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๐Ÿ”— Literature-Based Discovery

๐Ÿ”— Science

Literature-based discovery is a form of knowledge extraction and automated hypothesis generation that uses papers and other academic publications (the "literature") to find new relationships between existing knowledge (the "discovery"). The technique was pioneered by Don R. Swanson in the 1980s and has since seen widespread use.

Literature-based discovery does not generate new knowledge through laboratory experiments, as is customary for empirical sciences. Instead it seeks to connect existing knowledge from empirical results by bringing to light relationships that are implicated and "neglected". It is marked by empiricism and rationalism in concert or consilience.

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๐Ÿ”— Chandrasekhar Limit

๐Ÿ”— Physics ๐Ÿ”— Astronomy

The Chandrasekhar limit () is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about 1.4ย Mโ˜‰ (2.765ร—1030ย kg).

White dwarfs resist gravitational collapse primarily through electron degeneracy pressure (compare main sequence stars, which resist collapse through thermal pressure). The Chandrasekhar limit is the mass above which electron degeneracy pressure in the star's core is insufficient to balance the star's own gravitational self-attraction. Consequently, a white dwarf with a mass greater than the limit is subject to further gravitational collapse, evolving into a different type of stellar remnant, such as a neutron star or black hole. Those with masses up to the limit remain stable as white dwarfs.

The limit was named after Subrahmanyan Chandrasekhar, an Indian astrophysicist who improved upon the accuracy of the calculation in 1930, at the age of 20, in India by calculating the limit for a polytrope model of a star in hydrostatic equilibrium, and comparing his limit to the earlier limit found by E. C. Stoner for a uniform density star. Importantly, the existence of a limit, based on the conceptual breakthrough of combining relativity with Fermi degeneracy, was indeed first established in separate papers published by Wilhelm Anderson and E. C. Stoner in 1929. The limit was initially ignored by the community of scientists because such a limit would logically require the existence of black holes, which were considered a scientific impossibility at the time. The fact that the roles of Stoner and Anderson are often forgotten in the astronomy community has been noted.

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๐Ÿ”— Homomorphic encryption

๐Ÿ”— Computing ๐Ÿ”— Mathematics ๐Ÿ”— Computing/Software ๐Ÿ”— Cryptography ๐Ÿ”— Cryptography/Computer science ๐Ÿ”— Computing/Computer Security

Homomorphic encryption is a form of encryption that allows computation on ciphertexts, generating an encrypted result which, when decrypted, matches the result of the operations as if they had been performed on the plaintext.

Homomorphic encryption can be used for privacy-preserving outsourced storage and computation. This allows data to be encrypted and out-sourced to commercial cloud environments for processing, all while encrypted. In highly regulated industries, such as health care, homomorphic encryption can be used to enable new services by removing privacy barriers inhibiting data sharing. For example, predictive analytics in health care can be hard to apply due to medical data privacy concerns, but if the predictive analytics service provider can operate on encrypted data instead, these privacy concerns are diminished.

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๐Ÿ”— Vickreyโ€“Clarkeโ€“Groves Auction

๐Ÿ”— Economics ๐Ÿ”— Game theory

A Vickreyโ€“Clarkeโ€“Groves (VCG) auction is a type of sealed-bid auction of multiple items. Bidders submit bids that report their valuations for the items, without knowing the bids of the other bidders. The auction system assigns the items in a socially optimal manner: it charges each individual the harm they cause to other bidders. It gives bidders an incentive to bid their true valuations, by ensuring that the optimal strategy for each bidder is to bid their true valuations of the items. It is a generalization of a Vickrey auction for multiple items.

The auction is named after William Vickrey, Edward H. Clarke, and Theodore Groves for their papers that successively generalized the idea.

The VCG auction is a specific use of the more general VCG Mechanism. While the VCG auction tries to make a socially optimal allocation of items, VCG mechanisms allow for the selection of a socially optimal outcome out of a set of possible outcomes. If collusion is likely to occur among bidders, the VCG outperforms the generalized second-price auction for both revenues produced for the seller and allocative efficiency.

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๐Ÿ”— Kriegspiel

๐Ÿ”— Chess

Kriegspiel is a chess variant invented by Henry Michael Temple in 1899 and based upon the original Kriegsspiel (German for war game) developed by Georg von Reiswitz in 1812. In this game each player can see their own pieces, but not those of their opponent. For this reason, it is necessary to have a third person (or computer) act as an umpire, with full information about the progress of the game. When it is a player's turn he or she will attempt a move, which the umpire will declare to be 'legal' or 'illegal'. If the move is illegal, the player tries again; if it is legal, that move stands. Each player is given information about checks and captures. They may also ask the umpire if there are any legal captures with a pawn. Since the position of the opponent's pieces is unknown, Kriegspiel is a game of imperfect information. The game is sometimes referred to as blind chess.

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๐Ÿ”— Battle for Castle Itter

๐Ÿ”— Military history ๐Ÿ”— Military history/North American military history ๐Ÿ”— Military history/United States military history ๐Ÿ”— Military history/World War II ๐Ÿ”— Austria ๐Ÿ”— Military history/German military history ๐Ÿ”— Military history/French military history ๐Ÿ”— Military history/European military history

The Battle for Castle Itter was fought in the Austrian North Tyrol village of Itter on 5 May 1945, in the last days of the European Theater of World War II.

Troops of the 23rd Tank Battalion of the 12th Armored Division of the US XXI Corps led by Captain John C. "Jack" Lee, Jr., a number of Wehrmacht soldiers led by Major Josef "Sepp" Gangl, SS-Hauptsturmfรผhrer Kurt-Siegfried Schrader, and recently freed French prisoners of war defended Castle Itter against an attacking force from the 17th SS Panzergrenadier Division until relief from the American 142nd Infantry Regiment of the 36th Division of XXI Corps arrived.

The French prisoners included former prime ministers, generals and a tennis star. It is the only known time during the war in which Americans and Germans fought side-by-side. Popular accounts of the battle have called it the strangest battle of World War II.

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๐Ÿ”— Great Ape Personhood

๐Ÿ”— Philosophy ๐Ÿ”— Philosophy/Ethics ๐Ÿ”— Primates ๐Ÿ”— Animal rights

Great ape personhood is a movement to extend personhood and some legal protections to the non-human members of the Hominidae or great ape family: chimpanzees, bonobos, gorillas, and orangutans.

Advocates include primatologists Jane Goodall and Dawn Prince-Hughes, evolutionary biologist Richard Dawkins, philosophers Paola Cavalieri and Peter Singer, and legal scholar Steven Wise.

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๐Ÿ”— Engines of Creation, by K. Eric Drexler (1986)

๐Ÿ”— Books ๐Ÿ”— Transhumanism ๐Ÿ”— Alternative Views

Engines of Creation: The Coming Era of Nanotechnology is a 1986 molecular nanotechnology book written by K. Eric Drexler with a foreword by Marvin Minsky. An updated version was released in 2007. The book has been translated into Japanese, French, Spanish, Italian, Russian, and Chinese.

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๐Ÿ”— Gรถdel's ontological proof

๐Ÿ”— Philosophy ๐Ÿ”— Philosophy/Logic ๐Ÿ”— Philosophy/Contemporary philosophy ๐Ÿ”— Philosophy/Philosophy of religion ๐Ÿ”— Christianity ๐Ÿ”— Christianity/theology ๐Ÿ”— Military history/European military history

Gรถdel's ontological proof is a formal argument by the mathematician Kurt Gรถdel (1906โ€“1978) for the existence of God. The argument is in a line of development that goes back to Anselm of Canterbury (1033โ€“1109). St. Anselm's ontological argument, in its most succinct form, is as follows: "God, by definition, is that for which no greater can be conceived. God exists in the understanding. If God exists in the understanding, we could imagine Him to be greater by existing in reality. Therefore, God must exist." A more elaborate version was given by Gottfried Leibniz (1646โ€“1716); this is the version that Gรถdel studied and attempted to clarify with his ontological argument.

Gรถdel left a fourteen-point outline of his philosophical beliefs in his papers. Points relevant to the ontological proof include

4. There are other worlds and rational beings of a different and higher kind.
5. The world in which we live is not the only one in which we shall live or have lived.
13. There is a scientific (exact) philosophy and theology, which deals with concepts of the highest abstractness; and this is also most highly fruitful for science.
14. Religions are, for the most part, badโ€”but religion is not.

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๐Ÿ”— Surprisingly popular

๐Ÿ”— Psychology

The surprisingly popular answer is a wisdom of the crowd technique that taps into the expert minority opinion within a crowd. For a given question, a group is asked both "What do you think the right answer is?" and "What do you think the popular answer will be?" The answer that maximizes the average difference between the "right" answer and the "popular" answer is the "surprisingly popular" answer.

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