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🔗 Computer science 🔗 Mathematics

In computational complexity theory, the unique games conjecture (often referred to as UGC) is a conjecture made by Subhash Khot in 2002. The conjecture postulates that the problem of determining the approximate value of a certain type of game, known as a unique game, has NP-hard computational complexity. It has broad applications in the theory of hardness of approximation. If the unique games conjecture is true and P ≠ NP, then for many important problems it is not only impossible to get an exact solution in polynomial time (as postulated by the P versus NP problem), but also impossible to get a good polynomial-time approximation. The problems for which such an inapproximability result would hold include constraint satisfaction problems, which crop up in a wide variety of disciplines.

The conjecture is unusual in that the academic world seems about evenly divided on whether it is true or not.

🔗 Meteorology 🔗 Chemicals 🔗 Soil 🔗 Weather 🔗 Weather/Weather

Petrichor () is the earthy scent produced when rain falls on dry soil. The word is constructed from Greek petra (πέτρα), meaning "stone", and īchōr (ἰχώρ), the fluid that flows in the veins of the gods in Greek mythology.

🔗 Economics 🔗 Law

"The Nature of the Firm" (1937) is an article by Ronald Coase. It offered an economic explanation of why individuals choose to form partnerships, companies and other business entities rather than trading bilaterally through contracts on a market. The author was awarded the Nobel Memorial Prize in Economic Sciences in 1991 in part due to this paper. Despite the honor, the paper was written when Coase was an undergraduate and he described it later in life as "little more than an undergraduate essay."

The article argues that firms emerge because they are better equipped to deal with the transaction costs inherent in production and exchange than individuals are. Economists such as Oliver Williamson, Douglass North, Oliver Hart, Bengt Holmström, Arman Alchian and Harold Demsetz expanded on Coase's work on firms, transaction costs and contracts. Economists and political scientists have used insights from Coase's work to explain the functioning of organizations in general, not just firms. Coase's work strongly influenced the New Economics of Organization (New Institutional Economics).

Coase's article distinguished between markets as a coordination mechanism and firms as a coordination mechanism.

🔗 Journalism

Betteridge's law of headlines is an adage that states: "Any headline that ends in a question mark can be answered by the word no". It is named after Ian Betteridge, a British technology journalist who wrote about it in 2009, although the principle is much older. As with similar "laws" (e.g., Murphy's law), it is intended to be humorous rather than the literal truth. The adage fails to make sense with questions that are more open-ended than strict yes-no questions.

The maxim has been cited by other names since 1991, when a published compilation of Murphy's Law variants called it "Davis's law", a name that also crops up online (such as cited by linguist Mark Liberman), without any explanation of who Davis was. It has also been referred to as the "journalistic principle" and in 2007 was referred to in commentary as "an old truism among journalists".

🔗 Film 🔗 Film/Japanese cinema

Ornamental Hairpin (簪, Kanzashi) is a 1941 Japanese comedy-drama film written and directed by Hiroshi Shimizu. It is based on the short story Yottsu no yubune (四つの湯槽, lit. "The four bathtubs") by Masuji Ibuse.

🔗 Politics 🔗 Socialism 🔗 Chicago 🔗 Holidays 🔗 Organized Labour

International Workers' Day, also called Labour Day in some countries and often referred to as May Day, is a celebration of labourers and the working classes that is promoted by the international labour movement and occurs every year on 1 May, or the first Monday in May.

Traditionally, 1 May is the date of the European spring festival of May Day. The International Workers Congress held in Paris in 1889 established the Second International for labor, socialist, and Marxist parties. It adopted a resolution for a "great international demonstration" in support of working-class demands for the eight-hour day. The date was chosen by the American Federation of Labor to commemorate a general strike in the United States, which had begun on 1 May 1886 and culminated in the Haymarket affair on 4 May. The demonstration subsequently became a yearly event. The 1904 Sixth Conference of the Second International, called on "all Social Democratic Party organisations and trade unions of all countries to demonstrate energetically on the First of May for the legal establishment of the eight-hour day, for the class demands of the proletariat, and for universal peace".

The 1st of May, or first Monday in May, is a national public holiday in many countries, in most cases known as "International Workers' Day" or a similar name. Some countries celebrate a Labour Day on other dates significant to them, such as the United States and Canada, which celebrate Labor Day on the first Monday of September. In 1955, the Catholic Church dedicated 1 May to "Saint Joseph the Worker". Saint Joseph is the patron saint of workers and craftsmen, among others.

🔗 Biography

Albert Stevens (1887–1966), also known as patient CAL-1, was a victim of a human radiation experiment, and survived the highest known accumulated radiation dose in any human. On May 14, 1945, he was injected with 131 kBq (3.55 µCi) of plutonium without his knowledge or informed consent.

Plutonium remained present in his body for the remainder of his life, the amount decaying slowly through radioactive decay and biological elimination. Stevens died of heart disease some 20 years later, having accumulated an effective radiation dose of 64 Sv (6400 rem) over that period, i.e. an average of 3 Sv per year or 350 μSv/h. The current annual permitted dose for a radiation worker in the United States is 0.05 Sv (or 5 rem), i.e. an average of 5.7 μSv/h.

🔗 Computing 🔗 Mathematics

Codd's cellular automaton is a cellular automaton (CA) devised by the British computer scientist Edgar F. Codd in 1968. It was designed to recreate the computation- and construction-universality of von Neumann's CA but with fewer states: 8 instead of 29. Codd showed that it was possible to make a self-reproducing machine in his CA, in a similar way to von Neumann's universal constructor, but never gave a complete implementation.

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