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π Von Neumann-Landauer limit
Landauer's principle is a physical principle pertaining to the lower theoretical limit of energy consumption of computation. It holds that "any logically irreversible manipulation of information, such as the erasure of a bit or the merging of two computation paths, must be accompanied by a corresponding entropy increase in non-information-bearing degrees of freedom of the information-processing apparatus or its environment".
Another way of phrasing Landauer's principle is that if an observer loses information about a physical system, the observer loses the ability to extract work from that system.
A so-called logically-reversible computation, in which no information is erased, may in principle be carried out without releasing any heat. This has led to considerable interest in the study of reversible computing. Indeed, without reversible computing, increases in the number of computations-per-joule-of-energy-dissipated must come to a halt by about 2050: because the limit implied by Landauer's principle will be reached by then, according to Koomey's law.
At 20Β Β°C (room temperature, or 293.15Β K), the Landauer limit represents an energy of approximately 0.0175Β eV, or 2.805Β zJ. Theoretically, roomβtemperature computer memory operating at the Landauer limit could be changed at a rate of one billion bits per second (1Gbps) with energy being converted to heat in the memory media at the rate of only 2.805 trillionths of a watt (that is, at a rate of only 2.805 pJ/s). Modern computers use millions of times as much energy per second.
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- "Landauer's Principle" | 2023-05-27 | 80 Upvotes 32 Comments
- "Von Neumann-Landauer limit" | 2017-09-30 | 183 Upvotes 36 Comments
π Henry Kissinger turns 100 today
Henry Alfred Kissinger (; German: [ΛkΙͺsΙͺΕΙ]; born Heinz Alfred Kissinger, May 27, 1923) is an American diplomat, political theorist, geopolitical consultant, and politician who served as United States Secretary of State and National Security Advisor under the presidential administrations of Richard Nixon and Gerald Ford. For his actions negotiating a ceasefire in Vietnam, Kissinger received the 1973 Nobel Peace Prize under controversial circumstances.
Kissinger was a Jewish refugee who fled Nazi Germany with his family in 1938. Upon arriving in the United States, he excelled academically and graduated from Harvard College in 1950, where he studied under William Yandell Elliott. He earned his M.A. and Ph.D. degrees at Harvard University in 1951 and 1954, respectively.
A practitioner of Realpolitik, Kissinger played a prominent role in United States foreign policy between 1969 and 1977, pioneering the policy of dΓ©tente with the Soviet Union, orchestrating an opening of relations with the People's Republic of China, engaging in what became known as shuttle diplomacy in the Middle East to end the Yom Kippur War, and negotiating the Paris Peace Accords, which ended American involvement in the Vietnam War. Kissinger has also been associated with such controversial policies as the U.S. bombing of Cambodia during the Vietnam War, U.S. involvement in the 1973 Chilean military coup, a "green light" to Argentina's military junta for their Dirty War, and U.S. support for Pakistan during the Bangladesh Liberation War despite a genocide being perpetrated by Pakistan. After leaving government, he formed Kissinger Associates, an international geopolitical consulting firm. Kissinger has written over a dozen books on diplomatic history and international relations.
Kissinger remains a controversial and polarizing figure in U.S. politics, both venerated by some as a highly effective U.S. Secretary of State and condemned by others for allegedly tolerating or supporting war crimes committed by allied nation states during his tenure. A 2015 survey of top international relations scholars, conducted by College of William & Mary, ranked Kissinger as the most effective U.S. secretary of state in the 50 years to 2015. A centenarian, Kissinger is the oldest living former U.S. Cabinet member and the last surviving member of Nixon's Cabinet. The previous oldest cabinet member was George Shultz, who died at the age of 100 in February 2021.
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- "Henry Kissinger turns 100 today" | 2023-05-27 | 39 Upvotes 34 Comments
π Biosphere 2
Biosphere 2 is an American Earth system science research facility located in Oracle, Arizona. Its mission is to serve as a center for research, outreach, teaching, and lifelong learning about Earth, its living systems, and its place in the universe. It is a 3.14-acre (1.27-hectare) structure originally built to be an artificial, materially closed ecological system, or vivarium. It remains the largest closed ecological system ever created.
Constructed between 1987 and 1991, Biosphere 2 was originally meant to demonstrate the viability of closed ecological systems to support and maintain human life in outer space as a substitute for Earth's biosphere. It was designed to explore the web of interactions within life systems in a structure with different areas based on various biological biomes. In addition to the several biomes and living quarters for people, there was an agricultural area and work space to study the interactions between humans, farming, technology and the rest of nature as a new kind of laboratory for the study of the global ecology. Its mission was a two-year closure experiment with a crew of eight humans ("biospherians"). Long-term it was seen as a precursor to gaining knowledge about the use of closed biospheres in space colonization. As an experimental ecological facility it allowed the study and manipulation of a mini biospheric system without harming Earth's biosphere.
Its seven biome areas were a 1,900-square-meter (20,000Β sqΒ ft) rainforest, an 850-square-meter (9,100Β sqΒ ft) ocean with a coral reef, a 450-square-meter (4,800Β sqΒ ft) mangrove wetlands, a 1,300-square-metre (14,000Β sqΒ ft) savannah grassland, a 1,400-square-meter (15,000Β sqΒ ft) fog desert, and two anthropogenic biomes: a 2,500-square-meter (27,000Β sqΒ ft) agricultural system and a human habitat with living spaces, laboratories and workshops. Below ground was an extensive part of the technical infrastructure. Heating and cooling water circulated through independent piping systems and passive solar input through the glass space frame panels covering most of the facility, and electrical power was supplied into Biosphere 2 from an onsite natural gas energy center.
Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts ran into problems including low amounts of food and oxygen, die-offs of many animals and plants included in the experiment (though this was anticipated since the project used a strategy of deliberately "species-packing" anticipating losses as the biomes developed), group dynamic tensions among the resident crew, outside politics, and a power struggle over management and direction of the project. Nevertheless, the closure experiments set world records in closed ecological systems, agricultural production, health improvements with the high nutrient and low caloric diet the crew followed, and insights into the self-organization of complex biomic systems and atmospheric dynamics. The second closure experiment achieved total food sufficiency and did not require injection of oxygen.
In June 1994, during the middle of the second experiment, the managing company, Space Biosphere Ventures, was dissolved, and the facility was left in limbo. Columbia University assumed management of the facility in 1995 and used it to run experiments until 2003. It then appeared to be in danger of being demolished to make way for housing and retail stores, but was taken over for research by the University of Arizona in 2007. The University of Arizona took full ownership of the structure in 2011.
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- "Biosphere 2" | 2023-05-26 | 100 Upvotes 50 Comments
π Children's Games (Bruegel)
Children's Games is an oil-on-panel by Flemish Renaissance artist Pieter Bruegel the Elder, painted in 1560. It is currently held and exhibited at the Kunsthistorisches Museum in Vienna. The entire composition is full of children playing a wide variety of games. Over 90 different games that were played by children at the time have been identified.
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- "Children's Games (Bruegel)" | 2023-05-26 | 57 Upvotes 23 Comments
π The Alien and Seditions Act
The Alien and Sedition Acts were a set of four laws enacted in 1798 that applied restrictions to immigration and speech in the United States. The Naturalization Act increased the requirements to seek citizenship, the Alien Friends Act allowed the president to imprison and deport non-citizens, the Alien Enemies Act gave the president additional powers to detain non-citizens during times of war, and the Sedition Act criminalized false and malicious statements about the federal government. The Alien Friends Act and the Sedition Act expired after a set number of years, and the Naturalization Act was repealed in 1802. The Alien Enemies Act is still in effect.
The Alien and Sedition Acts were controversial. They were supported by the Federalist Party, and supporters argued that the bills strengthened national security during the Quasi-War, an undeclared naval war with France from 1798 to 1800. The acts were denounced by Democratic-Republicans as suppression of voters and violation of free speech under the First Amendment. While they were in effect, the Alien and Sedition Acts, and the Sedition Act in particular, were used to suppress publishers affiliated with the Democratic-Republicans, and several publishers were arrested for criticism of the Adams administration. The Democratic-Republicans took power in 1800, in part because of backlash to the Alien and Sedition Acts, and all but the Alien Enemies Act were eliminated by the next Congress. The Alien Enemies Act has been invoked several times since, particularly during World War II. The Alien and Sedition Acts are generally received negatively by modern historians, and the Supreme Court has since indicated that aspects of the laws would be found unconstitutional if challenged.
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- "The Alien and Seditions Act" | 2023-05-23 | 12 Upvotes 1 Comments
π Michel de Montaigne
Michel Eyquem, Seigneur de Montaigne ( mon-TAYN; French:Β [miΚΙl ekΙm dΙ mΙΜtΙΙ²]; 28 February 1533Β β 13 September 1592), known as Michel de Montaigne, was one of the most significant philosophers of the French Renaissance. He is known for popularizing the essay as a literary genre. His work is noted for its merging of casual anecdotes and autobiography with intellectual insight. Montaigne had a direct influence on numerous Western writers; his massive volume Essais contains some of the most influential essays ever written.
During his lifetime, Montaigne was admired more as a statesman than as an author. The tendency in his essays to digress into anecdotes and personal ruminations was seen as detrimental to proper style rather than as an innovation, and his declaration that "I am myself the matter of my book" was viewed by his contemporaries as self-indulgent. In time, however, Montaigne came to be recognized as embodying, perhaps better than any other author of his time, the spirit of freely entertaining doubt that began to emerge at that time. He is most famously known for his skeptical remark, ''Que sΓ§ay-je?" ("What do I know?", in Middle French; now rendered as "Que sais-je?" in modern French).
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- "Michel de Montaigne" | 2023-05-23 | 110 Upvotes 38 Comments
π You'll own nothing and be happy
You'll own nothing and be happy (alternatively you'll own nothing and you'll be happy) is a phrase originated by Danish Politician Ida Auken in a 2016 essay for the World Economic Forum. After appearing in a WEF video in 2016, the phrase began to be used by critics of the World Economic Forum (WEF) who accuse the WEF of desiring restrictions on ownership of private property.
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- "You'll own nothing and be happy" | 2023-05-22 | 70 Upvotes 52 Comments
π Golden parachutes: Record severance payments at Wikimedia Foundation
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- "Golden parachutes: Record severance payments at Wikimedia Foundation" | 2023-05-22 | 412 Upvotes 394 Comments
π Ellison's Cave
Ellison's Cave is a pit cave located in Walker County, on Pigeon Mountain in the Appalachian Plateaus of Northwest Georgia. It is the 12th deepest cave in the United States and features the deepest, unobstructed pit in the continental US named Fantastic Pit. The cave is over 12 miles long and extends 1063 feet vertically.
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- "Ellison's Cave" | 2023-05-21 | 46 Upvotes 20 Comments
π Papyrus Oxyrhynchus 69
Papyrus Oxyrhynchus 69 (P. Oxy. 69) is a complaint about a robbery, written in Greek. The manuscript was written on papyrus in the form of a sheet. It was discovered by Grenfell and Hunt in 1897 in Oxyrhynchus. The document was written on 21 November 190. Currently it is housed in the Haskell Oriental Institute at the University of Chicago (2061). The text was published by Grenfell and Hunt in 1898.
The beginning of the letter is lost. It is a petition to an unknown official describing the theft of some barley and asking that an investigation be carried out. The author is unknown. The measurements of the fragment are 178 by 115Β mm. The description of the crime scene is quite detailed:
... they broke down a door that led into the public street and had been blocked up with bricks, probably using a log of wood as a battering-ram. They then entered the house and contented themselves with taking what was stored there, 10 artabae of barley, which they carried off by the same way. We guessed that this was removed piecemeal by the said door from the marks of a rope dragged along in that direction, and pointed out this fact to the chief of the police of that village and to the other officials.
10 artabae are equivalent to approximately 30β40 kilograms (66β88Β lb) of barley.
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- "Papyrus Oxyrhynchus 69" | 2023-05-21 | 20 Upvotes 5 Comments