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🔗 Philosophy 🔗 Philosophy/Logic

Trivialism (from Latin trivialis 'found everywhere') is the logical theory that all statements (also known as propositions) are true and that all contradictions of the form "p and not p" (e.g. the ball is red and not red) are true. In accordance with this, a trivialist is a person who believes everything is true.

In classical logic, trivialism is in direct violation of Aristotle's law of noncontradiction. In philosophy, trivialism is considered by some to be the complete opposite of skepticism. Paraconsistent logics may use "the law of non-triviality" to abstain from trivialism in logical practices that involve true contradictions.

Theoretical arguments and anecdotes have been offered for trivialism to contrast it with theories such as modal realism, dialetheism and paraconsistent logics.

🔗 Mathematics 🔗 Systems 🔗 Systems/Chaos theory

In mathematics, the Cantor function is an example of a function that is continuous, but not absolutely continuous. It is a notorious counterexample in analysis, because it challenges naive intuitions about continuity, derivative, and measure. Though it is continuous everywhere and has zero derivative almost everywhere, its value still goes from 0 to 1 as its argument reaches from 0 to 1. Thus, in one sense the function seems very much like a constant one which cannot grow, and in another, it does indeed monotonically grow, by construction.

It is also referred to as the Cantor ternary function, the Lebesgue function, Lebesgue's singular function, the Cantor–Vitali function, the Devil's staircase, the Cantor staircase function, and the Cantor–Lebesgue function. Georg Cantor (1884) introduced the Cantor function and mentioned that Scheeffer pointed out that it was a counterexample to an extension of the fundamental theorem of calculus claimed by Harnack. The Cantor function was discussed and popularized by Scheeffer (1884), Lebesgue (1904) and Vitali (1905).

🔗 Physics 🔗 Energy

A traveling-wave reactor (TWR) is a proposed type of nuclear fission reactor that can convert fertile material into usable fuel through nuclear transmutation, in tandem with the burnup of fissile material. TWRs differ from other kinds of fast-neutron and breeder reactors in their ability to use fuel efficiently without uranium enrichment or reprocessing, instead directly using depleted uranium, natural uranium, thorium, spent fuel removed from light water reactors, or some combination of these materials. The concept is still in the development stage and no TWRs have ever been built.

The name refers to the fact that fission remains confined to a boundary zone in the reactor core that slowly advances over time. TWRs could theoretically run self-sustained for decades without refueling or removing spent fuel.

🔗 Denmark 🔗 Automobiles 🔗 Toys 🔗 Lego

A Lego tire is a rubber tire manufactured by the toy building block company The Lego Group for use on vehicles within their Lego building sets. The tires are available in a range of sizes depending on the application. Lego first began manufacturing tires in 1962 and included them in what would become their most popular set at the time. Previously, the only tire options for Lego users were either purchasing complete car kits from Lego, or building their own tires out of existing Lego blocks. Lego produced 318 million tires in 2011, making them the world's largest tire manufacturer by number of units produced.

🔗 Computer science

TLA⁺ is a formal specification language developed by Leslie Lamport. It is used to design, model, document, and verify programs, especially concurrent systems and distributed systems. TLA⁺ has been described as exhaustively-testable pseudocode, and its use likened to drawing blueprints for software systems; TLA is an acronym for Temporal Logic of Actions.

For design and documentation, TLA⁺ fulfills the same purpose as informal technical specifications. However, TLA⁺ specifications are written in a formal language of logic and mathematics, and the precision of specifications written in this language is intended to uncover design flaws before system implementation is underway.

Since TLA⁺ specifications are written in a formal language, they are amenable to finite model checking. The model checker finds all possible system behaviours up to some number of execution steps, and examines them for violations of desired invariance properties such as safety and liveness. TLA⁺ specifications use basic set theory to define safety (bad things won't happen) and temporal logic to define liveness (good things eventually happen).

TLA⁺ is also used to write machine-checked proofs of correctness both for algorithms and mathematical theorems. The proofs are written in a declarative, hierarchical style independent of any single theorem prover backend. Both formal and informal structured mathematical proofs can be written in TLA⁺; the language is similar to LaTeX, and tools exist to translate TLA⁺ specifications to LaTeX documents.

TLA⁺ was introduced in 1999, following several decades of research into a verification method for concurrent systems. A toolchain has since developed, including an IDE and distributed model checker. The pseudocode-like language PlusCal was created in 2009; it transpiles to TLA⁺ and is useful for specifying sequential algorithms. TLA⁺² was announced in 2014, expanding language support for proof constructs. The current TLA⁺ reference is The TLA⁺ Hyperbook by Leslie Lamport.

🔗 Religion 🔗 Visual arts 🔗 Buddhism 🔗 Asia

The Greco-Buddhist art or Gandhara art is the artistic manifestation of Greco-Buddhism, a cultural syncretism between Ancient Greek art and Buddhism. It had mainly evolved in the ancient region of Gandhara, located in the northwestern fringe of the Indian subcontinent.

The series of interactions leading to Gandhara art occurred over time, beginning with Alexander the Great's brief incursion into the area, followed by the Mauryan Emperor Ashoka converting the region to Buddhism. Buddhism became the prominent religion in the Indo-Greek Kingdoms. However, Greco-Buddhist art truly flowered and spread under the Kushan Empire, when the first surviving devotional images of the Buddha were created during the 1st-3rd centuries CE. Gandhara art reached its zenith from the 3rd-5th century CE, when most surviving motifs and artworks were produced.

Gandhara art is characterized by Buddhist subject matter, sometimes adapting Greco-Roman elements, rendered in a style and forms that are heavily influenced by Greco-Roman art. It has the strong idealistic realism and sensuous description of Hellenistic art, and it is believed to have produced the first representations of Gautama Buddha in human form, ending the early period of aniconism in Buddhism.

The representation of the human form in large sculpture had a considerable influence, both to the south in the rest of India, and to the east, where the spread of Buddhism carried its influence as far as Japan.

🔗 Technology 🔗 Africa 🔗 Finance & Investment 🔗 Africa/Tanzania 🔗 Afghanistan 🔗 Africa/Kenya

M-Pesa (M for mobile, pesa is Swahili for money) is a mobile phone-based money transfer, financing and microfinancing service, launched in 2007 by Vodafone for Safaricom and Vodacom, the largest mobile network operators in Kenya and Tanzania. It has since expanded to Afghanistan, South Africa, India and in 2014 to Romania and in 2015 to Albania. M-Pesa allows users to deposit, withdraw, transfer money and pay for goods and services (Lipa na M-Pesa) easily with a mobile device.

The service allows users to deposit money into an account stored on their cell phones, to send balances using PIN-secured SMS text messages to other users, including sellers of goods and services, and to redeem deposits for regular money. Users are charged a small fee for sending and withdrawing money using the service.

M-Pesa is a branchless banking service; M-Pesa customers can deposit and withdraw money from a network of agents that includes airtime resellers and retail outlets acting as banking agents.

M-Pesa has spread quickly, and by 2010 had become the most successful mobile-phone-based financial service in the developing world. By 2012, a stock of about 17 million M-Pesa accounts had been registered in Kenya. By June 2016, a total of 7 million M-Pesa accounts have been opened in Tanzania by Vodacom. The service has been lauded for giving millions of people access to the formal financial system and for reducing crime in otherwise largely cash-based societies.

🔗 Mathematics 🔗 Archaeology

The Ishango bone is a bone tool and possible mathematical object, dated to the Upper Paleolithic era. It is a dark brown length of bone, the fibula of a baboon, with a sharp piece of quartz affixed to one end, perhaps for engraving. It is thought by some to be a tally stick, as it has a series of what has been interpreted as tally marks carved in three columns running the length of the tool, though it has also been suggested that the scratches might have been to create a better grip on the handle or for some other non-mathematical reason. Others argue that the marks on the object are non-random and that it was likely a kind of counting tool and used to perform simple mathematical procedures.

🔗 Occupational Safety and Health

A criticality accident occurred on December 30, 1958, at the Los Alamos National Laboratory in Los Alamos, New Mexico, in the United States. It is one of 60 known criticality events that have occurred outside the controlled conditions of a nuclear reactor or test, though it was the third such event that took place in 1958 after events on June 16 at the Y-12 Plant in Oak Ridge, Tennessee, and on October 15 at the Vinča Nuclear Institute in Vinča, Yugoslavia. The accident involved plutonium compounds dissolved in liquid chemical reagents; within 35 hours, it killed chemical operator Cecil Kelley by severe radiation poisoning.

🔗 Telecommunications 🔗 Radio 🔗 Electronics 🔗 Engineering

A plasma antenna is a type of radio antenna currently in development in which plasma is used instead of the metal elements of a traditional antenna. A plasma antenna can be used for both transmission and reception. Although plasma antennas have only become practical in recent years, the idea is not new; a patent for an antenna using the concept was granted to J. Hettinger in 1919.

Early practical examples of the technology used discharge tubes to contain the plasma and are referred to as ionized gas plasma antennas. Ionized gas plasma antennas can be turned on and off and are good for stealth and resistance to electronic warfare and cyber attacks. Ionized gas plasma antennas can be nested such that the higher frequency plasma antennas are placed inside lower frequency plasma antennas. Higher frequency ionized gas plasma antenna arrays can transmit and receive through lower frequency ionized gas plasma antenna arrays. This means that the ionized gas plasma antennas can be co-located and ionized gas plasma antenna arrays can be stacked. Ionized gas plasma antennas can eliminate or reduce co-site interference. Smart ionized gas plasma antennas use plasma physics to shape and steer the antenna beams without the need of phased arrays. Satellite signals can be steered or focused in the reflective or refractive modes using banks of plasma tubes making unique ionized gas satellite plasma antennas. The thermal noise of ionized gas plasma antennas is less than in the corresponding metal antennas at the higher frequencies. Solid state plasma antennas (also known as plasma silicon antennas) with steerable directional functionality that can be manufactured using standard silicon chip fabrication techniques are now also in development. Plasma silicon antennas are candidates for use in WiGig (the planned enhancement to Wi-Fi), and have other potential applications, for example in reducing the cost of vehicle-mounted radar collision avoidance systems.