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🔗 Philosophy 🔗 Books 🔗 Philosophy/Philosophy of science 🔗 Science

The Two Cultures is the first part of an influential 1959 Rede Lecture by British scientist and novelist C. P. Snow which were published in book form as The Two Cultures and the Scientific Revolution the same year. Its thesis was that science and the humanities which represented "the intellectual life of the whole of western society" had become split into "two cultures" and that this division was a major handicap to both in solving the world's problems.

🔗 Electrical engineering

The cryotron is a switch that operates using superconductivity. The cryotron works on the principle that magnetic fields destroy superconductivity. This simple device consists of two superconducting wires (e.g. tantalum and niobium) with different critical temperature (Tc). The cryotron was invented by Dudley Allen Buck of the Massachusetts Institute of Technology Lincoln Laboratory.

As described by Buck, a straight wire of tantalum (having lower Tc) is wrapped around with a wire of niobium in a single layer coil. Both wires are electrically isolated from each other. When this device is immersed in a liquid helium bath both wires become superconducting and hence offer no resistance to the passage of electric current. Tantalum in superconducting state can carry large amount of current as compared to its normal state. Now when current is passed through the niobium coil (wrapped around tantalum) it produces a magnetic field, which in turn reduces (kills) the superconductivity of the tantalum wire and hence reduces the amount of the current that can flow through the tantalum wire. Hence one can control the amount of the current that can flow in the straight wire with the help of small current in the coiled wire. We can think of the tantalum straight wire as a "gate" and the coiled niobium as a "control".

The article by Buck includes descriptions of several logic circuits implemented using cryotrons, including: one stage of a binary adder, carry network, binary accumulator stage, and two stages of a cryotron stepping register.

A planar cryotron using thin films of lead and tin was developed in 1957 by John Bremer at General Electric's General Engineering Lab in Schenectady, New York. This was one of the first integrated circuits, although using superconductors rather than semiconductors. In the next few years, a demonstration computer was made and arrays with 2000 devices operated. A short history of this work is in the November 2007 newsletter of the IEEE History Center.

Juri Matisoo developed a version of the cryotron incorporating a Josephson junction switched by the magnetic field from a control wire. He also explained the shortcomings of traditional cryotrons in which the superconductive material must transition between superconducting and normal states to switch the device, and thus switch relatively slowly. Matisoo's cryotron switched between a conducting state in which 'pair tunneling' of electrons through the gate took place and a 'resistive' state where only single electrons were able to tunnel. The circuit was (like the traditional cryotron) capable of some amplification (i.e gain greater than unity) had a switching rate of less than 800 picoseconds. Although the requirement for cryogenic cooling limited its practicality, it wasn't until the late 2010s that commercial transistors came close to matching this performance.

There have been periods of renewed interest in various types of cryotron, IBM experimented with using them for limited applications in supercomputers during the 1980s and (as of 2020) there has been some investigation of their potential applications both to I/O and logic in prototype quantum computers.

🔗 Military history 🔗 Military history/Medieval warfare 🔗 Martial arts 🔗 Military history/Spanish military history 🔗 Spain 🔗 Military history/European military history 🔗 Fencing

La Verdadera Destreza is the conventional term for the Spanish tradition of fencing of the early modern period. The word destreza literally translates to 'dexterity' or 'skill, ability', and thus la verdadera destreza to 'the true skill' or 'the true art'.

While destreza is primarily a system of swordsmanship, it is intended to be a universal method of fighting, applicable to all weapons in principle, but in practice dedicated to the rapier specifically, or the rapier combined with a defensive weapon such as a cloak, a buckler or a parrying dagger, besides other weapons such as the late-renaissance two-handed montante; the flail; and polearms such as the pike and halberd.

Its precepts are based on reason, geometry, and tied to intellectual, philosophical, and moral ideals, incorporating various aspects of a well-rounded Renaissance humanist education, with a special focus on the writings of classical authors such as Aristotle, Euclid, and Plato.

The tradition is documented in scores of fencing manuals, but centers on the works of two primary authors, Jerónimo Sánchez de Carranza (Hieronimo de Carança, died c. 1608) and his student Luis Pacheco de Narváez (1570–1640).

🔗 Architecture 🔗 Politics 🔗 Politics of the United Kingdom

Hostile architecture is an intentional design strategy that uses elements of the built environment to guide or restrict behaviour in urban space as a form of crime prevention or order maintenance. It often targets people who use or rely on public space more than others, like people who are homeless and youth, by restricting the behaviours they engage in. Also known as defensive architecture, hostile design, unpleasant design, exclusionary design, or defensive urban design, hostile architecture is most typically associated with "anti-homeless spikes" – studs embedded in flat surfaces to make sleeping rough, uncomfortable, and impractical. Other measures include sloped window sills to stop people sitting, benches with armrests positioned to stop people lying on them, and water sprinklers that "intermittently come on but aren't really watering anything." Hostile architecture also seeks to deter skateboarding, littering, loitering, and public urination. Critics argue that such measures reinforce social divisions and create problems for all members of the public, especially seniors, people with disabilities, and children.

🔗 Polynesia 🔗 Writing systems 🔗 Chile

Rongorongo (; Rapa Nui: [ˈɾoŋoˈɾoŋo]) is a system of glyphs discovered in the 19th century on Easter Island that appears to be writing or proto-writing. Numerous attempts at decipherment have been made, none successfully. Although some calendrical and what might prove to be genealogical information has been identified, none of these glyphs can actually be read. If rongorongo does prove to be writing and proves to be an independent invention, it would be one of very few independent inventions of writing in human history.

Two dozen wooden objects bearing rongorongo inscriptions, some heavily weathered, burned, or otherwise damaged, were collected in the late 19th century and are now scattered in museums and private collections. None remain on Easter Island. The objects are mostly tablets shaped from irregular pieces of wood, sometimes driftwood, but include a chieftain's staff, a bird-man statuette, and two reimiro ornaments. There are also a few petroglyphs which may include short rongorongo inscriptions. Oral history suggests that only a small elite was ever literate and that the tablets were sacred.

Authentic rongorongo texts are written in alternating directions, a system called reverse boustrophedon. In a third of the tablets, the lines of text are inscribed in shallow fluting carved into the wood. The glyphs themselves are outlines of human, animal, plant, artifact and geometric forms. Many of the human and animal figures, such as glyphs 200 and 280 , have characteristic protuberances on each side of the head, possibly representing eyes.

Individual texts are conventionally known by a single uppercase letter and a name, such as Tablet C, the Mamari Tablet. The somewhat variable names may be descriptive or indicate where the object is kept, as in the Oar, the Snuffbox, the Small Santiago Tablet, and the Santiago Staff.

🔗 Books 🔗 Systems 🔗 Business 🔗 Psychology 🔗 United Kingdom 🔗 Engineering 🔗 Invention 🔗 Systems/Project management 🔗 Method engineering

Six Thinking Hats was written by Dr. Edward de Bono. "Six Thinking Hats" and the associated idea parallel thinking provide a means for groups to plan thinking processes in a detailed and cohesive way, and in doing so to think together more effectively.

In 2005, the tool found some use in the United Kingdom innovation sector, where it was offered by some facilitation companies and had been trialled within the United Kingdom's civil service.

🔗 Economics

The Penn effect is the economic finding that real income ratios between high and low income countries are systematically exaggerated by gross domestic product (GDP) conversion at market exchange rates. It is associated with what became the Penn World Table, and it has been a consistent econometric result since at least the 1950s.

The "Balassa–Samuelson effect" is a model cited as the principal cause of the Penn effect by neo-classical economics, as well as being a synonym of "Penn effect".

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/French military history 🔗 Military history/Cold War 🔗 Rocketry 🔗 Military history/European military history

The S3 was a French land-based Intermediate Range Ballistic Missile, equipped with a single 1.2-megatonne thermonuclear warhead. In France it is called an SSBS, for Sol-Sol Balistique Stratégique, or Ground-Ground Strategic Ballistic Missile.

🔗 Physics 🔗 Astronomy

Entropic gravity, also known as emergent gravity, is a theory in modern physics that describes gravity as an entropic force—a force with macro-scale homogeneity but which is subject to quantum-level disorder—and not a fundamental interaction. The theory, based on string theory, black hole physics, and quantum information theory, describes gravity as an emergent phenomenon that springs from the quantum entanglement of small bits of spacetime information. As such, entropic gravity is said to abide by the second law of thermodynamics under which the entropy of a physical system tends to increase over time.

At its simplest, the theory holds that when gravity becomes vanishingly weak—levels seen only at interstellar distances—it diverges from its classically understood nature and its strength begins to decay linearly with distance from a mass.

Entropic gravity provides the underlying framework to explain Modified Newtonian Dynamics, or MOND, which holds that at a gravitational acceleration threshold of approximately 1.2×10⁻¹⁰ m/s², gravitational strength begins to vary inversely (linearly) with distance from a mass rather than the normal inverse-square law of the distance. This is an exceedingly low threshold, measuring only 12 trillionths gravity's strength at earth's surface; an object dropped from a height of one meter would fall for 36 hours were earth's gravity this weak. It is also 3,000 times less than exists at the point where Voyager 1 crossed our solar system's heliopause and entered interstellar space.

The theory claims to be consistent with both the macro-level observations of Newtonian gravity as well as Einstein's theory of general relativity and its gravitational distortion of spacetime. Importantly, the theory also explains (without invoking the existence of dark matter and its accompanying math featuring new free parameters that are tweaked to obtain the desired outcome) why galactic rotation curves differ from the profile expected with visible matter.

The theory of entropic gravity posits that what has been interpreted as unobserved dark matter is the product of quantum effects that can be regarded as a form of positive dark energy that lifts the vacuum energy of space from its ground state value. A central tenet of the theory is that the positive dark energy leads to a thermal-volume law contribution to entropy that overtakes the area law of anti-de Sitter space precisely at the cosmological horizon.

The theory has been controversial within the physics community but has sparked research and experiments to test its validity.

Meta is a company performing big data analysis of scientific literature. Company is headquartered in Redwood City, California (formerly Toronto, Ontario, Canada) and operates Meta Science, a literature discovery platform. The company was acquired by the Chan Zuckerberg Initiative in 2017.