Random Articles (Page 3)
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🔗 Albert Stevens
Albert Stevens (1887–1966), also known as patient CAL-1, was a victim of a human radiation experiment, and survived the highest known accumulated radiation dose in any human. On May 14, 1945, he was injected with 131 kBq (3.55 µCi) of plutonium without his knowledge or informed consent.
Plutonium remained present in his body for the remainder of his life, the amount decaying slowly through radioactive decay and biological elimination. Stevens died of heart disease some 20 years later, having accumulated an effective radiation dose of 64 Sv (6400 rem) over that period, i.e. an average of 3 Sv per year or 350 μSv/h. The current annual permitted dose for a radiation worker in the United States is 0.05 Sv (or 5 rem), i.e. an average of 5.7 μSv/h.
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- "Albert Stevens" | 2019-08-22 | 66 Upvotes 3 Comments
🔗 Midget submarine
A midget submarine (also called a mini submarine) is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to 6 or 9, with little or no on-board living accommodation. They normally work with mother ships, from which they are launched and recovered and which provide living accommodation for the crew and support staff.
Both military and civilian midget submarines have been built. Military types work with surface ships and other submarines as mother ships. Civilian and non-combatant military types are generally called submersibles and normally work with surface ships.
Most early submarines would now be considered midget submarines, such as the United States Navy's USS Holland (SS-1) and the British Royal Navy's HMS Holland 1.
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- "Midget submarine" | 2019-08-08 | 22 Upvotes 9 Comments
🔗 Flâneur
Flâneur (French: [flɑnœʁ]) is a French term popularized in the nineteenth-century for a type of urban male "stroller", "lounger", "saunterer", or "loafer". The word has some nuanced additional meanings (including as a loanword into English). Traditionally depicted as male, a flâneur is an ambivalent figure of urban affluence and modernity, representing the ability to wander detached from society with no other purpose than to be an acute observer of industrialized, contemporary life. Flânerie is the act of strolling, with all of its accompanying associations. A near-synonym of the noun is boulevardier.
The flâneur was first a literary type from 19th-century France, essential to any picture of the streets of Paris. The word carried a set of rich associations: the man of leisure, the idler, the urban explorer, the connoisseur of the street. However, the flâneur's origins are to be found in journalism of the Restoration, and the politics of post-revolutionary public space. Drawing on the work of Charles Baudelaire who described the flâneur in his poetry and 1863 essay "The Painter of Modern Life", Walter Benjamin promoted 20th-century scholarly interest in the flâneur as an emblematic archetype of urban, modern (even modernist) experience. Following Benjamin, the flâneur has become an important symbol for scholars, artists, and writers. The classic French female counterpart is the passante, dating to the works of Marcel Proust, though a 21st-century academic coinage is flâneuse, and some English-language writers simply apply the masculine flâneur also to women. The term has acquired an additional architecture and urban planning sense, referring to passers-by who experience incidental or intentional psychological effects from the design of a structure.
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- "Flâneur" | 2024-04-17 | 30 Upvotes 12 Comments
🔗 Gauge blocks, a system for producing precision lengths
Gauge blocks (also known as gage blocks, Johansson gauges, slip gauges, or Jo blocks) are a system for producing precision lengths. The individual gauge block is a metal or ceramic block that has been precision ground and lapped to a specific thickness. Gauge blocks come in sets of blocks with a range of standard lengths. In use, the blocks are stacked to make up a desired length.
An important feature of gauge blocks is that they can be joined together with very little dimensional uncertainty. The blocks are joined by a sliding process called wringing, which causes their ultra-flat surfaces to cling together. A small number of gauge blocks can be used to create accurate lengths within a wide range. By using 3 blocks at a time taken from a set of 30 blocks, one may create any of the 1000 lengths from 3.000 to 3.999 mm in 0.001 mm steps (or .3000 to .3999 inches in 0.0001 inch steps). Gauge blocks were invented in 1896 by Swedish machinist Carl Edvard Johansson. They are used as a reference for the calibration of measuring equipment used in machine shops, such as micrometers, sine bars, calipers, and dial indicators (when used in an inspection role). Gauge blocks are the main means of length standardization used by industry.
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- "Gauge Block" | 2024-10-26 | 17 Upvotes 1 Comments
- "Gauge blocks, a system for producing precision lengths" | 2018-10-24 | 12 Upvotes 3 Comments
🔗 Berlin Gold Hat
The Berlin Gold Hat or Berlin Golden Hat (German: Berliner Goldhut) is a Late Bronze Age artefact made of thin gold leaf. It served as the external covering on a long conical brimmed headdress, probably of an organic material. It is now in the Neues Museum on Museum Island in Berlin, in a room by itself with an elaborate explanatory display.
The Berlin Gold Hat is the best preserved specimen among the four known conical golden hats known from Bronze Age Europe so far. Of the three others, two were found in southern Germany, and one in the west of France. All were found in the 19th and 20th centuries. It is generally assumed that the hats served as the insignia of deities or priests in the context of a sun cult that appears to have been widespread in Central Europe at the time. The hats are also suggested to have served astronomical/calendrical functions.
The Berlin Gold Hat was acquired in 1996 by the Berlin Museum für Vor- und Frühgeschichte as a single find without provenance. A comparative study of the ornaments and techniques in conjunction with dateable finds suggests that it was made in the Late Bronze Age, circa 1,000 to 800 BC.
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- "Berlin Gold Hat" | 2020-06-19 | 87 Upvotes 57 Comments
🔗 The Hacker's Diet
The Hacker's Diet (humorously subtitled "How to lose weight and hair through stress and poor nutrition") is a diet plan created by the founder of Autodesk, John Walker, outlined in an electronic book of the same name, that attempts to aid the process of weight loss by more accurately modeling how calories consumed and calories expended actually impact weight. Walker notes that much of our fat free mass introduces signal noise when trying to determine how much weight we're actually losing or gaining. With the help of a graphing tool (Excel is used in the book), he addresses these problems. Factoring in exercise, and through counting calories, one can calculate one's own total energy expenditure (basal metabolic rate, thermic effect of food, and day-to-day exercise) and cut back calorie intake or increase exercise to lose weight.
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- "The Hacker's Diet" | 2024-02-08 | 30 Upvotes 1 Comments
🔗 OSCAR 1
OSCAR I (aka OSCAR 1) is the first amateur radio satellite launched by Project OSCAR into low Earth orbit. OSCAR I was launched December 12, 1961, by a Thor-DM21 Agena B launcher from Vandenberg Air Force Base, Lompoc, California. The satellite, a rectangular box (30 x 25 x 12 cm) weighing 10 kg., was launched as a secondary payload (ballast) for Corona 9029, also known as Discoverer 36, the eighth and final launch of a KH-3 satellite.
The satellite had a battery-powered 140 mW transmitter operating in the 2-meter band (144.983 MHz), employed a monopole transmitting antenna 60 cm long extended from the center of the convex surface, but had no attitude control system. Like Sputnik 1, Oscar 1 carried only a simple beacon. For three weeks it transmitted its Morse Code message "HI". To this day, many organizations identify their Morse-transmitting satellites with "HI", which also indicates laughter in amateur telegraphy.
OSCAR I lasted 22 days ceasing operation on January 3, 1962, and re-entered January 31, 1962.
The uniqueness of the OSCAR-1 spacecraft was not only that it was built by amateurs, only about four years after the launch of Sputnik-1, but that it was the world's first piggyback satellite and the world's first private non-government spacecraft.
Immediately following the launch of OSCAR-1, United States vice president, Lyndon B. Johnson, honored it with a congratulatory telegram to the group sponsoring this momentous event in the history of Amateur Radio. It read: “For me this project is symbolic of the type of freedom for which this country stands — freedom of enterprise and freedom of participation on the part of individuals throughout the world.”
The original backup of OSCAR-1 has been restored and is fully operational, running off AC power. As of 2011 it is on display at ARRL HQ in Newington, Connecticut and continues to broadcast "HI" in Morse Code at 145 MHz.
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- "OSCAR 1" | 2015-11-15 | 28 Upvotes 6 Comments
🔗 National Popular Vote Interstate Compact
The National Popular Vote Interstate Compact (NPVIC) is an agreement among a group of U.S. states and the District of Columbia to award all their electoral votes to whichever presidential candidate wins the overall popular vote in the 50 states and the District of Columbia. The compact is designed to ensure that the candidate who receives the most votes nationwide is elected president, and it would come into effect only when it would guarantee that outcome. As of March 2020, it has been adopted by fifteen states and the District of Columbia. Together, they have 196 electoral votes, which is 36% of the Electoral College and 73% of the 270 votes needed to give the compact legal force. Certain legal questions, however, may affect implementation of the compact.
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- "National Popular Vote Interstate Compact" | 2024-08-12 | 38 Upvotes 63 Comments
- "National Popular Vote Interstate Compact" | 2016-11-10 | 19 Upvotes 7 Comments
🔗 Programma 101, the first commercial “desktop computer”
The Olivetti Programma 101, also known as Perottina or P101, is one of the first "all in one" commercial programmable desktop calculators, although not the first. Produced by Italian manufacturer Olivetti, based in Ivrea, Piedmont, and invented by the Italian engineer Pier Giorgio Perotto, the P101 has the main features of large computers of that period. It was launched at the 1964 New York World's Fair; volume production started in 1965. A futuristic design for its time, the Programma 101 was priced at $3,200 (equivalent to $26,000 in 2019). About 44,000 units were sold, primarily in the US.
It is usually called a printing programmable calculator or desktop calculator because its arithmetic instructions correspond to calculator operations.
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- "Programma 101, the first commercial “desktop computer”" | 2015-10-15 | 40 Upvotes 9 Comments
- "Programma 101" | 2014-02-02 | 66 Upvotes 17 Comments
🔗 The Ondioline
The Ondioline is an electronic keyboard instrument, invented in 1941 by the Frenchman Georges Jenny, and is a forerunner of today's synthesizers. It is sometimes called the "Jenny Ondioline."
The Ondioline is capable of creating a wide variety of sounds. Its keyboard has an unusual feature: it is suspended on special springs which makes it possible to introduce a natural vibrato if the player moves the keyboard (not the entire instrument) from side to side (laterally) with their playing hand. The result is an almost human-like vibrato that lends a wide range of expression to the Ondioline. The keyboard is also pressure-sensitive, and the instrument has a knee volume lever, as well.
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- "The Ondioline" | 2019-06-13 | 14 Upvotes 1 Comments