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🔗 Soviet Union 🔗 Firearms

The TP-82 (Russian: ТП-82) was a triple-barrelled Soviet pistol that was carried by cosmonauts on space missions.

It was intended as a survival aid to be used after landings and before recovery in the Siberian wilderness. The TP-82 was the result of cosmonaut Alexei Leonov's concerns after being stranded in the Siberian wilderness when his Voskhod capsule malfunctioned. He feared that the 9mm pistol that was provided in the survival kit would be ineffective against the Siberian wildlife, namely bears and wolves.

The upper two shotgun barrels used 12.5×70 mm ammunition (40 gauge), and the lower rifled barrel used 5.45×39mm ammunition developed for the AK-74 assault rifle. The TP-82 has a large lever on the left side of the receiver that opens the action and a small grip-safety under the trigger-guard that resembles a secondary trigger.

The pistol could be used for hunting, to defend against predators and for visible and audible distress signals. The detachable buttstock was also a machete that came with a canvas sheath. TP-82s were carried regularly on Soviet and Russian space missions from 1986 to 2007. They were part of the Soyuz Portable Emergency-Survival Kit (Носимый аварийный запас, Nosimyi Avariynyi Zapas, NAZ). In 2007, the media reported that the remaining ammunition for the TP-82 had become unusable and that a regular semi-automatic pistol would be used on future missions.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Geology 🔗 Explosives

Tired mountain syndrome is a condition in which underground nuclear testing fractures and weakens rock, increasing permeability and the risk of release of radionuclides and radioactive contamination of the environment. Locations said to have undergone the syndrome include the French Polynesian island of Moruroa, Rainier Mesa in the United States, the Dnepr 1 nuclear test site on the Kola Peninsula in Russia, possibly Mount Lazarev in the Novaya Zemlya Test Site in Russia, and Mount Mantap in North Korea.

The exercise paradox, also known as the workout paradox, refers to the finding that physical activity, while essential for maintaining overall health, does not necessarily lead to significant weight loss or increased calorie expenditure. This paradox challenges the common belief that more exercise equates to more calories burned and consequently, more weight loss.

🔗 Finance & Investment 🔗 Economics

In finance, the greater fool theory suggests that one can sometimes make money through the purchase of overvalued assets — items with a purchase price drastically exceeding the intrinsic value — if those assets can later be resold at an even higher price.

In this context, one "fool" might pay for an overpriced asset, on the assumption that he can probably sell it to an even "greater fool" and make a profit. This only works as long as there are new "greater fools" willing to pay higher and higher prices for the asset. Eventually, investors can no longer deny that the price is out of touch with reality, at which point a sell-off can cause the price to drop significantly until it is closer to its fair value.

🔗 Mathematics 🔗 Statistics

In statistics, the 68–95–99.7 rule, also known as the empirical rule, is a shorthand used to remember the percentage of values that lie within an interval estimate in a normal distribution: 68%, 95%, and 99.7% of the values lie within one, two, and three standard deviations of the mean, respectively.

In mathematical notation, these facts can be expressed as follows, where Pr() is the probability function, Χ is an observation from a normally distributed random variable, μ (mu) is the mean of the distribution, and σ (sigma) is its standard deviation:

${\displaystyle {\begin{aligned}\Pr(\mu -1\sigma \leq X\leq \mu +1\sigma )&\approx 68.27\%\\\Pr(\mu -2\sigma \leq X\leq \mu +2\sigma )&\approx 95.45\%\\\Pr(\mu -3\sigma \leq X\leq \mu +3\sigma )&\approx 99.73\%\end{aligned}}}$

The usefulness of this heuristic especially depends on the question under consideration.

In the empirical sciences, the so-called three-sigma rule of thumb (or 3σ rule) expresses a conventional heuristic that nearly all values are taken to lie within three standard deviations of the mean, and thus it is empirically useful to treat 99.7% probability as near certainty.

In the social sciences, a result may be considered "significant" if its confidence level is of the order of a two-sigma effect (95%), while in particle physics, there is a convention of a five-sigma effect (99.99994% confidence) being required to qualify as a discovery.

A weaker three-sigma rule can be derived from Chebyshev's inequality, stating that even for non-normally distributed variables, at least 88.8% of cases should fall within properly calculated three-sigma intervals. For unimodal distributions, the probability of being within the interval is at least 95% by the Vysochanskij–Petunin inequality. There may be certain assumptions for a distribution that force this probability to be at least 98%.

🔗 United States 🔗 Cities 🔗 United States/Texas 🔗 Dallas-Fort Worth

Fort Worth is a city in the U.S. state of Texas and the seat of Tarrant County, covering nearly 350 square miles (910 km²) into Denton, Johnson, Parker, and Wise counties. Fort Worth's population was 918,915 as of the official 2020 U.S. census count, making it the 11th-most populous city in the United States. Fort Worth is the second-largest city in the Dallas–Fort Worth metroplex, after Dallas, and the metropolitan area is the fourth-most populous metropolitan area in the United States and the most populous in Texas.

The city of Fort Worth was established in 1849 as an army outpost on a bluff overlooking the Trinity River. Fort Worth has historically been a center of the Texas Longhorn cattle trade. It still embraces its Western heritage and traditional architecture and design. USS Fort Worth (LCS-3) is the first ship of the United States Navy named after the city. Nearby Dallas has held a population majority in the metropolitan area for as long as records have been kept, yet Fort Worth has become one of the fastest-growing cities in the United States.

The city is the location of the Van Cliburn International Piano Competition and several museums designed by contemporary architects. The Kimbell Art Museum was designed by Louis Kahn, with an additional designs by Renzo Piano. The Modern Art Museum of Fort Worth was designed by Tadao Ando. The Amon Carter Museum of American Art, designed by Philip Johnson, houses American art. The Sid Richardson Museum, redesigned by David M. Schwarz, has a collection of Western art in the United States emphasizing Frederic Remington and Charles Russell. The Fort Worth Museum of Science and History was designed by Ricardo Legorreta of Mexico.

In addition, the city of Fort Worth is the location of several universities including, University of Texas at Arlington, Texas Christian University, Texas Wesleyan, University of North Texas Health Science Center, and Texas A&M University School of Law. Several multinational corporations, including Bell Textron, American Airlines, and BNSF Railway, are headquartered in Fort Worth.

🔗 Novels 🔗 Novels/Science fiction

The Carpet Makers (German original title: Die Haarteppichknüpfer), also published under the title The Hair Carpet Weavers, is a science fiction novel by German writer Andreas Eschbach, originally published in 1995. The first English language edition, released in 2005 by Tor Books, features a foreword by Orson Scott Card.

The book is set on a planet whose sole industry is weaving elaborate rugs. The carpets are made of human hair and require a lifetime of work to complete. The book is a series of inter-related stories that give increasingly more detail on the nature and purpose of the rugs and why the universe has tens of thousands of planets solely devoted to making such a thing, each thinking they are the only one.

There is a prequel to The Carpet Makers titled Quest (2001), which has not been translated into English so far.

🔗 Physics 🔗 Weather 🔗 Weather/Weather

A light pillar is an atmospheric optical phenomenon in which a vertical beam of light appears to extend above and/or below a light source. The effect is created by the reflection of light from tiny ice crystals that are suspended in the atmosphere or that comprise high-altitude clouds (e.g. cirrostratus or cirrus clouds). If the light comes from the Sun (usually when it is near or even below the horizon), the phenomenon is called a sun pillar or solar pillar. Light pillars can also be caused by the Moon or terrestrial sources, such as streetlights and erupting volcanoes.

🔗 Military history 🔗 Military history/Medieval warfare 🔗 Martial arts 🔗 Military history/Spanish military history 🔗 Spain 🔗 Military history/European military history 🔗 Fencing

La Verdadera Destreza is the conventional term for the Spanish tradition of fencing of the early modern period. The word destreza literally translates to 'dexterity' or 'skill, ability', and thus la verdadera destreza to 'the true skill' or 'the true art'.

While destreza is primarily a system of swordsmanship, it is intended to be a universal method of fighting, applicable to all weapons in principle, but in practice dedicated to the rapier specifically, or the rapier combined with a defensive weapon such as a cloak, a buckler or a parrying dagger, besides other weapons such as the late-renaissance two-handed montante; the flail; and polearms such as the pike and halberd.

Its precepts are based on reason, geometry, and tied to intellectual, philosophical, and moral ideals, incorporating various aspects of a well-rounded Renaissance humanist education, with a special focus on the writings of classical authors such as Aristotle, Euclid, and Plato.

The tradition is documented in scores of fencing manuals, but centers on the works of two primary authors, Jerónimo Sánchez de Carranza (Hieronimo de Carança, died c. 1608) and his student Luis Pacheco de Narváez (1570–1640).

🔗 Australia 🔗 Portugal 🔗 Australia/Australian maritime history 🔗 Australia/History of exploration

The theory of Portuguese discovery of Australia claims that early Portuguese navigators were the first Europeans to sight Australia between 1521 and 1524, well before the arrival of Dutch navigator Willem Janszoon in 1606 on board the Duyfken who is generally considered to be the first European discoverer. This is based on the following elements:

• The Dieppe maps, a group of 16th-century French world maps, which depict a large landmass between Indonesia and Antarctica. Labelled as Java la Grande, this land mass carries French, Portuguese, and Gallicized Portuguese placenames, and has been interpreted by some as corresponding to Australia's northwestern and eastern coasts.
• The presence of Portuguese colonies in Southeast Asia from the early 16th century, particularly Portuguese Timor – approximately 650 kilometres from the Australian coast – c. 1513–1516.
• Various antiquities found on Australian coastlines, claimed to be relics of early Portuguese voyages to Australia, which are more commonly regarded as evidence of Makassan visit of Northern Australia.

Precedence of Australia's discovery has also been claimed for China (Admiral Zheng), France, Spain, and even Phoenicia.