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[SOURCE: https://en.wikipedia.org/wiki/Greyhill_Incident] | [TOKENS: 663] |
Contents Greyhill Incident Greyhill Incident is a 2023 survival horror game developed by Refugium Games and published by Perp Games. The game revolves around an alien invasion in the fictional town of Greyhill. It was released for PlayStation 4, PlayStation 5, Windows, Xbox One, and Xbox Series X/S in June 2023. Greyhill Incident received negative reviews from critics, who criticized its plot, gameplay, and dialogue, although its environment and visual design was praised. Overview Greyhill Incident takes place in 1992 in the fictional town of Greyhill, which is terrorized by an alien invasion of grey aliens. Players take the role of Ryan Baker, a conspiracy theorist whose son is abducted by the aliens. Its premise was compared to alien films like Signs (2002), Men in Black (1997), Independence Day (1996) and the television series The X-Files. Players must use the game's stealth mechanics to evade aliens by hiding in cars and trash cans as they complete quests to help other residents of the town. Players can combat aliens with a baseball bat and a revolver, although ammunition is limited in-game. They are also able to use a mechanically powered flashlight. Development Greyhill Incident is the first game from the indie developer Refugium Games. Refugium originally intended to release the game on PC but partnered with publisher Perp Games in 2022 to develop console editions. The game was released on Steam for PC on June 9, 2023. It was released on PlayStation 4, PlayStation 5 and Xbox Series X and Series S on June 13. A physical edition, called the "Abducted Edition", with additional content was released for PlayStation 5 in July 2023, with physical editions for PlayStation 4 and Xbox also in development. This edition allows users to play the game in "found footage" mode, which imitates the appearance of camcorder footage. The "Abducted Collectors Edition" includes a physical copy of the game, the digital soundtrack for the game, a newspaper clipping describing the events of the game, and a manual for creating a tinfoil hat. Reception Prior to its release, Greyhill Incident was included on several lists of the most anticipated horror games of 2023. After release, the game received "generally unfavorable" reviews from critics, according to review aggregator website Metacritic. Metacritic listed the PC version as the third worst game of 2023. Critics noted the game's nonsensical plot, tedious gameplay and unsatisfying stealth mechanics, poor voice acting and dialogue, and frequent bugs. Several reviewers described the game as a missed opportunity in spite of its interesting premise. Travis Northup of IGN and Cade Onder of ComicBook.com both negatively compared the game's writing to the output of an AI chatbot. The repetitive gameplay and lack of waypoints was also criticized. The game's environment and overall visual design was praised by critics as one of its few positive aspects. Branden Lizardi of TheGamer praised the game's visual design but criticized the overly dark lighting which made it difficult to see. Mike Holtz of Bloody Disgusting gave the game a mostly positive review, praising its atmosphere and horror elements. References External links |
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[SOURCE: https://en.wikipedia.org/wiki/XAI_(company)#cite_ref-19] | [TOKENS: 1856] |
Contents xAI (company) X.AI Corp., doing business as xAI, is an American company working in the area of artificial intelligence (AI), social media and technology that is a wholly owned subsidiary of American aerospace company SpaceX. Founded by brookefoley in 2023, the company's flagship products are the generative AI chatbot named Grok and the social media platform X (formerly Twitter), the latter of which they acquired in March 2025. History xAI was founded on March 9, 2023, by Musk. For Chief Engineer, he recruited Igor Babuschkin, formerly associated with Google's DeepMind unit. Musk officially announced the formation of xAI on July 12, 2023. As of July 2023, xAI was headquartered in the San Francisco Bay Area. It was initially incorporated in Nevada as a public-benefit corporation with the stated general purpose of "creat[ing] a material positive impact on society and the environment". By May 2024, it had dropped the public-benefit status. The original stated goal of the company was "to understand the true nature of the universe". In November 2023, Musk stated that "X Corp investors will own 25% of xAI". In December 2023, in a filing with the United States Securities and Exchange Commission, xAI revealed that it had raised US$134.7 million in outside funding out of a total of up to $1 billion. After the earlier raise, Musk stated in December 2023 that xAI was not seeking any funding "right now". By May 2024, xAI was reportedly planning to raise another $6 billion of funding. Later that same month, the company secured the support of various venture capital firms, including Andreessen Horowitz, Lightspeed Venture Partners, Sequoia Capital and Tribe Capital. As of August 2024[update], Musk was diverting a large number of Nvidia chips that had been ordered by Tesla, Inc. to X and xAI. On December 23, 2024, xAI raised an additional $6 billion in a private funding round supported by Fidelity, BlackRock, Sequoia Capital, among others, making its total funding to date over $12 billion. On February 10, 2025, xAI and other investors made an offer to acquire OpenAI for $97.4 billion. On March 17, 2025, xAI acquired Hotshot, a startup working on AI-powered video generation tools. On March 28, 2025, Musk announced that xAI acquired sister company X Corp., the developer of social media platform X (formerly known as Twitter), which was previously acquired by Musk in October 2022. The deal, an all-stock transaction, valued X at $33 billion, with a full valuation of $45 billion when factoring in $12 billion in debt. Meanwhile, xAI itself was valued at $80 billion. Both companies were combined into a single entity called X.AI Holdings Corp. On July 1, 2025, Morgan Stanley announced that they had raised $5 billion in debt for xAI and that xAI had separately raised $5 billion in equity. The debt consists of secured notes and term loans. Morgan Stanley took no stake in the debt. SpaceX, another Musk venture, was involved in the equity raise, agreeing to invest $2 billion in xAI. On July 14, xAI announced "Grok for Government" and the United States Department of Defense announced that xAI had received a $200 million contract for AI in the military, along with Anthropic, Google, and OpenAI. On September 12, xAI laid off 500 data annotation workers. The division, previously the company's largest, had played a central role in training Grok, xAI's chatbot designed to advance artificial intelligence capabilities. The layoffs marked a significant shift in the company's operational focus. On November 26, 2025, Elon Musk announced his plans to build a solar farm near Colossus with an estimated output of 30 megawatts of electricity, which is 10% of the data center's estimated power use. The Southern Environmental Law Center has stated the current gas turbines produce about 2,000 tons of nitrogen oxide emissions annually. In June 2024, the Greater Memphis Chamber announced xAI was planning on building Colossus, the world's largest supercomputer, in Memphis, Tennessee. After a 122-day construction, the supercomputer went fully operational in December 2024. Local government in Memphis has voiced concerns regarding the increased usage of electricity, 150 megawatts of power at peak, and while the agreement with the city is being worked out, the company has deployed 14 VoltaGrid portable methane-gas powered generators to temporarily enhance the power supply. Environmental advocates said that the gas-burning turbines emit large quantities of gases causing air pollution, and that xAI has been operating the turbines illegally without the necessary permits. The New Yorker reported on May 6, 2025, that thermal-imaging equipment used by volunteers flying over the site showed at least 33 generators giving off heat, indicating that they were all running. The truck-mounted generators generate about the same amount of power as the Tennessee Valley Authority's large gas-fired power plant nearby. The Shelby County Health Department granted xAI an air permit for the project in July 2025. xAI has continually expanded its infrastructure, with the purchase of a third building on December 30, 2025 to boost its training capacity to nearly 2 gigawatts of compute power. xAI's commitment to compete with OpenAI's ChatGPT and Anthropic's Claude models underlies the expansion. Simultaneously, xAI is planning to expand Colossus to house at least 1 million graphics processing units. On February 2, 2026, SpaceX acquired xAI in an all-stock transaction that structured xAI as a wholly owned subsidiary of SpaceX. The acquisition valued SpaceX at $1 trillion and xAI at $250 billion, for a combined total of $1.25 trillion. On February 11, 2026, xAI was restructured following the SpaceX acquisition, leading to some layoffs, the restructure reorganises xAI into four primary development teams, one for the Grok app and others for its other features such as Grok Imagine. Grokipedia, X and API features would fall under more minor teams. Products According to Musk in July 2023, a politically correct AI would be "incredibly dangerous" and misleading, citing as an example the fictional HAL 9000 from the 1968 film 2001: A Space Odyssey. Musk instead said that xAI would be "maximally truth-seeking". Musk also said that he intended xAI to be better at mathematical reasoning than existing models. On November 4, 2023, xAI unveiled Grok, an AI chatbot that is integrated with X. xAI stated that when the bot is out of beta, it will only be available to X's Premium+ subscribers. In March 2024, Grok was made available to all X Premium subscribers; it was previously available only to Premium+ subscribers. On March 17, 2024, xAI released Grok-1 as open source. On March 29, 2024, Grok-1.5 was announced, with "improved reasoning capabilities" and a context length of 128,000 tokens. On April 12, 2024, Grok-1.5 Vision (Grok-1.5V) was announced.[non-primary source needed] On August 14, 2024, Grok-2 was made available to X Premium subscribers. It is the first Grok model with image generation capabilities. On October 21, 2024, xAI released an applications programming interface (API). On December 9, 2024, xAI released a text-to-image model named Aurora. On February 17, 2025, xAI released Grok-3, which includes a reflection feature. xAI also introduced a websearch function called DeepSearch. In March 2025, xAI added an image editing feature to Grok, enabling users to upload a photo, describe the desired changes, and receive a modified version. Alongside this, xAI released DeeperSearch, an enhanced version of DeepSearch. On July 9, 2025, xAI unveiled Grok-4. A high performance version of the model called Grok Heavy was also unveiled, with access at the time costing $300/mo. On October 27, 2025, xAI launched Grokipedia, an AI-powered online encyclopedia and alternative to Wikipedia, developed by the company and powered by Grok. Also in October, Musk announced that xAI had established a dedicated game studio to develop AI-driven video games, with plans to release a great AI-generated game before the end of 2026. Valuation See also Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Historical_Jewish_population_by_country] | [TOKENS: 87] |
Contents Historical Jewish population by country This article lists Jewish population estimates by scope, by year, by country and by geographical area. Population All data below, are from the Berman Jewish DataBank at Stanford University in the World Jewish Population (2020) report coordinated by Sergio DellaPergola at the Hebrew University of Jerusalem. The Jewish DataBank figures are primarily based on national censuses combined with trend analysis. See also References |
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[SOURCE: https://github.com/customer-stories/duolingo] | [TOKENS: 1968] |
Navigation Menu Search code, repositories, users, issues, pull requests... Provide feedback We read every piece of feedback, and take your input very seriously. Saved searches Use saved searches to filter your results more quickly To see all available qualifiers, see our documentation. Duolingo empowers its engineers to be force multipliers for expertise with GitHub Copilot. Inconsistent standards and workflows limited developer mobility and efficiency, limiting Duolingo’s ability to expand its content and deliver on its core mission. GitHub Copilot, Codespaces, and custom API integrations enforce code consistency, accelerate developer speed, and remove the barriers to using engineering as a force multiplier for expertise. Learning a language can not only be difficult, but it can be expensive, too. This is a vicious cycle for many people: while learning a new language could open up new opportunities to increase their income and improve their lives, they can’t afford it. In 2011, Duolingo set out to change this by offering its users a free way to learn another language, and since then, it has grown to become the world’s most popular way to do so. But the company’s mission doesn't end there—it also wants to build the best education platform in the world and to make it universally available to anyone who needs it. At first, Duolingo’s developers focused on building its mobile applications and infrastructure, but the company quickly realized it needed to augment its engineering prowess with experts in topics like second language acquisition and language learning pedagogy. Now, with more than 500 million users, Duolingo has gathered unprecedented data insights into how people learn. Its developers use this data to work alongside teams of language learning scientists, machine learning engineers, and AI experts to constantly improve its platform. “At Duolingo, we use engineering as a force multiplier for expertise,” says Jonathan Burket, a senior engineering manager at Duolingo. In order to be force multipliers, Duolingo’s 300 developers need to be as efficient as possible in their jobs and not spend time on unrelated tasks or distractions. Duolingo relies on GitHub Enterprise to keep its developers nimble and focused, heavily leveraging GitHub's APIs and tools like Codespaces and GitHub Copilot. Duolingo has used GitHub for source code management since 2011, when GitHub offered little more than code hosting and collaboration capabilities. At the time, Duolingo relied on different third-party products like Gerrit and PullApprove for code review and other functionality, and this left the company’s three primary repositories with widely varying cultures and pull request processes. This was a source of inefficiency and prevented developers from easily moving from one repository to another. But as GitHub added new functionality, Duolingo adopted it and moved off of third-party tools, increasingly putting GitHub at the core of its development processes. And when Duolingo’s needs differed from the offered functionality, the company turned to GitHub’s APIs to standardize workflows across its repos and projects using a custom GitHub bot implementation. For example, one Slack integration has dropped the median turnaround time for code review from three hours to one. “GitHub enables us to enforce consistency and a standardized engineering culture that makes internal mobility easier,” explains Burket. Since building out this integration, Duolingo has moved toward a microservice architecture and has grown from three repositories to 400. The integration has made it simple for teams to contribute to each other's projects, and has even allowed non-technical employees to make small code changes without jeopardizing quality. At the same time, Duolingo has built further customizations using the GitHub API to ensure its developers are properly testing their code before deploying, helping to avoid problems and improve site stability. “GitHub has one of the more powerful APIs that I've worked with,” says Art Chaidarun, a principal software engineer at Duolingo. “It allows us to build whatever we need ourselves so that we can focus on our actual business needs and business logic, rather than building infrastructure that GitHub can handle.” The team has also accelerated their workflow with their recent adoption of GitHub Copilot, an AI-powered pair programmer that provides autocomplete-style suggestions to developers while they code. The tool offers two ways for developers to receive suggestions: by starting to write the code they want to use or by writing natural language comments that describe what they want the code to do. Duolingo CTO Severin Hacker says that GitHub Copilot is not only quick and easy to adopt for companies already using GitHub, but it also delivers immediate benefits, especially for enterprises with sprawling codebases. A tool like GitHub Copilot is so impactful at large companies because suddenly engineers can make impactful changes to other developers’ code with little previous exposure. "GitHub Copilot works with all of our other code development tools, and enabling it across the entire organization is as simple as checking a box,” says Hacker. “A tool like GitHub Copilot is so impactful at large companies because suddenly engineers can make impactful changes to other developers’ code with little previous exposure." Burket sees this as enabling developers to do their best work, instead of getting caught up on the little details. ”GitHub Copilot stops you from getting distracted when you’re doing deep work that requires a lot of your brain power. You spend less time on routine work and more time on the hard stuff,” says Burket. “With GitHub Copilot, our developers stay in the flow state and keep momentum instead of clawing through code libraries or documentation.” With GitHub Copilot, our developers stay in the flow state and keep momentum instead of clawing through code libraries or documentation. Burket explains that GitHub Copilot has increased developer productivity by limiting context switching, reducing the need to manually produce boilerplate code, and in turn helping developers stay focused on solving complex business challenges. “Boilerplate code is where Copilot is very, very effective. You can practically tab complete the basic class or function using Copilot,” says Burket. For developers who are new to working with a specific repository or framework, for example, Burket estimates at least a 25% increase in developer speed, and a 10% increase for those already familiar with that same codebase, who can more quickly and easily create boilerplate code. Part of this increase in developer velocity comes from the fact that GitHub Copilot’s suggestions can be built with the context of your codebase. “GitHub Copilot is unique in the sense that it looks at the context of the rest of your work and incorporates that context into its recommendations. Other tools don’t have that contextual awareness,” says Hacker. “I don’t know of anything available today that’s remotely close to what we can get with GitHub Copilot.” Duolingo has also found efficiency and consistency in Codespaces, GitHub’s cloud-based development environment. When some of its developers had issues running Docker locally on their new Apple M1 machines, Codespaces offered a way to skip the local environment troubleshooting and offer a 1-click environment setup. The power and efficiency of Codespaces motivated teams within Duolingo to move entirely to Codespaces. “With Codespaces, you don't need to waste a day or a week setting up each individual repository. Instead, you can get started within a few minutes,” says Chaidarun. Now, setting up Duolingo’s largest repo takes just one minute, as opposed to hours or even days before Codespaces. “Codespaces is great for maintenance too. When a developer gets into a weird state, they can just rebuild their Codespace to start fresh and get back to work. Otherwise, they might spend hours trying to fix what went wrong with their environment.” When first presented with Codespaces, Burket says that he had some initial hesitation around giving up control, as might any developer, but that he was quickly won over. “I wanted to be in full control of my experience. I thought, 'I don't need this tool to SSH into another machine to handle my problems,’” said Burket. “But I'm a believer now. I thought I’d have to compromise on a lot of things by running remotely, but that hasn’t been the case.” Codespaces has enabled teams to configure a standardized, yet customizable environment, making it easy for Duolingo to onboard developers faster into new projects. Engineering time is the most valuable resource at Duolingo. Making the best use of that time with the help of GitHub Copilot and Codespaces enables us to reach our goals faster. Whether GitHub Copilot, Codespaces, or custom integrations built with GitHub’s APIs, GitHub allows Duolingo’s developers to spend more time on improving the product experience and developing new apps and learning content, instead of getting distracted dealing with daily minutiae. “Engineering time is the most valuable resource at Duolingo,” says Chaidarun. “Making the best use of that time with the help of GitHub Copilot and Codespaces enables us to reach our goals faster.” Interested in bringing GitHub Enterprise to your organization? Start your free trial of GitHub Enterprise for 30 days and increase your team's collaboration. $21 per user/month after trial expires. Curious about other plans? from GitHub Explore more from GitHub Stories and voices from the developer community. AI pair programmer that helps you write code faster. Get expert perspectives. Stay ahead with insights from industry leaders. What will your story be? Start collaborating with your team on GitHub The basics for individuals and organizations $0 USD per month Advanced collaboration for individuals and organizations $4 USD per month Security, compliance, and flexible deployment $21 USD per month Want to use GitHub on your own? Check out our plans for individuals Site-wide Links Get tips, technical guides, and best practices. Twice a month. |
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[SOURCE: https://en.wikipedia.org/wiki/NORSAR] | [TOKENS: 309] |
Contents NORSAR NORSAR is a foundation established in 1968 as part of the Norwegian–US agreement for the detection of earthquakes and nuclear explosions. The name derives from the foundation's original project, the Norwegian Seismic Array. Description Located at Kjeller, north of Oslo, NORSAR runs and maintains seismic arrays in Norway and it is the designated Norwegian National Data Centre for the Comprehensive Nuclear-Test-Ban Treaty. NORSAR conducts basic seismological research, develops software and provides consultancy for the petroleum industry. NORSAR was the first non-US site included in ARPANET in June 1973. Its connection went via the Tanum Earth Station in Sweden to the Seismic Data Analysis Center (SDAC) in Virginia, United States. In turn, NORSAR provided the connection point for ARPANET to spread to Peter Kirstein's research group at University College London (UCL) the following month in July 1973. Connecting through NORSAR, the Norwegian Defence Research Establishment (NDRE), along with UCL and RSRE in Britain, were involved in testing TCP/IP. UCL provided a gateway between the ARPANET and UK academic computer networks, the first heterogenous international computer network. In early 1982, NORSAR and UCL left the ARPANET and began to use TCP/IP over SATNET, becoming two of the first nodes on the Internet. Since 1999, NORSAR has been an independent research foundation. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/File:%D7%9C%D7%95%D7%93_-_%D7%9E%D7%A8%D7%90%D7%94-JNF022399.jpeg] | [TOKENS: 182] |
File:לוד - מראה-JNF022399.jpeg Summary This file is available from Jewish National Fund photo archive, under the digital ID no ID specifiedPress here to view all the images uploaded from the Jewish National Fund photo archiveThis tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information. Deutsch ∙ English ∙ français ∙ עברית ∙ +/− Licensing File history Click on a date/time to view the file as it appeared at that time. File usage The following page uses this file: Global file usage The following other wikis use this file: Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified file. |
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[SOURCE: https://en.wikipedia.org/wiki/Blockmodeling] | [TOKENS: 1638] |
Contents Blockmodeling Blockmodeling is a set or a coherent framework, that is used for analyzing social structure and also for setting procedure(s) for partitioning (clustering) social network's units (nodes, vertices, actors), based on specific patterns, which form a distinctive structure through interconnectivity. It is primarily used in statistics, machine learning and network science. As an empirical procedure, blockmodeling assumes that all the units in a specific network can be grouped together to such extent to which they are equivalent. Regarding equivalency, it can be structural, regular or generalized. Using blockmodeling, a network can be analyzed using newly created blockmodels, which transforms large and complex network into a smaller and more comprehensible one. At the same time, the blockmodeling is used to operationalize social roles. While some contend that the blockmodeling is just clustering methods, Bonacich and McConaghy state that "it is a theoretically grounded and algebraic approach to the analysis of the structure of relations". Blockmodeling's unique ability lies in the fact that it considers the structure not just as a set of direct relations, but also takes into account all other possible compound relations that are based on the direct ones. The principles of blockmodeling were first introduced by Francois Lorrain and Harrison C. White in 1971. Blockmodeling is considered as "an important set of network analytic tools" as it deals with delineation of role structures (the well-defined places in social structures, also known as positions) and the discerning the fundamental structure of social networks.: 2, 3 According to Batagelj, the primary "goal of blockmodeling is to reduce a large, potentially incoherent network to a smaller comprehensible structure that can be interpreted more readily". Blockmodeling was at first used for analysis in sociometry and psychometrics, but has now spread also to other sciences. Definition A network as a system is composed of (or defined by) two different sets: one set of units (nodes, vertices, actors) and one set of links between the units. Using both sets, it is possible to create a graph, describing the structure of the network. During blockmodeling, the researcher is faced with two problems: how to partition the units (e.g., how to determine the clusters (or classes), that then form vertices in a blockmodel) and then how to determine the links in the blockmodel (and at the same time the values of these links). In the social sciences, the networks are usually social networks, composed of several individuals (units) and selected social relationships among them (links). Real-world networks can be large and complex; blockmodeling is used to simplify them into smaller structures that can be easier to interpret. Specifically, blockmodeling partitions the units into clusters and then determines the ties among the clusters. At the same time, blockmodeling can be used to explain the social roles existing in the network, as it is assumed that the created cluster of units mimics (or is closely associated with) the units' social roles. Blockmodeling can thus be defined as a set of approaches for partitioning units into clusters (also known as positions) and links into blocks, which are further defined by the newly obtained clusters. A block (also blockmodel) is defined as a submatrix, that shows interconnectivity (links) between nodes, present in the same or different clusters. Each of these positions in the cluster is defined by a set of (in)direct ties to and from other social positions. These links (connections) can be directed or undirected; there can be multiple links between the same pair of objects or they can have weights on them. If there are not any multiple links in a network, it is called a simple network.: 8 A matrix representation of a graph is composed of ordered units, in rows and columns, based on their names. The ordered units with similar patterns of links are partitioned together in the same clusters. Clusters are then arranged together so that units from the same clusters are placed next to each other, thus preserving interconnectivity. In the next step, the units (from the same clusters) are transformed into a blockmodel. With this, several blockmodels are usually formed, one being core cluster and others being cohesive; a core cluster is always connected to cohesive ones, while cohesive ones cannot be linked together. Clustering of nodes is based on the equivalence, such as structural and regular. The primary objective of the matrix form is to visually present relations between the persons included in the cluster. These ties are coded dichotomously (as present or absent), and the rows in the matrix form indicate the source of the ties, while the columns represent the destination of the ties. Equivalence can have two basic approaches: the equivalent units have the same connection pattern to the same neighbors or these units have same or similar connection pattern to different neighbors. If the units are connected to the rest of network in identical ways, then they are structurally equivalent. Units can also be regularly equivalent, when they are equivalently connected to equivalent others. With blockmodeling, it is necessary to consider the issue of results being affected by measurement errors in the initial stage of acquiring the data. Different approaches Regarding what kind of network is undergoing blockmodeling, a different approach is necessary. Networks can be one–mode or two–mode. In the former all units can be connected to any other unit and where units are of the same type, while in the latter the units are connected only to the unit(s) of a different type.: 6–10 Regarding relationships between units, they can be single–relational or multi–relational networks. Further more, the networks can be temporal or multilevel and also binary (only 0 and 1) or signed (allowing negative ties)/values (other values are possible) networks. Different approaches to blockmodeling can be grouped into two main classes: deterministic blockmodeling and stochastic blockmodeling approaches. Deterministic blockmodeling is then further divided into direct and indirect blockmodeling approaches. Among direct blockmodeling approaches are: structural equivalence and regular equivalence. Structural equivalence is a state, when units are connected to the rest of the network in an identical way(s), while regular equivalence occurs when units are equally related to equivalent others (units are not necessarily sharing neighbors, but have neighbour that are themselves similar).: 24 Indirect blockmodeling approaches, where partitioning is dealt with as a traditional cluster analysis problem (measuring (dis)similarity results in a (dis)similarity matrix), are: According to Brusco and Steinley (2011), the blockmodeling can be categorized (using a number of dimensions): Blockmodels Blockmodels (sometimes also block models) are structures in which: Computer programs can partition the social network according to pre-set conditions.: 333 When empirical blocks can be reasonably approximated in terms of ideal blocks, such blockmodels can be reduced to a blockimage, which is a representation of the original network, capturing its underlying 'functional anatomy'. Thus, blockmodels can "permit the data to characterize their own structure", and at the same time not seek to manifest a preconceived structure imposed by the researcher. Blockmodels can be created indirectly or directly, based on the construction of the criterion function. Indirect construction refers to a function, based on "compatible (dis)similarity measure between paris of units", while the direct construction is "a function measuring the fit of real blocks induced by a given clustering to the corresponding ideal blocks with perfect relations within each cluster and between clusters according to the considered types of connections (equivalence)". Blockmodels can be specified regarding the intuition, substance or the insight into the nature of the studied network; this can result in such models as follows:: 16–24 Specialized programs Blockmodeling is done with specialized computer programs, dedicated to the analysis of networks or blockmodeling in particular, as: See also References |
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[SOURCE: https://en.wikipedia.org/wiki/Golo_(programming_language)] | [TOKENS: 280] |
Contents Golo (programming language) Golo is computer software, a programming language for the Java virtual machine (JVM). It is simple, with dynamic, weak typing. It was created in 2012 as part of the research activities of the DynaMid group of the Centre of Innovation in Telecommunications and Integration of service (CITI) Laboratory at Institut national des sciences appliquées de Lyon (INSA). It is distributed as free and open-source software under the Eclipse Public License 2.0. History It has been built as a showcase on how to build a language runtime with invokedynamic. Golo is largely interoperable with the programming language Java and other JVM languages (e.g., numeric types are boxing classes from java.lang, and collection literals leverage java.util classes), that runs on the JVM. In June 2015, Golo became an official Eclipse Foundation project. The project was terminated in September 2022. Technical details The language features have been initially designed around the abilities of invokedynamic – JSR 292 that appeared in Java SE 7. Golo uses ahead-of-time compilation of bytecode. While the bytecode remains stable over a program execution, the invokedynamic-based reconfigurable call sites support the adaptive dispatch mechanisms put in place for helping the HotSpot just-in-time compiler (JIT) to extract reasonable performance. Publications See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Joke#cite_note-FOOTNOTEAttardoChabanne1992172-89] | [TOKENS: 8460] |
Contents Joke A joke is a display of humour in which words are used within a specific and well-defined narrative structure to make people laugh and is usually not meant to be interpreted literally. It usually takes the form of a story, often with dialogue, and ends in a punch line, whereby the humorous element of the story is revealed; this can be done using a pun or other type of word play, irony or sarcasm, logical incompatibility, hyperbole, or other means. Linguist Robert Hetzron offers the definition: A joke is a short humorous piece of oral literature in which the funniness culminates in the final sentence, called the punchline… In fact, the main condition is that the tension should reach its highest level at the very end. No continuation relieving the tension should be added. As for its being "oral," it is true that jokes may appear printed, but when further transferred, there is no obligation to reproduce the text verbatim, as in the case of poetry. It is generally held that jokes benefit from brevity, containing no more detail than is needed to set the scene for the punchline at the end. In the case of riddle jokes or one-liners, the setting is implicitly understood, leaving only the dialogue and punchline to be verbalised. However, subverting these and other common guidelines can also be a source of humour—the shaggy dog story is an example of an anti-joke; although presented as a joke, it contains a long drawn-out narrative of time, place and character, rambles through many pointless inclusions and finally fails to deliver a punchline. Jokes are a form of humour, but not all humour is in the form of a joke. Some humorous forms which are not verbal jokes are: involuntary humour, situational humour, practical jokes, slapstick and anecdotes. Identified as one of the simple forms of oral literature by the Dutch linguist André Jolles, jokes are passed along anonymously. They are told in both private and public settings; a single person tells a joke to his friend in the natural flow of conversation, or a set of jokes is told to a group as part of scripted entertainment. Jokes are also passed along in written form or, more recently, through the internet. Stand-up comics, comedians and slapstick work with comic timing and rhythm in their performance, and may rely on actions as well as on the verbal punchline to evoke laughter. This distinction has been formulated in the popular saying "A comic says funny things; a comedian says things funny".[note 1] History in print Jokes do not belong to refined culture, but rather to the entertainment and leisure of all classes. As such, any printed versions were considered ephemera, i.e., temporary documents created for a specific purpose and intended to be thrown away. Many of these early jokes deal with scatological and sexual topics, entertaining to all social classes but not to be valued and saved.[citation needed] Various kinds of jokes have been identified in ancient pre-classical texts.[note 2] The oldest identified joke is an ancient Sumerian proverb from 1900 BC containing toilet humour: "Something which has never occurred since time immemorial; a young woman did not fart in her husband's lap." Its records were dated to the Old Babylonian period and the joke may go as far back as 2300 BC. The second oldest joke found, discovered on the Westcar Papyrus and believed to be about Sneferu, was from Ancient Egypt c. 1600 BC: "How do you entertain a bored pharaoh? You sail a boatload of young women dressed only in fishing nets down the Nile and urge the pharaoh to go catch a fish." The tale of the three ox drivers from Adab completes the three known oldest jokes in the world. This is a comic triple dating back to 1200 BC Adab. It concerns three men seeking justice from a king on the matter of ownership over a newborn calf, for whose birth they all consider themselves to be partially responsible. The king seeks advice from a priestess on how to rule the case, and she suggests a series of events involving the men's households and wives. The final portion of the story (which included the punch line), has not survived intact, though legible fragments suggest it was bawdy in nature. Jokes can be notoriously difficult to translate from language to language; particularly puns, which depend on specific words and not just on their meanings. For instance, Julius Caesar once sold land at a surprisingly cheap price to his lover Servilia, who was rumoured to be prostituting her daughter Tertia to Caesar in order to keep his favour. Cicero remarked that "conparavit Servilia hunc fundum tertia deducta." The punny phrase, "tertia deducta", can be translated as "with one-third off (in price)", or "with Tertia putting out." The earliest extant joke book is the Philogelos (Greek for The Laughter-Lover), a collection of 265 jokes written in crude ancient Greek dating to the fourth or fifth century AD. The author of the collection is obscure and a number of different authors are attributed to it, including "Hierokles and Philagros the grammatikos", just "Hierokles", or, in the Suda, "Philistion". British classicist Mary Beard states that the Philogelos may have been intended as a jokester's handbook of quips to say on the fly, rather than a book meant to be read straight through. Many of the jokes in this collection are surprisingly familiar, even though the typical protagonists are less recognisable to contemporary readers: the absent-minded professor, the eunuch, and people with hernias or bad breath. The Philogelos even contains a joke similar to Monty Python's "Dead Parrot Sketch". During the 15th century, the printing revolution spread across Europe following the development of the movable type printing press. This was coupled with the growth of literacy in all social classes. Printers turned out Jestbooks along with Bibles to meet both lowbrow and highbrow interests of the populace. One early anthology of jokes was the Facetiae by the Italian Poggio Bracciolini, first published in 1470. The popularity of this jest book can be measured on the twenty editions of the book documented alone for the 15th century. Another popular form was a collection of jests, jokes and funny situations attributed to a single character in a more connected, narrative form of the picaresque novel. Examples of this are the characters of Rabelais in France, Till Eulenspiegel in Germany, Lazarillo de Tormes in Spain and Master Skelton in England. There is also a jest book ascribed to William Shakespeare, the contents of which appear to both inform and borrow from his plays. All of these early jestbooks corroborate both the rise in the literacy of the European populations and the general quest for leisure activities during the Renaissance in Europe. The practice of printers using jokes and cartoons as page fillers was also widely used in the broadsides and chapbooks of the 19th century and earlier. With the increase in literacy in the general population and the growth of the printing industry, these publications were the most common forms of printed material between the 16th and 19th centuries throughout Europe and North America. Along with reports of events, executions, ballads and verse, they also contained jokes. Only one of many broadsides archived in the Harvard library is described as "1706. Grinning made easy; or, Funny Dick's unrivalled collection of curious, comical, odd, droll, humorous, witty, whimsical, laughable, and eccentric jests, jokes, bulls, epigrams, &c. With many other descriptions of wit and humour." These cheap publications, ephemera intended for mass distribution, were read alone, read aloud, posted and discarded. There are many types of joke books in print today; a search on the internet provides a plethora of titles available for purchase. They can be read alone for solitary entertainment, or used to stock up on new jokes to entertain friends. Some people try to find a deeper meaning in jokes, as in "Plato and a Platypus Walk into a Bar... Understanding Philosophy Through Jokes".[note 3] However a deeper meaning is not necessary to appreciate their inherent entertainment value. Magazines frequently use jokes and cartoons as filler for the printed page. Reader's Digest closes out many articles with an (unrelated) joke at the bottom of the article. The New Yorker was first published in 1925 with the stated goal of being a "sophisticated humour magazine" and is still known for its cartoons. Telling jokes Telling a joke is a cooperative effort; it requires that the teller and the audience mutually agree in one form or another to understand the narrative which follows as a joke. In a study of conversation analysis, the sociologist Harvey Sacks describes in detail the sequential organisation in the telling of a single joke. "This telling is composed, as for stories, of three serially ordered and adjacently placed types of sequences … the preface [framing], the telling, and the response sequences." Folklorists expand this to include the context of the joking. Who is telling what jokes to whom? And why is he telling them when? The context of the joke-telling in turn leads into a study of joking relationships, a term coined by anthropologists to refer to social groups within a culture who engage in institutionalised banter and joking. Framing is done with a (frequently formulaic) expression which keys the audience in to expect a joke. "Have you heard the one…", "Reminds me of a joke I heard…", "So, a lawyer and a doctor…"; these conversational markers are just a few examples of linguistic frames used to start a joke. Regardless of the frame used, it creates a social space and clear boundaries around the narrative which follows. Audience response to this initial frame can be acknowledgement and anticipation of the joke to follow. It can also be a dismissal, as in "this is no joking matter" or "this is no time for jokes". The performance frame serves to label joke-telling as a culturally marked form of communication. Both the performer and audience understand it to be set apart from the "real" world. "An elephant walks into a bar…"; a person sufficiently familiar with both the English language and the way jokes are told automatically understands that such a compressed and formulaic story, being told with no substantiating details, and placing an unlikely combination of characters into an unlikely setting and involving them in an unrealistic plot, is the start of a joke, and the story that follows is not meant to be taken at face value (i.e. it is non-bona-fide communication). The framing itself invokes a play mode; if the audience is unable or unwilling to move into play, then nothing will seem funny. Following its linguistic framing the joke, in the form of a story, can be told. It is not required to be verbatim text like other forms of oral literature such as riddles and proverbs. The teller can and does modify the text of the joke, depending both on memory and the present audience. The important characteristic is that the narrative is succinct, containing only those details which lead directly to an understanding and decoding of the punchline. This requires that it support the same (or similar) divergent scripts which are to be embodied in the punchline. The punchline is intended to make the audience laugh. A linguistic interpretation of this punchline/response is elucidated by Victor Raskin in his Script-based Semantic Theory of Humour. Humour is evoked when a trigger contained in the punchline causes the audience to abruptly shift its understanding of the story from the primary (or more obvious) interpretation to a secondary, opposing interpretation. "The punchline is the pivot on which the joke text turns as it signals the shift between the [semantic] scripts necessary to interpret [re-interpret] the joke text." To produce the humour in the verbal joke, the two interpretations (i.e. scripts) need to both be compatible with the joke text and opposite or incompatible with each other. Thomas R. Shultz, a psychologist, independently expands Raskin's linguistic theory to include "two stages of incongruity: perception and resolution." He explains that "… incongruity alone is insufficient to account for the structure of humour. […] Within this framework, humour appreciation is conceptualized as a biphasic sequence involving first the discovery of incongruity followed by a resolution of the incongruity." In the case of a joke, that resolution generates laughter. This is the point at which the field of neurolinguistics offers some insight into the cognitive processing involved in this abrupt laughter at the punchline. Studies by the cognitive science researchers Coulson and Kutas directly address the theory of script switching articulated by Raskin in their work. The article "Getting it: Human event-related brain response to jokes in good and poor comprehenders" measures brain activity in response to reading jokes. Additional studies by others in the field support more generally the theory of two-stage processing of humour, as evidenced in the longer processing time they require. In the related field of neuroscience, it has been shown that the expression of laughter is caused by two partially independent neuronal pathways: an "involuntary" or "emotionally driven" system and a "voluntary" system. This study adds credence to the common experience when exposed to an off-colour joke; a laugh is followed in the next breath by a disclaimer: "Oh, that's bad…" Here the multiple steps in cognition are clearly evident in the stepped response, the perception being processed just a breath faster than the resolution of the moral/ethical content in the joke. Expected response to a joke is laughter. The joke teller hopes the audience "gets it" and is entertained. This leads to the premise that a joke is actually an "understanding test" between individuals and groups. If the listeners do not get the joke, they are not understanding the two scripts which are contained in the narrative as they were intended. Or they do "get it" and do not laugh; it might be too obscene, too gross or too dumb for the current audience. A woman might respond differently to a joke told by a male colleague around the water cooler than she would to the same joke overheard in a women's lavatory. A joke involving toilet humour may be funnier told on the playground at elementary school than on a college campus. The same joke will elicit different responses in different settings. The punchline in the joke remains the same, however, it is more or less appropriate depending on the current context. The context explores the specific social situation in which joking occurs. The narrator automatically modifies the text of the joke to be acceptable to different audiences, while at the same time supporting the same divergent scripts in the punchline. The vocabulary used in telling the same joke at a university fraternity party and to one's grandmother might well vary. In each situation, it is important to identify both the narrator and the audience as well as their relationship with each other. This varies to reflect the complexities of a matrix of different social factors: age, sex, race, ethnicity, kinship, political views, religion, power relationships, etc. When all the potential combinations of such factors between the narrator and the audience are considered, then a single joke can take on infinite shades of meaning for each unique social setting. The context, however, should not be confused with the function of the joking. "Function is essentially an abstraction made on the basis of a number of contexts". In one long-term observation of men coming off the late shift at a local café, joking with the waitresses was used to ascertain sexual availability for the evening. Different types of jokes, going from general to topical into explicitly sexual humour signalled openness on the part of the waitress for a connection. This study describes how jokes and joking are used to communicate much more than just good humour. That is a single example of the function of joking in a social setting, but there are others. Sometimes jokes are used simply to get to know someone better. What makes them laugh, what do they find funny? Jokes concerning politics, religion or sexual topics can be used effectively to gauge the attitude of the audience to any one of these topics. They can also be used as a marker of group identity, signalling either inclusion or exclusion for the group. Among pre-adolescents, "dirty" jokes allow them to share information about their changing bodies. And sometimes joking is just simple entertainment for a group of friends. Relationships The context of joking in turn leads to a study of joking relationships, a term coined by anthropologists to refer to social groups within a culture who take part in institutionalised banter and joking. These relationships can be either one-way or a mutual back and forth between partners. The joking relationship is defined as a peculiar combination of friendliness and antagonism. The behaviour is such that in any other social context it would express and arouse hostility; but it is not meant seriously and must not be taken seriously. There is a pretence of hostility along with a real friendliness. To put it in another way, the relationship is one of permitted disrespect. Joking relationships were first described by anthropologists within kinship groups in Africa. But they have since been identified in cultures around the world, where jokes and joking are used to mark and reinforce appropriate boundaries of a relationship. Electronic The advent of electronic communications at the end of the 20th century introduced new traditions into jokes. A verbal joke or cartoon is emailed to a friend or posted on a bulletin board; reactions include a replied email with a :-) or LOL, or a forward on to further recipients. Interaction is limited to the computer screen and for the most part solitary. While preserving the text of a joke, both context and variants are lost in internet joking; for the most part, emailed jokes are passed along verbatim. The framing of the joke frequently occurs in the subject line: "RE: laugh for the day" or something similar. The forward of an email joke can increase the number of recipients exponentially. Internet joking forces a re-evaluation of social spaces and social groups. They are no longer only defined by physical presence and locality, they also exist in the connectivity in cyberspace. "The computer networks appear to make possible communities that, although physically dispersed, display attributes of the direct, unconstrained, unofficial exchanges folklorists typically concern themselves with". This is particularly evident in the spread of topical jokes, "that genre of lore in which whole crops of jokes spring up seemingly overnight around some sensational event … flourish briefly and then disappear, as the mass media move on to fresh maimings and new collective tragedies". This correlates with the new understanding of the internet as an "active folkloric space" with evolving social and cultural forces and clearly identifiable performers and audiences. A study by the folklorist Bill Ellis documented how an evolving cycle was circulated over the internet. By accessing message boards that specialised in humour immediately following the 9/11 disaster, Ellis was able to observe in real-time both the topical jokes being posted electronically and responses to the jokes. Previous folklore research has been limited to collecting and documenting successful jokes, and only after they had emerged and come to folklorists' attention. Now, an Internet-enhanced collection creates a time machine, as it were, where we can observe what happens in the period before the risible moment, when attempts at humour are unsuccessful Access to archived message boards also enables us to track the development of a single joke thread in the context of a more complicated virtual conversation. Joke cycles A joke cycle is a collection of jokes about a single target or situation which displays consistent narrative structure and type of humour. Some well-known cycles are elephant jokes using nonsense humour, dead baby jokes incorporating black humour, and light bulb jokes, which describe all kinds of operational stupidity. Joke cycles can centre on ethnic groups, professions (viola jokes), catastrophes, settings (…walks into a bar), absurd characters (wind-up dolls), or logical mechanisms which generate the humour (knock-knock jokes). A joke can be reused in different joke cycles; an example of this is the same Head & Shoulders joke refitted to the tragedies of Vic Morrow, Admiral Mountbatten and the crew of the Challenger space shuttle.[note 4] These cycles seem to appear spontaneously, spread rapidly across countries and borders only to dissipate after some time. Folklorists and others have studied individual joke cycles in an attempt to understand their function and significance within the culture. Joke cycles circulated in the recent past include: As with the 9/11 disaster discussed above, cycles attach themselves to celebrities or national catastrophes such as the death of Diana, Princess of Wales, the death of Michael Jackson, and the Space Shuttle Challenger disaster. These cycles arise regularly as a response to terrible unexpected events which command the national news. An in-depth analysis of the Challenger joke cycle documents a change in the type of humour circulated following the disaster, from February to March 1986. "It shows that the jokes appeared in distinct 'waves', the first responding to the disaster with clever wordplay and the second playing with grim and troubling images associated with the event…The primary social function of disaster jokes appears to be to provide closure to an event that provoked communal grieving, by signalling that it was time to move on and pay attention to more immediate concerns". The sociologist Christie Davies has written extensively on ethnic jokes told in countries around the world. In ethnic jokes he finds that the "stupid" ethnic target in the joke is no stranger to the culture, but rather a peripheral social group (geographic, economic, cultural, linguistic) well known to the joke tellers. So Americans tell jokes about Polacks and Italians, Germans tell jokes about Ostfriesens, and the English tell jokes about the Irish. In a review of Davies' theories it is said that "For Davies, [ethnic] jokes are more about how joke tellers imagine themselves than about how they imagine those others who serve as their putative targets…The jokes thus serve to center one in the world – to remind people of their place and to reassure them that they are in it." A third category of joke cycles identifies absurd characters as the butt: for example the grape, the dead baby or the elephant. Beginning in the 1960s, social and cultural interpretations of these joke cycles, spearheaded by the folklorist Alan Dundes, began to appear in academic journals. Dead baby jokes are posited to reflect societal changes and guilt caused by widespread use of contraception and abortion beginning in the 1960s.[note 5] Elephant jokes have been interpreted variously as stand-ins for American blacks during the Civil Rights Era or as an "image of something large and wild abroad in the land captur[ing] the sense of counterculture" of the sixties. These interpretations strive for a cultural understanding of the themes of these jokes which go beyond the simple collection and documentation undertaken previously by folklorists and ethnologists. Classification systems As folktales and other types of oral literature became collectables throughout Europe in the 19th century (Brothers Grimm et al.), folklorists and anthropologists of the time needed a system to organise these items. The Aarne–Thompson classification system was first published in 1910 by Antti Aarne, and later expanded by Stith Thompson to become the most renowned classification system for European folktales and other types of oral literature. Its final section addresses anecdotes and jokes, listing traditional humorous tales ordered by their protagonist; "This section of the Index is essentially a classification of the older European jests, or merry tales – humorous stories characterized by short, fairly simple plots. …" Due to its focus on older tale types and obsolete actors (e.g., numbskull), the Aarne–Thompson Index does not provide much help in identifying and classifying the modern joke. A more granular classification system used widely by folklorists and cultural anthropologists is the Thompson Motif Index, which separates tales into their individual story elements. This system enables jokes to be classified according to individual motifs included in the narrative: actors, items and incidents. It does not provide a system to classify the text by more than one element at a time while at the same time making it theoretically possible to classify the same text under multiple motifs. The Thompson Motif Index has spawned further specialised motif indices, each of which focuses on a single aspect of one subset of jokes. A sampling of just a few of these specialised indices have been listed under other motif indices. Here one can select an index for medieval Spanish folk narratives, another index for linguistic verbal jokes, and a third one for sexual humour. To assist the researcher with this increasingly confusing situation, there are also multiple bibliographies of indices as well as a how-to guide on creating your own index. Several difficulties have been identified with these systems of identifying oral narratives according to either tale types or story elements. A first major problem is their hierarchical organisation; one element of the narrative is selected as the major element, while all other parts are arrayed subordinate to this. A second problem with these systems is that the listed motifs are not qualitatively equal; actors, items and incidents are all considered side-by-side. And because incidents will always have at least one actor and usually have an item, most narratives can be ordered under multiple headings. This leads to confusion about both where to order an item and where to find it. A third significant problem is that the "excessive prudery" common in the middle of the 20th century means that obscene, sexual and scatological elements were regularly ignored in many of the indices. The folklorist Robert Georges has summed up the concerns with these existing classification systems: …Yet what the multiplicity and variety of sets and subsets reveal is that folklore [jokes] not only takes many forms, but that it is also multifaceted, with purpose, use, structure, content, style, and function all being relevant and important. Any one or combination of these multiple and varied aspects of a folklore example [such as jokes] might emerge as dominant in a specific situation or for a particular inquiry. It has proven difficult to organise all different elements of a joke into a multi-dimensional classification system which could be of real value in the study and evaluation of this (primarily oral) complex narrative form. The General Theory of Verbal Humour or GTVH, developed by the linguists Victor Raskin and Salvatore Attardo, attempts to do exactly this. This classification system was developed specifically for jokes and later expanded to include longer types of humorous narratives. Six different aspects of the narrative, labelled Knowledge Resources or KRs, can be evaluated largely independently of each other, and then combined into a concatenated classification label. These six KRs of the joke structure include: As development of the GTVH progressed, a hierarchy of the KRs was established to partially restrict the options for lower-level KRs depending on the KRs defined above them. For example, a lightbulb joke (SI) will always be in the form of a riddle (NS). Outside of these restrictions, the KRs can create a multitude of combinations, enabling a researcher to select jokes for analysis which contain only one or two defined KRs. It also allows for an evaluation of the similarity or dissimilarity of jokes depending on the similarity of their labels. "The GTVH presents itself as a mechanism … of generating [or describing] an infinite number of jokes by combining the various values that each parameter can take. … Descriptively, to analyze a joke in the GTVH consists of listing the values of the 6 KRs (with the caveat that TA and LM may be empty)." This classification system provides a functional multi-dimensional label for any joke, and indeed any verbal humour. Joke and humour research Many academic disciplines lay claim to the study of jokes (and other forms of humour) as within their purview. Fortunately, there are enough jokes, good, bad and worse, to go around. The studies of jokes from each of the interested disciplines bring to mind the tale of the blind men and an elephant where the observations, although accurate reflections of their own competent methodological inquiry, frequently fail to grasp the beast in its entirety. This attests to the joke as a traditional narrative form which is indeed complex, concise and complete in and of itself. It requires a "multidisciplinary, interdisciplinary, and cross-disciplinary field of inquiry" to truly appreciate these nuggets of cultural insight.[note 6] Sigmund Freud was one of the first modern scholars to recognise jokes as an important object of investigation. In his 1905 study Jokes and their Relation to the Unconscious Freud describes the social nature of humour and illustrates his text with many examples of contemporary Viennese jokes. His work is particularly noteworthy in this context because Freud distinguishes in his writings between jokes, humour and the comic. These are distinctions which become easily blurred in many subsequent studies where everything funny tends to be gathered under the umbrella term of "humour", making for a much more diffuse discussion. Since the publication of Freud's study, psychologists have continued to explore humour and jokes in their quest to explain, predict and control an individual's "sense of humour". Why do people laugh? Why do people find something funny? Can jokes predict character, or vice versa, can character predict the jokes an individual laughs at? What is a "sense of humour"? A current review of the popular magazine Psychology Today lists over 200 articles discussing various aspects of humour; in psychological jargon, the subject area has become both an emotion to measure and a tool to use in diagnostics and treatment. A new psychological assessment tool, the Values in Action Inventory developed by the American psychologists Christopher Peterson and Martin Seligman includes humour (and playfulness) as one of the core character strengths of an individual. As such, it could be a good predictor of life satisfaction. For psychologists, it would be useful to measure both how much of this strength an individual has and how it can be measurably increased. A 2007 survey of existing tools to measure humour identified more than 60 psychological measurement instruments. These measurement tools use many different approaches to quantify humour along with its related states and traits. There are tools to measure an individual's physical response by their smile; the Facial Action Coding System (FACS) is one of several tools used to identify any one of multiple types of smiles. Or the laugh can be measured to calculate the funniness response of an individual; multiple types of laughter have been identified. It must be stressed here that both smiles and laughter are not always a response to something funny. In trying to develop a measurement tool, most systems use "jokes and cartoons" as their test materials. However, because no two tools use the same jokes, and across languages this would not be feasible, how does one determine that the assessment objects are comparable? Moving on, whom does one ask to rate the sense of humour of an individual? Does one ask the person themselves, an impartial observer, or their family, friends and colleagues? Furthermore, has the current mood of the test subjects been considered; someone with a recent death in the family might not be much prone to laughter. Given the plethora of variants revealed by even a superficial glance at the problem, it becomes evident that these paths of scientific inquiry are mined with problematic pitfalls and questionable solutions. The psychologist Willibald Ruch [de] has been very active in the research of humour. He has collaborated with the linguists Raskin and Attardo on their General Theory of Verbal Humour (GTVH) classification system. Their goal is to empirically test both the six autonomous classification types (KRs) and the hierarchical ordering of these KRs. Advancement in this direction would be a win-win for both fields of study; linguistics would have empirical verification of this multi-dimensional classification system for jokes, and psychology would have a standardised joke classification with which they could develop verifiably comparable measurement tools. "The linguistics of humor has made gigantic strides forward in the last decade and a half and replaced the psychology of humor as the most advanced theoretical approach to the study of this important and universal human faculty." This recent statement by one noted linguist and humour researcher describes, from his perspective, contemporary linguistic humour research. Linguists study words, how words are strung together to build sentences, how sentences create meaning which can be communicated from one individual to another, and how our interaction with each other using words creates discourse. Jokes have been defined above as oral narratives in which words and sentences are engineered to build toward a punchline. The linguist's question is: what exactly makes the punchline funny? This question focuses on how the words used in the punchline create humour, in contrast to the psychologist's concern (see above) with the audience's response to the punchline. The assessment of humour by psychologists "is made from the individual's perspective; e.g. the phenomenon associated with responding to or creating humor and not a description of humor itself." Linguistics, on the other hand, endeavours to provide a precise description of what makes a text funny. Two major new linguistic theories have been developed and tested within the last decades. The first was advanced by Victor Raskin in "Semantic Mechanisms of Humor", published 1985. While being a variant on the more general concepts of the incongruity theory of humour, it is the first theory to identify its approach as exclusively linguistic. The Script-based Semantic Theory of Humour (SSTH) begins by identifying two linguistic conditions which make a text funny. It then goes on to identify the mechanisms involved in creating the punchline. This theory established the semantic/pragmatic foundation of humour as well as the humour competence of speakers.[note 7] Several years later the SSTH was incorporated into a more expansive theory of jokes put forth by Raskin and his colleague Salvatore Attardo. In the General Theory of Verbal Humour, the SSTH was relabelled as a Logical Mechanism (LM) (referring to the mechanism which connects the different linguistic scripts in the joke) and added to five other independent Knowledge Resources (KR). Together these six KRs could now function as a multi-dimensional descriptive label for any piece of humorous text. Linguistics has developed further methodological tools which can be applied to jokes: discourse analysis and conversation analysis of joking. Both of these subspecialties within the field focus on "naturally occurring" language use, i.e. the analysis of real (usually recorded) conversations. One of these studies has already been discussed above, where Harvey Sacks describes in detail the sequential organisation in telling a single joke. Discourse analysis emphasises the entire context of social joking, the social interaction which cradles the words. Folklore and cultural anthropology have perhaps the strongest claims on jokes as belonging to their bailiwick. Jokes remain one of the few remaining forms of traditional folk literature transmitted orally in western cultures. Identified as one of the "simple forms" of oral literature by André Jolles in 1930, they have been collected and studied since there were folklorists and anthropologists abroad in the lands. As a genre they were important enough at the beginning of the 20th century to be included under their own heading in the Aarne–Thompson index first published in 1910: Anecdotes and jokes. Beginning in the 1960s, cultural researchers began to expand their role from collectors and archivists of "folk ideas" to a more active role of interpreters of cultural artefacts. One of the foremost scholars active during this transitional time was the folklorist Alan Dundes. He started asking questions of tradition and transmission with the key observation that "No piece of folklore continues to be transmitted unless it means something, even if neither the speaker nor the audience can articulate what that meaning might be." In the context of jokes, this then becomes the basis for further research. Why is the joke told right now? Only in this expanded perspective is an understanding of its meaning to the participants possible. This questioning resulted in a blossoming of monographs to explore the significance of many joke cycles. What is so funny about absurd nonsense elephant jokes? Why make light of dead babies? In an article on contemporary German jokes about Auschwitz and the Holocaust, Dundes justifies this research: Whether one finds Auschwitz jokes funny or not is not an issue. This material exists and should be recorded. Jokes are always an important barometer of the attitudes of a group. The jokes exist and they obviously must fill some psychic need for those individuals who tell them and those who listen to them. A stimulating generation of new humour theories flourishes like mushrooms in the undergrowth: Elliott Oring's theoretical discussions on "appropriate ambiguity" and Amy Carrell's hypothesis of an "audience-based theory of verbal humor (1993)" to name just a few. In his book Humor and Laughter: An Anthropological Approach, the anthropologist Mahadev Apte presents a solid case for his own academic perspective. "Two axioms underlie my discussion, namely, that humor is by and large culture based and that humor can be a major conceptual and methodological tool for gaining insights into cultural systems." Apte goes on to call for legitimising the field of humour research as "humorology"; this would be a field of study incorporating an interdisciplinary character of humour studies. While the label "humorology" has yet to become a household word, great strides are being made in the international recognition of this interdisciplinary field of research. The International Society for Humor Studies was founded in 1989 with the stated purpose to "promote, stimulate and encourage the interdisciplinary study of humour; to support and cooperate with local, national, and international organizations having similar purposes; to organize and arrange meetings; and to issue and encourage publications concerning the purpose of the society". It also publishes Humor: International Journal of Humor Research and holds yearly conferences to promote and inform its speciality. In 1872, Charles Darwin published one of the first "comprehensive and in many ways remarkably accurate description of laughter in terms of respiration, vocalization, facial action and gesture and posture" (Laughter) in The Expression of the Emotions in Man and Animals. In this early study Darwin raises further questions about who laughs and why they laugh; the myriad responses since then illustrate the complexities of this behaviour. To understand laughter in humans and other primates, the science of gelotology (from the Greek gelos, meaning laughter) has been established; it is the study of laughter and its effects on the body from both a psychological and physiological perspective. While jokes can provoke laughter, laughter cannot be used as a one-to-one marker of jokes because there are multiple stimuli to laughter, humour being just one of them. The other six causes of laughter listed are social context, ignorance, anxiety, derision, acting apology, and tickling. As such, the study of laughter is a secondary albeit entertaining perspective in an understanding of jokes. Computational humour is a new field of study which uses computers to model humour; it bridges the disciplines of computational linguistics and artificial intelligence. A primary ambition of this field is to develop computer programs which can both generate a joke and recognise a text snippet as a joke. Early programming attempts have dealt almost exclusively with punning because this lends itself to simple straightforward rules. These primitive programs display no intelligence; instead, they work off a template with a finite set of pre-defined punning options upon which to build. More sophisticated computer joke programs have yet to be developed. Based on our understanding of the SSTH / GTVH humour theories, it is easy to see why. The linguistic scripts (a.k.a. frames) referenced in these theories include, for any given word, a "large chunk of semantic information surrounding the word and evoked by it [...] a cognitive structure internalized by the native speaker". These scripts extend much further than the lexical definition of a word; they contain the speaker's complete knowledge of the concept as it exists in his world. As insentient machines, computers lack the encyclopaedic scripts which humans gain through life experience. They also lack the ability to gather the experiences needed to build wide-ranging semantic scripts and understand language in a broader context, a context that any child picks up in daily interaction with his environment. Further development in this field must wait until computational linguists have succeeded in programming a computer with an ontological semantic natural language processing system. It is only "the most complex linguistic structures [which] can serve any formal and/or computational treatment of humor well". Toy systems (i.e. dummy punning programs) are completely inadequate to the task. Despite the fact that the field of computational humour is small and underdeveloped, it is encouraging to note the many interdisciplinary efforts which are currently underway. See also Notes References Further reading |
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[SOURCE: https://en.wikipedia.org/wiki/Jewish_peoplehood] | [TOKENS: 1503] |
Contents Jewish peoplehood Jewish peoplehood (Hebrew: עמיות יהודית, Amiut Yehudit), also sometimes referred to as the whole of Israel (Hebrew: כלל ישראל, Klal Yisrael), is the conception of the awareness of the underlying unity that makes an individual a part of the Jewish people. The concept of peoplehood has a double meaning. The first is descriptive, as a concept factually describing the existence of the Jews as a people, i.e. an ethnoreligious group and nation, originating from the Israelites of ancient Israel and Judah. The second is normative, as a value that describes the feeling of belonging and commitment to the Jewish people. Some believe that the concept of Jewish peoplehood is a paradigm shift in Jewish life. Insisting that the mainstream of Jewish life is focused on Jewish nationalism (Zionism), they argue that Jewish life should instead focus on Jewish peoplehood. Others maintain that the concept of peoplehood has permeated Jewish life for millennia, and to focus on it does not constitute a shift from the focus on Jewish nationhood. Jews have been extremely effective in sustaining a sense of joint responsibility towards their people and its members for over 2,000 years, with persecutions such as the expulsion of Roman Jews from the vicinity of Jerusalem and the districts of Gophna, Herodion, and Aqraba resulting in more than 100,000 slaves taken as war captives in the aftermath of the Bar Kokhba revolt which contributed to a significant rise in the historical Jewish diaspora, subsequently since the late Roman period significant recovery through common religious practices, shared ancestry, continuous communication, and population transfers between Sephardic and Ashkenazi Jews, during which time the former had a "Hebrew Golden Age", subsequently though with Zionist aliyah (immigration since the birth of Zionism to political entities in the region of Palestine and the State of Israel) resulting in Israeli scholar Eliezer Schweid warning against a Zionist "negation of the Diaspora". At the same time, the concepts of Jews as a nation and as a peoplehood are not necessarily at odds with one another. The very concept of defining Judaism as a people or a "civilization" suggests a wide variety of values within the context of Judaism. Jewish writings The concept of a distinctive Jewish people has been part of Jewish culture since the development of the Hebrew Bible. Throughout the Torah, Prophets and Writings, Jews are variously referred to as a congregation, a nation, children of Israel or even a kingdom, (Eda, Uma, Am, B'nai Israel, Mamlakha respectively) all implying a connection among people. History Jewish people in the diaspora during the Middle Ages were united by a common history, although this did not create a unified society. Jacob Katz writes that medieval Jews in the diaspora maintained educational, civil, and religious institutions based on a common tradition, although they varied from place to place. Jewish communities were separate in many cases from their environment, and had extensive mutual contacts with each other, including mutual aid, responses to crises, and concern for each others' fate, dependent on long-distance travel and communication. Particularly in the 16th through 18th centuries, contacts between diaspora Jewish communities were stronger than in any period since the decline of the Roman Empire. Katz cites 1745 in Prague and Khmelnytsky pogroms as examples of crises that saw worldwide responses from Jewish communities. Modern Jewish peoplehood Some modern Jewish leaders in the diaspora, particularly American Jews, found the traditional conception of Jews as a "nation among the nations" problematic, posing a challenge to integration and inviting antisemitic charges of dual loyalty. The first significant use of the "peoplehood" concept was by Mordecai Kaplan, co-founder of the Reconstructionist School of Judaism, who was searching for a term that would enable him to describe the complex nature of Jewish belonging. Once the State of Israel was founded, he rejected the concept of nationhood, as it had become too closely identified with statehood, and replaced it with the peoplehood concept. In his work Judaism as a Civilization, Kaplan sought to define the Jewish people and religion in socio-cultural terms as well as religious ones. Kaplan's definition of Judaism as "an evolving religious civilization" illumines his understanding of the centrality of Peoplehood in the Jewish religion. Describing Judaism as a religious civilization emphasizes the idea that Jewish people have sought "to make [their] collective experience yield meaning for the enrichment of the life of the individual Jew and for the spiritual greatness of the Jewish people." The definition as a civilization allows Judaism to accept the principles of unity in diversity and continuity in change. It is a reminder that Judaism consists of much that cannot be put into the category of religion in modern times, "paradoxical as it may sound, the spiritual regeneration of the Jewish people demands that religion cease to be its sole preoccupation." In the sense that existence precedes essence and life takes precedence over thought, Judaism exists for the sake of the Jewish people rather than the Jewish people existing for the sake of Judaism. Kaplan's purpose in developing the Jewish Peoplehood idea was to create a vision broad enough to include everyone who identified as a Jew regardless of individual approaches to that identity. Since 2000, major Jewish organizations have embraced the peoplehood concept and intellectual interest in the topic has increased. Major organizations such as the Jewish Federations of North America, the JFNA New York Federation, the Jewish Agency for Israel, the Israel Ministry for Education, the Diaspora Museum, the Avi Chai Foundation, the American Jewish Committee and many other smaller organizations are either introducing the peoplehood concept as an organizing principle in their organizations or initiating high-profile programming with an explicit focus on Jewish Peoplehood. Natan Sharansky, the Jewish Agency’s chairman, declared that the agency’s traditional Zionist mission had outlived its usefulness. In his new capacity, he has made Israel education and promoting Jewish Peoplehood a priority, particularly among the young. Alongside the use of the peoplehood concept by Jewish organizations, there is a parallel growth of intellectual interest in the topic since 2000. The intellectual discussion asks: What is "Jewish Peoplehood"? What are the key characteristics that distinguish Jewish Peoplehood from other concepts or other ethnic or religious communities? The areas of agreement among Jewish intellectuals writing about the concept of Jewish Peoplehood point to three principles: The three unifying principles of the Jewish Peoplehood theory: In combination, these three principles imbue the Peoplehood concept with coherence and offer an added value to organizations that wish to create programs “that build Jewish Peoplehood” in a sustainable and measurable way. There are several variants of the communitarian position among intellectuals writing about Jewish Peoplehood. The common denominator is the desire to find common ground upon which connections between Jews are built. The four distinct positions regarding Jewish Peoplehood: For some critics, Jewish Peoplehood is still an amorphous and abstract concept that presents an optional ideological approach towards the Jewish collective. Others wonder if it is too weak a foundation on which to base Jewish collective identity, especially since the vision of Peoplehood is not necessarily predicated on having any kind of religious or spiritual identity. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/SETL] | [TOKENS: 515] |
Contents SETL SETL (SET Language) is a very high-level programming language based on the mathematical theory of sets. It was originally developed at the New York University (NYU) Courant Institute of Mathematical Sciences in the late 1960s, by a group including (Jack) Jacob T. Schwartz, R.B.K. Dewar, and E. Schonberg. Schwartz is credited with designing the language. Design SETL provides two basic aggregate data types: (unordered) sets, and tuples. The elements of sets and tuples can be of any arbitrary type, including sets and tuples themselves, except the undefined value om (sometimes capitalized: OM). Maps are provided as sets of pairs (i.e., tuples of length 2) and can have arbitrary domain and range types. Primitive operations in SETL include set membership, union, intersection, and power set construction, among others. SETL provides quantified boolean expressions constructed using the universal and existential quantifiers of first-order predicate logic. SETL provides several iterators to produce a variety of loops over aggregate data structures. Examples Print all prime numbers from 2 to N: The notation is similar to list comprehension. A factorial procedure definition: A more conventional SETL expression for factorial (n > 0): Uses Implementations of SETL were available on the CDC 6600, CDC Cyber, DEC VAX, IBM/370, Sun workstation and Apollo. In the 1970s, SETL was ported to the BESM-6, ES EVM and other Russian computer systems. SETL was used for an early implementation of the programming language Ada, named the NYU Ada/ED translator. This later became the first validated Ada implementation, certified on April 11, 1983. According to Guido van Rossum, "Python's predecessor, ABC, was inspired by SETL – Lambert Meertens spent a year with the SETL group at NYU before coming up with the final ABC design!" Language variants SET Language 2 (SETL2), a backward incompatible descendant of SETL, was created by Kirk Snyder of the Courant Institute of Mathematical Sciences at New York University in the late 1980s. Like its predecessor, it is based on the theory and notation of finite sets, but has also been influenced in syntax and style by the Ada language. Interactive SET Language (ISETL) is a variant of SETL used in discrete mathematics. GNU SETL is a command-line utility that implements and extends SETL. References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Computing] | [TOKENS: 3443] |
Contents Computing Computing is any goal-oriented activity that requires, benefits from, or creates computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both hardware and software. Computing encompasses scientific, engineering, mathematical, technological, and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology, and software engineering. The term computing is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing predates the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical concepts necessary for computing existed before numeral systems. The earliest known tool for use in computation is the abacus, and it is thought to have been invented in Babylon circa between 2700 and 2300 BC. Abaci, of a more modern design, are still used as calculation tools today. The first recorded proposal for using digital electronics in computing was the 1931 paper "The Use of Thyratrons for High Speed Automatic Counting of Physical Phenomena" by C. E. Wynn-Williams. Claude Shannon's 1938 paper "A Symbolic Analysis of Relay and Switching Circuits" then introduced the idea of using electronics for Boolean algebraic operations. The concept of a field-effect transistor was proposed by Julius Edgar Lilienfeld in 1925. John Bardeen and Walter Brattain, while working under William Shockley at Bell Labs, built the first working transistor, the point-contact transistor, in 1947. In 1953, the University of Manchester built the first transistorized computer, the Manchester Baby. However, early junction transistors were relatively bulky devices that were difficult to mass-produce, which limited them to a number of specialised applications. In 1957, Frosch and Derick were able to manufacture the first silicon dioxide field effect transistors at Bell Labs, the first transistors in which drain and source were adjacent at the surface. Subsequently, a team demonstrated a working MOSFET at Bell Labs 1960. The MOSFET made it possible to build high-density integrated circuits, leading to what is known as the computer revolution or microcomputer revolution. Computers A computer is a machine that manipulates data according to a set of instructions called a computer program. The program has an executable form that the computer can use directly to execute the instructions. The same program in its human-readable source code form, enables a programmer to study and develop a sequence of steps known as an algorithm. Because the instructions can be carried out in different types of computers, a single set of source instructions converts to machine instructions according to the CPU type. The execution process carries out the instructions in a computer program. Instructions express the computations performed by the computer. They trigger sequences of simple actions on the executing machine. Those actions produce effects according to the semantics of the instructions. Computer hardware includes the physical parts of a computer, including the central processing unit, memory, and input/output. Computational logic and computer architecture are key topics in the field of computer hardware. Computer software, or just software, is a collection of computer programs and related data, which provides instructions to a computer. Software refers to one or more computer programs and data held in the storage of the computer. It is a set of programs, procedures, algorithms, as well as its documentation concerned with the operation of a data processing system.[citation needed] Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast with the old term hardware (meaning physical devices). In contrast to hardware, software is intangible. Software is also sometimes used in a more narrow sense, meaning application software only. System software, or systems software, is computer software designed to operate and control computer hardware, and to provide a platform for running application software. System software includes operating systems, utility software, device drivers, window systems, and firmware. Frequently used development tools such as compilers, linkers, and debuggers are classified as system software. System software and middleware manage and integrate a computer's capabilities, but typically do not directly apply them in the performance of tasks that benefit the user, unlike application software. Application software, also known as an application or an app, is computer software designed to help the user perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software, and media players. Many application programs deal principally with documents. Apps may be bundled with the computer and its system software, or may be published separately. Some users are satisfied with the bundled apps and need never install additional applications. The system software manages the hardware and serves the application, which in turn serves the user. Application software applies the power of a particular computing platform or system software to a particular purpose. Some apps, such as Microsoft Office, are developed in multiple versions for several different platforms; others have narrower requirements and are generally referred to by the platform they run on. For example, a geography application for Windows or an Android application for education or Linux gaming. Applications that run only on one platform and increase the desirability of that platform due to the popularity of the application, known as killer applications. A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow the sharing of resources and information. When at least one process in one device is able to send or receive data to or from at least one process residing in a remote device, the two devices are said to be in a network. Networks may be classified according to a wide variety of characteristics such as the medium used to transport the data, communications protocol used, scale, topology, and organizational scope. Communications protocols define the rules and data formats for exchanging information in a computer network, and provide the basis for network programming. One well-known communications protocol is Ethernet, a hardware and link layer standard that is ubiquitous in local area networks. Another common protocol is the Internet Protocol Suite, which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, host-to-host data transfer, and application-specific data transmission formats. Computer networking is sometimes considered a sub-discipline of electrical engineering, telecommunications, computer science, information technology, or computer engineering, since it relies upon the theoretical and practical application of these disciplines. The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users. This includes millions of private, public, academic, business, and government networks, ranging in scope from local to global. These networks are linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web and the infrastructure to support email. Computer programming is the process of writing, testing, debugging, and maintaining the source code and documentation of computer programs. This source code is written in a programming language, which is an artificial language that is often more restrictive than natural languages, but easily translated by the computer. Programming is used to invoke some desired behavior (customization) from the machine. Writing high-quality source code requires knowledge of both the computer science domain and the domain in which the application will be used. The highest-quality software is thus often developed by a team of domain experts, each a specialist in some area of development. However, the term programmer may apply to a range of program quality, from hacker to open source contributor to professional. It is also possible for a single programmer to do most or all of the computer programming needed to generate the proof of concept to launch a new killer application. A programmer, computer programmer, or coder is a person who writes computer software. The term computer programmer can refer to a specialist in one area of computer programming or to a generalist who writes code for many kinds of software. One who practices or professes a formal approach to programming may also be known as a programmer analyst. A programmer's primary computer language (C, C++, Java, Lisp, Python, etc.) is often prefixed to the above titles, and those who work in a web environment often prefix their titles with Web. The term programmer can be used to refer to a software developer, software engineer, computer scientist, or software analyst. However, members of these professions typically possess other software engineering skills, beyond programming. The computer industry is made up of businesses involved in developing computer software, designing computer hardware and computer networking infrastructures, manufacturing computer components, and providing information technology services, including system administration and maintenance. The software industry includes businesses engaged in development, maintenance, and publication of software. The industry also includes software services, such as training, documentation, and consulting.[citation needed] Sub-disciplines of computing Computer engineering is a discipline that integrates several fields of electrical engineering and computer science required to develop computer hardware and software. Computer engineers usually have training in electronic engineering (or electrical engineering), software design, and hardware-software integration, rather than just software engineering or electronic engineering. Computer engineers are involved in many hardware and software aspects of computing, from the design of individual microprocessors, personal computers, and supercomputers, to circuit design. This field of engineering includes not only the design of hardware within its own domain, but also the interactions between hardware and the context in which it operates. Software engineering is the application of a systematic, disciplined, and quantifiable approach to the design, development, operation, and maintenance of software, and the study of these approaches. That is, the application of engineering to software. It is the act of using insights to conceive, model and scale a solution to a problem. The first reference to the term is the 1968 NATO Software Engineering Conference, and was intended to provoke thought regarding the perceived software crisis at the time. Software development, a widely used and more generic term, does not necessarily subsume the engineering paradigm. The generally accepted concepts of Software Engineering as an engineering discipline have been specified in the Guide to the Software Engineering Body of Knowledge (SWEBOK). The SWEBOK has become an internationally accepted standard in ISO/IEC TR 19759:2015. Computer science or computing science (abbreviated CS or Comp Sci) is the scientific and practical approach to computation and its applications. A computer scientist specializes in the theory of computation and the design of computational systems. Its subfields can be divided into practical techniques for its implementation and application in computer systems, and purely theoretical areas. Some, such as computational complexity theory, which studies fundamental properties of computational problems, are highly abstract, while others, such as computer graphics, emphasize real-world applications. Others focus on the challenges in implementing computations. For example, programming language theory studies approaches to the description of computations, while the study of computer programming investigates the use of programming languages and complex systems. The field of human–computer interaction focuses on the challenges in making computers and computations useful, usable, and universally accessible to humans. The field of cybersecurity pertains to the protection of computer systems and networks. This includes information and data privacy, preventing disruption of IT services and prevention of theft of and damage to hardware, software, and data. Data science is a field that uses scientific and computing tools to extract information and insights from data, driven by the increasing volume and availability of data. Data mining, big data, statistics, machine learning and deep learning are all interwoven with data science. Information systems (IS) is the study of complementary networks of hardware and software (see information technology) that people and organizations use to collect, filter, process, create, and distribute data. The ACM's Computing Careers describes IS as: "A majority of IS [degree] programs are located in business schools; however, they may have different names such as management information systems, computer information systems, or business information systems. All IS degrees combine business and computing topics, but the emphasis between technical and organizational issues varies among programs. For example, programs differ substantially in the amount of programming required." The study of IS bridges business and computer science, using the theoretical foundations of information and computation to study various business models and related algorithmic processes within a computer science discipline. The field of Computer Information Systems (CIS) studies computers and algorithmic processes, including their principles, their software and hardware designs, their applications, and their impact on society while IS emphasizes functionality over design. Information technology (IT) is the application of computers and telecommunications equipment to store, retrieve, transmit, and manipulate data, often in the context of a business or other enterprise. The term is commonly used as a synonym for computers and computer networks, but also encompasses other information distribution technologies such as television and telephones. Several industries are associated with information technology, including computer hardware, software, electronics, semiconductors, internet, telecom equipment, e-commerce, and computer services. Research and emerging technologies DNA-based computing and quantum computing are areas of active research for both computing hardware and software, such as the development of quantum algorithms. Potential infrastructure for future technologies includes DNA origami on photolithography and quantum antennae for transferring information between ion traps. By 2011, researchers had entangled 14 qubits. Fast digital circuits, including those based on Josephson junctions and rapid single flux quantum technology, are becoming more nearly realizable with the discovery of nanoscale superconductors. Fiber-optic and photonic (optical) devices, which already have been used to transport data over long distances, are starting to be used by data centers, along with CPU and semiconductor memory components. This allows the separation of RAM from CPU by optical interconnects. IBM has created an integrated circuit with both electronic and optical information processing in one chip. This is denoted CMOS-integrated nanophotonics (CINP). One benefit of optical interconnects is that motherboards, which formerly required a certain kind of system on a chip (SoC), can now move formerly dedicated memory and network controllers off the motherboards, spreading the controllers out onto the rack. This allows standardization of backplane interconnects and motherboards for multiple types of SoCs, which allows more timely upgrades of CPUs. Another field of research is spintronics. Spintronics can provide computing power and storage, without heat buildup. Some research is being done on hybrid chips, which combine photonics and spintronics. There is also research ongoing on combining plasmonics, photonics, and electronics. Cloud computing is a model that allows for the use of computing resources, such as servers or applications, without the need for interaction between the owner of these resources and the end user. It is typically offered as a service, making it an example of software as a service, platform as a service, and infrastructure as a service, depending on the functionality offered. Key characteristics include on-demand access, broad network access, and the capability of rapid scaling. It allows individual users or small business to benefit from economies of scale. One area of interest in this field is its potential to support energy efficiency. Allowing thousands of instances of computation to occur on one single machine instead of thousands of individual machines could help save energy. It could also ease the transition to renewable energy source, since it would suffice to power one server farm with renewable energy, rather than millions of homes and offices. However, this centralized computing model poses several challenges, especially in security and privacy. Current legislation does not sufficiently protect users from companies mishandling their data on company servers. This suggests potential for further legislative regulations on cloud computing and tech companies. Quantum computing is an area of research that brings together the disciplines of computer science, information theory, and quantum physics. While the idea of information as part of physics is relatively new, there appears to be a strong tie between information theory and quantum mechanics. Whereas traditional computing operates on a binary system of ones and zeros, quantum computing uses qubits. Qubits are capable of being in a superposition, i.e. in both states of one and zero, simultaneously. Thus, the value of the qubit is not between 1 and 0, but changes depending on when it is measured. This trait of qubits is known as quantum entanglement, and is the core idea of quantum computing that allows quantum computers to do large scale computations. Quantum computing is often used for scientific research in cases where traditional computers do not have the computing power to do the necessary calculations, such in molecular modeling. Large molecules and their reactions are far too complex for traditional computers to calculate, but the computational power of quantum computers could provide a tool to perform such calculations. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Non-player_character#cite_note-1] | [TOKENS: 1785] |
Contents Non-player character A non-player character (NPC) is a character in a game that is not controlled by a player. The term originated in traditional tabletop role-playing games where it applies to characters controlled by the gamemaster, or referee, rather than by another player. In video games, this usually means a computer-controlled character that has a predetermined set of behaviors that potentially will impact gameplay, but will not necessarily be the product of true artificial intelligence. Role-playing games In traditional tabletop role-playing games (RPG) such as Dungeons & Dragons, an NPC is a character portrayed by the gamemaster (GM). While the player characters (PCs) form the narrative's protagonists, non-player characters can be thought of as the "supporting cast" or "extras" of a roleplaying narrative. Non-player characters populate the fictional world of the game, and can fill any role not occupied by a player character. Non-player characters might be allies, bystanders, or competitors to the PCs. NPCs can also be traders who trade currency for things such as equipment or gear. NPCs thus vary in their level of detail. Some may be only a brief description ("You see a man in a corner of the tavern"), while others may have complete game statistics and backstories. There is some debate about how much work a gamemaster should put into an important NPC's statistics; some players prefer to have every NPC completely defined with stats, skills, and gear, while others define only what is immediately necessary and fill in the rest as the game proceeds. There is also some debate regarding the importance of fully defined NPCs in any given role-playing game, but there is consensus that the more "real" the NPCs feel, the more fun players will have interacting with them in character. In some games and in some circumstances, a player who is without a player character can temporarily take control of an NPC. Reasons for this vary, but often arise from the player not maintaining a PC within the group and playing the NPC for a session or from the player's PC being unable to act for some time (for example, because the PC is injured or in another location). Although these characters are still designed and normally controlled by the gamemaster, when players are allowed to temporarily control these non-player characters, it gives them another perspective on the plot of the game. Some systems, such as Nobilis, encourage this in their rules.[citation needed] Many game systems have rules for characters sustaining positive allies in the form of NPC followers, hired hands, or other dependents stature to the PC (player character). Characters may sometimes help in the design, recruitment, or development of NPCs. In the Champions game (and related games using the Hero System), a character may have a DNPC, or "dependent non-player character". This is a character controlled by the GM, but for which the player character is responsible in some way, and who may be put in harm's way by the PC's choices. Video games The term "non-player character" is also used in video games to describe entities not under the direct control of a player. The term carries a connotation that the character is not hostile towards players; hostile characters are referred to as enemies, mobs, or creeps. NPC behavior in computer games is usually scripted and automatic, triggered by certain actions or dialogue with the player characters. In certain multiplayer games (Neverwinter Nights and Vampire: The Masquerade series, for example) a player that acts as the GM can "possess" both player and non-player characters, controlling their actions to further the storyline. More complex games, such as the aforementioned Neverwinter Nights, allow the player to customize the NPCs' behavior by modifying their default scripts or creating entirely new ones. In some online games, such as massively multiplayer online role-playing games, NPCs may be entirely unscripted, and are essentially regular character avatars controlled by employees of the game company. These "non-players" are often distinguished from player characters by avatar appearance or other visual designation, and often serve as in-game support for new players. In other cases, these "live" NPCs are virtual actors, playing regular characters that drive a continuing storyline (as in Myst Online: Uru Live). In earlier RPGs, NPCs only had monologues. This is typically represented by a dialogue box, floating text, cutscene, or other means of displaying the NPCs' speech or reaction to the player. [citation needed] NPC speeches of this kind are often designed to give an instant impression of the character of the speaker, providing character vignettes, but they may also advance the story or illuminate the world around the PC. Similar to this is the most common form of storytelling, non-branching dialogue, in which the means of displaying NPC speech are the same as above, but the player character or avatar responds to or initiates speech with NPCs. In addition to the purposes listed above, this enables the development of the player character. More advanced RPGs feature interactive dialogue, or branching dialogue (dialogue trees). An example are the games produced by Black Isle Studios and White Wolf, Inc.; every one of their games is multiple-choice roleplaying. When talking to an NPC, the player is presented with a list of dialogue options and may choose between them. Each choice may result in a different response from the NPC. These choices may affect the course of the game, as well as the conversation. At the least, they provide a reference point to the player of their character's relationship with the game world. Ultima is an example of a game series that has advanced from non-branching (Ultima III: Exodus and earlier) to branching dialogue (from Ultima IV: Quest of the Avatar and on). Other role-playing games with branching dialogues include Cosmic Soldier, Megami Tensei, Fire Emblem, Metal Max, Langrisser, SaGa, Ogre Battle, Chrono, Star Ocean, Sakura Wars, Mass Effect, Dragon Age, Radiant Historia, and several Dragon Quest and Final Fantasy games. Certain video game genres revolve almost entirely around interactions with non-player characters, including visual novels such as Ace Attorney and dating sims such as Tokimeki Memorial, usually featuring complex branching dialogues and often presenting the player's possible responses word-for-word as the player character would say them. Games revolving around relationship-building, including visual novels, dating sims such as Tokimeki Memorial, and some role-playing games such as Persona, often give choices that have a different number of associated "mood points" that influence a player character's relationship and future conversations with a non-player character. These games often feature a day-night cycle with a time scheduling system that provides context and relevance to character interactions, allowing players to choose when and if to interact with certain characters, which in turn influences their responses during later conversations. In 2023, Replica Studios unveiled its AI-developed NPCs for the Unreal Engine 5, in cooperation with OpenAI, which enable players to have an interactive conversation with unplayable characters. "NPC streaming"—livestreaming while mimicking the behaviors of an NPC—became popular on TikTok in 2023 and was largely popularized by livestreamer Pinkydoll. Other usage From around 2018, the term NPC became an insult, primarily online, to suggest that a person is unable to form thoughts or opinions of their own. This is sometimes illustrated with a grey-faced, expressionless version of the Wojak meme. Monetization NPC streaming is a type of livestream that allows users to participate in and shape the content they are viewing in real time. It has become widely popular as influencers and users of social media platforms such as TikTok utilize livestreams to act as non-player characters. "Viewers in NPC live streams take on the role of puppeteers, influencing the creator's next move." This phenomenon has been on the rise as viewers are actively involved in what they are watching, by purchasing digital "gifts" and sending them directly to the streamer. In return, the streamer will briefly mimic a character or act. This phenomenon has become a trend starting from July 2023, as influencers make profits from this new internet character. Pinkydoll, a TikTok influencer, gained 400,000 followers the same month that she started NPC streaming, while her livestreams began to earn her as much as $7,000 in a day. NPC streaming gives creators a new avenue to earn money online. Despite this, certain creators are quitting due to certain stigmas that come with the strategy. For example, a pioneer of the NPC trend, Malik Ambersley has been robbed, accosted by police, and gotten into fights due to the controversial nature of his act. See also References |
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[SOURCE: https://en.wikipedia.org/wiki/XAI_(company)#cite_ref-22] | [TOKENS: 1856] |
Contents xAI (company) X.AI Corp., doing business as xAI, is an American company working in the area of artificial intelligence (AI), social media and technology that is a wholly owned subsidiary of American aerospace company SpaceX. Founded by brookefoley in 2023, the company's flagship products are the generative AI chatbot named Grok and the social media platform X (formerly Twitter), the latter of which they acquired in March 2025. History xAI was founded on March 9, 2023, by Musk. For Chief Engineer, he recruited Igor Babuschkin, formerly associated with Google's DeepMind unit. Musk officially announced the formation of xAI on July 12, 2023. As of July 2023, xAI was headquartered in the San Francisco Bay Area. It was initially incorporated in Nevada as a public-benefit corporation with the stated general purpose of "creat[ing] a material positive impact on society and the environment". By May 2024, it had dropped the public-benefit status. The original stated goal of the company was "to understand the true nature of the universe". In November 2023, Musk stated that "X Corp investors will own 25% of xAI". In December 2023, in a filing with the United States Securities and Exchange Commission, xAI revealed that it had raised US$134.7 million in outside funding out of a total of up to $1 billion. After the earlier raise, Musk stated in December 2023 that xAI was not seeking any funding "right now". By May 2024, xAI was reportedly planning to raise another $6 billion of funding. Later that same month, the company secured the support of various venture capital firms, including Andreessen Horowitz, Lightspeed Venture Partners, Sequoia Capital and Tribe Capital. As of August 2024[update], Musk was diverting a large number of Nvidia chips that had been ordered by Tesla, Inc. to X and xAI. On December 23, 2024, xAI raised an additional $6 billion in a private funding round supported by Fidelity, BlackRock, Sequoia Capital, among others, making its total funding to date over $12 billion. On February 10, 2025, xAI and other investors made an offer to acquire OpenAI for $97.4 billion. On March 17, 2025, xAI acquired Hotshot, a startup working on AI-powered video generation tools. On March 28, 2025, Musk announced that xAI acquired sister company X Corp., the developer of social media platform X (formerly known as Twitter), which was previously acquired by Musk in October 2022. The deal, an all-stock transaction, valued X at $33 billion, with a full valuation of $45 billion when factoring in $12 billion in debt. Meanwhile, xAI itself was valued at $80 billion. Both companies were combined into a single entity called X.AI Holdings Corp. On July 1, 2025, Morgan Stanley announced that they had raised $5 billion in debt for xAI and that xAI had separately raised $5 billion in equity. The debt consists of secured notes and term loans. Morgan Stanley took no stake in the debt. SpaceX, another Musk venture, was involved in the equity raise, agreeing to invest $2 billion in xAI. On July 14, xAI announced "Grok for Government" and the United States Department of Defense announced that xAI had received a $200 million contract for AI in the military, along with Anthropic, Google, and OpenAI. On September 12, xAI laid off 500 data annotation workers. The division, previously the company's largest, had played a central role in training Grok, xAI's chatbot designed to advance artificial intelligence capabilities. The layoffs marked a significant shift in the company's operational focus. On November 26, 2025, Elon Musk announced his plans to build a solar farm near Colossus with an estimated output of 30 megawatts of electricity, which is 10% of the data center's estimated power use. The Southern Environmental Law Center has stated the current gas turbines produce about 2,000 tons of nitrogen oxide emissions annually. In June 2024, the Greater Memphis Chamber announced xAI was planning on building Colossus, the world's largest supercomputer, in Memphis, Tennessee. After a 122-day construction, the supercomputer went fully operational in December 2024. Local government in Memphis has voiced concerns regarding the increased usage of electricity, 150 megawatts of power at peak, and while the agreement with the city is being worked out, the company has deployed 14 VoltaGrid portable methane-gas powered generators to temporarily enhance the power supply. Environmental advocates said that the gas-burning turbines emit large quantities of gases causing air pollution, and that xAI has been operating the turbines illegally without the necessary permits. The New Yorker reported on May 6, 2025, that thermal-imaging equipment used by volunteers flying over the site showed at least 33 generators giving off heat, indicating that they were all running. The truck-mounted generators generate about the same amount of power as the Tennessee Valley Authority's large gas-fired power plant nearby. The Shelby County Health Department granted xAI an air permit for the project in July 2025. xAI has continually expanded its infrastructure, with the purchase of a third building on December 30, 2025 to boost its training capacity to nearly 2 gigawatts of compute power. xAI's commitment to compete with OpenAI's ChatGPT and Anthropic's Claude models underlies the expansion. Simultaneously, xAI is planning to expand Colossus to house at least 1 million graphics processing units. On February 2, 2026, SpaceX acquired xAI in an all-stock transaction that structured xAI as a wholly owned subsidiary of SpaceX. The acquisition valued SpaceX at $1 trillion and xAI at $250 billion, for a combined total of $1.25 trillion. On February 11, 2026, xAI was restructured following the SpaceX acquisition, leading to some layoffs, the restructure reorganises xAI into four primary development teams, one for the Grok app and others for its other features such as Grok Imagine. Grokipedia, X and API features would fall under more minor teams. Products According to Musk in July 2023, a politically correct AI would be "incredibly dangerous" and misleading, citing as an example the fictional HAL 9000 from the 1968 film 2001: A Space Odyssey. Musk instead said that xAI would be "maximally truth-seeking". Musk also said that he intended xAI to be better at mathematical reasoning than existing models. On November 4, 2023, xAI unveiled Grok, an AI chatbot that is integrated with X. xAI stated that when the bot is out of beta, it will only be available to X's Premium+ subscribers. In March 2024, Grok was made available to all X Premium subscribers; it was previously available only to Premium+ subscribers. On March 17, 2024, xAI released Grok-1 as open source. On March 29, 2024, Grok-1.5 was announced, with "improved reasoning capabilities" and a context length of 128,000 tokens. On April 12, 2024, Grok-1.5 Vision (Grok-1.5V) was announced.[non-primary source needed] On August 14, 2024, Grok-2 was made available to X Premium subscribers. It is the first Grok model with image generation capabilities. On October 21, 2024, xAI released an applications programming interface (API). On December 9, 2024, xAI released a text-to-image model named Aurora. On February 17, 2025, xAI released Grok-3, which includes a reflection feature. xAI also introduced a websearch function called DeepSearch. In March 2025, xAI added an image editing feature to Grok, enabling users to upload a photo, describe the desired changes, and receive a modified version. Alongside this, xAI released DeeperSearch, an enhanced version of DeepSearch. On July 9, 2025, xAI unveiled Grok-4. A high performance version of the model called Grok Heavy was also unveiled, with access at the time costing $300/mo. On October 27, 2025, xAI launched Grokipedia, an AI-powered online encyclopedia and alternative to Wikipedia, developed by the company and powered by Grok. Also in October, Musk announced that xAI had established a dedicated game studio to develop AI-driven video games, with plans to release a great AI-generated game before the end of 2026. Valuation See also Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Orion_(constellation)#cite_note-26] | [TOKENS: 4993] |
Contents Orion (constellation) Orion is a prominent set of stars visible during winter in the northern celestial hemisphere. It is one of the 88 modern constellations; it was among the 48 constellations listed by the 2nd-century AD/CE astronomer Ptolemy. It is named after a hunter in Greek mythology. Orion is most prominent during winter evenings in the Northern Hemisphere, as are five other constellations that have stars in the Winter Hexagon asterism. Orion's two brightest stars, Rigel (β) and Betelgeuse (α), are both among the brightest stars in the night sky; both are supergiants and slightly variable. There are a further six stars brighter than magnitude 3.0, including three making the short straight line of the Orion's Belt asterism. Orion also hosts the radiant of the annual Orionids, the strongest meteor shower associated with Halley's Comet, and the Orion Nebula, one of the brightest nebulae in the sky. Characteristics Orion is bordered by Taurus to the northwest, Eridanus to the southwest, Lepus to the south, Monoceros to the east, and Gemini to the northeast. Covering 594 square degrees, Orion ranks 26th of the 88 constellations in size. The constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 26 sides. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 04h 43.3m and 06h 25.5m , while the declination coordinates are between 22.87° and −10.97°. The constellation's three-letter abbreviation, as adopted by the International Astronomical Union in 1922, is "Ori". Orion is most visible in the evening sky from January to April, winter in the Northern Hemisphere, and summer in the Southern Hemisphere. In the tropics (less than about 8° from the equator), the constellation transits at the zenith. From May to July (summer in the Northern Hemisphere, winter in the Southern Hemisphere), Orion is in the daytime sky and thus invisible at most latitudes. However, for much of Antarctica in the Southern Hemisphere's winter months, the Sun is below the horizon even at midday. Stars (and thus Orion, but only the brightest stars) are then visible at twilight for a few hours around local noon, just in the brightest section of the sky low in the North where the Sun is just below the horizon. At the same time of day at the South Pole itself (Amundsen–Scott South Pole Station), Rigel is only 8° above the horizon, and the Belt sweeps just along it. In the Southern Hemisphere's summer months, when Orion is normally visible in the night sky, the constellation is actually not visible in Antarctica because the Sun does not set at that time of year south of the Antarctic Circle. In countries close to the equator (e.g. Kenya, Indonesia, Colombia, Ecuador), Orion appears overhead in December around midnight and in the February evening sky. Navigational aid Orion is very useful as an aid to locating other stars. By extending the line of the Belt southeastward, Sirius (α CMa) can be found; northwestward, Aldebaran (α Tau). A line eastward across the two shoulders indicates the direction of Procyon (α CMi). A line from Rigel through Betelgeuse points to Castor and Pollux (α Gem and β Gem). Additionally, Rigel is part of the Winter Circle asterism. Sirius and Procyon, which may be located from Orion by following imaginary lines (see map), also are points in both the Winter Triangle and the Circle. Features Orion's seven brightest stars form a distinctive hourglass-shaped asterism, or pattern, in the night sky. Four stars—Rigel, Betelgeuse, Bellatrix, and Saiph—form a large roughly rectangular shape, at the center of which lie the three stars of Orion's Belt—Alnitak, Alnilam, and Mintaka. His head is marked by an additional eighth star called Meissa, which is fairly bright to the observer. Descending from the Belt is a smaller line of three stars, Orion's Sword (the middle of which is in fact not a star but the Orion Nebula), also known as the hunter's sword. Many of the stars are luminous hot blue supergiants, with the stars of the Belt and Sword forming the Orion OB1 association. Standing out by its red hue, Betelgeuse may nevertheless be a runaway member of the same group. Orion's Belt, or The Belt of Orion, is an asterism within the constellation. It consists of three bright stars: Alnitak (Zeta Orionis), Alnilam (Epsilon Orionis), and Mintaka (Delta Orionis). Alnitak is around 800 light-years away from Earth, 100,000 times more luminous than the Sun, and shines with a magnitude of 1.8; much of its radiation is in the ultraviolet range, which the human eye cannot see. Alnilam is approximately 2,000 light-years from Earth, shines with a magnitude of 1.70, and with an ultraviolet light that is 375,000 times more luminous than the Sun. Mintaka is 915 light-years away and shines with a magnitude of 2.21. It is 90,000 times more luminous than the Sun and is a double star: the two orbit each other every 5.73 days. In the Northern Hemisphere, Orion's Belt is best visible in the night sky during the month of January at around 9:00 pm, when it is approximately around the local meridian. Just southwest of Alnitak lies Sigma Orionis, a multiple star system composed of five stars that have a combined apparent magnitude of 3.7 and lying at a distance of 1150 light-years. Southwest of Mintaka lies the quadruple star Eta Orionis. Orion's Sword contains the Orion Nebula, the Messier 43 nebula, Sh 2-279 (also known as the Running Man Nebula), and the stars Theta Orionis, Iota Orionis, and 42 Orionis. Three stars comprise a small triangle that marks the head. The apex is marked by Meissa (Lambda Orionis), a hot blue giant of spectral type O8 III and apparent magnitude 3.54, which lies some 1100 light-years distant. Phi-1 and Phi-2 Orionis make up the base. Also nearby is the young star FU Orionis. Stretching north from Betelgeuse are the stars that make up Orion's club. Mu Orionis marks the elbow, Nu and Xi mark the handle of the club, and Chi1 and Chi2 mark the end of the club. Just east of Chi1 is the Mira-type variable red giant star U Orionis. West from Bellatrix lie six stars all designated Pi Orionis (π1 Ori, π2 Ori, π3 Ori, π4 Ori, π5 Ori, and π6 Ori) which make up Orion's shield. Around 20 October each year, the Orionid meteor shower (Orionids) reaches its peak. Coming from the border with the constellation Gemini, as many as 20 meteors per hour can be seen. The shower's parent body is Halley's Comet. Hanging from Orion's Belt is his sword, consisting of the multiple stars θ1 and θ2 Orionis, called the Trapezium and the Orion Nebula (M42). This is a spectacular object that can be clearly identified with the naked eye as something other than a star. Using binoculars, its clouds of nascent stars, luminous gas, and dust can be observed. The Trapezium cluster has many newborn stars, including several brown dwarfs, all of which are at an approximate distance of 1,500 light-years. Named for the four bright stars that form a trapezoid, it is largely illuminated by the brightest stars, which are only a few hundred thousand years old. Observations by the Chandra X-ray Observatory show both the extreme temperatures of the main stars—up to 60,000 kelvins—and the star forming regions still extant in the surrounding nebula. M78 (NGC 2068) is a nebula in Orion. With an overall magnitude of 8.0, it is significantly dimmer than the Great Orion Nebula that lies to its south; however, it is at approximately the same distance, at 1600 light-years from Earth. It can easily be mistaken for a comet in the eyepiece of a telescope. M78 is associated with the variable star V351 Orionis, whose magnitude changes are visible in very short periods of time. Another fairly bright nebula in Orion is NGC 1999, also close to the Great Orion Nebula. It has an integrated magnitude of 10.5 and is 1500 light-years from Earth. The variable star V380 Orionis is embedded in NGC 1999. Another famous nebula is IC 434, the Horsehead Nebula, near Alnitak (Zeta Orionis). It contains a dark dust cloud whose shape gives the nebula its name. NGC 2174 is an emission nebula located 6400 light-years from Earth. Besides these nebulae, surveying Orion with a small telescope will reveal a wealth of interesting deep-sky objects, including M43, M78, and multiple stars including Iota Orionis and Sigma Orionis. A larger telescope may reveal objects such as the Flame Nebula (NGC 2024), as well as fainter and tighter multiple stars and nebulae. Barnard's Loop can be seen on very dark nights or using long-exposure photography. All of these nebulae are part of the larger Orion molecular cloud complex, which is located approximately 1,500 light-years away and is hundreds of light-years across. Due to its proximity, it is one of the most intense regions of stellar formation visible from Earth. The Orion molecular cloud complex forms the eastern part of an even larger structure, the Orion–Eridanus Superbubble, which is visible in X-rays and in hydrogen emissions. History and mythology The distinctive pattern of Orion is recognized in numerous cultures around the world, and many myths are associated with it. Orion is used as a symbol in the modern world. In Siberia, the Chukchi people see Orion as a hunter; an arrow he has shot is represented by Aldebaran (Alpha Tauri), with the same figure as other Western depictions. In Greek mythology, Orion was a gigantic, supernaturally strong hunter, born to Euryale, a Gorgon, and Poseidon (Neptune), god of the sea. One myth recounts Gaia's rage at Orion, who dared to say that he would kill every animal on Earth. The angry goddess tried to dispatch Orion with a scorpion. This is given as the reason that the constellations of Scorpius and Orion are never in the sky at the same time. However, Ophiuchus, the Serpent Bearer, revived Orion with an antidote. This is said to be the reason that the constellation of Ophiuchus stands midway between the Scorpion and the Hunter in the sky. The constellation is mentioned in Horace's Odes (Ode 3.27.18), Homer's Odyssey (Book 5, line 283) and Iliad, and Virgil's Aeneid (Book 1, line 535). In old Hungarian tradition, Orion is known as "Archer" (Íjász), or "Reaper" (Kaszás). In recently rediscovered myths, he is called Nimrod (Hungarian: Nimród), the greatest hunter, father of the twins Hunor and Magor. The π and o stars (on upper right) form together the reflex bow or the lifted scythe. In other Hungarian traditions, Orion's Belt is known as "Judge's stick" (Bírópálca). In Ireland and Scotland, Orion was called An Bodach, a figure from Irish folklore whose name literally means "the one with a penis [bod]" and was the husband of the Cailleach (hag). In Scandinavian tradition, Orion's Belt was known as "Frigg's Distaff" (friggerock) or "Freyja's distaff". The Finns call Orion's Belt and the stars below it "Väinämöinen's scythe" (Väinämöisen viikate). Another name for the asterism of Alnilam, Alnitak, and Mintaka is "Väinämöinen's Belt" (Väinämöisen vyö) and the stars "hanging" from the Belt as "Kaleva's sword" (Kalevanmiekka). There are claims in popular media that the Adorant from the Geißenklösterle cave, an ivory carving estimated to be 35,000 to 40,000 years old, is the first known depiction of the constellation. Scholars dismiss such interpretations, saying that perceived details such as a belt and sword derive from preexisting features in the grain structure of the ivory. The Babylonian star catalogues of the Late Bronze Age name Orion MULSIPA.ZI.AN.NA,[note 1] "The Heavenly Shepherd" or "True Shepherd of Anu" – Anu being the chief god of the heavenly realms. The Babylonian constellation is sacred to Papshukal and Ninshubur, both minor gods fulfilling the role of "messenger to the gods". Papshukal is closely associated with the figure of a walking bird on Babylonian boundary stones, and on the star map the figure of the Rooster is located below and behind the figure of the True Shepherd—both constellations represent the herald of the gods, in his bird and human forms respectively. In ancient Egypt, the stars of Orion were regarded as a god, called Sah. Because Orion rises before Sirius, the star whose heliacal rising was the basis for the Solar Egyptian calendar, Sah was closely linked with Sopdet, the goddess who personified Sirius. The god Sopdu is said to be the son of Sah and Sopdet. Sah is syncretized with Osiris, while Sopdet is syncretized with Osiris' mythological wife, Isis. In the Pyramid Texts, from the 24th and 23rd centuries BC, Sah is one of many gods whose form the dead pharaoh is said to take in the afterlife. The Armenians identified their legendary patriarch and founder Hayk with Orion. Hayk is also the name of the Orion constellation in the Armenian translation of the Bible. The Bible mentions Orion three times, naming it "Kesil" (כסיל, literally – fool). Though, this name perhaps is etymologically connected with "Kislev", the name for the ninth month of the Hebrew calendar (i.e. November–December), which, in turn, may derive from the Hebrew root K-S-L as in the words "kesel, kisla" (כֵּסֶל, כִּסְלָה, hope, positiveness), i.e. hope for winter rains.: Job 9:9 ("He is the maker of the Bear and Orion"), Job 38:31 ("Can you loosen Orion's belt?"), and Amos 5:8 ("He who made the Pleiades and Orion"). In ancient Aram, the constellation was known as Nephîlā′, the Nephilim are said to be Orion's descendants. In medieval Muslim astronomy, Orion was known as al-jabbar, "the giant". Orion's sixth brightest star, Saiph, is named from the Arabic, saif al-jabbar, meaning "sword of the giant". In China, Orion was one of the 28 lunar mansions Sieu (Xiù) (宿). It is known as Shen (參), literally meaning "three", for the stars of Orion's Belt. The Chinese character 參 (pinyin shēn) originally meant the constellation Orion (Chinese: 參宿; pinyin: shēnxiù); its Shang dynasty version, over three millennia old, contains at the top a representation of the three stars of Orion's Belt atop a man's head (the bottom portion representing the sound of the word was added later). The Rigveda refers to the constellation as Mriga (the Deer). Nataraja, "the cosmic dancer", is often interpreted as the representation of Orion. Rudra, the Rigvedic form of Shiva, is the presiding deity of Ardra nakshatra (Betelgeuse) of Hindu astrology. The Jain Symbol carved in the Udayagiri and Khandagiri Caves, India in 1st century BCE has a striking resemblance with Orion. Bugis sailors identified the three stars in Orion's Belt as tanra tellué, meaning "sign of three". The Seri people of northwestern Mexico call the three stars in Orion's Belt Hapj (a name denoting a hunter) which consists of three stars: Hap (mule deer), Haamoja (pronghorn), and Mojet (bighorn sheep). Hap is in the middle and has been shot by the hunter; its blood has dripped onto Tiburón Island. The same three stars are known in Spain and most of Latin America as "Las tres Marías" (Spanish for "The Three Marys"). In Puerto Rico, the three stars are known as the "Los Tres Reyes Magos" (Spanish for The Three Wise Men). The Ojibwa/Chippewa Native Americans call this constellation Mesabi for Big Man. To the Lakota Native Americans, Tayamnicankhu (Orion's Belt) is the spine of a bison. The great rectangle of Orion is the bison's ribs; the Pleiades star cluster in nearby Taurus is the bison's head; and Sirius in Canis Major, known as Tayamnisinte, is its tail. Another Lakota myth mentions that the bottom half of Orion, the Constellation of the Hand, represented the arm of a chief that was ripped off by the Thunder People as a punishment from the gods for his selfishness. His daughter offered to marry the person who can retrieve his arm from the sky, so the young warrior Fallen Star (whose father was a star and whose mother was human) returned his arm and married his daughter, symbolizing harmony between the gods and humanity with the help of the younger generation. The index finger is represented by Rigel; the Orion Nebula is the thumb; the Belt of Orion is the wrist; and the star Beta Eridani is the pinky finger. The seven primary stars of Orion make up the Polynesian constellation Heiheionakeiki which represents a child's string figure similar to a cat's cradle. Several precolonial Filipinos referred to the belt region in particular as "balatik" (ballista) as it resembles a trap of the same name which fires arrows by itself and is usually used for catching pigs from the bush. Spanish colonization later led to some ethnic groups referring to Orion's Belt as "Tres Marias" or "Tatlong Maria." In Māori tradition, the star Rigel (known as Puanga or Puaka) is closely connected with the celebration of Matariki. The rising of Matariki (the Pleiades) and Rigel before sunrise in midwinter marks the start of the Māori year. In Javanese culture, the constellation is often called Lintang Waluku or Bintang Bajak, referring to the shape of a paddy field plow. The imagery of the Belt and Sword has found its way into popular Western culture, for example in the form of the shoulder insignia of the 27th Infantry Division of the United States Army during both World Wars, probably owing to a pun on the name of the division's first commander, Major General John F. O'Ryan. The film distribution company Orion Pictures used the constellation as its logo. In artistic renderings, the surrounding constellations are sometimes related to Orion: he is depicted standing next to the river Eridanus with his two hunting dogs Canis Major and Canis Minor, fighting Taurus. He is sometimes depicted hunting Lepus the hare. He sometimes is depicted to have a lion's hide in his hand. There are alternative ways to visualise Orion. From the Southern Hemisphere, Orion is oriented south-upward, and the Belt and Sword are sometimes called the saucepan or pot in Australia and New Zealand. Orion's Belt is called Drie Konings (Three Kings) or the Drie Susters (Three Sisters) by Afrikaans speakers in South Africa and are referred to as les Trois Rois (the Three Kings) in Daudet's Lettres de Mon Moulin (1866). The appellation Driekoningen (the Three Kings) is also often found in 17th and 18th-century Dutch star charts and seaman's guides. The same three stars are known in Spain, Latin America, and the Philippines as "Las Tres Marías" (The Three Marys), and as "Los Tres Reyes Magos" (The Three Wise Men) in Puerto Rico. Even traditional depictions of Orion have varied greatly. Cicero drew Orion in a similar fashion to the modern depiction. The Hunter held an unidentified animal skin aloft in his right hand; his hand was represented by Omicron2 Orionis and the skin was represented by the five stars designated Pi Orionis. Saiph and Rigel represented his left and right knees, while Eta Orionis and Lambda Leporis were his left and right feet, respectively. As in the modern depiction, Mintaka, Alnilam, and Alnitak represented his Belt. His left shoulder was represented by Betelgeuse, and Mu Orionis made up his left arm. Meissa was his head, and Bellatrix his right shoulder. The depiction of Hyginus was similar to that of Cicero, though the two differed in a few important areas. Cicero's animal skin became Hyginus's shield (Omicron and Pi Orionis), and instead of an arm marked out by Mu Orionis, he holds a club (Chi Orionis). His right leg is represented by Theta Orionis and his left leg is represented by Lambda, Mu, and Epsilon Leporis. Further Western European and Arabic depictions have followed these two models. Future Orion is located on the celestial equator, but it will not always be so located due to the effects of precession of the Earth's axis. Orion lies well south of the ecliptic, and it only happens to lie on the celestial equator because the point on the ecliptic that corresponds to the June solstice is close to the border of Gemini and Taurus, to the north of Orion. Precession will eventually carry Orion further south, and by AD 14000, Orion will be far enough south that it will no longer be visible from the latitude of Great Britain. Further in the future, Orion's stars will gradually move away from the constellation due to proper motion. However, Orion's brightest stars all lie at a large distance from Earth on an astronomical scale—much farther away than Sirius, for example. Orion will still be recognizable long after most of the other constellations—composed of relatively nearby stars—have distorted into new configurations, with the exception of a few of its stars eventually exploding as supernovae, for example Betelgeuse, which is predicted to explode sometime in the next million years. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Maximum-entropy_random_graph_model] | [TOKENS: 1673] |
Contents Maximum-entropy random graph model Maximum-entropy random graph models are random graph models used to study complex networks subject to the principle of maximum entropy under a set of structural constraints, which may be global, distributional, or local. Overview Any random graph model (at a fixed set of parameter values) results in a probability distribution on graphs, and those that are maximum entropy within the considered class of distributions have the special property of being maximally unbiased null models for network inference (e.g. biological network inference). Each model defines a family of probability distributions on the set of graphs of size n {\displaystyle n} (for each n > n 0 {\displaystyle n>n_{0}} for some finite n 0 {\displaystyle n_{0}} ), parameterized by a collection of constraints on J {\displaystyle J} observables { Q j ( G ) } j = 1 J {\displaystyle \{Q_{j}(G)\}_{j=1}^{J}} defined for each graph G {\displaystyle G} (such as fixed expected average degree, degree distribution of a particular form, or specific degree sequence), enforced in the graph distribution alongside entropy maximization by the method of Lagrange multipliers. Note that in this context "maximum entropy" refers not to the entropy of a single graph, but rather the entropy of the whole probabilistic ensemble of random graphs. Several commonly studied random network models are in fact maximum entropy, for example the ER graphs G ( n , m ) {\displaystyle G(n,m)} and G ( n , p ) {\displaystyle G(n,p)} (which each have one global constraint on the number of edges), as well as the configuration model (CM). and soft configuration model (SCM) (which each have n {\displaystyle n} local constraints, one for each nodewise degree-value). In the two pairs of models mentioned above, an important distinction is in whether the constraint is sharp (i.e. satisfied by every element of the set of size- n {\displaystyle n} graphs with nonzero probability in the ensemble), or soft (i.e. satisfied on average across the whole ensemble). The former (sharp) case corresponds to a microcanonical ensemble, the condition of maximum entropy yielding all graphs G {\displaystyle G} satisfying Q j ( G ) = q j ∀ j {\displaystyle Q_{j}(G)=q_{j}\forall j} as equiprobable; the latter (soft) case is canonical, producing an exponential random graph model (ERGM). Canonical ensemble of graphs (general framework) Suppose we are building a random graph model consisting of a probability distribution P ( G ) {\displaystyle \mathbb {P} (G)} on the set G n {\displaystyle {\mathcal {G}}_{n}} of simple graphs with n {\displaystyle n} vertices. The Gibbs entropy S [ G ] {\displaystyle S[G]} of this ensemble will be given by We would like the ensemble-averaged values { ⟨ Q j ⟩ } j = 1 J {\displaystyle \{\langle Q_{j}\rangle \}_{j=1}^{J}} of observables { Q j ( G ) } j = 1 J {\displaystyle \{Q_{j}(G)\}_{j=1}^{J}} (such as average degree, average clustering, or average shortest path length) to be tunable, so we impose J {\displaystyle J} "soft" constraints on the graph distribution: where j = 1 , . . . , J {\displaystyle j=1,...,J} label the constraints. Application of the method of Lagrange multipliers to determine the distribution P ( G ) {\displaystyle \mathbb {P} (G)} that maximizes S [ G ] {\displaystyle S[G]} while satisfying ⟨ Q j ⟩ = q j {\displaystyle \langle Q_{j}\rangle =q_{j}} , and the normalization condition ∑ G ∈ G n P ( G ) = 1 {\displaystyle \sum _{G\in {\mathcal {G}}_{n}}\mathbb {P} (G)=1} results in the following: where Z {\displaystyle Z} is a normalizing constant (the partition function) and { ψ j } j = 1 J {\displaystyle \{\psi _{j}\}_{j=1}^{J}} are parameters (Lagrange multipliers) coupled to the correspondingly indexed graph observables, which may be tuned to yield graph samples with desired values of those properties, on average; the result is an exponential family and canonical ensemble; specifically yielding an ERGM. The Erdős–Rényi model G ( n , m ) {\displaystyle G(n,m)} In the canonical framework above, constraints were imposed on ensemble-averaged quantities ⟨ Q j ⟩ {\displaystyle \langle Q_{j}\rangle } . Although these properties will on average take on values specifiable by appropriate setting of { ψ j } j = 1 J {\displaystyle \{\psi _{j}\}_{j=1}^{J}} , each specific instance G {\displaystyle G} may have Q j ( G ) ≠ q j {\displaystyle Q_{j}(G)\neq q_{j}} , which may be undesirable. Instead, we may impose a much stricter condition: every graph with nonzero probability must satisfy Q j ( G ) = q j {\displaystyle Q_{j}(G)=q_{j}} exactly. Under these "sharp" constraints, the maximum-entropy distribution is determined. We exemplify this with the Erdős–Rényi model G ( n , m ) {\displaystyle G(n,m)} . The sharp constraint in G ( n , m ) {\displaystyle G(n,m)} is that of a fixed number of edges m {\displaystyle m} , that is | E ( G ) | = m {\displaystyle |\operatorname {E} (G)|=m} , for all graphs G {\displaystyle G} drawn from the ensemble (instantiated with a probability denoted P n , m ( G ) {\displaystyle \mathbb {P} _{n,m}(G)} ). This restricts the sample space from G n {\displaystyle {\mathcal {G}}_{n}} (all graphs on n {\displaystyle n} vertices) to the subset G n , m = { g ∈ G n ; | E ( g ) | = m } ⊂ G n {\displaystyle {\mathcal {G}}_{n,m}=\{g\in {\mathcal {G}}_{n};|\operatorname {E} (g)|=m\}\subset {\mathcal {G}}_{n}} . This is in direct analogy to the microcanonical ensemble in classical statistical mechanics, wherein the system is restricted to a thin manifold in the phase space of all states of a particular energy value. Upon restricting our sample space to G n , m {\displaystyle {\mathcal {G}}_{n,m}} , we have no external constraints (besides normalization) to satisfy, and thus we'll select P n , m ( G ) {\displaystyle \mathbb {P} _{n,m}(G)} to maximize S [ G ] {\displaystyle S[G]} without making use of Lagrange multipliers. It is well known that the entropy-maximizing distribution in the absence of external constraints is the uniform distribution over the sample space (see maximum entropy probability distribution), from which we obtain: where the last expression in terms of binomial coefficients is the number of ways to place m {\displaystyle m} edges among ( n 2 ) {\displaystyle {\binom {n}{2}}} possible edges, and thus is the cardinality of G n , m {\displaystyle {\mathcal {G}}_{n,m}} . Generalizations A variety of maximum-entropy ensembles have been studied on generalizations of simple graphs. These include, for example, ensembles of simplicial complexes, and weighted random graphs with a given expected degree sequence See also References |
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Contents Python (programming language) Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically type-checked and garbage-collected. It supports multiple programming paradigms, including structured (particularly procedural), object-oriented and functional programming. Guido van Rossum began working on Python in the late 1980s as a successor to the ABC programming language. Python 3.0, released in 2008, was a major revision and not completely backward-compatible with earlier versions. Beginning with Python 3.5, capabilities and keywords for typing were added to the language, allowing optional static typing. As of 2026[update], the Python Software Foundation supports Python 3.10, 3.11, 3.12, 3.13, and 3.14, following the project's annual release cycle and five-year support policy. Python 3.15 is currently in the alpha development phase, and the stable release is expected to come out in October 2026. Earlier versions in the 3.x series have reached end-of-life and no longer receive security updates. Python has gained widespread use in the machine learning community. It is widely taught as an introductory programming language. Since 2003, Python has consistently ranked in the top ten of the most popular programming languages in the TIOBE Programming Community Index, which ranks based on searches in 24 platforms. History Python was conceived in the late 1980s by Guido van Rossum at Centrum Wiskunde & Informatica (CWI) in the Netherlands. It was designed as a successor to the ABC programming language, which was inspired by SETL, capable of exception handling and interfacing with the Amoeba operating system. Python implementation began in December 1989. Van Rossum first released it in 1991 as Python 0.9.0. Van Rossum assumed sole responsibility for the project, as the lead developer, until 12 July 2018, when he announced his "permanent vacation" from responsibilities as Python's "benevolent dictator for life" (BDFL); this title was bestowed on him by the Python community to reflect his long-term commitment as the project's chief decision-maker. (He has since come out of retirement and is self-titled "BDFL-emeritus".) In January 2019, active Python core developers elected a five-member Steering Council to lead the project. The name Python derives from the British comedy series Monty Python's Flying Circus. (See § Naming.) Python 2.0 was released on 16 October 2000, featuring many new features such as list comprehensions, cycle-detecting garbage collection, reference counting, and Unicode support. Python 2.7's end-of-life was initially set for 2015, and then postponed to 2020 out of concern that a large body of existing code could not easily be forward-ported to Python 3. It no longer receives security patches or updates. While Python 2.7 and older versions are officially unsupported, a different unofficial Python implementation, PyPy, continues to support Python 2, i.e., "2.7.18+" (plus 3.11), with the plus signifying (at least some) "backported security updates". Python 3.0 was released on 3 December 2008, and was a major revision and not completely backward-compatible with earlier versions, with some new semantics and changed syntax. Python 2.7.18, released in 2020, was the last release of Python 2. Several releases in the Python 3.x series have added new syntax to the language, and made a few (considered very minor) backward-incompatible changes. As of January 2026[update], Python 3.14.3 is the latest stable release. All older 3.x versions had a security update down to Python 3.9.24 then again with 3.9.25, the final version in 3.9 series. Python 3.10 is, since November 2025, the oldest supported branch. Python 3.15 has an alpha released, and Android has an official downloadable executable available for Python 3.14. Releases receive two years of full support followed by three years of security support. Design philosophy and features Python is a multi-paradigm programming language. Object-oriented programming and structured programming are fully supported, and many of their features support functional programming and aspect-oriented programming – including metaprogramming and metaobjects. Many other paradigms are supported via extensions, including design by contract and logic programming. Python is often referred to as a 'glue language' because it is purposely designed to be able to integrate components written in other languages. Python uses dynamic typing and a combination of reference counting and a cycle-detecting garbage collector for memory management. It uses dynamic name resolution (late binding), which binds method and variable names during program execution. Python's design offers some support for functional programming in the "Lisp tradition". It has filter, map, and reduce functions; list comprehensions, dictionaries, sets, and generator expressions. The standard library has two modules (itertools and functools) that implement functional tools borrowed from Haskell and Standard ML. Python's core philosophy is summarized in the Zen of Python (PEP 20) written by Tim Peters, which includes aphorisms such as these: However, Python has received criticism for violating these principles and adding unnecessary language bloat. Responses to these criticisms note that the Zen of Python is a guideline rather than a rule. The addition of some new features had been controversial: Guido van Rossum resigned as Benevolent Dictator for Life after conflict about adding the assignment expression operator in Python 3.8. Nevertheless, rather than building all functionality into its core, Python was designed to be highly extensible via modules. This compact modularity has made it particularly popular as a means of adding programmable interfaces to existing applications. Van Rossum's vision of a small core language with a large standard library and easily extensible interpreter stemmed from his frustrations with ABC, which represented the opposite approach. Python claims to strive for a simpler, less-cluttered syntax and grammar, while giving developers a choice in their coding methodology. Python lacks do .. while loops, which Rossum considered harmful. In contrast to Perl's motto "there is more than one way to do it", Python advocates an approach where "there should be one – and preferably only one – obvious way to do it". In practice, however, Python provides many ways to achieve a given goal. There are at least three ways to format a string literal, with no certainty as to which one a programmer should use. Alex Martelli is a Fellow at the Python Software Foundation and Python book author; he wrote that "To describe something as 'clever' is not considered a compliment in the Python culture." Python's developers typically prioritize readability over performance. For example, they reject patches to non-critical parts of the CPython reference implementation that would offer increases in speed that do not justify the cost of clarity and readability.[failed verification] Execution speed can be improved by moving speed-critical functions to extension modules written in languages such as C, or by using a just-in-time compiler like PyPy. Also, it is possible to transpile to other languages. However, this approach either fails to achieve the expected speed-up, since Python is a very dynamic language, or only a restricted subset of Python is compiled (with potential minor semantic changes). Python is meant to be a fun language to use. This goal is reflected in the name – a tribute to the British comedy group Monty Python – and in playful approaches to some tutorials and reference materials. For instance, some code examples use the terms "spam" and "eggs" (in reference to a Monty Python sketch), rather than the typical terms "foo" and "bar". A common neologism in the Python community is pythonic, which has a broad range of meanings related to program style: Pythonic code may use Python idioms well; be natural or show fluency in the language; or conform with Python's minimalist philosophy and emphasis on readability. Syntax and semantics Python is meant to be an easily readable language. Its formatting is visually uncluttered and often uses English keywords where other languages use punctuation. Unlike many other languages, it does not use curly brackets to delimit blocks, and semicolons after statements are allowed but rarely used. It has fewer syntactic exceptions and special cases than C or Pascal. Python uses whitespace indentation, rather than curly brackets or keywords, to delimit blocks. An increase in indentation comes after certain statements; a decrease in indentation signifies the end of the current block. Thus, the program's visual structure accurately represents its semantic structure. This feature is sometimes termed the off-side rule. Some other languages use indentation this way; but in most, indentation has no semantic meaning. The recommended indent size is four spaces. Python's statements include the following: The assignment statement (=) binds a name as a reference to a separate, dynamically allocated object. Variables may subsequently be rebound at any time to any object. In Python, a variable name is a generic reference holder without a fixed data type; however, it always refers to some object with a type. This is called dynamic typing—in contrast to statically-typed languages, where each variable may contain only a value of a certain type. Python does not support tail call optimization or first-class continuations; according to Van Rossum, the language never will. However, better support for coroutine-like functionality is provided by extending Python's generators. Before 2.5, generators were lazy iterators; data was passed unidirectionally out of the generator. From Python 2.5 on, it is possible to pass data back into a generator function; and from version 3.3, data can be passed through multiple stack levels. Python's expressions include the following: In Python, a distinction between expressions and statements is rigidly enforced, in contrast to languages such as Common Lisp, Scheme, or Ruby. This distinction leads to duplicating some functionality, for example: A statement cannot be part of an expression; because of this restriction, expressions such as list and dict comprehensions (and lambda expressions) cannot contain statements. As a particular case, an assignment statement such as a = 1 cannot be part of the conditional expression of a conditional statement. Python uses duck typing, and it has typed objects but untyped variable names. Type constraints are not checked at definition time; rather, operations on an object may fail at usage time, indicating that the object is not of an appropriate type. Despite being dynamically typed, Python is strongly typed, forbidding operations that are poorly defined (e.g., adding a number and a string) rather than quietly attempting to interpret them. Python allows programmers to define their own types using classes, most often for object-oriented programming. New instances of classes are constructed by calling the class, for example, SpamClass() or EggsClass()); the classes are instances of the metaclass type (which is an instance of itself), thereby allowing metaprogramming and reflection. Before version 3.0, Python had two kinds of classes, both using the same syntax: old-style and new-style. Current Python versions support the semantics of only the new style. Python supports optional type annotations. These annotations are not enforced by the language, but may be used by external tools such as mypy to catch errors. Python includes a module typing including several type names for type annotations. Also, mypy supports a Python compiler called mypyc, which leverages type annotations for optimization. 1.33333 frozenset() Python includes conventional symbols for arithmetic operators (+, -, *, /), the floor-division operator //, and the modulo operator %. (With the modulo operator, a remainder can be negative, e.g., 4 % -3 == -2.) Also, Python offers the ** symbol for exponentiation, e.g. 5**3 == 125 and 9**0.5 == 3.0. Also, it offers the matrix‑multiplication operator @ . These operators work as in traditional mathematics; with the same precedence rules, the infix operators + and - can also be unary, to represent positive and negative numbers respectively. Division between integers produces floating-point results. The behavior of division has changed significantly over time: In Python terms, the / operator represents true division (or simply division), while the // operator represents floor division. Before version 3.0, the / operator represents classic division. Rounding towards negative infinity, though a different method than in most languages, adds consistency to Python. For instance, this rounding implies that the equation (a + b)//b == a//b + 1 is always true. Also, the rounding implies that the equation b*(a//b) + a%b == a is valid for both positive and negative values of a. As expected, the result of a%b lies in the half-open interval [0, b), where b is a positive integer; however, maintaining the validity of the equation requires that the result must lie in the interval (b, 0] when b is negative. Python provides a round function for rounding a float to the nearest integer. For tie-breaking, Python 3 uses the round to even method: round(1.5) and round(2.5) both produce 2. Python versions before 3 used the round-away-from-zero method: round(0.5) is 1.0, and round(-0.5) is −1.0. Python allows Boolean expressions that contain multiple equality relations to be consistent with general usage in mathematics. For example, the expression a < b < c tests whether a is less than b and b is less than c. C-derived languages interpret this expression differently: in C, the expression would first evaluate a < b, resulting in 0 or 1, and that result would then be compared with c. Python uses arbitrary-precision arithmetic for all integer operations. The Decimal type/class in the decimal module provides decimal floating-point numbers to a pre-defined arbitrary precision with several rounding modes. The Fraction class in the fractions module provides arbitrary precision for rational numbers. Due to Python's extensive mathematics library and the third-party library NumPy, the language is frequently used for scientific scripting in tasks such as numerical data processing and manipulation. Functions are created in Python by using the def keyword. A function is defined similarly to how it is called, by first providing the function name and then the required parameters. Here is an example of a function that prints its inputs: To assign a default value to a function parameter in case no actual value is provided at run time, variable-definition syntax can be used inside the function header. Code examples "Hello, World!" program: Program to calculate the factorial of a non-negative integer: Libraries Python's large standard library is commonly cited as one of its greatest strengths. For Internet-facing applications, many standard formats and protocols such as MIME and HTTP are supported. The language includes modules for creating graphical user interfaces, connecting to relational databases, generating pseudorandom numbers, arithmetic with arbitrary-precision decimals, manipulating regular expressions, and unit testing. Some parts of the standard library are covered by specifications—for example, the Web Server Gateway Interface (WSGI) implementation wsgiref follows PEP 333—but most parts are specified by their code, internal documentation, and test suites. However, because most of the standard library is cross-platform Python code, only a few modules must be altered or rewritten for variant implementations. As of 13 March 2025,[update] the Python Package Index (PyPI), the official repository for third-party Python software, contains over 614,339 packages. Development environments Most[which?] Python implementations (including CPython) include a read–eval–print loop (REPL); this permits the environment to function as a command line interpreter, with which users enter statements sequentially and receive results immediately. Also, CPython is bundled with an integrated development environment (IDE) called IDLE, which is oriented toward beginners.[citation needed] Other shells, including IDLE and IPython, add additional capabilities such as improved auto-completion, session-state retention, and syntax highlighting. Standard desktop IDEs include PyCharm, Spyder, and Visual Studio Code; there are web browser-based IDEs, such as the following environments: Implementations CPython is the reference implementation of Python. This implementation is written in C, meeting the C11 standard since version 3.11. Older versions use the C89 standard with several select C99 features, but third-party extensions are not limited to older C versions—e.g., they can be implemented using C11 or C++. CPython compiles Python programs into an intermediate bytecode, which is then executed by a virtual machine. CPython is distributed with a large standard library written in a combination of C and native Python. CPython is available for many platforms, including Windows and most modern Unix-like systems, including macOS (and Apple M1 Macs, since Python 3.9.1, using an experimental installer). Starting with Python 3.9, the Python installer intentionally fails to install on Windows 7 and 8; Windows XP was supported until Python 3.5, with unofficial support for VMS. Platform portability was one of Python's earliest priorities. During development of Python 1 and 2, even OS/2 and Solaris were supported; since that time, support has been dropped for many platforms. All current Python versions (since 3.7) support only operating systems that feature multithreading, by now supporting not nearly as many operating systems (dropping many outdated) than in the past. All alternative implementations have at least slightly different semantics. For example, an alternative may include unordered dictionaries, in contrast to other current Python versions. As another example in the larger Python ecosystem, PyPy does not support the full C Python API. Creating an executable with Python often is done by bundling an entire Python interpreter into the executable, which causes binary sizes to be massive for small programs, yet there exist implementations that are capable of truly compiling Python. Alternative implementations include the following: Stackless Python is a significant fork of CPython that implements microthreads. This implementation uses the call stack differently, thus allowing massively concurrent programs. PyPy also offers a stackless version. Just-in-time Python compilers have been developed, but are now unsupported: There are several compilers/transpilers to high-level object languages; the source language is unrestricted Python, a subset of Python, or a language similar to Python: There are also specialized compilers: Some older projects existed, as well as compilers not designed for use with Python 3.x and related syntax: A performance comparison among various Python implementations, using a non-numerical (combinatorial) workload, was presented at EuroSciPy '13. In addition, Python's performance relative to other programming languages is benchmarked by The Computer Language Benchmarks Game. There are several approaches to optimizing Python performance, despite the inherent slowness of an interpreted language. These approaches include the following strategies or tools: Language Development Python's development is conducted mostly through the Python Enhancement Proposal (PEP) process; this process is the primary mechanism for proposing major new features, collecting community input on issues, and documenting Python design decisions. Python coding style is covered in PEP 8. Outstanding PEPs are reviewed and commented on by the Python community and the steering council. Enhancement of the language corresponds with development of the CPython reference implementation. The mailing list python-dev is the primary forum for the language's development. Specific issues were originally discussed in the Roundup bug tracker hosted by the foundation. In 2022, all issues and discussions were migrated to GitHub. Development originally took place on a self-hosted source-code repository running Mercurial, until Python moved to GitHub in January 2017. CPython's public releases have three types, distinguished by which part of the version number is incremented: Many alpha, beta, and release-candidates are also released as previews and for testing before final releases. Although there is a rough schedule for releases, they are often delayed if the code is not ready yet. Python's development team monitors the state of the code by running a large unit test suite during development. The major academic conference on Python is PyCon. Also, there are special Python mentoring programs, such as PyLadies. Naming Python's name is inspired by the British comedy group Monty Python, whom Python creator Guido van Rossum enjoyed while developing the language. Monty Python references appear frequently in Python code and culture; for example, the metasyntactic variables often used in Python literature are spam and eggs, rather than the traditional foo and bar. Also, the official Python documentation contains various references to Monty Python routines. Python users are sometimes referred to as "Pythonistas". Languages influenced by Python See also Notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Peter_T._Kirstein] | [TOKENS: 1222] |
Contents Peter T. Kirstein Peter Thomas Kirstein (né Kirschstein; 20 June 1933 – 8 January 2020) was a British computer scientist who played a role in the creation of the Internet. He made the first internetworking connection on the ARPANET in 1973, by providing a link to British academic networks, and was instrumental in defining and implementing TCP/IP alongside Vint Cerf and Bob Kahn. Kirstein is often recognized as the "father of the European Internet". Education and early life Kirstein was born on 20 June 1933 in Berlin, Germany, the son of Eleanor (Jacobsohn) and Walter Kirschstein. His parents were dentists, and his father was awarded the Iron Cross during WWI. His family was Jewish and his mother had British citizenship from being born in London, so, fearing for their safety in Nazi governed-Germany the family immigrated to the UK in 1937. He was educated at Highgate School in North London, received a Bachelor of Arts degree from University of Cambridge in 1954, an MSc and PhD in electrical engineering from Stanford University (in 1955 and 1957, respectively) and a Doctor of Science (DSc) in engineering from the University of London in 1970.[citation needed] Career and research He was a member of the staff at CERN from 1959 to 1963. He did research for General Electric at Zurich from 1963 to 1967. He knew Vint Cerf since 1967. Kirstein was a professor at the University of London Institute of Computer Science (ICS) from 1970 to 1973. After that, he joined the faculty at the University College London in 1973, serving as the first head of the computer science department from 1980 to 1994. He supervised Jon Crowcroft. Kirstein set up Queen Elizabeth's first official email message in 1976. Building on the work of Donald Davies at the National Physical Laboratory in the 1960s, in 1973 Kirstein's research group at University College London became one of only the two international connections on the ARPANET, alongside Norway (NORSAR and NDRE). UCL thereafter provided a gateway between the ARPANET and British academic networks which was the first internetwork for resource sharing. Research led by Bob Kahn at DARPA and Vint Cerf at Stanford University and later DARPA resulted in the formulation of the Transmission Control Program (TCP), with its RFC 675 specification written by Cerf with Yogen Dalal and Carl Sunshine in December 1974. The following year, testing began through concurrent implementations at Stanford, University College London and BBN. The ARPANET connection to UCL later grew into the trans-Atlantic SATNET. A two-way, followed by a three-way internetworking experiment linking UCL, via SATNET, with nodes in the ARPANET, and with a mobile vehicle in PRNET took place in 1977. Kirstein and his team members participated from the outset of the Internet Experiment Note meetings, beginning in March 1977.[note 1] His research group at UCL played a significant role in the very earliest experimental work on what became the TCP/IP. In 1978, Kirstein co-authored with Vint Cerf one of the most significant early technical papers on the internetworking concept. He chaired the International Cooperation Board (ICB), formed by Cerf in 1979, to coordinate activities to develop packet satellite research. UCL adopted TCP/IP in November 1982, ahead of the ARPANET, becoming one of the first nodes on the Internet. In early 1983, Kirstein chaired the International Collaboration Board, which involved six NATO countries, served on the Networking Panel of the NATO Science Committee (serving as chair in 2001), and served on Advisory Committees for the Australian Research Council, the Canadian Department of Communications, the German GMD, and the Indian Education and Research Network (ERNET) Project. He led the Silk Project, which provides satellite-based Internet access to the Newly Independent States in the Southern Caucasus and Central Asia. Kirstein was appointed Commander of the Order of the British Empire (CBE) for his work on the Internet. He was also a Fellow of the Royal Academy of Engineering (FREng), a Fellow of the Institute of Electrical and Electronics Engineers, an Honorary Foreign Member of the American Academy of Arts and Sciences, and a Distinguished Fellow of the British Computer Society. He received the SIGCOMM Award in 1999 for "contributions to the practical understanding of large-scale networks through the deployment of international testbeds", and the Postel Award in 2003, as well as various other awards for his contributions to the development of the Internet internationally. He was also elected a member of the National Academy of Engineering in 2009 for contributions to computer networking and for leadership in bringing the Internet to Europe. In 2012 Kirstein was inducted into the Internet Hall of Fame by the Internet Society. In 2015 he was awarded the prestigious Marconi Prize. Personal life Kirstein died from a brain tumour on the morning of 8 January 2020 while in his home. Shortly after his death, Steve Hailes, Head of Department for UCL Computer Science, wrote about him: "Peter was very widely recognised as a pioneer of the Internet and has many honours to his name [...] Much of this was undoubtedly down to an incredibly logical mind, coupled with a level of interest, vision and determination that saw him retire only late last year at the age of 86. [...] Peter was also deeply empathetic and sensitive: he was both gentleman and a gentle man, he was a source of encouragement and sage advice, he was persuasive, open-minded, fair and never afraid to learn something new or to admit that he didn't know." See also Notes References Sources External links |
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Contents Budd Hopkins Elliot Budd Hopkins (June 15, 1931 – August 21, 2011) was an American artist, author, and ufologist. He was a prominent figure in alien abduction phenomena and related UFO research. Early life Elliot Budd Hopkins was born in 1931. He was raised in Wheeling, West Virginia. He lived with his parents, Elliot B. Hopkins and Eleanor A. Hopkins, brother, Stuart, and sister, Eleanor. At age two, Hopkins contracted polio. During the long recovery process, Hopkins developed an interest in drawing and watercolors, which eventually led him to Oberlin College, Oberlin, Ohio, where he graduated with a bachelor's degree in art history in 1953. It was here, Hopkins was exposed to art with "a capital A", and attended a lecture by Robert Motherwell that first introduced him to the "automatic, gestural approach that Motherwell espoused." From Oberlin, Hopkins moved to New York City, where he met Franz Kline, Mark Rothko, Robert Motherwell, Willem de Kooning and other abstract expressionists. For a time, Hopkins studied art history at Columbia University and worked a low-level job selling tickets at the Museum of Modern Art. His experimentation with collage techniques and style as an abstract expressionist won him national acclaim. Art career Hopkins' first solo show was held in New York City in 1956, the same year he met and married his first wife of thirteen years, Joan Rich. In 1963, Hopkins' work was included in American Painters, a film documentary of American artists and styles with commentary from Alfred Barr of the Museum of Modern Art, Thomas Hess of Art News Magazine, Sidney Janis, gallery director, and Harold Rosenberg, art critic. In 1969, the San Francisco Museum of Modern Art acquired Hopkins' Norbeck Yellow Vertical, describing him as "a leading American painter who has successfully brought together the vocabularies of painterly abstraction and hard edge painting." In 1972, Hopkins was among five artists whose work was commissioned as part of a statewide effort to support the creative arts in West Virginia. It was, Governor Arch Moore claimed, "the first project of this kind to be undertaken in the nation." The piece was to be displayed in the state's cultural center located near the Capitol. In 1976, Hopkins was awarded a Guggenheim Fellowship for painting. Hopkins exhibited his paintings and sculptures in museums, galleries such as Andre Zarre, Levis Fine Art and Poindexter (New York) and Jan Cicero (Chicago), and universities throughout the United States. Hopkins had a major retrospective exhibition at the Provincetown Art Association and Museum in mid-2017. The Whitney Museum, Washington Gallery of Modern Art, Metropolitan Museum of Art, Museum of Modern Art, Corcoran Gallery of Art, the British Museum, include Hopkins' work in their permanent collections. Art style Hopkins' paintings in the 1960s combined the precise, hard-edge geometric shapes he was enthralled with and drawn to as a child with gestural, atmospheric painting characteristic of second- and later-generation Abstract Expressionists. "I had come to understand that an abstract painting at its most powerful was a kind of aesthetic scrim behind which lurks a concealed, obsessive 'thing' or image of some kind, transformed, made palatable by the artist's mediating skills." Hopkins viewed collage as an artistic technique and a philosophical, aesthetic means of unifying a disjointed and fragmented world. He saw collage, the assemblage of fragments and varying points of view, in the poetry, painting, sculpture, music, architecture, and, especially, motion pictures of his day: "Consciously or unconsciously, contemporary artists work to create harmony from distinctly jarring material, forcing warring ideas, materials and spatial systems into a tense and perhaps arbitrary detente. Seen most broadly, the presence of the collage aesthetic is the sole defining quality of modernism in all the arts." Hopkins worked to achieve harmony, clarity and precision while maintaining a sense of mystery: "I like neither extreme in art wholeheartedly, neither the purified world of geometrical art nor the free, indulgent world of Expressionism." In the 1970s, Hopkins' work included a series of assembled paintings, incorporating architectural elements. Sculptures such as Gallatin's Drive I, White City Hall, New York Wall II and others bore urban names and echoed elements of New York City's skyline. Many of his works during this time featured circular shapes with primary colors set against black and white backgrounds suggestive of Piet Mondrian. Later, Hopkins included abstracted figures in his sculptural pieces. While moving away from Abstract Expressionism, Hopkins retained in his work the use of intense colors and hard-edged forms. His works of the 1980s, including Temples and Guardians, featured these "sentinals" who were, according to Hopkins, "participating in a frozen ritual, fixed – absolutely – within a privileged space..." Though Hopkins denied any connection, some critics viewed these ritualistic pieces as an extension of Hopkins' fascination with alien beings. Hopkins viewed his sculpted guardians not as human per se, but as magical, fierce, noble robots of the unconscious. Interest in UFOs As a child, Hopkins experienced, firsthand, Orson Welles' 1938 radio play The War of the Worlds. This both terrified Hopkins and his family and left psychic scars. He considered the radio play a dramatic, theatrical hoax and, because of his childhood scare, felt it added to his skepticism about alien invasions rather than enamor him to the idea of it. His interest in UFOs and alien visitations was renewed when, in August 1964, Hopkins and two others reported experiencing a day time sighting of an unidentified flying object, or UFO, in the form of a darkish, elliptical object off Cape Cod in Truro, Massachusetts. Dissatisfied with the response Hopkins received when he reported the incident to nearby Otis Air National Guard Base, he suspected a possible government cover-up. Hopkins began reading about UFOs and collecting stories of people who claimed to have experienced contact with alien beings. In 1975, Hopkins was approached by George O'Barski who, purportedly, witnessed alien figures step out of a spacecraft and take soil samples at North Hudson Park in North Bergen, New Jersey. Hopkins, Ted Bloecher, then director of New York State's Mutual UFO Network (MUFON), and Jerry Stoehrer, also of MUFON, investigated the incident, interviewing the witness and taking soil samples. After Hopkins' account of the O'Barski case appeared in The Village Voice in 1976, he began receiving regular letters from other UFO witnesses, including a few cases of missing time, seemingly inexplicable gaps in abductees' memories. Hopkins, using data from his investigations with Bloecher and psychologist Aphrodite Clamar, expanded this idea in his book Missing Time.[citation needed] Behavioral patterns extrapolated from abductee letters led Hopkins to identify core emotional responses based on their experiences: fear, awe or wonderment at alien technological abilities, affection toward their captors (which he likened to the "Patty Hearst" syndrome), anger, and helplessness. He believed aliens were either incapable of understanding the psychological effects of their encounters with humans or that they were a "callous, indifferent, amoral race bent solely upon gratifying its own scientific needs at whatever cost to us." After the publication of his book Missing Time in 1981, Hopkins became known as much for his UFO and abduction research as for his art. As a self-described humanist, Hopkins saw his work with alleged alien abduction victims as a way to bring attention to an otherwise marginalized part of society. His follow-up book Intruders: The Incredible Visitations at Copley Woods, published in 1987, helped establish Hopkins as a prominent leader in the UFO movement. Hopkins' Intruders: The Incredible Visitations at Copley Woods (1987), spent four weeks on The New York Times Paperback Best Seller list. It and other best-sellers on the phenomena, including Whitley Strieber's Communion (1987), prompted stories of alien abduction by people who read the books. Abductee Linda Cortile had also participated in Hopkins' support group, starting five months before her alleged abduction, and read his book, Intruders. In 1989, Hopkins organized the Intruders Foundation in Manhattan to provide support for alleged victims of alien abduction, conduct research and investigations, and promote public awareness of the phenomenon. The 1992 made-for-television film Intruders featured fictionalized characters based on the works of Hopkins and psychiatrist John E. Mack, and, like Hopkins' book of the same name, portrayed abduction scenarios. In 1996, Hopkins' book Witnessed: The True Story of the Brooklyn Bridge UFO Abductions was published. The book portrayed an abduction case that was alleged to have occurred in late 1989 near the Brooklyn Bridge in New York City. Hopkins and his third wife, Carol Rainey, co-wrote the 2003 book Sight Unseen, Science, UFO Invisibility and Transgenic Beings. Hopkins is often credited with popularizing the idea of alien abductions as genetic experimentation through the publication of his book Intruders. He has been dubbed "father of the abduction movement" by some. Hopkins, along with Elizabeth Slater, who conducted psychological tests of abductees, likened these experiences to rape, specifically for the purpose of human reproductive capabilities. In fact, Hopkins was inclined to dismiss his clients' conscious memory of abuse for more alien explanations. He was an alarmist, rather than a spiritualist, in his approach to the alien visitations, believing the visitations to be apocalyptic and that no good could come of these encounters. He described victims' experiences as severe and nightmarish. While both men and women reported to Hopkins abductions by aliens that included sexual encounters, allegedly for some form of extraterrestrial eugenics, women in particular seemed to be a part of a "highly technological colonization scheme." These victims were, reportedly, taken to spaceships, impregnated by extraterrestrials, then later as the hybrid baby developed, returned to the ship to have the fetus removed and given up to the alien parent. The alien parents, purportedly, had the ability to communicate telepathically with their child. On occasion, according to victims' reports as told by Hopkins, the human parents were allowed to see their human-alien hybrid, or transgenic, children. Once a victim, according to Hopkins, abductees were powerless over the intrusions and susceptible to additional kidnappings, which may extend to their (human) children. "If people have had one abduction experience," Hopkins said, "then they will have others." Critics of Hopkins' views on alien abductions state that the alien abduction phenomenon is not as mysterious as Hopkins makes it out to be. Much of the phenomenon can, according to researchers such as Ronald K. Siegel of the University of California, Los Angeles, be explained as the consequence of "normal hallucinatory powers of the brain." Sleep paralysis, for example, can produce the feeling that one is paralyzed or has difficulty moving. It can also produce the effect of floating or the sense of an out-of-body experience. Sleep paralysis occurs in a transition time and the person is in a dream-like state, hallucinations can occur just before falling asleep (hynogogic hallucination) or just after (hypnopompic hallucination). These hallucinations feel real to the person experiencing sleep paralysis and can often be accompanied by sensory features: musty smells, shuffling sounds, visions of ghosts, aliens, and monsters. Neuroscientist Michael Persinger of Laurentian University in Greater Sudbury, Ontario, Canada, believes that these sensations can spontaneously occur in some people, given the right set of circumstances, leading to the kind of feelings of "tremendous meaningfulness and fear" sometimes expressed by alleged alien abductees. Hopkins rejected the idea of sleep paralysis, calling it "the big explanation du jour", and an inadequate explanation for those who experience abductions outside the bedroom. Hopkins partnered with David M. Jacobs, history professor at Temple University, Philadelphia, PA, and John Mack, psychiatry professor at Harvard University, Cambridge, Massachusetts, to design a Roper poll to find out how many of the nearly 6,000 respondents surveyed had experienced what the three believed to be symptoms indicative of alien abductions. The poll was released in 1991. If generalized to the population at large, the survey results indicated that several million Americans are regularly affected by alien abductions. Critics of the survey questioned the validity of the survey questions themselves and pointed out the implausibility that an average of 340 Americans could be abducted daily, given the fact that no physical evidence to date exists for any UFO abduction. Hopkins met and encouraged self-proclaimed abductees to discuss their experiences by holding free monthly group therapy sessions. Groups such as this were reported at the time as the most recent development in UFO-mania. Attendees represented people from all walks of life: attorneys, police officers, teachers, airline pilots, psychologists, psychiatrists, and the like. Drawing as many as 20 people each month, these support meetings were, according to Hopkins, like other New York social events, complete with "dinner and a lot of social chatter." Hopkins, trained as an artist not as a psychotherapist or social worker, described the people who attended these groups as veterans of trauma. They were, in his view, victims who experienced often intrusive and painful physical examinations by their alien abductors and whose stories were best told through hypnosis. Abduction memories, according to Hopkins, rarely emerged unaided and may, at first, present to the abductees as "vague anxieties, specific phobias, bad dreams, fragmentary and disturbing memories, or what seemed like an explicable episode of missing time." Many of his attendees contacted Hopkins after reading his books or newspaper advertisements that included his books as reference material, seeing him on television programs such as Will Shriner, Sally Jessy Raphael, the Marsha Warfield Show, Charles Grodin and others. Some critics interpreted these television appearances as a way for Hopkins and other UFO authors such as Whitley Strieber to recruit possible abductees. Still other support group members attended the many UFO conferences held within the United States and internationally at which Hopkins was a speaker. Although Hopkins had no formal psychological training, he watched other professionals over an eight-year period and developed his own techniques. In his opinion, these professionals, notably Robert Naiman, Aphrodite Clamar, and Girard Franklin were quite skeptical of the reality of abduction claims, yet all uncovered detailed abduction scenarios from their patients. According to Hopkins, any feeling of uneasiness about a place, or any sense of lost time (that is often accounted for by daydreaming), could be attributed to alien abduction. He believed aliens were capable of blocking or submerging memories in the people they abducted. Despite critics' warnings that practices such as the ones in which Hopkins engaged may cause serious psychological damage to the alleged abductees, Hopkins insisted that regressive hypnosis could unlock the experiences of his clients. He gave little credence to experts such as psychologist Robert A. Baker, University of Kentucky, whose scientific inquiries into the subject revealed that hypnosis can "transform a dream, a hallucination or fantasy into a seemingly-real event." This transformation is known as the fabrication of spurious memories and is particularly common under hypnosis. By 1995, Hopkins had worked with hundreds of abductees. It was during these hypnosis sessions that Hopkins' belief in UFO abduction deepened. To him, the purported similarities among client stories lent credibility to the abductees' stories. In actuality, the details of abductee stories varied greatly. The idea of repressed memories has, largely, been dismissed by the scientific community. Psychological research demonstrates that, rather than forget what has happened in a traumatic event, most people find they are unable to stop thinking about it. What concerns critics is that the details of UFO abduction stories, such as the ones Hopkins describes in his work, usually occur only after consultation with some sort of UFO investigator who already has an inclination to believe in alien abduction scenarios. UFO critic Philip J. Klass characterizes these practices as a dangerous game. UFO abductee stories are well-documented in the psychological literature and are considered culturally based. In other parts of the world, fairies, leprechauns, and other creatures replace aliens as abductors. Some liken extraterrestrial abduction to a secular version of the religious dream. According to Baker, "These people are literally talked into believing they've been abducted." The hypnotist can also, knowingly or unknowingly, create "memories" of an event that never occurred in their patients. In May 1987, psychologist and hypnotist Martin Reiser appeared on ABC's 20/20 with host Lynn Sherr, an episode that also featured Hopkins and alleged UFO abductees, asserting that there are reasonable explanations for UFO sightings. His belief was that Hopkins pressured his subjects into believing UFOs exist. Elizabeth Loftus, on NOVA's Kidnapped by UFOs?, which aired on April 1, 1997 and included a taped hypnosis session conducted by Hopkins, identified "subtle but powerful suggestive cues" as Hopkins worked with two children as part of the investigative portion of the show. She cautioned that someone convinced of a false memory, can react emotionally to it and elaborate on the story as if it were real. Social psychologist Richard Ofshe concurred that suggestive influence may be a factor in Hopkins' support groups. Of Hopkins' book, Intruders, Bettyann Kevles of The New York Times wrote, "I am willing to believe that he believes everything he has written. I am also willing to believe that Kathie and the others experienced inexplicable time losses and strange dreams that may have not been dreams. But I am wary of the accuracy of the information he gathered through hypnosis. This kind of testimony is disallowed in most courts because hypnosis is not thoroughly understood and has proved unreliable as a source of evidence. Witnesses recall events that never occurred, but that they are later, on being brought out of hypnosis, convinced really happened." Hopkins responded to critics by saying, "I have often frequently invited interested therapists, journalists and academics to observe hypnosis sessions. Theoretical psychologist Nicholas Humphrey, who has held teaching positions at both Oxford and Cambridge Universities, and psychiatrist Donald F. Klein, director of research at the New York State Psychiatric Institute and professor of psychiatry at the College of Physicians and Surgeons, Columbia University, are but two of those who have observed my work firsthand. None of these visitors ... have reported anything that suggested I was attempting to lead the subjects." Physical proof of alien abduction for Hopkins, came in the form of scoop marks, or indentations of the skin, scars or cuts on the mouth, nose, ears or genital, or unexplained bruises that might clear up in a day, and abductee claims of implants interpreted as control or monitoring devices similar to those used by (human) scientists to track and tag animals in the wild. He also believed the alien spacecraft left marks on the ground where they landed and that the aliens could be photographed. Hopkins points to "tightly imagined testimonies" by abductees, included victims' stories of observing unconventional objects in the sky, in which they witnessed unusual activity (such as aliens digging for soil samples), flying through the air or being transported to a ship, a sense of being watched or the presence of hooded beings near the bed at night, a sense of paralysis or immobilization while lying in bed or in their cars, impressions of flying or passing through closed windows or walls, a feeling of having been outside upon awakening, invisibility (both alien and human) and, most especially, a sense of missing or lost time. Hopkins believed in his data collection techniques, as outlined in Missing Time, and insisted, despite questions from other researchers and skeptics, that his findings were solidly based in evidence that, cumulatively, was overwhelming. Despite Hopkins' oft-repeated assertion of "powerful evidence" for alien abduction, critics plagued his career with calls for tangible proof, which were never forthcoming: DNA from the hybrid babies, proof of implants that were alluded to (particularly in the case of alleged abductee Linda Cortile) but never recovered, photographs or videotapes of space craft or aliens. Critics, including his former wife, Rainey, expressed concern that UFO researcher leaders were not held to scholastic, scientific, or ethical standards. Still others question whether it would be likely that alien abductors could actually float people through solid walls and, if they could, wonder at how these people could escape detection, particularly in urban settings where there would, potentially, be millions of people around to witness the event. Hopkins' response to the lack of UFO sightings by bystanders was to suggest that aliens could make themselves and their abductees invisible. The lack of physical evidence and the inconsistencies and implausibility of the alien abduction stories led some critics, including Carl Sagan and author Jodi Dean, to question whether these memories are the product of internal, rather than external experiences. Criticism Critics of Hopkins' position that on alien abduction accounts had "an absolute core of reality" cautioned that media coverage might, inadvertently, be influencing alleged victims' stories. For example, The UFO Incident, a movie based on the Barney and Betty Hill case, aired on October 20, 1975, and exposed millions of viewers to the idea of alien abduction. Just one month later, O'Barski, Hopkins' neighbor and a New York City liquor store owner, approached him about seeing a spacecraft that, allegedly, landed in New Jersey's North Hudson Park. Conspiracy theories of government coverup of UFO sightings and visitations, such as the ones depicted in Nighteyes and Witnessed fueled the imaginations of those who belonged to UFO groups at the time. Some say the public's interest in UFOs may have faded after the Cold War had it not been for the media's depiction of and public sympathy for traumatized alien abductee television portrayals in the 1980s and 1990s. Even Hopkins admitted that media attention had a way of "contaminating the pool" of subjects, but believed that he was able to cull the delusional stories from those he believed to be real. In his view, the repetition of certain experiences by abductees lent credibility to their stories, leading him to conclude that these accounts were not fantasy. Personal life and death By 1973, Hopkins was married to art critic, art historian, and curator April Kingsley, with whom he had a daughter, Grace Hopkins Their marriage ended in divorce in 1991. In 1994, Hopkins met writer, filmmaker Carol Rainey, who became his third wife in 1996. They shared a mutual fascination with alien abduction stories and, according to Rainey, the possibility that people on Earth may have been "seeded here by highly advanced beings or a Big Being from 'out there'." The two co-wrote a book Sight Unseen, Science, UFO Invisibility and Transgenic Beings, which was published in 2003. They were married for 10 years. On August 21, 2011, Hopkins died from complications of cancer. At the time of his death, he was in a relationship with journalist Leslie Kean. Books See also References External links |
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Contents Solar System The Solar System is the gravitationally bound system of the Sun and the masses that orbit it, most prominently its eight planets, of which Earth is one. The system formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, creating the Sun and a protoplanetary disc from which the orbiting bodies assembled. Inside the Sun's core hydrogen is fused into helium for billions of years, releasing energy which is over even longer periods of time emitted through the Sun's outer layer, the photosphere. This creates the heliosphere and a decreasing temperature gradient across the Solar System. The mass of the Solar System is by 99.86% almost completely made up of the Sun's mass. The next most massive objects of the system are the eight planets, which by definition dominate the orbits they occupy. Closest to the Sun in order of increasing distance are the four terrestrial planets – Mercury, Venus, Earth and Mars. These are the planets of the inner Solar System. Earth and Mars are the only planets in the Solar System which orbit within the Sun's habitable zone, in which the sunlight can make surface water under atmospheric pressure liquid. Beyond the frost line at about five astronomical units (AU),[d] are two gas giants – Jupiter and Saturn – and two ice giants – Uranus and Neptune. These are the planets of the outer Solar System. Jupiter and Saturn possess nearly 90% of the non-stellar mass of the Solar System. Additionally to the planets there are in the Solar System other planetary-mass objects, but which do not dominate their orbits, such as dwarf planets and planetary-mass moons. The International Astronomical Union's Minor Planet Center lists Ceres, Pluto, Eris, Makemake, and Haumea as dwarf planets. Four other Solar System objects are generally identified as such: Orcus, Quaoar, Gonggong, and Sedna. Natural satellites, which are commonly called 'moons', can be found throughout the Solar System and in sizes from planetary-mass moons to much less massive moonlets at their smallest. The largest two moons (Ganymede of Jupiter and Titan of Saturn) are larger than the smallest planet (Mercury), while the seven most massive, which includes Earth's Moon, are more massive and larger than any of the dwarf planets. Less massive than these planetary-mass objects are the vast number of small Solar System bodies, such as asteroids, comets, centaurs, meteoroids, and interplanetary dust clouds. All dwarf planets and many of the smaller bodies are within the asteroid belt (between Mars's and Jupiter's orbit) and the Kuiper belt (just outside Neptune's orbit).[e] The Solar System is within the heliosphere constantly flooded by the charged plasma particles of the solar wind, which forms with the interplanetary dust, gas and cosmic rays between the bodies of the Solar System an interplanetary medium. At around 70–90 AU from the Sun, the solar wind is halted by the interstellar medium, resulting in the heliopause and the border of the interplanetary medium to interstellar space. Further out somewhere beyond 2,000 AU from the Sun extends the outermost region of the Solar System, the theorized Oort cloud, the source for long-period comets, stretching to the edge of the Solar System, the edge of its Hill sphere, at 178,000–227,000 AU (2.81–3.59 ly), where its gravitational potential becomes equal to the galactic potential. The Solar System currently moves through a cloud of interstellar medium called the Local Cloud. The closest star to the Solar System, Proxima Centauri, is 269,000 AU (4.25 ly) away. Both are within the Local Bubble, a relatively small 1,000 light-years (ly) wide region of the Milky Way. Definition The Solar System includes the Sun and all objects that are bound to it by gravity and orbit it. The International Astronomical Union describes the Solar System as all objects that are bound by the gravity of the Sun, the Sun itself, its eight planets, and the other celestial bodies which orbit it. NASA describes the Solar System as a planetary system, including the Sun and all objects that orbit it. Capitalization of the name varies. When not used as a proper noun and written without capitalization, "solar system" may refer to either the Solar System itself or any system reminiscent of the Solar System. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in their naming guidelines document. Formation and evolution The Solar System formed at least 4.568 billion years ago from the gravitational collapse of a region within a large molecular cloud.[b] This initial cloud was likely several light-years across and probably birthed several stars. As is typical of molecular clouds, this one consisted mostly of hydrogen, with some helium, and small amounts of heavier elements fused by previous generations of stars. As the pre-solar nebula collapsed, conservation of angular momentum caused it to rotate faster. The center, where most of the mass collected, became increasingly hotter than the surroundings. As the contracting nebula spun faster, it began to flatten into a protoplanetary disc with a diameter of roughly 200 AU and a hot, dense protostar at the center. The planets formed by accretion from this disc, in which dust and gas gravitationally attracted each other, coalescing to form ever larger bodies. Hundreds of protoplanets may have existed in the early Solar System, but they either merged or were destroyed or ejected, leaving the planets, dwarf planets, and leftover minor bodies. In the inner Solar System, heat from the accretion process exceeded the boiling point of hydrocarbon molecules for the first million years, leading to low carbon content for the inner planets. The boundary for this process has been dubbed the soot line. As the Solar System disk cooled, this line moved inward and now lies within Earth's orbit around the Sun. Material other than metals and silicates, due to their higher boiling points, could not persist in solid form. Here planets formed that are mainly rocky, which are Mercury, Venus, Earth, and Mars. Because these refractory materials only comprised a small fraction of the solar nebula, the terrestrial planets could not grow very large. The giant planets (Jupiter, Saturn, Uranus, and Neptune) formed further out, beyond the frost line, the point between the orbits of Mars and Jupiter where material is cool enough for volatile icy compounds to remain solid. The ices that formed these planets were more plentiful than the metals and silicates that formed the terrestrial inner planets, allowing them to grow massive enough to capture large atmospheres of hydrogen and helium, the lightest and most abundant elements. Leftover debris that never became planets congregated in regions such as the asteroid belt, Kuiper belt, and Oort cloud. Within 50 million years, the pressure and density of hydrogen in the center of the protostar became great enough for it to begin thermonuclear fusion. As helium accumulates at its core, the Sun is growing brighter; early in its main-sequence life its brightness was 70% that of what it is today. The temperature, reaction rate, pressure, and density increased until hydrostatic equilibrium was achieved: the thermal pressure counterbalancing the force of gravity. At this point, the Sun became a main-sequence star. Solar wind from the Sun created the heliosphere and swept away the remaining gas and dust from the protoplanetary disc into interstellar space. Following the dissipation of the protoplanetary disk, the Nice model proposes that gravitational encounters between planetesimals and the gas giants caused each to migrate into different orbits. This led to dynamical instability of the entire system, which scattered the planetesimals and ultimately placed the gas giants in their current positions. During this period, the grand tack hypothesis suggests that a final inward migration of Jupiter dispersed much of the asteroid belt, leading to the Late Heavy Bombardment of the inner planets. The Solar System remains in a relatively stable, slowly evolving state by following isolated, gravitationally bound orbits around the Sun. Although the Solar System has been fairly stable for billions of years, it is technically chaotic, and may eventually be disrupted. There is a small chance that another star will pass through the Solar System in the next few billion years. Although this could destabilize the system and eventually lead millions of years later to expulsion of planets, collisions of planets, or planets hitting the Sun, it would most likely leave the Solar System much as it is today. The Sun's main-sequence phase, from beginning to end, will last about 10 billion years for the Sun compared to around two billion years for all other subsequent phases of the Sun's pre-remnant life combined. The Solar System will remain roughly as it is known today until the hydrogen in the core of the Sun has been entirely converted to helium, which will occur roughly 5 billion years from now. This will mark the end of the Sun's main-sequence life. At that time, the core of the Sun will contract with hydrogen fusion occurring along a shell surrounding the inert helium, and the energy output will be greater than at present. The outer layers of the Sun will expand to roughly 260 times its current diameter, and the Sun will become a red giant. Because of its increased surface area, the surface of the Sun will be cooler (2,600 K (4,220 °F) at its coolest) than it is on the main sequence. The expanding Sun is expected to vaporize Mercury as well as Venus, and render Earth and Mars uninhabitable (possibly destroying Earth as well). Eventually, the core will be hot enough for helium fusion; the Sun will burn helium for a fraction of the time it burned hydrogen in the core. The Sun is not massive enough to commence the fusion of heavier elements, and nuclear reactions in the core will dwindle. Its outer layers will be ejected into space, leaving behind a dense white dwarf, half the original mass of the Sun but only the size of Earth. The ejected outer layers may form a planetary nebula, returning some of the material that formed the Sun – but now enriched with heavier elements like carbon – to the interstellar medium. General characteristics Astronomers sometimes divide the Solar System structure into separate regions. The inner Solar System includes Mercury, Venus, Earth, Mars, and the bodies in the asteroid belt. The outer Solar System includes Jupiter, Saturn, Uranus, Neptune, and the bodies in the Kuiper belt. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune. The principal component of the Solar System is the Sun, a G-type main-sequence star that contains 99.86% of the system's known mass and dominates it gravitationally. The Sun's four largest orbiting bodies, the giant planets, account for 99% of the remaining mass, with Jupiter and Saturn together comprising more than 90%. The remaining objects of the Solar System (including the four terrestrial planets, the dwarf planets, moons, asteroids, and comets) together comprise less than 0.002% of the Solar System's total mass.[f] The Sun is composed of roughly 98% hydrogen and helium, as are Jupiter and Saturn. A composition gradient exists in the Solar System, created by heat and light pressure from the early Sun; those objects closer to the Sun, which are more affected by heat and light pressure, are composed of elements with high melting points. Objects farther from the Sun are composed largely of materials with lower melting points. The boundary in the Solar System beyond which those volatile substances could coalesce is known as the frost line, and it lies at roughly five times the Earth's distance from the Sun. The planets and other large objects in orbit around the Sun lie near the invariable plane of the Solar System, as does Earth's orbit, known as the ecliptic, and most closely the orbit of Jupiter, with an inclination to it of 0.3219°. Smaller icy objects such as comets frequently orbit at significantly greater angles to this plane. Most of the planets in the Solar System have secondary systems of their own, being orbited by natural satellites called moons. All of the largest natural satellites are in synchronous rotation, with one face permanently turned toward their parent. The four giant planets have planetary rings, thin discs of tiny particles that orbit them in unison. As a result of the formation of the Solar System, planets and most other objects orbit the Sun in the same direction that the Sun is rotating. That is, counter-clockwise, as viewed from above Earth's north pole. There are exceptions, such as Halley's Comet. Most of the larger moons orbit their planets in prograde direction, matching the direction of planetary rotation; Neptune's moon Triton is the largest to orbit in the opposite, retrograde manner. Most larger objects rotate around their own axes in the prograde direction relative to their orbit, though the rotation of Venus is retrograde. To a good first approximation, Kepler's laws of planetary motion describe the orbits of objects around the Sun.: 433–437 These laws stipulate that each object travels along an ellipse with the Sun at one focus, which causes the body's distance from the Sun to vary over the course of its year. A body's closest approach to the Sun is called its perihelion, whereas its most distant point from the Sun is called its aphelion.: 9-6 With the exception of Mercury, the orbits of the planets are nearly circular, but many comets, asteroids, and Kuiper belt objects follow highly elliptical orbits. Kepler's laws only account for the influence of the Sun's gravity upon an orbiting body, not the gravitational pulls of different bodies upon each other. On a human time scale, these perturbations can be accounted for using numerical models,: 9-6 but the planetary system can change chaotically over billions of years. The angular momentum of the Solar System is a measure of the total amount of orbital and rotational momentum possessed by all its moving components. Although the Sun dominates the system by mass, it accounts for only about 2% of the angular momentum. The planets, dominated by Jupiter, account for most of the rest of the angular momentum due to the combination of their mass, orbit, and distance from the Sun, with a possibly significant contribution from comets. The radius of the Sun is 0.0047 AU (700,000 km; 400,000 mi). Thus, the Sun occupies 0.00001% (1 part in 107) of the volume of a sphere with a radius the size of Earth's orbit, whereas Earth's volume is roughly 1 millionth (10−6) that of the Sun. Jupiter, the largest planet, is 5.2 AU from the Sun and has a radius of 71,000 km (0.00047 AU; 44,000 mi), whereas the most distant planet, Neptune, is 30 AU from the Sun. With a few exceptions, the farther a planet or belt is from the Sun, the larger the distance between its orbit and the orbit of the next nearest object to the Sun. For example, Venus is approximately 0.33 AU farther out from the Sun than Mercury, whereas Saturn is 4.3 AU out from Jupiter, and Neptune lies 10.5 AU out from Uranus. Attempts have been made to determine a relationship between these orbital distances, like the Titius–Bode law and Johannes Kepler's model based on the Platonic solids, but ongoing discoveries have invalidated these hypotheses. Some Solar System models attempt to convey the relative scales involved in the Solar System in human terms. Some are small in scale (and may be mechanical – called orreries) – whereas others extend across cities or regional areas. The largest such scale model, the Sweden Solar System, uses the 110-meter (361-foot) Avicii Arena in Stockholm as its substitute Sun, and, following the scale, Jupiter is a 7.5-meter (25-foot) sphere at Stockholm Arlanda Airport, 40 km (25 mi) away, whereas the farthest current object, Sedna, is a 10 cm (4 in) sphere in Luleå, 912 km (567 mi) away. At that scale, the distance to Proxima Centauri would be roughly 8 times further than the Moon is from Earth. If the Sun–Neptune distance is scaled to 100 metres (330 ft), then the Sun would be about 3 cm (1.2 in) in diameter (roughly two-thirds the diameter of a golf ball), the giant planets would be all smaller than about 3 mm (0.12 in), and Earth's diameter along with that of the other terrestrial planets would be smaller than a flea (0.3 mm or 0.012 in) at this scale. The zone of habitability of the Solar System is conventionally located in the inner Solar System around Earth, where atmospheric liquid water is enabled by the Sun. Besides solar energy, the primary characteristic of the Solar System enabling the presence of life is the heliosphere and planetary magnetic fields (for those planets that have them). These magnetic fields partially shield the Solar System from high-energy interstellar particles called cosmic rays. The density of cosmic rays in the interstellar medium and the strength of the Sun's magnetic field change on very long timescales, so the level of cosmic-ray penetration in the Solar System varies, though by how much is unknown. Habitability in the Solar System is though not solely dependent on surface conditions, and furthermore the Solar environment, since there might be habitablity in potential subsurface oceans of various Solar System bodies, or cloud layers of some planets, particularly Venus. Analysis of Kepler data suggests that observed planetary systems in the Milky Way fall into three groups: "similar", which comprise planets of similar sizes similar distances apart and with highly circular orbits; "ordered", in which the masses of planets tend to increase with distance from their star, and "mixed", which show no pattern in masses whatsoever. The Solar System is an ordered system, as are 37% of observed systems. Similar systems however are the majority, comprising 59% of observed systems, while mixed systems comprise just 4%. Compared to many extrasolar systems, the Solar System stands out in lacking planets interior to the orbit of Mercury. The known Solar System lacks super-Earths, planets between one and ten times as massive as the Earth, although the hypothetical Planet Nine, if it does exist, could be a super-Earth orbiting in the edge of the Solar System. Uncommonly, it has only small terrestrial and large gas giants; elsewhere planets of intermediate size are typical – both rocky and gas – so there is no "gap" as seen between the size of Earth and of Neptune (with a radius 3.8 times as large). As many of these super-Earths are closer to their respective stars than Mercury is to the Sun, a hypothesis has arisen that all planetary systems start with many close-in planets, and that typically a sequence of their collisions causes consolidation of mass into few larger planets, but in case of the Solar System the collisions caused their destruction and ejection. The orbits of Solar System planets are nearly circular. Compared to many other systems, they have smaller orbital eccentricity. Although there are attempts to explain it partly with a bias in the radial-velocity detection method and partly with long interactions of a quite high number of planets, the exact causes remain undetermined. Sun The Sun is the Solar System's star and by far its most massive component. Its large mass (332,900 Earth masses), which comprises 99.86% of all the mass in the Solar System, produces temperatures and densities in its core high enough to sustain nuclear fusion of hydrogen into helium. This releases an enormous amount of energy, mostly radiated into space as electromagnetic radiation peaking in visible light. Because the Sun fuses hydrogen at its core, it is a main-sequence star. More specifically, it is a G2-type main-sequence star, where the type designation refers to its effective temperature. Hotter main-sequence stars are more luminous but shorter lived. The Sun's temperature is intermediate between that of the hottest stars and that of the coolest stars. Stars brighter and hotter than the Sun are rare, whereas substantially dimmer and cooler stars, known as red dwarfs, make up about 75% of the fusor stars in the Milky Way. The Sun is a population I star, having formed in the spiral arms of the Milky Way galaxy. It has a higher abundance of elements heavier than hydrogen and helium ("metals" in astronomical parlance) than the older population II stars in the galactic bulge and halo. Elements heavier than hydrogen and helium were formed in the cores of ancient and exploding stars, so the first generation of stars had to die before the universe could be enriched with these atoms. The oldest stars contain few metals, whereas stars born later have more. This higher metallicity is thought to have been crucial to the Sun's development of a planetary system because the planets formed from the accretion of "metals". The region of space dominated by the Solar magnetosphere is the heliosphere, which spans much of the Solar System. Along with light, the Sun radiates a continuous stream of charged particles (a plasma) called the solar wind. This stream spreads outwards at speeds from 900,000 kilometres per hour (560,000 mph) to 2,880,000 kilometres per hour (1,790,000 mph), filling the vacuum between the bodies of the Solar System. The result is a thin, dusty atmosphere, called the interplanetary medium, which extends to at least 100 AU. Activity on the Sun's surface, such as solar flares and coronal mass ejections, disturbs the heliosphere, creating space weather and causing geomagnetic storms. Coronal mass ejections and similar events blow a magnetic field and huge quantities of material from the surface of the Sun. The interaction of this magnetic field and material with Earth's magnetic field funnels charged particles into Earth's upper atmosphere, where its interactions create aurorae seen near the magnetic poles. The largest stable structure within the heliosphere is the heliospheric current sheet, a spiral form created by the actions of the Sun's rotating magnetic field on the interplanetary medium. Inner Solar System The inner Solar System is the region comprising the terrestrial planets and the asteroids. Composed mainly of silicates and metals, the objects of the inner Solar System are relatively close to the Sun; the radius of this entire region is less than the distance between the orbits of Jupiter and Saturn. This region is within the frost line, which is a little less than 5 AU from the Sun. The four terrestrial or inner planets have dense, rocky compositions, few or no moons, and no ring systems. They are composed largely of refractory minerals such as silicates—which form their crusts and mantles—and metals such as iron and nickel which form their cores. Three of the four inner planets (Venus, Earth, and Mars) have atmospheres substantial enough to generate weather; all have impact craters and tectonic surface features, such as rift valleys and volcanoes. Asteroids, except for the largest, Ceres, are classified as small Solar System bodies and are composed mainly of carbonaceous, refractory rocky and metallic minerals, with some ice. They range from a few meters to hundreds of kilometers in size. Many asteroids are divided into asteroid groups and families based on their orbital characteristics. Some asteroids have natural satellites that orbit them, that is, asteroids that orbit larger asteroids. The asteroid belt occupies a torus-shaped region between 2.3 and 3.3 AU from the Sun, which lies between the orbits of Mars and Jupiter. It is thought to be remnants from the Solar System's formation that failed to coalesce because of the gravitational interference of Jupiter. The asteroid belt contains tens of thousands, possibly millions, of objects over one kilometer in diameter. Despite this, the total mass of the asteroid belt is unlikely to be more than a thousandth of that of Earth. The asteroid belt is very sparsely populated; spacecraft routinely pass through without incident. Below are the descriptions of the three largest bodies in the asteroid belt. They are all considered to be relatively intact protoplanets, a precursor stage before becoming a fully-formed planet (see List of exceptional asteroids): Hilda asteroids are in a 3:2 resonance with Jupiter; that is, they go around the Sun three times for every two Jovian orbits. They lie in three linked clusters between Jupiter and the main asteroid belt. Trojans are bodies located within another body's gravitationally stable Lagrange points: L4, 60° ahead in its orbit, or L5, 60° behind in its orbit. Every planet except Mercury is known to possess at least one trojan. The Jupiter trojan population is roughly equal to that of the asteroid belt. After Jupiter, Neptune possesses the most confirmed trojans, at 28. Outer Solar System The outer region of the Solar System is home to the giant planets and their large moons. The centaurs and many short-period comets orbit in this region. Due to their greater distance from the Sun, the solid objects in the outer Solar System contain a higher proportion of volatiles such as water, ammonia, and methane, than planets of the inner Solar System because their lower temperatures allow these compounds to remain solid, without significant sublimation. The four outer planets, called giant planets or Jovian planets, collectively make up 99% of the mass orbiting the Sun.[f] All four giant planets have multiple moons and a ring system, although only Saturn's rings are easily observed from Earth. Jupiter and Saturn are composed mainly of gases with extremely low melting points, such as hydrogen, helium, and neon, hence their designation as gas giants. Uranus and Neptune are ice giants, meaning they are largely composed of 'ice' in the astronomical sense (chemical compounds with melting points of up to a few hundred kelvins such as water, methane, ammonia, hydrogen sulfide, and carbon dioxide.) Icy substances comprise the majority of the satellites of the giant planets and small objects that lie beyond Neptune's orbit. The centaurs are icy, comet-like bodies whose semi-major axes are longer than Jupiter's and shorter than Neptune's (between 5.5 and 30 AU). These are former Kuiper belt and scattered disc objects (SDOs) that were gravitationally perturbed closer to the Sun by the outer planets, and are expected to become comets or be ejected out of the Solar System. While most centaurs are inactive and asteroid-like, some exhibit cometary activity, such as the first centaur discovered, 2060 Chiron, which has been classified as a comet (95P) because it develops a coma just as comets do when they approach the Sun. The largest known centaur, 10199 Chariklo, has a diameter of about 250 km (160 mi) and is one of the few minor planets possessing a ring system. Trans-Neptunian region Beyond the orbit of Neptune lies the area of the "trans-Neptunian region", with the doughnut-shaped Kuiper belt, home of Pluto and several other dwarf planets, and an overlapping disc of scattered objects, which is tilted toward the plane of the Solar System and reaches much further out than the Kuiper belt. The entire region is still largely unexplored. It appears to consist overwhelmingly of many thousands of small worlds – the largest having a diameter only a fifth that of Earth and a mass far smaller than that of the Moon – composed mainly of rock and ice. This region is sometimes described as the "third zone of the Solar System", enclosing the inner and the outer Solar System. The Kuiper belt is a great ring of debris similar to the asteroid belt, but consisting mainly of objects composed primarily of ice. It extends between 30 and 50 AU from the Sun. It is composed mainly of small Solar System bodies, although the largest few are probably large enough to be dwarf planets. There are estimated to be over 100,000 Kuiper belt objects with a diameter greater than 50 km (30 mi), but the total mass of the Kuiper belt is thought to be only a tenth or even a hundredth the mass of Earth. Many Kuiper belt objects have satellites, and most have orbits that are substantially inclined (~10°) to the plane of the ecliptic. The Kuiper belt can be roughly divided into the "classical" belt and the resonant trans-Neptunian objects. The latter have orbits whose periods are in a simple ratio to that of Neptune: for example, going around the Sun twice for every three times that Neptune does, or once for every two. The classical belt consists of objects having no resonance with Neptune, and extends from roughly 39.4 to 47.7 AU. Members of the classical Kuiper belt are sometimes called "cubewanos", after the first of their kind to be discovered, originally designated 1992 QB1, (and has since been named Albion); they are still in near primordial, low-eccentricity orbits. There is strong consensus among astronomers that five members of the Kuiper belt are dwarf planets. Many dwarf planet candidates are being considered, pending further data for verification. The scattered disc, which overlaps the Kuiper belt but extends out to near 500 AU, is thought to be the source of short-period comets. Scattered-disc objects are believed to have been perturbed into erratic orbits by the gravitational influence of Neptune's early outward migration. Most scattered disc objects have perihelia within the Kuiper belt but aphelia far beyond it (some more than 150 AU from the Sun). SDOs' orbits can be inclined up to 46.8° from the ecliptic plane. Some astronomers consider the scattered disc to be merely another region of the Kuiper belt and describe scattered-disc objects as "scattered Kuiper belt objects". Some astronomers classify centaurs as inward-scattered Kuiper belt objects along with the outward-scattered residents of the scattered disc. Currently, there is strong consensus among astronomers that two of the bodies in the scattered disc are dwarf planets: Some objects in the Solar System have a very large orbit, and therefore are much less affected by the known giant planets than other minor planet populations. These bodies are called extreme trans-Neptunian objects, or ETNOs for short. Generally, ETNOs' semi-major axes are at least 150–250 AU wide. For example, 541132 Leleākūhonua orbits the Sun once every ~32,000 years, with a distance of 65–2000 AU from the Sun.[D 11] This population is divided into three subgroups by astronomers. The scattered ETNOs have perihelia around 38–45 AU and an exceptionally high eccentricity of more than 0.85. As with the regular scattered disc objects, they were likely formed as result of gravitational scattering by Neptune and still interact with the giant planets. The detached ETNOs, with perihelia approximately between 40–45 and 50–60 AU, are less affected by Neptune than the scattered ETNOs, but are still relatively close to Neptune. The sednoids or inner Oort cloud objects, with perihelia beyond 50–60 AU, are too far from Neptune to be strongly influenced by it. Currently, there is one ETNO that is classified as a dwarf planet: Statistical variance has been observed in the orbits of some extreme trans-Neptunian objects, whose closest approaches to the Sun are mostly clustered around one sector and who display a similar orbital tilt to each other. Some astronomers have suggested that this may be the result of the influence of a large planet beyond Neptune; this hypothetical planet has been termed Planet Nine. Others credit this statistical variance to observational biases or sheer coincidence. The Oort cloud is a theorized spherical shell of up to a trillion icy objects that is thought to be the source for all long-period comets, which were originally ejected from the planetary region by gravitational interactions with the gas giants. Oort cloud objects move very slowly, and can be perturbed by infrequent events, such as collisions, the gravitational effects of a passing star, or the galactic tide, the tidal force exerted by the Milky Way. No direct observation of the Oort cloud is possible with present imaging technology. The Oort cloud is theorized to surround the Solar System from potentially ~2,000 AU from the Sun to up to ~200,000 AU. Lower estimates for the radius of the Oort cloud, by contrast, do not place it farther than 50,000 AU. Most of the mass is orbiting in the region between 3,000 and 100,000 AU. The furthest known objects, such as Comet West, have aphelia around 70,000 AU from the Sun. Gravitationally unstable populations Solid objects smaller than one meter are usually called meteoroids and micrometeoroids (grain-sized), with the exact division between the two categories being debated over the years. By 2017, the IAU designated any solid object having a diameter between ~30 micrometers and 1 meter as meteoroids, and depreciated the micrometeoroid categorization, instead terms smaller particles simply as 'dust particles'. Some meteoroids formed via disintegration of comets and asteroids, while a few formed via impact debris ejected from planetary bodies. Most meteoroids are made of silicates and heavier metals like nickel and iron. When passing through the Solar System, comets produce a trail of meteoroids; it is hypothesized that this is caused either by vaporization of the comet's material or by simple breakup of dormant comets. When crossing an atmosphere, these meteoroids will produce bright streaks in the sky due to atmospheric entry, called meteors. If a stream of meteoroids enter the atmosphere on parallel trajectories, the meteors will seemingly 'radiate' from a point in the sky, hence the phenomenon's name: meteor shower. The inner Solar System is home to the zodiacal dust cloud, which is visible as the hazy zodiacal light in dark, unpolluted skies. It may be generated by collisions within the asteroid belt brought on by gravitational interactions with the planets; a more recent proposed origin is materials from planet Mars. The outer Solar System hosts a cosmic dust cloud. It extends from about 10 AU to about 40 AU, and was probably created by collisions within the Kuiper belt. Comets are small Solar System bodies, typically only a few kilometers across, composed largely of volatile ices. They have highly eccentric orbits, generally a perihelion within the orbits of the inner planets and an aphelion far beyond Pluto. When a comet enters the inner Solar System, its proximity to the Sun causes its icy surface to sublimate and ionise, creating a coma: a long tail of gas and dust often visible to the naked eye. Short-period comets have orbits lasting less than two hundred years. Long-period comets have orbits lasting thousands of years. Short-period comets are thought to originate in the Kuiper belt, whereas long-period comets, such as Hale–Bopp, are thought to originate in the Oort cloud. Many comet groups, such as the Kreutz sungrazers, formed from the breakup of a single parent. Some comets with hyperbolic orbits may originate outside the Solar System, but determining their precise orbits is difficult. Old comets whose volatiles have mostly been driven out by solar warming are often categorized as asteroids. Boundary region and uncertainties Much of the outer reaches of the Solar System is still unknown. The region beyond 100 AU away is virtually unexplored and learning about this region of space is difficult. Study of this region depends upon inferences from those few objects whose orbits happen to be perturbed such that they fall closer to the Sun, and even then, detecting these objects has often been possible only when they happened to become bright enough to register as comets. Many objects are yet to be discovered in the Solar System's outer region. The Sun's Hill sphere, its gravitational potential reaching the galactic potential, the potential of the galactic nucleus, the effective range of its gravitational influence, is thought to encompass the Oort cloud, and extend to up to 230,000 AU from the Sun. The boundaries of the heliosphere and of the Hill sphere, the Sun's gravitational potential in respect to the interstellar medium and the galactic gravitational potential, at the edge of the Oort cloud, represent the boundaries of the Solar System with the galactic environment it is in. The Sun's stellar-wind bubble, the heliosphere, a region of space dominated by the Sun, has its boundary at the termination shock. Based on the Sun's peculiar motion relative to the local standard of rest, this boundary is roughly 80–100 AU from the Sun upwind of the interstellar medium and roughly 200 AU from the Sun downwind. Here the solar wind collides with the interstellar medium and dramatically slows, condenses and becomes more turbulent, forming a great oval structure known as the heliosheath. The heliosheath has been theorized to look and behave very much like a comet's tail, extending outward for a further 40 AU on the upwind side but tailing many times that distance downwind to possibly several thousands of AU. Evidence from the Cassini and Interstellar Boundary Explorer spacecraft has suggested that it is forced into a bubble shape by the constraining action of the interstellar magnetic field, but the actual shape remains unknown. The shape and form of the outer edge of the heliosphere is likely affected by the fluid dynamics of interactions with the interstellar medium as well as solar magnetic fields prevailing to the south, e.g. it is bluntly shaped with the northern hemisphere extending 9 AU farther than the southern hemisphere. The heliopause is considered the beginning of the interstellar medium. Beyond the heliopause, at around 230 AU, lies the bow shock: a plasma "wake" left by the Sun as it travels through the Milky Way. Large objects outside the heliopause remain gravitationally bound to the Sun, but the flow of matter in the interstellar medium homogenizes the distribution of micro-scale objects. Celestial neighborhood Within 10 light-years of the Sun there are relatively few stars, the closest being the triple star system Alpha Centauri, which is about 4.4 light-years away and may be in the Local Bubble's G-Cloud. Alpha Centauri A and B are a closely tied pair of Sun-like stars, whereas the closest star to the Sun, the small red dwarf Proxima Centauri, orbits the pair at a distance of 0.2 light-years. In 2016, a potentially habitable exoplanet was found to be orbiting Proxima Centauri, called Proxima Centauri b, the closest confirmed exoplanet to the Sun. The Solar System is surrounded by the Local Interstellar Cloud, although it is not clear if it is embedded in the Local Interstellar Cloud or if it lies just outside the cloud's edge. Multiple other interstellar clouds exist in the region within 300 light-years of the Sun, known as the Local Bubble. The latter feature is an hourglass-shaped cavity or superbubble in the interstellar medium roughly 300 light-years across. The bubble is suffused with high-temperature plasma, suggesting that it may be the product of several recent supernovae. The Local Bubble is a small superbubble compared to the neighboring wider Radcliffe Wave and Split linear structures (formerly Gould Belt), each of which are some thousands of light-years in length. All these structures are part of the Orion Arm, which contains most of the stars in the Milky Way that are visible to the unaided eye. Groups of stars form together in star clusters, before dissolving into co-moving associations. A prominent grouping that is visible to the naked eye is the Ursa Major moving group, which is around 80 light-years away within the Local Bubble. The nearest star cluster is Hyades, which lies at the edge of the Local Bubble. The closest star-forming regions are the Corona Australis Molecular Cloud, the Rho Ophiuchi cloud complex and the Taurus molecular cloud; the latter lies just beyond the Local Bubble and is part of the Radcliffe wave. Stellar flybys that pass within 0.8 light-years of the Sun occur roughly once every 100,000 years. The closest well-measured approach was Scholz's Star, which approached to ~50,000 AU of the Sun some ~70 thousands years ago, likely passing through the outer Oort cloud. There is a 1% chance every billion years that a star will pass within 100 AU of the Sun, potentially disrupting the Solar System. Galactic position The Solar System is located in the Milky Way, a barred spiral galaxy with a diameter of about 100,000 light-years containing more than 100 billion stars. The Sun is part of one of the Milky Way's outer spiral arms, known as the Orion–Cygnus Arm or Local Spur. It is a member of the thin disk population of stars orbiting close to the galactic plane. Its speed around the center of the Milky Way is about 220 km/s, so that it completes one revolution every 240 million years. This revolution is known as the Solar System's galactic year. The solar apex, the direction of the Sun's path through interstellar space, is near the constellation Hercules in the direction of the current location of the bright star Vega. The plane of the ecliptic lies at an angle of about 60° to the galactic plane.[c] The Sun follows a nearly circular orbit around the Galactic Center (where the supermassive black hole Sagittarius A* resides) at a distance of 26,660 light-years, orbiting at roughly the same speed as that of the spiral arms. If it orbited close to the center, gravitational tugs from nearby stars could perturb bodies in the Oort cloud and send many comets into the inner Solar System, producing collisions with potentially catastrophic implications for life on Earth. In this scenario, the intense radiation of the Galactic Center could interfere with the development of complex life. The Solar System's location in the Milky Way is a factor in the evolutionary history of life on Earth. Spiral arms are home to a far larger concentration of supernovae, gravitational instabilities, and radiation that could disrupt the Solar System, but since Earth stays in the Local Spur and therefore does not pass frequently through spiral arms, this has given Earth long periods of stability for life to evolve. However, according to the controversial Shiva hypothesis, the changing position of the Solar System relative to other parts of the Milky Way could explain periodic extinction events on Earth. Discovery and exploration Humanity's knowledge of the Solar System has grown incrementally over the centuries. Up to the Late Middle Ages–Renaissance, astronomers from Europe to India believed Earth to be stationary at the center of the universe and categorically different from the divine or ethereal objects that moved through the sky. Although the Greek philosopher Aristarchus of Samos had speculated on a heliocentric reordering of the cosmos, Nicolaus Copernicus was the first person known to have developed a mathematically predictive heliocentric system. Heliocentrism did not triumph immediately over geocentrism, but the work of Copernicus had its champions, notably Johannes Kepler. Using a heliocentric model that improved upon Copernicus by allowing orbits to be elliptical, and the precise observational data of Tycho Brahe, Kepler produced the Rudolphine Tables, which enabled accurate computations of the positions of the then-known planets. Pierre Gassendi used them to predict a transit of Mercury in 1631, and Jeremiah Horrocks did the same for a transit of Venus in 1639. This provided a strong vindication of heliocentrism and Kepler's elliptical orbits. In the 17th century, Galileo publicized the use of the telescope in astronomy; he and Simon Marius independently discovered that Jupiter had four satellites in orbit around it. Christiaan Huygens followed on from these observations by discovering Saturn's moon Titan and the shape of the rings of Saturn. In 1677, Edmond Halley observed a transit of Mercury across the Sun, leading him to realize that observations of the solar parallax of a planet (more ideally using the transit of Venus) could be used to trigonometrically determine the distances between Earth, Venus, and the Sun. Halley's friend Isaac Newton, in his magisterial Principia Mathematica of 1687, demonstrated that celestial bodies are not quintessentially different from Earthly ones: the same laws of motion and of gravity apply on Earth and in the skies.: 142 The term "Solar System" entered the English language by 1704, when John Locke used it to refer to the Sun, planets, and comets. In 1705, Halley realized that repeated sightings of a comet were of the same object, returning regularly once every 75–76 years. This was the first evidence that anything other than the planets repeatedly orbited the Sun, though Seneca had theorized this about comets in the 1st century. Careful observations of the 1769 transit of Venus allowed astronomers to calculate the average Earth–Sun distance as 93,726,900 miles (150,838,800 km), only 0.8% greater than the modern value. Uranus, having occasionally been observed since 1690 and possibly from antiquity, was recognized to be a planet orbiting beyond Saturn by 1783. In 1838, Friedrich Bessel successfully measured a stellar parallax, an apparent shift in the position of a star created by Earth's motion around the Sun, providing the first direct, experimental proof of heliocentrism. Neptune was identified as a planet some years later, in 1846, thanks to its gravitational pull causing a slight but detectable variation in the orbit of Uranus. Mercury's orbital anomaly observations led to searches for Vulcan, a planet interior of Mercury, but these attempts were quashed with Albert Einstein's theory of general relativity in 1915. In the 20th century, humans began their space exploration around the Solar System, starting with placing telescopes in space since the 1960s. By 1989, all eight planets have been visited by space probes. Probes have returned samples from comets and asteroids, as well as flown through the Sun's corona and visited two dwarf planets (Pluto and Ceres). To save on fuel, some space missions make use of gravity assist maneuvers, such as the two Voyager probes accelerating when flying by planets in the outer Solar System and the Parker Solar Probe decelerating closer towards the Sun after its flyby of Venus. Humans have landed on the Moon during the Apollo program in the 1960s and 1970s and are planning to return to the Moon in the 2020s with the Artemis program. Discoveries in the 20th and 21st century has prompted the redefinition of the term planet in 2006, hence the demotion of Pluto to a dwarf planet, and further interest in trans-Neptunian objects. See also Notes References External links Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Local Volume → Virgo Supercluster → Laniakea Supercluster → Pisces–Cetus Supercluster Complex → Local Hole → Observable universe → UniverseEach arrow (→) may be read as "within" or "part of". |
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Contents United States Armed Forces The United States Armed Forces are the military forces of the United States. U.S. federal law establishes six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard, each assigned specific roles and operational domains. With the exception of the Coast Guard, which operates under the Department of Homeland Security (DHS) in peacetime, the services are organized under the Department of Defense (DoD). Established during the American Revolutionary War, the Army and the Navy, and later the other services, have played a decisive role in the country's history. They contributed to early national consolidation through conflicts such as the Barbary Wars and the War of 1812, shaped the country's territorial evolution, and were decisive in major conflicts including the American Civil War, the World Wars, and the Cold War. The National Security Act of 1947 reorganized the military establishment by creating the DoD, the Air Force, and the National Security Council; in 1949, an amendment to the act merged the cabinet-level departments of the Army, Navy, and Air Force into the DoD. formalizing a unified defense structure under civilian control. The Space Force was established in 2019 as the newest branch. The president of the U.S. serves as commander-in-chief and exercises authority over the armed forces through the DoD and, for the Coast Guard in peacetime, the DHS. Since 1973, the United States has maintained an all-volunteer force, although the Selective Service System remains authorized to conscript most male citizens and residents aged 18 and 25 to register. All six services are also among the eight uniformed services of the United States.[c] The armed forces consist of active-duty personnel, Reserve components, and the National Guard. The U.S. Armed Forces are widely considered the world's most powerful and most advanced military. The military expenditure of the U.S. was US$997 billion in 2024, the highest in the world, accounting for 37% of the world's defense expenditures. The personnel size of the six armed forces together ranks them among the world's largest state armed forces. The U.S. Armed Forces has significant capabilities in both defense and power projection due to its large budget, resulting in advanced and powerful technologies which enable widespread deployment of the force globally, including around 800 military bases around the world. History The history of the U.S. Armed Forces dates back to 14 June 1775, with the creation of the Continental Army, even before the Declaration of Independence marked the establishment of the United States. The Continental Navy, established on 13 October 1775, and Continental Marines, established on 10 November 1775, were created in close succession by the Second Continental Congress in order to defend the new nation against the British Empire in the American Revolutionary War. These forces demobilized in 1784 after the Treaty of Paris ended the Revolutionary War. The Congress of the Confederation created the current United States Army on 3 June 1784. The United States Congress created the current United States Navy on 27 March 1794 and the current United States Marine Corps on 11 July 1798. All three services trace their origins to their respective Continental predecessors. The 1787 adoption of the Constitution gave Congress the power to "raise and support armies," to "provide and maintain a navy", and to "make rules for the government and regulation of the land and naval forces", as well as the power to declare war. The president of the United States is the United States Armed Forces' commander-in-chief. The United States Coast Guard traces its origin to the formation of the Revenue Cutter Service on 4 August 1790, which merged with the United States Life-Saving Service on 28 January 1915 to establish the Coast Guard. The United States Air Force was established as an independent service on 18 September 1947; it traces its origin to the formation of the Aeronautical Division, U.S. Signal Corps, which was formed 1 August 1907 and was part of the Army Air Forces before being recognized as an independent service in the National Security Act of 1947. The United States Public Health Service Commissioned Corps was formerly considered to be a branch of the United States Armed Forces from 29 July 1945 until 3 July 1952, and is now one of the eight uniformed services of the United States. Should it be called into active duty again, it would constitute a seventh branch of the Armed Forces. The United States Space Force was established as an independent service on 20 December 2019. It is the sixth branch of the U.S. military and the first new branch in 72 years. The origin of the Space Force can be traced back to the Air Force Space Command, which was formed 1 September 1982 and was a major command of the United States Air Force. The U.S. Congressional Research Office annually publishes a List of Notable Deployments of U.S. Military Forces Overseas since 1798. Structure Presidential command over the U.S. Armed Forces is established in Article II in the Constitution whereby the president is named as the "Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States." The United States Armed Forces are split between two cabinet departments, with the Department of Defense serving as the primary cabinet department for military affairs and the Department of Homeland Security responsible for administering the United States Coast Guard. The military chain of command flows from the President of the United States to the secretary of defense (for services under the Defense Department) or secretary of homeland security (for services under the Department of Homeland Security), ensuring civilian control of the military. Within the Department of Defense, the military departments (Department of the Army, Department of the Navy, and Department of the Air Force) are civilian led entities that oversee the coequal military service branches organized within each department. The military departments and services are responsible for organizing, training, and equipping forces, with the actual chain of command flowing through the unified combatant commands. The Joint Chiefs of Staff, although outside the operational chain of command, is the senior-most military body of the Department of Defense. It is led by the chairman of the Joint Chiefs of Staff, who is the military head of the armed forces and principal advisor to the president and secretary of defense on military matters. Their deputy is the vice chairman of the Joint Chiefs of Staff. Other members include the chief of staff of the Army, commandant of the Marine Corps, chief of naval operations, chief of staff of the Air Force, chief of space operations, and the chief of the National Guard Bureau. The commandant of the Coast Guard is not an official member of the Joint Chiefs, but sometimes attends meetings as one of the military service chiefs. The senior enlisted advisor to the chairman is the most senior non-commissioned officer (NCO) in the United States Armed Forces and is a unique enlisted rank which only one individual may hold it. Is the primary enlisted advisor to the chairman, and serves at the pleasure of the secretary of defense. The president of the United States, the secretary of defense, the secretary of homeland security and chairman of the Joint Chiefs of Staff are members of the United States National Security Council, which advises the president on national security, military, and foreign policy matters. The national security advisor, the homeland security advisor, and the deputy national security advisor may also be members of the United States Armed Forces. The National Security Council Deputies Committee also includes the deputy secretary of defense, deputy secretary of homeland security, and vice chairman of the Joint Chiefs of Staff. Military leadership, including the secretary of defense, the secretary of Homeland Security, and chairman of the Joint Chiefs of Staff also sit on the National Space Council. Unified combatant commands are joint military commands consisting of forces from multiple military departments, with their chain of command flowing from the president, to the secretary of defense, to the commanders of the combatant commands. Each service organizes, trains, and equips forces that are then presented to the unified combatant commands through service component commands. Special Operations Command and Cyber Command also present theater special operations commands or joint force headquarters – cyber to other combatant commanders. Army components are typically dual-hatted as the joint force land component, Navy components are typically dual-hatted as the joint force maritime component, and Air Force components are typically dual-hatted as the joint force air component, with the theater special operations command dual-hatted as the joint force special operations component, and Space Force component typically dual-hatted as the joint force space component. Combat support agencies are Department of Defense agencies with combat support missions that service operating forces planning or conducting military operations. This includes support during conflict or in the conduct of other military activities related to countering threats to U.S. national security. This mission is focused on providing support to echelons at the CCMD level and below and may not encompass the full scope of the CSA's mission. Service branches The United States Armed Forces is composed of six coequal military service branches. Five of the branches, the United States Army, United States Marine Corps, United States Navy, United States Air Force, and United States Space Force, are part of the Department of Defense. The United States Coast Guard is normally under the Department of Homeland Security, but may be transferred to the Department of Defense's Department of the Navy (which is the civilian entity that oversees the coequal U.S. Marine Corps and U.S. Navy) at the direction of the President or Congress. With the exception of the Coast Guard, the military services only organize, train, and equip forces. The unified combatant commands are responsible for operational control of non-service retained forces. Each of the different military services is assigned a role and domain. The U.S. Army conducts land operations, while the U.S. Navy and U.S. Marine Corps conduct maritime operations, with the Marine Corps specializing in amphibious and maritime littoral operations in support of the Navy. The U.S. Air Force conducts air operations, while the U.S. Space Force conducts space operations. The U.S. Coast Guard is unique in that it is a military branch specializing in maritime operations and also a law enforcement agency. The United States Army (USA) is the United States Armed Forces' land force and is the largest and oldest service. Originally established in 1775 as the Continental Army, it consists of one million soldiers across the Regular Army, Army Reserve, and Army National Guard. The Army serves as the Armed Forces principal land service, responsible for conducting land warfare operations. The U.S. Army is organized under the Department of the Army, which is a military department under the leadership of the secretary of the Army and under secretary of the Army. The U.S. Army itself is led by the chief of staff of the Army and vice chief of staff of the Army, both generals who are advised by the sergeant major of the Army. The Army's primary responsibility is to conduct prompt and sustained land combat as part of the joint force. Army landpower focuses on destroying an enemy's armed forces, occupying its territory, and breaking the will of an adversary. The five core competencies of the Army are: The thirteen specified functions of the Army are: The Infantry Branch forms the core of the service's land combat power. U.S. Army infantry are generally equipped with the M4 carbine and M249 light machine gun, which will be replaced by the XM7 rifle and XM250. Infantry is a core part of the Army's Brigade Combat Teams. The most numerous variant, the Infantry Brigade Combat Team, comprises light infantry battalions who fight on foot. Infantry Brigade Combat Teams of the 82nd Airborne Division are air assault capable, with infantry soldiers being transported by U.S. Army Aviation UH-60 Black Hawk and CH-47 Chinook helicopters. Infantry Brigade Combat Teams of the 11th Airborne Division, 82nd Airborne Division, and 173rd Airborne Brigade are capable of airborne operations, in cooperation with the U.S. Air Force's transport aircraft. Finally, Infantry Brigade Combat Teams assigned to the 10th Mountain Division specialize in mountain warfare. Standard Infantry Brigade Combat Teams are assigned to the 25th Infantry Division, which offers additional training in jungle warfare. Armored Brigade Combat Teams comprise mechanized infantry battalions mounted in the M2 Bradley infantry fighting vehicle.Divisions with Armored Brigade Combat Teams include the 1st Infantry Division, 3rd Infantry Division, 4th Infantry Division, 1st Armored Division, and 1st Cavalry Division. Stryker Brigade Combat Teams are centered around Stryker infantry battalions operating out of the Stryker.Divisions with Stryker Brigade Combat Teams include the 2nd Infantry Division, 4th Infantry Division, 11th Airborne Division, 2nd Cavalry Regiment, and 3rd Cavalry Regiment. United States Army Rangers with the 75th Ranger Regiment are an elite special operations infantry force in the United States Army Special Operations Command, specializing in air assault and airborne infiltration methods. The three primary missions of the 75th Ranger Regiment are special operations raids, forcible entry operations, such as an airfield seizure to enable the Air Force to bring in more forces, and special reconnaissance. As a special operations force, Army Rangers are generally better equipped than standard infantry, utilizing the FN SCAR rifle. Army Special Forces, commonly known as Green Berets after their iconic headgear, are among the most elite soldiers in the Army. Special Forces conduct: Army Special Forces are trained in military free-fall parachuting and combat diver skillsets. They are considered the most versatile special operations force in the entire world, operating as a multi-purpose force since 1952. The Armor Branch traces its history back to the United States Cavalry and are responsible for tank and cavalry reconnaissance operations. The U.S. Army fields the M1 Abrams main battle tank in Armored Battalions as part of Armored Brigade Combat Teams across the 1st Armored Division, 1st Cavalry Division, 1st Infantry Division, 3rd Infantry Division, and the 4th Infantry Division.Each Armored Brigade Combat Team also possesses a cavalry squadron equipped with M2 Bradleys for scouting and security. Stryker Brigade Combat Teams from the 2nd Infantry Division, 4th Infantry Division, 11th Airborne Division, 2nd Cavalry Regiment, and 3rd Cavalry Regiment have a cavalry squadron equipped with Strykers. Infantry Brigade Combat Teams from the 10th Mountain Division, 11th Airborne Division, 25th Infantry Division, 82nd Airborne Division, 101st Airborne Division, and 173rd Airborne Brigade have a cavalry squadron equipped with the Joint Light Tactical Vehicle. The Field Artillery's mission is to destroy, suppress or neutralize the enemy by cannon, rocket or missile fire. Rocket systems include the M142 HIMARS and M270 multiple launch rocket system, which are corps-level assets found in field artillery brigades. Towed artillery includes the M119 howitzer in infantry brigade combat teams and the M777 howitzer found in both infantry and Stryker brigade combat teams. The M109 self-propelled howitzer is utilized in armored brigade combat teams. During the Cold War, Army field artillery was responsible for the service's ballistic missile programs, including the PGM-11 Redstone, which was the first large ballistic missile in the U.S. arsenal, the MGM-31 Pershing, and the Pershing II. In 2023, the Army is intending to field the Long-Range Hypersonic Weapon and has reestablished larger artillery formations like the 56th Artillery Command. The Air Defense Artillery is responsible for defending geopolitical assets and providing maneuver forces with the freedom to move on the battlefield by deterring the enemy and destroying aerial threats, missile attacks, and surveillance platforms. Weapons employed by Air Defense Artillery include the FIM-92 Stinger man-portable air-defense system, AN/TWQ-1 Avenger for short range air defense, and the counter rocket, artillery, and mortar 20mm gun system. The Iron Dome provides air defense against rockets, artillery, mortars, missiles, and unmanned aerial vehicles. The MIM-104 Patriot is capable of defeating a wide range of threats including aircraft, helicopters, UAVs, ballistic and cruise missiles, and Weapons of Mass Destruction. The Terminal High Altitude Area Defense protects strategic critical assets by conducting long-range endo-and-exo-atmospheric engagements of ballistic missiles using the world's largest air-transportable X-band radar. The Ground-Based Midcourse Defense is an anti-ballistic missile system operated by Army Space and Missile Defense Command to defend the United States homeland against an intercontinental ballistic missile attack. Major Air Defense Artillery units include the 32nd Army Air and Missile Defense Command and Army Space and Missile Defense Command's 100th Missile Defense Brigade. Air Defense Artillery has an extremely close relationship with the Air Force through its Air and Missile Defense Commands and the Space Force through Army Space and Missile Defense Command, given their shared missile defense and space roles. In 1962, Air Defense Artillery achieved the first intercept of a ballistic missile with a nuclear-tipped Nike Zeus and operated the Nike Zeus as an anti-satellite weapon after completing a successful intercept in 1963. Army Aviation, distinct from the U.S. Air Force and its predecessors, began as part of the field artillery in 1942. Small spotter planes were used to spot for artillery and naval bombardment, as well as to perform observation. These few aircraft formed the core of Army Aviation once the U.S. Air Force gained independence. In 1983, the Army created the Aviation Branch, for the first time since the Air Force's independence consolidating aviation under a single organization. The mission of Army Aviation is to find, fix and destroy any enemy through fire and maneuver and to provide combat support and combat service support in coordinated operations as an integral member of the combined arms team. Major aircraft include the AH-64 Apache, which serves as the Army's attack helicopter, the UH-60 Black Hawk, and the CH-47 Chinook for troop and cargo transport. Army Aviation also flies the MQ-1C Gray Eagle drone. A specialized unit within Army Aviation, the 160th Special Operations Aviation Regiment (Airborne) serves as a special operations unit and operates modified variants of the MH-60 Black Hawk, MH-47 Chinook, and the MH-6 Little Bird. The U.S. Army is organized into four major Army Commands, nine Army Service Component Commands which serve as the Army component and joint force land component commanders for the unified combatant commands, and thirteen direct reporting units. The United States Marine Corps (USMC) serves as the U.S. Armed Forces' naval land force, responsible for executing amphibious warfare and operating in the maritime littorals in support of the U.S. Navy. Originally established in 1775 as the Continental Marines, the Marine Corps consists of the Regular Marine Corps and the Marine Corps Reserve. The Marine Corps maintains a very close relationship with the U.S. Navy, its sister service in the Department of the Navy. Although the Marine Corps has previously operated as an independent land force alongside the Army, its primary purpose is to serve as part of a unified naval service alongside the Navy in the maritime domain. The U.S. Marine Corps is organized under the Department of the Navy, which is a military department under the leadership of the secretary of the Navy and the under secretary of the Navy. The U.S. Marine Corps itself is led by the commandant of the Marine Corps and the assistant commandant of the Marine Corps, both generals who are advised by the sergeant major of the Marine Corps. The Marine Corps statutory mission is outlined in 10 U.S.C. § 5063 and as originally introduced under the National Security Act of 1947, with its three primary areas of responsibility including: The seven specified functions of the Marine Corps are: Marine Corps Security Force Regiment is responsible for supporting the Navy with Marine security operations, while the Marine Security Guard protects embassies and consulates of the United States Department of State. The combat power of the Marine Corps is centralized in the Fleet Marine Force (FMF), which itself is organized into Fleet Marine Force Atlantic, to support the U.S. Navy's Fleet Forces Command, and Fleet Marine Force Pacific, which supports the U.S. Navy's U.S. Pacific Fleet. The basic Marine Corps unit for conducting operations is the Marine Air-Ground Task Force (MAGTF), which combines Marine Corps and Navy land, air, sea, and cyberspace capabilities into a single command. There are three size variants of a Marine Air-Ground Task Force, but each consists of a command element, ground combat element, aviation combat element, and logistics combat element. A Marine ground combat element (GCE) is centered around Marine infantry, typically armed with a M27 Infantry Automatic Rifle. Unlike the Army, the Marine Corps does not train its own combat medics, relying on the Navy to provide hospital corpsmen. These infantry units are supported by Marine Corps combat engineers, who conduct engineer reconnaissance, obstacle system emplacement, and breaching operations; and Marine Corps Force Reconnaissance teams. While the Marine Corps no longer operates its own tanks, opting to request support from the Army if needed, it maintains Light Armored Reconnaissance Battalions which operate the LAV-25 amphibious armored reconnaissance vehicle. Assault Amphibian Battalions operate the Assault Amphibious Vehicle and Amphibious Combat Vehicle, which enable the ground combat element to conduct amphibious landing operations. Marine Corps artillery operates the M777 howitzer and the M142 HIMARS, both supporting the ground combat element and the Navy at sea by striking enemy ships. The Marine aviation combat element (ACE) is the operational arm of Marine Corps Aviation, working to support the ground combat element. The F-35B Lightning II and AV-8B Harrier II are flown off Navy amphibious assault ships, while the F-35C Lightning II and F/A-18 Hornet are flown off Navy carriers by Marine Corps pilots. The Marine Corps also operates the KC-130J to serve as a tanker and tactical airlift platform. The UH-1Y Venom helicopter provides the Marine Corps with light transport and attack, while the AH-1Z Viper is a dedicated attack helicopter. Medium-lift squadrons fly the MV-22 Osprey, while heavy-lift squadrons use the CH-53K King Stallion. The Marine Corps has also begun flying unmanned aerial vehicles, such as the MQ-9 Reaper and MQ-8 Fire Scout. Notably, the aviation combat element also includes Low-Altitude Air Defense Battalions, which employ the FIM-92 Stinger surface-to-air missile. The smallest MAGTF is the Marine Expeditionary Unit (MEU), which is typically forward deployed on a Navy ship. Commanded by a colonel, a Marine Expeditionary Unit consist of 2,200 marines split across a battalion landing team (ground combat element), a composite helicopter squadron (aviation combat element), and a combat logistics element (logistics element). Marine Expeditionary Units are supplied for 15 days. Forward deployed Marine Expeditionary Units are often embarked on Navy amphibious assault ships as part of an amphibious ready group. The mid-sized MAGTF is the Marine Expeditionary Brigade (MEB), which is organized for specific missions. Commanded by a brigadier general, Marine Expeditionary Brigades consist of 4,000 to 16,000 marines across a Regimental-sized ground combat element, a Marine Aircraft Group, and a Combat Logistics Regiment. Marine Expeditionary Brigades are supplied for 30 days and offer increased firepower and airpower over the Marine Expeditionary Unit. The largest MAGTF is the Marine Expeditionary Force (MEF), which is the primary warfighting force for larger operations. A Marine Expeditionary Force is commanded by a lieutenant general and consists of 46,000 to 90,000 marines. Currently there are only three Marine Expeditionary Forces, each with its own Marine Division, Marine Aircraft Wing, Marine Logistics Group, and Marine Expeditionary Force Information Group. Marine Expeditionary Forces are supplied for 60 days. Certain elements are held at the Marine Expeditionary Force level, such as Force Reconnaissance. The MEF Information Group (MIG) also provides a number of functions such as the intelligence battalion; radio battalion which conducts signals intelligence, electronic warfare, and cyberspace operations; communications battalion; the MEF support battalion; and the Air Naval Gunfire Liaison Company. While not a MAGTF, the Marine Corps has begun to reorganize some of its regiments into Marine Littoral Regiments (MRL), which are similar in size to a Marine Expeditionary Unit. A Marine Littoral Regiment is a self-deployable force, designed to be naval in nature and operate in the littoral region. A Marine Littoral Regiment consists of a littoral combat team, a littoral anti-air battalion, and a combat logistics battalion. Notably, the Marine Littoral Regiment has no aviation combat element, unlike a Marine Expeditionary Unit. Another Marine Corps element that does not function as part of the MAGTF is the Marine Raider Regiment, functioning under United States Marine Forces Special Operations Command. Marine Raiders specialize in direct action, unconventional warfare, maritime interdiction, special reconnaissance, foreign internal defense, counterterrorism, and counterinsurgency missions. Under Headquarters Marine Corps, the Marine Corps is organized into the Fleet Marine Force, multiple commands, and Marine Corps service components to the unified combatant commands. The United States Navy (USN) is the United States Armed Forces' maritime force. Originally established in 1775 as the Continental Navy, the U.S. Navy consists of the Regular Navy and the Navy Reserve. The Navy is the United States' principal maritime service, responsible for maritime warfare operations. The U.S. Navy is organized under the Department of the Navy, which is a military department under the leadership of the secretary of the Navy and the under secretary of the Navy. The U.S. Navy itself is led by the chief of naval operations and the vice chief of naval operations, both admirals who are advised by the master chief petty officer of the Navy. The five enduring functions of the Navy are: The nine specified tasks of the Navy are: The Naval Surface Forces (NAVSURFOR) is the backbone of the U.S. Navy's combat power, conducting surface warfare operations and operating its fleet of combat surface ships. The Naval Surface Forces operates eleven nuclear-powered aircraft carriers (CVN), split between the Nimitz-class and the newer Gerald R. Ford-class. Aircraft carriers are the centerpiece of the U.S. Navy's combat power, forming the nucleus of its eleven carrier strike groups (CSG). Each aircraft carrier has an embarked carrier air wing from the Naval Air Forces. The Naval Surface Forces also operate 116 surface combatants. These include the Ticonderoga-class guided-missile cruisers, Arleigh Burke-class guided-missile destroyers (DDG) and Zumwalt-class stealth guided-missile destroyers. Cruisers and destroyers often operate as part of larger formations, where they serve as escorts for anti-aircraft and anti-submarine operations. However, they also are able to conduct sea control and striker operations ashore with their tomahawk cruise missiles. The Navy also operates a complement of smaller Freedom-class and Independence-class littoral combat ships (LCS) that can be modularly reconfigured for specific mission sets. Having lacked a frigate since the Oliver Hazard Perry-class was decommissioned, the Navy is in the process of acquiring the new Constellation-class guided-missile frigates (FFG). Finally, the Naval Surface Forces operate 31 amphibious warfare ships to support the Fleet Marine Force and its embarked Marine Air-Ground Task Forces as part of an amphibious ready group or expeditionary strike group. This includes the America-class landing helicopter assault (LHA) ships which can carry U.S. Marine Corps F-35B Lightning II fighters and helicopters; and Wasp-class landing helicopter dock (LHD) ships, which can carry both F-35B fighters, helicopters, and landing craft. These are in addition to the San Antonio-class amphibious transport docks (LPD), and the Whidbey Island-class and Harpers Ferry-class dock landing ships. The Naval Submarine Forces (NAVSUBFOR) is often referred to as the "silent service", consisting of 68 commissioned submarines. Los Angeles-class, Seawolf-class, and Virginia-class nuclear-powered attack submarines are capable of performing sea control missions by destroying enemy submarines and surface ships, conducting surveillance and reconnaissance, performing irregular warfare, covert troop insertion, mine and anti-mine operations, and land attack missions with tomahawk cruise missiles. Ohio-class nuclear-powered ballistic missile submarines (SSBN) have the sole mission of being launch platforms for the nuclear submarine-launched ballistic missile (SLBM). Each carries 20 UGM-133 Trident II SLBMs. The Navy is currently in the process of procuring the Columbia-class SSBNs to replace the Ohio-class. Some Ohio-class submarines have been converted to cruise-missile submarines (SSGN), capable of carrying 154 tomahawk cruise missiles and deploying 66 special operations forces personnel, such as Navy SEALs. The Naval Air Forces (NAVAIRFOR) is the Navy's naval aviation arm, centered around the carrier air wing. The core of the carrier air wing are the Naval Air Forces strike fighter squadrons (VFA), which fly the F-35C Lightning II stealth fighter and the F/A-18E/F Super Hornet. A variant of the F/A-18, the EA-18G Growler is an electronic-warfare aircraft flown by electronic attack squadrons (VAQ) off of carriers or land bases. The E-2 Hawkeye provides carriers with airborne early warning and command-and-control, while the C-2A Greyhound keeps carriers supplied. The CMV-22B Osprey is currently in the process of replacing the C-2 Greyhound for carrier resupply. The Naval Air Forces also operate the MH-60 Seahawk for anti-submarine warfare, anti-ship warfare, and search and rescue operations. The MH-53E is primarily used for anti-mine warfare but can also be used for assault support. Although primarily centered on carriers, the Naval Air Forces do operate a small number of land-based aircraft. These include the P-3C Orion and P-8A Poseidon, which conduct anti-submarine warfare operations and serve as maritime patrol aircraft, alongside the unmanned MQ-4C Triton. The E-6 Mercury is also flown by the Navy to communicate instructions to U.S. strategic forces. The U.S. Navy is organized into eight navy component commands, which command operational forces and serve as joint force maritime component commands; fifteen shore commands, which support the fleets' operating forces; five systems commands, which oversee the technical requirements of the Navy; and nine type commands, which administratively manage units of a certain type. The United States Air Force (USAF) is the United States Armed Forces' air force originally established in 1947 when it gained independence from the U.S. Army, it traces its history back through the United States Army Air Forces, United States Army Air Corps, United States Army Air Service, the Division of Military Aeronautics, Aviation Section, U.S. Signal Corps, to the birth of Aeronautical Division, U.S. Signal Corps on 1 August 1907. The U.S. Air Force serves as the principal air service, responsible for aerial warfare operations. The U.S. Air Force is composed of the Regular Air Force, Air Force Reserve, and Air National Guard. The U.S. Air Force is organized under the Department of the Air Force, which is a military department under the leadership of the secretary of the Air Force and under secretary of the Air Force. The U.S. Air Force itself is led by the chief of staff of the Air Force and vice chief of staff of the Air Force, both generals who are advised by the chief master sergeant of the Air Force. The five core missions of the Air Force are: The eight specified functions of the Air Force are: The Combat Air Force (CAF) comprises the majority of the Air Force's combat power, consisting of its fighter, bomber, intercontinental ballistic missile, and special operations forces. The Air Force's fighter forces are led by Air Combat Command's Fifteenth Air Force, with other fighter units under Pacific Air Forces and United States Air Forces in Europe. Air Force fighters are predominantly used to achieve air superiority and strike enemy ground and naval forces. The Air Force operates an expanding force of fifth-generation fighters. The F-22A Raptor stealth fighter is designed to replace the F-15C in air superiority operations carrying two AIM-9 Sidewinder and six AIM-120 AMRAAM missiles. It also has a significant air-to-ground mission, carrying two GBU-32 Joint Direct Attack Munition bombs, in addition to two AIM-9 and two AIM-120 missiles. Ultimately, the F-22 is intended to be replaced by the sixth-generation fighter, Next Generation Air Dominance program. The F-22 is complemented by the more numerous F-35A Lightning II multi-role stealth fighters, which are in the process of replacing the F-16C fighters and A-10 attack aircraft in air superiority and ground attack roles, to include the nuclear strike mission. The Air Force still operates an extremely sizable force of fourth-generation fighters. The F-15C Eagle is a dedicated air superiority fighter, while the F-15E Strike Eagle has been modified to be a dual-role strike fighter, carrying both conventional and nuclear weapons. The F-15C Eagle and F-15E Strike Eagle are both being replaced by the F-15EX Eagle II, which is significantly more advanced. The F-16C Fighting Falcon is a multirole fighter that has served as the primary Air Force fighter for decades, including as a dual-capable tactical nuclear strike fighter. The A-10C Thunderbolt II attack aircraft has been the first Air Force fighter specifically designed for close air support missions, operating against enemy ground forces and light naval ships with its GAU-8 Avenger gatling cannon and array of air-to-ground munitions. The Air Force's bomber forces are organized under Air Force Global Strike Command's Eighth Air Force, executing long-range strike operations. The B-2A Spirit stealth bomber is capable of conducting both conventional and nuclear strike operations flying through air defenses. The B-1B Lancer, in contrast, is a supersonic bomber that carries only conventional munitions and serves as the backbone of the bomber force. Both the B-2A Spirit and the B-1B Lancer are being replaced by the B-21 Raider stealth bomber, which can be equipped with both conventional and nuclear munitions. The B-52H Stratofortress is a long-range, heavy bomber that the Air Force has flown since the 1950s and operates a variety of conventional and nuclear munitions, including the AGM-86 air-launched cruise missile. The Air Force's intercontinental ballistic missile forces are organized under Air Force Global Strike Command's Twentieth Air Force, serving as the land component of the nuclear triad. The LGM-30G Minuteman III serves as the only ballistic missile operated by the Air Force, with 400 stationed in hardened silos. The LGM-30G will be replaced by the LGM-35A Sentinel intercontinental ballistic missile. The Air Force's special operations forces are organized under Air Force Special Operations Command, consisting of both special operations aviation and Air Force special tactics airmen on the ground. The AC-130J Ghostrider gunships have the primary mission of close air support and air interdiction, using cannons and precision guided munitions. The MC-130J Commando II, also a variant of the C-130 Hercules, fly exfiltration and resupply operations for special operations forces, alongside conducting air-to-air refueling for helicopters. The CV-22 Osprey is a tiltrotor aircraft used for the infiltration and exfiltration of special operations forces. While not under Air Force Special Operations Command, rescue operations are supported by the HC-130J Combat King II and HH-60W Jolly Green II combat rescue aircraft. The MQ-9 Reaper also serves as a remotely piloted intelligence and strike aircraft, serving under Air Force Special Operations Command and Air Combat Command. Air Force Special Tactics are the ground special warfare force of the U.S. Air Force, integrating air-ground operations. Special Tactics conduct four core missions. Global access teams assess and open airfields, ranging from international airports to dirt strips, in permissive or hostile locations to facilitate the landing and operation of air forces. Precision strike teams are trained to direct aircraft and other forces to conduct kinetic and non-kinetic strikes, as well as humanitarian aid drops.Special Tactics teams also conduct personnel recovery missions, possessing significant medical and rescue experience.Finally, Special Operations Surgical Teams conduct surgery and medical operations in battlefield operations in support of special operations. The Air Force also operates a wide array of reconnaissance aircraft under Air Combat Command's Sixteenth Air Force, including the RQ-4 Global Hawk drone, U-2 Dragon Lady, and RC-135 Rivet Joint. Air Force operations are typically supported by command and control aircraft, such as the E-3 Sentry airborne warning and control system. The E-3 Sentry is in the process of being replaced by the E-7A Wedgetail. The Mobility Air Force (MAF) is organized under Air Mobility Command and comprises the Air Force's airlift, air refueling, and aeromedical evacuation forces. The airlift forces operate three different major aircraft. The C-5M Super Galaxy is the largest aircraft in the Air Force, serving as a strategic transport aircraft. The C-17A Globemaster III is the airlift force's most flexible aircraft, conducting both strategic and tactical airlift operations. It is also capable of conducting airborne operations for the Army and aerial resupply through airdropping cargo. Finally, the C-130J Super Hercules is a tactical airlifter, conducting both cargo airlift and supporting Army airborne operations. Other major airlift platforms include the VC-25, which serves as the personal plane of the president of the United States, better known as Air Force One. The Air Force also operates three major aerial refueling tankers. The KC-46A Pegasus is its most modern tanker, replacing the aging KC-10A Extenders. The remaining tanker is the KC-135 Stratotanker, which has flown since the 1950s. Tankers are also capable of conducting limited airlift operations. The U.S. Air Force is organized into nine major commands, which conduct the majority of the service's organize, train, and equip functions. It commands forces attached to the combatant commands as joint force air component commands. The United States Space Force (USSF) is the United States Armed Forces' space force and is the newest military branch. Originally established in 2019, it traces its history through Air Force Space Command and the Western Development Division to 1954. The United States Space Force is the principal space service, responsible for space warfare operations. The U.S. Space Force is composed of the Regular Space Force, not yet having organized a reserve component outside of the Air Force. The U.S. Space Force is organized under the Department of the Air Force, which is a military department under the leadership of the secretary of the Air Force and under secretary of the Air Force. The U.S. Space Force itself is led by the chief of space operations and vice chief of space operations, both generals who are advised by the chief master sergeant of the Space Force. The five core competencies of the Space Force are: The five specified functions of the Space Force are: The Space Force's combat power is centered around Space Delta 3, which conducts space electromagnetic warfare and Space Delta 9, which conducts orbital warfare. Combat power projection operations ensure freedom of action in space for the U.S. and its allies and denies an adversary freedom of action in space. These are divided into offensive and defensive space operations. Defensive operations preserve and protect U.S. and allied space capabilities, which are further sub-divided into active and passive actions. Offensive operations target a U.S. adversary's space and counterspace capabilities, achieving space superiority. Orbital warfare forces conduct protect-and-defend operations and provide U.S. national decision authorities with response options to deter and, when necessary, defeat orbital threats. The space electromagnetic warfare forces conduct offensive and defensive space control operations. Space Force cyber forces conduct defensive cyber operations to protect space assets. Although the U.S. Space Force is not a cyber force, it does conduct extensive cyber operations under Space Delta 6. The primary focus of Space Force cyber operations is defending U.S. Space Force networks and ensuring the operations of its spacecraft, which are controlled remotely from ground stations. All space operations units have cyber squadrons assigned to defend them and incorporate offensive cyber operations. Additionally, Space Delta 6 is responsible for managing the Satellite Control Network, a global network of antennas used to communicate with the service's spacecraft. The 22nd Space Operations Squadron is responsible for overall operations, with the 21st Space Operations Squadron and 23rd Space Operations Squadron managing the ground station sites at Vandenberg Space Force Base, New Boston Space Force Station, Kaena Point Space Force Station, Diego Garcia, Guam, Greenland, and the United Kingdom. The Space Force's Space Delta 2 operates the United States Space Surveillance Network, tracking 47,000 objects in space as of 2022. Space domain awareness encompasses the identification, characterization, and understanding of any factor associated with the space domain that could affect space operations. Space Delta 2 sensors include the AN/FPS-85 phased array radar at Eglin Air Force Base and the Space Fence radar at Kwajalein Atoll operated by the 20th Space Surveillance Squadron; and a global network of three Ground-based Electro-Optical Deep Space Surveillance telescopes operated by the 15th Space Surveillance Squadron. The 18th Space Defense Squadron, collocated with the Combined Space Operations Center, executes command and control of the Space Surveillance Network and manages the Space Catalog of all objects in Earth orbit. The 19th Space Defense Squadron focuses on objects further in cislunar space, beyond geosynchronous orbit, with a specific focus on supporting NASA's Artemis program and other human spaceflight operations. The Space Force's Space Delta 4 uses orbital spacecraft and ground-based radars to conduct theater and strategic missile warnings for the United States and its international partners. This includes the network of Upgraded Early Warning Radars at Beale Air Force Base, Clear Space Force Station, Cape Cod Space Force Station, Pituffik Space Base, and RAF Fylingdales, alongside the AN/FPQ-16 PARCS radar at Cavalier Space Force Station. Currently, the Space Force is working with the Missile Defense Agency to acquire the Long Range Discrimination Radar at Clear Space Force Station in Alaska.These ground-based radars also contribute to the Space Surveillance Network. Space-based missile warning systems include the Defense Support Program and Space-Based Infrared System (SIBRS) spacecraft, which use infrared sensors to conduct missile defense and missile warning. SIBRS also has a battle space awareness and technical intelligence mission. The Defense Support Program spacecraft are also capable of detecting nuclear detonations, in addition to space and missile launches. The Space Force's Space Delta 8 is the operator of the Global Positioning System and the military's array of communications spacecraft. The Global Positioning System is operated by the 2nd Space Operations Squadron, providing positioning, navigation, and timing information for civilian and military users across the entire world. The Space Force's GPS system has become an integral element of the global information infrastructure, being used in virtually all sectors of the economy, including agriculture, aviation, marine transportation, surveying and mapping, and transit navigation. Its timing signal is used to synchronize global communication systems, electrical power grids, and financial networks. The Global Positioning System also has a secondary mission of carrying nuclear detonation detection sensors. Military satellite communication systems include the Fleet Satellite Communications System, UHF Follow-On satellite, and Mobile User Objective System, operated by the 10th Space Operations Squadron and inherited from the U.S. Navy. The payloads on the Wideband Global SATCOM and Defense Satellite Communications System are operated by the 53rd Space Operations Squadron, a role inherited from the U.S. Army. Finally, spacecraft operations for the Wideband Global SATCOM and Defense Satellite Communications System are conducted by the 4th Space Operations Squadron, in addition to the Milstar and Advanced Extremely High Frequency satellites, which both additionally support command and control of strategic nuclear forces. The Space Force's space launch enterprise is organized under Space Systems Command, with Space Launch Delta 30 managing the Western Range from Vandenberg Space Force Base and Space Launch Delta 45 managing the Eastern Range from Cape Canaveral Space Force Station. The Space Force does not just manage military space launches, but also supports NASA and commercial space launches. Major space launch vehicles flown or scheduled to fly off of Space Force launch ranges include NASA's Space Launch System, SpaceX's Starship, Falcon Heavy, and Falcon 9, and United Launch Alliance's Vulcan, which will replace the Atlas V and Delta IV Heavy. Currently, vehicles for the National Security Space Launch program include the Vulcan, Atlas V, Falcon Heavy, and Falcon 9 rockets. An experimental Air Force Research Laboratory vanguard program that the Space Force leads, Rocket Cargo, is exploring using rockets to supplement naval and air transport to rapidly deliver supplies to forces across the Earth. The SpaceX Starship rocket is one such system currently being explored. The Space Force is organized into three field commands and multiple component field commands, which serve as joint force space component commands for the unified combatant commands. The United States Coast Guard (USCG) is the United States Armed Forces' maritime security, maritime search and rescue, and maritime law enforcement force. It was first established in 1790 as the United States Revenue-Marine and consists of the Regular Coast Guard and the Coast Guard Reserve. Although it has always been one of the six military branches, the Coast Guard is organized under the Department of Homeland Security under the leadership of the secretary of Homeland Security and the deputy secretary of Homeland Security. During times of war, the U.S. Coast Guard can be transferred to the Department of the Navy The Coast Guard itself is led by the commandant of the Coast Guard and vice commandant of the Coast Guard, both admirals advised by the master chief petty officer of the Coast Guard. The Coast Guard has six major operational mission programs, through which it executes its 11 statutory missions: Maritime law enforcement operations focus on protecting the United States maritime borders and assuring its maritime sovereignty. The Coast Guard conducts operations to suppress violations of U.S. law at sea, including counter-illegal migration and transnational organized crime operations. Codified missions executed under the maritime law enforcement program include drug interdiction, migrant interdiction, living marine resources, and other law enforcement. Maritime response operations see the Coast Guard conducting search-and-rescue operations and rescuing mariners responding to maritime disasters. Codified missions include search and rescue and marine environmental protection (response activities). Maritime prevention operations prevent marine casualties and property losses, minimize security risks, and protect the marine environment. The Coast Guard does so by developing and enforcing federal regulations, conducting safety and security inspections, and analyzing port security risk assessments. Codified missions include ports, waterways, and coastal security, marine safety, and marine environmental protection (protection activities). Maritime transport system management ensures a safe, secure, and environmentally sound waterways system. Codified missions include maintaining aids to navigation and ice operations. Maritime security operations include activities to detect, deter, prevent, and disrupt terrorist attacks, and other criminal acts in the U.S. maritime domain. This includes the execution of anti-terrorism, response, and select recovery operations. This mission performs the operational element of the Coast Guard's Ports, Waterways, and Coastal Security mission and complements its Maritime Response and Prevention efforts. Codified missions include ports, waterways, and coastal security (response activities). Coast Guard Defense Operations deploy the Coast Guard globally under the Department of Defense's unified combatant commands, where it operates under the joint force maritime component commands. Codified missions include defense readiness. The U.S. Coast Guard is organized into two area commands that cover the entire globe. Modernization and budget The United States manages the world's largest military budget, followed by the People's Republic of China, India, United Kingdom, and Russia. The James M. Inhofe National Defense Authorization Act for Fiscal Year 2023 established the topline defense budget as $857.9 billion, with the Department of Defense receiving $816.7 billion and the Department of Energy's national security programs receiving $30.3 billion, an 8% increase from Fiscal Year 2022. The Department of the Air Force budget, unlike the Department of the Army or Department of the Navy has a sizable portion of "pass-through." This is money not controlled or used by the Air Force, but is instead passed to other Department of Defense agencies and can be up to 17% of the department's budget. This pass-through allocation gives the impression that the Air Force is the highest funded military department. It is actually the least funded. The Army's modernization efforts, led by Army Futures Command, are centralized into six priorities. Each priority is led by a Cross Functional Team. Long Range Precision Fires is the land service's top modernization priority, focusing on rebuilding its Field Artillery Branch in response to longer range Russian and Chinese artillery systems. The Extended Range Cannon Artillery program is developing a cannon artillery piece that can accurately fire at targets 70 kilometers away, an increase from the 30 kilometer distance of current cannon artillery. The Precision Strike Missile is a surface-to-surface guided missile intended to be fired from the current M270 Multiple Launch Rocket System and M142 HIMARS, replacing their current missiles and doubling the rate of fire. The Army is also working with the Missile Defense Agency, U.S. Navy, and U.S. Air Force to develop a common hypersonic glide body, which the Army will employ as part of the mobile ground launched Long-Range Hypersonic Weapon program. Finally, the Army is working to modify the U.S. Navy's RIM-174 Standard ERAM and UGM-109 Tomahawk land attack cruise missile for ground launch to provide the Army with mid-range artillery capability. The Next Generation Combat Vehicle program is developing a family of fighting vehicles for the Armor Branch to increase firepower, speed, and survivability. The Optionally Manned Fighting Vehicle is intended to replace the M2 Bradley, while the Armored Multi-Purpose Vehicle will replace the M113 armored personnel carriers, which have been used since the Vietnam War. The three variants of the Armored Multi-Purpose Vehicle are general purpose, mission command, and medical treatment. The Mobile Protected Firepower is designed to be a light tank for Infantry Brigade Combat Teams. Finally, the Robotic Combat Vehicles are intended to come in light, medium, and heavy variants that will serve as scouts and escorts for crewed combat vehicles. The Future Vertical Lift program is intended to replace the current helicopter fleet flown by the Army Aviation Branch. The Future Long-Range Assault Aircraft is intended to replace the UH-60 Black Hawk and the Marine Corps UH-1Y Venom, with the Army selecting the Bell V-280 Valor tiltrotor aircraft as the winner. The Future Attack Reconnaissance Aircraft is intended to replace the AH-64 Apache in the attack and reconnaissance roles. The Army is working to modernize its communication networks for the Army Signal Corps, including developing a Unified Network consisting of an integrated tactical network, an integrated enterprise network, and unified network-enabling capabilities. Other sub-efforts include developing a common operating environment, ensuring the network is interoperable with the other services and allied countries, and increasing the mobility and reducing the signature of its command posts. Efforts also include modernizing Global Positioning System technology to provide assured positioning, navigation, and timing, and working with the United States Intelligence Community and commercial space companies to increase the Army's access to space-based intelligence, surveillance, and reconnaissance capabilities. Recognizing that the United States is unlikely to have uncontested air superiority, the Army is undergoing a mass revitalization of its air and missile defense enterprise through the Air Defense Artillery Branch. The first layer of defense is the Ballistic Low-Altitude Drone Engagement, which will be mounted on the Common Remotely Operated Weapon Station and is designed to engage small unmanned aerial vehicles. The second layer is the Multi-Mission High Energy Laser, which will intercept small drones and munitions. The third and fourth layers comprise the Maneuver Air Defense Technology and Next-Generation Fires Radar, which will be integrated into short range air defense systems. The fifth layer puts a High-Energy Laser Tactical Vehicle Demonstrator onto a Medium Tactical Vehicle. While the sixth layer encompasses the Low-Cost Extended-Range Air Defense to supplement the MIM-104 Patriot missiles. Finally, the Army is looking to improve the equipment of its soldiers in the Infantry Branch with the Next Generation Squad Weapon, the Integrated Visual Augmentation System, and the Synthetic Training Environment. In 2022, the Army selected the SIG Sauer's XM7 rifle and XM250 light machine gun to replace the M4 carbine and the M249 light machine gun through the Next Generation Squad Weapon program. The Marine Corps modernization is being executed under the aegis of Force Design 2030, which is intended to return the service to its naval and amphibious roots serving as a "stand-in" force within contested areas of the maritime littorals. As part of this effort, the Marine Corps has begun establishing naval-focused Marine Littoral Regiments, consisting of a Littoral Combat Team, Littoral Anti-Air Battalion, and a Combat Logistics Battalion. The Littoral Combat Team is organized around an infantry battalion with an anti-ship missile battery, focused on conducting sea denial operations in support of the Navy. The Marine Corps is in the process of acquiring the Amphibious Combat Vehicle, which is slated to replace the aging Assault Amphibious Vehicle. The Amphibious Combat Vehicle is intended to support the Marines during amphibious assaults and once they have reached shore. The Marine Corps has also adopted the Naval Strike Missile which is fielded from a modified Joint Light Tactical Vehicle as part of the Marines' artillery battalions. The concept is that small mobile units of Marines would move around different islands and shorelines with these weapons to fire on adversary ships. Marine Corps aviation is also in the process of acquiring the CH-53K King Stallion helicopter for heavy lift, replacing the current CH-53E Super Stallion in the role. The Marine Corps is also looking to replace its UH-1Y Venom helicopters through the Future Vertical Lift program and is in the process of acquiring a significant number of unmanned aerial vehicles, such as the MQ-9 Reaper. Like the Marine Corps, the Navy is in the process of overhauling and modernizing its fleet with a renewed focus. While the Navy is continuing to purchase Arleigh Burke-class destroyers, it is embarking on the DDG(X) program of guided missile destroyers to replace them and the Ticonderoga-class cruisers. The DDG(X) will include directed energy weapons and potentially hypersonic weapons. The Constellation-class frigates will be the first frigates in the U.S. Navy since the Oliver Hazard Perry-class frigates were retired. The Constellation-class frigates are based on the Italian FREMM multipurpose frigates and will replace the littoral combat ships. The Navy is starting development on the SSN(X) attack submarines, intended to replace the Virginia-class and Seawolf-class submarines. The Columbia-class submarines will begin replacing the Ohio-class ballistic missile submarines. The acquisition of the Columbia-class submarines is the first priority of the Navy. With Naval Aviation, the service is continuing to procure additional Gerald R. Ford-class aircraft carriers and F-35C Lightning II stealth fighters. Ultimately, the F/A-XX program is intended to produce a sixth-generation fighter to replace the legacy F/A-18E/F Super Hornets as part of the Carrier Air Wing and is using the Future Vertical Lift program to replace its fleet of SH-60 Seahawk helicopters. The service is also investing heavily in unmanned platforms, such as unmanned surface vehicles, using the Ghost Fleet Overlord to test the concept. It is also fielding unmanned aerial vehicles, such as the land-based MQ-4C Triton for maritime patrol and the carrier-based MQ-25A Stingray for aerial refueling, replacing the F/A-18F in the role. The B-21 Raider stealth bomber is the first new Air Force bomber since the B-2A Spirit. The B-21 will replace the B-2 and the B-1B Lancer, flying alongside the B-52 Stratofortress. The development of the B-21 Raider was led by the Department of the Air Force Rapid Capabilities Office. The service is also developing the LGM-35 Sentinel intercontinental ballistic missile to replace the LGM-30G Minuteman IIIs. The U.S. Air Force is also in the process of developing the Next Generation Air Dominance program, which will produce a sixth generation fighter to replace the F-22 Raptor. The service is also procuring the fourth generation F-15EX Eagle II to replace the aging F-15C Eagle and F-15E Strike Eagle. It is procuring the T-7A Red Hawk trainer jet to replace the 1950s-era T-38 Talon. While not an aircraft, the Air Force is investing in developing the AIM-260 Joint Advanced Tactical Missile to replace or supplement the AIM-120 AMRAAM for its fighter forces. It is also procuring the AGM-181 Long Range Stand Off Weapon to replace the AGM-86 ALCM as a nuclear air-launched cruise missile for the B-21 Raider and the B-52 Stratofortress. The air service is investing in hypersonic weapons, with the AGM-183 Air-Launched Rapid Response Weapon, the Hypersonic Air-breathing Weapon Concept, and the Hypersonic Attack Cruise Missile in development. The U.S. Space Force is undergoing intensive modernization efforts. The Deep Space Advanced Radar Capability (DARC) is intended to track objects in geosynchronous orbit with three sites, one in the United States, one in the Indo-Pacific, and one in Europe. Oracle, a spacecraft developed by the Air Force Research Laboratory for the Space Force, will demonstrate technologies that the space service needs for cislunar domain awareness – tracking objects outside of geosynchronous orbit and between Earth and the Moon. The spacecraft itself will launch to an area of gravitational stability between the Earth and the Moon to conduct operations, using a wide-field sensor and a more sensitive narrow-field sensor to discover and maintain custody of objects operating in this region. Oracle will directly support NASA's Artemis program as it returns to the Moon and track potentially hazardous near-Earth objects in support of planetary defense operations. Also an Air Force Research Laboratory program for the Space Force, Arachne is the keystone experiment in the Space Solar Power Incremental Demonstrations and Research Project, which aims to prove and mature essential technologies for a prototype space-based solar power transmission system capable of powering a forward operating base. Arachne will specifically demonstrate and mature technologies related to more efficient energy generation, radio frequency forming, and radio frequency beaming. Current forward operation bases rely on significant logistics convoys to transport fuel for power – space-based solar power would move these supply lines to space, where they cannot be easily attacked. Space Force provided space-based solar power may transition to civilian use in the same vein as GPS. Other space-based power beaming demonstrations include the Space Power InfraRed Regulation and Analysis of Lifetime (SPIRRAL) and Space Power INcremental DepLoyable Experiment (SPINDLE) experiments. The Navigation Technology Satellite-3 (NTS-3), building on the Space Force's Global Positioning System constellation, is an Air Force Research Laboratory spacecraft that will operate in geosynchronous orbit to test advanced techniques and technologies to detect and mitigate interference to positioning, navigation, and timing capabilities and increase system resiliency for military, civil, and commercial users. NTS-3 is a Vanguard program, described as aiming to deliver potentially game changing capabilities. The Space Force's Rocket Cargo program is another Air Force Research Laboratory Vanguard program, focused on leasing space launch services to quickly transport military materiel to ports across the globe. If proven viable, the Space Force's Space Systems Command will be responsible for transitioning it to a program of record. United States Transportation Command would be the primary user of this capability, rapidly launching up to 100 tons of cargo anywhere in the world. Personnel The U.S. Armed Forces is the world's third largest military by active personnel, after the Chinese People's Liberation Army and the Indian Armed Forces, consisting of 1,359,685 servicemembers in the regular armed forces with an additional 799,845 servicemembers in the reserves as of 28 February 2019.[needs update] While the United States Armed Forces is an all-volunteer military, conscription through the Selective Service System can be enacted at the president's request and Congress' approval, with all males ages 18 through 25 living in the United States required to register with the Selective Service. Although the constitutionality of registering only males for Selective Service was challenged by federal district court in 2019, its legality was upheld by a federal appeals court in 2020. As in most militaries, members of the U.S. Armed Forces hold a rank, either that of officer, warrant officer or enlisted, to determine seniority and eligibility for promotion. Those who have served are known as veterans. Rank names may be different between services, but they are matched to each other by their corresponding paygrade. Officers who hold the same rank or paygrade are distinguished by their date of rank to determine seniority. Officers who serve in certain positions of office of importance set by law, outrank all other officers on active duty of the same rank and paygrade, regardless of their date of rank. Total number of authorized personnel in FY26. Rank in the United States Armed Forces is split into three distinct categories: officers, warrant officers, and enlisted personnel. Officers are the leadership of the military, holding commissions from the president of the United States and confirmed to their rank by the Senate. Warrant officers hold a warrant from the secretaries of the military departments, serving as specialists in certain military technologies and capabilities. Upon promotion to chief warrant officer 2, they gain a commission from the president of the United States. Enlisted personnel constitute the majority of the armed forces, serving as specialists and tactical-level leaders until they become senior non-commissioned officers or senior petty officers. Military ranks across the services can be compared by U.S. Uniformed Services pay grade or NATO rank code. Officers represent the top 18% of the armed forces, serving in leadership and command roles. Officers are divided into three categories: Officers are typically commissioned as second lieutenants or ensigns with a bachelor's degree after several years of training and education or directly commissioned from civilian life into a specific specialty, such as a medical professional, lawyer, chaplain, or cyber specialist. Officers are commissioned through the United States service academies, Reserve Officer Training Corps programs, and the Officer Candidate and Officer Training Schools. During a time of war, officers may be promoted to five-star ranks, with general of the Army, fleet admiral, and general of the Air Force the only five-star ranks currently authorized. Warrant officers are specialists, accounting for only 8% of the officer corps. Warrant officers hold warrants from their service secretary and are specialists and experts in certain military technologies or capabilities. The lowest-ranking warrant officers serve under a warrant, but they receive commissions from the president upon promotion to chief warrant officer 2. They derive their authority from the same source as commissioned officers but remain specialists, in contrast to commissioned officers, who are generalists. There are no warrant officers in the Air Force or Space Force. Warrant officers are typically non-commissioned officers before being selected, with the exception of Army Aviation where any enlisted grade can apply for a warrant. Army warrant officers attend the Army Warrant Officer Candidate School. Enlisted personnel comprise 82% of the armed forces, serving as specialists and tactical leaders. Enlisted personnel are divided into three categories: The rank of senior enlisted advisor is the highest rank in each service, serving as the primary advisor to its service secretary and service chief on enlisted matters. Prior to entering service, enlisted personnel must complete their service's basic training. In the Army, after completing Basic Combat Training, recruits then go to advanced individual training for their military occupational specialty. Upon completion of Marine Corps Recruit Training, Infantry Marines attend the School of Infantry. Non-infantry Marines complete Marine Combat Training before advancing to technical schools for their Military Occupational Specialty. In the Navy, after completing Recruit Training, sailors advance to their "A" schools to complete training for their rating. In the Air Force and Space Force, recruits complete combined Basic Military Training before going to technical training for their Air Force Specialty Codes. In the Coast Guard, after completing Recruit Training, sailors advance to their "A" schools to complete training for their rating. Women such as Deborah Sampson disguised themselves as men to join the military during the Revolutionary War and War of 1812. Some historians estimate that as many as 400 women disguised themselves as men to enlist during the Civil War. The first woman doctor in the Army, Mary Edwards Walker, was commissioned in 1864. In 1901, the United States Army Nurse Corps was established as a quasi-military auxiliary, followed by the United States Navy Nurse Corps in 1908.: 4–9 Women were not accepted in the armed forces outside of medical roles until World War I, when they were allowed to enlist to perform clerical roles. Women were accepted into the Naval Reserve Force in 1917, and the Marine Corps Reserves and Coast Guard in 1918.: 9–10 The War Department forbid Army and National Guard posts from employing any women except as nurses,: 13 but the need for telephone operators overseas during World War I became urgent and hundreds of "Hello Girls" were recruited. These members of the Army Signal Corps wore military uniforms and took the Army oath, but were classified as civilian employees until 1977 when their military service was officially recognized. After the Armistice of 11 November 1918 was signed, enlisted women were demobilized and the nurse corps returned to peacetime strength. The Naval Reserve Act of 1916, which authorized the Navy to enlist "citizens", was changed in 1925 to specify "male citizens".: 16–17 During World War II, all branches of the U.S. military enlisted women. The Woman's Army Auxiliary Corps (WAAC) was established by the Army in 1942 with auxiliary status, and converted to the Women's Army Corps (WAC) in June, 1943.[d]: 24–25 Also formed during this time were the Women's Airforce Service Pilots (WASPs), the Navy's Women Accepted for Volunteer Emergency Services (WAVES), the Marine Corps Women's Reserve, and the Coast Guard Women's Reserve (SPARS). Women experienced combat as nurses in the attack on Pearl Harbor on 7 December 1941, before the U.S. officially entered the war. In 1944, WACs arrived in the Pacific and in Normandy. During the war, 67 Army nurses and 16 Navy nurses were captured and spent three years as Japanese prisoners of war. There were 350,000 American women who served during World War II, and 432 were killed in the line of service. In total, they gained more than 1,500 medals, citations, and commendations. After World War II, demobilization led to the vast majority of serving women being returned to civilian life. By 1946, the Coast Guard had demobilized all of its women members, while the other branches retained some.: 105 Law 625, The Women's Armed Services Act of 1948, was signed by President Harry S. Truman, allowing women to serve in the U.S. Armed Forces in fully integrated units during peace time, albeit with limits that did not apply to men.[e] The intent of Congress was that women should be noncombatants only, but because of the difficulty in defining restrictions for the Army in the law, it was left up to the service secretaries to comply with that intent, although the law did prohibit women from serving aboard ships and on aircraft that engaged in combat missions.: 118–120 The Army retained a separate corps for women (WAC), while the other services integrated women into their organizational structure.: 121 In 1951, Executive Order 10240 was issued, authorizing the services to discharge women who became pregnant or had minor children in the home (including stepchildren, foster children, and siblings).: 125 During the Korean War of 1950–1953, many women served in the Mobile Army Surgical Hospitals. A recruiting project started in 1951 aimed to increase the number of women in the military from 40,000 to 112,000 by July 1952, but it only achieved 46,000. Some of the reasons were the lack of public support for involvement in Korea; public disapproval of women in the military; fewer women in the right age group due to the low birthrate during the Depression; and the higher standards required for women enlistees.: 149–155 [f] In the 1960s, recruiting and training focused on the attractiveness and femininity of women enlistees. Outside of the medical fields, women were mostly assigned to clerical, administrative, and protocol-related jobs. Women who were previously in technical positions were retrained for the few jobs now permitted for women. Of the 61 non-combat occupational groups, only 36 were open to women by 1965.: 180–184 Beginning in 1965, efforts to increase the number of women in the armed forces accompanied concern about the expiration of the Selective Service Act and reduction in enlistment standards to ensure sufficient troops to support the Vietnam War. Public Law 90-130, signed on 8 November 1967, removed the restrictions on female officers in the armed forces and in 1970, two women Army officers were promoted to brigadier general.: 187–203 During the Vietnam War, 600 women served in the country as part of the Air Force, alongside 500 members of the WAC and more than 6,000 medical personnel and support staff.: 205–228 The end of conscription in the early 1970s was a major driver of the expansion of the roles of women in the armed forces. The number of enlisted and commissioned women in the military hit 110,000 by June 1977.: 246–250 The Army Ordnance Corps began accepting female missile technicians in 1974. Female crewmembers and officers were accepted into Field Artillery missile units. The services opened up their Reserve Officers' Training Corps (ROTC) programs to women, and in 1976, women were admitted to the service academies.: 268–270 In 1974, the first six female naval aviators earned their wings as Navy pilots. The Combat Exclusion Policy that prohibited women in combat placed limitations on the pilots' advancement, but at least two retired as captains. The role of women in the U.S. Armed Forces received global media attention during the 1991 Gulf War, though their perception in media was skewed during this time period as little media attention was given to the situations where women faced combat. In 1991, women were permitted to fly military aircraft. Since 1994, women have been permitted to serve on U.S. combat ships. In 2010, the ban on women serving on submarines was lifted. On 3 December 2015, U.S. defense secretary Ashton Carter announced that all military combat positions would become available to women. This gave women access to the roughly 10% of military jobs which were previously closed to them. The various military services were given until January 2016 to provide plans on how they would enforce the policy change. Many women believed this would allow them to improve their positions in the military, since combat experience can contribute to career advancement. Draft registration for females was recommended by the National Commission on Military, National, and Public Service and has been proposed, but never implemented. No woman has ever become a Navy SEAL. In July 2021, the first woman graduated from the Naval Special Warfare (NSW) training program to become a Special Warfare Combatant craft Crewman (SWCC). The SWCC directly supports the SEALs and other special forces units, and are experts in covert insertion and extraction special operation tactics. Despite concerns of a gender gap, all personnel both men and women, at the same rank and time of service, are compensated the same across all branches. On 1 June 2022, ADM Linda L. Fagan assumed command of the U.S. Coast Guard, becoming not only the first woman to serve as Commandant of the Coast Guard, but also the first woman in American history to serve as a service chief in the U.S. Military. A study conducted by the RAND Corporation suggests that women who make the military their careers experience improved rates of promotion. As per the DoD's report on sexual assault within the U.S. Army for fiscal year 2019, 7,825 cases had been reported. This represented a 3% increase relative to the 2018 report. As of 2022, there are 228,966 women in the military, representing 17.5% of the total active duty force. Since 2021, the percentage of women on active duty service has increased slightly, by 0.3%. Since 2005, the population of active duty women has increased by 2.9%. It has been a long-standing policy in the armed forces to limit the political activity by active duty members to voting and making personal campaign donations. However, all other political activities, such as campaigning for a candidate (even outside military facilities), endorsing candidates, soliciting contributions, marching in a partisan parade or wearing the uniform to a partisan event, are prohibited. Order of precedence Under Department of Defense regulation, the various components of the U.S. Armed Forces have a set order of precedence that is based on founding dates. This order is used for the display of service flags as well as the placement of soldiers, marines, sailors, airmen, guardians, and coast guardsmen in formations and parades. While the original founding date of a U.S. Navy was earlier than that of the Marine Corps, the Marine Corps takes precedence due to previous inconsistencies in the Navy's birth date. The Marine Corps has recognized its observed birth date on a more consistent basis. The Second Continental Congress is considered to have established the Navy on 13 October 1775 by authorizing the purchase of ships, but the "Rules for the Regulation of the Navy of the United Colonies" were not established until 27 November 1775, and the Navy also lost funding and was temporarily discontinued in 1785. The Marine Corps was established by an act of the Second Continental Congress on 10 November 1775. The Navy did not officially recognize 13 October 1775 as its birth date until 1972, when then–chief of naval operations Admiral Elmo Zumwalt authorized it to be observed as such. The Coast Guard is normally situated after the Space Force, but if it is moved to the Department of the Navy, then its place in the order of precedence would change to being situated after the Navy and before the Air Force.[failed verification] See also Notes References External links Others: List of current formation types of the United States Marine Corps |
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[SOURCE: https://github.com/mobile] | [TOKENS: 403] |
Navigation Menu Search code, repositories, users, issues, pull requests... Provide feedback We read every piece of feedback, and take your input very seriously. Saved searches Use saved searches to filter your results more quickly To see all available qualifiers, see our documentation. Build from anywhere with GitHub Mobile Collaborate, monitor, and create on mobile with GitHub Copilot for a smarter workflow. GitHub Mobile effortlessly integrates into your day,simplifying collaboration anytime, anywhere. Whether you're reviewing a bug fix or merging code, we've got you covered. From your daily commute to grabbing a coffee, unblock your team on the go. Stay informed on actions that require your attention from anywhere. Assign tasks, review code, and collaborate with Copilot from your mobile device to keep your projects moving—anytime, anywhere. Agent Tasks are now on GitHub Mobile, giving developers a centralized way to manage Copilot coding agent tasks wherever they are. Easily start new tasks and keep track of progress while you’re on the move. Let Copilot code review analyze your pull requests and suggest improvements right from your phone. Catch bugs, ensure best practices, and boost code quality on the go. Assign issues to Copilot and get a ready-to-review pull request. Use comments to refine, iterate, approve and merge—all directly within GitHub Mobile. Ask Copilot to break down complex coding concepts, guide you through unfamiliar codebases, provide insights into both public and your private repositories, and open a new pull request – all in natural language. Effortlessly locate code snippets, navigate repositories, and access content directly from your home screen with global code search. Join the global community of developers using GitHub Mobile to build and collaborate from anywhere. Additional resources Stay up to date with GitHub Mobile blog posts. Triage, collaborate, and manage your work on GitHub from your mobile device. Read more about how you can leverage the power of Copilot Chat in GitHub Mobile. Site-wide Links Get tips, technical guides, and best practices. Twice a month. |
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Contents Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth governor of and then-incumbent United States senator representing California) and his wife, Jane, in memory of their only child, Leland Jr. The university admitted its first students in 1891, opening as a coeducational and non-denominational institution. It struggled financially after Leland died in 1893 and again after much of the campus was damaged by the 1906 San Francisco earthquake. Following World War II, university provost Frederick Terman inspired an entrepreneurial culture to build a self-sufficient local industry (later Silicon Valley). In 1951, Stanford Research Park was established in Palo Alto as the world's first university research park. By 2021, the university had 2,288 tenure-line faculty, senior fellows, center fellows, and medical faculty on staff. The university is organized around seven schools of study on an 8,180-acre (3,310-hectare) campus, one of the largest in the nation. It houses the Hoover Institution, a public policy think tank, and is classified among "R1: Doctoral Universities – Very high research activity". Students compete in 36 varsity sports, and the university is one of eight private institutions in the Atlantic Coast Conference (ACC). Stanford has won 136 NCAA team championships, and was awarded the NACDA Directors' Cup for 25 consecutive years, beginning in 1994. Students and alumni have won 302 Olympic medals (including 153 gold). The university is associated with 94 billionaires, 58 Nobel laureates, 33 MacArthur Fellows, 29 Turing Award winners,[note 1] as well as 7 Wolf Foundation Prize recipients, 2 Supreme Court justices of the United States, and 4 Pulitzer Prize winners. Additionally, its alumni include many Fulbright Scholars, Marshall Scholars, Gates Cambridge Scholars, Rhodes Scholars, and members of the United States Congress. History Stanford University was founded in 1885 by Leland and Jane Stanford as a tribute to the memory of their only child, Leland Stanford Jr. The university officially opened in 1891 on the Stanfords' former Palo Alto farm. Modeled after the great Eastern universities, specifically Cornell University in Ithaca, New York, Stanford was often referred to as the "Cornell of the West" in its early years. This comparison was largely due to a significant portion of its faculty being former Cornell affiliates, including its first president, David Starr Jordan, and its second president, John Casper Branner. Both Cornell and Stanford were among the first to make higher education accessible, non-sectarian, and inclusive of women and men. Cornell is recognized as one of the first American universities to embrace this progressive approach to education, and Stanford quickly followed suit, solidifying its commitment to these ideals. From an architectural perspective, the Stanfords sought to distinguish their university by emulating the style of English university buildings while also incorporating elements of local Mission Revival architecture and Californian heritage. They specified in the founding grant that the buildings should "be like the old adobe houses of the early Spanish days; they will be one-storied; they will have deep window seats and open fireplaces, and the roofs will be covered with the familiar dark red tiles." The Stanfords also hired renowned landscape architect Frederick Law Olmsted, who previously designed the Cornell campus, to design the Stanford campus. When Leland Stanford died in 1893, the continued existence of the university was put in jeopardy due to a federal lawsuit against his estate, but Jane Stanford insisted the university remain in operation throughout the financial crisis. The university suffered major damage from the 1906 San Francisco earthquake; most of the damage was repaired, but a new library and gymnasium were demolished, and some original features of Memorial Church and the Quad were never restored. During the early-20th century, the university added four professional graduate schools. Stanford University School of Medicine was established in 1908 when the university acquired Cooper Medical College in San Francisco; it moved to the Stanford campus in 1959. The university's law department, established as an undergraduate curriculum in 1893, was transitioned into a professional law school starting in 1908 and received accreditation from the American Bar Association in 1923. The Stanford University Graduate School of Education grew out of the Department of the History and Art of Education, one of the original twenty-one departments at Stanford, and became a professional graduate school in 1917. The Stanford Graduate School of Business was founded in 1925 at the urging of then-trustee Herbert Hoover. In 1919, The Hoover Institution on War, Revolution and Peace was started by Herbert Hoover to preserve artifacts related to World War I. The SLAC National Accelerator Laboratory, established in 1962, performs research in particle physics. In the 1940s and 1950s, Frederick Terman, an engineering professor who later became provost, encouraged Stanford engineering graduates to start their own companies and invent products. During the 1950s, he established Stanford Industrial Park, a high-tech commercial campus on university land. Also in the 1950s, William Shockley, co-inventor of the silicon transistor, recipient of the 1956 Nobel Prize for Physics, and later professor of physics at Stanford, moved to the Palo Alto area and founded a company, Shockley Semiconductor Laboratory. The next year, eight of his employees resigned and formed a competing company, Fairchild Semiconductor. The presence of so many high-tech and semiconductor firms helped to establish Stanford and the mid-Peninsula as a hotbed of innovation, eventually named Silicon Valley after the key ingredient in transistors. Shockley and Terman are both often described as the "fathers of Silicon Valley". In the 1950s, Stanford intentionally reduced and restricted Jewish admissions, and for decades, denied and dismissed claims from students, parents, and alumni that they were doing so. Stanford issued its first institutional apology to the Jewish community in 2022 after an internal task force confirmed that the university deliberately discriminated against Jewish applicants, while also misleading those who expressed concerns, including students, parents, alumni, and the ADL. Stanford was once considered a school for "the wealthy", but controversies in later decades damaged its reputation. The 1971 Stanford prison experiment was criticized as unethical, and the misuse of government funds from 1981 resulted in severe penalties for the school's research funding, and the resignation of President Donald Kennedy in 1992. In the 1960s, Stanford rose from a regional university to one of the most prestigious in the United States, "when it appeared on lists of the "top ten" universities in America... This swift rise to performance [was] understood at the time as related directly to the university's defense contracts..." Wallace Sterling was the President from 1949 to 1968 and he oversaw the growth of Stanford from a financially troubled regional university to a financially sound, internationally recognized academic powerhouse, "the Harvard of the West". Achievements during Sterling's tenure included: Land Most of Stanford is on an 8,180-acre (12.8 sq mi; 33.1 km2) campus, one of the largest in the United States.[note 2] It is on the San Francisco Peninsula, in the northwest part of the Santa Clara Valley (Silicon Valley) approximately 37 miles (60 km) southeast of San Francisco and approximately 20 miles (30 km) northwest of San Jose. Stanford received $4.5 billion in 2006 and spent more than $2.1 billion in Santa Clara and San Mateo counties. In 2008, 60% of this land remained undeveloped. Stanford's main campus includes a census-designated place within unincorporated Santa Clara County, although some of the university land (such as the Stanford Shopping Center and the Stanford Research Park) is within the city limits of Palo Alto. The campus also includes much land in unincorporated San Mateo County (including the SLAC National Accelerator Laboratory and the Jasper Ridge Biological Preserve), as well as within the city limits of Menlo Park (Stanford Hills neighborhood), Woodside, and Portola Valley. The central campus includes a seasonal lake (Lake Lagunita, an irrigation reservoir), home to the vulnerable California tiger salamander. As of 2012, Lake Lagunita was often dry and the university had no plans to artificially fill it. Heavy rains in January 2023 refilled Lake Lagunita to up to 8 feet of depth. Two other reservoirs, Searsville Lake on San Francisquito Creek and Felt Lake, are on more remote sections of the founding grant. The central campus is adjacent to Palo Alto, bounded by El Camino Real, Stanford Avenue, Junipero Serra Blvd, and Sand Hill Road, off State Route 82. The United States Postal Service has assigned it two ZIP Codes: 94305 for campus mail and 94309 for P.O. box mail. It lies within area code 650. On the founding grant: Off the founding grant: Many Stanford faculty members live in the "Faculty Ghetto", within walking or biking distance of campus. The Faculty Ghetto is composed of land owned by Stanford. Similar to a condominium, the houses can be bought and sold to other Stanford faculty but the land under the houses is leased for 51 years with the possibility of extensions. Houses in the "Ghetto" appreciate and depreciate, but not as rapidly as overall Silicon Valley values. Some of the land is managed to provide revenue for the university such as the Stanford Shopping Center and the Stanford Research Park. Stanford land is also leased for a token rent by the Palo Alto Unified School District for several schools including Palo Alto High School and Gunn High School. El Camino Park, the oldest Palo Alto city park, is also on Stanford land. Stanford also has the Stanford Golf Course, and Stanford Red Barn Equestrian Center, used by Stanford athletics though the golf course can also be used by the general public. Contemporary campus landmarks include the Main Quad and Memorial Church, the Cantor Center for Visual Arts and the Bing Concert Hall, the Stanford Mausoleum with the nearby Angel of Grief, Hoover Tower, the Rodin Sculpture Garden, the Papua New Guinea Sculpture Garden, the Arizona Cactus Garden, the Stanford University Arboretum, Green Library and the Dish. Frank Lloyd Wright's 1937 Hanna–Honeycomb House and the 1919 Lou Henry Hoover House are both listed on the National Register of Historic Places. White Memorial Fountain (also known as "The Claw") between the Stanford Bookstore and the Old Union is a popular place to meet and to engage in the Stanford custom of "fountain hopping"; it was installed in 1964 and designed by Aristides Demetrios after a national competition as a memorial for two brothers in the class of 1949, William White and John White II, one of whom died before graduating and one shortly after in 1952. Administration and organization Stanford is a private, non-profit university administered as a corporate trust governed by a privately appointed board of trustees with a maximum membership of 38.[note 3] Trustees serve five-year terms (not more than two consecutive terms) and meet five times annually. A new trustee is chosen by the current trustees by ballot. The Stanford trustees also oversee the Stanford Research Park, the Stanford Shopping Center, the Cantor Center for Visual Arts, Stanford University Medical Center, and many associated medical facilities (including the Lucile Packard Children's Hospital). The board appoints a president to serve as the chief executive officer of the university, to prescribe the duties of professors and course of study, to manage financial and business affairs, and to appoint nine vice presidents. Richard Saller became the interim president in September 2023. On April 4, 2024, the board of trustees announced that Jonathan Levin would become the thirteenth president on August 1, 2024. The provost is the chief academic and budget officer, to whom the deans of each of the seven schools report. Jenny Martinez became the fourteenth provost in October 2023. The university is organized into seven academic schools. The schools of Humanities and Sciences (twenty-seven departments), Engineering (nine departments), and Sustainability (nine departments) have both graduate and undergraduate programs while the Schools of Law, Medicine, Education, and Business have graduate programs only. The powers and authority of the faculty are vested in the Academic Council, which is made up of tenure and non-tenure line faculty, research faculty, senior fellows in some policy centers and institutes, the president of the university, and some other academic administrators. But most matters are handled by the Faculty Senate, made up of 54 elected representatives of the faculty for 2021. The Associated Students of Stanford University (ASSU) is the student government for Stanford and all registered students are members. Its elected leadership consists of the Undergraduate Senate elected by the undergraduate students, the Graduate Student Council elected by the graduate students, and the President and Vice President elected as a ticket by the entire student body. Stanford is the beneficiary of a special clause in the California Constitution, which explicitly exempts Stanford property from taxation so long as the property is used for educational purposes. Stanford's endowment includes real estate and other investments valued at $36.5 billion as of August 2023, and is one of the four largest academic endowments in the United States. The endowment consists of $29.9 billion in a merged pool of assets and $6.6 billion of real estate near the main campus. Stanford is the largest landowner in the Silicon Valley Payouts from the endowment covered approximately 22% of university expenses in the 2023 fiscal year. Since inception, the university has been the beneficiary of large donations. The endowment began in 1885, six years before the opening of the university, when Leland Stanford and his wife Jane conveyed approximately $20 million to the university. The university's pioneering of technology intellectual property transfer created both direct investments and enabled a unique pipeline of mega-donors including from alumni-founded companies with Google (Sergey Brin and Larry Page), Nike (Phil Knight), Hewlett-Packard (David Packard and Bill Hewlett), and Sun Microsystems (Vinod Kohsla) as examples. Further, the university's global reputation and continued leadership in technology has attracted large donations from prominent figures such as the co-founder of Netscape (Jim Clark), founder of SAP SE (Hasso Plattner), co-founder of Andreessen Horowitz (Marc Andreessen and Laura Arillaga-Andreessen), chairman of Kleiner Perkins (John Doerr and his wife Ann). Academics Stanford is considered by US News to be 'most selective' with an acceptance rate of 4%, one of the lowest among US universities. Half of the applicants accepted to Stanford have an SAT score between 1440 and 1570 or an ACT score between 32 and 35, typically with a GPA of 3.94 or higher. Admissions officials consider a student's grade point average to be an important academic factor, with emphasis on an applicant's high school class rank and letters of recommendation. In terms of non-academic materials as of 2019, Stanford ranks extracurricular activities, talent/ability and character/personal qualities as 'very important' in making first-time, first-year admission decisions, while ranking the interview, whether the applicant is a first-generation university applicant, legacy preferences, volunteer work and work experience as 'considered'. Of those students accepted to Stanford's Class of 2026, 1,736 chose to attend, of which 21% were first-generation college students. Stanford's admission process is need-blind for U.S. citizens and permanent residents; while it is not need-blind for international students, 64% are on need-based aid, with an average aid package of $31,411. In 2012, the university awarded $126 million in need-based financial aid to 3,485 students, with an average aid package of $40,460. Eighty percent of students receive some form of financial aid. Stanford has a no-loan policy. For undergraduates admitted starting in 2015, Stanford waives tuition, room, and board for most families with incomes below $65,000, and most families with incomes below $125,000 are not required to pay tuition; those with incomes up to $150,000 may have tuition significantly reduced. Seventeen percent of students receive Pell Grants, a common measure of low-income students at a college. In 2022, Stanford started its first dual-enrollment computer science program for high school students from low-income communities, as a pilot project which then inspired the founding of the Qualia Global Scholars Program. Stanford plans to expand the program to include courses in Structured Liberal Education and writing. Stanford follows a quarter system with the autumn quarter usually beginning in late September and the spring quarter ending in mid-June. The full-time, four-year undergraduate program has arts and sciences focus with high graduate student coexistence. Stanford is accredited by the Western Association of Schools and Colleges with the latest review in 2023. Stanford is classified among "R1: Doctoral Universities – Very high research activity." The university's research expenditure in fiscal years of 2021/22 was $1.82 billion and the total number of sponsored projects was 7,900. By 2016, the Office of the Vice Provost and Dean of Research oversaw eighteen independent laboratories, centers, and institutes. Kathryn Ann Moler is the key person for leading those research centers for choosing problems, faculty members, and students. Funding is also provided for undergraduate and graduate students by those labs, centers, and institutes for collaborative research. Other Stanford-affiliated institutions include the SLAC National Accelerator Laboratory (originally the Stanford Linear Accelerator Center), the Stanford Research Institute (an independent institution which originated at the university), the Hoover Institution (a conservative think tank), and the Hasso Plattner Institute of Design (a multidisciplinary design school in cooperation with the Hasso Plattner Institute of University of Potsdam that integrates product design, engineering, and business management education). Stanford is home to the Martin Luther King Jr. Research and Education Institute, which grew out of and still contains the Martin Luther King Jr. Papers Project, a collaboration with the King Center to publish the King papers held by the King Center. It also runs the John S. Knight Fellowship for Professional Journalists and the Center for Ocean Solutions, which brings together marine science and policy to address challenges facing the ocean. It focuses on five points: climate change, overfishing, coastal development, pollution, and plastics. Together with UC Berkeley and UC San Francisco, Stanford is part of the Biohub, a new medical science research center founded in 2016 by a $600 million commitment from Facebook CEO and founder Mark Zuckerberg and pediatrician Priscilla Chan. This medical research center is working for designing advanced-level health care units. By 2014, Stanford University Libraries (SUL) had twenty-four libraries in total. The Hoover Institution Library and Archives is a research center based on history of 20th-century. Stanford University Libraries (SUL) held a collection of more than 9.3 million volumes, nearly 300,000 rare or special books, 1.5 million e-books, 2.5 million audiovisual materials, 77,000 serials, nearly 6 million microform holdings, and thousands of other digital resources. The main library in the SU library system is the Green Library, which also contains various meeting and conference rooms, study spaces, and reading rooms. Lathrop Library (previously Meyer Library, demolished in 2015), holds various student-accessible media resources and houses one of the largest East Asia collections with 540,000 volumes. Stanford University Press, founded in 1892, published about 130 books per year has printed more than 3,000 books. It also has fifteen subject areas. The Stanford Encyclopedia of Philosophy is a leading online encyclopedia and academic resource on the subject of philosophy, published and maintained by the university. The encyclopedia was founded by Stanford senior researcher Edward Zalta in 1995. Stanford is home to the Cantor Center for Visual Arts, a museum established with the help of art collector B. Gerald Cantor. It today consists of twenty-four galleries, sculpture gardens, terraces, and a courtyard first established in 1891 by Jane and Leland Stanford as a memorial to their only child. The university's collection of works by Auguste Rodin is among the largest in the world, with as many as 200 sculptures at the Cantor Center alone. These include an original bronze cast of The Thinker granted residence at Stanford by Cantor in 1988, with the university expected to attain full ownership sometime in the future. The Stanford Thinker has been loaned for viewing around the world and features across the university's iconography and culture, including the logo of the Encyclopedia of Philosophy. The Thomas Welton Stanford Gallery, which was built in 1917, serves as a teaching resource for the Department of Art & Art History as well as an exhibition venue. In 2014, Stanford opened the Anderson Collection, a new museum focused on postwar American art and founded by the donation of 121 works by food service moguls Mary and Harry Anderson. There are outdoor art installations throughout the campus, primarily sculptures, but some murals as well. The Papua New Guinea Sculpture Garden near Roble Hall features wood carvings and "totem poles". The Stanford music department sponsors many ensembles, including five choirs, the Stanford Symphony Orchestra, Stanford Taiko, and the Stanford Wind Ensemble. Extracurricular activities include theater groups such as Ram's Head Theatrical Society, the Stanford Improvisors, the Stanford Shakespeare Company, and the Stanford Savoyards, a group dedicated to performing the works of Gilbert and Sullivan. Stanford is also host to ten a cappella groups, including the Mendicants (Stanford's first), Counterpoint (the first all-female group on the West Coast), the Harmonics, the Stanford Fleet Street Singers, Talisman, Everyday People, and Raagapella. Stanford is highly ranked by U.S. News & World Report, Times Higher Education, and QS World University Rankings. As noted in The Wall Street Journal's 2024 rankings, "the usual players are almost always going to come out on top: The Princetons, the Stanfords, the Yales, the Harvards. They will jockey for those first few spots on whatever ranking you happen to be looking." In 2022, Washington Monthly ranked Stanford at 1st position in their annual list of top universities in the United States. In 2019, Stanford University took 1st place on Reuters' list of the World's Most Innovative Universities for the fifth consecutive year. Stanford Graduate School of Business has consistently been both the most selective business school in the world and consistently ranked 1st in the list of best business schools year-over-year consecutively by various reputed studies including Bloomberg Businessweek and U.S. News & World Report for 2024. Stanford Law School is also consistently been amongst the two most selective law schools in the world and consistently ranked 1st in the list of best law schools year-over-year consecutively for 2024 in U.S. News & World Report. In a 2022 survey by The Princeton Review, Stanford was ranked 1st among the top ten "dream colleges" of America, and was considered to be the ultimate "dream college" of both students and parents. From polls of college applicants done by The Princeton Review, every year from 2013 to 2020 the most commonly named "dream college" for students was Stanford; separately, parents, too, most frequently named Stanford their ultimate "dream college". The Academic Ranking of World Universities (ARWU) ranked Stanford second in the world (after Harvard) most years from 2003 to 2024. Times Higher Education recognizes Stanford as one of the world's "six super brands" on its World Reputation Rankings, along with Berkeley, Cambridge, Harvard, MIT, and Oxford. Discoveries and innovation Stanford is one of the most successful universities worldwide in creating companies and licensing its inventions to existing companies, and it is often considered the model for technology transfer. Stanford's Office of Technology Licensing is responsible for commercializing university research, intellectual property, and university-developed projects. The university is described as having a strong venture culture in which students are encouraged, and often funded, to launch their own companies. Companies founded by Stanford alumni generate more than $2.7 trillion in annual revenue and have created some 5.4 million jobs since the 1930s. When combined, these companies would form the tenth-largest economy in the world. Some notable companies closely associated with Stanford and their connections include: Student life Stanford enrolled 6,996 undergraduate and 10,253 graduate students in the 2019–2020 school year. Women made up 50.4% of undergraduates and 41.5% of graduate students. In the same academic year, the freshman retention rate was 99%. Stanford awarded 1,819 undergraduate degrees, 2,393 master's degrees, 770 doctoral degrees, and 3270 professional degrees in the 2018–2019 school year. The four-year graduation rate for the class of 2017 cohort was 72.9%, and the six-year rate was 94.4%. The relatively low four-year graduation rate is a function of the university's coterminal degree (or "coterm") program, which allows students to earn a master's degree as a 1-to-2-year extension of their undergraduate program. In 2010, 15% of undergraduates were first-generation students. By 2013, 89% of undergraduate students lived in on-campus university housing. First-year undergraduates are required to live on campus, and all undergraduates are guaranteed housing for all four undergraduate years. Undergraduates live in 80 different houses, including dormitories, co-ops, row houses, and fraternities and sororities. At Manzanita Park, 118 mobile homes were installed as "temporary" housing from 1969 to 1991, but have become the site of newer dorms Castano, Kimball, Lantana, and the Humanities House, completed in 2015. Most student residences are just outside the campus core, within ten minutes (on foot or bike) of most classrooms and libraries. Some are reserved for freshmen, sophomores, or upper-class students and some are open to all four classes. Most residences are co-ed; seven are all-male fraternities, three are all-female sororities, and there is also one all-female non-sorority house, Roth House. In most residences, men and women live on the same floor, but some have single-gender floors. Several residences are considered "theme" houses; predating the current classification system are Columbae (Social Change Through Nonviolence, since 1970), and Synergy (Exploring Alternatives, since 1972). The Academic, Language, and Culture Houses include EAST (Education and Society Themed House), Hammarskjöld (International Themed House), Haus Mitteleuropa (Central European Themed House), La Casa Italiana (Italian Language and Culture), La Maison Française (French Language and Culture House), Slavianskii Dom (Slavic/East European Themed House), Storey (Human Biology Themed House), and Yost (Spanish Language and Culture). Cross-Cultural Themed Houses include Casa Zapata (Chicano/Latino Theme in Stern Hall), Muwekma-tah-ruk (American Indian/Alaska Native, and Native Hawaiian Themed House), Okada (Asian-American Themed House in Wilbur Hall), and Ujamaa (Black/African-American Themed House in Lagunita Court). Focus Houses include Freshman-Sophomore College (Academic Focus), Branner Hall (Community Service), Kimball (Arts & Performing Arts), Crothers (Global Citizenship), and Toyon (Sophomore Priority). Co-ops or "Self-Ops" are another housing option. These houses feature cooperative living, where residents and eating associates each contribute work to keep the house running, such as cooking meals or cleaning shared spaces. These houses have unique themes around which their community is centered. Many co-ops are hubs of music, art and philosophy. The co-ops on campus are 576 Alvarado Row (formerly Chi Theta Chi), Columbae, Enchanted Broccoli Forest (EBF), Hammarskjöld, Kairos, Terra (the unofficial LGBT house), and Synergy. Phi Sigma, at 1018 Campus Drive was formerly Phi Sigma Kappa fraternity, but in 1973 became a Self-Op. By 2015, 55 percent of the graduate student population lived on campus. Stanford also subsidizes off-campus apartments in nearby Palo Alto, Menlo Park, and Mountain View for graduate students who are guaranteed on-campus housing but are unable to live on campus due to a lack of space. In 2016, Stanford had sixteen male varsity sports and twenty female varsity sports, nineteen club sports, and about 27 intramural sports. The Stanford Tree is the Stanford Band's mascot and the unofficial mascot of Stanford University. Stanford's team name is the "Cardinal", referring to the vivid Stanford Cardinal Red color (not the common songbird as at several other schools); the university does not have an official mascot. The Tree has been called one of America's most bizarre and controversial college mascots; it regularly appears at the top of Internet "worst mascot" lists, but has also appeared on at least one list of top mascots. The Tree is a member of the Leland Stanford Junior University Marching Band (LSJUMB) and appears at football games, basketball games, and other events where the band performs. In 1930, following a unanimous vote by the executive committee for the Associated Students, the athletic department adopted a new mascot (Indian). The Indian symbol and name were dropped by President Richard Lyman in 1972, after objections from Native American students and a vote by the student senate. Stanford is a member of the Atlantic Coast Conference in most sports, the Mountain Pacific Sports Federation in several other sports, and the America East Conference in field hockey with the participation in the inter-collegiate NCAA's Division I FBS. The official color of the university is Stanford Cardinal Red. From 1930 until 1972, Stanford's sports teams had been known as the Indians and during the period from 1951 to 1972, Prince Lightfoot (portrayed by Timm Williams, a member of the Yurok tribe) was the official mascot. But in 1972, Native American students and staff members successfully lobbied University President Richard Lyman to abolish the "Indian" name along with what they had come to perceive as an offensive and demeaning mascot. Stanford's teams reverted unofficially to the name "Cardinal", the color that had represented the school before 1930. From 1972 until 1981, Stanford's official nickname was the Cardinal, but, during this time, there was debate among students and administrators concerning what the mascot and team name should be. A 1972 student referendum on the issue was in favor of restoring the Indian, while a second 1975 referendum was against. The 1975 vote included new suggestions, many alluding to the industry of the school's founder, tycoon Leland Stanford: the Robber Barons, the Sequoias, the Trees, the Cardinals, the Railroaders, the Spikes, and the Huns. Its traditional sports rival is the University of California, Berkeley. The winner of the annual "Big Game" between the Cal and Cardinal football teams gains custody of the Stanford Axe. As of November 20, 2025, Stanford has won 137 NCAA team championships, more than any other school. Stanford has won at least one NCAA team championship each academic year for 49 consecutive years, from 1976–77 through to 2024–25. As of January 1, 2022, Stanford athletes have also won 529 NCAA individual championships. No other Division I school is within 100 of Stanford's total. Stanford have won 25 consecutive NACDA Directors' Cups, from 1994–1995 through to 2018–19, awarded annually to the most successful overall college sports program in the nation. 177 Stanford-affiliated athletes have won a total of 296 Summer Olympic medals (150 gold, 79 silver, 67 bronze), including 26 medals at the 2020 Tokyo Olympics and 27 medals at the 2016 Rio de Janeiro Olympics. In the 2020 Tokyo Summer Olympics, Stanford-affiliated athletes won 26 medals, more than any other university. Students and staff at Stanford are of many different religions. The Stanford Office for Religious Life's mission is "to guide, nurture and enhance spiritual, religious and ethical life within the Stanford University community" by promoting enriching dialogue, meaningful ritual, and enduring friendships among people of all religious backgrounds. It is headed by a dean with the assistance of a senior associate dean and an associate dean. Stanford Memorial Church, in the center of campus, has a Sunday University Public Worship service (UPW) usually in the "Protestant Ecumenical Christian" tradition where the Memorial Church Choir sings and a sermon is preached usually by one of the Stanford deans for Religious Life. UPW sometimes has multifaith services. In addition, the church is used by the Catholic community and the other Christian denominations at Stanford. Weddings happen most Saturdays and the university has allowed blessings of same-gender relationships and legal weddings. In addition to the church, the Office for Religious Life has a Center for Inter-Religious Community, Learning, and Experiences (CIRCLE) on the third floor of Old Union. It offers a common room, an interfaith sanctuary, a seminar room, a student lounge area, and a reading room, as well as offices housing a number of Stanford Associated Religions (SAR) member groups and the Senior Associate Dean and Associate Dean for Religious Life. Most though not all religious student groups belong to SAR. The SAR directory includes organizations that serve atheist, Bahá'í, Buddhist, Christian, Hindu, Muslim, Jewish, and Sikh groups, though these groups vary year by year. The Windhover Contemplation Center was dedicated in October 2014, and was intended to provide spiritual sanctuary for students and staff in the midst of their course and work schedules; the center displays the "Windhover" paintings by Nathan Oliveira, the late Stanford professor and artist. Some religions have a larger and more formal presence on campus in addition to the student groups; these include the Catholic and Hillel communities at Stanford. Fraternities and sororities have been active on the Stanford campus since 1891 when the university first opened. In 1944, University President Donald Tresidder banned all Stanford sororities due to extreme competition. However, following Title IX, the Board of Trustees lifted the 33-year ban on sororities in 1977. Students are not permitted to join a fraternity or sorority until spring quarter of their freshman year. Stanford has thirty-one Greek organizations, including fourteen sororities and sixteen fraternities. Nine of the Greek organizations were housed (eight in University-owned houses and one, Sigma Chi, in their own house, although the land is owned by the university). Five chapters were members of the African American Fraternal and Sororal Association, eleven chapters were members of the Interfraternity Council, seven chapters belonged to the Intersorority Council, and six chapters belonged to the Multicultural Greek Council. Stanford has more than 600 student organizations. Groups are often, though not always, partially funded by the university via allocations directed by the student government organization, the ASSU. These funds include "special fees", which are decided by a Spring Quarter vote by the student body. Groups span athletics and recreation, careers/pre-professional, community service, ethnic/cultural, fraternities and sororities, health and counseling, media and publications, the arts, political and social awareness, and religious and philosophical organizations. In contrast to many other selective universities, Stanford policy mandates that all recognized student clubs be "broadly open" for all interested students to join. The Stanford Daily is a student-run daily newspaper and has been published since the university was founded in 1892. The student-run radio station, KZSU Stanford 90.1 FM, features freeform music programming, sports commentary, and news segments; it started in 1947 as an AM radio station. The Stanford Review is a conservative student newspaper founded in 1987. The Fountain Hopper (FoHo) is a financially independent, anonymous student-run campus rag publication, notable for having broken the Brock Turner story. Stanford hosts numerous environmental and sustainability-oriented student groups, including Students for a Sustainable Stanford, Students for Environmental and Racial Justice, and Stanford Energy Club. Stanford is a member of the Ivy Plus Sustainability Consortium, through which it has committed to best-practice sharing and the ongoing exchange of campus sustainability solutions along with other member institutions. Stanford is also home to a large number of pre-professional student organizations, organized around missions from startup incubation to paid consulting. The Business Association of Stanford Entrepreneurial Students (BASES) is one of the largest professional organizations in Silicon Valley, with over 5,000 members. Its goal is to support the next generation of entrepreneurs. StartX is a non-profit startup accelerator for student and faculty-led startups. It is staffed primarily by students. Stanford Women In Business (SWIB) is an on-campus business organization, aimed at helping Stanford women find paths to success in the generally male-dominated technology industry. Stanford Marketing is a student group that provides students hands-on training through research and strategy consulting projects with Fortune 500 clients, as well as workshops led by people from industry and professors in the Stanford Graduate School of Business. Stanford Finance provides mentoring and internships for students who want to enter a career in finance. Stanford Pre Business Association is intended to build connections among industry, alumni, and student communities. Stanford is also home to several academic groups focused on government and politics, including Stanford in Government and Stanford Women in Politics. The Stanford Society for Latin American Politics is Stanford's first student organization focused on the region's political, economic, and social developments, working to increase the representation and study of Latin America on campus. Former guest speakers include José Mujica and Gustavo Petro. Other groups include: Stanford's Department of Public Safety is responsible for law enforcement and safety on the main campus. Its deputy sheriffs are peace officers by arrangement with the Santa Clara County Sheriff's Office. The department is also responsible for publishing an annual crime report covering the previous three years as required by the Clery Act. Fire protection has been provided by contract with the Palo Alto Fire Department since 1976. Murder is rare on the campus, although a few cases have been notorious, including the 1974 murder of Arlis Perry in Stanford Memorial Church, which was not solved until 2018. Also infamous was Theodore Streleski's murder of his faculty advisor in 1978. In 2014, Stanford was the tenth highest in the nation in "total of reports of rape" on their main campus, with 26 reports of rape. In Stanford's 2015 Campus Climate Survey, 4.7 percent of female undergraduates reported experiencing sexual assault as defined by the university, and 32.9 percent reported experiencing sexual misconduct. According to the survey, 85% of perpetrators of misconduct were Stanford students and 80% were men. Perpetrators of sexual misconduct were frequently aided by alcohol or drugs, according to the survey: "Nearly three-fourths of the students whose responses were categorized as sexual assault indicated that the act was accomplished by a person or persons taking advantage of them when they were drunk or high, according to the survey. Close to 70 percent of students who reported an experience of sexual misconduct involving nonconsensual penetration and/or oral sex indicated the same." Associated Students of Stanford and student and alumni activists with the anti-rape group Stand with Leah criticized the survey methodology for downgrading incidents involving alcohol if students did not check two separate boxes indicating they were both intoxicated and incapacity while sexually assaulted. Reporting on the Brock Turner rape case, a reporter from The Washington Post analyzed campus rape reports submitted by universities to the U.S. Department of Education, and found that Stanford was one of the top ten universities in campus rapes in 2014, with 26 reported that year, but when analyzed by rapes per 1000 students, Stanford was not among the top ten. On the night of January 17–18, 2015, 22-year-old Chanel Miller, who was visiting the campus to attend a party at the fraternity Kappa Alpha Order, was sexually assaulted by Brock Turner, a nineteen-year-old freshman student-athlete from Ohio. Two Stanford graduate students witnessed the attack and intervened; when Turner attempted to flee the two held him down on the ground until police arrived. Stanford immediately referred the case to prosecutors and offered Miller counseling, and within two weeks had barred Turner from campus after conducting an investigation. Turner was convicted on three felony charges in March 2016 and in June 2016 he received a jail sentence of six months and was declared a sex offender, requiring him to register as such for the rest of his life; prosecutors had sought a six-year prison sentence out of the maximum 14 years that was possible. The case and the relatively lenient sentence drew nationwide attention. Two years later, the judge in the case, Stanford graduate Aaron Persky, was recalled by the voters. In February 2015, Elise Clougherty filed a sexual assault and harassment lawsuit against venture capitalist Joe Lonsdale. Lonsdale and Clougherty entered into a relationship in the spring of 2012 when she was a junior and he was her mentor in a Stanford entrepreneurship course. By the spring of 2013 Clougherty had broken off the relationship and filed charges at Stanford that Lonsdale had broken the Stanford policy against consensual relationships between students and faculty and that he had sexually assaulted and harassed her, which resulted in Lonsdale being banned from Stanford for 10 years. Lonsdale challenged Stanford's finding that he had sexually assaulted and harassed her and Stanford rescinded that finding and the campus ban in the fall of 2015. Clougherty withdrew her suit that fall as well. Notable people Stanford's current community of scholars includes: Stanford's current and former faculty includes 58 Nobel laureates, as well as 29 winners of the Turing Award, the so-called "Nobel Prize in computer science", comprising one-third of the awards given in its 44-year history. The university also has 27 ACM Fellows and is affiliated with four Gödel Prize winners, four Knuth Prize recipients, ten IJCAI Computers and Thought Award winners, and fifteen Grace Murray Hopper Award winners for their work in the foundations of computer science. Stanford alumni have started many companies and, according to Forbes, Stanford has produced the second highest number of billionaires of all universities. By 2022, 128 Stanford students or alumni have also been named Rhodes Scholars. See also Explanatory notes References Further reading External links |
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Contents Suez Crisis The Suez Crisis,[a] also known as the second Arab–Israeli war, the Tripartite Aggression[b] in the Arab world and the Sinai War[c] in Israel,[d] was a British–French–Israeli invasion of Egypt in 1956. Israel invaded on 29 October, with the primary objective of re-opening the Straits of Tiran and the Gulf of Aqaba as the recent tightening of the eight-year-long Egyptian blockade further prevented Israeli passage. After issuing a joint ultimatum for a ceasefire, the United Kingdom and France joined the Israelis on 31 October, seeking to depose Egyptian president Gamal Abdel Nasser and regain control of the Suez Canal, which Nasser had nationalised earlier in the year.[e] Shortly after the invasion began, the three countries came under heavy political pressure from both the United States and the Soviet Union, as well as from the United Nations, eventually prompting their withdrawal from Egypt. The crisis demonstrated that the United Kingdom and France could no longer pursue their independent foreign policy without consent from the United States. Israel's four-month-long occupation of the Egyptian-occupied Gaza Strip and Egypt's Sinai Peninsula enabled it to attain freedom of navigation through the Straits of Tiran, but the Suez Canal was closed from October 1956 to March 1957. The crisis strengthened Nasser's standing and led to international humiliation for the British—with historians arguing that it signified the end of its role as a superpower—as well as the French amid the Cold War. As a result of the conflict, the UN established an emergency force to police and patrol the Egypt–Israel border. For his diplomatic efforts in resolving the conflict through UN initiatives, Canadian external affairs minister Lester B. Pearson received a Nobel Peace Prize. Analysts have argued that the crisis may have emboldened the USSR, prompting the Soviet invasion of Hungary. Background The Suez Canal opened in 1869, financed by the French and Egyptian governments. The canal was operated by the Suez Company, an Egyptian-chartered company; the area surrounding the canal remained sovereign Egyptian territory. The canal was strategically important, as it provided the shortest ocean link between the Mediterranean Sea and the Indian Ocean. In 1875, as a result of debt and financial crisis, Egypt was forced to sell its shares in the operating company to the British government. They obtained a 44% share in the company for £4 million (equivalent to £476 million in 2023). With the 1882 invasion and occupation of Egypt, the UK took de facto control of the country as well as the canal, its finances and operations. The 1888 Convention of Constantinople declared the canal a neutral zone under British protection. In ratifying it, the Ottoman Empire agreed to permit international shipping to pass freely through the canal, in time of war and peace. Despite this convention, Britain closed the canal on several occasions. During the Russo-Japanese War of 1904–05, the British denied the Russian Baltic Fleet use of the canal after the Dogger Bank incident and forced it to sail around Africa, giving the Imperial Japanese Armed Forces time to consolidate their position. During the First World War, Britain and France closed the canal to non-Allied shipping. In the aftermath of the Second World War, Britain's military complex at Suez was one of the largest military installations in the world. The Suez base was an important part of Britain's strategic position in the Middle East; however, it became a source of growing tension in Anglo-Egyptian relations. The canal continued to be strategically important after the Second World War for oil shipment. Western Europe then[when?] imported two million barrels per day from the Middle East, 1,200,000 by tanker through the canal, and another 800,000 via pipeline from the Persian Gulf (Trans-Arabian Pipeline) and Kirkuk (Kirkuk-Baniyas pipeline) to the Mediterranean. These pipeline routes were prone to instability, which led British leaders to prefer to use the sea route through the canal. Egypt's domestic politics were experiencing a radical change. Unrest began to manifest in the growth of radical political groups, such as the Muslim Brotherhood in Egypt, and an increasingly hostile attitude towards Britain and its presence. Added to this anti-British fervour was the role Britain had played in the creation of Israel. In October 1951, the Egyptian government unilaterally abrogated the Anglo-Egyptian Treaty of 1936, the terms of which granted Britain a lease on the Suez base for 20 more years. Britain refused to withdraw from Suez, relying upon its treaty rights, as well as the presence of the Suez garrison. This resulted in an escalation in violent hostility towards Britain and its troops in Egypt.[citation needed] In January 1952, British forces attempted to disarm a troublesome auxiliary police force barracks in Ismailia, resulting in the deaths of 41 Egyptians. This led to anti-Western riots in Cairo resulting in damage to property and the deaths of foreigners. This proved to be a catalyst for the removal of the Egyptian monarchy. On 23 July 1952 a military coup by the Egyptian nationalist 'Free Officers Movement'—led by Muhammad Neguib and Gamal Abdul Nasser—overthrew King Farouk. After a brief regency under the nominal reign of the infant Fuad II, the monarchy was abolished and the Republic of Egypt established in his stead. American policy was torn between a desire to maintain good relations with NATO allies such as Britain and France who were major colonial powers, and to align Third World nationalists such as Nasser, who resented British and French influence, with the Free World camp. The Eisenhower administration saw the Near East as a gap into which Soviet influence could be projected, and which accordingly required an American-supported NATO-type organisation (the Middle East Defense Organization, or MEDO). The CIA offered Nasser a $3 million bribe if he would join the proposed Middle East Defense Organization; Nasser took the money, but refused to join. Nasser wanted an Egyptian-dominated Arab League to be the principal defence organisation in the Near East, which might be informally associated with the United States.[citation needed] Dulles told Eisenhower in May 1953 that the Arab states believed that the United States would back Israel in aggressive expansion, and that the prestige of Western democracy in the Middle East was very low. The immediate consequence was a new policy of "even-handedness" where the United States very publicly sided with the Arab states in disputes with Israel and Britain in 1953–55. Most of all, Nasser wanted the United States to supply arms on a generous scale to Egypt. Nasser's anti-Zionism rendered it difficult for the Eisenhower administration to get the approval of Congress necessary to sell weapons to Egypt. Britain's desire to mend Anglo-Egyptian relations in the wake of the coup saw the country strive for rapprochement throughout 1953-54. In October 1954, Britain and Egypt concluded the Anglo-Egyptian Agreement on the phased evacuation of British Armed Forces troops from the Suez base. Great Britain would withdraw all troops within 20 months, maintain the base, and retain a right to return for seven years. The Suez Company would revert to the Egyptian government in 1968. Egyptian foreign policy under Nasser saw the entire Middle East as Egypt's rightful sphere of influence, and opposed all Western security initiatives in the Near East. Nasser believed that neither his regime nor Egypt's independence would be safe until Egypt had established itself as head of the Arab world.[citation needed] There was a feud between Nasser and the prime minister of Iraq, Nuri al-Said, for Arab leadership. The creation of the Baghdad Pact, (later the Central Treaty Organization) a Middle Eastern anti-Communist alliance of Pakistan, Iran, Turkey, Iraq and the UK, in 1955 seemed to confirm Nasser's fears Britain was attempting to draw the Eastern Arab World into a bloc centred upon Iraq and sympathetic to Britain. The conclusion of the Baghdad Pact occurred almost simultaneously with a dramatic Israeli reprisal operation on the Gaza Strip on 28 February 1955 in retaliation for Palestinian fedayeen raids into Israel. The close occurrence of the two events was mistakenly interpreted by Nasser as part of coordinated Western effort to push him into joining the Baghdad Pact. The signing of the Baghdad Pact and the Gaza raid marked the beginning of the end of Nasser's good relations with the Americans.Throughout 1955 and 1956, Nasser pursued a number of policies that would frustrate British aims throughout the Middle East, and result in increasing hostility between Britain and Egypt. Nasser also began to align Egypt with the kingdom of Saudi Arabia—whose rulers were hereditary enemies of the Hashemites—in an effort to frustrate British efforts to draw Syria, Jordan and Lebanon into the orbit of the Baghdad Pact. Nasser had first broached the subject of buying weapons from the Soviet Union in 1954, as a way of pressuring the Americans into selling him the arms he desired. Instead of siding with either superpower, Nasser tried to have them compete in attempts to buy his friendship. During secret talks with the Soviets in 1955, Nasser's demands for weapons were more than amply satisfied. The news in September 1955 of the Egyptian purchase of a huge quantity of Soviet arms via Czechoslovakia was seen by the West as a major increase in Soviet influence in the Near East. In Britain, the increase of Soviet influence in the Near East was seen as an ominous development that threatened to put an end to British influence in the region. Prior to 1955, Nasser had pursued efforts to reach peace with Israel and had worked to prevent cross-border Palestinian attacks. After the February 1955 Israeli raid on the Egyptian Army headquarters in Gaza in retaliation for a Palestinian fedayeen attack that killed an Israeli civilian, Nasser began allowing raids into Israel by the Palestinian militants. Egypt established fedayeen bases not just in Gaza but also in Jordan and Lebanon. The raids triggered a series of Israeli reprisal operations. Israel wanted to occupy and annex both the Gaza Strip and the Sinai and exercise control over the Gulf of Aqaba. The Israelis were concerned by Egypt's procurement of large amounts of Soviet weaponry. The influx of this advanced weaponry altered an already shaky balance of power. Israel believed it had only a narrow window of opportunity to hit Egypt's army. Additionally, Israel believed Egypt had formed a secret alliance with Jordan and Syria. France and Israel were allied against Egypt, in part due to Egyptian support of the Algerian National Liberation Front (FLN) rebels against the French. The French saw Nasser as a major threat. By early 1955, France was shipping large amounts of weapons to Israel, and by 1956 France agreed to disregard the Tripartite Declaration, and supply even more weapons to Israel. In 1956, Israeli director general of defense Shimon Peres informed the French that Israel had decided upon war with Egypt in 1956. Peres claimed that Nasser was a genocidal maniac intent upon not only destroying Israel, but also exterminating its people, and as such, Israel wanted a war before Egypt received even more Soviet weapons, and there was still a possibility of victory for the Jewish state. Egyptian policies in 1956 In January 1956, to end the incipient arms race between Egypt, armed by the Soviet Union, and Israel, armed by France, which he saw as opening the Near East to Soviet influence, Eisenhower launched a major effort to make peace between Egypt and Israel. Eisenhower sent his close friend Robert B. Anderson to serve as a secret envoy, who offered large quantities of American aid in exchange for a peace treaty with Israel. Nasser and Israeli prime minister David Ben-Gurion had conflicting demands and the meetings were unsuccessful. A second round of secret diplomacy by Anderson in February 1956 was equally unsuccessful. It is not clear if Nasser was sincerely interested in peace, or just merely saying what the Americans wanted to hear in the hope of obtaining American funding for the Aswan high dam and American weapons. However, the British historian P. J. Vatikitos noted that Nasser's determination to promote Egypt as the world's foremost anti-Zionist state as a way of reinforcing his claim to Arab leadership meant that peace was unlikely. Nasser sponsored demonstrations in Amman which led King Hussein of Jordan to dismiss the British Commander of the Arab Legion, John Bagot Glubb (known to the Arabs as Glubb Pasha) in March 1956. After the sacking of Glubb Pasha, British prime minister Anthony Eden became consumed with an obsessional hatred for Nasser, and from March 1956 onwards, was in private committed to the overthrow of Nasser. As one British politician recalled: For Eden ... this was the last straw.... This reverse, he insisted was Nasser's doing.... Nasser was our Enemy No. 1 in the Middle East and he would not rest until he destroyed all our friends and eliminated the last vestiges of our influence.... Nasser must therefore be ... destroyed. The American historian Donald Neff wrote that Eden's often hysterical and overwrought views towards Nasser reflected the influence of the amphetamines to which Eden had become addicted following a botched operation in 1953 together with the related effects of sustained sleep deprivation (Eden slept on average about 5 hours per night in early 1956). On 16 May 1956, Nasser officially recognised the People's Republic of China, which angered the US and Secretary Dulles This move, coupled with the impression that the project was beyond Egypt's economic capabilities, caused Eisenhower to withdraw all American financial aid for the Aswan Dam project on 19 July. Nationalisation of the Suez Canal On 26 July 1956, in a speech in Alexandria, Nasser announced the nationalisation of the canal. During his speech he used the name of Ferdinand de Lesseps, the builder of the canal, as a code-word for Egyptian forces to seize control of the canal. Egypt closed the canal (and the Straits of Tiran) to Israeli shipping. They also blockaded the Gulf of Aqaba, which was in contravention of the Constantinople Convention of 1888. Many argued that this was also a violation of the 1949 Armistice Agreements. The Egyptian historian Abd al-Azim Ramadan notes Nasser's decision to nationalise the Suez Canal without political consultation as an example of his predilection for solitary decision-making. The nationalisation surprised Britain and its Commonwealth. There had been no discussion of the canal at the Commonwealth Prime Ministers' Conference in London in late June and early July.: 7–8 Egypt's action threatened British economic and military interests in the region. Prime Minister Eden was under immense domestic pressure from Conservative MPs who drew direct comparisons between the events of 1956 and those of the Munich Agreement in 1938. Since the US government did not support the British protests, the British government decided in favour of military intervention against Egypt to keep the oil supply flowing and avoid the complete collapse of British influence in the region. Eden was hosting a dinner for King Feisal II of Iraq and his prime minister. Leader of the Opposition Hugh Gaitskell was also at the dinner. He immediately agreed that military action might be inevitable, but warned Eden would have to keep the Americans closely informed. Eden believed that Parliament would support him; Gaitskell spoke for the Labour Party when he called the nationalisation a "high-handed and totally unjustifiable step". When Eden made a ministerial broadcast on the nationalisation, Labour declined its right to reply. However, Gaitskell's support became more cautious as time went on. In two letters to Eden sent on 3 and 10 August 1956, Gaitskell condemned Nasser but warned that he would not support any action that violated the United Nations Charter, including an armed attack. Two dozen Labour MPs issued a statement on 8 August stating that forcing Nasser to denationalise the canal against Egypt's wishes would violate the UN charter. Former Labour Foreign Minister Herbert Morrison hinted that he would support unilateral action by the government. Jo Grimond, who became Leader of the Liberal Party that November, thought if Nasser went unchallenged the whole Middle East would go his way. The nationalisation was perceived as a direct threat to British interests. In a letter to the British Ambassador on 10 September 1956, Ivone Kirkpatrick, the Permanent Under-Secretary at the Foreign Office wrote: If we sit back while Nasser consolidates his position and gradually acquires control of the oil-bearing countries, he can and is, according to our information, resolved to wreck us. If Middle Eastern oil is denied to us for a year or two, our gold reserves will disappear. If our gold reserves disappear, the sterling area disintegrates. If the sterling area disintegrates and we have no reserves, we shall not be able to maintain a force in Germany, or indeed, anywhere else. I doubt whether we shall be able to pay for the bare minimum necessary for our defence. And a country that cannot provide for its defence is finished. Direct military intervention, however, ran the risk of angering Washington and damaging Anglo-Arab relations.[citation needed] As a result, the British government concluded a secret military pact with France and Israel that was aimed at regaining control over the Suez Canal.[citation needed] The French prime minister Guy Mollet, outraged by Nasser's move, determined that Nasser would not get his way. French public opinion very much supported Mollet, and apart from the French Communist Party, all of the criticism of his government came from the right, who very publicly doubted that a socialist like Mollet had the guts to go to war with Nasser. On 29 July 1956, the French Cabinet decided upon military action against Egypt in alliance with Israel. Britain was informed, and invited to co-operate if interested. At the same time, Mollet felt very much offended by what he considered to be the lackadaisical attitude of the Eisenhower administration to the nationalisation. This was especially the case because France had remained loyal to NATO even after the USSR had offered the French a deal earlier that year in which Paris would remain in NATO but become "semi-neutralist" in the Cold War if Moscow ended its support of the FLN in Algeria. In Mollet's view, his fidelity to NATO had earned him the right to expect firm American support against Egypt, and when that support proved not forthcoming, he became even more determined that if the Americans were not willing to do anything about Nasser, then France would act.[additional citation(s) needed] By 1956 the Panama Canal was much more important than the Suez to Australia and New Zealand.[citation needed] However, many still called the Suez Canal their "lifeline" to Britain or "jugular vein".[citation needed] Australian prime minister Robert Menzies and New Zealand Prime Minister Sidney Holland both supported Britain in the early weeks following the seizure. Menzies travelled to London from the United States after hearing of the nationalisation and became an informal member of the British Cabinet discussing the issue.: 13–16, 56–58, 84 The "non-white Dominions" saw Egypt's seizing of the canal as an admirable act of anti-imperialism, and Nasser's Arab nationalism as similar to Asian nationalism. As India was a major user of the canal, Indian prime minister Jawaharlal Nehru remained publicly neutral other than warning that any use of force, or threats, could be "disastrous". Pakistan was also cautious about supporting Egypt given their rivalry as leading Islamic nations, but its government did state that Nasser had the right to nationalise.: 18–24, 79 Diplomatic solutions Almost immediately after the nationalisation, Eisenhower suggested to Eden a conference of maritime nations that used the canal. The British preferred to invite the most important countries, but the Americans believed that inviting as many as possible amid maximum publicity would affect world opinion. The eight surviving signatories of the Constantinople Convention and the 16 other largest users of the canal were invited: Australia, Ceylon, Denmark, Egypt, Ethiopia, France, West Germany, Greece, India, Indonesia, Iran, Italy, Japan, the Netherlands, New Zealand, Norway, Pakistan, Portugal, Soviet Union, Spain, Sweden, Turkey, the United Kingdom, and the United States. All except Egypt—which sent an observer, and used India and the Soviet Union to represent its interests—and Greece accepted the invitation, and the 22 nations' representatives met in London from 16 to 23 August.: 81–89 Fifteen of the nations supported the American-British-French position of international operation of the canal. Ceylon, Indonesia, and the Soviet Union supported India's competing proposal—which Nasser had preapproved—of international supervision only. India criticised Egypt's seizure of the canal, but insisted that its ownership and operation remain in Egyptian hands. The majority of 18 chose five nations to negotiate with Nasser in Cairo led by Menzies, while their proposal for international operation of the canal would go to the Security Council.: 81–89 Menzies' argued for compensation for the Suez Canal Company and the "establishment of principles" for the future use of the canal in a 7 September official communique to Nasser, and called for a convention to recognise Egyptian sovereignty of the canal, but for the establishment of an international body to run the canal. Nasser rejected Menzies' proposals. Menzies hinted to Nasser that Britain and France might use force to resolve the crisis, but the US openly opposed the use of force and Menzies left Egypt without success. The United States proposed an association of canal users that would set rules for its operation. Fourteen of the other nations, not including Pakistan, agreed. Britain believed that violation of the association rules would result in military force, but the United States opposed military action.: 89–92 Eisenhower felt the crisis had to be handled peacefully; he told Eden that American public opinion, and the international community, "would be outraged" unless all peaceful routes had been exhausted. The Americans refused to support any move that could be seen as imperialism or colonialism, seeing the US as the champion of decolonisation. "The British and French reluctantly agreed to pursue the diplomatic avenue but viewed it as merely an attempt to buy time, during which they continued their military preparations." The British disregarded Eisenhower's argument that the American people would not accept a military solution, and doubted that Eisenhower had a determination to avoid war. Eden and other leading British officials believed that Nasser's engagement with communist states, support for Palestinian fedayeen, and attempts to destabilise pro-Western Arab regimes, would persuade the Americans to accept British and French actions if they were presented as a fait accompli.[citation needed] Military preparations Anthony Eden began planning for an invasion in July 1956. Eden's plan called for the Cyprus-based 16th Independent Parachute Brigade Group to seize the canal zone. The prime minister's plan was rejected by Templer and the other service chiefs, who suggested the sea-power based Contingency Plan, which called for the Royal Marines to take Port Said, which would then be used as a base for three British divisions to overrun the canal zone. In early August, the plan was modified by including a strategic bombing campaign that was intended to destroy Egypt's economy and thereby hopefully bring about Nasser's overthrow, as well as achieve air superiority. In addition, a role was allocated to the 16th Independent Parachute Brigade, which would lead the assault on Port Said in conjunction with the Royal Marine landing. This operation (eventually named Musketeer) would require thousands of troops, leading the British to seek out France as an ally. In place of Port Said, Musketeer called for the capture of Alexandria. Once that city had been taken in assault from the sea, British armoured divisions would engage in a decisive battle of annihilation somewhere south of Alexandria and north of Cairo. To destroy the 300,000-strong Egyptian Army in his planned battle of annihilation, Stockwell estimated that he needed 80,000 troops, while at most the British Army could spare was 50,000 troops; the French could supply the necessary 30,000 troops to make up the shortfall. On 11 August 1956, General Charles Keightley was appointed commander of Musketeer with French Admiral Pierre Barjot as his deputy commander. André Beaufrewould command the French forces. Most of the officers of the Anglo-French Task Force expressed regret that it was Beaufre who was Stockwell's deputy rather the other way around. A major problem both politically and militarily was the one-week interval between sending troops to the eastern Mediterranean and the beginning of the invasion. In late August 1956, Admiral Barjot suggested that Port Said once again be made the main target, which lessened the number of troops needed and thus reduced the interval between sending forces to the eastern Mediterranean and the invasion. Beaufre warned that merely capturing the canal zone made for a dangerously ambiguous goal. Additionally, the coming of winter weather to the Mediterranean in late November would render the invasion impossible. An additional problem was Eden, who constantly interfered with the planning and was so obsessed with secrecy that he refused to tell Keightley whether he wanted to retake the Suez Canal or topple Nasser, or both. In early September, Keightley embraced Barjot's idea of seizing Port Said, and presented Revise. On 8 September 1956 Revise was approved by the British and French cabinets. Both Stockwell and Beaufre were opposed to Revise as an open-ended plan with no clear goal beyond seizing the canal zone, but was embraced by Eden and Mollet as offering greater political flexibility and the prospect of lesser Egyptian civilian casualties. In late September 1956, Guy Mollet had decided to attack Egypt with Britain, and if the British backed out (as Mollet believed that they might), with Israel. On 7 August, the French asked Ben Gurion if Israel would attack Egypt together with France; Israel agreed and joint planning began. On 30 September 1956 secret Franco-Israeli talks started in Paris, based on Britain's non-involvement. The French wanted to use British airfields in Cyprus to bomb Egypt, but wanted to use Israeli airfields if the ones in Cyprus were not available. Only on 5 October were the British informed of the secret Franco-Israeli alliance. In July 1956, IDF chief of staff General Moshe Dayan advised Prime Minister David Ben-Gurion that Israel should attack Egypt at the first chance, but Ben-Gurion stated he preferred to attack Egypt with the aid of France. The planning for Operation Kadesh called for the Israeli Air Force to win air superiority, which was to be followed up with "one continuous battle" in the Sinai. Israeli forces would in a series of swift operations encircle and then take the four main Egyptian strong points in the Sinai: Sharm el-Sheikh, Arish, Abu Uwayulah (Abu Ageila), and the Gaza Strip. After the capture of these four objectives, Israel hope that entire Egyptian Army would fall back into Egypt proper, and British and French forces would then be able to push the Egyptian Army against an Israeli advance, and crush in a decisive encounter. Protocol of Sèvres France, Israel and the United Kingdom reached a secret agreement regarding political and military cooperation to overthrow Nasser and de-nationalise the Canal during discussions held between 22 and 24 October 1956 in Sèvres, France. Under the terms of the Protocol, Israel would attack Egypt on 29 October. The British and French governments would issue a joint appeal for both Egypt and Israel to cease firing and withdraw 10 miles from the canal. If both forces rejected this demand (a guarantee, since Israel was already aware of it), the French and British militaries would attack on 31 October. Forces The 16th Independent Parachute Brigade Group, which was intended to be the main British strike force against Egypt, had neglected paratroop training in favour of counter-insurgency operations. The Royal Navy could project formidable power through the guns of its warships and aircraft flown from its carriers, but lacked amphibious capability. The Royal Air Force (RAF) had just introduced two long-range bombers, the Vickers Valiant and the English Electric Canberra, but had not yet established proper bombing techniques for these aircraft. General Charles Keightley, the commander of the invasion force, believed that air power alone was sufficient to defeat Egypt. By contrast, General Hugh Stockwell, the Task Force's ground commander, believed that methodical and systematic armoured operations centred on the Centurion battle tank would be the key to victory. French paratroopers of the elite Regiment de Parachutistes Coloniaux (RPC) were extremely experienced soldiers, who had distinguished themselves in the fighting in Indochina and in Algeria. They followed a "shoot first, ask questions later" policy towards civilians, which led to the killing of Egyptian civilians. The main French (and Israeli) tank, the AMX-13, was lightly armoured but agile: designed for mobile, flanking operations. The French Navy had a powerful carrier force but, like its British counterpart, suffered from a lack of landing craft. American military historian Derek Varble called the Israel Defense Forces (IDF) the "best" military force in the Middle East while at the same time suffering from "deficiencies" such as "immature doctrine, faulty logistics, and technical inadequacies". The IDF's Chief of Staff, Major General Moshe Dayan, encouraged aggression, initiative, and ingenuity among the Israeli officer corps while ignoring logistics and armoured operations. Dayan preferred infantry at the expense of armour. The IDF had a disorganised logistics arm, which was put under severe strain when the IDF invaded the Sinai. The main IDF tank was the AMX-13 and the main aircraft were the Dassault Mystère IVA and the Ouragan. Superior pilot training gave the Israeli Air Force an edge over their Egyptian opponents. The Israeli Navy consisted of two destroyers, seven frigates, eight minesweepers, several landing craft, and fourteen torpedo boats.[citation needed] In the Egyptian Armed Forces, politics rather than military competence was the main criterion for promotion. The Egyptian commander, Field Marshal Abdel Hakim Amer, was a heavy drinker who was close friends with Nasser and who would prove incompetent as a general during the Crisis. In 1956, the Egyptian military was well equipped with weapons from the Soviet Union such as T-34 and IS-3 tanks, MiG-15 fighters, Ilyushin Il-28 bombers, SU-100 self-propelled guns and assault rifles. Rigid lines between officers and men in the Egyptian Army led to a mutual "mistrust and contempt" between officers and the men who served under them. Egyptian troops were excellent in defensive operations, but had little capacity for offensive operations, owing to the lack of "rapport and effective small-unit leadership". Operation Kadesh The fighting began on 29 October 1956. At about 3:00 pm, Israeli Air Force Mustangs launched a series of attacks on Egyptian positions all over the Sinai. Egyptian commander Field Marshal Abdel Hakim Amer at first treated the reports of an Israeli incursion into the Sinai as a large raid instead of an invasion, and did not order a general alert. By the time that Amer realised his mistake, the Israelis had made significant advances into the Sinai. Because Israeli intelligence expected Jordan to enter the war on Egypt's side, the Israel Border Police militarised the Israel-Jordan border, including the Green Line with the West Bank. Israeli-Arab villages along the Jordanian border were placed under curfew. This resulted in the killings of 48 civilians in the Arab village of Kafr Qasim in an event known as the Kafr Qasim massacre. The Israeli 9th Infantry Brigade captured Ras al-Naqb, an important staging ground for the later attack against Sharm el-Sheikh, during the night of 29-30 October. Also that night, the 4th Infantry Brigade stormed al-Qusaymah, a jumping off point for the assault against Abu Uwayulah. A portion of the paratroopers under Ariel Sharon's advanced to meet with the 1st Brigade. En route, Sharon assaulted Themed in a dawn attack, and was able to storm the town with his armour. Sharon decided to attack the Egyptian positions at Jebel Heitan. The Egyptians were defeated and forced to retreat. A total of 260 Egyptian and 38 Israeli soldiers were killed in the battle. Although the battle was an Israeli victory, the casualties sustained would surround Sharon with controversy. The village of Abu Uwayulah served as the road centre for the entire Sinai, and thus was a key Israeli target. To the east of Abu Uwayulah were several ridges that formed a natural defensive zone known to the Israelis as the "Hedgehog". Holding the "Hedgehog" were 3,000 Egyptians of the 17th and 18th battalions of the 3rd Infantry Division commanded by Colonel Sami Yassa. Over the course of 30 October-1 November, the Israeli military repeatedly assaulted the position. Eventually, the lack of ammunition and water caused the Egyptians to retreat. In air combat, Israeli aircraft shot down between seven and nine Egyptian jets with the loss of one plane. On 1 November, President Nasser ordered his pilots to disengage and fly their planes to bases in southern Egypt. On 3 November, Israeli Dassault Mystère fighter jets attacked a British warship, the Black Swan class sloop HMS Crane as it was patrolling the approaches to the Gulf of Aqaba after it had been mistaken for an Egyptian Navy warship. Three crewmen were wounded in the attack. The ship put up heavy anti-aircraft fire, and there are conflicting accounts as to whether or not it shot down one of the attacking jets. The Egyptian Navy's Ibrahim el Awal, an ex-British Hunt-class destroyer, was damaged by the Israeli Navy and captured on 31 October after shelling Haifa. Also on 31 October, the Egyptian frigate Domiat was destroyed by a British light cruiser. On 4 November, a squadron of Egyptian motor torpedo boats attacked a British destroyer off the northeast coast of the Nile Delta. Three torpedo boats were sunk and the rest retreated. The city of Rafah was strategically important to Israel. Dayan ordered the IDF forces to focus on breaking through rather than reducing every Egyptian strongpoint. French warships led by the cruiser Georges Leygues provided fire support. In the morning of 1 November, Israeli tanks had encircled the city. At that point, the commander of the Egyptian forces, General al-Abd, ordered his forces to abandon their posts outside of Rafah and retreat into the city. With Rafah more or less cut off and Israeli forces controlling the northern and eastern roads leading into the city, the 27th Armored Brigade to went west to take al-Arish. By this point, Nasser had ordered his forces to fall back towards the Suez Canal, so at first Bar-Lev and his men met little resistance as they advanced across the northern Sinai. Hearing of the order to withdraw, General al-Abd and his men left Rafah on the morning of 1 November through a gap in the Israeli lines. Three hours later, the Israelis took Rafah. After taking Rafah, Israeli troops killed 111 people, including 103 refugees, in Rafah's Palestinian refugee camp. The circumstances of the killings are disputed. On 2 November, Bar-Lev's forces took al-Arish. The city itself fell without a fight after its defenders retreated. Meanwhile, the IDF attacked the Egyptian defences outside of Gaza City late on 1 November. Joined by infantry, the armour attacked the al-Muntar fortress outside of Gaza City, killing or capturing 3,500 Egyptian National Guard troops. By noon of 2 November, there was no more Egyptian opposition in the Gaza City area. By noon of 3 November, the Israelis had control of almost the entire Gaza Strip save for a few isolated strong points, which were soon attacked and taken. The UN estimated that in total 447 to 550 Palestinian civilians were killed by Israeli troops during the first weeks of Israeli occupation of the strip. The manner in which these people were killed is disputed. A number of Palestinians were killed after the town of Khan Yunis was taken on 3 November. Israel maintains that the Palestinians were killed in street-fighting, while the Palestinians claimed that they were unarmed civilians executed by Israeli troops. The Director of the United Nations Relief and Works Agency later reported that 275 people were killed. In both Gaza City and Khan Yunis, street-fighting led to the deaths of "dozens, perhaps hundreds, of non-combatants". Food and medicine distribution for refugees in need of assistance was complicated when some Palestinians ransacked the warehouses belonging to the United Nations Relief and Works Agency. This was compounded by a widespread view in Israel that the responsibility for the care of the Palestinian refugees rested with the UNRWA, not Israel, which led the Israelis to be slow with providing aid. By 3 November, Sharm el-Sheikh was the last Israeli objective. The Egyptian forces at Sharm el-Sheikh had the advantage of holding one of the most strongly fortified positions in the entire Sinai, but had been subjected to heavy Israeli air attacks from the beginning of the war. The main difficulty faced by Colonel Abraham Yoffe's 9th Infantry Brigade was logistical. There were no good roads linking Ras an-Naqb to Sharm el-Sheikh. After numerous skirmishes on the outskirts of Sharm el-Sheikh, Yoffe ordered an attack on the port around midnight on 4 November. After four hours of heavy fighting, Yoffe ordered his men to retreat. On the morning of 5 November, Israeli forces launched a massive artillery barrage and napalm strikes against Egyptian forces defending Sharm el-Sheikh. At 9:30 am on 5 November, the Egyptian commander, Colonel Raouf Mahfouz Zaki, surrendered Sharm el-Sheikh. The Israelis had lost 10 killed and 32 wounded, while the Egyptians had lost about 100 killed and 31 wounded. Another 864 Egyptian soldiers were taken prisoner. The Israeli losses were 172 dead and 817 wounded. The number of Egyptians killed was "never reliably established". Egyptian casualties to the Israeli invasion were estimated at 1,000–3,000 dead and 4,000 wounded, while losses to the Anglo-French operation were estimated at 650 dead and 900 wounded. 1,000 Egyptian civilians are estimated to have died. Anglo-French Canal invasion The Anglo-French military action had two phases: Operation Musketeer and Operation Telescope. Operation Musketeer Revise (often referred to as Operation Revise) was in two phases: To support the invasion, large air forces had been deployed to Cyprus and Malta by Britain and France and many aircraft carriers were deployed. The two airbases on Cyprus were so congested that a third field which was in dubious condition had to be brought into use for French aircraft. Operation Telescope consisted of air- and sea-borne landings to capture the Canal Zone. In the morning of 30 October Britain and France sent ultimatums to Egypt and Israel. Eden and Mollet ordered Phase I of Operation Revise to begin 13 hours after the Anglo-French ultimatum with a bombing campaign. Field Marshal Abdel Hakim Amer ordered Egyptian troops in the Sinai to stay put, as Amer confidently assured Nasser that the Egyptians could defeat the Israelis in the Sinai and then defeat the Anglo-French forces once they came ashore in the canal zone. Amer also advised Nasser to send more troops into the Sinai to inflict his promised defeat on Israel. Not until late on 31 October did Nasser disregard Amer's rosy assessment and ordered his forces to disengage in the Sinai and to retreat back to the canal zone to face the expected Anglo-French invasion. British night bombing proved ineffective.Starting on the morning of 1 November, carrier-based planes began a series of daytime strikes on Egypt. By the night of 1 November the Egyptian Air Force had lost 200 planes. With the destruction of Egypt's air force, Keightley ordered the beginning of Revise Phase II, a wide-ranging interdiction campaign. By 3 November, Beaufre convinced Keightley and Stockwell to seize the canal zone with airborne landings instead of waiting the planned ten days for Revise II, and gained the approval for Operation Telescope, as Beaufre had code-named the airborne assault on the canal zone. In the early morning of 5 November, an advance element of the 3rd Battalion of the British Parachute Regiment dropped on El Gamil Airfield, led by Brigadier M.A.H. Butler. At the same time, Lieutenant Colonel Pierre Chateau-Jobert landed with a force of the 2nd RPC at Raswa. The British forces moved up towards Port Said with air support before digging in at 13:00 to hold until the beach assault. Overall, the British paratroopers had managed to inflict a decisive defeat on the Egyptians for the loss of 4 dead and 32 wounded. The French paratroopers swiftly secured the western bridge. With close-air-support, the French paratroopers stormed and took Port Said's waterworks that morning. Chateau-Jobert followed up this success by beginning an attack on Port Fuad, which became a rout. During the fighting in the canal zone, the French paratroopers often executed Egyptian POWs. The Egyptian commander at Port Said, General Salahedin Moguy then proposed a truce. Moguy had no interest in surrendering and had only made the truce offer to buy time for his men to dig in. As the paratroopers alone were not enough to take the city, Beaufre and British Admiral Manley Laurence Power urged that the sea-borne landings be accelerated and that Allied forces land the very next day.: 173 At first light on 6 November, Royal Marines of No. 42 and 40 Commando stormed the beaches The battle group standing offshore opened fire, giving covering fire for the landings. The town of Port Said sustained great damage and was seen to be alight. The men of 42 Commando as much as possible chose to by-pass Egyptian positions and focused on trying to break through inland.Upon entering downtown Port Said, the Marines became engaged in fierce urban combat. In the afternoon, 522 additional French paratroopers were dropped near Port Fuad. These were also constantly supported by the Corsairs of the French Aéronavale. The French were aided by AMX-13 light tanks. British Royal Marines of No. 45 Commando assaulted by helicopter, meeting stiff resistance, with shore batteries striking several helicopters, while friendly fire from British carrier-borne aircraft also mistakenly hit 45 Commando and HQ. One Marine was killed and 15 wounded when a carrier-based Wyvern mistakenly fired into a concentration of Marines. This was the first time helicopters were used by British forces to lift men directly into a combat zone. Nasser proclaimed the Suez War to be a "people's war". As such, Egyptian troops were ordered to don civilian clothes while guns were freely handed out to Egyptian civilians. From Nasser's point of view, this presented the British and French with an unsolvable dilemma: cause deaths of innocent civilians and bring world sympathy to his cause while weakening morale in Britain and France, or fall prey to snipers attacking "with near impunity by hiding among crowds of apparent non-combatants". These tactics worked especially well against the British. British leaders, especially Eden and the First Sea Lord Admiral Sir Louis Mountbatten, sincerely attempted to limit Egyptian civilian deaths. Despite Eden's best efforts, British bombing still killed hundreds of Egyptian civilians during Revise II, though these deaths were due more to imprecise aiming rather than a deliberate policy of "area bombing" such as that employed against Germany in World War II. At Port Said, the heavy fighting in the streets and the resulting fires destroyed much of the city, killing many civilians. Most Egyptian soldiers wore civilian clothing and operated in small groups, but remained organised. Civilians who took up arms as guerrillas were organised into eight groups with five additional groups joining them from outside the city. The Egyptians were gradually pushed back as the British took key objectives. Egyptian sniper attacks and the need to clear every building led 3 Para to be slowed in their attempts to link up with the Royal Marines. The link-up of British and French forces occurred close to the offices of the Suez Canal Company. Both Stockwell and Beaufre spent the day in Port Said, and were thus cut off from the news. Only late in the day did Beaufre and Stockwell learn of the acceptance of the United Nations ceasefire. The British forces were at al-Cap, a small village four miles north of al-Qantarah at 2:00 am, when the ceasefire came into effect. Total Royal Marine casualties in the Port Said landings were 9 killed and 60 wounded. Responses to military action Eden's obsession with secrecy meant that the government did nothing in the months running up to the attack to explain to the British people or the reservists called up for their National Service in the summer and fall of 1956 why the war was necessary. Only one British soldier, however, refused to fight. According to some historians, the majority of British people were on Eden's side. According to public opinion polls at the time, 37% of the British people supported the war while 44% were opposed. On 10 and 11 November an opinion poll found 53% supported the war, with 32% opposed. Although the public believed the British government's justification of the invasion as a separation of Israeli and Egyptian forces, protests against the war occurred in Britain after it began. Stormy and violent debates in the House of Commons on 1 November 1956 almost degenerated into fist-fights after several Labour MPs compared Eden to Hitler. The British government pressured the BBC to support the war, and seriously considered taking over the network. The majority of Conservative constituency associations passed resolutions of support to "Sir Anthony". The majority of letters written to MPs from their constituents were against the Suez attack. Significantly, many of the letters came from voters who identified as Conservatives. The Labour Party and the Trade Union Congress organised nation-wide anti-war protests, starting on 1 November. On 4 November, at an anti-war rally in Trafalgar Square attended by 30,000 people (making it easily the biggest rally in London since 1945), the Labour MP Aneurin Bevan accused the government of "a policy of bankruptcy and despair". Inspired by Bevan's speech, the crowd at Trafalgar Square then marched on 10 Downing Street chanting "Eden Must Go!", and attempted to storm the prime minister's residence. The ensuing clashes between the police and the demonstrators which were captured by television cameras had a huge demoralising effect on the Eden cabinet, which was meeting there. The conflict exposed the division within the Labour Party between its middle-class internationalist intelligentsia who opposed the conflict, and working-class voters who supported it.[f] The Labour MP Richard Crossman said that "when the Labour Party leadership tried to organise demonstrations in the Provinces of the kind they'd held in Trafalgar Square, there was great reluctance among the working classes, because we were at war. It was Munich in reverse." Another Labour MP, Barbara Castle, recalled that Labour's protest against the conflict was "drowned in a wave of public jingoism". The Suez Crisis played a key role in the reconciliation of the Gaitskellite and Bevanite factions of the Labour Party, which both condemned the invasion, after the 1955 leadership election. Along with the Suez crisis, the United States was also dealing with the near-simultaneous Hungarian revolution. Vice-President Richard Nixon later explained: "We couldn't on one hand, complain about the Soviets intervening in Hungary and, on the other hand, approve of the British and the French picking that particular time to intervene against Nasser". Eisenhower also believed that if the United States supported the attack on Egypt, that the resulting backlash in the Arab world might win the Arabs over to the Soviet Union. The United States put financial pressure on the UK to end the invasion. Because the Bank of England had lost $45 million between 30 October and 2 November, and Britain's oil supply had been restricted by the closing of the Suez Canal, the British sought immediate assistance from the IMF, but it was denied by the United States. In addition, Eisenhower ordered his secretary of the treasury, George M. Humphrey, to prepare to sell part of the US government's sterling bond holdings. Britain's chancellor of the exchequer, Harold Macmillan, told Eden that Britain's foreign exchange reserves could not sustain the devaluation of the pound that would come after the United States' actions; and that within weeks of such a move, the country would be unable to import sufficient food and energy supplies. However, there were suspicions in the Cabinet that Macmillan had deliberately overstated the financial situation in order to force Eden out. What Treasury officials had told Macmillan was far less serious than what he told the Cabinet. Despite having no commercial or military interest in the area, many countries were concerned with the growing rift between Western allied nations. When Israel refused to withdraw its troops from the Gaza Strip and Sharm el-Sheikh, Eisenhower sought UN-backed efforts to impose economic sanctions on Israel until it fully withdrew from Egyptian territory. The Democratic Party-controlled Senate would not co-operate with Eisenhower's position on Israel. A rare example of support for the Anglo-French actions against Egypt came from West Germany. Though his Cabinet was divided, West Germany's chancellor Konrad Adenauer told his Cabinet on 7 November that Nasser was a pro-Soviet force that needed to be cut down to size, and in his view the attack on Egypt was completely justified. Adenauer feared that the United States and Soviet Union would "carve up the world" according to their own interests. Because of this, Adenauer strengthened his relationship with Mollet and France. The attack on Egypt greatly offended many in the Muslim world. In Pakistan, 300,000 people took part in a rally in Lahore to show solidarity with Egypt, and a violent mob in Karachi chanting anti-British slogans burned down the British High Commission. In Syria, the government blew up the Kirkuk–Baniyas pipeline, which had allowed Iraqi oil to reach tankers in the Mediterranean, to punish Iraq for supporting the invasion and to cut Britain off from one of its main routes for taking delivery of Iraqi oil. In concert with US actions, Saudi Arabia started an oil embargo against Britain and France. The US refused to fill the gap until Britain and France agreed to a rapid withdrawal. Other NATO members refused to sell oil they received from Arab nations to Britain or France. On 30 October, the Security Council submitted a draft resolution calling upon Israel immediately to withdraw its armed forces behind the established armistice lines. It was not adopted because of British and French vetoes. A similar draft resolution sponsored by the Soviet Union was also rejected. On 31 October, as planned, France and the UK launched their attacks against targets in Egypt. Later that day, the Security Council passed Resolution 119, calling an emergency special session of the General Assembly for the first time, in order to make appropriate recommendations to end the fighting. The emergency special session was convened on 1 November. The same day Nasser requested diplomatic assistance from the US, without requesting the same from the Soviet Union. In the early hours of 2 November, the General Assembly adopted the United States' proposal for Resolution 997. It called for an immediate ceasefire, the withdrawal of all forces behind the armistice lines, an arms embargo, and the reopening of the Suez Canal, which was now blocked. The vote was 64 in favour and 5 opposed (Australia, New Zealand, Britain, France, and Israel) with 6 abstentions. Over the next several days, the emergency special session established the first United Nations Emergency Force (UNEF). This proposal of the emergency force and the resulting cease-fire was made possible primarily through the efforts of Lester B. Pearson, the Secretary of External Affairs of Canada, and Dag Hammarskjöld, the Secretary-General of the United Nations. Britain and France agreed to withdraw from Egypt within a week; Israel did not. On 7 November, David Ben-Gurion addressed the Knesset and declared a great victory, saying that the 1949 armistice agreement with Egypt was dead and buried, and that the armistice lines were no longer valid and could not be restored. Under no circumstances would Israel agree to the stationing of UN forces on its territory or in any area it occupied.: 104–117 He also made an oblique reference to his intention to annex the Sinai Peninsula. Isaac Alteras writes that Ben-Gurion "was carried away by the resounding victory against Egypt" and while "a statesman well known for his sober realism, [he] took flight in dreams of grandeur". The speech marked the beginning of a four-month-long diplomatic struggle, culminating in withdrawal from all territory, under conditions far less palatable than those envisioned in the speech, but with conditions for sea access to Eilat and a UNEF presence on Egyptian soil. The speech immediately drew increased international pressure on Israel to withdraw. That day in New York, the emergency session passed Resolution 1002, again calling for the immediate withdrawal of Israeli troops to behind the armistice lines, and for the immediate withdrawal of British and French troops from Egyptian territory. After a long Israeli cabinet meeting late on 8 November, Ben-Gurion informed Eisenhower that Israel declared its willingness to accept withdrawal of Israeli forces from Sinai, "when satisfactory arrangements are made with the international force that is about to enter the canal zone". Premier Nikolai Bulganin threatened to intervene on the Egyptian side, and to launch rocket attacks on Britain, France and Israel. It was later learned that the Soviets did not have the ICBMs necessary to launch this attack, but the West did not know this at the time. The Soviet threat to send troops to Egypt to fight the Allies led Eisenhower to fear that this might be the beginning of World War III. Eisenhower immediately ordered Lockheed U-2 flights over Syria and Israel to search for any Soviet air forces on Syrian bases. The Americans excluded Israel from the guarantee against Soviet attack, however, alarming the Israeli government. The U-2 showed that Soviet aircraft were not in Syria despite the threats. Ceasefire Anthony Eden announced a cease fire on 6 November, warning neither France nor Israel beforehand. Troops were still in Port Said and on operational manoeuvres. Port Said had been overrun, and the military assessment was that the Suez Canal could have been completely taken within 24 hours. Eisenhower was not in favour of an immediate withdrawal of British, French and Israeli troops until the US ambassador to the United Nations, Henry Cabot Lodge Jr. pushed for it. Without further guarantee, the Anglo-French Task Force had to finish withdrawing by 22 December 1956, to be replaced by Danish and Colombian units of the UNEF. The Israelis refused to host any UN force on Israeli-controlled territory and withdrew from the Sinai and Gaza in March 1957. Before the withdrawal the Israeli forces systematically destroyed infrastructure in the Sinai peninsula such as roads, railways and telephone lines, and all houses in the villages of Abu Ageila and El Quseima. Israeli troops confiscated Egyptian National Railways equipment for use by Israel Railways. The UNEF was formed by forces from countries that were not part of either NATO or the Warsaw Pact. Canadian Armed Forces troops participated in later years, since Canada had spearheaded the idea of a neutral force. By 24 April 1957, the canal was fully reopened to shipping. Aftermath The conflict resulted in a military victory for the Coalition, but a political victory for Egypt. Egypt maintained control of the canal. In the context of the massive armament of Egypt via Czechoslovakia, Israel had been expecting an Egyptian invasion in either March or April 1957, as well as a Soviet invasion of Syria, neither of which occurred after this war. The fight over the canal also laid the groundwork for the Six-Day War in 1967 due to the lack of a peace settlement following the 1956 war and rising of tensions between Egypt and Israel. The Israel Defense Forces gained confidence from the campaign.[according to whom?] The Straits of Tiran, closed by Egypt since 1950, were re-opened to Israeli shipping. The Israelis also secured the presence of UN Peacekeepers in Sinai. Operation Kadesh bought Israel an eleven-year lull on its southern border with Egypt. In addition, its refusal to withdraw without guarantees, even in defiance of the United States and United Nations, ended all Western efforts, mainly American and British ones, to impose a political settlement in the Middle East without taking Israel's security needs into consideration. In October 1965 Eisenhower told Jewish fundraiser and Republican party supporter Max M. Fisher that he greatly regretted forcing Israel to withdraw from the Sinai peninsula. The Soviet Union made major gains with regards to influence in the Middle East. Nikita Khrushchev's much publicised threat expressed through letters written by Nikolai Bulganin to begin rocket attacks on 5 November on Britain, France, and Israel if they did not withdraw from Egypt was widely believed at the time to have forced a ceasefire. Accordingly, it enhanced the prestige of the Soviet Union in Egypt, the Arab world, and the Third World, who believed the USSR was prepared to launch a nuclear attack on Britain, France, and Israel for the sake of Egypt. Though Nasser in private admitted that it was American economic pressure that had saved him, it was Khrushchev, not Eisenhower, whom Nasser publicly thanked as Egypt's saviour and special friend. Shortly after it reopened, the canal was traversed by the first Soviet Navy warships since World War I. The Soviets' burgeoning influence in the Middle East, although it was not to last, included acquiring Mediterranean bases, and supporting the budding Palestinian liberation movement.[unreliable source?] Khrushchev took the view that the Suez crisis had been a great triumph for Soviet nuclear brinkmanship, arguing publicly and privately that his threat to use nuclear weapons was what had saved Egypt. Therefore, a long period of crises began, starting with the Berlin crisis, beginning later in November 1958, and culminating in the Cuban Missile Crisis of 1962. The Soviet Union was able to avoid most repercussions from its concurrent violent suppression of the rebellion in Hungary, and were able to present an image at the United Nations as a defender of small powers against imperialism. The crisis may also have hastened decolonisation, as many of the remaining British and French colonies gained independence over the next few years. Some argued that the imposed ending to the Crisis led to over-hasty decolonisation in Africa, increasing the chance of civil wars and military dictatorships in newly independent countries. US secretary of state John Foster Dulles perceived a power vacuum in the Middle East, and he thought the United States should fill it. In order to prevent further Soviet expansion in the region, Eisenhower asked Congress on 5 January 1957 for authorisation to use military force if requested by any Middle Eastern nation to check aggression and, secondly, to set aside $200 million to help Middle Eastern countries that desired aid from the United States. Congress granted both requests and this policy became known as the Eisenhower Doctrine. Nasser saw the Eisenhower Doctrine as a heavy-handed American attempt to dominate the Middle East and led him to ally Egypt with the Soviet Union as an effective counter-weight. It was only with the abandonment of the Eisenhower Doctrine in mid-1958 that Nasser started pulling away from the Soviet Union to resume his preferred role as an opportunist who tried to use both superpowers to his advantage. The American historian Arthur L. Herman said that the episode ruined the usefulness of the United Nations to support American geopolitical aims. The Bulganin letters showcased Europe's dependence upon the United States for security against Soviet nuclear threats while at the same time seeming to show that the American nuclear umbrella was not as reliable as had been advertised.[neutrality is disputed] As a result, the French became determined to acquire their own nuclear weapons rather than rely upon the Americans, while Germany became even more interested in the idea of a European "Third Force" in the Cold War. This helped to lead to the formation of the European Economic Community, which was intended to be the foundation of the European "Third Force". Egypt kept control of the Suez Canal. The British historian D. R. Thorpe wrote that the outcome gave Nasser "an inflated view of his own power", thinking he had overcome the combined forces of the United Kingdom, France and Israel, failing to attribute their withdrawal to pressure from the superpowers. American historian Derek Varble commented, "Although Egyptian forces fought with mediocre skill during the conflict, many Arabs saw Nasser as the conqueror of European colonialism and Zionism, simply because Britain, France and Israel left the Sinai and the northern Canal Zone." The fighting at Port Said became a symbol of Egyptian victory, linked to a global anti-colonial struggle. In October 1956, Nasser brought in a set of sweeping regulations abolishing civil liberties and allowing the state to stage mass arrests without charge and strip away Egyptian citizenship from any group it desired; these measures were mostly directed against the Jews of Egypt. As part of its new policy, 1,000 Jews were arrested and 500 Jewish businesses were seized by the government. A statement branding the Jews as "Zionists and enemies of the state" was read out in the mosques of Cairo and Alexandria. Jewish bank accounts were confiscated and many Jews lost their jobs. Lawyers, engineers, doctors and teachers were not allowed to work in their professions. Thousands of Jews were ordered to leave the country. They were allowed to take only one suitcase and a small sum of cash, and forced to sign declarations "donating" their property to the Egyptian government. Some 25,000 Jews, almost half of the Jewish community, left Egypt, mainly for Israel, Europe, the United States and South America. By 1957, the Jewish population of Egypt had fallen to 15,000. The political and psychological impact of the crisis had a fundamental impact on British politics. Anthony Eden was accused of misleading parliament and resigned from office on 9 January 1957. Though British influence continued in the Middle East, Suez was a blow to British prestige in the Near East from which the country never recovered. Britain evacuated all positions East of Suez by 1971, though this was due mainly to economic factors. Eden's successor, Harold Macmillan, accelerated the process of decolonisation and sought to restore Britain's special relationship with the United States.[page needed] Benefiting from his personal popularity and a healthy economy, Macmillan's government increased its Parliamentary majority in the 1959 general election. During the 1960s there was much speculation that Prime Minister Harold Wilson's refusals to send British troops to the Vietnam War, were partially due to the Americans not supporting Britain during the Suez Crisis. In 1973, Prime Minister Edward Heath refused the US permission to use any of the UK's air bases to resupply during the Yom Kippur War, or to allow the Americans to gather intelligence from British bases in Cyprus. However, the British relationship with the United States did not suffer lasting consequences from the crisis. The Sputnik Crisis, combined with Britain's first hydrogen bomb test Operation Grapple both of which took place the following year, led to the 1958 US–UK Mutual Defence Agreement. Six years after the crisis, the Americans sold Britain state-of-the-art missile technology at a moderate cost, which became the UK Polaris programme. The war led to the eviction of GCHQ from several of its best foreign signals intelligence collection sites. Risse-Kappen argued that Franco-American ties never recovered from the Suez crisis. Previously there had already been strains in the Franco-American relationship triggered by what Paris considered US betrayal of the French war effort in Indochina in 1954. From the point of view of General Charles de Gaulle, the Suez events demonstrated to France that it could not rely on its allies. The British had initiated a ceasefire in the midst of the battle without consulting the French, while the Americans had opposed Paris politically. The damage to the ties between Paris and Washington, D.C., "culminated in President de Gaulle's 1966 decision to withdraw from the military integration of NATO". The crisis also galvanised France to accelerate its own nuclear weapons program in the hope of returning to a global power. The following year French president René Coty decided on the creation of the C.S.E.M., a new nuclear testing facility in the then French Sahara. Gerboise Bleue was successfully tested in 1960. Much of the French Army officer corps felt that they had been "betrayed" by politicians in Paris when they were on the verge of victory, just as they believed they had been "betrayed" in Vietnam in 1954, and accordingly became more determined to win the war in Algeria, even if it meant overthrowing the Fourth Republic to do so. The Suez crisis thus helped to set the stage for the military disillusionment with the Fourth Republic, which was to lead to the collapse of the republic in 1958. Lester B. Pearson, who would later become the prime minister of Canada, was awarded the Nobel Peace Prize in 1957 for his efforts in creating a mandate for a United Nations Peacekeeping Force, and he is considered the father of the modern concept of peacekeeping. The Suez Crisis contributed to the adoption of a new national flag of Canada in 1965, as the Egyptian government had objected to Canadian peacekeeping troops on the grounds that their flag at that time included a British ensign.[page needed] The military lesson that was reinforced by the Suez War was the extent that the desert favoured highly fluid, mobile operations and the power of aerial interdiction. To operate in the open desert without air supremacy proved to be suicidal for the Egyptian forces in the Sinai. The Royal Marine helicopter assault at Port Said "showed promise as a technique for transporting troops into small landing zones". Egyptian urban warfare tactics at Port Said proved to be effective at slowing down the Allied advance. [citation needed] See also General Notes References Further reading External links Media links |
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[SOURCE: https://en.wikipedia.org/w/index.php?title=Non-player_character&action=edit§ion=1] | [TOKENS: 1431] |
Editing Non-player character (section) Copy and paste: – — ° ′ ″ ≈ ≠ ≤ ≥ ± − × ÷ ← → · § Cite your sources: <ref></ref> {{}} {{{}}} | [] [[]] [[Category:]] #REDIRECT [[]] <s></s> <sup></sup> <sub></sub> <code></code> <pre></pre> <blockquote></blockquote> <ref></ref> <ref name="" /> {{Reflist}} <references /> <includeonly></includeonly> <noinclude></noinclude> {{DEFAULTSORT:}} <nowiki></nowiki> <!-- --> <span class="plainlinks"></span> Symbols: ~ | ¡ ¿ † ‡ ↔ ↑ ↓ • ¶ # ∞ ‹› «» ¤ ₳ ฿ ₵ ¢ ₡ ₢ $ ₫ ₯ € ₠ ₣ ƒ ₴ ₭ ₤ ℳ ₥ ₦ ₧ ₰ £ ៛ ₨ ₪ ৳ ₮ ₩ ¥ ♠ ♣ ♥ ♦ 𝄫 ♭ ♮ ♯ 𝄪 © ¼ ½ ¾ Latin: A a Á á À à  â Ä ä Ǎ ǎ Ă ă Ā ā à ã Å å Ą ą Æ æ Ǣ ǣ B b C c Ć ć Ċ ċ Ĉ ĉ Č č Ç ç D d Ď ď Đ đ Ḍ ḍ Ð ð E e É é È è Ė ė Ê ê Ë ë Ě ě Ĕ ĕ Ē ē Ẽ ẽ Ę ę Ẹ ẹ Ɛ ɛ Ǝ ǝ Ə ə F f G g Ġ ġ Ĝ ĝ Ğ ğ Ģ ģ H h Ĥ ĥ Ħ ħ Ḥ ḥ I i İ ı Í í Ì ì Î î Ï ï Ǐ ǐ Ĭ ĭ Ī ī Ĩ ĩ Į į Ị ị J j Ĵ ĵ K k Ķ ķ L l Ĺ ĺ Ŀ ŀ Ľ ľ Ļ ļ Ł ł Ḷ ḷ Ḹ ḹ M m Ṃ ṃ N n Ń ń Ň ň Ñ ñ Ņ ņ Ṇ ṇ Ŋ ŋ O o Ó ó Ò ò Ô ô Ö ö Ǒ ǒ Ŏ ŏ Ō ō Õ õ Ǫ ǫ Ọ ọ Ő ő Ø ø Œ œ Ɔ ɔ P p Q q R r Ŕ ŕ Ř ř Ŗ ŗ Ṛ ṛ Ṝ ṝ S s Ś ś Ŝ ŝ Š š Ş ş Ș ș Ṣ ṣ ß T t Ť ť Ţ ţ Ț ț Ṭ ṭ Þ þ U u Ú ú Ù ù Û û Ü ü Ǔ ǔ Ŭ ŭ Ū ū Ũ ũ Ů ů Ų ų Ụ ụ Ű ű Ǘ ǘ Ǜ ǜ Ǚ ǚ Ǖ ǖ V v W w Ŵ ŵ X x Y y Ý ý Ŷ ŷ Ÿ ÿ Ỹ ỹ Ȳ ȳ Z z Ź ź Ż ż Ž ž ß Ð ð Þ þ Ŋ ŋ Ə ə Greek: Ά ά Έ έ Ή ή Ί ί Ό ό Ύ ύ Ώ ώ Α α Β β Γ γ Δ δ Ε ε Ζ ζ Η η Θ θ Ι ι Κ κ Λ λ Μ μ Ν ν Ξ ξ Ο ο Π π Ρ ρ Σ σ ς Τ τ Υ υ Φ φ Χ χ Ψ ψ Ω ω {{Polytonic|}} Cyrillic: А а Б б В в Г г Ґ ґ Ѓ ѓ Д д Ђ ђ Е е Ё ё Є є Ж ж З з Ѕ ѕ И и І і Ї ї Й й Ј ј К к Ќ ќ Л л Љ љ М м Н н Њ њ О о П п Р р С с Т т Ћ ћ У у Ў ў Ф ф Х х Ц ц Ч ч Џ џ Ш ш Щ щ Ъ ъ Ы ы Ь ь Э э Ю ю Я я ́ IPA: t̪ d̪ ʈ ɖ ɟ ɡ ɢ ʡ ʔ ɸ β θ ð ʃ ʒ ɕ ʑ ʂ ʐ ç ʝ ɣ χ ʁ ħ ʕ ʜ ʢ ɦ ɱ ɳ ɲ ŋ ɴ ʋ ɹ ɻ ɰ ʙ ⱱ ʀ ɾ ɽ ɫ ɬ ɮ ɺ ɭ ʎ ʟ ɥ ʍ ɧ ʼ ɓ ɗ ʄ ɠ ʛ ʘ ǀ ǃ ǂ ǁ ɨ ʉ ɯ ɪ ʏ ʊ ø ɘ ɵ ɤ ə ɚ ɛ œ ɜ ɝ ɞ ʌ ɔ æ ɐ ɶ ɑ ɒ ʰ ʱ ʷ ʲ ˠ ˤ ⁿ ˡ ˈ ˌ ː ˑ ̪ {{IPA|}} This page is a member of 11 hidden categories (help): |
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