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πŸ”— Job guarantee

πŸ”— Economics

A job guarantee (JG) is an economic policy proposal aimed at providing a sustainable solution to the dual problems of inflation and unemployment. Its aim is to create full employment and price stability, by having the state promise to hire unemployed workers as an employer of last resort (ELR).

The economic policy stance currently dominant around the world uses unemployment as a policy tool to control inflation; when inflation rises, the government pursues contractionary fiscal or monetary policy, creating a buffer stock of unemployed people, reducing wage demands, and ultimately inflation. When inflationary expectations subside, expansionary policy aims to produce the opposite effect. In Marxian terms, the unemployed serve as a reserve army of labor. By contrast, in a job guarantee program, a buffer stock of employed people (employed in the job guarantee program) provides the same protection against inflation without the social costs of unemployment, hence potentially fulfilling the dual mandate of full employment and price stability.

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πŸ”— Akrasia

πŸ”— Philosophy πŸ”— Psychology πŸ”— Philosophy/Ancient philosophy πŸ”— Philosophy/Ethics

Akrasia (; Greek ἀκρασία, "lacking command" or "weakness", occasionally transliterated as acrasia or Anglicised as acrasy or acracy) is a lack of self-control, or acting against one's better judgment. Beginning with Plato, a variety of philosophers have attempted to determine whether or not akrasia exists and how to best define it.

πŸ”— Star Lifting

πŸ”— Architecture

Star lifting is any of several hypothetical processes by which a sufficiently advanced civilization (specifically, one of Kardashev-II or higher) could remove a substantial portion of a star's matter which can then be re-purposed, while possibly optimizing the star's energy output and lifespan at the same time. The term appears to have been coined by David Criswell.

Stars already lose a small flow of mass via solar wind, coronal mass ejections, and other natural processes. Over the course of a star's life on the main sequence this loss is usually negligible compared to the star's total mass; only at the end of a star's life when it becomes a red giant or a supernova is a large proportion of material ejected. The star lifting techniques that have been proposed would operate by increasing this natural plasma flow and manipulating it with magnetic fields.

Stars have deep gravity wells, so the energy required for such operations is large. For example, lifting solar material from the surface of the Sun to infinity requires 2.1 Γ— 1011 J/kg. This energy could be supplied by the star itself, collected by a Dyson sphere; using 10% of the Sun's total power output would allow 5.9 Γ— 1021 kilograms of matter to be lifted per year (0.0000003% of the Sun's total mass), or 8% of the mass of Earth's moon.

πŸ”— Phone Cloning

πŸ”— Telecommunications πŸ”— Law Enforcement

Phone cloning is the copying of identity from one cellular device to another.

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πŸ”— Diatoms make 20% of Earth's oxygen and can double in population every 24 hours

πŸ”— Geology πŸ”— Marine life πŸ”— Algae

Diatoms (diÑ-tom-os 'cut in half', from diÑ, 'through' or 'apart'; and the root of tém-n-ō, 'I cut'.) are a major group of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion metric tons of silicon each year from the waters in which they live, and contribute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up a system of fresh-water lakes.

Diatoms are unicellular: they occur either as solitary cells or in colonies, which can take the shape of ribbons, fans, zigzags, or stars. Individual cells range in size from 2 to 200 micrometers. In the presence of adequate nutrients and sunlight, an assemblage of living diatoms doubles approximately every 24 hours by asexual multiple fission; the maximum life span of individual cells is about six days. Diatoms have two distinct shapes: a few (centric diatoms) are radially symmetric, while most (pennate diatoms) are broadly bilaterally symmetric. A unique feature of diatom anatomy is that they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule. These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as "jewels of the sea" and "living opals". Movement in diatoms primarily occurs passively as a result of both water currents and wind-induced water turbulence; however, male gametes of centric diatoms have flagella, permitting active movement for seeking female gametes. Similar to plants, diatoms convert light energy to chemical energy by photosynthesis, although this shared autotrophy evolved independently in both lineages. Unusually for autotrophic organisms, diatoms possess a urea cycle, a feature that they share with animals, although this cycle is used to different metabolic ends in diatoms. The family Rhopalodiaceae also possess a cyanobacterial endosymbiont called a spheroid body. This endosymbiont has lost its photosynthetic properties, but has kept its ability to perform nitrogen fixation, allowing the diatom to fix atmospheric nitrogen.

The study of diatoms is a branch of phycology. Diatoms are classified as eukaryotes, organisms with a membrane-bound cell nucleus, that separates them from the prokaryotes archaea and bacteria. Diatoms are a type of plankton called phytoplankton, the most common of the plankton types. Diatoms also grow attached to benthic substrates, floating debris, and on macrophytes. They comprise an integral component of the periphyton community. Another classification divides plankton into eight types based on size: in this scheme, diatoms are classed as microalgae. Several systems for classifying the individual diatom species exist. Fossil evidence suggests that diatoms originated during or before the early Jurassic period, which was about 150 to 200 million years ago.

Diatoms are used to monitor past and present environmental conditions, and are commonly used in studies of water quality. Diatomaceous earth (diatomite) is a collection of diatom shells found in the earth's crust. They are soft, silica-containing sedimentary rocks which are easily crumbled into a fine powder and typically have a particle size of 10 to 200 ΞΌm. Diatomaceous earth is used for a variety of purposes including for water filtration, as a mild abrasive, in cat litter, and as a dynamite stabilizer.

πŸ”— Avro Canada VZ-9 Avrocar

πŸ”— United States πŸ”— Technology πŸ”— Aviation πŸ”— Military history πŸ”— Military history/Military aviation πŸ”— Military history/North American military history πŸ”— Military history/United States military history πŸ”— Military history/Military science, technology, and theory πŸ”— Canada πŸ”— Aviation/aircraft πŸ”— Engineering πŸ”— Cold War πŸ”— Military history/Military land vehicles πŸ”— Military history/Canadian military history

The Avro Canada VZ-9 Avrocar was a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single "turborotor" blowing exhaust out the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer.

Originally designed as a fighter-like aircraft capable of very high speeds and altitudes, the project was repeatedly scaled back over time and the U.S. Air Force eventually abandoned it. Development was then taken up by the U.S. Army for a tactical combat aircraft requirement, a sort of high-performance helicopter. In flight testing, the Avrocar proved to have unresolved thrust and stability problems that limited it to a degraded, low-performance flight envelope; subsequently, the project was cancelled in September 1961.

Through the history of the program, the project was referred to by a number of different names. Avro referred to the efforts as Project Y, with individual vehicles known as Spade and Omega. Project Y-2 was later funded by the U.S. Air Force, who referred to it as WS-606A, Project 1794 and Project Silver Bug. When the U.S. Army joined the efforts it took on its final name "Avrocar", and the designation "VZ-9", part of the U.S. Army's VTOL projects in the VZ series.

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πŸ”— Prince Rupert's Drop

πŸ”— Philosophy/Logic πŸ”— Glass

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πŸ”— DCF77

πŸ”— Germany πŸ”— Time πŸ”— Radio Stations

DCF77 is a German longwave time signal and standard-frequency radio station. It started service as a standard-frequency station on 1 January 1959. In June 1973 date and time information was added. Its primary and backup transmitter are located at 50Β°0β€²56β€³N 9Β°00β€²39β€³E in Mainflingen, about 25Β km south-east of Frankfurt am Main, Germany. The transmitter generates a nominal power of 50Β kW, of which about 30 to 35Β kW can be radiated via a T-antenna.

DCF77 is controlled by the Physikalisch-Technische Bundesanstalt (PTB), Germany's national physics laboratory and transmits in continuous operation (24 hours). It is operated by Media Broadcast GmbH (previously a subsidiary of Deutsche Telekom AG), on behalf of the PTB. With Media Broadcast GmbH, a temporal transmission availability of at least 99.7% per year or under 26.28 hours of annual downtime has been agreed upon. Most service interruptions are short-term disconnections of under two minutes. Longer lasting transmission service interruptions are generally caused by strong winds, freezing rain or snow-induced T-antenna movement. This manifests itself in electrical detuning of the antenna resonance circuit and hence a measurable phase modulation of the received signal. When the maladjustment is too large, the transmitter is taken out of service temporarily. In the year 2002, almost 99.95% availability, or just over 4.38 hours of downtime, was realized. The timestamp sent is either in Coordinated Universal Time (UTC)+1 or UTC+2 depending on daylight saving time.

The highly accurate 77.5Β kHz (approximately 3868.3Β m wavelength) carrier signal is generated from local atomic clocks that are linked with the German master clocks at the PTB in Braunschweig. The DCF77 time signal is used for the dissemination of the German national legal time to the public.

Radio clocks and watches have been very popular in Europe since the late 1980s and, in mainland Europe, most of them use the DCF77 signal to set their time automatically. Further industrial time-keeping systems at railway stations, in the field of telecommunication and information technology, and at radio and TV stations are radio-controlled by DCF77 as well as tariff change-over clocks of energy supply companies and clocks in traffic-light facilities.

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  • "DCF77" | 2021-06-30 | 67 Upvotes 37 Comments

πŸ”— Superformula

πŸ”— Mathematics

The superformula is a generalization of the superellipse and was proposed by Johan Gielis around 2000. Gielis suggested that the formula can be used to describe many complex shapes and curves that are found in nature. Gielis has filed a patent application related to the synthesis of patterns generated by the superformula.

In polar coordinates, with r {\displaystyle r} the radius and Ο† {\displaystyle \varphi } the angle, the superformula is:

r ( Ο† ) = ( | cos ⁑ ( m 1 Ο† 4 ) a | n 2 + | sin ⁑ ( m 2 Ο† 4 ) b | n 3 ) βˆ’ 1 n 1 . {\displaystyle r\left(\varphi \right)=\left(\left|{\frac {\cos \left({\frac {m_{1}\varphi }{4}}\right)}{a}}\right|^{n_{2}}+\left|{\frac {\sin \left({\frac {m_{2}\varphi }{4}}\right)}{b}}\right|^{n_{3}}\right)^{-{\frac {1}{n_{1}}}}.}

By choosing different values for the parameters a , b , m 1 , m 2 , n 1 , n 2 , {\displaystyle a,b,m_{1},m_{2},n_{1},n_{2},} and n 3 , {\displaystyle n_{3},} different shapes can be generated.

The formula was obtained by generalizing the superellipse, named and popularized by Piet Hein, a Danish mathematician.

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πŸ”— Alamut (Bartol Novel)

πŸ”— Novels πŸ”— Slovenia

Alamut is a novel by Vladimir Bartol, first published in 1938 in Slovenian, dealing with the story of Hassan-i Sabbah and the Hashshashin, and named after their Alamut fortress. The maxim of the novel is "Nothing is an absolute reality; all is permitted". This book was one of the inspirations for the video game series Assassin's Creed.

Bartol first started to conceive the novel in the early 1930s, when he lived in Paris. In the French capital, he met with the Slovene literary critic Josip Vidmar, who introduced him to the story of Hassan-i Sabbah. A further stimulation for the novel came from the assassination of Alexander I of Yugoslavia perpetrated by Croatian and Bulgarian radical nationalists, on the alleged commission of the Italian fascist government. When it was originally published, the novel was sarcastically dedicated to Benito Mussolini.

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