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π Kunyu Wanguo Quantu
Kunyu Wanguo Quantu, printed in China at the request of the Wanli Emperor during 1602 by the Italian Catholic missionary Matteo Ricci and Chinese collaborators, Mandarin Zhong Wentao and the technical translator, Li Zhizao, is the earliest known Chinese world map with the style of European maps. It has been referred to as the Impossible Black Tulip of Cartography, "because of its rarity, importance and exoticism". The map was crucial in expanding Chinese knowledge of the world. It was eventually exported to Korea then Japan and was influential there as well, though less so than Alenio's Zhifang Waiji.
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- "Kunyu Wanguo Quantu" | 2021-11-02 | 45 Upvotes 3 Comments
π Memetics
Memetics is a theory of the evolution of culture based on Darwinian principles with the meme as the unit of culture. The term "meme" was coined by biologist Richard Dawkins in his 1976 book The Selfish Gene, to illustrate the principle that he later called "Universal Darwinism". All evolutionary processes depend on information being copied, varied, and selected, a process also known as variation with selective retention. The information that is copied is called the replicator, and genes are the replicator for biological evolution. Dawkins proposed that the same process drives cultural evolution, and he called this second replicator the "meme". He gave as examples, tunes, catchphrases, fashions, and technologies. Like genes, memes are selfish replicators and have causal efficacy; in other words, their properties influence their chances of being copied and passed on. Some succeed because they are valuable or useful to their human hosts while others are more like viruses.
Just as genes can work together to form co-adapted gene complexes, so groups of memes acting together form co-adapted meme complexes or memeplexes. Memeplexes include (among many other things) languages, traditions, scientific theories, financial institutions, and religions. Dawkins famously referred to religions as "viruses of the mind".
Among proponents of memetics are psychologist Susan Blackmore, author of The Meme Machine, who argues that when our ancestors began imitating behaviours, they let loose a second replicator and co-evolved to become the "meme machines" that copy, vary, and select memes in culture. Philosopher Daniel Dennett develops memetics extensively, notably in his books Darwin's Dangerous Idea, and From Bacteria to Bach and Back. He describes the units of memes as "the smallest elements that replicate themselves with reliability and fecundity." and claims that "Human consciousness is itself a huge complex of memes." In The Beginning of Infinity, physicist David Deutsch contrasts static societies that depend on anti-rational memes suppressing innovation and creativity, with dynamic societies based on rational memes that encourage enlightenment values, scientific curiosity, and progress.
Criticisms of memetics include claims that memes do not exist, that the analogy with genes is false, that the units cannot be specified, that culture does not evolve through imitation, and that the sources of variation are intelligently designed rather than random. Critics of memetics include biologist Stephen Jay Gould who calls memetics a "meaningless metaphor". Philosopher Dan Sperber argues against memetics as a viable approach to cultural evolution because cultural items are not directly copied or imitated but are reproduced. Anthropologist Robert Boyd and biologist Peter Richerson work within the alternative, and more mainstream, field of cultural evolution theory and gene-culture coevolution. Dual inheritance theory has much in common with memetics but rejects the idea that memes are replicators. From this perspective, memetics is seen as just one of several approaches to cultural evolution and one that is generally considered less useful than the alternatives of gene-culture coevolution or dual inheritance theory. The main difference is that dual inheritance theory ultimately depends on biological advantage to genes, whereas memetics treats memes as a second replicator in its own right. Memetics also extends to the analysis of Internet culture and Internet memes.
π Lithophone
A lithophone is a musical instrument consisting of a rock or pieces of rock which are struck to produce musical notes. Notes may be sounded in combination (producing harmony) or in succession (melody). The lithophone is an idiophone comparable to instruments such as the glockenspiel, vibraphone, xylophone and marimba.
In the Hornbostel-Sachs classification system, lithophones are designated as '111.22' β directly-struck percussion plaques.
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- "Lithophone" | 2020-02-22 | 54 Upvotes 7 Comments
π Black Hole Electron
In physics, there is a speculative hypothesis that, if there were a black hole with the same mass, charge and angular momentum as an electron, it would share other properties of the electron. Most notably, Brandon Carter showed in 1968 that the magnetic moment of such an object would match that of an electron. This is interesting because calculations ignoring special relativity and treating the electron as a small rotating sphere of charge give a magnetic moment roughly half the experimental value (see Gyromagnetic ratio).
However, Carter's calculations also show that a would-be black hole with these parameters would be "super-extremal". Thus, unlike a true black hole, this object would display a naked singularity, meaning a singularity in spacetime not hidden behind an event horizon. It would also give rise to closed timelike curves.
Standard quantum electrodynamics (QED), currently the most comprehensive theory of particles, treats the electron as a point particle. There is no evidence that the electron is a black hole (or naked singularity) or not. Furthermore, since the electron is quantum-mechanical in nature, any description purely in terms of general relativity is paradoxical until a better model based on understanding of quantum nature of blackholes and gravitational behaviour of quantum particles is developed by research. Hence, the idea of a black hole electron remains strictly hypothetical.
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- "Black Hole Electron" | 2023-09-06 | 64 Upvotes 38 Comments
- "Black Hole Electron" | 2023-03-11 | 19 Upvotes 2 Comments
π Kim Peek
Laurence Kim Peek (November 11, 1951Β β December 19, 2009) was an American savant. Known as a "megasavant", he had an exceptional memory, but he also experienced social difficulties, possibly resulting from a developmental disability related to congenital brain abnormalities. He was the inspiration for the autistic savant character Raymond Babbitt in the movie Rain Man. Although Peek was previously diagnosed with autism, it is now thought that he instead had FG syndrome.
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- "Kim Peek" | 2019-10-13 | 125 Upvotes 49 Comments
π Old Elbe Tunnel
Old Elbe Tunnel or St. Pauli Elbe Tunnel (German: Alter Elbtunnel colloquially or St. Pauli Elbtunnel officially) which opened in 1911, is a pedestrian and vehicle tunnel in Hamburg. The 426 m (1,398 ft) long tunnel was a technical sensation; 24 m (80 ft) beneath the surface, two 6 m (20 ft) diameter tubes connect central Hamburg with the docks and shipyards on the south side of the river Elbe. This was a big improvement for tens of thousands of workers in one of the busiest harbors in the world.
Six large lifts on either side of the tunnel carry pedestrians and vehicles to the bottom. The two tunnels are both still in operation, though due to their limited capacity by today's standards, other bridges and tunnels have been built and taken over most of the traffic.
In 2008 approximately 300,000 cars, 63,000 bicycles, and 700,000 pedestrians used the tunnel. The tunnel is opened 24 hours for pedestrians and bicycles. For motorized vehicles, opening times are currently Monday to Friday from 5:20Β a.m. to 8:00Β p.m. and on Saturdays from 5:20Β a.m. to 4:00Β p.m.
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- "Old Elbe Tunnel" | 2022-10-12 | 147 Upvotes 54 Comments
π Williams tube β cathode ray tube used as computer memory
The Williams tube, or the WilliamsβKilburn tube after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first random-access digital storage device, and was used successfully in several early computers.
The Williams tube works by displaying a grid of dots on a cathode ray tube (CRT). Due to the way CRTs work, this creates a small charge of static electricity over each dot. The charge at the location of each of the dots is read by a thin metal sheet just in front of the display. Since the display faded over time, it was periodically refreshed. It cycles faster than earlier acoustic delay line memory, at the speed of the electrons inside the vacuum tube, rather than at the speed of sound. However, the system was adversely affected by any nearby electrical fields, and required constant alignment to keep operational. WilliamsβKilburn tubes were used primarily on high-speed computer designs.
Williams and Kilburn applied for British patents on 11 December 1946, and 2 October 1947, followed by United States patent applications on 10 December 1947, and 16 May 1949.
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- "Williams tube β cathode ray tube used as computer memory" | 2015-11-26 | 57 Upvotes 16 Comments
π The Cuckoo's Egg
The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage is a 1989 book written by Clifford Stoll. It is his first-person account of the hunt for a computer hacker who broke into a computer at the Lawrence Berkeley National Laboratory (LBNL).
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- "The Cuckoo's Egg" | 2019-01-29 | 14 Upvotes 10 Comments
π Hogmanay
Hogmanay ( HOG-mΙ-nay, -β NAY, Scots:Β [ΛhΙΙ‘mΙΛneΛ]) is the Scots word for the last day of the old year and is synonymous with the celebration of the New Year in the Scottish manner. It is normally followed by further celebration on the morning of New Year's Day (1 January) or in some cases, 2 Januaryβa Scottish bank holiday.
The origins of Hogmanay are unclear, but it may be derived from Norse and Gaelic observances of the winter solstice. Customs vary throughout Scotland, and usually include gift-giving and visiting the homes of friends and neighbours, with special attention given to the first-foot, the first guest of the new year.
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- "Hogmanay" | 2022-12-27 | 90 Upvotes 47 Comments
π Quasi-Zenith Satellite System
The Quasi-Zenith Satellite System (QZSS) (Japanese: ζΊε€©ι θ‘ζγ·γΉγγ , Hepburn: juntenchΕ eisei shisutemu), also known as Michibiki (γΏγ‘γ³γ, "guidance"), is a regional navigation satellite system (RNSS) and a satellite-based augmentation system (SBAS) developed by the Japanese government to enhance the United States-operated Global Positioning System (GPS) in the Asia-Oceania regions, with a focus on Japan. The goal of QZSS is to provide highly precise and stable positioning services in the Asia-Oceania region, compatible with GPS. Four-satellite QZSS services were available on a trial basis as of 12 January 2018, and officially started on 1 November 2018. A satellite navigation system independent of GPS is planned for 2023 with seven satellites. In May 2023 it was announced that the system would expand to eleven satellites.
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- "Quasi-Zenith Satellite System" | 2026-02-22 | 24 Upvotes 4 Comments