Have a deep view into what people are curious about.

🔗 Caves

Snottite, also snoticle, is a microbial mat of single-celled extremophilic bacteria which hang from the walls and ceilings of caves and are similar to small stalactites, but have the consistency of nasal mucus. In the Frasassi Caves in Italy, over 70% of cells in Snottite have been identified as Acidithiobacillus thiooxidans, with smaller populations including an archaeon in the uncultivated 'G-plasma' clade of Thermoplasmatales (>15%) and a bacterium in the Acidimicrobiaceae family (>5%).

The bacteria derive their energy from chemosynthesis of volcanic sulfur compounds including H₂S and warm-water solution dripping down from above, producing sulfuric acid. Because of this, their waste products are highly acidic (approaching pH=0), with similar properties to battery acid. Researchers at the University of Texas have suggested that this sulfuric acid may be a more significant cause of cave formation than the usual explanation offered of the carbonic acid formed from carbon dioxide dissolved in water.

Snottites were brought to attention by researchers Diana Northup and Penny Boston studying them (and other organisms) in a toxic sulfur cave called Cueva de Villa Luz (Cave of the Lighted House), in Tabasco, Mexico. Snottites were first discovered in this cave by Jim Pisarowicz in 1986, who also coined the term.

The BBC series Wonders of the Solar System saw Professor Brian Cox examining snottites and positing that if there is life on Mars, it may be similarly primitive and hidden beneath the surface of the Red Planet.

🔗 Aviation 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Aviation/aircraft 🔗 Military history/Maritime warfare

The Boeing MQ-25 Stingray is an aerial refueling drone that resulted from the Carrier-Based Aerial-Refueling System (CBARS) program, which grew out of the earlier Unmanned Carrier-Launched Airborne Surveillance and Strike (UCLASS) program. The MQ-25 first flew on 19 September 2019.

🔗 Computing 🔗 Computing/Computer hardware

The iAPX 432 (Intel Advanced Performance Architecture) is a discontinued computer architecture introduced in 1981. It was Intel's first 32-bit processor design. The main processor of the architecture, the general data processor, is implemented as a set of two separate integrated circuits, due to technical limitations at the time. Although some early 8086, 80186 and 80286-based systems and manuals also used the iAPX prefix for marketing reasons, the iAPX 432 and the 8086 processor lines are completely separate designs with completely different instruction sets.

The project started in 1975 as the 8800 (after the 8008 and the 8080) and was intended to be Intel's major design for the 1980s. Unlike the 8086, which was designed the following year as a successor to the 8080, the iAPX 432 was a radical departure from Intel's previous designs meant for a different market niche, and completely unrelated to the 8080 or x86 product lines.

The iAPX 432 project is considered a commercial failure for Intel, and was discontinued in 1986.

🔗 Human rights 🔗 History 🔗 Military history 🔗 Crime 🔗 China 🔗 Politics 🔗 Socialism 🔗 Law Enforcement 🔗 Sociology 🔗 Sociology/social movements 🔗 Military history/Cold War 🔗 Military history/Asian military history 🔗 Military history/Chinese military history

The Tiananmen Square protests or Tiananmen Square Incident, commonly known in mainland China as the June Fourth Incident (Chinese: 六四事件; pinyin: liùsì shìjiàn, literally six-four incident), were student-led demonstrations held in Tiananmen Square in Beijing during 1989. The popular national movement inspired by the Beijing protests is sometimes called the '89 Democracy Movement (Chinese: 八九民運; pinyin: bājiǔ mínyùn). The protests started on April 15 and were forcibly suppressed on June 4 when the government declared martial law and sent the military to occupy central parts of Beijing. In what became known as the Tiananmen Square Massacre (Chinese: 天安門大屠殺; pinyin: tiān'ānmén dà túshā), troops with assault rifles and tanks fired at the demonstrators and those trying to block the military's advance into Tiananmen Square. Estimates of the death toll vary from several hundred to several thousand, with thousands more wounded.

Set off by the death of pro-reform Communist general secretary Hu Yaobang in April 1989, amid the backdrop of rapid economic development and social changes in post-Mao China, the protests reflected anxieties about the country's future in the popular consciousness and among the political elite. The reforms of the 1980s had led to a nascent market economy which benefited some people but seriously disaffected others, and the one-party political system also faced a challenge of legitimacy. Common grievances at the time included inflation, corruption, limited preparedness of graduates for the new economy, and restrictions on political participation. The students called for greater accountability, constitutional due process, democracy, freedom of the press, and freedom of speech, although they were highly disorganized and their goals varied. At the height of the protests, about 1 million people assembled in the Square.

As the protests developed, the authorities responded with both conciliatory and hardline tactics, exposing deep divisions within the party leadership. By May, a student-led hunger strike galvanized support for the demonstrators around the country, and the protests spread to some 400 cities. Ultimately, China's paramount leader Deng Xiaoping and other Communist Party elders believed the protests to be a political threat and resolved to use force. The State Council declared martial law on May 20 and mobilized as many as 300,000 troops to Beijing. The troops advanced into central parts of Beijing on the city's major thoroughfares in the early morning hours of June 4, killing both demonstrators and bystanders in the process.

The international community, human rights organizations, and political analysts condemned the Chinese government for the massacre. Western countries imposed arms embargoes on China. The Chinese government made widespread arrests of protesters and their supporters, suppressed other protests around China, expelled foreign journalists, strictly controlled coverage of the events in the domestic press, strengthened the police and internal security forces, and demoted or purged officials it deemed sympathetic to the protests. More broadly, the suppression halted the policies of liberalization in the 1980s. Considered a watershed event, the protests set the limits on political expression in China up to the present day. Its memory is widely associated with questioning the legitimacy of Communist Party rule and remains one of the most sensitive and most widely censored topics in China.

🔗 International relations 🔗 Spaceflight 🔗 Law 🔗 Politics 🔗 International relations/International law 🔗 British Overseas Territories

The Outer Space Treaty, formally the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, is a treaty that forms the basis of international space law. The treaty was opened for signature in the United States, the United Kingdom, and the Soviet Union on 27 January 1967, and entered into force on 10 October 1967. As of June 2019, 109 countries are parties to the treaty, while another 23 have signed the treaty but have not completed ratification. In addition, Taiwan, which is currently recognized by 14 UN member states, ratified the treaty prior to the United Nations General Assembly's vote to transfer China's seat to the People's Republic of China (PRC) in 1971.

Among the Outer Space Treaty's main points are that it prohibits the placing of nuclear weapons in space, it limits the use of the Moon and all other celestial bodies to peaceful purposes only, and establishes that space shall be free for exploration and use by all nations, but that no nation may claim sovereignty of outer space or any celestial body. The Outer Space Treaty does not ban military activities within space, military space forces, or the weaponization of space, with the exception of the placement of weapons of mass destruction in space. It is mostly a non-armament treaty and offers insufficient and ambiguous regulations to newer space activities such as lunar and asteroid mining.

🔗 Lists 🔗 Martial arts 🔗 Sumo

Kimarite (決まり手, "Deciding technique") are winning techniques in a sumo bout. For each bout in a Grand Sumo tournament (or honbasho), a sumo referee, or gyōji, will decide and announce the type of kimarite used by the winner. It is possible (although rare) for the judges to modify this decision later. Records of the kimarite are kept and statistical information on the preferred techniques of different wrestlers can be deduced easily. For example, a pie chart of the kimarite used by each sekitori in the past year can be found on the Japan Sumo Association webpage.

Since 2001, the Japan Sumo Association recognizes 82 types of kimarite (and 5 winning non-techniques), but only about a dozen are used regularly. For example, yorikiri, oshidashi and hatakikomi are frequent methods used to win bouts. In addition to kimarite, a bout can end in a disqualification if either wrestler makes a foul (禁手, kinjite), such as striking with a closed fist.

The following is a full list of kimarite. Literal translations of the Japanese are also given.

🔗 Oceans

Tide-Predicting Machine No. 2, also known as Old Brass Brains, was a special-purpose mechanical computer that uses gears, pulleys, chains, and other mechanical components to compute the height and time of high and low tides for specific locations. The machine can perform tide calculations much faster than a person could do with pencil and paper. The U.S. Coast and Geodetic Survey put the machine into operation in 1910. It was used until 1965, when it was replaced by an electronic computer.

🔗 Mammals

The nocturnal bottleneck hypothesis is a hypothesis to explain several mammalian traits. In 1942, Gordon Lynn Walls described this concept which states that placental mammals were mainly or even exclusively nocturnal through most of their evolutionary story, starting with their origin 225 million years ago, and only ending with the demise of the non-avian dinosaurs 66 million years ago. While some mammal groups have later evolved to fill diurnal niches, the approximately 160 million years spent as nocturnal animals has left a lasting legacy on basal anatomy and physiology, and most mammals are still nocturnal.

🔗 Computer science

In computer science, the sleeping barber problem is a classic inter-process communication and synchronization problem between multiple operating system processes. The problem is analogous to that of keeping a barber working when there are customers, resting when there are none, and doing so in an orderly manner.

The Sleeping Barber Problem is often attributed to Edsger Dijkstra (1965), one of the pioneers in computer science.