Random Articles (Page 305)
Have a deep view into what people are curious about.
๐ Intelligent Disobedience
Intelligent disobedience occurs where a service animal trained to help a disabled person goes directly against the owner's instructions in an effort to make a better decision. This behavior is a part of the dog's training and is central to a service animal's success on the job. The concept of intelligent disobedience has been in use and a common part of service animals' training since at least 1936.
Discussed on
- "Intelligent Disobedience" | 2020-05-25 | 212 Upvotes 84 Comments
๐ Flocken Elektrowagen
The Flocken Elektrowagen is a four-wheeled electric car designed by Andreas Flocken (1845โ1913), manufactured in 1888 by Maschinenfabrik A. Flocken in Coburg. It is regarded as the first real electric car.
Discussed on
- "Flocken Elektrowagen" | 2025-01-18 | 17 Upvotes 3 Comments
๐ Pitch Drop Experiment
The pitch drop experiment is a long-term experiment which measures the flow of a piece of pitch over many years. 'Pitch' is the name for any of a number of highly viscous liquids which appear solid; most commonly bitumen. At room temperature, tar pitch flows at a very low rate, taking several years to form a single drop.
Discussed on
- "Pitch Drop Experiment" | 2024-01-29 | 82 Upvotes 32 Comments
- "Pitch Drop Experiment" | 2020-02-06 | 97 Upvotes 30 Comments
๐ Long line (topology)
In topology, the long line (or Alexandroff line) is a topological space somewhat similar to the real line, but in a certain way "longer". It behaves locally just like the real line, but has different large-scale properties (e.g., it is neither Lindelรถf nor separable). Therefore, it serves as one of the basic counterexamples of topology. Intuitively, the usual real-number line consists of a countable number of line segments [0,ย 1) laid end-to-end, whereas the long line is constructed from an uncountable number of such segments.
Discussed on
- "Long line (topology)" | 2015-05-02 | 46 Upvotes 21 Comments
๐ Rhind Mathematical Papyrus
The Rhind Mathematical Papyrus (RMP; also designated as papyrus British Museum 10057 and pBM 10058) is one of the best known examples of ancient Egyptian mathematics. It is named after Alexander Henry Rhind, a Scottish antiquarian, who purchased the papyrus in 1858 in Luxor, Egypt; it was apparently found during illegal excavations in or near the Ramesseum. It dates to around 1550 BC. The British Museum, where the majority of the papyrus is now kept, acquired it in 1865 along with the Egyptian Mathematical Leather Roll, also owned by Henry Rhind. There are a few small fragments held by the Brooklyn Museum in New York City and an 18ย cm (7.1ย in) central section is missing. It is one of the two well-known Mathematical Papyri along with the Moscow Mathematical Papyrus. The Rhind Papyrus is larger than the Moscow Mathematical Papyrus, while the latter is older.
The Rhind Mathematical Papyrus dates to the Second Intermediate Period of Egypt. It was copied by the scribe Ahmes (i.e., Ahmose; Ahmes is an older transcription favoured by historians of mathematics), from a now-lost text from the reign of king Amenemhat III (12th dynasty). Written in the hieratic script, this Egyptian manuscript is 33ย cm (13ย in) tall and consists of multiple parts which in total make it over 5ย m (16ย ft) long. The papyrus began to be transliterated and mathematically translated in the late 19th century. The mathematical translation aspect remains incomplete in several respects. The document is dated to Year 33 of the Hyksos king Apophis and also contains a separate later historical note on its verso likely dating from the period ("Year 11") of his successor, Khamudi.
In the opening paragraphs of the papyrus, Ahmes presents the papyrus as giving "Accurate reckoning for inquiring into things, and the knowledge of all things, mysteriesย ... all secrets". He continues with:
This book was copied in regnal year 33, month 4 of Akhet, under the majesty of the King of Upper and Lower Egypt, Awserre, given life, from an ancient copy made in the time of the King of Upper and Lower Egypt Nimaatre. The scribe Ahmose writes this copy.
Several books and articles about the Rhind Mathematical Papyrus have been published, and a handful of these stand out. The Rhind Papyrus was published in 1923 by Peet and contains a discussion of the text that followed Griffith's Book I, II and III outline. Chace published a compendium in 1927โ29 which included photographs of the text. A more recent overview of the Rhind Papyrus was published in 1987 by Robins and Shute.
Discussed on
- "Rhind Mathematical Papyrus" | 2023-04-02 | 42 Upvotes 30 Comments
๐ Novikov Self-Consistency Principle
The Novikov self-consistency principle, also known as the Novikov self-consistency conjecture and Larry Niven's law of conservation of history, is a principle developed by Russian physicist Igor Dmitriyevich Novikov in the mid-1980s. Novikov intended it to solve the problem of paradoxes in time travel, which is theoretically permitted in certain solutions of general relativity that contain what are known as closed timelike curves. The principle asserts that if an event exists that would cause a paradox or any "change" to the past whatsoever, then the probability of that event is zero. It would thus be impossible to create time paradoxes.
๐ Bouba/Kiki Effect
The bouba/kiki effect is a non-arbitrary mapping between speech sounds and the visual shape of objects. It was first documented by Wolfgang Kรถhler in 1929 using nonsense words. The effect has been observed in American university students, Tamil speakers in India, young children, and infants, and has also been shown to occur with familiar names. It is absent in individuals who are congenitally blind and reduced in autistic individuals. The effect was investigated using fMRI in 2018.
Discussed on
- "Bouba/Kiki Effect" | 2024-06-16 | 257 Upvotes 170 Comments
- "Bouba/Kiki Effect" | 2021-07-19 | 238 Upvotes 94 Comments
๐ Antimacassar
An antimacassar is a small cloth placed over the backs or arms of chairs, or the head or cushions of a sofa, to prevent soiling of the permanent fabric underneath. The name also refers to the cloth flap 'collar' on a sailor's shirt or top, used to keep macassar oil off the uniform.
Macassar oil was an unguent for the hair commonly used by men in the early 19th century, and reputed to have been manufactured from ingredients purchased in the port of Makassar in the Dutch East Indies. The poet Byron called it "thine incomparable oil, Macassar". The fashion for oiled hair became so widespread in the Victorian and the Edwardian period that housewives began to cover the arms and backs of their chairs with washable cloths to prevent the fabric coverings from being soiled. Around 1850, these started to be known as antimacassars. They were also installed in theatres, from 1865.
They came to have elaborate patterns, often in matching sets for the various items of parlour furniture; they were either made at home using a variety of techniques such as crochet or tatting, or purchased. The original antimacassars were usually made of stiff white crochet-work, but in the third quarter of the 19th century they became simpler and softer, usually fabric embroidered with a simple pattern in wool or silk.
By the beginning of the 20th century, antimacassars had become so associated in people's minds with the Victorian period that the word briefly became a figurative term for it. For example, antimacassars are suggestive of old-fashioned, Victorian-era women in Rebecca West's novel The Return of the Soldier.
Antimacassars are also used on the seat headrests of commercial passenger transport vehicles, such as trains, buses and, especially, aircraft, to prevent the transmission of hair dressings and conditions between passengers, simplify maintenance, and extend the life of fabrics.
Discussed on
- "Antimacassar" | 2024-01-02 | 39 Upvotes 4 Comments
๐ Rubber hose animation
Rubber hose animation was the first animation style that became standardized in the American animation field. The defining feature is the curving motion most things possess, resembling that of a rubber hose. While the style fell out of fashion during the 1930s, there has been a minor revitalization of it in recent years with works such as the video games Cuphead and Bendy and the Ink Machine, and the film Steven Universe: The Movie.
Discussed on
- "Rubber hose animation" | 2023-09-11 | 71 Upvotes 18 Comments
๐ Trans-African Highway Network
The Trans-African Highway network comprises transcontinental road projects in Africa being developed by the United Nations Economic Commission for Africa (UNECA), the African Development Bank (ADB), and the African Union in conjunction with regional international communities. They aim to promote trade and alleviate poverty in Africa through highway infrastructure development and the management of road-based trade corridors. The total length of the nine highways in the network is 56,683ย km (35,221ย mi).
In some documents the highways are referred to as "Trans-African Corridors" or "Road Corridors" rather than highways. The name Trans-African Highway and its variants are not in wide common usage outside of planning and development circles, and as of 2014 one does not see them signposted as such or labelled on maps, except in Kenya and Uganda where the MombasaโNairobiโKampalaโFort Portal section (or the KampalaโKigali feeder road) of Trans-African Highway 8 is sometimes referred to as the "Trans-Africa Highway".
Discussed on
- "Trans-African Highway Network" | 2023-09-08 | 13 Upvotes 4 Comments