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πŸ”— Sinking of the Rainbow Warrior

πŸ”— International relations πŸ”— France πŸ”— Military history πŸ”— Terrorism πŸ”— New Zealand πŸ”— Military history/Intelligence πŸ”— International relations/International law πŸ”— Military history/Maritime warfare πŸ”— Military history/French military history πŸ”— Shipwrecks πŸ”— International relations/United Nations πŸ”— New Zealand/New Zealand politics πŸ”— Military history/European military history πŸ”— Crime and Criminal Biography πŸ”— Project-independent assessment πŸ”— Crime and Criminal Biography/Terrorism πŸ”— Auckland

The sinking of the Rainbow Warrior, codenamed OpΓ©ration Satanique, was a bombing operation by the "action" branch of the French foreign intelligence services, the Direction gΓ©nΓ©rale de la sΓ©curitΓ© extΓ©rieure (DGSE), carried out on 10 July 1985. During the operation, two operatives sank the flagship of the Greenpeace fleet, the Rainbow Warrior, at the Port of Auckland in New Zealand on its way to a protest against a planned French nuclear test in Moruroa. Fernando Pereira, a photographer, drowned on the sinking ship.

France initially denied responsibility, but two French agents were captured by New Zealand Police and charged with arson, conspiracy to commit arson, willful damage, and murder. As the truth came out, the scandal resulted in the resignation of the French Defence Minister Charles Hernu. The two agents pleaded guilty to manslaughter and were sentenced to ten years in prison. They spent a little over two years confined to the French island of Hao before being freed by the French government.

Several political figures, including then New Zealand Prime Minister David Lange, have referred to the bombing as an act of terrorism or state-sponsored terrorism.

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πŸ”— Pykrete

πŸ”— Technology πŸ”— Military history πŸ”— Military history/North American military history πŸ”— Military history/Military science, technology, and theory πŸ”— Architecture πŸ”— United Kingdom πŸ”— Transport πŸ”— Military history/Maritime warfare πŸ”— Military history/World War II πŸ”— Civil engineering πŸ”— Engineering πŸ”— Transport/Maritime πŸ”— Military history/Canadian military history πŸ”— Military history/European military history πŸ”— Military history/British military history

Pykrete is a frozen ice alloy , originally made of approximately 14 percent sawdust or some other form of wood pulp (such as paper) and 86 percent ice by weight (6 to 1 by weight). During World War II, Geoffrey Pyke proposed it as a candidate material for a supersized aircraft carrier for the British Royal Navy. Pykrete features unusual properties, including a relatively slow melting rate due to its low thermal conductivity, as well as a vastly improved strength and toughness compared to ordinary ice. These physical properties can make the material comparable to concrete, as long as the material is kept frozen.

Pykrete is slightly more difficult to form than concrete, as it expands during the freezing process. However, it can be repaired and maintained using seawater as a raw material. The mixture can be moulded into any shape and frozen, and it will be tough and durable, as long as it is kept at or below freezing temperature. Resistance to gradual creep or sagging is improved by lowering the temperature further, to βˆ’15Β Β°C (5Β Β°F).

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πŸ”— Wow signal

πŸ”— History πŸ”— Physics πŸ”— Telecommunications πŸ”— Skepticism πŸ”— Astronomy πŸ”— History of Science πŸ”— Physics/History πŸ”— Paranormal

The Wow! signal was a strong narrowband radio signal received on August 15, 1977, by Ohio State University's Big Ear radio telescope in the United States, then used to support the search for extraterrestrial intelligence. The signal appeared to come from the direction of the constellation Sagittarius and bore the expected hallmarks of extraterrestrial origin.

Astronomer Jerry R. Ehman discovered the anomaly a few days later while reviewing the recorded data. He was so impressed by the result that he circled the reading on the computer printout, "6EQUJ5", and wrote the comment "Wow!" on its side, leading to the event's widely used name.

The entire signal sequence lasted for the full 72-second window during which Big Ear was able to observe it, but has not been detected since, despite several subsequent attempts by Ehman and others. Many hypotheses have been advanced on the origin of the emission, including natural and human-made sources, but none of them adequately explains the signal.

Although the Wow! signal had no detectable modulationβ€”a technique used to transmit information over radio wavesβ€”it remains the strongest candidate for an alien radio transmission ever detected.

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πŸ”— Luhn Algorithm for validating credit cards

πŸ”— Computing πŸ”— Mathematics

The Luhn algorithm or Luhn formula, also known as the "modulus 10" or "mod 10" algorithm, named after its creator, IBM scientist Hans Peter Luhn, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers, National Provider Identifier numbers in the United States, Canadian Social Insurance Numbers, Israel ID Numbers, South African ID Numbers, Greek Social Security Numbers (Ξ‘ΞœΞšΞ‘), and survey codes appearing on McDonald's, Taco Bell, and Tractor Supply Co. receipts. It is described in U.S. Patent No. 2,950,048, filed on January 6, 1954, and granted on August 23, 1960.

The algorithm is in the public domain and is in wide use today. It is specified in ISO/IEC 7812-1. It is not intended to be a cryptographically secure hash function; it was designed to protect against accidental errors, not malicious attacks. Most credit cards and many government identification numbers use the algorithm as a simple method of distinguishing valid numbers from mistyped or otherwise incorrect numbers.

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πŸ”— Pando (tree)

πŸ”— United States πŸ”— Plants πŸ”— United States/Utah

Pando (Latin for "I spread out"), also known as the trembling giant, is a clonal colony of an individual male quaking aspen (Populus tremuloides) determined to be a single living organism by identical genetic markers and assumed to have one massive underground root system. The plant is located in the Fremont River Ranger District of the Fishlake National Forest at the western edge of the Colorado Plateau in south-central Utah, United States, around 1 mile (1.6Β km) southwest of Fish Lake. Pando occupies 43 hectares (106 acres) and is estimated to weigh collectively 6,000,000 kilograms (6,600 short tons), making it the heaviest known organism. The root system of Pando, at an estimated 80,000 years old, is among the oldest known living organisms.

Pando is currently thought to be dying. Though the exact reasons are not known, it is thought to be a combination of factors including drought, grazing, human development, and fire suppression. The Western Aspen Alliance, a research group at Utah State University’s S.J. & Jessie E. Quinney College of Natural Resources, has been studying the tree in an effort to save it, and the United States Forest Service is currently experimenting with several 5-acre (2Β ha) sections of it in an effort to find a means to save it. Grazing animals have threatened Pando's ability to produce young offsprings to replace trees that are dying. Human development in the area is another threat, these two threats have caused pando trees to shrink in size and decrease over the past 50 years.

A study published in October 2018 concludes that Pando has not been growing for the past 30–40 years. Human interference was named as the primary cause, with the study specifically citing people allowing cattle and deer populations to thrive, their grazing resulting in fewer saplings and dying individual trees.

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πŸ”— FILE_ID.DIZ

πŸ”— Computing

FILE_ID.DIZ is a plain text file containing a brief content description of the archive in which it is included. It was originally used in archives distributed through bulletin board systems (BBS), and still in the warez scene.

Bulletin boards commonly accept uploaded files from their users. The BBS software would prompt the user to supply a description for the uploaded file, but these descriptions were often less than useful. BBS system operators spent many hours going over the upload descriptions correcting and editing the descriptions. The FILE_ID.DIZ inclusion in archives was designed to address this problem.

FILE_ID stands for "file identification". DIZ stands for Description In Zipfile.

Clark Development and the Association of Shareware Professionals supported the idea of this becoming a standard for file descriptions. Clark rewrote the PCBDescribe program and included it with their PCBoard BBS software. The ASP urged their members to use this description file format in their distributions. Michael Leavitt, an employee of Clark Development, released the file specification and his PCBDescribe program source code to the public domain and urged other BBS software companies to support the DIZ file.

SysOps could add a common third-party script written in PPL, called "DIZ/2-PCB" that would process, rewrite, verify, and format DIZ files from archives as they were uploaded to a BBS. The software would extract the archive, examine the contents, compile a report, import the DIZ description file and then format it according to your liking. During this time, it was usual practice to add additional lines to the description, such as ads exclaiming the source of the uploaded BBS.

Traditionally, a FILE_ID.DIZ should be "up to 10 lines of text, each line being no more than 45 characters long." according to the specification v1.9.

The concept of DIZ files was to allow a concise description of uploaded files to be automatically applied. Advertisements and "high ASCII" artwork were specifically prohibited.

Even since the decline of the dial-up bulletin board system, FILE_ID.DIZ files are still utilized by the warez scene in their releases of unlicensed software. They are commonly bundled as part of the complete packaging by self-described pirate groups, and indicate the number of disks, and other basic information. Along with the NFO file, it is essential to the release. Especially in terms of unlicensed software ("warez"), it was common for each file in a sequential compressed archive (an archive intentionally split into multiple parts at creation so the parts can then be individually downloaded by slower connections like dial-up. Example: .rar, .r00, .r01, .r02, etc.), to contain this file. This probably contributed to its extended popularity after the decline of the bulletin board system in the late 1990s and early 2000s until now, since even casual consumers of unlicensed software would have stumbled upon it due to its abundance.

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πŸ”— Liquid Breathing

πŸ”— Medicine πŸ”— Medicine/Pulmonology πŸ”— Physiology πŸ”— Scuba diving πŸ”— Physiology/respiratory

Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen-rich liquid (such as a perfluorocarbon), rather than breathing air.

This requires certain physical properties such as respiratory gas solubility, density, viscosity, vapor pressure, and lipid solubility which some, but not all, perfluorochemicals (perfluorocarbon) have. Thus, it is critical to choose the appropriate PFC for a specific biomedical application, such as liquid ventilation, drug delivery or blood substitutes. The physical properties of PFC liquids vary substantially; however, the one common property is their high solubility for respiratory gases. In fact, these liquids carry more oxygen and carbon dioxide than blood.

In theory, liquid breathing could assist in the treatment of patients with severe pulmonary or cardiac trauma, especially in pediatric cases. Liquid breathing has also been proposed for use in deep diving and space travel. Despite some recent advances in liquid ventilation, a standard mode of application has not yet been established.

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πŸ”— Needleman-Wunsch Algorithm

πŸ”— Computer science πŸ”— Molecular and Cell Biology πŸ”— Computational Biology

The Needleman–Wunsch algorithm is an algorithm used in bioinformatics to align protein or nucleotide sequences. It was one of the first applications of dynamic programming to compare biological sequences. The algorithm was developed by Saul B. Needleman and Christian D. Wunsch and published in 1970. The algorithm essentially divides a large problem (e.g. the full sequence) into a series of smaller problems, and it uses the solutions to the smaller problems to find an optimal solution to the larger problem. It is also sometimes referred to as the optimal matching algorithm and the global alignment technique. The Needleman–Wunsch algorithm is still widely used for optimal global alignment, particularly when the quality of the global alignment is of the utmost importance. The algorithm assigns a score to every possible alignment, and the purpose of the algorithm is to find all possible alignments having the highest score.

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πŸ”— John von Neumann

πŸ”— Biography πŸ”— Computing πŸ”— Mathematics πŸ”— Military history πŸ”— Military history/North American military history πŸ”— Military history/United States military history πŸ”— Military history/Military science, technology, and theory πŸ”— Physics πŸ”— Economics πŸ”— Philosophy πŸ”— Philosophy/Logic πŸ”— Biography/science and academia πŸ”— Philosophy/Philosophy of science πŸ”— Philosophy/Contemporary philosophy πŸ”— Military history/Military biography πŸ”— Biography/military biography πŸ”— History of Science πŸ”— Computing/Computer science πŸ”— Philosophy/Philosophers πŸ”— Education πŸ”— Hungary πŸ”— Military history/World War II πŸ”— Military history/Cold War πŸ”— Physics/History πŸ”— Physics/Biographies πŸ”— Game theory πŸ”— Eastern Europe

John von Neumann (; Hungarian: Neumann JΓ‘nos Lajos, pronouncedΒ [ˈnΙ’jmΙ’n ˈjaːnoΚƒ ˈlΙ’joΚƒ]; December 28, 1903 – FebruaryΒ 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. Von Neumann was generally regarded as the foremost mathematician of his time and said to be "the last representative of the great mathematicians"; who integrated both pure and applied sciences.

He made major contributions to a number of fields, including mathematics (foundations of mathematics, functional analysis, ergodic theory, representation theory, operator algebras, geometry, topology, and numerical analysis), physics (quantum mechanics, hydrodynamics, and quantum statistical mechanics), economics (game theory), computing (Von Neumann architecture, linear programming, self-replicating machines, stochastic computing), and statistics.

He was a pioneer of the application of operator theory to quantum mechanics in the development of functional analysis, and a key figure in the development of game theory and the concepts of cellular automata, the universal constructor and the digital computer.

He published over 150 papers in his life: about 60 in pure mathematics, 60 in applied mathematics, 20 in physics, and the remainder on special mathematical subjects or non-mathematical ones. His last work, an unfinished manuscript written while he was in hospital, was later published in book form as The Computer and the Brain.

His analysis of the structure of self-replication preceded the discovery of the structure of DNA. In a short list of facts about his life he submitted to the National Academy of Sciences, he stated, "The part of my work I consider most essential is that on quantum mechanics, which developed in GΓΆttingen in 1926, and subsequently in Berlin in 1927–1929. Also, my work on various forms of operator theory, Berlin 1930 and Princeton 1935–1939; on the ergodic theorem, Princeton, 1931–1932."

During World War II, von Neumann worked on the Manhattan Project with theoretical physicist Edward Teller, mathematician StanisΕ‚aw Ulam and others, problem solving key steps in the nuclear physics involved in thermonuclear reactions and the hydrogen bomb. He developed the mathematical models behind the explosive lenses used in the implosion-type nuclear weapon, and coined the term "kiloton" (of TNT), as a measure of the explosive force generated.

After the war, he served on the General Advisory Committee of the United States Atomic Energy Commission, and consulted for a number of organizations, including the United States Air Force, the Army's Ballistic Research Laboratory, the Armed Forces Special Weapons Project, and the Lawrence Livermore National Laboratory. As a Hungarian Γ©migrΓ©, concerned that the Soviets would achieve nuclear superiority, he designed and promoted the policy of mutually assured destruction to limit the arms race.

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πŸ”— Atmos Clock

πŸ”— Brands πŸ”— Time

Atmos is the brand name of a mechanical torsion pendulum clock manufactured by Jaeger-LeCoultre in Switzerland which does not need to be wound manually. It gets the energy it needs to run from temperature and atmospheric pressure changes in the environment, and can run for years without human intervention.

The clock is driven by a mainspring, which is wound by the expansion and contraction of liquid and gaseous ethyl chloride in an internal hermetically sealed bellows. The ethyl chloride vaporises into an expansion chamber as the temperature rises, compressing a spiral spring; with a fall in temperature the gas condenses and the spring slackens. This motion constantly winds the mainspring. A temperature variation of only one degree in the range between 15Β Β°C (59Β Β°F) and 30Β Β°C (86Β Β°F), or a pressure variation of 3 mmHg, is sufficient for two days' operation.

In order to run the clock on this small amount of energy, everything inside the Atmos has to work in as friction-free a manner as possible. For timekeeping it uses a torsion pendulum, which consumes less energy than an ordinary pendulum. The torsion pendulum has a period of precisely one minute; thirty seconds to rotate in one direction and thirty seconds to return to the starting position. This is thirty times slower than the 0.994 m (39.1 in) seconds pendulum typically found in a longcase clock, where each swing (or half-period) takes one second.

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