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🔗 Biography 🔗 France 🔗 Physics 🔗 Skepticism 🔗 Physics/Biographies 🔗 Physics/Publications

The Bogdanov affair was an academic dispute regarding the legitimacy of a series of theoretical physics papers written by French twins Igor and Grichka Bogdanov (alternately spelt Bogdanoff). These papers were published in reputable scientific journals, and were alleged by their authors to culminate in a proposed theory for describing what occurred at and before the Big Bang.

The controversy began in 2002, with an allegation that the twins, celebrities in France for hosting science-themed TV shows, had obtained PhDs with nonsensical work. Rumours spread on Usenet newsgroups that their work was a deliberate hoax intended to target weaknesses in the peer review system that physics journals use to select papers for publication. While the Bogdanov brothers continued to defend the veracity of their work, the debate over whether or not it represented a contribution to physics spread from Usenet to many other Internet forums, eventually receiving coverage in the mainstream media. A Centre national de la recherche scientifique (CNRS) internal report later concluded that their theses had no scientific value.

The incident prompted criticism of the Bogdanovs' approach to science popularization, led to multiple lawsuits, and provoked reflection among physicists as to how and why the peer review system can fail.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Computer science 🔗 Cryptography 🔗 Cryptography/Computer science 🔗 Computing/Computer Security

Post-quantum cryptography (sometimes referred to as quantum-proof, quantum-safe or quantum-resistant) refers to cryptographic algorithms (usually public-key algorithms) that are thought to be secure against an attack by a quantum computer. As of 2019, this is not true for the most popular public-key algorithms, which can be efficiently broken by a sufficiently strong quantum computer. The problem with currently popular algorithms is that their security relies on one of three hard mathematical problems: the integer factorization problem, the discrete logarithm problem or the elliptic-curve discrete logarithm problem. All of these problems can be easily solved on a sufficiently powerful quantum computer running Shor's algorithm. Even though current, publicly known, experimental quantum computers lack processing power to break any real cryptographic algorithm, many cryptographers are designing new algorithms to prepare for a time when quantum computing becomes a threat. This work has gained greater attention from academics and industry through the PQCrypto conference series since 2006 and more recently by several workshops on Quantum Safe Cryptography hosted by the European Telecommunications Standards Institute (ETSI) and the Institute for Quantum Computing.

In contrast to the threat quantum computing poses to current public-key algorithms, most current symmetric cryptographic algorithms and hash functions are considered to be relatively secure against attacks by quantum computers. While the quantum Grover's algorithm does speed up attacks against symmetric ciphers, doubling the key size can effectively block these attacks. Thus post-quantum symmetric cryptography does not need to differ significantly from current symmetric cryptography. See section on symmetric-key approach below.

🔗 Environment 🔗 Meteorology 🔗 Astronomy 🔗 Middle Ages 🔗 Middle Ages/History 🔗 Geology 🔗 Glaciers 🔗 Solar System

The 774–775 carbon-14 spike is an observed increase of 1.2% in the concentration of carbon-14 isotope in tree rings dated to 774 or 775, which is about 20 times as high as the normal background rate of variation. It was discovered during a study of Japanese cedar trees, with the year of occurrence determined through dendrochronology. A surge in beryllium isotope ¹⁰
Be, detected in Antarctic ice cores, has also been associated with the 774–775 event. It is known as the Miyake event or the Charlemagne event and it produced the largest and most rapid rise in carbon-14 ever recorded.

The event appears to have been global, with the same carbon-14 signal found in tree rings from Germany, Russia, the United States, Finland and New Zealand.

The signal exhibits a sharp increase of around 1.2% followed by a slow decline (see Figure 1), which is typical for an instant production of carbon-14 in the atmosphere, indicating that the event was short in duration. The globally averaged production of carbon-14 for this event is calculated as Q = 1.3×10⁸ ± 0.2×10⁸ atoms/cm².

🔗 Greece 🔗 Songs

"Misirlou" (Greek: Μισιρλού < Turkish: Mısırlı 'Egyptian' < Arabic: مصر Miṣr 'Egypt') is a folk song from the Eastern Mediterranean region. The original author of the song is not known, but Arabic, Greek, and Jewish musicians were playing it by the 1920s. The earliest known recording of the song is a 1927 Greek rebetiko/tsifteteli composition. There are also Arabic belly dancing, Albanian, Armenian, Serbian, Persian, Indian and Turkish versions of the song. This song was popular from the 1920s onwards in the Arab American, Armenian American and Greek American communities who settled in the United States.

The song was a hit in 1946 for Jan August, an American pianist and xylophonist nicknamed "the one-man piano duet". It gained worldwide popularity through Dick Dale's 1962 American surf rock version, originally titled "Miserlou", which popularized the song in Western popular culture; Dale's version was influenced by an earlier Arabic folk version played with an oud. Various versions have since been recorded, mostly based on Dale's version, including other surf and rock versions by bands such as the Beach Boys, the Ventures, and the Trashmen, as well as international orchestral easy listening (exotica) versions by musicians such as Martin Denny and Arthur Lyman. Dale's surf rock version was heard in the 1994 film Pulp Fiction.

🔗 Chess

Kasparov versus the World was a game of chess played in 1999 over the Internet. Conducting the white pieces, Garry Kasparov faced the rest of the world in consultation, with the World Team moves to be decided by plurality vote. Over 50,000 people from more than 75 countries participated in the game.

The host and promoter of the match was the MSN Gaming Zone, with sponsorship from First USA bank. After 62 moves played over four months, Kasparov won the game. Contrary to expectations, the game produced a mixture of deep tactical and strategic ideas, and although Kasparov won, he admitted that he had never expended as much effort on any other game in his life. He later said, "It is the greatest game in the history of chess. The sheer number of ideas, the complexity, and the contribution it has made to chess make it the most important game ever played."

🔗 Iran 🔗 London 🔗 British Museum 🔗 Visual arts 🔗 Sculpture

The Oxus treasure (Persian: گنجینه آمودریا) is a collection of about 180 surviving pieces of metalwork in gold and silver, the majority rather small, plus perhaps about 200 coins, from the Achaemenid Persian period which were found by the Oxus river about 1877-1880. The exact place and date of the find remain unclear, and it is likely that many other pieces from the hoard were melted down for bullion; early reports suggest there were originally some 1500 coins, and mention types of metalwork that are not among the surviving pieces. The metalwork is believed to date from the sixth to fourth centuries BC, but the coins show a greater range, with some of those believed to belong to the treasure coming from around 200 BC. The most likely origin for the treasure is that it belonged to a temple, where votive offerings were deposited over a long period. How it came to be deposited is unknown.

As a group, the treasure is the most important survival of what was once an enormous production of Achaemenid work in precious metal. It displays a very wide range of quality of execution, with the many gold votive plaques mostly crudely executed, some perhaps by the donors themselves, while other objects are of superb quality, presumably that expected by the court.

The British Museum now has nearly all the surviving metalwork, with one of the pair of griffin-headed bracelets on loan from the Victoria and Albert Museum, and displays them in Room 52. The group arrived at the museum by different routes, with many items bequeathed to the nation by Augustus Wollaston Franks. The coins are more widely dispersed, and more difficult to firmly connect with the treasure. A group believed to come from it is in the Hermitage Museum in Saint Petersburg, and other collections have examples.

🔗 International relations 🔗 Ancient Egypt 🔗 Politics 🔗 Sociology 🔗 Asia

A hydraulic empire, also known as a hydraulic despotism, hydraulic society, hydraulic civilization, or water monopoly empire, is a social or government structure which maintains power and control through exclusive control over access to water. It arises through the need for flood control and irrigation, which requires central coordination and a specialized bureaucracy.

Often associated with these terms and concepts is the notion of a water dynasty. This body is a political structure which is commonly characterized by a system of hierarchy and control often based on class or caste. Power, both over resources (food, water, energy) and a means of enforcement such as the military, is vital for the maintenance of control.

🔗 Technology

A moving walkway, also known as an autowalk, moving sidewalk, moving pavement, people-mover, travolator, or travelator, is a slow-moving conveyor mechanism that transports people across a horizontal or inclined plane over a short to medium distance. Moving walkways can be used by standing or walking on them. They are often installed in pairs, one for each direction.

🔗 Books

Amusing Ourselves to Death: Public Discourse in the Age of Show Business (1985) is a book by educator Neil Postman. The book's origins lay in a talk Postman gave to the Frankfurt Book Fair in 1984. He was participating in a panel on George Orwell's Nineteen Eighty-Four and the contemporary world. In the introduction to his book, Postman said that the contemporary world was better reflected by Aldous Huxley's Brave New World, whose public was oppressed by their addiction to amusement, rather than by Orwell's work, where they were oppressed by state control.

Postman's book has been translated into eight languages and sold some 200,000 copies worldwide. In 2005, Postman's son Andrew reissued the book in a 20th anniversary edition.

🔗 Electronics

In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a sampler, which converts a continuous function or signal into a discrete sequence. For a given sampling rate (samples per second), the Nyquist frequency (cycles per second) is the frequency whose cycle-length (or period) is twice the interval between samples, thus 0.5 cycle/sample. For example, audio CDs have a sampling rate of 44100 samples/second. At 0.5 cycle/sample, the corresponding Nyquist frequency is 22050 cycles/second (Hz). Conversely, the Nyquist rate for sampling a 22050 Hz signal is 44100 samples/second.

When the highest frequency (bandwidth) of a signal is less than the Nyquist frequency of the sampler, the resulting discrete-time sequence is said to be free of the distortion known as aliasing, and the corresponding sample rate is said to be above the Nyquist rate for that particular signal.

In a typical application of sampling, one first chooses the highest frequency to be preserved and recreated, based on the expected content (voice, music, etc.) and desired fidelity. Then one inserts an anti-aliasing filter ahead of the sampler. Its job is to attenuate the frequencies above that limit. Finally, based on the characteristics of the filter, one chooses a sample rate (and corresponding Nyquist frequency) that will provide an acceptably small amount of aliasing. In applications where the sample rate is pre-determined (such as the CD rate), the filter is chosen based on the Nyquist frequency, rather than vice versa.