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🔗 Spaceflight

HAL/S (High-order Assembly Language/Shuttle) is a real-time aerospace programming language compiler and cross-compiler for avionics applications used by NASA and associated agencies (JPL, etc.). It has been used in many U.S. space projects since 1973 and its most significant use was in the Space Shuttle program (approximately 85% of the Shuttle software is coded in HAL/S). It was designed by Intermetrics in 1972 for NASA and delivered in 1973. HAL/S is written in XPL, a dialect of PL/I. Although HAL/S is designed primarily for programming on-board computers, it is general enough to meet nearly all the needs in the production, verification, and support of aerospace and other real-time applications. According to documentation from 2005, it was being maintained by the HAL/S project of United Space Alliance.

🔗 Medicine 🔗 Dogs 🔗 Psychology 🔗 Anthropology 🔗 India 🔗 Medicine/Psychiatry

Puppy pregnancy syndrome (PPS) is a psychosomatic illness in humans brought on by mass hysteria.

The syndrome is thought to be localized in villages in several states of India, including West Bengal, Assam, Bihar, Jharkhand, Orissa, and Chhattisgarh, and has been reported by tens of thousands of individuals. It is far more prevalent in areas with little access to education.

People suffering from PPS believe that shortly after being bitten by a dog, puppies are conceived within their abdomen. This is said to be especially likely if the dog is sexually excited at the time of the attack. Victims are said to bark like dogs and have reported being able to see the puppies inside them when looking at water or hear them growling in their abdomen. It is believed that the victims will eventually die – especially men, who will give birth to their puppies through the penis.

Witch doctors offer oral cures, which they claim will dissolve the puppies, allowing them to pass through the digestive system and be excreted "without the knowledge of the patient".

Doctors in India have tried to educate the public about the dangers of believing in this condition. Most sufferers are referred to psychiatric services, but in some instances patients fail to take anti-rabies medication before symptom onset, thinking that they are pregnant with a puppy and that folk medicine will cure them. This misbelief is further compounded by witch doctors who state that their medicine will fail if sufferers seek standard treatment.

Some psychiatrists believe that PPS meets the criteria for a culture-bound disorder.

🔗 Computing 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Cryptography 🔗 Cryptography/Computer science 🔗 Cold War 🔗 NATO

Link 16 is a military tactical data link network used by NATO and nations allowed by the MIDS International Program Office (IPO). Its specification is part of the family of Tactical Data Links.

With Link 16, military aircraft as well as ships and ground forces may exchange their tactical picture in near-real time. Link 16 also supports the exchange of text messages, imagery data and provides two channels of digital voice (2.4 kbit/s or 16 kbit/s in any combination). Link 16 is defined as one of the digital services of the JTIDS / MIDS in NATO's Standardization Agreement STANAG 5516. MIL-STD-6016 is the related United States Department of Defense Link 16 MIL-STD.

🔗 Medicine 🔗 Athletics 🔗 Food and drink 🔗 Medicine/Toxicology 🔗 Sports 🔗 Horse racing

The poppy seed defence is a commonly cited reason to avoid any sanction for failing a drug test. The defence asserts that a suspect's positive result was a result of the person having consumed poppy seeds prior to taking the test. It has been recognised in medical and legal fields as a valid defence.

🔗 Solar System 🔗 Solar System/Moon

The Moon illusion is an optical illusion which causes the Moon to appear larger near the horizon than it does higher up in the sky. It has been known since ancient times and recorded by various cultures. The explanation of this illusion is still debated.

🔗 Chemistry 🔗 Animals 🔗 Molecular Biology/Molecular and Cell Biology

Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial arthropods such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic bacteria such as those from the genus Vibrio; in others, it is autogenic, produced by the animals themselves.

In a general sense, the principal chemical reaction in bioluminescence involves a light-emitting molecule and an enzyme, generally called luciferin and luciferase, respectively. Because these are generic names, luciferins and luciferases are often distinguished by the species or group, e.g. firefly luciferin. In all characterized cases, the enzyme catalyzes the oxidation of the luciferin.

In some species, the luciferase requires other cofactors, such as calcium or magnesium ions, and sometimes also the energy-carrying molecule adenosine triphosphate (ATP). In evolution, luciferins vary little: one in particular, coelenterazine, is found in 11 different animal phyla, though in some of these, the animals obtain it through their diet. Conversely, luciferases vary widely between different species, which is evidence that bioluminescence has arisen over 40 times in evolutionary history.

Both Aristotle and Pliny the Elder mentioned that damp wood sometimes gives off a glow. Many centuries later Robert Boyle showed that oxygen was involved in the process, in both wood and glowworms. It was not until the late nineteenth century that bioluminescence was properly investigated. The phenomenon is widely distributed among animal groups, especially in marine environments. On land it occurs in fungi, bacteria and some groups of invertebrates, including insects.

The uses of bioluminescence by animals include counterillumination camouflage, mimicry of other animals, for example to lure prey, and signaling to other individuals of the same species, such as to attract mates. In the laboratory, luciferase-based systems are used in genetic engineering and biomedical research. Researchers are also investigating the possibility of using bioluminescent systems for street and decorative lighting, and a bioluminescent plant has been created.

🔗 Computing 🔗 Computing/Computer Security

An .XIP file is a XAR archive which can be digitally signed for integrity. The .XIP file format was introduced in OS X 10.9, along with Apple's release of Swift. .XIP allows for a digital signature to be applied and verified on the receiving system before the archive is expanded. When a XIP file is opened (by double-clicking), Archive Utility will automatically expand it (but only if the digital signature is intact).

Apple has reserved the right to use the .XIP file format exclusively, removing it from public use since release. Starting with macOS Sierra, only .XIP archives signed by Apple will be expanded. Developers who had been using .XIP archives were required to move to using signed installer packages or disk images.

🔗 Chess

Quiescence search is an algorithm typically used to extend search at unstable nodes in minimax game trees in game-playing computer programs. It is an extension of the evaluation function to defer evaluation until the position is stable enough to be evaluated statically, that is, without considering the history of the position or future moves from the position. It mitigates the effect of the horizon problem faced by AI engines for various games like chess and Go.

Human players usually have enough intuition to decide whether to abandon a bad-looking move, or search a promising move to a great depth. A quiescence search attempts to emulate this behavior by instructing a computer to search "volatile" positions to a greater depth than "quiet" ones to make sure there are no hidden traps and to get a better estimate of its value.

Any sensible criterion may be used to distinguish "quiet" positions from "volatile" positions. One common criterion is that moves exist in the position that can dramatically change the valuation of the position, such as captures in chess or Go. As the main motive of quiescence search is to get a stable value out of a static evaluation function, it may also make sense to detect wide fluctuations in values returned by a simple heuristic evaluator over several ply, i.e. a history criterion. The quiescence search continues as along as the position remains volatile according to the criterion. In order to get the quiescence search to terminate, plies are usually restricted to moves that deal directly with the threat, such as moves that capture and recapture (often called a 'capture search') in chess. In highly "unstable" games like Go and reversi, a rather large proportion of computer time may be spent on quiescence searching.

🔗 Novels 🔗 Novels/Science fiction 🔗 Science Fiction 🔗 Novels/Short story

"The Last Question" is a science fiction short story by American writer Isaac Asimov. It first appeared in the November 1956 issue of Science Fiction Quarterly and was anthologized in the collections Nine Tomorrows (1959), The Best of Isaac Asimov (1973), Robot Dreams (1986), The Best Science Fiction of Isaac Asimov (1986), the retrospective Opus 100 (1969), and in Isaac Asimov: The Complete Stories, Vol. 1 (1990). While he also considered it one of his best works, “The Last Question” was Asimov's favorite short story of his own authorship, and is one of a loosely connected series of stories concerning a fictional computer called Multivac. Asimov's Three Laws of Robotics, which were first formulated in 1940, outline the criteria for robotic existence in relation to humans. Humanity's relationship to Multivac is questioned on the subject of entropy. The story overlaps science fiction, theology, and philosophy.  

🔗 Chess

El Ajedrecista (English: The Chess Player) is an automaton built in 1912 by Leonardo Torres y Quevedo, one of the first autonomous machines capable of playing chess. As opposed to the human-operated The Turk and Ajeeb, El Ajedrecista was a true automaton built to play chess without human guidance. It played an endgame with three chess pieces, automatically moving a white king and a rook to checkmate the black king moved by a human opponent.

The device could be considered the first computer game in history. It created great excitement when it made its debut, at the University of Paris in 1914. It was first widely mentioned in Scientific American as "Torres and His Remarkable Automatic Devices" on November 6, 1915.

The automaton does not deliver checkmate in the minimum number of moves, nor always within the 50 moves allotted by the fifty-move rule, because of the simple algorithm that calculates the moves. It did, however, checkmate the opponent every time. If an illegal move was made by the opposite player, the automaton would signal it by turning on a light. If the opposing player made three illegal moves, the automaton would stop playing.