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🔗 Computing

Constraint logic programming is a form of constraint programming, in which logic programming is extended to include concepts from constraint satisfaction. A constraint logic program is a logic program that contains constraints in the body of clauses. An example of a clause including a constraint is A(X,Y) :- X+Y>0, B(X), C(Y). In this clause, X+Y>0 is a constraint; A(X,Y), B(X), and C(Y) are literals as in regular logic programming. This clause states one condition under which the statement A(X,Y) holds: X+Y is greater than zero and both B(X) and C(Y) are true.

As in regular logic programming, programs are queried about the provability of a goal, which may contain constraints in addition to literals. A proof for a goal is composed of clauses whose bodies are satisfiable constraints and literals that can in turn be proved using other clauses. Execution is performed by an interpreter, which starts from the goal and recursively scans the clauses trying to prove the goal. Constraints encountered during this scan are placed in a set called constraint store. If this set is found out to be unsatisfiable, the interpreter backtracks, trying to use other clauses for proving the goal. In practice, satisfiability of the constraint store may be checked using an incomplete algorithm, which does not always detect inconsistency.

🔗 Physics 🔗 Energy

Thorium-based nuclear power generation is fueled primarily by the nuclear fission of the isotope uranium-233 produced from the fertile element thorium. According to proponents, a thorium fuel cycle offers several potential advantages over a uranium fuel cycle—including much greater abundance of thorium found on Earth, superior physical and nuclear fuel properties, and reduced nuclear waste production. However, development of thorium power has significant start-up costs. Proponents also cite the low weaponization potential as an advantage of thorium due to how difficult it is to weaponize the specific uranium-233/232 and plutonium-238 isotopes produced by thorium reactors, while critics say that development of breeder reactors in general (including thorium reactors, which are breeders by nature) increases proliferation concerns. As of 2020, there are no operational thorium reactors in the world.

A nuclear reactor consumes certain specific fissile isotopes to produce energy. Currently, the most common types of nuclear reactor fuel are:

• Uranium-235, purified (i.e. "enriched") by reducing the amount of uranium-238 in natural mined uranium. Most nuclear power has been generated using low-enriched uranium (LEU), whereas high-enriched uranium (HEU) is necessary for weapons.
• Plutonium-239, transmuted from uranium-238 obtained from natural mined uranium.

Some believe thorium is key to developing a new generation of cleaner, safer nuclear power. According to a 2011 opinion piece by a group of scientists at the Georgia Institute of Technology, considering its overall potential, thorium-based power "can mean a 1000+ year solution or a quality low-carbon bridge to truly sustainable energy sources solving a huge portion of mankind’s negative environmental impact."

After studying the feasibility of using thorium, nuclear scientists Ralph W. Moir and Edward Teller suggested that thorium nuclear research should be restarted after a three-decade shutdown and that a small prototype plant should be built.

🔗 Mammals

Tuffi (born 1946, India – died 1989, Paris, France) was a female Asian elephant that became famous in West Germany during 1950 when she accidentally fell from the Wuppertal Schwebebahn into the River Wupper underneath.

On 21 July 1950, the circus director Franz Althoff (de) had Tuffi, then four years old, traveled on the suspended monorail in Wuppertal, as a publicity stunt. The elephant trumpeted wildly and ran through the carriage, broke through a window and fell 12 metres (39 ft) down into the River Wupper, suffering only minor injuries. A panic had broken out in the carriage and some passengers were injured. Althoff helped the elephant out of the water. Both the circus director and the official who had allowed the ride were fined. Tuffi was sold to Cirque Alexis Gruss (fr) in 1968; she died there in 1989.

No photograph of the incident is known; a widely circulated postcard picture is a montage. A building near the location of the incident, between the stations Alter Markt and Adlerbrücke, features a painting of Tuffi. A local milk-factory has chosen the name as a brand.

The Wuppertal tourist information keeps an assortment of Tuffi-related souvenirs, local websites show original pictures.

In 1970 Marguerita Eckel and Ernst-Andreas Ziegler published a children's picture book about the incident titled Tuffi und die Schwebebahn (“Tuffi and the suspension railway”).

🔗 Lists

The following article lists the indebted companies in the world by total corporate debt according estimates by the British-Australian investment firm Janus Henderson. In 2019, the total debt of the 900 most indebted companies was $8,325 billion. The most indebted companies were in the oil and gas, utilities, telecommunication and automotive industries. The word's most indebted company in 2019 was Volkswagen AG.

🔗 Canada 🔗 Politics 🔗 Canada/Quebec 🔗 Canada/Political parties and politicians in Canada

The Quebec sovereignty movement (French: Mouvement souverainiste du Québec) is a political movement whose objective is to achieve the sovereignty of Quebec, a province of Canada since 1867, including in all matters related to any provision of Quebec's public order that is applicable on its territory. Sovereignists suggest that the people of Quebec make use of their right to self-determination – a principle that includes the possibility of choosing between integration with a third state, political association with another state or independence – so that Quebecois, collectively and by democratic means, give themselves a sovereign state with its own independent constitution.

Quebec sovereignists believe that with such a sovereign state, the Quebec nation will be better equipped to promote its own economic, social, ecological and cultural development. Quebec's sovereignist movement is based on Quebec nationalism.

🔗 Archaeology 🔗 Cities 🔗 Dacia

This is a list of present-day cities by the time period over which they have been continuously inhabited as a city. The age claims listed are generally disputed. Differences in opinion can result from different definitions of "city" as well as "continuous habitation" and historical evidence is often disputed. Caveats (and sources) to the validity of each claim are discussed in the "Notes" column.

🔗 Computer science 🔗 Philosophy 🔗 Psychology 🔗 Philosophy/Social and political philosophy 🔗 Philosophy/Philosophy of science 🔗 Philosophy/Contemporary philosophy 🔗 Philosophy/Philosophy of mind 🔗 Sociology 🔗 Cultural Evolution

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.

🔗 United States 🔗 Computing 🔗 Marketing & Advertising 🔗 Microsoft 🔗 United States/American television

“Where do you want to go today?” was the title of Microsoft’s second global image advertising campaign. The broadcast, print and outdoor advertising campaign was launched in November 1994 through the advertising agency Wieden+Kennedy. The campaign had Microsoft spending $100 million through July 1995, of which $25 million would be spent during the holiday shopping season ending in December 1994.

Tony Kaye directed a series of television ads filmed in Hong Kong, Prague and New York City that showed a broad range of people using their PCs. The television ads were first broadcast in Australia on November 13, the following day in both the United States and Canada, with Britain, France and Germany seeing the spots in subsequent days. An eight-page print ad described the personal computer as “an open opportunity for everybody” that “[facilitates] the flow of information so that good ideas—wherever they come from—can be shared”, and was placed in mass-market magazines including National Geographic, Newsweek, People, Rolling Stone and Sports Illustrated.

The New York Times described the campaign as taking “a winsome, humanistic approach to demystifying technology”. However, the Times reported in August 1995 that the response to Microsoft’s campaign in the advertising trade press had been “lukewarm” and quoted Brad Johnson of Advertising Age as stating that “Microsoft is on version 1.0 in advertising. Microsoft is not standing still. It will improve its advertising.” Microsoft’s Steve Ballmer, then the firm’s executive vice president, acknowledged that the response to the campaign had been “chilly”.

In June 1999, Microsoft announced that it would be ending its nearly five-year-long relationship with Wieden+Kennedy, shifting $100 million (~$166 million in 2022) in billings to McCann Erickson Worldwide Advertising in a split that was described by The New York Times as mutual. Dan Wieden, president and chief creative officer of the advertising agency, characterized the relationship with Microsoft as “intense” and said that it had “run its course”.

🔗 Mathematics

In mathematics, tetration (or hyper-4) is an operation based on iterated, or repeated, exponentiation. It is the next hyperoperation after exponentiation, but before pentation. The word was coined by Reuben Louis Goodstein from tetra- (four) and iteration.

Under the definition as repeated exponentiation, the notation ${\displaystyle {^{n}a}}$ means ${\displaystyle {a^{a^{\cdot ^{\cdot ^{a}}}}}}$, where n copies of a are iterated via exponentiation, right-to-left, I.e. the application of exponentiation ${\displaystyle n-1}$ times. n is called the "height" of the function, while a is called the "base," analogous to exponentiation. It would be read as "the nth tetration of a".

Tetration is also defined recursively as

${\displaystyle {^{n}a}:={\begin{cases}1&{\text{if }}n=0\\a^{\left(^{(n-1)}a\right)}&{\text{if }}n>0\end{cases}}}$,

allowing for attempts to extend tetration to non-natural numbers such as real and complex numbers.

The two inverses of tetration are called the super-root and the super-logarithm, analogous to the nth root and the logarithmic functions. None of the three functions are elementary.

Tetration is used for the notation of very large numbers.