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🔗 Geology

The Messinian Salinity Crisis (MSC), also referred to as the Messinian Event, and in its latest stage as the Lago Mare event, was a geological event during which the Mediterranean Sea went into a cycle of partly or nearly complete desiccation throughout the latter part of the Messinian age of the Miocene epoch, from 5.96 to 5.33 Ma (million years ago). It ended with the Zanclean flood, when the Atlantic reclaimed the basin.

Sediment samples from below the deep seafloor of the Mediterranean Sea, which include evaporite minerals, soils, and fossil plants, show that the precursor of the Strait of Gibraltar closed tight about 5.96 million years ago, sealing the Mediterranean off from the Atlantic. This resulted in a period of partial desiccation of the Mediterranean Sea, the first of several such periods during the late Miocene. After the strait closed for the last time around 5.6 Ma, the region's generally dry climate at the time dried the Mediterranean basin out nearly completely within a thousand years. This massive desiccation left a deep dry basin, reaching 3 to 5 km (1.9 to 3.1 mi) deep below normal sea level, with a few hypersaline pockets similar to today's Dead Sea. Then, around 5.5 Ma, less dry climatic conditions resulted in the basin receiving more freshwater from rivers, progressively filling and diluting the hypersaline lakes into larger pockets of brackish water (much like today's Caspian Sea). The Messinian Salinity Crisis ended with the Strait of Gibraltar finally reopening 5.33 Ma, when the Atlantic rapidly filled up the Mediterranean basin in what is known as the Zanclean flood.

Even today, the Mediterranean is considerably saltier than the North Atlantic, owing to its near isolation by the Strait of Gibraltar and its high rate of evaporation. If the Strait of Gibraltar closes again (which is likely to happen in the near future on a geological time scale), the Mediterranean would mostly evaporate in about a thousand years, after which continued northward movement of Africa may obliterate the Mediterranean altogether.

Only the inflow of Atlantic water maintains the present Mediterranean level. When that was shut off sometime between 6.5 to 6 MYBP, net evaporative loss set in at the rate of around 3,300 cubic kilometers yearly. At that rate, the 3.7 million cubic kilometres of water in the basin would dry up in scarcely more than a thousand years, leaving an extensive layer of salt some tens of meters thick and raising global sea level about 12 meters.

🔗 France 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/World War I 🔗 Military history/French military history 🔗 Military history/Military land vehicles 🔗 Military history/European military history

The Boirault machine (French: Appareil Boirault), was an early French experimental landship, designed in 1914 and built in early 1915. It has been considered as "another interesting ancestor of the tank", and described as a "rhomboid-shaped skeleton tank without armour, with single overhead track". Ultimately, the machine was deemed impractical and was nicknamed Diplodocus militaris. It preceded the design and development of the English Little Willie tank by six months.

🔗 Computing 🔗 Military history 🔗 Military history/Military science, technology, and theory

Fifth-generation warfare (5GW) is warfare that is conducted primarily through non-kinetic military action, such as social engineering, misinformation, cyberattacks, along with emerging technologies such as artificial intelligence and fully autonomous systems. Fifth generation warfare has been described by Daniel Abbot as a war of "information and perception". There is no widely agreed upon definition of fifth-generation warfare, and it has been rejected by some scholars, including William S. Lind, who was one of the original theorists of fourth-generation warfare.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/Cold War 🔗 Pritzker Military Library 🔗 Firearms

The M-28 or M-29 Davy Crockett Weapon System was the tactical nuclear recoilless gun (smoothbore) for firing the M-388 nuclear projectile that was deployed by the United States during the Cold War. It was one of the smallest nuclear weapon systems ever built, with a yield between 10 and 20 tons TNT equivalent (40–80 gigajoules). It is named after American folk hero, soldier, and congressman Davy Crockett.

🔗 Philosophy 🔗 Philosophy/Logic

Buridan's ass is an illustration of a paradox in philosophy in the conception of free will. It refers to a hypothetical situation wherein an ass that is equally hungry and thirsty is placed precisely midway between a stack of hay and a pail of water. Since the paradox assumes the ass will always go to whichever is closer, it dies of both hunger and thirst since it cannot make any rational decision between the hay and water. A common variant of the paradox substitutes two identical piles of hay for the hay and water; the ass, unable to choose between the two, dies of hunger.

The paradox is named after the 14th-century French philosopher Jean Buridan, whose philosophy of moral determinism it satirizes. Although the illustration is named after Buridan, philosophers have discussed the concept before him, notably Aristotle, who used the example of a man equally hungry and thirsty, and Al-Ghazali, who used a man faced with the choice of equally good dates.

A version of this situation appears as metastability in digital electronics, when a circuit must decide between two states based on an input that is in itself undefined (neither zero nor one). Metastability becomes a problem if the circuit spends more time than it should in this "undecided" state, which is usually set by the speed of the clock the system is using.

🔗 Mathematics 🔗 Statistics

Local regression or local polynomial regression, also known as moving regression, is a generalization of the moving average and polynomial regression. Its most common methods, initially developed for scatterplot smoothing, are LOESS (locally estimated scatterplot smoothing) and LOWESS (locally weighted scatterplot smoothing), both pronounced . They are two strongly related non-parametric regression methods that combine multiple regression models in a k-nearest-neighbor-based meta-model. In some fields, LOESS is known and commonly referred to as Savitzky–Golay filter (proposed 15 years before LOESS).

LOESS and LOWESS thus build on "classical" methods, such as linear and nonlinear least squares regression. They address situations in which the classical procedures do not perform well or cannot be effectively applied without undue labor. LOESS combines much of the simplicity of linear least squares regression with the flexibility of nonlinear regression. It does this by fitting simple models to localized subsets of the data to build up a function that describes the deterministic part of the variation in the data, point by point. In fact, one of the chief attractions of this method is that the data analyst is not required to specify a global function of any form to fit a model to the data, only to fit segments of the data.

The trade-off for these features is increased computation. Because it is so computationally intensive, LOESS would have been practically impossible to use in the era when least squares regression was being developed. Most other modern methods for process modeling are similar to LOESS in this respect. These methods have been consciously designed to use our current computational ability to the fullest possible advantage to achieve goals not easily achieved by traditional approaches.

A smooth curve through a set of data points obtained with this statistical technique is called a loess curve, particularly when each smoothed value is given by a weighted quadratic least squares regression over the span of values of the y-axis scattergram criterion variable. When each smoothed value is given by a weighted linear least squares regression over the span, this is known as a lowess curve; however, some authorities treat lowess and loess as synonyms.

🔗 Internet 🔗 Novels

Victory Garden is a work of electronic literature by American author Stuart Moulthrop. It was written in StorySpace and published by Eastgate Systems in 1992. It is often discussed along with Michael Joyce's afternoon, a story as an important work of hypertext fiction.

🔗 United States 🔗 Biography 🔗 United States/Massachusetts 🔗 Mammals 🔗 Zoo

Hoover (c. 1971 – July 25, 1985) was a harbor seal who was able to imitate basic human speech.

🔗 Environment 🔗 Economics 🔗 Philosophy 🔗 Politics 🔗 Philosophy/Ethics 🔗 Game theory 🔗 Fisheries and Fishing

In economic science, the tragedy of the commons is a situation in which individual users, who have open access to a resource unhampered by shared social structures or formal rules that govern access and use, act independently according to their own self-interest and, contrary to the common good of all users, cause depletion of the resource through their uncoordinated action. The concept originated in an essay written in 1833 by the British economist William Forster Lloyd, who used a hypothetical example of the effects of unregulated grazing on common land (also known as a "common") in Great Britain and Ireland. The concept became widely known as the "tragedy of the commons" over a century later after an article written by Garrett Hardin in 1968. Faced with evidence of historical and existing commons, Hardin later retracted his original thesis, stating that the title should have been "The Tragedy of the Unmanaged Commons".

Although taken as a hypothetical example by Lloyd, the historical demise of the commons of Britain and Europe resulted not from misuse of long-held rights of usage by the commoners, but from the commons' owners enclosing and appropriating the land, abrogating the commoners' rights.

Although open-access resource systems may collapse due to overuse (such as in overfishing), many examples have existed and still do exist where members of a community with regulated access to a common resource co-operate to exploit those resources prudently without collapse, or even creating "perfect order". Elinor Ostrom was awarded the 2009 Nobel Memorial Prize in Economic Sciences for demonstrating this concept in her book Governing the Commons, which included examples of how local communities were able to do this without top-down regulations or privatization. On the other hand, Dieter Helm argues that these examples are context-specific and the tragedy of the commons "is not generally solved this way. If it were, the destruction of nature would not have occurred."

In a modern economic context, "commons" is taken to mean any open-access and unregulated resource such as the atmosphere, oceans, rivers, ocean fish stocks, or even an office refrigerator. In a legal context, it is a type of property that is neither private nor public, but rather held jointly by the members of a community, who govern access and use through social structures, traditions, or formal rules.

In environmental science, the "tragedy of the commons" is often cited in connection with sustainable development, meshing economic growth and environmental protection, as well as in the debate over global warming. It has also been used in analyzing behavior in the fields of economics, evolutionary psychology, anthropology, game theory, politics, taxation, and sociology.

🔗 Meteorology 🔗 Tropical cyclones

A hypercane is a hypothetical class of extreme tropical cyclone that could form if ocean temperatures reached approximately 50 °C (122 °F), which is 15 °C (27 °F) warmer than the warmest ocean temperature ever recorded. Such an increase could be caused by a large asteroid or comet impact, a large supervolcanic eruption, a large submarine flood basalt, or extensive global warming. There is some speculation that a series of hypercanes resulting from an impact by a large asteroid or comet contributed to the demise of the non-avian dinosaurs. The hypothesis was created by Kerry Emanuel of MIT, who also coined the term.