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πŸ”— Cantor function, a.k.a. devil's staircase: increasing function with 0 derivative

πŸ”— Mathematics πŸ”— Systems πŸ”— Systems/Chaos theory

In mathematics, the Cantor function is an example of a function that is continuous, but not absolutely continuous. It is a notorious counterexample in analysis, because it challenges naive intuitions about continuity, derivative, and measure. Though it is continuous everywhere and has zero derivative almost everywhere, its value still goes from 0 to 1 as its argument reaches from 0 to 1. Thus, in one sense the function seems very much like a constant one which cannot grow, and in another, it does indeed monotonically grow, by construction.

It is also referred to as the Cantor ternary function, the Lebesgue function, Lebesgue's singular function, the Cantor–Vitali function, the Devil's staircase, the Cantor staircase function, and the Cantor–Lebesgue function. Georg CantorΒ (1884) introduced the Cantor function and mentioned that Scheeffer pointed out that it was a counterexample to an extension of the fundamental theorem of calculus claimed by Harnack. The Cantor function was discussed and popularized by Scheeffer (1884), Lebesgue (1904) and Vitali (1905).

πŸ”— Capitol Hill Autonomous Zone

πŸ”— United States πŸ”— Socialism πŸ”— Urban studies and planning πŸ”— Cooperatives πŸ”— United States/Washington - Seattle πŸ”— Micronations πŸ”— United States/Washington πŸ”— Anarchism πŸ”— Black Lives Matter

The Capitol Hill Autonomous Zone (CHAZ or the Zone), also known as Free Capitol Hill, is a self-declared intentional community and commune of around 200 residents, covering about six city blocks in the Capitol Hill neighborhood of Seattle, Washington. The zone was established on June 8, 2020 after the East Precinct was abandoned by the Seattle Police Department.

πŸ”— Whistler (Radio)

πŸ”— Physics πŸ”— Meteorology πŸ”— Radio

A whistler is a very low frequency or VLF electromagnetic (radio) wave generated by lightning. Frequencies of terrestrial whistlers are 1Β kHz to 30Β kHz, with a maximum amplitude usually at 3Β kHz to 5Β kHz. Although they are electromagnetic waves, they occur at audio frequencies, and can be converted to audio using a suitable receiver. They are produced by lightning strikes (mostly intracloud and return-path) where the impulse travels along the Earth's magnetic field lines from one hemisphere to the other. They undergo dispersion of several kHz due to the slower velocity of the lower frequencies through the plasma environments of the ionosphere and magnetosphere. Thus they are perceived as a descending tone which can last for a few seconds. The study of whistlers categorizes them into Pure Note, Diffuse, 2-Hop, and Echo Train types.

Voyager 1 and 2 spacecraft detected whistler-like activity in the vicinity of Jupiter known as "Jovian Whistlers", implying the presence of lightning there.

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πŸ”— The Theory of American Decline

πŸ”— United States πŸ”— Economics πŸ”— Politics

American decline is a term used by various analysts to describe the diminishing power of the United States geopolitically, militarily, financially, economically, socially, and in health and the environment. There has been a debate between declinists, those who believe America is in decline, and exceptionalists, those who feel America is immortal.

Some analysts say that the U.S. was in decline long before Donald Trump ran for presidency; becoming the first presidential candidate to promote the idea that the U.S. was in decline. While others suggest the decline either stems from or has accelerated with Trump's foreign policy and the "country’s ongoing withdrawal from the global arena." According to Noam Chomsky, America's decline started at the end of WWII, dismissing the "remarkable rhetoric of the several years of triumphalism in the 1990s" as "mostly self-delusion".

Gallup's pollsters recently reported that worldwide approval of U.S. leadership has plunged from 48% in 2016 to a record low of 30% in 2018, in part due to the increasingly isolationist stances of Donald Trump. This drop places the U.S. a notch below China's 31% and leaving Germany as the most popular power with an approval of 41%. Michael Hudson describes financial pillar as paramount, resulting from bank-created money with compound interest and the inbuilt refusal to forgive debts as the fatal flaw.

China's challenging the U.S. for global predominance constitutes the core issue in the debate over the American decline.

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πŸ”— Maillard reaction

πŸ”— Food and drink πŸ”— Chemistry

The Maillard reaction ( my-YAR; French: [majaʁ]) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and many other foods undergo this reaction. It is named after French chemist Louis-Camille Maillard, who first described it in 1912 while attempting to reproduce biological protein synthesis.

The reaction is a form of non-enzymatic browning which typically proceeds rapidly from around 140 to 165Β Β°C (280 to 330Β Β°F). Many recipes call for an oven temperature high enough to ensure that a Maillard reaction occurs. At higher temperatures, caramelization (the browning of sugars, a distinct process) and subsequently pyrolysis (final breakdown leading to burning) become more pronounced.

The reactive carbonyl group of the sugar reacts with the nucleophilic amino group of the amino acid, and forms a complex mixture of poorly characterized molecules responsible for a range of aromas and flavors. This process is accelerated in an alkaline environment (e.g., lye applied to darken pretzels; see lye roll), as the amino groups (RNH3+ β†’ RNH2) are deprotonated, and hence have an increased nucleophilicity. This reaction is the basis for many of the flavoring industry's recipes. At high temperatures, a probable carcinogen called acrylamide can form. This can be discouraged by heating at a lower temperature, adding asparaginase, or injecting carbon dioxide.

In the cooking process, Maillard reactions can produce hundreds of different flavor compounds depending on the chemical constituents in the food, the temperature, the cooking time, and the presence of air. These compounds, in turn, often break down to form yet more new flavor compounds. Flavor scientists have used the Maillard reaction over the years to make artificial flavors.

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πŸ”— 86-DOS

πŸ”— Computing πŸ”— Computing/Software

86-DOS is a discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit. Initially known as QDOS (Quick and Dirty Operating System), the name was changed to 86-DOS once SCP started licensing the operating system in 1980.

86-DOS had a command structure and application programming interface that imitated that of Digital Research's CP/M operating system, which made it easy to port programs from the latter. The system was licensed and then purchased by Microsoft and developed further as MS-DOS and PCΒ DOS.

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πŸ”— 555 Timer IC Integrated Circuit

πŸ”— Electronics

The 555 timer IC is an integrated circuit (chip) used in a variety of timer, delay, pulse generation, and oscillator applications. Derivatives provide two (556) or four (558) timing circuits in one package. Introduced in 1972 by Signetics, the 555 is still in widespread use due to its low price, ease of use, and stability. Numerous companies have made the original bipolar timers and similar low-power CMOS timers too. As of 2003, it was estimated that 1 billion units were manufactured every year. The 555 is the most popular integrated circuit ever manufactured.

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πŸ”— Mean World Syndrome

πŸ”— Psychology

Mean world syndrome is a cognitive bias where people perceive the world to be more dangerous than it actually is due to long-term, moderate to heavy exposure to violence-related content on mass media.

Mean world syndrome asserts that viewers who are exposed to violence-related content can experience increased fear, anxiety, pessimism and heightened state of alert in response to perceived threats. This is because media (namely television) consumed by viewers has the power to directly influence and inform their attitudes, beliefs and opinions about the world.

Dr. George Gerbner, who coined the term mean world syndrome in the 1970s, began his research on the effects of violent media on individuals’ attitudes by claiming that a major cultural shift was taking place, where "who tells the stories of a culture really governs human behavior. It used to be the parent, the school, the church, the community. Now it's a handful of global conglomerates that have nothing to tell, but a great deal to sell."

Since TV was becoming an ever increasing presence in the average American household and the amount of violence on TV was growing exponentially, Gerbner conducted several large-scale studies that upheld his hypothesis: those who watched moderate to large amounts of TV believed the world to be a more dangerous place.

Since the 1970s, numerous studies have corroborated Gerbner's findings that moderate to heavy viewing of violence-related content on TV increased depression, fear, anxiety, anger, pessimism, post-traumatic stress and substance use. For example, in 2009, the American Academy of Pediatrics released a policy statement on media violence which concluded that β€œextensive research evidence indicates that media violence can contribute to aggressive behavior, desensitization to violence, nightmares, and fear of being harmed.”

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πŸ”— Fred Hampton

πŸ”— United States πŸ”— Biography πŸ”— Chicago πŸ”— African diaspora πŸ”— United States/FBI πŸ”— Civil Rights Movement πŸ”— Illinois πŸ”— Biography/Actors and Filmmakers

Fredrick Allen Hampton (August 30, 1948 – December 4, 1969) was an American activist and revolutionary socialist. He came to prominence in Chicago as chairman of the Illinois chapter of the Black Panther Party (BPP), and deputy chairman of the national BPP. In this capacity, he founded a prominent multicultural political organization, the Rainbow Coalition that initially included the Black Panthers, Young Patriots and the Young Lords, and an alliance among major Chicago street gangs to help them end infighting, and work for social change.

In 1967, Hampton was identified by the Federal Bureau of Investigation as a radical threat. The FBI tried to subvert his activities in Chicago, sowing disinformation among these groups and placing a counterintelligence operative in the local Panthers. In December 1969, Hampton was shot and killed in his bed during a predawn raid at his Chicago apartment by a tactical unit of the Cook County State's Attorney's Office in conjunction with the Chicago Police Department and the Federal Bureau of Investigation; during the raid, another Panther was killed and several seriously wounded. In January 1970, a coroner's jury held an inquest and ruled the deaths of Hampton and Mark Clark to be justifiable homicide.

A civil lawsuit was later filed on behalf of the survivors and the relatives of Hampton and Clark. It was resolved in 1982 by a settlement of $1.85 million; the City of Chicago, Cook County, and the federal government each paid one-third to a group of nine plaintiffs. Given revelations about the illegal COINTELPRO program and documents associated with the killings, scholars now widely consider Hampton's death an assassination under the FBI's initiative.

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πŸ”— The Illiac IV Computer

πŸ”— Computing πŸ”— Computing/Computer hardware

The ILLIAC IV was the first massively parallel computer. The system was originally designed to have 256 64-bit floating point units (FPUs) and four central processing units (CPUs) able to process 1 billion operations per second. Due to budget constraints, only a single "quadrant" with 64 FPUs and a single CPU was built. Since the FPUs all had to process the same instruction – ADD, SUB etc. – in modern terminology the design would be considered to be single instruction, multiple data, or SIMD.

The concept of building a computer using an array of processors came to Daniel Slotnick while working as a programmer on the IAS machine in 1952. A formal design did not start until 1960, when Slotnick was working at Westinghouse Electric and arranged development funding under a US Air Force contract. When that funding ended in 1964, Slotnick moved to the University of Illinois and joined the Illinois Automatic Computer (ILLIAC) team. With funding from Advanced Research Projects Agency (ARPA), they began the design of a newer concept with 256 64-bit processors instead of the original concept with 1,024 1-bit processors.

While the machine was being built at Burroughs, the university began building a new facility to house it. Political tension over the funding from the US Department of Defense led to the ARPA and the University fearing for the machine's safety. When the first 64-processor quadrant of the machine was completed in 1972, it was sent to the NASA Ames Research Center in California. After three years of thorough modification to fix various flaws, ILLIAC IV was connected to the ARPANet for distributed use in November 1975, becoming the first network-available supercomputer, beating the Cray-1 by nearly 12 months.

Running at half its design speed, the one-quadrant ILLIAC IV delivered 50Β MFLOP peak, making it the fastest computer in the world at that time. It is also credited with being the first large computer to use solid-state memory, as well as the most complex computer built to date, with over 1 million gates. Generally considered a failure due to massive budget overruns, the design was instrumental in the development of new techniques and systems for programming parallel systems. In the 1980s, several machines based on ILLIAC IV concepts were successfully delivered.

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