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🔗 Astronomy 🔗 Astronomy/Solar System

The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto. They are the most readily visible Solar System objects after Saturn, the dimmest of the classical planets; though their closeness to bright Jupiter makes naked-eye observation very difficult, they are readily seen with common binoculars, even under night sky conditions of high light pollution. The invention of the telescope enabled the discovery of the moons in 1610. Through this, they became the first Solar System objects discovered since humans have started tracking the classical planets, and the first objects to be found to orbit any planet beyond Earth.

They are planetary-mass moons and among the largest objects in the Solar System. All four, along with Titan, Triton, and Earth's Moon, are larger than any of the Solar System's dwarf planets. The largest, Ganymede, is the largest moon in the Solar System and surpasses the planet Mercury in size (though not mass). Callisto is only slightly smaller than Mercury in size; the smaller ones, Io and Europa, are about the size of the Moon. The three inner moons — Io, Europa, and Ganymede — are in a 4:2:1 orbital resonance with each other. While the Galilean moons are spherical, all of Jupiter's remaining moons have irregular forms because they are too small for their self-gravitation to pull them into spheres.

The Galilean moons are named after Galileo Galilei, who observed them in either December 1609 or January 1610, and recognized them as satellites of Jupiter in March 1610; they remained the only known moons of Jupiter until the discovery of the fifth largest moon of Jupiter Amalthea in 1892. Galileo initially named his discovery the Cosmica Sidera ("Cosimo's stars") or Medicean Stars, but the names that eventually prevailed were chosen by Simon Marius. Marius discovered the moons independently at nearly the same time as Galileo, 8 January 1610, and gave them their present individual names, after mythological characters that Zeus seduced or abducted, which were suggested by Johannes Kepler in his Mundus Jovialis, published in 1614. Their discovery showed the importance of the telescope as a tool for astronomers by proving that there were objects in space that cannot be seen by the naked eye. The discovery of celestial bodies orbiting something other than Earth dealt a serious blow to the then-accepted (among educated Europeans) Ptolemaic world system, a geocentric theory in which everything orbits around Earth.

🔗 Visual arts

A pointing machine is a measuring tool used by stone sculptors and woodcarvers to accurately copy plaster, clay or wax sculpture models into wood or stone. In essence the device is a pointing needle that can be set to any position and then fixed. It further consists of brass or stainless steel rods and joints which can be placed into any position and then tightened. It is not actually a machine; its name is derived from the Italian macchinetta di punta. The invention of the tool has been ascribed to both the French sculptor and medallist Nicolas-Marie Gatteaux (1751–1832) and to the British sculptor John Bacon (1740–1799). It was later perfected by Canova. However, similar devices were used in ancient times, when the copying of Greek sculptures for the Roman market was a large industry.

🔗 Psychology

Mean world syndrome is a cognitive bias where people perceive the world to be more dangerous than it actually is due to long-term, moderate to heavy exposure to violence-related content on mass media.

Mean world syndrome asserts that viewers who are exposed to violence-related content can experience increased fear, anxiety, pessimism and heightened state of alert in response to perceived threats. This is because media (namely television) consumed by viewers has the power to directly influence and inform their attitudes, beliefs and opinions about the world.

Dr. George Gerbner, who coined the term mean world syndrome in the 1970s, began his research on the effects of violent media on individuals’ attitudes by claiming that a major cultural shift was taking place, where "who tells the stories of a culture really governs human behavior. It used to be the parent, the school, the church, the community. Now it's a handful of global conglomerates that have nothing to tell, but a great deal to sell."

Since TV was becoming an ever increasing presence in the average American household and the amount of violence on TV was growing exponentially, Gerbner conducted several large-scale studies that upheld his hypothesis: those who watched moderate to large amounts of TV believed the world to be a more dangerous place.

Since the 1970s, numerous studies have corroborated Gerbner's findings that moderate to heavy viewing of violence-related content on TV increased depression, fear, anxiety, anger, pessimism, post-traumatic stress and substance use. For example, in 2009, the American Academy of Pediatrics released a policy statement on media violence which concluded that “extensive research evidence indicates that media violence can contribute to aggressive behavior, desensitization to violence, nightmares, and fear of being harmed.”

🔗 Economics 🔗 Numismatics

In economics, Gresham's law is a monetary principle stating that "bad money drives out good". For example, if there are two forms of commodity money in circulation, which are accepted by law as having similar face value, the more valuable commodity will gradually disappear from circulation.

The law was named in 1860 by Henry Dunning Macleod, after Sir Thomas Gresham (1519–1579), who was an English financier during the Tudor dynasty. However, the concept itself had been previously expressed by others, including by Aristophanes in his play The Frogs, which dates from around the end of the 5th century BC, in the 14th century by Nicole Oresme c. 1350, in his treatise On the Origin, Nature, Law, and Alterations of Money, and by jurist and historian Al-Maqrizi (1364–1442) in the Mamluk Empire; and in 1519 by Nicolaus Copernicus in a treatise called Monetae cudendae ratio For this reason, it is occasionally known as the Gresham–Copernicus' law.

🔗 Computing

The Olivetti Programma 101, also known as Perottina or P101, is one of the first "all in one" commercial programmable desktop calculators, although not the first. Produced by Italian manufacturer Olivetti, based in Ivrea, Piedmont, and invented by the Italian engineer Pier Giorgio Perotto, the P101 has the main features of large computers of that period. It was launched at the 1964 New York World's Fair; volume production started in 1965. A futuristic design for its time, the Programma 101 was priced at $3,200 (equivalent to $26,000 in 2019). About 44,000 units were sold, primarily in the US.

It is usually called a printing programmable calculator or desktop calculator because its arithmetic instructions correspond to calculator operations.

🔗 Computing 🔗 Computing/Computer hardware 🔗 Computing/Computer Security

A Kensington Security Slot (also called a K-Slot or Kensington lock) is part of an anti-theft system designed in the early 1990s and patented by Kryptonite in 1999–2000, assigned to Schlage in 2002, and since 2005 owned and marketed by Kensington Computer Products Group, a division of ACCO Brands.

🔗 Climate change 🔗 Oceans 🔗 Limnology and Oceanography

The ocean temperature varies by depth, geographical location and season. Both the temperature and salinity of ocean water differs. Warm surface water is generally saltier than the cooler deep or polar waters; in polar regions, the upper layers of ocean water are cold and fresh. Deep ocean water is cold, salty water found deep below the surface of Earth's oceans. This water has a very uniform temperature, around 0-3 °C. The ocean temperature also depends on the amount of solar radiation falling on its surface. In the tropics, with the Sun nearly overhead, the temperature of the surface layers can rise to over 30 °C (86 °F) while near the poles the temperature in equilibrium with the sea ice is about −2 °C (28 °F). There is a continuous circulation of water in the oceans. Thermohaline circulation (THC) is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes. Warm surface currents cool as they move away from the tropics, and the water becomes denser and sinks. The cold water moves back towards the equator as a deep sea current, driven by changes in the temperature and density of the water, before eventually welling up again towards the surface.

Ocean temperature as a term is used either for the temperature in the ocean at any depth, or specifically for the ocean temperatures that are not near the surface (in which case it is synonymous with "deep ocean temperature").

It is clear that the oceans are warming as a result of climate change and this rate of warming is increasing.^: 9 The upper ocean (above 700 m) is warming fastest, but the warming trend extends throughout the ocean. In 2022, the global ocean was the hottest ever recorded by humans.

🔗 Brands 🔗 Chemistry 🔗 Invention 🔗 Polymers

Starlite is an intumescent material claimed to be able to withstand and insulate from extreme heat. It was invented by British amateur chemist and hairdresser Maurice Ward (1933-2011) during the 1970s and 1980s, and received significant publicity after coverage of the material aired in 1990 on the BBC science and technology show Tomorrow's World. The name Starlite was coined by Ward's granddaughter Kimberly.

The American company Thermashield, LLC claims to have acquired the rights to Starlite in 2013 and replicated it. It is the only company to have itself publicly demonstrated the technology and have samples tested by third parties.

🔗 Soviet Union 🔗 Military history 🔗 Italy 🔗 Military history/World War II 🔗 Military history/Russian, Soviet and CIS military history 🔗 Military history/Italian military history 🔗 Military history/European military history

The Charge of the "Savoia Cavalleria" at Izbushensky was a clash between the Italian cavalry Regiment "Savoia Cavalleria" (3rd) and the Soviet 812th Rifle Regiment (304th Rifle Division) that took place on August 24, 1942, near the hamlet (khutor) of Izbushensky (Избушенский), close to the junction between the Don and Khopyor rivers. Though a minor skirmish in the theatre of operation of the Eastern Front, the Izbushensky charge had great propaganda resonance in Italy and it is still remembered as one of the last significant cavalry charges in history.