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🔗 England 🔗 Food and drink

English coffeehouses in the 17th and 18th centuries were public social places where men would meet for conversation and commerce. For the price of a penny, customers purchased a cup of coffee and admission. Travellers introduced coffee as a beverage to England during the mid-17th century; previously it had been consumed mainly for its supposed medicinal properties. Coffeehouses also served tea and hot chocolate as well as a light meal.

The historian Brian Cowan describes English coffeehouses as "places where people gathered to drink coffee, learn the news of the day, and perhaps to meet with other local residents and discuss matters of mutual concern." Topics like the Yellow Fever would also be discussed. The absence of alcohol created an atmosphere in which it was possible to engage in more serious conversation than in an alehouse. Coffeehouses also played an important role in the development of financial markets and newspapers.

Topics discussed included politics and political scandals, daily gossip, fashion, current events, and debates surrounding philosophy and the natural sciences. Historians often associate English coffeehouses, during the 17th and 18th centuries, with the intellectual and cultural history of the Age of Enlightenment: they were an alternate sphere, supplementary to the university. Political groups frequently used coffeehouses as meeting places.

🔗 Mathematics

The superformula is a generalization of the superellipse and was proposed by Johan Gielis around 2000. Gielis suggested that the formula can be used to describe many complex shapes and curves that are found in nature. Gielis has filed a patent application related to the synthesis of patterns generated by the superformula.

In polar coordinates, with ${\displaystyle r}$ the radius and ${\displaystyle \varphi }$ the angle, the superformula is:

${\displaystyle r\left(\varphi \right)=\left(\left|{\frac {\cos \left({\frac {m_{1}\varphi }{4}}\right)}{a}}\right|^{n_{2}}+\left|{\frac {\sin \left({\frac {m_{2}\varphi }{4}}\right)}{b}}\right|^{n_{3}}\right)^{-{\frac {1}{n_{1}}}}.}$

By choosing different values for the parameters ${\displaystyle a,b,m_{1},m_{2},n_{1},n_{2},}$ and ${\displaystyle n_{3},}$ different shapes can be generated.

The formula was obtained by generalizing the superellipse, named and popularized by Piet Hein, a Danish mathematician.

🔗 Biography 🔗 Correction and Detention Facilities

Mark DeFriest (born August 18, 1960), known as the Houdini of Florida, is an American man known for his repeated escapes from prison, having successfully done so 7 times. Born in rural Florida, he was arrested for the first time in 1978, serving for a year. In 1980, DeFriest was sentenced to four years in prison for violating probation via illegal firearms possession, having initially been arrested for retrieving work tools that his recently deceased father had willed him before the will had completed probate. His sentence has since been repeatedly extended for having attempted to escape 13 times (including one count of armed robbery during one attempt), as well as collecting hundreds of disciplinary reports for minor infractions, leading to a cumulative stay of 34 years in prison.

DeFriest has cumulatively spent 27 years in solitary confinement. Following publicity, DeFriest was granted parole and released on 5 February 2019. Ten days later, he was rearrested as he checked into a mental health facility.

🔗 Computing

In computer science, the ostrich algorithm is a strategy of ignoring potential problems on the basis that they may be exceedingly rare. It is named for the ostrich effect which is defined as "to stick one's head in the sand and pretend there is no problem". It is used when it is more cost-effective to allow the problem to occur than to attempt its prevention.

🔗 Physics

The Elitzur–Vaidman bomb-tester is a quantum mechanics thought experiment that uses interaction-free measurements to verify that a bomb is functional without having to detonate it. It was conceived in 1993 by Avshalom Elitzur and Lev Vaidman. Since their publication, real-world experiments have confirmed that their theoretical method works as predicted.

The bomb tester takes advantage of two characteristics of elementary particles, such as photons or electrons: nonlocality and wave-particle duality. By placing the particle in a quantum superposition, it is possible for the experiment to verify that the bomb works without triggering its detonation, although there is still a 50% chance that the bomb will detonate in the effort.

🔗 Horse racing

Potoooooooo or variations of Pot-8-Os (1773 – November 1800) was an 18th-century thoroughbred racehorse who won over 30 races and defeated some of the greatest racehorses of the time. He went on to be a sire. He is now best known for the unusual spelling of his name, pronounced 'Potatoes'.

🔗 Biography 🔗 Mathematics 🔗 Environment 🔗 Iran 🔗 Biography/science and academia 🔗 Astronomy 🔗 Geography 🔗 History of Science 🔗 Astrology 🔗 Middle Ages 🔗 Islam 🔗 Middle Ages/History 🔗 Central Asia 🔗 Maps 🔗 Iraq 🔗 Biography/Core biographies 🔗 Islam/Muslim scholars

Muḥammad ibn Mūsā al-Khwārizmī (Persian: Muḥammad Khwārizmī محمد بن موسی خوارزمی‎; c. 780 – c. 850), Arabized as al-Khwarizmi with al- and formerly Latinized as Algorithmi, was a Persian polymath who produced works in mathematics, astronomy, and geography. Around 820 CE he was appointed as the astronomer and head of the library of the House of Wisdom in Baghdad.

Al-Khwarizmi's popularizing treatise on algebra (The Compendious Book on Calculation by Completion and Balancing, c. 813–833 CE) presented the first systematic solution of linear and quadratic equations. One of his principal achievements in algebra was his demonstration of how to solve quadratic equations by completing the square, for which he provided geometric justifications. Because he was the first to treat algebra as an independent discipline and introduced the methods of "reduction" and "balancing" (the transposition of subtracted terms to the other side of an equation, that is, the cancellation of like terms on opposite sides of the equation), he has been described as the father or founder of algebra. The term algebra itself comes from the title of his book (specifically the word al-jabr meaning "completion" or "rejoining"). His name gave rise to the terms algorism and algorithm. His name is also the origin of (Spanish) guarismo and of (Portuguese) algarismo, both meaning digit.

In the 12th century, Latin translations of his textbook on arithmetic (Algorithmo de Numero Indorum) which codified the various Indian numerals, introduced the decimal positional number system to the Western world. The Compendious Book on Calculation by Completion and Balancing, translated into Latin by Robert of Chester in 1145, was used until the sixteenth century as the principal mathematical text-book of European universities.

In addition to his best-known works, he revised Ptolemy's Geography, listing the longitudes and latitudes of various cities and localities. He further produced a set of astronomical tables and wrote about calendaric works, as well as the astrolabe and the sundial. He also made important contributions to trigonometry, producing accurate sine and cosine tables, and the first table of tangents.

🔗 Technology 🔗 Computing 🔗 Computing/Software 🔗 Software 🔗 Software/Computing 🔗 C/C++ 🔗 Java

ArcaOS is a proprietary operating system based on OS/2, developed and marketed by Arca Noae, LLC under license from IBM. It was first released in 2017 and builds on OS/2 Warp 4.52 by adding support for new hardware, fixing defects and limitations in the operating system, and by including new applications and tools, and includes some Linux/Unix tool compatibility. It is targeted at professional users who need to run their OS/2 applications on new hardware, as well as personal users of OS/2.

Like OS/2 Warp, ArcaOS is a 32-bit single user, multiprocessing, preemptive multitasking operating system for the x86 architecture. It is supported on both physical hardware and virtual machine hypervisors.

🔗 Biography 🔗 Economics 🔗 Biography/science and academia 🔗 United Kingdom 🔗 Virginia 🔗 Chicago 🔗 Virginia/Albemarle County

Ronald Harry Coase (; 29 December 1910 – 2 September 2013) was a British economist and author. He was the Clifton R. Musser Professor of Economics at the University of Chicago Law School, where he arrived in 1964 and remained for the rest of his life. He received the Nobel Memorial Prize in Economic Sciences in 1991.

Coase, who believed economists should study real markets and not theoretical ones, established the case for the corporation as a means to pay the costs of operating a marketplace. Coase is best known for two articles in particular: "The Nature of the Firm" (1937), which introduces the concept of transaction costs to explain the nature and limits of firms; and "The Problem of Social Cost" (1960), which suggests that well-defined property rights could overcome the problems of externalities (see Coase theorem). Additionally, Coase's transaction costs approach is currently influential in modern organizational economics, where it was reintroduced by Oliver E. Williamson.

🔗 Mathematics

A wallpaper group (or plane symmetry group or plane crystallographic group) is a mathematical classification of a two-dimensional repetitive pattern, based on the symmetries in the pattern. Such patterns occur frequently in architecture and decorative art, especially in textiles and tiles as well as wallpaper.

The simplest wallpaper group, Group p1, applies when there is no symmetry other than the fact that a pattern repeats over regular intervals in two dimensions, as shown in the section on p1 below.

Consider the following examples of patterns with more forms of symmetry:

Examples A and B have the same wallpaper group; it is called p4m in the IUC notation and *442 in the orbifold notation. Example C has a different wallpaper group, called p4g or 4*2 . The fact that A and B have the same wallpaper group means that they have the same symmetries, regardless of details of the designs, whereas C has a different set of symmetries despite any superficial similarities.

The number of symmetry groups depends on the number of dimensions in the patterns. Wallpaper groups apply to the two-dimensional case, intermediate in complexity between the simpler frieze groups and the three-dimensional space groups. Subtle differences may place similar patterns in different groups, while patterns that are very different in style, color, scale or orientation may belong to the same group.

A proof that there were only 17 distinct groups of such planar symmeries was first carried out by Evgraf Fedorov in 1891 and then derived independently by George Pólya in 1924. The proof that the list of wallpaper groups was complete only came after the much harder case of space groups had been done. The seventeen possible wallpaper groups are listed below in § The seventeen groups.