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🔗 Soviet Union 🔗 Military history 🔗 Military history/Cold War 🔗 Cold War 🔗 Military history/Russian, Soviet and CIS military history

On 26 September 1983, the nuclear early-warning radar of the Soviet Union reported the launch of one intercontinental ballistic missile with four more missiles behind it, from bases in the United States. These missile attack warnings were suspected to be false alarms by Stanislav Petrov, an officer of the Soviet Air Defence Forces on duty at the command center of the early-warning system. He decided to wait for corroborating evidence—of which none arrived—rather than immediately relaying the warning up the chain-of-command. This decision is seen as having prevented a retaliatory nuclear attack against the United States and its NATO allies, which would likely have resulted in an escalation to a full-scale nuclear war. Investigation of the satellite warning system later determined that the system had indeed malfunctioned.

🔗 Mathematics

In geometry, Prince Rupert's cube (named after Prince Rupert of the Rhine) is the largest cube that can pass through a hole cut through a unit cube, i.e. through a cube whose sides have length 1, without splitting the cube into two pieces. Its side length is approximately 6% larger than that of the unit cube through which it passes. The problem of finding the largest square that lies entirely within a unit cube is closely related, and has the same solution.

The original proposition posed by Prince Rupert of the Rhine was that a cube could be passed through a hole made in another cube of the same size without splitting the cube into two pieces.

🔗 United States/U.S. Government 🔗 United States

"Stellar Wind" (or "Stellarwind") was the code name of a warrantless surveillance program begun under the George W. Bush administration's President's Surveillance Program (PSP). The National Security Agency (NSA) program was approved by President Bush shortly after the September 11, 2001 attacks and was revealed by Thomas Tamm to The New York Times in 2004. Stellar Wind was a prelude to new legal structures that allowed President Bush and President Barack Obama to reproduce each of those programs and expand their reach.

🔗 France 🔗 Military history 🔗 Politics 🔗 Military history/Intelligence 🔗 Judaism 🔗 Military history/French military history 🔗 Jewish history 🔗 European history 🔗 Military history/European military history

The Dreyfus Affair (French: l'affaire Dreyfus, pronounced [lafɛːʁ dʁɛfys]) was a political scandal that divided the Third French Republic from 1894 until its resolution in 1906. "The Affair", as it is known in French, has come to symbolise modern injustice in the Francophone world, and it remains one of the most notable examples of a complex miscarriage of justice and antisemitism. The role played by the press and public opinion proved influential in the conflict.

The scandal began in December 1894 when Captain Alfred Dreyfus was convicted of treason. Dreyfus was a 35-year-old Alsatian French artillery officer of Jewish descent. He was sentenced to life imprisonment for allegedly communicating French military secrets to the German Embassy in Paris, and was imprisoned on Devil's Island in French Guiana, where he spent nearly five years.

In 1896, evidence came to light—primarily through an investigation instigated by Georges Picquart, head of counter-espionage—which identified the real culprit as a French Army major named Ferdinand Walsin Esterhazy. When high-ranking military officials suppressed the new evidence, a military court unanimously acquitted Esterhazy after a trial lasting only two days. The Army laid additional charges against Dreyfus, based on forged documents. Subsequently, Émile Zola's open letter J'Accuse…!, stoked a growing movement of support for Dreyfus, putting pressure on the government to reopen the case.

In 1899, Dreyfus was returned to France for another trial. The intense political and judicial scandal that ensued divided French society between those who supported Dreyfus (now called "Dreyfusards"), such as Sarah Bernhardt, Anatole France, Henri Poincaré and Georges Clemenceau, and those who condemned him (the anti-Dreyfusards), such as Édouard Drumont, the director and publisher of the antisemitic newspaper La Libre Parole. The new trial resulted in another conviction and a 10-year sentence, but Dreyfus was pardoned and released. In 1906, Dreyfus was exonerated and reinstated as a major in the French Army. He served during the whole of World War I, ending his service with the rank of lieutenant-colonel. He died in 1935.

The affair from 1894 to 1906 divided France into pro-republican, anticlerical, Dreyfusards and pro-Army, mostly Catholic "anti-Dreyfusards". It embittered French politics and encouraged radicalisation.

🔗 Physics 🔗 Electronics 🔗 Professional sound production

Pink noise or ​¹⁄_f noise is a signal or process with a frequency spectrum such that the power spectral density (energy or power per frequency interval) is inversely proportional to the frequency of the signal. In pink noise, each octave (halving or doubling in frequency) carries an equal amount of noise energy.

Pink noise is one of the most common signals in biological systems.

The name arises from the pink appearance of visible light with this power spectrum. This is in contrast with white noise which has equal intensity per frequency interval.

🔗 Medicine

The Therac-25 was a computer-controlled radiation therapy machine produced by Atomic Energy of Canada Limited (AECL) in 1982 after the Therac-6 and Therac-20 units (the earlier units had been produced in partnership with CGR of France).

It was involved in at least six accidents between 1985 and 1987, in which patients were given massive overdoses of radiation. Because of concurrent programming errors, it sometimes gave its patients radiation doses that were hundreds of times greater than normal, resulting in death or serious injury. These accidents highlighted the dangers of software control of safety-critical systems, and they have become a standard case study in health informatics and software engineering. Additionally the overconfidence of the engineers and lack of proper due diligence to resolve reported software bugs are highlighted as an extreme case where the engineers' overconfidence in their initial work and failure to believe the end users' claims caused drastic repercussions.

🔗 Biography 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/Military biography 🔗 Military history/World War II 🔗 Military history/Russian, Soviet and CIS military history

Ivan Mikhailovich Chisov (Russian: Иван Михайлович Чисов, Ukrainian: Іван Михайлович Чиссов; 1916–1986) was a Soviet Air Force lieutenant who survived a fall of approximately 7,000 meters (23,000 feet). Some references give the spelling of his last name as Chissov (Russian: Чиссов, Ukrainian: Чиссов).

🔗 Computing

In computer storage, Bélády's anomaly is the phenomenon in which increasing the number of page frames results in an increase in the number of page faults for certain memory access patterns. This phenomenon is commonly experienced when using the first-in first-out (FIFO) page replacement algorithm. In FIFO, the page fault may or may not increase as the page frames increase, but in Optimal and stack-based algorithms like LRU, as the page frames increase the page fault decreases. László Bélády demonstrated this in 1969.

In common computer memory management, information is loaded in specific-sized chunks. Each chunk is referred to as a page. Main memory can hold only a limited number of pages at a time. It requires a frame for each page it can load. A page fault occurs when a page is not found, and might need to be loaded from disk into memory.

When a page fault occurs and all frames are in use, one must be cleared to make room for the new page. A simple algorithm is FIFO: whichever page has been in the frames the longest is the one that is cleared. Until Bélády's anomaly was demonstrated, it was believed that an increase in the number of page frames would always result in the same number of or fewer page faults.

🔗 Biography 🔗 New York (state) 🔗 New York (state)/Columbia University

Randolph Silliman Bourne (; May 30, 1886 – December 22, 1918) was a progressive writer and intellectual born in Bloomfield, New Jersey, and a graduate of Columbia University. He is considered to be a spokesman for the young radicals living during World War I. His articles appeared in journals including The Seven Arts and The New Republic. Bourne is best known for his essays, especially his unfinished work "The State," discovered after he died. From this essay (which was published posthumously and included in Untimely Papers) comes the phrase "war is the health of the state" which laments the success of governments in arrogating authority and resources during conflicts.

🔗 Australia 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Intelligence 🔗 Australia/Australia, New Zealand and South Pacific military history 🔗 Military history/Australia, New Zealand and South Pacific military history 🔗 Australia/Northern Territory

Pine Gap is the commonly used name for a US satellite surveillance base and Australian Earth station approximately 18 kilometres (11 mi) south-west of the town of Alice Springs, Northern Territory in the centre of Australia which is jointly operated by Australia and the United States. Since 1988, it has been officially called the Joint Defence Facility Pine Gap (JDFPG); previously, it was misleadingly known as Joint Defence Space Research Facility.

The station is partly run by the US Central Intelligence Agency (CIA), US National Security Agency (NSA), and US National Reconnaissance Office (NRO) and is a key contributor to the NSA's global interception effort, which included the ECHELON program. The classified NRO name of the Pine Gap base is Australian Mission Ground Station (AMGS), while the unclassified cover term for the NSA function of the facility is RAINFALL.