Slavery in Iran was abolished in 1929. Mauritania became the last state to abolish slavery - in 1905, 1981, and again in August 2007. Oman abolished slavery in 1970, and Saudi Arabia and Yemen abolished slavery in 1962 under pressure from Britain. However, slavery claiming the sanction of Islam is documented at present in the predominantly Islamic countries of the Sahel, and is also practiced by ISIS and Boko Haram. It is also practiced in countries like Libya and Mauritania - despite being outlawed.

🔗 Spaceflight 🔗 Physics 🔗 Rocketry

The Tsiolkovsky rocket equation, classical rocket equation, or ideal rocket equation is a mathematical equation that describes the motion of vehicles that follow the basic principle of a rocket: a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity can thereby move due to the conservation of momentum.

${\displaystyle \Delta v=v_{\text{e}}\ln {\frac {m_{0}}{m_{f}}}=I_{\text{sp}}g_{0}\ln {\frac {m_{0}}{m_{f}}}}$

where:

${\displaystyle \Delta v\ }$ is delta-v – the maximum change of velocity of the vehicle (with no external forces acting).

${\displaystyle m_{0}}$ is the initial total mass, including propellant, also known as wet mass.

${\displaystyle m_{f}}$ is the final total mass without propellant, also known as dry mass.

${\displaystyle v_{\text{e}}=I_{\text{sp}}g_{0}}$ is the effective exhaust velocity, where:

${\displaystyle I_{\text{sp}}}$ is the specific impulse in dimension of time.

${\displaystyle g_{0}}$ is standard gravity.

${\displaystyle \ln }$ is the natural logarithm function.