To stay up to date you can also follow on Mastodon.

🔗 Music theory 🔗 Tunings, Temperaments, and Scales

In music theory, the circle of fifths (or circle of fourths) is the relationship among the 12 tones of the chromatic scale, their corresponding key signatures, and the associated major and minor keys. More specifically, it is a geometrical representation of relationships among the 12 pitch classes of the chromatic scale in pitch class space.

🔗 England 🔗 Linguistics 🔗 Linguistics/Applied Linguistics 🔗 Languages 🔗 Politics of the United Kingdom

Linguistic purism in English is the preference for using words of native origin rather than foreign-derived ones. "Native" can mean "Anglo-Saxon" or it can be widened to include all Germanic words. Linguistic purism in English primarily focuses on words of Latinate and Greek origin, due to their prominence in the English language and the belief that they may be difficult to understand. In its mildest form, it merely means using existing native words instead of foreign-derived ones (such as using begin instead of commence). In a less mild form, it also involves coining new words from Germanic roots (such as wordstock for vocabulary). In a more extreme form, it also involves reviving native words which are no longer widely used (such as ettle for intend). The resulting language is sometimes called Anglish (coined by the author and humorist Paul Jennings), or Roots English (referring to the idea that it is a "return to the roots" of English). The mild form is often advocated as part of Plain English, but the more extreme form has been and is still a fringe movement; the latter can also be undertaken as a form of constrained writing.

English linguistic purism is discussed by David Crystal in the Cambridge Encyclopedia of the English Language. The idea dates at least to the inkhorn term controversy of the 16th and 17th centuries. In the 19th century, writers such as Charles Dickens, Thomas Hardy and William Barnes advocated linguistic purism and tried to introduce words like birdlore for ornithology and bendsome for flexible. A notable supporter in the 20th century was George Orwell, who had a preference for plain Saxon words over complex Latin or Greek ones, and the idea continues to have advocates today.

🔗 Military history 🔗 Africa 🔗 United Kingdom 🔗 Military history/African military history 🔗 Africa/Tanzania 🔗 British Empire 🔗 Military history/European military history 🔗 Military history/British military history

The Anglo-Zanzibar War was a military conflict fought between the United Kingdom and the Zanzibar Sultanate on 27 August 1896. The conflict lasted between 38 and 45 minutes, marking it as the shortest recorded war in history. The immediate cause of the war was the death of the pro-British Sultan Hamad bin Thuwaini on 25 August 1896 and the subsequent succession of Sultan Khalid bin Barghash. The British authorities preferred Hamud bin Muhammed, who was more favourable to British interests, as sultan. In accordance with a treaty signed in 1886, a condition for accession to the sultanate was that the candidate obtain the permission of the British consul, and Khalid had not fulfilled this requirement. The British considered this a casus belli and sent an ultimatum to Khalid demanding that he order his forces to stand down and leave the palace. In response, Khalid called up his palace guard and barricaded himself inside the palace.

The ultimatum expired at 09:00 East Africa Time (EAT) on 27 August, by which time the British had gathered three cruisers, two gunboats, 150 marines and sailors, and 900 Zanzibaris in the harbour area. The Royal Navy contingent were under the command of Rear-Admiral Harry Rawson and the pro-Anglo Zanzibaris were commanded by Brigadier-General Lloyd Mathews of the Zanzibar army (who was also the First Minister of Zanzibar). Around 2,800 Zanzibaris defended the palace; most were recruited from the civilian population, but they also included the sultan's palace guard and several hundred of his servants and slaves. The defenders had several artillery pieces and machine guns, which were set in front of the palace sighted at the British ships. A bombardment, opened at 09:02, set the palace on fire and disabled the defending artillery. A small naval action took place, with the British sinking the Zanzibari royal yacht HHS Glasgow and two smaller vessels. Some shots were also fired ineffectually at the pro-British Zanzibari troops as they approached the palace. The flag at the palace was shot down and fire ceased at 09:40.

The sultan's forces sustained roughly 500 casualties, while only one British sailor was injured. Sultan Khalid received asylum in the German consulate before escaping to German East Africa (in the mainland part of present Tanzania). The British quickly placed Sultan Hamud in power at the head of a puppet government. The war marked the end of the Zanzibar Sultanate as a sovereign state and the start of a period of heavy British influence.

🔗 Role-playing games 🔗 Horror 🔗 Games

Mafia (also known as The Werewolves) is a social deduction game, created by Dimitry Davidoff in 1986. The game models a conflict between two groups: an informed minority (the mafiosi or the werewolves), and an uninformed majority (the villagers). At the start of the game, each player is secretly assigned a role affiliated with one of these teams. The game has two alternating phases: first, a night role, during which those with night killing powers may covertly kill other players, and second, a day role, in which surviving players debate the identities of players and vote to eliminate a suspect. The game continues until a faction achieves its win condition; for the village, this usually means eliminating the evil minority, while for the minority this usually means reaching numerical parity with the village and eliminating any rival evil groups.

🔗 Computer science

In computer science, Linda is a model of coordination and communication among several parallel processes operating upon objects stored in and retrieved from shared, virtual, associative memory. It was developed by Sudhir Ahuja at AT&T Bell Laboratories in collaboration with David Gelernter and Nicholas Carriero at Yale University in 1986.

🔗 Biography 🔗 Mathematics 🔗 Statistics 🔗 Systems 🔗 Biography/science and academia 🔗 Systems/Visualization 🔗 Graphic design

Edward Rolf Tufte (; born March 14, 1942) is an American statistician and professor emeritus of political science, statistics, and computer science at Yale University. He is noted for his writings on information design and as a pioneer in the field of data visualization.

🔗 Biography 🔗 California 🔗 California/San Francisco Bay Area 🔗 Finance & Investment 🔗 Business

Ronald Crawford Conway (born March 9, 1951) is an American angel investor and philanthropist, often described as one of Silicon Valley's "super angels". Conway is recognized as a strong networker.

🔗 Meteorology 🔗 Chemicals 🔗 Soil 🔗 Weather

Petrichor () is the earthy scent produced when rain falls on dry soil. The word is constructed from Greek petra (πέτρα), meaning "stone", and īchōr (ἰχώρ), the fluid that flows in the veins of the gods in Greek mythology.

🔗 Computing 🔗 Physics 🔗 Systems 🔗 Systems/Cybernetics

Bremermann's limit, named after Hans-Joachim Bremermann, is a limit on the maximum rate of computation that can be achieved in a self-contained system in the material universe. It is derived from Einstein's mass-energy equivalency and the Heisenberg uncertainty principle, and is c²/h ≈ 1.36 × 10⁵⁰ bits per second per kilogram. This value is important when designing cryptographic algorithms, as it can be used to determine the minimum size of encryption keys or hash values required to create an algorithm that could never be cracked by a brute-force search.

For example, a computer with the mass of the entire Earth operating at the Bremermann's limit could perform approximately 10⁷⁵ mathematical computations per second. If one assumes that a cryptographic key can be tested with only one operation, then a typical 128-bit key could be cracked in under 10⁻³⁶ seconds. However, a 256-bit key (which is already in use in some systems) would take about two minutes to crack. Using a 512-bit key would increase the cracking time to approaching 10⁷² years, without increasing the time for encryption by more than a constant factor (depending on the encryption algorithms used).

The limit has been further analysed in later literature as the maximum rate at which a system with energy spread ${\displaystyle \Delta E}$ can evolve into an orthogonal and hence distinguishable state to another, ${\displaystyle \Delta t={\frac {\pi \hbar }{2\Delta E}}.}$ In particular, Margolus and Levitin have shown that a quantum system with average energy E takes at least time ${\displaystyle \Delta t={\frac {\pi \hbar }{2E}}}$ to evolve into an orthogonal state. However, it has been shown that access to quantum memory in principle allows computational algorithms that require arbitrarily small amount of energy/time per one elementary computation step.

The angel problem is a question in combinatorial game theory proposed by John Horton Conway. The game is commonly referred to as the Angels and Devils game. The game is played by two players called the angel and the devil. It is played on an infinite chessboard (or equivalently the points of a 2D lattice). The angel has a power k (a natural number 1 or higher), specified before the game starts. The board starts empty with the angel at the origin. On each turn, the angel jumps to a different empty square which could be reached by at most k moves of a chess king, i.e. the distance from the starting square is at most k in the infinity norm. The devil, on its turn, may add a block on any single square not containing the angel. The angel may leap over blocked squares, but cannot land on them. The devil wins if the angel is unable to move. The angel wins by surviving indefinitely.

The angel problem is: can an angel with high enough power win?

There must exist a winning strategy for one of the players. If the devil can force a win then it can do so in a finite number of moves. If the devil cannot force a win then there is always an action that the angel can take to avoid losing and a winning strategy for it is always to pick such a move. More abstractly, the "pay-off set" (i.e., the set of all plays in which the angel wins) is a closed set (in the natural topology on the set of all plays), and it is known that such games are determined. Of course, for any infinite game, if player 2 doesn't have a winning strategy, player 1 can always pick a move that leads to a position where player 2 doesn't have a winning strategy, but in some games, simply playing forever doesn't confer a win to player 1, and that's why undetermined games may exist.

Conway offered a reward for a general solution to this problem ($100 for a winning strategy for an angel of sufficiently high power, and $1000 for a proof that the devil can win irrespective of the angel's power). Progress was made first in higher dimensions. In late 2006, the original problem was solved when independent proofs appeared, showing that an angel can win. Bowditch proved that a 4-angel (that is, an angel with power k=4) can win and Máthé and Kloster gave proofs that a 2-angel can win. At this stage, it has not been confirmed by Conway who is to be the recipient of his prize offer, or whether each published and subsequent solution will also earn $100 US.