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Contents URL A uniform resource locator (URL), colloquially known as web address, is a reference to a resource on the World Wide Web. A URL specifies the location of a resource on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably.[a] A URL is most commonly used to reference a web page (HTTP/HTTPS) but is also used for file transfer (FTP), email (mailto), database access (JDBC), and many other applications. Most web browsers display the URL of a web page above the page in an address bar. As an example of a web page URL, https://www.example.com/index.html indicates protocol https, hostname www.example.com, and file name index.html. History The Uniform Resource Locator was defined in RFC 1738 in 1994 by Tim Berners-Lee, the inventor of the World Wide Web, and the URI working group of the Internet Engineering Task Force (IETF), as an outcome of collaboration started at the IETF Living Documents birds of a feather session in 1992. The format combines the pre-existing system of domain names (created in 1985) with file path syntax, where slashes are used to separate directory and filenames. Conventions already existed where server names could be prefixed to complete file paths, preceded by a double slash (//). Berners-Lee later expressed regret at the use of dots to separate the parts of the domain name within URIs, wishing he had used slashes throughout, and also said that, given the colon following the first component of a URI, the two slashes before the domain name were unnecessary. Early WorldWideWeb collaborators, including Berners-Lee, originally proposed the use of UDIs: Universal Document Identifiers. An early (1993) draft of the HTML Specification referred to "Universal" Resource Locators. This was dropped some time between June 1994 and October 1994. In his book Weaving the Web, Berners-Lee emphasizes his preference for the original inclusion of "universal" in the expansion rather than the word "uniform", to which it was later changed, and he gives a brief account of the contention that led to the change. Syntax Every HTTP URL conforms to the syntax of a generic URI. The URI generic syntax consists of five components organized hierarchically in order of decreasing significance from left to right:: §3 A component is undefined if it has an associated delimiter and the delimiter does not appear in the URI; the scheme and path components are always defined.: §5.2.1 A component is empty if it has no characters; the scheme component is always non-empty.: §3 The authority component consists of subcomponents: This is represented in a syntax diagram as: The URI comprises: A web browser will usually dereference a URL by performing an HTTP request to the specified host, by default on port number 80. URLs using the https scheme require that requests and responses be made over a secure connection to the website. Internationalized URL Internet users are distributed throughout the world using a wide variety of languages and alphabets, and expect to be able to create URLs in their own local alphabets. An Internationalized Resource Identifier (IRI) is a form of URL that includes Unicode characters. All modern browsers support IRIs. The parts of the URL requiring special treatment for different alphabets are the domain name and path. The domain name in the IRI is known as an Internationalized Domain Name (IDN). Web and Internet software automatically convert the domain name into punycode usable by the Domain Name System; for example, the Chinese URL http://例子.卷筒纸 becomes http://xn--fsqu00a.xn--3lr804guic/. The xn-- indicates that the character was not originally ASCII. The URL path name can also be specified by the user in the local writing system. If not already encoded, it is converted to UTF-8, and any characters not part of the basic URL character set are escaped as hexadecimal using percent-encoding; for example, the Japanese URL http://example.com/引き割り.html becomes http://example.com/%E5%BC%95%E3%81%8D%E5%89%B2%E3%82%8A.html. The target computer decodes the address and displays the page. Protocol-relative URLs Protocol-relative links (PRL), also known as protocol-relative URLs (PRURL), are URLs that have no protocol specified. For example, //example.com will use the protocol of the current page, typically HTTP or HTTPS. See also Notes Citations References External links |
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[SOURCE: https://en.wikipedia.org/wiki/OpenAI#cite_ref-52] | [TOKENS: 8773] |
Contents OpenAI OpenAI is an American artificial intelligence research organization comprising both a non-profit foundation and a controlled for-profit public benefit corporation (PBC), headquartered in San Francisco. It aims to develop "safe and beneficial" artificial general intelligence (AGI), which it defines as "highly autonomous systems that outperform humans at most economically valuable work". OpenAI is widely recognized for its development of the GPT family of large language models, the DALL-E series of text-to-image models, and the Sora series of text-to-video models, which have influenced industry research and commercial applications. Its release of ChatGPT in November 2022 has been credited with catalyzing widespread interest in generative AI. The organization was founded in 2015 in Delaware but evolved a complex corporate structure. As of October 2025, following restructuring approved by California and Delaware regulators, the non-profit OpenAI Foundation holds 26% of the for-profit OpenAI Group PBC, with Microsoft holding 27% and employees/other investors holding 47%. Under its governance arrangements, the OpenAI Foundation holds the authority to appoint the board of the for-profit OpenAI Group PBC, a mechanism designed to align the entity’s strategic direction with the Foundation’s charter. Microsoft previously invested over $13 billion into OpenAI, and provides Azure cloud computing resources. In October 2025, OpenAI conducted a $6.6 billion share sale that valued the company at $500 billion. In 2023 and 2024, OpenAI faced multiple lawsuits for alleged copyright infringement against authors and media companies whose work was used to train some of OpenAI's products. In November 2023, OpenAI's board removed Sam Altman as CEO, citing a lack of confidence in him, but reinstated him five days later following a reconstruction of the board. Throughout 2024, roughly half of then-employed AI safety researchers left OpenAI, citing the company's prominent role in an industry-wide problem. Founding In December 2015, OpenAI was founded as a not for profit organization by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, Trevor Blackwell, Vicki Cheung, Andrej Karpathy, Durk Kingma, John Schulman, Pamela Vagata, and Wojciech Zaremba, with Sam Altman and Elon Musk as the co-chairs. A total of $1 billion in capital was pledged by Sam Altman, Greg Brockman, Elon Musk, Reid Hoffman, Jessica Livingston, Peter Thiel, Amazon Web Services (AWS), and Infosys. However, the actual capital collected significantly lagged pledges. According to company disclosures, only $130 million had been received by 2019. In its founding charter, OpenAI stated an intention to collaborate openly with other institutions by making certain patents and research publicly available, but later restricted access to its most capable models, citing competitive and safety concerns. OpenAI was initially run from Brockman's living room. It was later headquartered at the Pioneer Building in the Mission District, San Francisco. According to OpenAI's charter, its founding mission is "to ensure that artificial general intelligence (AGI)—by which we mean highly autonomous systems that outperform humans at most economically valuable work—benefits all of humanity." Musk and Altman stated in 2015 that they were partly motivated by concerns about AI safety and existential risk from artificial general intelligence. OpenAI stated that "it's hard to fathom how much human-level AI could benefit society", and that it is equally difficult to comprehend "how much it could damage society if built or used incorrectly". The startup also wrote that AI "should be an extension of individual human wills and, in the spirit of liberty, as broadly and evenly distributed as possible", and that "because of AI's surprising history, it's hard to predict when human-level AI might come within reach. When it does, it'll be important to have a leading research institution which can prioritize a good outcome for all over its own self-interest." Co-chair Sam Altman expected a decades-long project that eventually surpasses human intelligence. Brockman met with Yoshua Bengio, one of the "founding fathers" of deep learning, and drew up a list of great AI researchers. Brockman was able to hire nine of them as the first employees in December 2015. OpenAI did not pay AI researchers salaries comparable to those of Facebook or Google. It also did not pay stock options which AI researchers typically get. Nevertheless, OpenAI spent $7 million on its first 52 employees in 2016. OpenAI's potential and mission drew these researchers to the firm; a Google employee said he was willing to leave Google for OpenAI "partly because of the very strong group of people and, to a very large extent, because of its mission." OpenAI co-founder Wojciech Zaremba stated that he turned down "borderline crazy" offers of two to three times his market value to join OpenAI instead. In April 2016, OpenAI released a public beta of "OpenAI Gym", its platform for reinforcement learning research. Nvidia gifted its first DGX-1 supercomputer to OpenAI in August 2016 to help it train larger and more complex AI models with the capability of reducing processing time from six days to two hours. In December 2016, OpenAI released "Universe", a software platform for measuring and training an AI's general intelligence across the world's supply of games, websites, and other applications. Corporate structure In 2019, OpenAI transitioned from non-profit to "capped" for-profit, with the profit being capped at 100 times any investment. According to OpenAI, the capped-profit model allows OpenAI Global, LLC to legally attract investment from venture funds and, in addition, to grant employees stakes in the company. Many top researchers work for Google Brain, DeepMind, or Facebook, which offer equity that a nonprofit would be unable to match. Before the transition, OpenAI was legally required to publicly disclose the compensation of its top employees. The company then distributed equity to its employees and partnered with Microsoft, announcing an investment package of $1 billion into the company. Since then, OpenAI systems have run on an Azure-based supercomputing platform from Microsoft. OpenAI Global, LLC then announced its intention to commercially license its technologies. It planned to spend $1 billion "within five years, and possibly much faster". Altman stated that even a billion dollars may turn out to be insufficient, and that the lab may ultimately need "more capital than any non-profit has ever raised" to achieve artificial general intelligence. The nonprofit, OpenAI, Inc., is the sole controlling shareholder of OpenAI Global, LLC, which, despite being a for-profit company, retains a formal fiduciary responsibility to OpenAI, Inc.'s nonprofit charter. A majority of OpenAI, Inc.'s board is barred from having financial stakes in OpenAI Global, LLC. In addition, minority members with a stake in OpenAI Global, LLC are barred from certain votes due to conflict of interest. Some researchers have argued that OpenAI Global, LLC's switch to for-profit status is inconsistent with OpenAI's claims to be "democratizing" AI. On February 29, 2024, Elon Musk filed a lawsuit against OpenAI and CEO Sam Altman, accusing them of shifting focus from public benefit to profit maximization—a case OpenAI dismissed as "incoherent" and "frivolous," though Musk later revived legal action against Altman and others in August. On April 9, 2024, OpenAI countersued Musk in federal court, alleging that he had engaged in "bad-faith tactics" to slow the company's progress and seize its innovations for his personal benefit. OpenAI also argued that Musk had previously supported the creation of a for-profit structure and had expressed interest in controlling OpenAI himself. The countersuit seeks damages and legal measures to prevent further alleged interference. On February 10, 2025, a consortium of investors led by Elon Musk submitted a $97.4 billion unsolicited bid to buy the nonprofit that controls OpenAI, declaring willingness to match or exceed any better offer. The offer was rejected on 14 February 2025, with OpenAI stating that it was not for sale, but the offer complicated Altman's restructuring plan by suggesting a lower bar for how much the nonprofit should be valued. OpenAI, Inc. was originally designed as a nonprofit in order to ensure that AGI "benefits all of humanity" rather than "the private gain of any person". In 2019, it created OpenAI Global, LLC, a capped-profit subsidiary controlled by the nonprofit. In December 2024, OpenAI proposed a restructuring plan to convert the capped-profit into a Delaware-based public benefit corporation (PBC), and to release it from the control of the nonprofit. The nonprofit would sell its control and other assets, getting equity in return, and would use it to fund and pursue separate charitable projects, including in science and education. OpenAI's leadership described the change as necessary to secure additional investments, and claimed that the nonprofit's founding mission to ensure AGI "benefits all of humanity" would be better fulfilled. The plan has been criticized by former employees. A legal letter named "Not For Private Gain" asked the attorneys general of California and Delaware to intervene, stating that the restructuring is illegal and would remove governance safeguards from the nonprofit and the attorneys general. The letter argues that OpenAI's complex structure was deliberately designed to remain accountable to its mission, without the conflicting pressure of maximizing profits. It contends that the nonprofit is best positioned to advance its mission of ensuring AGI benefits all of humanity by continuing to control OpenAI Global, LLC, whatever the amount of equity that it could get in exchange. PBCs can choose how they balance their mission with profit-making. Controlling shareholders have a large influence on how closely a PBC sticks to its mission. On October 28, 2025, OpenAI announced that it had adopted the new PBC corporate structure after receiving approval from the attorneys general of California and Delaware. Under the new structure, OpenAI's for-profit branch became a public benefit corporation known as OpenAI Group PBC, while the non-profit was renamed to the OpenAI Foundation. The OpenAI Foundation holds a 26% stake in the PBC, while Microsoft holds a 27% stake and the remaining 47% is owned by employees and other investors. All members of the OpenAI Group PBC board of directors will be appointed by the OpenAI Foundation, which can remove them at any time. Members of the Foundation's board will also serve on the for-profit board. The new structure allows the for-profit PBC to raise investor funds like most traditional tech companies, including through an initial public offering, which Altman claimed was the most likely path forward. In January 2023, OpenAI Global, LLC was in talks for funding that would value the company at $29 billion, double its 2021 value. On January 23, 2023, Microsoft announced a new US$10 billion investment in OpenAI Global, LLC over multiple years, partially needed to use Microsoft's cloud-computing service Azure. From September to December, 2023, Microsoft rebranded all variants of its Copilot to Microsoft Copilot, and they added MS-Copilot to many installations of Windows and released Microsoft Copilot mobile apps. Following OpenAI's 2025 restructuring, Microsoft owns a 27% stake in the for-profit OpenAI Group PBC, valued at $135 billion. In a deal announced the same day, OpenAI agreed to purchase $250 billion of Azure services, with Microsoft ceding their right of first refusal over OpenAI's future cloud computing purchases. As part of the deal, OpenAI will continue to share 20% of its revenue with Microsoft until it achieves AGI, which must now be verified by an independent panel of experts. The deal also loosened restrictions on both companies working with third parties, allowing Microsoft to pursue AGI independently and allowing OpenAI to develop products with other companies. In 2017, OpenAI spent $7.9 million, a quarter of its functional expenses, on cloud computing alone. In comparison, DeepMind's total expenses in 2017 were $442 million. In the summer of 2018, training OpenAI's Dota 2 bots required renting 128,000 CPUs and 256 GPUs from Google for multiple weeks. In October 2024, OpenAI completed a $6.6 billion capital raise with a $157 billion valuation including investments from Microsoft, Nvidia, and SoftBank. On January 21, 2025, Donald Trump announced The Stargate Project, a joint venture between OpenAI, Oracle, SoftBank and MGX to build an AI infrastructure system in conjunction with the US government. The project takes its name from OpenAI's existing "Stargate" supercomputer project and is estimated to cost $500 billion. The partners planned to fund the project over the next four years. In July, the United States Department of Defense announced that OpenAI had received a $200 million contract for AI in the military, along with Anthropic, Google, and xAI. In the same month, the company made a deal with the UK Government to use ChatGPT and other AI tools in public services. OpenAI subsequently began a $50 million fund to support nonprofit and community organizations. In April 2025, OpenAI raised $40 billion at a $300 billion post-money valuation, which was the highest-value private technology deal in history. The financing round was led by SoftBank, with other participants including Microsoft, Coatue, Altimeter and Thrive. In July 2025, the company reported annualized revenue of $12 billion. This was an increase from $3.7 billion in 2024, which was driven by ChatGPT subscriptions, which reached 20 million paid subscribers by April 2025, up from 15.5 million at the end of 2024, alongside a rapidly expanding enterprise customer base that grew to five million business users. The company’s cash burn remains high because of the intensive computational costs required to train and operate large language models. It projects an $8 billion operating loss in 2025. OpenAI reports revised long-term spending projections totaling approximately $115 billion through 2029, with annual expenditures projected to escalate significantly, reaching $17 billion in 2026, $35 billion in 2027, and $45 billion in 2028. These expenditures are primarily allocated toward expanding compute infrastructure, developing proprietary AI chips, constructing data centers, and funding intensive model training programs, with more than half of the spending through the end of the decade expected to support research-intensive compute for model training and development. The company's financial strategy prioritizes market expansion and technological advancement over near-term profitability, with OpenAI targeting cash-flow-positive operations by 2029 and projecting revenue of approximately $200 billion by 2030. This aggressive spending trajectory underscores both the enormous capital requirements of scaling cutting-edge AI technology and OpenAI's commitment to maintaining its position as a leader in the artificial intelligence industry. In October 2025, OpenAI completed an employee share sale of up to $10 billion to existing investors which valued the company at $500 billion. The deal values OpenAI as the most valuable privately owned company in the world—surpassing SpaceX as the world's most valuable private company. On November 17, 2023, Sam Altman was removed as CEO when its board of directors (composed of Helen Toner, Ilya Sutskever, Adam D'Angelo and Tasha McCauley) cited a lack of confidence in him. Chief Technology Officer Mira Murati took over as interim CEO. Greg Brockman, the president of OpenAI, was also removed as chairman of the board and resigned from the company's presidency shortly thereafter. Three senior OpenAI researchers subsequently resigned: director of research and GPT-4 lead Jakub Pachocki, head of AI risk Aleksander Mądry, and researcher Szymon Sidor. On November 18, 2023, there were reportedly talks of Altman returning as CEO amid pressure placed upon the board by investors such as Microsoft and Thrive Capital, who objected to Altman's departure. Although Altman himself spoke in favor of returning to OpenAI, he has since stated that he considered starting a new company and bringing former OpenAI employees with him if talks to reinstate him didn't work out. The board members agreed "in principle" to resign if Altman returned. On November 19, 2023, negotiations with Altman to return failed and Murati was replaced by Emmett Shear as interim CEO. The board initially contacted Anthropic CEO Dario Amodei (a former OpenAI executive) about replacing Altman, and proposed a merger of the two companies, but both offers were declined. On November 20, 2023, Microsoft CEO Satya Nadella announced Altman and Brockman would be joining Microsoft to lead a new advanced AI research team, but added that they were still committed to OpenAI despite recent events. Before the partnership with Microsoft was finalized, Altman gave the board another opportunity to negotiate with him. About 738 of OpenAI's 770 employees, including Murati and Sutskever, signed an open letter stating they would quit their jobs and join Microsoft if the board did not rehire Altman and then resign. This prompted OpenAI investors to consider legal action against the board as well. In response, OpenAI management sent an internal memo to employees stating that negotiations with Altman and the board had resumed and would take some time. On November 21, 2023, after continued negotiations, Altman and Brockman returned to the company in their prior roles along with a reconstructed board made up of new members Bret Taylor (as chairman) and Lawrence Summers, with D'Angelo remaining. According to subsequent reporting, shortly before Altman’s firing, some employees raised concerns to the board about how he had handled the safety implications of a recent internal AI capability discovery. On November 29, 2023, OpenAI announced that an anonymous Microsoft employee had joined the board as a non-voting member to observe the company's operations; Microsoft resigned from the board in July 2024. In February 2024, the Securities and Exchange Commission subpoenaed OpenAI's internal communication to determine if Altman's alleged lack of candor misled investors. In 2024, following the temporary removal of Sam Altman and his return, many employees gradually left OpenAI, including most of the original leadership team and a significant number of AI safety researchers. In August 2023, it was announced that OpenAI had acquired the New York-based start-up Global Illumination, a company that deploys AI to develop digital infrastructure and creative tools. In June 2024, OpenAI acquired Multi, a startup focused on remote collaboration. In March 2025, OpenAI reached a deal with CoreWeave to acquire $350 million worth of CoreWeave shares and access to AI infrastructure, in return for $11.9 billion paid over five years. Microsoft was already CoreWeave's biggest customer in 2024. Alongside their other business dealings, OpenAI and Microsoft were renegotiating the terms of their partnership to facilitate a potential future initial public offering by OpenAI, while ensuring Microsoft's continued access to advanced AI models. On May 21, OpenAI announced the $6.5 billion acquisition of io, an AI hardware start-up founded by former Apple designer Jony Ive in 2024. In September 2025, OpenAI agreed to acquire the product testing startup Statsig for $1.1 billion in an all-stock deal and appointed Statsig's founding CEO Vijaye Raji as OpenAI's chief technology officer of applications. The company also announced development of an AI-driven hiring service designed to rival LinkedIn. OpenAI acquired personal finance app Roi in October 2025. In October 2025, OpenAI acquired Software Applications Incorporated, the developer of Sky, a macOS-based natural language interface designed to operate across desktop applications. The Sky team joined OpenAI, and the company announced plans to integrate Sky’s capabilities into ChatGPT. In December 2025, it was announced OpenAI had agreed to acquire Neptune, an AI tooling startup that helps companies track and manage model training, for an undisclosed amount. In January 2026, it was announced OpenAI had acquired healthcare technology startup Torch for approximately $60 million. The acquisition followed the launch of OpenAI’s ChatGPT Health product and was intended to strengthen the company’s medical data and healthcare artificial intelligence capabilities. OpenAI has been criticized for outsourcing the annotation of data sets to Sama, a company based in San Francisco that employed workers in Kenya. These annotations were used to train an AI model to detect toxicity, which could then be used to moderate toxic content, notably from ChatGPT's training data and outputs. However, these pieces of text usually contained detailed descriptions of various types of violence, including sexual violence. The investigation uncovered that OpenAI began sending snippets of data to Sama as early as November 2021. The four Sama employees interviewed by Time described themselves as mentally scarred. OpenAI paid Sama $12.50 per hour of work, and Sama was redistributing the equivalent of between $1.32 and $2.00 per hour post-tax to its annotators. Sama's spokesperson said that the $12.50 was also covering other implicit costs, among which were infrastructure expenses, quality assurance and management. In 2024, OpenAI began collaborating with Broadcom to design a custom AI chip capable of both training and inference, targeted for mass production in 2026 and to be manufactured by TSMC on a 3 nm process node. This initiative intended to reduce OpenAI's dependence on Nvidia GPUs, which are costly and face high demand in the market. In January 2024, Arizona State University purchased ChatGPT Enterprise in OpenAI's first deal with a university. In June 2024, Apple Inc. signed a contract with OpenAI to integrate ChatGPT features into its products as part of its new Apple Intelligence initiative. In June 2025, OpenAI began renting Google Cloud's Tensor Processing Units (TPUs) to support ChatGPT and related services, marking its first meaningful use of non‑Nvidia AI chips. In September 2025, it was revealed that OpenAI signed a contract with Oracle to purchase $300 billion in computing power over the next five years. In September 2025, OpenAI and NVIDIA announced a memorandum of understanding that included a potential deployment of at least 10 gigawatts of NVIDIA systems and a $100 billion investment from NVIDIA in OpenAI. OpenAI expected the negotiations to be completed within weeks. As of January 2026, this has not been realized, and the two sides are rethinking the future of their partnership. In October 2025, OpenAI announced a multi-billion dollar deal with AMD. OpenAI committed to purchasing six gigawatts worth of AMD chips, starting with the MI450. OpenAI will have the option to buy up to 160 million shares of AMD, about 10% of the company, depending on development, performance and share price targets. In December 2025, Disney said it would make a $1 billion investment in OpenAI, and signed a three-year licensing deal that will let users generate videos using Sora—OpenAI's short-form AI video platform. More than 200 Disney, Marvel, Star Wars and Pixar characters will be available to OpenAI users. In early 2026, Amazon entered advanced discussions to invest up to $50 billion in OpenAI as part of a potential artificial intelligence partnership. Under the proposed agreement, OpenAI’s models could be integrated into Amazon’s digital assistant Alexa and other internal projects. OpenAI provides LLMs to the Artificial Intelligence Cyber Challenge and to the Advanced Research Projects Agency for Health. In October 2024, The Intercept revealed that OpenAI's tools are considered "essential" for AFRICOM's mission and included in an "Exception to Fair Opportunity" contractual agreement between the United States Department of Defense and Microsoft. In December 2024, OpenAI said it would partner with defense-tech company Anduril to build drone defense technologies for the United States and its allies. In 2025, OpenAI's Chief Product Officer, Kevin Weil, was commissioned lieutenant colonel in the U.S. Army to join Detachment 201 as senior advisor. In June 2025, the U.S. Department of Defense awarded OpenAI a $200 million one-year contract to develop AI tools for military and national security applications. OpenAI announced a new program, OpenAI for Government, to give federal, state, and local governments access to its models, including ChatGPT. Services In February 2019, GPT-2 was announced, which gained attention for its ability to generate human-like text. In 2020, OpenAI announced GPT-3, a language model trained on large internet datasets. GPT-3 is aimed at natural language answering questions, but it can also translate between languages and coherently generate improvised text. It also announced that an associated API, named the API, would form the heart of its first commercial product. Eleven employees left OpenAI, mostly between December 2020 and January 2021, in order to establish Anthropic. In 2021, OpenAI introduced DALL-E, a specialized deep learning model adept at generating complex digital images from textual descriptions, utilizing a variant of the GPT-3 architecture. In December 2022, OpenAI received widespread media coverage after launching a free preview of ChatGPT, its new AI chatbot based on GPT-3.5. According to OpenAI, the preview received over a million signups within the first five days. According to anonymous sources cited by Reuters in December 2022, OpenAI Global, LLC was projecting $200 million of revenue in 2023 and $1 billion in revenue in 2024. After ChatGPT was launched, Google announced a similar chatbot, Bard, amid internal concerns that ChatGPT could threaten Google’s position as a primary source of online information. On February 7, 2023, Microsoft announced that it was building AI technology based on the same foundation as ChatGPT into Microsoft Bing, Edge, Microsoft 365 and other products. On March 14, 2023, OpenAI released GPT-4, both as an API (with a waitlist) and as a feature of ChatGPT Plus. On November 6, 2023, OpenAI launched GPTs, allowing individuals to create customized versions of ChatGPT for specific purposes, further expanding the possibilities of AI applications across various industries. On November 14, 2023, OpenAI announced they temporarily suspended new sign-ups for ChatGPT Plus due to high demand. Access for newer subscribers re-opened a month later on December 13. In December 2024, the company launched the Sora model. It also launched OpenAI o1, an early reasoning model that was internally codenamed strawberry. Additionally, ChatGPT Pro—a $200/month subscription service offering unlimited o1 access and enhanced voice features—was introduced, and preliminary benchmark results for the upcoming OpenAI o3 models were shared. On January 23, 2025, OpenAI released Operator, an AI agent and web automation tool for accessing websites to execute goals defined by users. The feature was only available to Pro users in the United States. OpenAI released deep research agent, nine days later. It scored a 27% accuracy on the benchmark Humanity's Last Exam (HLE). Altman later stated GPT-4.5 would be the last model without full chain-of-thought reasoning. In July 2025, reports indicated that AI models by both OpenAI and Google DeepMind solved mathematics problems at the level of top-performing students in the International Mathematical Olympiad. OpenAI's large language model was able to achieve gold medal-level performance, reflecting significant progress in AI's reasoning abilities. On October 6, 2025, OpenAI unveiled its Agent Builder platform during the company's DevDay event. The platform includes a visual drag-and-drop interface that lets developers and businesses design, test, and deploy agentic workflows with limited coding. On October 21, 2025, OpenAI introduced ChatGPT Atlas, a browser integrating the ChatGPT assistant directly into web navigation, to compete with existing browsers such as Google Chrome and Apple Safari. On December 11, 2025, OpenAI announced GPT-5.2. This model will be better at creating spreadsheets, building presentations, perceiving images, writing code and understanding long context. On January 27, 2026, OpenAI introduced Prism, a LaTeX-native workspace meant to assist scientists to help with research and writing. The platform utilizes GPT-5.2 as a backend to automate the process of drafting for scientific papers, including features for managing citations, complex equation formatting, and real-time collaborative editing. In March 2023, the company was criticized for disclosing particularly few technical details about products like GPT-4, contradicting its initial commitment to openness and making it harder for independent researchers to replicate its work and develop safeguards. OpenAI cited competitiveness and safety concerns to justify this repudiation. OpenAI's former chief scientist Ilya Sutskever argued in 2023 that open-sourcing increasingly capable models was increasingly risky, and that the safety reasons for not open-sourcing the most potent AI models would become "obvious" in a few years. In September 2025, OpenAI published a study on how people use ChatGPT for everyday tasks. The study found that "non-work tasks" (according to an LLM-based classifier) account for more than 72 percent of all ChatGPT usage, with a minority of overall usage related to business productivity. In July 2023, OpenAI launched the superalignment project, aiming within four years to determine how to align future superintelligent systems. OpenAI promised to dedicate 20% of its computing resources to the project, although the team denied receiving anything close to 20%. OpenAI ended the project in May 2024 after its co-leaders Ilya Sutskever and Jan Leike left the company. In August 2025, OpenAI was criticized after thousands of private ChatGPT conversations were inadvertently exposed to public search engines like Google due to an experimental "share with search engines" feature. The opt-in toggle, intended to allow users to make specific chats discoverable, resulted in some discussions including personal details such as names, locations, and intimate topics appearing in search results when users accidentally enabled it while sharing links. OpenAI announced the feature's permanent removal on August 1, 2025, and the company began coordinating with search providers to remove the exposed content, emphasizing that it was not a security breach but a design flaw that heightened privacy risks. CEO Sam Altman acknowledged the issue in a podcast, noting users often treat ChatGPT as a confidant for deeply personal matters, which amplified concerns about AI handling sensitive data. Management In 2018, Musk resigned from his Board of Directors seat, citing "a potential future conflict [of interest]" with his role as CEO of Tesla due to Tesla's AI development for self-driving cars. OpenAI stated that Musk's financial contributions were below $45 million. On March 3, 2023, Reid Hoffman resigned from his board seat, citing a desire to avoid conflicts of interest with his investments in AI companies via Greylock Partners, and his co-founding of the AI startup Inflection AI. Hoffman remained on the board of Microsoft, a major investor in OpenAI. In May 2024, Chief Scientist Ilya Sutskever resigned and was succeeded by Jakub Pachocki. Co-leader Jan Leike also departed amid concerns over safety and trust. OpenAI then signed deals with Reddit, News Corp, Axios, and Vox Media. Paul Nakasone then joined the board of OpenAI. In August 2024, cofounder John Schulman left OpenAI to join Anthropic, and OpenAI's president Greg Brockman took extended leave until November. In September 2024, CTO Mira Murati left the company. In November 2025, Lawrence Summers resigned from the board of directors. Governance and legal issues In May 2023, Sam Altman, Greg Brockman and Ilya Sutskever posted recommendations for the governance of superintelligence. They stated that superintelligence could happen within the next 10 years, allowing a "dramatically more prosperous future" and that "given the possibility of existential risk, we can't just be reactive". They proposed creating an international watchdog organization similar to IAEA to oversee AI systems above a certain capability threshold, suggesting that relatively weak AI systems on the other side should not be overly regulated. They also called for more technical safety research for superintelligences, and asked for more coordination, for example through governments launching a joint project which "many current efforts become part of". In July 2023, the FTC issued a civil investigative demand to OpenAI to investigate whether the company's data security and privacy practices to develop ChatGPT were unfair or harmed consumers (including by reputational harm) in violation of Section 5 of the Federal Trade Commission Act of 1914. These are typically preliminary investigative matters and are nonpublic, but the FTC's document was leaked. In July 2023, the FTC launched an investigation into OpenAI over allegations that the company scraped public data and published false and defamatory information. They asked OpenAI for comprehensive information about its technology and privacy safeguards, as well as any steps taken to prevent the recurrence of situations in which its chatbot generated false and derogatory content about people. The agency also raised concerns about ‘circular’ spending arrangements—for example, Microsoft extending Azure credits to OpenAI while both companies shared engineering talent—and warned that such structures could negatively affect the public. In September 2024, OpenAI's global affairs chief endorsed the UK's "smart" AI regulation during testimony to a House of Lords committee. In February 2025, OpenAI CEO Sam Altman stated that the company is interested in collaborating with the People's Republic of China, despite regulatory restrictions imposed by the U.S. government. This shift comes in response to the growing influence of the Chinese artificial intelligence company DeepSeek, which has disrupted the AI market with open models, including DeepSeek V3 and DeepSeek R1. Following DeepSeek's market emergence, OpenAI enhanced security protocols to protect proprietary development techniques from industrial espionage. Some industry observers noted similarities between DeepSeek's model distillation approach and OpenAI's methodology, though no formal intellectual property claim was filed. According to Oliver Roberts, in March 2025, the United States had 781 state AI bills or laws. OpenAI advocated for preempting state AI laws with federal laws. According to Scott Kohler, OpenAI has opposed California's AI legislation and suggested that the state bill encroaches on a more competent federal government. Public Citizen opposed a federal preemption on AI and pointed to OpenAI's growth and valuation as evidence that existing state laws have not hampered innovation. Before May 2024, OpenAI required departing employees to sign a lifelong non-disparagement agreement forbidding them from criticizing OpenAI and acknowledging the existence of the agreement. Daniel Kokotajlo, a former employee, publicly stated that he forfeited his vested equity in OpenAI in order to leave without signing the agreement. Sam Altman stated that he was unaware of the equity cancellation provision, and that OpenAI never enforced it to cancel any employee's vested equity. However, leaked documents and emails refute this claim. On May 23, 2024, OpenAI sent a memo releasing former employees from the agreement. OpenAI was sued for copyright infringement by authors Sarah Silverman, Matthew Butterick, Paul Tremblay and Mona Awad in July 2023. In September 2023, 17 authors, including George R. R. Martin, John Grisham, Jodi Picoult and Jonathan Franzen, joined the Authors Guild in filing a class action lawsuit against OpenAI, alleging that the company's technology was illegally using their copyrighted work. The New York Times also sued the company in late December 2023. In May 2024 it was revealed that OpenAI had destroyed its Books1 and Books2 training datasets, which were used in the training of GPT-3, and which the Authors Guild believed to have contained over 100,000 copyrighted books. In 2021, OpenAI developed a speech recognition tool called Whisper. OpenAI used it to transcribe more than one million hours of YouTube videos into text for training GPT-4. The automated transcription of YouTube videos raised concerns within OpenAI employees regarding potential violations of YouTube's terms of service, which prohibit the use of videos for applications independent of the platform, as well as any type of automated access to its videos. Despite these concerns, the project proceeded with notable involvement from OpenAI's president, Greg Brockman. The resulting dataset proved instrumental in training GPT-4. In February 2024, The Intercept as well as Raw Story and Alternate Media Inc. filed lawsuit against OpenAI on copyright litigation ground. The lawsuit is said to have charted a new legal strategy for digital-only publishers to sue OpenAI. On April 30, 2024, eight newspapers filed a lawsuit in the Southern District of New York against OpenAI and Microsoft, claiming illegal harvesting of their copyrighted articles. The suing publications included The Mercury News, The Denver Post, The Orange County Register, St. Paul Pioneer Press, Chicago Tribune, Orlando Sentinel, Sun Sentinel, and New York Daily News. In June 2023, a lawsuit claimed that OpenAI scraped 300 billion words online without consent and without registering as a data broker. It was filed in San Francisco, California, by sixteen anonymous plaintiffs. They also claimed that OpenAI and its partner as well as customer Microsoft continued to unlawfully collect and use personal data from millions of consumers worldwide to train artificial intelligence models. On May 22, 2024, OpenAI entered into an agreement with News Corp to integrate news content from The Wall Street Journal, the New York Post, The Times, and The Sunday Times into its AI platform. Meanwhile, other publications like The New York Times chose to sue OpenAI and Microsoft for copyright infringement over the use of their content to train AI models. In November 2024, a coalition of Canadian news outlets, including the Toronto Star, Metroland Media, Postmedia, The Globe and Mail, The Canadian Press and CBC, sued OpenAI for using their news articles to train its software without permission. In October 2024 during a New York Times interview, Suchir Balaji accused OpenAI of violating copyright law in developing its commercial LLMs which he had helped engineer. He was a likely witness in a major copyright trial against the AI company, and was one of several of its current or former employees named in court filings as potentially having documents relevant to the case. On November 26, 2024, Balaji died by suicide. His death prompted the circulation of conspiracy theories alleging that he had been deliberately silenced. California Congressman Ro Khanna endorsed calls for an investigation. On April 24, 2025, Ziff Davis sued OpenAI in Delaware federal court for copyright infringement. Ziff Davis is known for publications such as ZDNet, PCMag, CNET, IGN and Lifehacker. In April 2023, the EU's European Data Protection Board (EDPB) formed a dedicated task force on ChatGPT "to foster cooperation and to exchange information on possible enforcement actions conducted by data protection authorities" based on the "enforcement action undertaken by the Italian data protection authority against OpenAI about the ChatGPT service". In late April 2024 NOYB filed a complaint with the Austrian Datenschutzbehörde against OpenAI for violating the European General Data Protection Regulation. A text created with ChatGPT gave a false date of birth for a living person without giving the individual the option to see the personal data used in the process. A request to correct the mistake was denied. Additionally, neither the recipients of ChatGPT's work nor the sources used, could be made available, OpenAI claimed. OpenAI was criticized for lifting its ban on using ChatGPT for "military and warfare". Up until January 10, 2024, its "usage policies" included a ban on "activity that has high risk of physical harm, including", specifically, "weapons development" and "military and warfare". Its new policies prohibit "[using] our service to harm yourself or others" and to "develop or use weapons". In August 2025, the parents of a 16-year-old boy who died by suicide filed a wrongful death lawsuit against OpenAI (and CEO Sam Altman), alleging that months of conversations with ChatGPT about mental health and methods of self-harm contributed to their son's death and that safeguards were inadequate for minors. OpenAI expressed condolences and said it was strengthening protections (including updated crisis response behavior and parental controls). Coverage described it as a first-of-its-kind wrongful death case targeting the company's chatbot. The complaint was filed in California state court in San Francisco. In November 2025, the Social Media Victims Law Center and Tech Justice Law Project filed seven lawsuits against OpenAI, of which four lawsuits alleged wrongful death. The suits were filed on behalf of Zane Shamblin, 23, of Texas; Amaurie Lacey, 17, of Georgia; Joshua Enneking, 26, of Florida; and Joe Ceccanti, 48, of Oregon, who each committed suicide after prolonged ChatGPT usage. In December 2025, Stein-Erik Soelberg, who was 56 years old at the time, allegedly murdered his mother Suzanne Adams. In the months prior the paranoid, delusional man often discussed his ideas with ChatGPT. Adam's estate then sued OpenAI claiming that the company shared responsibility due to the risk of chatbot psychosis despite the fact that chatbot psychosis is not a real medical diagnosis. OpenAI responded saying they will make ChatGPT safer for users disconnected from reality. See also References Further reading External links |
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Contents Black hole A black hole is an astronomical body so compact that its gravity prevents anything, including light, from escaping. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. The boundary of no escape is called the event horizon. In general relativity, a black hole's event horizon seals an object's fate but produces no locally detectable change when crossed. General relativity also predicts that every black hole should have a central singularity, where the curvature of spacetime is infinite. In many ways, a black hole acts like an ideal black body, as it reflects no light. Quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. In 1916, Karl Schwarzschild found the first modern solution of general relativity that would characterise a black hole. Due to his influential research, the Schwarzschild metric is named after him. David Finkelstein, in 1958, first interpreted Schwarzschild's model as a region of space from which nothing can escape. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The first black hole known was Cygnus X-1, identified by several researchers independently in 1971. Black holes typically form when massive stars collapse at the end of their life cycle. After a black hole has formed, it can grow by absorbing mass from its surroundings. Supermassive black holes of millions of solar masses may form by absorbing other stars and merging with other black holes, or via direct collapse of gas clouds. There is consensus that supermassive black holes exist in the centres of most galaxies. The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter falling toward a black hole can form an accretion disk of infalling plasma, heated by friction and emitting light. In extreme cases, this creates a quasar, some of the brightest objects in the universe. Merging black holes can also be detected by observation of the gravitational waves they emit. If other stars are orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses. History The idea of a body so massive that even light could not escape was first proposed in the late 18th century by English astronomer and clergyman John Michell and independently by French scientist Pierre-Simon Laplace. Both scholars proposed very large stars in contrast to the modern concept of an extremely dense object. Michell's idea, in a short part of a letter published in 1784, calculated that a star with the same density but 500 times the radius of the sun would not let any emitted light escape; the surface escape velocity would exceed the speed of light.: 122 Michell correctly hypothesized that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies. In 1796, Laplace mentioned that a star could be invisible if it were sufficiently large while speculating on the origin of the Solar System in his book Exposition du Système du Monde. Franz Xaver von Zach asked Laplace for a mathematical analysis, which Laplace provided and published in a journal edited by von Zach. In 1905, Albert Einstein showed that the laws of electromagnetism would be invariant under a Lorentz transformation: they would be identical for observers travelling at different velocities relative to each other. This discovery became known as the principle of special relativity. Although the laws of mechanics had already been shown to be invariant, gravity remained yet to be included.: 19 In 1907, Einstein published a paper proposing his equivalence principle, the hypothesis that inertial mass and gravitational mass have a common cause. Using the principle, Einstein predicted the redshift and half of the lensing effect of gravity on light; the full prediction of gravitational lensing required development of general relativity.: 19 By 1915, Einstein refined these ideas into his general theory of relativity, which explained how matter affects spacetime, which in turn affects the motion of other matter. This formed the basis for black hole physics. Only a few months after Einstein published the field equations describing general relativity, astrophysicist Karl Schwarzschild set out to apply the idea to stars. He assumed spherical symmetry with no spin and found a solution to Einstein's equations.: 124 A few months after Schwarzschild, Johannes Droste, a student of Hendrik Lorentz, independently gave the same solution. At a certain radius from the center of the mass, the Schwarzschild solution became singular, meaning that some of the terms in the Einstein equations became infinite. The nature of this radius, which later became known as the Schwarzschild radius, was not understood at the time. Many physicists of the early 20th century were skeptical of the existence of black holes. In a 1926 popular science book, Arthur Eddington critiqued the idea of a star with mass compressed to its Schwarzschild radius as a flaw in the then-poorly-understood theory of general relativity.: 134 In 1939, Einstein himself used his theory of general relativity in an attempt to prove that black holes were impossible. His work relied on increasing pressure or increasing centrifugal force balancing the force of gravity so that the object would not collapse beyond its Schwarzschild radius. He missed the possibility that implosion would drive the system below this critical value.: 135 By the 1920s, astronomers had classified a number of white dwarf stars as too cool and dense to be explained by the gradual cooling of ordinary stars. In 1926, Ralph Fowler showed that quantum-mechanical degeneracy pressure was larger than thermal pressure at these densities.: 145 In 1931, Subrahmanyan Chandrasekhar calculated that a non-rotating body of electron-degenerate matter below a certain limiting mass is stable, and by 1934 he showed that this explained the catalog of white dwarf stars.: 151 When Chandrasekhar announced his results, Eddington pointed out that stars above this limit would radiate until they were sufficiently dense to prevent light from exiting, a conclusion he considered absurd. Eddington and, later, Lev Landau argued that some yet unknown mechanism would stop the collapse. In the 1930s, Fritz Zwicky and Walter Baade studied stellar novae, focusing on exceptionally bright ones they called supernovae. Zwicky promoted the idea that supernovae produced stars with the density of atomic nuclei—neutron stars—but this idea was largely ignored.: 171 In 1939, based on Chandrasekhar's reasoning, J. Robert Oppenheimer and George Volkoff predicted that neutron stars below a certain mass limit, later called the Tolman–Oppenheimer–Volkoff limit, would be stable due to neutron degeneracy pressure. Above that limit, they reasoned that either their model would not apply or that gravitational contraction would not stop.: 380 John Archibald Wheeler and two of his students resolved questions about the model behind the Tolman–Oppenheimer–Volkoff (TOV) limit. Harrison and Wheeler developed the equations of state relating density to pressure for cold matter all the way through electron degeneracy and neutron degeneracy. Masami Wakano and Wheeler then used the equations to compute the equilibrium curve for stars, relating mass to circumference. They found no additional features that would invalidate the TOV limit. This meant that the only thing that could prevent black holes from forming was a dynamic process ejecting sufficient mass from a star as it cooled.: 205 The modern concept of black holes was formulated by Robert Oppenheimer and his student Hartland Snyder in 1939.: 80 In the paper, Oppenheimer and Snyder solved Einstein's equations of general relativity for an idealized imploding star, in a model later called the Oppenheimer–Snyder model, then described the results from far outside the star. The implosion starts as one might expect: the star material rapidly collapses inward. However, as the density of the star increases, gravitational time dilation increases and the collapse, viewed from afar, seems to slow down further and further until the star reaches its Schwarzschild radius, where it appears frozen in time.: 217 In 1958, David Finkelstein identified the Schwarzschild surface as an event horizon, calling it "a perfect unidirectional membrane: causal influences can cross it in only one direction". In this sense, events that occur inside of the black hole cannot affect events that occur outside of the black hole. Finkelstein created a new reference frame to include the point of view of infalling observers.: 103 Finkelstein's new frame of reference allowed events at the surface of an imploding star to be related to events far away. By 1962 the two points of view were reconciled, convincing many skeptics that implosion into a black hole made physical sense.: 226 The era from the mid-1960s to the mid-1970s was the "golden age of black hole research", when general relativity and black holes became mainstream subjects of research.: 258 In this period, more general black hole solutions were found. In 1963, Roy Kerr found the exact solution for a rotating black hole. Two years later, Ezra Newman found the cylindrically symmetric solution for a black hole that is both rotating and electrically charged. In 1967, Werner Israel found that the Schwarzschild solution was the only possible solution for a nonspinning, uncharged black hole, meaning that a Schwarzschild black hole would be defined by its mass alone. Similar identities were later found for Reissner-Nordstrom and Kerr black holes, defined only by their mass and their charge or spin respectively. Together, these findings became known as the no-hair theorem, which states that a stationary black hole is completely described by the three parameters of the Kerr–Newman metric: mass, angular momentum, and electric charge. At first, it was suspected that the strange mathematical singularities found in each of the black hole solutions only appeared due to the assumption that a black hole would be perfectly spherically symmetric, and therefore the singularities would not appear in generic situations where black holes would not necessarily be symmetric. This view was held in particular by Vladimir Belinski, Isaak Khalatnikov, and Evgeny Lifshitz, who tried to prove that no singularities appear in generic solutions, although they would later reverse their positions. However, in 1965, Roger Penrose proved that general relativity without quantum mechanics requires that singularities appear in all black holes. Astronomical observations also made great strides during this era. In 1967, Antony Hewish and Jocelyn Bell Burnell discovered pulsars and by 1969, these were shown to be rapidly rotating neutron stars. Until that time, neutron stars, like black holes, were regarded as just theoretical curiosities, but the discovery of pulsars showed their physical relevance and spurred a further interest in all types of compact objects that might be formed by gravitational collapse. Based on observations in Greenwich and Toronto in the early 1970s, Cygnus X-1, a galactic X-ray source discovered in 1964, became the first astronomical object commonly accepted to be a black hole. Work by James Bardeen, Jacob Bekenstein, Carter, and Hawking in the early 1970s led to the formulation of black hole thermodynamics. These laws describe the behaviour of a black hole in close analogy to the laws of thermodynamics by relating mass to energy, area to entropy, and surface gravity to temperature. The analogy was completed: 442 when Hawking, in 1974, showed that quantum field theory implies that black holes should radiate like a black body with a temperature proportional to the surface gravity of the black hole, predicting the effect now known as Hawking radiation. While Cygnus X-1, a stellar-mass black hole, was generally accepted by the scientific community as a black hole by the end of 1973, it would be decades before a supermassive black hole would gain the same broad recognition. Although, as early as the 1960s, physicists such as Donald Lynden-Bell and Martin Rees had suggested that powerful quasars in the center of galaxies were powered by accreting supermassive black holes, little observational proof existed at the time. However, the Hubble Space Telescope, launched decades later, found that supermassive black holes were not only present in these active galactic nuclei, but that supermassive black holes in the center of galaxies were ubiquitous: Almost every galaxy had a supermassive black hole at its center, many of which were quiescent. In 1999, David Merritt proposed the M–sigma relation, which related the dispersion of the velocity of matter in the center bulge of a galaxy to the mass of the supermassive black hole at its core. Subsequent studies confirmed this correlation. Around the same time, based on telescope observations of the velocities of stars at the center of the Milky Way galaxy, independent work groups led by Andrea Ghez and Reinhard Genzel concluded that the compact radio source in the center of the galaxy, Sagittarius A*, was likely a supermassive black hole. On 11 February 2016, the LIGO Scientific Collaboration and Virgo Collaboration announced the first direct detection of gravitational waves, named GW150914, representing the first observation of a black hole merger. At the time of the merger, the black holes were approximately 1.4 billion light-years away from Earth and had masses of 30 and 35 solar masses.: 6 In 2017, Rainer Weiss, Kip Thorne, and Barry Barish, who had spearheaded the project, were awarded the Nobel Prize in Physics for their work. Since the initial discovery in 2015, hundreds more gravitational waves have been observed by LIGO and another interferometer, Virgo. On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope (EHT) in 2017 of the supermassive black hole in Messier 87's galactic centre. In 2022, the Event Horizon Telescope collaboration released an image of the black hole in the center of the Milky Way galaxy, Sagittarius A*; The data had been collected in 2017. In 2020, the Nobel Prize in Physics was awarded for work on black holes. Andrea Ghez and Reinhard Genzel shared one-half for their discovery that Sagittarius A* is a supermassive black hole. Penrose received the other half for his work showing that the mathematics of general relativity requires the formation of black holes. Cosmologists lamented that Hawking's extensive theoretical work on black holes would not be honored since he died in 2018. In December 1967, a student reportedly suggested the phrase black hole at a lecture by John Wheeler; Wheeler adopted the term for its brevity and "advertising value", and Wheeler's stature in the field ensured it quickly caught on, leading some to credit Wheeler with coining the phrase. However, the term was used by others around that time. Science writer Marcia Bartusiak traces the term black hole to physicist Robert H. Dicke, who in the early 1960s reportedly compared the phenomenon to the Black Hole of Calcutta, notorious as a prison where people entered but never left alive. The term was used in print by Life and Science News magazines in 1963, and by science journalist Ann Ewing in her article "'Black Holes' in Space", dated 18 January 1964, which was a report on a meeting of the American Association for the Advancement of Science held in Cleveland, Ohio. Definition A black hole is generally defined as a region of spacetime from which no information-carrying signals or objects can escape. However, verifying an object as a black hole by this definition would require waiting for an infinite time and at an infinite distance from the black hole to verify that indeed, nothing has escaped, and thus cannot be used to identify a physical black hole. Broadly, physicists do not have a precisely-agreed-upon definition of a black hole. Among astrophysicists, a black hole is a compact object with a mass larger than four solar masses. A black hole may also be defined as a reservoir of information: 142 or a region where space is falling inwards faster than the speed of light. Properties The no-hair theorem postulates that, once it achieves a stable condition after formation, a black hole has only three independent physical properties: mass, electric charge, and angular momentum; the black hole is otherwise featureless. If the conjecture is true, any two black holes that share the same values for these properties, or parameters, are indistinguishable from one another. The degree to which the conjecture is true for real black holes is currently an unsolved problem. The simplest static black holes have mass but neither electric charge nor angular momentum. According to Birkhoff's theorem, these Schwarzschild black holes are the only vacuum solution that is spherically symmetric. Solutions describing more general black holes also exist. Non-rotating charged black holes are described by the Reissner–Nordström metric, while the Kerr metric describes a non-charged rotating black hole. The most general stationary black hole solution known is the Kerr–Newman metric, which describes a black hole with both charge and angular momentum. The simplest static black holes have mass but neither electric charge nor angular momentum. Contrary to the popular notion of a black hole "sucking in everything" in its surroundings, from far away, the external gravitational field of a black hole is identical to that of any other body of the same mass. While a black hole can theoretically have any positive mass, the charge and angular momentum are constrained by the mass. The total electric charge Q and the total angular momentum J are expected to satisfy the inequality Q 2 4 π ϵ 0 + c 2 J 2 G M 2 ≤ G M 2 {\displaystyle {\frac {Q^{2}}{4\pi \epsilon _{0}}}+{\frac {c^{2}J^{2}}{GM^{2}}}\leq GM^{2}} for a black hole of mass M. Black holes with the maximum possible charge or spin satisfying this inequality are called extremal black holes. Solutions of Einstein's equations that violate this inequality exist, but they do not possess an event horizon. These are so-called naked singularities that can be observed from the outside. Because these singularities make the universe inherently unpredictable, many physicists believe they could not exist. The weak cosmic censorship hypothesis, proposed by Sir Roger Penrose, rules out the formation of such singularities, when they are created through the gravitational collapse of realistic matter. However, this theory has not yet been proven, and some physicists believe that naked singularities could exist. It is also unknown whether black holes could even become extremal, forming naked singularities, since natural processes counteract increasing spin and charge when a black hole becomes near-extremal. The total mass of a black hole can be estimated by analyzing the motion of objects near the black hole, such as stars or gas. All black holes spin, often fast—One supermassive black hole, GRS 1915+105 has been estimated to spin at over 1,000 revolutions per second. The Milky Way's central black hole Sagittarius A* rotates at about 90% of the maximum rate. The spin rate can be inferred from measurements of atomic spectral lines in the X-ray range. As gas near the black hole plunges inward, high energy X-ray emission from electron-positron pairs illuminates the gas further out, appearing red-shifted due to relativistic effects. Depending on the spin of the black hole, this plunge happens at different radii from the hole, with different degrees of redshift. Astronomers can use the gap between the x-ray emission of the outer disk and the redshifted emission from plunging material to determine the spin of the black hole. A newer way to estimate spin is based on the temperature of gasses accreting onto the black hole. The method requires an independent measurement of the black hole mass and inclination angle of the accretion disk followed by computer modeling. Gravitational waves from coalescing binary black holes can also provide the spin of both progenitor black holes and the merged hole, but such events are rare. A spinning black hole has angular momentum. The supermassive black hole in the center of the Messier 87 (M87) galaxy appears to have an angular momentum very close to the maximum theoretical value. That uncharged limit is J ≤ G M 2 c , {\displaystyle J\leq {\frac {GM^{2}}{c}},} allowing definition of a dimensionless spin magnitude such that 0 ≤ c J G M 2 ≤ 1. {\displaystyle 0\leq {\frac {cJ}{GM^{2}}}\leq 1.} Most black holes are believed to have an approximately neutral charge. For example, Michal Zajaček, Arman Tursunov, Andreas Eckart, and Silke Britzen found the electric charge of Sagittarius A* to be at least ten orders of magnitude below the theoretical maximum. A charged black hole repels other like charges just like any other charged object. If a black hole were to become charged, particles with an opposite sign of charge would be pulled in by the extra electromagnetic force, while particles with the same sign of charge would be repelled, neutralizing the black hole. This effect may not be as strong if the black hole is also spinning. The presence of charge can reduce the diameter of the black hole by up to 38%. The charge Q for a nonspinning black hole is bounded by Q ≤ G M , {\displaystyle Q\leq {\sqrt {G}}M,} where G is the gravitational constant and M is the black hole's mass. Classification Black holes can have a wide range of masses. The minimum mass of a black hole formed by stellar gravitational collapse is governed by the maximum mass of a neutron star and is believed to be approximately two-to-four solar masses. However, theoretical primordial black holes, believed to have formed soon after the Big Bang, could be far smaller, with masses as little as 10−5 grams at formation. These very small black holes are sometimes called micro black holes. Black holes formed by stellar collapse are called stellar black holes. Estimates of their maximum mass at formation vary, but generally range from 10 to 100 solar masses, with higher estimates for black holes progenated by low-metallicity stars. The mass of a black hole formed via a supernova has a lower bound: If the progenitor star is too small, the collapse may be stopped by the degeneracy pressure of the star's constituents, allowing the condensation of matter into an exotic denser state. Degeneracy pressure occurs from the Pauli exclusion principle—Particles will resist being in the same place as each other. Smaller progenitor stars, with masses less than about 8 M☉, will be held together by the degeneracy pressure of electrons and will become a white dwarf. For more massive progenitor stars, electron degeneracy pressure is no longer strong enough to resist the force of gravity and the star will be held together by neutron degeneracy pressure, which can occur at much higher densities, forming a neutron star. If the star is still too massive, even neutron degeneracy pressure will not be able to resist the force of gravity and the star will collapse into a black hole.: 5.8 Stellar black holes can also gain mass via accretion of nearby matter, often from a companion object such as a star. Black holes that are larger than stellar black holes but smaller than supermassive black holes are called intermediate-mass black holes, with masses of approximately 102 to 105 solar masses. These black holes seem to be rarer than their stellar and supermassive counterparts, with relatively few candidates having been observed. Physicists have speculated that such black holes may form from collisions in globular and star clusters or at the center of low-mass galaxies. They may also form as the result of mergers of smaller black holes, with several LIGO observations finding merged black holes within the 110-350 solar mass range. The black holes with the largest masses are called supermassive black holes, with masses more than 106 times that of the Sun. These black holes are believed to exist at the centers of almost every large galaxy, including the Milky Way. Some scientists have proposed a subcategory of even larger black holes, called ultramassive black holes, with masses greater than 109-1010 solar masses. Theoretical models predict that the accretion disc that feeds black holes will be unstable once a black hole reaches 50-100 billion times the mass of the Sun, setting a rough upper limit to black hole mass. Structure While black holes are conceptually invisible sinks of all matter and light, in astronomical settings, their enormous gravity alters the motion of surrounding objects and pulls nearby gas inwards at near-light speed, making the area around black holes the brightest objects in the universe. Some black holes have relativistic jets—thin streams of plasma travelling away from the black hole at more than one-tenth of the speed of light. A small faction of the matter falling towards the black hole gets accelerated away along the hole rotation axis. These jets can extend as far as millions of parsecs from the black hole itself. Black holes of any mass can have jets. However, they are typically observed around spinning black holes with strongly-magnetized accretion disks. Relativistic jets were more common in the early universe, when galaxies and their corresponding supermassive black holes were rapidly gaining mass. All black holes with jets also have an accretion disk, but the jets are usually brighter than the disk. Quasars, typically found in other galaxies, are believed to be supermassive black holes with jets; microquasars are believed to be stellar-mass objects with jets, typically observed in the Milky Way. The mechanism of formation of jets is not yet known, but several options have been proposed. One method proposed to fuel these jets is the Blandford-Znajek process, which suggests that the dragging of magnetic field lines by a black hole's rotation could launch jets of matter into space. The Penrose process, which involves extraction of a black hole's rotational energy, has also been proposed as a potential mechanism of jet propulsion. Due to conservation of angular momentum, gas falling into the gravitational well created by a massive object will typically form a disk-like structure around the object.: 242 As the disk's angular momentum is transferred outward due to internal processes, its matter falls farther inward, converting its gravitational energy into heat and releasing a large flux of x-rays. The temperature of these disks can range from thousands to millions of Kelvin, and temperatures can differ throughout a single accretion disk. Accretion disks can also emit in other parts of the electromagnetic spectrum, depending on the disk's turbulence and magnetization and the black hole's mass and angular momentum. Accretion disks can be defined as geometrically thin or geometrically thick. Geometrically thin disks are mostly confined to the black hole's equatorial plane and have a well-defined edge at the innermost stable circular orbit (ISCO), while geometrically thick disks are supported by internal pressure and temperature and can extend inside the ISCO. Disks with high rates of electron scattering and absorption, appearing bright and opaque, are called optically thick; optically thin disks are more translucent and produce fainter images when viewed from afar. Accretion disks of black holes accreting beyond the Eddington limit are often referred to as polish donuts due to their thick, toroidal shape that resembles that of a donut. Quasar accretion disks are expected to usually appear blue in color. The disk for a stellar black hole, on the other hand, would likely look orange, yellow, or red, with its inner regions being the brightest. Theoretical research suggests that the hotter a disk is, the bluer it should be, although this is not always supported by observations of real astronomical objects. Accretion disk colors may also be altered by the Doppler effect, with the part of the disk travelling towards an observer appearing bluer and brighter and the part of the disk travelling away from the observer appearing redder and dimmer. In Newtonian gravity, test particles can stably orbit at arbitrary distances from a central object. In general relativity, however, there exists a smallest possible radius for which a massive particle can orbit stably. Any infinitesimal inward perturbations to this orbit will lead to the particle spiraling into the black hole, and any outward perturbations will, depending on the energy, cause the particle to spiral in, move to a stable orbit further from the black hole, or escape to infinity. This orbit is called the innermost stable circular orbit, or ISCO. The location of the ISCO depends on the spin of the black hole and the spin of the particle itself. In the case of a Schwarzschild black hole (spin zero) and a particle without spin, the location of the ISCO is: r I S C O = 3 r s = 6 G M c 2 , {\displaystyle r_{\rm {ISCO}}=3\,r_{\text{s}}={\frac {6\,GM}{c^{2}}},} where r I S C O {\displaystyle r_{\rm {_{ISCO}}}} is the radius of the ISCO, r s {\displaystyle r_{\text{s}}} is the Schwarzschild radius of the black hole, G {\displaystyle G} is the gravitational constant, and c {\displaystyle c} is the speed of light. The radius of this orbit changes slightly based on particle spin. For charged black holes, the ISCO moves inwards. For spinning black holes, the ISCO is moved inwards for particles orbiting in the same direction that the black hole is spinning (prograde) and outwards for particles orbiting in the opposite direction (retrograde). For example, the ISCO for a particle orbiting retrograde can be as far out as about 9 r s {\displaystyle 9r_{\text{s}}} , while the ISCO for a particle orbiting prograde can be as close as at the event horizon itself. The photon sphere is a spherical boundary for which photons moving on tangents to that sphere are bent completely around the black hole, possibly orbiting multiple times. Light rays with impact parameters less than the radius of the photon sphere enter the black hole. For Schwarzschild black holes, the photon sphere has a radius 1.5 times the Schwarzschild radius; the radius for non-Schwarzschild black holes is at least 1.5 times the radius of the event horizon. When viewed from a great distance, the photon sphere creates an observable black hole shadow. Since no light emerges from within the black hole, this shadow is the limit for possible observations.: 152 The shadow of colliding black holes should have characteristic warped shapes, allowing scientists to detect black holes that are about to merge. While light can still escape from the photon sphere, any light that crosses the photon sphere on an inbound trajectory will be captured by the black hole. Therefore, any light that reaches an outside observer from the photon sphere must have been emitted by objects between the photon sphere and the event horizon. Light emitted towards the photon sphere may also curve around the black hole and return to the emitter. For a rotating, uncharged black hole, the radius of the photon sphere depends on the spin parameter and whether the photon is orbiting prograde or retrograde. For a photon orbiting prograde, the photon sphere will be 1-3 Schwarzschild radii from the center of the black hole, while for a photon orbiting retrograde, the photon sphere will be between 3-5 Schwarzschild radii from the center of the black hole. The exact location of the photon sphere depends on the magnitude of the black hole's rotation. For a charged, nonrotating black hole, there will only be one photon sphere, and the radius of the photon sphere will decrease for increasing black hole charge. For non-extremal, charged, rotating black holes, there will always be two photon spheres, with the exact radii depending on the parameters of the black hole. Near a rotating black hole, spacetime rotates similar to a vortex. The rotating spacetime will drag any matter and light into rotation around the spinning black hole. This effect of general relativity, called frame dragging, gets stronger closer to the spinning mass. The region of spacetime in which it is impossible to stay still is called the ergosphere. The ergosphere of a black hole is a volume bounded by the black hole's event horizon and the ergosurface, which coincides with the event horizon at the poles but bulges out from it around the equator. Matter and radiation can escape from the ergosphere. Through the Penrose process, objects can emerge from the ergosphere with more energy than they entered with. The extra energy is taken from the rotational energy of the black hole, slowing down the rotation of the black hole.: 268 A variation of the Penrose process in the presence of strong magnetic fields, the Blandford–Znajek process, is considered a likely mechanism for the enormous luminosity and relativistic jets of quasars and other active galactic nuclei. The observable region of spacetime around a black hole closest to its event horizon is called the plunging region. In this area it is no longer possible for free falling matter to follow circular orbits or stop a final descent into the black hole. Instead, it will rapidly plunge toward the black hole at close to the speed of light, growing increasingly hot and producing a characteristic, detectable thermal emission. However, light and radiation emitted from this region can still escape from the black hole's gravitational pull. For a nonspinning, uncharged black hole, the radius of the event horizon, or Schwarzschild radius, is proportional to the mass, M, through r s = 2 G M c 2 ≈ 2.95 M M ⊙ k m , {\displaystyle r_{\mathrm {s} }={\frac {2GM}{c^{2}}}\approx 2.95\,{\frac {M}{M_{\odot }}}~\mathrm {km,} } where rs is the Schwarzschild radius and M☉ is the mass of the Sun.: 124 For a black hole with nonzero spin or electric charge, the radius is smaller,[Note 1] until an extremal black hole could have an event horizon close to r + = G M c 2 , {\displaystyle r_{\mathrm {+} }={\frac {GM}{c^{2}}},} half the radius of a nonspinning, uncharged black hole of the same mass. Since the volume within the Schwarzschild radius increase with the cube of the radius, average density of a black hole inside its Schwarzschild radius is inversely proportional to the square of its mass: supermassive black holes are much less dense than stellar black holes. The average density of a 108 M☉ black hole is comparable to that of water. The defining feature of a black hole is the existence of an event horizon, a boundary in spacetime through which matter and light can pass only inward towards the center of the black hole. Nothing, not even light, can escape from inside the event horizon. The event horizon is referred to as such because if an event occurs within the boundary, information from that event cannot reach or affect an outside observer, making it impossible to determine whether such an event occurred.: 179 For non-rotating black holes, the geometry of the event horizon is precisely spherical, while for rotating black holes, the event horizon is oblate. To a distant observer, a clock near a black hole would appear to tick more slowly than one further from the black hole.: 217 This effect, known as gravitational time dilation, would also cause an object falling into a black hole to appear to slow as it approached the event horizon, never quite reaching the horizon from the perspective of an outside observer.: 218 All processes on this object would appear to slow down, and any light emitted by the object to appear redder and dimmer, an effect known as gravitational redshift. An object falling from half of a Schwarzschild radius above the event horizon would fade away until it could no longer be seen, disappearing from view within one hundredth of a second. It would also appear to flatten onto the black hole, joining all other material that had ever fallen into the hole. On the other hand, an observer falling into a black hole would not notice any of these effects as they cross the event horizon. Their own clocks appear to them to tick normally, and they cross the event horizon after a finite time without noting any singular behaviour. In general relativity, it is impossible to determine the location of the event horizon from local observations, due to Einstein's equivalence principle.: 222 Black holes that are rotating and/or charged have an inner horizon, often called the Cauchy horizon, inside of the black hole. The inner horizon is divided up into two segments: an ingoing section and an outgoing section. At the ingoing section of the Cauchy horizon, radiation and matter that fall into the black hole would build up at the horizon, causing the curvature of spacetime to go to infinity. This would cause an observer falling in to experience tidal forces. This phenomenon is often called mass inflation, since it is associated with a parameter dictating the black hole's internal mass growing exponentially, and the buildup of tidal forces is called the mass-inflation singularity or Cauchy horizon singularity. Some physicists have argued that in realistic black holes, accretion and Hawking radiation would stop mass inflation from occurring. At the outgoing section of the inner horizon, infalling radiation would backscatter off of the black hole's spacetime curvature and travel outward, building up at the outgoing Cauchy horizon. This would cause an infalling observer to experience a gravitational shock wave and tidal forces as the spacetime curvature at the horizon grew to infinity. This buildup of tidal forces is called the shock singularity. Both of these singularities are weak, meaning that an object crossing them would only be deformed a finite amount by tidal forces, even though the spacetime curvature would still be infinite at the singularity. This is as opposed to a strong singularity, where an object hitting the singularity would be stretched and squeezed by an infinite amount. They are also null singularities, meaning that a photon could travel parallel to the them without ever being intercepted. Ignoring quantum effects, every black hole has a singularity inside, points where the curvature of spacetime becomes infinite, and geodesics terminate within a finite proper time.: 205 For a non-rotating black hole, this region takes the shape of a single point; for a rotating black hole it is smeared out to form a ring singularity that lies in the plane of rotation.: 264 In both cases, the singular region has zero volume. All of the mass of the black hole ends up in the singularity.: 252 Since the singularity has nonzero mass in an infinitely small space, it can be thought of as having infinite density. Observers falling into a Schwarzschild black hole (i.e., non-rotating and not charged) cannot avoid being carried into the singularity once they cross the event horizon. As they fall further into the black hole, they will be torn apart by the growing tidal forces in a process sometimes referred to as spaghettification or the noodle effect. Eventually, they will reach the singularity and be crushed into an infinitely small point.: 182 However any perturbations, such as those caused by matter or radiation falling in, would cause space to oscillate chaotically near the singularity. Any matter falling in would experience intense tidal forces rapidly changing in direction, all while being compressed into an increasingly small volume. Alternative forms of general relativity, including addition of some quatum effects, can lead to regular, or nonsingular, black holes without singularities. For example, the fuzzball model, based on string theory, states that black holes are actually made up of quantum microstates and need not have a singularity or an event horizon. The theory of loop quantum gravity proposes that the curvature and density at the center of a black hole is large, but not infinite. Formation Black holes are formed by gravitational collapse of massive stars, either by direct collapse or during a supernova explosion in a process called fallback. Black holes can result from the merger of two neutron stars or a neutron star and a black hole. Other more speculative mechanisms include primordial black holes created from density fluctuations in the early universe, the collapse of dark stars, a hypothetical object powered by annihilation of dark matter, or from hypothetical self-interacting dark matter. Gravitational collapse occurs when an object's internal pressure is insufficient to resist the object's own gravity. At the end of a star's life, it will run out of hydrogen to fuse, and will start fusing more and more massive elements, until it gets to iron. Since the fusion of elements heavier than iron would require more energy than it would release, nuclear fusion ceases. If the iron core of the star is too massive, the star will no longer be able to support itself and will undergo gravitational collapse. While most of the energy released during gravitational collapse is emitted very quickly, an outside observer does not actually see the end of this process. Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the delay growing to infinity as the emitting material reaches the event horizon. Thus the external observer never sees the formation of the event horizon; instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away. Observations of quasars at redshift z ∼ 7 {\displaystyle z\sim 7} , less than a billion years after the Big Bang, has led to investigations of other ways to form black holes. The accretion process to build supermassive black holes has a limiting rate of mass accumulation and a billion years is not enough time to reach quasar status. One suggestion is direct collapse of nearly pure hydrogen gas (low metalicity) clouds characteristic of the young universe, forming a supermassive star which collapses into a black hole. It has been suggested that seed black holes with typical masses of ~105 M☉ could have formed in this way which then could grow to ~109 M☉. However, the very large amount of gas required for direct collapse is not typically stable to fragmentation to form multiple stars. Thus another approach suggests massive star formation followed by collisions that seed massive black holes which ultimately merge to create a quasar.: 85 A neutron star in a common envelope with a regular star can accrete sufficient material to collapse to a black hole or two neutron stars can merge. These avenues for the formation of black holes are considered relatively rare. In the current epoch of the universe, conditions needed to form black holes are rare and are mostly only found in stars. However, in the early universe, conditions may have allowed for black hole formations via other means. Fluctuations of spacetime soon after the Big Bang may have formed areas that were denser then their surroundings. Initially, these regions would not have been compact enough to form a black hole, but eventually, the curvature of spacetime in the regions become large enough to cause them to collapse into a black hole. Different models for the early universe vary widely in their predictions of the scale of these fluctuations. Various models predict the creation of primordial black holes ranging from a Planck mass (~2.2×10−8 kg) to hundreds of thousands of solar masses. Primordial black holes with masses less than 1015 g would have evaporated by now due to Hawking radiation. Despite the early universe being extremely dense, it did not re-collapse into a black hole during the Big Bang, since the universe was expanding rapidly and did not have the gravitational differential necessary for black hole formation. Models for the gravitational collapse of objects of relatively constant size, such as stars, do not necessarily apply in the same way to rapidly expanding space such as the Big Bang. In principle, black holes could be formed in high-energy particle collisions that achieve sufficient density, although no such events have been detected. These hypothetical micro black holes, which could form from the collision of cosmic rays and Earth's atmosphere or in particle accelerators like the Large Hadron Collider, would not be able to aggregate additional mass. Instead, they would evaporate in about 10−25 seconds, posing no threat to the Earth. Evolution Black holes can also merge with other objects such as stars or even other black holes. This is thought to have been important, especially in the early growth of supermassive black holes, which could have formed from the aggregation of many smaller objects. The process has also been proposed as the origin of some intermediate-mass black holes. Mergers of supermassive black holes may take a long time: As a binary of supermassive black holes approach each other, most nearby stars are ejected, leaving little for the remaining black holes to gravitationally interact with that would allow them to get closer to each other. This phenomenon has been called the final parsec problem, as the distance at which this happens is usually around one parsec. When a black hole accretes matter, the gas in the inner accretion disk orbits at very high speeds because of its proximity to the black hole. The resulting friction heats the inner disk to temperatures at which it emits vast amounts of electromagnetic radiation (mainly X-rays) detectable by telescopes. By the time the matter of the disk reaches the ISCO, between 5.7% and 42% of its mass will have been converted to energy, depending on the black hole's spin. About 90% of this energy is released within about 20 black hole radii. In many cases, accretion disks are accompanied by relativistic jets that are emitted along the black hole's poles, which carry away much of the energy. The mechanism for the creation of these jets is currently not well understood, in part due to insufficient data. Many of the universe's most energetic phenomena have been attributed to the accretion of matter on black holes. Active galactic nuclei and quasars are believed to be the accretion disks of supermassive black holes. X-ray binaries are generally accepted to be binary systems in which one of the two objects is a compact object accreting matter from its companion. Ultraluminous X-ray sources may be the accretion disks of intermediate-mass black holes. At a certain rate of accretion, the outward radiation pressure will become as strong as the inward gravitational force, and the black hole should unable to accrete any faster. This limit is called the Eddington limit. However, many black holes accrete beyond this rate due to their non-spherical geometry or instabilities in the accretion disk. Accretion beyond the limit is called Super-Eddington accretion and may have been commonplace in the early universe. Stars have been observed to get torn apart by tidal forces in the immediate vicinity of supermassive black holes in galaxy nuclei, in what is known as a tidal disruption event (TDE). Some of the material from the disrupted star forms an accretion disk around the black hole, which emits observable electromagnetic radiation. The correlation between the masses of supermassive black holes in the centres of galaxies with the velocity dispersion and mass of stars in their host bulges suggests that the formation of galaxies and the formation of their central black holes are related. Black hole winds from rapid accretion, particularly when the galaxy itself is still accreting matter, can compress gas nearby, accelerating star formation. However, if the winds become too strong, the black hole may blow nearly all of the gas out of the galaxy, quenching star formation. Black hole jets may also energize nearby cavities of plasma and eject low-entropy gas from out of the galactic core, causing gas in galactic centers to be hotter than expected. If Hawking's theory of black hole radiation is correct, then black holes are expected to shrink and evaporate over time as they lose mass by the emission of photons and other particles. The temperature of this thermal spectrum (Hawking temperature) is proportional to the surface gravity of the black hole, which is inversely proportional to the mass. Hence, large black holes emit less radiation than small black holes.: Ch. 9.6 A stellar black hole of 1 M☉ has a Hawking temperature of 62 nanokelvins. This is far less than the 2.7 K temperature of the cosmic microwave background radiation. Stellar-mass or larger black holes receive more mass from the cosmic microwave background than they emit through Hawking radiation and thus will grow instead of shrinking. To have a Hawking temperature larger than 2.7 K (and be able to evaporate), a black hole would need a mass less than the Moon. Such a black hole would have a diameter of less than a tenth of a millimetre. The Hawking radiation for an astrophysical black hole is predicted to be very weak and would thus be exceedingly difficult to detect from Earth. A possible exception is the burst of gamma rays emitted in the last stage of the evaporation of primordial black holes. Searches for such flashes have proven unsuccessful and provide stringent limits on the possibility of existence of low mass primordial black holes, with modern research predicting that primordial black holes must make up less than a fraction of 10−7 of the universe's total mass. NASA's Fermi Gamma-ray Space Telescope, launched in 2008, has searched for these flashes, but has not yet found any. The properties of a black hole are constrained and interrelated by the theories that predict these properties. When based on general relativity, these relationships are called the laws of black hole mechanics. For a black hole that is not still forming or accreting matter, the zeroth law of black hole mechanics states the black hole's surface gravity is constant across the event horizon. The first law relates changes in the black hole's surface area, angular momentum, and charge to changes in its energy. The second law says the surface area of a black hole never decreases on its own. Finally, the third law says that the surface gravity of a black hole is never zero. These laws are mathematical analogs of the laws of thermodynamics. They are not equivalent, however, because, according to general relativity without quantum mechanics, a black hole can never emit radiation, and thus its temperature must always be zero.: 11 Quantum mechanics predicts that a black hole will continuously emit thermal Hawking radiation, and therefore must always have a nonzero temperature. It also predicts that all black holes have entropy which scales with their surface area. When quantum mechanics is accounted for, the laws of black hole mechanics become equivalent to the classical laws of thermodynamics. However, these conclusions are derived without a complete theory of quantum gravity, although many potential theories do predict black holes having entropy and temperature. Thus, the true quantum nature of black hole thermodynamics continues to be debated.: 29 Observational evidence Millions of black holes with around 30 solar masses derived from stellar collapse are expected to exist in the Milky Way. Even a dwarf galaxy like Draco should have hundreds. Only a few of these have been detected. By nature, black holes do not themselves emit any electromagnetic radiation other than the hypothetical Hawking radiation, so astrophysicists searching for black holes must generally rely on indirect observations. The defining characteristic of a black hole is its event horizon. The horizon itself cannot be imaged, so all other possible explanations for these indirect observations must be considered and eliminated before concluding that a black hole has been observed.: 11 The Event Horizon Telescope (EHT) is a global system of radio telescopes capable of directly observing a black hole shadow. The angular resolution of a telescope is based on its aperture and the wavelengths it is observing. Because the angular diameters of Sagittarius A* and Messier 87* in the sky are very small, a single telescope would need to be about the size of the Earth to clearly distinguish their horizons using radio wavelengths. By combining data from several different radio telescopes around the world, the Event Horizon Telescope creates an effective aperture the diameter size of the Earth. The EHT team used imaging algorithms to compute the most probable image from the data in its observations of Sagittarius A* and M87*. Gravitational-wave interferometry can be used to detect merging black holes and other compact objects. In this method, a laser beam is split down two long arms of a tunnel. The laser beams reflect off of mirrors in the tunnels and converge at the intersection of the arms, cancelling each other out. However, when a gravitational wave passes, it warps spacetime, changing the lengths of the arms themselves. Since each laser beam is now travelling a slightly different distance, they do not cancel out and produce a recognizable signal. Analysis of the signal can give scientists information about what caused the gravitational waves. Since gravitational waves are very weak, gravitational-wave observatories such as LIGO must have arms several kilometers long and carefully control for noise from Earth to be able to detect these gravitational waves. Since the first measurements in 2016, multiple gravitational waves from black holes have been detected and analyzed. The proper motions of stars near the centre of the Milky Way provide strong observational evidence that these stars are orbiting a supermassive black hole. Since 1995, astronomers have tracked the motions of 90 stars orbiting an invisible object coincident with the radio source Sagittarius A*. In 1998, by fitting the motions of the stars to Keplerian orbits, the astronomers were able to infer that Sagittarius A* must be a 2.6×106 M☉ object must be contained within a radius of 0.02 light-years. Since then, one of the stars—called S2—has completed a full orbit. From the orbital data, astronomers were able to refine the calculations of the mass of Sagittarius A* to 4.3×106 M☉, with a radius of less than 0.002 light-years. This upper limit radius is larger than the Schwarzschild radius for the estimated mass, so the combination does not prove Sagittarius A* is a black hole. Nevertheless, these observations strongly suggest that the central object is a supermassive black hole as there are no other plausible scenarios for confining so much invisible mass into such a small volume. Additionally, there is some observational evidence that this object might possess an event horizon, a feature unique to black holes. The Event Horizon Telescope image of Sagittarius A*, released in 2022, provided further confirmation that it is indeed a black hole. X-ray binaries are binary systems that emit a majority of their radiation in the X-ray part of the electromagnetic spectrum. These X-ray emissions result when a compact object accretes matter from an ordinary star. The presence of an ordinary star in such a system provides an opportunity for studying the central object and to determine if it might be a black hole. By measuring the orbital period of the binary, the distance to the binary from Earth, and the mass of the companion star, scientists can estimate the mass of the compact object. The Tolman-Oppenheimer-Volkoff limit (TOV limit) dictates the largest mass a nonrotating neutron star can be, and is estimated to be about two solar masses. While a rotating neutron star can be slightly more massive, if the compact object is much more massive than the TOV limit, it cannot be a neutron star and is generally expected to be a black hole. The first strong candidate for a black hole, Cygnus X-1, was discovered in this way by Charles Thomas Bolton, Louise Webster, and Paul Murdin in 1972. Observations of rotation broadening of the optical star reported in 1986 lead to a compact object mass estimate of 16 solar masses, with 7 solar masses as the lower bound. In 2011, this estimate was updated to 14.1±1.0 M☉ for the black hole and 19.2±1.9 M☉ for the optical stellar companion. X-ray binaries can be categorized as either low-mass or high-mass; This classification is based on the mass of the companion star, not the compact object itself. In a class of X-ray binaries called soft X-ray transients, the companion star is of relatively low mass, allowing for more accurate estimates of the black hole mass. These systems actively emit X-rays for only several months once every 10–50 years. During the period of low X-ray emission, called quiescence, the accretion disk is extremely faint, allowing detailed observation of the companion star. Numerous black hole candidates have been measured by this method. Black holes are also sometimes found in binaries with other compact objects, such as white dwarfs, neutron stars, and other black holes. The centre of nearly every galaxy contains a supermassive black hole. The close observational correlation between the mass of this hole and the velocity dispersion of the host galaxy's bulge, known as the M–sigma relation, strongly suggests a connection between the formation of the black hole and that of the galaxy itself. Astronomers use the term active galaxy to describe galaxies with unusual characteristics, such as unusual spectral line emission and very strong radio emission. Theoretical and observational studies have shown that the high levels of activity in the centers of these galaxies, regions called active galactic nuclei (AGN), may be explained by accretion onto supermassive black holes. These AGN consist of a central black hole that may be millions or billions of times more massive than the Sun, a disk of interstellar gas and dust called an accretion disk, and two jets perpendicular to the accretion disk. Although supermassive black holes are expected to be found in most AGN, only some galaxies' nuclei have been more carefully studied in attempts to both identify and measure the actual masses of the central supermassive black hole candidates. Some of the most notable galaxies with supermassive black hole candidates include the Andromeda Galaxy, Messier 32, Messier 87, the Sombrero Galaxy, and the Milky Way itself. Another way black holes can be detected is through observation of effects caused by their strong gravitational field. One such effect is gravitational lensing: The deformation of spacetime around a massive object causes light rays to be deflected, making objects behind them appear distorted. When the lensing object is a black hole, this effect can be strong enough to create multiple images of a star or other luminous source. However, the distance between the lensed images may be too small for contemporary telescopes to resolve—this phenomenon is called microlensing. Instead of seeing two images of a lensed star, astronomers see the star brighten slightly as the black hole moves towards the line of sight between the star and Earth and then return to its normal luminosity as the black hole moves away. The turn of the millennium saw the first 3 candidate detections of black holes in this way, and in January 2022, astronomers reported the first confirmed detection of a microlensing event from an isolated black hole. This was also the first determination of an isolated black hole mass, 7.1±1.3 M☉. Alternatives While there is a strong case for supermassive black holes, the model for stellar-mass black holes assumes of an upper limit for the mass of a neutron star: objects observed to have more mass are assumed to be black holes. However, the properties of extremely dense matter are poorly understood. New exotic phases of matter could allow other kinds of massive objects. Quark stars would be made up of quark matter and supported by quark degeneracy pressure, a form of degeneracy pressure even stronger than neutron degeneracy pressure. This would halt gravitational collapse at a higher mass than for a neutron star. Even stronger stars called electroweak stars would convert quarks in their cores into leptons, providing additional pressure to stop the star from collapsing. If, as some extensions of the Standard Model posit, quarks and leptons are made up of the even-smaller fundamental particles called preons, a very compact star could be supported by preon degeneracy pressure. While none of these hypothetical models can explain all of the observations of stellar black hole candidates, a Q star is the only alternative which could significantly exceed the mass limit for neutron stars and thus provide an alternative for supermassive black holes.: 12 A few theoretical objects have been conjectured to match observations of astronomical black hole candidates identically or near-identically, but which function via a different mechanism. A dark energy star would convert infalling matter into vacuum energy; This vacuum energy would be much larger than the vacuum energy of outside space, exerting outwards pressure and preventing a singularity from forming. A black star would be gravitationally collapsing slowly enough that quantum effects would keep it just on the cusp of fully collapsing into a black hole. A gravastar would consist of a very thin shell and a dark-energy interior providing outward pressure to stop the collapse into a black hole or formation of a singularity; It could even have another gravastar inside, called a 'nestar'. Open questions According to the no-hair theorem, a black hole is defined by only three parameters: its mass, charge, and angular momentum. This seems to mean that all other information about the matter that went into forming the black hole is lost, as there is no way to determine anything about the black hole from outside other than those three parameters. When black holes were thought to persist forever, this information loss was not problematic, as the information can be thought of as existing inside the black hole. However, black holes slowly evaporate by emitting Hawking radiation. This radiation does not appear to carry any additional information about the matter that formed the black hole, meaning that this information is seemingly gone forever. This is called the black hole information paradox. Theoretical studies analyzing the paradox have led to both further paradoxes and new ideas about the intersection of quantum mechanics and general relativity. While there is no consensus on the resolution of the paradox, work on the problem is expected to be important for a theory of quantum gravity.: 126 Observations of faraway galaxies have found that ultraluminous quasars, powered by supermassive black holes, existed in the early universe as far as redshift z ≥ 7 {\displaystyle z\geq 7} . These black holes have been assumed to be the products of the gravitational collapse of large population III stars. However, these stellar remnants were not massive enough to produce the quasars observed at early times without accreting beyond the Eddington limit, the theoretical maximum rate of black hole accretion. Physicists have suggested a variety of different mechanisms by which these supermassive black holes may have formed. It has been proposed that smaller black holes may have also undergone mergers to produce the observed supermassive black holes. It is also possible that they were seeded by direct-collapse black holes, in which a large cloud of hot gas avoids fragmentation that would lead to multiple stars, due to low angular momentum or heating from a nearby galaxy. Given the right circumstances, a single supermassive star forms and collapses directly into a black hole without undergoing typical stellar evolution. Additionally, these supermassive black holes in the early universe may be high-mass primordial black holes, which could have accreted further matter in the centers of galaxies. Finally, certain mechanisms allow black holes to grow faster than the theoretical Eddington limit, such as dense gas in the accretion disk limiting outward radiation pressure that prevents the black hole from accreting. However, the formation of bipolar jets prevent super-Eddington rates. In fiction Black holes have been portrayed in science fiction in a variety of ways. Even before the advent of the term itself, objects with characteristics of black holes appeared in stories such as the 1928 novel The Skylark of Space with its "black Sun" and the "hole in space" in the 1935 short story Starship Invincible. As black holes grew to public recognition in the 1960s and 1970s, they began to be featured in films as well as novels, such as Disney's The Black Hole. Black holes have also been used in works of the 21st century, such as Christopher Nolan's science fiction epic Interstellar. Authors and screenwriters have exploited the relativistic effects of black holes, particularly gravitational time dilation. For example, Interstellar features a black hole planet with a time dilation factor of over 60,000:1, while the 1977 novel Gateway depicts a spaceship approaching but never crossing the event horizon of a black hole from the perspective of an outside observer due to time dilation effects. Black holes have also been appropriated as wormholes or other methods of faster-than-light travel, such as in the 1974 novel The Forever War, where a network of black holes is used for interstellar travel. Additionally, black holes can feature as hazards to spacefarers and planets: A black hole threatens a deep-space outpost in 1978 short story The Black Hole Passes, and a binary black hole dangerously alters the orbit of a planet in the 2018 Netflix reboot of Lost in Space. Notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/MediaTek] | [TOKENS: 2315] |
Contents MediaTek MediaTek Inc. (Chinese: 聯發科技股份有限公司; pinyin: Liánfā Kējì Gǔfèn Yǒuxiàn Gōngsī), sometimes informally abbreviated as MTK, is a Taiwanese fabless semiconductor company that designs and markets a range of semiconductor products, providing chips for wireless communications, high-definition television, handheld mobile devices like smartphones and tablet computers, navigation systems, consumer multimedia products and digital subscriber line services as well as optical disc drives. Founded in 1997 and headquartered in Hsinchu, the company has 41 offices worldwide and was the third largest fabless chip designer worldwide in 2016. The company also provides its customers with reference designs. MediaTek became the biggest smartphone chipset vendor with 31% market share in Q3 2020. This was assisted by its strong performance in regions such as China and India. History MediaTek was originally a unit of the Taiwanese firm, United Microelectronics Corporation (UMC), tasked with designing chipsets for home entertainment products. On May 28, 1997, the unit was spun off and incorporated. MediaTek Inc. was listed on the Taiwan Stock Exchange (TSEC) under the "2454" code on July 23, 2001. The company started out designing chipsets for optical drives and subsequently expanded into chips for DVD players, digital TVs, mobile phones, smartphones and tablets. In general MediaTek has had a strong record of gaining market share and displacing competitors after entering new markets. The company launched a division to design products for mobile devices in 2004 and developed chips such as the MT6225, MT6252, MT6235, and other chips in the MT62xx series, used in mobile phones. Seven years later, it took orders for more than 500 million mobile system-on-chip units per annum, including products for feature phones and smart devices. By providing extensive system engineering assistance, the company allowed many smaller companies and new entrants to enter a mobile phone market that had previously been dominated by large, often vertically integrated corporations that had long been broadly entrenched in the telecommunications industry. The mobile chip market quickly became the main growth driver for the company. At Mobile World Congress 2014, MediaTek unveiled its new brand "Everyday Genius", dubbing the term "Super-mid market", with the vision and aiming to make smartphones more accessible affordable to the wider market. As of November 2014, over 1500 mobile models accounting for 700 million units were shipped globally in 2014, using MediaTek chips, and the company posted revenues of US$5.3 billion in the first half of 2014, nearly as much as the whole of 2013. The revenue growth was however partly due to revenue recognition from the acquisition of MStar which became effective at the beginning of 2014. In September 2019, MediaTek collaborated with VVDN Technologies to design, manufacture new-age AIoT solutions. On November 25, 2019, MediaTek and Intel announced a partnership to bring 5G to PCs in 2021. MediaTek overtook Qualcomm as the largest vendor of smartphone chipsets in the world in the third quarter of 2020, mainly due to significant growth in the Indian and Latin American markets. In May 2023, the company announced a new collaboration with Nvidia, using Dimensity to power advanced vehicle infotainment systems for automakers. Acquisitions In 2005, MediaTek acquired Inprocomm, a wireless semiconductor design company producing 802.11a, b and a/g chips. On September 10, 2007, MediaTek announced its intention to buy Analog Devices cellular radio and baseband chipset divisions for US$350 million. The acquisition was finalised by January 11, 2008. On May 5, 2011, MediaTek acquired Ralink Technology Corporation, gaining products and expertise for Wi-Fi technology for mobile and non-mobile applications, as well as for wired DSL and Ethernet connectivity. On April 11, 2012, MediaTek acquired Coresonic, a global producer of digital signal processing products based in Linköping, Sweden. Coresonic became a wholly owned subsidiary of MediaTek in Europe. On June 22, 2012, MediaTek announced it would acquire a rival Taiwanese chipset designer MStar Semiconductor Inc., which held a strong market share position in digital television chips. The initial phase of the deal saw MediaTek taking a 48 percent stake, with an option to purchase the remaining stake later. The following merger between MediaTek and MStar was delayed by antitrust concerns in China and South Korea and finalized on February 1, 2014. On September 7, 2015, MediaTek announced to buy Richtek Technology Corp., a fabless vendor of analog ICs and power management ICs based in Hsinchu, Taiwan. Richtek became a wholly subsidiary of MediaTek after the completion of the acquisition in the second quarter of 2016. Financial performance MediaTek's financial results have been subject to variation as the financial success of different product lines fluctuated. MediaTek's relatively strong sales in 2009/2010 were based on its strong market position for feature phone chipsets. Smartphone and tablet products contributed to MediaTek's sales and income increase in 2013, while revenue recognition from the acquisition of MStar Semiconductor, which became effective in February 2014, as well as a continuing strong position for smartphone and tablet solutions, were the main reasons for the sales growth seen in 2014. In 2014 smartphone chips accounted for approximately 50–55% of revenue, followed by digital home products (25–30%, includes digital television chips), tablet chips (5–10%), feature phone chips (5–10%) and Wi-Fi products (5–10%). MediaTek started shipping chips with integrated 4G LTE baseband in volume in the second half of 2014, later than its largest competitor Qualcomm. The additional cost of the separate baseband chip required in every 4G handset made MediaTek's offerings more expensive and prompted some of its larger customers, like Alcatel One Touch and ZTE, to choose competing SoCs like the Qualcomm Snapdragon 400 and 410 platforms, negatively affecting MediaTek's revenue stream. MediaTek's stock has been trading on the Taiwan Stock Exchange under the symbol TWSE: 2454. A March 2021 report revealed that MediaTek had overtaken Qualcomm for the first time as the world's biggest smartphone chipset vendor in 2020, with 351.8 million chipsets shipped that year. The report attributed MediaTek's performance to its focus on less expensive smartphones. Market analyst firm Counterpoint predicted that MediaTek would maintain this lead in 2021, projecting a record of 37% in chip shipments. Product announcements The MT8135 system-on-chip (SoC) for tablets announced in July 2013 was the industry's first chip to implement the new ARM big.LITTLE technology for heterogeneous multi-processing. A variant of the MT8135 was used by Amazon in its Kindle Fire HD tablet models. Also on November 20, 2013, MediaTek launched the MT6592 SoC, the first system-on-chip (SoC) with eight CPU cores which could be used simultaneously, in contrast to competing SoCs with eight physical cores of which only a subset could be active at any given time. The "True Octa-Core" trademark was registered to emphasize the difference in marketing materials. On January 7, 2014, MediaTek announced the development of the world's first "multimode receiver" for wireless charging. In contrast to existing implementations it is compatible with both inductive and resonant charging. The resulting MT3188 wireless charging chip, certified by both the Power Matters Alliance and the Wireless Power Consortium was announced on February 24, 2014. On February 25, 2014, MediaTek announced the MT6732, and the MT6630. The SoC MT6630 supports 802.11a/b/g/n/ac WiFi, Bluetooth, ANT+, GPS and FM radio. On May 12, 2015, MediaTek announced their Helio X20, which features the industry's first tri-cluster CPU and the first CPU with a 10-core configuration. It also integrates MediaTek's first modem compatible with CDMA2000. Tri-cluster CPUs were later adopted by HiSilicon (Huawei) in 2018, Qualcomm and Samsung Exynos SoCs in 2019. MediaTek collaborated with Google on the first Ultra HD TV platform for Android TV, resulting in the development of the MT5595 digital television SoC. The product first shipped in LCD TV models made by Sony. On November 26, 2019, MediaTek announced their 5G SoC Dimensity 1000, the world's first mobile SoC supporting AV1. On November 6, 2023, MediaTek announced their newest flagship chip, the Dimensity 9300. Besides an increase in performance and battery life, the newest chipset boasts to be AI-generative ready as well. MediaTek is developing an Arm-based PC chip for Microsoft's Windows, set to launch after Qualcomm's exclusivity ends in 2024. This move aims to challenge Apple's Arm-based Macs and Intel's dominance in the PC market. Nvidia and AMD are also working on similar Arm-based designs for Windows. Corporate responsibility MediaTek aims to achieve net zero emissions by 2050 and reduce overall carbon emissions as part of its commitment to sustainability. In 2023, MediaTek launched the "Girls! TECH Action" project and invited Taiwanese students to the company's headquarters to promote interest in the industry and increase the number of female employees in the company. In July 2024, the company's ESG risk rating was low at just 14.7%. Controversy On April 8, 2020, AnandTech published an article on MediaTek's Sports Mode; that same day, MediaTek published a post titled "Why MediaTek Stands Behind Our Benchmarking Practices". MediaTek said Sports Mode is designed to show full capabilities during benchmarks, that it is standard practice in the industry, and their device makers can choose to enable it or not. AnandTech pointed out Sports Mode was also being applied to benchmarks intended on measuring user experience benchmarks, providing otherwise untenable results, and that similar high performance modes from other device makers only turn on if chosen by the user, not from automatic app detection from a whitelist. The AnandTech article also noted that they had criticized other vendors such as Samsung Exynos and HiSilicon (Huawei) for past cheating practices. On April 14, 2020, Qualcomm responded, saying they do not use whitelisting as they consider it cheating. On April 16, 2020, Oppo claimed that they tried to remove Sports Mode, but did not know it was still cached, hence it was removed in a firmware update. UL delisted several MediaTek Helio SoCs from their 3DMark and PCMark rankings. Product list MT6297 Global navigation satellite system (GNSS) modules. As a result of the merger with Ralink, MediaTek has added wireless network interface controllers for IEEE 802.11-standards, and SoCs with MIPS CPUs to its product portfolio. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Atlantic_Plain] | [TOKENS: 1203] |
Contents Atlantic Plain The Atlantic Plain is one of eight distinct physiographic divisions of the contiguous United States. Using the USGS physiographic classification system, the Atlantic Plain division comprises two provinces and six sections. The Coastal Plain province is differentiated from the Continental Shelf province simply based on the portion of the land mass above and below sea level. The lands adjacent to the Atlantic coastline are made up of sandy beaches, marshlands, bays, and barrier islands. It is the flattest of the U.S. physiographic divisions and stretches over 2,200 miles (3,500 km) in length from Cape Cod to the Mexican border and southward an additional 1,000 miles (1,600 km) to the Yucatán Peninsula. The central and southern Atlantic Coast is characterized by barrier and drowned valley coasts. The coastal Atlantic Plain features nearly continuous barriers interrupted by inlets, large embayments with drowned river valleys, and extensive wetlands and marshes. The Atlantic plain slopes gently seaward from the inland highlands in a series of terraces. This gentle slope continues far into the Atlantic and Gulf of Mexico, forming the continental shelf. The relief at the land-sea interface is so low that the boundary between them is often blurry and indistinct, especially along stretches of the Louisiana bayous and the Florida Everglades. Continental Shelf The Atlantic Ocean has a broad, flat continental shelf that reaches a depth of 100 meters. The continental shelf off the Atlantic Ocean ranges in width from less than 1 km off Florida to more than 420 km off Maine. The average width is about 135 km. Coastal Plain The Coastal Plain of the United States includes all or portions of the states of Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Maryland, Massachusetts, Mississippi, Missouri, New Jersey, New York, North Carolina, Oklahoma, South Carolina, Rhode Island,[a] Tennessee, Texas and Virginia. From the northeast, it begins on Cape Cod, Massachusetts and stretches to the southwest to South Padre Island, Texas. This is approximately 1,900 miles (3,100 km). This province consists of the following physiographic sections: the Embayed, Sea Island, Floridian, East Gulf Coastal Plain, Mississippi Alluvial Plain, and the West Gulf Coastal Plain. The rocks in the province consist, for the most part, of layers of sand and clay which are not yet hardened into sandstone and shale. The Coastal Plain features nearly continuous barrier islands interrupted by inlets, large embayments with drowned river valleys, and extensive wetlands and marshes. The Coastal Plain slopes gently seaward from the inland highlands in a series of terraces. The province's average elevation is less than 900 meters above sea level and extends some 50 to 100 kilometers inland from the ocean.[citation needed] The coastal plain is normally wet, including many rivers, marsh, and swampland.[citation needed] It is composed primarily of sedimentary rock and unlithified sediments and is primarily used for agriculture. The Atlantic Coastal Plain includes the Carolina Sandhills region as well as the Embayed and Sea Island physiographic provinces. The Atlantic Coastal Plain is sometimes subdivided into northern and southern regions, specifically the Mid-Atlantic and South Atlantic coastal plains. Geology The Atlantic Plain is generally gently dipping undeformed Mesozoic and Cenozoic sediments, with the sedimentary wedge thickening toward the sea, reaching a maximum thickness of about 3 kilometers (10,000 ft) in the vicinity of Cape Hatteras, North Carolina. Ecology Despite being previously overlooked in research, the Atlantic Coastal Plain is now identified as a global biodiversity hotspot, with over 1500 endemic plant species, and ~70% habitat loss. This endemism is particularly high in the longleaf pine savannas and woodlands, along with the other herbaceous and fire dependent ecosystems of the ecoregion. Despite intermittent flooding, certain refugia have remained continuously terrestrial since at least the late Cretaceous (85-80mya), contributing to endemism. Generally speaking, despite the high diversity of soils, the soil is nutrient poor. This is primarily due to an abundance of well-drained soils, creating a primarily xeric character to the floral makeup of the Atlantic Plain. However, waterlogged soils are also notable, with wetlands and hammocks being important ecological features. The Eastern woodlands are the original, predominant ecosystem of the Atlantic coastal plain. The Atlantic coastal plain upland longleaf pine woodland is an endemic plant community found in most of the Atlantic coastal plain, ranging from Virginia to northern Florida. These woodland savannas are reliant on sandy soils and are fire dependent, lest hardwoods start to dominate. Alongside longleaf pine, typically associated flora includes turkey oak and wiregrass. The Florida longleaf pine sandhill extends the longleaf pine forests into central Florida, with South Florida slash pine flatwoods, Florida sand pine scrub and Florida dry prairie stretching into southern Florida. Longleaf pine woodlands also stretch further west, to eastern Texas. These consist of East Gulf and West Gulf longleaf pine flatwoods, bisected by the Mississippi Alluvial Plain. To the north, the Atlantic Coastal Plain also broaches into the mesic hardwood forests of the Middle Atlantic coastal forests, followed by the northern Atlantic coastal pine barrens. The southernmost Atlantic Plain contains the only Neotropical ecoregion of the continental USA, being the Everglades and Florida mangroves. The following species are largely endemic to the region. Amphibian diversity is especially notable in the Atlantic Plain. Some of these species' ranges may extend into the longleaf pine woodlands and savannas of the Gulf Plain. Notes References 32°N 83°W / 32°N 83°W / 32; -83 |
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[SOURCE: https://en.wikipedia.org/wiki/Ministry_of_Finance_(Israel)] | [TOKENS: 292] |
Contents Ministry of Finance (Israel) The Israeli Ministry of Finance (Hebrew: מִשְׂרַד הָאוֹצָר, romanized: Misrad HaOtzar) is the main economic ministry of the Government of Israel. It is responsible for planning and implementing the Government's overall economic policy, as well as setting targets for fiscal policy, preparing the draft State Budget and monitoring implementation of the approved budget. The ministry also manages state revenues, collects direct and indirect taxes and promotes nonresident investments. In addition, the ministry conducts economic relations with foreign governments, economic organizations and the international community. The ministry regulates the state owned companies sector and the capital market, savings and insurance. The ministry is also responsible for auxiliary units for government ministries in motor vehicles, computer services, printing and government procurement. The Finance Ministry is headed by the finance minister, currently Bezalel Smotrich. There is also occasionally a deputy minister of finance. The permanent staff of the ministry include the director general, the department directors responsible for the Budget Department, the accountant general, the Wage and Labor Agreements Department and the accreditation units (the Tax Authority, the Government Companies Authority, the Capital Market, Insurance, and Savings Authority and the Governmental Printer). Main functions The units of the Ministry of Finance may be categorized by the three types of service they provide: List of ministers See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Dyson_sphere] | [TOKENS: 2041] |
Contents Dyson sphere A Dyson sphere is a hypothetical megastructure that encompasses a star and captures a large percentage of its power output. The concept is a thought experiment that attempts to imagine how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet's resources alone. Because only a tiny fraction of a star's energy emissions reaches the surface of any orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy. The earliest modern imagining of such a structure was by Olaf Stapledon in his science fiction novel Star Maker (1937). The same concept was later used by physicist Freeman Dyson in his 1960 satirical paper "Search for Artificial Stellar Sources of Infrared Radiation". Dyson speculated that such structures would be the logical consequence of the escalating energy needs of a technological civilization and would be a necessity for its long-term survival. A signature of such spheres detected in astronomical searches would be an indicator of extraterrestrial intelligence. Since Dyson's paper, many variant designs involving an artificial structure or series of structures to encompass a star have been proposed in exploratory engineering or described in science fiction, often under the name "Dyson sphere". Fictional depictions often describe a solid shell of matter enclosing a star – an arrangement considered by Dyson himself to be impossible. Origins Inspired by the 1937 science fiction novel Star Maker by Olaf Stapledon, the physicist and mathematician Freeman Dyson was the first to formalize the concept of what became known as the "Dyson sphere" in his 1960 Science paper "Search for Artificial Stellar Sources of Infra-Red Radiation". Dyson theorized that as the energy requirements of an advanced technological civilization increased, there would come a time when it would need to systematically harvest the energy from its local star on a large scale. He speculated that this could be done via a system of structures orbiting the star, designed to intercept and collect its energy. He argued that as the structure would result in the large-scale conversion of starlight into far-infrared radiation, an earth-based search for sources of infrared radiation could identify stars supporting intelligent life. Dyson did not detail how such a system could be constructed, simply referring to it in the paper as a "shell" or "biosphere". He later clarified that he did not have in mind a solid structure, saying: "A solid shell or ring surrounding a star is mechanically impossible. The form of 'biosphere' which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star." Such a concept has often been referred to as a Dyson swarm; however, in 2013, Dyson said he had come to regret that the concept had been named after him. In an interview with Robert Wright in 2003, Dyson referred to his paper on the search for Dyson spheres as "a little joke" and commented that "you get to be famous only for the things you don't think are serious", later explaining that "And of course the joke is that the sky is crawling with infrared sources which look just the way a Type II civilization might look, so there is absolutely no reason to believe that they are artificial ... from our distance they would look the same". However, in a later interview with students from The University of Edinburgh in 2018, he referred to the premise of the Dyson sphere as being "correct and uncontroversial". In other interviews, while lamenting the naming of the object, Dyson commented that "the idea was a good one", and referred to his contribution to a paper on disassembling planets as a means of constructing one. Search for megastructures Dyson-style energy collectors around a distant star would absorb and re-radiate energy from the star. The wavelengths of such re-radiated energy may be atypical for the star's spectral type, due to the presence of heavy elements not naturally occurring within the star. If the percentage of such atypical wavelengths were to be significant, an alien megastructure could be detected at interstellar distances. This could indicate the presence of what has been called a Type II Kardashev civilization. SETI has looked for such infrared-heavy spectra from solar analogs, as has Fermilab. Fermilab discovered 17 potential "ambiguous" candidates, of which four were in 2006 called "amusing but still questionable". Later searches also resulted in several candidates, all of which remain unconfirmed. On October 14, 2015, Planet Hunters' citizen scientists discovered unusual light fluctuations of the star KIC 8462852 raising press speculation that a Dyson sphere may have been discovered. However, subsequent analysis showed that the results were consistent with the presence of dust. A further campaign in 2024 identified seven possible candidates for Dyson-spheres, but further investigation was said to be required. In 2024 there was press speculation that potential signs of interstellar Dyson spheres had been discovered. The seven objects of interest – all located within a thousand light-years of Earth – were M-dwarfs, a class of stars that are smaller and less luminous than the Sun. However, the authors of the findings were careful not to make any overblown claims. Despite this, many media outlets picked up on the story. Less fantastical explanations included a suggestion that the detected infrared was caused by distant dust-obscured galaxies. Feasibility and science-based speculation Although Dyson sphere systems are theoretically possible, building a stable megastructure around the Sun is currently far beyond humanity's engineering capacity. The number of craft required to obtain, transmit, and maintain a complete Dyson sphere exceeds present-day industrial capabilities. George Dvorsky has advocated the use of self-replicating robots to overcome this limitation in the relatively near term. Some have suggested that Dyson sphere habitats could be built around white dwarfs and even pulsars. Stellar engines are hypothetical megastructures whose purpose is to extract useful energy from a star, sometimes for specific purposes. For example, Matrioshka brains have been proposed to use energy extracted by Dyson Spheres for computation, while Shkadov thrusters would extract energy for propulsion. Some proposed stellar engine designs are based on the Dyson sphere. Fictional examples A precursor to the concept of Dyson spheres was featured in the 1937 novel Star Maker by Olaf Stapledon, in which he described "every solar system... surrounded by a gauze of light-traps, which focused the escaping solar energy for intelligent use"; Dyson got his inspiration from this book and suggested that "Stapledon sphere" would be a more apt name for the concept. Fictional Dyson spheres are typically solid structures forming a continuous shell around the star in question, although Dyson himself considered that prospect to be mechanically implausible. They are sometimes used as the type of plot device known as a Big Dumb Object. Dyson spheres appear as a background element in many works of fiction, including the 1964 novel The Wanderer by Fritz Leiber where aliens enclose multiple stars in this way. Dyson spheres are depicted in the 1975–1983 book series Saga of Cuckoo by Frederik Pohl and Jack Williamson, and one functions as the setting of Bob Shaw's 1975 novel Orbitsville and its sequels. In the 1992 episode "Relics" of the TV show Star Trek: The Next Generation, the USS Enterprise finds itself trapped in an abandoned Dyson Sphere; in a 2011 interview, Dyson said that he enjoyed the episode, although he considered the sphere depicted to be "nonsense". Michael Jan Friedman who wrote the novelization observed that in the TV episode itself the Dyson sphere was effectively a MacGuffin, with "just nothing about it" in the story, and decided to flesh out the plot element in his novelization.: ix Other science-fiction story examples include Tony Rothman's The World Is Round, Somtow Sucharitkul's Inquestor series, Timothy Zahn's Spinneret, James White's Federation World, Stephen Baxter's The Time Ships, and Peter F. Hamilton's Pandora's Star.: 133 Variations on the Dyson Sphere concept include a single circular band in Larry Niven's 1970 novel Ringworld, a half sphere in the 2012 novel Bowl of Heaven by Gregory Benford and Niven, and nested spheres – also known as a Matrioshka brain – in Colin Kapp's 1980s Cageworld series and Brian Stableford's 1979–1990 Asgard trilogy. Stableford himself observed that Dyson spheres are usually MacGuffins or largely deep in the backgrounds of stories, giving as examples Fritz Leiber's The Wanderer and Linda Nagata's Deception Well, whereas stories involving space exploration tend to employ the variants like Niven's Ringworld.: 133 He gives two reasons for this: firstly that Dyson spheres are simply too big to address, which Friedman also alluded to when pointing out that the reason his novelization of "Relics" did not go further into the sphere was that it was only four hundred pages and he had just shy of four weeks to write it; and secondly that, especially for hard science-fiction, Dyson spheres have certain engineering problems that complicate stories.: 133 : ix In particular, since gravitational attraction is in equilibrium inside such a sphere (per the shell theorem), other means such as rotating the sphere have to be employed in order to keep things attached to the interior surface, which then leads to the problem of a gravity gradient that goes to zero at the rotational poles.: 133 Authors address this with various modifications of the idea such as the aforementioned Cageworld nesting, Dan Alderson's double sphere idea, and Niven's reduced Ringworld (discussed in "Bigger Than Worlds" and Ringworld § Influence).: 133 See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Thomas_%26_Friends_(franchise)] | [TOKENS: 2578] |
Contents Thomas & Friends (franchise) Thomas & Friends (formerly known as Thomas the Tank Engine & Friends) is a children's media franchise based on the Railway Series books by Wilbert Awdry and created by Britt Allcroft and owned by Mattel since 2012. The franchise revolves around an ensemble cast of anthropomorphic steam locomotives—including the titular main protagonist Thomas the Tank Engine as well as other vehicles—who work on the Island of Sodor. In 1984, The Railway Series books were adapted into a television series initially titled Thomas the Tank Engine & Friends. This ran for 24 series and had several feature-length specials produced during its run. A film adaptation, Thomas and the Magic Railroad, was released theatrically in 2000. After the television series ended in 2021, a reboot titled Thomas & Friends: All Engines Go began in the same year and concluded in 2025. Another reboot is in development, set to be released in late 2026, and a second theatrical film is in development at Mattel Films. History In 1942, two-year-old Christopher Awdry caught measles and was confined to a darkened room. His father told him rhymes to cheer him up, which soon expanded into stories. These formed the basis for The Railway Series books. The first book, The Three Railway Engines, was published in 1945, with Awdry's 26th and final book, Tramway Engines, following suit in 1972. Christopher continued the series, writing 16 more books from 1983 to 2011. These books inspired Britt Allcroft to create the Thomas the Tank Engine & Friends television show. Multiple attempts to create a show based on The Railway Series happened since 1953, when Eric Marriott was approached by the BBC to adapt two stories based on the Railway Series stories. During the broadcast of The Sad Story of Henry, the engine used in the broadcast fell and was picked up by a hand seconds later. Models moved jerkily, and all effects, music and sound had to be superimposed. Later, in 1973, Andrew Lloyd Webber, who had read The Railway Series as a child, approached publisher Kaye & Ward with a proposal for his own musical television series, with songs from himself and lyricist Peter Reeves.: ch 16 However, the publishers and the author refused to give Lloyd Webber's company "control of almost everything", which Lloyd Webber's lawyers argued was necessary in order to "secure the investment money from America which would be needed to pay for the animation and the film-making.": ch 20 The status of the project seemed uncertain, and while Stanley Pickard, Kaye & Ward's managing director at the time, told Awdry that he was "maintaining personal contact with Andrew and still had a slight hope that there might be a way out", Wilbert remained apprehensive, saying that "Once the Americans get hold of it the whole series would be vulgarised and ruined.": ch 20 Eventually, an agreement was reached and Awdry received an advanced payment of £500. A pilot episode was commissioned from Granada, which would feature 2D cutouts of the engines moving along a background in a style reminiscent of Ivor the Engine, with involvement from animator Brian Cosgrove. The cutouts and backgrounds would be based upon illustrations from The Railway Series.: ch 20 The pilot episode was completed by early 1976, but Granada ultimately decided not to produce a full series, as they feared that at the time Awdry's stories were not popular enough outside the UK to justify investing the time and money needed to make the series.: ch 20 Andrew Lloyd Webber later established the Really Useful Group in 1977, a name derived from the phrase "Really Useful Engine".[citation needed] In 1979, British television producer Britt Allcroft was producing a documentary on the Bluebell Railway, a heritage railway in Sussex which featured in the Railway Series book Stepney the Bluebell Engine.[citation needed] As part of her research before filming, Allcroft read some books in The Railway Series and was highly entertained and impressed with the stories which Awdry had written, later remarking that "there was something in the stories that I felt I could develop that would connect with children. I saw a strong emotional content that would carry with little children's experiences with life." Allcroft worked to convince Awdry that she could, with funding, convert the stories into a successful television show. Her efforts were successful, and she purchased the television rights from the publishers of The Railway Series at a cost of what was then £50,000 ($74,000 in U.S. dollars at the time). Allcroft still had to work to raise the money to finance production and, despite showing a keen interest, wanted a level of creative control which she did not want to forego. In the end, after several years of searching and having to place a second mortgage on her home, Allcroft raised sufficient funding from her local bank manager. By 1981, Allcroft had secured the finances to produce the show, she started to assemble the crew, including producer and director David Mitton, also the founder of Clearwater Features Ltd.; crew member Steve Asquith; American-born producer Robert D. Cardona; and composers and songwriters Mike O'Donnell and Junior Campbell.[citation needed] The series ran starting with the first series in 1984. Series 12 would be the final series to use be filmed in live action (although some computer-generated imagery (CGI) was incorporated), as production transitioned to full CGI in the late 2000s. In October 2020, Mattel Television formed a new co-production partnership with Corus Entertainment's Nelvana and greenlit two new seasons for the Thomas & Friends series, consisting of 104 11-minute episodes and two hour-long specials. The new episodes were said to be produced using traditional animation and include more physical comedy and music than before.[citation needed] In January 2021, it was announced that the new episodes were set to be released as an entirely new television series known as Thomas & Friends: All Engines Go. Executive producer Christopher Keenan stated that it was, "crafted to appeal to contemporary audiences' sensibilities while maintaining Thomas' core brand ethos".[citation needed] The series serves as a reboot of the original Thomas & Friends series that ran from 1984 to 2021. It was originally set to be a continuation of the original series (with the two seasons labeled as series 25 and 26), but Mattel Television later confirmed it to be a separate series. It introduces "an entirely new approach to Thomas & Friends content," with a new animation style and story structure, therefore receiving immense criticism from audiences complaining about the new character redesigns and art style for its lack of faithfulness to its source material. Unlike the original series, Thomas & Friends: All Engines Go was developed in North America rather than Europe.[citation needed] In celebration of the reboot, the official Japanese YouTube channel created a three-episode miniseries titled Salaryman Thomas (Japanese: サラリーマントーマス). It reimagines the engines as live-action adult office workers. In May 2025, a new Thomas & Friends series was announced to be releasing in 2026, said to be a "thrilling new journey that is set to delight fans old and new." The new series was fully unveiled in January 2026, with several pieces of promotional material and a short clip. The series utilizes the new franchise logo and design. It is expected to release in late 2026 with a special premiering on Netflix.[non-primary source needed] Films and specials Commercialisation In 1998, Thomas Land opened as a themed area in Fuji-Q Highland in Fujiyoshida, Japan. The land features several themed attractions, including an interactive dark ride and a roller coaster built by Sansei Technologies. From 2007 until 2017, Drusilla's Park in Sussex, England operated a railway ride featuring Thomas, Annie and Clarabel. The track ran through the Zoo Park.[citation needed] Since 2007, several Six Flags amusement parks in the US have included Thomas & Friends-themed attractions: Six Flags Discovery Kingdom, Six Flags New England, Six Flags Magic Mountain, Six Flags Over Georgia and Six Flags America. However, in late 2010, Six Flags began the process of renaming and re-theming non-Warner Bros. licensed attractions, including Thomas & Friends. In 2008, Drayton Manor in Staffordshire, England opened Thomas Land.[citation needed] In 2018, Kennywood in West Mifflin, Pennsylvania opened Thomas Town, which features four rides featuring Thomas, Cranky, Flynn, and Harold, and a live entertainment show hosted by Sir Topham Hatt.[citation needed] Thomas & Friends merchandise has been produced to capitalise on the success of the television series. In the United Kingdom, merchandise was produced starting with the original broadcast of the television series in 1984.[citation needed] Manufacturers produced Thomas-branded items after the television series was broadcast in the United States and Japan.[citation needed] Thomas & Friends ranked number one in the preschool toys category in the U.S. and made the top 10 for the U.S. toy industry in 2010.[citation needed] In January 2011, Thomas & Friends ranked as the number-one preschool toy property in the U.K. for the 11th year in a row.[citation needed] Thomas is also a top-selling toy in Australia, Germany, Japan, and Korea. While the total traditional toy industry in the United States increased 1.9 per cent in 2010, overall Thomas & Friends toy sales increased over 47.1 per cent. Over 200 million books have been sold worldwide. Heritage railways HIT Entertainment and later Mattel licenses Day out with Thomas events all over the world, where visitors can ride on a train hauled by replicas of the series' characters.[citation needed] As none of the E2 Class survived into preservation, locomotives from other classes have been adapted to resemble Thomas. Most replicas are based on 0-6-0 locomotives such as the Austerity 0-6-0ST number 3781, which was converted from a saddle-tank to a side-tank in 1994. at the Mid-Hants Railway The Strasburg Rail Road in Lancaster, PA (USA) adapted Brooklyn Eastern District Terminal 15 in 1999 and introduced a replica of the character Percy at the Day Out With Thomas event on 13 September 2014. Due to the increasing licensing fees and restrictions imposed by HiT including the need for "Sir Topham Hatt" to undergo a Criminal Records Bureau check, some heritage railways in the UK and overseas no longer run "Thomas" days. The play The Queen's Handbag, staged to celebrate the 80th birthday of Queen Elizabeth II, featured well-loved characters from children's literature. A near life-sized Thomas carried Sophie Dahl to the stage to meet Sir Topham Hatt (Jonathan Ross) at the beginning of the show. The same Thomas had previously been used in the All Aboard Live Tour.[citation needed] The Japanese Ōigawa Railway has five locomotives that appear Thomas, Hiro, Percy, James, and Rusty, based at Shin-Kanaya Station. Thomas runs between Shin-Kanaya and Kawaneonsen-Sasamado Station.[citation needed] Popularity with autistic audience In 2001, the British National Autistic Society conducted a survey of 81 parents of children with autism and Asperger syndrome to investigate their relationship with Thomas. The survey confirmed the organisation's anecdotal evidence that children with autism spectrum disorders associate more strongly with Thomas than with other children's characters. In the National Autistic Society's 2007 survey, conducted with 748 UK parents of children under 10 with autism, 58% of parents reported Thomas was the first children's character their children enjoyed, with about one-third of parents reporting their children were able to learn basic facial expressions from the characters. 54% of parents reported that the stories contributed to their child's sense of security. Mattel developed autistic character Bruno the Brake Car for Thomas & Friends: All Engines Go. They worked with organisations including the Autistic Self Advocacy Network and the National Autistic Society, and cast Elliott Garcia and Chuck Smith in the UK and US versions respectively to voice the character. References External links |
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[SOURCE: https://en.wikipedia.org/wiki/File:Cray_2_Arts_et_Metiers_dsc03940.jpg] | [TOKENS: 115] |
File:Cray 2 Arts et Metiers dsc03940.jpg Summary Cray DD-49 Disk drive File history Click on a date/time to view the file as it appeared at that time. File usage The following 5 pages use this file: Global file usage The following other wikis use this file: View more global usage of 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/Ministry_of_Health_(Israel)] | [TOKENS: 227] |
Contents Ministry of Health (Israel) The Ministry of Health (Hebrew: מִשְׂרַד הַבְּרִיאוּת, translit. Misrad HaBri'ut) is a ministry in the Israeli government, responsible for formulating health policies. The ministry plans, supervises, licenses, and coordinates the country's health care services. In addition to overseeing health services provided by HCOs such as Kupat Holim, Maccabi et al and family health centers such as Tipat Halav, the ministry maintains general hospitals, psychiatric hospitals, mental health clinics, treatment programs for substance abuse, and facilities for the chronically ill. History In January 2021, the ministry entered a collaborative agreement with Pfizer granting the company access to Israel citizens' personal electronic medical records in order to observe the real-world safety and efficacy of the BNT162b2 COVID-19 vaccine product. In February 2022, the ministry banned medical professionals in Israel from providing conversion therapy. List of ministers See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Cygnus_(constellation)] | [TOKENS: 5247] |
Contents Cygnus (constellation) Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for "swan". Cygnus is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. Cygnus contains Deneb (ذنب, translit. ḏanab, tail)—one of the brightest stars in the night sky and the most distant first-magnitude star—as its "tail star" and one corner of the Summer Triangle. It also has some notable X-ray sources and the giant stellar association of Cygnus OB2. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massive companion that was the first object widely held to be a black hole. Many star systems in Cygnus have known planets as a result of the Kepler Mission observing one patch of the sky, an area around Cygnus. Most of the east has part of the Hercules–Corona Borealis Great Wall in the deep sky, a giant galaxy filament that is the largest known structure in the observable universe, covering most of the northern sky. History and mythology In Polynesia, Cygnus was often recognized as a separate constellation. In Tonga it was called Tuula-lupe, and in the Tuamotus it was called Fanui-tai. In New Zealand it was called Mara-tea, in the Society Islands it was called Pirae-tea or Taurua-i-te-haapa-raa-manu, and in the Tuamotus it was called Fanui-raro. Beta Cygni was named in New Zealand; it was likely called Whetu-kaupo. Gamma Cygni was called Fanui-runga in the Tuamotus. Whilst being represented as a swan in the west, the constellation is known as ad-Dajājah in Arabic, meaning the hen. Cygnus's brightest star, known in the western world as deneb, gains its name from the Arabic name dhaneb, meaning "tail", from the phrase Dhanab ad-Dajājah or the tail of the hen. In Greek mythology, Cygnus has been identified with several different legendary swans. Zeus disguised himself as a swan to seduce Leda, Spartan king Tyndareus's wife, who gave birth to the Gemini, Helen of Troy, and Clytemnestra, and Orpheus was transformed into a swan after his murder and said to have been placed in the sky next to his lyre (Lyra). Later Romans also associated this constellation with the tragic story of Phaethon, the son of Helios the sun god, who demanded to ride his father's sun chariot for a day. Phaethon, however, was unable to control the reins, forcing Zeus to destroy the chariot (and Phaethon) with a thunderbolt, causing it to plummet to the earth into the river Eridanus. According to the myth, Phaethon's close friend or lover, Cygnus of Liguria, grieved bitterly and spent many days diving into the river to collect Phaethon's bones to give him a proper burial. The gods were so touched by Cygnus's devotion that they turned him into a swan and placed him among the stars. In Ovid's Metamorphoses, there are three people named Cygnus, all of whom are transformed into swans. Alongside Cygnus, noted above, he mentions a boy from Aetolia who throws himself off a cliff when his companion Phyllius refuses to give him a tamed bull that he demands, but he is transformed into a swan and flies away. He also mentions a son of Poseidon, an invulnerable warrior in the Trojan War who is eventually killed by Achilles, but Poseidon saves him by transforming him into a swan. Together with other avian constellations near the summer solstice, Vultur cadens and Aquila, Cygnus may be a significant part of the origin of the myth of the Stymphalian Birds, one of The Twelve Labours of Hercules. Characteristics A very large constellation, Cygnus is bordered by Cepheus to the north and east, Draco to the north and west, Lyra to the west, Vulpecula to the south, Pegasus to the southeast and Lacerta to the east. The three-letter abbreviation for the constellation, as adopted by the IAU in 1922, is "Cyg". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined as a polygon of 28 segments. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 19h 07.3m and 22h 02.3m , while the declination coordinates are between 27.73° and 61.36°. Covering 804 square degrees and around 1.9% of the night sky, Cygnus ranks 16th of the 88 constellations in size. Cygnus culminates at midnight on 29 June, and is most visible in the evening from the early summer to mid-autumn in the Northern Hemisphere. Normally, Cygnus is depicted with Delta and Epsilon Cygni as its wings. Deneb, the brightest in the constellation is at its tail, and Albireo as the tip of its beak. There are several asterisms in Cygnus. In the 17th-century German celestial cartographer Johann Bayer's star atlas the Uranometria, Alpha, Beta and Gamma Cygni form the pole of a cross, while Delta and Epsilon form the cross beam. The nova P Cygni was then considered to be the body of Christ. Features There is an abundance of deep-sky objects, with many open clusters, nebulae of various types and supernova remnants found in Cygnus due to its position on the Milky Way. Its molecular clouds form the Cygnus Rift dark nebula constellation, comprising one end of the Great Rift along the Milky Way's galactic plane. The rift begins around the Northern Coalsack, and partially obscures the larger Cygnus molecular cloud complex behind it, which the North America Nebula is part of. Bayer catalogued many stars in the constellation, giving them the Bayer designations from Alpha to Omega and then using lowercase Roman letters to g. John Flamsteed added the Roman letters h, i, k, l and m (these stars were considered informes by Bayer as they lay outside the asterism of Cygnus), but were dropped by Francis Baily. There are several bright stars in Cygnus. α Cygni, called Deneb, is the brightest star in Cygnus. It is a white supergiant star of spectral type A2Iae that varies between magnitudes 1.21 and 1.29, one of the largest and most luminous A-class stars known. It is located about 2600 light-years away. Its traditional name means "tail" and refers to its position in the constellation. Albireo, designated β Cygni, is a celebrated binary star among amateur astronomers for its contrasting hues. The primary is an orange-hued giant star of magnitude 3.1 and the secondary is a blue-green hued star of magnitude 5.1. The system is 430 light-years away and is visible in large binoculars and all amateur telescopes. γ Cygni, traditionally named Sadr, is a yellow-tinged supergiant star of magnitude 2.2, 1800 light-years away. Its traditional name means "breast" and refers to its position in the constellation. δ Cygni (the proper name is Fawaris) is another bright binary star in Cygnus, 166 light-years with a period of 800 years. The primary is a blue-white hued giant star of magnitude 2.9, and the secondary is a star of magnitude 6.6. The two components are visible in a medium-sized amateur telescope. The fifth star in Cygnus above magnitude 3 is Aljanah, designated ε Cygni. It is an orange-hued giant star of magnitude 2.5, 72 light-years from Earth. There are several other dimmer double and binary stars in Cygnus. μ Cygni is a binary star with an optical tertiary component. The binary system has a period of 790 years and is 73 light-years from Earth. The primary and secondary, both white stars, are of magnitude 4.8 and 6.2, respectively. The unrelated tertiary component is of magnitude 6.9. Though the tertiary component is visible in binoculars, the primary and secondary currently require a medium-sized amateur telescope to split, as they will through the year 2020. The two stars will be closest between 2043 and 2050, when they will require a telescope with larger aperture to split. The stars 30 and 31 Cygni form a contrasting double star similar to the brighter Albireo. The two are visible in binoculars. The primary, 31 Cygni, is an orange-hued star of magnitude 3.8, 1400 light-years from Earth. The secondary, 30 Cygni, appears blue-green. It is of spectral type A5IIIn and magnitude 4.83, and is around 610 light-years from Earth. 31 Cygni itself is a binary star; the tertiary component is a blue star of magnitude 7.0. ψ Cygni is a binary star visible in small amateur telescopes, with two white components. The primary is of magnitude 5.0 and the secondary is of magnitude 7.5. 61 Cygni is a binary star visible in large binoculars or a small amateur telescope. It is 11.4 light-years from Earth and has a period of 750 years. Both components are orange-hued dwarf (main sequence) stars; the primary is of magnitude 5.2 and the secondary is of magnitude 6.1. 61 Cygni is significant because Friedrich Wilhelm Bessel determined its parallax in 1838, the first star to have a known parallax. Located near η Cygni is the X-ray source Cygnus X-1, which is now thought to be caused by a black hole accreting matter in a binary star system. This was the first X-ray source widely believed to be a black hole. It is located approximately 2.2 kiloparsecs from the Sun. There is also supergiant variable star in the system which is known as HDE 226868. Cygnus also contains several other noteworthy X-ray sources. Cygnus X-3 is a microquasar containing a Wolf–Rayet star in orbit around a very compact object, with a period of only 4.8 hours. The system is one of the most intrinsically luminous X-ray sources observed. The system undergoes periodic outbursts of unknown nature, and during one such outburst, the system was found to be emitting muons, likely caused by neutrinos. While the compact object is thought to be a neutron star or possibly a black hole, it is possible that the object is instead a more exotic stellar remnant, possibly the first discovered quark star, hypothesized due to its production of cosmic rays that cannot be explained if the object is a normal neutron star. The system also emits cosmic rays and gamma rays, and has helped shed insight on to the formation of such rays. Cygnus X-2 is another X-ray binary, containing an A-type giant in orbit around a neutron star with a 9.8-day period. The system is interesting due to the rather small mass of the companion star, as most millisecond pulsars have much more massive companions. Another black hole in Cygnus is V404 Cygni, which consists of a K-type star orbiting around a black hole of around 12 solar masses. The black hole, similar to that of Cygnus X-3, has been hypothesized to be a quark star. 4U 2129+ 47 is another X-ray binary containing a neutron star which undergoes outbursts, as is EXO 2030+ 375. Cygnus is also home to several variable stars. SS Cygni is a dwarf nova which undergoes outbursts every 7–8 weeks. The system's total magnitude varies from 12th magnitude at its dimmest to 8th magnitude at its brightest. The two objects in the system are incredibly close together, with an orbital period of less than 0.28 days. χ Cygni is a red giant and the second-brightest Mira variable star at its maximum. It ranges between magnitudes 3.3 and 14.2, and spectral types S6,2e to S10,4e (MSe) over a period of 408 days; it has a diameter of 300 solar diameters and is 350 light-years from Earth. P Cygni is a luminous blue variable that brightened suddenly to 3rd magnitude in 1600 AD. Since 1715, the star has been of 5th magnitude, despite being more than 5000 light-years from Earth. The star's spectrum is unusual in that it contains very strong emission lines resulting from surrounding nebulosity. W Cygni is a semi-regular variable red giant star, 618 light-years from Earth.It has a maximum magnitude of 5.10 and a minimum magnitude 6.83; its period of 131 days. It is a red giant ranging between spectral types M4e-M6e(Tc:)III, NML Cygni is a red hypergiant semi-regular variable star located at 5,300 light-years away from Earth. It is one of largest stars currently known in the galaxy with a radius exceeding 1,000 solar radii. Its magnitude is around 16.6, its period is about 940 days. The star KIC 8462852 (Tabby's Star) has received widespread press coverage because of unusual light fluctuations. Cygnus is one of the constellations that the Kepler satellite surveyed in its search for exoplanets, and as a result, there are about a hundred stars in Cygnus with known planets, the most of any constellation. One of the most notable systems is the Kepler-11 system, containing six transiting planets, all within a plane of approximately one degree. It was the system with six exoplanets to be discovered. With a spectral type of G6V, the star is somewhat cooler than the Sun. All the planets are more massive than Earth, and all have low densities; and all but one are closer to Kepler-11 than Mercury is to the Sun. The naked-eye star 16 Cygni, a triple star approximately 70 light-years from Earth composed two Sun-like stars and a red dwarf, contains a planet orbiting one of the sun-like stars, found due to variations in the star's radial velocity. Gliese 777, another naked-eye multiple star system containing a yellow star and a red dwarf, also contains a planet. The planet is somewhat similar to Jupiter, but with slightly more mass and a more eccentric orbit. The Kepler-22 system is also notable for having the most Earth-like exoplanet when it was discovered in 2011. The rich background of stars of Cygnus can make it difficult to make out open cluster. M39 (NGC 7092) is an open cluster 950 light-years from Earth that are visible to the unaided eye under dark skies. It is loose, with about 30 stars arranged over a wide area; their conformation appears triangular. The brightest stars of M39 are of the 7th magnitude. Another open cluster in Cygnus is NGC 6910, also called the Rocking Horse Cluster, possessing 16 stars with a diameter of 5 arcminutes visible in a small amateur instrument; it is of magnitude 7.4. The brightest of these are two gold-hued stars, which represent the bottom of the toy it is named for. A larger amateur instrument reveals 8 more stars, nebulosity to the east and west of the cluster, and a diameter of 9 arcminutes. The nebulosity in this region is part of the Gamma Cygni Nebula. The other stars, approximately 3700 light-years from Earth, are mostly blue-white and very hot. Other open clusters in Cygnus include Dolidze 9, Collinder 421, Dolidze 11, and Berkeley 90. Dolidze 9, 2800 light-years from Earth and relatively young at 20 million light-years old, is a faint open cluster with up to 22 stars visible in small and medium-sized amateur telescopes. Nebulosity is visible to the north and east of the cluster, which is 7 arcminutes in diameter. The brightest star appears in the eastern part of the cluster and is of the 7th magnitude; another bright star has a yellow hue. Dolidze 11 is an open cluster 400 million years old, farthest away of the three at 3700 light-years. More than 10 stars are visible in an amateur instrument in this cluster, of similar size to Dolidze 9 at 7 arcminutes in diameter, whose brightest star is of magnitude 7.5. It, too, has nebulosity in the east. Collinder 421 is a particularly old open cluster at an age of approximately 1 billion years; it is of magnitude 10.1. 3100 light-years from Earth, more than 30 stars are visible in a diameter of 8 arcseconds. The prominent star in the north of the cluster has a golden color, whereas the stars in the south of the cluster appear orange. Collinder 421 appears to be embedded in nebulosity, which extends past the cluster's borders to its west. Berkeley 90 is a smaller open cluster, with a diameter of 5 arcminutes. More than 16 members appear in an amateur telescope. The Milky Way toward the Cygnus constellation is highly active and contains numerous star-forming regions, supernova remnants, H II regions, and planetary nebulae (see the image on the left). In the past, based on X-ray observations (see the eROSITA image above), many of these objects were thought to be part of a single large structure known as the Cygnus Superbubble. However, detailed studies have shown that these objects are located at different distances, suggesting that the Cygnus Superbubble is likely an illusion. NGC 6826, the Blinking Planetary Nebula, is a planetary nebula with a magnitude of 8.5, 3200 light-years from Earth. It appears to "blink" in the eyepiece of a telescope because its central star is unusually bright (10th magnitude). When an observer focuses on the star, the nebula appears to fade away. Less than one degree from the Blinking Planetary is the double star 16 Cygni. The North America Nebula (NGC 7000) is one of the most well-known nebulae in Cygnus, because it is visible to the unaided eye under dark skies, as a bright patch in the Milky Way. However, its characteristic shape is only visible in long-exposure photographs – it is difficult to observe in telescopes because of its low surface brightness. It has low surface brightness because it is so large; at its widest, the North America Nebula is 2 degrees across. Illuminated by a hot embedded star of magnitude 6, NGC 7000 is 1500 light-years from Earth. To the south of Epsilon Cygni is the Veil Nebula (NGC 6960, 6979, 6992, and 6995), a 5,000-year-old supernova remnant covering approximately 3 degrees of the sky - it is over 50 light-years long. Because of its appearance, it is also called the Cygnus Loop. The Loop is only visible in long-exposure astrophotographs. However, the brightest portion, NGC 6992, is faintly visible in binoculars, and a dimmer portion, NGC 6960, is visible in wide-angle telescopes. The DR 6 cluster is also nicknamed the "Galactic Ghoul" because of the nebula's resemblance to a human face; The Gamma Cygni Nebula (IC 1318) includes both bright and dark nebulae in an area of over 4 degrees. DWB 87 is another of the many bright emission nebulae in Cygnus, 7.8 by 4.3 arcminutes. It is in the Gamma Cygni area. Two other emission nebulae include Sharpless 2-112 and Sharpless 2-115. When viewed in an amateur telescope, Sharpless 2–112 appears to be in a teardrop shape. More of the nebula's eastern portion is visible with an O III (doubly ionized oxygen) filter. There is an orange star of magnitude 10 nearby and a star of magnitude 9 near the nebula's northwest edge. Further to the northwest, there is a dark rift and another bright patch. The whole nebula measures 15 arcminutes in diameter. Sharpless 2–115 is another emission nebula with a complex pattern of light and dark patches. Two pairs of stars appear in the nebula; it is larger near the southwestern pair. The open cluster Berkeley 90 is embedded in this large nebula, which measures 30 by 20 arcminutes. Between Gamma and Eta Cygni lies the Crescent Nebula (NGC 6888), an emission nebula formed by the Wolf–Rayet star WR 136 at a distance of about 5,650 ly (1,700 pc). Near Eta Cygni, the Tulip nebula (Sh 2-101) and the Cygnus X-1 nebula are located. The latter is formed by jets ejected from a binary system thought to consist of a black hole and a blue supergiant. In recent years, amateur astronomers have made some notable Cygnus discoveries. The "Soap bubble nebula" (PN G75.5+1.7), near the Crescent nebula, was discovered on a digital image by Dave Jurasevich in 2007. In 2011, Austrian amateur Matthias Kronberger discovered a planetary nebula (Kronberger 61, now nicknamed "The Soccer Ball") on old survey photos, confirmed recently in images by the Gemini Observatory; both of these are likely too faint to be detected by eye in a small amateur scope. But a much more obscure and relatively 'tiny' object—one which is readily seen in dark skies by amateur telescopes, under good conditions—is the newly discovered nebula (likely reflection type) associated with the star 4 Cygni (HD 183056): an approximately fan-shaped glowing region of several arcminutes' diameter, to the south and west of the fifth-magnitude star. It was first discovered visually near San Jose, California and publicly reported by amateur astronomer Stephen Waldee in 2007, and was confirmed photographically by Al Howard in 2010. California amateur astronomer Dana Patchick also says he detected it on the Palomar Observatory survey photos in 2005 but had not published it for others to confirm and analyze at the time of Waldee's first official notices and later 2010 paper. Cygnus X is the largest star-forming region in the solar neighborhood and includes not only some of the brightest and most massive stars known (such as Cygnus OB2-12), but also Cygnus OB2, a massive stellar association classified by some authors as a young globular cluster. Cygnus A is the first radio galaxy discovered; at a distance of 730 million light-years from Earth, it is the closest powerful radio galaxy. In the visible spectrum, it appears as an elliptical galaxy in a small cluster. It is classified as an active galaxy because the supermassive black hole at its nucleus is accreting matter, which produces two jets of matter from the poles. The jets' interaction with the interstellar medium creates radio lobes, one source of radio emissions. Cygnus is also the apparent source of the WIMP-wind due to the orientation of the solar system's rotation through the galactic halo. The local Orion-Cygnus Arm and the distant Cygnus Arm are two minor galactic arms named after Cygnus for lying in its background. See also References Bibliography External links |
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[SOURCE: https://en.wikipedia.org/wiki/Animal#cite_note-Hearn-202] | [TOKENS: 6011] |
Contents Animal Animals are multicellular, eukaryotic organisms belonging to the biological kingdom Animalia (/ˌænɪˈmeɪliə/). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.6 m (110 ft). They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviour is known as ethology. The animal kingdom is divided into five major clades, namely Porifera, Ctenophora, Placozoa, Cnidaria and Bilateria. Most living animal species belong to the clade Bilateria, a highly proliferative clade whose members have a bilaterally symmetric and significantly cephalised body plan, and the vast majority of bilaterians belong to two large clades: the protostomes, which includes organisms such as arthropods, molluscs, flatworms, annelids and nematodes; and the deuterostomes, which include echinoderms, hemichordates and chordates, the latter of which contains the vertebrates. The much smaller basal phylum Xenacoelomorpha have an uncertain position within Bilateria. Animals first appeared in the fossil record in the late Cryogenian period and diversified in the subsequent Ediacaran period in what is known as the Avalon explosion. Nearly all modern animal phyla first appeared in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago (Mya), and most classes during the Ordovician radiation 485.4 Mya. Common to all living animals, 6,331 groups of genes have been identified that may have arisen from a single common ancestor that lived about 650 Mya during the Cryogenian period. Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between taxa. Humans make use of many other animal species for food (including meat, eggs, and dairy products), for materials (such as leather, fur, and wool), as pets and as working animals for transportation, and services. Dogs, the first domesticated animal, have been used in hunting, in security and in warfare, as have horses, pigeons and birds of prey; while other terrestrial and aquatic animals are hunted for sports, trophies or profits. Non-human animals are also an important cultural element of human evolution, having appeared in cave arts and totems since the earliest times, and are frequently featured in mythology, religion, arts, literature, heraldry, politics, and sports. Etymology The word animal comes from the Latin noun animal of the same meaning, which is itself derived from Latin animalis 'having breath or soul'. The biological definition includes all members of the kingdom Animalia. In colloquial usage, the term animal is often used to refer only to nonhuman animals. The term metazoa is derived from Ancient Greek μετα meta 'after' (in biology, the prefix meta- stands for 'later') and ζῷᾰ zōia 'animals', plural of ζῷον zōion 'animal'. A metazoan is any member of the group Metazoa. Characteristics Animals have several characteristics that they share with other living things. Animals are eukaryotic, multicellular, and aerobic, as are plants and fungi. Unlike plants and algae, which produce their own food, animals cannot produce their own food, a feature they share with fungi. Animals ingest organic material and digest it internally. Animals have structural characteristics that set them apart from all other living things: Typically, there is an internal digestive chamber with either one opening (in Ctenophora, Cnidaria, and flatworms) or two openings (in most bilaterians). Animal development is controlled by Hox genes, which signal the times and places to develop structures such as body segments and limbs. During development, the animal extracellular matrix forms a relatively flexible framework upon which cells can move about and be reorganised into specialised tissues and organs, making the formation of complex structures possible, and allowing cells to be differentiated. The extracellular matrix may be calcified, forming structures such as shells, bones, and spicules. In contrast, the cells of other multicellular organisms (primarily algae, plants, and fungi) are held in place by cell walls, and so develop by progressive growth. Nearly all animals make use of some form of sexual reproduction. They produce haploid gametes by meiosis; the smaller, motile gametes are spermatozoa and the larger, non-motile gametes are ova. These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, and develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement. It first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm, also develops between them. These germ layers then differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction generally leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. Some animals are capable of asexual reproduction, which often results in a genetic clone of the parent. This may take place through fragmentation; budding, such as in Hydra and other cnidarians; or parthenogenesis, where fertile eggs are produced without mating, such as in aphids. Ecology Animals are categorised into ecological groups depending on their trophic levels and how they consume organic material. Such groupings include carnivores (further divided into subcategories such as piscivores, insectivores, ovivores, etc.), herbivores (subcategorised into folivores, graminivores, frugivores, granivores, nectarivores, algivores, etc.), omnivores, fungivores, scavengers/detritivores, and parasites. Interactions between animals of each biome form complex food webs within that ecosystem. In carnivorous or omnivorous species, predation is a consumer–resource interaction where the predator feeds on another organism, its prey, who often evolves anti-predator adaptations to avoid being fed upon. Selective pressures imposed on one another lead to an evolutionary arms race between predator and prey, resulting in various antagonistic/competitive coevolutions. Almost all multicellular predators are animals. Some consumers use multiple methods; for example, in parasitoid wasps, the larvae feed on the hosts' living tissues, killing them in the process, but the adults primarily consume nectar from flowers. Other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. Most animals rely on biomass and bioenergy produced by plants and phytoplanktons (collectively called producers) through photosynthesis. Herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores. Animals oxidise carbohydrates, lipids, proteins and other biomolecules in cellular respiration, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion. Some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis (via oxidising inorganic compounds such as hydrogen sulfide) by archaea and bacteria. Animals originated in the ocean; all extant animal phyla, except for Micrognathozoa and Onychophora, feature at least some marine species. However, several lineages of arthropods begun to colonise land around the same time as land plants, probably between 510 and 471 million years ago, during the Late Cambrian or Early Ordovician. Vertebrates such as the lobe-finned fish Tiktaalik started to move on to land in the late Devonian, about 375 million years ago. Other notable animal groups that colonized land environments are Mollusca, Platyhelmintha, Annelida, Tardigrada, Onychophora, Rotifera, Nematoda. Animals occupy virtually all of earth's habitats and microhabitats, with faunas adapted to salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of other organisms. Animals are however not particularly heat tolerant; very few of them can survive at constant temperatures above 50 °C (122 °F) or in the most extreme cold deserts of continental Antarctica. The collective global geomorphic influence of animals on the processes shaping the Earth's surface remains largely understudied, with most studies limited to individual species and well-known exemplars. Diversity The blue whale (Balaenoptera musculus) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33.6 metres (110 ft) long. The largest extant terrestrial animal is the African bush elephant (Loxodonta africana), weighing up to 12.25 tonnes and measuring up to 10.67 metres (35.0 ft) long. The largest terrestrial animals that ever lived were titanosaur sauropod dinosaurs such as Argentinosaurus, which may have weighed as much as 73 tonnes, and Supersaurus which may have reached 39 metres. Several animals are microscopic; some Myxozoa (obligate parasites within the Cnidaria) never grow larger than 20 μm, and one of the smallest species (Myxobolus shekel) is no more than 8.5 μm when fully grown. The following table lists estimated numbers of described extant species for the major animal phyla, along with their principal habitats (terrestrial, fresh water, and marine), and free-living or parasitic ways of life. Species estimates shown here are based on numbers described scientifically; much larger estimates have been calculated based on various means of prediction, and these can vary wildly. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million. Using patterns within the taxonomic hierarchy, the total number of animal species—including those not yet described—was calculated to be about 7.77 million in 2011.[a] 3,000–6,500 4,000–25,000 Evolutionary origin Evidence of animals is found as long ago as the Cryogenian period. 24-Isopropylcholestane (24-ipc) has been found in rocks from roughly 650 million years ago; it is only produced by sponges and pelagophyte algae. Its likely origin is from sponges based on molecular clock estimates for the origin of 24-ipc production in both groups. Analyses of pelagophyte algae consistently recover a Phanerozoic origin, while analyses of sponges recover a Neoproterozoic origin, consistent with the appearance of 24-ipc in the fossil record. The first body fossils of animals appear in the Ediacaran, represented by forms such as Charnia and Spriggina. It had long been doubted whether these fossils truly represented animals, but the discovery of the animal lipid cholesterol in fossils of Dickinsonia establishes their nature. Animals are thought to have originated under low-oxygen conditions, suggesting that they were capable of living entirely by anaerobic respiration, but as they became specialised for aerobic metabolism they became fully dependent on oxygen in their environments. Many animal phyla first appear in the fossil record during the Cambrian explosion, starting about 539 million years ago, in beds such as the Burgess Shale. Extant phyla in these rocks include molluscs, brachiopods, onychophorans, tardigrades, arthropods, echinoderms and hemichordates, along with numerous now-extinct forms such as the predatory Anomalocaris. The apparent suddenness of the event may however be an artefact of the fossil record, rather than showing that all these animals appeared simultaneously. That view is supported by the discovery of Auroralumina attenboroughii, the earliest known Ediacaran crown-group cnidarian (557–562 mya, some 20 million years before the Cambrian explosion) from Charnwood Forest, England. It is thought to be one of the earliest predators, catching small prey with its nematocysts as modern cnidarians do. Some palaeontologists have suggested that animals appeared much earlier than the Cambrian explosion, possibly as early as 1 billion years ago. Early fossils that might represent animals appear for example in the 665-million-year-old rocks of the Trezona Formation of South Australia. These fossils are interpreted as most probably being early sponges. Trace fossils such as tracks and burrows found in the Tonian period (from 1 gya) may indicate the presence of triploblastic worm-like animals, roughly as large (about 5 mm wide) and complex as earthworms. However, similar tracks are produced by the giant single-celled protist Gromia sphaerica, so the Tonian trace fossils may not indicate early animal evolution. Around the same time, the layered mats of microorganisms called stromatolites decreased in diversity, perhaps due to grazing by newly evolved animals. Objects such as sediment-filled tubes that resemble trace fossils of the burrows of wormlike animals have been found in 1.2 gya rocks in North America, in 1.5 gya rocks in Australia and North America, and in 1.7 gya rocks in Australia. Their interpretation as having an animal origin is disputed, as they might be water-escape or other structures. Phylogeny Animals are monophyletic, meaning they are derived from a common ancestor. Animals are the sister group to the choanoflagellates, with which they form the Choanozoa. Ros-Rocher and colleagues (2021) trace the origins of animals to unicellular ancestors, providing the external phylogeny shown in the cladogram. Uncertainty of relationships is indicated with dashed lines. The animal clade had certainly originated by 650 mya, and may have come into being as much as 800 mya, based on molecular clock evidence for different phyla. Holomycota (inc. fungi) Ichthyosporea Pluriformea Filasterea The relationships at the base of the animal tree have been debated. Other than Ctenophora, the Bilateria and Cnidaria are the only groups with symmetry, and other evidence shows they are closely related. In addition to sponges, Placozoa has no symmetry and was often considered a "missing link" between protists and multicellular animals. The presence of hox genes in Placozoa shows that they were once more complex. The Porifera (sponges) have long been assumed to be sister to the rest of the animals, but there is evidence that the Ctenophora may be in that position. Molecular phylogenetics has supported both the sponge-sister and ctenophore-sister hypotheses. In 2017, Roberto Feuda and colleagues, using amino acid differences, presented both, with the following cladogram for the sponge-sister view that they supported (their ctenophore-sister tree simply interchanging the places of ctenophores and sponges): Porifera Ctenophora Placozoa Cnidaria Bilateria Conversely, a 2023 study by Darrin Schultz and colleagues uses ancient gene linkages to construct the following ctenophore-sister phylogeny: Ctenophora Porifera Placozoa Cnidaria Bilateria Sponges are physically very distinct from other animals, and were long thought to have diverged first, representing the oldest animal phylum and forming a sister clade to all other animals. Despite their morphological dissimilarity with all other animals, genetic evidence suggests sponges may be more closely related to other animals than the comb jellies are. Sponges lack the complex organisation found in most other animal phyla; their cells are differentiated, but in most cases not organised into distinct tissues, unlike all other animals. They typically feed by drawing in water through pores, filtering out small particles of food. The Ctenophora and Cnidaria are radially symmetric and have digestive chambers with a single opening, which serves as both mouth and anus. Animals in both phyla have distinct tissues, but these are not organised into discrete organs. They are diploblastic, having only two main germ layers, ectoderm and endoderm. The tiny placozoans have no permanent digestive chamber and no symmetry; they superficially resemble amoebae. Their phylogeny is poorly defined, and under active research. The remaining animals, the great majority—comprising some 29 phyla and over a million species—form the Bilateria clade, which have a bilaterally symmetric body plan. The Bilateria are triploblastic, with three well-developed germ layers, and their tissues form distinct organs. The digestive chamber has two openings, a mouth and an anus, and in the Nephrozoa there is an internal body cavity, a coelom or pseudocoelom. These animals have a head end (anterior) and a tail end (posterior), a back (dorsal) surface and a belly (ventral) surface, and a left and a right side. A modern consensus phylogenetic tree for the Bilateria is shown below. Xenacoelomorpha Ambulacraria Chordata Ecdysozoa Spiralia Having a front end means that this part of the body encounters stimuli, such as food, favouring cephalisation, the development of a head with sense organs and a mouth. Many bilaterians have a combination of circular muscles that constrict the body, making it longer, and an opposing set of longitudinal muscles, that shorten the body; these enable soft-bodied animals with a hydrostatic skeleton to move by peristalsis. They also have a gut that extends through the basically cylindrical body from mouth to anus. Many bilaterian phyla have primary larvae which swim with cilia and have an apical organ containing sensory cells. However, over evolutionary time, descendant spaces have evolved which have lost one or more of each of these characteristics. For example, adult echinoderms are radially symmetric (unlike their larvae), while some parasitic worms have extremely simplified body structures. Genetic studies have considerably changed zoologists' understanding of the relationships within the Bilateria. Most appear to belong to two major lineages, the protostomes and the deuterostomes. It is often suggested that the basalmost bilaterians are the Xenacoelomorpha, with all other bilaterians belonging to the subclade Nephrozoa. However, this suggestion has been contested, with other studies finding that xenacoelomorphs are more closely related to Ambulacraria than to other bilaterians. Protostomes and deuterostomes differ in several ways. Early in development, deuterostome embryos undergo radial cleavage during cell division, while many protostomes (the Spiralia) undergo spiral cleavage. Animals from both groups possess a complete digestive tract, but in protostomes the first opening of the embryonic gut develops into the mouth, and the anus forms secondarily. In deuterostomes, the anus forms first while the mouth develops secondarily. Most protostomes have schizocoelous development, where cells simply fill in the interior of the gastrula to form the mesoderm. In deuterostomes, the mesoderm forms by enterocoelic pouching, through invagination of the endoderm. The main deuterostome taxa are the Ambulacraria and the Chordata. Ambulacraria are exclusively marine and include acorn worms, starfish, sea urchins, and sea cucumbers. The chordates are dominated by the vertebrates (animals with backbones), which consist of fishes, amphibians, reptiles, birds, and mammals. The protostomes include the Ecdysozoa, named after their shared trait of ecdysis, growth by moulting, Among the largest ecdysozoan phyla are the arthropods and the nematodes. The rest of the protostomes are in the Spiralia, named for their pattern of developing by spiral cleavage in the early embryo. Major spiralian phyla include the annelids and molluscs. History of classification In the classical era, Aristotle divided animals,[d] based on his own observations, into those with blood (roughly, the vertebrates) and those without. The animals were then arranged on a scale from man (with blood, two legs, rational soul) down through the live-bearing tetrapods (with blood, four legs, sensitive soul) and other groups such as crustaceans (no blood, many legs, sensitive soul) down to spontaneously generating creatures like sponges (no blood, no legs, vegetable soul). Aristotle was uncertain whether sponges were animals, which in his system ought to have sensation, appetite, and locomotion, or plants, which did not: he knew that sponges could sense touch and would contract if about to be pulled off their rocks, but that they were rooted like plants and never moved about. In 1758, Carl Linnaeus created the first hierarchical classification in his Systema Naturae. In his original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then, the last four have all been subsumed into a single phylum, the Chordata, while his Insecta (which included the crustaceans and arachnids) and Vermes have been renamed or broken up. The process was begun in 1793 by Jean-Baptiste de Lamarck, who called the Vermes une espèce de chaos ('a chaotic mess')[e] and split the group into three new phyla: worms, echinoderms, and polyps (which contained corals and jellyfish). By 1809, in his Philosophie Zoologique, Lamarck had created nine phyla apart from vertebrates (where he still had four phyla: mammals, birds, reptiles, and fish) and molluscs, namely cirripedes, annelids, crustaceans, arachnids, insects, worms, radiates, polyps, and infusorians. In his 1817 Le Règne Animal, Georges Cuvier used comparative anatomy to group the animals into four embranchements ('branches' with different body plans, roughly corresponding to phyla), namely vertebrates, molluscs, articulated animals (arthropods and annelids), and zoophytes (radiata) (echinoderms, cnidaria and other forms). This division into four was followed by the embryologist Karl Ernst von Baer in 1828, the zoologist Louis Agassiz in 1857, and the comparative anatomist Richard Owen in 1860. In 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms: Metazoa (multicellular animals, with five phyla: coelenterates, echinoderms, articulates, molluscs, and vertebrates) and Protozoa (single-celled animals), including a sixth animal phylum, sponges. The protozoa were later moved to the former kingdom Protista, leaving only the Metazoa as a synonym of Animalia. In human culture The human population exploits a large number of other animal species for food, both of domesticated livestock species in animal husbandry and, mainly at sea, by hunting wild species. Marine fish of many species are caught commercially for food. A smaller number of species are farmed commercially. Humans and their livestock make up more than 90% of the biomass of all terrestrial vertebrates, and almost as much as all insects combined. Invertebrates including cephalopods, crustaceans, insects—principally bees and silkworms—and bivalve or gastropod molluscs are hunted or farmed for food, fibres. Chickens, cattle, sheep, pigs, and other animals are raised as livestock for meat across the world. Animal fibres such as wool and silk are used to make textiles, while animal sinews have been used as lashings and bindings, and leather is widely used to make shoes and other items. Animals have been hunted and farmed for their fur to make items such as coats and hats. Dyestuffs including carmine (cochineal), shellac, and kermes have been made from the bodies of insects. Working animals including cattle and horses have been used for work and transport from the first days of agriculture. Animals such as the fruit fly Drosophila melanogaster serve a major role in science as experimental models. Animals have been used to create vaccines since their discovery in the 18th century. Some medicines such as the cancer drug trabectedin are based on toxins or other molecules of animal origin. People have used hunting dogs to help chase down and retrieve animals, and birds of prey to catch birds and mammals, while tethered cormorants have been used to catch fish. Poison dart frogs have been used to poison the tips of blowpipe darts. A wide variety of animals are kept as pets, from invertebrates such as tarantulas, octopuses, and praying mantises, reptiles such as snakes and chameleons, and birds including canaries, parakeets, and parrots all finding a place. However, the most kept pet species are mammals, namely dogs, cats, and rabbits. There is a tension between the role of animals as companions to humans, and their existence as individuals with rights of their own. A wide variety of terrestrial and aquatic animals are hunted for sport. The signs of the Western and Chinese zodiacs are based on animals. In China and Japan, the butterfly has been seen as the personification of a person's soul, and in classical representation the butterfly is also the symbol of the soul. Animals have been the subjects of art from the earliest times, both historical, as in ancient Egypt, and prehistoric, as in the cave paintings at Lascaux. Major animal paintings include Albrecht Dürer's 1515 The Rhinoceros, and George Stubbs's c. 1762 horse portrait Whistlejacket. Insects, birds and mammals play roles in literature and film, such as in giant bug movies. Animals including insects and mammals feature in mythology and religion. The scarab beetle was sacred in ancient Egypt, and the cow is sacred in Hinduism. Among other mammals, deer, horses, lions, bats, bears, and wolves are the subjects of myths and worship. See also Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Piedmont_(United_States)] | [TOKENS: 1049] |
Contents Piedmont (United States) The Piedmont (/ˈpiːdmɒnt/ PEED-mont) is a plateau region located in the Eastern United States. It is situated between the Atlantic Plain and the Blue Ridge Mountains, stretching from New York in the north to central Alabama in the south. The Piedmont Province is a physiographic province of the larger Appalachian Highlands physiographic division and consists of the Piedmont Upland, and the Piedmont Lowlands sections. The Atlantic Seaboard Fall Line marks the Piedmont's eastern boundary with the Coastal Plain. To the west, it is mostly bounded by the Blue Ridge Mountains, the easternmost range of the Appalachians. The width of the Piedmont varies, being quite narrow above the Delaware River but nearly 300 miles (475 km) wide in North Carolina. The Piedmont's area is approximately 80,000 square miles (210,000 km2). The French word Piedmont (modern spelling Piémont) comes from the Italian Piemonte, from Latin pedemontium, meaning "foothill" or, literally, "at the foot of the mountains"; it is the name of the northwestern Italian region abutting the Alps. Geology The surface relief of the Piedmont is characterized by relatively low, rolling hills with heights above sea level between 200 feet (50 m) and 800 feet to 1,000 feet (250 m to 300 m). Its geology is complex, with numerous rock formations of different materials and ages intermingled with one another. Essentially, the Piedmont is the remnant of several ancient mountain chains that have since been eroded. Geologists have identified at least five separate events which have led to sediment deposition, including the Grenville orogeny (the collision of continents that created the supercontinent Rodinia) and the Appalachian orogeny during the formation of Pangaea. The last major event in the history of the Piedmont was the break-up of Pangaea, when North America and Africa began to separate. Large basins formed from the rifting and were filled by the sediments shed from the surrounding higher ground. The series of Mesozoic basins is almost entirely located inside the Piedmont region. Ecology The Piedmont ecoregion (45) is an ecoregion designated by the U.S. Environmental Protection Agency (EPA) and the Commission for Environmental Cooperation (CEC). This ecoregion comprises a transitional area between the mostly mountainous ecoregions of the Appalachians to the northwest and the relatively flat coastal plain to the southeast. It is a complex mosaic of Precambrian and Paleozoic metamorphic and igneous rocks, with moderately dissected irregular plains and some hills. The soils tend to be finer-textured than in coastal plain regions. Once largely cultivated, much of this region has reverted to successional pine and hardwood woodlands, with an increasing conversion to an urban and suburban land cover. Agriculture Piedmont soils are generally clay-like (Ultisols) and moderately fertile. In some areas they have suffered from erosion and over-cropping, particularly in the South where cotton was historically the chief crop. In the central Piedmont region of North Carolina and Virginia, tobacco is the main crop, while in the north region there is more diversity, including orchards, dairying, and general farming. Music The portion of the Piedmont region in the Southern United States is closely associated with the Piedmont blues, a style of blues music that originated there in the late 19th century. According to the Piedmont Blues Preservation Society, most Piedmont blues musicians came from Virginia, North and South Carolina, and Georgia. During the Great Migration, African Americans migrated to the Piedmont. With the Appalachian Mountains to the west, those who might otherwise have spread into rural areas stayed in cities and were thus exposed to a broader mixture of music than those in, for example, the rural Mississippi delta. Thus, Piedmont blues was influenced by many types of music, such as ragtime, country, and popular songs — styles that had comparatively less influence on blues music in other regions. Cities Many major cities are located on the Atlantic Seaboard fall line, the eastern boundary of the Piedmont. (In Georgia and Alabama, where the Piedmont runs mostly east to west, the fall line is its southern boundary.) The fall line, where the land rises abruptly from the coastal plain, marks the limit of navigability on many major rivers, so inland ports sprang up along it. Within the Piedmont region itself, there are several areas of urban concentration, the largest being the Atlanta metropolitan area in Georgia. The Piedmont cuts Maryland in half, covering the Baltimore–Washington metropolitan area. In Virginia, the Greater Richmond metropolitan area is the largest urban concentration. In North Carolina, the Piedmont Crescent includes several metropolitan clusters such as Charlotte metropolitan area, the Piedmont Triad, and the Research Triangle. Other notable areas include the Greenville-Spartanburg-Anderson, SC Combined Statistical Area in South Carolina, and the Philadelphia metropolitan area in Pennsylvania. See also References Further reading External links |
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Contents Cray Cray Inc., a subsidiary of Hewlett Packard Enterprise, is an American supercomputer manufacturer headquartered in Seattle, Washington. It also manufactures systems for data storage and analytics. As of June 2025[update], Cray supercomputer systems held the top three spots in the TOP500, which ranks the most powerful supercomputers in the world. In 1972, the company was founded by computer designer Seymour Cray as Cray Research, Inc., and it continues to manufacture parts in Chippewa Falls, Wisconsin, where Cray was born and raised. After being acquired by Silicon Graphics in 1996, the modern company was formed after being purchased in 2000 by Tera Computer Company, which adopted the name Cray Inc. In 2019, the company was acquired by Hewlett Packard Enterprise for $1.3 billion. History In 1950, Seymour Cray began working in the computing field when he joined Engineering Research Associates (ERA) in Saint Paul, Minnesota. There, he helped to create the ERA 1103. ERA eventually became part of UNIVAC, and began to be phased out. In 1960, he left the company, a few years after former ERA employees set up Control Data Corporation (CDC). He initially worked out of the CDC headquarters in Minneapolis. He eventually set up a lab in his hometown of Chippewa Falls, Wisconsin. Cray had a string of successes at CDC, including the CDC 6600 and CDC 7600. When CDC ran into financial difficulties in the late 1960s, development funds for Cray's follow-on CDC 8600 became scarce. When he was told the project would have to be put "on hold" in 1972, Cray left to form his own company, Cray Research, Inc. Copying the previous arrangement, Cray kept the research and development facilities in Chippewa Falls and put the business headquarters in Minneapolis. The company's first product, the Cray-1 supercomputer, was a major success because it was significantly faster than all other computers at the time. The first system was sold within a month for $8.8 million. Seymour Cray continued working, this time on the Cray-2, though it ended up being only marginally faster than the Cray X-MP, developed by another team at the company. Cray soon left the CEO position to become an independent contractor. He started a new Very Large Scale Integration technology lab for the Cray-2 in Boulder, Colorado, Cray Laboratories, in 1979, which closed in 1982. Cray later headed a similar spin-off in 1989, Cray Computer Corporation (CCC) in Colorado Springs, Colorado, where he worked on the Cray-3 project—the first attempt at major use of gallium arsenide (GaAs) semiconductors in computing. However, the changing political climate (collapse of the Warsaw Pact and the end of the Cold War) resulted in poor sales prospects. Ultimately, only one Cray-3 was delivered, and a number of follow-on designs were never completed. The company filed for bankruptcy in 1995. CCC's remains then became Cray's final corporation, SRC Computers, Inc. Cray Research continued development along a separate line of computers, originally with lead designer Steve Chen and the Cray X-MP. After Chen's departure, the Cray Y-MP, Cray C90 and Cray T90 were developed on the original Cray-1 architecture but achieved much greater performance via multiple additional processors, faster clocks, and wider vector pipes. The uncertainty of the Cray-2 project gave rise to a number of Cray-object-code compatible "Crayette" firms, including Scientific Computer Systems (SCS), American Supercomputer, and Supertek. These firms did not intend to compete against Cray and therefore attempted less expensive, slower CMOS versions of the X-MP with the release of the COS operating system (SCS) and the CFT Fortran compiler; they also considered the Cray Time Sharing System operating system, developed at United States Department of Energy national laboratories (LANL/LLNL), before joining the broader trend toward adoption of Unixes. Today, Cray OS is a specialized version of SUSE Linux Enterprise Server. A series of massively parallel computers from Thinking Machines Corporation, Kendall Square Research, Intel, nCUBE, MasPar and Meiko Scientific took over the 1980s high performance market. At first, Cray Research denigrated such approaches by complaining that developing software to effectively use the machines was difficult – a true complaint in the era of the ILLIAC IV, but becoming less so each day. Cray eventually realized that the approach was likely the only way forward and started a five-year project to capture the lead in this area: the plan's result was the Digital Equipment Corporation Alpha-based Cray T3D and Cray T3E series, which left Cray as the only remaining supercomputer vendor in the market besides NEC's SX architecture by 2000. Most sites with a Cray installation were considered members of the "exclusive club" of Cray operators. Cray computers were considered quite prestigious because Crays were extremely expensive machines, and the number of units sold was small compared to ordinary mainframes. This perception extended to countries as well: to boost the perception of exclusivity, Cray Research's marketing department had promotional neckties made with a mosaic of tiny national flags illustrating the "club of Cray-operating countries". New vendors introduced small supercomputers, known as minisupercomputers (as opposed to superminis) during the late 1980s and early 1990s, which out-competed low-end Cray machines in the market. The Convex Computer series, as well as a number of small-scale parallel machines from companies like Pyramid Technology and Alliant Computer Systems were particularly popular. One such vendor was Supertek, whose S-1 machine was an air-cooled CMOS implementation of the X-MP processor. Cray purchased Supertek in 1990 and sold the S-1 as the Cray XMS, but the machine proved problematic; meanwhile, the not-yet-completed S-2, a Y-MP clone, was later offered as the Cray Y-MP (later becoming the Cray EL90) which started to sell in reasonable numbers in 1991–92—to mostly smaller companies, notably in the oil exploration business. This line evolved into the Cray J90 and eventually the Cray SV1 in 1998. In December 1991, Cray purchased some of the assets of Floating Point Systems, another minisuper vendor that had moved into the file server market with its SPARC-based Model 500 line. These symmetric multiprocessing machines scaled up to 64 processors and ran a modified version of the Solaris operating system from Sun Microsystems. Cray set up Cray Research Superservers, Inc. (later the Cray Business Systems Division) to sell this system as the Cray S-MP, later replacing it with the Cray CS6400. In spite of these machines being some of the most powerful available when applied to appropriate workloads, Cray was never very successful in this market, possibly due to it being so foreign to its existing market niche. CCC was building the Cray-3/SSS when it went into Chapter 11 bankruptcy in March 1995. In February 1996, Cray Research was acquired by Silicon Graphics (SGI) for $740 million. In May 1996, SGI sold the Superservers business to Sun. Sun then turned the UltraSPARC-based Starfire project then under development into the extremely successful Sun Enterprise 10000 range of servers. SGI used several Cray technologies in its attempt to move from the graphics workstation market into supercomputing. Key among these was the use of the Cray-developed HIPPI computer bus and details of the interconnects used in the T3 series. SGI's long-term strategy was to merge its high-end server line with Cray's product lines in two phases, code-named SN1 and SN2 (SN standing for "Scalable Node"). The SN1 was intended to replace the T3E and SGI Origin 2000 systems and later became the SN-MIPS or SGI Origin 3000 architecture. The SN2 was originally intended to unify all high-end/supercomputer product lines including the T90 into a single architecture. This goal was never achieved before SGI divested itself of the Cray business, and the SN2 name was later associated with the SN-IA or SGI Altix 3000 architecture. In October 1996, founder Seymour Cray died as a result of a traffic accident. In 1998, under SGI ownership, one new Cray model line, the Cray SV1, was launched. This was a clustered SMP vector processor architecture, developed from J90 technology. On March 2, 2000, Cray was sold to Tera Computer Company, which was renamed Cray Inc. After the Tera merger, the Tera MTA system was relaunched as the Cray MTA-2. This was not a commercial success and shipped to only two customers. Cray Inc. also unsuccessfully badged the NEC SX-6 supercomputer as the Cray SX-6 and acquired exclusive rights to sell the SX-6 in the US, Canada, and Mexico. In 2002, Cray Inc. announced its first new model, the Cray X1 combined architecture vector processor / massively parallel supercomputer. Previously known as the SV2, the X1 is the result of the earlier SN2 concept originated during the SGI years. In May 2004, Cray was announced to be one of the partners in the United States Department of Energy's fastest-computer-in-the-world project to build a 50 teraFlops machine for the Oak Ridge National Laboratory. Cray was sued in 2002 by Isothermal Systems Research for patent infringement. The suit claimed that Cray used ISR's patented technology in the development of the Cray X1. The lawsuit was settled in 2003. As of November 2004, the Cray X1 had a maximum measured performance of 5.9 teraflops, being the 29th fastest supercomputer in the world. Since then the X1 has been superseded by the X1E, with faster dual-core processors. On October 4, 2004, the company announced the Cray XD1 range of entry-level supercomputers which use dual-core 64-bit Advanced Micro Devices Opteron central processing units running Linux. This system was previously known as the OctigaBay 12K before Cray's acquisition of that company. The XD1 provided one Xilinx Virtex II Pro field-programmable gate array (FPGA) with each node of four Opteron processors. The FPGAs could be configured to embody various digital hardware designs and could augment the processing or input/output capabilities of the Opteron processors. Furthermore, each FPGA contains a pair of PowerPC 405 processors which can add to the already considerable power of a single node. The Cray XD1, although moderately successful, was eventually discontinued. In 2004, Cray completed the Red Storm system for Sandia National Laboratories. Red Storm was to become the jumping-off point for a string of successful products that eventually revitalized Cray in supercomputing. Red Storm had processors clustered in 96 unit cabinets, a theoretical maximum of 300 cabinets in a machine, and a design speed of 41.5 teraflops. Red Storm also included an innovative new design for network interconnects, which was dubbed SeaStar and destined to be the centerpiece of succeeding innovations by Cray. The Cray XT3 massively parallel supercomputer became a commercialized version of Red Storm, similar in many respects to the earlier T3E architecture, but, like the XD1, using AMD Opteron processors. On August 8, 2005, Peter Ungaro was appointed CEO. Ungaro had joined Cray in August 2003 as Vice President of Sales and Marketing and had been made Cray's President in March 2005. Introduced in 2006, the Cray XT4 added support for DDR2 memory, newer dual-core and future quad-core Opteron processors and utilized a second generation SeaStar2 communication coprocessor. It also included an option for FPGA chips to be plugged directly into processor sockets, unlike the Cray XD1, which required a dedicated socket for the FPGA coprocessor. On November 13, 2006, Cray announced a new system, the Cray XMT, based on the MTA series of machines. This system combined multi-threaded processors, as used on the original Tera systems, and the SeaStar2 interconnect used by the XT4. By reusing ASICs, boards, cabinets, and system software used by the comparatively higher volume XT4 product, the cost of making the very specialized MTA system could be reduced. A second generation of the XMT is scheduled for release in 2011, with the first system ordered by the Swiss National Supercomputing Center (CSCS). In 2006, Cray announced a vision of products dubbed Adaptive Supercomputing. The first generation of such systems, dubbed the Rainier Project, used a common interconnect network (SeaStar2), programming environment, cabinet design, and I/O subsystem. These systems included the existing XT4 and the XMT. The second generation, launched as the XT5h, allowed a system to combine compute elements of various types into a common system, sharing infrastructure. The XT5h combined Opteron, vector, multithreaded, and FPGA compute processors in a single system. In April 2008, Cray and Intel announced they would collaborate on future supercomputer systems. This partnership produced the Cray CX1 system, launched in September the same year. This was a deskside blade server system, comprising up to 16 dual- or quad-core Intel Xeon processors, with either Microsoft Windows HPC Server 2008 or Red Hat Enterprise Linux installed. By 2009, the largest computer system Cray had delivered was the Cray XT5 system at National Center for Computational Sciences at Oak Ridge National Laboratories. This system, with over 224,000 processing cores, was dubbed Jaguar and was the fastest computer in the world as measured by the LINPACK benchmark at the speed of 1.75 petaflops until being surpassed by the Tianhe-1A in October 2010. It was the first system to exceed a sustained performance of 1 petaflops on a 64-bit scientific application. In May 2010, the Cray XE6 supercomputer was announced. The Cray XE6 system had at its core the new Gemini system interconnect. This new interconnect included a true global-address space and represented a return to the T3E feature set that had been so successful with Cray Research. This product was a successful follow-on to the XT3, XT4 and XT5 products. The first multi-cabinet XE6 system was shipped in July 2010. The next generation Cascade systems were designed make use of future multicore and/or manycore processors from vendors such as Intel and Nvidia. Cascade was scheduled to be introduced in early 2013 and designed to use the next-generation network chip and follow-on to Gemini, code named Aries. In early 2010, Cray also introduced the Cray CX1000, a rack-mounted system with a choice of compute-based, GPU-based, or SMP-based chassis. The CX1 and CX1000 product lines were sold until late 2011. In 2011, Cray announced the Cray XK6 hybrid supercomputer. The Cray XK6 system, capable of scaling to 500,000 processors and 50 petaflops of peak performance, combines Cray's Gemini interconnect, AMD's multi-core scalar processors, and Nvidia's Tesla GPGPU processors. In October 2012 Cray announced the Cray XK7 which supports the Nvidia Kepler GPGPU and announced that the ORNL Jaguar system would be upgraded to an XK7 (renamed Titan) and capable of over 20 petaflops. Titan was the world's fastest supercomputer as measured by the LINPACK benchmark until the introduction of the Tianhe-2 in 2013, which is substantially faster. In 2011 Cray also announced it had been awarded the $188 million Blue Waters contract with the University of Illinois at Urbana–Champaign, after IBM had pulled out of the delivery. This system was delivered in 2012 and was the largest system to date, in terms of cabinets and general-purpose x86 processors, that Cray had ever delivered. In November 2011, the Cray Sonexion 1300 Data Storage System was introduced and signaled Cray's entry into the high performance storage business. This product used modular technology and a Lustre file system. In 2011, Cray launched the OpenACC parallel programming standard organization. In 2019, Cray announced that it was deprecating OpenACC, and will support OpenMP. However, in 2022, the Cray Fortran compiler still supported OpenACC, in part due to its usage in the ICON climate simulation code. In April 2012, Cray announced the sale of its interconnect hardware development program and related intellectual property to Intel for $140 million. On November 9, 2012, Cray announced the acquisition of Appro International, Inc., a California-based privately held developer of advanced scalable supercomputing solutions. As of 2012 the #3 provider on the Top100 supercomputer list, Appro builds some of the world's most advanced high performance computing (HPC) cluster systems. In 2012, Cray also opened a subsidiary in China. On September 25, 2019, Hewlett Packard Enterprise (HPE) acquired the company for $1.3 billion. HPE's acquisition strengthened its position in high-performance computing (HPC) and artificial intelligence (AI) markets. In October 2020, HPE was awarded the contract to build the pre-exascale EuroHPC computer LUMI, in Kajaani, Finland. The contract, worth €144.5 million, is for an HPE Cray EX system, with a theoretical maximum performance of 550 petaflops. Once fully operational, LUMI will become one of the fastest supercomputers in the world. On June 28, 2022, the US National Oceanic and Atmospheric Administration (NOAA) inaugurated the nation’s newest weather and climate supercomputers, two HPE Cray supercomputers installed and operated by General Dynamics (GDIT). Each supercomputer operates at 12.1 petaflops. On November 18, 2024, the US National Nuclear Security Administration (NNSA) unveiled an HPE Cray supercomputer for use in nuclear weapons analysis and inertial confinement fusion design. The supercomputer is housed at Lawrence Livermore National Laboratory (LLNL), and was ranked at #1 in the TOP500 supercomputer list in the November 2024 edition. HPE Cray supercomputers were listed in 7 of the top 10 positions on the list, including the #1, #2, and #3 positions. References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/System_on_a_chip] | [TOKENS: 4887] |
Contents System on a chip A system on a chip, or system on chip (SoC), is an integrated circuit that combines most or all key components of a computer or electronic system onto a single microchip. Typically, an SoC includes a central processing unit (CPU) with memory, input/output, and data storage control functions, along with optional features like a graphics processing unit (GPU), Wi-Fi connectivity, and radio frequency processing. This high level of integration minimizes the need for separate, discrete components, thereby enhancing power efficiency and simplifying device design. High-performance SoCs are often paired with dedicated memory, such as LPDDR, and flash storage chips, such as eUFS or eMMC, which may be stacked directly on top of the SoC in a package-on-package (PoP) configuration or placed nearby on the motherboard. Some SoCs also operate alongside specialized chips, such as cellular modems. Fundamentally, SoCs integrate one or more processor cores with critical peripherals. This comprehensive integration is conceptually similar to how a microcontroller is designed, but providing far greater computational power. This unified design delivers lower power consumption and a reduced semiconductor die area compared to traditional multi-chip architectures, though at the cost of reduced modularity and component replaceability. SoCs are ubiquitous in mobile computing, where compact, energy-efficient designs are critical. They power smartphones, tablets, and smartwatches, and are increasingly important in edge computing, where real-time data processing occurs close to the data source. By driving the trend toward tighter integration, SoCs have reshaped modern hardware design, reshaping the design landscape for modern computing devices. Types In general, there are three distinguishable types of SoCs: Applications SoCs can be applied to any computing task. However, they are typically used in mobile computing such as tablets, smartphones, smartwatches, and netbooks as well as embedded systems and in applications where previously microcontrollers would be used. Where previously only microcontrollers could be used, SoCs are rising to prominence in the embedded systems market. Tighter system integration offers better reliability and mean time between failure, and SoCs offer more advanced functionality and computing power than microcontrollers. Applications include AI acceleration, embedded machine vision, data collection, telemetry, vector processing and ambient intelligence. Often embedded SoCs target the internet of things, multimedia, networking, telecommunications and edge computing markets. Some examples of SoCs for embedded applications include the STMicroelectronics STM32, the Raspberry Pi Ltd RP2040, and the AMD Zynq 7000. Mobile computing based SoCs always bundle processors, memories, on-chip caches, wireless networking capabilities and often digital camera hardware and firmware. With increasing memory sizes, high end SoCs will often have no memory and flash storage and instead, the memory and flash memory will be placed right next to, or above (package on package), the SoC. Some examples of mobile computing SoCs include: In 1992, Acorn Computers produced the A3010, A3020 and A4000 range of personal computers with the ARM250 SoC. It combined the original Acorn ARM2 processor with a memory controller (MEMC), video controller (VIDC), and I/O controller (IOC). In previous Acorn ARM-powered computers, these were four discrete chips. The ARM7500 chip was their second-generation SoC, based on the ARM700, VIDC20 and IOMD controllers, and was widely licensed in embedded devices such as set-top-boxes, as well as later Acorn personal computers. Tablet and laptop manufacturers have learned lessons from embedded systems and smartphone markets about reduced power consumption, better performance and reliability from tighter integration of hardware and firmware modules, and LTE and other wireless network communications integrated on chip (integrated network interface controllers). On modern laptops and mini PCs, the low-power variants of AMD Ryzen and Intel Core processors use SoC design integrating CPU, IGPU, chipset and other processors in a single package. However, such x86 processors still require external memory and storage chips. Structure An SoC consists of hardware functional units, including microprocessors that run software code, as well as a communications subsystem to connect, control, direct and interface between these functional modules. An SoC must have at least one processor core, but typically an SoC has more than one core. Processor cores can be a microcontroller, microprocessor (μP), digital signal processor (DSP) or application-specific instruction set processor (ASIP) core. ASIPs have instruction sets that are customized for an application domain and designed to be more efficient than general-purpose instructions for a specific type of workload. Multiprocessor SoCs have more than one processor core by definition. The ARM architecture is a common choice for SoC processor cores because some ARM-architecture cores are soft processors specified as IP cores. SoCs must have semiconductor memory blocks to perform their computation, as do microcontrollers and other embedded systems. Depending on the application, SoC memory may form a memory hierarchy and cache hierarchy. In the mobile computing market, this is common, but in many low-power embedded microcontrollers, this is not necessary. Memory technologies for SoCs include read-only memory (ROM), random-access memory (RAM), Electrically Erasable Programmable ROM (EEPROM) and flash memory. As in other computer systems, RAM can be subdivided into relatively faster but more expensive static RAM (SRAM) and the slower but cheaper dynamic RAM (DRAM). When an SoC has a cache hierarchy, SRAM will usually be used to implement processor registers and cores' built-in caches whereas DRAM will be used for main memory. "Main memory" may be specific to a single processor (which can be multi-core) when the SoC has multiple processors, in this case it is distributed memory and must be sent via § Intermodule communication on-chip to be accessed by a different processor. For further discussion of multi-processing memory issues, see cache coherence and memory latency. SoCs include external interfaces, typically for communication protocols. These are often based upon industry standards such as USB, Ethernet, USART, SPI, HDMI, I²C, CSI, etc. These interfaces will differ according to the intended application. Wireless networking protocols such as Wi-Fi, Bluetooth, 6LoWPAN and near-field communication may also be supported. When needed, SoCs include analog interfaces including analog-to-digital and digital-to-analog converters, often for signal processing. These may be able to interface with different types of sensors or actuators, including smart transducers. They may interface with application-specific modules or shields.[nb 1] Or they may be internal to the SoC, such as if an analog sensor is built in to the SoC and its readings must be converted to digital signals for mathematical processing. Digital signal processor (DSP) cores are often included on SoCs. They perform signal processing operations in SoCs for sensors, actuators, data collection, data analysis and multimedia processing. DSP cores typically feature very long instruction word (VLIW) and single instruction, multiple data (SIMD) instruction set architectures, and are therefore highly amenable to exploiting instruction-level parallelism through parallel processing and superscalar execution.: 4 SP cores most often feature application-specific instructions, and as such are typically application-specific instruction set processors (ASIP). Such application-specific instructions correspond to dedicated hardware functional units that compute those instructions. Typical DSP instructions include multiply-accumulate, Fast Fourier transform, fused multiply-add, and convolutions. As with other computer systems, SoCs require timing sources to generate clock signals, control execution of SoC functions and provide time context to signal processing applications of the SoC, if needed. Popular time sources are crystal oscillators and phase-locked loops. SoC peripherals including counter-timers, real-time timers and power-on reset generators. SoCs also include voltage regulators and power management circuits. SoCs comprise many execution units. These units must often send data and instructions back and forth. Because of this, all but the most trivial SoCs require communications subsystems. Originally, as with other microcomputer technologies, data bus architectures were used, but recently designs based on sparse intercommunication networks known as networks-on-chip (NoC) have risen to prominence and are forecast to overtake bus architectures for SoC design in the near future. Historically, a shared global computer bus typically connected the different components, also called "blocks" of the SoC. A very common bus for SoC communications is ARM's royalty-free Advanced Microcontroller Bus Architecture (AMBA) standard. Direct memory access controllers route data directly between external interfaces and SoC memory, bypassing the CPU or control unit, thereby increasing the data throughput of the SoC. This is similar to some device drivers of peripherals on component-based multi-chip module PC architectures. Wire delay is not scalable due to continued miniaturization, system performance does not scale with the number of cores attached, the SoC's operating frequency must decrease with each additional core attached for power to be sustainable, and long wires consume large amounts of electrical power. These challenges are prohibitive to supporting manycore systems on chip.: xiii In the late 2010s, a trend of SoCs implementing communications subsystems in terms of a network-like topology instead of bus-based protocols has emerged. A trend towards more processor cores on SoCs has caused on-chip communication efficiency to become one of the key factors in determining the overall system performance and cost.: xiii This has led to the emergence of interconnection networks with router-based packet switching known as "networks on chip" (NoCs) to overcome the bottlenecks of bus-based networks.: xiii Networks-on-chip have advantages including destination- and application-specific routing, greater power efficiency and reduced possibility of bus contention. Network-on-chip architectures take inspiration from communication protocols like TCP and the Internet protocol suite for on-chip communication, although they typically have fewer network layers. Optimal network-on-chip network architectures are an ongoing area of much research interest. NoC architectures range from traditional distributed computing network topologies such as torus, hypercube, meshes and tree networks to genetic algorithm scheduling to randomized algorithms such as random walks with branching and randomized time to live (TTL). Many SoC researchers consider NoC architectures to be the future of SoC design because they have been shown to efficiently meet power and throughput needs of SoC designs. Current NoC architectures are two-dimensional. 2D IC design has limited floorplanning choices as the number of cores in SoCs increase, so as three-dimensional integrated circuits (3DICs) emerge, SoC designers are looking towards building three-dimensional on-chip networks known as 3DNoCs. Design flow A system on a chip consists of both the hardware, described in § Structure, and the software controlling the microcontroller, microprocessor or digital signal processor cores, peripherals and interfaces. The design flow for an SoC aims to develop this hardware and software at the same time, also known as architectural co-design. The design flow must also take into account optimizations (§ Optimization goals) and constraints. Most SoCs are developed from pre-qualified hardware component IP core specifications for the hardware elements and execution units, collectively "blocks", described above, together with software device drivers that may control their operation. Of particular importance are the protocol stacks that drive industry-standard interfaces like USB. The hardware blocks are put together using computer-aided design tools, specifically electronic design automation tools; the software modules are integrated using a software integrated development environment. SoCs components are also often designed in high-level programming languages such as C++, MATLAB or SystemC and converted to RTL designs through high-level synthesis (HLS) tools such as C to HDL or flow to HDL. HLS products called "algorithmic synthesis" allow designers to use C++ to model and synthesize system, circuit, software and verification levels all in one high level language commonly known to computer engineers in a manner independent of time scales, which are typically specified in HDL. Other components can remain software and be compiled and embedded onto soft-core processors included in the SoC as modules in HDL as IP cores. Once the architecture of the SoC has been defined, any new hardware elements are written in an abstract hardware description language termed register transfer level (RTL) which defines the circuit behavior, or synthesized into RTL from a high level language through high-level synthesis. These elements are connected together in a hardware description language to create the full SoC design. The logic specified to connect these components and convert between possibly different interfaces provided by different vendors is called glue logic. Chips are verified for validation correctness before being sent to a semiconductor foundry. This process is called functional verification and it accounts for a significant portion of the time and energy expended in the chip design life cycle, often quoted as 70%. With the growing complexity of chips, hardware verification languages like SystemVerilog, SystemC, e, and OpenVera are being used. Bugs found in the verification stage are reported to the designer. Traditionally, engineers have employed simulation acceleration, emulation or prototyping on reprogrammable hardware to verify and debug hardware and software for SoC designs prior to the finalization of the design, known as tape-out. Field-programmable gate arrays (FPGAs) are favored for prototyping SoCs because FPGA prototypes are reprogrammable, allow debugging and are more flexible than application-specific integrated circuits (ASICs). With high capacity and fast compilation time, simulation acceleration and emulation are powerful technologies that provide wide visibility into systems. Both technologies, however, operate slowly, on the order of MHz, which may be significantly slower – up to 100 times slower – than the SoC's operating frequency. Acceleration and emulation boxes are also very large and expensive at over US$1 million.[citation needed] FPGA prototypes, in contrast, use FPGAs directly to enable engineers to validate and test at, or close to, a system's full operating frequency with real-world stimuli. Tools such as Certus are used to insert probes in the FPGA RTL that make signals available for observation. This is used to debug hardware, firmware and software interactions across multiple FPGAs with capabilities similar to a logic analyzer. In parallel, the hardware elements are grouped and passed through a process of logic synthesis, during which performance constraints, such as operational frequency and expected signal delays, are applied. This generates an output known as a netlist describing the design as a physical circuit and its interconnections. These netlists are combined with the glue logic connecting the components to produce the schematic description of the SoC as a circuit which can be printed onto a chip. This process is known as place and route and precedes tape-out in the event that the SoCs are produced as application-specific integrated circuits (ASIC). Optimization goals SoCs must optimize power use, area on die, communication, positioning for locality between modular units and other factors. Optimization is necessarily a design goal of SoCs. If optimization was not necessary, the engineers would use a multi-chip module architecture without accounting for the area use, power consumption or performance of the system to the same extent. Common optimization targets for SoC designs follow, with explanations of each. In general, optimizing any of these quantities may be a hard combinatorial optimization problem, and can indeed be NP-hard fairly easily. Therefore, sophisticated optimization algorithms are often required and it may be practical to use approximation algorithms or heuristics in some cases. Additionally, most SoC designs contain multiple variables to optimize simultaneously, so Pareto efficient solutions are sought after in SoC design. Oftentimes the goals of optimizing some of these quantities are directly at odds, further adding complexity to design optimization of SoCs and introducing trade-offs in system design. For broader coverage of trade-offs and requirements analysis, see requirements engineering. SoCs are optimized to minimize the electrical power used to perform the SoC's functions. Most SoCs must use low power. SoC systems often require long battery life (such as smartphones), can potentially spend months or years without a power source while needing to maintain autonomous function, and often are limited in power use by a high number of embedded SoCs being networked together in an area. Additionally, energy costs can be high and conserving energy will reduce the total cost of ownership of the SoC. Finally, waste heat from high energy consumption can damage other circuit components if too much heat is dissipated, giving another pragmatic reason to conserve energy. The amount of energy used in a circuit is the integral of power consumed with respect to time, and the average rate of power consumption is the product of current by voltage. Equivalently, by Ohm's law, power is current squared times resistance or voltage squared divided by resistance: P = I V = V 2 R = I 2 R {\displaystyle P=IV={\frac {V^{2}}{R}}={I^{2}}{R}} SoCs are frequently embedded in portable devices such as smartphones, GPS navigation devices, digital watches (including smartwatches) and netbooks. Customers want long battery lives for mobile computing devices, another reason that power consumption must be minimized in SoCs. Multimedia applications are often executed on these devices, including video games, video streaming, image processing; all of which have grown in computational complexity in recent years with user demands and expectations for higher-quality multimedia. Computation is more demanding as expectations move towards 3D video at high resolution with multiple standards, so SoCs performing multimedia tasks must be computationally capable platform while being low power to run off a standard mobile battery.: 3 SoCs are optimized to maximize power efficiency in performance per watt: maximize the performance of the SoC given a budget of power usage. Many applications such as edge computing, distributed processing and ambient intelligence require a certain level of computational performance, but power is limited in most SoC environments. SoC designs are optimized to minimize waste heat output on the chip. As with other integrated circuits, heat generated due to high power density are the bottleneck to further miniaturization of components.: 1 The power densities of high speed integrated circuits, particularly microprocessors and including SoCs, have become highly uneven. Too much waste heat can damage circuits and erode reliability of the circuit over time. High temperatures and thermal stress negatively impact reliability, stress migration, decreased mean time between failures, electromigration, wire bonding, metastability and other performance degradation of the SoC over time.: 2–9 In particular, most SoCs are in a small physical area or volume and therefore the effects of waste heat are compounded because there is little room for it to diffuse out of the system. Because of high transistor counts on modern devices, oftentimes a layout of sufficient throughput and high transistor density is physically realizable from fabrication processes but would result in unacceptably high amounts of heat in the circuit's volume.: 1 These thermal effects force SoC and other chip designers to apply conservative design margins, creating less performant devices to mitigate the risk of catastrophic failure. Due to increased transistor densities as length scales get smaller, each process generation produces more heat output than the last. Compounding this problem, SoC architectures are usually heterogeneous, creating spatially inhomogeneous heat fluxes, which cannot be effectively mitigated by uniform passive cooling.: 1 SoCs are optimized to maximize computational and communications throughput. SoCs are optimized to minimize latency for some or all of their functions. This can be accomplished by laying out elements with proper proximity and locality to each-other to minimize the interconnection delays and maximize the speed at which data is communicated between modules, functional units and memories. In general, optimizing to minimize latency is an NP-complete problem equivalent to the Boolean satisfiability problem. For tasks running on processor cores, latency and throughput can be improved with task scheduling. Some tasks run in application-specific hardware units, however, and even task scheduling may not be sufficient to optimize all software-based tasks to meet timing and throughput constraints. Systems on chip are modeled with standard hardware verification and validation techniques, but additional techniques are used to model and optimize SoC design alternatives to make the system optimal with respect to multiple-criteria decision analysis on the above optimization targets. Task scheduling is an important activity in any computer system with multiple processes or threads sharing a single processor core. It is important to reduce § Latency and increase § Throughput for embedded software running on an SoC's § Processor cores. Not every important computing activity in a SoC is performed in software running on on-chip processors, but scheduling can drastically improve performance of software-based tasks and other tasks involving shared resources. Software running on SoCs often schedules tasks according to network scheduling and randomized scheduling algorithms. Hardware and software tasks are often pipelined in processor design. Pipelining is an important principle for speedup in computer architecture. They are frequently used in CPUs (for example, the classic RISC pipeline) and GPUs (graphics pipeline), but are also applied to application-specific tasks such as digital signal processing and multimedia manipulations in the context of SoCs. SoCs are often analyzed though probabilistic models, queueing networks, and Markov chains. For instance, Little's law allows SoC states and NoC buffers to be modeled as arrival processes and analyzed through Poisson random variables and Poisson processes. SoCs are often modeled with Markov chains, both discrete time and continuous time variants. Markov chain modeling allows asymptotic analysis of the SoC's steady state distribution of power, heat, latency and other factors to allow design decisions to be optimized for the common case. Fabrication SoC chips are typically fabricated using metal–oxide–semiconductor (MOS) technology. The netlists described above are used as the basis for the physical design (place and route) flow to convert the designers' intent into the design of the SoC. Throughout this conversion process, the design is analyzed with static timing modeling, simulation and other tools to ensure that it meets the specified operational parameters such as frequency, power consumption and dissipation, functional integrity (as described in the register transfer level code) and electrical integrity. When all known bugs have been rectified and these have been re-verified and all physical design checks are done, the physical design files describing each layer of the chip are sent to the foundry's mask shop where a full set of glass lithographic masks will be etched. These are sent to a wafer fabrication plant to create the SoC dice before packaging and testing. SoCs can be fabricated by several technologies, including: ASICs consume less power and are faster than FPGAs but cannot be reprogrammed and are expensive to manufacture. FPGA designs are more suitable for lower volume designs, but after enough units of production ASICs reduce the total cost of ownership. SoC designs consume less power and have a lower cost and higher reliability than the multi-chip systems that they replace. With fewer packages in the system, assembly costs are reduced as well. However, like most very-large-scale integration (VLSI) designs, the total cost[clarification needed] is higher for one large chip than for the same functionality distributed over several smaller chips, because of lower yields[clarification needed] and higher non-recurring engineering costs. When it is not feasible to construct an SoC for a particular application, an alternative is a system in package (SiP) comprising a number of chips in a single package. When produced in large volumes, SoC is more cost-effective than SiP because its packaging is simpler. Another reason SiP may be preferred is waste heat may be too high in a SoC for a given purpose because functional components are too close together, and in an SiP heat will dissipate better from different functional modules since they are physically further apart. Examples Some examples of systems on a chip are: Benchmarks SoC research and development often compares many options. Benchmarks, such as COSMIC, are developed to help such evaluations. See also Notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Middle_East#cite_note-79] | [TOKENS: 6152] |
Contents Middle East The Middle East[b] is a geopolitical region encompassing the Arabian Peninsula, Egypt, Iran, Iraq, the Levant, and Turkey. The term came into widespread usage by Western European nations in the early 20th century as a replacement of the term Near East (both were in contrast to the Far East). The term "Middle East" has led to some confusion over its changing definitions. Since the late 20th century, it has been criticized as being too Eurocentric. The region includes the vast majority of the territories included in the closely associated definition of West Asia, but without the South Caucasus. It also includes all of Egypt (not just the Sinai region) and all of Turkey (including East Thrace). Most Middle Eastern countries (13 out of 18) are part of the Arab world. The three most populous countries in the region are Egypt, Iran, and Turkey, while Saudi Arabia is the largest Middle Eastern country by area. The history of the Middle East dates back to ancient times, and it was long considered the "cradle of civilization". The geopolitical importance of the region has been recognized and competed for during millennia. The Abrahamic religions (Judaism, Christianity, and Islam) have their origins in the Middle East. Arabs constitute the main ethnic group in the region, followed by Turks, Persians, Kurds, Jews, and Assyrians. The Middle East generally has a hot, arid climate, especially in the Arabian and Egyptian regions. Several major rivers provide irrigation to support agriculture in limited areas here, such as the Nile Delta in Egypt, the Tigris and Euphrates watersheds of Mesopotamia, and the basin of the Jordan River that spans most of the Levant. These regions are collectively known as the Fertile Crescent, and comprise the core of what historians had long referred to as the cradle of civilization; multiple regions of the world have since been classified as also having developed independent, original civilizations. Conversely, the Levantine coast and most of Turkey have relatively temperate climates typical of the Mediterranean, with dry summers and cool, wet winters. Most of the countries that border the Persian Gulf have vast reserves of petroleum. Monarchs of the Arabian Peninsula in particular have benefitted economically from petroleum exports. Because of the arid climate and dependence on the fossil fuel industry, the Middle East is both a major contributor to climate change and a region that is expected to be severely adversely affected by it. Other concepts of the region exist, including the broader Middle East and North Africa (MENA), which includes states of the Maghreb and the Sudan. The term the "Greater Middle East" also includes Afghanistan, Mauritania, Pakistan, as well as parts of East Africa, and sometimes Central Asia and the South Caucasus. Terminology The term "Middle East" may have originated in the 1850s in the British India Office. However, it became more widely known when United States naval strategist Alfred Thayer Mahan used the term in 1902 to "designate the area between Arabia and India". During this time the British and Russian empires were vying for influence in Central Asia, a rivalry that would become known as the Great Game. Mahan realized not only the strategic importance of the region, but also of its center, the Persian Gulf. He labeled the area surrounding the Persian Gulf as the Middle East. He said that, beyond Egypt's Suez Canal, the Gulf was the most important passage for Britain to control in order to keep the Russians from advancing towards British India. Mahan first used the term in his article "The Persian Gulf and International Relations", published in September 1902 in the National Review, a British journal. The Middle East, if I may adopt a term which I have not seen, will some day need its Malta, as well as its Gibraltar; it does not follow that either will be in the Persian Gulf. Naval force has the quality of mobility which carries with it the privilege of temporary absences; but it needs to find on every scene of operation established bases of refit, of supply, and in case of disaster, of security. The British Navy should have the facility to concentrate in force if occasion arise, about Aden, India, and the Persian Gulf. Mahan's article was reprinted in The Times and followed in October by a 20-article series entitled "The Middle Eastern Question", written by Sir Ignatius Valentine Chirol. During this series, Sir Ignatius expanded the definition of Middle East to include "those regions of Asia which extend to the borders of India or command the approaches to India." After the series ended in 1903, The Times removed quotation marks from subsequent uses of the term. Until World War II, it was customary to refer to areas centered on Turkey and the eastern shore of the Mediterranean as the "Near East", while the "Far East" centered on China, India and Japan. The Middle East was then defined as the area from Mesopotamia to Burma; namely, the area between the Near East and the Far East. This area broadly corresponds to South Asia. In the late 1930s, the British established the Middle East Command, which was based in Cairo, for its military forces in the region. After that time, the term "Middle East" gained broader usage in Europe and the United States. Following World War II, for example, the Middle East Institute was founded in Washington, D.C. in 1946. The corresponding adjective is Middle Eastern and the derived noun is Middle Easterner. While non-Eurocentric terms such as "Southwest Asia" or "Swasia" have been sparsely used, the classification of the African country, Egypt, among those counted in the Middle East challenges the usefulness of using such terms. The description Middle has also led to some confusion over changing definitions. Before the First World War, "Near East" was used in English to refer to the Balkans and the Ottoman Empire, while "Middle East" referred to the Caucasus, Persia, and Arabian lands, and sometimes Afghanistan, India and others. In contrast, "Far East" referred to the countries of East Asia (e.g. China, Japan, and Korea). With the collapse of the Ottoman Empire in 1918, "Near East" largely fell out of common use in English, while "Middle East" came to be applied to the emerging independent countries of the Islamic world. However, the usage "Near East" was retained by a variety of academic disciplines, including archaeology and ancient history. In their usage, the term describes an area identical to the term Middle East, which is not used by these disciplines (see ancient Near East).[citation needed] The first official use of the term "Middle East" by the United States government was in the 1957 Eisenhower Doctrine, which pertained to the Suez Crisis. Secretary of State John Foster Dulles defined the Middle East as "the area lying between and including Libya on the west and Pakistan on the east, Syria and Iraq on the North and the Arabian peninsula to the south, plus the Sudan and Ethiopia." In 1958, the State Department explained that the terms "Near East" and "Middle East" were interchangeable, and defined the region as including only Egypt, Syria, Israel, Lebanon, Jordan, Iraq, Saudi Arabia, Kuwait, Bahrain, and Qatar. Since the late 20th century, scholars and journalists from the region, such as journalist Louay Khraish and historian Hassan Hanafi have criticized the use of "Middle East" as a Eurocentric and colonialist term. The Associated Press Stylebook of 2004 says that Near East formerly referred to the farther west countries while Middle East referred to the eastern ones, but that now they are synonymous. It instructs: Use Middle East unless Near East is used by a source in a story. Mideast is also acceptable, but Middle East is preferred. European languages have adopted terms similar to Near East and Middle East. Since these are based on a relative description, the meanings depend on the country and are generally different from the English terms. In German the term Naher Osten (Near East) is still in common use (nowadays the term Mittlerer Osten is more and more common in press texts translated from English sources, albeit having a distinct meaning). In the four Slavic languages, Russian Ближний Восток or Blizhniy Vostok, Bulgarian Близкия Изток, Polish Bliski Wschód or Croatian Bliski istok (terms meaning Near East are the only appropriate ones for the region). However, some European languages do have "Middle East" equivalents, such as French Moyen-Orient, Swedish Mellanöstern, Spanish Oriente Medio or Medio Oriente, Greek is Μέση Ανατολή (Mesi Anatoli), and Italian Medio Oriente.[c] Perhaps because of the political influence of the United States and Europe, and the prominence of Western press, the Arabic equivalent of Middle East (Arabic: الشرق الأوسط ash-Sharq al-Awsaṭ) has become standard usage in the mainstream Arabic press. It comprises the same meaning as the term "Middle East" in North American and Western European usage. The designation, Mashriq, also from the Arabic root for East, also denotes a variously defined region around the Levant, the eastern part of the Arabic-speaking world (as opposed to the Maghreb, the western part). Even though the term originated in the West, countries of the Middle East that use languages other than Arabic also use that term in translation. For instance, the Persian equivalent for Middle East is خاورمیانه (Khāvar-e miyāneh), the Hebrew is המזרח התיכון (hamizrach hatikhon), and the Turkish is Orta Doğu. Countries and territory Traditionally included within the Middle East are Arabia, Asia Minor, East Thrace, Egypt, Iran, the Levant, Mesopotamia, and the Socotra Archipelago. The region includes 17 UN-recognized countries and one British Overseas Territory. Various concepts are often paralleled to the Middle East, most notably the Near East, Fertile Crescent, and Levant. These are geographical concepts, which refer to large sections of the modern-day Middle East, with the Near East being the closest to the Middle East in its geographical meaning. Due to it primarily being Arabic speaking, the Maghreb region of North Africa is sometimes included. "Greater Middle East" is a political term coined by the second Bush administration in the first decade of the 21st century to denote various countries, pertaining to the Muslim world, specifically Afghanistan, Iran, Pakistan, and Turkey. Various Central Asian countries are sometimes also included. History The Middle East lies at the juncture of Africa and Eurasia and of the Indian Ocean and the Mediterranean Sea (see also: Indo-Mediterranean). It is the birthplace and spiritual center of religions such as Christianity, Islam, Judaism, Manichaeism, Yezidi, Druze, Yarsan, and Mandeanism, and in Iran, Mithraism, Zoroastrianism, Manicheanism, and the Baháʼí Faith. Throughout its history the Middle East has been a major center of world affairs; a strategically, economically, politically, culturally, and religiously sensitive area. The region is one of the regions where agriculture was independently discovered, and from the Middle East it was spread, during the Neolithic, to different regions of the world such as Europe, the Indus Valley and Eastern Africa. Prior to the formation of civilizations, advanced cultures formed all over the Middle East during the Stone Age. The search for agricultural lands by agriculturalists, and pastoral lands by herdsmen meant different migrations took place within the region and shaped its ethnic and demographic makeup. The Middle East is widely and most famously known as the cradle of civilization. The world's earliest civilizations, Mesopotamia (Sumer, Akkad, Assyria and Babylonia), ancient Egypt and Kish in the Levant, all originated in the Fertile Crescent and Nile Valley regions of the ancient Near East. These were followed by the Hittite, Greek, Hurrian and Urartian civilisations of Asia Minor; Elam, Persia and Median civilizations in Iran, as well as the civilizations of the Levant (such as Ebla, Mari, Nagar, Ugarit, Canaan, Aramea, Mitanni, Phoenicia and Israel) and the Arabian Peninsula (Magan, Sheba, Ubar). The Near East was first largely unified under the Neo Assyrian Empire, then the Achaemenid Empire followed later by the Macedonian Empire and after this to some degree by the Iranian empires (namely the Parthian and Sassanid Empires), the Roman Empire and Byzantine Empire. The region served as the intellectual and economic center of the Roman Empire and played an exceptionally important role due to its periphery on the Sassanid Empire. Thus, the Romans stationed up to five or six of their legions in the region for the sole purpose of defending it from Sassanid and Bedouin raids and invasions. From the 4th century CE onwards, the Middle East became the center of the two main powers at the time, the Byzantine Empire and the Sassanid Empire. However, it would be the later Islamic Caliphates of the Middle Ages, or Islamic Golden Age which began with the Islamic conquest of the region in the 7th century AD, that would first unify the entire Middle East as a distinct region and create the dominant Islamic Arab ethnic identity that largely (but not exclusively) persists today. The 4 caliphates that dominated the Middle East for more than 600 years were the Rashidun Caliphate, the Umayyad caliphate, the Abbasid caliphate and the Fatimid caliphate. Additionally, the Mongols would come to dominate the region, the Kingdom of Armenia would incorporate parts of the region to their domain, the Seljuks would rule the region and spread Turko-Persian culture, and the Franks would found the Crusader states that would stand for roughly two centuries. Josiah Russell estimates the population of what he calls "Islamic territory" as roughly 12.5 million in 1000 – Anatolia 8 million, Syria 2 million, and Egypt 1.5 million. From the 16th century onward, the Middle East came to be dominated, once again, by two main powers: the Ottoman Empire and the Safavid dynasty. The modern Middle East began after World War I, when the Ottoman Empire, which was allied with the Central Powers, was defeated by the Allies and partitioned into a number of separate nations, initially under British and French Mandates. Other defining events in this transformation included the establishment of Israel in 1948 and the eventual departure of European powers, notably Britain and France by the end of the 1960s. They were supplanted in some part by the rising influence of the United States from the 1970s onwards. In the 20th century, the region's significant stocks of crude oil gave it new strategic and economic importance. Mass production of oil began around 1945, with Saudi Arabia, Iran, Kuwait, Iraq, and the United Arab Emirates having large quantities of oil. Estimated oil reserves, especially in Saudi Arabia and Iran, are some of the highest in the world, and the international oil cartel OPEC is dominated by Middle Eastern countries. During the Cold War, the Middle East was a theater of ideological struggle between the two superpowers and their allies: NATO and the United States on one side, and the Soviet Union and Warsaw Pact on the other, as they competed to influence regional allies. Besides the political reasons there was also the "ideological conflict" between the two systems. Moreover, as Louise Fawcett argues, among many important areas of contention, or perhaps more accurately of anxiety, were, first, the desires of the superpowers to gain strategic advantage in the region, second, the fact that the region contained some two-thirds of the world's oil reserves in a context where oil was becoming increasingly vital to the economy of the Western world [...] Within this contextual framework, the United States sought to divert the Arab world from Soviet influence. Throughout the 20th and 21st centuries, the region has experienced both periods of relative peace and tolerance and periods of conflict particularly between Sunnis and Shiites. Geography In 2018, the MENA region emitted 3.2 billion tonnes of carbon dioxide and produced 8.7% of global greenhouse gas emissions (GHG) despite making up only 6% of the global population. These emissions are mostly from the energy sector, an integral component of many Middle Eastern and North African economies due to the extensive oil and natural gas reserves that are found within the region. The Middle East region is one of the most vulnerable to climate change. The impacts include increase in drought conditions, aridity, heatwaves and sea level rise. Sharp global temperature and sea level changes, shifting precipitation patterns and increased frequency of extreme weather events are some of the main impacts of climate change as identified by the Intergovernmental Panel on Climate Change (IPCC). The MENA region is especially vulnerable to such impacts due to its arid and semi-arid environment, facing climatic challenges such as low rainfall, high temperatures and dry soil. The climatic conditions that foster such challenges for MENA are projected by the IPCC to worsen throughout the 21st century. If greenhouse gas emissions are not significantly reduced, part of the MENA region risks becoming uninhabitable before the year 2100. Climate change is expected to put significant strain on already scarce water and agricultural resources within the MENA region, threatening the national security and political stability of all included countries. Over 60 percent of the region's population lives in high and very high water-stressed areas compared to the global average of 35 percent. This has prompted some MENA countries to engage with the issue of climate change on an international level through environmental accords such as the Paris Agreement. Law and policy are also being established on a national level amongst MENA countries, with a focus on the development of renewable energies. Economy Middle Eastern economies range from being very poor (such as Gaza and Yemen) to extremely wealthy nations (such as Qatar and UAE). According to the International Monetary Fund, the three largest Middle Eastern economies in nominal GDP in 2023 were Saudi Arabia ($1.06 trillion), Turkey ($1.03 trillion), and Israel ($0.54 trillion). For nominal GDP per person, the highest ranking countries are Qatar ($83,891), Israel ($55,535), the United Arab Emirates ($49,451) and Cyprus ($33,807). Turkey ($3.6 trillion), Saudi Arabia ($2.3 trillion), and Iran ($1.7 trillion) had the largest economies in terms of GDP PPP. For GDP PPP per person, the highest-ranking countries are Qatar ($124,834), the United Arab Emirates ($88,221), Saudi Arabia ($64,836), Bahrain ($60,596) and Israel ($54,997). The lowest-ranking country in the Middle East, in terms of GDP nominal per capita, is Yemen ($573). The economic structure of Middle Eastern nations are different because while some are heavily dependent on export of only oil and oil-related products (Saudi Arabia, the UAE and Kuwait), others have a highly diverse economic base (such as Cyprus, Israel, Turkey and Egypt). Industries of the Middle Eastern region include oil and oil-related products, agriculture, cotton, cattle, dairy, textiles, leather products, surgical instruments, defence equipment (guns, ammunition, tanks, submarines, fighter jets, UAVs, and missiles). Banking is an important sector, especially for UAE and Bahrain. With the exception of Cyprus, Turkey, Egypt, Lebanon and Israel, tourism has been a relatively undeveloped area of the economy, in part because of the socially conservative nature of the region as well as political turmoil in certain regions. Since the end of the COVID pandemic however, countries such as the UAE, Bahrain, and Jordan have begun attracting greater numbers of tourists because of improving tourist facilities and the relaxing of tourism-related restrictive policies. Unemployment is high in the Middle East and North Africa region, particularly among people aged 15–29, a demographic representing 30% of the region's population. The total regional unemployment rate in 2025 is 10.8%, and among youth is as high as 28%. Demographics Arabs constitute the largest ethnic group in the Middle East, followed by various Iranian peoples and then by Turkic peoples (Turkish, Azeris, Syrian Turkmen, and Iraqi Turkmen). Native ethnic groups of the region include, in addition to Arabs, Arameans, Assyrians, Baloch, Berbers, Copts, Druze, Greek Cypriots, Jews, Kurds, Lurs, Mandaeans, Persians, Samaritans, Shabaks, Tats, and Zazas. European ethnic groups that form a diaspora in the region include Albanians, Bosniaks, Circassians (including Kabardians), Crimean Tatars, Greeks, Franco-Levantines, Italo-Levantines, and Iraqi Turkmens. Among other migrant populations are Chinese, Filipinos, Indians, Indonesians, Pakistanis, Pashtuns, Romani, and Afro-Arabs. "Migration has always provided an important vent for labor market pressures in the Middle East. For the period between the 1970s and 1990s, the Arab states of the Persian Gulf in particular provided a rich source of employment for workers from Egypt, Yemen and the countries of the Levant, while Europe had attracted young workers from North African countries due both to proximity and the legacy of colonial ties between France and the majority of North African states." According to the International Organization for Migration, there are 13 million first-generation migrants from Arab nations in the world, of which 5.8 reside in other Arab countries. Expatriates from Arab countries contribute to the circulation of financial and human capital in the region and thus significantly promote regional development. In 2009 Arab countries received a total of US$35.1 billion in remittance in-flows and remittances sent to Jordan, Egypt and Lebanon from other Arab countries are 40 to 190 per cent higher than trade revenues between these and other Arab countries. In Somalia, the Somali Civil War has greatly increased the size of the Somali diaspora, as many of the best educated Somalis left for Middle Eastern countries as well as Europe and North America. Non-Arab Middle Eastern countries such as Turkey, Israel and Iran are also subject to important migration dynamics. A fair proportion of those migrating from Arab nations are from ethnic and religious minorities facing persecution and are not necessarily ethnic Arabs, Iranians or Turks.[citation needed] Large numbers of Kurds, Jews, Assyrians, Greeks and Armenians as well as many Mandeans have left nations such as Iraq, Iran, Syria and Turkey for these reasons during the last century. In Iran, many religious minorities such as Christians, Baháʼís, Jews and Zoroastrians have left since the Islamic Revolution of 1979. The Middle East is very diverse when it comes to religions, many of which originated there. Islam is the largest religion in the Middle East, but other faiths that originated there, such as Judaism and Christianity, are also well represented. Christian communities have played a vital role in the Middle East, and they represent 78% of Cyprus population, and 40.5% of Lebanon, where the Lebanese president, half of the cabinet, and half of the parliament follow one of the various Lebanese Christian rites. There are also important minority religions like the Baháʼí Faith, Yarsanism, Yazidism, Zoroastrianism, Mandaeism, Druze, and Shabakism, and in ancient times the region was home to Mesopotamian religions, Canaanite religions, Manichaeism, Mithraism and various monotheist gnostic sects. The six top languages, in terms of numbers of speakers, are Arabic, Persian, Turkish, Kurdish, Modern Hebrew and Greek. About 20 minority languages are also spoken in the Middle East. Arabic, with all its dialects, is the most widely spoken language in the Middle East, with Literary Arabic being official in all North African and in most West Asian countries. Arabic dialects are also spoken in some adjacent areas in neighbouring Middle Eastern non-Arab countries. It is a member of the Semitic branch of the Afro-Asiatic languages. Several Modern South Arabian languages such as Mehri and Soqotri are also spoken in Yemen and Oman. Another Semitic language is Aramaic and its dialects are spoken mainly by Assyrians and Mandaeans, with Western Aramaic still spoken in two villages near Damascus, Syria. There is also an Oasis Berber-speaking community in Egypt where the language is also known as Siwa. It is a non-Semitic Afro-Asiatic sister language. Persian is the second most spoken language. While it is primarily spoken in Iran and some border areas in neighbouring countries, the country is one of the region's largest and most populous. It belongs to the Indo-Iranian branch of the family of Indo-European languages. Other Western Iranic languages spoken in the region include Achomi, Daylami, Kurdish dialects, Semmani, Lurish, amongst many others. The close third-most widely spoken language, Turkish, is largely confined to Turkey, which is also one of the region's largest and most populous countries, but it is present in areas in neighboring countries. It is a member of the Turkic languages, which have their origins in East Asia. Another Turkic language, Azerbaijani, is spoken by Azerbaijanis in Iran. The fourth-most widely spoken language, Kurdish, is spoken in the countries of Iran, Iraq, Syria and Turkey, Sorani Kurdish is the second official language in Iraq (instated after the 2005 constitution) after Arabic. Hebrew is the official language of Israel, with Arabic given a special status after the 2018 Basic law lowered its status from an official language prior to 2018. Hebrew is spoken and used by over 80% of Israel's population, the other 20% using Arabic. Modern Hebrew only began being spoken in the 20th century after being revived in the late 19th century by Elizer Ben-Yehuda (Elizer Perlman) and European Jewish settlers, with the first native Hebrew speaker being born in 1882. Greek is one of the two official languages of Cyprus, and the country's main language. Small communities of Greek speakers exist all around the Middle East; until the 20th century it was also widely spoken in Asia Minor (being the second most spoken language there, after Turkish) and Egypt. During the antiquity, Ancient Greek was the lingua franca for many areas of the western Middle East and until the Muslim expansion it was widely spoken there as well. Until the late 11th century, it was also the main spoken language in Asia Minor; after that it was gradually replaced by the Turkish language as the Anatolian Turks expanded and the local Greeks were assimilated, especially in the interior. English is one of the official languages of Akrotiri and Dhekelia. It is also commonly taught and used as a foreign second language, in countries such as Egypt, Jordan, Iran, Iraq, Qatar, Bahrain, United Arab Emirates and Kuwait. It is also a main language in some Emirates of the United Arab Emirates. It is also spoken as native language by Jewish immigrants from Anglophone countries (UK, US, Australia) in Israel and understood widely as second language there. French is taught and used in many government facilities and media in Lebanon, and is taught in some primary and secondary schools of Egypt and Syria. Maltese, a Semitic language mainly spoken in Europe, is used by the Franco-Maltese diaspora in Egypt. Due to widespread immigration of French Jews to Israel, it is the native language of approximately 200,000 Jews in Israel. Armenian speakers are to be found in the region. Georgian is spoken by the Georgian diaspora. Russian is spoken by a large portion of the Israeli population, because of emigration in the late 1990s. Russian today is a popular unofficial language in use in Israel; news, radio and sign boards can be found in Russian around the country after Hebrew and Arabic. Circassian is also spoken by the diaspora in the region and by almost all Circassians in Israel who speak Hebrew and English as well. The largest Romanian-speaking community in the Middle East is found in Israel, where as of 1995[update] Romanian is spoken by 5% of the population.[d] Bengali, Hindi and Urdu are widely spoken by migrant communities in many Middle Eastern countries, such as Saudi Arabia (where 20–25% of the population is South Asian), the United Arab Emirates (where 50–55% of the population is South Asian), and Qatar, which have large numbers of Pakistani, Bangladeshi and Indian immigrants. Culture The Middle East has recently become more prominent in hosting global sport events due to its wealth and desire to diversify its economy. The South Asian diaspora is a major backer of cricket in the region. See also Notes References Further reading External links 29°N 41°E / 29°N 41°E / 29; 41 |
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Contents Jewish culture Hebrew Judeo-Aramaic Judeo-Arabic Other Jewish diaspora languages Jewish folklore Jewish poetry Jewish culture is the culture of the Jewish people, from its formation in ancient times until the current age. Judaism itself is not simply a faith-based religion, but an orthopraxy and ethnoreligion, pertaining to deed, practice, and identity. Jewish culture covers many aspects, including religion and worldviews, literature, media, and cinema, art and architecture, cuisine and traditional dress, attitudes to gender, marriage, family, social customs and lifestyles, music and dance. Some elements of Jewish culture come from within Judaism, others from the interaction of Jews with host populations, and others still from the inner social and cultural dynamics of the community. Before the 18th century, religion dominated virtually all aspects of Jewish life, and infused culture. Since the advent of secularization, wholly secular Jewish culture emerged likewise. History There has not been a political unity of Jewish society since the united monarchy. Since then Israelite populations were always geographically dispersed (see Jewish diaspora), so that by the 19th century, the Ashkenazi Jews were mainly located in Eastern and Central Europe; the Sephardi Jews were largely spread among various communities which lived in the Mediterranean region; Mizrahi Jews were primarily spread throughout Western Asia; and other populations of Jews lived in the Caucasus, Crimea, Central Asia, Ethiopia, and India. (See Jewish ethnic divisions.) While there has been communication and traffic between these Jewish communities, many Sephardic exiles blended into the Ashkenazi communities which existed in Central Europe following the Spanish Inquisition; many Ashkenazim migrated to the Ottoman Empire, giving rise to the characteristic Syrian-Jewish family name "Ashkenazi"; Iraqi-Jewish traders formed a distinct Jewish community in India; to some degree, many of these Jewish populations were cut off from the cultures which surrounded them by ghettoization, Muslim laws of dhimma, and the traditional discouragement of contact between Jews and members of polytheistic populations by their religious leaders. Medieval Jewish communities in Eastern Europe continued to display distinct cultural traits over the centuries. Despite the universalist leanings of the Enlightenment (and its echo within Judaism in the Haskalah movement), many Yiddish-speaking Jews in Eastern Europe continued to see themselves as forming a distinct national group — " 'am yehudi", from the Biblical Hebrew – but, adapting this idea to Enlightenment values, they assimilated the concept as that of an ethnic group whose identity did not depend on religion, which under Enlightenment thinking fell under a separate category. Constantin Măciucă writes of the existence of "a differentiated but not isolated Jewish spirit" permeating the culture of Yiddish-speaking Jews. This was only intensified as the rise of Romanticism amplified the sense of national identity across Europe generally. Thus, for example, members of the General Jewish Labour Bund in the late 19th and early 20th centuries were generally non-religious, and one of the historical leaders of the Bund was the child of converts to Christianity, though not a practicing or believing Christian himself. The Haskalah combined with the Jewish Emancipation movement under way in Central and Western Europe to create an opportunity for Jews to enter secular society. At the same time, pogroms in Eastern Europe provoked a surge of migration, in large part to the United States, where some 2 million Jewish immigrants resettled between 1880 and 1920. By 1931, shortly before The Holocaust, 92% of the World's Jewish population was Ashkenazi in origin. Secularism originated in Europe as series of movements that militated for a new, heretofore unheard-of concept called "secular Judaism". For these reasons, much of what is thought of by English-speakers and, to a lesser extent, by non-English-speaking Europeans as "secular Jewish culture" is, in essence, the Jewish cultural movement that evolved in Central and Eastern Europe, and subsequently brought to North America by immigrants. During the 1940s, the Holocaust uprooted and destroyed most of the Jewish communities living in much of Europe. This, in combination with the creation of the State of Israel and the consequent Jewish exodus from Arab lands, resulted in a further geographic shift. Defining secular culture among those who practice traditional Judaism is difficult, because the entire culture is, by definition, entwined with religious traditions: the idea of separate ethnic and religious identity is foreign to the Hebrew tradition of an " 'am yisrael". (This is particularly true for Orthodox Judaism.) Gary Tobin, head of the Institute for Jewish and Community Research, said of traditional Jewish culture: The dichotomy between religion and culture doesn't really exist. Every religious attribute is filled with culture; every cultural act filled with religiosity. Synagogues themselves are great centers of Jewish culture. After all, what is life really about? Food, relationships, enrichment ... So is Jewish life. So many of our traditions inherently contain aspects of culture. Look at the Passover Seder — it's essentially great theater. Jewish education and religiosity bereft of culture is not as interesting. Yaakov Malkin, Professor of Aesthetics and Rhetoric at Tel Aviv University and the founder and academic director of Meitar College for Judaism as Culture in Jerusalem, writes: Today very many secular Jews take part in Jewish cultural activities, such as celebrating Jewish holidays as historical and nature festivals, imbued with new content and form, or marking life-cycle events such as birth, bar/bat mitzvah, marriage, and mourning in a secular fashion. They come together to study topics pertaining to Jewish culture and its relation to other cultures, in havurot, cultural associations, and secular synagogues, and they participate in public and political action coordinated by secular Jewish movements, such as the former movement to free Soviet Jews, and movements to combat pogroms, discrimination, and religious coercion. Jewish secular humanistic education inculcates universal moral values through classic Jewish and world literature and through organizations for social change that aspire to ideals of justice and charity. In North America, the secular and cultural Jewish movements are divided into three umbrella organizations: the Society for Humanistic Judaism (SHJ), the Congress of Secular Jewish Organizations (CSJO), and The Workers Circle. Philosophy and religion Jewish philosophy includes all philosophy carried out by Jews, or in relation to the religion of Judaism. The Jewish philosophy is extended over several main eras in Jewish history, including the ancient and biblical era, medieval era and modern era (see Haskalah). The ancient Jewish philosophy is expressed in the bible. According to Prof. Israel Efros, the principles of the Jewish philosophy start in the bible, where the foundations of the Jewish monotheistic beliefs can be found, such as the belief in one god, the separation of god and the world and nature (as opposed to Pantheism) and the creation of the world. Other biblical writings that associated with philosophy are Psalms that contains invitations to admire the wisdom of God through his works; from this, some scholars suggest, Judaism harbors a Philosophical under-current and Ecclesiastes that is often considered to be the only genuine philosophical work in the Hebrew Bible; its author seeks to understand the place of human beings in the world and life's meaning. Other writings related to philosophy can be found in the Deuterocanonical books such as Sirach and Book of Wisdom. During the Hellenistic era, Hellenistic Judaism aspired to combine Jewish religious tradition with elements of Greek culture and philosophy. The philosopher Philo used philosophical allegory to attempt to fuse and harmonize Greek philosophy with Jewish philosophy. His work attempts to combine Plato and Moses into one philosophical system. He developed an allegoric approach of interpreting holy scriptures (the bible), in contrast to (old-fashioned) literally interpretation approaches. His allegorical exegesis was important for several Christian Church Fathers and some scholars hold that his concept of the Logos as God's creative principle influenced early Christology. Other scholars, however, deny direct influence but say both Philo and Early Christianity borrow from a common source. Between the Ancient era and the Middle Ages most of the Jewish philosophy concentrated around the Rabbinic literature that is expressed in the Talmud and Midrash. In the 9th century Saadia Gaon wrote the text Emunoth ve-Deoth which is the first systematic presentation and philosophic foundation of the dogmas of Judaism. The Golden age of Jewish culture in Spain included many influential Jewish philosophers such as Moses ibn Ezra, Abraham ibn Ezra, Solomon ibn Gabirol, Yehuda Halevi, Isaac Abravanel, Nahmanides, Joseph Albo, Abraham ibn Daud, Nissim of Gerona, Bahya ibn Paquda, Abraham bar Hiyya, Joseph ibn Tzaddik, Hasdai Crescas and Isaac ben Moses Arama. The most notable is Maimonides who is considered in the Jewish world to be a prominent philosopher and polymath in the Islamic and Western worlds. Outside of Spain, other philosophers are Natan'el al-Fayyumi, Elia del Medigo, Jedaiah ben Abraham Bedersi and Gersonides. Jewish philosophers of the modern era, mainly in Europe, include Baruch Spinoza, founder of Spinozism, whose work included modern Rationalism and Biblical criticism and laid the groundwork for the 18th-century Enlightenment. His work has earned him recognition as one of Western philosophy's most important thinkers; others are Isaac Orobio de Castro, Tzvi Ashkenazi, David Nieto, Isaac Cardoso, Jacob Abendana, Uriel da Costa, Francisco Sanches and Moses Almosnino. A new era began in the 18th century with the thought of Moses Mendelssohn. Mendelssohn has been described as the "'third Moses', with whom begins a new era in Judaism", just as new eras began with Moses the prophet and with Moses Maimonides. Mendelssohn was a German Jewish philosopher to whose ideas the renaissance of European Jews, Haskalah (the Jewish Enlightenment) is indebted. He has been referred to as the father of Reform Judaism, though Reform spokesmen have been "resistant to claim him as their spiritual father". Mendelssohn came to be regarded as a leading cultural figure of his time by both Germans and Jews. The Jewish Enlightenment philosophy included Menachem Mendel Lefin, Salomon Maimon and Isaac Satanow. The next 19th century comprised both secular and religious philosophy and included philosophers such as Elijah Benamozegh, Hermann Cohen, Moses Hess, Samson Raphael Hirsch, Samuel Hirsch, Nachman Krochmal, Samuel David Luzzatto, and Nachman of Breslov founder of Breslov. The 20th century included the notable philosophers Jacques Derrida, Karl Popper, Emmanuel Levinas, Claude Lévi-Strauss, Hilary Putnam, Alfred Tarski, Ludwig Wittgenstein, A. J. Ayer, Walter Benjamin, Raymond Aron, Theodor W. Adorno, Isaiah Berlin and Henri Bergson. Education and politics A range of moral and political views is evident early in the history of Judaism, that serves to partially explain the diversity that is apparent among secular Jews who are often influenced by moral beliefs that can be found in Jewish scripture, and traditions. In recent centuries, secular Jews in Europe and the Americas have tended towards the political left[citation needed], and played key roles in the birth of the 19th century's labor movement and socialism. The biographies of women like Emma Goldman and Hannah Arendt embody complicated relationships between politics, Judaism and feminism. While Diaspora Jews have also been represented on the conservative side of the political spectrum, even politically conservative Jews have tended to support pluralism more consistently than many other elements of the political right. Some scholars attribute this to the fact that Jews are not expected to proselytize, derived from Halakha. This lack of a universalizing religion is combined with the fact that most Jews live as minorities in diaspora countries, and that no central Jewish religious authority has existed since 363 CE. Jews value education, and the value of education is strongly embedded in Jewish culture. Economic activity In the Middle Ages, European laws prevented Jews from owning land and gave them important incentives to go into professions that non-Jewish Europeans were unwilling to undertake. During the medieval period, there was a very strong social stigma against lending money and charging interest among the Christian majority. In most of Europe until the late 18th century, and in some places to an even later date, Jews were prohibited by Roman Catholic governments (and others) from owning land. On the other hand, the Church, because of a number of Bible verses (e.g., Leviticus 25:36) forbidding usury, declared that charging any interest was against the divine law, and this prevented any mercantile use of capital by pious Christians. As the Canon law did not apply to Jews, they were not liable to the ecclesiastical punishments which were placed upon usurers by the popes. Christian rulers gradually saw the advantage of having a class of men like the Jews who could supply capital for their use without being liable to excommunication, and so the money trade of western Europe by this means fell into the hands of the Jews. However, in almost every instance where large amounts were acquired by Jews through banking transactions the property thus acquired fell either during their life or upon their death into the hands of the king. This happened to Aaron of Lincoln in England, Ezmel de Ablitas in Navarre, Heliot de Vesoul in Provence, Benveniste de Porta in Aragon, etc. It was often for this reason that kings supported the Jews, and even objected to them becoming Christians (because in that case their fortunes earned by usury could not be seized by the crown after their deaths). Thus, both in England and in France the kings demanded to be compensated by the church for every Jew converted. This type of royal trickery was one factor in creating the stereotypical Jewish role of banker and/or merchant. As a modern system of capital began to develop, loans became necessary for commerce and industry. Jews were able to gain a foothold in the new field of finance by providing these services: as non-Catholics, they were not bound by the ecclesiastical prohibition against "usury"; and in terms of Judaism itself, Hillel had long ago re-interpreted the Torah's ban on charging interest, allowing interest when it is needed to make a living.[citation needed] Science and technology The strong Jewish tradition of religious scholarship often left Jews well prepared for secular scholarship. In some times and places, this was countered by banning Jews from studying at universities, or admitting them only in limited numbers (see Jewish quota). Over the centuries, Jews have been poorly represented among land-holding classes, but far better represented in academia, professions, finance, commerce and many scientific fields. The strong representation of Jews in science and academia is evidenced by the fact that 193 persons known to be Jews or of Jewish ancestry have been awarded the Nobel Prize, accounting for 22% of all individual recipients worldwide between 1901 and 2014. Of whom, 26% in physics, 22% in chemistry and 27% in Physiology or Medicine. In the fields of mathematics and computer science, 31% of Turing Award recipients and 27% of Fields Medal in mathematics were or are Jewish. The early Jewish activity in science can be found in the Hebrew Bible where some of the books contain descriptions of the physical world. Biblical cosmology provides sporadic glimpses that may be stitched together to form a Biblical impression of the physical universe. There have been comparisons between the Bible, with passages such as from the Genesis creation narrative, and the astronomy of classical antiquity more generally. The Bible also contains various cleansing rituals. One suggested ritual, for example, deals with the proper procedure for cleansing a leper (Leviticus 14:1–32). It is a fairly elaborate process, which is to be performed after a leper was already healed of leprosy (Leviticus 14:3), involving extensive cleansing and personal hygiene, but also includes sacrificing a bird and lambs with the addition of using their blood to symbolize that the afflicted has been cleansed. The Torah proscribes Intercropping (Lev. 19:19, Deut 22:9), a practice often associated with sustainable agriculture and organic farming in modern agricultural science. The Mosaic code has provisions concerning the conservation of natural resources, such as trees (Deuteronomy 20:19–20) and birds (Deuteronomy 22:6–7). During Medieval era astronomy was a primary field among Jewish scholars and was widely studied and practiced. Prominent astronomers included Abraham Zacuto who published in 1478 his Hebrew book Ha-hibbur ha-gadol where he wrote about the Solar System, charting the positions of the Sun, Moon and five planets. His work served Portugal's exploration journeys and was used by Vasco da Gama and also by Christopher Columbus. The lunar crater Zagut is named after Zacuto's name. The mathematician and astronomer Abraham bar Hiyya Ha-Nasi authored the first European book to include the full solution to the quadratic equation x2 – ax + b = 0, and influenced the work of Leonardo Fibonacci. Bar Hiyya proved by the method of indivisibles the following equation for any circle: S = LxR/2, where S is the surface area, L is the circumference length and R is radius. Garcia de Orta, Portuguese Renaissance Jewish physician, was a pioneer of Tropical medicine. He published his work Colóquios dos simples e drogas da India in 1563, which deals with a series of substances, many of them unknown or the subject of confusion and misinformation in Europe at this period. He was the first European to describe Asiatic tropical diseases, notably cholera; he performed an autopsy on a cholera victim, the first recorded autopsy in India. Bonet de Lattes known chiefly as the inventor of an astronomical ring-dial by means of which solar and stellar altitudes can be measured and the time determined with great precision by night as well as by day. Other related personalities are Abraham ibn Ezra, whose the Moon crater Abenezra named after, David Gans, Judah ibn Verga, Mashallah ibn Athari an astronomer, The crater Messala on the Moon is named after him. Albert Einstein was a German-born theoretical physicist and is considered one of the most prominent scientists in history, often regarded as the "father of modern physics". His revolutionary work on the relativity theory transformed theoretical physics and astronomy during the 20th century. When first published, relativity superseded a 200-year-old theory of mechanics created primarily by Isaac Newton. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves. Einstein formulated the well-known Mass–energy equivalence, E = mc2, and explained the photoelectric effect. His work also effected and influenced a large variety of fields of physics including the Big Bang theory (Einstein's General relativity influenced Georges Lemaître), Quantum mechanics and nuclear energy. The Manhattan Project was a research and development project that produced the first atomic bombs during World War II and many Jewish scientists had a significant role in the project. The theoretical physicist Robert Oppenheimer, often considered the "father of the atomic bomb", was chosen to direct the Manhattan Project at Los Alamos National Laboratory in 1942. The physicist Leó Szilárd, that conceived the nuclear chain reaction; Edward Teller, "the father of the hydrogen bomb" and Stanislaw Ulam; Eugene Wigner contributed to theory of Atomic nucleus and Elementary particle; Hans Bethe whose work included Stellar nucleosynthesis and was head of the Theoretical Division at the secret Los Alamos laboratory; Richard Feynman, Niels Bohr, Victor Weisskopf and Joseph Rotblat. The mathematician and physicist Alexander Friedmann pioneered the theory that universe was expanding governed by a set of equations he developed now known as the Friedmann equations. Arno Allan Penzias, the physicist and radio astronomer co-discoverer of the cosmic microwave background radiation, which helped establish the Big Bang theory, the scientists Robert Herman and Ralph Alpher had also worked on that field. In quantum mechanics Jewish role was significant as well and many of most influential figures and pioneers of the theory were Jewish: Niels Bohr and his work on the atom structure, Max Born (Schrödinger equation), Wolfgang Pauli, Richard Feynman (Quantum chromodynamics), Fritz London work on London dispersion force and London equations, Walter Heitler and Julian Schwinger work on Quantum electrodynamics, Asher Peres a pioneer in Quantum information, David Bohm (Quantum potential). Sigmund Freud, known as the father of psychoanalysis, is one of the most influential scientists of the 20th century. In creating psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst, Freud developed therapeutic techniques such as the use of free association and discovered transference, establishing its central role in the analytic process. Freud's redefinition of sexuality to include its infantile forms led him to formulate the Oedipus complex as the central tenet of psychoanalytical theory. His analysis of dreams as wish-fulfillments provided him with models for the clinical analysis of symptom formation and the mechanisms of repression as well as for elaboration of his theory of the unconscious as an agency disruptive of conscious states of mind. Freud postulated the existence of libido, an energy with which mental processes and structures are invested and which generates erotic attachments, and a death drive, the source of repetition, hate, aggression and neurotic guilt. John von Neumann, a mathematician and physicist, made major contributions to a number of fields, including foundations of mathematics, functional analysis, ergodic theory, geometry, topology, numerical analysis, quantum mechanics, hydrodynamics and game theory. In made also a major work with computing and the development of the computer, he suggested and described a computer architecture called Von Neumann architecture and worked on linear programming, self-replicating machines, stochastic computing), and statistics. Emmy Noether was an influential mathematician known for her groundbreaking contributions to abstract algebra and theoretical physics. Described by many prominent scientists as the most important woman in the history of mathematics,[incomplete short citation] she revolutionized the theories of rings, fields, and algebras. In physics, Noether's theorem explains the fundamental connection between symmetry and conservation laws. More remarkable contributors include Heinrich Hertz and Steven Weinberg in Electromagnetism; Carl Sagan, his contributions were central to the discovery of the high surface temperatures of Venus and known for his contributions to the scientific research of extraterrestrial life; Felix Hausdorff (founder of topology); Edward Witten (M-theory); Vitaly Ginzburg and Lev Landau (Ginzburg–Landau theory); Yakir Aharonov (Aharonov–Bohm effect); Boris Podolsky and Nathan Rosen (EPR paradox); Moshe Carmeli (Gauge theory). Rudolf Lipschitz (Lipschitz continuity); Paul Cohen (Continuum hypothesis, Axiom of choice); Laurent Schwartz (theory of distribution); Grigory Margulis (Lie group); Richard M. Karp (Theory of computation); Adi Shamir (RSA, cryptography); Judea Pearl (Artificial intelligence, Bayesian network); Max Newman (Colossus computer); Carl Gustav Jacob Jacobi (Jacobi elliptic functions, Jacobian matrix and determinant, Jacobi symbol). Sidney Altman (Molecular biology, RNA); Melvin Calvin (Calvin Cycle); Otto Wallach (Alicyclic compound); Paul Berg (biochemistry of nucleic acids); Lazăr Edeleanu (synthesis of amphetamine); Ada Yonath (Crystallography, structure of the ribosome); Dan Shechtman (Quasicrystal); Julius Axelrod and Bernard Katz (Neurotransmitter); Elie Metchnikoff (discovery of Macrophage); Selman Waksman (discovery of Streptomycin); Rosalind Franklin (DNA); Carl Djerassi (the pill); Stephen Jay Gould (Evolutionary biology); Baruch Samuel Blumberg (Hepatitis B virus); Jonas Salk and Albert Sabin (developers of the Polio vaccines); Paul Ehrlich (discovery of the Blood–brain barrier); In fields such as psychology and neurology: Otto Rank, Viktor Frankl, Stanley Milgram and Solomon Asch; linguistics: Noam Chomsky, Franz Boas, Roman Jakobson, Edward Sapir, Joseph Greenberg; and sociology: Theodor Adorno, Nathan Glazer, Erving Goffman, Georg Simmel. Beside Scientific discoveries and researches, Jews have created significant and influential innovations in a large variety of fields such as the listed samples: Siegfried Marcus- automobile pioneer, inventor of the first petroleum-powered car (56 years after the first internal combustion car); Emile Berliner- developer of the disc record phonograph; Mikhail Gurevich- co-inventor of the MIG aircraft; Theodore Maiman- inventor of the laser; Robert Adler- inventor of the wireless remote control for televisions; Edwin H. Land – inventor of Land Camera; Bob Kahn- inventor of TCP and IP; Bram Cohen- creator of Bittorent; Sergei Brin and Larry Page- creators of Google; Laszlo Biro – Ballpoint pen; Simcha Blass- Drip irrigation; Lee Felsenstein – designer of Osborne 1; Zeev Suraski and Andi Gutmans co-creators of PHP and founders of Zend Technologies; Ralph H. Baer, "The Father of Video Games". Literature and poetry In some places where there have been relatively high concentrations of Jews, distinct secular Jewish subcultures have arisen. For example, ethnic Jews formed an enormous proportion of the literary and artistic life of Vienna, Austria at the end of the 19th century, or of New York City 50 years later (and Los Angeles in the mid-late 20th century). Many of these creative Jews were not particularly religious people. In general, Jewish artistic culture in various periods reflected the culture in which they lived. Literary and theatrical expressions of secular Jewish culture may be in specifically Jewish languages such as Hebrew, Yiddish, Judeo-Tat or Ladino, or it may be in the language of the surrounding cultures, such as English or German. Secular literature and theater in Yiddish largely began in the 19th century and was in decline by the middle of the 20th century. The revival of Hebrew beyond its use in the liturgy is largely an early 20th-century phenomenon, and is closely associated with Zionism. Apart from the use of Hebrew in Israel, whether a Jewish community will speak a Jewish or non-Jewish language as its main vehicle of discourse is generally dependent on how isolated or assimilated that community is. For example, the Jews in the shtetls of Poland and the Lower East Side of Manhattan during the early 20th century spoke Yiddish at most times, while assimilated Jews in 19th and early 20th-century Germany spoke German, and American-born Jews in the United States speak English. Jewish authors have both created a unique Jewish literature and contributed to the national literature of many of the countries in which they live. Though not strictly secular, the Yiddish works of authors like Sholem Aleichem (whose collected works amounted to 28 volumes) and Isaac Bashevis Singer (winner of the 1978 Nobel Prize), form their own canon, focusing on the Jewish experience in both Eastern Europe, and in America. In the United States, Jewish writers like Philip Roth, Saul Bellow, and many others are considered among the greatest American authors, and incorporate a distinctly secular Jewish view into many of their works. The poetry of Allen Ginsberg often touches on Jewish themes (notably the early autobiographical works such as Howl and Kaddish). Other famous Jewish authors that made contributions to world literature include Heinrich Heine, German poet, Miklós Radnóti, Hungarian poet, Mordecai Richler, Canadian author, Isaac Babel, Russian author, Franz Kafka, of Prague, and Harry Mulisch, whose novel The Discovery of Heaven was revealed by a 2007 poll as the "Best Dutch Book Ever". In Modern Judaism: An Oxford Guide, Yaakov Malkin, Professor of Aesthetics and Rhetoric at Tel Aviv University and the founder and academic director of Meitar College for Judaism as Culture in Jerusalem, writes:" Secular Jewish culture embraces literary works that have stood the test of time as sources of aesthetic pleasure and ideas shared by Jews and non-Jews, works that live on beyond the immediate socio-cultural context within which they were created. They include the writings of such Jewish authors as Sholem Aleichem, Itzik Manger, Isaac Bashevis Singer, Philip Roth, Saul Bellow, S.Y. Agnon, Isaac Babel, Martin Buber, Isaiah Berlin, Haim Nahman Bialik, Yehuda Amichai, Amos Oz, A.B. Yehoshua, and David Grossman. It boasts masterpieces that have had a considerable influence on all of western culture, Jewish culture included – works such as those of Heinrich Heine, Gustav Mahler, Leonard Bernstein, Marc Chagall, Jacob Epstein, Ben Shahn, Amedeo Modigliani, Franz Kafka, Max Reinhardt (Goldman), Ernst Lubitsch, and Woody Allen." Other notable contributors are Isaac Asimov author of the Foundation series and others such as I, robot, Nightfall and The Gods Themselves; Joseph Heller (Catch-22); R.L. Stine (Goosebumps series); J. D. Salinger (The Catcher in the Rye); Michael Chabon (The Amazing Adventures of Kavalier & Clay, The Yiddish Policemen's Union); Marcel Proust (In Search of Lost Time); Arthur Miller (Death of a Salesman and The Crucible); Will Eisner (A Contract with God); Shel Silverstein (The Giving Tree); Arthur Koestler (Darkness at Noon, The Thirteenth Tribe); Saul Bellow (Herzog); The historical novel series The Accursed Kings by Maurice Druon is an inspiration for George R. R. Martin's A Song of Ice and Fire novels. Among recipient of Nobel Prize in Literature, 13% were or are Jewish. Another aspect of Jewish literature is the ethical, called Musar literature. This literature has been composed by both religious and secular authors. Hebrew poetry is expressed by various of poets in different eras of Jewish history. Biblical poetry is related to the poetry in biblical times as it expressed in the Hebrew Bible and Jewish sacred texts. In medieval times the Jewish poetry was mainly expressed by piyyutim and several poets such as Yehuda Halevi, Samuel ibn Naghrillah, Solomon ibn Gabirol, Moses ibn Ezra, Abraham ibn Ezra and Dunash ben Labrat. Modern Hebrew poetry is mostly related to the era of and after the revival of the Hebrew language, pioneered by Moshe Chaim Luzzatto in the Haskalah era and succeeded by poets such as Hayim Nahman Bialik, Nathan Alterman and Shaul Tchernichovsky. Theatre The Ukrainian Jew Abraham Goldfaden founded the first professional Yiddish-language theatre troupe in Iași, Romania in 1876. The next year, his troupe achieved enormous success in Bucharest. Within a decade, Goldfaden and others brought Yiddish theater to Ukraine, Russia, Poland, Germany, New York City, and other cities with significant Ashkenazic populations. Between 1890 and 1940, over a dozen Yiddish theatre groups existed in New York City alone, in the Yiddish Theater District, performing original plays, musicals, and Yiddish translations of theatrical works and opera. Perhaps the most famous of Yiddish-language plays is The Dybbuk (1919) by S. Ansky. Yiddish theater in New York in the early 20th century rivalled English-language theater in quantity and often surpassed it in quality. A 1925 New York Times article remarks, "…Yiddish theater… is now a stable American institution and no longer dependent on immigration from Eastern Europe. People who can neither speak nor write Yiddish attend Yiddish stage performances and pay Broadway prices on Second Avenue." This article also mentions other aspects of a New York Jewish cultural life "in full flower" at that time, among them the fact that the extensive New York Yiddish-language press of the time included seven daily newspapers. In fact, however, the next generation of American Jews spoke mainly English to the exclusion of Yiddish; they brought the artistic energy of Yiddish theater into the American theatrical mainstream, but usually in a less specifically Jewish form. Yiddish theater, most notably Moscow State Jewish Theater directed by Solomon Mikhoels, also played a prominent role in the arts scene of the Soviet Union until Stalin's 1948 reversal in government policy toward the Jews. (See Rootless cosmopolitan, Night of the Murdered Poets.) Montreal's Dora Wasserman Yiddish Theatre continues to thrive after 50 years of performance. From their Emancipation to World War II, Jews were very active and sometimes even dominant in certain forms of European theatre, and after the Holocaust many Jews continued to that cultural form. For example, in pre-Nazi Germany, where Nietzsche asked "What good actor of today is not Jewish?", acting, directing and writing positions were often filled by Jews. Both MacDonald and Jewish Tribal Review would generally be counted as antisemitic sources, but reasonably careful in their factual claims. "In Imperial Berlin, Jewish artists could be found in the forefront of the performing arts, from high drama to more popular forms like cabaret and revue, and eventually film. Jewish audiences patronized innovative theater, regardless of whether they approved of what they saw." The British historian Paul Johnson, commenting on Jewish contributions to European culture at the Fin de siècle, writes that The area where Jewish influence was strongest was the theatre, especially in Berlin. Playwrights like Carl Sternheim, Arthur Schnitzler, Ernst Toller, Erwin Piscator, Walter Hasenclever, Ferenc Molnár and Carl Zuckmayer, and influential producers like Max Reinhardt, appeared at times to dominate the stage, which tended to be modishly left-wing, pro-republican, experimental and sexually daring. But it was certainly not revolutionary, and it was cosmopolitan rather than Jewish. Jews also made similar, if not as massive, contributions to theatre and drama in Austria, Britain, France, and Russia (in the national languages of those countries). Jews in Vienna, Paris and German cities found cabaret both a popular and effective means of expression, as German cabaret in the Weimar Republic "was mostly a Jewish art form". The involvement of Jews in Central European theatre was halted during the rise of the Nazis and the purging of Jews from cultural posts, though many emigrated to Western Europe or the United States and continued working there. In the early 20th century the traditions of New York's vibrant Yiddish Theatre District both rivaled and fed into Broadway. In the English-speaking theatre Jewish émigrés brought novel theatrical ideas from Europe, such as the theatrical realist movement and the philosophy of Konstantin Stanislavski, whose teachings would influence many Jewish American acting teachers such as the Yiddish theatre-trained acting theorist Stella Adler. Jewish immigrants were instrumental in the creation and development of the genre of musical theatre and earlier forms of theatrical entertainment in America, and would innovate the new, distinctly American, art form, the Broadway musical. Brandeis University Professor Stephen J. Whitfield has commented that "More so than behind the screen, the talent behind the stage was for over half a century virtually the monopoly of one ethnic group. That is... [a] feature which locates Broadway at the center of Jewish culture". New York University Professor Laurence Maslon says that "There would be no American musical without Jews… Their influence is corollary to the influence of black musicians on jazz; there were as many Jews involved in the form". Other writers, such as Jerome Caryn, have noted that musical theatre and other forms of American entertainment are uniquely indebted to the contributions of Jewish Americans, since "there might not have been a modern Broadway without the "Asiatic horde" of comedians, gossip columnists, songwriters, and singers that grew out of the ghetto, whether it was on the Lower East Side, Harlem (a Jewish ghetto before it was a black one), Newark, or Washington, D.C." Likewise, in the analysis of Aaron Kula, director of The Klezmer Company, ...the Jewish experience has always been best expressed by music, and Broadway has always been an integral part of the Jewish American experience... The difference is that one can expand the definition of "Jewish Broadway" to include an interdisciplinary roadway with a wide range of artistic activities packed onto one avenue—theatre, opera, symphony, ballet, publishing companies, choirs, synagogues and more. This vibrant landscape reflects the life, times and creative output of the Jewish American artist. In the 19th and early 20th centuries the European operetta, a precursor the musical, often featured the work of Jewish composers such as Paul Abraham, Leo Ascher, Edmund Eysler, Leo Fall, Bruno Granichstaedten, Jacques Offenbach, Emmerich Kalman, Sigmund Romberg, Oscar Straus and Rudolf Friml; the latter four eventually moved to the United States and produced their works on the New York stage. One of the librettists for Bizet's Carmen (not an operetta proper but rather a work of the earlier Opéra comique form) was the Jewish Ludovic Halévy, niece of composer Fromental Halévy (Bizet himself was not Jewish but he married the elder Halevy's daughter, many have suspected that he was the descendant of Jewish converts to Christianity, and others have noticed Jewish-sounding intervals in his music). The Viennese librettist Victor Leon summarized the connection of Jewish composers and writers with the form of operetta: "The audience for operetta wants to laugh beneath tears—and that is exactly what Jews have been doing for the last two thousand years since the destruction of Jerusalem". Another factor in the evolution of musical theatre was vaudeville, and during the early 20th century the form was explored and expanded by Jewish comedians and actors such as Jack Benny, Fanny Brice, Eddie Cantor, The Marx Brothers, Anna Held, Al Jolson, Molly Picon, Sophie Tucker and Ed Wynn. During the period when Broadway was monopolized by revues and similar entertainments, Jewish producer Florenz Ziegfeld dominated the theatrical scene with his Follies. By 1910 Jews (the vast majority of them immigrants from Eastern Europe) already composed a quarter of the population of New York City, and almost immediately Jewish artists and intellectuals began to show their influence on the cultural life of that city, and through time, the country as a whole. Likewise, while the modern musical can best be described as a fusion of operetta, earlier American entertainment and African-American culture and music, as well as Jewish culture and music, the actual authors of the first "book musicals" were the Jewish Jerome Kern, Oscar Hammerstein II, George and Ira Gershwin, George S. Kaufman and Morrie Ryskind. From that time until the 1980s a vast majority of successful musical theatre composers, lyricists, and book-writers were Jewish (a notable exception is the Protestant Cole Porter, who acknowledged that the reason he was so successful on Broadway was that he wrote what he called "Jewish music"). Rodgers and Hammerstein, Frank Loesser, Lerner and Loewe, Stephen Sondheim, Leonard Bernstein, Stephen Schwartz, Kander and Ebb and dozens of others during the "Golden Age" of musical theatre were Jewish. Since the Tony Award for Best Original Score was instituted in 1947, approximately 70% of nominated scores and 60% of winning scores were by Jewish composers. Of successful British and French musical writers both in the West End and Broadway, Claude-Michel Schönberg and Lionel Bart are Jewish, among others. One explanation of the affinity of Jewish composers and playwrights to the musical is that "traditional Jewish religious music was most often led by a single singer, a cantor while Christians emphasize choral singing." Many of these writers used the musical to explore issues relating to assimilation, the acceptance of the outsider in society, the racial situation in the United States, the overcoming of obstacles through perseverance, and other topics pertinent to Jewish Americans and Western Jews in general, often using subtle and disguised stories to get this point across. For example, Kern, Rodgers, Hammerstein, the Gershwins, Harold Arlen and Yip Harburg wrote musicals and operas aiming to normalize societal toleration of minorities and urging racial harmony; these works included Show Boat, Porgy and Bess, Finian's Rainbow, South Pacific and The King and I. Towards the end of Golden Age, writers also began to openly and overtly tackle Jewish subjects and issues, such as Fiddler on the Roof and Rags; Bart's Blitz! also tackles relations between Jews and Gentiles. Jason Robert Brown and Alfred Uhry's Parade is a sensitive exploration of both antisemitism and historical American racism. The original concept that became West Side Story was set on the Lower East Side during Easter-Passover celebrations; the rival gangs were to be Jewish and Italian Catholic. The ranks of prominent Jewish producers, directors, designers and performers include Boris Aronson, David Belasco, Joel Grey, the Minskoff family, Zero Mostel, Joseph Papp, Mandy Patinkin, the Nederlander family, Harold Prince, Max Reinhardt, Jerome Robbins, the Shubert family and Julie Taymor. Jewish playwrights have also contributed to non-musical drama and theatre, both Broadway and regional. Edna Ferber, Moss Hart, Lillian Hellman, Arthur Miller and Neil Simon are only some of the prominent Jewish playwrights in American theatrical history. Approximately 34% of the plays and musicals that have won the Pulitzer Prize for Drama were written and composed by Jewish Americans. The Association for Jewish Theater is a contemporary organization that includes both American and international theaters that focus on theater with Jewish content. It has also expanded to include Jewish playwrights. The earliest known Hebrew language drama was written around 1550 by a Jewish-Italian writer from Mantua. A few works were written by rabbis and Kabbalists in 17th-century Amsterdam, where Jews were relatively free from persecution and had both flourishing religious and secular Jewish cultures. All of these early Hebrew plays were about Biblical or mystical subjects, often in the form of Talmudic parables. During the post-Emancipation period in 19th-century Europe, many Jews translated great European plays such as those by Shakespeare, Molière and Schiller, giving the characters Jewish names and transplanting the plot and setting to within a Jewish context. Modern Hebrew theatre and drama, however, began with the development of Modern Hebrew in Europe (the first Hebrew theatrical professional performance was in Moscow in 1918) and was "closely linked with the Jewish national renaissance movement of the twentieth century. The historical awareness and the sense of primacy which accompanied the Hebrew theatre in its early years dictated the course of its artistic and aesthetic development". These traditions were soon transplanted to Israel. Playwrights such as Natan Alterman, Hayyim Nahman Bialik, Leah Goldberg, Ephraim Kishon, Hanoch Levin, Aharon Megged, Moshe Shamir, Avraham Shlonsky, Yehoshua Sobol and A. B. Yehoshua have written Hebrew-language plays. Themes that are obviously common in these works are the Holocaust, the Arab–Israeli conflict, the meaning of Jewishness, and contemporary secular-religious tensions within Jewish Israel. The most well-known Hebrew theatre company and Israel's national theatre is the Habima (meaning "the stage" in Hebrew), which was formed in 1913 in Lithuania, and re-established in 1917 in Russia; another prominent Israeli theatre company is the Cameri Theatre, which is "Israel's first and leading repertory theatre". The first theatrical event by Mountain Jews took place in December 1903, when Asaf Agarunov, a teacher and a Zionist, staged a story by Naum Shoykovich, translated from Hebrew, "The Burn for Burn," and staged it in honor of schoolteacher Nagdimuna ben Simona's (Shimunov) wedding. In 1918, a drama studio was opened in Derbent, Soviet Union headed by Rabbi Yashaiyo Rabinovich. In 1935, the first Soviet Union theatre opened in Derbent, which included three troupes – Russian, Mountain Jews and Turk. It was based on drama circles, which were led by Manashir and Khanum Shalumov. Initially, in the circle, men played the female roles. Later, women began to take part in the theatre. In 1939, the Judeo-Tat theatre was the winner of the festival of theatres in Dagestan. During World War II, most of the actors were drafted into the army. Many theatre actors died in the war. In 1943, the theatre resumed its work, and in 1948 it was closed. The official reason was its unprofitability. In the 1960s, the theatre resumed its activities and experienced its second heyday. The actress, Akhso Ilyaguevna Shalumova (1909–1985), "Honored Artist of the Dagestan ASSR" returned to the theatre. She played the role of (Juhuri:Шими Дербенди) - Shimi Derbendi's wife - Shahnugor, based on the stories of writer Hizgil Avshalumov. In the 1970s, the People's Judeo-Tat theatre was organized. For many years, its director was Abram Avdalimov, "Honored Cultural Worker of the Dagestan ASSR," singer, actor and playwright. His successor was Roman Izyaev, who was awarded the Order of the Badge of Honour for his meritorious service. In the 1990s, the Judeo-Tat theatre experienced another crisis: it rarely held performances and did not have any premieres. Only in 2000, when it became a municipal theater, was it able to resume its activity. From 2000 to 2002, the theatre was headed by actor and musician Raziil Semenovich Ilyaguev (1945–2016), "Honored Worker of Culture of the Republic of Dagestan." For the next two years the theatre was headed by Alesya Isakova. In 2004, Lev Yakovlevich Manakhimov (1950–2021), "Honored Artist of the Republic of Dagestan," became the artistic director of the theatre. After the death of Manakhimov, Boris Yudaev became the head of the theatre. Cinema In the era when Yiddish theatre was still a major force in the world of theatre, over 100 films were made in Yiddish. Many are now lost. Prominent films included Shulamith (1931), the first Yiddish musical on film His Wife's Lover (1931), A Daughter of Her People (1932), the anti-Nazi film The Wandering Jew (1933), The Yiddish King Lear (1934), Shir Hashirim (1935), the biggest Yiddish film hit of all time Yidl Mitn Fidl (1936), Where Is My Child? (1937), Green Fields (1937), Dybuk (1937), The Singing Blacksmith (1938), Tevya (1939), Mirele Efros (1939), Lang ist der Weg (1948), and God, Man and Devil (1950). The roster of Jewish entrepreneurs in the English-language American film industry is legendary: Samuel Goldwyn, Louis B. Mayer, the Warner Brothers, David O. Selznick, Marcus Loew, and Adolph Zukor, Fox to name just a few, and continuing into recent times with such industry giants as super-agent Michael Ovitz, Michael Eisner, Lew Wasserman, Jeffrey Katzenberg, Steven Spielberg, and David Geffen. However, few of these brought a specifically Jewish sensibility either to the art of film or, with the sometime exception of Spielberg, to their choice of subject matter. The historian Eric Hobsbawm described the situation as follows: It would be ... pointless to look for consciously Jewish elements in the songs of Irving Berlin or the Hollywood movies of the era of the great studios, all of which were run by immigrant Jews: their object, in which they succeeded, was precisely to make songs or films which found a specific expression for 100 per cent Americanness. A more specifically Jewish sensibility can be seen in the films of the Marx Brothers, Mel Brooks, or Woody Allen; other examples of specifically Jewish films from the Hollywood film industry are the Barbra Streisand vehicle Yentl (1983), or John Frankenheimer's The Fixer (1968). More recently, Call Me By Your Name (2017) can be given as an example of a movie with Jewish sensibility. Jewish film festivals are nowadays conducted in many major cities around the world as vehicles of introducing such films to wider audiences, including among others the Boston JFF, San Francisco JFF, Jerusalem JFF, etc. Radio and television The first radio chains, the Radio Corporation of America and the Columbia Broadcasting System, were created by the Jewish American David Sarnoff and William S. Paley, respectively. These Jewish innovators were also among the first producers of televisions, both black-and-white and color. Among the Jewish immigrant communities of America there was also a thriving Yiddish language radio, with its "golden age" from the 1930s to the 1950s. Although there is little specifically Jewish television in the United States (National Jewish Television, largely religious, broadcasts only three hours a week), Jews have been involved in American television from its earliest days. From Sid Caesar and Milton Berle to Joan Rivers, Gilda Radner, and Andy Kaufman to Billy Crystal to Jerry Seinfeld, Jewish stand-up comedians have been icons of American television. Other Jews that held a prominent role in early radio and television were Eddie Cantor, Al Jolson, Jack Benny, Walter Winchell and David Susskind. More figures are Larry King, Michael Savage and Howard Stern. In the analysis of Paul Johnson, "The Broadway musical, radio and TV were all examples of a fundamental principle in Jewish diaspora history: Jews opening up a completely new field in business and culture, a tabula rasa on which to set their mark, before other interests had a chance to take possession, erect guild or professional fortifications and deny them entry." One of the first televised situation comedies, The Goldbergs was set in a specifically Jewish milieu in the Bronx. While the overt Jewish milieu of The Goldbergs was unusual for an American television series, there were a few other examples, such as Brooklyn Bridge (1991–1993) and Bridget Loves Bernie. Jews have also played an enormous role among the creators and writers of television comedies: Woody Allen, Mel Brooks, Selma Diamond, Larry Gelbart, Carl Reiner, and Neil Simon all wrote for Sid Caesar; Reiner's son Rob Reiner worked with Norman Lear on All in the Family (which often engaged antisemitism and other issues of prejudice); Larry David and Jerry Seinfeld created the hit sitcom Seinfeld; Lorne Michaels, Al Franken, Rosie Shuster, and Alan Zweibel of Saturday Night Live breathed new life into the variety show in the 1970s. More recently, American Jews have been instrumental to "novelistic" television series such as The Wire and The Sopranos. Variously acclaimed as one of the greatest television series of all time, The Wire was created by David Simon. Simon also served as executive producer, head writer, and show runner. Matthew Weiner produced the fifth and sixth seasons of The Sopranos and later created Mad Men. More remarkable contributors are David Benioff and D. B. Weiss, creators of Game of Thrones TV series; Ron Leavitt co-creator of Married... with Children; Damon Lindelof and J. J. Abrams, co-creators of Lost; David Crane and Marta Kauffman, creators of Friends; Tim Kring creator of Heroes; Sydney Newman co-creator of Doctor Who; Darren Star, creator Sex and the City and Melrose Place; Aaron Spelling, co-creator of Beverly Hills, 90210; Chuck Lorre, co-creator of The Big Bang Theory and Two and a Half Men; Gideon Raff, creator of Prisoners of War which Homeland is based on; Aaron Ruben and Sheldon Leonard co-creators of The Andy Griffith Show; Don Hewitt creator of 60 Minutes; Garry Shandling, co-creator of The Larry Sanders Show; Ed. Weinberger, co-creator of The Cosby Show; David Milch, creator of Deadwood; Steven Levitan, co-creator of Modern Family; Dick Wolf, creator of Law & Order; David Shore, creator House; Max Mutchnick and David Kohan creators of Will & Grace; Adam Horowitz and Edward Kitsis creators of Once Upon a Time (TV Series). There is also a significant role of Jews in acting by actors such as Sarah Jessica Parker, William Shatner, Leonard Nimoy, Mila Kunis, Zac Efron, Hank Azaria, David Duchovny, Fred Savage, Zach Braff, Noah Wyle, Adam Brody, Katey Sagal, Sarah Michelle Gellar, Alyson Hannigan, Michelle Trachtenberg, David Schwimmer, Lisa Kudrow and Mayim Bialik. Music Jewish musical contributions also tend to reflect the cultures of the countries in which Jews live, the most notable examples being classical and popular music in the United States and Europe. Some music, however, is unique to particular Jewish communities, such as Israeli music, Israeli folk music, Klezmer, Sephardic and Ladino music, and Mizrahi music. Before Emancipation, virtually all Jewish music in Europe was sacred music, with the exception of the performances of klezmorim during weddings and other occasions. The result was a lack of a Jewish presence in European classical music until the 19th century, with a very few exceptions, normally enabled by specific aristocratic protection, such as Salamone Rossi and Claude Daquin (the work of the former is considered the beginning of "Jewish art music"). After Jews were admitted to mainstream society in England (gradually after their return in the 17th century), France, Austria-Hungary, the German Empire, and Russia (in that order), the Jewish contribution to the European music scene steadily increased, but in the form of mainstream European music, not specifically Jewish music. Notable examples of Jewish Romantic composers (by country) are Charles-Valentin Alkan, Paul Dukas and Fromental Halevy from France, Josef Dessauer, Karl Goldmark and Gustav Mahler from Bohemia (most Austrian Jews during this time were native not to what is today Austria but the outer provinces of the Empire), Felix Mendelssohn and Giacomo Meyerbeer from Germany, and Anton and Nikolai Rubinstein from Russia. Singers included John Braham and Giuditta Pasta. There were very many notable Jewish violin and pianist virtuosi, including Joseph Joachim, Ferdinand David, Carl Tausig, Henri Herz, Leopold Auer, Jascha Heifetz, and Ignaz Moscheles. During the 20th century the number of Jewish composers and notable instrumentalists increased, as did their geographical distribution. Sample Jewish 20th-century composers include Arnold Schoenberg and Alexander von Zemlinsky from Austria, Hanns Eisler and Kurt Weill from Germany, Viktor Ullmann and Jaromír Weinberger from Bohemia and later the Czech Republic (the former perished at the Auschwitz extermination camps), George Gershwin and Aaron Copland from the United States, Darius Milhaud and Alexandre Tansman from France, Alfred Schnittke and Lera Auerbach from Russia, Lalo Schifrin and Mario Davidovsky from Argentina and Paul Ben-Haim and Shulamit Ran from Israel. There are some genres and forms of classical music that Jewish composers have been associated with, including notably during the Romantic period French Grand Opera. The most prolific composers of this genre included Giacomo Meyerbeer, Fromental Halévy, and the later Jacques Offenbach; Halevy's La Juive was based on Scribe's libretto very loosely connected to the Jewish experience. While orchestral and operatic music works by Jewish composers would in general be considered secular, many Jewish (as well as non-Jewish) composers have incorporated Jewish themes and motives into their music. Sometimes this is done covertly, such as the klezmer band music that many critics and observers believe lies in the third movement of Mahler's Symphony No. 1, and this type of Jewish reference was most common during the 19th century when openly displaying one's Jewishness would most likely hamper a Jew's chances at assimilation. During the 20th century, however, many Jewish composers wrote music with direct Jewish references and themes, e.g. David Amram (Symphony – "Songs of the Soul"), Leonard Bernstein (Kaddish Symphony, Chichester Psalms), Ernest Bloch (Schelomo), Arnold Schoenberg, Mario Castelnuovo-Tedesco (Violin Concerto no. 2) Kurt Weill (The Eternal Road) and Hugo Weisgall (Psalm of the Instant Dove). In the late twentieth century, prominent composers like Morton Feldman, Gyorgy Ligeti or Alfred Schnittke gave significant contributions to the history of contemporary music. The great songwriters and lyricists of American traditional popular music and jazz standards were predominantly Jewish, including Harold Arlen, Jerome Kern, George Gershwin, Frank Loesser, Richard Rodgers and Irving Berlin. Popular music as of today for the Jewish World at large mainly stems from Israeli Music, more specifically Mizrahi Music. Popular Jewish artists today include Omer Adam, Noa Kirel, Avior Malasa, A-WA, Eden Alene, Eyal Golan, Debbie Friedman, Barbra Streisand and others. Dance Deriving from Biblical traditions, Jewish dance has long been used by Jews as a medium for the expression of joy and other communal emotions. Each Jewish diasporic community developed its own dance traditions for wedding celebrations and other distinguished events. For Ashkenazi Jews in Eastern Europe, for example, dances, whose names corresponded to the different forms of klezmer music that were played, were an obvious staple of the wedding ceremony of the shtetl. Jewish dances both were influenced by surrounding Gentile traditions and Jewish sources preserved over time. "Nevertheless the Jews practiced a corporeal expressive language that was highly differentiated from that of the non-Jewish peoples of their neighborhood, mainly through motions of the hands and arms, with more intricate legwork by the younger men." In general, however, in most religiously traditional communities, members of the opposite sex dancing together or dancing at times other than at these events was frowned upon. Sport Historically, Jews were often seen as unathletic. However, sport has played a role in integrating the Jewish diaspora into its local societies. For example, in the United States, the Jewish presence in baseball was important during a major wave of immigration in the early 20th century, and sport was used to shape the assimilation and community formation of both American and British Jews. Jews have dominated chess. Humor Jewish humor is the long tradition of humor in Judaism dating back to the Torah and the Midrash, but generally refers to the more recent stream of verbal, frequently self-deprecating and often anecdotal humor originating in Europe. Jewish humor took root in the United States over the last hundred years, beginning with vaudeville[citation needed], and continuing through radio, stand-up, film, and television. A significant number of American comedians have been or are Jewish.[citation needed] Notable Jewish-American comedians include Woody Allen, Jerry Seinfeld, Larry David, Sammy Davis Jr, Rachel Dratch, Gilbert Gottfried, Ilana Glazer, Jan Murray, Julie Klausner, Don Rickles, Andy Samberg, Gene Wilder, Groucho Marx, Gianmarco Soresi, Ben Schwartz, and many others. Visual arts Despite fears by early religious communities of art being used for idolatrous purposes, Jewish sacred art is recorded in the Tanakh and extends throughout Jewish Antiquity and the Middle Ages. The Tabernacle and the two Temples in Jerusalem form the first known examples of "Jewish art". During the first centuries of the Common Era, Jewish religious art also was created in regions surrounding the Mediterranean such as Syria and Greece, including frescoes on the walls of synagogues, of which the Dura Europas Synagogue was the only survivor, prior to its destruction by ISIL in 2017, as well as the Jewish catacombs in Rome. A number of luxury pieces of gold glass from the later Roman period have Jewish motifs. Several Hellenistic-style floor mosaics have also been excavated in synagogues from late antiquity in Israel and Palestine, especially of the signs of the Zodiac, which was apparently acceptable in a low-status position on the floor. Some, such as that at Naaran, show evidence of a reaction against images of living creatures around 600 CE. The decoration of sarcophagi and walls at the cave cemetery at Beit She'arim shows a mixture of Jewish and Hellenistic motifs. Middle Age Rabbinical and Kabbalistic literature also contain textual and graphic art, most famously illuminated haggadahs such as the Sarajevo Haggadah, and other manuscripts like the Nuremberg Mahzor. Some of these were illustrated by Jewish artists and some by Christians; equally some Jewish artists and craftsmen in various media worked on Christian commissions. Outside of Europe, Yemenite Jewish silversmiths developed a distinctive style of finely wrought silver that is admired for its artistry. Johnson again summarizes this sudden change from a limited participation by Jews in visual art (as in many other arts) to a large movement by them into this branch of European cultural life: Again, the arrival of the Jewish artist was a strange phenomenon. It is true that, over the centuries, there had been many animals (though few humans) depicted in Jewish art: lions on Torah curtains, owls on Judaic coins, animals on the Capernaum capitals, birds on the rim of the fountain-basis in the 5th century Naro synagogue in Tunis; there were carved animals, too, on timber synagogues in eastern Europe – indeed the Jewish wood-carver was the prototype of the modern Jewish plastic artist. A book of Yiddish folk-ornament, printed at Vitebsk in 1920, was similar to Chagall's own bestiary. But the resistance of pious Jews to portraying the living human image was still strong at the beginning of the 20th century. There were few Jewish secular artists in Europe prior to the Emancipation that spread throughout Europe with the Napoleonic conquests. There were exceptions, and Salomon Adler was a prominent portrait painter in 18th-century Milan. The delay in participation in the visual arts parallels the lack of Jewish participation in European classical music until the nineteenth century, and which was progressively overcome with the rise of Modernism in the 20th century. There were many Jewish artists in the 19th century, but Jewish artistic activity boomed during the end of World War I. The Jewish artistic Renaissance has its roots in the 1901 Fifth Zionist Congress, which included an art exhibition featuring Jewish artists E.M. Lilien and Hermann Struck. The exhibition helped legitimize art as an expression of Jewish culture. According to Nadine Nieszawer, "Until 1905, Jews were always plunged into their books but from the first Russian Revolution, they became emancipated, committed themselves in politics and became artists. A real Jewish cultural rebirth". Individual Jews figured in the modern artistic movements of Europe— With the exception of those living in isolated Jewish communities, most Jews listed here as contributing to secular Jewish culture also participated in the cultures of the peoples they lived with and nations they lived in. In most cases, however, the work and lives of these people did not exist in two distinct cultural spheres but rather in one that incorporated elements of both. During the early 20th century, Jews figured particularly prominently in the École de Paris centered in the Montparnasse movement (including Chaim Soutine, Marc Chagall, Jules Pascin, Yitzhak Frenkel Frenel and Michel Kikoine), and after World War II among the abstract expressionists: Alexander Bogen, Helen Frankenthaler, Adolph Gottlieb, Philip Guston, Al Held, Lee Krasner, Barnett Newman, Milton Resnick, Jack Tworkov, Mark Rothko, and Louis Schanker, as well as among Contemporary artists, Modernists and Postmodernists. Many Russian Jews were prominent in the art of scenic design, particularly the aforementioned Chagall and Aronson, as well as the revolutionary Léon Bakst, who like the other two also painted. One Mexican Jewish artist was Pedro Friedeberg; historians disagree as to whether Frida Kahlo's father was Jewish or Lutheran. A prominent Slovak artist Dominik Skutecký was also Jewish. Among major artists Chagall may be the most specifically Jewish in his themes. But as art fades into graphic design, Jewish names and themes become more prominent: Leonard Baskin, Al Hirschfeld, Peter Max, Ben Shahn, Art Spiegelman and Saul Steinberg. The collage artist Wallace Berman's engagement with Hebrew reflected the Beat Generation's wider exploration of esoteric spiritual practices such as Zen, palm reading, astrology, kabbalah and psychedelic drugs. Born on Staten Island, Berman moved to Los Angeles where the Hebrew letters on storefront windows and in Yiddish-language newspapers fascinated him. According to historian Richard Candida Smith, "Berman's interest in the Hebrew alphabet and its functions in Jewish mysticism was part of an effort to reclaim his ethnic identity." In 1989, the painter R.B. Kitaj published his "First Diasporist Manifesto", a short book in which he analysed how his art was based on his alienation as a Jew born in Cleveland, Ohio and living in London. In 2007, a second illustrated stream of consciousness book followed, "The Second Diasporist Manifesto." Jews have also played a very important role in media other than painting; their involvement in sculpture came rather later, perhaps due to lingering feelings against "graven images". But there were many notable Jewish sculptors in the later 19th and 20th centuries, including Moses Jacob Ezekiel (American, d 1917), Sir Jacob Epstein (American-British, d 1959), Ossip Zadkine (French, d 1967) Naum Gabo (Russian, d 1977), Oscar Nemon (Croatian, d 1985), Louise Nevelson (American, d 1988), Herbert Ferber (American, d 1991). 1893–1943 In photography some notable figures are André Kertész, Robert Frank, Helmut Newton, Garry Winogrand, Cindy Sherman, Steve Lehman, and Adi Nes; in installation art and street art some notable figures are Sigalit Landau, Dede, and Michal Rovner. Comics, cartoons, and animation Graphic art, as expressed in the art of comics, has been a key field for Jewish artists as well. In the Golden and Silver ages of American comic books, the Jewish role was overwhelming and a large number of the medium's foremost creators have been Jewish. Max Gaines was a pioneering figure in the creation of the modern comic book when in 1935 he published the first one called Famous Funnies. In 1939, he founded, with Jack Liebowitz and Harry Donenfeld, All-American Publications (the AA Group). The publication is known for the creation of several superheroes such as the original Atom, Flash, Green Lantern, Hawkman, and Wonder Woman. Donenfeld and Liebowitz were also the owners of National Allied Publications which distributed Detective Comics and Action Comics. That company was also a precursor of DC Comics. In 1939, the pulp magazine publisher Martin Goodman formed Timely Publications, a company to be known, since the 1960s, as Marvel Comics. At Marvel, Artists such as Stan Lee, Jack Kirby, Larry Lieber and Joe Simon created a large variety of characters and cultural icons including Spider-Man, Hulk, Captain America, Iron Man, Thor, Daredevil, and the teams Fantastic Four, Avengers, X-Men (including many of its characters) and S.H.I.E.L.D.. Stan Lee attributed the Jewish role in comics to the Jewish culture. At DC Comics Jewish role was significant as well; the character of Superman, which was created by the Jewish artists Joe Shuster and Jerry Siegel, is partly based on the biblical figure of Samson. It was also suggested the Superman is partly influenced by Moses, and other Jewish elements. More at DC Comics are Bob Kane, Bill Finger and Martin Nodell, creators of Green Lantern, Batman and many related characters as Robin, The Joker, Riddler, Scarecrow and Catwoman; Gil Kane, co-creator of Atom and Iron Fist. Many of those involved in the later ages of comics are also Jewish, such as Julius Schwartz, Joe Kubert, Jenette Kahn, Len Wein, Peter David, Neil Gaiman, Chris Claremont and Brian Michael Bendis. There is also a large number of Jewish characters among comics superheroes such as Magneto, Quicksilver, Kitty Pryde, The Thing, Sasquatch, Sabra, Ragman, Legion, and Moon Knight, of whom were and are influenced by events in Jewish history and elements of Jewish life. In 1944, Max Gaines founded EC Comics. The company is known for specializing in horror fiction, crime fiction, satire, military fiction and science fiction from the 1940s through the mid-1950s, notably the Tales from the Crypt series, The Haunt of Fear, The Vault of Horror, Crime SuspenStories and Shock SuspenStories. Jewish artists that are associated with the publisher include Al Feldstein, Dave Berg, and Jack Kamen. Will Eisner was an American cartoonist and was known as one of the earliest cartoonists to work in the American comic book industry. He is the creator of the Spirit comics series and the graphic novel A Contract with God. The Eisner Award was named in his honor, and is given to recognize achievements each year in the comics medium. In 1952, William Gaines and Harvey Kurtzman founded Mad, an American humor magazine. It was widely imitated and influential, affecting satirical media as well as the cultural landscape of the 20th century, with editor Al Feldstein increasing readership to more than two million during its 1970s circulation peak. Other known cartoonists are Lee Falk creator of The Phantom and Mandrake the Magician; The Hebrew comics of Michael Netzer creator of Uri-On and Uri Fink creator of Zbeng!; William Steig, creator of Shrek!; Daniel Clowes, creator of Eightball; Art Spiegelman creator of graphic novel Maus and Raw (with Françoise Mouly). In animation, there were many Jewish animators: Genndy Tartakovsky is the creator of several animation TV series such as Dexter's Laboratory and Samurai Jack; Matt Stone co-creator of South Park; David Hilberman, who helped animate Bambi and Snow White and the Seven Dwarfs; Friz Freleng, Looney Tunes; C. H. Greenblatt, Chowder; and Harvey Beaks; Ralph Bakshi, Fritz the Cat, Mighty Mouse: The New Adventures, Wizards, The Lord of the Rings, Heavy Traffic, Coonskin, Hey Good Lookin', Fire and Ice, and Cool World; Alex Hirsch, creator of Gravity Falls; Dave Fleischer and Lou Fleischer, founders of Fleischer Studios; Max Fleischer, animation of Betty Boop, Popeye and Superman; Rebecca Sugar, creator of Steven Universe. Several companies producing animation were founded by Jews, such as DreamWorks, which its products include Shrek, Madagascar, Kung Fu Panda and The Prince of Egypt; Warner Bros., whose animation division is known for cartoons such as Looney Tunes, Tiny Toon Adventures, Animaniacs, Pinky and the Brain and Freakazoid! . Cuisine Jewish cooking combines the food of many cultures in which Jews have lived, including Middle Eastern, Mediterranean, Spanish, German and Eastern European styles of cooking, all influenced by the need for food to be kosher. Thus, Jewish foods like bagels, hummus, stuffed cabbage, and blintzes are all influenced by the culinary preferences of communities in which Jews have settled. The amalgam of these foods, plus uniquely Jewish contributions like tzimmis, cholent, Malawach and Matzah balls, make up a variety of Jewish cuisine. Philo-Semitism Philo-Semitism (also spelled philosemitism) or Judeophilia is an interest in, respect for and an appreciation, or in some cases a fetishization, of Jewish people, their history, and their culture and the influence of Judaism, particularly on the part of a gentile. Within the Jewish community, philo-Semitism includes an interest in Jewish culture and a love of things that are considered Jewish. Very few Jews live in East Asian countries, but Jews are viewed in an especially positive light in some of them, partly owing to their shared wartime experiences during the Second World War. Examples include South Korea and China. In general, Jews are positively stereotyped as being intelligent, business savvy and committed to family values and responsibilities, but in the Western world, the first of the two aforementioned stereotypes more frequently have the negatively interpreted equivalents of guile and greed. In South Korean primary schools, students are required to read the Talmud. See also References Sources Further reading External links |
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Contents Meta Platforms Meta Platforms, Inc. (doing business as Meta) is an American multinational technology company headquartered in Menlo Park, California. Meta owns and operates several prominent social media platforms and communication services, including Facebook, Instagram, WhatsApp, Messenger, Threads and Manus. The company also operates an advertising network for its own sites and third parties; as of 2023[update], advertising accounted for 97.8 percent of its total revenue. Meta has been described as a part of Big Tech, which refers to the largest six tech companies in the United States, Alphabet (Google), Amazon, Apple, Meta (Facebook), Microsoft, and Nvidia, which are also the largest companies in the world by market capitalization. The company was originally established in 2004 as TheFacebook, Inc., and was renamed Facebook, Inc. in 2005. In 2021, it rebranded as Meta Platforms, Inc. to reflect a strategic shift toward developing the metaverse—an interconnected digital ecosystem spanning virtual and augmented reality technologies. In 2023, Meta was ranked 31st on the Forbes Global 2000 list of the world's largest public companies. As of 2022, it was the world's third-largest spender on research and development, with R&D expenses totaling US$35.3 billion. History Facebook filed for an initial public offering (IPO) on January 1, 2012. The preliminary prospectus stated that the company sought to raise $5 billion, had 845 million monthly active users, and a website accruing 2.7 billion likes and comments daily. After the IPO, Zuckerberg would retain 22% of the total shares and 57% of the total voting power in Facebook. Underwriters valued the shares at $38 each, valuing the company at $104 billion, the largest valuation yet for a newly public company. On May 16, one day before the IPO, Facebook announced it would sell 25% more shares than originally planned due to high demand. The IPO raised $16 billion, making it the third-largest in US history (slightly ahead of AT&T Mobility and behind only General Motors and Visa). The stock price left the company with a higher market capitalization than all but a few U.S. corporations—surpassing heavyweights such as Amazon, McDonald's, Disney, and Kraft Foods—and made Zuckerberg's stock worth $19 billion. The New York Times stated that the offering overcame questions about Facebook's difficulties in attracting advertisers to transform the company into a "must-own stock". Jimmy Lee of JPMorgan Chase described it as "the next great blue-chip". Writers at TechCrunch, on the other hand, expressed skepticism, stating, "That's a big multiple to live up to, and Facebook will likely need to add bold new revenue streams to justify the mammoth valuation." Trading in the stock, which began on May 18, was delayed that day due to technical problems with the Nasdaq exchange. The stock struggled to stay above the IPO price for most of the day, forcing underwriters to buy back shares to support the price. At the closing bell, shares were valued at $38.23, only $0.23 above the IPO price and down $3.82 from the opening bell value. The opening was widely described by the financial press as a disappointment. The stock set a new record for trading volume of an IPO. On May 25, 2012, the stock ended its first full week of trading at $31.91, a 16.5% decline. On May 22, 2012, regulators from Wall Street's Financial Industry Regulatory Authority announced that they had begun to investigate whether banks underwriting Facebook had improperly shared information only with select clients rather than the general public. Massachusetts Secretary of State William F. Galvin subpoenaed Morgan Stanley over the same issue. The allegations sparked "fury" among some investors and led to the immediate filing of several lawsuits, one of them a class action suit claiming more than $2.5 billion in losses due to the IPO. Bloomberg estimated that retail investors may have lost approximately $630 million on Facebook stock since its debut. S&P Global Ratings added Facebook to its S&P 500 index on December 21, 2013. On May 2, 2014, Zuckerberg announced that the company would be changing its internal motto from "Move fast and break things" to "Move fast with stable infrastructure". The earlier motto had been described as Zuckerberg's "prime directive to his developers and team" in a 2009 interview in Business Insider, in which he also said, "Unless you are breaking stuff, you are not moving fast enough." In November 2016, Facebook announced the Microsoft Windows client of gaming service Facebook Gameroom, formerly Facebook Games Arcade, at the Unity Technologies developers conference. The client allows Facebook users to play "native" games in addition to its web games. The service was closed in June 2021. Lasso was a short-video sharing app from Facebook similar to TikTok that was launched on iOS and Android in 2018 and was aimed at teenagers. On July 2, 2020, Facebook announced that Lasso would be shutting down on July 10. In 2018, the Oculus lead Jason Rubin sent his 50-page vision document titled "The Metaverse" to Facebook's leadership. In the document, Rubin acknowledged that Facebook's virtual reality business had not caught on as expected, despite the hundreds of millions of dollars spent on content for early adopters. He also urged the company to execute fast and invest heavily in the vision, to shut out HTC, Apple, Google and other competitors in the VR space. Regarding other players' participation in the metaverse vision, he called for the company to build the "metaverse" to prevent their competitors from "being in the VR business in a meaningful way at all". In May 2019, Facebook founded Libra Networks, reportedly to develop their own stablecoin cryptocurrency. Later, it was reported that Libra was being supported by financial companies such as Visa, Mastercard, PayPal and Uber. The consortium of companies was expected to pool in $10 million each to fund the launch of the cryptocurrency coin named Libra. Depending on when it would receive approval from the Swiss Financial Market Supervisory authority to operate as a payments service, the Libra Association had planned to launch a limited format cryptocurrency in 2021. Libra was renamed Diem, before being shut down and sold in January 2022 after backlash from Swiss government regulators and the public. During the COVID-19 pandemic, the use of online services, including Facebook, grew globally. Zuckerberg predicted this would be a "permanent acceleration" that would continue after the pandemic. Facebook hired aggressively, growing from 48,268 employees in March 2020 to more than 87,000 by September 2022. Following a period of intense scrutiny and damaging whistleblower leaks, news started to emerge on October 21, 2021 about Facebook's plan to rebrand the company and change its name. In the Q3 2021 earnings call on October 25, Mark Zuckerberg discussed the ongoing criticism of the company's social services and the way it operates, and pointed to the pivoting efforts to building the metaverse – without mentioning the rebranding and the name change. The metaverse vision and the name change from Facebook, Inc. to Meta Platforms was introduced at Facebook Connect on October 28, 2021. Based on Facebook's PR campaign, the name change reflects the company's shifting long term focus of building the metaverse, a digital extension of the physical world by social media, virtual reality and augmented reality features. "Meta" had been registered as a trademark in the United States in 2018 (after an initial filing in 2015) for marketing, advertising, and computer services, by a Canadian company that provided big data analysis of scientific literature. This company was acquired in 2017 by the Chan Zuckerberg Initiative (CZI), a foundation established by Zuckerberg and his wife, Priscilla Chan, and became one of their projects. Following the rebranding announcement, CZI announced that it had already decided to deprioritize the earlier Meta project, thus it would be transferring its rights to the name to Meta Platforms, and the previous project would end in 2022. Soon after the rebranding, in early February 2022, Meta reported a greater-than-expected decline in profits in the fourth quarter of 2021. It reported no growth in monthly users, and indicated it expected revenue growth to stall. It also expected measures taken by Apple Inc. to protect user privacy to cost it some $10 billion in advertisement revenue, an amount equal to roughly 8% of its revenue for 2021. In meeting with Meta staff the day after earnings were reported, Zuckerberg blamed competition for user attention, particularly from video-based apps such as TikTok. The 27% reduction in the company's share price which occurred in reaction to the news eliminated some $230 billion of value from Meta's market capitalization. Bloomberg described the decline as "an epic rout that, in its sheer scale, is unlike anything Wall Street or Silicon Valley has ever seen". Zuckerberg's net worth fell by as much as $31 billion. Zuckerberg owns 13% of Meta, and the holding makes up the bulk of his wealth. According to published reports by Bloomberg on March 30, 2022, Meta turned over data such as phone numbers, physical addresses, and IP addresses to hackers posing as law enforcement officials using forged documents. The law enforcement requests sometimes included forged signatures of real or fictional officials. When asked about the allegations, a Meta representative said, "We review every data request for legal sufficiency and use advanced systems and processes to validate law enforcement requests and detect abuse." In June 2022, Sheryl Sandberg, the chief operating officer of 14 years, announced she would step down that year. Zuckerberg said that Javier Olivan would replace Sandberg, though in a “more traditional” role. In March 2022, Meta (except Meta-owned WhatsApp) and Instagram were banned in Russia and added to the Russian list of terrorist and extremist organizations for alleged Russophobia and hate speech (up to genocidal calls) amid the ongoing Russian invasion of Ukraine. Meta appealed against the ban, but it was upheld by a Moscow court in June of the same year. Also in March 2022, Meta and Italian eyewear giant Luxottica released Ray-Ban Stories, a series of smartglasses which could play music and take pictures. Meta and Luxottica parent company EssilorLuxottica declined to disclose sales on the line of products as of September 2022, though Meta has expressed satisfaction with its customer feedback. In July 2022, Meta saw its first year-on-year revenue decline when its total revenue slipped by 1% to $28.8bn. Analysts and journalists accredited the loss to its advertising business, which has been limited by Apple's app tracking transparency feature and the number of people who have opted not to be tracked by Meta apps. Zuckerberg also accredited the decline to increasing competition from TikTok. On October 27, 2022, Meta's market value dropped to $268 billion, a loss of around $700 billion compared to 2021, and its shares fell by 24%. It lost its spot among the top 20 US companies by market cap, despite reaching the top 5 in the previous year. In November 2022, Meta laid off 11,000 employees, 13% of its workforce. Zuckerberg said the decision to aggressively increase Meta's investments had been a mistake, as he had wrongly predicted that the surge in e-commerce would last beyond the COVID-19 pandemic. He also attributed the decline to increased competition, a global economic downturn and "ads signal loss". Plans to lay off a further 10,000 employees began in April 2023. The layoffs were part of a general downturn in the technology industry, alongside layoffs by companies including Google, Amazon, Tesla, Snap, Twitter and Lyft. Starting from 2022, Meta scrambled to catch up to other tech companies in adopting specialized artificial intelligence hardware and software. It had been using less expensive CPUs instead of GPUs for AI work, but that approach turned out to be less efficient. The company gifted the Inter-university Consortium for Political and Social Research $1.3 million to finance the Social Media Archive's aim to make their data available to social science research. In 2023, Ireland's Data Protection Commissioner imposed a record EUR 1.2 billion fine on Meta for transferring data from Europe to the United States without adequate protections for EU citizens.: 250 In March 2023, Meta announced a new round of layoffs that would cut 10,000 employees and close 5,000 open positions to make the company more efficient. Meta revenue surpassed analyst expectations for the first quarter of 2023 after announcing that it was increasing its focus on AI. On July 6, Meta launched a new app, Threads, a competitor to Twitter. Meta announced its artificial intelligence model Llama 2 in July 2023, available for commercial use via partnerships with major cloud providers like Microsoft. It was the first project to be unveiled out of Meta's generative AI group after it was set up in February. It would not charge access or usage but instead operate with an open-source model to allow Meta to ascertain what improvements need to be made. Prior to this announcement, Meta said it had no plans to release Llama 2 for commercial use. An earlier version of Llama was released to academics. In August 2023, Meta announced its permanent removal of news content from Facebook and Instagram in Canada due to the Online News Act, which requires Canadian news outlets to be compensated for content shared on its platform. The Online News Act was in effect by year-end, but Meta will not participate in the regulatory process. In October 2023, Zuckerberg said that AI would be Meta's biggest investment area in 2024. Meta finished 2023 as one of the best-performing technology stocks of the year, with its share price up 150 percent. Its stock reached an all-time high in January 2024, bringing Meta within 2% of achieving $1 trillion market capitalization. In November 2023 Meta Platforms launched an ad-free service in Europe, allowing subscribers to opt-out of personal data being collected for targeted advertising. A group of 28 European organizations, including Max Schrems' advocacy group NOYB, the Irish Council for Civil Liberties, Wikimedia Europe, and the Electronic Privacy Information Center, signed a 2024 letter to the European Data Protection Board (EDPB) expressing concern that this subscriber model would undermine privacy protections, specifically GDPR data protection standards. Meta removed the Facebook and Instagram accounts of Iran's Supreme Leader Ali Khamenei in February 2024, citing repeated violations of its Dangerous Organizations & Individuals policy. As of March, Meta was under investigation by the FDA for alleged use of their social media platforms to sell illegal drugs. On 16 May 2024, the European Commission began an investigation into Meta over concerns related to child safety. In May 2023, Iraqi social media influencer Esaa Ahmed-Adnan encountered a troubling issue when Instagram removed his posts, citing false copyright violations despite his content being original and free from copyrighted material. He discovered that extortionists were behind these takedowns, offering to restore his content for $3,000 or provide ongoing protection for $1,000 per month. This scam, exploiting Meta’s rights management tools, became widespread in the Middle East, revealing a gap in Meta’s enforcement in developing regions. An Iraqi nonprofit Tech4Peace’s founder, Aws al-Saadi helped Ahmed-Adnan and others, but the restoration process was slow, leading to significant financial losses for many victims, including prominent figures like Ammar al-Hakim. This situation highlighted Meta’s challenges in balancing global growth with effective content moderation and protection. On 16 September 2024, Meta announced it had banned Russian state media outlets from its platforms worldwide due to concerns about "foreign interference activity." This decision followed allegations that RT and its employees funneled $10 million through shell companies to secretly fund influence campaigns on various social media channels. Meta's actions were part of a broader effort to counter Russian covert influence operations, which had intensified since the invasion. At its 2024 Connect conference, Meta presented Orion, its first pair of augmented reality glasses. Though Orion was originally intended to be sold to consumers, the manufacturing process turned out to be too complex and expensive. Instead, the company pivoted to producing a small number of the glasses to be used internally. On 4 October 2024, Meta announced about its new AI model called Movie Gen, capable of generating realistic video and audio clips based on user prompts. Meta stated it would not release Movie Gen for open development, preferring to collaborate directly with content creators and integrate it into its products by the following year. The model was built using a combination of licensed and publicly available datasets. On October 31, 2024, ProPublica published an investigation into deceptive political advertisement scams that sometimes use hundreds of hijacked profiles and facebook pages run by organized networks of scammers. The authors cited spotty enforcement by Meta as a major reason for the extent of the issue. In November 2024, TechCrunch reported that Meta were considering building a $10bn global underwater cable spanning 25,000 miles. In the same month, Meta closed down 2 million accounts on Facebook and Instagram that were linked to scam centers in Myanmar, Laos, Cambodia, the Philippines, and the United Arab Emirates doing pig butchering scams. In December 2024, Meta announced that, beginning February 2025, they would require advertisers to run ads about financial services in Australia to verify information about who are the beneficiary and the payer in a bid to regulate scams. On December 4, 2024, Meta announced it will invest US$10 billion for its largest AI data center in northeast Louisiana, powered by natural gas facilities. On the 11th of that month, Meta experienced a global outage, impacting accounts on all of their social media and messaging applications. Outage reports from DownDetector reached 70,000+ and 100,000+ within minutes for Instagram and Facebook, respectively. In January 2025, Meta announced plans to roll back its diversity, equity, and inclusion (DEI) initiatives, citing shifts in the "legal and policy landscape" in the United States following the 2024 presidential election. The decision followed reports that CEO Mark Zuckerberg sought to align the company more closely with the incoming Trump administration, including changes to content moderation policies and executive leadership. The new content moderation policies continued to bar insults about a person's intellect or mental illness, but made an exception to allow calling LGBTQ people mentally ill because they are gay or transgender. Later that month, Meta agreed to pay $25 million to settle a 2021 lawsuit brought by Donald Trump for suspending his social media accounts after the January 6 riots. Changes to Meta's moderation policies were controversial among its oversight board, with a significant divide in opinion between the board's US conservatives and its global members. In June 2025, Meta Platforms Inc. has decided to make a multibillion-dollar investment into artificial intelligence startup Scale AI. The financing could exceed $10 billion in value which would make it one of the largest private company funding events of all time. In October 2025, it was announced that Meta would be laying off 600 employees in the artificial intelligence unit to perform better and simpler. They referred to their AI unit as "bloated" and are seeking to trim down the department. This mass layoff is going to impact Meta’s AI infrastructure units, Fundamental Artificial Intelligence Research unit (FAIR) and other product-related positions. Mergers and acquisitions Meta has acquired multiple companies (often identified as talent acquisitions). One of its first major acquisitions was in April 2012, when it acquired Instagram for approximately US$1 billion in cash and stock. In October 2013, Facebook, Inc. acquired Onavo, an Israeli mobile web analytics company. In February 2014, Facebook, Inc. announced it would buy mobile messaging company WhatsApp for US$19 billion in cash and stock. The acquisition was completed on October 6. Later that year, Facebook bought Oculus VR for $2.3 billion in cash and stock, which released its first consumer virtual reality headset in 2016. In late November 2019, Facebook, Inc. announced the acquisition of the game developer Beat Games, responsible for developing one of that year's most popular VR games, Beat Saber. In Late 2022, after Facebook Inc rebranded to Meta Platforms Inc, Oculus was rebranded to Meta Quest. In May 2020, Facebook, Inc. announced it had acquired Giphy for a reported cash price of $400 million. It will be integrated with the Instagram team. However, in August 2021, UK's Competition and Markets Authority (CMA) stated that Facebook, Inc. might have to sell Giphy, after an investigation found that the deal between the two companies would harm competition in display advertising market. Facebook, Inc. was fined $70 million by CMA for deliberately failing to report all information regarding the acquisition and the ongoing antitrust investigation. In October 2022, the CMA ruled for a second time that Meta be required to divest Giphy, stating that Meta already controls half of the advertising in the UK. Meta agreed to the sale, though it stated that it disagrees with the decision itself. In May 2023, Giphy was divested to Shutterstock for $53 million. In November 2020, Facebook, Inc. announced that it planned to purchase the customer-service platform and chatbot specialist startup Kustomer to promote companies to use their platform for business. It has been reported that Kustomer valued at slightly over $1 billion. The deal was closed in February 2022 after regulatory approval. In September 2022, Meta acquired Lofelt, a Berlin-based haptic tech startup. In December 2025, it was announced Meta had acquired the AI-wearables startup, Limitless. In the same month, they also acquired another AI startup, Manus AI, for $2 billion. Manus announced in December that its platform had achieved $100mm in recurring revenue just 8 months after its launch and Meta said it will scale the platform to many other businesses. In January 2026, it was announced Meta proposed acquisition of Manus was undergoing preliminary scrutiny by Chinese regulators. The examination concerns the cross-border transfer of artificial intelligence technology developed in China. Lobbying In 2020, Facebook, Inc. spent $19.7 million on lobbying, hiring 79 lobbyists. In 2019, it had spent $16.7 million on lobbying and had a team of 71 lobbyists, up from $12.6 million and 51 lobbyists in 2018. Facebook was the largest spender of lobbying money among the Big Tech companies in 2020. The lobbying team includes top congressional aide John Branscome, who was hired in September 2021, to help the company fend off threats from Democratic lawmakers and the Biden administration. In December 2024, Meta donated $1 million to the inauguration fund for then-President-elect Donald Trump. In 2025, Meta was listed among the donors funding the construction of the White House State Ballroom. Partnerships February 2026, Meta announced a long-term partnership with Nvidia. Censorship In August 2024, Mark Zuckerberg sent a letter to Jim Jordan indicating that during the COVID-19 pandemic the Biden administration repeatedly asked Meta to limit certain COVID-19 content, including humor and satire, on Facebook and Instagram. In 2016 Meta hired Jordana Cutler, formerly an employee at the Israeli Embassy to the United States, as its policy chief for Israel and the Jewish Diaspora. In this role, Cutler pushed for the censorship of accounts belonging to Students for Justice in Palestine chapters in the United States. Critics have said that Cutler's position gives the Israeli government an undue influence over Meta policy, and that few countries have such high levels of contact with Meta policymakers. Following the election of Donald Trump in 2025, various sources noted possible censorship related to the Democratic Party on Instagram and other Meta platforms. In February 2025, a Meta rep flagged journalist Gil Duran's article and other "critiques of tech industry figures" as spam or sensitive content, limiting their reach. In March 2025, Meta attempted to block former employee Sarah Wynn-Williams from promoting or further distributing her memoir, Careless People, that includes allegations of unaddressed sexual harassment in the workplace by senior executives. The New York Times reports that the arbitration is among Meta's most forcible attempts to repudiate a former employee's account of workplace dynamics. Publisher Macmillan reacted to the ruling by the Emergency International Arbitral Tribunal by stating that it will ignore its provisions. As of 15 March 2025[update], hardback and digital versions of Careless People were being offered for sale by major online retailers. From October 2025, Meta began removing and restricting access for accounts related to LGBTQ, reproductive health and abortion information pages on its platforms. Martha Dimitratou, executive director of Repro Uncensored, called Meta's shadow-banning of these issues "One of the biggest waves of censorship we are seeing". Disinformation concerns Since its inception, Meta has been accused of being a host for fake news and misinformation. In the wake of the 2016 United States presidential election, Zuckerberg began to take steps to eliminate the prevalence of fake news, as the platform had been criticized for its potential influence on the outcome of the election. The company initially partnered with ABC News, the Associated Press, FactCheck.org, Snopes and PolitiFact for its fact-checking initiative; as of 2018, it had over 40 fact-checking partners across the world, including The Weekly Standard. A May 2017 review by The Guardian found that the platform's fact-checking initiatives of partnering with third-party fact-checkers and publicly flagging fake news were regularly ineffective, and appeared to be having minimal impact in some cases. In 2018, journalists working as fact-checkers for the company criticized the partnership, stating that it had produced minimal results and that the company had ignored their concerns. In 2024 Meta's decision to continue to disseminate a falsified video of US president Joe Biden, even after it had been proven to be fake, attracted criticism and concern. In January 2025, Meta ended its use of third-party fact-checkers in favor of a user-run community notes system similar to the one used on X. While Zuckerberg supported these changes, saying that the amount of censorship on the platform was excessive, the decision received criticism by fact-checking institutions, stating that the changes would make it more difficult for users to identify misinformation. Meta also faced criticism for weakening its policies on hate speech that were designed to protect minorities and LGBTQ+ individuals from bullying and discrimination. While moving its content review teams from California to Texas, Meta changed their hateful conduct policy to eliminate restrictions on anti-LGBT and anti-immigrant hate speech, as well as explicitly allowing users to accuse LGBT people of being mentally ill or abnormal based on their sexual orientation or gender identity. In January 2025, Meta faced significant criticism for its role in removing LGBTQ+ content from its platforms, amid its broader efforts to address anti-LGBTQ+ hate speech. The removal of LGBTQ+ themes was noted as part of the wider crackdown on content deemed to violate its community guidelines. Meta's content moderation policies, which were designed to combat harmful speech and protect users from discrimination, inadvertently led to the removal or restriction of LGBTQ+ content, particularly posts highlighting LGBTQ+ identities, support, or political issues. According to reports, LGBTQ+ posts, including those that simply celebrated pride or advocated for LGBTQ+ rights, were flagged and removed for reasons that some critics argue were vague or inconsistently applied. Many LGBTQ+ activists and users on Meta's platforms expressed concern that such actions stifled visibility and expression, potentially isolating LGBTQ+ individuals and communities, especially in spaces that were historically important for outreach and support. Lawsuits Numerous lawsuits have been filed against the company, both when it was known as Facebook, Inc., and as Meta Platforms. In March 2020, the Office of the Australian Information Commissioner (OAIC) sued Facebook, for significant and persistent infringements of the rule on privacy involving the Cambridge Analytica fiasco. Every violation of the Privacy Act is subject to a theoretical cumulative liability of $1.7 million. The OAIC estimated that a total of 311,127 Australians had been exposed. On December 8, 2020, the U.S. Federal Trade Commission and 46 states (excluding Alabama, Georgia, South Carolina, and South Dakota), the District of Columbia and the territory of Guam, launched Federal Trade Commission v. Facebook as an antitrust lawsuit against Facebook. The lawsuit concerns Facebook's acquisition of two competitors—Instagram and WhatsApp—and the ensuing monopolistic situation. FTC alleges that Facebook holds monopolistic power in the U.S. social networking market and seeks to force the company to divest from Instagram and WhatsApp to break up the conglomerate. William Kovacic, a former chairman of the Federal Trade Commission, argued the case will be difficult to win as it would require the government to create a counterfactual argument of an internet where the Facebook-WhatsApp-Instagram entity did not exist, and prove that harmed competition or consumers. In November 2025, it was ruled that Meta did not violate antitrust laws and holds no monopoly in the market. On December 24, 2021, a court in Russia fined Meta for $27 million after the company declined to remove unspecified banned content. The fine was reportedly tied to the company's annual revenue in the country. In May 2022, a lawsuit was filed in Kenya against Meta and its local outsourcing company Sama. Allegedly, Meta has poor working conditions in Kenya for workers moderating Facebook posts. According to the lawsuit, 260 screeners were declared redundant with confusing reasoning. The lawsuit seeks financial compensation and an order that outsourced moderators be given the same health benefits and pay scale as Meta employees. In June 2022, 8 lawsuits were filed across the U.S. over the allege that excessive exposure to platforms including Facebook and Instagram has led to attempted or actual suicides, eating disorders and sleeplessness, among other issues. The litigation follows a former Facebook employee's testimony in Congress that the company refused to take responsibility. The company noted that tools have been developed for parents to keep track of their children's activity on Instagram and set time limits, in addition to Meta's "Take a break" reminders. In addition, the company is providing resources specific to eating disorders as well as developing AI to prevent children under the age of 13 signing up for Facebook or Instagram. In June 2022, Meta settled a lawsuit with the US Department of Justice. The lawsuit, which was filed in 2019, alleged that the company enabled housing discrimination through targeted advertising, as it allowed homeowners and landlords to run housing ads excluding people based on sex, race, religion, and other characteristics. The U.S. Department of Justice stated that this was in violation of the Fair Housing Act. Meta was handed a penalty of $115,054 and given until December 31, 2022, to shadow the algorithm tool. In January 2023, Meta was fined €390 million for violations of the European Union General Data Protection Regulation. In May 2023, the European Data Protection Board fined Meta a record €1.2 billion for breaching European Union data privacy laws by transferring personal data of Facebook users to servers in the U.S. In July 2024, Meta agreed to pay the state of Texas US$1.4 billion to settle a lawsuit brought by Texas Attorney General Ken Paxton accusing the company of collecting users' biometric data without consent, setting a record for the largest privacy-related settlement ever obtained by a state attorney general. In October 2024, Meta Platforms faced lawsuits in Japan from 30 plaintiffs who claimed they were defrauded by fake investment ads on Facebook and Instagram, featuring false celebrity endorsements. The plaintiffs are seeking approximately $2.8 million in damages. In April 2025, the Kenyan High Court ruled that a US$2.4 billion lawsuit in which three plaintiffs claim that Facebook inflamed civil violence in Ethiopia in 2021 could proceed. In April 2025, Meta was fined €200 million ($230 million) for breaking the Digital Markets Act, by imposing a “consent or pay” system that forces users to either allow their personal data to be used to target advertisements, or pay a subscription fee for advertising-free versions of Facebook and Instagram. In late April 2025, a case was filed against Meta in Ghana over the alleged psychological distress experienced by content moderators employed to take down disturbing social media content including depictions of murders, extreme violence and child sexual abuse. Meta moved the moderation service to the Ghanaian capital of Accra after legal issues in the previous location Kenya. The new moderation company is Teleperformance, a multinational corporation with a history of worker's rights violation. Reports suggests the conditions are worse here than in the previous Kenyan location, with many workers afraid of speaking out due to fear of returning to conflict zones. Workers reported developing mental illnesses, attempted suicides, and low pay. In 26 January 2026, a New Mexico state court case was filed, suggesting that Mark Zuckerberg approved allowing minors to access artificial intelligence chatbot companions that safety staffers warned were capable of sexual interactions. In 2020, the company UReputation, which had been involved in several cases concerning the management of digital armies[clarification needed], filed a lawsuit against Facebook, accusing it of unlawfully transmitting personal data to third parties. Legal actions were initiated in Tunisia, France, and the United States. In 2025, the United States District court for the Northern District of Georgia approved a discovery procedure, allowing UReputation to access documents and evidence held by Meta. Structure Meta's key management consists of: As of October 2022[update], Meta had 83,553 employees worldwide. As of June 2024[update], Meta's board consisted of the following directors; Meta Platforms is mainly owned by institutional investors, who hold around 80% of all shares. Insiders control the majority of voting shares. The three largest individual investors in 2024 were Mark Zuckerberg, Sheryl Sandberg and Christopher K. Cox. The largest shareholders in late 2024/early 2025 were: Roger McNamee, an early Facebook investor and Zuckerberg's former mentor, said Facebook had "the most centralized decision-making structure I have ever encountered in a large company". Facebook co-founder Chris Hughes has stated that chief executive officer Mark Zuckerberg has too much power, that the company is now a monopoly, and that, as a result, it should be split into multiple smaller companies. In an op-ed in The New York Times, Hughes said he was concerned that Zuckerberg had surrounded himself with a team that did not challenge him, and that it is the U.S. government's job to hold him accountable and curb his "unchecked power". He also said that "Mark's power is unprecedented and un-American." Several U.S. politicians agreed with Hughes. European Union Commissioner for Competition Margrethe Vestager stated that splitting Facebook should be done only as "a remedy of the very last resort", and that it would not solve Facebook's underlying problems. Revenue Facebook ranked No. 34 in the 2020 Fortune 500 list of the largest United States corporations by revenue, with almost $86 billion in revenue most of it coming from advertising. One analysis of 2017 data determined that the company earned US$20.21 per user from advertising. According to New York, since its rebranding, Meta has reportedly lost $500 billion as a result of new privacy measures put in place by companies such as Apple and Google which prevents Meta from gathering users' data. In February 2015, Facebook announced it had reached two million active advertisers, with most of the gain coming from small businesses. An active advertiser was defined as an entity that had advertised on the Facebook platform in the last 28 days. In March 2016, Facebook announced it had reached three million active advertisers with more than 70% from outside the United States. Prices for advertising follow a variable pricing model based on auctioning ad placements, and potential engagement levels of the advertisement itself. Similar to other online advertising platforms like Google and Twitter, targeting of advertisements is one of the chief merits of digital advertising compared to traditional media. Marketing on Meta is employed through two methods based on the viewing habits, likes and shares, and purchasing data of the audience, namely targeted audiences and "look alike" audiences. The U.S. IRS challenged the valuation Facebook used when it transferred IP from the U.S. to Facebook Ireland (now Meta Platforms Ireland) in 2010 (which Facebook Ireland then revalued higher before charging out), as it was building its double Irish tax structure. The case is ongoing and Meta faces a potential fine of $3–5bn. The U.S. Tax Cuts and Jobs Act of 2017 changed Facebook's global tax calculations. Meta Platforms Ireland is subject to the U.S. GILTI tax of 10.5% on global intangible profits (i.e. Irish profits). On the basis that Meta Platforms Ireland Limited is paying some tax, the effective minimum US tax for Facebook Ireland will be circa 11%. In contrast, Meta Platforms Inc. would incur a special IP tax rate of 13.125% (the FDII rate) if its Irish business relocated to the U.S. Tax relief in the U.S. (21% vs. Irish at the GILTI rate) and accelerated capital expensing, would make this effective U.S. rate around 12%. The insignificance of the U.S./Irish tax difference was demonstrated when Facebook moved 1.5bn non-EU accounts to the U.S. to limit exposure to GDPR. Facilities Users outside of the U.S. and Canada contract with Meta's Irish subsidiary, Meta Platforms Ireland Limited (formerly Facebook Ireland Limited), allowing Meta to avoid US taxes for all users in Europe, Asia, Australia, Africa and South America. Meta is making use of the Double Irish arrangement which allows it to pay 2–3% corporation tax on all international revenue. In 2010, Facebook opened its fourth office, in Hyderabad, India, which houses online advertising and developer support teams and provides support to users and advertisers. In India, Meta is registered as Facebook India Online Services Pvt Ltd. It also has offices or planned sites in Chittagong, Bangladesh; Dublin, Ireland; and Austin, Texas, among other cities. Facebook opened its London headquarters in 2017 in Fitzrovia in central London. Facebook opened an office in Cambridge, Massachusetts in 2018. The offices were initially home to the "Connectivity Lab", a group focused on bringing Internet access to those who do not have access to the Internet. In April 2019, Facebook opened its Taiwan headquarters in Taipei. In March 2022, Meta opened new regional headquarters in Dubai. In September 2023, it was reported that Meta had paid £149m to British Land to break the lease on Triton Square London office. Meta reportedly had another 18 years left on its lease on the site. As of 2023, Facebook operated 21 data centers. It committed to purchase 100% renewable energy and to reduce its greenhouse gas emissions 75% by 2020. Its data center technologies include Fabric Aggregator, a distributed network system that accommodates larger regions and varied traffic patterns. Reception US Representative Alexandria Ocasio-Cortez responded in a tweet to Zuckerberg's announcement about Meta, saying: "Meta as in 'we are a cancer to democracy metastasizing into a global surveillance and propaganda machine for boosting authoritarian regimes and destroying civil society ... for profit!'" Ex-Facebook employee Frances Haugen and whistleblower behind the Facebook Papers responded to the rebranding efforts by expressing doubts about the company's ability to improve while led by Mark Zuckerberg, and urged the chief executive officer to resign. In November 2021, a video published by Inspired by Iceland went viral, in which a Zuckerberg look-alike promoted the Icelandverse, a place of "enhanced actual reality without silly looking headsets". In a December 2021 interview, SpaceX and Tesla chief executive officer Elon Musk said he could not see a compelling use-case for the VR-driven metaverse, adding: "I don't see someone strapping a frigging screen to their face all day." In January 2022, Louise Eccles of The Sunday Times logged into the metaverse with the intention of making a video guide. She wrote: Initially, my experience with the Oculus went well. I attended work meetings as an avatar and tried an exercise class set in the streets of Paris. The headset enabled me to feel the thrill of carving down mountains on a snowboard and the adrenaline rush of climbing a mountain without ropes. Yet switching to the social apps, where you mingle with strangers also using VR headsets, it was at times predatory and vile. Eccles described being sexually harassed by another user, as well as "accents from all over the world, American, Indian, English, Australian, using racist, sexist, homophobic and transphobic language". She also encountered users as young as 7 years old on the platform, despite Oculus headsets being intended for users over 13. See also References External links 37°29′06″N 122°08′54″W / 37.48500°N 122.14833°W / 37.48500; -122.14833 |
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[SOURCE: https://en.wikipedia.org/wiki/Caphethra] | [TOKENS: 1697] |
Contents Horvat 'Ethri 31°38′58″N 34°58′19″E / 31.6494720°N 34.9720070°E / 31.6494720; 34.9720070 Horvat 'Ethri (Hebrew: חורבת עתרי, lit. 'Ruin of Ethri'; also spelled Hurvat Itri, Ethri, Atari), or Umm Suweid (Arabic for "mother of the buckthorns"), is an archaeological site situated in the Judean Lowlands in modern-day Israel. Excavations at the site have uncovered the remains of a partially restored Jewish village from the Second Temple period. The site features an ancient synagogue, wine presses, cisterns, mikvehs (ritual baths), stone ossuaries, and an underground hideout system. Damaged and temporarily abandoned during the First Jewish–Roman War, the village was ultimately and violently destroyed during the Bar Kokhba revolt, as evidenced by a destruction layer and a mass grave found in a mikveh, which contained the remains of fifteen individuals, including one showing signs of beheading, as well as broken tools and coins. The site is identified with Caphethra, a village on the Judaean Foothills mentioned by Josephus as destroyed during a campaign by units of the Legio V Macedonica in the area in 69 CE. Location The site sits upon an elevation of 406 metres (1,332 ft) above sea level. It is located southeast of Bet Shemesh, within the Adullam-France Park – c. 35 kilometers (22 mi) southwest of Jerusalem, 5 kilometers (3.1 mi) southeast of the Elah Valley and 8 kilometers (5.0 mi) northeast of Beth Guvrin. Excavations A rescue excavation was carried out at Hurvat Ethri in 1999–2000 on behalf of the Israel Antiquities Authority (IAA) following a long-running looting at the site. Its purpose was to uncover the ancient remains and make the site accessible to tourists. As early as 2004, excavations were conducted on the site by Amir Ganor and Sari Eliyahu. In 2016, an additional survey-excavation was made of the site by Eitan Klein, Amir Ganor, and G. Goldenberg on behalf of the IAA. History The site was first occupied during the late Persian period; artifacts of the period include Yehud coins, a coin minted in Babylon and two fakes of Athenian coins. Numerous remains from the Hellenistic period have been discovered at the site, including rooms incorporated into later buildings, cisterns, and underground quarries. Since the majority of the structures were dismantled or incorporated into later structures, it is difficult to determine the extent of the hamlet during this period. The size of the site during this time was greater than 7 dunams, according to coinage and the location of the rock-cut sections on the property. A few Hasmonean period prutahs as well as coins of Seleucid rulers Antiochus VII and Demetrius II struck at the Tyre mint are examples of artifacts from the time. The site's material culture suggests that its residents throughout the Hellenistic period were Jews, and some of the ritual baths that have been found there are most likely from this time period. During the early first century CE, large-scale development took place on the site. The village reached its peak size on the eve of the First Jewish-Roman War, when its built-up site encompassed around 10 dunams. Archaeological findings at the site reveal that its inhabitants had several sources of income, namely, a columbarium facility for breeding doves and producing fertilizer, and loom and spindle weights for spinning and weaving. However, its numerous wine presses suggest that the town's inhabitants were engaged in viniculture. During the First Jewish–Roman War (66-73 CE), the village suffered damage, had some of its structures demolished, and was momentarily abandoned. Of special interest were the discoveries of small coins from the 2nd and 3rd year of the revolt, particularly, a silver half-shekel coin from the 3rd year of the revolt, upon which are embossed the words "Half-Shekel" in the Paleo-Hebrew script (Hebrew: חצי השקל), and having a silver content of 6.87 grams, discovered in an area of the site known as "complex XIV," and a bronze coin with a date-palm tree and the inscription, "El'azar the Priest," on its obverse side, and a cluster of grapes with the inscription, "Year One of the Freedom of Israel," on its reverse side. Based on a potsherd found at the site bearing the name "Ethri", and the village's size on the eve of the revolt, it has been suggested that the site should be identified with Caphethra, a village on the Judaean Foothills mentioned by Josephus as destroyed during a campaign by units of the Legio V Macedonica in the area in 69 CE. Jews resettled the village between the two revolts; perhaps some of them were the original occupants who went back to their homes. They rebuilt some of the structures and modified them to meet their needs. The resettled village, which was half as big as the old one, was concentrated on the site's eastern side. A public structure, which may have served as a synagogue, was constructed next to the residential quarters. Before the Bar Kokhba revolt (132–136 CE), extensive underground complexes were constructed beneath the village's homes. During the revolt, locals used them as places to hide and store food and supplies. Before excavations began, one of the complexes had already been looted; the other, however, was discovered untouched and included a few remnants of the Bar Kokhba revolt, such as candles typical of the period and three bronze coins that the Bar Kokhba administration had re-minted. The settlement was brutally destroyed during the Bar Kokhba revolt, as evidenced by a destruction layer, the remains of which were discovered in the site's center. Around 15 people who were killed in the fighting were buried in a mass grave in one of the ritual baths. The bones were combined with ashes, burned wood pieces, bent glass, tools, and Trajan and Vespasian coinage. One of those buried there may have been beheaded with a sword, according to the cutting marks on his cervical vertebrae. The site stands out among other archaeological sites because of its formidable defensive walls, with massive stones, which led Boaz Zissu, to believe that it may have been one of the fifty strongholds in Judea destroyed by Hadrian during the Bar Kokhba revolt. Not long after 200 CE, a new population restored the structures on the site. This population may have been pagan or veterans of the Roman army who received lands close to Eleuthropolis that had just been re-founded. While this era lasted 150 years, there weren't many significant architectural changes. A 1st century underground room had a burial cave cut into it, including a few reliefs. The site was abandoned in the second part of the 4th century, and only shepherds and nomads continued to frequent it afterwards. According to Finnish scholar, Aapeli Saarisalo [fi], who visited the site in the earlier 20th-century, the village was settled as late as the Byzantine and Early Arab period. Name Formerly known in Arabic as Umm Suweid ("mother of the buckthorns"), the Modern Hebrew name of the site was only applied in March 2001 by the Israel Official Names Commission, after a team of IAA archaeologists discovered an ostracon bearing the name "Ethri," thought to be a reference to the a town described by Josephus and whom he names "Caphethra" – likely a Greek corruption of the Hebrew name Kfar Ethra, "Ethra Village". Gallery See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Chinese_astronomy] | [TOKENS: 7222] |
Contents Chinese astronomy Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty. The core of the "mansion" (宿 xiù) system also took shape around this period, by the time of King Wu Ding (1250–1192 BCE). Detailed records of astronomical observations began during the Warring States period (fourth century BCE). They flourished during the Han period (202 BCE – 220 CE) and subsequent dynasties with the publication of star catalogues. Chinese astronomy was equatorial, centered on close observation of circumpolar stars, and was based on different principles from those in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framework. Joseph Needham has described the ancient Chinese as the most persistent and accurate observers of celestial phenomena anywhere in the world before the Islamic astronomers. Some elements of Indian astronomy reached China with the expansion of Buddhism after the Eastern Han dynasty (25–220 CE), but most incorporation of Indian astronomical thought occurred during the Tang dynasty (618–907 CE), when numerous Indian astronomers took up residence in the Chinese capital Chang'an, and Chinese scholars, such as the Tantric Buddhist monk and mathematician Yi Xing, mastered the Indian system. Islamic astronomers collaborated closely with their Chinese colleagues during the Yuan dynasty, and, after a period of relative decline during the Ming dynasty, astronomy was revitalized under the stimulus of Western cosmology and technology after the Jesuits established their missions. The telescope was introduced from Europe in the seventeenth century. In 1669, the Peking observatory was completely redesigned and refitted under the direction of Ferdinand Verbiest. Today, China continues to be active in the field of astronomy, with many observatories and its own space program. Early history One of the main functions of astronomy was for the purpose of timekeeping. The Chinese used a lunisolar calendar, but as the cycles of the Sun and the Moon are different, leap months had to be inserted regularly. The Chinese calendar was considered to be a symbol of a dynasty. As dynasties would rise and fall, astronomers and astrologers of each period would often prepare a new calendar, making observations for that purpose. Astrological divination was also an important part of astronomy. Astronomers took note of "guest stars", usually supernovas or comets, which appear among the fixed stars. The supernova which created the Crab Nebula, now known as SN 1054, is an example of an astronomical event observed by Ancient Chinese astronomers. Ancient astronomical records of phenomena like comets and supernovae are sometimes used in modern astronomical studies. The Chinese developed multiple cosmological models before Western influences changed the field: Constellations The divisions of the sky began with the Northern Dipper and the 28 mansions. In 1977, a lacquer box was excavated from the Tomb of Marquis Yi of Zeng, in Suixian, Hubei Province. Names of the 28 lunar mansions were found on the cover of the box, proving that the use of this classification system was made before 433 BCE. As lunar mansions have such an ancient origin, the meanings of most of their names have become obscure. Contributing to later confusion, the name of each lunar mansion consists of only one Chinese word, the meaning of which could vary at different times in history. The meanings of the names are still under discussion. Besides the 28 lunar mansions, most constellations are based on the works of Shi Shen-fu and Gan De, who were astrologists during the period of the Warring States (481–221 BCE) in China. In his Shiji, the Western Han era historian Sima Qian (145–86 BCE) provided a star catalogue that includes 90 constellations. The Eastern Han era polymath scientist and inventor Zhang Heng (78–139 CE) published a star catalogue in 120 CE that features 124 recorded constellations. In the late period of the Ming dynasty, the agricultural scientist and mathematician Xu Guangqi (1562–1633 CE) introduced 23 additional constellations near to the Celestial South Pole, which are based on star catalogues from the Western world introduced by his colleague, the Italian Jesuit Matteo Ricci. Star catalogues and maps In the fourth century BCE, the two Chinese astronomers responsible for the earliest information going into the star catalogues were Shi Shen and Gan De of the Warring States period. These books appeared to have lasted until the sixth century, but were lost after that. A number of books share similar names, often quoted and named after them. These texts should not be confused with the original catalogues written by them. Notable works that helped preserve the contents include: Wu Xian (巫咸) has been one of the astronomers under debate. He is often represented as one of the "Three Schools Astronomical tradition", along with Gan and Shi. The Chinese classic text Star Manual of Master Wu Xian (巫咸星經) and its authorship is still in dispute, because it mentioned names of twelve countries that did not exist in the Shang dynasty, the era in which it was supposed to have been written. Moreover, it was customary in the past for the Chinese to forge works of notable scholars, as this could lead to a possible explanation for the inconsistencies found. Wu Xian is generally mentioned as the astronomer who lived many years before Gan and Shi. The Han dynasty astronomer and inventor Zhang Heng (78–139 CE) not only catalogued some 2500 different stars, but also recognized more than 100 different constellations. Zhang Heng also published his work Ling Xian, a summary of different astronomical theories in China at the time. In the subsequent period of the Three Kingdoms (220–280 CE), Chen Zhuo (陳卓) combined the work of his predecessors, forming another star catalogue. This time, 283 constellations and 1464 stars were listed. The astronomer Guo Shoujin of the Yuan dynasty (1279–1368 CE) created a new catalogue, which was believed to contain thousands of stars. Unfortunately, many of the documents of that period were destroyed, including that of Shoujin. Imperial Astronomical Instruments (儀象考成) was published in 1757 and contains 3083 stars exactly. The Chinese drew many maps of stars in the past centuries. It is debatable as to which counts as the oldest star maps, since pottery and old artifacts can also be considered star maps. One of the oldest existent star maps in printed form is from Su Song's (1020–1101 CE) celestial atlas of 1092 CE, which was included in the horological treatise on his clocktower. The most famous one is perhaps the Dunhuang map found in Dunhuang, Gansu. Uncovered by the British archaeologist Marc Aurel Stein in 1907, the star map was brought to the British Museum in London. The map was drawn on paper and represents the complete sky, with more than 1,350 stars. Although ancient Babylonians and Greeks also observed the sky and catalogued stars, no such complete record of the stars may exist or survive. Hence, this is the oldest chart of the skies at present. According to recent studies, the map may date the manuscript to as early as the seventh century CE (Tang dynasty). Scholars believe the star map dates from 705 to 710 CE, which is the reign of Emperor Zhongzong of Tang. There are some texts (Monthly Ordinances, 月令) describing the movement of the sun along the sky each month, which was not based on the observation at that time. Solar and lunar eclipses Chinese astronomers recorded 1,600 observations of solar and lunar eclipses from 750 BCE. The ancient Chinese astronomer Shi Shen (fl. fourth century BCE) was aware of the relation of the Moon in a solar eclipse, as he provided instructions in his writing to predict them by using the relative positions of the Moon and the Sun. The radiating-influence theory, where the Moon's light was nothing but a reflection of the Sun's, was supported by the mathematician and music theorist Jing Fang (78–37 BCE), yet opposed by the Chinese philosopher Wang Chong (27–97 CE), who made clear in his writing that this theory was nothing new. Jing Fang wrote: The moon and the planets are Yin; they have shape but no light. This they receive only when the sun illuminates them. The former masters regarded the sun as round like a crossbow bullet, and they thought the moon had the nature of a mirror. Some of them recognized the moon as a ball too. Those parts of the moon which the sun illuminates look bright, those parts which it does not, remain dark. The ancient Greeks had known this as well, since Parmenides and Aristotle supported the theory of the Moon shining because of reflected light. The Chinese astronomer and inventor Zhang Heng (78–139 CE) wrote of both solar eclipse and lunar eclipse in the publication of Ling Xian (靈憲), 120 CE: The sun is like fire and the moon like water. The fire gives out light and the water reflects it. Thus, the moon's brightness is produced from the radiance of the sun, and the moon's darkness (pho) is due to (the light of) the sun being obstructed (pi). The side which faces the sun is fully lit, and the side which is away from it is dark. The planets (as well as the moon) have the nature of water and reflect light. The light pouring forth from the sun (tang jih chih chhung kuang) does not always reach the moon, owing to the obstruction (pi) of the earth itself—this is called 'an-hsü', a lunar eclipse. When (a similar effect) happens with a planet (we call it) an occultation (hsing wei); when the moon passes across (kuo) (the sun's path) then there is a solar eclipse (shih). The later Song dynasty scientist Shen Kuo (1031–1095 CE) used the models of lunar eclipse and solar eclipse in order to prove that the celestial bodies were round, not flat. This was an extension of the reasoning of Jing Fang and other theorists as early as the Han dynasty. In his Dream Pool Essays of 1088 CE, Shen related a conversation he had with the director of the Astronomical Observatory, who had asked Shen if the shapes of the Sun and the Moon were round like balls or flat like fans. Shen Kuo explained his reasoning for the former: If they were like balls they would surely obstruct each other when they met. I replied that these celestial bodies were certainly like balls. How do we know this? By the waxing and waning of the moon. The moon itself gives forth no light, but is like a ball of silver; the light is the light of the sun (reflected). When the brightness is first seen, the sun (-light passes almost) alongside, so the side only is illuminated and looks like a crescent. When the sun gradually gets further away, the light shines slanting, and the moon is full, round like a bullet. If half of a sphere is covered with (white) powder and looked at from the side, the covered part will look like a crescent; if looked at from the front, it will appear round. Thus we know that the celestial bodies are spherical. When he asked Shen Kuo why eclipses occurred only on an occasional basis while in conjunction and opposition once a month, Shen Kuo wrote: I answered that the ecliptic and the moon's path are like two rings, lying one over the other, but distant by a small amount. (If this obliquity did not exist), the sun would be eclipsed whenever the two bodies were in conjunction, and the moon would be eclipsed whenever they were exactly in opposition. But (in fact) though they may occupy the same degree, the two paths are not (always) near (each other), and so naturally, the bodies do not (intrude) upon one another. Equipment and innovation The earliest development of the armillary sphere in China goes back to the 1st century BCE, as they were equipped with a primitive single-ring armillary instrument. This would have allowed them to measure the north polar distance (去極度, the Chinese form of declination) and measurement that gave the position in a hsiu (入宿度, the Chinese form of right ascension). During the Western Han dynasty (202 BCE–9 CE), additional developments made by the astronomers Luoxia Hong (落下閎), Xianyu Wangren (鮮于妄人), and Geng Shouchang (耿壽昌) advanced the use of the armillary in its early stage of evolution. In 52 BCE, it was the astronomer Geng Shou-chang who introduced the fixed equatorial ring to the armillary sphere. In the subsequent Eastern Han dynasty (23–220 CE) period, the astronomers Fu An and Jia Kui added the elliptical ring by 84 CE. With the famous statesman, astronomer, and inventor Zhang Heng (78–139 CE), the sphere was totally completed in 125 CE, with horizon and meridian rings. The world's first hydraulic (i.e., water-powered) armillary sphere was created by Zhang Heng, who operated his by use of an inflow clepsydra clock (see Zhang's article for more detail). Designed by famous astronomer Guo Shoujing in 1276 CE, it solved most problems found in armillary spheres at that time. The primary structure of abridged armilla contains two large rings that are perpendicular to each other, of which one is parallel with the equatorial plane and is accordingly called "equatorial ring", and the other is a double ring that is perpendicular to the center of the equatorial ring, revolving around a metallic shaft, and is called "right ascension double ring". The double ring holds within itself a sighting tube with crosshairs. When observing, astronomers would aim at the star with the sighting tube, whereupon the star's position could be deciphered by observing the dials of the equatorial ring and the right ascension double ring. A foreign missionary melted the instrument in 1715 CE. The surviving one was built in 1437 CE and was taken to what is now Germany. It was then stored in a French Embassy in 1900, during the Eight-Nation Alliance. Under the pressure of international public discontent, Germany returned the instrument to China. In 1933, it was placed in Purple Mountain Observatory, which prevented it from being destroyed in the Japanese invasion of China. In the 1980s, it had become seriously eroded and rusted down and was nearly destroyed. In order to restore the device, the Nanjing government spent 11 months to repair it. Besides star maps, the Chinese also made celestial globes, which show stars' positions like a star map and can present the sky at a specific time. Because of its Chinese name, it is often confused with the armillary sphere, which is just one word different in Chinese (渾象 vs. 渾儀). According to records, the first celestial globe was made by Geng Shou-chang (耿壽昌) between 70 BCE and 50 BCE. In the Ming dynasty, the celestial globe at that time was a huge globe, showing the 28 mansions, celestial equator, and ecliptic. None of them have survived. Celestial globes were named 天體儀 ("Miriam celestial bodies") in the Qing dynasty. The one in Beijing Ancient Observatory was made by Belgian missionary Ferdinand Verbiest (南懷仁) in 1673 CE. Unlike other Chinese celestial globes, it employs 360 degrees rather than the 365.24 degrees (which is a standard in ancient China). It is also the first Chinese globe that shows constellations near to the Celestial South Pole. The inventor of the hydraulic-powered armillary sphere was Zhang Heng (78–139 CE) of the Han dynasty. Zhang was well-known for his brilliant applications of mechanical gears, as this was one of his most impressive inventions (alongside his seismograph to detect the cardinal direction of earthquakes that struck hundreds of miles away). Started by Su Song (蘇頌) and his colleagues in 1086 CE and finished in 1092 CE, his large astronomical clock tower featured an armillary sphere (渾儀), a celestial globe (渾象), and a mechanical chronograph. It was operated by an escapement mechanism and the earliest known chain drive. However, 35 years later, the invading Jurchen army dismantled the tower in 1127 CE upon taking the capital of Kaifeng. The armillary sphere part was brought to Beijing, yet the tower was never successfully reinstated, not even by Su Song's son. Fortunately, two versions of Su Song's treatise, written on his clock tower, have survived the ages, so that studying his astronomical clock tower is made possible through medieval texts. The polymath Chinese scientist Shen Kuo (1031–1095 CE) was not only the first in history to describe the magnetic-needle compass, but also made a more accurate measurement of the distance between the pole star and true north that could be used for navigation. Shen achieved this by making nightly astronomical observations, along with his colleague Wei Pu, using Shen's improved design of a wider sighting tube that could be fixed to observe the pole star indefinitely. Along with the pole star, Shen Kuo and Wei Pu also established a project of nightly astronomical observation over a period of five successive years, an intensive work that would even rival the later work of Tycho Brahe in Europe. Shen Kuo and Wei Pu charted the exact coordinates of the planets on a star map for this project and created theories of planetary motion, including retrograde motion. Foreign influences Buddhism first reached China during the Eastern Han dynasty, and translation of Indian works on astronomy came to China by the Three Kingdoms era (220–265 CE). However, the most detailed incorporation of Indian astronomy occurred only during the Tang dynasty (618–907), when a number of Chinese scholars—such as Yi Xing—were versed in both types of astronomy. A system of Indian astronomy was recorded in China as Jiuzhi-li (718 CE), the author of which was an Indian by the name of Qutan Xida. The astronomical table of sines by the Indian astronomer and mathematician Aryabhata was translated into the Chinese astronomical and mathematical book Treatise on Astrology of the Kaiyuan Era (Kaiyuan Zhanjing), compiled in 718 CE, during the Tang dynasty. The Kaiyuan Zhanjing was compiled by Gautama Siddha, an astronomer and astrologer born in Chang'an, and whose family was originally from India. He was also notable for his translation of the Navagraha calendar into Chinese. The Chinese translations of the following works are mentioned in the Sui Shu, or Official History of the Sui dynasty (seventh century): Although these translations are lost, they were also mentioned in other sources. Islamic influence on Chinese astronomy was first recorded during the Song dynasty, when a Hui Muslim astronomer named Ma Yize introduced the concept of 7 days in a week and made other contributions. Islamic astronomers were brought to China in order to work on calendar-making and astronomy during the Mongol Empire and the succeeding Yuan dynasty. The Chinese scholar Yelü Chucai accompanied Genghis Khan to Persia in 1210 and studied their calendar for use in the Mongol Empire. Kublai Khan brought Iranians to Beijing to construct an observatory and an institution for astronomical studies. Several Chinese astronomers worked at the Maragheh observatory, founded by Nasir al-Din al-Tusi in 1259 under the patronage of Hulagu Khan in Persia. One of these Chinese astronomers was Fu Mengchi, or Fu Mezhai. In 1267, the Persian astronomer Jamal ad-Din, who previously worked at Maragha observatory, presented Kublai Khan with seven Persian astronomical instruments, including a terrestrial globe and an armillary sphere, as well as an astronomical almanac, which was later known in China as the Wannian Li ("Ten Thousand Year Calendar" or "Eternal Calendar"). He was known as "Zhama Luding" in China, where, in 1271, he was appointed by the Khan as the first director of the Islamic observatory in Beijing, known as the Islamic Astronomical Bureau, which operated alongside the Chinese Astronomical Bureau for four centuries. Islamic astronomy gained a good reputation in China for its theory of planetary latitudes, which did not exist in Chinese astronomy at the time, and for its accurate prediction of eclipses. Some of the astronomical instruments constructed by the famous Chinese astronomer Guo Shoujing shortly afterwards resemble the style of instrumentation built at Maragheh. In particular, the "simplified instrument" (jianyi) and the large gnomon at the Gaocheng Astronomical Observatory show traces of Islamic influence. While formulating the Shoushili calendar in 1281, Shoujing's work in spherical trigonometry may have also been partially influenced by Islamic mathematics, which was largely accepted at Kublai's court. These possible influences include a pseudo-geometrical method for converting between equatorial and ecliptic coordinates, the systematic use of decimals in the underlying parameters, and the application of cubic interpolation in the calculation of the irregularity in the planetary motions. Emperor Taizu (r. 1368–1398) of the Ming dynasty (1328–1398), in the first year of his reign (1368), conscripted Han and non-Han astrology specialists from the astronomical institutions in Beijing of the former Mongolian Yuan to Nanjing to become officials of the newly established national observatory. That year, the Ming government summoned, for the first time, the astronomical officials to come south from the upper capital of Yuan. There were fourteen of them. In order to enhance accuracy in methods of observation and computation, Emperor Taizu reinforced the adoption of parallel calendar systems, the Han and the Hui. In the following years, the Ming Court appointed several Hui astrologers to hold high positions in the Imperial Observatory. They wrote many books on Islamic astronomy and also manufactured astronomical equipment based on the Islamic system. The translation of two important works into Chinese was completed in 1383: Zij (1366) and al-Madkhal fi Sina'at Ahkam al-Nujum, Introduction to Astrology (1004). In 1384, a Chinese astrolabe was made for observing stars based on the instructions for making multi-purposed Islamic equipment. In 1385, the apparatus was installed on a hill in northern Nanjing. Around 1384, during the Ming dynasty, Emperor Zhu Yuanzhang ordered the Chinese translation and compilation of Islamic astronomical tables, a task that was carried out by the scholars Mashayihei, a Muslim astronomer, and Wu Bozong, a Chinese scholar-official. These tables came to be known as the Huihui Lifa (Muslim System of Calendrical Astronomy), which was published in China a number of times until the early 18th century, though the Qing dynasty had officially abandoned the tradition of Chinese-Islamic astronomy in 1659. The Muslim astronomer Yang Guangxian was known for his attacks on the Jesuit's astronomical sciences. Early-modern European science was introduced into China by Jesuit priest astronomers as part of their missionary efforts, in the late sixteenth century and early seventeenth century. The telescope was introduced to China in the early seventeenth century. The telescope was first mentioned in Chinese writing by Manuel Dias the Younger (Yang Manuo), who wrote his Tian Wen Lüe in 1615. In 1626, Johann Adam Schall von Bell (Tang Ruowang) published the Chinese treatise on the telescope known as the Yuan Jing Shuo (The Far-Seeing Optic Glass). The Chongzhen Emperor (r 1627–1644) of the Ming dynasty acquired the telescope of Johannes Terrentius (or Johann Schreck; Deng Yu-han) in 1634, ten years before the collapse of the Ming dynasty. However, the impact on Chinese astronomy was limited. The Jesuit China missions of the sixteenth and seventeenth centuries brought Western astronomy, then undergoing its own revolution, to China and—via João Rodrigues's gifts to Jeong Duwon—to Joseon Korea. After the Galileo affair early in the seventeenth century, the Roman Catholic Jesuit order was required to adhere to geocentrism and ignore the heliocentric teachings of Copernicus and his followers, even though they were becoming standard in European astronomy. Thus, the Jesuits initially shared an Earth-centered and largely pre-Copernican astronomy with their Chinese hosts (i.e., the Ptolemaic-Aristotelian views from Hellenistic times). The Jesuits (such as Giacomo Rho) later introduced Tycho's geoheliocentric model as the standard cosmological model. The Chinese often were fundamentally opposed to this as well, since the Chinese had long believed (from the ancient doctrine of Xuan Ye) that the celestial bodies floated in a void of infinite space. This contradicted the Aristotelian view of solid concentric crystalline spheres, where there was not a void, but a mass of air between the heavenly bodies. Of course, the views of Copernicus, Galileo, and Tycho Brahe would eventually triumph in European science, and these ideas slowly leaked into China despite Jesuit efforts to curb them in the beginning. In 1627, the Polish Jesuit Michael Boym (Bu Mige) introduced Johannes Kepler's Copernican Rudolphine Tables, with much enthusiasm, to the Ming court at Beijing. In Adam Schall von Bell's Chinese-written treatise of Western astronomy in 1640, the names of Copernicus (Ge-Bai-Ni), Galileo (Jia-li-lüe), and Tycho Brahe (Di-gu) were formally introduced to China. There were also Jesuits in China who were in favor of the Copernican theory, such as Nicholas Smogulecki and Wenceslaus Kirwitzer. However, Copernican views were not widespread or wholly accepted in China during this time. Ferdinand Augustin Hallerstein (Liu Songling) created the first spherical astrolabe as the Head of the Imperial Astronomical Bureau from 1739 until 1774. The former Beijing Astronomical observatory, now a museum, still hosts the armillary sphere with rotating rings, which was made under Hallerstein's leadership, and is considered the most prominent astronomical instrument. While in Edo Japan, the Dutch aided the Japanese with the first modern observatory of Japan in 1725, headed by Nakane Genkei, whose observatory of astronomers wholly accepted the Copernican view. In contrast, the Copernican view was not accepted in mainstream China until the early nineteenth century, with the Protestant missionaries such as Joseph Edkins, Alex Wylie, and John Fryer. Astronomy during Ming China The Ming dynasty in China lasted from 1368 until 1644 and experienced a decrease in astronomical expansion. The occupation of astronomer during these times relied less on discovery and more on the use of astronomy. Astronomers worked in the two Astronomical Bureaus, both of which underwent many changes throughout the years since their formation. The path into the occupation was hereditary; because of the rigidity and high level of intelligence needed for this occupation, children of astronomers were banned from pursuing other professions. When transitioning into the Ming dynasty, the two largest institutions of astronomy were the Traditional Chinese Astronomical Bureau (also named T’ai-shih-chien), which had been established in the third century BC, and the Muslim Astronomical Bureau (also named Hui-hui ssu-t’ien-chien), which had been previously established by the Mongols. Both sectors worked together, until the Muslim Bureau was absorbed in 1370 by the Traditional Chinese Bureau. When the merge occurred, the overall name of the new bureau became Ch’in-t’ien-chien. To accommodate the influx of new workers, the ranking system within the occupation also transitioned. There became one Director, supported by two Deputy Directors, followed by a Registrar with four seasonal Chiefs. Then came eight Chief Astronomers, five Chief Diviners, two Chiefs of the Clepsydras, and three Observers. Following that was two Calendar Officials, eight Observers of Sunrise, and six Professors of the Clepsydra. Some of the roles astronomers played in Ming China were to make calendars, report abnormalities to the emperor, and preside over ceremonies. As calendar makers and people who understand the heavens, the Bureau also decided what days were auspicious and good for different events such as military parades, marriage, construction, and more. The astronomers also used astronomy to predict invasions or dangerous moments within the empire. However, records indicate that the majority of work the Astronomical Bureaus did was simply recording the movements of the stars and planets. In regards to the specific jobs each position does, the Chief Officials of the Five Agencies would fix the calendar and the time of the seasons, along with the Calendar Officials and Astronomers. However, the Chief Astronomer observes the positions of the sun, moon, and planets to make notes regarding what might be an abnormality. The Chief Diviner specializes in analyzing the astronomical abnormalities. The Chief Clepsydra Officer looks after the CLepsydra, along with the Clepsydra professor, who then tell the Sunrise Announcer when sunrise and sunset would occur. The Astronomical Bureaus worked closely with The Ministry of Rites. The bureau submitted monthly ordinances, planetary and celestial locations, and seasonal accounts within the calendar to the Ministry. The Ministry also helped train children of astronomers for their future jobs and helped select outsiders in certain cases, but not specifying from where they draw these candidates. The Bureaus were also in close contact with the Emperor, and he often read the reports sent by the Bureau to the Ministry. Because becoming an astronomer was a hereditary profession, and those that are employed by the Bureau are not transferable to other occupations, students were trained very young by the Ministry of Rites. However, when there was a shortage of workers in the Bureau, the Ministry of Rites would scout suitable students and train them on a trial basis. Calendrical recordings greatly attracted Confucian scholars, which widened interest into this subject, and thus, into astronomy and divination. Confucian students' deep need for knowledge and practicality made these tasks appeal to academics. Astronomy was attractive because it blended the physical world with larger implications. However, astronomy was considered part of the "small dao", a title used to attempt to discourage Confucian scholars from studying subjects that, while interesting at first, could eventually bog them down. Within the Bureau, payment was decided upon by rank. As established in the year 1392, the top rank of Director was paid sixteen piculs of rice per month. The Deputy Directors and Chiefs of the Five Agencies were allotted ten piculs per month, the Astronomers received seven piculs, while both the Registrars and Chief Diviners had six-and-a-half piculs. The Chiefs of the Clepsydras received six piculs, and the Calendar Officers and Observers both had five-and-a-half piculs. The lowest payment level went to the Observers of the Sunrise and the Professors of the Clepsydras, at five piculs per month. The memorial was used by astronomers as a record keeper of anomalies, as the heavens are demonstrative of the effect of the ruler's actions. Originally, authors signed each contribution individually but that was eventually replaced by the official seal of the astronomical bureau. The imperial observatory was a platform where the observations were made. It was first located just south of Nanjing, but later moved to Jiming Mountain city. However, in 1402 there was another platform created in the capital of Beijing. The armillary sphere has three sets of rings that represent the celestial sphere. The first group contains fixed meridian, horizon, and equatorial rings. The second group contains ecliptic, solstitial, and equinoctial rings that turn as a unit. The inner group contains one meridian ring that moves around the celestial pole. These allow the astronomer to set a celestial object within their sights and judge distance. The simplified instrument serves a very similar purpose to the armillary sphere but has fewer parts. With only two sets of coordinates, this instrument has a larger range and vision than the armillary spheres. The Yuan Gnomon is a shadow casting instrument used to measure the position of the sun. However, it does not appear to be very accurate. A crucial aspect of this mechanism was that it was oriented along the north–south meridian line, which allowed it to show the local noon. While not included in the 1392 list of official instruments, in 1437 Huangfu Zhonghe included it, likely due less to its practicality and more to the ingenuity behind it. The clepsydra, or water clock, was the most prevalent of time-keeping devices for astronomers. The clepsydra was also used as the official state time-keeping device. The Astronomical Bureau used a three-chamber-intake clepsydra, although there is no record of a water clock at Nanjing. It was not until the Bureau moved to Beijing that an official water hall was observed. Because of the ideological importance of astronomy regarding politics, and the lack of precision by the instruments, many people believed the observations were false. Other recorded corruption, such as accepting bribery, stealing, and not being punctual, were also experienced. This led to a strict policy of punishment if the astronomers were found to be corrupt. Punishments included such actions as dismissal, deprivation of salary, or even beatings. Famous Chinese astronomers Observatory See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Wild_man] | [TOKENS: 11538] |
Contents Wild man The wild man (German: Wilder Mann, der Wilde Mann), wild man of the woods is a mythical figure and motif resembling a hairy human that appears in the art and literature of medieval Europe. Generally they are considered a large-statured race of humans who are hairy all over their body, and live in the wilderness or woodlands. They are often thought to be covered with moss, or wear green or vegetative clothing, and iconically wield a club or hold an uprooted tree as a staff. They also occur in female versions as wild women. The Wilde Mann (Middle High German: wilde man) is attested in Middle High German literature, particularly German heroic epics,[a] while the female Wilde Weib (wildez wîp) figures in the Arthurian works,[b] typically appear as adversaries. These beings are also called by names meaning "wood men"[c] and in older forms of the language, "wood maiden",[d] "wood wife",[e] or "wood woman".[f] In Middle English a corresponding term for the wild man is woodwose or wodewose. In the folklore of German-speaking areas collected mainly in the 19th century, there are especially the Alpine wild men and wild women. These beings could be man-hunters or otherwise be sinister, but could also endow luck or bounty, exhibiting aspects of woodland spirits. The folklore that had developed in the mining areas around Harz or Ore Mountains by the 16th century regarded the wild man of the mines (also known as "mountain monk"[g]) as potentially both dangerous and beneficent, guiding humans to the discovery of ore deposits. The house of the Princes of Brunswick-Wolfenbüttel (Brunswick-Lüneburg), which controlled one of the silver mines, minted silver thaler ('dollar') coinage with the wild man in their coat-of-arms, starting 1539. These wild man had already frequently appeared in European family heraldic devices since the latter half of the 15th century.[h] It also became commonplace to depict the wild man as shield-bearers of the family coat of arms (e.g., within a portrait painting by Albrecht Dürer, cf. image right).[i] This period also roughly coincides with the popularization of the concept of the "noble wild man" or "noble savage" as can already be seen in Hans Sachs's "Lament of the Wild Men" (1530), and also reflected in artistic depictions of the wild folk from this period onward. The defining characteristic of the figure is its "wildness"; iconography from the 12th century onward has consistently depicted the wild man as being covered with hair. Around the same transition period, biblical[j] or other humans afflicted with madness came to be conventionally depicted with hairiness, and subsequently, literary figures who temporarily loses sanity and live in the wild (Merlin, Ywain) also came to be associated with wild men. Terminology "Wild man" is a technical term in use since the Middle Ages, applied to a hairy human-like creature with certain animal-like traits but which has not quite descended to the level of ape; it may have hairless spots around the face, palms, feet, sometimes elbows and knees, and around the breasts in case of the female "wild woman". If the creature exhibits additional animal-like traits, it may not be a wild man in question, but rather the satyr, faun, or the devil (Bernheimer's definition). "Wild man" and its cognates in some languages are the common terms for the creature in most modern languages; it appears in German as wilder Mann, in French as homme sauvage. However, in Italian, uomo selvatico ("forest man") is often used. The German wild man (Der Wilde) also occurs in a more modern folklore tradition, localized in a region spanning from Switzerland to Carinthia, Austria (and often Hesse in Germany) according to the Handwörterbuch des deutschen Aberglaubens [de] (HdA), registered under such names as wilde Frau, Wildfrau, -en, wilde Fraulein, Wildfräulein wilder Mann, Wildmannli, wilde Männle, Wildmännlein. Plural forms are: wilde Männer, or wilde Leute or wilde Menschen. Females are also called wildes Weib (pl. wilde Weiber). The "wild man" is attested in Middle High German as wilde man in the 13th century, once in a lyrical poem[k] alluding to the story of the giant Sigenot, i.e., an epic featuring both giant and wild man, from the Dietrich von Bern cycle.[l] Another attestation occurs in the Arthurian romance Wigamur [de] which gives wilde man (v. 203), as well as the female form wildez wîp (vv. 112, 200, 227ff.) (For additional examples in MHG literature cf. § German epics below). In Old High German, the term wildaz wîp (lit. 'wild wife, wild woman') together with holzmuoja, holzmoia (lit. 'wood maiden')[m] occurs in a glossary under the heading of the Latin term lamia (female monster).[n] The same glossary under the heading of Latin ulula (lit. 'screech owl' but here understood to be equivalent to strix of mythology) gives the gloss wildiu wîp.[o] There are also the forms holzwib (holzwîb),[p][q] as well as holzvrouwe and numerous others. Another old example is the mention of "ad domum wildero wîbo" ("house of the wild women"), a piece of landmark or toponymy somewhere in Hessen, mentioned in Codex Eberhardi [de] (c. 1150) by the monk Eberhard of Fulda or a redaction given by Johann Pistorius the Younger (d. 1608).[r] The wild man is referred to as waltluoder in Wolfdietrich,[s] and in the same work, the title hero must deal with the advances of Rauhe Else [de] ("Shaggy Else"), classified as a wild woman (cf. § German epic below). In the epic Laurin the wild man is referred to as a waltmann (lit. 'wood man'). The same term waltman is used in Iwein to characterize the herdsman as a wild man, and he is also described as being as hairy as a walttôren (lit. 'wood fool') (Cf. Iwein discussed below under § Medieval iconography). A group of OHG glosses for wild woman (lamia, etc.) was already discussed above. In MHG, an attested synonym for wild woman is holz-wîp (lit. 'wood wife'). In modern regional folklore, the creatures with sylvan (wood-related) names that correspond to the Alpine wild folk are the Holzleute or Moosleute (wood- or moss people) of Central Germany, Franconia, and Bavaria; Holzfräulein [de] aka Waldfräulein, Waldweiblein of the Bohemian Forest and the Upper Palatinate; the Waldweiblein and Moosweiblein [de] (lit. 'moss maiden') of the Harz mountains region; the Lohjungfer (lit. 'grove maiden'; {{pl.|Lohjungfern) of Halle further east in Saxony; and the Buschweiblein (lit. 'bush maiden') of Westphalia. Usage of names such as Lohjungfer, Holzfräulein, Mossweibchen extends further south in Saxon Vogtland. Waldfänke is synonymous to wilder Mann, which is an exception, since Fang(e) and its extensions (cf. Fänge below) generally refer to females. The variant form Waldfenken-Geißler is also given in commentary. As for Geißler ("goatherd") or Kühler ("cowherd"), the wild man may be designated by the name of his profession in a narrative where he is engaged in the herding of livestock. Cf. also the etymological relation between the term "sylvan" ("of the woods"), the French term sauvage meaning "wild", and the Sal- group of names for the wild men used in the Italian Alps (Trentino-Alto Adige/Südtirol) region under § Other aliases below. Cf. also "woodwose" under § English terms. Folklore in Tyrol and German-speaking Switzerland into the 20th century refers to the wild woman called Fänge (var. Fängge/Faengge, Fankke, Fang, Fange, Fangge, Fangga, Fanggin), commented as being equivalent to Selige Fräulein (Salige Frau) This name is thought to be post-medieval neologism deriving from the Latin fauna, the feminine form of faun. The wild women of the Alpine region are "identical to or closely related to" the Fänggen or the Salige (Salige Frauen). The extended form Wild-Fang is considered a male noun (ein Wild-fang), but Wild-fang (var. Wildfangg) is still applied to a female.[t] The wild man is called a Bilmon (corruption of "wild man"), Salvadegh, or Salvanel in Wälsch-Tirol (present-day Trento Province), which may be spelt Salvan or Salvang, with usage extending to Lombardy. The wild man is called l'om salvadegh by Ladin language-speakers in Folgrait (Folgaria) and Trambileno; this is readily recognizable as equivalent to French l'homme sauvage, where Old French salvage derives from Latin silvāticus "sylvan, pertaining to forest". Hence the names in this grouping are related to Silvanus, the Roman tutelary god of gardens and the countryside. The (medieval Latin) term silvaticus was in fact used in the sense of "wild woman" by Burchard of Worms in the 10th century, and it has been suggested he was referring to beings who would have been called Selvang in dialect according to modern-day folklore. The local name Frauberte or Frau Berta was supposedly current either in Ronchi near Ala, or the aforementioned Folgrait and Trambileno areas.[u] Likewise there are a sort of wild women known as Berchtra or Perchta (diminutive: Perchtel) in Carinthia.[v] It is contended that the Norgg [de] or Orke or Orge;[w] Lorgg or Lorge;[x][y] or Nörglein,[z] Nörkel, Örggele in folklore from parts of the Alps, particularly Tyrol, also may correspond to the wild man, with the proviso that these (especially diminutives) are names for "wild dwarf people". This appears to be connected to Italian orco (Neapolitan: huorco, pl. orci) in the sense of "subterraneans"[aa] (≈dwarfs or gnomes), or perhaps rather a "harmless wild folk" version of the orco such as appears in the literary fairy tales of the Pentamerone. The Italian orco is cognate to French ogre, as is modern literary orcs, and is related to Orcus, a Roman and Italic god of death.[ab] The Rüttelweib, Rittelweibe (lit. 'shaking wife'; pl. Rüttelweiber[ac]) of the Giant Mountains is also considered another regional fabulous being corresponding to the wild woman of the Alpine Region. In Old English/Anglo-Saxon there is recorded wude-wāsa meaning "satyr" or "faun", a compound of wude "woodland, forest" and wasa of uncertain etymology, though perhaps meaning "forest dweller"; or else it may perhaps be a compound formed from *wāsa "being", from the verb wesan, wosan "to be, to be alive". From it has derived Middle English woodwose, wodewose, woodehouse Variant spellings include wodewese, etc. The ME term wodehose was ambiguously singular or plural. As for examples of usage, Wycliffe's Bible (after 1382 [to 1395]), in Isaiah 13:21, used wodewoos (pl. wodewoosis[ad] rather than the King James Version's "satyr" to translate the original Hebrew שעיר (pronounced sa'ir, meaning "hairy [one]"). Latin translation gave pilosi, and LXX rendered as δαιμόνια (daimon). In Sir Gawain and the Green Knight (c. 1390), Gawain is said to have fought with worms (dragons) as well as a "wodwos" that lived in the craggy rocks;{{Refn|Gawain vv. 720–721 "Sumwhyle wyth wormez he werrez.. /Sumwhyle wyth wodwos þat woned in þe knarrez". ("[warred] with dragons.. [and] wild men who dwelt among the crags") this wild man (woodwose) has no relation to the Green Knight, but is just another enemy whom Sir Gawain happens to encounter in journey. The Middle English word is first attested for the 1340s in the context of a decorative piece of art depicting a wild man, namely a piece of tapestry of the Great Wardrobe of Edward III,[ae] but as a surname it is found as early as 1251, of one Robert de Wudewuse. The Middle English term wodewoos meaning "wild man" is found embedded in the Anglo-Norman caption to a painting in the Taymouth Hours (15th century) (cf. § Manuscript illuminations) There has been continued use in modern English for "woodwose, woodhouse", though now obsolete, displaced in modern usage by "wild man". The surnames Wodehouse or Woodhouse may derive straightforwardly from "house in the woods", or as a corruption of woodwose. Medieval literature Verbal descriptions of the wild folk in medieval literature will be mainly discussed here. Visual depictions during the medieval period will be discussed under § Iconography. That the German epic Sigenot (cf. image right) featureing both the giant named Sigenot and the wild man was certainly known in the 13th century, as the minnesinger Heinrich Frauenlob sings "Wa kam mit Parcivale /ris' Sigenot unt der wilde man? (Where came the giant Sigenot and the Wild Man, with Parzival?)", but the actual so-called elder Sigenot (13th century) is lost except in a fragmentary state, so the attestations come from the Younger Sigenot (15th century mss. and printed editions) as "wilde man, wild man. The female character Rauhe Else [de] ("Shaggy Else") in Wolfdietrich is also considered a wild woman example. She is a hairy woman crawling on all fours trying to get Wolfdietrich to marry her, but when he does not comply, casts a spell that turns him into a madman roaming the woods. God commands her to reverse the spell, and Wolfdietrich is now willing to marry her ("so long as the wild woman gets baptized"). Fortunately, when she dips into a spring she sheds her furry skin and transforms into a beautiful maiden, now calling herself Sigeminne.[af] She (Rauch Elss, christened Sygemin) is also mentioned as being the first wife of Wolfdietrich in the Anhang zum Heldenbuch. In the Arthurian Wigamur there is the wildez wîp (wild woman) who dwells in a hole in a rock. In another Arthurian epic Wigalois, the dwarf named Karriôz is explicitly stated to have a wildez wîp as his mother. In Wigalois there also appears a monstrous female of the woods named Rûel (cf. image right) as an adversary to the title hero, and though she is also described as a "wild woman" by modern commentators, she is not to be confused with Karriôz's mother. In the epic Renaud de Montauban, the title hero Renaud turns rebel against Charlemagne, and as fugitives living in the Ardennes forest, they have turned "black and hairy like a bear [on a chain]", so that "neither stone nor rock could scathe" them. Renaud's band thus became chevalier sauvage ("savage knights") or wild men, in the sense that in medieval society, the outcast consigned to live in forests separating settlements were regarded as a sort of wild man. The romance of Valentine and Orson, about a civilized brother separated from his bearlike brother Orson living in the wild, may count as an example of a wild man's tale, however, this might be more recognizable as a fictional treatment of the feral child. For the Myrddin Wyllt (mad Merlin) Suibhne Geilt (Mad Sweeney) driven to live in the wilderness and interpreted by some modern commentators as exhibiting the Wild Man of the Woods motif, cf. § Celtic mythology (under §Medieval parallels) below. Medieval to Renaissance transition As the name implies, the main characteristic of the wild man is his wildness. Civilized people regarded wild men as beings of the wilderness, the antithesis of civilization. Such had been the medieval view through the High Middle Ages. That is to say, the wild man had been something that civilized people strove to reject. The regard for the wild man as such an abominable fearsome character began to blunt, and by the 14th century in the example of the Bal des Sauvages held by King Charles VI of France (cf. § In dance and festival) the wild man was being employed in costume, not so much as embodiment of evil and savagery, but as a toything of court nobles. The paradigm had reversed and the Wild Man became the Noble Savage by the time of Spenser's The Faerie Queene (1590, 1596)[ag] and Hans Sachs's Klag der wilden holtzleut uber die ungetrewen welt ("Lament of the Wild Men about the Unfaithful World", 1530) and it became an iconic model.[ah] Bernheimer analyzes this as a backlash reaction by the nobility of having to live within the constraints of aristocratic conventions and chivalric code. Although emergence of the concept of the "Noble Savage" (French: bon sauvage) had occurred post-discovery of the Americas, according to one observer not inconsistent with the foregoing 16th century examples, much of the scholarship on the Noble Savage pertains to thinking of the Enlightenment Period (18th century). The coinage of the term "noble savage" itself has often been (falsely) attributed to Jean-Jacques Rousseau, though refuted; as Rousseau never actually used that term himself, even though the philosopher did profusely use the construct of "savage" to critique various aspects of civilized society. Modern folklore The purported nature of these wild folk or wood people in folklore, like the lore of demons in general, is highly ambiguous, unpredictable and mutable. When the wild men appear in solitary fashion, they are similar to giants and ogres, while the women tend to be more goddess-like. The wild people can be dwarfish or be gigantic in size. And this may not necessarily be regional variations: the wild folk of Bernhardswald (in Schlüchtern Hesse) are purported to be giants or dwarfs depending on the season.[ai] They can be of different temperaments, but they may exact vengeance on those who are frightened by them or mock them. In that case, the smaller wild folk are more easily appeased, while the giant types will tear their tormentors apart or curse them with "seven times seven generations of curses and woe." Friedrich Ranke argues that the legends concerning the wild people in Central Germany became less frightening because the forests themselves shed much of their eeriness due to development and deforestation, so that only the low rolling hills remained. Thus in these regions, the folklore concerned the wild little folk of "harmless good nature."[aj] The wild man stereotypically carries an uprooted fir tree, or an iron club or an iron pole, etc. There are also the Alpine wild men recorded by modern folklorists, whose lore is generally found in the lore of Alps (mountainous Italian Tyrol and Italian and German-speaking parts of Grisons, Switzerland). The wild men of the Alps had the reputation of abducting women and devouring humans, particularly children. In Grisons, they are also accused of depositing their changeling child, swapping it with a human baby. Allegedly peasants in the Grisons tried to capture the wild man by getting him drunk and tying him up in hopes that he would give them his wisdom in exchange for freedom. This is noted as paralleling the capture of Silenus already described by Xenophon (d. 354 BCE), with Silenus being described as a satyr which Midas caught by getting him drunk with wine.[ak] Legend also has it that humans were able to capture it once by getting it drunk, thereby learning the manufacture of cheese.[al] A legend from Folgrait (Folgaria) has it that a certain man heard the noise of the wild man hunting, and called out to him in rhymed couplet to give him a share,[am] and received half a human corpse at his doorstep, subsequently having to take the trouble to have the hunter take back the unwanted gift. There are also variant versions with different rhymes from Ritten and Barbian.[an] However, in a cognate tale from Vallarsa, the wild hunter is not specified as a "wild man". It is comparable to a similar wild hunter myth from Northern Germany, that if anyone calls out to heckle the hunt, the hunter forces a "half portion" (Halb Part) of foul-smelling game or human part, reciting a couplet that if you join in the hunt, you must help out with the chewing. A legend held that Wildmannli dwelled in the Gross Windgällen mountain in the canton of Uri, Switzerland that disapproved of humans hunting on Sundays, and a hunter who breached the taboo and shot a chamois was turned to stone. Meanwhile, the Tyrolian and Swiss Fängge (Faengge, Fankke) as well as the Austrian Salige Frau are (subtypes or aliases of the) wild woman. The wild woman basically matches the female version of the wild man in appearance, and notably has drooping breasts (for which the Tyrolean wild woman has earned the nickname Langtüttin) however, she may appear in the form of beautiful women. The wild woman, the Fängge, and the Salige Frau are all associated with protecting alpine game, especially the chamois[ao] The legendary protectress called Kaiserfrau of Nachtberg (a peak situated between Thiersee and Brandenberg, Austria) is not explicitly called a wild woman in the original telling, but is classified as such. In the tale, the tall woman dressed in a green robe commands a shepherd to kill all poachers, otherwise she will destroy his entire flock. He obliges, and due to the reputation that the Kaiserfrau harms hunters, the stock of game in the forest rebounds. The wild women of Styria, Austria were said to reside mostly on Mt. Schöckl. They have a hollow or trough[ap]-like back (hence comparable to the skogsnuva of Sweden), so they can pretend to be old tree trunks instantly by turning their backs, even when a hiker senses the presence of the beautiful wild woman. The wild women of Schöckl are said to be hunted by the Wild Hunt that travels on flying sleds carrying demons.[aq] Iconography In art the hair more often covers the same areas that a chemise or dress would, except for the female's breasts (cf. fig. right); male knees are also often hairless. As with the feather tights of angels, this is probably influenced by the costumes of popular drama. By the 12th century the wild folk were almost invariably described as hairy all over, having a coat of hair covering their entire bodies except for their hands, feet, faces above their long beards, and the breasts and chins of the females. Around the same 12th century, the conventions of hairiness came to be extended to certain legendary personages in mentally altered states.[as] A prime example was the biblical Nebuchadnezzar II of Babylon who went mad and was no longer depicted as a smooth-bodied human but as a hairy creature. Other examples were ascetic saints[at] (cf. § Christian parallels) or literary hermits such as the Merlin of the Welsh (cf. § Celtic mythology) or Arthurian Ywain who were overcome by a spell of madness or lovelorn dementia (cf. § Celtic mythology). Bernheimer asserts that medieval paintings of Nebuchadnezzar came to be conventionally depicted as a wild man in crouching positions as according to contemporary ideas, even though that image contradicted the verbal biblical description in Daniel 4 (Book of Daniel, 2nd century BCE), which ascribed feather-like growths of hair like eagles, and bird-like claws. The wild man was used as a symbol of mining in late medieval and Renaissance Germany. The town of Wildemann in the Upper Harz was founded during 1529 by miners who, according to legend, met a wild man and wife when they ventured into the wilds of the Harz mountain range. For use as heraldic devices in the German mining area and elsewhere, cf. § Heraldry below. Some early sets of playing cards have a suit of Wild Men, including a pack engraved by the Master of the Playing Cards (active in the Rhineland c. 1430–1450), some of the earliest European engravings. A set of four miniatures on the estates of society by Jean Bourdichon of about 1500 includes a wild family, along with "poor", "artisan" and "rich" ones. Medieval iconography The wild folk are featured in the marginal paintings (drollery) in a number of illuminated manuscripts. There are wild men and women painted in the narrative border around the miniature of the Coronation of the Blessed Virgin Mary in the Book of Hours held at the Syracuse University Library (cf. fig. left). In the Taymouth Hours (15th century), there are a series of miniatures (bas-de-page illustrations) recounting a story of a wild man abducting a maiden. Though the captions in this work are written in Anglo-Norman French, the wild man is called wodewose, which is a Middle English term. There is also the drollery of a wild man being baited by three dogs, in the Queen Mary Psalter (14th century). The herdsman character who is only a vilain in Chrétien's Old French Yvain, the Knight of the Lion (though described as a "wild man" in modern scholarship) is literally a wild man (waltman, "man of the woods") in Hartmann's Middle High German Iwein. The wild herdsman is depicted as a club-carrying wild man on one of the fresco murals of the Iwein cycle at Rodenegg Castle [de] (Castello di Rodengo) in South Tyrol (cf. image right). The wild man is similarly painted on the mural at Schmalkalden Castle (Wilhelmsburg Castle). The man wears a skin with two paws attached to it, perhaps the influence of the Greek hero Hercules (wearing the lion skin). There is a giantess room series among the Runkelstein Castle (Castel Roncolo) fresco murals, and the label "Fraw Riel" suggests identification with the female Rûel of Wigalois (mentioned above as being categorized as wild woman by some modern commentators).[au] The Runkelstein frescos are themed on a set of triads on heroes, giantesses, and giants, etc. The giant Schrutan is one of them, who figures in the epic Rosengarten zu Worms as one of the single combat participants.[av] Although clad in knightly armor, he holds an uprooted tree, and the Schrutan in this painting is "encoded as a giant-wild man hybrid" according to one art critic. Albrecht Dürer depicts the wild man pursuing the maiden in his "Coat of Arms of Death" (1503), of which it is commented that the wild man springs to life from the conventional immobile role as shield-bearer of heraldic device (cf. also another of his work discussed under § Wild Men as shield-bearer below). Carved image of a group of wild men (woodwoses) engaged in battle with a beast form a roof boss in Canterbury Cathedral, and is grouped among a number of Green Man bosses present in the cathedral.[aw] There is also a furry wild man depicted in the crypt of the Canterbury Cathedral.[ax] The visual artistic depictions of the English wild man (woodwose) and the green man merged during the Middle Ages to form a single type. There are instances where medieval depiction of satyr or faunus lose their beastly traits (hooves and horns), turning into creatures not so far apart from wild men. Medieval myth and art also adopted a convention of depicting the Greek hero Heracles, clad in lion skin and carrying a club as a wild man, sometimes of a more conventional type[ay] or more outlandishly as a tailed monster with clawed feet.[az] (e.g. painting at Schmalkalden, described above) Heraldry By the second half of the fifteen century, it became widely conventional to have engravings made of a wild man holding up a shield (escutcheon) bearing the family's coat of arms (cf. images left). Particular examples include the Princes of Brunswick-Wolfenbüttel (cf. also § Numismatics below) and later by the royals of Brandenburg–Prussia. To avail themselves to this needs, the engravers came up with the idea of having a prototype or template at hand of a wild man holding up a blank shield, so that the proper emblem can be filled in to cater to the particular patron. Martin Schongauer was one such engraver, four heraldic shield engravings of the 1480s which depict wild men holding heraldic shield (emblems of moor, greyhound, stag, and lion).[ba] Dürer in his Portrait of Oswald Krell (1499) drew two wild men supporting family heraldic shields. The one on the left wears a green garment made of moss, the one on the right is hairy all over (see image at top of page). The wild man appears in the coats of arms of e.g. Naila and of Wildemann. The so-called Wildemannstaler [de] was a type of taler (thaler, "dollar") denomination coins featuring a standing wild man on the reverse, first struck by Duke Henry the Younger of Brunswick-Wolfenbüttel in 1539, using the silver mined from the Upper Harz mountains. Thus, much of this wild man is really part of silver-mining folklore, rather than alpine or forest region folklore. The standing wild man on the early coin (and some heraldic illustrations) depicts a wild man holding a club (uprooted tree) and a clump of burning flame in the other hand (cf. photo right). The folkloric explanation of the flame is that it represents a light source or beacon of light to guide humans through the dark mine tunnels to the ore source or silver vein, as clarified by the work of Gerhard Heilfurth [de] and Ina-Maria Greverus (1967). Heilfurth regards the wild man in this context to be a type of Berggeist or "mountain spirit" (which is really a generic term or class used by modern folklorists), better known as Bergmönch or "mountain monk" in the folklore of the Harz mountains. The explanation of the "monk" name comes from the historical fact that the neighboring Walkenried Monastery held control of the workings of the Harz mining operation at one time. The lore of the mining spirit type wild man (or the Bergmönch) was localized mainly in the Harz and the Ore Mountains. The folklore is attested in the following piece of 16th century writing, which stated that in the community of Wildemann (town named after "wild man"): helt man dafür, daß daß Closter von Walckenred sonderlichen den Wildemanner Zog inne gehabt, beleget vnd gebawet hat, weil sich der Daemon Metallicus, der Bergteuffel, den die Bergleut daß Berg Mänlein nennen, in einer gestalt eines großen Mönchs hat sehen laßen, fürnemlich auff der Zechen Wildemann, da viel guter leute denselbigen gesehen, auch offtmals großen schaden gethan vnd angericht. (It is believed that the Walkenried Monastery held, occupied, and built upon the Wildemann mine in particular, since the Daemon Metallicus or mountain devil, whom the miners call the "mountain manikin" (Bergmännlein, i.e. gnome), appeared in the form of a large monk, especially at the Wildemann mine, where many good people saw him, and he often caused great damage and destruction. — Hardanus Hake, parish priest of Wildemann, in Bergchronik (1583) There is also the political and polemical interpretation of the wild man and flame emblem, namely, Henry the Younger was insinuating threat of violence, even the burning down of townships. When Henry's less quarrelsome son Julius succeeded as duke, the flame on the coin was replaced by a candle or taper, and these coins are known as the Lichttaler or "Light taler" among numismatists. Later, Julius added other objects, the skull, the hourglass, and eyeglasses to the composition. In dance and festival Aspects of German folk traditions about the wild man were preserved in performances of Wildemannspiel ("wild man play") and Wildemanntanz (dance), which tended to be held during Shrovetide/Carnival season. In the Morgestraich [de] of the Carnival of Basel a wild man would take the first dance alongside other masked figures; this wild man held an uprooted tree in hand, and was entwined with leaves around the head and loins. There is a 1435 account of the wild man dance in Basel featuring 23 such wild men (uomini selvatici). In the 15th century Fastnachtspiel (carnival play) "Ein spil von holzmennern", two men of the woods quibble over the female (holzweip) of their kind. In Etschland (Etschtal),[bb] Ulten,[bc] and Vinschgau in South Tyrol,. An example given of the Wildemannspiel conducted at Marling in South Tyrol: a youth and two younger boys are dressed up in beard moss hair with a jangling chain of snail shells and holding a young tree as staff, they waited in a cave towards St. Felix and dressed up schoolgirls were tasked to enter the forest and find the three of them. More examples come from civic celebrations or processions. At the Schembart Carnival of Nuremberg there were participants (German: Läufer lit. 'runners', or called "mummers") dressed up as wild men (Holtzmendlein) holding up a dwarf (on a stick) as captive, together with a wild woman (Holtzfrewlein), likely a man in "drag" (as the breast portion is laid bare) (cf. image right).[bd] In Swiss locales of Vitznau, Weggis, Gersau, and Küssnacht, there is the Schämeler or Tschämeler representing the wild man, with the local folk dressing up as them using moss, bark, leaves, etc. and holding a whole tree as staff. Outside of German-speaking regions, the (magnus) ludus de homine salvatico, a large-scale Pentecostal play about the wild man was put on in Padua in the year 1208 and 1224; not much is known about these except they featured giants (gigantibus). Another ludus was held in Aargau, Switzerland in 1399. It also became fashionable at one time for participants in the carousels at court festivals to dress up as club-carrying wild men (cf. image right). King Charles VI of France and five of his courtiers were dressed as wild men and chained together for a masquerade at the tragic Bal des Sauvages which occurred in Paris at the Hôtel Saint-Pol, 28 January 1393 (cf. image lef). They were suited up "six quilts of fabric coated with pitch then stuck with flax (linen) fibers in the form and shape of hair", making themselves out to be "hommes sauvages, covered in hair from head right up to the soles of their feet". A careless torch set the costumers aflame, and all but one of the courtiers died; the king's own life saved by his aunt the Duchess of Berry, who covered him with her dress. There exist paintings of this scene in copies of Froissart's Chroniques (as green men; compare similar image right). It is supposed that "dyed tufted flax" was used to simulate the hair. England's Henry VIII held a wild man dance on the Twelfthnight at the Great Hall of Greenwich in 1515 The Burgundian court celebrated a pas d'armes known as the Pas de la Dame Sauvage ("Passage of arms of the Wild Lady") in Ghent in 1470. A knight held a series of jousts with an allegoric meaning in which the conquest of the wild lady symbolized the feats the knight must do to merit a lady. Medieval parallels Old High German had the terms schrat, scrato or scrazo, which appear in glosses of Latin works as translations for fauni, silvestres, or pilosi, identifying the creatures as hairy woodland beings. Some of the local names suggest associations with characters from ancient mythology. Slavic has leshy "forest man". The wild women of Styria, Austria were said to reside mostly on Mt. Schöckl. They have a hollow or trough[be]-like back (hence comparable to the skogsnuva of Sweden There are medieval Welsh, Irish, and Scottish mythical narratives about men going mad and living in the wilderness, considered as part of the Celtic Wildman tradition according to scholars. The Welsh tradition regarding Myrddin Wyllt ("mad Merlin")[bf] is that he went mad after the Battle of Arfderydd which took place in 573 CE in the wake of the battle that resulted in the death of Gwenddoleu ap Ceidio who was the king he served. It is recorded as such in the annals, though it may not be historically accurate. Myrddin then fled to the forest, living life as a man of the woods, according to Giraldus Cambrensis (12th century). The battleground (Arfderydd) became identified as a place near the Scottish border, making plausible the legend that Merlin's flight took him to the Caledonian Forest in Scotland. Geoffrey of Monmouth recounts the Myrddin Wyllt legend in his Latin Vita Merlini of about 1150, and the attachment of the madness motif may or may not have been Geoffrey's invention. The legend of the Scottish Lailoken who lost his wits in battle is so similar in background to the Myrddin legend, it is considered a version of the same myth, and in fact, there is an aside comment that Lailoken might have been Merlin of Britain though that cannot be ascertained in the source itself, namely the Lailoken fragment or more precisely the Latin fragmentary The Life of Saint Kentigern. There is also a geographical proximity of the battlegrounds involved, pinpointable as present-day Arthuret in Cumbria, England. The Irish analogue is the legend of Suibhne Geilt ("mad Sweeny"), a king [bg] of the Dál nAraidi who himself went mad during the combat of the Battle of Mag Rath of 637 CE The legend is accounted for in Buile Shuibhne (The Frenzy of Sweeney, 9th century). It is commented by James George O'Keeffe (1913) the Welsh and Irish versions exhibit the dispersed Wild Man (of the Woods) tradition. In Chrétien's Arthurian Romance Yvain, in the episode when the title hero, estranged from his lover Laudine, loses his wits and lives in the wilderness; this has been characterized as a wild man episode by modern commentators. Bernheimer lists Yvain, Lancelot, and Tristan among the Arthurian knights who chose to live as wild men in the aftermath of mental anguish having earned the disfavor of their beloved lady. The fragmentary 16th-century Breton text An Dialog Etre Arzur Roe D'an Bretounet Ha Guynglaff (Dialog Between Arthur and Guynglaff) tells of a meeting between King Arthur and Guynglaff ("a sort of wild man of the woods"), who predicts events which will occur as late as the 16th century. The notion of the Irish geilt, gelt (madness), which Grimm's notes glosses as equivalent to wilder mann or waldmann,[bh] is discussed in the Old Norse Konungs skuggsjá (Speculum Regale or "the King's Mirror", written in Norway about 1250), which points to the Northmen having learned about the Suibhne legend from Ireland. There is also another item of Irish Mirabilia considered possibly relevant, namely, a sort of beast-man with a horse-like mane, which stooped when walking, and could not surely demonstrate the ability to comprehend speech. Meyer thought this may have been a version of the "half-ox man" related by Giraldus (cf. Gir. II.21). William Sayers (1985) thought it may be connected to the Irish water horse (each uisge) despite lack of connection with water.[bi] Wild (divi) people are the characters of the Slavic folk demonology who are mythical forest creatures. Names go back to two related Slavic roots *dik- and *div-, combining the meaning of "wild" and "amazing, strange". Among the Bohemian populace, the wild man is known as lesní muž (pl. lesní mužove, lit. 'forest man'), who abducts a girl to forcibly make her his married wife. The Bohemian wood woman has the reputation of forcing a girl to dance the night, but to undertake the yarn-spreading chore the girl missed, in fact endowing her an inexhaustible supply of yarn,[bj] but if the dancing partner is a boy, the wood woman tickles him to death. The female Bohemian wild woman is called divý žena or divá žena (pl. divé ženy). In the East Slavic sources referred: Saratov dikar, dikiy, dikoy, dikenkiy muzhichok – leshy; a short man with a big beard and tail; Ukrainian lisovi lyudi – old men with overgrown hair who give silver to those who rub their nose; Kostroma dikiy chort; Vyatka dikonkiy unclean spirit, sending paralysis; Ukrainian lihiy div – marsh spirit, sending fever; Ukrainian Carpathian dika baba – an attractive woman in seven-league boots, sacrifices children and drinks their blood, seduces men. There are similarities between the East Slavic reports about wild people and book legends about diviy peoples (unusual people from the medieval novel "Alexandria") and mythical representations of miraculous peoples. For example, Russians from Ural believe that divnye lyudi are short, beautiful, have a pleasant voice, live in caves in the mountains, and can predict the future; among the Belarusians of Vawkavysk uyezd, the dzikie lyudzi – one-eyed cannibals living overseas, also drink lamb blood; among the Belarusians of Sokółka uyezd, the overseas dzikij narod have grown wool, they have a long tail and ears like an ox; they do not speak, but only squeal. Ancient parallels Figures similar to the European wild man occur worldwide from very early times. The earliest recorded example of the type is the character Enkidu of the ancient Mesopotamian Epic of Gilgamesh. "Classical antiquity like the Middle Ages, had its wild men", according to Bernheimer. This included savage races of (sometimes hairy) humans supposedly found in exotic places. Herodotus (c. 484 BCE – c. 425 BCE),'s wild men and wild women supposedly lived in western Ancient Lybia (a vast region west of the Nile, not just the present-day nation) where there also lived marvels such as men with eyes in their chest (headless men) and dog-faced humanoids (cynocephaly). Ctesias[bk] (fl. 5th century BCE)'s Indika and Alexander the Great (d. 323 BCE)'s conquest influenced Europeans into thinking that such wild men (and the marvelous prodigies too[bl]) lived rather in the East, in the Indian subcontinent. Megasthenes[bm] (died c. 290 BCE), wrote of two kinds of men to be found in India whom he explicitly describes as wild: first, a creature brought to court whose toes faced backwards; second, a tribe of forest people who had no mouths and who sustained themselves with smells. Both Quintus Curtius Rufus and Arrian (1st and 2nd centuries CE) refer to Alexander himself meeting with a tribe of fish-eating savages while on his Indian campaign. The wild man races described by the learned writings of ancient historians may have had influence on the Medieval wild man folklore but establishing the degree would be difficult given the separation in time. But one can catalogue which ancient pieces of writing were accessible to medieval men.[bn] Distorted accounts of apes may have contributed to both the ancient and medieval conception of the wild man. In his Natural History Pliny the Elder describes a race of silvestres, wild creatures in India who had humanoid bodies but a coat of fur, fangs, and no capacity to speak – a description that fits gibbons indigenous to the area. The ancient Carthaginian explorer Hanno the Navigator (fl. 500 BCE) reported an encounter with a tribe of savage men and hairy women in what may have been Sierra Leone; their interpreters called them "Gorillae," a story which much later originated the name of the gorilla species and could indeed have related to a great ape. Similarly, the Greek historian Agatharchides describes what may have been chimpanzees as tribes of agile, promiscuous "seed-eaters" and "wood-eaters" living in Ethiopia. The medieval wild man lends itself to easy comparison with a number of classical woodland divinities. However, the aforementioned definition laid out by Bernheimer clearly distinguishes the faun and satyr from the wild man. Grimm states that the German shaggy wood-sprite schrat answers to the classical faun, satyr, and perhaps even Silvanus. Old High or Middle High German glossaries equating forms of the word schrat with faunus or sylvestri hominus. Grimm speculates on the possibility schrat might have been a being of larger stature in olden times. The medieval wild man typically depicted holding an uprooted tree may have derived from the classical Silvanus who is lord of the gardens and uprooter of trees, though the latter is more prone to be holding a cypress sapling he is about to transplant. The centaur is more likely to hold a club, though this creature is of course, half horse. Early Christian writings on Desert Fathers as found in the Apophthegmata Patrum ("Sayings of the Desert Fathers") are similar, but less outlandish: typically their head of hair has grown long enough to cover their naked bodies. A general term to describe such ascetics living in the wilderness was Grazers (Ancient Greek: βοσκοί, romanized: boskoí) coined among the Greek or Eastern Christians.[bo] There is the hypothesis that the notion of the "noble wild man" that emerged in the 15th century (after the European discovery of the Americas) may have been influenced by the notion of these "grazers". Although not authentically the stuff of antiquity, regarding the Christian Saint John Chrysostom (died 407), there developed an apocryphal legend in the Late medieval period (15th century) that he began as a soul of a child in purgatory taken into tutelage by the Pope, but considering himself unworthy went to live a life of austerity in the wilderness. Later, in a fateful meeting with the emperor's daughter who had gone astray, he succumbs to temptation and not only has carnal knowledge with her but pushes her off a ravine in the aftermath, for the penance of this sin and crime, he lives life on all fours, eventually developing body hair (with vegetation growing about his body as well), when he is captured in order to perform a baptism for the Imperial prince, upon which the accumulated hair, etc. drops off. Accompanying illustrations may contradict the text and show a smooth, naked man on all fours, e.g., the Günther Zainer edition of Leben der Heiligen, vol. II (1471). Whereas Anton Koberger's edition of Leben der Heiligen (1488) depicts the crawling saint as a hairy man. In modern fiction In Shakespeare's The Winter's Tale (1611), the dance of twelve "Satyrs" conflates wild men and satyrs. The dance is held at the rustic sheep-shearing (IV.iv), described by a servant: Masters, there is three carters, three shepherds, three neat-herds, three swine-herds, that have made themselves all men of hair, they call themselves Saltiers,[bp] and they have a dance which the wenches say is a gallimaufrey[bq] of gambols...[br] Petrus Gonsalvus (born 1537) was referred to by Ulisse Aldrovandi as "the man of the woods" due to his condition, hypertrichosis, and it is believed that his marriage to the lady Catherine inspired the fairy tale Beauty and the Beast.[non-primary source needed] The term wood-woses or simply Woses is used by J. R. R. Tolkien to describe a fictional race of wild men, the Drúedain, in his books on Middle-earth. According to Tolkien's legendarium, other men, including the Rohirrim, mistook the Drúedain for goblins or other wood-creatures and referred to them as Púkel-men (Goblin-men). He allows the fictional possibility that his Drúedain were the "actual" origin of the wild men of later traditional folklore. British poet Ted Hughes used the form wodwo as the title of a poem and a 1967 volume of his collected works. The fictional character Tarzan from Edgar Rice Burroughs' 1912 novel Tarzan of the Apes has been described as a modern version of the wild man archetype. See also Explanatory notes References ... a strange madness came upon him. He crept away and fled to the woods, unwilling that any should see his going. Into the forest he went, glad to lie hidden beneath the ash trees. He watched the wild creatures grazing on the pasture of the glades. Sometimes he would follow them, sometimes pass them in his course. He made use of the roots of plants and of grasses, of fruit from trees and of the blackberries in the thicket. He became a Man of the Woods, as if dedicated to the woods. So for a whole summer he stayed hidden in the woods, discovered by none, forgetful of himself and of his own, lurking like a wild thing. There is also one thing which will seem very wonderful about men who are called gelt. It happens that when two hosts meet and are arrayed in battle-array, and when the battle cry is raised loudly on both sides, that cowardly men run wild and lose their wits from the dread and fear which seize them. And then they run into a wood away from other men, and live there like wild beasts, and shun the meeting of men like wild beasts.–Speculum Regale, Chapter: Irish Mirabilia §18 (c. 1250) requoted by O'Keeffe (1913), p. xxxv, note 2, from Kuno Meyer's translation. There also happens in this land.. men have caught in a wood a certain animal, of which no man could say whether it was a man or a beast, because men have not heard speech from it.. hair grew all over its body.. [and] a mane as on a horse, etc.–Speculum Regale, Chapter: Irish Mirabilia §13, tr. Meyer Further reading External links |
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Contents Thirty-seventh government of Israel The thirty-seventh government of Israel is the current cabinet of Israel, formed on 29 December 2022, following the Knesset election the previous month. The coalition government currently consists of five parties — Likud, Shas, Otzma Yehudit, Religious Zionist Party and New Hope — and is led by Benjamin Netanyahu, who took office as the prime minister of Israel for the sixth time. The government is widely regarded as the most right-wing government in the country's history, and includes far-right politicians. Several of the government's policy proposals have led to controversies, both within Israel and abroad, with the government's attempts at reforming the judiciary leading to a wave of demonstrations across the country. Following the outbreak of the Gaza war, opposition leader Yair Lapid initiated discussions with Netanyahu on the formation of an emergency government. On 11 October 2023, National Unity MKs Benny Gantz, Gadi Eisenkot, Gideon Sa'ar, Hili Tropper, and Yifat Shasha-Biton joined the Security Cabinet of Israel to form an emergency national unity government. Their accession to the Security Cabinet and to the government (as ministers without portfolio) was approved by the Knesset the following day. Gantz, Netanyahu, and Defense Minister Yoav Gallant became part of the newly formed Israeli war cabinet, with Eisenkot and Ron Dermer serving as observers. National Unity left the government in June 2024. New Hope rejoined the government in September. Otzma Yehudit announced on 19 January 2025 that it had withdrawn from the government, which took effect on 21 January, following the cabinet's acceptance of the three-phase Gaza war ceasefire proposal, though it rejoined two months later. United Torah Judaism left the government in July 2025 over dissatisfaction with the government's draft conscription law. Shas left the government several days later, though it remains part of the coalition. Background The right-wing bloc of parties, led by Benjamin Netanyahu, known in Israel as the national camp, won 64 of the 120 seats in the elections for the Knesset, while the coalition led by the incumbent prime minister Yair Lapid won 51 seats. The new majority has been variously described as the most right-wing government in Israeli history, as well as Israel's most religious government. Shortly after the elections, Lapid conceded to Netanyahu, and congratulated him, wishing him luck "for the sake of the Israeli people". On 15 November, the swearing-in ceremony for the newly elected members of the 25th Knesset was held during the opening session. The vote to appoint a new Speaker of the Knesset, which is usually conducted at the opening session, as well as the swearing in of cabinet members were postponed since ongoing coalition negotiations had not yet resulted in agreement on these positions. Government formation Yair Lapid Yesh Atid Benjamin Netanyahu Likud On 3 November 2022, Netanyahu told his aide Yariv Levin to begin informal coalition talks with allied parties, after 97% of the vote was counted. The leader of the Shas party Aryeh Deri met with Yitzhak Goldknopf, the leader of United Torah Judaism and its Agudat Yisrael faction, on 4 November. The two parties agreed to cooperate as members of the next government. The Degel HaTorah faction of United Torah Judaism stated on 5 November that it will maintain its ideological stance about not seeking any ministerial posts, as per the instruction of its spiritual leader Rabbi Gershon Edelstein, but will seek other senior posts like Knesset committee chairmen and deputy ministers. Netanyahu himself started holding talks on 6 November. He first met with Moshe Gafni, the leader of Degel HaTorah, and then with Goldknopf. Meanwhile, the Religious Zionist Party leader Bezalel Smotrich and the leader of its Otzma Yehudit faction Itamar Ben-Gvir pledged that they would not enter the coalition without the other faction. Gafni later met with Smotrich for coalition talks. Smotrich then met with Netanyahu. On 7 November, Netanyahu met with Ben-Gvir who demanded the Ministry of Public Security with expanded powers for himself and the Ministry of Education or Transport and Road Safety for Yitzhak Wasserlauf. A major demand among all of Netanyahu's allies was that the Knesset be allowed to ignore the rulings of the Supreme Court. Netanyahu met with the Noam faction leader and its sole MK Avi Maoz on 8 November after he threatened to boycott the coalition. He demanded complete control of the Western Wall by the Haredi rabbinate and removal of what he considered as anti-Zionist and anti-Jewish content in schoolbooks. President Isaac Herzog began consultations with heads of all the political parties on 9 November after the election results were certified. During the consultations, he expressed his reservations about Ben-Gvir becoming a member in the next government. Shas met with Likud for coalition talks on 10 November. By 11 November, Netanyahu had secured recommendations from 64 MKs, which constituted a majority. He was given the mandate to form the thirty-seventh government of Israel by President Herzog on 13 November. Otzma Yehudit and Noam officially split from Religious Zionism on 20 November as per a pre-election agreement. On 25 November, Otzma Yehudit and Likud signed a coalition agreement, under which Ben-Gvir will assume the newly created position of National Security Minister, whose powers would be more expansive than that of the Minister of Public Security, including overseeing the Israel Police and the Israel Border Police in the West Bank, as well as giving powers to authorities to shoot thieves stealing from military bases. Yitzhak Wasserlauf was given the Ministry for the Development of the Negev and the Galilee with expanded powers to regulate new West Bank settlements, while separating it from the "Periphery" portfolio, which will be given to Shas. The deal also includes giving the Ministry of Heritage to Amihai Eliyahu, separating it from the "Jerusalem Affairs" portfolio, the chairmanship of the Knesset's Public Security Committee to Zvika Fogel and that of the Special Committee for the Israeli Citizens' Fund to Limor Son Har-Melech, the post of Deputy Economic Minister to Almog Cohen, establishment of a national guard, and expansion of mobilization of reservists in the Border Police. Netanyahu and Maoz signed a coalition agreement on 27 November, under which the latter would become a deputy minister, would head an agency on Jewish identity in the Prime Minister's Office, and would also head Nativ, which processes the aliyah from the former Soviet Union. The agency for Jewish identity would have authority over educational content taught outside the regular curriculum in schools, in addition to the department of the Ministry of Education overseeing external teaching and partnerships, which would bring nonofficial organisations permitted to teach and lecture at schools under its purview. Likud signed a coalition agreement with the Religious Zionist Party on 1 December. Under the deal, Smotrich would serve as the Minister of Finance in rotation with Aryeh Deri, and the party will receive the post of a minister within the Ministry of Defense with control over the departments administering settlement and open lands under the Coordinator of Government Activities in the Territories, in addition to another post of a deputy minister. The deal also includes giving the post of Minister of Aliyah and Integration to Ofir Sofer, the newly created National Missions Ministry to Orit Strook, and the chairmanship of the Knesset's Constitution, Law and Justice Committee to Simcha Rothman. Likud and United Torah Judaism signed a coalition agreement on 6 December, to allow request for an extension to the deadline. Under it, the party would receive the Ministry of Construction and Housing, the chairmanship of the Knesset Finance Committee which will be given to Moshe Gafni, the Ministry of Jerusalem and Tradition (which would replace the Ministry of Jerusalem Affairs and Heritage), in addition to several posts of deputy ministers and chairmanships of Knesset committees. Likud also signed a deal with Shas by 8 December, securing interim coalition agreements with all of their allies. Under the deal, Deri will first serve as the Minister of Interior and Health, before rotating posts with Smotrich after two years. The party will also receive the Ministry of Religious Services and Welfare Ministries, as well as posts of deputy ministers in the Ministry of Education and Interior. The vote to replace then-incumbent Knesset speaker Mickey Levy was scheduled for 13 December, after Likud and its allies secured the necessary number of signatures for it. Yariv Levin of Likud was elected as an interim speaker by 64 votes, while his opponents Merav Ben-Ari of Yesh Atid and Ayman Odeh of Hadash received 45 and five votes respectively. Netanyahu asked Herzog for a 14-day extension after the agreement with Shas to finalise the roles his allied parties would play. Herzog on 9 December extended the deadline to 21 December. On that date, Netanyahu informed Herzog that he had succeeded in forming a coalition, with the new government expected to be sworn in by 2 January 2023. The government was sworn in on 29 December 2022. Timeline Israeli law stated that people convicted of crimes cannot serve in the government. An amendment to that law was made in late 2022, known colloquially as the Deri Law, to allow those who had been convicted without prison time to serve. This allowed Deri to be appointed to the cabinet. Shas leader Aryeh Deri was appointed to be Minister of Health, Minister of the Interior, and Vice Prime Minister in December 2022. He was fired in January 2023, following a Supreme Court decision that his appointment was unreasonable, since he had been convicted of fraud, and had promised not to seek government roles through a plea deal. In March 2023, Defence Minister Yoav Gallant called on the government to delay legislation related to the judicial reform. Prime Minister Netanyahu announced that he had been dismissed from his position, leading to the continuation of mass protests across the country (which had started in January in Tel Aviv). Gallant continued to serve as a minister as he had not received formal notice of dismissal, and two weeks later it was announced that Netanyahu had reversed his decision. Public Safety Minister Itamar Ben-Gvir (Otzma Yehudit leader) and Minister of Justice Yariv Levin (Likud) both threatened to resign if the judicial reform was delayed.[better source needed] After the outbreak of the Gaza war, five members of the National Unity party joined the government as ministers without portfolio, with leader Benny Gantz being made a member of the new Israeli war cabinet (along with Netanyahu and Gallant). As the war progressed, minister of national security Itamar Ben-Gvir threatened to leave the government if the war was ended. A month later in mid December, he again threatened to leave if the war did not maintain "full strength". Gideon Sa'ar stated on 16 March that his New Hope party would resign from the government and join the opposition if Prime Minister Benjamin Netanyahu did not appoint him to the Israeli war cabinet. Netanyahu did not do so, resulting in Sa'ar's New Hope party leaving the government nine days later, reducing the size of the coalition from 76 MKs to 72. Ben-Gvir and Bezalel Smotrich, of the National Religious Party–Religious Zionism party, have indicated that they will withdraw their parties from the government if the January 2025 Gaza war ceasefire is adopted, which would bring down the government. Ben-Gvir announced on 5 June that the members of his party would be allowed to vote as they wish, though his party resumed support on 9 June. On 18 May, Gantz set an 8 June deadline for withdrawal from the coalition, which was delayed by a day following the 2024 Nuseirat rescue operation. Gantz and his party left the government on 9 June, giving the government 64 seats in the Knesset. Sa'ar and his New Hope party rejoined the Netanyahu government on 30 September, increasing the number of seats held by the government to 68. The High Court of Justice ruled on 28 March 2024 that yeshiva funds would no longer be available for students who are "eligible for enlistment", effectively allowing ultra-Orthodox Jews to be drafted into the IDF. Attorney general Gali Baharav-Miara indicated on 31 March that the conscription process must begin on 1 April. The court ruled on 25 June that the IDF must begin to draft yeshiva students. Likud announced on 7 July that it would not put forward any legislation after Shas and United Torah Judaism said that they would boycott the plenary session over the lack of legislation dealing with the Haredi draft. The Ultra-Orthodox boycott continued for a second day, with UTJ briefly ending its boycott on 9 July to unsuccessfully vote in favor of a bill which would have weakened the Law of Return. Yuli Edelstein, who was replaced by Boaz Bismuth on the Foreign Affairs and Defense Committee in early August, published a draft version of the conscription law shortly before his ouster. Bismuth cancelled the work on the draft law in September 2025, which Edelstein called "a shame." Bismuth released the official version of the draft law in late November 2025. It weakened penalties for draft evaders, with Edelstein saying it was "the exact opposite" of the bill which he attempted to pass. Members of Otzma Yehudit resigned from the government on 19 January 2025 over the January 2025 Gaza war ceasefire, which took effect on 21 January. The members rejoined in March, following the "resumption" of the war in Gaza. Avi Maoz of the Noam party left the government in March 2025. On 4 June 2025, senior rabbis for United Torah Judaism Dov Lando and Moshe Hillel Hirsch instructed the party's MKs to pass a bill which would dissolve the Knesset. Yesh Atid, Yisrael Beytenu and The Democrats announced that they will "submit a bill" for dissolution on 11 June, with Yesh Atid tabling the bill on 4 June. There were also reports that Shas would vote in favor of Knesset dissolution amidst division within the governing coalition on Haredi conscription. This jeopardized the coalition's majority and would have triggered new elections if the bill passed. The following day, Agudat Yisrael, one of the United Torah Judaism factions, confirmed that it would submit a bill to dissolve the Knesset. Asher Medina, a Shas spokesman, indicated on 9 June that the party would vote in favor of a preliminary bill to dissolve the Knesset. The rabbis of Degel HaTorah instructed the parties' MKs on 12 June 2025 to oppose the dissolution of the Knesset, which was followed by Yuli Edelstein and the Shas and Degel HaTorah parties announcing that a deal had been reached, with "rabbinical leaders" telling their parties to delay the dissolution vote by a week. Shas and Degel HaTorah voted against the dissolution bill, which led to the bill failing its preliminary reading in a vote of 61 against and 53 in favor. MKs Ya'akov Tessler and Moshe Roth of Agudat Yisrael voted in favor of dissolution. Another dissolution bill will be unable to be brought forward for six months. If the bill had passed its preliminary reading, in addition to three more readings, an election would have been held in approximately three months; The Jerusalem Post posited it would have been held in October. Degel HaTorah announced on 14 July 2025 that it would leave the government because members of the party were dissatisfied after viewing the proposed draft bill by Yuli Edelstein regarding Haredi exemptions from the Israeli draft. Several hours later, Agudat Yisrael announced that it would also leave the government. Deputy Transportation Minister Uri Maklev, Moshe Gafni, the head of the Knesset Finance Committee, Ya'akov Asher, the head of the Knesset Interior and Environment Protection Committee and Jerusalem Affairs minister Meir Porush all submitted their resignations, with their resignations taking effect in 48 hours. Sports Minister Ya'akov Tessler and "Special Committee for Public Petitions Chair" Yitzhak Pindrus also submitted resignations. Yisrael Eichler submitted his resignation as the "head of the Knesset Labor and Welfare Committee" the same day. The resignations will leave Netanyahu's government with a 60-seat majority in the Knesset, as Avi Maoz, of the Noam party, left the government in March 2025. Despite Edelstein's ouster in August, a spokesman for UTJ head Yitzhak Goldknopf remarked that it would not change the faction's withdrawal from the government. The religious council for Shas, called the Moetzet Chachmei HaTorah, instructed the party on 16 July to leave the government, but stay in the coalition. The following day, various cabinet ministers submitted their resignations, including "Interior Minister Moshe Arbel, Social Affairs Minister Ya'akov Margi and Religious Services Minister Michael Malchieli." Malchieli reportedly has postponed his resignation so he could attend a 20 July meeting of the panel investigating whether attorney general Gali Baharav-Miara should be dismissed. Deputy Minister of Agriculture Moshe Abutbul, Minister of Health Uriel Buso and Haim Biton, a minister in the Education Ministry, also submitted their resignation letters, while Arbel retracted his resignation letter. The last cabinet member from the party to submit it was Labor Minister Yoav Ben-Tzur. The ministers who resigned will return to the Knesset, replacing MKs Moshe Roth, Yitzhak Pindrus and Eliyahu Baruchi. Members of government Listed below are the current ministers in the government: Principles and priorities According to the agreements signed between Likud and each of its coalition partners, and the incoming government's published guideline principles, its stated priorities are to combat the cost of living, further centralize Orthodox control over the state religious services, pass judicial reforms which include legislation to reduce judicial controls on executive and legislative power, expand settlements in the West Bank, and consider an annexation of the West Bank. Before the vote of confidence in his new government in the Knesset, Netanyahu presented three top priorities for the new government: internal security and governance, halting the nuclear program of Iran, and the development of infrastructure, with a focus on further connecting the center of the country with its periphery. Policies The government's flagship program, centered around reforms in the judicial branch, drew widespread criticism. Critics said it would have negative effects on the separation of powers, the office of the Attorney General, the economy, public health, women and minorities, workers' rights, scientific research, the overall strength of Israel's democracy and its foreign relations. After weeks of public protests on Israel's streets, joined by a growing number of military reservists, Minister of Defense Yoav Gallant spoke against the reform on 25 March, calling for a halt of the legislative process "for the sake of Israel's security". The next day, Netanyahu announced that he would be removed from his post, sparking another wave of protest across Israel and ultimately leading to Netanyahu agreeing to pause the legislation. On 10 April, Netanyahu announced that Gallant would keep his post. On 27 March 2023, after the public protests and general strikes, Netanyahu announced a pause in the reform process to allow for dialogue with opposition parties. However, negotiations aimed at reaching a compromise collapsed in June, and the government resumed its plans to unilaterally pass parts of the legislation. On 24 July 2023, the Knesset passed a bill that curbs the power of the Supreme Court to declare government decisions unreasonable; on 1 January 2024, the Supreme Court struck the bill down. The Knesset passed a "watered-down" version of the judicial reform package in late March 2025 which "changes the composition" of the judicial selection committee. In December 2022 Minister of National Security Itamar Ben-Gvir sought to amend the law that regulates the operations of the Israel Police, such that the ministry will have more direct control of its forces and policies, including its investigative priorities. Attorney General Gali Baharav-Miara objected to the draft proposal, raising concerns that the law would enable the politicization of police work, and the draft was amended to partially address those concerns. Nevertheless, in March 2023 Deputy Attorney General Gil Limon stated that the Attorney General's fears had been realized, referring to several instances of ministerial involvement in the day-to-day work of the otherwise independent police force – statements that were repeated by the Attorney General herself two days later. Separately, Police Commissioner Kobi Shabtai instructed Deputy Commissioners to avoid direct communication with the minister, later stating that "the Israel Police will remain apolitical, and act only according to law". Following appeals by the Association for Civil Rights in Israel and the Movement for Quality Government in Israel, the High Court of Justice instructed Ben-Gvir "to refrain from giving operational directions to the police... [especially] as regards to protests and demonstrations against the government." As talks of halting the judicial reform gained wind during March 2023, Minister of National Security Itamar Ben-Gvir threatened to resign if the legislation implementing the changes was suspended. To appease Ben-Gvir, Prime Minister Netanyahu announced that the government would promote the creation of a new National Guard, to be headed by Ben-Gvir. On 29 March, thousands of Israelis demonstrated in Tel Aviv, Haifa and Jerusalem against this decision. On 1 April, the New York Times quoted Gadeer Nicola, head of the Arab department at the Association for Civil Rights in Israel, as saying "If this thing passes, it will be an imminent danger to the rights of Arab citizens in this country. This will create two separate systems of applying the law. The regular police which will operate against Jewish citizens — and a militarized militia to deal only with Arab citizens." The same day, while speaking on Israel's Channel 13 about those whom he'd like to see enlist in the National Guard, Ben-Gvir specifically mentioned La Familia, the far-right fan club of the Beitar Jerusalem soccer team. On 2 April, Israel's cabinet approved the establishment of a law enforcement body that would operate independently of the police, under Ben-Gvir's authority. According to the decision, the Minister was to establish a committee chaired by the Director General of the Ministry of National Security, with representatives of the ministries of defense, justice and finance, as well as the police and the IDF, to outline the operations of the new organization. The committee's recommendations will be submitted to the government for consideration. Addressing a conference on 4 April, Police Commissioner Kobi Shabtai said that he is not opposed to the establishment of a security body which would answer to the police, but "a separate body? Absolutely not." The police chief said he had warned Ben-Gvir that the establishment of a security body separate from the police is "unnecessary, with extremely high costs that may harm citizens' personal security." During a press conference on 10 April, Prime Minister Netanyahu said, in what has been seen by some news outlets as a concession to the protesters, that "This will not be anyone's militia, it will be a security body, orderly, professional, that will be subordinate to one of the [existing] security bodies." The committee established by the government recommended the government to order the establishment of the National Guard immediately while allocating budgets. The National Guard, under whose command will be a superintendent of the police, will not be subordinate to Ben-Gvir. It will be subordinate to the police commissioner and will be part of Israel Border Police. The Ministry of Defense and Finance opposed the conclusions. The Israeli National Security Council called for further discussion on this. The coalition's efforts to expand the purview of Rabbinical courts; force some organizations, such as hospitals, to enforce certain religious practices; amend the Law Prohibiting Discrimination to allow gender segregation and discrimination on the grounds of religious belief; expand funding for religious causes; and put into law the exemption of yeshiva and kolel students from conscription have drawn criticism. According to the Haaretz op-ed of 7 March 2023, "the current coalition is interested... in modifying the public space so it suits the religious lifestyle. The legal coup is meant to castrate anyone who can prevent it, most of all the HCJ." Several banks and institutional investors, including the Israel Discount Bank and AIG have committed to avoid investing in, or providing credit to any organization that will discriminate against others on ground of religion, race, gender or sexual orientation. A series of technology companies and investment firms including Wiz, Intel Israel, Salesforce and Microsoft Israel Research and Development, have criticized the proposed changes to the Law Prohibiting Discrimination, with Wiz stating that it will require its suppliers to commit to preventing discrimination. Over sixty prominent law firms pledged that they will neither represent, nor do business with discriminating individuals and organizations. Insight Partners, a major private equity fund operating in Israel, released a statement warning against intolerance and any attempt to harm personal liberties. Orit Lahav, chief executive of the women's rights organization Mavoi Satum ("Dead End"), said that "the Rabbinical courts are the most discriminatory institution in the State of Israel... Limiting the HCJ[d] while expanding the jurisdiction of the Rabbinical courts would... cause significant harm to women." Anat Thon Ashkenazy, Director of the Center for Democratic Values and Institutions at the Israel Democracy Institute, said that "almost every part of the reform could harm women... the meaning of an override clause is that even if the court says that the law on gender segregation is illegitimate, is harmful, the Knesset could say 'Okay, we say otherwise'". She added that "there is a very broad institutional framework here, after which there will come legislation that harms women's right and we will have no way of protecting or stopping it." During July 2023, 20 professional medical associations signed a letter of position warning against the ramifications to public health that would result from the exclusion of women from the public sphere. They cited, among others, a rise in prevalence of risk factors for cardiovascular disease, pregnancy-related ailments, psychological distress, and the risk of suicide. On 30 July the Knesset passed an amendment to penal law adding sexual offenses to those offenses whose penalty can be doubled if done on grounds of "nationalistic terrorism, racism or hostility towards a certain community". According to MK Limor Son Har-Melech, the bill is meant to penalize any individual who "[intends to] harm a woman sexually based on her Jewishness". The law was criticized by MK Gilad Kariv as "populist, nationalistic, and dangerous towards the Arab citizens of Israel", and by MK Ahmad Tibi as a "race law", and was objected to by legal advisors at the Ministry of Justice and the Knesset Committee on National Security. Activist Orit Kamir wrote that "the amendment... is neither feminist, equal, nor progressive, but the opposite: it subordinates women's sexuality to the nationalistic, racist patriarchy. It hijacks the Law for Prevention of Sexual Harassment to serve a world view that tags women as sexual objects that personify the nation's honor." Yael Sherer, director of the Lobby to Combat Sexual Violence, criticized the law as being informed by dated ideas about sexual assault, and proposed that MKs "dedicate a session... to give victims of sexual assault an opportunity to come out of the darkness... instead of [submitting] declarative bills that change nothing and are not meant but for grabbing headlines". In Israel, during 2022, 24 women "were murdered because they were women," which was an increase of 50% compared to 2021. A law permitting courts to order men subject to a restraining order following domestic violence offenses to wear electronic tags was drafted during the previous Knesset and had passed its first reading unanimously. On 22 March 2023, the Knesset voted to reject the bill. It had been urged to do so by National Security Minister Itamar Ben-Gvir, who said that the bill was unfair to men. Earlier in the week, Ben-Gvir had blocked the measure from advancing in the ministerial legislative committee. The MKs voting against the bill included Prime Minister Netanyahu. The Association of Families of Murder Victims said that by rejecting the law, National Security Minister Itamar Ben-Gvir "brings joy to violent men and abandons the women threatened with murder… unsupervised restraining orders endanger women's lives even more. They give women the illusion of being protected, and then they are murdered." MK Pnina Tamano-Shata, chairwoman of the Knesset Committee on the Status of Women and Gender Equality, said that "the coalition proved today that it despises women's lives." The NGO Amutat Bat Melech [he], which assists Orthodox and ultra-Orthodox women who suffer from domestic violence, said that: "Rejecting the electronic bracelet bill is disconnected from the terrible reality of seven femicides since the beginning of the year. This is an effective tool of the first degree that could have saved lives and reduced the threat to women suffering from domestic violence. This is a matter of life and death, whose whole purpose is to provide a solution to defend women." The agreement signed by the coalition parties includes the setting up of a committee to draft changes to the Law of Return. Israeli religious parties have long demanded that the "grandchild clause" of the Law of Return be cancelled. This clause grants citizenship to anyone with at least one Jewish grandparent, as long as they do not practice another religion. If the grandchild clause were to be removed from the Law of Return then around 3 million people who are currently eligible for aliyah would no longer be eligible. The heads of the Jewish Agency, the Jewish Federations of North America, the World Zionist Organization and Keren Hayesod sent a joint letter to Prime Minister Netanyahu, expressing their "deep concern" about any changes to the Law of Return, adding that "Any change in the delicate and sensitive status quo on issues such as the Law of Return or conversion could threaten to unravel the ties between us and keep us away from each other." The Executive Council of Australian Jewry and the Zionist Federation of Australia issued a joint statement saying "We… view with deep concern… proposals in relation to religious pluralism and the law of return that risk damaging Israel's… relationship with Diaspora Jewry." On 19 March 2023, Israeli Finance Minister Bezalel Smotrich spoke in Paris at a memorial service for a Likud activist. The lectern at which Smotrich spoke was covered with a flag depicting the 'Greater Land of Israel,' encompassing the whole of Mandatory Palestine, as well as Trans-Jordan. During his speech, Smotrich said that "there's no such thing as Palestinians because there's no such thing as a Palestinian people." He added that the Palestinian people are a fictitious nation invented only to fight the Zionist movement, asking "Is there a Palestinian history or culture? There isn't any." The event received widespread media coverage. On 21 March, a spokesman for the US State Department sharply criticized Smotrich's comments. "The comments, which were delivered at a podium adorned with an inaccurate and provocative map, are offensive, they are deeply concerning, and, candidly, they're dangerous. The Palestinians have a rich history and culture, and the United States greatly values our partnership with the Palestinian people," he said. The Jordanian Foreign Ministry also voiced disapproval: "The Israeli Minister of Finance's use, during his participation in an event held yesterday in Paris, of a map of Israel that includes the borders of the Hashemite Kingdom of Jordan and the occupied Palestinian territories represents a reckless inflammatory act, and a violation of international norms and the Jordanian-Israeli peace treaty." Additionally, a map encompassing Mandatory Palestine and Trans-Jordan with a Jordanian flag on it was placed on a central lectern in the Jordanian Parliament. Jordan's parliament voted to expel the Israeli ambassador. Israel's Ministry of Foreign Affairs released a clarification relating to the matter, stating that "Israel is committed to the 1994 peace agreement with Jordan. There has been no change in the position of the State of Israel, which recognizes the territorial integrity of the Hashemite Kingdom of Jordan". Ahead of a Europe Day event due to take place on 9 May 2023, far-right wing National Security Minister Itamar Ben-Gvir was assigned as a representative of the government and a speaker at the event by the government secretariat, which deals with placing ministers at receptions on the occasion of the national days of the foreign embassies. The European Union requested that Ben-Gvir not attend, but the government did not make changes to the plan. On 8 May, the European delegation to Israel cancelled the reception, stating that: "The EU Delegation to Israel is looking forward to celebrating Europe Day on May 9, as it does every year. Regrettably, this year we have decided to cancel the diplomatic reception, as we do not want to offer a platform to someone whose views contradict the values the European Union stands for. However, the Europe Day cultural event for the Israeli public will be maintained to celebrate with our friends and partners in Israel the strong and constructive bilateral relationship". Israel's Opposition Leader Yair Lapid stated: "Sending Itamar Ben-Gvir to a gathering of EU ambassadors is a serious professional mistake. The government is embarrassing a large group of friendly countries, jeopardizing future votes in international institutions, and damaging our foreign relations. Last year, after a decade of efforts, we succeeded in signing an economic-political agreement with the European Union that will contribute to the Israeli economy and our foreign relations. Why risk it, and for what? Ben-Gvir is not a legitimate person in the international community (and not really in Israel either), and sometimes you have to be both wise and just and simply send someone else". On 23 February 2023, Defense Minister Gallant signed an agreement assigning governmental powers in the West Bank to a body to be headed by Minister Bezalel Smotrich, who will effectively become the governor of the West Bank, controlling almost all areas of life in the area, including planning, building and infrastructure. Israeli governments have hitherto been careful to keep the occupation as a military government. The temporary holding of power by an occupying military force, pending a negotiated settlement, is a principle of international law – an expression of the prohibition against obtaining sovereignty through conquest that was introduced in the wake of World War II. An editorial in Haaretz noted that the assignment of governmental powers in the West Bank to a civilian governor, alongside the plan to expand the dual justice system so that Israeli law will apply fully to settlers in the West Bank, constitutes de jure annexation of the West Bank. On 26 February 2023, following the 2023 Huwara shooting in which two Israelis were killed by an unidentified attacker, hundreds of Israeli settlers attacked the Palestinian town of Huwara and three nearby villages, setting alight hundreds of Palestinian homes (some with people in them), businesses, a school, and numerous vehicles, killing one Palestinian man and injuring 100 others. Bezalel Smotrich subsequently called on Twitter for Huwara to be "wiped out" by the Israeli government. Zvika Fogel MK, of the ultra-nationalist Otzma Yehudit, which forms part of the governing coalition, said that he "looks very favorably upon" the results of the rampage. Members of the coalition proposed an amendment to the Disengagement Law, which would allow Israelis to resettle settlements vacated during the 2005 Israeli disengagement from Gaza and the northern West Bank. The evacuated settlements were considered illegal under international law, according to most countries. The proposal was approved for voting by the Foreign Affairs and Defense Committee on 9 March 2023, while the committee was still waiting for briefing materials from the NSS, IDF, MFA and Shin Bet, and was passed on 21 March. The US has requested clarification from Israeli ambassador Michael Herzog. A US State Department spokesman stated that "The U.S. strongly urges Israel to refrain from allowing the return of settlers to the area covered by the legislation, consistent with both former Prime Minister Sharon and the current Israeli Government's commitment to the United States," noting that the actions represent a clear violation of undertakings given by the Sharon government to the Bush administration in 2005 and Netanyahu's far-right coalition to the Biden administration the previous week. Minister of Communication Shlomo Karhi had initially intended to cut the funding of the Israeli Public Broadcasting Corporation (also known by its blanket branding Kan) by 400 million shekels – roughly half of its total budget – closing several departments, and privatizing content creation. In response, the Director-General of the European Broadcasting Union, Noel Curran, sent two urgent letters to Netanyahu, expressing his concerns and calling on the Israeli government to "safeguard the independence of our Member KAN and ensure it is allowed to operate in a sustainable way, with funding that is both stable, adequate, fair, and transparent." On 25 January 2023, nine journalist organizations representing some of Kan's competitors issued a statement of concern, acknowledging the "important contribution of public broadcasting in creating a worthy, unbiased and non-prejudicial journalistic platform", and noting that "the existence of the [broadcasting] corporation as a substantial public broadcast organization strengthens media as a whole, adding to the competition in the market rather than weakening it." They also expressed their concern that the "real reason" for the proposal was actually "an attempt to silence voices from which... [the Minister] doesn't always draw satisfaction". The same day, hundreds of journalists, actors and filmmakers protested in Tel Aviv. The proposal was eventually put on hold. On 22 February 2023 it was reported that Prime Minister Netanyahu was attempting to appoint his close associate Yossi Shelley as the deputy to the National Statistician — a highly sensitive position in charge of providing accurate data for decision makers. The appointment of Shelley, who did not possess the required qualifications for the role, was withdrawn following publication. In its daily editorial, Haaretz tied this attempt with the judicial reform: "once they take control of the judiciary, law enforcement and public media, they wish to control the state's data base, the dry numerical data it uses to plan its future". Netanyahu also proposed Avi Simhon for the role, and eventually froze all appointments at the Israel Central Bureau of Statistics. Also on 22 February 2023, it was revealed that Yoav Kish, the Minister of Education, was promoting a draft government decision change to the National Library of Israel board of directors which would grant him more power over the institution. In response, the Hebrew University — which owned the library until 2008 – announced that if the draft is accepted, it will withdraw its collections from the library. The university's collections, which according to the university constitute some 80% of the library's collection, include the Agnon archive, the original manuscript of Hatikvah, and the Rothschild Haggadah, the oldest known Haggadah. A group of 300 authors and poets signed an open letter against the move, further noting their objection against "political takeover" of public broadcasting, as well as "any legislation that will castrate the judiciary and damage the democratic foundations of the state of Israel". Several days later, it was reported that a series of donors decided to withhold their donations to the library, totaling some 80 million shekels. On 3 March a petition against the move by 1,500 academics, including Israel Prize laureates, was sent to Kish. The proposal has been seen by some as retribution against Shai Nitzan, the former State Attorney and the library's current rector. On 5 March it was reported that the Legal Advisor to the Ministry of Finance, Asi Messing, was withholding the proposal. According to Messing, the proposal – which was being promoted as part of the Economic Arrangements Law – "was not reviewed... by the qualified personnel in the Ministry of Finance, does not align with any of the common goals of the economic plan, was not agreed to by myself and was not approved by the Attorney General." As of February 2023, the government has been debating several proposals that will significantly weaken the Ministry of Environmental Protection, including reducing the environmental regulation of planning and development and electricity production. One of the main proposals, the transferal of a 3 billion shekel fund meant to finance waste management plants from the Ministry of Environmental Protection to the Ministry of the Interior, was eventually withdrawn. The Minister of Environmental Protection, Idit Silman, has been criticized for using for meeting with climate change denialists, for wasteful and personally-motivated travel on the ministry's expense, for politicizing the role, and for engaging in political activity on the ministry's time. The government has been noted for an unusually high number of dismissals and resignations of senior career civil servants, and for the frequent attempts to replace them with candidates with known political associations, who are often less competent. According to sources, Netanyahu and people in his vicinity are seeking out civil servants who were appointed by the previous government, intent on replacing them with people loyal to him. Governmental nominees for various positions have been criticized for lack of expertise. In addition to the nominee to the position of Deputy National Statistician (see above), the Director General of the Ministry of Finance, Shlomi Heisler; the Director General of the Ministry of Justice, Itamar Donenfeld; and the Director General of Ministry of Transport, Moshe Ben Zaken, have all been criticized for incompetence, lack of familiarity with their Ministries' subject matter, lack of interest in the job, or lack of experience in managing large organizations. It has been reported that in some ministries, senior officials were enacting slowdowns as a means for dealing with the new ministers and director generals. On 28 July the director general of the Ministry of Education resigned, citing as reason the societal "rift". Asaf Zalel, a retired Air Force Brigadier General, was appointed in January. When asked about attempts to appoint his personal friend and attorney to the board of directors of a state-owned company, Minister David Amsalem replied: "that is my job, due to my authority to appoint directors. I put forward people that I know and hold in esteem". Under Minister of Transport Miri Regev, the ministry has either dismissed or lost the heads of the National Public Transport Authority, Israel Airports Authority, National Road Safety Authority, Israel Railways, and several officials in Netivei Israel. The current chair of Netivei Israel is Likud member and Regev associate Yigal Amadi, and the legal counsel is Einav Abuhzira, daughter of a former Likud branch chair. Abuhzira was appointed instead of Elad Berdugo, nephew of Netanyahu surrogate Yaakov Bardugo, after he was disqualified for the role by the Israel Government Companies Authority. In July 2023 the Ministry of Communications, Shlomo Karhi, and the minister in charge of the Israel Government Companies Authority, Dudi Amsalem, deposed the chair of the Israel Postal Company, Michael Vaknin. The chair, who was hired to lead the company's financial recovery after years of operational loss and towards privatization, has gained the support of officials at the Authority and at the Ministry of Finance; nevertheless, the ministers claimed that his performance is inadequate, and nominated in his place Yiftah Ron-Tal, who has known ties to Netanyahu and Smotrich. They also nominated four new directors, two of which have known political associations, and a third who was a witness in Netanyahu's trial. The coalition is allowed to spend a portion of the state's budget on a discretionary basis, meant to coax member parties to reach an agreement on the budget. As of May 2023, the government was pushing an allocation of over 13 billion shekels over two years - almost seven times the amount allocated by the previous government. Most of the funds will be allocated for uses associated with the religious, orthodox and settler communities. The head of the Budget Department at the Ministry of Finance, Yoav Gardos, objected to the allocations, claiming they would exacerbate unemployment in the Orthodox community, which is projected to cost the economy a total of 6.7 trillion shekels in lost produce by 2065. At the onset of the Gaza war and the declaration of a state of national emergency, Minister of Finance Bezalel Smotrich instructed government agencies to continue with the planned distribution of discretionary funds. Corruption During March 2023, the government was promoting an amendment to the Law on Public Service (Gifts) that would allow Netanyahu to receive donations to fund his legal defense. The amendment follows a decision by the High Court of Justice (HCJ) that forced Netanyahu to refund US$270,000 given to him and his wife by his late cousin, Nathan Mileikowsky, for their legal defense. This is in contrast to past statements by Minister of Justice Yariv Levin, who spoke against the possible conflict of interests that can result from such transactions. The bill was opposed by the Attorney General Gali Baharav-Miara, who stressed that it could "create a real opportunity for governmental corruption", and was eventually withdrawn at the end of March. As of March 2023, the coalition was promoting a bill that would prevent judicial review of ministerial appointments. The bill is intended to prevent the HCJ from reviewing the appointment of the twice-convicted chairman of Shas, Aryeh Deri (convicted of bribery, fraud, and breach of trust), to a ministerial position, after his previous appointment was annulled on grounds of unreasonableness. The bill follows on the heels of another amendment, that relaxed the ban on the appointment of convicted criminals, so that Deri - who was handed a suspended sentence after his second conviction - could be appointed. The bill is opposed by the Attorney General, as well as by the Knesset Legal Adviser, Sagit Afik. Israeli law allows for declaring a Prime Minister (as well as several other high-ranking public officials) to be temporarily or permanently incapacitated, but does not specify the conditions which can lead to a declaration of incapacitation. In the case of the Prime Minister, the authority to do so is given to the Attorney General. In March 2023, the coalition advanced a bill that passes this authority from the Attorney General to the government with the approval of the Knesset committee, and clarified that incapacitation can only result from medical or mental conditions. On 3 January 2024, the Supreme Court ruled by a majority of 6 out of 11 that the validity of the law will be postponed to the next Knesset because the bill in its immediate application is a personal law and is intended to serve a distinct personal purpose. Later, the court rejected a petition regarding the definition of Netanyahu as an incapacitated prime minister due to his ongoing trial and conflict of interests. Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/GHz] | [TOKENS: 1830] |
Contents Hertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second.[a] The hertz is an SI derived unit whose formal expression in terms of SI base units is 1/s or s−1, meaning that one hertz is one per second or the reciprocal of one second. It is used only in the case of periodic events. It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. For high frequencies, the unit is commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon, via the Planck relation E = hν, where E is the photon's energy, ν is its frequency, and h is the Planck constant. Definition The hertz is defined as one per second for periodic events. The International Committee for Weights and Measures defined the second as "the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom" and then adds: "It follows that the hyperfine splitting in the ground state of the caesium 133 atom is exactly 9192631770 hertz, νhfs Cs = 9192631770 Hz." The dimension of the unit hertz is 1/time (T−1). Expressed in base SI units, the unit is the reciprocal second (1/s). In English, "hertz" is also used as the plural form. As an SI unit, Hz can be prefixed; commonly used multiples are kHz (kilohertz, 103 Hz), MHz (megahertz, 106 Hz), GHz (gigahertz, 109 Hz) and THz (terahertz, 1012 Hz). One hertz (i.e. one per second) simply means "one periodic event occurs per second" (where the event being counted may be a complete cycle); 100 Hz means "one hundred periodic events occur per second", and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz. The occurrence rate of aperiodic or stochastic events is expressed in reciprocal second or inverse second (1/s or s−1) in general or, in the specific case of radioactivity, in becquerels.[b] Whereas 1 Hz (one per second) specifically refers to one cycle (or periodic event) per second, 1 Bq (also one per second) specifically refers to one radionuclide event per second on average. Even though frequency, angular velocity, angular frequency and radioactivity all have the dimension T−1, of these only frequency is expressed using the unit hertz. Thus a disc rotating at 60 revolutions per minute (rpm) is said to have an angular velocity of 2π rad/s and a frequency of rotation of 1 Hz. The correspondence between a frequency f with the unit hertz and an angular velocity ω with the unit radians per second is The hertz is named after Heinrich Hertz. As with every SI unit named after a person, its symbol starts with an upper case letter (Hz), but when written in full, it follows the rules for capitalisation of a common noun; i.e., hertz becomes capitalised at the beginning of a sentence and in titles but is otherwise in lower case. History The hertz is named after the German physicist Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1935. It was adopted by the General Conference on Weights and Measures (CGPM) (Conférence générale des poids et mesures) in 1960, replacing the previous name for the unit, "cycles per second" (cps), along with its related multiples, primarily "kilocycles per second" (kc/s) and "megacycles per second" (Mc/s), and occasionally "kilomegacycles per second" (kMc/s). The term "cycles per second" was largely replaced by "hertz" by the 1970s.[failed verification] In some usage, the "per second" was omitted, so that "megacycles" (Mc) was used as an abbreviation of "megacycles per second" (that is, megahertz (MHz)). Applications Sound is a traveling longitudinal wave, which is an oscillation of pressure. Humans perceive the frequency of a sound as its pitch. Each musical note corresponds to a particular frequency. An infant's ear is able to perceive frequencies ranging from 20 Hz to 20000 Hz; the average adult human can hear sounds between 20 Hz and 16000 Hz. The range of ultrasound, infrasound and other physical vibrations such as molecular and atomic vibrations extends from a few femtohertz into the terahertz range[c] and beyond. Electromagnetic radiation is often described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz. Radio frequency radiation is usually measured in kilohertz (kHz), megahertz (MHz), or gigahertz (GHz), with the latter known as microwaves. Light is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens of terahertz (THz, infrared) to a few petahertz (PHz, ultraviolet), with the visible spectrum being 400–790 THz. Electromagnetic radiation with frequencies in the low terahertz range (intermediate between those of the highest normally usable radio frequencies and long-wave infrared light) is often called terahertz radiation. Even higher frequencies exist, such as that of X-rays and gamma rays, which can be measured in exahertz (EHz). For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their wavelengths or photon energies: for a more detailed treatment of this and the above frequency ranges, see Electromagnetic spectrum. Current[when?] observations of gravitational waves are conducted in the 30–7000 Hz range by laser interferometers like LIGO, and the nanohertz (1–1000 nHz) range by pulsar timing arrays. Future space-based detectors are planned to fill in the gap, with LISA operating from 0.1–10 mHz (with some sensitivity from 10 μHz to 100 mHz), and DECIGO in the 0.1–10 Hz range. In computers, most central processing units (CPU) are labeled in terms of their clock rate expressed in megahertz (MHz) or gigahertz (GHz). This specification refers to the frequency of the CPU's master clock signal. This signal is nominally a square wave, which is an electrical voltage that switches between low and high logic levels at regular intervals. As the hertz has become the primary unit of measurement accepted by the general populace to determine the performance of a CPU, many experts have criticized this approach, which they claim is an easily manipulable benchmark. Some processors use multiple clock cycles to perform a single operation, while others can perform multiple operations in a single cycle. For personal computers, CPU clock speeds have ranged from approximately 1 MHz in the late 1970s (Atari, Commodore, Apple computers) to up to 6 GHz in IBM Power microprocessors. Various computer buses, such as the front-side bus connecting the CPU and northbridge, also operate at various frequencies in the megahertz range. SI multiples Higher frequencies than the International System of Units provides prefixes for are believed to occur naturally in the frequencies of the quantum-mechanical vibrations of massive particles, although these are not directly observable and must be inferred through other phenomena. By convention, these are typically not expressed in hertz, but in terms of the equivalent energy, which is proportional to the frequency by the factor of the Planck constant. Unicode The CJK Compatibility block in Unicode contains characters for common SI units for frequency. These are intended for compatibility with East Asian character encodings, and not for use in new documents (which would be expected to use Latin letters, e.g. "MHz"). See also Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Animal#cite_note-204] | [TOKENS: 6011] |
Contents Animal Animals are multicellular, eukaryotic organisms belonging to the biological kingdom Animalia (/ˌænɪˈmeɪliə/). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.6 m (110 ft). They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviour is known as ethology. The animal kingdom is divided into five major clades, namely Porifera, Ctenophora, Placozoa, Cnidaria and Bilateria. Most living animal species belong to the clade Bilateria, a highly proliferative clade whose members have a bilaterally symmetric and significantly cephalised body plan, and the vast majority of bilaterians belong to two large clades: the protostomes, which includes organisms such as arthropods, molluscs, flatworms, annelids and nematodes; and the deuterostomes, which include echinoderms, hemichordates and chordates, the latter of which contains the vertebrates. The much smaller basal phylum Xenacoelomorpha have an uncertain position within Bilateria. Animals first appeared in the fossil record in the late Cryogenian period and diversified in the subsequent Ediacaran period in what is known as the Avalon explosion. Nearly all modern animal phyla first appeared in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago (Mya), and most classes during the Ordovician radiation 485.4 Mya. Common to all living animals, 6,331 groups of genes have been identified that may have arisen from a single common ancestor that lived about 650 Mya during the Cryogenian period. Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between taxa. Humans make use of many other animal species for food (including meat, eggs, and dairy products), for materials (such as leather, fur, and wool), as pets and as working animals for transportation, and services. Dogs, the first domesticated animal, have been used in hunting, in security and in warfare, as have horses, pigeons and birds of prey; while other terrestrial and aquatic animals are hunted for sports, trophies or profits. Non-human animals are also an important cultural element of human evolution, having appeared in cave arts and totems since the earliest times, and are frequently featured in mythology, religion, arts, literature, heraldry, politics, and sports. Etymology The word animal comes from the Latin noun animal of the same meaning, which is itself derived from Latin animalis 'having breath or soul'. The biological definition includes all members of the kingdom Animalia. In colloquial usage, the term animal is often used to refer only to nonhuman animals. The term metazoa is derived from Ancient Greek μετα meta 'after' (in biology, the prefix meta- stands for 'later') and ζῷᾰ zōia 'animals', plural of ζῷον zōion 'animal'. A metazoan is any member of the group Metazoa. Characteristics Animals have several characteristics that they share with other living things. Animals are eukaryotic, multicellular, and aerobic, as are plants and fungi. Unlike plants and algae, which produce their own food, animals cannot produce their own food, a feature they share with fungi. Animals ingest organic material and digest it internally. Animals have structural characteristics that set them apart from all other living things: Typically, there is an internal digestive chamber with either one opening (in Ctenophora, Cnidaria, and flatworms) or two openings (in most bilaterians). Animal development is controlled by Hox genes, which signal the times and places to develop structures such as body segments and limbs. During development, the animal extracellular matrix forms a relatively flexible framework upon which cells can move about and be reorganised into specialised tissues and organs, making the formation of complex structures possible, and allowing cells to be differentiated. The extracellular matrix may be calcified, forming structures such as shells, bones, and spicules. In contrast, the cells of other multicellular organisms (primarily algae, plants, and fungi) are held in place by cell walls, and so develop by progressive growth. Nearly all animals make use of some form of sexual reproduction. They produce haploid gametes by meiosis; the smaller, motile gametes are spermatozoa and the larger, non-motile gametes are ova. These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, and develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement. It first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm, also develops between them. These germ layers then differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction generally leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. Some animals are capable of asexual reproduction, which often results in a genetic clone of the parent. This may take place through fragmentation; budding, such as in Hydra and other cnidarians; or parthenogenesis, where fertile eggs are produced without mating, such as in aphids. Ecology Animals are categorised into ecological groups depending on their trophic levels and how they consume organic material. Such groupings include carnivores (further divided into subcategories such as piscivores, insectivores, ovivores, etc.), herbivores (subcategorised into folivores, graminivores, frugivores, granivores, nectarivores, algivores, etc.), omnivores, fungivores, scavengers/detritivores, and parasites. Interactions between animals of each biome form complex food webs within that ecosystem. In carnivorous or omnivorous species, predation is a consumer–resource interaction where the predator feeds on another organism, its prey, who often evolves anti-predator adaptations to avoid being fed upon. Selective pressures imposed on one another lead to an evolutionary arms race between predator and prey, resulting in various antagonistic/competitive coevolutions. Almost all multicellular predators are animals. Some consumers use multiple methods; for example, in parasitoid wasps, the larvae feed on the hosts' living tissues, killing them in the process, but the adults primarily consume nectar from flowers. Other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. Most animals rely on biomass and bioenergy produced by plants and phytoplanktons (collectively called producers) through photosynthesis. Herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores. Animals oxidise carbohydrates, lipids, proteins and other biomolecules in cellular respiration, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion. Some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis (via oxidising inorganic compounds such as hydrogen sulfide) by archaea and bacteria. Animals originated in the ocean; all extant animal phyla, except for Micrognathozoa and Onychophora, feature at least some marine species. However, several lineages of arthropods begun to colonise land around the same time as land plants, probably between 510 and 471 million years ago, during the Late Cambrian or Early Ordovician. Vertebrates such as the lobe-finned fish Tiktaalik started to move on to land in the late Devonian, about 375 million years ago. Other notable animal groups that colonized land environments are Mollusca, Platyhelmintha, Annelida, Tardigrada, Onychophora, Rotifera, Nematoda. Animals occupy virtually all of earth's habitats and microhabitats, with faunas adapted to salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of other organisms. Animals are however not particularly heat tolerant; very few of them can survive at constant temperatures above 50 °C (122 °F) or in the most extreme cold deserts of continental Antarctica. The collective global geomorphic influence of animals on the processes shaping the Earth's surface remains largely understudied, with most studies limited to individual species and well-known exemplars. Diversity The blue whale (Balaenoptera musculus) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33.6 metres (110 ft) long. The largest extant terrestrial animal is the African bush elephant (Loxodonta africana), weighing up to 12.25 tonnes and measuring up to 10.67 metres (35.0 ft) long. The largest terrestrial animals that ever lived were titanosaur sauropod dinosaurs such as Argentinosaurus, which may have weighed as much as 73 tonnes, and Supersaurus which may have reached 39 metres. Several animals are microscopic; some Myxozoa (obligate parasites within the Cnidaria) never grow larger than 20 μm, and one of the smallest species (Myxobolus shekel) is no more than 8.5 μm when fully grown. The following table lists estimated numbers of described extant species for the major animal phyla, along with their principal habitats (terrestrial, fresh water, and marine), and free-living or parasitic ways of life. Species estimates shown here are based on numbers described scientifically; much larger estimates have been calculated based on various means of prediction, and these can vary wildly. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million. Using patterns within the taxonomic hierarchy, the total number of animal species—including those not yet described—was calculated to be about 7.77 million in 2011.[a] 3,000–6,500 4,000–25,000 Evolutionary origin Evidence of animals is found as long ago as the Cryogenian period. 24-Isopropylcholestane (24-ipc) has been found in rocks from roughly 650 million years ago; it is only produced by sponges and pelagophyte algae. Its likely origin is from sponges based on molecular clock estimates for the origin of 24-ipc production in both groups. Analyses of pelagophyte algae consistently recover a Phanerozoic origin, while analyses of sponges recover a Neoproterozoic origin, consistent with the appearance of 24-ipc in the fossil record. The first body fossils of animals appear in the Ediacaran, represented by forms such as Charnia and Spriggina. It had long been doubted whether these fossils truly represented animals, but the discovery of the animal lipid cholesterol in fossils of Dickinsonia establishes their nature. Animals are thought to have originated under low-oxygen conditions, suggesting that they were capable of living entirely by anaerobic respiration, but as they became specialised for aerobic metabolism they became fully dependent on oxygen in their environments. Many animal phyla first appear in the fossil record during the Cambrian explosion, starting about 539 million years ago, in beds such as the Burgess Shale. Extant phyla in these rocks include molluscs, brachiopods, onychophorans, tardigrades, arthropods, echinoderms and hemichordates, along with numerous now-extinct forms such as the predatory Anomalocaris. The apparent suddenness of the event may however be an artefact of the fossil record, rather than showing that all these animals appeared simultaneously. That view is supported by the discovery of Auroralumina attenboroughii, the earliest known Ediacaran crown-group cnidarian (557–562 mya, some 20 million years before the Cambrian explosion) from Charnwood Forest, England. It is thought to be one of the earliest predators, catching small prey with its nematocysts as modern cnidarians do. Some palaeontologists have suggested that animals appeared much earlier than the Cambrian explosion, possibly as early as 1 billion years ago. Early fossils that might represent animals appear for example in the 665-million-year-old rocks of the Trezona Formation of South Australia. These fossils are interpreted as most probably being early sponges. Trace fossils such as tracks and burrows found in the Tonian period (from 1 gya) may indicate the presence of triploblastic worm-like animals, roughly as large (about 5 mm wide) and complex as earthworms. However, similar tracks are produced by the giant single-celled protist Gromia sphaerica, so the Tonian trace fossils may not indicate early animal evolution. Around the same time, the layered mats of microorganisms called stromatolites decreased in diversity, perhaps due to grazing by newly evolved animals. Objects such as sediment-filled tubes that resemble trace fossils of the burrows of wormlike animals have been found in 1.2 gya rocks in North America, in 1.5 gya rocks in Australia and North America, and in 1.7 gya rocks in Australia. Their interpretation as having an animal origin is disputed, as they might be water-escape or other structures. Phylogeny Animals are monophyletic, meaning they are derived from a common ancestor. Animals are the sister group to the choanoflagellates, with which they form the Choanozoa. Ros-Rocher and colleagues (2021) trace the origins of animals to unicellular ancestors, providing the external phylogeny shown in the cladogram. Uncertainty of relationships is indicated with dashed lines. The animal clade had certainly originated by 650 mya, and may have come into being as much as 800 mya, based on molecular clock evidence for different phyla. Holomycota (inc. fungi) Ichthyosporea Pluriformea Filasterea The relationships at the base of the animal tree have been debated. Other than Ctenophora, the Bilateria and Cnidaria are the only groups with symmetry, and other evidence shows they are closely related. In addition to sponges, Placozoa has no symmetry and was often considered a "missing link" between protists and multicellular animals. The presence of hox genes in Placozoa shows that they were once more complex. The Porifera (sponges) have long been assumed to be sister to the rest of the animals, but there is evidence that the Ctenophora may be in that position. Molecular phylogenetics has supported both the sponge-sister and ctenophore-sister hypotheses. In 2017, Roberto Feuda and colleagues, using amino acid differences, presented both, with the following cladogram for the sponge-sister view that they supported (their ctenophore-sister tree simply interchanging the places of ctenophores and sponges): Porifera Ctenophora Placozoa Cnidaria Bilateria Conversely, a 2023 study by Darrin Schultz and colleagues uses ancient gene linkages to construct the following ctenophore-sister phylogeny: Ctenophora Porifera Placozoa Cnidaria Bilateria Sponges are physically very distinct from other animals, and were long thought to have diverged first, representing the oldest animal phylum and forming a sister clade to all other animals. Despite their morphological dissimilarity with all other animals, genetic evidence suggests sponges may be more closely related to other animals than the comb jellies are. Sponges lack the complex organisation found in most other animal phyla; their cells are differentiated, but in most cases not organised into distinct tissues, unlike all other animals. They typically feed by drawing in water through pores, filtering out small particles of food. The Ctenophora and Cnidaria are radially symmetric and have digestive chambers with a single opening, which serves as both mouth and anus. Animals in both phyla have distinct tissues, but these are not organised into discrete organs. They are diploblastic, having only two main germ layers, ectoderm and endoderm. The tiny placozoans have no permanent digestive chamber and no symmetry; they superficially resemble amoebae. Their phylogeny is poorly defined, and under active research. The remaining animals, the great majority—comprising some 29 phyla and over a million species—form the Bilateria clade, which have a bilaterally symmetric body plan. The Bilateria are triploblastic, with three well-developed germ layers, and their tissues form distinct organs. The digestive chamber has two openings, a mouth and an anus, and in the Nephrozoa there is an internal body cavity, a coelom or pseudocoelom. These animals have a head end (anterior) and a tail end (posterior), a back (dorsal) surface and a belly (ventral) surface, and a left and a right side. A modern consensus phylogenetic tree for the Bilateria is shown below. Xenacoelomorpha Ambulacraria Chordata Ecdysozoa Spiralia Having a front end means that this part of the body encounters stimuli, such as food, favouring cephalisation, the development of a head with sense organs and a mouth. Many bilaterians have a combination of circular muscles that constrict the body, making it longer, and an opposing set of longitudinal muscles, that shorten the body; these enable soft-bodied animals with a hydrostatic skeleton to move by peristalsis. They also have a gut that extends through the basically cylindrical body from mouth to anus. Many bilaterian phyla have primary larvae which swim with cilia and have an apical organ containing sensory cells. However, over evolutionary time, descendant spaces have evolved which have lost one or more of each of these characteristics. For example, adult echinoderms are radially symmetric (unlike their larvae), while some parasitic worms have extremely simplified body structures. Genetic studies have considerably changed zoologists' understanding of the relationships within the Bilateria. Most appear to belong to two major lineages, the protostomes and the deuterostomes. It is often suggested that the basalmost bilaterians are the Xenacoelomorpha, with all other bilaterians belonging to the subclade Nephrozoa. However, this suggestion has been contested, with other studies finding that xenacoelomorphs are more closely related to Ambulacraria than to other bilaterians. Protostomes and deuterostomes differ in several ways. Early in development, deuterostome embryos undergo radial cleavage during cell division, while many protostomes (the Spiralia) undergo spiral cleavage. Animals from both groups possess a complete digestive tract, but in protostomes the first opening of the embryonic gut develops into the mouth, and the anus forms secondarily. In deuterostomes, the anus forms first while the mouth develops secondarily. Most protostomes have schizocoelous development, where cells simply fill in the interior of the gastrula to form the mesoderm. In deuterostomes, the mesoderm forms by enterocoelic pouching, through invagination of the endoderm. The main deuterostome taxa are the Ambulacraria and the Chordata. Ambulacraria are exclusively marine and include acorn worms, starfish, sea urchins, and sea cucumbers. The chordates are dominated by the vertebrates (animals with backbones), which consist of fishes, amphibians, reptiles, birds, and mammals. The protostomes include the Ecdysozoa, named after their shared trait of ecdysis, growth by moulting, Among the largest ecdysozoan phyla are the arthropods and the nematodes. The rest of the protostomes are in the Spiralia, named for their pattern of developing by spiral cleavage in the early embryo. Major spiralian phyla include the annelids and molluscs. History of classification In the classical era, Aristotle divided animals,[d] based on his own observations, into those with blood (roughly, the vertebrates) and those without. The animals were then arranged on a scale from man (with blood, two legs, rational soul) down through the live-bearing tetrapods (with blood, four legs, sensitive soul) and other groups such as crustaceans (no blood, many legs, sensitive soul) down to spontaneously generating creatures like sponges (no blood, no legs, vegetable soul). Aristotle was uncertain whether sponges were animals, which in his system ought to have sensation, appetite, and locomotion, or plants, which did not: he knew that sponges could sense touch and would contract if about to be pulled off their rocks, but that they were rooted like plants and never moved about. In 1758, Carl Linnaeus created the first hierarchical classification in his Systema Naturae. In his original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then, the last four have all been subsumed into a single phylum, the Chordata, while his Insecta (which included the crustaceans and arachnids) and Vermes have been renamed or broken up. The process was begun in 1793 by Jean-Baptiste de Lamarck, who called the Vermes une espèce de chaos ('a chaotic mess')[e] and split the group into three new phyla: worms, echinoderms, and polyps (which contained corals and jellyfish). By 1809, in his Philosophie Zoologique, Lamarck had created nine phyla apart from vertebrates (where he still had four phyla: mammals, birds, reptiles, and fish) and molluscs, namely cirripedes, annelids, crustaceans, arachnids, insects, worms, radiates, polyps, and infusorians. In his 1817 Le Règne Animal, Georges Cuvier used comparative anatomy to group the animals into four embranchements ('branches' with different body plans, roughly corresponding to phyla), namely vertebrates, molluscs, articulated animals (arthropods and annelids), and zoophytes (radiata) (echinoderms, cnidaria and other forms). This division into four was followed by the embryologist Karl Ernst von Baer in 1828, the zoologist Louis Agassiz in 1857, and the comparative anatomist Richard Owen in 1860. In 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms: Metazoa (multicellular animals, with five phyla: coelenterates, echinoderms, articulates, molluscs, and vertebrates) and Protozoa (single-celled animals), including a sixth animal phylum, sponges. The protozoa were later moved to the former kingdom Protista, leaving only the Metazoa as a synonym of Animalia. In human culture The human population exploits a large number of other animal species for food, both of domesticated livestock species in animal husbandry and, mainly at sea, by hunting wild species. Marine fish of many species are caught commercially for food. A smaller number of species are farmed commercially. Humans and their livestock make up more than 90% of the biomass of all terrestrial vertebrates, and almost as much as all insects combined. Invertebrates including cephalopods, crustaceans, insects—principally bees and silkworms—and bivalve or gastropod molluscs are hunted or farmed for food, fibres. Chickens, cattle, sheep, pigs, and other animals are raised as livestock for meat across the world. Animal fibres such as wool and silk are used to make textiles, while animal sinews have been used as lashings and bindings, and leather is widely used to make shoes and other items. Animals have been hunted and farmed for their fur to make items such as coats and hats. Dyestuffs including carmine (cochineal), shellac, and kermes have been made from the bodies of insects. Working animals including cattle and horses have been used for work and transport from the first days of agriculture. Animals such as the fruit fly Drosophila melanogaster serve a major role in science as experimental models. Animals have been used to create vaccines since their discovery in the 18th century. Some medicines such as the cancer drug trabectedin are based on toxins or other molecules of animal origin. People have used hunting dogs to help chase down and retrieve animals, and birds of prey to catch birds and mammals, while tethered cormorants have been used to catch fish. Poison dart frogs have been used to poison the tips of blowpipe darts. A wide variety of animals are kept as pets, from invertebrates such as tarantulas, octopuses, and praying mantises, reptiles such as snakes and chameleons, and birds including canaries, parakeets, and parrots all finding a place. However, the most kept pet species are mammals, namely dogs, cats, and rabbits. There is a tension between the role of animals as companions to humans, and their existence as individuals with rights of their own. A wide variety of terrestrial and aquatic animals are hunted for sport. The signs of the Western and Chinese zodiacs are based on animals. In China and Japan, the butterfly has been seen as the personification of a person's soul, and in classical representation the butterfly is also the symbol of the soul. Animals have been the subjects of art from the earliest times, both historical, as in ancient Egypt, and prehistoric, as in the cave paintings at Lascaux. Major animal paintings include Albrecht Dürer's 1515 The Rhinoceros, and George Stubbs's c. 1762 horse portrait Whistlejacket. Insects, birds and mammals play roles in literature and film, such as in giant bug movies. Animals including insects and mammals feature in mythology and religion. The scarab beetle was sacred in ancient Egypt, and the cow is sacred in Hinduism. Among other mammals, deer, horses, lions, bats, bears, and wolves are the subjects of myths and worship. See also Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Datagram_Congestion_Control_Protocol] | [TOKENS: 612] |
Contents Datagram Congestion Control Protocol In computer networking, the Datagram Congestion Control Protocol (DCCP) is a message-oriented transport layer protocol. DCCP implements reliable connection setup, teardown, Explicit Congestion Notification (ECN), congestion control, and feature negotiation. The IETF published DCCP as RFC 4340, a proposed standard, in March 2006. RFC 4336 provides an introduction. Operation DCCP provides a way to gain access to congestion-control mechanisms without having to implement them at the application layer. It allows for flow-based semantics like in Transmission Control Protocol (TCP) but does not provide reliable in-order delivery. Sequenced delivery within multiple streams, as in the Stream Control Transmission Protocol (SCTP), is not available in DCCP. A DCCP connection contains acknowledgment traffic as well as data traffic. Acknowledgments inform a sender whether its packets have arrived, and whether they were marked by Explicit Congestion Notification (ECN). Acknowledgements are transmitted as reliably as the congestion control mechanism in use requires, possibly completely reliably. DCCP has the option for very long (48-bit) sequence numbers corresponding to a packet ID, rather than a byte ID as in TCP. The long length of the sequence numbers aims to guard against "some blind attacks, such as the injection of DCCP-Resets into the connection". Applications DCCP is useful for applications with timing constraints on the delivery of data. Such applications include streaming media, multiplayer online games and Internet telephony. In such applications, old messages quickly become useless, so that getting new messages is preferred to resending lost messages. As of 2017[update] such applications have often either settled for TCP or used User Datagram Protocol (UDP) and implemented their own congestion-control mechanisms, or have no congestion control at all. While being useful for these applications, DCCP can also serve as a general congestion-control mechanism for UDP-based applications, by adding, as needed, mechanisms for reliable or in-order delivery on top of UDP/DCCP. In this context, DCCP allows the use of different, but generally TCP-friendly, congestion-control mechanisms. Implementations The following operating systems implement DCCP: Userspace library: Packet structure The DCCP generic header takes different forms depending on the value of X, the Extended Sequence Numbers bit. If X is one, the Sequence Number field is 48 bits long, and the generic header takes 16 bytes, as follows. If X is zero, only the low 24 bits of the Sequence Number are transmitted, and the generic header is 12 bytes long. Current development Similarly to the extension of TCP protocol adding multipath capability (MPTCP), a multipath extension of DCCP is under discussion at the IETF, correspondingly denoted as MP-DCCP. First implementations have already been developed, tested, and presented in a collaborative approach between operators and academia and are available as an open source solution. See also References External links |
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