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π LagΓ’ri Hasan Γelebi
LagΓ’ri Hasan Γelebi was an Ottoman aviator who, according to the account written by traveller Evliya Γelebi, made a successful crewed rocket flight.
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- "LagΓ’ri Hasan Γelebi" | 2022-07-25 | 90 Upvotes 29 Comments
π Tide-Predicting Machine No. 2
Tide-Predicting Machine No. 2, also known as Old Brass Brains, was a special-purpose mechanical computer that uses gears, pulleys, chains, and other mechanical components to compute the height and time of high and low tides for specific locations. The machine can perform tide calculations much faster than a person could do with pencil and paper. The U.S. Coast and Geodetic Survey put the machine into operation in 1910. It was used until 1965, when it was replaced by an electronic computer.
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- "Tide-Predicting Machine No. 2" | 2018-08-12 | 82 Upvotes 13 Comments
π Mammalian diving reflex
The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It optimizes respiration by preferentially distributing oxygen stores to the heart and brain, enabling submersion for an extended time.
The diving reflex is exhibited strongly in aquatic mammals, such as seals, otters, dolphins, and muskrats, and exists as a lesser response in other animals, including adult humans, babies up to 6 months old (see infant swimming), and diving birds, such as ducks and penguins.
The diving reflex is triggered specifically by chilling and wetting the nostrils and face while breath-holding, and is sustained via neural processing originating in the carotid chemoreceptors. The most noticeable effects are on the cardiovascular system, which displays peripheral vasoconstriction, slowed heart rate, redirection of blood to the vital organs to conserve oxygen, release of red blood cells stored in the spleen, and, in humans, heart rhythm irregularities. Although aquatic animals have evolved profound physiological adaptations to conserve oxygen during submersion, the apnea and its duration, bradycardia, vasoconstriction, and redistribution of cardiac output occur also in terrestrial animals as a neural response, but the effects are more profound in natural divers.
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- "Mammalian diving reflex" | 2016-03-27 | 73 Upvotes 29 Comments
π Avro Canada VZ-9 Avrocar
The Avro Canada VZ-9 Avrocar was a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the CoandΔ effect to provide lift and thrust from a single "turborotor" blowing exhaust out the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer.
Originally designed as a fighter-like aircraft capable of very high speeds and altitudes, the project was repeatedly scaled back over time and the U.S. Air Force eventually abandoned it. Development was then taken up by the U.S. Army for a tactical combat aircraft requirement, a sort of high-performance helicopter. In flight testing, the Avrocar proved to have unresolved thrust and stability problems that limited it to a degraded, low-performance flight envelope; subsequently, the project was cancelled in September 1961.
Through the history of the program, the project was referred to by a number of different names. Avro referred to the efforts as Project Y, with individual vehicles known as Spade and Omega. Project Y-2 was later funded by the U.S. Air Force, who referred to it as WS-606A, Project 1794 and Project Silver Bug. When the U.S. Army joined the efforts it took on its final name "Avrocar", and the designation "VZ-9", part of the U.S. Army's VTOL projects in the VZ series.
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- "Avro Canada VZ-9 Avrocar" | 2022-08-23 | 31 Upvotes 9 Comments
- "Avro Canada VZ-9 Avrocar" | 2020-08-15 | 35 Upvotes 5 Comments
π Anton (computer)
Anton is a massively parallel supercomputer designed and built by D. E. Shaw Research in New York, first running in 2008. It is a special-purpose system for molecular dynamics (MD) simulations of proteins and other biological macromolecules. An Anton machine consists of a substantial number of application-specific integrated circuits (ASICs), interconnected by a specialized high-speed, three-dimensional torus network.
Unlike earlier special-purpose systems for MD simulations, such as MDGRAPE-3 developed by RIKEN in Japan, Anton runs its computations entirely on specialized ASICs, instead of dividing the computation between specialized ASICs and general-purpose host processors.
Each Anton ASIC contains two computational subsystems. Most of the calculation of electrostatic and van der Waals forces is performed by the high-throughput interaction subsystem (HTIS). This subsystem contains 32 deeply pipelined modules running at 800Β MHz arranged much like a systolic array. The remaining calculations, including the bond forces and the fast Fourier transforms (used for long-range electrostatics), are performed by the flexible subsystem. This subsystem contains four general-purpose Tensilica cores (each with cache and scratchpad memory) and eight specialized but programmable SIMD cores called geometry cores. The flexible subsystem runs at 400Β MHz.
Anton's network is a 3D torus and thus each chip has 6 inter-node links with a total in+out bandwidth of 607.2 Gbit/s. An inter-node link is composed of two equal one-way links (one traveling in each direction), with each one-way link having 50.6 Gbit/s of bandwidth. Each one-way link is composed of 11 lanes, where a lane is a differential pair of wires signaling at 4.6 Gbit/s. The per-hop latency in Anton's network is 50Β ns. Each ASIC is also attached to its own DRAM bank, enabling large simulations.
The performance of a 512-node Anton machine is over 17,000 nanoseconds of simulated time per day for a protein-water system consisting of 23,558 atoms. In comparison, MD codes running on general-purpose parallel computers with hundreds or thousands of processor cores achieve simulation rates of up to a few hundred nanoseconds per day on the same chemical system. The first 512-node Anton machine became operational in October 2008. The multiple petaFLOP, distributed-computing project Folding@home has achieved similar aggregate ensemble simulation timescales, comparable to the total time of a single continuous simulation on Anton, specifically achieving the 1.5-millisecond range in January 2010.
The Anton supercomputer is named after Anton van Leeuwenhoek, who is often referred to as "the father of microscopy" because he built high-precision optical instruments and used them to visualize a wide variety of organisms and cell types for the first time.
The ANTON 2 machine with four 512 nodes and substantially increased speed and problem size has been described.
The National Institutes of Health have supported an ANTON for the biomedical research community at the Pittsburgh Supercomputing Center, Carnegie-Mellon University, and recently approved support of an ANTON 2 there.
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- "Anton (Computer)" | 2020-04-08 | 91 Upvotes 45 Comments
- "Anton (computer)" | 2015-11-26 | 54 Upvotes 9 Comments
π Obsolete German Units of Measurement
The obsolete units of measurement of German-speaking countries consist of a variety of units, with varying local standard definitions. Some of these units are still used in everyday speech and even in stores and on street markets as shorthand for similar amounts in the metric system. For example, some customers ask for one pound (ein Pfund) of something when they want 500Β grams.
The metric system became compulsory on 1 January 1872, in Germany and on 1 January 1876, in Austria.
Some obsolete German units have names similar to units that were traditionally used in other countries, and that are still used in the United Kingdom (imperial units) and the United States (United States customary units).
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- "Obsolete German Units of Measurement" | 2021-04-11 | 84 Upvotes 105 Comments
π Kevinism
In German, Kevinismus ("Kevinism") is the negative preconception German people have of Germans with trendy, exotic-sounding first names considered to be an indicator of a low social class. The protypical example is Kevin, which like most such names came to Germany from Anglo-American culture. Sometimes Chantalismus ("Chantalism") is used as a female equivalent, from the French name Chantal.
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- "Kevinism" | 2022-08-23 | 37 Upvotes 1 Comments
π Carthago delenda est
"Ceterum censeo Carthaginem esse delendam", or "Ceterum autem censeo Carthaginem esse delendam" (English: "Furthermore, I consider that Carthage must be destroyed"), often abbreviated to "Carthago delenda est" (English: "Carthage must be destroyed"), is a Latin oratorical phrase pronounced by Cato the Censor, a politician of the Roman Republic. The phrase originates from debates held in the Roman Senate prior to the Third Punic War (149β146 BC) between Rome and Carthage, where Cato is said to have used it as the conclusion to all his speeches in order to push for the war.
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- "Carthago delenda est" | 2019-07-21 | 64 Upvotes 62 Comments
π Terfenol-D
Terfenol-D, an alloy of the formula TbxDy1βxFe2 (xΒ βΒ 0.3), is a magnetostrictive material. It was initially developed in the 1970s by the Naval Ordnance Laboratory in United States. The technology for manufacturing the material efficiently was developed in the 1980s at Ames Laboratory under a U.S. Navy-funded program. It is named after terbium, iron (Fe), Naval Ordnance Laboratory (NOL), and the D comes from dysprosium.
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- "Terfenol-D" | 2021-09-27 | 90 Upvotes 24 Comments
π Everywhere at the End of Time
Everywhere at the End of Time is the eleventh recording by the Caretaker, an alias of English electronic musician Leyland Kirby. Released between 2016 and 2019, its six studio albums use degrading loops of sampled ballroom music to portray the progression of Alzheimer's disease. Inspired by the success of An Empty Bliss Beyond This World (2011), Kirby produced Everywhere as his final major work under the alias. The albums were produced in Krakow and released over six-month periods to "give a sense of time passing". The album covers are abstract paintings by his friend Ivan Seal. The series drew comparisons to the works of composer William Basinski and electronic musician Burial; later stages were influenced by avant-gardist composer John Cage.
The series comprises six hours of music, portraying a range of emotions and characterised by noise throughout. Although the first three stages are similar to An Empty Bliss, the last three stages depart from Kirby's earlier ambient works. The albums reflect the patient's disorder and death, their feelings, and the phenomenon of terminal lucidity. To promote the series, Kirby partnered with anonymous visual artist Weirdcore to make music videos. At first, concerned about whether the series would seem pretentious, Kirby thought of not creating Everywhere at all; he spent more time producing it than any of his other releases. The album covers received attention from a French art exhibition named after the Caretaker's Everywhere, an Empty Bliss (2019), a compilation of archived songs.
As each stage was released, the series received increasingly positive reviews from critics; its length and dementia-driven concept led many reviewers to feel emotional about the complete edition. Considered to be Kirby's magnum opus, Everywhere was one of the most praised music releases of the 2010s. Caregivers of people with dementia also praised the albums for increasing empathy for patients among younger listeners, although some medics felt the series was too linear. It became an Internet phenomenon in the early 2020s, emerging in TikTok videos as a listening challenge, being transformed into a mod for the video game Friday Night Funkin' (2020), and appearing in internet memes.
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- "Everywhere at the End of Time" | 2022-11-03 | 31 Upvotes 5 Comments