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🔗 Philosophy 🔗 Philosophy/Philosophical literature 🔗 Books 🔗 Philosophy/Logic

Gödel, Escher, Bach: An Eternal Golden Braid, also known as GEB, is a 1979 book by Douglas Hofstadter. By exploring common themes in the lives and works of logician Kurt Gödel, artist M. C. Escher, and composer Johann Sebastian Bach, the book expounds concepts fundamental to mathematics, symmetry, and intelligence. Through illustration and analysis, the book discusses how, through self-reference and formal rules, systems can acquire meaning despite being made of "meaningless" elements. It also discusses what it means to communicate, how knowledge can be represented and stored, the methods and limitations of symbolic representation, and even the fundamental notion of "meaning" itself.

In response to confusion over the book's theme, Hofstadter emphasized that Gödel, Escher, Bach is not about the relationships of mathematics, art, and music—but rather about how cognition emerges from hidden neurological mechanisms. One point in the book presents an analogy about how individual neurons in the brain coordinate to create a unified sense of a coherent mind by comparing it to the social organization displayed in a colony of ants.

The tagline "a metaphorical fugue on minds and machines in the spirit of Lewis Carroll" was used by the publisher to describe the book.

🔗 Computing 🔗 Computer science

In theoretical computer science, the π-calculus (or pi-calculus) is a process calculus. The π-calculus allows channel names to be communicated along the channels themselves, and in this way it is able to describe concurrent computations whose network configuration may change during the computation.

The π-calculus is simple, it has few terms and so is a small, yet expressive language (see #Syntax). Functional programs can be encoded into the π-calculus, and the encoding emphasises the dialogue nature of computation, drawing connections with game semantics. Extensions of the π-calculus, such as the spi calculus and applied π, have been successful in reasoning about cryptographic protocols. Beside the original use in describing concurrent systems, the π-calculus has also been used to reason about business processes and molecular biology.

🔗 Biography 🔗 Medicine 🔗 Biography/science and academia 🔗 History of Science 🔗 Hungary 🔗 Medicine/Society and Medicine

Ignaz Philipp Semmelweis (German: [ˈɪɡnaːts ˈzɛml̩vaɪs]; Hungarian: Semmelweis Ignác Fülöp [ˈsɛmmɛlvɛjs ˈiɡnaːts ˈfyløp]; 1 July 1818 – 13 August 1865) was a Hungarian physician and scientist of German descent who was an early pioneer of antiseptic procedures and was described as the "saviour of mothers". Postpartum infection, also known as puerperal fever or childbed fever, consists of any bacterial infection of the reproductive tract following birth and in the 19th century was common and often fatal. Semmelweis discovered that the incidence of infection could be drastically reduced by requiring healthcare workers in obstetrical clinics to disinfect their hands. In 1847, he proposed hand washing with chlorinated lime solutions at Vienna General Hospital's First Obstetrical Clinic, where doctors' wards had thrice the mortality of midwives' wards. The maternal mortality rate dropped from 18% to less than 2%, and he published a book of his findings, Etiology, Concept and Prophylaxis of Childbed Fever, in 1861.

Despite his research, Semmelweis's observations conflicted with the established scientific and medical opinions of the time and his ideas were rejected by the medical community. He could offer no theoretical explanation for his findings of reduced mortality due to hand-washing, and some doctors were offended at the suggestion that they should wash their hands and mocked him for it. In 1865, the increasingly outspoken Semmelweis allegedly suffered a nervous breakdown and was committed to an asylum by his colleagues. In the asylum, he was beaten by the guards. He died 14 days later from a gangrenous wound on his right hand that may have been caused by the beating.

His findings earned widespread acceptance only years after his death, when Louis Pasteur confirmed the germ theory, giving Semmelweis' observations a theoretical explanation, and Joseph Lister, acting on Pasteur's research, practised and operated using hygienic methods with great success.

🔗 Technology 🔗 Software 🔗 Software/Computing 🔗 Apps

Bitchat is a peer-to-peer encrypted messaging app developed by Jack Dorsey, co‑founder of Twitter (now X) and Block, Inc. Announced in July 2025, Bitchat enables users to send messages via Bluetooth Low Energy (BLE) mesh networks without requiring internet connections, cellular service, user accounts, or central servers. Bitchat also uses the internet-based Nostr protocol for global reach.

🔗 Animal anatomy 🔗 Neuroscience 🔗 Anatomy 🔗 Anatomy/Neuroanatomy

The enteric nervous system (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system (ANS) and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract. It is capable of acting independently of the sympathetic and parasympathetic nervous systems, although it may be influenced by them. The ENS is also called the second brain.It is derived from neural crest cells.

The enteric nervous system is capable of operating independently of the brain and spinal cord, but does rely on innervation from the autonomic nervous system via the vagus nerve and prevertebral ganglia in healthy subjects. However, studies have shown that the system is operable with a severed vagus nerve. The neurons of the enteric nervous system control the motor functions of the system, in addition to the secretion of gastrointestinal enzymes. These neurons communicate through many neurotransmitters similar to the CNS, including acetylcholine, dopamine, and serotonin. The large presence of serotonin and dopamine in the gut are key areas of research for neurogastroenterologists.

🔗 Computing 🔗 Computer science 🔗 Mathematics

The P versus NP problem is a major unsolved problem in computer science. It asks whether every problem whose solution can be quickly verified can also be solved quickly.

It is one of the seven Millennium Prize Problems selected by the Clay Mathematics Institute, each of which carries a US$1,000,000 prize for the first correct solution.

The informal term quickly, used above, means the existence of an algorithm solving the task that runs in polynomial time, such that the time to complete the task varies as a polynomial function on the size of the input to the algorithm (as opposed to, say, exponential time). The general class of questions for which some algorithm can provide an answer in polynomial time is called "class P" or just "P". For some questions, there is no known way to find an answer quickly, but if one is provided with information showing what the answer is, it is possible to verify the answer quickly. The class of questions for which an answer can be verified in polynomial time is called NP, which stands for "nondeterministic polynomial time".

An answer to the P = NP question would determine whether problems that can be verified in polynomial time can also be solved in polynomial time. If it turned out that P ≠ NP, which is widely believed, it would mean that there are problems in NP that are harder to compute than to verify: they could not be solved in polynomial time, but the answer could be verified in polynomial time.

Aside from being an important problem in computational theory, a proof either way would have profound implications for mathematics, cryptography, algorithm research, artificial intelligence, game theory, multimedia processing, philosophy, economics and many other fields.

🔗 Religion 🔗 Philosophy 🔗 Philosophy/Philosophy of religion 🔗 Philosophy/Ethics 🔗 Christianity 🔗 Christianity/theology 🔗 Christianity/Calvinism

The Protestant work ethic, also known as the Calvinist work ethic or the Puritan work ethic, is a work ethic concept in scholarly sociology, economics and historiography. It emphasizes that diligence, discipline, and frugality are a result of a person's subscription to the values espoused by the Protestant faith, particularly Calvinism.

The phrase was initially coined in 1905 by Max Weber in his book The Protestant Ethic and the Spirit of Capitalism. Weber asserted that Protestant ethics and values, along with the Calvinist doctrines of asceticism and predestination, enabled the rise and spread of capitalism. It is one of the most influential and cited books in sociology, although the thesis presented has been controversial since its release. In opposition to Weber, historians such as Fernand Braudel and Hugh Trevor-Roper assert that the Protestant work ethic did not create capitalism and that capitalism developed in pre-Reformation Catholic communities. Just as priests and caring professionals are deemed to have a vocation (or "calling" from God) for their work, according to the Protestant work ethic the "lowly" workman also has a noble vocation which he can fulfill through dedication to his work.

The concept is often credited with helping to define the societies of Northern, Central and Northwestern Europe as well as the United States of America.

🔗 Cognitive science

Cognitive grammar is a cognitive approach to language developed by Ronald Langacker, which hypothesizes that grammar, semantics, and lexicon exist on a continuum instead of as separate processes altogether. This approach to language was one of the first projects of cognitive linguistics. In this system, grammar is not a formal system operating independently of meaning. Rather, grammar is itself meaningful and inextricable from semantics.

Construction grammar is a similar focus of cognitive approaches to grammar. While cognitive grammar emphasizes the study of the cognitive principles that give rise to linguistic organization, construction grammar aims to provide a more descriptively and formally detailed account of the linguistic units that comprise a particular language.

Langacker first explicates the system of cognitive grammar in his seminal, two-volume work Foundations of Cognitive Grammar. Volume one is titled "Theoretical Prerequisites", and it explores Langacker's hypothesis that grammar may be deconstructed into patterns that come together in order to represent concepts. This volume concentrates on the broad scope of language especially in terms of the relationship between grammar and semantics. Volume two is titled "Descriptive Application", as it moves beyond the first volume to elaborate on the ways in which Langacker's previously described theories may be applied. Langacker invites his reader to utilize the tools presented in Foundations' first volume in a wide range of, mainly English, grammatical situations.

🔗 Mammals

The nocturnal bottleneck hypothesis is a hypothesis to explain several mammalian traits. In 1942, Gordon Lynn Walls described this concept which states that placental mammals were mainly or even exclusively nocturnal through most of their evolutionary story, starting with their origin 225 million years ago, and only ending with the demise of the non-avian dinosaurs 66 million years ago. While some mammal groups have later evolved to fill diurnal niches, the approximately 160 million years spent as nocturnal animals has left a lasting legacy on basal anatomy and physiology, and most mammals are still nocturnal.

🔗 France 🔗 Crime 🔗 Visual arts

The Bouvier Affair was a number of international lawsuits that started in 2015, and subsequent events. The lawsuits allege that Swiss art shipper and dealer Yves Bouvier defrauded his clients by misrepresenting the original cost of art works and subsequently overcharging them. The affair has played out in courts in Monaco, Switzerland, France, the US, Hong Kong and Singapore.

The alleged victims are "high net worth individuals" in the UK, the US, Asia and Europe, most notably Monaco-based Russian oligarch Dmitry Rybolovlev.

As of February 2018, Bouvier was facing criminal charges in France, Monaco and also in Switzerland after the Geneva Prosecutor opened a new case there.