Random Articles (Page 2)
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π Great Man-Made River
The Great Man-Made River (GMMR, Ψ§ΩΩΩΨ± Ψ§ΩΨ΅ΩΨ§ΨΉΩ Ψ§ΩΨΉΨΈΩΩ ) is a network of pipes that supplies fresh water obtained from the Nubian Sandstone Aquifer System fossil aquifer across Libya. It is the world's largest irrigation project. The project utilizes a pipeline system that pumps water from the Nubian Sandstone Aquifer System from down south in Libya to cities in the populous Libyan northern Mediterranean coast including Tripoli and Benghazi. The water covers a distance of up to 1,600 kilometers and provides 70% of all freshwater used in Libya.
According to its website, it is the largest underground network of pipes (2,820 kilometres (1,750Β mi)) and aqueducts in the world. It consists of more than 1,300 wells, most more than 500 m deep, and supplies 6,500,000 m3 of fresh water per day to the cities of Tripoli, Benghazi, Sirte and elsewhere. The late Libyan Leader Muammar Gaddafi described it as the "Eighth Wonder of the World".
Discussed on
- "Great Man-Made River" | 2021-03-07 | 128 Upvotes 48 Comments
π The American Chestnut Tree
The American chestnut (Castanea dentata) is a large deciduous tree of the beech family native to eastern North America. The American chestnut was one of the most important forest trees throughout its range and was considered the finest chestnut tree in the world.
The species was devastated by chestnut blight, a fungal disease that came from Chinese chestnut trees introduced into North America from East Asia. It is estimated that between 3 and 4 billion American chestnut trees were destroyed in the first half of the 20th century by chestnut blight after the blight's initial discovery in North America in 1904. Very few mature specimens of the tree exist within its historical range, although many small shoots of the former live trees remain. There are hundreds of large (2 to 5Β ft diameter) American chestnuts outside its historical range, some in areas where less virulent strains of the pathogen are more common, such as the 600 to 800 large trees in Northern Michigan. The species is listed as endangered in the United States and Canada. American chestnuts are also susceptible to ink disease, particularly in the southern part of its native range. This susceptibility to ink disease may have contributed to the devastation of the species.
Several groups are attempting to create blight-resistant American chestnuts. Scientists at the SUNY College of Environmental Science and Forestry created the Darling 58 cultivar of American chestnut by inserting the oxalate oxidase gene from wheat into the genome of an American chestnut. When expressed in the cambium of the Darling 58 cultivar, oxalate oxidase detoxifies oxalic acid, resulting in a tree that still gets infected by the blight fungus but that resists girdling of the trunk and survives such infection. As of 2021, the researchers who developed this cultivar are working towards applying for government permission to make these trees available to the public. If approved, these chestnut trees would be the first genetically modified forest trees released into the wild in the United States. Cross-breeding of chestnut species represents an alternate approach to restoring the American chestnut. One approach has been cross-breeding among different partially blight-resistant American chestnuts, with the goal of developing a cultivar with high resistance. Another approach is to crossbreed American chestnuts with Chinese chestnut trees, which are moderately blight-resistant, and then to backcross with American chestnuts, with the goal of creating a cultivar with most of the genetic heritage of American but retaining the blight resistance of the Chinese chestnut.
Discussed on
- "The American Chestnut Tree" | 2022-02-14 | 118 Upvotes 73 Comments
π Accumulation by Dispossession
Accumulation by dispossession is a concept presented by the Marxist geographer David Harvey. It defines neoliberal capitalist policies that result in a centralization of wealth and power in the hands of a few by dispossessing the public and private entities of their wealth or land. Such policies are visible in many western nations from the 1970s and to the present day. Harvey argues these policies are guided mainly by four practices: privatization, financialization, management and manipulation of crises, and state redistributions.
Discussed on
- "Accumulation by Dispossession" | 2025-12-15 | 21 Upvotes 1 Comments
π Dogme 95
Dogme 95 is a 1995 avant-garde filmmaking movement founded by the Danish directors Lars von Trier and Thomas Vinterberg, who created the "Dogme 95 Manifesto" and the "Vows of Chastity" (Danish: kyskhedslΓΈfter). These were rules to create films based on the traditional values of story, acting, and theme, and excluding the use of elaborate special effects or technology. It was supposedly created as an attempt to "take back power for the directors as artists", as opposed to the studio. They were later joined by fellow Danish directors Kristian Levring and SΓΈren Kragh-Jacobsen, forming the Dogme 95 Collective or the Dogme Brethren. Dogme (pronouncedΒ [ΛtΚwmΙ]) is the Danish word for dogma.
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- "Dogme 95" | 2023-04-01 | 110 Upvotes 84 Comments
π The Covox Speech Thing
The Covox Speech Thing is an external audio device attached to the computer to output digital sound. It was composed of a primitive 8-bit DAC using a resistor ladder and an analogue signal output, and plugged into the printer port of the PC.
The Speech Thing was introduced on December 18, 1987 by Covox, Inc of Eugene, Oregon, for about US$70 (US$79.95 as of 1989), but as its parts were much cheaper than the complete plug, and as its design was fairly simple, people soon started to build their own variants. The plug was used long into the 1990s, as sound cards were still very expensive at that time. The plug was also quite popular in the demoscene.
An inherent problem of the design is that it requires very precise resistors. If normal parts are used, the values get shuffled, especially for quiet sounds, resulting in distortion. Nevertheless, the sound quality of the Covox plug is far superior compared to the PC speaker; even today, a self-built Covox plug is still an inexpensive way to give old computers sound capabilities.
Discussed on
- "The Covox Speech Thing" | 2022-04-18 | 13 Upvotes 1 Comments
π The Emu War
The Emu War, also known as the Great Emu War, was a nuisance wildlife management military operation undertaken in Australia over the latter part of 1932 to address public concern over the number of emus said to be running amok in the Campion district of Western Australia. The unsuccessful attempts to curb the population of emus, a large flightless bird indigenous to Australia, employed soldiers armed with Lewis gunsβleading the media to adopt the name "Emu War" when referring to the incident. While a number of the birds were killed, the emu population persisted and continued to cause crop destruction.
Discussed on
- "The Emu War" | 2020-02-05 | 80 Upvotes 34 Comments
π Japanese Aesthetics
Japanese aesthetics comprise a set of ancient ideals that include wabi (transient and stark beauty), sabi (the beauty of natural patina and aging), and yΕ«gen (profound grace and subtlety). These ideals, and others, underpin much of Japanese cultural and aesthetic norms on what is considered tasteful or beautiful. Thus, while seen as a philosophy in Western societies, the concept of aesthetics in Japan is seen as an integral part of daily life. Japanese aesthetics now encompass a variety of ideals; some of these are traditional while others are modern and sometimes influenced by other cultures.
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- "Japanese Aesthetics" | 2023-12-22 | 26 Upvotes 2 Comments
π Cyclorama
A cyclorama is a panoramic image on the inside of a cylindrical platform, designed to give viewers standing in the middle of the cylinder a 360Β° view, and also a building designed to show a panoramic image. The intended effect is to make viewers, surrounded by the panoramic image, feel as if they were standing in the midst of the place depicted in the image.
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- "Cyclorama" | 2022-01-09 | 26 Upvotes 10 Comments
π Diffractive Solar Sail
A diffractive solar sail, or diffractive lightsail, is a type of solar sail which relies on diffraction instead of reflection for its propulsion. Current diffractive sail designs use thin metamaterial films, containing micrometer-size gratings based on polarization or subwavelength refractive structures, causing light to spread out (i.e. diffract) and thereby exert radiation pressure when it passes through them.
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- "Diffractive Solar Sail" | 2023-11-03 | 45 Upvotes 16 Comments
π Sparse Distributed Memory
Sparse distributed memory (SDM) is a mathematical model of human long-term memory introduced by Pentti Kanerva in 1988 while he was at NASA Ames Research Center. It is a generalized random-access memory (RAM) for long (e.g., 1,000 bit) binary words. These words serve as both addresses to and data for the memory. The main attribute of the memory is sensitivity to similarity, meaning that a word can be read back not only by giving the original write address but also by giving one close to it, as measured by the number of mismatched bits (i.e., the Hamming distance between memory addresses).
SDM implements transformation from logical space to physical space using distributed data representation and storage, similarly to encoding processes in human memory. A value corresponding to a logical address is stored into many physical addresses. This way of storing is robust and not deterministic. A memory cell is not addressed directly. If input data (logical addresses) are partially damaged at all, we can still get correct output data.
The theory of the memory is mathematically complete and has been verified by computer simulation. It arose from the observation that the distances between points of a high-dimensional space resemble the proximity relations between concepts in human memory. The theory is also practical in that memories based on it can be implemented with conventional RAM-memory elements.
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- "Sparse Distributed Memory" | 2018-10-30 | 24 Upvotes 7 Comments