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🔗 Biography 🔗 Military history 🔗 Architecture 🔗 Greece 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 Military history/World War II 🔗 Military history/Cold War 🔗 Dance 🔗 Composers 🔗 Dance/Ballet 🔗 Classical music 🔗 Military history/Balkan military history 🔗 Biography/Musicians 🔗 Military history/European military history

Iannis Xenakis (also spelt as Yannis Xenakis) (Greek: Γιάννης (Ιάννης) Ξενάκης [ˈʝanis kseˈnacis]; 29 May 1922 – 4 February 2001) was a Greek-French composer, music theorist, architect, performance director and engineer. After 1947, he fled Greece, becoming a naturalized citizen of France. He is considered an important post-World War II composer whose works helped revolutionize 20th-century classical music.

Xenakis pioneered the use of mathematical models in music such as applications of set theory, stochastic processes and game theory and was also an important influence on the development of electronic and computer music. He integrated music with architecture, designing music for pre-existing spaces, and designing spaces to be integrated with specific music compositions and performances.

Among his most important works are Metastaseis (1953–54) for orchestra, which introduced independent parts for every musician of the orchestra; percussion works such as Psappha (1975) and Pléïades (1979); compositions that introduced spatialization by dispersing musicians among the audience, such as Terretektorh (1966); electronic works created using Xenakis's UPIC system; and the massive multimedia performances Xenakis called polytopes, that were a summa of his interests and skills. Among the numerous theoretical writings he authored, the book Formalized Music: Thought and Mathematics in Composition (French edition 1963, English translation 1971) is regarded as one of his most important. As an architect, Xenakis is primarily known for his early work under Le Corbusier: the Sainte Marie de La Tourette, on which the two architects collaborated, and the Philips Pavilion at Expo 58, which Xenakis designed by himself.

🔗 Novels 🔗 Novels/Science fiction 🔗 Science Fiction 🔗 Solar System/Mars 🔗 Solar System

The Mars trilogy is a series of science fiction novels by Kim Stanley Robinson that chronicles the settlement and terraforming of the planet Mars through the personal and detailed viewpoints of a wide variety of characters spanning almost two centuries. Ultimately more utopian than dystopian, the story focuses on egalitarian, sociological, and scientific advances made on Mars, while Earth suffers from overpopulation and ecological disaster.

The three novels are Red Mars (1992), Green Mars (1993), and Blue Mars (1996). The Martians (1999) is a collection of short stories set in the same fictional universe. Red Mars won the BSFA Award in 1992 and Nebula Award for Best Novel in 1993. Green Mars won the Hugo Award for Best Novel and Locus Award for Best Science Fiction Novel in 1994. Blue Mars also won the Hugo and Locus Awards in 1997.

Icehenge (1984), Robinson's first novel about Mars, is not set in this universe but deals with similar themes and plot elements. The trilogy shares some similarities with Robinson's more recent novel 2312 (2012); for instance, the terraforming of Mars and the extreme longevity of the characters in both novels.

🔗 Aviation 🔗 Telecommunications 🔗 Guild of Copy Editors

In the U.S., Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight. Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 leaves it up to the airlines to determine if devices can be used in flight, allowing use of "Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used."

In Europe, regulations and technology have allowed the limited introduction of the use of passenger mobile phones on some commercial flights, and elsewhere in the world many airlines are moving towards allowing mobile phone use in flight. Many airlines still do not allow the use of mobile phones on aircraft. Those that do often ban the use of mobile phones during take-off and landing.

Many passengers are pressing airlines and their governments to allow and deregulate mobile phone use, while some airlines, under the pressure of competition, are also pushing for deregulation or seeking new technology which could solve the present problems. On the other hand, official aviation agencies and safety boards are resisting any relaxation of the present safety rules unless and until it can be conclusively shown that it would be safe to do so. There are both technical and social factors which make the issues more complex than a simple discussion of safety versus hazard.

🔗 Board and table games

Rithmomachy (or Rithmomachia, also Arithmomachia, Rythmomachy, Rhythmomachy, or sundry other variants; sometimes known as The Philosophers' Game) is a highly complex, early European mathematical board game. The earliest known description of it dates from the eleventh century. A literal translation of the name is "The Battle of the Numbers". The game is much like chess, except most methods of capture depend on the numbers inscribed on each piece.

It has been argued that between the twelfth and sixteenth centuries, "rithmomachia served as a practical exemplar for teaching the contemplative values of Boethian mathematical philosophy, which emphasized the natural harmony and perfection of number and proportion. The game, Moyer argues, was used both as a mnemonic drill for the study of Boethian number theory and, more importantly, as a vehicle for moral education, by reminding players of the mathematical harmony of creation."

🔗 Mathematics

In symbolic computation (or computer algebra), at the intersection of mathematics and computer science, the Risch algorithm is an algorithm for indefinite integration. It is used in some computer algebra systems to find antiderivatives. It is named after the American mathematician Robert Henry Risch, a specialist in computer algebra who developed it in 1968.

The algorithm transforms the problem of integration into a problem in algebra. It is based on the form of the function being integrated and on methods for integrating rational functions, radicals, logarithms, and exponential functions. Risch called it a decision procedure, because it is a method for deciding whether a function has an elementary function as an indefinite integral, and if it does, for determining that indefinite integral.

The complete description of the Risch algorithm takes over 100 pages. The Risch–Norman algorithm is a simpler, faster, but less powerful variant that was developed in 1976 by Arthur Norman.

🔗 United States 🔗 Military history 🔗 Philosophy 🔗 Philosophy/Logic 🔗 Military history/Military biography

The McNamara fallacy (also known as the quantitative fallacy), named for Robert McNamara, the US Secretary of Defense from 1961 to 1968, involves making a decision based solely on quantitative observations (or metrics) and ignoring all others. The reason given is often that these other observations cannot be proven.

The first step is to measure whatever can be easily measured. This is OK as far as it goes. The second step is to disregard that which can't be easily measured or to give it an arbitrary quantitative value. This is artificial and misleading. The third step is to presume that what can't be measured easily really isn't important. This is blindness. The fourth step is to say that what can't be easily measured really doesn't exist. This is suicide.

The fallacy refers to McNamara's belief as to what led the United States to defeat in the Vietnam War—specifically, his quantification of success in the war (e.g., in terms of enemy body count), ignoring other variables.

🔗 Chemistry 🔗 Plants

Lignum nephriticum (Latin for "kidney wood") is a traditional diuretic that was derived from the wood of two tree species, the narra (Pterocarpus indicus) and the Mexican kidneywood (Eysenhardtia polystachya). The wood is capable of turning the color of water it comes in contact with into beautiful opalescent hues that change depending on light and angle, the earliest known record of the phenomenon of fluorescence. Due to this strange property, it became well known in Europe from the 16th to the early 18th-century. Cups made from lignum nephriticum were given as gifts to royalty. Water drunk from such cups, as well as imported powders and extracts from lignum nephriticum, were thought to have great medicinal properties.

The lignum nephriticum derived from Mexican kidneywood was known as the coatli, coatl, or cuatl ("snake water") or tlapalezpatli ("blood-tincture medicine") in the Nahuatl language. It was traditionally used by the Aztec people as a diuretic prior to European contact. Similarly, the lignum nephriticum cups made from narra wood were part of the native industry of the Philippines before the arrival of the Spanish. The cups were manufactured in southern Luzon, particularly in the Naga region. The name of which was derived from the abundance of the narra trees, which was known as naga in the Bikol language (literally "serpent" or "dragon").

🔗 Novels 🔗 Novels/Science fiction 🔗 Science Fiction

Dune: The Butlerian Jihad is a 2002 science fiction novel by Brian Herbert and Kevin J. Anderson, set in the fictional Dune universe created by Frank Herbert. It is the first book in the Legends of Dune prequel trilogy, which takes place over 10,000 years before the events of Frank Herbert's celebrated 1965 novel Dune. The series chronicles the fictional Butlerian Jihad, a crusade by the last free humans in the universe against the thinking machines, a violent and dominating force led by the sentient computer Omnius.

Dune: The Butlerian Jihad rose to #7 on The New York Times Best Seller list in its second week of publication.

🔗 Computer Security 🔗 Computer Security/Computing

In computer security, a billion laughs attack is a type of denial-of-service (DoS) attack which is aimed at parsers of XML documents.

It is also referred to as an XML bomb or as an exponential entity expansion attack.

🔗 United States 🔗 Mathematics

Garfield's proof of the Pythagorean theorem is an original proof of the Pythagorean theorem discovered by James A. Garfield (November 19, 1831 – September 19, 1881), the 20th president of the United States. The proof appeared in print in the New-England Journal of Education (Vol. 3, No.14, April 1, 1876). At the time of the publication of the proof Garfield was a congressman from Ohio. He assumed the office of President on March 4, 1881, and served in that position until his death on September 19, 1881, having succumbed to injuries sustained when he was shot in an assassination in July. Garfield is thus far the only President of the United States to have contributed anything original to mathematics. The proof is nontrivial and, according to the historian of mathematics William Dunham, "Garfield's is really a very clever proof." The proof appears as the 231st proof in The Pythagorean Proposition, a compendium of 370 different proofs of the Pythagorean theorem.