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๐Ÿ”— Fazlur Khan: The engineer who made it possible to live in the sky

๐Ÿ”— Biography ๐Ÿ”— Bangladesh ๐Ÿ”— Architecture ๐Ÿ”— Skyscrapers ๐Ÿ”— Civil engineering ๐Ÿ”— Chicago ๐Ÿ”— Illinois

Fazlur Rahman Khan (Bengali: เฆซเฆœเฆฒเงเฆฐ เฆฐเฆนเฆฎเฆพเฆจ เฆ–เฆพเฆจ, Fozlur Rรดhman Khan) (3 April 1929 โ€“ 27 March 1982) was a Bangladeshi-American structural engineer and architect, who initiated important structural systems for skyscrapers. Considered the "father of tubular designs" for high-rises, Khan was also a pioneer in computer-aided design (CAD). He was the structural engineer of the Sears Tower working with Architect Bruce Graham, since renamed Willis Tower, the tallest building in the world from 1973 until 1998, and the 100-story John Hancock Center.

Khan, more than any other individual, ushered in a renaissance in skyscraper construction during the second half of the 20th century. He has been called the "Einstein of structural engineering" and the "Greatest Structural Engineer of the 20th Century" for his innovative use of structural systems that remain fundamental to modern skyscraper design and construction. In his honor, the Council on Tall Buildings and Urban Habitat established the Fazlur Khan Lifetime Achievement Medal, as one of their CTBUH Skyscraper Awards.

Although best known for skyscrapers, Khan was also an active designer of other kinds of structures, including the Hajj airport terminal, the McMathโ€“Pierce solar telescope, and several stadium structures.

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๐Ÿ”— Attempto Controlled English

๐Ÿ”— Computer science ๐Ÿ”— Linguistics ๐Ÿ”— Languages

Attempto Controlled English (ACE) is a controlled natural language, i.e. a subset of standard English with a restricted syntax and restricted semantics described by a small set of construction and interpretation rules. It has been under development at the University of Zurich since 1995. In 2013, ACE version 6.7 was announced.

ACE can serve as knowledge representation, specification, and query language, and is intended for professionals who want to use formal notations and formal methods, but may not be familiar with them. Though ACE appears perfectly natural โ€“ it can be read and understood by any speaker of English โ€“ it is in fact a formal language.

ACE and its related tools have been used in the fields of software specifications, theorem proving, text summaries, ontologies, rules, querying, medical documentation and planning.

Here are some simple examples:

  1. Every woman is a human.
  2. A woman is a human.
  3. A man tries-on a new tie. If the tie pleases his wife then the man buys it.

ACE construction rules require that each noun be introduced by a determiner (a, every, no, some, at least 5, ...). Regarding the list of examples above, ACE interpretation rules decide that (1) is interpreted as universally quantified, while (2) is interpreted as existentially quantified. Sentences like "Women are human" do not follow ACE syntax and are consequently not valid.

Interpretation rules resolve the anaphoric references in (3): the tie and it of the second sentence refer to a new tie of the first sentence, while his and the man of the second sentence refer to a man of the first sentence. Thus an ACE text is a coherent entity of anaphorically linked sentences.

The Attempto Parsing Engine (APE) translates ACE texts unambiguously into discourse representation structures (DRS) that use a variant of the language of first-order logic. A DRS can be further translated into other formal languages, for instance AceRules with various semantics, OWL, and SWRL. Translating an ACE text into (a fragment of) first-order logic allows users to reason about the text, for instance to verify, to validate, and to query it.

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๐Ÿ”— Kerckhoffs's principle

๐Ÿ”— Cryptography ๐Ÿ”— Cryptography/Computer science ๐Ÿ”— Citizendium Porting

Kerckhoffs's principle (also called Kerckhoffs's desideratum, assumption, axiom, doctrine or law) of cryptography was stated by Netherlands born cryptographer Auguste Kerckhoffs in the 19th century: A cryptosystem should be secure even if everything about the system, except the key, is public knowledge.

Kerckhoffs's principle was reformulated (or possibly independently formulated) by American mathematician Claude Shannon as "the enemy knows the system", i.e., "one ought to design systems under the assumption that the enemy will immediately gain full familiarity with them". In that form, it is called Shannon's maxim. This concept is widely embraced by cryptographers, in contrast to "security through obscurity", which is not.

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๐Ÿ”— Regional Handwriting Variation

๐Ÿ”— Linguistics ๐Ÿ”— Writing systems

Although people in many parts of the world share common alphabets and numeral systems (versions of the Latin writing system are used throughout the Americas, Australia, and much of Europe and Africa; the Arabic numerals are nearly universal), styles of handwritten letterforms vary between individuals, and sometimes also vary systematically between regions.

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๐Ÿ”— Shot tower

๐Ÿ”— Architecture ๐Ÿ”— Firearms ๐Ÿ”— Metalworking

A shot tower is a tower designed for the production of small diameter shot balls by freefall of molten lead, which is then caught in a water basin. The shot is primarily used for projectiles in shotguns, and also for ballast, radiation shielding and other applications where small lead balls are useful.

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๐Ÿ”— Liquid Democracy

๐Ÿ”— Politics

Liquid democracy is a form of delegative democracy whereby an electorate has the option of vesting voting power in delegates as well as voting directly themselves. Liquid democracy is a broad category of either already-existing or proposed popular-control apparatuses. Voters can either vote directly or delegate their vote to other participants; voters may also select different delegates for different issues. In other words, individual A of a society can delegate their power to another individual B โ€“ and withdraw such power again at any time.

Liquid democracy lies between direct and representative democracy. In direct democracy, participants must vote personally on all issues, while in representative democracy participants vote for representatives once in certain election cycles. Meanwhile, liquid democracy does not depend on representatives but rather on a weighted and transitory delegation of votes. Liquid democracy through elections can empower individuals to become sole interpreters of the interests of the nation. It allows for citizens to vote directly on policy issues, delegate their votes on one or multiple policy areas to delegates of their choosing, delegate votes to one or more people, delegated to them as a weighted voter, or get rid of their votes' delegations whenever they please.

Most of the available academic literature on liquid democracy is based on empirical research rather than on specific conceptualization or theories. Experiments have mostly been conducted on a local-level or exclusively through online platforms, however polity examples are listed below.

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๐Ÿ”— Red Mercury

๐Ÿ”— Military history ๐Ÿ”— Military history/Military science, technology, and theory ๐Ÿ”— Military history/Weaponry ๐Ÿ”— Elements ๐Ÿ”— Military history/Cold War

Red mercury is purportedly a substance of uncertain composition used in the creation of nuclear weapons, as well as other weapons systems. Because of the great secrecy surrounding the development and manufacture of nuclear weapons, there is no proof that red mercury exists. However, all samples of alleged "red mercury" analyzed in the public literature have proven to be well-known, common red substances of no interest to weapons makers.

Red mercury is therefore considered a hoax, perpetrated by con artists who sought to take advantage of gullible buyers on the black market for arms. There have been reports of "red mercury" on the international black markets since 1979, but the hoax seems to have been most common in the early 1990s, with very high asking prices.

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๐Ÿ”— William of Rubruck

๐Ÿ”— Biography ๐Ÿ”— France ๐Ÿ”— Middle Ages ๐Ÿ”— Middle Ages/History ๐Ÿ”— Biography/arts and entertainment ๐Ÿ”— Christianity ๐Ÿ”— Catholicism ๐Ÿ”— Middle Ages/Crusades ๐Ÿ”— Military history/Crusades ๐Ÿ”— Belgium ๐Ÿ”— Christianity/Christianity in China

William of Rubruck (Dutch: Willem van Rubroeck, Latin: Gulielmus de Rubruquis; fl.โ€‰1248โ€“1255) was a Flemish Franciscan missionary and explorer.

He is best known for his travels to various parts of the Middle East and Central Asia in the 13th century, including the Mongol Empire. His account of his travels is one of the masterpieces of medieval travel literature, comparable to those of Marco Polo and Ibn Battuta.

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๐Ÿ”— Miyamoto Musashi's Final Work

๐Ÿ”— Philosophy ๐Ÿ”— Philosophy/Philosophical literature ๐Ÿ”— Books ๐Ÿ”— Philosophy/Modern philosophy ๐Ÿ”— Japan ๐Ÿ”— Philosophy/Eastern philosophy

The "Dokkลdล" (Japanese: ็จ่กŒ้“) ("The Path of Aloneness", "The Way to Go Forth Alone", or "The Way of Walking Alone"), is a short work written by Miyamoto Musashi a week before he died in 1645. It consists of 21 precepts. "Dokkodo" was largely composed on the occasion of Musashi giving away his possessions in preparation for death, and was dedicated to his favorite disciple, Terao Magonojล (to whom the earlier Go rin no sho [The Book of Five Rings] had also been dedicated), who took them to heart. "Dokkลdล" expresses a stringent, honest, and ascetic view of life.

The 21 precepts of Dokkodo:

1. Accept everything just the way it is.

2. Do not seek pleasure for its own sake.

3. Do not, under any circumstances, depend on a partial feeling.

4. Think lightly of yourself and deeply of the world.

5. Be detached from desire your whole life long.

6. Do not regret what you have done.

7. Never be jealous.

8. Never let yourself be saddened by a separation.

9. Resentment and complaint are appropriate neither for oneself or others.

10. Do not let yourself be guided by the feeling of lust or love.

11. In all things have no preferences.

12. Be indifferent to where you live.

13. Do not pursue the taste of good food.

14. Do not hold on to possessions you no longer need.

15. Do not act following customary beliefs.

16. Do not collect weapons or practice with weapons beyond what is useful.

17. Do not fear death.

18. Do not seek to possess either goods or fiefs for your old age.

19. Respect Buddha and the gods without counting on their help.

20. You may abandon your own body but you must preserve your honour.

21. Never stray from the Way.

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๐Ÿ”— James Lovelock Has Died

๐Ÿ”— Biography ๐Ÿ”— Climate change ๐Ÿ”— Environment ๐Ÿ”— Biography/science and academia ๐Ÿ”— Energy

James Ephraim Lovelock (26 July 1919 โ€“ 26 July 2022) was a British independent scientist, environmentalist and futurist. He was best known for proposing the Gaia hypothesis, which postulates that the Earth functions as a self-regulating system.

With a PhD in medicine, Lovelock began his career performing cryopreservation experiments on rodents, including successfully thawing frozen specimens. His methods were influential in the theories of cryonics (the cryopreservation of humans). He invented the electron capture detector, and using it, became the first to detect the widespread presence of chlorofluorocarbons in the atmosphere. While designing scientific instruments for NASA, he developed the Gaia hypothesis.

In the 2000s, he proposed a method of climate engineering to restore carbon dioxideโ€“consuming algae. He was an outspoken member of Environmentalists for Nuclear, asserting that fossil fuel interests have been behind opposition to nuclear energy, citing the effects of carbon dioxide as being harmful to the environment, and warning of global warming due to the greenhouse effect. He authored several environmental science books based upon the Gaia hypothesis from the late 1970s.

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