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🔗 Mathematics

John von Neumann's universal constructor is a self-replicating machine in a cellular automata (CA) environment. It was designed in the 1940s, without the use of a computer. The fundamental details of the machine were published in von Neumann's book Theory of Self-Reproducing Automata, completed in 1966 by Arthur W. Burks after von Neumann's death.

Von Neumann's goal was to specify an abstract machine which, when run, would replicate itself. In his design, the machine consists of three parts: a 'blueprint' for itself, a mechanism that can read any blueprint and construct the machine (sans blueprint) specified by that blueprint, and a 'copy machine' that can make copies of any blueprint. After the mechanism has been used to construct the machine specified by the blueprint, the copy machine is used to create a copy of that blueprint, and this copy is placed into the new machine, resulting in a working replication of the original machine. Some machines will do this backwards, copying the blueprint and then building a machine.

To define his machine in more detail, von Neumann invented the concept of a cellular automaton. The one he used consists of a two-dimensional grid of cells, each of which can be in one of 29 states at any point in time. At each timestep, each cell updates its state depending on the states of the surrounding cells at the prior timestep. The rules governing these updates are identical for all cells.

The universal constructor is a certain pattern of cell states in this cellular automaton. It contains one line of cells that serve as a 'tape', encoding a sequence of instructions that serve as a 'blueprint' for the machine. The machine reads these instructions one by one and performs the corresponding actions. The instructions direct the machine to use its 'construction arm' to build a copy of the machine, without tape, at some other location in the cell grid. The tape can't contain instructions to build an equally long tape, just as a container can't contain a container of the same size. Therefore, the machine contains a separate 'copy machine' which reads the tape and places a copy into the newly constructed machine. The resulting new machine and tape is identical to the old one, and it proceeds to replicate again.

🔗 Russia 🔗 Food and drink

An anti-café (sometimes called a pay-per-minute café or a time club) is a venue that offers working space, food and drink, where customers pay only for the time they spend there. Anti-cafés became popular around 2011 in Russia and some CIS countries, with further independent anti-cafés opening across the world. Anti-cafés include the Ziferblat chain, founded by Russian writer Ivan Mitin in December 2010 in Moscow, the "Slow Time" café in Wiesbaden opened in 2013, and "Dialogues" in Bangalore.

Anti-cafés mostly target entrepreneurs, digital nomads, students, and creatives who need a cheap and convenient place to get their work done and meet other professionals. They can also be used by companies as a place give presentations and press conferences at low cost.

🔗 Biography 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Women's History 🔗 Military history/Military biography 🔗 Military history/Early Modern warfare 🔗 Military history/American Revolutionary War 🔗 Biography/military biography 🔗 Military history/Intelligence

Agent 355 (died after 1780) was the code name of a female spy during the American Revolution, part of the Culper Ring. Agent 355 was one of the first spies for the United States, but her real identity is unknown. The number, 355, could be de-crypted from the system the Culper Ring used to mean "lady."

🔗 Aviation 🔗 Aviation/aircraft

The Airbus Beluga XL (Airbus A330-743L) is a large transport aircraft based on the Airbus A330 airliner. The aircraft entered service with Airbus Transport on 9 January 2020 to replace the Airbus Beluga in the movement of oversized aircraft components, for example wings. The Beluga XL made its first flight on 19 July 2018, and received its type certification on 13 November 2019.

It made its first operational flight on January 9, 2020, and by January 20, had entered full-time service.

🔗 Computer science 🔗 Systems 🔗 Human–Computer Interaction

In artificial intelligence, an expert system is a computer system emulating the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning through bodies of knowledge, represented mainly as if–then rules rather than through conventional procedural code. The first expert systems were created in the 1970s and then proliferated in the 1980s. Expert systems were among the first truly successful forms of artificial intelligence (AI) software. An expert system is divided into two subsystems: the inference engine and the knowledge base. The knowledge base represents facts and rules. The inference engine applies the rules to the known facts to deduce new facts. Inference engines can also include explanation and debugging abilities.

🔗 Technology 🔗 Internet culture 🔗 Visual arts 🔗 Computer graphics 🔗 Artificial Intelligence

Slop is low-quality media—including writing and images—made using generative artificial intelligence technology. Coined in the 2020s, the term has a derogatory connotation akin to "spam".

It has been variously defined as "digital clutter", "filler content produced by AI tools that prioritize speed and quantity over substance and quality", and "shoddy or unwanted AI content in social media, art, books and, increasingly, in search results".

Jonathan Gilmore, Professor of Philosophy at the City University of New York, describes the "incredibly banal, realistic style" of AI slop as being "very easy to process".

🔗 Climate change 🔗 Environment 🔗 Automobiles

Rolling coal (also spelled rollin' coal) is the practice of modifying a diesel engine to emit large amounts of black or grey sooty exhaust fumes—diesel fuel that has not undergone complete combustion.

Rolling coal is a form of anti-environmentalism. Such modifications may include the intentional removal of the particulate filter. Practitioners often additionally modify their vehicles by installing smoke switches, large exhausts, and smoke stacks. Modifications to a vehicle to enable rolling coal may cost from US$200 to US$5,000.

🔗 Biography

John Socha-Leialoha (born 1958) is a software developer best known for creating Norton Commander, the first orthodox file manager. The original Norton Commander was written for DOS. Over the years, Socha's design for file management has been extended and cloned many times.

John grew up in the woods of Wisconsin, earned a BS degree in Electrical Engineering from University of Wisconsin–Madison, and his PhD in Applied Physics from Cornell University. He now lives in Bellevue, Washington with his wife. His son, John Avi, is a graduate of the University of Washington.

Starting in September 2010, John began working at Microsoft officially.

🔗 Disability

The curb cut effect is the phenomenon of disability-friendly features being used and appreciated by a larger group than the people they were designed for. For example, many hearing people use closed captioning. The phenomenon is named for curb cuts – miniature ramps comprising parts of sidewalk – which were first made for wheelchair access in particular places, but are now universal and no longer widely recognized as a disability-accessibility feature.

The curb cut effect is a subset of universal design, which is the purposeful design of an environment so that it is accessible to all people regardless of ability or disability. The curb cut effect differs slightly from universal design as the curb cut phenomenon is often unintentional rather than purposeful, but results in a similar outcome.

🔗 Architecture 🔗 Pakistan

Osama bin Laden's compound, known locally as the Waziristan Haveli (Urdu: وزیرستان حویلی‎), was an upper-class mansion that was used as a safe house for militant Islamist Osama bin Laden, who was shot and killed there by U.S. forces on May 2, 2011. The compound was located at the end of a dirt road 1,300 metres (0.8 mi) southwest of the Pakistan Military Academy in Bilal Town, Abbottabad, Pakistan, a suburb housing many retired military officers. Bin Laden was reported to have evaded capture by living in a section of the house for at least five years, having no Internet or phone connection, and hiding away from the public, who were allegedly unaware of his presence.

Completed in 2005, the main buildings in the compound lay on a 3,500-square-metre (38,000 sq ft) plot of land, much larger than those of nearby houses. Its perimeter was 3.7- to 5.5-metre (12 to 18 ft) concrete walls topped with barbed wire, and there were two security gates. The compound had very few windows. Little more than five years old, the compound's ramshackle buildings were badly in need of repainting. The grounds contained a well-kept vegetable garden, rabbits, some 100 chickens and a cow. The house itself did not stand out architecturally from others in the neighbourhood, except for its size and exaggerated security measures; for example, the third-floor balcony had a 2-metre (7 ft) privacy wall. Photographs inside the house showed excessive clutter and modest furnishings. After the American mission, there was extensive interest in and reporting about the compound and its design. To date, the Pakistani government has not responded to any allegations as to who had built the structure.

After the September 11 attacks in 2001, the U.S. searched for bin Laden for nearly 10 years. By tracking his courier Abu Ahmed al-Kuwaiti to the compound, U.S. officials surmised that bin Laden was hiding there. During a raid on May 2, 2011, 24 members of the United States Naval Special Warfare Development Group arrived by helicopter, breached a wall using explosives, and entered the compound in search of bin Laden. After the operation was completed and bin Laden was killed, Pakistan demolished the structure in February 2012.