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π Island of Stability
In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. Its theoretical existence is attributed to stabilizing effects of predicted "magic numbers" of protons and neutrons in the superheavy mass region.
Several predictions have been made regarding the exact location of the island of stability, though it is generally thought to center near copernicium and flerovium isotopes in the vicinity of the predicted closed neutron shell at NΒ =Β 184. These models strongly suggest that the closed shell will confer further stability towards fission and alpha decay. While these effects are expected to be greatest near atomic number ZΒ =Β 114 and NΒ =Β 184, the region of increased stability is expected to encompass several neighboring elements, and there may also be additional islands of stability around heavier nuclei that are doubly magic (having magic numbers of both protons and neutrons). Estimates of the stability of the elements on the island are usually around a half-life of minutes or days; some estimates predict half-lives of millions of years.
Although the nuclear shell model predicting magic numbers has existed since the 1940s, the existence of long-lived superheavy nuclides has not been definitively demonstrated. Like the rest of the superheavy elements, the nuclides on the island of stability have never been found in nature; thus, they must be created artificially in a nuclear reaction to be studied. Scientists have not found a way to carry out such a reaction, for it is likely that new types of reactions will be needed to populate nuclei near the center of the island. Nevertheless, the successful synthesis of superheavy elements up to ZΒ =Β 118 (oganesson) with up to 177 neutrons demonstrates a slight stabilizing effect around elements 110 to 114 that may continue in unknown isotopes, supporting the existence of the island of stability.
π Elfstedentocht
The Elfstedentocht (Dutch pronunciation: [Ιlf'steΛdΙ(n)tΙxt]; West Frisian: AlvestΓͺdetocht [ΙlvΙΛstΙΛdΙtΙΟt], English: Eleven cities tour) is a long-distance tour skating event on natural ice, almost 200 kilometres (120Β mi) long, which is held both as a speed skating competition (with 300 contestants) and a leisure tour (with 16,000 skaters). It is held in the province of Friesland in the north of the Netherlands, leading past all eleven historical cities of the province. The tour is held at most once a year, only when the natural ice along the entire course is at least 15 centimetres (6Β in) thick; sometimes on consecutive years, other times with gaps that may exceed 20 years. When the ice is suitable, the tour is announced and starts within 48 hours.
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- "Elfstedentocht" | 2023-06-11 | 12 Upvotes 2 Comments
- "Elfstedentocht" | 2021-02-08 | 295 Upvotes 124 Comments
π Crash-Only Software
Crash-only software refers to computer programs that handle failures by simply restarting, without attempting any sophisticated recovery. Correctly written components of crash-only software can microreboot to a known-good state without the help of a user. Since failure-handling and normal startup use the same methods, this can increase the chance that bugs in failure-handling code will be noticed, except when there are leftover artifacts, such as data corruption from a severe failure, that don't occur during normal startup.
Crash-only software also has benefits for end-users. All too often, applications do not save their data and settings while running, only at the end of their use. For example, word processors usually save settings when they are closed. A crash-only application is designed to save all changed user settings soon after they are changed, so that the persistent state matches that of the running machine. No matter how an application terminates (be it a clean close or the sudden failure of a laptop battery), the state will persist.
Discussed on
- "Crash-Only Software" | 2021-02-08 | 10 Upvotes 4 Comments
π Long Hundred
The long hundred, also known as the great hundred or twelfty, is the number that was referred to as "hundred" in Germanic languages prior to the 15th century, which is now known as 120, one hundred and twenty, or six score. The number was simply described as hundred and translated into Latin in Germanic-speaking countries as centum (Roman numeral C), but the qualifier "long" is now added because present English uses the word "hundred" exclusively to refer to the number of five score (100) instead.
The long hundred was 120 but the long thousand was reckoned decimally as 10 long hundreds (1200).
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- "Long Hundred" | 2021-02-08 | 97 Upvotes 106 Comments
π Society for Preventing Parents from Naming Their Children Jennifer
The Society for Preventing Parents from Naming Their Children Jennifer (SPPNTCJ) was a popular and sometimes controversial website that contributed to early web culture, online from 1996 to 2000. The SPPNTCJ home page was created and updated by Jennifer Farwell, one of the three founding members of the SPPNTCJ. Other founding members were Jennifer Rich and Jennifer Ang.
The SPPNTCJ began as an inside joke on an email discussion list that both Farwell and Rich subscribed to, which included five or more Jennifers who actively posted at that time. One of the Jennifers tossed out the comment that there should be "a society for preventing parents from naming their children Jennifer." The idea took off, and Farwell created the SPPNTCJ's website. It welcomed more than 2 million visitors while online.
During its run, the SPPNTCJ was noted by the Richmond Times-Dispatch, Yahoo! Internet Life magazine, Thunder Bay Television News, 580 CKPR radio program Tech Talk, California State University, Chico, SignsOnSanDiego.com, WebMD and more. It received several Internet "cool site" acknowledgments, from Cool Central, Seven Wonders, Twoeys, Fallen Thinkers, and Secret Einstein.
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- "Society for Preventing Parents from Naming Their Children Jennifer" | 2021-02-08 | 19 Upvotes 7 Comments
π Clerihew
A clerihew () is a whimsical, four-line biographical poem invented by Edmund Clerihew Bentley. The first line is the name of the poem's subject, usually a famous person put in an absurd light, or revealing something unknown or spurious about them. The rhyme scheme is AABB, and the rhymes are often forced. The line length and metre are irregular. Bentley invented the clerihew in school and then popularized it in books. One of his best known is this (1905):
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- "Clerihew" | 2021-02-07 | 69 Upvotes 34 Comments
π List of Helicopter Prison Escapes
A helicopter prison escape is made when an inmate escapes from a prison by means of a helicopter. This list includes prisoner escapes where a helicopter was used in an attempt to free prisoners from a place of internment, a prison or correctional facility.
One of the earliest instances of using a helicopter to escape a prison was the escape of Joel David Kaplan, nicknamed "Man Fan", on August 19, 1971 from the Santa Martha Acatitla in Mexico. Kaplan was a New York businessman who not only escaped the prison but eventually got out of Mexico and went on to write a book about his experience, The 10-Second Jailbreak.
France has had more recorded helicopter escape attempts than any other country, with at least 11. One of the most notable French jail breaks occurred in 1986, when the wife of bank robber Michel Vaujour studied for months to learn how to fly a helicopter. Using her newly acquired skills, she rented a white helicopter and flew low over Paris to pluck her husband off the roof of his fortress prison. Vaujour was later seriously wounded in a shootout with police, and his pilot wife was arrested.
The record for most helicopter escapes goes to convicted murderer Pascal Payet, who has used helicopters to escape from prisons in 2001, 2003, and most recently 2007.
Another multiple helicopter escapee is Vasilis Paleokostas who on February 22, 2009 escaped for the second time from the same prison. Because of this, many prisons have taken applicable precautions, such as nets or cables strung over open prison courtyards.
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- "List of Helicopter Prison Escapes" | 2021-02-06 | 17 Upvotes 4 Comments
π Colorless green ideas sleep furiously
Colorless green ideas sleep furiously is a sentence composed by Noam Chomsky in his 1957 book Syntactic Structures as an example of a sentence that is grammatically correct, but semantically nonsensical. The sentence was originally used in his 1955 thesis The Logical Structure of Linguistic Theory and in his 1956 paper "Three Models for the Description of Language". Although the sentence is grammatically correct, no obvious understandable meaning can be derived from it, and thus it demonstrates the distinction between syntax and semantics. As an example of a category mistake, it was used to show the inadequacy of certain probabilistic models of grammar, and the need for more structured models.
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- "Colorless green ideas sleep furiously" | 2021-02-06 | 15 Upvotes 18 Comments
π Bangui Magnetic Anomaly
The Bangui magnetic anomaly is a local variation in the Earth's magnetic field centered at Bangui, the capital of Central African Republic. The magnetic anomaly is roughly elliptical, about 700Β km ΓΒ 1,000Β km (430Β mi ΓΒ 620Β mi), and covers most of the country, making it one of the "largest and most intense crustal magnetic anomalies on the African continent". The anomaly was discovered in the late 1950s, explored in the 1970s, and named in 1982. Its origin remains unclear.
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- "Bangui Magnetic Anomaly" | 2021-02-02 | 82 Upvotes 15 Comments
π Tartar Relation
The Tartar Relation (Latin: Hystoria Tartarorum, "History of the Tartars") is an ethnographic report on the Mongol Empire composed by a certain C. de Bridia in Latin in 1247. It is one of the most detailed accounts of the history and customs of the Mongols to appear in Europe around that time.
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- "Tartar Relation" | 2021-01-31 | 45 Upvotes 3 Comments