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π USA built 151 Aircraft carriers in WWII
The escort carrier or escort aircraft carrier (U.S. hull classification symbol CVE), also called a "jeep carrier" or "baby flattop" in the United States Navy (USN) or "Woolworth Carrier" by the Royal Navy, was a small and slow type of aircraft carrier used by the Royal Navy, the Royal Canadian Navy, the United States Navy, the Imperial Japanese Navy and Imperial Japanese Army Air Force in World War II. They were typically half the length and a third the displacement of larger fleet carriers, slower, more-lightly armed and armored, and carried fewer planes. Escort carriers were most often built upon a commercial ship hull, so they were cheaper and could be built quickly. This was their principal advantage as they could be completed in greater numbers as a stop-gap when fleet carriers were scarce. However, the lack of protection made escort carriers particularly vulnerable, and several were sunk with great loss of life. The light carrier (U.S. hull classification symbol CVL) was a similar concept to the escort carrier in most respects, but was fast enough to operate alongside fleet carriers.
Escort carriers were too slow to keep up with the main forces consisting of fleet carriers, battleships, and cruisers. Instead, they were used to escort merchant ship convoys, defending them from enemy threats such as submarines and planes. In the invasions of mainland Europe and Pacific islands, escort carriers provided air support to ground forces during amphibious operations. Escort carriers also served as backup aircraft transports for fleet carriers, and ferried aircraft of all military services to points of delivery.
In the Battle of the Atlantic, escort carriers were used to protect convoys against U-boats. Initially escort carriers accompanied the merchant ships and helped to fend off attacks from aircraft and submarines. As numbers increased later in the war, escort carriers also formed part of hunter-killer groups that sought out submarines instead of being attached to a particular convoy.
In the Pacific theater, CVEs provided air support of ground troops in the Battle of Leyte Gulf. They lacked the speed and weapons to counter enemy fleets, relying on the protection of a Fast Carrier Task Force. However, at the Battle off Samar, one U.S. task force of escort carriers and destroyers managed to successfully defend itself against a much larger Japanese force of battleships and cruisers. The Japanese met a furious defense of carrier aircraft, screening destroyers, and destroyer escorts.
Of the 151 aircraft carriers built in the U.S. during World War II, 122 were escort carriers, though no examples survive. The Casablanca class was the most numerous class of aircraft carrier, with 50 launched. Second was the Bogue class, with 45 launched.
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- "USA built 151 Aircraft carriers in WWII" | 2023-09-17 | 43 Upvotes 69 Comments
π The Amiga Smart File System
The Smart File System (SFS) is a journaling filesystem used on Amiga computers and AmigaOS-derived operating systems (though some support also exists for IBM PC compatibles). It is designed for performance, scalability and integrity, offering improvements over standard Amiga filesystems as well as some special or unique features.
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- "The Amiga Smart File System" | 2019-09-01 | 129 Upvotes 32 Comments
π Refal programming language
Refal ("[of] Recursive functions' algorithmic language") "is functional programming language oriented toward symbolic computations", including "string processing, language translation, [and] artificial intelligence". It is one of the oldest members of this family, first conceived of in 1966 as a theoretical tool, with the first implementation appearing in 1968. Refal was intended to combine mathematical simplicity with practicality for writing large and sophisticated programs.
One of the first functional programming languages to do so, and unlike Lisp of its time, Refal is based on pattern matching. Its pattern matching works in conjunction with term rewriting.
The basic data structure of Lisp and Prolog is a linear list built by cons operation in a sequential manner, thus with O(n) access to list's nth element. Refal's lists are built and scanned from both ends, with pattern matching working for nested lists as well as the top-level one. In effect, the basic data structure of Refal is a tree rather than a list. This gives freedom and convenience in creating data structures while using only mathematically simple control mechanisms of pattern matching and substitution.
Refal also includes a feature called the freezer to support efficient partial evaluation.
Refal can be applied to the processing and transformation of tree structures, similarly to XSLT.
Discussed on
- "Refal programming language" | 2015-11-01 | 33 Upvotes 12 Comments
- "Refal programming language" | 2009-12-18 | 31 Upvotes 3 Comments
π KarTrak, a bar code system designed to automatically identify rail cars
KarTrak, sometimes KarTrak ACI (for Automatic Car Identification) is a colored bar code system designed to automatically identify rail cars and other rolling stock. KarTrak was made a requirement in North America, but technical problems led to abandonment of the system in the late 1970s.
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- "KarTrak, a bar code system designed to automatically identify rail cars" | 2014-08-31 | 11 Upvotes 1 Comments
π Satellite killed by trajectory patent
AMC-14 is a communications satellite. Initially owned by SES Americom, AMC-14 was designed to be placed in geostationary orbit, following launch on a Proton rocket. Built by Lockheed Martin and based on the A2100 satellite bus, AMC-14 was to have been located at 61.5Β° west longitude for DISH Network service.
It was launched atop a Proton-M/Briz-M rocket at 23:18:55 GMT on 14 March 2008, from LC-200/39 at the Baikonur Cosmodrome in Kazakhstan. The satellite was placed in an unusable orbit, following a malfunction of the Briz-M upper stage. Over a six-month period, it was maneuvered into a geosynchronous orbit, and is now near 35Β° East and in an inclined orbit.
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- "Satellite killed by trajectory patent" | 2012-05-20 | 195 Upvotes 71 Comments
π The Thing
The Thing, also known as the Great Seal bug, was one of the first covert listening devices (or "bugs") to use passive techniques to transmit an audio signal. It was concealed inside a gift given by the Soviet Union to W. Averell Harriman, the United States Ambassador to the Soviet Union, on August 4, 1945. Because it was passive, needing electromagnetic energy from an outside source to become energized and activate, it is considered a predecessor of Radio-Frequency Identification (RFID) technology.
Discussed on
- "The Thing (Listening Device)" | 2021-06-29 | 14 Upvotes 3 Comments
- "The Thing" | 2019-06-11 | 599 Upvotes 104 Comments
- "Great Seal bug" | 2014-08-13 | 10 Upvotes 1 Comments
- "Thing (listening device)" | 2011-03-03 | 49 Upvotes 8 Comments
π The Schmidt insect sting pain index
The Schmidt sting pain index is a pain scale rating the relative pain caused by different hymenopteran stings. It is mainly the work of Justin O. Schmidt (born 1947), an entomologist at the Carl Hayden Bee Research Center in Arizona, United States. Schmidt has published a number of papers on the subject, and claims to have been stung by the majority of stinging Hymenoptera.
His original paper in 1983 was a way to systematize and compare the hemolytic properties of insect venoms. A table contained in the paper included a column that rated sting pain, starting from 0 for stings that are completely ineffective against humans, progressing through 2, a familiar pain such as that caused by a common bee or wasp sting, and finishing at 4 for the most painful stings; in the original paper, only the bullet ant, Paraponera clavata, was given a rating of 4. Later revised versions of the index added Synoeca septentrionalis, along with tarantula hawks as the only species to share this ranking. In later versions, some descriptions of the most painful examples were given, e.g.: "Paraponera clavata stings induced immediate, excruciating pain and numbness to pencil-point pressure, as well as trembling in the form of a totally uncontrollable urge to shake the affected part."
Schmidt has repeatedly refined his scale, including a paper published in 1990, which classifies the stings of 78 species and 41 genera of Hymenoptera, and culminating in a book published in 2016.
An entry in The Straight Dope reported that "implausibly exact numbers" which do not appear in any of Schmidtβs published scientific papers were "wheedled out of him" by Outside magazine for an article it published in 1996.
In September 2015, Schmidt was co-awarded the Ig Nobel Physiology and Entomology prize with Michael Smith for their Hymenoptera research.
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- "The Schmidt insect sting pain index" | 2021-01-25 | 15 Upvotes 8 Comments
π Musth
Musth or must (an Urdu word, from Persian, lit.βdrunk) is a periodic condition in bull (male) elephants characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones.
Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times (in specific individuals these testosterone levels can even reach as much as 140 times the normal). However, whether this hormonal surge is the sole cause of musth, or merely a contributing factor, is unknown.
Scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth.
Discussed on
- "Musth" | 2020-04-06 | 77 Upvotes 15 Comments
π Early 20th Century Technocracy Movement
The technocracy movement is a social and ideological movement which arose in the early 20th century. Technocracy was popular in the United States and Canada for a brief period in the early 1930s, before it was overshadowed by other proposals for dealing with the crisis of the Great Depression. The technocracy movement proposed replacing politicians and businesspeople with scientists and engineers who had the technical expertise to manage the economy.
The movement was committed to abstaining from all revolutionary and political activities. It gained strength in the 1930s but in 1940, due to an alleged initial opposition to the Second World War, was banned in Canada. The ban was lifted in 1943 when it was apparent that 'Technocracy Inc. was committed to the war effort, proposing a program of total conscription.' The movement continued to expand during the remainder of the war and new sections were formed in Ontario and the Maritime Provinces.
In the post-war years, perhaps due to the growing distrust of socialism in the cold war, membership and interest in technocracy decreased. Though now relatively insignificant, the Technocracy movement survives into the present day, and as of 2013, was continuing to publish a newsletter, maintain a website, and hold member meetings. Smaller groups included the Technical Alliance, The New Machine and the Utopian Society of America, though Bellamy had the most success due to his nationalistic stances, and Veblen's rhetoric, removing the current pricing system and his blueprint for a national directorate to reorganize all produced goods and supply, and ultimately to radically increase all industrial output.
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- "Early 20th Century Technocracy Movement" | 2015-11-18 | 29 Upvotes 18 Comments
π Nuclear Football
The nuclear football (also known as the atomic football, the president's emergency satchel, the Presidential Emergency Satchel, the button, the black box, or just the football) is a briefcase, the contents of which are to be used by the President of the United States to authorize a nuclear attack while away from fixed command centers, such as the White House Situation Room. It functions as a mobile hub in the strategic defense system of the United States. It is held by an aide-de-camp.