To stay up to date you can also follow on Mastodon.

A crinkle crankle wall, also known as a crinkum crankum, serpentine, ribbon or wavy wall, is an unusual type of garden wall built in a serpentine pattern with alternating curves.

The crinkle crankle wall economizes on bricks, despite its sinuous configuration, because it can be made just one brick thin. If a wall this thin were to be made in a straight line, without buttresses, it would easily topple over. The alternate convex and concave curves in the wall provide stability and help it to resist lateral forces.

"Crinkle crankle" is an ablaut reduplication, defined as something with bends and turns, first attested in 1598 (though "crinkle" and "crankle" have somewhat longer histories). However, it was not until the 18th century that the term began to be applied to wavy walls. At that time these garden walls were usually aligned east-west, so that one side faced south to catch the warming sun and were historically used for growing fruit.

Many crinkle crankle walls are found in the East Anglia region of England where the marshes of The Fens were drained by Dutch engineers starting in the mid-1600s. The walls' construction is attributed to these engineers who called them slangenmuur, meaning snake wall.  The county of Suffolk claims at least 50 examples, twice as many as in the whole of the rest of the country, and where crinkle crankle is said to derive from a local dialect. In the estate village of Easton the noted crinkle crankle wall running from the former manor house to All Saints' Church is supposed to be the longest existing example. In Lymington, Hampshire, there are at least two examples of crinkle crankle walls. The oldest is thought to have been constructed at the time of the Napoleonic Wars (1803–1815) by exiled Hanoverian soldiers living in the adjacent house.

As a minor part of a larger system of fortification, such a wall may have been used to force oncoming troops to break ranks from closed to open ranks, and further expose them to defensive assault.

Thomas Jefferson (1743–1826) incorporated so-called serpentine walls into the architecture of the University of Virginia, which he founded. Flanking both sides of its landmark rotunda and extending down the length of the lawn are ten pavilions, each with its own walled garden separated by crinkle crankle walls. Although some authorities claim Jefferson invented this design, he was merely adapting a well-established English style of construction. A university document in his own hand shows how he calculated the savings and combined aesthetics with utility.

🔗 Aviation 🔗 Disaster management 🔗 Aviation/Aviation accident 🔗 Occupational Safety and Health

Aviation safety means the state of an aviation system or organization in which risks associated with aviation activities, related to, or in direct support of the operation of aircraft, are reduced and controlled to an acceptable level. It encompasses the theory, practice, investigation, and categorization of flight failures, and the prevention of such failures through regulation, education, and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.

Aviation safety should not be confused with airport security which includes all of the measures taken to combat intentional malicious acts.

🔗 Film 🔗 Africa 🔗 Film/American cinema 🔗 Guild of Copy Editors 🔗 Animal rights

Roar is a 1981 American adventure comedy film written, produced, and directed by Noel Marshall. Roar's story follows Hank, a naturalist who lives on a nature preserve in Africa with lions, tigers, and other big cats. When his family visits him, they are instead confronted by the group of animals. The film stars Marshall as Hank and Tippi Hedren as his wife Madeleine, with Melanie Griffith, and Marshall's sons John and Jerry Marshall in supporting roles.

In 1969, while Hedren was filming Satan's Harvest in Mozambique, she and Marshall had occasion to observe a pride of lions move into a recently vacated house, driven by increased poaching. They decided to make a film centered around that theme, bringing rescued big cats into their homes in California and living with them. Filming began in 1976; it was finished after five years. The film was fully completed after 11 years in production.

Roar was not initially released in North America; in 1981, Noel and John Marshall privately released it internationally. It was also acquired by Filmways Pictures and Alpha Films. Despite performing well in Germany and Japan, Roar was a box office failure, grossing $2 million worldwide against a $17 million budget. In 2015, 34 years after the film's original release, it was released in theaters in the United States by Drafthouse Films. Roar's message of protection for African wildlife as well as its animal interactions were praised by critics, but its plot, story, inconsistent tone, dialogue, and editing were criticized.

The cast and crew members of Roar faced dangerous situations during filming; seventy people, including the film's stars, were injured as a result of multiple animal attacks. Flooding from a dam destroyed much of the set and equipment during its production, and the film's budget increased drastically. In 1983, Hedren founded the Roar Foundation and established the Shambala Preserve sanctuary, to house the animals appearing in the film. She also wrote a book, The Cats of Shambala (1985), about many of the film's events. The film has been described as "the most dangerous film ever made" and "the most expensive home movie ever made", and has gained a cult following.

🔗 Internet 🔗 Hong Kong

Hong Kong Internet eXchange (HKIX; Chinese: 香港互聯網交換中心) is an internet exchange point in Hong Kong. The cooperative project is initiated by the Information Technology Services Centre (ITSC) of the Chinese University of Hong Kong (CUHK) providing the service free of charge. It is now operated by HKIX Limited, a wholly owned subsidiary of the CUHK Foundation.

The aim of the HKIX is to connect Internet service providers (ISPs) in Hong Kong so that intra-Hong Kong traffic can be exchanged locally without routing through the US or other countries. 99% internet interaction in Hong Kong goes through the centre, and HKIX acts as Hong Kong's network backbone. According to Cloudflare, HKIX is the largest internet exchange point in Asia.

🔗 Mathematics

In number theory, a weird number is a natural number that is abundant but not semiperfect.

In other words, the sum of the proper divisors (divisors including 1 but not itself) of the number is greater than the number, but no subset of those divisors sums to the number itself.

🔗 Physics

The Einstein–Szilard or Einstein refrigerator is an absorption refrigerator which has no moving parts, operates at constant pressure, and requires only a heat source to operate. It was jointly invented in 1926 by Albert Einstein and his former student Leó Szilárd, who patented it in the U.S. on November 11, 1930 (U.S. Patent 1,781,541). The three working fluids in this design are water, ammonia and butane. The Einstein refrigerator is a development of the original three-fluid patent by the Swedish inventors Baltzar von Platen and Carl Munters.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Philately 🔗 Libraries 🔗 Military history/World War II 🔗 Military history/European military history 🔗 Military history/British military history

V-mail, short for Victory Mail, was a hybrid mail process used by the United States during the Second World War as the primary and secure method to correspond with soldiers stationed abroad. To reduce the cost of transferring an original letter through the military postal system, a V-mail letter would be censored, copied to film, and printed back to paper upon arrival at its destination. The V-mail process is based on the earlier British Airgraph process.

🔗 Companies 🔗 Finance & Investment

Renaissance Technologies LLC is an American hedge fund firm based in East Setauket, New York, on Long Island, which specializes in systematic trading using quantitative models derived from mathematical and statistical analyses. The firm is regarded as one of the "most secretive and successful" hedge funds in the world. Their signature Medallion fund is famed for the best record in investing history. Renaissance was founded in 1982 by James Simons, an award-winning mathematician and former Cold War code breaker.

In 1988, the firm established its most profitable portfolio, the Medallion Fund, which used an improved and expanded form of Leonard Baum's mathematical models, improved by algebraist James Ax, to explore correlations from which they could profit. Jim Berlekamp was instrumental in evolving trading to shorter-dated, pure systems driven decision-making. The hedge fund was named Medallion in honor of the math awards that Simons and Ax had won.

Renaissance's flagship Medallion fund, which is run mostly for fund employees, is famed for the best track record on Wall Street, returning more than 66 percent annualized before fees and 39 percent after fees over a 30-year span from 1988 to 2018. Renaissance offers two portfolios to outside investors—Renaissance Institutional Equities Fund (RIEF) and Renaissance Institutional Diversified Alpha (RIDA).

Simons ran Renaissance until his retirement in late 2009. The company is now run by Peter Brown (after Robert Mercer resigned). Both of them were computer scientists specializing in computational linguistics who joined Renaissance in 1993 from IBM Research. Simons continues to play a role at the firm as non-executive chairman and remains invested in its funds, particularly the secretive and consistently profitable black-box strategy known as Medallion. Because of the success of Renaissance in general and Medallion in particular, Simons has been described as the best money manager on earth.

🔗 Physics

The Mpemba effect is a process in which hot water can freeze faster than cold water. The phenomenon is temperature-dependent. There is disagreement about the parameters required to produce the effect and about its theoretical basis.

The Mpemba effect is named after Tanzanian scientist Erasto Bartholomeo Mpemba (b.1950) who discovered it in 1963. There were preceding ancient accounts of similar phenomena, but these lacked sufficient detail to attempt verification.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry

The M65 atomic cannon, often called "Atomic Annie", was an artillery piece built by the United States and capable of firing a nuclear device. It was developed in the early 1950s, at the beginning of the Cold War, and fielded, between April 1955 and December 1962, in West Germany, South Korea and on Okinawa.