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🔗 Palaeontology 🔗 Geology 🔗 Extinction

The Permian–Triassic extinction event, also known as the P–Tr extinction, the P–T extinction, the End-Permian Extinction, and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras, approximately 252 million years ago. It is the Earth's most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It was the largest known mass extinction of insects. Some 57% of all biological families and 83% of all genera became extinct.

There is evidence for one to three distinct pulses, or phases, of extinction. Potential causes for those pulses include one or more large meteor impact events, massive volcanic eruptions (such as the Siberian Traps), and climate change brought on by large releases of underwater methane or methane-producing microbes.

The speed of the recovery from the extinction is disputed. Some scientists estimate that it took 10 million years (until the Middle Triassic), due both to the severity of the extinction and because grim conditions returned periodically for another 5 million years. However, studies in Bear Lake County, near Paris, Idaho, showed a relatively quick rebound in a localized Early Triassic marine ecosystem, taking around 2 million years to recover, suggesting that the impact of the extinction may have been felt less severely in some areas than others.

🔗 Military history 🔗 Numismatics 🔗 Military history/World War II 🔗 Indonesia 🔗 Japan 🔗 Military history/Asian military history 🔗 Military history/Japanese military history

Japanese invasion money, officially known as Southern Development Bank Notes (Japanese: 大東亜戦争軍票 Dai Tō-A Sensō gunpyō, "Greater East Asia War military scrip"), was currency issued by the Japanese Military Authority, as a replacement for local currency after the conquest of colonies and other states in World War II. In February 1942 in Japan, laws were passed establishing the Wartime Finance Bank and the Southern Development Bank. Both institutions issued bonds to raise funds. The former loaned money primarily to military industries, but also to a wide range of other ventures, including hydroelectric generators, electric power companies, shipbuilding and petroleum. The latter provided financial services in areas occupied by the Japanese military, and Southern Development Bank notes were in fact used as de facto military scrip. In December 1942, the outstanding balance of Southern Development Bank notes stood at more than 470 million; in March 1945, more than 13 billion.

Already engaged in war with China, in 1940 the Japanese expanded the scope of their military operations in Asia and finally entered the Second World War in late 1941 with the attack on Pearl Harbor. Japan invaded various Asian countries, occupying vast territories and setting up military administrations.

Beginning with the capture of the Philippines, the Japanese military confiscated all hard currency, both on a federal and individual level, replacing it with locally printed notes bearing a proclamation of military issue. All notes bore the name of the Imperial Japanese government, and some notes proclaimed the "promises to pay the bearer on demand". Called “Mickey Mouse Money" by local Filipinos, it was valueless after the overthrow of the Japanese, and tons of it were burned. Japanese troops were ordered to destroy bank records and any remaining currency prior to capitulation.

With the end of World War II, the currency circulated bearing the Japanese name immediately lost any value it once possessed and was discarded en masse. Money that was issued included the Philippines, Burma (now Myanmar), Malaya, North Borneo and Sarawak (now Malaysia), Singapore, Brunei, the Dutch East Indies (now Indonesia) and some areas of Oceania (New Guinea and the Solomon and Gilbert islands). Large amounts of the currency were obtained by Allied forces and civilians at the end of the war; many were kept as wartime souvenirs, and are now in both private and museum collections.

🔗 Religion 🔗 Women's History 🔗 Japan 🔗 Japan/Religion 🔗 Religion/New religious movements 🔗 Japan/Shinto

Oomoto (大本, Ōmoto, Great Source, or Great Origin), also known as Oomoto-kyo (大本教, Ōmoto-kyō), is a religion founded in 1892 by Deguchi Nao (1836–1918), often categorised as a new Japanese religion originated from Shinto. The spiritual leaders of the movement have predominantly been women; however, Deguchi Onisaburō (1871–1948) has been considered an important figure in Omoto as a seishi (spiritual teacher). Since 2001, the movement has been guided by its fifth leader, Kurenai Deguchi.

🔗 Mathematics

John von Neumann's universal constructor is a self-replicating machine in a cellular automata (CA) environment. It was designed in the 1940s, without the use of a computer. The fundamental details of the machine were published in von Neumann's book Theory of Self-Reproducing Automata, completed in 1966 by Arthur W. Burks after von Neumann's death.

Von Neumann's goal was to specify an abstract machine which, when run, would replicate itself. In his design, the machine consists of three parts: a 'blueprint' for itself, a mechanism that can read any blueprint and construct the machine (sans blueprint) specified by that blueprint, and a 'copy machine' that can make copies of any blueprint. After the mechanism has been used to construct the machine specified by the blueprint, the copy machine is used to create a copy of that blueprint, and this copy is placed into the new machine, resulting in a working replication of the original machine. Some machines will do this backwards, copying the blueprint and then building a machine.

To define his machine in more detail, von Neumann invented the concept of a cellular automaton. The one he used consists of a two-dimensional grid of cells, each of which can be in one of 29 states at any point in time. At each timestep, each cell updates its state depending on the states of the surrounding cells at the prior timestep. The rules governing these updates are identical for all cells.

The universal constructor is a certain pattern of cell states in this cellular automaton. It contains one line of cells that serve as a 'tape', encoding a sequence of instructions that serve as a 'blueprint' for the machine. The machine reads these instructions one by one and performs the corresponding actions. The instructions direct the machine to use its 'construction arm' to build a copy of the machine, without tape, at some other location in the cell grid. The tape can't contain instructions to build an equally long tape, just as a container can't contain a container of the same size. Therefore, the machine contains a separate 'copy machine' which reads the tape and places a copy into the newly constructed machine. The resulting new machine and tape is identical to the old one, and it proceeds to replicate again.

🔗 Evolutionary biology 🔗 Molecular Biology 🔗 Molecular Biology/Genetics

In evolutionary biology and population genetics, the error threshold (or critical mutation rate) is a limit on the number of base pairs a self-replicating molecule may have before mutation will destroy the information in subsequent generations of the molecule. The error threshold is crucial to understanding "Eigen's paradox".

The error threshold is a concept in the origins of life (abiogenesis), in particular of very early life, before the advent of DNA. It is postulated that the first self-replicating molecules might have been small ribozyme-like RNA molecules. These molecules consist of strings of base pairs or "digits", and their order is a code that directs how the molecule interacts with its environment. All replication is subject to mutation error. During the replication process, each digit has a certain probability of being replaced by some other digit, which changes the way the molecule interacts with its environment, and may increase or decrease its fitness, or ability to reproduce, in that environment.

🔗 California 🔗 Business 🔗 Politics 🔗 Trains 🔗 Politics/American politics 🔗 Trains/Rapid transit 🔗 Buses 🔗 Trains/Streetcars

The notion of a General Motors streetcar conspiracy emerged after General Motors (GM) and other companies were convicted of monopolizing the sale of buses and supplies to National City Lines (NCL) and its subsidiaries. In the same case, the defendants were accused of conspiring to own or control transit systems, in violation of Section 1 of the Sherman Antitrust act. The suit created lingering suspicions that the defendants had in fact plotted to dismantle streetcar systems in many cities in the United States as an attempt to monopolize surface transportation.

Between 1938 and 1950, National City Lines and its subsidiaries, American City Lines and Pacific City Lines—with investment from GM, Firestone Tire, Standard Oil of California (through a subsidiary), Federal Engineering, Phillips Petroleum, and Mack Trucks—gained control of additional transit systems in about 25 cities. Systems included St. Louis, Baltimore, Los Angeles, and Oakland. NCL often converted streetcars to bus operations in that period, although electric traction was preserved or expanded in some locations. Other systems, such as San Diego's, were converted by outgrowths of the City Lines. Most of the companies involved were convicted in 1949 of conspiracy to monopolize interstate commerce in the sale of buses, fuel, and supplies to NCL subsidiaries, but were acquitted of conspiring to monopolize the transit industry.

The story as an urban legend has been written about by Martha Bianco, Scott Bottles, Sy Adler, Jonathan Richmond, and Robert Post. It has been explored several times in print, film, and other media, notably in Who Framed Roger Rabbit, Taken for a Ride, Internal Combustion, and The End of Suburbia.

Only a handful of U.S. cities, including San Francisco, New Orleans, Newark, Cleveland, Philadelphia, Pittsburgh, and Boston, have surviving legacy rail urban transport systems based on streetcars, although their systems are significantly smaller than they once were. Other cities are re-introducing streetcars. In some cases, the streetcars do not actually ride on the street. Boston had all of its downtown lines elevated or buried by the mid-1920s, and most of the surviving lines at grade operate on their own right of way. However, San Francisco's and Philadelphia's lines do have large portions of the route that ride on the street as well as using tunnels.

🔗 Psychology

Psychohistory is an amalgam of psychology, history, and related social sciences and the humanities. It examines the "why" of history, especially the difference between stated intention and actual behavior. Psychobiography, childhood, group dynamics, mechanisms of psychic defense, dreams, and creativity are primary areas of research. It works to combine the insights of psychology, especially psychoanalysis, with the research methodology of the social sciences and humanities to understand the emotional origin of the behavior of individuals, groups and nations, past and present. Work in the field has been done in the areas of childhood, creativity, dreams, family dynamics, overcoming adversity, personality, political and presidential psychobiography. There are major psychohistorical studies of studies of anthropology, art, ethnology, history, politics and political science, and much else.

🔗 Philosophy 🔗 Philosophy/Contemporary philosophy 🔗 Philosophy/Ethics

The trolley problem is a thought experiment in ethics. It is generally considered to represent a classic clash between two schools of moral thought, utilitarianism and deontological ethics. The general form of the problem is this:

There is a runaway trolley barreling down the railway tracks. Ahead, on the tracks, there are five people tied up and unable to move. The trolley is headed straight for them. You are standing some distance off in the train yard, next to a lever. If you pull this lever, the trolley will switch to a different set of tracks. However, you notice that there is one person on the side track. You have two options:

1. Do nothing and allow the trolley to kill the five people on the main track.
2. Pull the lever, diverting the trolley onto the side track where it will kill one person.

Which is the more ethical option? Or, more simply: What is the right thing to do?

Philippa Foot introduced this modern form of the problem in 1967. Judith Thomson, Frances Kamm, and Peter Unger have also analysed the dilemma extensively.

Earlier forms of the problem predated Foot's publication. Frank Chapman Sharp included a version in a moral questionnaire given to undergraduates at the University of Wisconsin in 1905. In this variation, the railway's switchman controlled the switch, and the lone individual to be sacrificed (or not) was the switchman's child. The German legal scholar Hans Welzel discussed a similar problem in 1951. In his commentary on the Talmud, published long before his death in 1953, Avrohom Yeshaya Karelitz discussed the similar question of whether it is ethical to deflect a projectile from a larger crowd toward a smaller one.

Beginning in 2001, the trolley problem and its variants have been used extensively in empirical research on moral psychology. Trolley problems have also been a topic of popular books. The problem arises in discussing the ethics of autonomous vehicle design, which may require programming to choose whom or what to strike when a collision appears to be unavoidable.

🔗 Religion 🔗 Classical Greece and Rome 🔗 Greece

The agōgē (Greek: ἀγωγή in Attic Greek, or ἀγωγά, agōgā in Doric Greek) was the rigorous education and training program mandated for all male Spartan citizens, except for the firstborn son in the ruling houses, Eurypontid and Agiad. The training involved cultivating loyalty to the Spartan group, military training (e.g., pain tolerance), hunting, dancing, singing, and social (communicating) preparation. The word agōgē had various meaning in ancient Greek, but in this context it generally meant leading, guidance, or training.

According to folklore, agōgē was introduced by the semi-mythical Spartan law-giver Lycurgus but its origins are thought to be between the 7th and 6th centuries BC when the state trained male citizens from the ages of seven to twenty-one.

The aim of the system was to produce strong and capable warriors to serve the Spartan army. It encouraged conformity and the importance of the Spartan state over one's personal interest and generated the future elites of Sparta. The men would become the "walls of Sparta" because Sparta was the only Greek city with no defensive walls after they had been demolished at the order of Lycurgus. Discipline was strict and the males were encouraged to fight amongst themselves to determine the strongest member of the group.

The agōgē was prestigious throughout the Greek world, and many aristocratic families from other cities vied to send their sons to Sparta to participate in the agōgē for varying periods of time. The Spartans were very selective in which young men they would permit to enroll. Such honors were usually awarded to the próxenoi (πρόξενοι) of Sparta in other cities and to a few other families of supreme ancestry and importance.

🔗 Philosophy 🔗 Philosophy/Logic

The raven paradox, also known as Hempel's paradox, Hempel's ravens, or rarely the paradox of indoor ornithology, is a paradox arising from the question of what constitutes evidence for a statement. Observing objects that are neither black nor ravens may formally increase the likelihood that all ravens are black even though, intuitively, these observations are unrelated.

This problem was proposed by the logician Carl Gustav Hempel in the 1940s to illustrate a contradiction between inductive logic and intuition.