New Articles (Page 52)
To stay up to date you can also follow on Mastodon.
π Gunung Padang
Gunung Padang is a megalithic site located in Karyamukti, Campaka, Cianjur Regency, West Java, Indonesia, 30 kilometres (19Β mi) southwest of the regency seat or 8 kilometres (5.0Β mi) from Lampegan station. Located at 885 metres (2,904Β ft) above sea level, the site covers a hill, an extinct volcano, in a series of five terraces bordered by retaining walls of stone that are accessed by 370 successive andesite steps rising about 95 metres (312Β ft). It is covered with massive hexagonal stone columns of volcanic origin. The Sundanese people consider the site sacred and believe it was the result of King Siliwangi's attempt to build a palace in one night.
Gunung Padang consists of a series of five artificial terraces, one rectangular and four trapezoidal, that occur, one through five, at successively higher elevations. These terraces also become sucessively smaller with elevation with the first terrace as the lowest and largest and the fifth terrace as the highest and smallest. These terraces lie along the a central, longitudinal NW-SE axis. They are artificial platforms created by lowering high spots and filling in low spots with fill until a flat surface was achieved. The terrace perimeters consist of perimeter retaining walls formed by volcanic polygonal columns stacked horizontally and posted vertically as posts. This terrace complex is accessed by a central stairway with 370 steps, an inclination of 45 degrees, and a length of 110Β m (360Β ft).
Discussed on
- "Gunung Padang" | 2023-10-04 | 18 Upvotes 24 Comments
π The Gulf War Did Not Take Place
The Gulf War Did Not Take Place (French: La Guerre du Golfe n'a pas eu lieu) is a collection of three short essays by Jean Baudrillard published in the French newspaper LibΓ©ration and British paper The Guardian between January and March 1991.
While the author acknowledges that the events and violence of what has been called the Gulf War took place, he asks if the events that took place were really as they were presented, and could they be called a war? The title is a reference to the play The Trojan War Will Not Take Place by Jean Giraudoux (in which characters attempt to prevent what the audience knows is inevitable).
Discussed on
- "The Gulf War Did Not Take Place" | 2023-10-03 | 42 Upvotes 37 Comments
π Karmarkar's algorithm β Patent controversy β can mathematics be patented?
Karmarkar's algorithm is an algorithm introduced by Narendra Karmarkar in 1984 for solving linear programming problems. It was the first reasonably efficient algorithm that solves these problems in polynomial time. The ellipsoid method is also polynomial time but proved to be inefficient in practice.
Denoting as the number of variables and as the number of bits of input to the algorithm, Karmarkar's algorithm requires operations on -digit numbers, as compared to such operations for the ellipsoid algorithm. The runtime of Karmarkar's algorithm is thus
using FFT-based multiplication (see Big O notation).
Karmarkar's algorithm falls within the class of interior-point methods: the current guess for the solution does not follow the boundary of the feasible set as in the simplex method, but moves through the interior of the feasible region, improving the approximation of the optimal solution by a definite fraction with every iteration and converging to an optimal solution with rational data.
π The man who did not have a conversation in over 50 years
AndrΓ‘s Toma (5 December 1925 β 30 March 2004) was a Hungarian soldier taken prisoner by the Red Army in 1945, then discovered living in a Russian psychiatric hospital in 2000. He was probably the last prisoner of war from the Second World War to be repatriated.
Because Toma never learned Russian and nobody at the hospital spoke Hungarian, he had apparently not had a single conversation in over 50 years, a situation of great interest for the fields of psychiatry and psycholinguistics.
Discussed on
- "The man who did not have a conversation in over 50 years" | 2023-09-30 | 213 Upvotes 61 Comments
π SIMH β Old Computer Emulator
SIMH is a free and open source, multi-platform multi-system emulator. It is maintained by Bob Supnik, a former DEC engineer and DEC vice president, and has been in development in one form or another since the 1960s.
Discussed on
- "SIMH β Old Computer Emulator" | 2023-09-29 | 92 Upvotes 63 Comments
π Third Normal Form
Third normal form (3NF) is a database schema design approach for relational databases which uses normalizing principles to reduce the duplication of data, avoid data anomalies, ensure referential integrity, and simplify data management. It was defined in 1971 by Edgar F. Codd, an English computer scientist who invented the relational model for database management.
A database relation (e.g. a database table) is said to meet third normal form standards if all the attributes (e.g. database columns) are functionally dependent on solely the primary key. Codd defined this as a relation in second normal form where all non-prime attributes depend only on the candidate keys and do not have a transitive dependency on another key.
A hypothetical example of a failure to meet third normal form would be a hospital database having a table of patients which included a column for the telephone number of their doctor. The phone number is dependent on the doctor, rather than the patient, thus would be better stored in a table of doctors. The negative outcome of such a design is that a doctor's number will be duplicated in the database if they have multiple patients, thus increasing both the chance of input error and the cost and risk of updating that number should it change (compared to a third normal form-compliant data model that only stores a doctor's number once on a doctor table).
Codd later realized that 3NF did not eliminate all undesirable data anomalies and developed a stronger version to address this in 1974, known as BoyceβCodd normal form.
Discussed on
- "Third Normal Form" | 2023-09-28 | 11 Upvotes 3 Comments
π Heckler's Veto
In the United States, a heckler's veto is a situation in which a party who disagrees with a speaker's message is able to unilaterally trigger events that result in the speaker being silenced. For example, a heckler can disrupt a speech to the point that the speech is canceled.
In the legal sense, a heckler's veto occurs when the speaker's right is curtailed or restricted by the government in order to prevent a reacting party's behavior. The common example is the termination of a speech or demonstration in the interest of maintaining the public peace based on the anticipated negative reaction of someone opposed to that speech or demonstration.
The term heckler's veto was coined by University of Chicago professor of law Harry Kalven. Colloquially, the concept is invoked in situations where hecklers or demonstrators silence a speaker without intervention of the law.
Discussed on
- "Heckler's Veto" | 2023-09-28 | 36 Upvotes 9 Comments
π Nuclear Engine for Rocket Vehicle Application (Nerva)
The Nuclear Engine for Rocket Vehicle Application (NERVA) was a nuclear thermal rocket engine development program that ran for roughly two decades. Its principal objective was to "establish a technology base for nuclear rocket engine systems to be utilized in the design and development of propulsion systems for space mission application". It was a joint effort of the Atomic Energy Commission (AEC) and the National Aeronautics and Space Administration (NASA), and was managed by the Space Nuclear Propulsion Office (SNPO) until the program ended in January 1973. SNPO was led by NASA's Harold Finger and AEC's Milton Klein.
NERVA had its origins in Project Rover, an AEC research project at the Los Alamos Scientific Laboratory (LASL) with the initial aim of providing a nuclear-powered upper stage for the United States Air Force intercontinental ballistic missiles. Nuclear thermal rocket engines promised to be more efficient than chemical ones. After the formation of NASA in 1958, Project Rover was continued as a civilian project and was reoriented to producing a nuclear powered upper stage for NASA's Saturn V Moon rocket. Reactors were tested at very low power before being shipped to Jackass Flats in the Nevada Test Site. While LASL concentrated on reactor development, NASA built and tested complete rocket engines.
The AEC, SNPO, and NASA considered NERVA a highly successful program in that it met or exceeded its program goals. It demonstrated that nuclear thermal rocket engines were a feasible and reliable tool for space exploration, and at the end of 1968 SNPO deemed that the latest NERVA engine, the XE, met the requirements for a human mission to Mars. It had strong political support from Senators Clinton P. Anderson and Margaret Chase Smith but was cancelled by President Richard Nixon in 1973. Although NERVA engines were built and tested as much as possible with flight-certified components and the engine was deemed ready for integration into a spacecraft, they never flew in space.
Discussed on
- "Nuclear Engine for Rocket Vehicle Application (Nerva)" | 2023-09-28 | 28 Upvotes 9 Comments
π Prophetic Perfect Tense
The prophetic perfect tense is a literary technique used in the Bible that describes future events that are so certain to happen that they are referred to in the past tense as if they had already happened.
Discussed on
- "Prophetic Perfect Tense" | 2023-09-28 | 154 Upvotes 96 Comments
π 'No Way to Prevent This,' Says Only Nation Where This Regularly Happens
"'No Way to Prevent This', Says Only Nation Where This Regularly Happens" is the title of a series of articles perennially published by the American news satire organization The Onion satirizing the frequency of mass shootings in the United States and the lack of action taken in the wake of such incidents.
Each article is about 200 words long, detailing the location of the shooting and the number of victims, but otherwise remaining essentially the same. A fictitious residentβusually of a state in which the shooting did not take placeβis quoted as saying that the shooting was "a terrible tragedy", but "there's nothing anyone can do to stop them." The article ends by saying that the United States is the "only economically advanced nation in the world where roughly two mass shootings have occurred every month for the past eight years," and that Americans view themselves and the situation as "helpless".
Discussed on
- "'No Way to Prevent This,' Says Only Nation Where This Regularly Happens" | 2023-09-28 | 59 Upvotes 56 Comments