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πŸ”— Halton Sequence

πŸ”— Statistics

In statistics, Halton sequences are sequences used to generate points in space for numerical methods such as Monte Carlo simulations. Although these sequences are deterministic, they are of low discrepancy, that is, appear to be random for many purposes. They were first introduced in 1960 and are an example of a quasi-random number sequence. They generalize the one-dimensional van der Corput sequences.

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πŸ”— Chaitin's Constant

πŸ”— Mathematics

In the computer science subfield of algorithmic information theory, a Chaitin constant (Chaitin omega number) or halting probability is a real number that, informally speaking, represents the probability that a randomly constructed program will halt. These numbers are formed from a construction due to Gregory Chaitin.

Although there are infinitely many halting probabilities, one for each method of encoding programs, it is common to use the letter Ξ© to refer to them as if there were only one. Because Ξ© depends on the program encoding used, it is sometimes called Chaitin's construction instead of Chaitin's constant when not referring to any specific encoding.

Each halting probability is a normal and transcendental real number that is not computable, which means that there is no algorithm to compute its digits. Indeed, each halting probability is Martin-LΓΆf random, meaning there is not even any algorithm which can reliably guess its digits.

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πŸ”— Rule of Three (Computer Programming)

πŸ”— Computing πŸ”— Computing/Software

Rule of three ("Three strikes and you refactor") is a code refactoring rule of thumb to decide when similar pieces of code should be refactored to avoid duplication. It states that two instances of similar code don't require refactoring, but when similar code is used three times, it should be extracted into a new procedure. The rule was popularised by Martin Fowler in Refactoring and attributed to Don Roberts.

Duplication is considered a bad practice in programming because it makes the code harder to maintain. When the rule encoded in a replicated piece of code changes, whoever maintains the code will have to change it in all places correctly.

However, choosing an appropriate design to avoid duplication might benefit from more examples to see patterns in. Attempting premature refactoring risks selecting a wrong abstraction, which can result in worse code as new requirements emerge and will eventually need to be refactored again.

The rule implies that the cost of maintenance certainly outweighs the cost of refactoring and potential bad design when there are three copies, and may or may not if there are only two copies.

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πŸ”— WarGames was released today 40 years ago

πŸ”— United States πŸ”— Video games πŸ”— Computing πŸ”— Film πŸ”— Military history πŸ”— Military history/North American military history πŸ”— Military history/United States military history πŸ”— Film/American cinema πŸ”— United States/Film - American cinema πŸ”— Science Fiction πŸ”— Computer Security πŸ”— Computer Security/Computing πŸ”— Military history/Cold War πŸ”— Cold War πŸ”— United States/Washington - Seattle πŸ”— United States/Washington πŸ”— Film/War films πŸ”— Military history/War films

WarGames is a 1983 American science fiction techno-thriller film written by Lawrence Lasker and Walter F. Parkes and directed by John Badham. The film, which stars Matthew Broderick, Dabney Coleman, John Wood, and Ally Sheedy, follows David Lightman (Broderick), a young hacker who unwittingly accesses a United States military supercomputer programmed to simulate, predict and execute nuclear war against the Soviet Union.

WarGames was a critical and commercial success, grossing $125Β million worldwide against a $12Β million budget. The film was nominated for three Academy Awards.

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πŸ”— Iron law of prohibition

πŸ”— Economics πŸ”— Law Enforcement

The iron law of prohibition is a term coined by Richard Cowan in 1986 which posits that as law enforcement becomes more intense, the potency of prohibited substances increases. Cowan put it this way: "the harder the enforcement, the harder the drugs."

This law is an application of the Alchian–Allen effect; Libertarian judge James P. Gray calls the law the "cardinal rule of prohibition", and notes that is a powerful argument for the legalization of drugs. It is based on the premise that when drugs or alcohol are prohibited, they will be produced in black markets in more concentrated and powerful forms, because these more potent forms offer better efficiency in the business modelβ€”they take up less space in storage, less weight in transportation, and they sell for more money. Economist Mark Thornton writes that the iron law of prohibition undermines the argument in favor of prohibition, because the higher potency forms are less safe for the consumer.

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πŸ”— Koomey's law

πŸ”— Computing

Koomey's law describes a trend in the history of computing hardware: for about a half-century, the number of computations per joule of energy dissipated doubled about every 1.57 years. Professor Jonathan Koomey described the trend in a 2010 paper in which he wrote that "at a fixed computing load, the amount of battery you need will fall by a factor of two every year and a half."

This trend had been remarkably stable since the 1950s (R2 of over 98%). But in 2011, Koomey re-examined this data and found that after 2000, the doubling slowed to about once every 2.6 years. This is related to the slowing of Moore's Law, the ability to build smaller transistors; and the end around 2005 of Dennard scaling, the ability to build smaller transistors with constant power density.

"The difference between these two growth rates is substantial. A doubling every year and a half results in a 100-fold increase in efficiency every decade. A doubling every two and a half years yields just a 16-fold increase", Koomey wrote.

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πŸ”— Dancing Plague of 1518

πŸ”— History πŸ”— France πŸ”— Medicine πŸ”— Dance

The Dancing Plague of 1518, or Dance Epidemic of 1518, was a case of dancing mania that occurred in Strasbourg, Alsace (modern-day France), in the Holy Roman Empire from July 1518 to September 1518. Somewhere between 50 and 400 people took to dancing for weeks.

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πŸ”— Kyshtym Disaster

πŸ”— Soviet Union πŸ”— Russia πŸ”— Russia/technology and engineering in Russia πŸ”— Environment πŸ”— Disaster management πŸ”— Energy πŸ”— Russia/history of Russia πŸ”— Science Policy

The Kyshtym disaster, sometimes referred to as the Mayak disaster or Ozyorsk disaster in newer sources, was a radioactive contamination accident that occurred on 29 September 1957 at Mayak, a plutonium production site for nuclear weapons and nuclear fuel reprocessing plant located in the closed city of Chelyabinsk-40 (now Ozyorsk) in Chelyabinsk Oblast, Russian SFSR, Soviet Union.

The disaster was the second worst nuclear incident (by radioactivity released) after the Chernobyl disaster. It measured as a Level 6 disaster on the International Nuclear Event Scale (INES), making it the third highest on the INES (which ranks by population impact), behind Chernobyl (evacuated 335,000 people) and the Fukushima Daiichi nuclear disaster (evacuated 154,000 people) which are both Level 7 on the INES. At least twenty-two villages were exposed to radiation from the Kyshtym disaster, with a total population of around 10,000 people evacuated. Some were evacuated after a week, but it took almost two years for evacuations to occur at other sites.

The disaster spread hot particles over more than 52,000 square kilometres (20,000Β sqΒ mi), where at least 270,000 people lived. Since Chelyabinsk-40 (later renamed Chelyabinsk-65 until 1994) was not marked on maps, the disaster was named after Kyshtym, the nearest known town.

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πŸ”— The Begum's Fortune

πŸ”— Oregon πŸ”— Novels πŸ”— Novels/19th century

The Begum's Fortune (French: Les Cinq cents millions de la BΓ©gum, literally "the 500 millions of the begum"), also published as The Begum's Millions, is an 1879 novel by Jules Verne, with some utopian elements and other elements that seem clearly dystopian. It is noteworthy as the first published book in which Verne was cautionary, and somewhat pessimistic about the development of science and technology.

Long after The Begum's Fortune was published, it came out that its story is based on a manuscript by Paschal Grousset, a Corsican revolutionary who had participated in the Paris Commune and was at the time living in exile in the United States and London. It was bought by Pierre-Jules Hetzel, the publisher of most of Verne's books. The attribution of plot elements between Grousset's original text and Verne's work on it has not been completely defined. Later, Verne worked similarly on two more books by Grousset and published them under his name, before the revolutionary finally got a pardon and was able to return to France and resume publication in his own name.

The book first appeared in a hasty and poorly done English translation soon after its publication in Frenchβ€”one of the bad translations considered to have damaged Verne's reputation in the English-speaking world. W. H. G. Kingston was near death and deeply in debt at the time. His wife, Mrs. A. K. Kingston, who did the translation for him, was certainly otherwise preoccupied than with the accuracy of the text and may have had to rely on outside help. In 2005 a new translation from the French was made by Stanford Luce and published by Wesleyan University.

I. O. Evans, in his introduction to his "Fitzroy Edition" of The Begum's Fortune, suggested a connection between the creation of artificial satellites in this novel and the publication of The Brick Moon by Edward Everett Hale in 1869.

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πŸ”— Man on the Clapham Omnibus

πŸ”— Law πŸ”— 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.

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