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🔗 Technology

A Tesla valve, called by Tesla a valvular conduit, is a fixed-geometry passive check valve. It allows a fluid to flow preferentially in one direction, without moving parts. The device is named after Nikola Tesla, who was awarded U.S. Patent 1,329,559 in 1920 for its invention. The patent application describes the invention as follows:

The interior of the conduit is provided with enlargements, recesses, projections, baffles, or buckets which, while offering virtually no resistance to the passage of the fluid in one direction, other than surface friction, constitute an almost impassable barrier to its flow in the opposite direction.

Tesla illustrates this with the drawing, showing one possible construction with a series of eleven flow-control segments, although any other number of such segments could be used as desired to increase or decrease the flow regulation effect.

One computational fluid dynamics simulation of Tesla valves with two and four segments showed that the flow resistance in the blocking (or reverse) direction was about 15 and 40 times greater, respectively, than the unimpeded (or forward) direction. This lends support to Tesla's patent assertion that in the valvular conduit in his diagram, a pressure ratio "approximating 200 can be obtained so that the device acts as a slightly leaking valve".

The Tesla valve is used in microfluidic applications and offers advantages such as scalability, durability, and ease of fabrication in a variety of materials.

🔗 Skepticism 🔗 Psychology 🔗 Sociology 🔗 Paranormal

Nobel disease or Nobelitis is the embracing of strange or scientifically unsound ideas by some Nobel Prize winners, usually later in life. It has been argued that the effect results, in part, from a tendency for Nobel winners to feel empowered by the award to speak on topics outside their specific area of expertise, although it is unknown whether Nobel Prize winners are more prone to this tendency than other individuals. Paul Nurse, co-winner of the 2001 Nobel Prize in Physiology or Medicine, warned later laureates against "believing you are expert in almost everything, and being prepared to express opinions about most issues with great confidence, sheltering behind the authority that the Nobel Prize can give you". Nobel disease has been described as a "tongue in cheek" term.

🔗 United States 🔗 Companies 🔗 Telecommunications 🔗 United States/Colorado

Qwest Communications International, Inc. was a large United States telecommunications carrier. Qwest provided local service in 14 western and midwestern U.S. states: Arizona, Colorado, Idaho, Iowa, Minnesota, Montana, Nebraska, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming.

On April 22, 2010, CenturyLink announced it would acquire Qwest in a stock transaction. The merger closed on April 1, 2011. Qwest began doing business as CenturyLink in August 2011.

Qwest provided voice, Internet backbone data services, and digital television in some areas. It operated in three segments: Wireline Services, Wireless Services, and Other Services. The Wireline Services segment provided local voice, long-distance voice, and data and Internet (DSL) services to consumers, businesses, and wholesale customers, as well as access services to wholesale customers. The Wireless Services segment was achieved by a partnership with Verizon Wireless. Qwest also partnered with DirecTV to provide digital television service to its customers. In Phoenix, Denver, Salt Lake City, Boise, and Omaha, Qwest offered Qwest Choice TV (later also known as Qwest Digital Television), an IPTV service over DSL. This service was retired in October 2008 (after being no longer available to new customers in May 2008), leaving DirecTV as the only TV service Qwest provided. Qwest Choice TV customers were moved to DirecTV. The Other Services segment primarily involved the sublease of real estate assets, such as space in office buildings, warehouses, and other properties.

Qwest Communications also provided long-distance services and broadband data, as well as voice and video communications globally. The company sold its products and services to small businesses, governmental entities, and public and private educational institutions through various channels, including direct-sales marketing, telemarketing, arrangements with third-party agents, company's Web site, and partnership relations. As of September 13, 2005, Qwest had 98 retail stores in 14 states. Qwest Communications was headquartered in Denver, Colorado at 1801 California Street, in the second tallest building in Denver at 53 stories. The majority of Qwest occupational or non-management employees were represented by two labor unions; the Communications Workers of America and in Montana, the International Brotherhood of Electrical Workers. Qwest also had software development centers in Bangalore and Noida (New Delhi), India called Qwest Software Services.

NAR 2 (Serbian Nastavni Računar 2, en. Educational Computer 2) is a theoretical model of a 32-bit word computer created by Faculty of Mathematics of University of Belgrade professor Nedeljko Parezanović as an enhancement to its predecessor, NAR 1. It was used for Assembly language and Computer architecture courses. The word "nar" means Pomegranate in Serbian. Many NAR 2 simulators have been created — for instance, one was named "Šljiva" (en. plum) as that fruit grows in Serbia, while "nar" does not.

🔗 Europe 🔗 Musical Instruments 🔗 Percussion

A pyrophone, also known as a "fire/explosion organ" or "fire/explosion calliope" is a musical instrument in which notes are sounded by explosions, or similar forms of rapid combustion, rapid heating, or the like, such as burners in cylindrical glass tubes, creating light and sound. It was invented by physicist and musician Georges Frédéric Eugène Kastner (born 1852 in Strasbourg, France – died 1882 in Bonn, Germany), son of composer Jean-Georges Kastner, around 1870.

🔗 Internet culture 🔗 Science Fiction 🔗 Robotics 🔗 Discrimination 🔗 English Language 🔗 Star Wars 🔗 Artificial Intelligence

"Clanker" is a derogatory term for robots and artificial intelligence (AI) software. The term has been used in Star Wars media, first appearing in the franchise's 2005 video game Star Wars: Republic Commando. By 2025, the term had become widely used to express hatred or distaste for machines ranging from delivery robots to large language models. This trend has been attributed to anxiety around the negative societal effects of AI.

🔗 Europe

The European Green Belt initiative is a grassroots movement for nature conservation and sustainable development along the corridor of the former Iron Curtain. The term refers to both an environmental initiative as well as the area it concerns. The initiative is carried out under the patronage of the International Union for Conservation of Nature and Mikhail Gorbachev. It is the aim of the initiative to create the backbone of an ecological network that runs from the Barents to the Black and Adriatic Seas.

The European Green Belt as an area follows the route of the former Iron Curtain and connects National Parks, Nature Parks, Biosphere Reserves and transboundary protected areas as well as non-protected valuable habitats along or across the (former) borders.

🔗 Mathematics

In mathematics, a combinatorial explosion is the rapid growth of the complexity of a problem due to how the combinatorics of the problem is affected by the input, constraints, and bounds of the problem. Combinatorial explosion is sometimes used to justify the intractability of certain problems. Examples of such problems include certain mathematical functions, the analysis of some puzzles and games, and some pathological examples which can be modelled as the Ackermann function.

🔗 Pharmacology

The oligodynamic effect (from Greek oligos "few", and dynamis "force") is a biocidal effect of metals, especially heavy metals, that occurs even in low concentrations.

In modern times, the effect was observed by Karl Wilhelm von Nägeli, although he did not identify the cause. Scholarly texts from ancient India promoted the use of brass and silver in ritual cleansing practice as well as in consumption of food and drink. The ancient Indian medical text Sushruta Samhita promoted the use of specific metals in surgical procedures as a measure to prevent infection. Brass doorknobs and silverware both exhibit this effect to an extent.