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🔗 Computing 🔗 Reference works 🔗 Belgium

The Mundaneum was an institution which aimed to gather together all the world's knowledge and classify it according to a system developed called the Universal Decimal Classification. It was developed at the turn of the 20th century by Belgian lawyers Paul Otlet and Henri La Fontaine. The Mundaneum has been identified as a milestone in the history of data collection and management, and (somewhat more tenuously) as a precursor to the Internet.

In the 21st century, the Mundaneum is a non-profit organisation based in Mons, Belgium that runs an exhibition space, website and archive which celebrate the legacy of the original Mundaneum.

🔗 Internet culture 🔗 Economics

You'll own nothing and be happy (alternatively you'll own nothing and you'll be happy) is a phrase originated by Danish Politician Ida Auken in a 2016 essay for the World Economic Forum. After appearing in a WEF video in 2016, the phrase began to be used by critics of the World Economic Forum (WEF) who accuse the WEF of desiring restrictions on ownership of private property.

🔗 Computing 🔗 Automobiles

MISRA C is a set of software development guidelines for the C programming language developed by The MISRA Consortium. Its aims are to facilitate code safety, security, portability and reliability in the context of embedded systems, specifically those systems programmed in ISO C / C90 / C99.

There is also a set of guidelines for MISRA C++ not covered by this article.

🔗 Mathematics 🔗 Physics

Shor's algorithm is a polynomial-time quantum computer algorithm for integer factorization. Informally, it solves the following problem: Given an integer ${\displaystyle N}$, find its prime factors. It was invented in 1994 by the American mathematician Peter Shor.

On a quantum computer, to factor an integer ${\displaystyle N}$, Shor's algorithm runs in polynomial time (the time taken is polynomial in ${\displaystyle \log N}$, the size of the integer given as input). Specifically, it takes quantum gates of order ${\displaystyle O\!\left((\log N)^{2}(\log \log N)(\log \log \log N)\right)}$ using fast multiplication, thus demonstrating that the integer-factorization problem can be efficiently solved on a quantum computer and is consequently in the complexity class BQP. This is almost exponentially faster than the most efficient known classical factoring algorithm, the general number field sieve, which works in sub-exponential time — ${\displaystyle O\!\left(e^{1.9(\log N)^{1/3}(\log \log N)^{2/3}}\right)}$. The efficiency of Shor's algorithm is due to the efficiency of the quantum Fourier transform, and modular exponentiation by repeated squarings.

If a quantum computer with a sufficient number of qubits could operate without succumbing to quantum noise and other quantum-decoherence phenomena, then Shor's algorithm could be used to break public-key cryptography schemes, such as the widely used RSA scheme. RSA is based on the assumption that factoring large integers is computationally intractable. As far as is known, this assumption is valid for classical (non-quantum) computers; no classical algorithm is known that can factor integers in polynomial time. However, Shor's algorithm shows that factoring integers is efficient on an ideal quantum computer, so it may be feasible to defeat RSA by constructing a large quantum computer. It was also a powerful motivator for the design and construction of quantum computers, and for the study of new quantum-computer algorithms. It has also facilitated research on new cryptosystems that are secure from quantum computers, collectively called post-quantum cryptography.

In 2001, Shor's algorithm was demonstrated by a group at IBM, who factored ${\displaystyle 15}$ into ${\displaystyle 3\times 5}$, using an NMR implementation of a quantum computer with ${\displaystyle 7}$ qubits. After IBM's implementation, two independent groups implemented Shor's algorithm using photonic qubits, emphasizing that multi-qubit entanglement was observed when running the Shor's algorithm circuits. In 2012, the factorization of ${\displaystyle 15}$ was performed with solid-state qubits. Also, in 2012, the factorization of ${\displaystyle 21}$ was achieved, setting the record for the largest integer factored with Shor's algorithm.

🔗 Technology 🔗 Trains

An atmospheric railway uses differential air pressure to provide power for propulsion of a railway vehicle. A static power source can transmit motive power to the vehicle in this way, avoiding the necessity of carrying mobile power generating equipment. The air pressure, or partial vacuum (i.e., negative relative pressure) can be conveyed to the vehicle in a continuous pipe, where the vehicle carries a piston running in the tube. Some form of re-sealable slot is required to enable the piston to be attached to the vehicle. Alternatively the entire vehicle may act as the piston in a large tube.

Several variants of the principle were proposed in the early 19th century, and a number of practical forms were implemented, but all were overcome by unforeseen disadvantages and discontinued within a few years.

A modern proprietary system has been developed and is in use for short-distance applications. Porto Alegre Metro airport connection is one of them.

🔗 Ancient Near East 🔗 Assyria 🔗 Mythology 🔗 Project-independent assessment 🔗 Intertranswiki/OKA

The Descent of Inanna into the Underworld (or, in its Akkadian version, Descent of Ishtar into the Underworld) or Angalta ("From the Great Sky") is a Sumerian myth that narrates the descent of the goddess Inanna (Ishtar in Akkadian) into the Underworld to overthrow its ruler, her sister Ereshkigal, the "Queen of the Dead." But following the removal of her adornments, she perishes and her corpse is suspended on a nail. The god Enki intervenes indirectly, restoring Inanna to life. However, on her return journey, Inanna is required to deliver another living human in exchange for her freedom. She selects Dumuzi, her spouse, who is abruptly transported to the Underworld. In response to the pleas of Dumuzi's sister, Geshtinanna, his circumstances are somewhat ameliorated: he is permitted to remain in the Underworld for only a portion of the year, with his sister assuming his role for the remaining duration.

The myth exists in two main versions: one in Sumerian and the other in Akkadian. The Akkadian version was first discovered and translated in the 1860s. The existence of the longer and older Sumerian version was first established in the early 20th century, but it required approximately fifty years for epigraphists to fully reconstruct and translate it.

The story of Descent of Inanna into the Underworld offers insights into Mesopotamian culture through its numerous characters and developed plot. The influence of this culture on subsequent civilizations is evident in the traces of Mesopotamian elements found in Greece, Phoenicia, and the Old Testament. In the 20th century, the story was used by some psychoanalysis theorists to illustrate psychic mechanisms.

🔗 United States 🔗 Biography 🔗 California 🔗 Aviation 🔗 Spaceflight 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Biography/science and academia 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 LGBT studies 🔗 Aviation/aerospace biography 🔗 Chemistry 🔗 Military history/World War II 🔗 Military history/Cold War 🔗 Libertarianism 🔗 California/Southern California 🔗 California/Los Angeles area 🔗 Thelema 🔗 Occult

John Whiteside Parsons (born Marvel Whiteside Parsons; October 2, 1914 – June 17, 1952) was an American rocket engineer, chemist, and Thelemite occultist. Associated with the California Institute of Technology (Caltech), Parsons was one of the principal founders of both the Jet Propulsion Laboratory (JPL) and the Aerojet Engineering Corporation. He invented the first rocket engine to use a castable, composite rocket propellant, and pioneered the advancement of both liquid-fuel and solid-fuel rockets.

Born in Los Angeles, Parsons was raised by a wealthy family on Orange Grove Boulevard in Pasadena. Inspired by science fiction literature, he developed an interest in rocketry in his childhood and in 1928 began amateur rocket experiments with school friend Edward S. Forman. He dropped out of Pasadena Junior College and Stanford University due to financial difficulties during the Great Depression, and in 1934 he united with Forman and graduate Frank Malina to form the Caltech-affiliated Guggenheim Aeronautical Laboratory (GALCIT) Rocket Research Group, supported by GALCIT chairman Theodore von Kármán. In 1939 the GALCIT Group gained funding from the National Academy of Sciences (NAS) to work on Jet-Assisted Take Off (JATO) for the U.S. military. After the U.S. entered World War II, they founded Aerojet in 1942 to develop and sell JATO technology; the GALCIT Group became JPL in 1943.

Following some brief involvement with Marxism in 1939, Parsons converted to Thelema, the new religious movement founded by the English occultist Aleister Crowley. Together with his first wife, Helen Northrup, Parsons joined the Agape Lodge, the Californian branch of the Thelemite Ordo Templi Orientis (O.T.O.) in 1941. At Crowley's bidding, Parsons replaced Wilfred Talbot Smith as its leader in 1942 and ran the Lodge from his mansion on Orange Grove Boulevard. Parsons was expelled from JPL and Aerojet in 1944 owing to the Lodge's infamous reputation and to his hazardous workplace conduct.

In 1945, Parsons separated from Helen, after having an affair with her sister Sara; when Sara left him for L. Ron Hubbard, Parsons conducted the Babalon Working, a series of rituals intended to invoke the Thelemic goddess Babalon on Earth. He and Hubbard continued the working with Marjorie Cameron, whom Parsons married in 1946. After Hubbard and Sara defrauded him of his life savings, Parsons resigned from the O.T.O., then held various jobs while acting as a consultant for Israel's rocket program. Amid McCarthyism, Parsons was accused of espionage and left unable to work in rocketry. In 1952 Parsons died at the age of 37 in a home laboratory explosion that attracted national media attention; the police ruled it an accident, but many associates suspected suicide or murder.

Parsons's libertarian and occult writings were published posthumously. Historians of Western esoteric tradition cite him as one of the more prominent figures in propagating Thelema across North America. Although academic interest in his scientific career was negligible, historians have come to recognize Parsons's contributions to rocket engineering. For these innovations, his advocacy of space exploration and human spaceflight, and his role in founding JPL and Aerojet, Parsons is regarded as among the most important figures in the history of the U.S. space program. He has been the subject of several biographies and fictionalized portrayals.

🔗 Video games 🔗 Chess

1K ZX Chess is a 1982 chess program for the unexpanded Sinclair ZX81.

🔗 Spaceflight

The Nuclear Engine for Rocket Vehicle Application (NERVA) was a nuclear thermal rocket engine development program that ran for roughly two decades. Its principal objective was to "establish a technology base for nuclear rocket engine systems to be utilized in the design and development of propulsion systems for space mission application". It was a joint effort of the Atomic Energy Commission (AEC) and the National Aeronautics and Space Administration (NASA), and was managed by the Space Nuclear Propulsion Office (SNPO) until the program ended in January 1973. SNPO was led by NASA's Harold Finger and AEC's Milton Klein.

NERVA had its origins in Project Rover, an AEC research project at the Los Alamos Scientific Laboratory (LASL) with the initial aim of providing a nuclear-powered upper stage for the United States Air Force intercontinental ballistic missiles. Nuclear thermal rocket engines promised to be more efficient than chemical ones. After the formation of NASA in 1958, Project Rover was continued as a civilian project and was reoriented to producing a nuclear powered upper stage for NASA's Saturn V Moon rocket. Reactors were tested at very low power before being shipped to Jackass Flats in the Nevada Test Site. While LASL concentrated on reactor development, NASA built and tested complete rocket engines.

The AEC, SNPO, and NASA considered NERVA a highly successful program in that it met or exceeded its program goals. It demonstrated that nuclear thermal rocket engines were a feasible and reliable tool for space exploration, and at the end of 1968 SNPO deemed that the latest NERVA engine, the XE, met the requirements for a human mission to Mars. It had strong political support from Senators Clinton P. Anderson and Margaret Chase Smith but was cancelled by President Richard Nixon in 1973. Although NERVA engines were built and tested as much as possible with flight-certified components and the engine was deemed ready for integration into a spacecraft, they never flew in space.