To stay up to date you can also follow on Mastodon.

🔗 Mathematics 🔗 Statistics 🔗 Sociology

The friendship paradox is the phenomenon first observed by the sociologist Scott L. Feld in 1991 that most people have fewer friends than their friends have, on average. It can be explained as a form of sampling bias in which people with greater numbers of friends have an increased likelihood of being observed among one's own friends. In contradiction to this, most people believe that they have more friends than their friends have.

The same observation can be applied more generally to social networks defined by other relations than friendship: for instance, most people's sexual partners have had (on the average) a greater number of sexual partners than they have.

🔗 Mathematics

In mathematics and computing, Fibonacci coding is a universal code which encodes positive integers into binary code words. It is one example of representations of integers based on Fibonacci numbers. Each code word ends with "11" and contains no other instances of "11" before the end.

The Fibonacci code is closely related to the Zeckendorf representation, a positional numeral system that uses Zeckendorf's theorem and has the property that no number has a representation with consecutive 1s. The Fibonacci code word for a particular integer is exactly the integer's Zeckendorf representation with the order of its digits reversed and an additional "1" appended to the end.

🔗 Africa 🔗 Ancient Near East 🔗 Ancient Egypt 🔗 Greece 🔗 Turkey 🔗 Archaeology

The Late Bronze Age collapse was a dark age transition in a large area covering much of Southeast Europe, West Asia and North Africa (comprising the overlapping regions of the Near East, the Eastern Mediterranean and North Africa, with the Balkans, the Aegean, Anatolia, and the Caucasus), which took place from the Late Bronze Age to the emerging Early Iron Age. It was a transition which historians believe was violent, sudden, and culturally disruptive, and involved societal collapse for some civilizations during the 12th century BCE. The palace economy of Mycenaean Greece, the Aegean region and Anatolia that characterized the Late Bronze Age disintegrated, transforming into the small isolated village cultures of the Greek Dark Ages. The Hittite Empire of Anatolia and the Levant collapsed, while states such as the Middle Assyrian Empire in Mesopotamia and the New Kingdom of Egypt survived but were considerably weakened.

Competing and even mutually compatible theories for the ultimate cause of the Late Bronze Age collapse have been made since the 19th century. These include volcanic eruptions, droughts, invasions by the Sea Peoples or migrations of Dorians, economic disruptions due to the rising use of ironworking, and changes in military technology and methods of war that saw the decline of chariot warfare.

🔗 United States 🔗 Biography 🔗 Marketing & Advertising 🔗 Judaism 🔗 Jewish history 🔗 Vienna

Edward Louis Bernays (; German: [bɛɐ̯ˈnaɪs]; November 22, 1891 − March 9, 1995) was an Austrian-American pioneer in the field of public relations and propaganda, referred to in his obituary as "the father of public relations". Bernays was named one of the 100 most influential Americans of the 20th century by Life. He was the subject of a full length biography by Larry Tye called The Father of Spin (1999) and later an award-winning 2002 documentary for the BBC by Adam Curtis called The Century of the Self.

His best-known campaigns include a 1929 effort to promote female smoking by branding cigarettes as feminist "Torches of Freedom" and his work for the United Fruit Company connected with the CIA-orchestrated overthrow of the democratically elected Guatemalan government in 1954. He worked for dozens of major American corporations including Procter & Gamble and General Electric, and for government agencies, politicians, and non-profit organizations.

Of his many books, Crystallizing Public Opinion (1923) and Propaganda (1928) gained special attention as early efforts to define and theorize the field of public relations. Citing works of writers such as Gustave Le Bon, Wilfred Trotter, Walter Lippmann, and his own double uncle Sigmund Freud, he described the masses as irrational and subject to herd instinct—and outlined how skilled practitioners could use crowd psychology and psychoanalysis to control them in desirable ways.

🔗 Measurement

In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10⁻⁶), parts-per-billion (ppb, 10⁻⁹), parts-per-trillion (ppt, 10⁻¹²) and parts-per-quadrillion (ppq, 10⁻¹⁵). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous.

🔗 Geography 🔗 Maps

The Peirce quincuncial projection is a conformal map projection developed by Charles Sanders Peirce in 1879. The projection has the distinctive property that it can be tiled ad infinitum on the plane, with edge-crossings being completely smooth except for four singular points per tile. The projection has seen use in digital photography for portraying 360° views. The description quincuncial refers to the arrangement of four quadrants of the globe around the center hemisphere in an overall square pattern. Typically the projection is oriented such that the north pole lies at the center.

🔗 Germany 🔗 Time 🔗 Radio Stations

DCF77 is a German longwave time signal and standard-frequency radio station. It started service as a standard-frequency station on 1 January 1959. In June 1973 date and time information was added. Its primary and backup transmitter are located at 50°0′56″N 9°00′39″E in Mainflingen, about 25 km south-east of Frankfurt am Main, Germany. The transmitter generates a nominal power of 50 kW, of which about 30 to 35 kW can be radiated via a T-antenna.

DCF77 is controlled by the Physikalisch-Technische Bundesanstalt (PTB), Germany's national physics laboratory and transmits in continuous operation (24 hours). It is operated by Media Broadcast GmbH (previously a subsidiary of Deutsche Telekom AG), on behalf of the PTB. With Media Broadcast GmbH, a temporal transmission availability of at least 99.7% per year or under 26.28 hours of annual downtime has been agreed upon. Most service interruptions are short-term disconnections of under two minutes. Longer lasting transmission service interruptions are generally caused by strong winds, freezing rain or snow-induced T-antenna movement. This manifests itself in electrical detuning of the antenna resonance circuit and hence a measurable phase modulation of the received signal. When the maladjustment is too large, the transmitter is taken out of service temporarily. In the year 2002, almost 99.95% availability, or just over 4.38 hours of downtime, was realized. The timestamp sent is either in Coordinated Universal Time (UTC)+1 or UTC+2 depending on daylight saving time.

The highly accurate 77.5 kHz (approximately 3868.3 m wavelength) carrier signal is generated from local atomic clocks that are linked with the German master clocks at the PTB in Braunschweig. The DCF77 time signal is used for the dissemination of the German national legal time to the public.

Radio clocks and watches have been very popular in Europe since the late 1980s and, in mainland Europe, most of them use the DCF77 signal to set their time automatically. Further industrial time-keeping systems at railway stations, in the field of telecommunication and information technology, and at radio and TV stations are radio-controlled by DCF77 as well as tariff change-over clocks of energy supply companies and clocks in traffic-light facilities.

🔗 United States 🔗 Biography 🔗 Women's History 🔗 Christianity 🔗 Gender Studies 🔗 United States/Rhode Island 🔗 Christianity/Religious Society of Friends (Quakers)

The Public Universal Friend (born Jemima Wilkinson; November 29, 1752 – July 1, 1819) was an American preacher born in Cumberland, Rhode Island, to Quaker parents. After suffering a severe illness in 1776, the Friend claimed to have died and been reanimated as a genderless evangelist named the Public Universal Friend, and afterward shunned both birth name and gendered pronouns. In androgynous clothes, the Friend preached throughout the northeastern United States, attracting many followers who became the Society of Universal Friends.

The Public Universal Friend's theology was broadly similar to that of most Quakers. The Friend stressed free will, opposed slavery, and supported sexual abstinence. The most committed members of the Society of Universal Friends were a group of unmarried women who took leading roles in their households and community. In the 1790s, members of the Society acquired land in Western New York where they formed the township of Jerusalem near Penn Yan, New York. The Society of Universal Friends ceased to exist by the 1860s. Many writers have portrayed the Friend as a woman, and either a manipulative fraudster, or a pioneer for women's rights; others have viewed the preacher as transgender or non-binary and a figure in trans history.

🔗 Video games

Bob's Game (stylized as "bob's game") was a role-playing video game being developed by independent video game developer Robert Pelloni since 2003/2004. The project is most notable for Pelloni developing the game using open source software development tools and Nintendo's refusal to license him the official SDK as well as Bob's response to that decision.

🔗 Military history 🔗 Disaster management 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Energy

This article lists notable military accidents involving nuclear material. Civilian accidents are listed at List of civilian nuclear accidents. For a general discussion of both civilian and military accidents, see nuclear and radiation accidents. For other lists, see Lists of nuclear disasters and radioactive incidents.