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🔗 Classical Greece and Rome 🔗 Bible 🔗 Time

In Roman timekeeping, a day was divided into periods according to the available technology. Initially, the day was divided into two parts: the ante meridiem (before noon) and the post meridiem (after noon). With the introduction of the Greek sundial to Rome from the Samnites circa 293 BC, the period of the natural day from sunrise to sunset was divided into twelve hours.

🔗 Korea 🔗 Korea/one or more inactive working groups

Yongsan Electronics Market (Korean: 용산전자상가) is a retail area in Seoul, South Korea. Comprising over 20 buildings, it houses 5,000 stores that sell appliances, stereos, computers and peripherals, office equipment, telephones, lighting equipment, electronic games and software, videos, and CDs.

The market has a variety of stores, each with different operating procedures. Some stores operate like traditional retail shops, with set prices, name brands, and warranties. Other shops accept, or even expect, customers to bargain and may not have any posted prices for items.

The Electronics Market is located on Subway line 1, at Yongsan Station, at Exit 2. Entrance is from the train station through the Terminal Shopping Center or by walking around the station at ground level to enter the market. It may also be reached by the subway line to Sinyongsan station.

Merchants at Yongsan Electronics Market compete for customer attention, leading shopgoers to coin the term yongpari (용팔이), with pari (팔이) meaning "fly", to criticize their behavior. Due to this publicity, the President of the Hyundai I shopping mall announced in 2008 that it seeks to improve misconduct and offer improved customer service.

🔗 Russia 🔗 History 🔗 Skepticism 🔗 Sociology 🔗 Urban studies and planning 🔗 Russia/language and literature of Russia 🔗 Cities 🔗 European history 🔗 Russia/history of Russia

In politics and economics, a Potemkin village is any construction (literal or figurative) whose sole purpose is to provide an external façade to a country which is faring poorly, making people believe that the country is faring better, although statistics and charts would state otherwise. The term comes from stories of a fake portable village built solely to impress Empress Catherine II by her former lover Grigory Potemkin, during her journey to Crimea in 1787. While modern historians claim accounts of this portable village are exaggerated, the original story was that Potemkin erected phony portable settlements along the banks of the Dnieper River in order to impress the Russian Empress; the structures would be disassembled after she passed, and re-assembled farther along her route to be viewed again as if another example. The term is a translation of the Russian: потёмкинские деревни (IPA: /pɐˈtʲɵmkʲɪnskʲɪɪ dʲɪˈrʲɛvnʲɪ/; romanization: potyómkinskiye derévni).

🔗 Engineering

A wax motor is a linear actuator device that converts thermal energy into mechanical energy by exploiting the phase-change behaviour of waxes. During melting, wax typically expands in volume by 5–20% (Freund et al. 1982).

A wide range of waxes can be used in wax motors, ranging from highly refined hydrocarbons to waxes extracted from vegetable matter. Specific examples include paraffin waxes in the straight-chain n-alkanes series. These melt and solidify over a well-defined and narrow temperature range.

🔗 Physics 🔗 Measurement

In particle physics and physical cosmology, Planck units are a system of units of measurement defined exclusively in terms of four universal physical constants: c, G, ħ, and k_B. Expressing one of these physical constants in terms of Planck units yields a numerical value of 1. They are a system of natural units, defined using fundamental properties of nature (specifically, properties of free space) rather than properties of a chosen prototype object. Originally proposed in 1899 by German physicist Max Planck, they are relevant in research on unified theories such as quantum gravity.

The term Planck scale refers to quantities of space, time, energy and other units that are similar in magnitude to corresponding Planck units. This region may be characterized by particle energies of around 10¹⁹ GeV or 10⁹ J, time intervals of around 10⁻⁴³ s and lengths of around 10⁻³⁵ m (approximately the energy-equivalent of the Planck mass, the Planck time and the Planck length, respectively). At the Planck scale, the predictions of the Standard Model, quantum field theory and general relativity are not expected to apply, and quantum effects of gravity are expected to dominate. One example is represented by the conditions in the first 10⁻⁴³ seconds of our universe after the Big Bang, approximately 13.8 billion years ago.

The four universal constants that, by definition, have a numerical value 1 when expressed in these units are:

• c, the speed of light in vacuum,
• G, the gravitational constant,
• ħ, the reduced Planck constant, and
• k_B, the Boltzmann constant.

Variants of the basic idea of Planck units exist, such as alternate choices of normalization that give other numerical values to one or more of the four constants above.

🔗 Africa 🔗 Geology 🔗 Archaeology 🔗 Africa/Mauritania

The Richat Structure, also called Guelb er Richât (Arabic: قلب الريشات, romanized: Qalb ar-Rīšāt), is a prominent circular geological feature in the Sahara's Adrar Plateau, near Ouadane, west–central Mauritania, Northwest Africa. In the local dialect, Richat means feather and it also is known locally in Arabic as tagense. Tagense refers to the circular opening of the leather pouch used to draw water from local wells.

It is an eroded geological dome, 40 kilometres (25 mi) in diameter, exposing sedimentary rock in layers which appear as concentric rings. Igneous rock is exposed inside and there are spectacular rhyolites and gabbros which have undergone hydrothermal alteration, and a central megabreccia. The structure is also the location of exceptional accumulations of Acheulean archaeological artifacts.

🔗 United States/U.S. Government 🔗 United States 🔗 Mass surveillance 🔗 Espionage 🔗 California 🔗 California/San Francisco Bay Area 🔗 Telecommunications

Room 641A is a telecommunication interception facility operated by AT&T for the U.S. National Security Agency, as part of its warrantless surveillance program as authorized by the Patriot Act. The facility commenced operations in 2003 and its purpose was publicly revealed in 2006.

🔗 China 🔗 Capitalism 🔗 Culture

Neijuan, sometimes known by the English term involution, is a Chinese term that describes a condition in which a system, institution, or competitive process continues to intensify in effort, complexity, or participation without a corresponding increase in output, efficiency, or collective benefit. Neijuan is the Chinese calque of the English word involution. Neijuan is written with two characters which mean 'inside' and 'curling/rolling'.

Neijuan had been used to describe an uneven distribution of social, economic, and educational resources and ongoing economic malaise, especially in terms of higher education bodies and labor markets. On a macroeconomic level, neijuan has led to overproduction and diminishing returns for capital owners who engage in fierce price wars that aggravate deflationary pressures in a pure unregulated market. When capital owners are driven by competition they must work increasingly more for little or no marginal gain despite falling prices for consumers so price fixing or 'price leadership' becomes impossible. On a personal level, neijuan reflects a life of being overworked, stressed, anxious and feeling trapped, a lifestyle where many face the negative effects of living a very competitive life for nothing.

🔗 United States 🔗 Germany 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Former countries 🔗 Haiti

The United States occupation of Haiti began on July 28, 1915, when 330 US Marines landed at Port-au-Prince, Haiti, after the National City Bank of New York (now Citibank) convinced US President Woodrow Wilson to take control of the country's political and financial interests. The occupation took place following years of socioeconomic instability within Haiti that culminated with the lynching of Haitian President Vilbrun Guillaume Sam by a mob angered by his executions of political prisoners.

During the occupation, Haiti had three new presidents while the United States ruled as a military regime through martial law, led by Marines and the US-created Gendarmerie of Haiti. A corvée system of forced labor was used by the US for infrastructure projects, resulting in hundreds to thousands of deaths. The occupation ended the constitutional ban on foreign ownership of land, which had existed since the foundation of Haiti.

The occupation ended on August 1, 1934, after President Franklin D. Roosevelt reaffirmed an August 1933 disengagement agreement. The last contingent of Marines departed on August 15, 1934, after a formal transfer of authority to the Gendarmerie of Haiti.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Books 🔗 Business

War Is a Racket is a speech and a 1935 short book by Smedley D. Butler, a retired United States Marine Corps Major General and two-time Medal of Honor recipient. Based on his career military experience, Butler discusses how business interests commercially benefit from warfare. He had been appointed commanding officer of the Gendarmerie during the 1915–1934 United States occupation of Haiti.

After Butler retired from the US Marine Corps in October 1931, he made a nationwide tour in the early 1930s giving his speech "War Is a Racket". The speech was so well received that he wrote a longer version as a short book published in 1935. His work was condensed in Reader's Digest as a book supplement, which helped popularize his message. In an introduction to the Reader's Digest version, Lowell Thomas, who wrote Butler’s oral autobiography, praised Butler's "moral as well as physical courage".