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🔗 Scramble for Africa
The Scramble for Africa, also called the Partition of Africa or the Conquest of Africa, was the invasion, occupation, division, and colonisation of African territory by European powers during a short period known to historians as the New Imperialism (between 1881 and 1914). In 1870, only 10 percent of Africa was under formal European control; by 1914 this had increased to almost 90 percent of the continent, with only Ethiopia (Abyssinia), the Dervish state (a portion of present-day Somalia) and Liberia still being independent. There were multiple motivations for European colonizers, including desire for valuable resources available throughout the continent, the quest for national prestige, tensions between pairs of European powers, religious missionary zeal and internal African native politics.
The Berlin Conference of 1884, which regulated European colonisation and trade in Africa, is usually referred to as the ultimate point of the Scramble for Africa. Consequent to the political and economic rivalries among the European empires in the last quarter of the 19th century, the partitioning, or splitting up of Africa was how the Europeans avoided warring amongst themselves over Africa. The later years of the 19th century saw the transition from "informal imperialism" by military influence and economic dominance, to direct rule, bringing about colonial imperialism.
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- "Scramble for Africa" | 2019-01-31 | 26 Upvotes 14 Comments
🔗 Sex in Space
Sex in space is human sexual activity in the weightlessness of outer space. It presents difficulties for the performance of most sexual activities due to Newton's third law. According to the law, if the couple remain attached, their movements will counter each other. Consequently, their actions will not change their velocity unless they are affected by another, unattached, object. Some difficulty could occur due to drifting into other objects. If the couple have a combined velocity relative to other objects, collisions could occur. There have been suggestions that conception and pregnancy in off-Earth environments could be an issue.
As of 2009, with NASA planning long-term missions for lunar settlements with goals to explore and colonize space, the topic has taken a respected place in life sciences. Scientist Stephen Hawking publicly concluded in 2006 that possibly human survival itself will depend on successfully contending with the extreme environments of space.
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- "Sex in Space" | 2020-01-09 | 16 Upvotes 4 Comments
🔗 $100 Hamburger
$100 hamburger ("hundred-dollar hamburger") is aviation slang for the excuse a general aviation pilot might use to fly.
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- "$100 Hamburger" | 2025-06-14 | 139 Upvotes 52 Comments
🔗 Out-of-Place Artifact
An out-of-place artifact (OOPArt) is an artifact of historical, archaeological, or paleontological interest found in an unusual context, which challenges conventional historical chronology by its presence in that context. Such artifacts may appear "too advanced" for the technology known to have existed at the time, or may suggest human presence at a time before humans are known to have existed. Other examples may suggest contact between different cultures that is hard to account for with conventional historical understanding.
The term is used in fringe science such as cryptozoology, as well as by proponents of ancient astronaut theories, young Earth creationists, and paranormal enthusiasts. It can describe a wide variety of objects, from anomalies studied by mainstream science to pseudoarchaeology far outside the mainstream to objects that have been shown to be hoaxes or to have mundane explanations.
Critics argue that most purported OOPArts which are not hoaxes are the result of mistaken interpretation and wishful thinking, such as a mistaken belief that a particular culture could not have created an artifact or technology due to a lack of knowledge or materials. In some cases, the uncertainty results from inaccurate descriptions. For example, the Wolfsegg Iron was said to be a perfect cube, but in fact it is not; the Klerksdorp spheres were said to be perfect spheres, but they are not. The Iron pillar of Delhi was said to be "rust proof", but it has some rust near its base; its relative resistance to corrosion is due to slag inclusions left over from the manufacturing conditions and environmental factors.
Supporters regard OOPArts as evidence that mainstream science is overlooking huge areas of knowledge, either willfully or through ignorance. Many writers or researchers who question conventional views of human history have used purported OOPArts in attempts to bolster their arguments. Creation science often relies on allegedly anomalous finds in the archaeological record to challenge scientific chronologies and models of human evolution. Claimed OOPArts have been used to support religious descriptions of prehistory, ancient astronaut theories, and the notion of vanished civilizations that possessed knowledge or technology more advanced than that known in modern times.
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- "Out-of-Place Artifact" | 2019-07-16 | 77 Upvotes 45 Comments
🔗 Comparison of parser generators
This is a list of notable lexer generators and parser generators for various language classes.
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- "Comparison of parser generators" | 2013-01-27 | 25 Upvotes 11 Comments
🔗 European Green Belt
The European Green Belt initiative is a grassroots movement for nature conservation and sustainable development along the corridor of the former Iron Curtain. The term refers to both an environmental initiative as well as the area it concerns. The initiative is carried out under the patronage of the International Union for Conservation of Nature and Mikhail Gorbachev. It is the aim of the initiative to create the backbone of an ecological network that runs from the Barents to the Black and Adriatic Seas.
The European Green Belt as an area follows the route of the former Iron Curtain and connects National Parks, Nature Parks, Biosphere Reserves and transboundary protected areas as well as non-protected valuable habitats along or across the (former) borders.
🔗 Man or boy test
The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not.
There are quite a few ALGOL60 translators in existence which have been designed to handle recursion and non-local references properly, and I thought perhaps a little test-program may be of value. Hence I have written the following simple routine, which may separate the man-compilers from the boy-compilers.
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- "Man or boy test" | 2019-11-28 | 148 Upvotes 61 Comments
🔗 Desiderata
"Desiderata" (Latin: "things desired") is an early 1920s prose poem by the American writer Max Ehrmann. Although he copyrighted it in 1927, he distributed copies of it without a required copyright notice during 1933 and c. 1942, thereby forfeiting his US copyright. Largely unknown in the author's lifetime, its use in devotional and spoken word recordings in 1960 and 1971 called it to the attention of the world.
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- "Desiderata by Max Ehrmann" | 2022-08-19 | 60 Upvotes 36 Comments
- "Desiderata" | 2013-02-06 | 148 Upvotes 39 Comments
🔗 Zip gun
Improvised firearms (sometimes called zip guns or pipe guns) are firearms manufactured other than by a firearms manufacturer or a gunsmith, and are typically constructed by adapting existing materials to the purpose. They range in quality from crude weapons that are as much a danger to the user as the target to high-quality arms produced by cottage industries using salvaged and repurposed materials.
Improvised firearms are commonly used as tools by criminals and insurgents and are often associated with such groups; other uses include self-defense in lawless areas and hunting game in poor rural areas.
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- "Zip gun" | 2018-09-15 | 50 Upvotes 36 Comments
🔗 Crystal Detector
A crystal detector is an obsolete electronic component used in some early 20th century radio receivers that consists of a piece of crystalline mineral which rectifies the alternating current radio signal. It was employed as a detector (demodulator) to extract the audio modulation signal from the modulated carrier, to produce the sound in the earphones. It was the first type of semiconductor diode, and one of the first semiconductor electronic devices. The most common type was the so-called cat whisker detector, which consisted of a piece of crystalline mineral, usually galena (lead sulfide), with a fine wire touching its surface.
The "asymmetric conduction" of electric current across electrical contacts between a crystal and a metal was discovered in 1874 by Karl Ferdinand Braun. Crystals were first used as radio wave detectors in 1894 by Jagadish Chandra Bose in his microwave experiments. Bose first patented a crystal detector in 1901. The crystal detector was developed into a practical radio component mainly by G. W. Pickard, who began research on detector materials in 1902 and found hundreds of substances that could be used in forming rectifying junctions. The physical principles by which they worked were not understood at the time they were used, but subsequent research into these primitive point contact semiconductor junctions in the 1930s and 1940s led to the development of modern semiconductor electronics.
The unamplified radio receivers that used crystal detectors were called crystal radios. The crystal radio was the first type of radio receiver that was used by the general public, and became the most widely used type of radio until the 1920s. It became obsolete with the development of vacuum tube receivers around 1920, but continued to be used until World War II and remains a common educational project today thanks to its simple design.
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- "Crystal Detector" | 2021-11-26 | 28 Upvotes 16 Comments