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πŸ”— Gabriel's Horn

πŸ”— Mathematics

Gabriel's horn (also called Torricelli's trumpet) is a geometric figure which has infinite surface area but finite volume. The name refers to the Abrahamic tradition identifying the archangel Gabriel as the angel who blows the horn to announce Judgment Day, associating the divine, or infinite, with the finite. The properties of this figure were first studied by Italian physicist and mathematician Evangelista Torricelli in the 17th century.

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πŸ”— The Last Question

πŸ”— Novels πŸ”— Novels/Science fiction πŸ”— Science Fiction πŸ”— Novels/Short story

"The Last Question" is a science fiction short story by American writer Isaac Asimov. It first appeared in the November 1956 issue of Science Fiction Quarterly and was anthologized in the collections Nine Tomorrows (1959), The Best of Isaac Asimov (1973), Robot Dreams (1986), The Best Science Fiction of Isaac Asimov (1986), the retrospective Opus 100 (1969), and in Isaac Asimov: The Complete Stories, Vol. 1 (1990). While he also considered it one of his best works, β€œThe Last Question” was Asimov's favorite short story of his own authorship, and is one of a loosely connected series of stories concerning a fictional computer called Multivac. Asimov's Three Laws of Robotics, which were first formulated in 1940, outline the criteria for robotic existence in relation to humans. Humanity's relationship to Multivac is questioned on the subject of entropy. The story overlaps science fiction, theology, and philosophy. Β 

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πŸ”— Bouncing bomb

πŸ”— Aviation πŸ”— Military history πŸ”— Military history/Military aviation πŸ”— Military history/Military science, technology, and theory πŸ”— Military history/Weaponry πŸ”— Aviation/aircraft πŸ”— Military history/World War II πŸ”— Military history/European military history πŸ”— Military history/British military history

A bouncing bomb is a bomb designed to bounce to a target across water in a calculated manner to avoid obstacles such as torpedo nets, and to allow both the bomb's speed on arrival at the target and the timing of its detonation to be pre-determined, in a similar fashion to a regular naval depth charge. The inventor of the first such bomb was the British engineer Barnes Wallis, whose "Upkeep" bouncing bomb was used in the RAF's Operation Chastise of May 1943 to bounce into German dams and explode underwater, with effect similar to the underground detonation of the Grand Slam and Tallboy earthquake bombs, both of which he also invented.

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πŸ”— Pattern theory

Pattern theory, formulated by Ulf Grenander, is a mathematical formalism to describe knowledge of the world as patterns. It differs from other approaches to artificial intelligence in that it does not begin by prescribing algorithms and machinery to recognize and classify patterns; rather, it prescribes a vocabulary to articulate and recast the pattern concepts in precise language. Broad in its mathematical coverage, Pattern Theory spans algebra and statistics, as well as local topological and global entropic properties.

In addition to the new algebraic vocabulary, its statistical approach is novel in its aim to:

  • Identify the hidden variables of a data set using real world data rather than artificial stimuli, which was previously commonplace.
  • Formulate prior distributions for hidden variables and models for the observed variables that form the vertices of a Gibbs-like graph.
  • Study the randomness and variability of these graphs.
  • Create the basic classes of stochastic models applied by listing the deformations of the patterns.
  • Synthesize (sample) from the models, not just analyze signals with them.

The Brown University Pattern Theory Group was formed in 1972 by Ulf Grenander. Many mathematicians are currently working in this group, noteworthy among them being the Fields Medalist David Mumford. Mumford regards Grenander as his "guru" in Pattern Theory.

πŸ”— Person from Porlock

πŸ”— Biography πŸ”— Poetry πŸ”— United Kingdom

The person from Porlock was an unwelcome visitor to Samuel Taylor Coleridge during his composition of the poem Kubla Khan in 1797. Coleridge claimed to have perceived the entire course of the poem in a dream (possibly an opium-induced haze), but was interrupted by this visitor from Porlock while in the process of writing it. Kubla Khan, only 54 lines long, was never completed. Thus "person from Porlock", "man from Porlock", or just "Porlock" are literary allusions to unwanted intruders who disrupt inspired creativity.

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πŸ”— Cherokee Syllabary

πŸ”— Languages πŸ”— Writing systems πŸ”— Indigenous peoples of North America

The Cherokee syllabary is a syllabary invented by Sequoyah in the late 1810s and early 1820s to write the Cherokee language. His creation of the syllabary is particularly noteworthy as he could not previously read any script. He first experimented with logograms, but his system later developed into a syllabary. In his system, each symbol represents a syllable rather than a single phoneme; the 85 (originally 86) characters provide a suitable method to write Cherokee. Although some symbols resemble Latin, Greek, and Cyrillic letters, they are not used to represent the same sounds.

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πŸ”— Unexplained red flashes on the moon's surface

πŸ”— Astronomy πŸ”— Moon πŸ”— Solar System

A transient lunar phenomenon (TLP) or lunar transient phenomenon (LTP) is a short-lived light, color, or change in appearance on the surface of the Moon. The term was created by Patrick Moore in his co-authorship of NASA Technical Report R-277 Chronological Catalog of Reported Lunar Events, published in 1968.

Claims of short-lived lunar phenomena go back at least 1,000 years, with some having been observed independently by multiple witnesses or reputable scientists. Nevertheless, the majority of transient lunar phenomenon reports are irreproducible and do not possess adequate control experiments that could be used to distinguish among alternative hypotheses to explain their origins.

Most lunar scientists will acknowledge transient events such as outgassing and impact cratering do occur over geologic time. The controversy lies in the frequency of such events.

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πŸ”— Clanging

πŸ”— Medicine πŸ”— Psychology πŸ”— Disability

Clanging (or clang associations) is a symptom of mental disorders, primarily found in patients with schizophrenia and bipolar disorder. This symptom is also referred to as association chaining, and sometimes, glossomania.

Steuber defines it as "repeating chains of words that are associated semantically or phonetically with no relevant context". This may include compulsive rhyming or alliteration without apparent logical connection between words.

Clanging refers specifically to behavior that is situationally inappropriate. While a poet rhyming is not evidence of mental illness, disorganized speech that impedes the patient's ability to communicate is a disorder in itself, often seen in schizophrenia.

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πŸ”— Aaron Swartz

πŸ”— United States πŸ”— Biography πŸ”— Internet πŸ”— Computing πŸ”— Internet culture πŸ”— New York City πŸ”— Biography/science and academia πŸ”— Biography/arts and entertainment πŸ”— United States/Massachusetts πŸ”— Chicago πŸ”— Open πŸ”— United States/Massachusetts - Boston πŸ”— Open Access

Aaron Hillel Swartz (November 8, 1986 – January 11, 2013) was an American computer programmer, entrepreneur, writer, political organizer, and Internet hacktivist. He was involved in the development of the web feed format RSS, the Markdown publishing format, the organization Creative Commons, and the website framework web.py, and joined the social news site Reddit six months after its founding. He was given the title of co-founder of Reddit by Y Combinator owner Paul Graham after the formation of Not a Bug, Inc. (a merger of Swartz's project Infogami and Redbrick Solutions, a company run by Alexis Ohanian and Steve Huffman). Swartz's work also focused on civic awareness and activism. He helped launch the Progressive Change Campaign Committee in 2009 to learn more about effective online activism. In 2010, he became a research fellow at Harvard University's Safra Research Lab on Institutional Corruption, directed by Lawrence Lessig. He founded the online group Demand Progress, known for its campaign against the Stop Online Piracy Act.

In 2011, Swartz was arrested by Massachusetts Institute of Technology (MIT) police on state breaking-and-entering charges, after connecting a computer to the MIT network in an unmarked and unlocked closet, and setting it to download academic journal articles systematically from JSTOR using a guest user account issued to him by MIT. Federal prosecutors, led by Carmen Ortiz, later charged him with two counts of wire fraud and eleven violations of the Computer Fraud and Abuse Act, carrying a cumulative maximum penalty of $1Β million in fines, 35 years in prison, asset forfeiture, restitution, and supervised release. Swartz declined a plea bargain under which he would have served six months in federal prison. Two days after the prosecution rejected a counter-offer by Swartz, he was found dead by suicide in his Brooklyn apartment. In 2013, Swartz was inducted posthumously into the Internet Hall of Fame.

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