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🔗 Mathematics

In number theory, a formula for primes is a formula generating the prime numbers, exactly and without exception. No such formula which is efficiently computable is known. A number of constraints are known, showing what such a "formula" can and cannot be.

🔗 Military history 🔗 Poland 🔗 Hungary 🔗 Military history/World War II 🔗 Jewish history 🔗 European history 🔗 Military history/Polish military history 🔗 Military history/European military history

Witold's Report, also known as Pilecki's Report, is a report about the Auschwitz concentration camp written in 1943 by Witold Pilecki, a Polish military officer and agent of the Polish resistance. Pilecki volunteered in 1940 to be imprisoned in Auschwitz to organize a resistance movement and send out information about it. His was the first comprehensive record of a Holocaust death camp to be obtained by the Allies. He escaped from the camp in April 1943.

The report includes details about the gas chambers, "Selektion" and the sterilization experiments. It states that there were three crematoria in Auschwitz II able to cremate 8000 people daily.

Pilecki's Report preceded and complemented the Auschwitz Protocols, compiled from late 1943, which warned about the mass murder and other atrocities taking place inside the camp. The latter consists of the Polish Major's Report by Jerzy Tabeau, who escaped with Roman Cieliczko on 19 November 1943 and compiled a report between December 1943 and January 1944; the Vrba-Wetzler report; and the Rosin-Mordowicz report.

🔗 Color

Pantone 448 C, also referred to as "the ugliest colour in the world", is a colour in the Pantone colour system. Described as a "drab dark brown", it was selected in 2016 as the colour for plain tobacco and cigarette packaging in Australia, after market researchers determined that it was the least attractive colour. The Australian Department of Health initially referred to the colour as "olive green", but the name was changed after concerns were expressed by the Australian Olive Association.

Since 2016, the same colour has also been used for plain cigarette packaging in France, the United Kingdom, Israel, Norway, New Zealand, Slovenia, Saudi Arabia, and Turkey.

The colour has also been widely but erroneously reported as being known as "opaque couché"; in fact this is simply French for "layered opaque", in reference to being used on coated paper. The confusion appears to have arisen because "PANTONE opaque couché" is the French name of a swatch library (palette) used in Adobe Illustrator containing this colour and intended for printing in solid ink colours on coated paper; in English this library is known as "PANTONE solid coated".

🔗 Color

In many languages, the colors described in English as "blue" and "green" are colexified, i.e. expressed using a single cover term. To describe this English lexical gap, linguists use the portmanteau word grue, from green and blue, which the philosopher Nelson Goodman coined—with a different meaning—in his 1955 Fact, Fiction, and Forecast to illustrate his "new riddle of induction".

The exact definition of "blue" and "green" may be complicated by the speakers not primarily distinguishing the hue, but using terms that describe other color components such as saturation and luminosity, or other properties of the object being described. For example, "blue" and "green" might be distinguished, but a single term might be used for both if the color is dark. Furthermore, green might be associated with yellow, and blue with black or gray.

According to Brent Berlin and Paul Kay's 1969 study Basic Color Terms: Their Universality and Evolution, distinct terms for brown, purple, pink, orange and grey will not emerge in a language until the language has made a distinction between green and blue. In their account of the development of color terms the first terms to emerge are those for white/black (or light/dark), red and green/yellow.

🔗 Viruses 🔗 Statistics 🔗 Computational Biology

A super-spreader is an unusually contagious organism infected with a disease. In context of a human-borne illness, a super-spreader is an individual who is more likely to infect others, compared with a typical infected person. Such super-spreaders are of particular concern in epidemiology.

Some cases of super-spreading conform to the 80/20 rule, where approximately 20% of infected individuals are responsible for 80% of transmissions, although super-spreading can still be said to occur when super-spreaders account for a higher or lower percentage of transmissions. In epidemics with super-spreading, the majority of individuals infect relatively few secondary contacts.

Super-spreading events are shaped by multiple factors including a decline in herd immunity, nosocomial infections, virulence, viral load, misdiagnosis, airflow dynamics, immune suppression, and co-infection with another pathogen.

🔗 Biography 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/Military biography 🔗 Military history/World War II 🔗 Military history/Russian, Soviet and CIS military history

Ivan Mikhailovich Chisov (Russian: Иван Михайлович Чисов, Ukrainian: Іван Михайлович Чиссов; 1916–1986) was a Soviet Air Force lieutenant who survived a fall of approximately 7,000 meters (23,000 feet). Some references give the spelling of his last name as Chissov (Russian: Чиссов, Ukrainian: Чиссов).

🔗 United States 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Canada 🔗 Agriculture 🔗 Canada/British Columbia 🔗 United States/Washington 🔗 Canada/Geography of Canada 🔗 Military history/European military history 🔗 Military history/British military history 🔗 Agriculture/Livestock

The Pig War was a confrontation in 1859 between the United States and United Kingdom over the British–U.S. border in the San Juan Islands, between Vancouver Island (present-day Canada) and the State of Washington. The Pig War, so called because it was triggered by the shooting of a pig, is also called the Pig Episode, the Pig and Potato War, the San Juan Boundary Dispute and the Northwestern Boundary Dispute. Aside from the death of one pig, this dispute was a bloodless conflict.

🔗 Technology

Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radii.

It was invented by the German carriage builder Georg Lankensperger in Munich in 1817, then patented by his agent in England, Rudolph Ackermann (1764–1834) in 1818 for horse-drawn carriages. Erasmus Darwin may have a prior claim as the inventor dating from 1758.

Bohm Dialogue (also known as Bohmian Dialogue or "Dialogue in the Spirit of David Bohm") is a freely flowing group conversation in which participants attempt to reach a common understanding, experiencing everyone's point of view fully, equally and nonjudgementally. This can lead to new and deeper understanding. The purpose is to solve the communication crises that face society, and indeed the whole of human nature and consciousness. It utilizes a theoretical understanding of the way thoughts relate to universal reality. It is named after physicist David Bohm who originally proposed this form of dialogue.

🔗 Death 🔗 Glass

Defenestration (from Old French fenestre, inherited from Latin fenestra) is the act of throwing someone or something out of a window. The term was coined around the time of an incident in Prague Castle in the year 1618 which became the spark that started the Thirty Years' War. This was done in "good Bohemian style"; this referred to the defenestration which had occurred in Prague's City Hall almost 200 years earlier (July 1419), which also on that occasion led to war: the Hussite war. The word comes from the New Latin de- (down from) and fenestra (window or opening). Likewise, it can also refer to the condition of being thrown out of a window, as in "The Defenestration of Ermintrude Inch".

While the act of defenestration connotes the forcible or peremptory removal of an adversary, and the term is sometimes used in just that sense, it also suggests breaking the windows in the process (de- also means removal).