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🔗 International relations 🔗 Politics

Policy laundering is the disguising of the origins of political decisions, laws, or international treaties. The term is based on the similar money laundering.

🔗 Mathematics 🔗 Physics

Stochastic resonance (SR) is a phenomenon where a signal that is normally too weak to be detected by a sensor, can be boosted by adding white noise to the signal, which contains a wide spectrum of frequencies. The frequencies in the white noise corresponding to the original signal's frequencies will resonate with each other, amplifying the original signal while not amplifying the rest of the white noise (thereby increasing the signal-to-noise ratio which makes the original signal more prominent). Further, the added white noise can be enough to be detectable by the sensor, which can then filter it out to effectively detect the original, previously undetectable signal.

This phenomenon of boosting undetectable signals by resonating with added white noise extends to many other systems, whether electromagnetic, physical or biological, and is an area of research.

🔗 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.

🔗 Toys

A pop-pop boat is a toy with a very simple steam engine without moving parts, typically powered by a candle or vegetable oil burner. The name comes from the noise made by some versions of the boats. Other names are putt-putt boat, crazy boat, flash-steamer, hot-air-boat, pulsating water engine boat. Around the world they may be called Can-Can-boot, Knatterboot, toc-toc, Puf-Puf boat, Poof Poof craft, Phut-Phut, or Pouet-Pouet.

🔗 Science

Operation Serenata de Amor is an artificial intelligence project to analyze public spending in Brazil. The project has been funded by a recurrent financing campaign since September 7, 2016, and came in the wake of major scandals of misappropriation of public funds in Brazil, such as the Mensalão scandal and what was revealed in the Operation Car Wash investigations.

The analysis began with data from the National Congress and then expanded to other types of budget and other instances of government, such as the Federal Senate. The project is built through collaboration on GitHub and using a public group with more than 600 participants on Telegram.

The name "Serenata de Amor," which means "serenade of love," was taken from a popular cashew cream bonbon produced by Chocolates Garoto in Brazil.

The Stigler diet is an optimization problem named for George Stigler, a 1982 Nobel Laureate in economics, who posed the following problem:

For a moderately active man weighing 154 pounds, how much of each of 77 foods should be eaten on a daily basis so that the man’s intake of nine nutrients will be at least equal to the recommended dietary allowances (RDAs) suggested by the National Research Council in 1943, with the cost of the diet being minimal?

The nutrient RDAs required to be met in Stigler’s experiment were calories, protein, calcium, iron, as well as vitamins A, B₁, B₂, B₃, and C. The result was an annual budget allocated to foods such as evaporated milk, cabbage, dried navy beans, and beef liver at a cost of approximately $0.11 a day in 1939 U.S. dollars.

While the name “Stigler Diet” was applied after the experiment by outsiders, according to Stigler, “No one recommends these diets for anyone, let alone everyone.” The Stigler diet has been much ridiculed for its lack of variety and palatability; however, his methodology has received praise and is considered to be some of the earliest work in linear programming.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry

The MIM-104 Patriot is a surface-to-air missile (SAM) system, the primary of its kind used by the United States Army and several allied nations. It is manufactured by the U.S. defense contractor Raytheon and derives its name from the radar component of the weapon system. The AN/MPQ-53 at the heart of the system is known as the "Phased Array Tracking Radar to Intercept on Target" which is a backronym for PATRIOT. The Patriot System replaced the Nike Hercules system as the U.S. Army's primary High to Medium Air Defense (HIMAD) system, and replaced the MIM-23 Hawk system as the U.S. Army's medium tactical air defense system. In addition to these roles, Patriot has been given the function of the U.S. Army's anti-ballistic missile (ABM) system, which is now Patriot's primary mission. The system is expected to stay fielded until at least 2040.

Patriot uses an advanced aerial interceptor missile and high-performance radar systems. Patriot was developed at Redstone Arsenal in Huntsville, Alabama, which had previously developed the Safeguard ABM system and its component Spartan and hypersonic speed Sprint missiles. The symbol for Patriot is a drawing of a Revolutionary War-era Minuteman.

Patriot systems have been sold to the Netherlands, Poland, Germany, Egypt, Japan, Israel, Saudi Arabia, Kuwait, Republic of China (Taiwan), Greece, Spain, United Arab Emirates, Qatar and Romania. South Korea purchased several second-hand Patriot systems from Germany after North Korea test-launched ballistic missiles to the Sea of Japan and proceeded with underground nuclear testing in 2006. Jordan also purchased several second-hand Patriot systems from Germany. Poland hosts training rotations of a battery of U.S. Patriot launchers. This started in the town of Morąg in May 2010 but was later moved further from the Russian border to Toruń and Ustka due to Russian objections. On December 4, 2012, NATO authorized the deployment of Patriot missile launchers in Turkey to protect the country from missiles fired in the civil war in neighboring Syria. Patriot was one of the first tactical systems in the U.S. Department of Defense's (DoD) to employ lethal autonomy in combat.

The Patriot system gained notoriety during the Persian Gulf War of 1991 with the claimed engagement of over 40 Iraqi Scud missiles, but those claims became a source of controversy. The system was successfully used against Iraqi missiles in 2003 Iraq War, and has been also used by Saudi and Emirati forces in the Yemen conflict against Houthi missile attacks. The Patriot system achieved its first undisputed shootdowns of enemy aircraft in the service of the Israeli Air Defense Command. Israeli MIM-104D batteries shot down two Hamas UAVs during Operation Protective Edge on August 31, 2014 and later, on September 23, 2014, an Israeli Patriot battery shot down a Syrian Air Force Sukhoi Su-24 which had penetrated Israeli airspace, achieving the first shootdown of a manned enemy aircraft in the world for the system.

🔗 Dogs

The eastern coyote (Canis latrans var.) is a wild North American canine of both coyote and wolf parentage. The hybridization likely first occurred in the Great Lakes region, as western coyotes moved east. It was first noticed during the early 1930s to the late 1940s, and likely originated in the aftermath of the extirpation of the gray wolf in southeastern Ontario, Labrador and Quebec, thus allowing coyotes to colonize the former wolf ranges and mix with the remnant wolf populations. This hybrid is smaller than the eastern wolf and holds smaller territories, but is larger and holds more extensive home ranges than the typical western coyote.

🔗 Computing 🔗 Computing/Software

In computer programming jargon, a heisenbug is a software bug that seems to disappear or alter its behavior when one attempts to study it. The term is a pun on the name of Werner Heisenberg, the physicist who first asserted the observer effect of quantum mechanics, which states that the act of observing a system inevitably alters its state. In electronics the traditional term is probe effect, where attaching a test probe to a device changes its behavior.

Similar terms, such as bohrbug, mandelbug, hindenbug, and schrödinbug (see the section on related terms) have been occasionally proposed for other kinds of unusual software bugs, sometimes in jest; however, unlike the term heisenbug, they are not widely known or used.

🔗 Mathematics

A prime number (or a prime) is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself. However, 6 is composite because it is the product of two numbers (2 × 3) that are both smaller than 6. Primes are central in number theory because of the fundamental theorem of arithmetic: every natural number greater than 1 is either a prime itself or can be factorized as a product of primes that is unique up to their order.

The property of being prime is called primality. A simple but slow method of checking the primality of a given number ${\displaystyle n}$, called trial division, tests whether ${\displaystyle n}$ is a multiple of any integer between 2 and ${\displaystyle {\sqrt {n}}}$. Faster algorithms include the Miller–Rabin primality test, which is fast but has a small chance of error, and the AKS primality test, which always produces the correct answer in polynomial time but is too slow to be practical. Particularly fast methods are available for numbers of special forms, such as Mersenne numbers. As of December 2018 the largest known prime number has 24,862,048 decimal digits.

There are infinitely many primes, as demonstrated by Euclid around 300 BC. No known simple formula separates prime numbers from composite numbers. However, the distribution of primes within the natural numbers in the large can be statistically modelled. The first result in that direction is the prime number theorem, proven at the end of the 19th century, which says that the probability of a randomly chosen number being prime is inversely proportional to its number of digits, that is, to its logarithm.

Several historical questions regarding prime numbers are still unsolved. These include Goldbach's conjecture, that every even integer greater than 2 can be expressed as the sum of two primes, and the twin prime conjecture, that there are infinitely many pairs of primes having just one even number between them. Such questions spurred the development of various branches of number theory, focusing on analytic or algebraic aspects of numbers. Primes are used in several routines in information technology, such as public-key cryptography, which relies on the difficulty of factoring large numbers into their prime factors. In abstract algebra, objects that behave in a generalized way like prime numbers include prime elements and prime ideals.