Hint: You are looking at the most popular articles. If you are interested in popular topics instead, click here.

🔗 Technology 🔗 Canada 🔗 Guild of Copy Editors 🔗 Engineering

A screw drive is a system used to turn a screw. At a minimum, it is a set of shaped cavities and protrusions on the screw head that allows torque to be applied to it. Usually, it also involves a mating tool, such as a screwdriver, that is used to turn it. The following heads are categorized based on commonality, with some of the less-common drives being classified as "tamper-resistant".

Most heads come in a range of sizes, typically distinguished by a number, such as "Phillips #00". These sizes do not necessarily describe a particular dimension of the drive shape, but rather are arbitrary designations.

🔗 Philosophy 🔗 Philosophy/Logic

The nirvana fallacy is the informal fallacy of comparing actual things with unrealistic, idealized alternatives. It can also refer to the tendency to assume there is a perfect solution to a particular problem. A closely related concept is the "perfect solution fallacy."

By creating a false dichotomy that presents one option which is obviously advantageous—while at the same time being completely implausible—a person using the nirvana fallacy can attack any opposing idea because it is imperfect. Under this fallacy, the choice is not between real world solutions; it is, rather, a choice between one realistic achievable possibility and another unrealistic solution that could in some way be "better".

🔗 Russia 🔗 Russia/demographics and ethnography of Russia 🔗 Ukraine 🔗 Visual arts 🔗 Russia/history of Russia 🔗 Russia/visual arts in Russia

Reply of the Zaporozhian Cossacks to Sultan Mehmed IV of the Ottoman Empire, also known as Cossacks of Saporog Are Drafting a Manifesto (Russian: Запорожцы пишут письмо турецкому султану), is a painting by Russian artist Ilya Repin. The 2.03 m (6 foot 7 inch) by 3.58 m (11 foot 9 inch) canvas was started in 1880 and finished in 1891. Repin recorded the years of work along the lower edge of the canvas. Alexander III bought the painting for 35,000 rubles, at the time the greatest sum ever paid for a Russian painting. Since then, the canvas has been exhibited in the State Russian Museum in Saint Petersburg.

🔗 Statistics

Berkson's paradox also known as Berkson's bias or Berkson's fallacy is a result in conditional probability and statistics which is often found to be counterintuitive, and hence a veridical paradox. It is a complicating factor arising in statistical tests of proportions. Specifically, it arises when there is an ascertainment bias inherent in a study design. The effect is related to the explaining away phenomenon in Bayesian networks, and conditioning on a collider in graphical models.

It is often described in the fields of medical statistics or biostatistics, as in the original description of the problem by Joseph Berkson.

🔗 Philosophy 🔗 Science Fiction 🔗 Literature 🔗 Philosophy/Epistemology

Sturgeon's revelation (as expounded by Theodore Sturgeon), referred to as Sturgeon's law, is an adage cited as "ninety percent of everything is crap." The sentence derives from quotations by Sturgeon, an American science fiction author and critic; although Sturgeon coined another adage he termed "Sturgeon's law", the "ninety percent crap" remark became Sturgeon's law.

The phrase was derived from Sturgeon's observation while science fiction was often derided for its low quality by critics, the majority of examples of works in other fields could equally be seen to be of low quality, and science fiction was thus no different in that regard from other art forms.

🔗 United States/U.S. Government 🔗 United States 🔗 Espionage 🔗 Cats

Acoustic Kitty was a CIA project launched by the Central Intelligence Agency Directorate of Science & Technology, which in the 1960s intended to use cats to spy on the Kremlin and Soviet embassies. In an hour-long procedure a veterinary surgeon implanted a microphone in the cat's ear canal, a small radio transmitter at the base of its skull and a thin wire into its fur.

This would allow the cat to innocuously record and transmit sound from its surroundings. Due to problems with distraction, the cat's sense of hunger had to be addressed in another operation. Victor Marchetti, a former CIA officer, said Project Acoustic Kitty cost about $20 million.

The first Acoustic Kitty mission was to eavesdrop on two men in a park outside the Soviet compound on Wisconsin Avenue in Washington, D.C. The cat was released nearby, but was hit and allegedly killed by a taxi almost immediately. However, this was disputed in 2013 by Robert Wallace, a former Director of the CIA's Office of Technical Service, who said that the project was abandoned due to the difficulty of training the cat to behave as required, and "the equipment was taken out of the cat; the cat was re-sewn for a second time, and lived a long and happy life afterwards". Subsequent tests also failed. Shortly thereafter the project was considered a failure and declared to be a total loss. However, other accounts report more success for the project.

The project was cancelled in 1967. A closing memorandum said that the CIA researchers believed that they could train cats to move short distances, but that "the environmental and security factors in using this technique in a real foreign situation force us to conclude that for our (intelligence) purposes, it would not be practical." The project was disclosed in 2001, when some CIA documents were declassified.

🔗 Linguistics

Ghoti is a creative respelling of the word fish, used to illustrate irregularities in English spelling and pronunciation.

🔗 Technology 🔗 Physics

The Geneva drive or Maltese cross is a gear mechanism that translates a continuous rotation movement into intermittent rotary motion.

The rotating drive wheel is usually equipped with a pin that reaches into a slot located in the other wheel (driven wheel) that advances it by one step at a time. The drive wheel also has an elevated circular blocking disc that "locks" the rotating driven wheel in position between steps.

🔗 Typography 🔗 Primates