Have a deep view into what people are curious about.

🔗 Chess 🔗 Hungary 🔗 Turkey

The Turk, also known as the Mechanical Turk or Automaton Chess Player (German: Schachtürke, "chess Turk"; Hungarian: A Török), was a fake chess-playing machine constructed in the late 18th century. From 1770 until its destruction by fire in 1854 it was exhibited by various owners as an automaton, though it was eventually revealed to be an elaborate hoax. Constructed and unveiled in 1770 by Wolfgang von Kempelen (Hungarian: Kempelen Farkas; 1734–1804) to impress the Empress Maria Theresa of Austria, the mechanism appeared to be able to play a strong game of chess against a human opponent, as well as perform the knight's tour, a puzzle that requires the player to move a knight to occupy every square of a chessboard exactly once.

The Turk was in fact a mechanical illusion that allowed a human chess master hiding inside to operate the machine. With a skilled operator, the Turk won most of the games played during its demonstrations around Europe and the Americas for nearly 84 years, playing and defeating many challengers including statesmen such as Napoleon Bonaparte and Benjamin Franklin. The device was later purchased in 1804 and exhibited by Johann Nepomuk Mälzel. The chess masters who secretly operated it included Johann Allgaier, Boncourt, Aaron Alexandre, William Lewis, Jacques Mouret, and William Schlumberger, but the operators within the mechanism during Kempelen's original tour remain a mystery.

🔗 Ancient Egypt 🔗 Color 🔗 Archaeology 🔗 Visual arts

Mummy brown, also known as Egyptian brown or Caput Mortuum,^: 254 is a rich brown bituminous pigment with good transparency, sitting between burnt umber and raw umber in tint. The pigment was made from the flesh of mummies mixed with white pitch and myrrh. Mummy brown was extremely popular from the mid-eighteenth to the nineteenth centuries. However, fresh supplies of mummies diminished, and artists were less satisfied with the pigment's permanency and finish. By 1915, demand had significantly declined. Suppliers ceased to offer it by the middle of the twentieth century.^: 82

Mummy brown was one of the favourite colours of the Pre-Raphaelites. It was used by many artists, including Eugene Delacroix, William Beechey, Edward Burne-Jones, Lawrence Alma-Tadema, and Martin Drolling.

🔗 Numismatics 🔗 Numismatics/Cryptocurrency 🔗 Cryptocurrency

A proof-of-work (PoW) system (or protocol, or function) is a consensus mechanism. It deters denial-of-service attacks and other service abuses such as spam on a network by requiring some work from the service requester, usually meaning processing time by a computer. The concept was invented by Cynthia Dwork and Moni Naor as presented in a 1993 journal article. The term "proof of work" was first coined and formalized in a 1999 paper by Markus Jakobsson and Ari Juels.

A key feature of these schemes is their asymmetry: the work must be moderately hard (yet feasible) on the requester side but easy to check for the service provider. This idea is also known as a CPU cost function, client puzzle, computational puzzle, or CPU pricing function. It is distinct from a CAPTCHA, which is intended for a human to solve quickly, while being difficult to solve for a computer.

🔗 Religion 🔗 Classical Greece and Rome 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Cryptography 🔗 Cryptography/Computer science 🔗 Latin 🔗 Christianity 🔗 Jewish history 🔗 Occult 🔗 Mysticism

The Sator Square (or Rotas Square) is a word square containing a five-word Latin palindrome. The earliest form has ROTAS as the top line, but in time the version with SATOR on the top line became dominant. It is a 5X5 square made up of five 5-letter words, thus consisting of 25 letters in total. These 25 letters are all derived from 8 Latin letters: 5 consonants (S, T, R, P, N) and 3 vowels (A, E, O).

In particular, this is a square 2D palindrome, which is when a square text admits four symmetries: identity, two diagonal reflections, and 180 degree rotation. As can be seen, the text may be read top-to-bottom, bottom-to-top, left-to-right, or right-to-left; and it may be rotated 180 degrees and still be read in all those ways.

The Sator Square is the earliest dateable 2D palindrome. It was found in the ruins of Pompeii, at Herculaneum, a city buried in the ash of Mount Vesuvius in 79 AD. It consists of a sentence written in Latin: "Sator Arepo Tenet Opera Rotas." Its translation has been the subject of speculation with no clear consensus; see below for details.

Other 2D Palindrome examples may be found carved on stone tablets or pressed into clay before being fired.

🔗 Sociology

Xennials or xennials (also known as the Oregon Trail Generation and Generation Catalano) are the micro-generation of people on the cusp of the Generation X and Millennial demographic cohorts. Researchers and popular media use birth years from the late 1970s to the early 1980s. Xennials are described as having had an analog childhood and a digital young adulthood.

In 2020, xennial was included in the Oxford Dictionary of English.

🔗 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%.

🔗 Aviation 🔗 Computing

The E6B flight computer is a form of circular slide rule used in aviation. It is an instance of an analog calculating device still being used in the 21st century.

They are mostly used in flight training, because these flight computers have been replaced with electronic planning tools or software and websites that make these calculations for the pilots. These flight computers are used during flight planning (on the ground before takeoff) to aid in calculating fuel burn, wind correction, time en route, and other items. In the air, the flight computer can be used to calculate ground speed, estimated fuel burn and updated estimated time of arrival. The back is designed for wind vector solutions, i.e., determining how much the wind is affecting one's speed and course. They are frequently referred to by the nickname "whiz wheel".

🔗 Psychology

The Truman Show delusion, informally known as Truman syndrome, is a type of delusion in which the person believes that their lives are staged reality shows, or that they are being watched on cameras. The term was coined in 2008 by brothers Joel Gold and Ian Gold, a psychiatrist and a neurophilosopher, respectively, after the film The Truman Show.

The Truman Show delusion is not officially recognized nor listed in the Diagnostic and Statistical Manual of the American Psychiatric Association.

🔗 Philosophy 🔗 Philosophy/Philosophical literature 🔗 Books

Systems of Survival: A Dialogue on the Moral Foundations of Commerce and Politics is a book written by American urban activist Jane Jacobs in 1992.

It describes two fundamental and distinct ethical systems, or syndromes as she calls them: that of the Guardian and that of Commerce. She argues that these supply direction for the conduct of human life within societies, and understanding the tension between them can help us with public policy and personal choices.

A milk watcher, milk saver, pot watcher, pot minder, milk guard, or boil over preventer is a cooking utensil placed at the bottom of a pot to prevent the foaming boil-over of liquids by collecting small bubbles of steam into one large bubble.