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π Punjabi Mexican Americans
The Punjabi Mexican American community, the majority of which is localized to Yuba City, California, is a distinctive ethnicity holding its roots in a migration pattern that occurred almost a century ago. The first meeting of these cultures occurred in the Imperial and Central Valleys in 1907, near the largest irrigation system in the Western Hemisphere.
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- "Punjabi Mexican Americans" | 2023-09-07 | 44 Upvotes 10 Comments
π Failed intercept at Dhahran caused by a software error in handling of timestamps
The MIM-104 Patriot is a surface-to-air missile (SAM) system, the primary of its kind used by the United States Army and several allied nations. It is manufactured by the U.S. defense contractor Raytheon and derives its name from the radar component of the weapon system. The AN/MPQ-53 at the heart of the system is known as the "Phased Array Tracking Radar to Intercept on Target" which is a backronym for PATRIOT. The Patriot System replaced the Nike Hercules system as the U.S. Army's primary High to Medium Air Defense (HIMAD) system, and replaced the MIM-23 Hawk system as the U.S. Army's medium tactical air defense system. In addition to these roles, Patriot has been given the function of the U.S. Army's anti-ballistic missile (ABM) system, which is now Patriot's primary mission. The system is expected to stay fielded until at least 2040.
Patriot uses an advanced aerial interceptor missile and high-performance radar systems. Patriot was developed at Redstone Arsenal in Huntsville, Alabama, which had previously developed the Safeguard ABM system and its component Spartan and hypersonic speed Sprint missiles. The symbol for Patriot is a drawing of a Revolutionary War-era Minuteman.
Patriot systems have been sold to the Netherlands, Poland, Germany, Egypt, Japan, Israel, Saudi Arabia, Kuwait, Republic of China (Taiwan), Greece, Spain, United Arab Emirates, Qatar and Romania. South Korea purchased several second-hand Patriot systems from Germany after North Korea test-launched ballistic missiles to the Sea of Japan and proceeded with underground nuclear testing in 2006. Jordan also purchased several second-hand Patriot systems from Germany. Poland hosts training rotations of a battery of U.S. Patriot launchers. This started in the town of MorΔ g in May 2010 but was later moved further from the Russian border to ToruΕ and Ustka due to Russian objections. On December 4, 2012, NATO authorized the deployment of Patriot missile launchers in Turkey to protect the country from missiles fired in the civil war in neighboring Syria. Patriot was one of the first tactical systems in the U.S. Department of Defense's (DoD) to employ lethal autonomy in combat.
The Patriot system gained notoriety during the Persian Gulf War of 1991 with the claimed engagement of over 40 Iraqi Scud missiles, but those claims became a source of controversy. The system was successfully used against Iraqi missiles in 2003 Iraq War, and has been also used by Saudi and Emirati forces in the Yemen conflict against Houthi missile attacks. The Patriot system achieved its first undisputed shootdowns of enemy aircraft in the service of the Israeli Air Defense Command. Israeli MIM-104D batteries shot down two Hamas UAVs during Operation Protective Edge on August 31, 2014 and later, on September 23, 2014, an Israeli Patriot battery shot down a Syrian Air Force Sukhoi Su-24 which had penetrated Israeli airspace, achieving the first shootdown of a manned enemy aircraft in the world for the system.
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- "Failed intercept at Dhahran caused by a software error in handling of timestamps" | 2018-02-28 | 205 Upvotes 86 Comments
- "Patriot missile software failure, 28 soldiers died. Fix: reboot the system" | 2010-09-06 | 110 Upvotes 74 Comments
π Arecibo message
The Arecibo message is a 1974 interstellar radio message carrying basic information about humanity and Earth sent to globular star cluster M13. It was meant as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials.
The message was broadcast into space a single time via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo radio telescope in Puerto Rico on 16 November 1974. The message was aimed at the current location of M13 some 25,000 light years away because M13 was a large and close collection of stars that was available in the sky at the time and place of the ceremony. The message forms the image shown here when translated into graphics, characters, and spaces.
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- "Arecibo message" | 2018-05-09 | 73 Upvotes 46 Comments
π Digital sundial
A digital sundial is a clock that indicates the current time with numerals formed by the sunlight striking it. Like a classical sundial, the device contains no moving parts. It uses no electricity nor other manufactured sources of energy. The digital display changes as the sun advances in its daily course.
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- "Digital sundial" | 2014-07-16 | 232 Upvotes 47 Comments
π Tesler's Law
The law of conservation of complexity, also known as Tesler's Law, or Waterbed Theory, is an adage in humanβcomputer interaction stating that every application has an inherent amount of complexity that cannot be removed or hidden. Instead, it must be dealt with, either in product development or in user interaction.
This poses the question of who should be exposed to the complexity. For example, should a software developer add complexity to the software code to make the interaction simpler for the user or should the user deal with a complex interface so that the software code can be simple?
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- "Tesler's Law" | 2026-07-26 | 14 Upvotes 3 Comments
π $100 Billion USD oops
The 2018 Samsung fat-finger error was a fat-finger error on April 8th 2018 in which an employee of Samsung Securities mistakenly distributed shares worth US$100,000,000,000 to employees. The company is the stock trading arm of the Samsung conglomerate and is engaged in financial services including securities and investment banking sectors primarily in Korea, China, the United States, the United Kingdom, Japan, and Hong Kong.
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- "$100 Billion USD oops" | 2018-12-14 | 18 Upvotes 18 Comments
π Homo Sovieticus
Homo Sovieticus (Dog Latin for "Soviet Man") is a pejorative for an average conformist person in the Soviet Union and other countries of the Eastern Bloc. The term was popularized by Soviet writer and sociologist Aleksandr Zinovyev, who wrote the book titled Homo Sovieticus.
Michel Heller asserted that the term was coined in the introduction of a 1974 monograph "Sovetskye lyudi" ("Soviet People") to describe the next level of evolution of humanity thanks to the success of Marxist social experiment.
In a book published in 1981, but available in samizdat in the 1970s, Zinovyev also coined an abbreviation homosos (Π³ΠΎΠΌΠΎΡΠΎΡ, literally a homosucker).
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- "Homo Sovieticus" | 2022-03-01 | 65 Upvotes 61 Comments
π Lambda lifting
Lambda lifting is a meta-process that restructures a computer program so that functions are defined independently of each other in a global scope. An individual "lift" transforms a local function into a global function. It is a two step process, consisting of;
- Eliminating free variables in the function by adding parameters.
- Moving functions from a restricted scope to broader or global scope.
The term "lambda lifting" was first introduced by Thomas Johnsson around 1982 and was historically considered as a mechanism for implementing functional programming languages. It is used in conjunction with other techniques in some modern compilers.
Lambda lifting is not the same as closure conversion. It requires all call sites to be adjusted (adding extra arguments to calls) and does not introduce a closure for the lifted lambda expression. In contrast, closure conversion does not require call sites to be adjusted but does introduce a closure for the lambda expression mapping free variables to values.
The technique may be used on individual functions, in code refactoring, to make a function usable outside the scope in which it was written. Lambda lifts may also be repeated, in order to transform the program. Repeated lifts may be used to convert a program written in lambda calculus into a set of recursive functions, without lambdas. This demonstrates the equivalence of programs written in lambda calculus and programs written as functions. However it does not demonstrate the soundness of lambda calculus for deduction, as the eta reduction used in lambda lifting is the step that introduces cardinality problems into the lambda calculus, because it removes the value from the variable, without first checking that there is only one value that satisfies the conditions on the variable (see Curry's paradox).
Lambda lifting is expensive on processing time for the compiler. An efficient implementation of lambda lifting is on processing time for the compiler.
In the untyped lambda calculus, where the basic types are functions, lifting may change the result of beta reduction of a lambda expression. The resulting functions will have the same meaning, in a mathematical sense, but are not regarded as the same function in the untyped lambda calculus. See also intensional versus extensional equality.
The reverse operation to lambda lifting is lambda dropping.
Lambda dropping may make the compilation of programs quicker for the compiler, and may also increase the efficiency of the resulting program, by reducing the number of parameters, and reducing the size of stack frames. However it makes a function harder to re-use. A dropped function is tied to its context, and can only be used in a different context if it is first lifted.
Discussed on
- "Lambda lifting" | 2018-09-22 | 75 Upvotes 23 Comments
π Viewtron
Viewtron was an online service offered by Knight-Ridder and AT&T from 1983 to 1986. Patterned after the British Post Office's Prestel system, it started as a videotex service requiring users to have a special terminal, the AT&T Sceptre. As home computers became important in the marketplace, the development focus shifted to IBM, Apple, Commodore and other personal computers.
Viewtron differed from contemporary services like CompuServe and The Source by emphasizing news from The Miami Herald and Associated Press and e-commerce services from JCPenney and other merchants over computer-oriented services such as file downloads or online chat. Intended to be "the McDonald's of videotex," Viewtron was specifically targeted toward users who would be apprehensive about using a computer.
Viewtron also offered airline schedules from the Official Airline Guide (OAG), real estate research from Century 21, e-cards from Hallmark, product information from Consumer Reports, educational software from Scott Foresman, online auctions, financial services from American Express and EF Hutton, as well as limited online banking services as part of a research program into the uses and costs of banking online that included 20 US and Canadian banks.
At its height, Viewtron was operated in at least 15 cities by various newspaper companies. After six years of research and an investment reportedly in excess of $50 million, Viewtron never turned a profit, and, despite its developer's forecasts of breaking even in two years, Knight Ridder did not expect it ever would be profitable. AT&T had invested over $100 million in the project, but was forced to write off that investment as part of its court-ordered breakup. Viewtron closed on March 31, 1986, after an attempt by the Independent Commodore Users Group to buy the service failed.
A feature tying Viewtron to local newspapers was envisioned, with printed text instructing users how to access further information online, but it was never implemented.
In 2008, PCWorld magazine named Viewtron to a list of the biggest project failures in information technology (IT) history.
Discussed on
- "Viewtron" | 2018-08-30 | 27 Upvotes 10 Comments
π Asemic Writing
Asemic writing is a wordless open semantic form of writing. The word asemic means "having no specific semantic content", or "without the smallest unit of meaning". With the non-specificity of asemic writing there comes a vacuum of meaning, which is left for the reader to fill in and interpret. All of this is similar to the way one would deduce meaning from an abstract work of art. Where asemic writing distinguishes itself among traditions of abstract art is in the asemic author's use of gestural constraint, and the retention of physical characteristics of writing such as lines and symbols. Asemic writing is a hybrid art form that fuses text and image into a unity, and then sets it free to arbitrary subjective interpretations. It may be compared to free writing or writing for its own sake, instead of writing to produce verbal context. The open nature of asemic works allows for meaning to occur across linguistic understanding; an asemic text may be "read" in a similar fashion regardless of the reader's natural language. Multiple meanings for the same symbolism are another possibility for an asemic work, that is, asemic writing can be polysemantic or have zero meaning, infinite meanings, or its meaning can evolve over time. Asemic works leave for the reader to decide how to translate and explore an asemic text; in this sense, the reader becomes co-creator of the asemic work.
In 1997, visual poets Tim Gaze and Jim Leftwich first applied the word asemic to name their quasi-calligraphic writing gestures. They then began to distribute them to poetry magazines both online and in print. The authors explored sub-verbal and sub-letteral forms of writing, and textual asemia as a creative option and as an intentional practice. Since the late 1990s, asemic writing has blossomed into a worldwide literary/art movement. It has especially grown in the early part of the 21st century, though there is an acknowledgement of a long and complex history, which precedes the activities of the current asemic movement, especially with regards to abstract calligraphy, wordless writing, and verbal writing damaged beyond the point of legibility. Jim Leftwich has recently stated that an asemic condition of an asemic work is an impossible goal, and that it is not possible to create an art/literary work entirely without meaning. He has begun to use the term "pansemic" too. He also explained (in 2020): "The term 'pansemia' didn't replace the term 'asemia' in my thinking (nor did 'pansemic' replace 'asemic'); it merely assisted me in expanding my understanding of the theory and practice of asemic writing". Others such as author Travis Jeppesen have found the term asemic to be problematic because "it seems to infer writing with no meaning."
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- "Asemic Writing" | 2022-06-04 | 23 Upvotes 8 Comments