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🔗 Apple Inc. 🔗 Video games 🔗 Chess

Battle Chess is a computer game version of chess in which the chess pieces come to life and battle one another when capturing. It was originally developed and released by Interplay Entertainment for the Amiga in 1988 and subsequently on many other systems, including 3DO Interactive Multiplayer, Acorn Archimedes, Amiga CD32, Amiga CDTV, Apple IIGS, Apple IIe, Atari ST, Commodore 64, MS-DOS, FM Towns, NES, Mac OS, NEC PC-9801, X68000 and Microsoft Windows. In 1991, Battle Chess Enhanced was released by Interplay for the PC, featuring improved VGA graphics and a symphonic musical score that played from the CD-ROM.

Battle Chess was critically acclaimed and commercially successful, resulting in two official follow-ups as well as several inspired games. Its remake, Battle Chess: Game of Kings, was released on Steam on December 11, 2015.

🔗 Mathematics

Reverse mathematics is a program in mathematical logic that seeks to determine which axioms are required to prove theorems of mathematics. Its defining method can briefly be described as "going backwards from the theorems to the axioms", in contrast to the ordinary mathematical practice of deriving theorems from axioms. It can be conceptualized as sculpting out necessary conditions from sufficient ones.

The reverse mathematics program was foreshadowed by results in set theory such as the classical theorem that the axiom of choice and Zorn's lemma are equivalent over ZF set theory. The goal of reverse mathematics, however, is to study possible axioms of ordinary theorems of mathematics rather than possible axioms for set theory.

Reverse mathematics is usually carried out using subsystems of second-order arithmetic, where many of its definitions and methods are inspired by previous work in constructive analysis and proof theory. The use of second-order arithmetic also allows many techniques from recursion theory to be employed; many results in reverse mathematics have corresponding results in computable analysis. Recently, higher-order reverse mathematics has been introduced, in which the focus is on subsystems of higher-order arithmetic, and the associated richer language.

The program was founded by Harvey Friedman (1975, 1976) and brought forward by Steve Simpson. A standard reference for the subject is (Simpson 2009), while an introduction for non-specialists is (Stillwell 2018). An introduction to higher-order reverse mathematics, and also the founding paper, is (Kohlenbach (2005)).

🔗 Mathematics 🔗 Statistics

In statistical hypothesis testing, a type I error is the rejection of a true null hypothesis (also known as a "false positive" finding or conclusion), while a type II error is the non-rejection of a false null hypothesis (also known as a "false negative" finding or conclusion). Much of statistical theory revolves around the minimization of one or both of these errors, though the complete elimination of either is a statistical impossibility for non-deterministic algorithms. By selecting a low threshold (cut-off) value and modifying the alpha (p) level, the quality of the hypothesis test can be increased. The knowledge of Type I errors and Type II errors is widely used in medical science, biometrics and computer science.

🔗 United States 🔗 Oregon 🔗 Canada 🔗 Canada/British Columbia 🔗 Indigenous peoples of North America 🔗 Mythology 🔗 United States/Washington

"Thunderbird and Whale" is an indigenous myth belonging to the mythological traditions of a number of tribes from the Pacific Northwest.

🔗 United States 🔗 Languages 🔗 United States/Mississippi

"Thank God for Mississippi" is an adage used in the United States, particularly in the South, that is generally used when discussing rankings of U.S. states. Since the U.S. state of Mississippi commonly ranks at or near the bottom of such rankings, residents of other states also ranking near the bottom may say, "Thank God for Mississippi," since the presence of that state in 50th place spares them the shame of being ranked last.

Examples include rankings of educational achievement, business opportunities, political progressiveness, obesity rates, overall health, the poverty rate, life expectancy, or other objective criteria of the quality of life or government in the 50 states. The phrase is in use even among state government officials and journalists, though occasionally with a slight twist.

Mississippi's poor reputation is such a common trope in American culture that when Mississippi does indeed rank well in something, the phrase "Thank God for Mississippi" may get brought up just to discuss how it does not apply in the given circumstance. The saying comes from Mississippi's poor ranking as compared to the other 49 states, not from a global perspective.

🔗 United States 🔗 Finance & Investment 🔗 Economics 🔗 Business

The Panic of 1907 – also known as the 1907 Bankers' Panic or Knickerbocker Crisis – was a financial crisis that took place in the United States over a three-week period starting in mid-October, when the New York Stock Exchange fell almost 50% from its peak the previous year. Panic occurred, as this was during a time of economic recession, and there were numerous runs on banks and trust companies. The 1907 panic eventually spread throughout the nation when many state and local banks and businesses entered bankruptcy. Primary causes of the run included a retraction of market liquidity by a number of New York City banks and a loss of confidence among depositors, exacerbated by unregulated side bets at bucket shops.

The panic was triggered by the failed attempt in October 1907 to corner the market on stock of the United Copper Company. When this bid failed, banks that had lent money to the cornering scheme suffered runs that later spread to affiliated banks and trusts, leading a week later to the downfall of the Knickerbocker Trust Company—New York City's third-largest trust. The collapse of the Knickerbocker spread fear throughout the city's trusts as regional banks withdrew reserves from New York City banks. Panic extended across the nation as vast numbers of people withdrew deposits from their regional banks. It is the 9th largest decline in U.S. stock market history.

The panic might have deepened if not for the intervention of financier J. P. Morgan, who pledged large sums of his own money, and convinced other New York bankers to do the same, to shore up the banking system. This highlighted the impotence of the nation's Independent Treasury system, which managed the nation's money supply yet was unable to inject liquidity back into the market. By November, the financial contagion had largely ended, only to be replaced by a further crisis. This was due to the heavy borrowing of a large brokerage firm that used the stock of Tennessee Coal, Iron and Railroad Company (TC&I) as collateral. Collapse of TC&I's stock price was averted by an emergency takeover by Morgan's U.S. Steel Corporation—a move approved by anti-monopolist president Theodore Roosevelt. The following year, Senator Nelson W. Aldrich, a leading Republican, established and chaired a commission to investigate the crisis and propose future solutions, leading to the creation of the Federal Reserve System.

🔗 Computing 🔗 Bulgaria

Pravetz (Правец in the original Cyrillic, series 8 and series 16) were Bulgarian computers, manufactured mainly in the town of Pravetz. Some components and software were produced in Stara Zagora, Plovdiv, and other Bulgarian cities.

🔗 Computing

A long-running debate in computer science known as the Protocol Wars occurred from the 1970s to the 1990s when engineers, organizations and nations became polarized over the issue of which communication protocol would result in the best and most robust computer networks. This culminated in the Internet–OSI Standards War in the late 1980s and early 1990s, which was ultimately "won" by the Internet protocol suite ("TCP/IP") by the mid-1990s and has since resulted in most other protocols disappearing.

The pioneers of packet switching technology built computer networks to research data communications in the early 1970s. As public data networks emerged in the mid to late 1970s, the debate about interface standards was described as a "battle for access standards". An international collaboration between several national postal, telegraph and telephone ("PTT") providers and commercial operators developed the X.25 standard in 1976, which was adopted on public networks providing global coverage. Several proprietary standards also emerged, most notably IBM's Systems Network Architecture.

The United States Department of Defense developed and tested TCP/IP during the 1970s in collaboration with universities and researchers in the United States, United Kingdom and France. IPv4 was released in 1981 and the DoD made it standard for all military computer networking. By 1984, an international reference model known as the OSI model had been agreed on, with which TCP/IP was not compatible. Many governments in Europe – particularly France, West Germany, the United Kingdom and the European Economic Community – and also the United States Department of Commerce mandated compliance with the OSI model and the US Department of Defense planned to transition away from TCP/IP to OSI.

Meanwhile, the development of a complete Internet protocol suite by 1989, and partnerships with the telecommunication and computer industry to incorporate TCP/IP software into various operating systems laid the foundation for the widespread adoption of TCP/IP as a comprehensive protocol suite. While OSI developed its networking standards in the late 1980s, TCP/IP came into widespread use on multi-vendor networks for internetworking and as the core component of the emerging Internet.

🔗 Biography 🔗 Mathematics 🔗 Military history 🔗 Military history/Military biography 🔗 Cryptography 🔗 Cryptography/Computer science 🔗 Military history/European military history 🔗 Military history/British military history

William Thomas "Bill" Tutte OC FRS FRSC (; 14 May 1917 – 2 May 2002) was a British codebreaker and mathematician. During the Second World War, he made a brilliant and fundamental advance in cryptanalysis of the Lorenz cipher, a major Nazi German cipher system which was used for top-secret communications within the Wehrmacht High Command. The high-level, strategic nature of the intelligence obtained from Tutte's crucial breakthrough, in the bulk decrypting of Lorenz-enciphered messages specifically, contributed greatly, and perhaps even decisively, to the defeat of Nazi Germany. He also had a number of significant mathematical accomplishments, including foundation work in the fields of graph theory and matroid theory.

Tutte's research in the field of graph theory proved to be of remarkable importance. At a time when graph theory was still a primitive subject, Tutte commenced the study of matroids and developed them into a theory by expanding from the work that Hassler Whitney had first developed around the mid 1930s. Even though Tutte's contributions to graph theory have been influential to modern graph theory and many of his theorems have been used to keep making advances in the field, most of his terminology was not in agreement with their conventional usage and thus his terminology is not used by graph theorists today. "Tutte advanced graph theory from a subject with one text (D. Kőnig's) toward its present extremely active state."