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🔗 Physics 🔗 Education 🔗 Toys

The Gilbert U-238 Atomic Energy Lab was a toy lab set designed to allow children to create and watch nuclear and chemical reactions using radioactive material. The Atomic Energy Lab was released by the A. C. Gilbert Company in 1950.

🔗 Maps

In cartography, a trap street is a fictitious entry in the form of a misrepresented street on a map, often outside the area the map nominally covers, for the purpose of "trapping" potential copyright violators of the map who, if caught, would be unable to explain the inclusion of the "trap street" on their map as innocent. On maps that are not of streets, other "copyright trap" features (such as nonexistent towns, or mountains with the wrong elevations) may be inserted or altered for the same purpose.

Trap streets are often nonexistent streets; but sometimes, rather than actually depicting a street where none exists, a map will misrepresent the nature of a street in a fashion that can still be used to detect copyright violators but is less likely to interfere with navigation. For instance, a map might add nonexistent bends to a street, or depict a major street as a narrow lane, without changing its location or its connections to other streets.

Trap streets are rarely acknowledged by publishers. One known case is a popular driver's atlas for the city of Athens, Greece, which has a warning inside its front cover that potential copyright violators should beware of trap streets.

🔗 Religion 🔗 Classical Greece and Rome 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Cryptography 🔗 Cryptography/Computer science 🔗 Latin 🔗 Christianity 🔗 Jewish history 🔗 Occult 🔗 Mysticism

The Sator Square (or Rotas Square) is a word square containing a five-word Latin palindrome. The earliest form has ROTAS as the top line, but in time the version with SATOR on the top line became dominant. It is a 5X5 square made up of five 5-letter words, thus consisting of 25 letters in total. These 25 letters are all derived from 8 Latin letters: 5 consonants (S, T, R, P, N) and 3 vowels (A, E, O).

In particular, this is a square 2D palindrome, which is when a square text admits four symmetries: identity, two diagonal reflections, and 180 degree rotation. As can be seen, the text may be read top-to-bottom, bottom-to-top, left-to-right, or right-to-left; and it may be rotated 180 degrees and still be read in all those ways.

The Sator Square is the earliest dateable 2D palindrome. It was found in the ruins of Pompeii, at Herculaneum, a city buried in the ash of Mount Vesuvius in 79 AD. It consists of a sentence written in Latin: "Sator Arepo Tenet Opera Rotas." Its translation has been the subject of speculation with no clear consensus; see below for details.

Other 2D Palindrome examples may be found carved on stone tablets or pressed into clay before being fired.

🔗 Computing 🔗 Books 🔗 Computing/Software

The Cathedral and the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary (abbreviated CatB) is an essay, and later a book, by Eric S. Raymond on software engineering methods, based on his observations of the Linux kernel development process and his experiences managing an open source project, fetchmail. It examines the struggle between top-down and bottom-up design. The essay was first presented by the author at the Linux Kongress on May 27, 1997 in Würzburg (Germany) and was published as part of the book in 1999.

The illustration on the cover of the book is a 1913 painting by Liubov Popova titled Composition with Figures and belongs to the collection of the State Tretyakov Gallery. The book was released under the Open Publication License v2.0 around 1999.

🔗 Game theory

Parrondo's paradox, a paradox in game theory, has been described as: A combination of losing strategies becomes a winning strategy. It is named after its creator, Juan Parrondo, who discovered the paradox in 1996. A more explanatory description is:

There exist pairs of games, each with a higher probability of losing than winning, for which it is possible to construct a winning strategy by playing the games alternately.

Parrondo devised the paradox in connection with his analysis of the Brownian ratchet, a thought experiment about a machine that can purportedly extract energy from random heat motions popularized by physicist Richard Feynman. However, the paradox disappears when rigorously analyzed. Winning strategies consisting of a combinations of losing strategies have been explored in biology before Parrondo's paradox was published. More recently, problems in evolutionary biology and ecology have been modeled and explained in terms of the paradox.

🔗 United States 🔗 Chicago 🔗 United States/American Old West 🔗 Organized Labour 🔗 United States/U.S. history

Pinkerton is a private security guard and detective agency established around 1850 in the United States by Scottish-born American cooper Allan Pinkerton and Chicago attorney Edward Rucker as the North-Western Police Agency, which later became Pinkerton & Co, and finally the Pinkerton National Detective Agency. It is currently a subsidiary of Swedish-based Securitas AB. Pinkerton became famous when he claimed to have foiled the Baltimore Plot to assassinate president-elect Abraham Lincoln in 1861. Lincoln later hired Pinkerton agents to conduct espionage against the Confederacy and act as his personal security during the American Civil War.

The Pinkerton National Detective Agency hired women and minorities from its founding because they were useful as spies, a practice uncommon at the time. At the height of their power, the Pinkerton Detective Agency was the largest private law enforcement organization in the world.

Following the Civil War, the Pinkertons began conducting operations against organized labor. During the labor strikes of the late 19th and early 20th centuries, businesses hired the Pinkerton Agency to infiltrate unions, supply guards, keep strikers and suspected unionists out of factories, and recruit goon squads to intimidate workers. During the Homestead Strike of 1892, Pinkerton agents were called in to reinforce the strikebreaking measures of industrialist Henry Clay Frick, who was acting on behalf of Andrew Carnegie, the head of Carnegie Steel. Tensions between the workers and strikebreakers erupted into violence which led to the deaths of three Pinkerton agents and nine steelworkers. During the late nineteenth century, the Pinkertons were also hired as guards in coal, iron, and lumber disputes in Illinois, Michigan, New York, Pennsylvania, and West Virginia. Pinkertons were also involved in other strikes such as the Great Railroad Strike of 1877.

During the 20th century, Pinkerton rebranded itself into a personal security and risk management firm. The company has continued to exist in various forms through to the present day, and is now a division of the Swedish security company Securitas AB, operating as "Pinkerton Consulting & Investigations, Inc. d.b.a. Pinkerton Corporate Risk Management". The former Government Services division, PGS, now operates as "Securitas Critical Infrastructure Services, Inc.".

🔗 Environment 🔗 India 🔗 Birds

Nine species of vulture can be found living in India, but most are now in danger of extinction after a rapid and major population collapse in recent decades. In the early 1980s, three species of Gyps vultures (the white-rumped vulture, the long-billed vulture and the slender-billed vulture) had a combined estimated population of 40 million in South Asia, but as of 2017, the total population numbered only 19,000 (6,000, 12,000, and 1,000 respectively). With a catastrophic loss of over 99.95% of all the vultures in South Asia, the Indian vulture crisis represents the sharpest decline of any animal known to man in the same number of years. A major contributing factor in declining populations of vultures is believed to be widespread use of drugs such as diclofenac, once commonly used as a livestock anti-inflammatory drug. Veterinary usage of diclofenac has been banned in India since 2006. The IUCN Red Data Book has listed Gyps bengalensis as "critically endangered". In winter 2012, 56 vultures in three species (Eurasian griffon, cinereous vulture, Egyptian vulture) and 10 steppe eagles were found dead at a dumping site in Jorbeer, Rajasthan. Six Eurasian griffons were found dead in May 2013 due to dehydration and wing weakness. The area has been declared as a conserved forest area, but the carcass dumping site is not part of the protected area.

The dramatic vulture decline observed across India presents a range of ecological threats, by influencing the numbers and distribution of other scavenging species. Increased feral dog populations have been reported all over India, posing many associated disease risks such as rabies to humans and wildlife. India already accounts for a very high incidence of rabies cases, and an absolute shortage of quality anti-rabies vaccine in rural areas can aggravate the problem even further. Similarly, increased crow populations at carcass sites near settlement areas pose a risk of infections to poultry, domesticated birds, and humans. Prevalence and concentration of diclofenac residues in ungulate carcasses is important for India's threatened vulture populations. A small proportion (< 0.8%) of ungulate carcasses containing lethal levels of diclofenac is enough to cause the observed rapid decline of vultures population. (Bohra D L)

Vultures previously played an important role in public sanitation in India and their disappearance has resulted in a number of problems, and as such numerous conservation schemes are in place to assist in the recovery of vulture populations.

🔗 Chemicals 🔗 Dentistry

Tin(II) fluoride, commonly referred to commercially as stannous fluoride (from Latin stannum, 'tin'), is a chemical compound with the formula SnF₂. It is a colourless solid used as an ingredient in toothpastes.

🔗 France 🔗 Law

Droit de suite (French for "right to follow") or Artist's Resale Right (ARR) is a right granted to artists or their heirs, in some jurisdictions, to receive a fee on the resale of their works of art. This should be contrasted with policies such as the American first-sale doctrine, where artists do not have the right to control or profit from subsequent sales.

🔗 Mass surveillance 🔗 Business 🔗 Psychology 🔗 Sociology

The Hawthorne effect is a type of human behavior reactivity in which individuals modify an aspect of their behavior in response to their awareness of being observed. The effect was discovered in the context of research conducted at the Hawthorne Western Electric plant; however, some scholars feel the descriptions are apocryphal.

The original research involved workers who made electrical relays at the Hawthorne Works, a Western Electric plant in Cicero, Illinois. Between 1924 and 1927, the lighting study was conducted. Workers experienced a series of lighting changes in which productivity was said to increase with almost any change in the lighting. This turned out not to be true. In the study that was associated with Elton Mayo, which ran from 1928 to 1932, a series of changes in work structure were implemented (e.g., changes in rest periods) in a group of five women. However, this was a methodologically poor, uncontrolled study that did not permit any firm conclusions to be drawn.

One of the later interpretations by Landsberger suggested that the novelty of being research subjects and the increased attention from such could lead to temporary increases in workers' productivity. This interpretation was dubbed "the Hawthorne effect".