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🔗 Technology 🔗 Television

A Nipkow disk (sometimes Anglicized as Nipkov disk; patented in 1884), also known as scanning disk, is a mechanical, rotating, geometrically operating image scanning device, patented in 1885 by Paul Gottlieb Nipkow. This scanning disk was a fundamental component in mechanical television through the 1920s and 1930s.

🔗 Russia 🔗 Russia/technology and engineering in Russia 🔗 Russia/mass media in Russia 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Intelligence 🔗 Military history/Russian, Soviet and CIS military history 🔗 Radio Stations

UVB-76, also known as "The Buzzer", is a nickname given by radio listeners to a shortwave radio station that broadcasts on the frequencies 4625 and 4810 kHz. It broadcasts a short, monotonous buzz tone , repeating at a rate of approximately 25 tones per minute, 24 hours per day. Sometimes, the buzzer signal is interrupted and a voice transmission in Russian takes place. The first reports were made of a station on this frequency in 1973.

🔗 Medicine 🔗 Iran 🔗 History of Science 🔗 Middle Ages 🔗 Islam 🔗 Middle Ages/History 🔗 Turkey

A bimaristan (Persian: بيمارستان‎, romanized: bīmārestān; Arabic: بِيْمَارِسْتَان‎, romanized: bīmāristān), also known as dar al-shifa (also darüşşifa in Turkish) or simply maristan, is a hospital in the historic Islamic world.

🔗 International relations 🔗 History 🔗 Europe 🔗 Politics 🔗 Poland 🔗 Lithuania 🔗 Eastern Europe

Intermarium (Polish: Międzymorze, Polish pronunciation: [mʲɛnd͡zɨˈmɔʐɛ]) was a geopolitical project conceived by politicians in successor states of the former Polish–Lithuanian Commonwealth in several iterations, some of which anticipated the inclusion as well of other, neighboring states. The proposed multinational polity would have extended across territories lying between the Baltic, Black and Adriatic Seas, hence the name meaning "Between-Seas".

Prospectively a federation of Central and Eastern European countries, the post-World War I Intermarium plan pursued by Polish leader and former political prisoner of the Russian Empire, Józef Piłsudski (1867–1935), sought to recruit to the proposed federation the Baltic states (Lithuania, Latvia, Estonia), Finland, Belarus, Ukraine, Hungary, Romania, Yugoslavia and Czechoslovakia. The Polish name Międzymorze (from między, "between"; and morze, "sea"), meaning "Between-Seas", was rendered into Latin as "Intermarium."

The proposed federation was meant to emulate the Polish–Lithuanian Commonwealth, stretching from the Baltic Sea to the Black Sea, that, from the end of the 16th century to the end of the 18th, had united the Kingdom of Poland and the Grand Duchy of Lithuania. Intermarium complemented Piłsudski's other geopolitical vision, Prometheism, whose goal was the dismemberment of the Russian Empire and that Empire's divestment of its territorial acquisitions.

Intermarium was, however, perceived by some Lithuanians as a threat to their newly established independence, and by some Ukrainians as a threat to their aspirations for independence, and while France backed the proposal, it was opposed by Russia and by most other Western powers. Within two decades of the failure of Piłsudski's grand scheme, all the countries that he had viewed as candidates for membership in the Intermarium federation had fallen to the Soviet Union or Nazi Germany, except for Finland (which suffered some territorial losses in the 1939–40 Winter War with the Soviet Union).

🔗 Technology 🔗 Computing 🔗 Computing/Early computers

The Water Integrator (Russian: Гидравлический интегратор) was an early analog computer built in the Soviet Union in 1936 by Vladimir Sergeevich Lukyanov. It functioned by careful manipulation of water through a room full of interconnected pipes and pumps. The water level in various chambers (with precision to fractions of a millimeter) represented stored numbers, and the rate of flow between them represented mathematical operations. This machine was capable of solving inhomogeneous differential equations.

The first versions of Lukyanov's integrators were rather experimental, made of tin and glass tubes, and each integrator could be used to solve only one problem. In the 1930s it was the only computer in the Soviet Union for solving partial differential equations.

In 1941, Lukyanov created a hydraulic integrator of modular design, which made it possible to assemble a machine for solving various problems. Two-dimensional and three-dimensional hydraulic integrators were designed.

In 1949–1955, an integrator in the form of standard unified units was developed at the NIISCHETMASH Institute. In 1955, the Ryazan plant of calculating and analytical machines began the serial production of integrators with the factory brand name “IGL” (russian: Интегратор Гидравлический Лукьянова - integrator of the Lukyanov hydraulic system). Integrators were widely distributed, delivered to Czechoslovakia, Poland, Bulgaria and China.

A water integrator was used in the design of the Karakum Canal in the 1940s, and the construction of the Baikal–Amur Mainline in the 1970s. Water analog computers were used in the Soviet Union until the 1980s for large-scale modelling. They were used in geology, mine construction, metallurgy, rocket production and other fields.

Currently, two hydraulic integrators are kept in the Polytechnic Museum in Moscow.

🔗 United States 🔗 Skepticism 🔗 United States/Washington - Seattle 🔗 United States/Washington

The Seattle windshield pitting epidemic is a phenomenon which affected Bellingham, Seattle, and other communities of Washington state in April, 1954; it is considered an example of a mass delusion. It was characterized by widespread observation of previously unnoticed windshield holes, pits and dings, leading residents to believe that a common causative agent was at work. It was originally thought to be the work of vandals but the rate of pitting was so great that residents began to attribute it to everything from sand flea eggs to nuclear bomb testing.

Originating in Bellingham in March, police initially believed the work to be vandals using BB guns. However the pitting was soon observed in the nearby towns of Sedro Woolley and Mount Vernon and by mid-April, appeared to have spread to the town of Anacortes on Fidalgo Island.

Within a week, the news and the so-called "pitting epidemic" had reached metropolitan Seattle. As the newspapers began to feature the story, more and more reports of pitting were called in. Motorists began stopping police cars to report damage. Car lots and parking garages reported particularly severe attacks.

Several hypotheses for the widespread damage were postulated:

• Some thought that a new million-watt radio transmitter at nearby Jim Creek Naval Radio Station was producing waves that caused physical oscillations in glass;
• Some believed it to be the work of cosmic rays;
• Some reported seeing glass bubbles form right before their eyes, believing it to be the work of sand fleas.

By April 15, close to 3,000 windshields had been reported as affected. Mayor Allan Pomeroy contacted Washington Governor Arthur B. Langlie, then President Dwight D. Eisenhower asking for assistance.

Finally, Sergeant Max Allison of the Seattle police crime laboratory stated that the pitting reports consisted of "5 per cent hoodlum-ism, and 95 per cent public hysteria." By April 17, the pitting suddenly stopped.

The "Seattle Windshield Pitting Epidemic" as it is called has become a textbook case of collective delusion (not "mass hysteria" as reported). Although natural windshield pitting had been going on for some time, it was only when the media called public attention to it that people actually looked at their windshields and saw damage they had never noticed before.

🔗 California 🔗 California/San Francisco Bay Area 🔗 History 🔗 Viruses

The Anti-Mask League of San Francisco was an organization formed to protest an ordinance which required people in San Francisco, California to wear masks during the 1918 influenza pandemic. The ordinance it protested lasted less than one month before being repealed. Due to the short period of the league's existence, its exact membership is difficult to determine; however, an estimated 4,000–5,000 citizens showed up to a meeting to protest the second ordinance in January 1919. Opposition to similar ordinances during the COVID-19 pandemic in the United States led to renewed interest in, and comparisons with, the Anti-Mask League.

🔗 Biography 🔗 Apple Inc.

Jordan K. Hubbard (born April 8, 1963) is an open source software developer, authoring software such as the Ardent Window Manager and various other open source tools and libraries before co-founding the FreeBSD project with Nate Williams and Rodney W. Grimes in 1993, for which he contributed the initial FreeBSD Ports collection, package management system and sysinstall. In July 2001 Hubbard joined Apple Computer in the role of manager of the BSD technology group. In 2005, his title was "Director of UNIX Technology" and in October 2007, Hubbard was promoted to "Director of Engineering of Unix Technologies" at Apple where he remained until June 2013.

On July 15, 2013, he became CTO of iXsystems where he also led the FreeNAS open source project.

On March 24, 2017, he announced his plan to depart from iXsystems and that he would be joining TwoPoreGuys, a Biotechnology company, as VP of Engineering. From January 2019 - April 2020 he was part of the Engineering Leadership team at Uber and, as of April 2020, is currently Sr. Director for GPU Compute SW at NVidia [1].

🔗 Mathematics

A Penrose tiling is an example of an aperiodic tiling. Here, a tiling is a covering of the plane by non-overlapping polygons or other shapes, and aperiodic means that shifting any tiling with these shapes by any finite distance, without rotation, cannot produce the same tiling. However, despite their lack of translational symmetry, Penrose tilings may have both reflection symmetry and fivefold rotational symmetry. Penrose tilings are named after mathematician and physicist Roger Penrose, who investigated them in the 1970s.

There are several different variations of Penrose tilings with different tile shapes. The original form of Penrose tiling used tiles of four different shapes, but this was later reduced to only two shapes: either two different rhombi, or two different quadrilaterals called kites and darts. The Penrose tilings are obtained by constraining the ways in which these shapes are allowed to fit together. This may be done in several different ways, including matching rules, substitution tiling or finite subdivision rules, cut and project schemes, and coverings. Even constrained in this manner, each variation yields infinitely many different Penrose tilings.

Penrose tilings are self-similar: they may be converted to equivalent Penrose tilings with different sizes of tiles, using processes called inflation and deflation. The pattern represented by every finite patch of tiles in a Penrose tiling occurs infinitely many times throughout the tiling. They are quasicrystals: implemented as a physical structure a Penrose tiling will produce diffraction patterns with Bragg peaks and five-fold symmetry, revealing the repeated patterns and fixed orientations of its tiles. The study of these tilings has been important in the understanding of physical materials that also form quasicrystals. Penrose tilings have also been applied in architecture and decoration, as in the floor tiling shown.

🔗 Mathematics 🔗 Physics

Earnshaw's theorem states that a collection of point charges cannot be maintained in a stable stationary equilibrium configuration solely by the electrostatic interaction of the charges. This was first proven by British mathematician Samuel Earnshaw in 1842. It is usually referenced to magnetic fields, but was first applied to electrostatic fields.

Earnshaw's theorem applies to classical inverse-square law forces (electric and gravitational) and also to the magnetic forces of permanent magnets, if the magnets are hard (the magnets do not vary in strength with external fields). Earnshaw's theorem forbids magnetic levitation in many common situations.

If the materials are not hard, Braunbeck's extension shows that materials with relative magnetic permeability greater than one (paramagnetism) are further destabilising, but materials with a permeability less than one (diamagnetic materials) permit stable configurations.