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Contents Elon Musk Elon Reeve Musk (/ˈiːlɒn/ EE-lon; born June 28, 1971) is a businessman and entrepreneur known for his leadership of Tesla, SpaceX, Twitter, and xAI. Musk has been the wealthiest person in the world since 2025; as of February 2026,[update] Forbes estimates his net worth to be around US$852 billion. Born into a wealthy family in Pretoria, South Africa, Musk emigrated in 1989 to Canada; he has Canadian citizenship since his mother was born there. He received bachelor's degrees in 1997 from the University of Pennsylvania before moving to California to pursue business ventures. In 1995, Musk co-founded the software company Zip2. Following its sale in 1999, he co-founded X.com, an online payment company that later merged to form PayPal, which was acquired by eBay in 2002. Musk also became an American citizen in 2002. In 2002, Musk founded the space technology company SpaceX, becoming its CEO and chief engineer; the company has since led innovations in reusable rockets and commercial spaceflight. Musk joined the automaker Tesla as an early investor in 2004 and became its CEO and product architect in 2008; it has since become a leader in electric vehicles. In 2015, he co-founded OpenAI to advance artificial intelligence (AI) research, but later left; growing discontent with the organization's direction and their leadership in the AI boom in the 2020s led him to establish xAI, which became a subsidiary of SpaceX in 2026. In 2022, he acquired the social network Twitter, implementing significant changes, and rebranding it as X in 2023. His other businesses include the neurotechnology company Neuralink, which he co-founded in 2016, and the tunneling company the Boring Company, which he founded in 2017. In November 2025, a Tesla pay package worth $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Musk was the largest donor in the 2024 U.S. presidential election, where he supported Donald Trump. After Trump was inaugurated as president in early 2025, Musk served as Senior Advisor to the President and as the de facto head of the Department of Government Efficiency (DOGE). After a public feud with Trump, Musk left the Trump administration and returned to managing his companies. Musk is a supporter of global far-right figures, causes, and political parties. His political activities, views, and statements have made him a polarizing figure. Musk has been criticized for COVID-19 misinformation, promoting conspiracy theories, and affirming antisemitic, racist, and transphobic comments. His acquisition of Twitter was controversial due to a subsequent increase in hate speech and the spread of misinformation on the service, following his pledge to decrease censorship. His role in the second Trump administration attracted public backlash, particularly in response to DOGE. The emails he sent to Jeffrey Epstein are included in the Epstein files, which were published between 2025–26 and became a topic of worldwide debate. Early life Elon Reeve Musk was born on June 28, 1971, in Pretoria, South Africa's administrative capital. He is of British and Pennsylvania Dutch ancestry. His mother, Maye (née Haldeman), is a model and dietitian born in Saskatchewan, Canada, and raised in South Africa. Musk therefore holds both South African and Canadian citizenship from birth. His father, Errol Musk, is a South African electromechanical engineer, pilot, sailor, consultant, emerald dealer, and property developer, who partly owned a rental lodge at Timbavati Private Nature Reserve. His maternal grandfather, Joshua N. Haldeman, who died in a plane crash when Elon was a toddler, was an American-born Canadian chiropractor, aviator and political activist in the technocracy movement who moved to South Africa in 1950. Elon has a younger brother, Kimbal, a younger sister, Tosca, and four paternal half-siblings. Musk was baptized as a child in the Anglican Church of Southern Africa. Despite both Elon and Errol previously stating that Errol was a part owner of a Zambian emerald mine, in 2023, Errol recounted that the deal he made was to receive "a portion of the emeralds produced at three small mines". Errol was elected to the Pretoria City Council as a representative of the anti-apartheid Progressive Party and has said that his children shared their father's dislike of apartheid. After his parents divorced in 1979, Elon, aged around 9, chose to live with his father because Errol Musk had an Encyclopædia Britannica and a computer. Elon later regretted his decision and became estranged from his father. Elon has recounted trips to a wilderness school that he described as a "paramilitary Lord of the Flies" where "bullying was a virtue" and children were encouraged to fight over rations. In one incident, after an altercation with a fellow pupil, Elon was thrown down concrete steps and beaten severely, leading to him being hospitalized for his injuries. Elon described his father berating him after he was discharged from the hospital. Errol denied berating Elon and claimed, "The [other] boy had just lost his father to suicide, and Elon had called him stupid. Elon had a tendency to call people stupid. How could I possibly blame that child?" Elon was an enthusiastic reader of books, and had attributed his success in part to having read The Lord of the Rings, the Foundation series, and The Hitchhiker's Guide to the Galaxy. At age ten, he developed an interest in computing and video games, teaching himself how to program from the VIC-20 user manual. At age twelve, Elon sold his BASIC-based game Blastar to PC and Office Technology magazine for approximately $500 (equivalent to $1,600 in 2025). Musk attended Waterkloof House Preparatory School, Bryanston High School, and then Pretoria Boys High School, where he graduated. Musk was a decent but unexceptional student, earning a 61/100 in Afrikaans and a B on his senior math certification. Musk applied for a Canadian passport through his Canadian-born mother to avoid South Africa's mandatory military service, which would have forced him to participate in the apartheid regime, as well as to ease his path to immigration to the United States. While waiting for his application to be processed, he attended the University of Pretoria for five months. Musk arrived in Canada in June 1989, connected with a second cousin in Saskatchewan, and worked odd jobs, including at a farm and a lumber mill. In 1990, he entered Queen's University in Kingston, Ontario. Two years later, he transferred to the University of Pennsylvania, where he studied until 1995. Although Musk has said that he earned his degrees in 1995, the University of Pennsylvania did not award them until 1997 – a Bachelor of Arts in physics and a Bachelor of Science in economics from the university's Wharton School. He reportedly hosted large, ticketed house parties to help pay for tuition, and wrote a business plan for an electronic book-scanning service similar to Google Books. In 1994, Musk held two internships in Silicon Valley: one at energy storage startup Pinnacle Research Institute, which investigated electrolytic supercapacitors for energy storage, and another at Palo Alto–based startup Rocket Science Games. In 1995, he was accepted to a graduate program in materials science at Stanford University, but did not enroll. Musk decided to join the Internet boom of the 1990s, applying for a job at Netscape, to which he reportedly never received a response. The Washington Post reported that Musk lacked legal authorization to remain and work in the United States after failing to enroll at Stanford. In response, Musk said he was allowed to work at that time and that his student visa transitioned to an H1-B. According to numerous former business associates and shareholders, Musk said he was on a student visa at the time. Business career In 1995, Musk, his brother Kimbal, and Greg Kouri founded the web software company Zip2 with funding from a group of angel investors. They housed the venture at a small rented office in Palo Alto. Replying to Rolling Stone, Musk denounced the notion that they started their company with funds borrowed from Errol Musk, but in a tweet, he recognized that his father contributed 10% of a later funding round. The company developed and marketed an Internet city guide for the newspaper publishing industry, with maps, directions, and yellow pages. According to Musk, "The website was up during the day and I was coding it at night, seven days a week, all the time." To impress investors, Musk built a large plastic structure around a standard computer to create the impression that Zip2 was powered by a small supercomputer. The Musk brothers obtained contracts with The New York Times and the Chicago Tribune, and persuaded the board of directors to abandon plans for a merger with CitySearch. Musk's attempts to become CEO were thwarted by the board. Compaq acquired Zip2 for $307 million in cash in February 1999 (equivalent to $590,000,000 in 2025), and Musk received $22 million (equivalent to $43,000,000 in 2025) for his 7-percent share. In 1999, Musk co-founded X.com, an online financial services and e-mail payment company. The startup was one of the first federally insured online banks, and, in its initial months of operation, over 200,000 customers joined the service. The company's investors regarded Musk as inexperienced and replaced him with Intuit CEO Bill Harris by the end of the year. The following year, X.com merged with online bank Confinity to avoid competition. Founded by Max Levchin and Peter Thiel, Confinity had its own money-transfer service, PayPal, which was more popular than X.com's service. Within the merged company, Musk returned as CEO. Musk's preference for Microsoft software over Unix created a rift in the company and caused Thiel to resign. Due to resulting technological issues and lack of a cohesive business model, the board ousted Musk and replaced him with Thiel in 2000.[b] Under Thiel, the company focused on the PayPal service and was renamed PayPal in 2001. In 2002, PayPal was acquired by eBay for $1.5 billion (equivalent to $2,700,000,000 in 2025) in stock, of which Musk—the largest shareholder with 11.72% of shares—received $175.8 million (equivalent to $320,000,000 in 2025). In 2017, Musk purchased the domain X.com from PayPal for an undisclosed amount, stating that it had sentimental value. In 2001, Musk became involved with the nonprofit Mars Society and discussed funding plans to place a growth-chamber for plants on Mars. Seeking a way to launch the greenhouse payloads into space, Musk made two unsuccessful trips to Moscow to purchase intercontinental ballistic missiles (ICBMs) from Russian companies NPO Lavochkin and Kosmotras. Musk instead decided to start a company to build affordable rockets. With $100 million of his early fortune, (equivalent to $180,000,000 in 2025) Musk founded SpaceX in May 2002 and became the company's CEO and Chief Engineer. SpaceX attempted its first launch of the Falcon 1 rocket in 2006. Although the rocket failed to reach Earth orbit, it was awarded a Commercial Orbital Transportation Services program contract from NASA, then led by Mike Griffin. After two more failed attempts that nearly caused Musk to go bankrupt, SpaceX succeeded in launching the Falcon 1 into orbit in 2008. Later that year, SpaceX received a $1.6 billion NASA contract (equivalent to $2,400,000,000 in 2025) for Falcon 9-launched Dragon spacecraft flights to the International Space Station (ISS), replacing the Space Shuttle after its 2011 retirement. In 2012, the Dragon vehicle docked with the ISS, a first for a commercial spacecraft. Working towards its goal of reusable rockets, in 2015 SpaceX successfully landed the first stage of a Falcon 9 on a land platform. Later landings were achieved on autonomous spaceport drone ships, an ocean-based recovery platform. In 2018, SpaceX launched the Falcon Heavy; the inaugural mission carried Musk's personal Tesla Roadster as a dummy payload. Since 2019, SpaceX has been developing Starship, a reusable, super heavy-lift launch vehicle intended to replace the Falcon 9 and Falcon Heavy. In 2020, SpaceX launched its first crewed flight, the Demo-2, becoming the first private company to place astronauts into orbit and dock a crewed spacecraft with the ISS. In 2024, NASA awarded SpaceX an $843 million (equivalent to $865,000,000 in 2025) contract to build a spacecraft that NASA will use to deorbit the ISS at the end of its lifespan. In 2015, SpaceX began development of the Starlink constellation of low Earth orbit satellites to provide satellite Internet access. After the launch of prototype satellites in 2018, the first large constellation was deployed in May 2019. As of May 2025[update], over 7,600 Starlink satellites are operational, comprising 65% of all operational Earth satellites. The total cost of the decade-long project to design, build, and deploy the constellation was estimated by SpaceX in 2020 to be $10 billion (equivalent to $12,000,000,000 in 2025).[c] During the Russian invasion of Ukraine, Musk provided free Starlink service to Ukraine, permitting Internet access and communication at a yearly cost to SpaceX of $400 million (equivalent to $440,000,000 in 2025). However, Musk refused to block Russian state media on Starlink. In 2023, Musk denied Ukraine's request to activate Starlink over Crimea to aid an attack against the Russian navy, citing fears of a nuclear response. Tesla, Inc., originally Tesla Motors, was incorporated in July 2003 by Martin Eberhard and Marc Tarpenning. Both men played active roles in the company's early development prior to Musk's involvement. Musk led the Series A round of investment in February 2004; he invested $6.35 million (equivalent to $11,000,000 in 2025), became the majority shareholder, and joined Tesla's board of directors as chairman. Musk took an active role within the company and oversaw Roadster product design, but was not deeply involved in day-to-day business operations. Following a series of escalating conflicts in 2007 and the 2008 financial crisis, Eberhard was ousted from the firm.[page needed] Musk assumed leadership of the company as CEO and product architect in 2008. A 2009 lawsuit settlement with Eberhard designated Musk as a Tesla co-founder, along with Tarpenning and two others. Tesla began delivery of the Roadster, an electric sports car, in 2008. With sales of about 2,500 vehicles, it was the first mass production all-electric car to use lithium-ion battery cells. Under Musk, Tesla has since launched several well-selling electric vehicles, including the four-door sedan Model S (2012), the crossover Model X (2015), the mass-market sedan Model 3 (2017), the crossover Model Y (2020), and the pickup truck Cybertruck (2023). In May 2020, Musk resigned as chairman of the board as part of the settlement of a lawsuit from the SEC over him tweeting that funding had been "secured" for potentially taking Tesla private. The company has also constructed multiple lithium-ion battery and electric vehicle factories, called Gigafactories. Since its initial public offering in 2010, Tesla stock has risen significantly; it became the most valuable carmaker in summer 2020, and it entered the S&P 500 later that year. In October 2021, it reached a market capitalization of $1 trillion (equivalent to $1,200,000,000,000 in 2025), the sixth company in U.S. history to do so. Musk provided the initial concept and financial capital for SolarCity, which his cousins Lyndon and Peter Rive founded in 2006. By 2013, SolarCity was the second largest provider of solar power systems in the United States. In 2014, Musk promoted the idea of SolarCity building an advanced production facility in Buffalo, New York, triple the size of the largest solar plant in the United States. Construction of the factory started in 2014 and was completed in 2017. It operated as a joint venture with Panasonic until early 2020. Tesla acquired SolarCity for $2 billion in 2016 (equivalent to $2,700,000,000 in 2025) and merged it with its battery unit to create Tesla Energy. The deal's announcement resulted in a more than 10% drop in Tesla's stock price; at the time, SolarCity was facing liquidity issues. Multiple shareholder groups filed a lawsuit against Musk and Tesla's directors, stating that the purchase of SolarCity was done solely to benefit Musk and came at the expense of Tesla and its shareholders. Tesla directors settled the lawsuit in January 2020, leaving Musk the sole remaining defendant. Two years later, the court ruled in Musk's favor. In 2016, Musk co-founded Neuralink, a neurotechnology startup, with an investment of $100 million. Neuralink aims to integrate the human brain with artificial intelligence (AI) by creating devices that are embedded in the brain. Such technology could enhance memory or allow the devices to communicate with software. The company also hopes to develop devices to treat neurological conditions like spinal cord injuries. In 2022, Neuralink announced that clinical trials would begin by the end of the year. In September 2023, the Food and Drug Administration approved Neuralink to initiate six-year human trials. Neuralink has conducted animal testing on macaques at the University of California, Davis. In 2021, the company released a video in which a macaque played the video game Pong via a Neuralink implant. The company's animal trials—which have caused the deaths of some monkeys—have led to claims of animal cruelty. The Physicians Committee for Responsible Medicine has alleged that Neuralink violated the Animal Welfare Act. Employees have complained that pressure from Musk to accelerate development has led to botched experiments and unnecessary animal deaths. In 2022, a federal probe was launched into possible animal welfare violations by Neuralink.[needs update] In 2017, Musk founded the Boring Company to construct tunnels; he also revealed plans for specialized, underground, high-occupancy vehicles that could travel up to 150 miles per hour (240 km/h) and thus circumvent above-ground traffic in major cities. Early in 2017, the company began discussions with regulatory bodies and initiated construction of a 30-foot (9.1 m) wide, 50-foot (15 m) long, and 15-foot (4.6 m) deep "test trench" on the premises of SpaceX's offices, as that required no permits. The Los Angeles tunnel, less than two miles (3.2 km) in length, debuted to journalists in 2018. It used Tesla Model Xs and was reported to be a rough ride while traveling at suboptimal speeds. Two tunnel projects announced in 2018, in Chicago and West Los Angeles, have been canceled. A tunnel beneath the Las Vegas Convention Center was completed in early 2021. Local officials have approved further expansions of the tunnel system. April 14, 2022 In early 2017, Musk expressed interest in buying Twitter and had questioned the platform's commitment to freedom of speech. By 2022, Musk had reached 9.2% stake in the company, making him the largest shareholder.[d] Musk later agreed to a deal that would appoint him to Twitter's board of directors and prohibit him from acquiring more than 14.9% of the company. Days later, Musk made a $43 billion offer to buy Twitter. By the end of April Musk had successfully concluded his bid for approximately $44 billion. This included approximately $12.5 billion in loans and $21 billion in equity financing. Having backtracked on his initial decision, Musk bought the company on October 27, 2022. Immediately after the acquisition, Musk fired several top Twitter executives including CEO Parag Agrawal; Musk became the CEO instead. Under Elon Musk, Twitter instituted monthly subscriptions for a "blue check", and laid off a significant portion of the company's staff. Musk lessened content moderation and hate speech also increased on the platform after his takeover. In late 2022, Musk released internal documents relating to Twitter's moderation of Hunter Biden's laptop controversy in the lead-up to the 2020 presidential election. Musk also promised to step down as CEO after a Twitter poll, and five months later, Musk stepped down as CEO and transitioned his role to executive chairman and chief technology officer (CTO). Despite Musk stepping down as CEO, X continues to struggle with challenges such as viral misinformation, hate speech, and antisemitism controversies. Musk has been accused of trying to silence some of his critics such as Twitch streamer Asmongold, who criticized him during one of his streams. Musk has been accused of removing their accounts' blue checkmarks, which hinders visibility and is considered a form of shadow banning, or suspending their accounts without justification. Other activities In August 2013, Musk announced plans for a version of a vactrain, and assigned engineers from SpaceX and Tesla to design a transport system between Greater Los Angeles and the San Francisco Bay Area, at an estimated cost of $6 billion. Later that year, Musk unveiled the concept, dubbed the Hyperloop, intended to make travel cheaper than any other mode of transport for such long distances. In December 2015, Musk co-founded OpenAI, a not-for-profit artificial intelligence (AI) research company aiming to develop artificial general intelligence, intended to be safe and beneficial to humanity. Musk pledged $1 billion of funding to the company, and initially gave $50 million. In 2018, Musk left the OpenAI board. Since 2018, OpenAI has made significant advances in machine learning. In July 2023, Musk launched the artificial intelligence company xAI, which aims to develop a generative AI program that competes with existing offerings like OpenAI's ChatGPT. Musk obtained funding from investors in SpaceX and Tesla, and xAI hired engineers from Google and OpenAI. December 16, 2022 Musk uses a private jet owned by Falcon Landing LLC, a SpaceX-linked company, and acquired a second jet in August 2020. His heavy use of the jets and the consequent fossil fuel usage have received criticism. Musk's flight usage is tracked on social media through ElonJet. In December 2022, Musk banned the ElonJet account on Twitter, and made temporary bans on the accounts of journalists that posted stories regarding the incident, including Donie O'Sullivan, Keith Olbermann, and journalists from The New York Times, The Washington Post, CNN, and The Intercept. In October 2025, Musk's company xAI launched Grokipedia, an AI-generated online encyclopedia that he promoted as an alternative to Wikipedia. Articles on Grokipedia are generated and reviewed by xAI's Grok chatbot. Media coverage and academic analysis described Grokipedia as frequently reusing Wikipedia content but framing contested political and social topics in line with Musk's own views and right-wing narratives. A study by Cornell University researchers and NBC News stated that Grokipedia cites sources that are blacklisted or considered "generally unreliable" on Wikipedia, for example, the conspiracy site Infowars and the neo-Nazi forum Stormfront. Wired, The Guardian and Time criticized Grokipedia for factual errors and for presenting Musk himself in unusually positive terms while downplaying controversies. Politics Musk is an outlier among business leaders who typically avoid partisan political advocacy. Musk was a registered independent voter when he lived in California. Historically, he has donated to both Democrats and Republicans, many of whom serve in states in which he has a vested interest. Since 2022, his political contributions have mostly supported Republicans, with his first vote for a Republican going to Mayra Flores in the 2022 Texas's 34th congressional district special election. In 2024, he started supporting international far-right political parties, activists, and causes, and has shared misinformation and numerous conspiracy theories. Since 2024, his views have been generally described as right-wing. Musk supported Barack Obama in 2008 and 2012, Hillary Clinton in 2016, Joe Biden in 2020, and Donald Trump in 2024. In the 2020 Democratic Party presidential primaries, Musk endorsed candidate Andrew Yang and expressed support for Yang's proposed universal basic income, and endorsed Kanye West's 2020 presidential campaign. In 2021, Musk publicly expressed opposition to the Build Back Better Act, a $3.5 trillion legislative package endorsed by Joe Biden that ultimately failed to pass due to unanimous opposition from congressional Republicans and several Democrats. In 2022, gave over $50 million to Citizens for Sanity, a conservative political action committee. In 2023, he supported Republican Ron DeSantis for the 2024 U.S. presidential election, giving $10 million to his campaign, and hosted DeSantis's campaign announcement on a Twitter Spaces event. From June 2023 to January 2024, Musk hosted a bipartisan set of X Spaces with Republican and Democratic candidates, including Robert F. Kennedy Jr., Vivek Ramaswamy, and Dean Phillips. In October 2025, former vice-president Kamala Harris commented that it was a mistake from the Democratic side to not invite Musk to a White House electric vehicle event organized in August 2021 and featuring executives from General Motors, Ford and Stellantis, despite Tesla being "the major American manufacturer of extraordinary innovation in this space." Fortune remarked that this was a nod to United Auto Workers and organized labor. Harris said presidents should put aside political loyalties when it came to recognizing innovation, and guessed that the non-invitation impacted Musk's perspective. Fortune noted that, at the time, Musk said, "Yeah, seems odd that Tesla wasn't invited." A month later, he criticized Biden as "not the friendliest administration." Jacob Silverman, author of the book Gilded Rage: Elon Musk and the Radicalization of Silicon Valley, said that the tech industry represented by Musk, Thiel, Andreessen and other capitalists, actually flourished under Biden, but the tech leaders chose Trump for their common ground on cultural issues. By early 2024, Musk had become a vocal and financial supporter of Donald Trump. In July 2024, minutes after the attempted assassination of Donald Trump, Musk endorsed him for president saying; "I fully endorse President Trump and hope for his rapid recovery." During the presidential campaign, Musk joined Trump on stage at a campaign rally, and during the campaign promoted conspiracy theories and falsehoods about Democrats, election fraud and immigration, in support of Trump. Musk was the largest individual donor of the 2024 election. In 2025, Musk contributed $19 million to the Wisconsin Supreme Court race, hoping to influence the state's future redistricting efforts and its regulations governing car manufacturers and dealers. In 2023, Musk said he shunned the World Economic Forum because it was boring. The organization commented that they had not invited him since 2015. He has participated in Dialog, dubbed "Tech Bilderberg" and organized by Peter Thiel and Auren Hoffman, though. Musk's international political actions and comments have come under increasing scrutiny and criticism, especially from the governments and leaders of France, Germany, Norway, Spain and the United Kingdom, particularly due to his position in the U.S. government as well as ownership of X. An NBC News analysis found he had boosted far-right political movements to cut immigration and curtail regulation of business in at least 18 countries on six continents since 2023. During his speech after the second inauguration of Donald Trump, Musk twice made a gesture interpreted by many as a Nazi or a fascist Roman salute.[e] He thumped his right hand over his heart, fingers spread wide, and then extended his right arm out, emphatically, at an upward angle, palm down and fingers together. He then repeated the gesture to the crowd behind him. As he finished the gestures, he said to the crowd, "My heart goes out to you. It is thanks to you that the future of civilization is assured." It was widely condemned as an intentional Nazi salute in Germany, where making such gestures is illegal. The Anti-Defamation League said it was not a Nazi salute, but other Jewish organizations disagreed and condemned the salute. American public opinion was divided on partisan lines as to whether it was a fascist salute. Musk dismissed the accusations of Nazi sympathies, deriding them as "dirty tricks" and a "tired" attack. Neo-Nazi and white supremacist groups celebrated it as a Nazi salute. Multiple European political parties demanded that Musk be banned from entering their countries. The concept of DOGE emerged in a discussion between Musk and Donald Trump, and in August 2024, Trump committed to giving Musk an advisory role, with Musk accepting the offer. In November and December 2024, Musk suggested that the organization could help to cut the U.S. federal budget, consolidate the number of federal agencies, and eliminate the Consumer Financial Protection Bureau, and that its final stage would be "deleting itself". In January 2025, the organization was created by executive order, and Musk was designated a "special government employee". Musk led the organization and was a senior advisor to the president, although his official role is not clear. In sworn statement during a lawsuit, the director of the White House Office of Administration stated that Musk "is not an employee of the U.S. DOGE Service or U.S. DOGE Service Temporary Organization", "is not the U.S. DOGE Service administrator", and has "no actual or formal authority to make government decisions himself". Trump said two days later that he had put Musk in charge of DOGE. A federal judge has ruled that Musk acted as the de facto leader of DOGE. Musk's role in the second Trump administration, particularly in response to DOGE, has attracted public backlash. He was criticized for his treatment of federal government employees, including his influence over the mass layoffs of the federal workforce. He has prioritized secrecy within the organization and has accused others of violating privacy laws. A Senate report alleged that Musk could avoid up to $2 billion in legal liability as a result of DOGE's actions. In May 2025, Bill Gates accused Musk of "killing the world's poorest children" through his cuts to USAID, which modeling by Boston University estimated had resulted in 300,000 deaths by this time, most of them of children. By November 2025, the estimated death toll had increased to 400,000 children and 200,000 adults. Musk announced on May 28, 2025, that he would depart from the Trump administration as planned when the special government employee's 130 day deadline expired, with a White House official confirming that Musk's offboarding from the Trump administration was already underway. His departure was officially confirmed during a joint Oval Office press conference with Trump on May 30, 2025. @realDonaldTrump is in the Epstein files. That is the real reason they have not been made public. June 5, 2025 After leaving office, Musk criticized the Trump administration's Big Beautiful Bill, calling it a "disgusting abomination" due to its provisions increasing the deficit. A feud began between Musk and Trump, with its most notable event being Musk alleging Trump had ties to sex offender Jeffrey Epstein on X (formerly Twitter) on June 5, 2025. Trump responded on Truth Social stating that Musk went "CRAZY" after the "EV Mandate" was purportedly taken away and threatened to cut Musk's government contracts. Musk then called for a third Trump impeachment. The next day, Trump stated that he did not wish to reconcile with Musk, and added that Musk would face "very serious consequences" if he funds Democratic candidates. On June 11, Musk publicly apologized for the tweets against Trump, saying they "went too far". Views November 6, 2022 Rejecting the conservative label, Musk has described himself as a political moderate, even as his views have become more right-wing over time. His views have been characterized as libertarian and far-right, and after his involvement in European politics, they have received criticism from world leaders such as Emmanuel Macron and Olaf Scholz. Within the context of American politics, Musk supported Democratic candidates up until 2022, at which point he voted for a Republican for the first time. He has stated support for universal basic income, gun rights, freedom of speech, a tax on carbon emissions, and H-1B visas. Musk has expressed concern about issues such as artificial intelligence (AI) and climate change, and has been a critic of wealth tax, short-selling, and government subsidies. An immigrant himself, Musk has been accused of being anti-immigration, and regularly blames immigration policies for illegal immigration. He is also a pronatalist who believes population decline is the biggest threat to civilization, and identifies as a cultural Christian. Musk has long been an advocate for space colonization, especially the colonization of Mars. He has repeatedly pushed for humanity colonizing Mars, in order to become an interplanetary species and lower the risks of human extinction. Musk has promoted conspiracy theories and made controversial statements that have led to accusations of racism, sexism, antisemitism, transphobia, disseminating disinformation, and support of white pride. While describing himself as a "pro-Semite", his comments regarding George Soros and Jewish communities have been condemned by the Anti-Defamation League and the Biden White House. Musk was criticized during the COVID-19 pandemic for making unfounded epidemiological claims, defying COVID-19 lockdowns restrictions, and supporting the Canada convoy protest against vaccine mandates. He has amplified false claims of white genocide in South Africa. Musk has been critical of Israel's actions in the Gaza Strip during the Gaza war, praised China's economic and climate goals, suggested that Taiwan and China should resolve cross-strait relations, and was described as having a close relationship with the Chinese government. In Europe, Musk expressed support for Ukraine in 2022 during the Russian invasion, recommended referendums and peace deals on the annexed Russia-occupied territories, and supported the far-right Alternative for Germany political party in 2024. Regarding British politics, Musk blamed the 2024 UK riots on mass migration and open borders, criticized Prime Minister Keir Starmer for what he described as a "two-tier" policing system, and was subsequently attacked as being responsible for spreading misinformation and amplifying the far-right. He has also voiced his support for far-right activist Tommy Robinson and pledged electoral support for Reform UK. In February 2026, Musk described Spanish Prime Minister Pedro Sánchez as a "tyrant" following Sánchez's proposal to prohibit minors under the age of 16 from accessing social media platforms. Legal affairs In 2018, Musk was sued by the U.S. Securities and Exchange Commission (SEC) for a tweet stating that funding had been secured for potentially taking Tesla private.[f] The securities fraud lawsuit characterized the tweet as false, misleading, and damaging to investors, and sought to bar Musk from serving as CEO of publicly traded companies. Two days later, Musk settled with the SEC, without admitting or denying the SEC's allegations. As a result, Musk and Tesla were fined $20 million each, and Musk was forced to step down for three years as Tesla chairman but was able to remain as CEO. Shareholders filed a lawsuit over the tweet, and in February 2023, a jury found Musk and Tesla not liable. Musk has stated in interviews that he does not regret posting the tweet that triggered the SEC investigation. In 2019, Musk stated in a tweet that Tesla would build half a million cars that year. The SEC reacted by asking a court to hold him in contempt for violating the terms of the 2018 settlement agreement. A joint agreement between Musk and the SEC eventually clarified the previous agreement details, including a list of topics about which Musk needed preclearance. In 2020, a judge blocked a lawsuit that claimed a tweet by Musk regarding Tesla stock price ("too high imo") violated the agreement. Freedom of Information Act (FOIA)-released records showed that the SEC concluded Musk had subsequently violated the agreement twice by tweeting regarding "Tesla's solar roof production volumes and its stock price". In October 2023, the SEC sued Musk over his refusal to testify a third time in an investigation into whether he violated federal law by purchasing Twitter stock in 2022. In February 2024, Judge Laurel Beeler ruled that Musk must testify again. In January 2025, the SEC filed a lawsuit against Musk for securities violations related to his purchase of Twitter. In January 2024, Delaware judge Kathaleen McCormick ruled in a 2018 lawsuit that Musk's $55 billion pay package from Tesla be rescinded. McCormick called the compensation granted by the company's board "an unfathomable sum" that was unfair to shareholders. The Delaware Supreme Court overturned McCormick's decision in December 2025, restoring Musk's compensation package and awarding $1 in nominal damages. Personal life Musk became a U.S. citizen in 2002. From the early 2000s until late 2020, Musk resided in California, where both Tesla and SpaceX were founded. He then relocated to Cameron County, Texas, saying that California had become "complacent" about its economic success. While hosting Saturday Night Live in 2021, Musk stated that he has Asperger syndrome (an outdated term for autism spectrum disorder). When asked about his experience growing up with Asperger's syndrome in a TED2022 conference in Vancouver, Musk stated that "the social cues were not intuitive ... I would just tend to take things very literally ... but then that turned out to be wrong — [people were not] simply saying exactly what they mean, there's all sorts of other things that are meant, and [it] took me a while to figure that out." Musk suffers from back pain and has undergone several spine-related surgeries, including a disc replacement. In 2000, he contracted a severe case of malaria while on vacation in South Africa. Musk has stated he uses doctor-prescribed ketamine for occasional depression and that he doses "a small amount once every other week or something like that"; since January 2024, some media outlets have reported that he takes ketamine, marijuana, LSD, ecstasy, mushrooms, cocaine and other drugs. Musk at first refused to comment on his alleged drug use, before responding that he had not tested positive for drugs, and that if drugs somehow improved his productivity, "I would definitely take them!". The New York Times' investigations revealed Musk's overuse of ketamine and numerous other drugs, as well as strained family relationships and concerns from close associates who have become troubled by his public behavior as he became more involved in political activities and government work. According to The Washington Post, President Trump described Musk as "a big-time drug addict". Through his own label Emo G Records, Musk released a rap track, "RIP Harambe", on SoundCloud in March 2019. The following year, he released an EDM track, "Don't Doubt Ur Vibe", featuring his own lyrics and vocals. Musk plays video games, which he stated has a "'restoring effect' that helps his 'mental calibration'". Some games he plays include Quake, Diablo IV, Elden Ring, and Polytopia. Musk once claimed to be one of the world's top video game players but has since admitted to "account boosting", or cheating by hiring outside services to achieve top player rankings. Musk has justified the boosting by claiming that all top accounts do it so he has to as well to remain competitive. In 2024 and 2025, Musk criticized the video game Assassin's Creed Shadows and its creator Ubisoft for "woke" content. Musk posted to X that "DEI kills art" and specified the inclusion of the historical figure Yasuke in the Assassin's Creed game as offensive; he also called the game "terrible". Ubisoft responded by saying that Musk's comments were "just feeding hatred" and that they were focused on producing a game not pushing politics. Musk has fathered at least 14 children, one of whom died as an infant. The Wall Street Journal reported in 2025 that sources close to Musk suggest that the "true number of Musk's children is much higher than publicly known". He had six children with his first wife, Canadian author Justine Wilson, whom he met while attending Queen's University in Ontario, Canada; they married in 2000. In 2002, their first child Nevada Musk died of sudden infant death syndrome at the age of 10 weeks. After his death, the couple used in vitro fertilization (IVF) to continue their family; they had twins in 2004, followed by triplets in 2006. The couple divorced in 2008 and have shared custody of their children. The elder twin he had with Wilson came out as a trans woman and, in 2022, officially changed her name to Vivian Jenna Wilson, adopting her mother's surname because she no longer wished to be associated with Musk. Musk began dating English actress Talulah Riley in 2008. They married two years later at Dornoch Cathedral in Scotland. In 2012, the couple divorced, then remarried the following year. After briefly filing for divorce in 2014, Musk finalized a second divorce from Riley in 2016. Musk then dated the American actress Amber Heard for several months in 2017; he had reportedly been "pursuing" her since 2012. In 2018, Musk and Canadian musician Grimes confirmed they were dating. Grimes and Musk have three children, born in 2020, 2021, and 2022.[g] Musk and Grimes originally gave their eldest child the name "X Æ A-12", which would have violated California regulations as it contained characters that are not in the modern English alphabet; the names registered on the birth certificate are "X" as a first name, "Æ A-Xii" as a middle name, and "Musk" as a last name. They received criticism for choosing a name perceived to be impractical and difficult to pronounce; Musk has said the intended pronunciation is "X Ash A Twelve". Their second child was born via surrogacy. Despite the pregnancy, Musk confirmed reports that the couple were "semi-separated" in September 2021; in an interview with Time in December 2021, he said he was single. In October 2023, Grimes sued Musk over parental rights and custody of X Æ A-Xii. Elon Musk has taken X Æ A-Xii to multiple official events in Washington, D.C. during Trump's second term in office. Also in July 2022, The Wall Street Journal reported that Musk allegedly had an affair with Nicole Shanahan, the wife of Google co-founder Sergey Brin, in 2021, leading to their divorce the following year. Musk denied the report. Musk also had a relationship with Australian actress Natasha Bassett, who has been described as "an occasional girlfriend". In October 2024, The New York Times reported Musk bought a Texas compound for his children and their mothers, though Musk denied having done so. Musk also has four children with Shivon Zilis, director of operations and special projects at Neuralink: twins born via IVF in 2021, a child born in 2024 via surrogacy and a child born in 2025.[h] On February 14, 2025, Ashley St. Clair, an influencer and author, posted on X claiming to have given birth to Musk's son Romulus five months earlier, which media outlets reported as Musk's supposed thirteenth child.[i] On February 22, 2025, it was reported that St Clair had filed for sole custody of her five-month-old son and for Musk to be recognised as the child's father. On March 31, 2025, Musk wrote that, while he was unsure if he was the father of St. Clair's child, he had paid St. Clair $2.5 million and would continue paying her $500,000 per year.[j] Later reporting from the Wall Street Journal indicated that $1 million of these payments to St. Clair were structured as a loan. In 2014, Musk and Ghislaine Maxwell appeared together in a photograph taken at an Academy Awards after-party, which Musk later described as a "photobomb". The January 2026 Epstein files contain emails between Musk and Epstein from 2012 to 2013, after Epstein's first conviction. Emails released on January 30, 2026, indicated that Epstein invited Musk to visit his private island on multiple occasions. The correspondence showed that while Epstein repeatedly encouraged Musk to attend, Musk did not visit the island. In one instance, Musk discussed the possibility of attending a party with his then-wife Talulah Riley and asked which day would be the "wildest party"; according to the emails, the visit did not take place after Epstein later cancelled the plans.[k] On Christmas day in 2012, Musk emailed Epstein asking "Do you have any parties planned? I’ve been working to the edge of sanity this year and so, once my kids head home after Christmas, I really want to hit the party scene in St Barts or elsewhere and let loose. The invitation is much appreciated, but a peaceful island experience is the opposite of what I’m looking for". Epstein replied that the "ratio on my island" might make Musk's wife uncomfortable to which Musk responded, "Ratio is not a problem for Talulah". On September 11, 2013, Epstein sent an email asking Musk if he had any plans for coming to New York for the opening of the United Nations General Assembly where many "interesting people" would be coming to his house to which Musk responded that "Flying to NY to see UN diplomats do nothing would be an unwise use of time". Epstein responded by stating "Do you think i am retarded. Just kidding, there is no one over 25 and all very cute." Musk has denied any close relationship with Epstein and described him as a "creep" who attempted to ingratiate himself with influential people. When Musk was asked in 2019 if he introduced Epstein to Mark Zuckerberg, Musk responded: "I don’t recall introducing Epstein to anyone, as I don’t know the guy well enough to do so." The released emails nonetheless showed cordial exchanges on a range of topics, including Musk's inquiry about parties on the island. The correspondence also indicated that Musk suggested hosting Epstein at SpaceX, while Epstein separately discussed plans to tour SpaceX and bring "the girls", though there is no evidence that such a visit occurred. Musk has described the release of the files a "distraction", later accusing the second Trump administration of suppressing them to protect powerful individuals, including Trump himself.[l] Wealth Elon Musk is the wealthiest person in the world, with an estimated net worth of US$690 billion as of January 2026, according to the Bloomberg Billionaires Index, and $852 billion according to Forbes, primarily from his ownership stakes in SpaceX and Tesla. Having been first listed on the Forbes Billionaires List in 2012, around 75% of Musk's wealth was derived from Tesla stock in November 2020, although he describes himself as "cash poor". According to Forbes, he became the first person in the world to achieve a net worth of $300 billion in 2021; $400 billion in December 2024; $500 billion in October 2025; $600 billion in mid-December 2025; $700 billion later that month; and $800 billion in February 2026. In November 2025, a Tesla pay package worth potentially $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Public image Although his ventures have been highly influential within their separate industries starting in the 2000s, Musk only became a public figure in the early 2010s. He has been described as an eccentric who makes spontaneous and impactful decisions, while also often making controversial statements, contrary to other billionaires who prefer reclusiveness to protect their businesses. Musk's actions and his expressed views have made him a polarizing figure. Biographer Ashlee Vance described people's opinions of Musk as polarized due to his "part philosopher, part troll" persona on Twitter. He has drawn denouncement for using his platform to mock the self-selection of personal pronouns, while also receiving praise for bringing international attention to matters like British survivors of grooming gangs. Musk has been described as an American oligarch due to his extensive influence over public discourse, social media, industry, politics, and government policy. After Trump's re-election, Musk's influence and actions during the transition period and the second presidency of Donald Trump led some to call him "President Musk", the "actual president-elect", "shadow president" or "co-president". Awards for his contributions to the development of the Falcon rockets include the American Institute of Aeronautics and Astronautics George Low Transportation Award in 2008, the Fédération Aéronautique Internationale Gold Space Medal in 2010, and the Royal Aeronautical Society Gold Medal in 2012. In 2015, he received an honorary doctorate in engineering and technology from Yale University and an Institute of Electrical and Electronics Engineers Honorary Membership. Musk was elected a Fellow of the Royal Society (FRS) in 2018.[m] In 2022, Musk was elected to the National Academy of Engineering. Time has listed Musk as one of the most influential people in the world in 2010, 2013, 2018, and 2021. Musk was selected as Time's "Person of the Year" for 2021. Then Time editor-in-chief Edward Felsenthal wrote that, "Person of the Year is a marker of influence, and few individuals have had more influence than Musk on life on Earth, and potentially life off Earth too." Notes References Works cited Further reading External links |
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Editing Social network (section) Copy and paste: – — ° ′ ″ ≈ ≠ ≤ ≥ ± − × ÷ ← → · § Cite your sources: <ref></ref> {{}} {{{}}} | [] [[]] [[Category:]] #REDIRECT [[]] <s></s> <sup></sup> <sub></sub> <code></code> <pre></pre> <blockquote></blockquote> <ref></ref> <ref name="" /> {{Reflist}} <references /> <includeonly></includeonly> <noinclude></noinclude> {{DEFAULTSORT:}} <nowiki></nowiki> <!-- --> <span class="plainlinks"></span> Symbols: ~ | ¡ ¿ † ‡ ↔ ↑ ↓ • ¶ # ∞ ‹› «» ¤ ₳ ฿ ₵ ¢ ₡ ₢ $ ₫ ₯ € ₠ ₣ ƒ ₴ ₭ ₤ ℳ ₥ ₦ ₧ ₰ £ ៛ ₨ ₪ ৳ ₮ ₩ ¥ ♠ ♣ ♥ ♦ 𝄫 ♭ ♮ ♯ 𝄪 © ¼ ½ ¾ Latin: A a Á á À à  â Ä ä Ǎ ǎ Ă ă Ā ā à ã Å å Ą ą Æ æ Ǣ ǣ B b C c Ć ć Ċ ċ Ĉ ĉ Č č Ç ç D d Ď ď Đ đ Ḍ ḍ Ð ð E e É é È è Ė ė Ê ê Ë ë Ě ě Ĕ ĕ Ē ē Ẽ ẽ Ę ę Ẹ ẹ Ɛ ɛ Ǝ ǝ Ə ə F f G g Ġ ġ Ĝ ĝ Ğ ğ Ģ ģ H h Ĥ ĥ Ħ ħ Ḥ ḥ I i İ ı Í í Ì ì Î î Ï ï Ǐ ǐ Ĭ ĭ Ī ī Ĩ ĩ Į į Ị ị J j Ĵ ĵ K k Ķ ķ L l Ĺ ĺ Ŀ ŀ Ľ ľ Ļ ļ Ł ł Ḷ ḷ Ḹ ḹ M m Ṃ ṃ N n Ń ń Ň ň Ñ ñ Ņ ņ Ṇ ṇ Ŋ ŋ O o Ó ó Ò ò Ô ô Ö ö Ǒ ǒ Ŏ ŏ Ō ō Õ õ Ǫ ǫ Ọ ọ Ő ő Ø ø Œ œ Ɔ ɔ P p Q q R r Ŕ ŕ Ř ř Ŗ ŗ Ṛ ṛ Ṝ ṝ S s Ś ś Ŝ ŝ Š š Ş ş Ș ș Ṣ ṣ ß T t Ť ť Ţ ţ Ț ț Ṭ ṭ Þ þ U u Ú ú Ù ù Û û Ü ü Ǔ ǔ Ŭ ŭ Ū ū Ũ ũ Ů ů Ų ų Ụ ụ Ű ű Ǘ ǘ Ǜ ǜ Ǚ ǚ Ǖ ǖ V v W w Ŵ ŵ X x Y y Ý ý Ŷ ŷ Ÿ ÿ Ỹ ỹ Ȳ ȳ Z z Ź ź Ż ż Ž ž ß Ð ð Þ þ Ŋ ŋ Ə ə Greek: Ά ά Έ έ Ή ή Ί ί Ό ό Ύ ύ Ώ ώ Α α Β β Γ γ Δ δ Ε ε Ζ ζ Η η Θ θ Ι ι Κ κ Λ λ Μ μ Ν ν Ξ ξ Ο ο Π π Ρ ρ Σ σ ς Τ τ Υ υ Φ φ Χ χ Ψ ψ Ω ω {{Polytonic|}} Cyrillic: А а Б б В в Г г Ґ ґ Ѓ ѓ Д д Ђ ђ Е е Ё ё Є є Ж ж З з Ѕ ѕ И и І і Ї ї Й й Ј ј К к Ќ ќ Л л Љ љ М м Н н Њ њ О о П п Р р С с Т т Ћ ћ У у Ў ў Ф ф Х х Ц ц Ч ч Џ џ Ш ш Щ щ Ъ ъ Ы ы Ь ь Э э Ю ю Я я ́ IPA: t̪ d̪ ʈ ɖ ɟ ɡ ɢ ʡ ʔ ɸ β θ ð ʃ ʒ ɕ ʑ ʂ ʐ ç ʝ ɣ χ ʁ ħ ʕ ʜ ʢ ɦ ɱ ɳ ɲ ŋ ɴ ʋ ɹ ɻ ɰ ʙ ⱱ ʀ ɾ ɽ ɫ ɬ ɮ ɺ ɭ ʎ ʟ ɥ ʍ ɧ ʼ ɓ ɗ ʄ ɠ ʛ ʘ ǀ ǃ ǂ ǁ ɨ ʉ ɯ ɪ ʏ ʊ ø ɘ ɵ ɤ ə ɚ ɛ œ ɜ ɝ ɞ ʌ ɔ æ ɐ ɶ ɑ ɒ ʰ ʱ ʷ ʲ ˠ ˤ ⁿ ˡ ˈ ˌ ː ˑ ̪ {{IPA|}} This page is a member of 6 hidden categories (help): |
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[SOURCE: https://en.wikipedia.org/wiki/SQR] | [TOKENS: 665] |
Contents SQR SQR (Hyperion SQR Production Reporting, Part of OBIEE) is a programming language designed for generating reports from database management systems. The name is an abbreviation of Structured Query Reporter, which suggests its relationship to SQL (Structured Query Language). Any SQL statement can be embedded in an SQR program. History In the early 80's SQR was a 'free' add-on to Gupta's SQLBase. At the time SQLBase was the only relational database that ran on IBM PCs (x86) machines. SQR was written by Israel Stern in Cleveland, Ohio, probably around 1984 or 1985. SQ Software created SQR in the mid 1980s. It had a marketing agreement with D & N Systems, which changed its name to SQL Solutions and was later acquired by Sybase Inc in the early 1990s. To avoid competing directly with Oracle Corporation, Sybase had a marketing and development agreement with MITI for the Oracle database compatible versions of SQR. MITI acquired the full rights to SQR in the mid-1990s. MITI changed its name to SQRiBE Technologies in 1997. Brio Technology acquired SQRiBE in August, 1999. Brio Technology later changed its name to Brio Software. Brio licensed its source code to PeopleSoft Inc. sometime around 2000. Hyperion Solutions Corporation acquired Brio Software in October, 2003. Oracle Corporation acquired PeopleSoft in December, 2004. In March 2007, Oracle Corporation acquired Hyperion Solutions. SQR-related products General components Features SQR is notable for its database and printing functions. It can embed any SQL statement almost anywhere in a program. One configuration of SQR can access multidimensional databases such as Essbase. It can combine database reads with print instructions, flexibly format data and page breaks, and print variable fonts, sizes, and colors. SQR contains a graph generation command that offers dozens of parameters for adjusting content and appearance. Syntax SQR has four scalar data types. The first three are numeric (variables begin with “#”), character string (variables begin with “$”), and date (variables begin with “$”, same as with character string variables.). Date variables must be declared, to be distinguished from character string variables. Numeric variables may be of more specific types: integer, floating point,...). Database column variables begin with “&”. The values of database columns are set only by a SQL “select” statement; no other command can change their values. SQR has an array data structure. An array has one or more fields, each of one of the available types. Each field may have multiple occurrences, giving SQR the equivalent of two-dimensional arrays. SQR has commands that manipulate multiple items within a single array. SQR has four control structures. The first three are if-else-end, while-end, and evaluate. The fourth is the embedded SQL “select” statement, which allows SQR statements to be executed for each row of data in a loop. SQR has commands to open, read, write, append, and close computer files. File input and output is sequential and record-oriented only; random access is not supported. See also Further reading References |
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[SOURCE: https://en.wikipedia.org/wiki/Mars#cite_note-144] | [TOKENS: 11899] |
Contents Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", for its orange-red appearance. Mars is a desert-like rocky planet with a tenuous atmosphere that is primarily carbon dioxide (CO2). At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from −153 to 20 °C (−243 to 68 °F), and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, fog, frost, larger polar regions of permafrost and ice caps (with seasonal CO2 snow), but no bodies of liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. Its diameter, 6,779 km (4,212 mi), is about half the Earth's, or twice the Moon's, and its surface area is the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south divide, the Martian dichotomy, with the northern hemisphere mainly consisting of relatively flat, low lying plains, and the southern hemisphere of cratered highlands. Geologically, the planet is fairly active with marsquakes trembling underneath the ground, but also hosts many enormous volcanoes that are extinct (the tallest is Olympus Mons, 21.9 km or 13.6 mi tall), as well as one of the largest canyons in the Solar System (Valles Marineris, 4,000 km or 2,500 mi long). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos. With a significant axial tilt of 25 degrees, Mars experiences seasons, like Earth (which has an axial tilt of 23.5 degrees). A Martian solar year is equal to 1.88 Earth years (687 Earth days), a Martian solar day (sol) is equal to 24.6 hours. Mars formed along with the other planets approximately 4.5 billion years ago. During the martian Noachian period (4.5 to 3.5 billion years ago), its surface was marked by meteor impacts, valley formation, erosion, the possible presence of water oceans and the loss of its magnetosphere. The Hesperian period (beginning 3.5 billion years ago and ending 3.3–2.9 billion years ago) was dominated by widespread volcanic activity and flooding that carved immense outflow channels. The Amazonian period, which continues to the present, is the currently dominating and remaining influence on geological processes. Because of Mars's geological history, the possibility of past or present life on Mars remains an area of active scientific investigation, with some possible traces needing further examination. Being visible with the naked eye in Earth's sky as a red wandering star, Mars has been observed throughout history, acquiring diverse associations in different cultures. In 1963 the first flight to Mars took place with Mars 1, but communication was lost en route. The first successful flyby exploration of Mars was conducted in 1965 with Mariner 4. In 1971 Mariner 9 entered orbit around Mars, being the first spacecraft to orbit any body other than the Moon, Sun or Earth; following in the same year were the first uncontrolled impact (Mars 2) and first successful landing (Mars 3) on Mars. Probes have been active on Mars continuously since 1997. At times, more than ten probes have simultaneously operated in orbit or on the surface, more than at any other planet beyond Earth. Mars is an often proposed target for future crewed exploration missions, though no such mission is currently planned. Natural history Scientists have theorized that during the Solar System's formation, Mars was created as the result of a random process of run-away accretion of material from the protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points, such as chlorine, phosphorus, and sulfur, are much more common on Mars than on Earth; these elements were probably pushed outward by the young Sun's energetic solar wind. After the formation of the planets, the inner Solar System may have been subjected to the so-called Late Heavy Bombardment. About 60% of the surface of Mars shows a record of impacts from that era, whereas much of the remaining surface is probably underlain by immense impact basins caused by those events. However, more recent modeling has disputed the existence of the Late Heavy Bombardment. There is evidence of an enormous impact basin in the Northern Hemisphere of Mars, spanning 10,600 by 8,500 kilometres (6,600 by 5,300 mi), or roughly four times the size of the Moon's South Pole–Aitken basin, which would be the largest impact basin yet discovered if confirmed. It has been hypothesized that the basin was formed when Mars was struck by a Pluto-sized body about four billion years ago. The event, thought to be the cause of the Martian hemispheric dichotomy, created the smooth Borealis basin that covers 40% of the planet. A 2023 study shows evidence, based on the orbital inclination of Deimos (a small moon of Mars), that Mars may once have had a ring system 3.5 billion years to 4 billion years ago. This ring system may have been formed from a moon, 20 times more massive than Phobos, orbiting Mars billions of years ago; and Phobos would be a remnant of that ring. Epochs: The geological history of Mars can be split into many periods, but the following are the three primary periods: Geological activity is still taking place on Mars. The Athabasca Valles is home to sheet-like lava flows created about 200 million years ago. Water flows in the grabens called the Cerberus Fossae occurred less than 20 million years ago, indicating equally recent volcanic intrusions. The Mars Reconnaissance Orbiter has captured images of avalanches. Physical characteristics Mars is approximately half the diameter of Earth or twice that of the Moon, with a surface area only slightly less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity. Mars is the only presently known example of a desert planet, a rocky planet with a surface akin to that of Earth's deserts. The red-orange appearance of the Martian surface is caused by iron(III) oxide (nanophase Fe2O3) and the iron(III) oxide-hydroxide mineral goethite. It can look like butterscotch; other common surface colors include golden, brown, tan, and greenish, depending on the minerals present. Like Earth, Mars is differentiated into a dense metallic core overlaid by less dense rocky layers. The outermost layer is the crust, which is on average about 42–56 kilometres (26–35 mi) thick, with a minimum thickness of 6 kilometres (3.7 mi) in Isidis Planitia, and a maximum thickness of 117 kilometres (73 mi) in the southern Tharsis plateau. For comparison, Earth's crust averages 27.3 ± 4.8 km in thickness. The most abundant elements in the Martian crust are silicon, oxygen, iron, magnesium, aluminum, calcium, and potassium. Mars is confirmed to be seismically active; in 2019, it was reported that InSight had detected and recorded over 450 marsquakes and related events. Beneath the crust is a silicate mantle responsible for many of the tectonic and volcanic features on the planet's surface. The upper Martian mantle is a low-velocity zone, where the velocity of seismic waves is lower than surrounding depth intervals. The mantle appears to be rigid down to the depth of about 250 km, giving Mars a very thick lithosphere compared to Earth. Below this the mantle gradually becomes more ductile, and the seismic wave velocity starts to grow again. The Martian mantle does not appear to have a thermally insulating layer analogous to Earth's lower mantle; instead, below 1050 km in depth, it becomes mineralogically similar to Earth's transition zone. At the bottom of the mantle lies a basal liquid silicate layer approximately 150–180 km thick. The Martian mantle appears to be highly heterogenous, with dense fragments up to 4 km across, likely injected deep into the planet by colossal impacts ~4.5 billion years ago; high-frequency waves from eight marsquakes slowed as they passed these localized regions, and modeling indicates the heterogeneities are compositionally distinct debris preserved because Mars lacks plate tectonics and has a sluggishly convecting interior that prevents complete homogenization. Mars's iron and nickel core is at least partially molten, and may have a solid inner core. It is around half of Mars's radius, approximately 1650–1675 km, and is enriched in light elements such as sulfur, oxygen, carbon, and hydrogen. The temperature of the core is estimated to be 2000–2400 K, compared to 5400–6230 K for Earth's solid inner core. In 2025, based on data from the InSight lander, a group of researchers reported the detection of a solid inner core 613 kilometres (381 mi) ± 67 kilometres (42 mi) in radius. Mars is a terrestrial planet with a surface that consists of minerals containing silicon and oxygen, metals, and other elements that typically make up rock. The Martian surface is primarily composed of tholeiitic basalt, although parts are more silica-rich than typical basalt and may be similar to andesitic rocks on Earth, or silica glass. Regions of low albedo suggest concentrations of plagioclase feldspar, with northern low albedo regions displaying higher than normal concentrations of sheet silicates and high-silicon glass. Parts of the southern highlands include detectable amounts of high-calcium pyroxenes. Localized concentrations of hematite and olivine have been found. Much of the surface is deeply covered by finely grained iron(III) oxide dust. The Phoenix lander returned data showing Martian soil to be slightly alkaline and containing elements such as magnesium, sodium, potassium and chlorine. These nutrients are found in soils on Earth, and are necessary for plant growth. Experiments performed by the lander showed that the Martian soil has a basic pH of 7.7, and contains 0.6% perchlorate by weight, concentrations that are toxic to humans. Streaks are common across Mars and new ones appear frequently on steep slopes of craters, troughs, and valleys. The streaks are dark at first and get lighter with age. The streaks can start in a tiny area, then spread out for hundreds of metres. They have been seen to follow the edges of boulders and other obstacles in their path. The commonly accepted hypotheses include that they are dark underlying layers of soil revealed after avalanches of bright dust or dust devils. Several other explanations have been put forward, including those that involve water or even the growth of organisms. Environmental radiation levels on the surface are on average 0.64 millisieverts of radiation per day, and significantly less than the radiation of 1.84 millisieverts per day or 22 millirads per day during the flight to and from Mars. For comparison the radiation levels in low Earth orbit, where Earth's space stations orbit, are around 0.5 millisieverts of radiation per day. Hellas Planitia has the lowest surface radiation at about 0.342 millisieverts per day, featuring lava tubes southwest of Hadriacus Mons with potentially levels as low as 0.064 millisieverts per day, comparable to radiation levels during flights on Earth. Although Mars has no evidence of a structured global magnetic field, observations show that parts of the planet's crust have been magnetized, suggesting that alternating polarity reversals of its dipole field have occurred in the past. This paleomagnetism of magnetically susceptible minerals is similar to the alternating bands found on Earth's ocean floors. One hypothesis, published in 1999 and re-examined in October 2005 (with the help of the Mars Global Surveyor), is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded. Geography and features Although better remembered for mapping the Moon, Johann Heinrich von Mädler and Wilhelm Beer were the first areographers. They began by establishing that most of Mars's surface features were permanent and by more precisely determining the planet's rotation period. In 1840, Mädler combined ten years of observations and drew the first map of Mars. Features on Mars are named from a variety of sources. Albedo features are named for classical mythology. Craters larger than roughly 50 km are named for deceased scientists and writers and others who have contributed to the study of Mars. Smaller craters are named for towns and villages of the world with populations of less than 100,000. Large valleys are named for the word "Mars" or "star" in various languages; smaller valleys are named for rivers. Large albedo features retain many of the older names but are often updated to reflect new knowledge of the nature of the features. For example, Nix Olympica (the snows of Olympus) has become Olympus Mons (Mount Olympus). The surface of Mars as seen from Earth is divided into two kinds of areas, with differing albedo. The paler plains covered with dust and sand rich in reddish iron oxides were once thought of as Martian "continents" and given names like Arabia Terra (land of Arabia) or Amazonis Planitia (Amazonian plain). The dark features were thought to be seas, hence their names Mare Erythraeum, Mare Sirenum and Aurorae Sinus. The largest dark feature seen from Earth is Syrtis Major Planum. The permanent northern polar ice cap is named Planum Boreum. The southern cap is called Planum Australe. Mars's equator is defined by its rotation, but the location of its Prime Meridian was specified, as was Earth's (at Greenwich), by choice of an arbitrary point; Mädler and Beer selected a line for their first maps of Mars in 1830. After the spacecraft Mariner 9 provided extensive imagery of Mars in 1972, a small crater (later called Airy-0), located in the Sinus Meridiani ("Middle Bay" or "Meridian Bay"), was chosen by Merton E. Davies, Harold Masursky, and Gérard de Vaucouleurs for the definition of 0.0° longitude to coincide with the original selection. Because Mars has no oceans, and hence no "sea level", a zero-elevation surface had to be selected as a reference level; this is called the areoid of Mars, analogous to the terrestrial geoid. Zero altitude was defined by the height at which there is 610.5 Pa (6.105 mbar) of atmospheric pressure. This pressure corresponds to the triple point of water, and it is about 0.6% of the sea level surface pressure on Earth (0.006 atm). For mapping purposes, the United States Geological Survey divides the surface of Mars into thirty cartographic quadrangles, each named for a classical albedo feature it contains. In April 2023, The New York Times reported an updated global map of Mars based on images from the Hope spacecraft. A related, but much more detailed, global Mars map was released by NASA on 16 April 2023. The vast upland region Tharsis contains several massive volcanoes, which include the shield volcano Olympus Mons. The edifice is over 600 km (370 mi) wide. Because the mountain is so large, with complex structure at its edges, giving a definite height to it is difficult. Its local relief, from the foot of the cliffs which form its northwest margin to its peak, is over 21 km (13 mi), a little over twice the height of Mauna Kea as measured from its base on the ocean floor. The total elevation change from the plains of Amazonis Planitia, over 1,000 km (620 mi) to the northwest, to the summit approaches 26 km (16 mi), roughly three times the height of Mount Everest, which in comparison stands at just over 8.8 kilometres (5.5 mi). Consequently, Olympus Mons is either the tallest or second-tallest mountain in the Solar System; the only known mountain which might be taller is the Rheasilvia peak on the asteroid Vesta, at 20–25 km (12–16 mi). The dichotomy of Martian topography is striking: northern plains flattened by lava flows contrast with the southern highlands, pitted and cratered by ancient impacts. It is possible that, four billion years ago, the Northern Hemisphere of Mars was struck by an object one-tenth to two-thirds the size of Earth's Moon. If this is the case, the Northern Hemisphere of Mars would be the site of an impact crater 10,600 by 8,500 kilometres (6,600 by 5,300 mi) in size, or roughly the area of Europe, Asia, and Australia combined, surpassing Utopia Planitia and the Moon's South Pole–Aitken basin as the largest impact crater in the Solar System. Mars is scarred by 43,000 impact craters with a diameter of 5 kilometres (3.1 mi) or greater. The largest exposed crater is Hellas, which is 2,300 kilometres (1,400 mi) wide and 7,000 metres (23,000 ft) deep, and is a light albedo feature clearly visible from Earth. There are other notable impact features, such as Argyre, which is around 1,800 kilometres (1,100 mi) in diameter, and Isidis, which is around 1,500 kilometres (930 mi) in diameter. Due to the smaller mass and size of Mars, the probability of an object colliding with the planet is about half that of Earth. Mars is located closer to the asteroid belt, so it has an increased chance of being struck by materials from that source. Mars is more likely to be struck by short-period comets, i.e., those that lie within the orbit of Jupiter. Martian craters can[discuss] have a morphology that suggests the ground became wet after the meteor impact. The large canyon, Valles Marineris (Latin for 'Mariner Valleys, also known as Agathodaemon in the old canal maps), has a length of 4,000 kilometres (2,500 mi) and a depth of up to 7 kilometres (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one-fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 kilometres (277 mi) long and nearly 2 kilometres (1.2 mi) deep. Valles Marineris was formed due to the swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where 150 kilometres (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two-tectonic plate arrangement. Images from the Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter have revealed seven possible cave entrances on the flanks of the volcano Arsia Mons. The caves, named after loved ones of their discoverers, are collectively known as the "seven sisters". Cave entrances measure from 100 to 252 metres (328 to 827 ft) wide and they are estimated to be at least 73 to 96 metres (240 to 315 ft) deep. Because light does not reach the floor of most of the caves, they may extend much deeper than these lower estimates and widen below the surface. "Dena" is the only exception; its floor is visible and was measured to be 130 metres (430 ft) deep. The interiors of these caverns may be protected from micrometeoroids, UV radiation, solar flares and high energy particles that bombard the planet's surface. Martian geysers (or CO2 jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions. Similarly sized dust will settle from the thinner Martian atmosphere sooner than it would on Earth. For example, the dust suspended by the 2001 global dust storms on Mars only remained in the Martian atmosphere for 0.6 years, while the dust from Mount Pinatubo took about two years to settle. However, under current Martian conditions, the mass movements involved are generally much smaller than on Earth. Even the 2001 global dust storms on Mars moved only the equivalent of a very thin dust layer – about 3 μm thick if deposited with uniform thickness between 58° north and south of the equator. Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols. Atmosphere Mars lost its magnetosphere 4 billion years ago, possibly because of numerous asteroid strikes, so the solar wind interacts directly with the Martian ionosphere, lowering the atmospheric density by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected ionized atmospheric particles trailing off into space behind Mars, and this atmospheric loss is being studied by the MAVEN orbiter. Compared to Earth, the atmosphere of Mars is quite rarefied. Atmospheric pressure on the surface today ranges from a low of 30 Pa (0.0044 psi) on Olympus Mons to over 1,155 Pa (0.1675 psi) in Hellas Planitia, with a mean pressure at the surface level of 600 Pa (0.087 psi). The highest atmospheric density on Mars is equal to that found 35 kilometres (22 mi) above Earth's surface. The resulting mean surface pressure is only 0.6% of Earth's 101.3 kPa (14.69 psi). The scale height of the atmosphere is about 10.8 kilometres (6.7 mi), which is higher than Earth's 6 kilometres (3.7 mi), because the surface gravity of Mars is only about 38% of Earth's. The atmosphere of Mars consists of about 96% carbon dioxide, 1.93% argon and 1.89% nitrogen along with traces of oxygen and water. The atmosphere is quite dusty, containing particulates about 1.5 μm in diameter which give the Martian sky a tawny color when seen from the surface. It may take on a pink hue due to iron oxide particles suspended in it. Despite repeated detections of methane on Mars, there is no scientific consensus as to its origin. One suggestion is that methane exists on Mars and that its concentration fluctuates seasonally. The existence of methane could be produced by non-biological process such as serpentinization involving water, carbon dioxide, and the mineral olivine, which is known to be common on Mars, or by Martian life. Compared to Earth, its higher concentration of atmospheric CO2 and lower surface pressure may be why sound is attenuated more on Mars, where natural sources are rare apart from the wind. Using acoustic recordings collected by the Perseverance rover, researchers concluded that the speed of sound there is approximately 240 m/s for frequencies below 240 Hz, and 250 m/s for those above. Auroras have been detected on Mars. Because Mars lacks a global magnetic field, the types and distribution of auroras there differ from those on Earth; rather than being mostly restricted to polar regions as is the case on Earth, a Martian aurora can encompass the planet. In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25 times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month. Mars has seasons, alternating between its northern and southern hemispheres, similar to on Earth. Additionally the orbit of Mars has, compared to Earth's, a large eccentricity and approaches perihelion when it is summer in its southern hemisphere and winter in its northern, and aphelion when it is winter in its southern hemisphere and summer in its northern. As a result, the seasons in its southern hemisphere are more extreme and the seasons in its northern are milder than would otherwise be the case. The summer temperatures in the south can be warmer than the equivalent summer temperatures in the north by up to 30 °C (54 °F). Martian surface temperatures vary from lows of about −110 °C (−166 °F) to highs of up to 35 °C (95 °F) in equatorial summer. The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure (about 1% that of the atmosphere of Earth), and the low thermal inertia of Martian soil. The planet is 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight. Mars has the largest dust storms in the Solar System, reaching speeds of over 160 km/h (100 mph). These can vary from a storm over a small area, to gigantic storms that cover the entire planet. They tend to occur when Mars is closest to the Sun, and have been shown to increase global temperature. Seasons also produce dry ice covering polar ice caps. Hydrology While Mars contains water in larger amounts, most of it is dust covered water ice at the Martian polar ice caps. The volume of water ice in the south polar ice cap, if melted, would be enough to cover most of the surface of the planet with a depth of 11 metres (36 ft). Water in its liquid form cannot persist on the surface due to Mars's low atmospheric pressure, which is less than 1% that of Earth. Only at the lowest of elevations are the pressure and temperature high enough for liquid water to exist for short periods. Although little water is present in the atmosphere, there is enough to produce clouds of water ice and different cases of snow and frost, often mixed with snow of carbon dioxide dry ice. Landforms visible on Mars strongly suggest that liquid water has existed on the planet's surface. Huge linear swathes of scoured ground, known as outflow channels, cut across the surface in about 25 places. These are thought to be a record of erosion caused by the catastrophic release of water from subsurface aquifers, though some of these structures have been hypothesized to result from the action of glaciers or lava. One of the larger examples, Ma'adim Vallis, is 700 kilometres (430 mi) long, much greater than the Grand Canyon, with a width of 20 kilometres (12 mi) and a depth of 2 kilometres (1.2 mi) in places. It is thought to have been carved by flowing water early in Mars's history. The youngest of these channels is thought to have formed only a few million years ago. Elsewhere, particularly on the oldest areas of the Martian surface, finer-scale, dendritic networks of valleys are spread across significant proportions of the landscape. Features of these valleys and their distribution strongly imply that they were carved by runoff resulting from precipitation in early Mars history. Subsurface water flow and groundwater sapping may play important subsidiary roles in some networks, but precipitation was probably the root cause of the incision in almost all cases. Along craters and canyon walls, there are thousands of features that appear similar to terrestrial gullies. The gullies tend to be in the highlands of the Southern Hemisphere and face the Equator; all are poleward of 30° latitude. A number of authors have suggested that their formation process involves liquid water, probably from melting ice, although others have argued for formation mechanisms involving carbon dioxide frost or the movement of dry dust. No partially degraded gullies have formed by weathering and no superimposed impact craters have been observed, indicating that these are young features, possibly still active. Other geological features, such as deltas and alluvial fans preserved in craters, are further evidence for warmer, wetter conditions at an interval or intervals in earlier Mars history. Such conditions necessarily require the widespread presence of crater lakes across a large proportion of the surface, for which there is independent mineralogical, sedimentological and geomorphological evidence. Further evidence that liquid water once existed on the surface of Mars comes from the detection of specific minerals such as hematite and goethite, both of which sometimes form in the presence of water. The chemical signature of water vapor on Mars was first unequivocally demonstrated in 1963 by spectroscopy using an Earth-based telescope. In 2004, Opportunity detected the mineral jarosite. This forms only in the presence of acidic water, showing that water once existed on Mars. The Spirit rover found concentrated deposits of silica in 2007 that indicated wet conditions in the past, and in December 2011, the mineral gypsum, which also forms in the presence of water, was found on the surface by NASA's Mars rover Opportunity. It is estimated that the amount of water in the upper mantle of Mars, represented by hydroxyl ions contained within Martian minerals, is equal to or greater than that of Earth at 50–300 parts per million of water, which is enough to cover the entire planet to a depth of 200–1,000 metres (660–3,280 ft). On 18 March 2013, NASA reported evidence from instruments on the Curiosity rover of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock. Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of 60 centimetres (24 in), during the rover's traverse from the Bradbury Landing site to the Yellowknife Bay area in the Glenelg terrain. In September 2015, NASA announced that they had found strong evidence of hydrated brine flows in recurring slope lineae, based on spectrometer readings of the darkened areas of slopes. These streaks flow downhill in Martian summer, when the temperature is above −23 °C, and freeze at lower temperatures. These observations supported earlier hypotheses, based on timing of formation and their rate of growth, that these dark streaks resulted from water flowing just below the surface. However, later work suggested that the lineae may be dry, granular flows instead, with at most a limited role for water in initiating the process. A definitive conclusion about the presence, extent, and role of liquid water on the Martian surface remains elusive. Researchers suspect much of the low northern plains of the planet were covered with an ocean hundreds of meters deep, though this theory remains controversial. In March 2015, scientists stated that such an ocean might have been the size of Earth's Arctic Ocean. This finding was derived from the ratio of protium to deuterium in the modern Martian atmosphere compared to that ratio on Earth. The amount of Martian deuterium (D/H = 9.3 ± 1.7 10−4) is five to seven times the amount on Earth (D/H = 1.56 10−4), suggesting that ancient Mars had significantly higher levels of water. Results from the Curiosity rover had previously found a high ratio of deuterium in Gale Crater, though not significantly high enough to suggest the former presence of an ocean. Other scientists caution that these results have not been confirmed, and point out that Martian climate models have not yet shown that the planet was warm enough in the past to support bodies of liquid water. Near the northern polar cap is the 81.4 kilometres (50.6 mi) wide Korolev Crater, which the Mars Express orbiter found to be filled with approximately 2,200 cubic kilometres (530 cu mi) of water ice. In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior (which is 12,100 cubic kilometers). During observations from 2018 through 2021, the ExoMars Trace Gas Orbiter spotted indications of water, probably subsurface ice, in the Valles Marineris canyon system. Orbital motion Mars's average distance from the Sun is roughly 230 million km (143 million mi), and its orbital period is 687 (Earth) days. The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds. A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours. The gravitational potential difference and thus the delta-v needed to transfer between Mars and Earth is the second lowest for Earth. The axial tilt of Mars is 25.19° relative to its orbital plane, which is similar to the axial tilt of Earth. As a result, Mars has seasons like Earth, though on Mars they are nearly twice as long because its orbital period is that much longer. In the present day, the orientation of the north pole of Mars is close to the star Deneb. Mars has a relatively pronounced orbital eccentricity of about 0.09; of the seven other planets in the Solar System, only Mercury has a larger orbital eccentricity. It is known that in the past, Mars has had a much more circular orbit. At one point, 1.35 million Earth years ago, Mars had an eccentricity of roughly 0.002, much less than that of Earth today. Mars's cycle of eccentricity is 96,000 Earth years compared to Earth's cycle of 100,000 years. Mars has its closest approach to Earth (opposition) in a synodic period of 779.94 days. It should not be confused with Mars conjunction, where the Earth and Mars are at opposite sides of the Solar System and form a straight line crossing the Sun. The average time between the successive oppositions of Mars, its synodic period, is 780 days; but the number of days between successive oppositions can range from 764 to 812. The distance at close approach varies between about 54 and 103 million km (34 and 64 million mi) due to the planets' elliptical orbits, which causes comparable variation in angular size. At their furthest Mars and Earth can be as far as 401 million km (249 million mi) apart. Mars comes into opposition from Earth every 2.1 years. The planets come into opposition near Mars's perihelion in 2003, 2018 and 2035, with the 2020 and 2033 events being particularly close to perihelic opposition. The mean apparent magnitude of Mars is +0.71 with a standard deviation of 1.05. Because the orbit of Mars is eccentric, the magnitude at opposition from the Sun can range from about −3.0 to −1.4. The minimum brightness is magnitude +1.86 when the planet is near aphelion and in conjunction with the Sun. At its brightest, Mars (along with Jupiter) is second only to Venus in apparent brightness. Mars usually appears distinctly yellow, orange, or red. When farthest away from Earth, it is more than seven times farther away than when it is closest. Mars is usually close enough for particularly good viewing once or twice at 15-year or 17-year intervals. Optical ground-based telescopes are typically limited to resolving features about 300 kilometres (190 mi) across when Earth and Mars are closest because of Earth's atmosphere. As Mars approaches opposition, it begins a period of retrograde motion, which means it will appear to move backwards in a looping curve with respect to the background stars. This retrograde motion lasts for about 72 days, and Mars reaches its peak apparent brightness in the middle of this interval. Moons Mars has two relatively small (compared to Earth's) natural moons, Phobos (about 22 km (14 mi) in diameter) and Deimos (about 12 km (7.5 mi) in diameter), which orbit at 9,376 km (5,826 mi) and 23,460 km (14,580 mi) around the planet. The origin of both moons is unclear, although a popular theory states that they were asteroids captured into Martian orbit. Both satellites were discovered in 1877 by Asaph Hall and were named after the characters Phobos (the deity of panic and fear) and Deimos (the deity of terror and dread), twins from Greek mythology who accompanied their father Ares, god of war, into battle. Mars was the Roman equivalent to Ares. In modern Greek, the planet retains its ancient name Ares (Aris: Άρης). From the surface of Mars, the motions of Phobos and Deimos appear different from that of the Earth's satellite, the Moon. Phobos rises in the west, sets in the east, and rises again in just 11 hours. Deimos, being only just outside synchronous orbit – where the orbital period would match the planet's period of rotation – rises as expected in the east, but slowly. Because the orbit of Phobos is below a synchronous altitude, tidal forces from Mars are gradually lowering its orbit. In about 50 million years, it could either crash into Mars's surface or break up into a ring structure around the planet. The origin of the two satellites is not well understood. Their low albedo and carbonaceous chondrite composition have been regarded as similar to asteroids, supporting a capture theory. The unstable orbit of Phobos would seem to point toward a relatively recent capture. But both have circular orbits near the equator, which is unusual for captured objects, and the required capture dynamics are complex. Accretion early in the history of Mars is plausible, but would not account for a composition resembling asteroids rather than Mars itself, if that is confirmed. Mars may have yet-undiscovered moons, smaller than 50 to 100 metres (160 to 330 ft) in diameter, and a dust ring is predicted to exist between Phobos and Deimos. A third possibility for their origin as satellites of Mars is the involvement of a third body or a type of impact disruption. More-recent lines of evidence for Phobos having a highly porous interior, and suggesting a composition containing mainly phyllosilicates and other minerals known from Mars, point toward an origin of Phobos from material ejected by an impact on Mars that reaccreted in Martian orbit, similar to the prevailing theory for the origin of Earth's satellite. Although the visible and near-infrared (VNIR) spectra of the moons of Mars resemble those of outer-belt asteroids, the thermal infrared spectra of Phobos are reported to be inconsistent with chondrites of any class. It is also possible that Phobos and Deimos were fragments of an older moon, formed by debris from a large impact on Mars, and then destroyed by a more recent impact upon the satellite. More recently, a study conducted by a team of researchers from multiple countries suggests that a lost moon, at least fifteen times the size of Phobos, may have existed in the past. By analyzing rocks which point to tidal processes on the planet, it is possible that these tides may have been regulated by a past moon. Human observations and exploration The history of observations of Mars is marked by oppositions of Mars when the planet is closest to Earth and hence is most easily visible, which occur every couple of years. Even more notable are the perihelic oppositions of Mars, which are distinguished because Mars is close to perihelion, making it even closer to Earth. The ancient Sumerians named Mars Nergal, the god of war and plague. During Sumerian times, Nergal was a minor deity of little significance, but, during later times, his main cult center was the city of Nineveh. In Mesopotamian texts, Mars is referred to as the "star of judgement of the fate of the dead". The existence of Mars as a wandering object in the night sky was also recorded by the ancient Egyptian astronomers and, by 1534 BCE, they were familiar with the retrograde motion of the planet. By the period of the Neo-Babylonian Empire, the Babylonian astronomers were making regular records of the positions of the planets and systematic observations of their behavior. For Mars, they knew that the planet made 37 synodic periods, or 42 circuits of the zodiac, every 79 years. They invented arithmetic methods for making minor corrections to the predicted positions of the planets. In Ancient Greece, the planet was known as Πυρόεις. Commonly, the Greek name for the planet now referred to as Mars, was Ares. It was the Romans who named the planet Mars, for their god of war, often represented by the sword and shield of the planet's namesake. In the fourth century BCE, Aristotle noted that Mars disappeared behind the Moon during an occultation, indicating that the planet was farther away. Ptolemy, a Greek living in Alexandria, attempted to address the problem of the orbital motion of Mars. Ptolemy's model and his collective work on astronomy was presented in the multi-volume collection later called the Almagest (from the Arabic for "greatest"), which became the authoritative treatise on Western astronomy for the next fourteen centuries. Literature from ancient China confirms that Mars was known by Chinese astronomers by no later than the fourth century BCE. In the East Asian cultures, Mars is traditionally referred to as the "fire star" (火星) based on the Wuxing system. In 1609 Johannes Kepler published a 10 year study of Martian orbit, using the diurnal parallax of Mars, measured by Tycho Brahe, to make a preliminary calculation of the relative distance to the planet. From Brahe's observations of Mars, Kepler deduced that the planet orbited the Sun not in a circle, but in an ellipse. Moreover, Kepler showed that Mars sped up as it approached the Sun and slowed down as it moved farther away, in a manner that later physicists would explain as a consequence of the conservation of angular momentum.: 433–437 In 1610 the first use of a telescope for astronomical observation, including Mars, was performed by Italian astronomer Galileo Galilei. With the telescope the diurnal parallax of Mars was again measured in an effort to determine the Sun-Earth distance. This was first performed by Giovanni Domenico Cassini in 1672. The early parallax measurements were hampered by the quality of the instruments. The only occultation of Mars by Venus observed was that of 13 October 1590, seen by Michael Maestlin at Heidelberg. By the 19th century, the resolution of telescopes reached a level sufficient for surface features to be identified. On 5 September 1877, a perihelic opposition to Mars occurred. The Italian astronomer Giovanni Schiaparelli used a 22-centimetre (8.7 in) telescope in Milan to help produce the first detailed map of Mars. These maps notably contained features he called canali, which, with the possible exception of the natural canyon Valles Marineris, were later shown to be an optical illusion. These canali were supposedly long, straight lines on the surface of Mars, to which he gave names of famous rivers on Earth. His term, which means "channels" or "grooves", was popularly mistranslated in English as "canals". Influenced by the observations, the orientalist Percival Lowell founded an observatory which had 30- and 45-centimetre (12- and 18-in) telescopes. The observatory was used for the exploration of Mars during the last good opportunity in 1894, and the following less favorable oppositions. He published several books on Mars and life on the planet, which had a great influence on the public. The canali were independently observed by other astronomers, like Henri Joseph Perrotin and Louis Thollon in Nice, using one of the largest telescopes of that time. The seasonal changes (consisting of the diminishing of the polar caps and the dark areas formed during Martian summers) in combination with the canals led to speculation about life on Mars, and it was a long-held belief that Mars contained vast seas and vegetation. As bigger telescopes were used, fewer long, straight canali were observed. During observations in 1909 by Antoniadi with an 84-centimetre (33 in) telescope, irregular patterns were observed, but no canali were seen. The first spacecraft from Earth to visit Mars was Mars 1 of the Soviet Union, which flew by in 1963, but contact was lost en route. NASA's Mariner 4 followed and became the first spacecraft to successfully transmit from Mars; launched on 28 November 1964, it made its closest approach to the planet on 15 July 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth, and captured the first images of another planet from deep space. Once spacecraft visited the planet during the 1960s and 1970s, many previous concepts of Mars were radically broken. After the results of the Viking life-detection experiments, the hypothesis of a dead planet was generally accepted. The data from Mariner 9 and Viking allowed better maps of Mars to be made. Until 1997 and after Viking 1 shut down in 1982, Mars was only visited by three unsuccessful probes, two flying past without contact (Phobos 1, 1988; Mars Observer, 1993), and one (Phobos 2 1989) malfunctioning in orbit before reaching its destination Phobos. In 1997 Mars Pathfinder became the first successful rover mission beyond the Moon and started together with Mars Global Surveyor (operated until late 2006) an uninterrupted active robotic presence at Mars that has lasted until today. It produced complete, extremely detailed maps of the Martian topography, magnetic field and surface minerals. Starting with these missions a range of new improved crewless spacecraft, including orbiters, landers, and rovers, have been sent to Mars, with successful missions by the NASA (United States), Jaxa (Japan), ESA, United Kingdom, ISRO (India), Roscosmos (Russia), the United Arab Emirates, and CNSA (China) to study the planet's surface, climate, and geology, uncovering the different elements of the history and dynamic of the hydrosphere of Mars and possible traces of ancient life. As of 2023[update], Mars is host to ten functioning spacecraft. Eight are in orbit: 2001 Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, MAVEN, ExoMars Trace Gas Orbiter, the Hope orbiter, and the Tianwen-1 orbiter. Another two are on the surface: the Mars Science Laboratory Curiosity rover and the Perseverance rover. Collected maps are available online at websites including Google Mars. NASA provides two online tools: Mars Trek, which provides visualizations of the planet using data from 50 years of exploration, and Experience Curiosity, which simulates traveling on Mars in 3-D with Curiosity. Planned missions to Mars include: As of February 2024[update], debris from these types of missions has reached over seven tons. Most of it consists of crashed and inactive spacecraft as well as discarded components. In April 2024, NASA selected several companies to begin studies on providing commercial services to further enable robotic science on Mars. Key areas include establishing telecommunications, payload delivery and surface imaging. Habitability and habitation During the late 19th century, it was widely accepted in the astronomical community that Mars had life-supporting qualities, including the presence of oxygen and water. However, in 1894 W. W. Campbell at Lick Observatory observed the planet and found that "if water vapor or oxygen occur in the atmosphere of Mars it is in quantities too small to be detected by spectroscopes then available". That observation contradicted many of the measurements of the time and was not widely accepted. Campbell and V. M. Slipher repeated the study in 1909 using better instruments, but with the same results. It was not until the findings were confirmed by W. S. Adams in 1925 that the myth of the Earth-like habitability of Mars was finally broken. However, even in the 1960s, articles were published on Martian biology, putting aside explanations other than life for the seasonal changes on Mars. The current understanding of planetary habitability – the ability of a world to develop environmental conditions favorable to the emergence of life – favors planets that have liquid water on their surface. Most often this requires the orbit of a planet to lie within the habitable zone, which for the Sun is estimated to extend from within the orbit of Earth to about that of Mars. During perihelion, Mars dips inside this region, but Mars's thin (low-pressure) atmosphere prevents liquid water from existing over large regions for extended periods. The past flow of liquid water demonstrates the planet's potential for habitability. Recent evidence has suggested that any water on the Martian surface may have been too salty and acidic to support regular terrestrial life. The environmental conditions on Mars are a challenge to sustaining organic life: the planet has little heat transfer across its surface, it has poor insulation against bombardment by the solar wind due to the absence of a magnetosphere and has insufficient atmospheric pressure to retain water in a liquid form (water instead sublimes to a gaseous state). Mars is nearly, or perhaps totally, geologically dead; the end of volcanic activity has apparently stopped the recycling of chemicals and minerals between the surface and interior of the planet. Evidence suggests that the planet was once significantly more habitable than it is today, but whether living organisms ever existed there remains unknown. The Viking probes of the mid-1970s carried experiments designed to detect microorganisms in Martian soil at their respective landing sites and had positive results, including a temporary increase in CO2 production on exposure to water and nutrients. This sign of life was later disputed by scientists, resulting in a continuing debate, with NASA scientist Gilbert Levin asserting that Viking may have found life. A 2014 analysis of Martian meteorite EETA79001 found chlorate, perchlorate, and nitrate ions in sufficiently high concentrations to suggest that they are widespread on Mars. UV and X-ray radiation would turn chlorate and perchlorate ions into other, highly reactive oxychlorines, indicating that any organic molecules would have to be buried under the surface to survive. Small quantities of methane and formaldehyde detected by Mars orbiters are both claimed to be possible evidence for life, as these chemical compounds would quickly break down in the Martian atmosphere. Alternatively, these compounds may instead be replenished by volcanic or other geological means, such as serpentinite. Impact glass, formed by the impact of meteors, which on Earth can preserve signs of life, has also been found on the surface of the impact craters on Mars. Likewise, the glass in impact craters on Mars could have preserved signs of life, if life existed at the site. The Cheyava Falls rock discovered on Mars in June 2024 has been designated by NASA as a "potential biosignature" and was core sampled by the Perseverance rover for possible return to Earth and further examination. Although highly intriguing, no definitive final determination on a biological or abiotic origin of this rock can be made with the data currently available. Several plans for a human mission to Mars have been proposed, but none have come to fruition. The NASA Authorization Act of 2017 directed NASA to study the feasibility of a crewed Mars mission in the early 2030s; the resulting report concluded that this would be unfeasible. In addition, in 2021, China was planning to send a crewed Mars mission in 2033. Privately held companies such as SpaceX have also proposed plans to send humans to Mars, with the eventual goal to settle on the planet. As of 2024, SpaceX has proceeded with the development of the Starship launch vehicle with the goal of Mars colonization. In plans shared with the company in April 2024, Elon Musk envisions the beginning of a Mars colony within the next twenty years. This would be enabled by the planned mass manufacturing of Starship and initially sustained by resupply from Earth, and in situ resource utilization on Mars, until the Mars colony reaches full self sustainability. Any future human mission to Mars will likely take place within the optimal Mars launch window, which occurs every 26 months. The moon Phobos has been proposed as an anchor point for a space elevator. Besides national space agencies and space companies, groups such as the Mars Society and The Planetary Society advocate for human missions to Mars. In culture Mars is named after the Roman god of war (Greek Ares), but was also associated with the demi-god Heracles (Roman Hercules) by ancient Greek astronomers, as detailed by Aristotle. This association between Mars and war dates back at least to Babylonian astronomy, in which the planet was named for the god Nergal, deity of war and destruction. It persisted into modern times, as exemplified by Gustav Holst's orchestral suite The Planets, whose famous first movement labels Mars "The Bringer of War". The planet's symbol, a circle with a spear pointing out to the upper right, is also used as a symbol for the male gender. The symbol dates from at least the 11th century, though a possible predecessor has been found in the Greek Oxyrhynchus Papyri. The idea that Mars was populated by intelligent Martians became widespread in the late 19th century. Schiaparelli's "canali" observations combined with Percival Lowell's books on the subject put forward the standard notion of a planet that was a drying, cooling, dying world with ancient civilizations constructing irrigation works. Many other observations and proclamations by notable personalities added to what has been termed "Mars Fever". In the present day, high-resolution mapping of the surface of Mars has revealed no artifacts of habitation, but pseudoscientific speculation about intelligent life on Mars still continues. Reminiscent of the canali observations, these speculations are based on small scale features perceived in the spacecraft images, such as "pyramids" and the "Face on Mars". In his book Cosmos, planetary astronomer Carl Sagan wrote: "Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears." The depiction of Mars in fiction has been stimulated by its dramatic red color and by nineteenth-century scientific speculations that its surface conditions might support not just life but intelligent life. This gave way to many science fiction stories involving these concepts, such as H. G. Wells's The War of the Worlds, in which Martians seek to escape their dying planet by invading Earth; Ray Bradbury's The Martian Chronicles, in which human explorers accidentally destroy a Martian civilization; as well as Edgar Rice Burroughs's series Barsoom, C. S. Lewis's novel Out of the Silent Planet (1938), and a number of Robert A. Heinlein stories before the mid-sixties. Since then, depictions of Martians have also extended to animation. A comic figure of an intelligent Martian, Marvin the Martian, appeared in Haredevil Hare (1948) as a character in the Looney Tunes animated cartoons of Warner Brothers, and has continued as part of popular culture to the present. After the Mariner and Viking spacecraft had returned pictures of Mars as a lifeless and canal-less world, these ideas about Mars were abandoned; for many science-fiction authors, the new discoveries initially seemed like a constraint, but eventually the post-Viking knowledge of Mars became itself a source of inspiration for works like Kim Stanley Robinson's Mars trilogy. See also Notes References Further reading External links Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Local Volume → Virgo Supercluster → Laniakea Supercluster → Pisces–Cetus Supercluster Complex → Local Hole → Observable universe → UniverseEach arrow (→) may be read as "within" or "part of". |
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[SOURCE: https://en.wikipedia.org/wiki/Social_network#cite_note-Gile-65] | [TOKENS: 5247] |
Contents Social network 1800s: Martineau · Tocqueville · Marx · Spencer · Le Bon · Ward · Pareto · Tönnies · Veblen · Simmel · Durkheim · Addams · Mead · Weber · Du Bois · Mannheim · Elias A social network is a social structure consisting of a set of social actors (such as individuals or organizations), networks of dyadic ties, and other social interactions between actors. The social network perspective provides a set of methods for analyzing the structure of whole social entities along with a variety of theories explaining the patterns observed in these structures. The study of these structures uses social network analysis to identify local and global patterns, locate influential entities, and examine dynamics of networks. For instance, social network analysis has been used in studying the spread of misinformation on social media platforms or analyzing the influence of key figures in social networks. Social networks and the analysis of them is an inherently interdisciplinary academic field which emerged from social psychology, sociology, statistics, and graph theory. Georg Simmel authored early structural theories in sociology emphasizing the dynamics of triads and "web of group affiliations". Jacob Moreno is credited with developing the first sociograms in the 1930s to study interpersonal relationships. These approaches were mathematically formalized in the 1950s and theories and methods of social networks became pervasive in the social and behavioral sciences by the 1980s. Social network analysis is now one of the major paradigms in contemporary sociology, and is also employed in a number of other social and formal sciences. Together with other complex networks, it forms part of the nascent field of network science. Overview The social network is a theoretical construct useful in the social sciences to study relationships between individuals, groups, organizations, or even entire societies (social units, see differentiation). The term is used to describe a social structure determined by such interactions. The ties through which any given social unit connects represent the convergence of the various social contacts of that unit. This theoretical approach is, necessarily, relational. An axiom of the social network approach to understanding social interaction is that social phenomena should be primarily conceived and investigated through the properties of relations between and within units, instead of the properties of these units themselves. Thus, one common criticism of social network theory is that individual agency is often ignored although this may not be the case in practice (see agent-based modeling). Precisely because many different types of relations, singular or in combination, form these network configurations, network analytics are useful to a broad range of research enterprises. In social science, these fields of study include, but are not limited to anthropology, biology, communication studies, economics, geography, information science, organizational studies, social psychology, sociology, and sociolinguistics. History In the late 1890s, both Émile Durkheim and Ferdinand Tönnies foreshadowed the idea of social networks in their theories and research of social groups. Tönnies argued that social groups can exist as personal and direct social ties that either link individuals who share values and belief (Gemeinschaft, German, commonly translated as "community") or impersonal, formal, and instrumental social links (Gesellschaft, German, commonly translated as "society"). Durkheim gave a non-individualistic explanation of social facts, arguing that social phenomena arise when interacting individuals constitute a reality that can no longer be accounted for in terms of the properties of individual actors. Georg Simmel, writing at the turn of the twentieth century, pointed to the nature of networks and the effect of network size on interaction and examined the likelihood of interaction in loosely knit networks rather than groups. Major developments in the field can be seen in the 1930s by several groups in psychology, anthropology, and mathematics working independently. In psychology, in the 1930s, Jacob L. Moreno began systematic recording and analysis of social interaction in small groups, especially classrooms and work groups (see sociometry). In anthropology, the foundation for social network theory is the theoretical and ethnographic work of Bronislaw Malinowski, Alfred Radcliffe-Brown, and Claude Lévi-Strauss. A group of social anthropologists associated with Max Gluckman and the Manchester School, including John A. Barnes, J. Clyde Mitchell and Elizabeth Bott Spillius, often are credited with performing some of the first fieldwork from which network analyses were performed, investigating community networks in southern Africa, India and the United Kingdom. Concomitantly, British anthropologist S. F. Nadel codified a theory of social structure that was influential in later network analysis. In sociology, the early (1930s) work of Talcott Parsons set the stage for taking a relational approach to understanding social structure. Later, drawing upon Parsons' theory, the work of sociologist Peter Blau provides a strong impetus for analyzing the relational ties of social units with his work on social exchange theory. By the 1970s, a growing number of scholars worked to combine the different tracks and traditions. One group consisted of sociologist Harrison White and his students at the Harvard University Department of Social Relations. Also independently active in the Harvard Social Relations department at the time were Charles Tilly, who focused on networks in political and community sociology and social movements, and Stanley Milgram, who developed the "six degrees of separation" thesis. Mark Granovetter and Barry Wellman are among the former students of White who elaborated and championed the analysis of social networks. Beginning in the late 1990s, social network analysis experienced work by sociologists, political scientists, and physicists such as Duncan J. Watts, Albert-László Barabási, Peter Bearman, Nicholas A. Christakis, James H. Fowler, and others, developing and applying new models and methods to emerging data available about online social networks, as well as "digital traces" regarding face-to-face networks. Levels of analysis In general, social networks are self-organizing, emergent, and complex, such that a globally coherent pattern appears from the local interaction of the elements that make up the system. These patterns become more apparent as network size increases. However, a global network analysis of, for example, all interpersonal relationships in the world is not feasible and is likely to contain so much information as to be uninformative. Practical limitations of computing power, ethics and participant recruitment and payment also limit the scope of a social network analysis. The nuances of a local system may be lost in a large network analysis, hence the quality of information may be more important than its scale for understanding network properties. Thus, social networks are analyzed at the scale relevant to the researcher's theoretical question. Although levels of analysis are not necessarily mutually exclusive, there are three general levels into which networks may fall: micro-level, meso-level, and macro-level. At the micro-level, social network research typically begins with an individual, snowballing as social relationships are traced, or may begin with a small group of individuals in a particular social context. Dyadic level: A dyad is a social relationship between two individuals. Network research on dyads may concentrate on structure of the relationship (e.g. multiplexity, strength), social equality, and tendencies toward reciprocity/mutuality. Triadic level: Add one individual to a dyad, and you have a triad. Research at this level may concentrate on factors such as balance and transitivity, as well as social equality and tendencies toward reciprocity/mutuality. In the balance theory of Fritz Heider the triad is the key to social dynamics. The discord in a rivalrous love triangle is an example of an unbalanced triad, likely to change to a balanced triad by a change in one of the relations. The dynamics of social friendships in society has been modeled by balancing triads. The study is carried forward with the theory of signed graphs. Actor level: The smallest unit of analysis in a social network is an individual in their social setting, i.e., an "actor" or "ego." Egonetwork analysis focuses on network characteristics, such as size, relationship strength, density, centrality, prestige and roles such as isolates, liaisons, and bridges. Such analyses, are most commonly used in the fields of psychology or social psychology, ethnographic kinship analysis or other genealogical studies of relationships between individuals. Subset level: Subset levels of network research problems begin at the micro-level, but may cross over into the meso-level of analysis. Subset level research may focus on distance and reachability, cliques, cohesive subgroups, or other group actions or behavior. In general, meso-level theories begin with a population size that falls between the micro- and macro-levels. However, meso-level may also refer to analyses that are specifically designed to reveal connections between micro- and macro-levels. Meso-level networks are low density and may exhibit causal processes distinct from interpersonal micro-level networks. Organizations: Formal organizations are social groups that distribute tasks for a collective goal. Network research on organizations may focus on either intra-organizational or inter-organizational ties in terms of formal or informal relationships. Intra-organizational networks themselves often contain multiple levels of analysis, especially in larger organizations with multiple branches, franchises or semi-autonomous departments. In these cases, research is often conducted at a work group level and organization level, focusing on the interplay between the two structures. Experiments with networked groups online have documented ways to optimize group-level coordination through diverse interventions, including the addition of autonomous agents to the groups. Randomly distributed networks: Exponential random graph models of social networks became state-of-the-art methods of social network analysis in the 1980s. This framework has the capacity to represent social-structural effects commonly observed in many human social networks, including general degree-based structural effects commonly observed in many human social networks as well as reciprocity and transitivity, and at the node-level, homophily and attribute-based activity and popularity effects, as derived from explicit hypotheses about dependencies among network ties. Parameters are given in terms of the prevalence of small subgraph configurations in the network and can be interpreted as describing the combinations of local social processes from which a given network emerges. These probability models for networks on a given set of actors allow generalization beyond the restrictive dyadic independence assumption of micro-networks, allowing models to be built from theoretical structural foundations of social behavior. Scale-free networks: A scale-free network is a network whose degree distribution follows a power law, at least asymptotically. In network theory a scale-free ideal network is a random network with a degree distribution that unravels the size distribution of social groups. Specific characteristics of scale-free networks vary with the theories and analytical tools used to create them, however, in general, scale-free networks have some common characteristics. One notable characteristic in a scale-free network is the relative commonness of vertices with a degree that greatly exceeds the average. The highest-degree nodes are often called "hubs", and may serve specific purposes in their networks, although this depends greatly on the social context. Another general characteristic of scale-free networks is the clustering coefficient distribution, which decreases as the node degree increases. This distribution also follows a power law. The Barabási model of network evolution shown above is an example of a scale-free network. Rather than tracing interpersonal interactions, macro-level analyses generally trace the outcomes of interactions, such as economic or other resource transfer interactions over a large population. Large-scale networks: Large-scale network is a term somewhat synonymous with "macro-level." It is primarily used in social and behavioral sciences, and in economics. Originally, the term was used extensively in the computer sciences (see large-scale network mapping). Complex networks: Most larger social networks display features of social complexity, which involves substantial non-trivial features of network topology, with patterns of complex connections between elements that are neither purely regular nor purely random (see, complexity science, dynamical system and chaos theory), as do biological, and technological networks. Such complex network features include a heavy tail in the degree distribution, a high clustering coefficient, assortativity or disassortativity among vertices, community structure (see stochastic block model), and hierarchical structure. In the case of agency-directed networks these features also include reciprocity, triad significance profile (TSP, see network motif), and other features. In contrast, many of the mathematical models of networks that have been studied in the past, such as lattices and random graphs, do not show these features. Theoretical links Various theoretical frameworks have been imported for the use of social network analysis. The most prominent of these are Graph theory, Balance theory, Social comparison theory, and more recently, the Social identity approach. Few complete theories have been produced from social network analysis. Two that have are structural role theory and heterophily theory. The basis of Heterophily Theory was the finding in one study that more numerous weak ties can be important in seeking information and innovation, as cliques have a tendency to have more homogeneous opinions as well as share many common traits. This homophilic tendency was the reason for the members of the cliques to be attracted together in the first place. However, being similar, each member of the clique would also know more or less what the other members knew. To find new information or insights, members of the clique will have to look beyond the clique to its other friends and acquaintances. This is what Granovetter called "the strength of weak ties". Structural holes In the context of networks, social capital exists where people have an advantage because of their location in a network. Contacts in a network provide information, opportunities and perspectives that can be beneficial to the central player in the network. Most social structures tend to be characterized by dense clusters of strong connections. Information within these clusters tends to be rather homogeneous and redundant. Non-redundant information is most often obtained through contacts in different clusters. When two separate clusters possess non-redundant information, there is said to be a structural hole between them. Thus, a network that bridges structural holes will provide network benefits that are in some degree additive, rather than overlapping. An ideal network structure has a vine and cluster structure, providing access to many different clusters and structural holes. Networks rich in structural holes are a form of social capital in that they offer information benefits. The main player in a network that bridges structural holes is able to access information from diverse sources and clusters. For example, in business networks, this is beneficial to an individual's career because he is more likely to hear of job openings and opportunities if his network spans a wide range of contacts in different industries/sectors. This concept is similar to Mark Granovetter's theory of weak ties, which rests on the basis that having a broad range of contacts is most effective for job attainment. Structural holes have been widely applied in social network analysis, resulting in applications in a wide range of practical scenarios as well as machine learning-based social prediction. Research clusters Research has used network analysis to examine networks created when artists are exhibited together in museum exhibition. Such networks have been shown to affect an artist's recognition in history and historical narratives, even when controlling for individual accomplishments of the artist. Other work examines how network grouping of artists can affect an individual artist's auction performance. An artist's status has been shown to increase when associated with higher status networks, though this association has diminishing returns over an artist's career. In J.A. Barnes' day, a "community" referred to a specific geographic location and studies of community ties had to do with who talked, associated, traded, and attended church with whom. Today, however, there are extended "online" communities developed through telecommunications devices and social network services. Such devices and services require extensive and ongoing maintenance and analysis, often using network science methods. Community development studies, today, also make extensive use of such methods. Complex networks require methods specific to modelling and interpreting social complexity and complex adaptive systems, including techniques of dynamic network analysis. Mechanisms such as Dual-phase evolution explain how temporal changes in connectivity contribute to the formation of structure in social networks. The study of social networks is being used to examine the nature of interdependencies between actors and the ways in which these are related to outcomes of conflict and cooperation. Areas of study include cooperative behavior among participants in collective actions such as protests; promotion of peaceful behavior, social norms, and public goods within communities through networks of informal governance; the role of social networks in both intrastate conflict and interstate conflict; and social networking among politicians, constituents, and bureaucrats. In criminology and urban sociology, much attention has been paid to the social networks among criminal actors. For example, murders can be seen as a series of exchanges between gangs. Murders can be seen to diffuse outwards from a single source, because weaker gangs cannot afford to kill members of stronger gangs in retaliation, but must commit other violent acts to maintain their reputation for strength. Diffusion of ideas and innovations studies focus on the spread and use of ideas from one actor to another or one culture and another. This line of research seeks to explain why some become "early adopters" of ideas and innovations, and links social network structure with facilitating or impeding the spread of an innovation. A case in point is the social diffusion of linguistic innovation such as neologisms. Experiments and large-scale field trials (e.g., by Nicholas Christakis and collaborators) have shown that cascades of desirable behaviors can be induced in social groups, in settings as diverse as Honduras villages, Indian slums, or in the lab. Still other experiments have documented the experimental induction of social contagion of voting behavior, emotions, risk perception, and commercial products. In demography, the study of social networks has led to new sampling methods for estimating and reaching populations that are hard to enumerate (for example, homeless people or intravenous drug users.) For example, respondent driven sampling is a network-based sampling technique that relies on respondents to a survey recommending further respondents. The field of sociology focuses almost entirely on networks of outcomes of social interactions. More narrowly, economic sociology considers behavioral interactions of individuals and groups through social capital and social "markets". Sociologists, such as Mark Granovetter, have developed core principles about the interactions of social structure, information, ability to punish or reward, and trust that frequently recur in their analyses of political, economic and other institutions. Granovetter examines how social structures and social networks can affect economic outcomes like hiring, price, productivity and innovation and describes sociologists' contributions to analyzing the impact of social structure and networks on the economy. Analysis of social networks is increasingly incorporated into health care analytics, not only in epidemiological studies but also in models of patient communication and education, disease prevention, mental health diagnosis and treatment, and in the study of health care organizations and systems. Human ecology is an interdisciplinary and transdisciplinary study of the relationship between humans and their natural, social, and built environments. The scientific philosophy of human ecology has a diffuse history with connections to geography, sociology, psychology, anthropology, zoology, and natural ecology. In the study of literary systems, network analysis has been applied by Anheier, Gerhards and Romo, De Nooy, Senekal, and Lotker, to study various aspects of how literature functions. The basic premise is that polysystem theory, which has been around since the writings of Even-Zohar, can be integrated with network theory and the relationships between different actors in the literary network, e.g. writers, critics, publishers, literary histories, etc., can be mapped using visualization from SNA. Research studies of formal or informal organization relationships, organizational communication, economics, economic sociology, and other resource transfers. Social networks have also been used to examine how organizations interact with each other, characterizing the many informal connections that link executives together, as well as associations and connections between individual employees at different organizations. Many organizational social network studies focus on teams. Within team network studies, research assesses, for example, the predictors and outcomes of centrality and power, density and centralization of team instrumental and expressive ties, and the role of between-team networks. Intra-organizational networks have been found to affect organizational commitment, organizational identification, interpersonal citizenship behaviour. Social capital is a form of economic and cultural capital in which social networks are central, transactions are marked by reciprocity, trust, and cooperation, and market agents produce goods and services not mainly for themselves, but for a common good. Social capital is split into three dimensions: the structural, the relational and the cognitive dimension. The structural dimension describes how partners interact with each other and which specific partners meet in a social network. Also, the structural dimension of social capital indicates the level of ties among organizations. This dimension is highly connected to the relational dimension which refers to trustworthiness, norms, expectations and identifications of the bonds between partners. The relational dimension explains the nature of these ties which is mainly illustrated by the level of trust accorded to the network of organizations. The cognitive dimension analyses the extent to which organizations share common goals and objectives as a result of their ties and interactions. Social capital is a sociological concept about the value of social relations and the role of cooperation and confidence to achieve positive outcomes. The term refers to the value one can get from their social ties. For example, newly arrived immigrants can make use of their social ties to established migrants to acquire jobs they may otherwise have trouble getting (e.g., because of unfamiliarity with the local language). A positive relationship exists between social capital and the intensity of social network use. In a dynamic framework, higher activity in a network feeds into higher social capital which itself encourages more activity. This particular cluster focuses on brand-image and promotional strategy effectiveness, taking into account the impact of customer participation on sales and brand-image. This is gauged through techniques such as sentiment analysis which rely on mathematical areas of study such as data mining and analytics. This area of research produces vast numbers of commercial applications as the main goal of any study is to understand consumer behaviour and drive sales. In many organizations, members tend to focus their activities inside their own groups, which stifles creativity and restricts opportunities. A player whose network bridges structural holes has an advantage in detecting and developing rewarding opportunities. Such a player can mobilize social capital by acting as a "broker" of information between two clusters that otherwise would not have been in contact, thus providing access to new ideas, opinions and opportunities. British philosopher and political economist John Stuart Mill, writes, "it is hardly possible to overrate the value of placing human beings in contact with persons dissimilar to themselves.... Such communication [is] one of the primary sources of progress." Thus, a player with a network rich in structural holes can add value to an organization through new ideas and opportunities. This in turn, helps an individual's career development and advancement. A social capital broker also reaps control benefits of being the facilitator of information flow between contacts. Full communication with exploratory mindsets and information exchange generated by dynamically alternating positions in a social network promotes creative and deep thinking. In the case of consulting firm Eden McCallum, the founders were able to advance their careers by bridging their connections with former big three consulting firm consultants and mid-size industry firms. By bridging structural holes and mobilizing social capital, players can advance their careers by executing new opportunities between contacts. There has been research that both substantiates and refutes the benefits of information brokerage. A study of high tech Chinese firms by Zhixing Xiao found that the control benefits of structural holes are "dissonant to the dominant firm-wide spirit of cooperation and the information benefits cannot materialize due to the communal sharing values" of such organizations. However, this study only analyzed Chinese firms, which tend to have strong communal sharing values. Information and control benefits of structural holes are still valuable in firms that are not quite as inclusive and cooperative on the firm-wide level. In 2004, Ronald Burt studied 673 managers who ran the supply chain for one of America's largest electronics companies. He found that managers who often discussed issues with other groups were better paid, received more positive job evaluations and were more likely to be promoted. Thus, bridging structural holes can be beneficial to an organization, and in turn, to an individual's career. Computer networks combined with social networking software produce a new medium for social interaction. A relationship over a computerized social networking service can be characterized by context, direction, and strength. The content of a relation refers to the resource that is exchanged. In a computer-mediated communication context, social pairs exchange different kinds of information, including sending a data file or a computer program as well as providing emotional support or arranging a meeting. With the rise of electronic commerce, information exchanged may also correspond to exchanges of money, goods or services in the "real" world. Social network analysis methods have become essential to examining these types of computer mediated communication. In addition, the sheer size and the volatile nature of social media has given rise to new network metrics. A key concern with networks extracted from social media is the lack of robustness of network metrics given missing data. Based on the pattern of homophily, ties between people are most likely to occur between nodes that are most similar to each other, or within neighbourhood segregation, individuals are most likely to inhabit the same regional areas as other individuals who are like them. Therefore, social networks can be used as a tool to measure the degree of segregation or homophily within a social network. Social Networks can both be used to simulate the process of homophily but it can also serve as a measure of level of exposure of different groups to each other within a current social network of individuals in a certain area. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Oberon] | [TOKENS: 1491] |
Contents Oberon Oberon (/ˈoʊbərɒn/) is a king of the fairies in medieval and Renaissance literature. He is best known as a character in William Shakespeare's play A Midsummer Night's Dream, in which he is King of the Fairies and spouse of Titania, Queen of the Fairies. Etymology Oberon is a variant spelling of Auberon, earlier Alberon, the origin of which is uncertain, though it may be connected with Alberich and Aubrey, or might else be derived from the Old High German elements adal 'noble' + ber(n) 'bear'. French heroic song Oberon is first attested as the name of a fairy king in the early 13th century chanson de geste entitled Les Prouesses et faitz du noble Huon de Bordeaux, wherein the eponymous hero encounters King Oberon of the fairies as he passes through a forest. Huon is forewarned by a hermit not to speak to Oberon, but his courtesy causes him to answer the fairy king's greetings and so wins his friendship and aid. The fairy king is dwarfish in height, though very handsome. He explains that, at his birth, an offended fairy cursed him not to grow past three years of age (one of the earliest examples of the wicked fairy godmother folklore motif) but relented and gave him great beauty as compensation. In this story, he is said to be the child of Morgan le Fay and Julius Caesar. A manuscript of the romance in the city of Turin contains a prologue to the story of Huon de Bordeaux in the shape of a separate romance of Auberon and four sequels and there are later French versions as well. He is given some Celtic trappings, such as a magical cup (similar to the Holy Grail or the cornucopia) that is ever full. "The magic cup supplied their evening meal; for such was its virtue that it afforded not only wine, but more solid fare when desired", according to Thomas Bulfinch. Shakespeare saw or heard of the French heroic song through the c. 1540 translation by John Bourchier, Lord Berners, called Huon of Burdeuxe. In Philip Henslowe's diary, there is a note of a performance of a play Hewen of Burdoche on 28 December 1593. A Midsummer Night's Dream In William Shakespeare's A Midsummer Night's Dream, written in 1595/96, Oberon is the king of all of the fairies and is engaged in a dispute with his wife Titania, the fairy queen. They are arguing over custody of a child whom Oberon wants to raise to be his henchman. Titania wants to keep and raise the child for the sake of her mortal friend and follower who died giving birth to him. Because Oberon and Titania are both powerful spirits connected to nature, their feuding disrupts the weather. Titania describes the consequences of their fighting: Therefore the winds, piping to us in vain, As in revenge, have suck'd up from the sea Contagious fogs; which falling in the land Have every pelting river made so proud That they have overborne their continents: The ox hath therefore stretch'd his yoke in vain, The ploughman lost his sweat, and the green corn Hath rotted ere his youth attain'd a beard; The fold stands empty in the drowned field, And crows are fatted with the murrion flock; The nine men's morris is fill'd up with mud, And the quaint mazes in the wanton green For lack of tread are undistinguishable: The human mortals want their winter here; No night is now with hymn or carol blest: Therefore the moon, the governess of floods, Pale in her anger, washes all the air, That rheumatic diseases do abound: And thorough this distemperature we see The seasons alter: hoary-headed frosts Far in the fresh lap of the crimson rose, And on old Hiems' thin and icy crown An odorous chaplet of sweet summer buds Is, as in mockery, set: the spring, the summer, The childing autumn, angry winter, change Their wonted liveries, and the mazed world, By their increase, now knows not which is which: And this same progeny of evils comes From our debate, from our dissension; We are their parents and original. — A Midsummer Night's Dream, Act 2, Scene 1 Oberon tricks Titania into giving him back the child using the juice from a special flower that makes one "madly dote upon the next live thing that it sees". The flower was accidentally struck by Cupid's arrow when he attempted to shoot a young maiden in a field, infusing the flower with love. Oberon sends his servant, Puck, to fetch the flower, which he does successfully. Furious that Titania will not give him the child, Oberon puts juice from the magical flower in her eyes while she is asleep, the effect of which will cause Titania to fall in love with the first living thing she sees upon awakening. Titania awakens and finds herself madly in love with Bottom, an actor from the rude mechanicals whose head was just transformed into that of a donkey, thanks to a curse from Puck. Meanwhile, two couples have entered the forest: lovers Hermia and Lysander are pursued by Demetrius, who also loves Hermia, and Helena, who loves Demetrius. Oberon witnesses Demetrius rejecting Helena, admires her amorous determination, and decides to help her. He sends Puck to put some of the juice in Demetrius's eyes, describing him as "a youth in Athenian clothing", to make him fall in love with Helena. Puck finds Lysander – who is also a youth wearing Athenian clothing – and puts the love potion on Lysander's eyes. When Lysander wakes, he sees Helena first and falls in love with her. Meanwhile, Demetrius has also been anointed with the flower and awakes to see Helena, pursued by Lysander, and a fight breaks out between the two young men. Oberon is furious with Puck and casts a sleeping spell on the forest, making Puck reverse the potion on Lysander, admonishing Puck to not reverse the effects on Demetrius. Both couples awake and begin the journey back to Athens. Oberon now looks upon Titania and her lover, Bottom, and feels sorry for what he has done. He reverses the spell using a magic herb. When she wakes, she is confused, thinking that she had a dream. Oberon explains that the dream was real and the two reunite happily. They then return to Athens in the epilogue to bless the couples, becoming once again the benevolent fairy king and queen. Other historical and cultural references A fanciful etymology was given for the name Oberon by Charles Mackay in his book The Gaelic Etymology of the Languages of Western Europe along with many other theories on words found in the English language that have not found mainstream acceptance. In popular culture References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Virtual_reality_applications] | [TOKENS: 7146] |
Contents Virtual reality applications There are many applications of virtual reality (VR). Applications have been developed in a variety of domains, such as architectural and urban design, industrial designs, restorative nature experiences, healthcare and clinical therapies, digital marketing and activism, education and training, engineering and robotics, entertainment, virtual communities, fine arts, heritage and archaeology, occupational safety, as well as social science and psychology. Virtual Reality (VR) is revolutionizing industries by enabling immersive, interactive simulations that greatly improve the work of professionals in these industries. VR is changing how experts approach problems and come up with creative solutions in a variety of fields, including architecture and urban planning, where it helps visualize intricate structures and simulate entire cities, and healthcare and surgery, where it enhances accuracy and patient safety. As evidenced by successful collaborative operations using VR platforms, advancements in VR enable surgeons to train in risk-free environments and sketch out treatments customized for particular patients. VR applications promote technical proficiency, offer practical experience, and improve patient outcomes by decreasing errors and boosting productivity in medical education. Beyond healthcare, virtual reality (VR) plays a key role in improving education and training through realistic, interactive settings, designing safer workplaces, and producing calming nature experiences. These developments demonstrate VR's ability to revolutionize a variety of industries, but issues like affordability, usability, and realism still need to be addressed. VR also extends its impact into the marketing world, where immersive 3D experiences engage customers in unique ways that get them excited about products. Additionally, VR's role in mental health through therapies for PTSD and anxiety disorders demonstrates its psychological value. Architecture and urban design One of the first recorded uses of virtual reality in architecture was in the late 1990s when the University of North Carolina virtually modeled Sitterman Hall, home of its computer science department. Designers wore a headset and used a hand controller to simulate moving around a virtual space. With an Autodesk Revit model, they could "walk through" a schematic. VR enables architects to better understand the details of a project, such as the transition of materials, sightlines, or visual displays of wall stress, wind loads, solar heat gain, or other engineering factors. By 2010, VR programs had been developed for urban regeneration, planning and transportation projects. Entire cities were simulated in VR. Industrial design Virtual reality and artificial intelligence are used by automotive firms like Porsche and BMW to optimize their production chains. Software developers are building VR solutions to skip redundant design workflow phases and meet end-user expectations faster and more accurately.[unreliable source?] Restorative nature experiences Studies on exposure to nature environments show how they are able to help individuals relax, recover attention capacity and cognitive function, reduce stress and stimulate positive moods. The Attention Restoration Theory and Stress Recovery Theory explain the mechanisms by which VR nature environments can lead to mental restoration. This is in contrast to urban environments that have shown to be less restorative. Immersive virtual reality technology is able to replicate believable restorative nature experiences, either using 360 degree video footage or environments created from 3D real-time rendering, often developed using game engines like Unreal Engine or Unity. This is useful for users who cannot access certain areas, for example, senior citizens or residents of nursing homes who face physical restraints or complications. In 2016, the Southwest Florida Eagle Cam introduced a spherical webcam offering a live immersive virtual reality experience. Healthcare and medicine VR is being applied to a wide range of medical areas, including medical education, training, surgery and diagnostic assistance for healthcare staff. For healthcare professionals, by exploring computer generated, three-dimensional (3D), multimedia sensory environments in real time, whether realistic or artificial, they can gain practical knowledge that can be used in clinical practice. For patients, VR can be utilised for surgery, rehabilitation and training to alleviate medical symptoms and cure diseases. VR began to appear in rehabilitation in the 2000s. With the rise of COVID-19 in 2020, opportunities for clinical training and education were greatly reduced due to the lack of availability of clinical educators and the need to establish social distancing by avoiding in-person interaction. However, in recent years, there has been a resurge in funding, thus, many institutions have developed simulations to teach their medical students. Particularly in the field of diabetes, a study named DEVICE (Diabetes Emergencies: Virtual Interactive Clinical Education) allowed non-specialist clinics to undergo training so that they can better identify and treat diabetes patients. VR is being increasingly used to train surgeons by providing realistic surgery simulators that replicate real-life scenarios. These tools allow for hands-on practice in a safe environment, improving precision and skills without the risks associated with real patients. This allows new surgeons to practice and receive feedback without needing an expert surgeon to walk them through the process. Research shows that physicians who experience VR simulations improved their dexterity and performance in the operating room significantly more than control groups. A 2020 study found that clinical students trained through VR scored higher across various areas, including diagnosis, surgical methods, and overall performance, compared to those taught traditionally. Trainees may use real instruments and video equipment to practice in simulated surgeries. Through the revolution of computational analysis abilities, fully immersive VR models are currently available in neurosurgery training. Ventriculostomy catheters insertion, endoscopic and endovascular simulations are used in neurosurgical residency training centers across the world. Experts see VR training as an essential part of the curriculum of future training of neurosurgeons. In one of these studies for example, from 2022, Participants were given a touch-screen monitor, two surgical handlers, and two-foot pedals that were designed to emulate a real world laparoscopic simulator. When participants were asked to perform simulated surgery tasks (Figure 1), they performed significantly better than a control group that wasn't training using VR. In addition to doing better on tasks, those who got VR training demonstrated significant time savings and enhanced performance in the previously mentioned critical areas. Participants who trained using virtual reality also demonstrated reduced cognitive load, suggesting that they were able to learn the content with significantly less mental strain. These findings demonstrate how VR-based simulators, which provide a secure and entertaining environment for practicing surgical techniques, have the potential to completely transform laparoscopic training. VR technology has emerged as a potential tool for medical training, particularly due to the shortage of skilled surgeons. By creating highly realistic and interactive virtual environments, VR simulations have potential to enhance surgical skills, improve patient safety, and reduce training costs. A 2020 study compared the performance of experienced and less experienced surgeons in a VR simulation for spine surgery. The results indicated that novice surgeons who underwent VR training were able to identify and correct errors more effectively than those who relied solely on traditional training methods. VR simulations offer a potentially cost-effective and efficient training method. While traditional methods, such as cadaver labs and physical simulations, require significant resources, VR simulations can be accessed remotely and customized to individual needs. VR can produce a three-dimensional representation of a particular patient's anatomy that allows surgeons to map out the surgery ahead of time. This can be used in neurosurgery, allowing neurosurgeons to design a surgical procedure tailored to the patient prior to the operation which enhances surgical success. The first collaborative virtual reality surgery was successfully performed in June 2022, in Brazil by pediatric surgeon Noor Ul Owase Jeelani, of Great Ormond Street Hospital in London. The surgery, a separation of conjoined twins, was conducted collaboratively in a "virtual reality room" by Dr. Jeelani and Dr. Gabriel Mufarrej, head of paediatric surgery at Instituto Estadual do Cerebro Paulo Niemeyer in Brazil. Similarly, experts examined the state of virtual reality (VR) in surgical education today, emphasizing its advantages for patient safety (e.g., electrosurgical procedures), nontechnical skills (e.g., teamwork), and technical skills (e.g., laparoscopy). The conference's objectives were to evaluate the potential of VR simulation technology for surgical training and provide best practices for its application. They found that VR simulation can make it easier for surgeons to an airtight space and an area with proper ventilation. VR simulation can also teach surgeons about safety factors and about the importance of breaks and factors leading to potential failures and problems. Virtual reality exposure therapy (VRET) is a form of exposure therapy for treating anxiety disorders such as post-traumatic stress disorder (PTSD) and phobias. Studies have indicated that by combining VRET with behavioral therapy, patients experience a reduction of symptoms. In some cases, patients no longer met the DSM-5 criteria for PTSD.[verification needed] Virtual reality has also been tested in the field of behavioral activation (BA) therapy. BA therapy encourages patients to change their mood by scheduling positive activities into their day-to-day life. Due to a lack of access to trained providers, physical constraints or financial reasons, many patients are not able to attend BA therapy. Researchers are trying to overcome these challenges by providing BA therapy via virtual reality, enabling patients, especially elderly adults, to engage in activities that they would not be able to attend without VR. Possibly, the so-called "BA-inspired VR protocols" can improve mood, life satisfaction, and likelihood of depression. A VR therapy has been designed to help people with psychosis and agoraphobia manage their avoidance of outside environments. In the therapy, users wear a headset, and a virtual character provides psychological advice and guides them as they explore simulated environments (such as a café or a busy street). The National Institute for Health and Care Excellence (NICE) is assessing the therapy to see if it should be recommended on the National Health Service (NHS). Another mentioned area of VR therapy is the treatment of eating disorders and body image disorders. Individuals can make your own body image by having a subject embody avatars with different characteristics. With this, people can practice handling these stressful situations and simulate and practice, such as grocery shopping or observing one's own body in the mirror. According to Mittal Himani, "Virtual Reality Distraction Therapy provides many levels of interactions to patients allowing the use of many senses thus encouraging them to be immersed in the virtual world experience. The higher the user's immersion means more attention in the virtual world and less attention to other signals of pain. A research study using VR as a distraction intervention was conducted in 2 sessions over a period of 8 weeks with 28 participants." Immersive VR can motivate exercise with challenged sedentary users, applicable in rehabilitation centers or senior citizen homes, increasing users' quality of life and independence through increased physical activity. In particular, some companies and researchers are adapting VR for fitness, motivating physical therapy or exercise, either by contextualizing, like biking through VR-based experiences (see right image), or by using gamification to encourage exercise. Immersive VR has also been shown useful for acute pain management, on the theory that it may distract people, reducing their experience of pain. Research has shown that dementia patients given virtual reminiscence therapy experienced reduced incidences of dementia related symptoms. Virtual reminiscence therapy creates virtual environments tailored to the patient, allowing them to remember old memories more easily, which may improve overall quality of life. However, for some diseases like Parkinson's disease, evidence of its benefits compared to other rehabilitation methods is lacking. A 2018 review on the effectiveness of VR mirror therapy and robotics found no significant benefit. Other than directly using VR in therapy, medical researchers are also using VR to study different conditions, for instance, researchers have leveraged VR to investigate how people with social anxiety learn and make decisions. Ultimately, researchers aim to better understand medical conditions, in order to improve medical intervention and therapy. Digital marketing Virtual reality presents an opportunity and an alternative channel for digital marketing. The International Data Corporation expected spending to increase for augmented reality (AR) and virtual reality, forecasting a compound annual growth rate of 198% from 2015 to 2020. Revenues were expected to rise to $143.3 billion in 2020. Global spending on digital advertisements was forecasted to increase to $335.5 billion by 2020. A 2015 study found that 75% of companies on Forbes' World's Most Valuable Brands list had developed a VR or AR experience. Although VR is not widespread among consumers compared to other forms of digital media, many companies have invested in VR. Some companies adopted VR to enhance workplace collaboration. VR can present high definition, three-dimensional interactive imaging. The benefits of VR marketing were observed by Suh and Lee through via laboratory experiments: with a VR interface, participants' emotions were engaged, and their product knowledge and product attitude noticeably increased. Both studies indicate an increased desire to purchase products marketed through VR. However, these benefits showed minimal return on investment (ROI). Suh and Lee found that products primarily experienced through hearing and vision (but not other senses) benefit more from VR marketing. Advertisements that appear during a VR experience (interruption marketing) may be considered invasive. Consumers can choose whether they wish to accept an ad. To mitigate this, organizations can require the user to download a mobile app before experiencing their VR campaign. Non-profit organizations have used VR to bring potential supporters closer to distant social, political and environmental issues in immersive ways not possible with traditional media. Panoramic views of the conflict in Syria and face-to-face encounters with computer-generated imagery (CGI) tigers in Nepal are some examples. Retailers can use VR to show how a product will fit in consumers' homes. Consumers looking at digital photos of the products can virtually spin the product to view it from the side or back. Architectural design firms can allow clients to tour virtual models of proposed or existing buildings to market their product, replacing scale models or floor plans with VR models. Education and training VR is used to help learners develop skills without the real-world consequences of failing, especially useful in realms with life-or-death implications. The specific device used to provide the VR experience, whether it be through a mobile phone or desktop computer, does not appear to impact the educational benefits received by the learner. In recent case studies, the VR training approach not only leads to better understandings, but also higher satisfaction amongst individuals. The number of errors can be reduced and the completion time for specific tasks can be shortened. An increasing number of companies rely on virtual reality when it comes to onboarding of employees. VR onboarding is cheaper and more efficient compared to conventional training, as no demo equipment is required. NASA has used VR technology for decades, the most notable being their use of immersive VR to train astronauts before flights. VR simulations include exposure to zero-gravity work environments, training on how to spacewalk and tool usage using low-cost tool mock-ups. Flight simulators are another form of VR training. They can range from a fully enclosed module to computer monitors providing the pilot's point of view. Driving simulations can train tank drivers on the basics before allowing them to operate the real vehicle. Similar principles are applied in truck driving simulators for specialized vehicles such as fire trucks. As these drivers often have limited opportunity for real-world experience, VR training provides additional training time. Immersive VR can be used as a tool in the high school classroom to help students learn and be immersed in their subject matter. Immersive VR has been used to teach students interactively for both humanities subjects like history and STEM subjects like physics. VR laboratories have been set in up in some schools to provide students with immersive VR experiences focused on specific curriculum outcomes and subject matter. Through VR mediums such as Google Cardboard, foreign languages have also been taught in the classroom by teachers. These few examples showcase some of the applications of VR in the secondary classroom. At the collegiate level, VR is also being applied to help enhance student education in core subjects such as science, geography, and history. Virtual reality (VR) technology has emerged as a significant tool in medical training and education. Specifically, there has been a major leap in innovation in surgical simulation and surgical real-time enhancement. Studies done at North Carolina medical institutions have demonstrated improvement in technical performance and skills among medical students and active surgeons using VR training as compared to traditional training, especially in procedures such as total hip arthroplasty. Alongside this, other VR simulation programs, improve basic coordination, instrument handling, and procedure-based skills. These simulations aim to have high ratings for feedback and haptic touch, which provides a more realistic surgical feel. Studies show significant improvement in task completion time and scores after 4-week training sessions. This simulation environment also allows surgeons to practice without risk to real patients, promoting patient safety. Based on data from research conducted by the University Hospitals Schleswig-Holstein and collaborators from other institutions, medical students and surgeons with years of experience, show marked performance boosts after practicing with VR technology. Another recent study at North Carolina University of Chapel Hill has shown that developing VR systems has allowed for laparoscopic imaging integration, real-time skin layer visualization, and enhanced surgical precision capabilities. These are examples of how studies have shown surgeons can take advantage of additional virtual reality simulation practices, which can create incredible experiences, provide customized scenarios, and provide independent learning with haptic feedback. These VR systems need to be realistic enough for education tools alongside being able to measure the performance of a surgeon. Other studies in VR have used VR to improve Type and Screen (T&S) procedural training for medical practitioners, addressing the challenges of traditional training methods. T&S is critical for blood typing and antibody screening to ensure patient safety during transfusions. The traditional training method is "See One, Do One, Teach One" or SODOTO, which tends to fall short due to a limited amount of teachers and resources. In order to tackle this problem, a VR-based training program was created and developed using Unity3D, allowing surgeons to train through an effective, safe, and repeatable alternative. This VR system came with a head-mounted display and Leap Motion Controller, which simulated a hospital environment. There was also full equipment, procedures, and realistic blood drawing and sterilization. Additionally, error notifications and progress reports enhanced this training experience. The three main factors that were studied through this experiment were content, motivation, and readiness, and the statistical analysis throughout this study confirmed strong correlations between these factors and the program's reliability and impact. This is one of the many cases where combining VR with traditional training can really enhance practical skills and prepare surgeons for their future. In 2017 there was a study done on the VR platforms Oculus and Gear VR, to evaluate their effectiveness in teaching medical and health science students about spinal anatomy. It examined the performance of student perceptions and the potential side effects associated with each device. While there are a lot of benefits to using VR technology, there are also some adverse effects such as nausea and blurred vision. Especially he participants using the Gear VR technology. This group ended up experiencing up to 40% more issues compared to the Oculus Rift group. Even with many drawbacks, this study concluded that mobile-based Gear VR was a cost-effective alternative to Oculus Rift, and that even with mobile VR devices, medical students can train for a more practical and affordable price. Some potential future challenges of this technology would be enhancing complex scenarios alongside the realism aspects. These technologies would need to incorporate stress-inducing factors along with other realistic simulation ideas. Furthermore, there would be a strong need to keep things cost-effective with an abundance of availability. In 1982, Thomas A. Furness III presented the United States Air Force with a working model of his virtual flight simulator, the Visually Coupled Airborne Systems Simulator (VCASS).[citation needed] The second phase of his project, which he called the "Super Cockpit", added high-resolution (for the time) graphics and a responsive display. The United Kingdom has been using VR in military training since the 1980s. The United States military announced the Dismounted Soldier Training System in 2012. It was cited as the first fully immersive military VR training system. Virtual training environments have been claimed to increase realism while minimizing costs, for example, by saving ammunition. In 2016, researchers at the U.S. Army Research Laboratory reported that instructor feedback is necessary for virtual training. Virtual training has been used for combined arms training and instructing soldiers to learn when to shoot. Military programs such as Battle Command Knowledge Systems (BCKS) and Advanced Soldier Sensor Information and Technology (ASSIST) were intended to assist the development of virtual technology. Described goals of the ASSIST initiative were to develop software and wearable sensors for soldiers to improve battlefield awareness and data collection. Researchers stated that these programs would allow the soldier to update their virtual environment as conditions change. Virtual Battlespace 3 (VBS3, successor to the earlier versions named VBS1 and VBS2) is a widely used military training solution adapted from a commercial off the shelf product. Live, Virtual, Constructive – Integrated Architecture (LVC-IA) is a U.S. military technology that allows for multiple training systems to work together to create an integrated training environment. Reported primary uses of the LVC-IA were live training, virtual training, and constructive training. In 2014, the LVC-IA version 1.3 included VBS3. Many mining accidents can be attributed to inadequate or insufficient training. With VR training, one may simulate the exposure to a real working environment, without the associated risk. VR headsets have been used in the training of athletes, such as in American football, when player Jayden Daniels used a Cognilize VR system at Louisiana State University and Washington Commanders. Engineering and robotics In the mid-to-late 1990s, 3D computer-aided design (CAD) data took over when video projectors, 3D tracking, and computer technology enabled its use in VR environments. Active shutter glasses and multi-surface projection units appeared. VR has been used in automotive, aerospace, and ground transportation original equipment manufacturers. VR aids prototyping, assembly, service and performance use-cases. This enables engineers from different disciplines to experience their design. Engineers can view the bridge, building or other structure from any angle. Simulations allow engineers to test their structure's resistance to winds, weight, and other elements. Besides, VR can control robots in telepresence, teleoperation and telerobotic systems. VR has been used in experiments that investigate how robots can be applied as an intuitive human user interface. Another example is remotely controlled robots in dangerous environments. Smart Manufacturing (SmartMFG), also referred to as Industry 4.0, represents the latest advancement in manufacturing technologies, integrating automation and data exchange. According to the National Institute of Standards and Technology (NIST), SmartMFG involves fully integrated collaborative manufacturing systems that respond in real-time to changing demands and conditions. At its core, SmartMFG incorporates cyber-physical systems (CPS) and the Internet of Things (IoT) to seamlessly connect data across different stages of the manufacturing process. The rise of 3D printing, coupled with SmartMFG, allows for the production of unique, cost-effective products without increased lead time. The incorporation of AR technologies further enhances SmartMFG, providing tools for human-machine interaction (HMI). AR devices offer safety improvements and reduce physical demands on workers in production plants, guiding users in a virtual environment. This technology facilitates the design and customization of products within the SmartMFG framework, increasing interaction complexity and supporting manual data input (MDI) systems. Entertainment Early commercial virtual reality headsets were released for gaming during the early-mid 1990s. These included the Virtual Boy, iGlasses, Cybermaxx and VFX1 Headgear. Since 2010, commercial headsets for VR gaming include the Oculus Rift, HTC Vive and PlayStation VR. The Samsung Gear VR is an example of a phone-based device. Other modern examples of VR for gaming include the Wii Remote, the Kinect, and the PlayStation Move/PlayStation Eye, all of which track and send player motions to the game. Many devices complement VR with controllers or haptic feedback. VR-specific and VR versions of popular video games have been released. Films produced for VR permit the audience to view scenes in 360 degrees. This can involve the use of VR cameras to produce interactive films and series. Pornography makers use VR, usually for POV-style porn. In 2015, Disney was one of the first to include 360-content in popular culture, utilising the Nokia OZO camera to film 360 degrees videos for The Jungle Book (2016 film) and create VR content. The 2016 World Chess Championship match between Magnus Carlsen and Sergey Karjakin was promoted as "the first in any sport to be broadcast in 360-degree virtual reality." However, a VR telecast featuring Oklahoma hosting Ohio State, preceded it on September 17, 2016. The telecasts (which used roughly 180 degrees of rotation, not the 360 required for full VR) were made available through paid smartphone apps and head-mounted displays. VR can allow individuals to virtually attend concerts, these VR concerts can be enhanced using feedback from the user's heartbeat and brainwaves. VR can also be used for music videos and music visualization or visual music applications. Immersive audio technologies, such as the Nokia OZO, can create an immersive listening experience. through head-tracking and precise directivity of sound. In 2015, roller coasters and theme parks began to incorporate VR to match visual effects with haptic feedback. The Void is a theme park in Pleasant Grove, Utah, that offers VR attractions that stimulate multiple senses. In March 2018, a VR water slide was launched using a waterproof headset. Virtual communities Large virtual communities and metaverse platforms have formed around social virtual worlds that can be accessed with VR technologies. Popular examples include VRChat, Horizon Worlds, Rec Room, and AltspaceVR, but also social virtual worlds that were originally developed without support for VR, for example Roblox. Minecraft, which is considered a virtual community by some, does not support VR but can be made to do so through modding.[citation needed] Fine arts David Em was the first fine artist to create navigable virtual worlds, in the 1970s. His early work was done on mainframes at Information International, Inc., Jet Propulsion Laboratory, and California Institute of Technology. Jeffrey Shaw with Legible City in 1988 and Matt Mullican with Five into One in 1991, were among the first to exhibit elaborate VR artworks. Virtopia was the first VR artwork to premiere at a film festival. Created by artist and researcher Jacquelyn Ford Morie with researcher Mike Goslin, it debuted at the 1992 Florida Film Festival. A more developed version of the project appeared at the 1993 Florida Film Festival. Other artists to explore the early artistic potential of VR through the 1990s include Jeffrey Shaw, Ulrike Gabriel, Char Davies, Maurice Benayoun, Knowbotic Research, Rebecca Allen and Perry Hoberman. The first Canadian virtual reality film festival was the FIVARS Festival of International Virtual & Augmented Reality Stories, founded in 2015 by Keram Malicki-Sánchez. In 2016, the first Polish VR program, The Abakanowicz Art Room was realized – it documented the art office of Magdalena Abakanowicz, made by Jarosław Pijarowski and Paweł Komorowski. Some museums have begun making some of their content virtual reality accessible including the British Museum and the Guggenheim. Great Paintings VR is a fully immersive virtual reality museum on Steam. It provides more than 1000 famous paintings from different museums of all over the world. Heritage and archaeology Virtual reality enables heritage sites to be recreated. The sites may be restricted or provide no access for the public, such as caves, damaged or destroyed structures, or sensitive environments that are closed to allow them to recover from overuse. The first use of VR in a heritage application was in 1994, when a museum provided visitors an interactive "walk-through" of a 3D reconstruction of Dudley Castle in England as it was in 1550. This consisted of a computer-controlled laserdisc-based system designed by engineer Colin Johnson. The system was featured in a conference held by the British Museum in November 1994. Occupational safety VR simulates real workplaces for occupational safety and health (OSH) purposes. Within work scenarios, for example, some parts of a machine move of their own accord while others can be moved by human operators. Perspective, angle of view, and acoustic and haptic properties change according to where the operator is standing and how he or she moves relative to the environment. VR can be used for OSH purposes to: Social science and psychology Virtual reality offers social scientists and psychologists a cost-effective tool to study and replicate interactions in a controlled environment. It allows an individual to embody an avatar. "Embodying" another being presents a different experience from simply imagining that you are someone else. Researchers have used immersion to investigate how digital stimuli can alter human perception, emotion and physiological states, and how can change social interactions, in addition to studying how digital interaction can enact social change in the physical world. Studies have considered how the form we take in virtual reality can affect our perception and actions. One study suggested that embodying the body of a child can cause objects to be perceived as much larger than otherwise. Another study found that white individuals who embodied the form of a dark-skinned avatar performed a drumming task with a more varied style than otherwise. Research exploring perception, emotions and physiological responses within VR suggest that virtual environments can alter how a person responds to stimuli. For example, a virtual park coupled affects subjects' anxiety levels. Similarly, simulated driving through dark areas in a virtual tunnel can induce fear. Social interaction with virtual characters has been shown to produce physiological responses such as changes in heart rate and galvanic skin responses. Research suggests that a strong presence can facilitate an emotional response, and this emotional response can further increase the feeling of presence. Similarly, breaks in the presence (or a loss in the sense of presence) can cause physiological changes.[clarification needed] Researchers have utilized embodied VR perspective-taking to evaluate whether changing a person's self-representation may help in reducing bias against particular social groups. However, the nature of any relationship between embodiment and bias is not yet defined. Individuals who embodied old people demonstrated a significant reduction in negative stereotyping when compared with individuals embodying young people. Similarly, light-skinned individuals placed in dark-bodied avatars showed a reduction in their implicit racial bias. However, other research has shown individuals taking the form of a black avatar had higher levels of implicit racial bias favoring whites after leaving the virtual environment. One of the most general abilities in order to perform in everyday life is spatial cognition, which involves orientation, navigation etc. Especially in the field of its investigation, virtual reality became an invaluable tool, since it allows to test the performance of subjects in an environment which is highly immersive and controllable at the same time. Furthermore, the newest head-mounted displays allow also the implementation of eye-tracking, which provides precious insight in cognitive processes, for example in terms of attention. Starting in the early 2020s, virtual reality has also been discussed as a technological tool that may support people's grieving process, based on digital recreations of deceased individuals. In 2021, this practice received particular media attention following a South Korean TV documentary, which invited a grieving mother to interact with a virtual replica of her deceased daughter. Subsequently, scientists have debated several potential implications of such endeavors, including its potential to facilitate adaptive mourning behavior, but also the many ethical challenges involved. Animal Agriculture Some researchers in intensive animal farming have explored the idea of placing virtual reality headsets on farm animals. Concepts have been proposed for both chickens and cattle. Others have explored the idea of using virtual reality with humans to kill animals or perform other slaughterhouse work remotely. Both uses are controversial In 2019, a story over a Russian dairy farm testing VR on cows went viral, thought it is not fully clear if this occurred as shown in viral photos. The reported aim was to decrease stress by showing images of pasture in the VR googles. They claimed milk yields increased. Many researchers in the area are skeptical of ther claims. They noted that the pressure from googles themselves would likely increase stress. Cattle vision optics are different to humans, making headsets unlikely to work without modification. They also argued that many of the cows had never seen pasture making it unlikely for them to have an emotional response to the visual alone without the other sensory input. The concept has faced criticism from researchers, members of the general public, and animal rights and animal welfare groups. Many researchers are skeptical of the claimed benefits, the lack of scientific rigor or study details in previous attempts, and argue it may increase stress. Members of the public on social media alongside groups such as world animal protection have compared the practice to the matrix, with some satirically calling it "the Mootrix". Mercy for Animals has criticized the potential uses of VR in slaughterhouses. They said it would "turn butchering animals into a kind of gruesome video game" and that it wouldn't make conditions any better for farm animals. Obstacles As of 1997[update], motion sickness is still a major issue for virtual reality, caused by the delay between a motion and the updating of the screen image. Users often report discomfort, for example, one study reported that all 12 participants complained of at least two side effects, while three had to withdraw from severe nausea and dizziness. Along with motion sickness, users can also become distracted by the new technology hardware. A study showed how when VR was incorporated into a laboratory environment, the students felt more engaged with the concept, but retained less information due to the new distraction. Additionally, virtual reality users "remove" themselves from their physical environment. This creates a risk that the user will experience a mishap while moving. The Russian news agency, TASS, reported a death from VR use in 2017, when a 44-year old man "tripped and crashed into a glass table, suffered wounds and died on the spot from a loss of blood". It is thought to be the first death from VR use. Besides, immersion in a virtual world may potentially lead to social exclusion, which may decrease positive mood and increase anger. Some researchers believe that users' behavior in virtual reality may have a lasting psychological impact when they return to the physical world. Philosopher David Pearce argues that even with the most sophisticated VR, "there is no evidence that our subjective quality of life would on average significantly surpass the quality of life of our hunter-gatherer ancestors". According to Pearce, without genetically reprogramming the negative feedback mechanisms of the brain, one returns to one's baseline level of happiness or ill-being, which is determined by one's genes and life history. He thus argues that VR, like any other "purely environmental improvement", cannot deliver a sustainable level of elevated happiness on its own. References |
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[SOURCE: https://en.wikipedia.org/wiki/Mars#cite_note-NASA-20150318-145] | [TOKENS: 11899] |
Contents Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", for its orange-red appearance. Mars is a desert-like rocky planet with a tenuous atmosphere that is primarily carbon dioxide (CO2). At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from −153 to 20 °C (−243 to 68 °F), and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, fog, frost, larger polar regions of permafrost and ice caps (with seasonal CO2 snow), but no bodies of liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. Its diameter, 6,779 km (4,212 mi), is about half the Earth's, or twice the Moon's, and its surface area is the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south divide, the Martian dichotomy, with the northern hemisphere mainly consisting of relatively flat, low lying plains, and the southern hemisphere of cratered highlands. Geologically, the planet is fairly active with marsquakes trembling underneath the ground, but also hosts many enormous volcanoes that are extinct (the tallest is Olympus Mons, 21.9 km or 13.6 mi tall), as well as one of the largest canyons in the Solar System (Valles Marineris, 4,000 km or 2,500 mi long). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos. With a significant axial tilt of 25 degrees, Mars experiences seasons, like Earth (which has an axial tilt of 23.5 degrees). A Martian solar year is equal to 1.88 Earth years (687 Earth days), a Martian solar day (sol) is equal to 24.6 hours. Mars formed along with the other planets approximately 4.5 billion years ago. During the martian Noachian period (4.5 to 3.5 billion years ago), its surface was marked by meteor impacts, valley formation, erosion, the possible presence of water oceans and the loss of its magnetosphere. The Hesperian period (beginning 3.5 billion years ago and ending 3.3–2.9 billion years ago) was dominated by widespread volcanic activity and flooding that carved immense outflow channels. The Amazonian period, which continues to the present, is the currently dominating and remaining influence on geological processes. Because of Mars's geological history, the possibility of past or present life on Mars remains an area of active scientific investigation, with some possible traces needing further examination. Being visible with the naked eye in Earth's sky as a red wandering star, Mars has been observed throughout history, acquiring diverse associations in different cultures. In 1963 the first flight to Mars took place with Mars 1, but communication was lost en route. The first successful flyby exploration of Mars was conducted in 1965 with Mariner 4. In 1971 Mariner 9 entered orbit around Mars, being the first spacecraft to orbit any body other than the Moon, Sun or Earth; following in the same year were the first uncontrolled impact (Mars 2) and first successful landing (Mars 3) on Mars. Probes have been active on Mars continuously since 1997. At times, more than ten probes have simultaneously operated in orbit or on the surface, more than at any other planet beyond Earth. Mars is an often proposed target for future crewed exploration missions, though no such mission is currently planned. Natural history Scientists have theorized that during the Solar System's formation, Mars was created as the result of a random process of run-away accretion of material from the protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points, such as chlorine, phosphorus, and sulfur, are much more common on Mars than on Earth; these elements were probably pushed outward by the young Sun's energetic solar wind. After the formation of the planets, the inner Solar System may have been subjected to the so-called Late Heavy Bombardment. About 60% of the surface of Mars shows a record of impacts from that era, whereas much of the remaining surface is probably underlain by immense impact basins caused by those events. However, more recent modeling has disputed the existence of the Late Heavy Bombardment. There is evidence of an enormous impact basin in the Northern Hemisphere of Mars, spanning 10,600 by 8,500 kilometres (6,600 by 5,300 mi), or roughly four times the size of the Moon's South Pole–Aitken basin, which would be the largest impact basin yet discovered if confirmed. It has been hypothesized that the basin was formed when Mars was struck by a Pluto-sized body about four billion years ago. The event, thought to be the cause of the Martian hemispheric dichotomy, created the smooth Borealis basin that covers 40% of the planet. A 2023 study shows evidence, based on the orbital inclination of Deimos (a small moon of Mars), that Mars may once have had a ring system 3.5 billion years to 4 billion years ago. This ring system may have been formed from a moon, 20 times more massive than Phobos, orbiting Mars billions of years ago; and Phobos would be a remnant of that ring. Epochs: The geological history of Mars can be split into many periods, but the following are the three primary periods: Geological activity is still taking place on Mars. The Athabasca Valles is home to sheet-like lava flows created about 200 million years ago. Water flows in the grabens called the Cerberus Fossae occurred less than 20 million years ago, indicating equally recent volcanic intrusions. The Mars Reconnaissance Orbiter has captured images of avalanches. Physical characteristics Mars is approximately half the diameter of Earth or twice that of the Moon, with a surface area only slightly less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity. Mars is the only presently known example of a desert planet, a rocky planet with a surface akin to that of Earth's deserts. The red-orange appearance of the Martian surface is caused by iron(III) oxide (nanophase Fe2O3) and the iron(III) oxide-hydroxide mineral goethite. It can look like butterscotch; other common surface colors include golden, brown, tan, and greenish, depending on the minerals present. Like Earth, Mars is differentiated into a dense metallic core overlaid by less dense rocky layers. The outermost layer is the crust, which is on average about 42–56 kilometres (26–35 mi) thick, with a minimum thickness of 6 kilometres (3.7 mi) in Isidis Planitia, and a maximum thickness of 117 kilometres (73 mi) in the southern Tharsis plateau. For comparison, Earth's crust averages 27.3 ± 4.8 km in thickness. The most abundant elements in the Martian crust are silicon, oxygen, iron, magnesium, aluminum, calcium, and potassium. Mars is confirmed to be seismically active; in 2019, it was reported that InSight had detected and recorded over 450 marsquakes and related events. Beneath the crust is a silicate mantle responsible for many of the tectonic and volcanic features on the planet's surface. The upper Martian mantle is a low-velocity zone, where the velocity of seismic waves is lower than surrounding depth intervals. The mantle appears to be rigid down to the depth of about 250 km, giving Mars a very thick lithosphere compared to Earth. Below this the mantle gradually becomes more ductile, and the seismic wave velocity starts to grow again. The Martian mantle does not appear to have a thermally insulating layer analogous to Earth's lower mantle; instead, below 1050 km in depth, it becomes mineralogically similar to Earth's transition zone. At the bottom of the mantle lies a basal liquid silicate layer approximately 150–180 km thick. The Martian mantle appears to be highly heterogenous, with dense fragments up to 4 km across, likely injected deep into the planet by colossal impacts ~4.5 billion years ago; high-frequency waves from eight marsquakes slowed as they passed these localized regions, and modeling indicates the heterogeneities are compositionally distinct debris preserved because Mars lacks plate tectonics and has a sluggishly convecting interior that prevents complete homogenization. Mars's iron and nickel core is at least partially molten, and may have a solid inner core. It is around half of Mars's radius, approximately 1650–1675 km, and is enriched in light elements such as sulfur, oxygen, carbon, and hydrogen. The temperature of the core is estimated to be 2000–2400 K, compared to 5400–6230 K for Earth's solid inner core. In 2025, based on data from the InSight lander, a group of researchers reported the detection of a solid inner core 613 kilometres (381 mi) ± 67 kilometres (42 mi) in radius. Mars is a terrestrial planet with a surface that consists of minerals containing silicon and oxygen, metals, and other elements that typically make up rock. The Martian surface is primarily composed of tholeiitic basalt, although parts are more silica-rich than typical basalt and may be similar to andesitic rocks on Earth, or silica glass. Regions of low albedo suggest concentrations of plagioclase feldspar, with northern low albedo regions displaying higher than normal concentrations of sheet silicates and high-silicon glass. Parts of the southern highlands include detectable amounts of high-calcium pyroxenes. Localized concentrations of hematite and olivine have been found. Much of the surface is deeply covered by finely grained iron(III) oxide dust. The Phoenix lander returned data showing Martian soil to be slightly alkaline and containing elements such as magnesium, sodium, potassium and chlorine. These nutrients are found in soils on Earth, and are necessary for plant growth. Experiments performed by the lander showed that the Martian soil has a basic pH of 7.7, and contains 0.6% perchlorate by weight, concentrations that are toxic to humans. Streaks are common across Mars and new ones appear frequently on steep slopes of craters, troughs, and valleys. The streaks are dark at first and get lighter with age. The streaks can start in a tiny area, then spread out for hundreds of metres. They have been seen to follow the edges of boulders and other obstacles in their path. The commonly accepted hypotheses include that they are dark underlying layers of soil revealed after avalanches of bright dust or dust devils. Several other explanations have been put forward, including those that involve water or even the growth of organisms. Environmental radiation levels on the surface are on average 0.64 millisieverts of radiation per day, and significantly less than the radiation of 1.84 millisieverts per day or 22 millirads per day during the flight to and from Mars. For comparison the radiation levels in low Earth orbit, where Earth's space stations orbit, are around 0.5 millisieverts of radiation per day. Hellas Planitia has the lowest surface radiation at about 0.342 millisieverts per day, featuring lava tubes southwest of Hadriacus Mons with potentially levels as low as 0.064 millisieverts per day, comparable to radiation levels during flights on Earth. Although Mars has no evidence of a structured global magnetic field, observations show that parts of the planet's crust have been magnetized, suggesting that alternating polarity reversals of its dipole field have occurred in the past. This paleomagnetism of magnetically susceptible minerals is similar to the alternating bands found on Earth's ocean floors. One hypothesis, published in 1999 and re-examined in October 2005 (with the help of the Mars Global Surveyor), is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded. Geography and features Although better remembered for mapping the Moon, Johann Heinrich von Mädler and Wilhelm Beer were the first areographers. They began by establishing that most of Mars's surface features were permanent and by more precisely determining the planet's rotation period. In 1840, Mädler combined ten years of observations and drew the first map of Mars. Features on Mars are named from a variety of sources. Albedo features are named for classical mythology. Craters larger than roughly 50 km are named for deceased scientists and writers and others who have contributed to the study of Mars. Smaller craters are named for towns and villages of the world with populations of less than 100,000. Large valleys are named for the word "Mars" or "star" in various languages; smaller valleys are named for rivers. Large albedo features retain many of the older names but are often updated to reflect new knowledge of the nature of the features. For example, Nix Olympica (the snows of Olympus) has become Olympus Mons (Mount Olympus). The surface of Mars as seen from Earth is divided into two kinds of areas, with differing albedo. The paler plains covered with dust and sand rich in reddish iron oxides were once thought of as Martian "continents" and given names like Arabia Terra (land of Arabia) or Amazonis Planitia (Amazonian plain). The dark features were thought to be seas, hence their names Mare Erythraeum, Mare Sirenum and Aurorae Sinus. The largest dark feature seen from Earth is Syrtis Major Planum. The permanent northern polar ice cap is named Planum Boreum. The southern cap is called Planum Australe. Mars's equator is defined by its rotation, but the location of its Prime Meridian was specified, as was Earth's (at Greenwich), by choice of an arbitrary point; Mädler and Beer selected a line for their first maps of Mars in 1830. After the spacecraft Mariner 9 provided extensive imagery of Mars in 1972, a small crater (later called Airy-0), located in the Sinus Meridiani ("Middle Bay" or "Meridian Bay"), was chosen by Merton E. Davies, Harold Masursky, and Gérard de Vaucouleurs for the definition of 0.0° longitude to coincide with the original selection. Because Mars has no oceans, and hence no "sea level", a zero-elevation surface had to be selected as a reference level; this is called the areoid of Mars, analogous to the terrestrial geoid. Zero altitude was defined by the height at which there is 610.5 Pa (6.105 mbar) of atmospheric pressure. This pressure corresponds to the triple point of water, and it is about 0.6% of the sea level surface pressure on Earth (0.006 atm). For mapping purposes, the United States Geological Survey divides the surface of Mars into thirty cartographic quadrangles, each named for a classical albedo feature it contains. In April 2023, The New York Times reported an updated global map of Mars based on images from the Hope spacecraft. A related, but much more detailed, global Mars map was released by NASA on 16 April 2023. The vast upland region Tharsis contains several massive volcanoes, which include the shield volcano Olympus Mons. The edifice is over 600 km (370 mi) wide. Because the mountain is so large, with complex structure at its edges, giving a definite height to it is difficult. Its local relief, from the foot of the cliffs which form its northwest margin to its peak, is over 21 km (13 mi), a little over twice the height of Mauna Kea as measured from its base on the ocean floor. The total elevation change from the plains of Amazonis Planitia, over 1,000 km (620 mi) to the northwest, to the summit approaches 26 km (16 mi), roughly three times the height of Mount Everest, which in comparison stands at just over 8.8 kilometres (5.5 mi). Consequently, Olympus Mons is either the tallest or second-tallest mountain in the Solar System; the only known mountain which might be taller is the Rheasilvia peak on the asteroid Vesta, at 20–25 km (12–16 mi). The dichotomy of Martian topography is striking: northern plains flattened by lava flows contrast with the southern highlands, pitted and cratered by ancient impacts. It is possible that, four billion years ago, the Northern Hemisphere of Mars was struck by an object one-tenth to two-thirds the size of Earth's Moon. If this is the case, the Northern Hemisphere of Mars would be the site of an impact crater 10,600 by 8,500 kilometres (6,600 by 5,300 mi) in size, or roughly the area of Europe, Asia, and Australia combined, surpassing Utopia Planitia and the Moon's South Pole–Aitken basin as the largest impact crater in the Solar System. Mars is scarred by 43,000 impact craters with a diameter of 5 kilometres (3.1 mi) or greater. The largest exposed crater is Hellas, which is 2,300 kilometres (1,400 mi) wide and 7,000 metres (23,000 ft) deep, and is a light albedo feature clearly visible from Earth. There are other notable impact features, such as Argyre, which is around 1,800 kilometres (1,100 mi) in diameter, and Isidis, which is around 1,500 kilometres (930 mi) in diameter. Due to the smaller mass and size of Mars, the probability of an object colliding with the planet is about half that of Earth. Mars is located closer to the asteroid belt, so it has an increased chance of being struck by materials from that source. Mars is more likely to be struck by short-period comets, i.e., those that lie within the orbit of Jupiter. Martian craters can[discuss] have a morphology that suggests the ground became wet after the meteor impact. The large canyon, Valles Marineris (Latin for 'Mariner Valleys, also known as Agathodaemon in the old canal maps), has a length of 4,000 kilometres (2,500 mi) and a depth of up to 7 kilometres (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one-fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 kilometres (277 mi) long and nearly 2 kilometres (1.2 mi) deep. Valles Marineris was formed due to the swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where 150 kilometres (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two-tectonic plate arrangement. Images from the Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter have revealed seven possible cave entrances on the flanks of the volcano Arsia Mons. The caves, named after loved ones of their discoverers, are collectively known as the "seven sisters". Cave entrances measure from 100 to 252 metres (328 to 827 ft) wide and they are estimated to be at least 73 to 96 metres (240 to 315 ft) deep. Because light does not reach the floor of most of the caves, they may extend much deeper than these lower estimates and widen below the surface. "Dena" is the only exception; its floor is visible and was measured to be 130 metres (430 ft) deep. The interiors of these caverns may be protected from micrometeoroids, UV radiation, solar flares and high energy particles that bombard the planet's surface. Martian geysers (or CO2 jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions. Similarly sized dust will settle from the thinner Martian atmosphere sooner than it would on Earth. For example, the dust suspended by the 2001 global dust storms on Mars only remained in the Martian atmosphere for 0.6 years, while the dust from Mount Pinatubo took about two years to settle. However, under current Martian conditions, the mass movements involved are generally much smaller than on Earth. Even the 2001 global dust storms on Mars moved only the equivalent of a very thin dust layer – about 3 μm thick if deposited with uniform thickness between 58° north and south of the equator. Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols. Atmosphere Mars lost its magnetosphere 4 billion years ago, possibly because of numerous asteroid strikes, so the solar wind interacts directly with the Martian ionosphere, lowering the atmospheric density by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected ionized atmospheric particles trailing off into space behind Mars, and this atmospheric loss is being studied by the MAVEN orbiter. Compared to Earth, the atmosphere of Mars is quite rarefied. Atmospheric pressure on the surface today ranges from a low of 30 Pa (0.0044 psi) on Olympus Mons to over 1,155 Pa (0.1675 psi) in Hellas Planitia, with a mean pressure at the surface level of 600 Pa (0.087 psi). The highest atmospheric density on Mars is equal to that found 35 kilometres (22 mi) above Earth's surface. The resulting mean surface pressure is only 0.6% of Earth's 101.3 kPa (14.69 psi). The scale height of the atmosphere is about 10.8 kilometres (6.7 mi), which is higher than Earth's 6 kilometres (3.7 mi), because the surface gravity of Mars is only about 38% of Earth's. The atmosphere of Mars consists of about 96% carbon dioxide, 1.93% argon and 1.89% nitrogen along with traces of oxygen and water. The atmosphere is quite dusty, containing particulates about 1.5 μm in diameter which give the Martian sky a tawny color when seen from the surface. It may take on a pink hue due to iron oxide particles suspended in it. Despite repeated detections of methane on Mars, there is no scientific consensus as to its origin. One suggestion is that methane exists on Mars and that its concentration fluctuates seasonally. The existence of methane could be produced by non-biological process such as serpentinization involving water, carbon dioxide, and the mineral olivine, which is known to be common on Mars, or by Martian life. Compared to Earth, its higher concentration of atmospheric CO2 and lower surface pressure may be why sound is attenuated more on Mars, where natural sources are rare apart from the wind. Using acoustic recordings collected by the Perseverance rover, researchers concluded that the speed of sound there is approximately 240 m/s for frequencies below 240 Hz, and 250 m/s for those above. Auroras have been detected on Mars. Because Mars lacks a global magnetic field, the types and distribution of auroras there differ from those on Earth; rather than being mostly restricted to polar regions as is the case on Earth, a Martian aurora can encompass the planet. In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25 times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month. Mars has seasons, alternating between its northern and southern hemispheres, similar to on Earth. Additionally the orbit of Mars has, compared to Earth's, a large eccentricity and approaches perihelion when it is summer in its southern hemisphere and winter in its northern, and aphelion when it is winter in its southern hemisphere and summer in its northern. As a result, the seasons in its southern hemisphere are more extreme and the seasons in its northern are milder than would otherwise be the case. The summer temperatures in the south can be warmer than the equivalent summer temperatures in the north by up to 30 °C (54 °F). Martian surface temperatures vary from lows of about −110 °C (−166 °F) to highs of up to 35 °C (95 °F) in equatorial summer. The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure (about 1% that of the atmosphere of Earth), and the low thermal inertia of Martian soil. The planet is 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight. Mars has the largest dust storms in the Solar System, reaching speeds of over 160 km/h (100 mph). These can vary from a storm over a small area, to gigantic storms that cover the entire planet. They tend to occur when Mars is closest to the Sun, and have been shown to increase global temperature. Seasons also produce dry ice covering polar ice caps. Hydrology While Mars contains water in larger amounts, most of it is dust covered water ice at the Martian polar ice caps. The volume of water ice in the south polar ice cap, if melted, would be enough to cover most of the surface of the planet with a depth of 11 metres (36 ft). Water in its liquid form cannot persist on the surface due to Mars's low atmospheric pressure, which is less than 1% that of Earth. Only at the lowest of elevations are the pressure and temperature high enough for liquid water to exist for short periods. Although little water is present in the atmosphere, there is enough to produce clouds of water ice and different cases of snow and frost, often mixed with snow of carbon dioxide dry ice. Landforms visible on Mars strongly suggest that liquid water has existed on the planet's surface. Huge linear swathes of scoured ground, known as outflow channels, cut across the surface in about 25 places. These are thought to be a record of erosion caused by the catastrophic release of water from subsurface aquifers, though some of these structures have been hypothesized to result from the action of glaciers or lava. One of the larger examples, Ma'adim Vallis, is 700 kilometres (430 mi) long, much greater than the Grand Canyon, with a width of 20 kilometres (12 mi) and a depth of 2 kilometres (1.2 mi) in places. It is thought to have been carved by flowing water early in Mars's history. The youngest of these channels is thought to have formed only a few million years ago. Elsewhere, particularly on the oldest areas of the Martian surface, finer-scale, dendritic networks of valleys are spread across significant proportions of the landscape. Features of these valleys and their distribution strongly imply that they were carved by runoff resulting from precipitation in early Mars history. Subsurface water flow and groundwater sapping may play important subsidiary roles in some networks, but precipitation was probably the root cause of the incision in almost all cases. Along craters and canyon walls, there are thousands of features that appear similar to terrestrial gullies. The gullies tend to be in the highlands of the Southern Hemisphere and face the Equator; all are poleward of 30° latitude. A number of authors have suggested that their formation process involves liquid water, probably from melting ice, although others have argued for formation mechanisms involving carbon dioxide frost or the movement of dry dust. No partially degraded gullies have formed by weathering and no superimposed impact craters have been observed, indicating that these are young features, possibly still active. Other geological features, such as deltas and alluvial fans preserved in craters, are further evidence for warmer, wetter conditions at an interval or intervals in earlier Mars history. Such conditions necessarily require the widespread presence of crater lakes across a large proportion of the surface, for which there is independent mineralogical, sedimentological and geomorphological evidence. Further evidence that liquid water once existed on the surface of Mars comes from the detection of specific minerals such as hematite and goethite, both of which sometimes form in the presence of water. The chemical signature of water vapor on Mars was first unequivocally demonstrated in 1963 by spectroscopy using an Earth-based telescope. In 2004, Opportunity detected the mineral jarosite. This forms only in the presence of acidic water, showing that water once existed on Mars. The Spirit rover found concentrated deposits of silica in 2007 that indicated wet conditions in the past, and in December 2011, the mineral gypsum, which also forms in the presence of water, was found on the surface by NASA's Mars rover Opportunity. It is estimated that the amount of water in the upper mantle of Mars, represented by hydroxyl ions contained within Martian minerals, is equal to or greater than that of Earth at 50–300 parts per million of water, which is enough to cover the entire planet to a depth of 200–1,000 metres (660–3,280 ft). On 18 March 2013, NASA reported evidence from instruments on the Curiosity rover of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock. Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of 60 centimetres (24 in), during the rover's traverse from the Bradbury Landing site to the Yellowknife Bay area in the Glenelg terrain. In September 2015, NASA announced that they had found strong evidence of hydrated brine flows in recurring slope lineae, based on spectrometer readings of the darkened areas of slopes. These streaks flow downhill in Martian summer, when the temperature is above −23 °C, and freeze at lower temperatures. These observations supported earlier hypotheses, based on timing of formation and their rate of growth, that these dark streaks resulted from water flowing just below the surface. However, later work suggested that the lineae may be dry, granular flows instead, with at most a limited role for water in initiating the process. A definitive conclusion about the presence, extent, and role of liquid water on the Martian surface remains elusive. Researchers suspect much of the low northern plains of the planet were covered with an ocean hundreds of meters deep, though this theory remains controversial. In March 2015, scientists stated that such an ocean might have been the size of Earth's Arctic Ocean. This finding was derived from the ratio of protium to deuterium in the modern Martian atmosphere compared to that ratio on Earth. The amount of Martian deuterium (D/H = 9.3 ± 1.7 10−4) is five to seven times the amount on Earth (D/H = 1.56 10−4), suggesting that ancient Mars had significantly higher levels of water. Results from the Curiosity rover had previously found a high ratio of deuterium in Gale Crater, though not significantly high enough to suggest the former presence of an ocean. Other scientists caution that these results have not been confirmed, and point out that Martian climate models have not yet shown that the planet was warm enough in the past to support bodies of liquid water. Near the northern polar cap is the 81.4 kilometres (50.6 mi) wide Korolev Crater, which the Mars Express orbiter found to be filled with approximately 2,200 cubic kilometres (530 cu mi) of water ice. In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior (which is 12,100 cubic kilometers). During observations from 2018 through 2021, the ExoMars Trace Gas Orbiter spotted indications of water, probably subsurface ice, in the Valles Marineris canyon system. Orbital motion Mars's average distance from the Sun is roughly 230 million km (143 million mi), and its orbital period is 687 (Earth) days. The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds. A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours. The gravitational potential difference and thus the delta-v needed to transfer between Mars and Earth is the second lowest for Earth. The axial tilt of Mars is 25.19° relative to its orbital plane, which is similar to the axial tilt of Earth. As a result, Mars has seasons like Earth, though on Mars they are nearly twice as long because its orbital period is that much longer. In the present day, the orientation of the north pole of Mars is close to the star Deneb. Mars has a relatively pronounced orbital eccentricity of about 0.09; of the seven other planets in the Solar System, only Mercury has a larger orbital eccentricity. It is known that in the past, Mars has had a much more circular orbit. At one point, 1.35 million Earth years ago, Mars had an eccentricity of roughly 0.002, much less than that of Earth today. Mars's cycle of eccentricity is 96,000 Earth years compared to Earth's cycle of 100,000 years. Mars has its closest approach to Earth (opposition) in a synodic period of 779.94 days. It should not be confused with Mars conjunction, where the Earth and Mars are at opposite sides of the Solar System and form a straight line crossing the Sun. The average time between the successive oppositions of Mars, its synodic period, is 780 days; but the number of days between successive oppositions can range from 764 to 812. The distance at close approach varies between about 54 and 103 million km (34 and 64 million mi) due to the planets' elliptical orbits, which causes comparable variation in angular size. At their furthest Mars and Earth can be as far as 401 million km (249 million mi) apart. Mars comes into opposition from Earth every 2.1 years. The planets come into opposition near Mars's perihelion in 2003, 2018 and 2035, with the 2020 and 2033 events being particularly close to perihelic opposition. The mean apparent magnitude of Mars is +0.71 with a standard deviation of 1.05. Because the orbit of Mars is eccentric, the magnitude at opposition from the Sun can range from about −3.0 to −1.4. The minimum brightness is magnitude +1.86 when the planet is near aphelion and in conjunction with the Sun. At its brightest, Mars (along with Jupiter) is second only to Venus in apparent brightness. Mars usually appears distinctly yellow, orange, or red. When farthest away from Earth, it is more than seven times farther away than when it is closest. Mars is usually close enough for particularly good viewing once or twice at 15-year or 17-year intervals. Optical ground-based telescopes are typically limited to resolving features about 300 kilometres (190 mi) across when Earth and Mars are closest because of Earth's atmosphere. As Mars approaches opposition, it begins a period of retrograde motion, which means it will appear to move backwards in a looping curve with respect to the background stars. This retrograde motion lasts for about 72 days, and Mars reaches its peak apparent brightness in the middle of this interval. Moons Mars has two relatively small (compared to Earth's) natural moons, Phobos (about 22 km (14 mi) in diameter) and Deimos (about 12 km (7.5 mi) in diameter), which orbit at 9,376 km (5,826 mi) and 23,460 km (14,580 mi) around the planet. The origin of both moons is unclear, although a popular theory states that they were asteroids captured into Martian orbit. Both satellites were discovered in 1877 by Asaph Hall and were named after the characters Phobos (the deity of panic and fear) and Deimos (the deity of terror and dread), twins from Greek mythology who accompanied their father Ares, god of war, into battle. Mars was the Roman equivalent to Ares. In modern Greek, the planet retains its ancient name Ares (Aris: Άρης). From the surface of Mars, the motions of Phobos and Deimos appear different from that of the Earth's satellite, the Moon. Phobos rises in the west, sets in the east, and rises again in just 11 hours. Deimos, being only just outside synchronous orbit – where the orbital period would match the planet's period of rotation – rises as expected in the east, but slowly. Because the orbit of Phobos is below a synchronous altitude, tidal forces from Mars are gradually lowering its orbit. In about 50 million years, it could either crash into Mars's surface or break up into a ring structure around the planet. The origin of the two satellites is not well understood. Their low albedo and carbonaceous chondrite composition have been regarded as similar to asteroids, supporting a capture theory. The unstable orbit of Phobos would seem to point toward a relatively recent capture. But both have circular orbits near the equator, which is unusual for captured objects, and the required capture dynamics are complex. Accretion early in the history of Mars is plausible, but would not account for a composition resembling asteroids rather than Mars itself, if that is confirmed. Mars may have yet-undiscovered moons, smaller than 50 to 100 metres (160 to 330 ft) in diameter, and a dust ring is predicted to exist between Phobos and Deimos. A third possibility for their origin as satellites of Mars is the involvement of a third body or a type of impact disruption. More-recent lines of evidence for Phobos having a highly porous interior, and suggesting a composition containing mainly phyllosilicates and other minerals known from Mars, point toward an origin of Phobos from material ejected by an impact on Mars that reaccreted in Martian orbit, similar to the prevailing theory for the origin of Earth's satellite. Although the visible and near-infrared (VNIR) spectra of the moons of Mars resemble those of outer-belt asteroids, the thermal infrared spectra of Phobos are reported to be inconsistent with chondrites of any class. It is also possible that Phobos and Deimos were fragments of an older moon, formed by debris from a large impact on Mars, and then destroyed by a more recent impact upon the satellite. More recently, a study conducted by a team of researchers from multiple countries suggests that a lost moon, at least fifteen times the size of Phobos, may have existed in the past. By analyzing rocks which point to tidal processes on the planet, it is possible that these tides may have been regulated by a past moon. Human observations and exploration The history of observations of Mars is marked by oppositions of Mars when the planet is closest to Earth and hence is most easily visible, which occur every couple of years. Even more notable are the perihelic oppositions of Mars, which are distinguished because Mars is close to perihelion, making it even closer to Earth. The ancient Sumerians named Mars Nergal, the god of war and plague. During Sumerian times, Nergal was a minor deity of little significance, but, during later times, his main cult center was the city of Nineveh. In Mesopotamian texts, Mars is referred to as the "star of judgement of the fate of the dead". The existence of Mars as a wandering object in the night sky was also recorded by the ancient Egyptian astronomers and, by 1534 BCE, they were familiar with the retrograde motion of the planet. By the period of the Neo-Babylonian Empire, the Babylonian astronomers were making regular records of the positions of the planets and systematic observations of their behavior. For Mars, they knew that the planet made 37 synodic periods, or 42 circuits of the zodiac, every 79 years. They invented arithmetic methods for making minor corrections to the predicted positions of the planets. In Ancient Greece, the planet was known as Πυρόεις. Commonly, the Greek name for the planet now referred to as Mars, was Ares. It was the Romans who named the planet Mars, for their god of war, often represented by the sword and shield of the planet's namesake. In the fourth century BCE, Aristotle noted that Mars disappeared behind the Moon during an occultation, indicating that the planet was farther away. Ptolemy, a Greek living in Alexandria, attempted to address the problem of the orbital motion of Mars. Ptolemy's model and his collective work on astronomy was presented in the multi-volume collection later called the Almagest (from the Arabic for "greatest"), which became the authoritative treatise on Western astronomy for the next fourteen centuries. Literature from ancient China confirms that Mars was known by Chinese astronomers by no later than the fourth century BCE. In the East Asian cultures, Mars is traditionally referred to as the "fire star" (火星) based on the Wuxing system. In 1609 Johannes Kepler published a 10 year study of Martian orbit, using the diurnal parallax of Mars, measured by Tycho Brahe, to make a preliminary calculation of the relative distance to the planet. From Brahe's observations of Mars, Kepler deduced that the planet orbited the Sun not in a circle, but in an ellipse. Moreover, Kepler showed that Mars sped up as it approached the Sun and slowed down as it moved farther away, in a manner that later physicists would explain as a consequence of the conservation of angular momentum.: 433–437 In 1610 the first use of a telescope for astronomical observation, including Mars, was performed by Italian astronomer Galileo Galilei. With the telescope the diurnal parallax of Mars was again measured in an effort to determine the Sun-Earth distance. This was first performed by Giovanni Domenico Cassini in 1672. The early parallax measurements were hampered by the quality of the instruments. The only occultation of Mars by Venus observed was that of 13 October 1590, seen by Michael Maestlin at Heidelberg. By the 19th century, the resolution of telescopes reached a level sufficient for surface features to be identified. On 5 September 1877, a perihelic opposition to Mars occurred. The Italian astronomer Giovanni Schiaparelli used a 22-centimetre (8.7 in) telescope in Milan to help produce the first detailed map of Mars. These maps notably contained features he called canali, which, with the possible exception of the natural canyon Valles Marineris, were later shown to be an optical illusion. These canali were supposedly long, straight lines on the surface of Mars, to which he gave names of famous rivers on Earth. His term, which means "channels" or "grooves", was popularly mistranslated in English as "canals". Influenced by the observations, the orientalist Percival Lowell founded an observatory which had 30- and 45-centimetre (12- and 18-in) telescopes. The observatory was used for the exploration of Mars during the last good opportunity in 1894, and the following less favorable oppositions. He published several books on Mars and life on the planet, which had a great influence on the public. The canali were independently observed by other astronomers, like Henri Joseph Perrotin and Louis Thollon in Nice, using one of the largest telescopes of that time. The seasonal changes (consisting of the diminishing of the polar caps and the dark areas formed during Martian summers) in combination with the canals led to speculation about life on Mars, and it was a long-held belief that Mars contained vast seas and vegetation. As bigger telescopes were used, fewer long, straight canali were observed. During observations in 1909 by Antoniadi with an 84-centimetre (33 in) telescope, irregular patterns were observed, but no canali were seen. The first spacecraft from Earth to visit Mars was Mars 1 of the Soviet Union, which flew by in 1963, but contact was lost en route. NASA's Mariner 4 followed and became the first spacecraft to successfully transmit from Mars; launched on 28 November 1964, it made its closest approach to the planet on 15 July 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth, and captured the first images of another planet from deep space. Once spacecraft visited the planet during the 1960s and 1970s, many previous concepts of Mars were radically broken. After the results of the Viking life-detection experiments, the hypothesis of a dead planet was generally accepted. The data from Mariner 9 and Viking allowed better maps of Mars to be made. Until 1997 and after Viking 1 shut down in 1982, Mars was only visited by three unsuccessful probes, two flying past without contact (Phobos 1, 1988; Mars Observer, 1993), and one (Phobos 2 1989) malfunctioning in orbit before reaching its destination Phobos. In 1997 Mars Pathfinder became the first successful rover mission beyond the Moon and started together with Mars Global Surveyor (operated until late 2006) an uninterrupted active robotic presence at Mars that has lasted until today. It produced complete, extremely detailed maps of the Martian topography, magnetic field and surface minerals. Starting with these missions a range of new improved crewless spacecraft, including orbiters, landers, and rovers, have been sent to Mars, with successful missions by the NASA (United States), Jaxa (Japan), ESA, United Kingdom, ISRO (India), Roscosmos (Russia), the United Arab Emirates, and CNSA (China) to study the planet's surface, climate, and geology, uncovering the different elements of the history and dynamic of the hydrosphere of Mars and possible traces of ancient life. As of 2023[update], Mars is host to ten functioning spacecraft. Eight are in orbit: 2001 Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, MAVEN, ExoMars Trace Gas Orbiter, the Hope orbiter, and the Tianwen-1 orbiter. Another two are on the surface: the Mars Science Laboratory Curiosity rover and the Perseverance rover. Collected maps are available online at websites including Google Mars. NASA provides two online tools: Mars Trek, which provides visualizations of the planet using data from 50 years of exploration, and Experience Curiosity, which simulates traveling on Mars in 3-D with Curiosity. Planned missions to Mars include: As of February 2024[update], debris from these types of missions has reached over seven tons. Most of it consists of crashed and inactive spacecraft as well as discarded components. In April 2024, NASA selected several companies to begin studies on providing commercial services to further enable robotic science on Mars. Key areas include establishing telecommunications, payload delivery and surface imaging. Habitability and habitation During the late 19th century, it was widely accepted in the astronomical community that Mars had life-supporting qualities, including the presence of oxygen and water. However, in 1894 W. W. Campbell at Lick Observatory observed the planet and found that "if water vapor or oxygen occur in the atmosphere of Mars it is in quantities too small to be detected by spectroscopes then available". That observation contradicted many of the measurements of the time and was not widely accepted. Campbell and V. M. Slipher repeated the study in 1909 using better instruments, but with the same results. It was not until the findings were confirmed by W. S. Adams in 1925 that the myth of the Earth-like habitability of Mars was finally broken. However, even in the 1960s, articles were published on Martian biology, putting aside explanations other than life for the seasonal changes on Mars. The current understanding of planetary habitability – the ability of a world to develop environmental conditions favorable to the emergence of life – favors planets that have liquid water on their surface. Most often this requires the orbit of a planet to lie within the habitable zone, which for the Sun is estimated to extend from within the orbit of Earth to about that of Mars. During perihelion, Mars dips inside this region, but Mars's thin (low-pressure) atmosphere prevents liquid water from existing over large regions for extended periods. The past flow of liquid water demonstrates the planet's potential for habitability. Recent evidence has suggested that any water on the Martian surface may have been too salty and acidic to support regular terrestrial life. The environmental conditions on Mars are a challenge to sustaining organic life: the planet has little heat transfer across its surface, it has poor insulation against bombardment by the solar wind due to the absence of a magnetosphere and has insufficient atmospheric pressure to retain water in a liquid form (water instead sublimes to a gaseous state). Mars is nearly, or perhaps totally, geologically dead; the end of volcanic activity has apparently stopped the recycling of chemicals and minerals between the surface and interior of the planet. Evidence suggests that the planet was once significantly more habitable than it is today, but whether living organisms ever existed there remains unknown. The Viking probes of the mid-1970s carried experiments designed to detect microorganisms in Martian soil at their respective landing sites and had positive results, including a temporary increase in CO2 production on exposure to water and nutrients. This sign of life was later disputed by scientists, resulting in a continuing debate, with NASA scientist Gilbert Levin asserting that Viking may have found life. A 2014 analysis of Martian meteorite EETA79001 found chlorate, perchlorate, and nitrate ions in sufficiently high concentrations to suggest that they are widespread on Mars. UV and X-ray radiation would turn chlorate and perchlorate ions into other, highly reactive oxychlorines, indicating that any organic molecules would have to be buried under the surface to survive. Small quantities of methane and formaldehyde detected by Mars orbiters are both claimed to be possible evidence for life, as these chemical compounds would quickly break down in the Martian atmosphere. Alternatively, these compounds may instead be replenished by volcanic or other geological means, such as serpentinite. Impact glass, formed by the impact of meteors, which on Earth can preserve signs of life, has also been found on the surface of the impact craters on Mars. Likewise, the glass in impact craters on Mars could have preserved signs of life, if life existed at the site. The Cheyava Falls rock discovered on Mars in June 2024 has been designated by NASA as a "potential biosignature" and was core sampled by the Perseverance rover for possible return to Earth and further examination. Although highly intriguing, no definitive final determination on a biological or abiotic origin of this rock can be made with the data currently available. Several plans for a human mission to Mars have been proposed, but none have come to fruition. The NASA Authorization Act of 2017 directed NASA to study the feasibility of a crewed Mars mission in the early 2030s; the resulting report concluded that this would be unfeasible. In addition, in 2021, China was planning to send a crewed Mars mission in 2033. Privately held companies such as SpaceX have also proposed plans to send humans to Mars, with the eventual goal to settle on the planet. As of 2024, SpaceX has proceeded with the development of the Starship launch vehicle with the goal of Mars colonization. In plans shared with the company in April 2024, Elon Musk envisions the beginning of a Mars colony within the next twenty years. This would be enabled by the planned mass manufacturing of Starship and initially sustained by resupply from Earth, and in situ resource utilization on Mars, until the Mars colony reaches full self sustainability. Any future human mission to Mars will likely take place within the optimal Mars launch window, which occurs every 26 months. The moon Phobos has been proposed as an anchor point for a space elevator. Besides national space agencies and space companies, groups such as the Mars Society and The Planetary Society advocate for human missions to Mars. In culture Mars is named after the Roman god of war (Greek Ares), but was also associated with the demi-god Heracles (Roman Hercules) by ancient Greek astronomers, as detailed by Aristotle. This association between Mars and war dates back at least to Babylonian astronomy, in which the planet was named for the god Nergal, deity of war and destruction. It persisted into modern times, as exemplified by Gustav Holst's orchestral suite The Planets, whose famous first movement labels Mars "The Bringer of War". The planet's symbol, a circle with a spear pointing out to the upper right, is also used as a symbol for the male gender. The symbol dates from at least the 11th century, though a possible predecessor has been found in the Greek Oxyrhynchus Papyri. The idea that Mars was populated by intelligent Martians became widespread in the late 19th century. Schiaparelli's "canali" observations combined with Percival Lowell's books on the subject put forward the standard notion of a planet that was a drying, cooling, dying world with ancient civilizations constructing irrigation works. Many other observations and proclamations by notable personalities added to what has been termed "Mars Fever". In the present day, high-resolution mapping of the surface of Mars has revealed no artifacts of habitation, but pseudoscientific speculation about intelligent life on Mars still continues. Reminiscent of the canali observations, these speculations are based on small scale features perceived in the spacecraft images, such as "pyramids" and the "Face on Mars". In his book Cosmos, planetary astronomer Carl Sagan wrote: "Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears." The depiction of Mars in fiction has been stimulated by its dramatic red color and by nineteenth-century scientific speculations that its surface conditions might support not just life but intelligent life. This gave way to many science fiction stories involving these concepts, such as H. G. Wells's The War of the Worlds, in which Martians seek to escape their dying planet by invading Earth; Ray Bradbury's The Martian Chronicles, in which human explorers accidentally destroy a Martian civilization; as well as Edgar Rice Burroughs's series Barsoom, C. S. Lewis's novel Out of the Silent Planet (1938), and a number of Robert A. Heinlein stories before the mid-sixties. Since then, depictions of Martians have also extended to animation. A comic figure of an intelligent Martian, Marvin the Martian, appeared in Haredevil Hare (1948) as a character in the Looney Tunes animated cartoons of Warner Brothers, and has continued as part of popular culture to the present. After the Mariner and Viking spacecraft had returned pictures of Mars as a lifeless and canal-less world, these ideas about Mars were abandoned; for many science-fiction authors, the new discoveries initially seemed like a constraint, but eventually the post-Viking knowledge of Mars became itself a source of inspiration for works like Kim Stanley Robinson's Mars trilogy. See also Notes References Further reading External links Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Local Volume → Virgo Supercluster → Laniakea Supercluster → Pisces–Cetus Supercluster Complex → Local Hole → Observable universe → UniverseEach arrow (→) may be read as "within" or "part of". |
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Contents 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 Squeak Squeak is an object-oriented, class-based, and reflective programming language. It was derived from Smalltalk-80 by a group that included some of Smalltalk-80's original developers, initially at Apple Computer, then at Walt Disney Imagineering, where it was intended for use in internal Disney projects. The group later was supported by HP Labs and SAP. Squeak runs on a stack virtual machine (VM), allowing for a high degree of portability. The Squeak system includes code for generating a new version of the VM on which it runs, along with a VM simulator written in Squeak. Developers Dan Ingalls, an important contributor to the Squeak project, wrote the paper upon which Squeak is built, and constructed the architecture for five generations of the Smalltalk language. Alan Kay is an important contributor to the Squeak project, and Squeak incorporates many elements of his proposed Dynabook concept. User interface frameworks Squeak includes four user interface frameworks: Uses Many Squeak contributors collaborate on Open Cobalt, a free and open source virtual world browser and construction toolkit built on Squeak. The first version of Scratch was implemented in Squeak. OpenQwaq, a virtual conferencing and collaboration system, is based on Squeak. Squeak is also used in the Nintendo ES operating system. License Squeak 4.0 and later may be downloaded at no cost, including source code, as a prebuilt virtual machine image licensed under the MIT License, with the exception of some of the original Apple code, which is governed by the Apache License. Squeak was originally released by Apple under its own Squeak License. While source code was available and modification permitted, the Squeak License contained an indemnity clause that prevented it from qualifying as true free and open-source software. In 2006, Apple relicensed Squeak twice. First, in May, Apple used its own Apple Public Source License, which satisfies the Free Software Foundation's concept of a Free Software License and has attained official approval from the Open Source Initiative as an Open Source License. However, The Apple Public Source License fails to conform to the Debian Free Software Guidelines. To enable inclusion of Etoys in the One Laptop Per Child project, a second relicensing was undertaken using the Apache License. At this point, an effort was also made to address the issue of code contributed by members of the Squeak community, which it was not in Apple's power to unilaterally relicense. For each contribution made under the Squeak License since 1996, a relicensing statement was obtained authorizing distribution under the MIT license, and finally in March 2010, the result was released as Squeak 4.0, now under combined MIT and Apache licenses. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Social_network#cite_note-Heckathorn-66] | [TOKENS: 5247] |
Contents Social network 1800s: Martineau · Tocqueville · Marx · Spencer · Le Bon · Ward · Pareto · Tönnies · Veblen · Simmel · Durkheim · Addams · Mead · Weber · Du Bois · Mannheim · Elias A social network is a social structure consisting of a set of social actors (such as individuals or organizations), networks of dyadic ties, and other social interactions between actors. The social network perspective provides a set of methods for analyzing the structure of whole social entities along with a variety of theories explaining the patterns observed in these structures. The study of these structures uses social network analysis to identify local and global patterns, locate influential entities, and examine dynamics of networks. For instance, social network analysis has been used in studying the spread of misinformation on social media platforms or analyzing the influence of key figures in social networks. Social networks and the analysis of them is an inherently interdisciplinary academic field which emerged from social psychology, sociology, statistics, and graph theory. Georg Simmel authored early structural theories in sociology emphasizing the dynamics of triads and "web of group affiliations". Jacob Moreno is credited with developing the first sociograms in the 1930s to study interpersonal relationships. These approaches were mathematically formalized in the 1950s and theories and methods of social networks became pervasive in the social and behavioral sciences by the 1980s. Social network analysis is now one of the major paradigms in contemporary sociology, and is also employed in a number of other social and formal sciences. Together with other complex networks, it forms part of the nascent field of network science. Overview The social network is a theoretical construct useful in the social sciences to study relationships between individuals, groups, organizations, or even entire societies (social units, see differentiation). The term is used to describe a social structure determined by such interactions. The ties through which any given social unit connects represent the convergence of the various social contacts of that unit. This theoretical approach is, necessarily, relational. An axiom of the social network approach to understanding social interaction is that social phenomena should be primarily conceived and investigated through the properties of relations between and within units, instead of the properties of these units themselves. Thus, one common criticism of social network theory is that individual agency is often ignored although this may not be the case in practice (see agent-based modeling). Precisely because many different types of relations, singular or in combination, form these network configurations, network analytics are useful to a broad range of research enterprises. In social science, these fields of study include, but are not limited to anthropology, biology, communication studies, economics, geography, information science, organizational studies, social psychology, sociology, and sociolinguistics. History In the late 1890s, both Émile Durkheim and Ferdinand Tönnies foreshadowed the idea of social networks in their theories and research of social groups. Tönnies argued that social groups can exist as personal and direct social ties that either link individuals who share values and belief (Gemeinschaft, German, commonly translated as "community") or impersonal, formal, and instrumental social links (Gesellschaft, German, commonly translated as "society"). Durkheim gave a non-individualistic explanation of social facts, arguing that social phenomena arise when interacting individuals constitute a reality that can no longer be accounted for in terms of the properties of individual actors. Georg Simmel, writing at the turn of the twentieth century, pointed to the nature of networks and the effect of network size on interaction and examined the likelihood of interaction in loosely knit networks rather than groups. Major developments in the field can be seen in the 1930s by several groups in psychology, anthropology, and mathematics working independently. In psychology, in the 1930s, Jacob L. Moreno began systematic recording and analysis of social interaction in small groups, especially classrooms and work groups (see sociometry). In anthropology, the foundation for social network theory is the theoretical and ethnographic work of Bronislaw Malinowski, Alfred Radcliffe-Brown, and Claude Lévi-Strauss. A group of social anthropologists associated with Max Gluckman and the Manchester School, including John A. Barnes, J. Clyde Mitchell and Elizabeth Bott Spillius, often are credited with performing some of the first fieldwork from which network analyses were performed, investigating community networks in southern Africa, India and the United Kingdom. Concomitantly, British anthropologist S. F. Nadel codified a theory of social structure that was influential in later network analysis. In sociology, the early (1930s) work of Talcott Parsons set the stage for taking a relational approach to understanding social structure. Later, drawing upon Parsons' theory, the work of sociologist Peter Blau provides a strong impetus for analyzing the relational ties of social units with his work on social exchange theory. By the 1970s, a growing number of scholars worked to combine the different tracks and traditions. One group consisted of sociologist Harrison White and his students at the Harvard University Department of Social Relations. Also independently active in the Harvard Social Relations department at the time were Charles Tilly, who focused on networks in political and community sociology and social movements, and Stanley Milgram, who developed the "six degrees of separation" thesis. Mark Granovetter and Barry Wellman are among the former students of White who elaborated and championed the analysis of social networks. Beginning in the late 1990s, social network analysis experienced work by sociologists, political scientists, and physicists such as Duncan J. Watts, Albert-László Barabási, Peter Bearman, Nicholas A. Christakis, James H. Fowler, and others, developing and applying new models and methods to emerging data available about online social networks, as well as "digital traces" regarding face-to-face networks. Levels of analysis In general, social networks are self-organizing, emergent, and complex, such that a globally coherent pattern appears from the local interaction of the elements that make up the system. These patterns become more apparent as network size increases. However, a global network analysis of, for example, all interpersonal relationships in the world is not feasible and is likely to contain so much information as to be uninformative. Practical limitations of computing power, ethics and participant recruitment and payment also limit the scope of a social network analysis. The nuances of a local system may be lost in a large network analysis, hence the quality of information may be more important than its scale for understanding network properties. Thus, social networks are analyzed at the scale relevant to the researcher's theoretical question. Although levels of analysis are not necessarily mutually exclusive, there are three general levels into which networks may fall: micro-level, meso-level, and macro-level. At the micro-level, social network research typically begins with an individual, snowballing as social relationships are traced, or may begin with a small group of individuals in a particular social context. Dyadic level: A dyad is a social relationship between two individuals. Network research on dyads may concentrate on structure of the relationship (e.g. multiplexity, strength), social equality, and tendencies toward reciprocity/mutuality. Triadic level: Add one individual to a dyad, and you have a triad. Research at this level may concentrate on factors such as balance and transitivity, as well as social equality and tendencies toward reciprocity/mutuality. In the balance theory of Fritz Heider the triad is the key to social dynamics. The discord in a rivalrous love triangle is an example of an unbalanced triad, likely to change to a balanced triad by a change in one of the relations. The dynamics of social friendships in society has been modeled by balancing triads. The study is carried forward with the theory of signed graphs. Actor level: The smallest unit of analysis in a social network is an individual in their social setting, i.e., an "actor" or "ego." Egonetwork analysis focuses on network characteristics, such as size, relationship strength, density, centrality, prestige and roles such as isolates, liaisons, and bridges. Such analyses, are most commonly used in the fields of psychology or social psychology, ethnographic kinship analysis or other genealogical studies of relationships between individuals. Subset level: Subset levels of network research problems begin at the micro-level, but may cross over into the meso-level of analysis. Subset level research may focus on distance and reachability, cliques, cohesive subgroups, or other group actions or behavior. In general, meso-level theories begin with a population size that falls between the micro- and macro-levels. However, meso-level may also refer to analyses that are specifically designed to reveal connections between micro- and macro-levels. Meso-level networks are low density and may exhibit causal processes distinct from interpersonal micro-level networks. Organizations: Formal organizations are social groups that distribute tasks for a collective goal. Network research on organizations may focus on either intra-organizational or inter-organizational ties in terms of formal or informal relationships. Intra-organizational networks themselves often contain multiple levels of analysis, especially in larger organizations with multiple branches, franchises or semi-autonomous departments. In these cases, research is often conducted at a work group level and organization level, focusing on the interplay between the two structures. Experiments with networked groups online have documented ways to optimize group-level coordination through diverse interventions, including the addition of autonomous agents to the groups. Randomly distributed networks: Exponential random graph models of social networks became state-of-the-art methods of social network analysis in the 1980s. This framework has the capacity to represent social-structural effects commonly observed in many human social networks, including general degree-based structural effects commonly observed in many human social networks as well as reciprocity and transitivity, and at the node-level, homophily and attribute-based activity and popularity effects, as derived from explicit hypotheses about dependencies among network ties. Parameters are given in terms of the prevalence of small subgraph configurations in the network and can be interpreted as describing the combinations of local social processes from which a given network emerges. These probability models for networks on a given set of actors allow generalization beyond the restrictive dyadic independence assumption of micro-networks, allowing models to be built from theoretical structural foundations of social behavior. Scale-free networks: A scale-free network is a network whose degree distribution follows a power law, at least asymptotically. In network theory a scale-free ideal network is a random network with a degree distribution that unravels the size distribution of social groups. Specific characteristics of scale-free networks vary with the theories and analytical tools used to create them, however, in general, scale-free networks have some common characteristics. One notable characteristic in a scale-free network is the relative commonness of vertices with a degree that greatly exceeds the average. The highest-degree nodes are often called "hubs", and may serve specific purposes in their networks, although this depends greatly on the social context. Another general characteristic of scale-free networks is the clustering coefficient distribution, which decreases as the node degree increases. This distribution also follows a power law. The Barabási model of network evolution shown above is an example of a scale-free network. Rather than tracing interpersonal interactions, macro-level analyses generally trace the outcomes of interactions, such as economic or other resource transfer interactions over a large population. Large-scale networks: Large-scale network is a term somewhat synonymous with "macro-level." It is primarily used in social and behavioral sciences, and in economics. Originally, the term was used extensively in the computer sciences (see large-scale network mapping). Complex networks: Most larger social networks display features of social complexity, which involves substantial non-trivial features of network topology, with patterns of complex connections between elements that are neither purely regular nor purely random (see, complexity science, dynamical system and chaos theory), as do biological, and technological networks. Such complex network features include a heavy tail in the degree distribution, a high clustering coefficient, assortativity or disassortativity among vertices, community structure (see stochastic block model), and hierarchical structure. In the case of agency-directed networks these features also include reciprocity, triad significance profile (TSP, see network motif), and other features. In contrast, many of the mathematical models of networks that have been studied in the past, such as lattices and random graphs, do not show these features. Theoretical links Various theoretical frameworks have been imported for the use of social network analysis. The most prominent of these are Graph theory, Balance theory, Social comparison theory, and more recently, the Social identity approach. Few complete theories have been produced from social network analysis. Two that have are structural role theory and heterophily theory. The basis of Heterophily Theory was the finding in one study that more numerous weak ties can be important in seeking information and innovation, as cliques have a tendency to have more homogeneous opinions as well as share many common traits. This homophilic tendency was the reason for the members of the cliques to be attracted together in the first place. However, being similar, each member of the clique would also know more or less what the other members knew. To find new information or insights, members of the clique will have to look beyond the clique to its other friends and acquaintances. This is what Granovetter called "the strength of weak ties". Structural holes In the context of networks, social capital exists where people have an advantage because of their location in a network. Contacts in a network provide information, opportunities and perspectives that can be beneficial to the central player in the network. Most social structures tend to be characterized by dense clusters of strong connections. Information within these clusters tends to be rather homogeneous and redundant. Non-redundant information is most often obtained through contacts in different clusters. When two separate clusters possess non-redundant information, there is said to be a structural hole between them. Thus, a network that bridges structural holes will provide network benefits that are in some degree additive, rather than overlapping. An ideal network structure has a vine and cluster structure, providing access to many different clusters and structural holes. Networks rich in structural holes are a form of social capital in that they offer information benefits. The main player in a network that bridges structural holes is able to access information from diverse sources and clusters. For example, in business networks, this is beneficial to an individual's career because he is more likely to hear of job openings and opportunities if his network spans a wide range of contacts in different industries/sectors. This concept is similar to Mark Granovetter's theory of weak ties, which rests on the basis that having a broad range of contacts is most effective for job attainment. Structural holes have been widely applied in social network analysis, resulting in applications in a wide range of practical scenarios as well as machine learning-based social prediction. Research clusters Research has used network analysis to examine networks created when artists are exhibited together in museum exhibition. Such networks have been shown to affect an artist's recognition in history and historical narratives, even when controlling for individual accomplishments of the artist. Other work examines how network grouping of artists can affect an individual artist's auction performance. An artist's status has been shown to increase when associated with higher status networks, though this association has diminishing returns over an artist's career. In J.A. Barnes' day, a "community" referred to a specific geographic location and studies of community ties had to do with who talked, associated, traded, and attended church with whom. Today, however, there are extended "online" communities developed through telecommunications devices and social network services. Such devices and services require extensive and ongoing maintenance and analysis, often using network science methods. Community development studies, today, also make extensive use of such methods. Complex networks require methods specific to modelling and interpreting social complexity and complex adaptive systems, including techniques of dynamic network analysis. Mechanisms such as Dual-phase evolution explain how temporal changes in connectivity contribute to the formation of structure in social networks. The study of social networks is being used to examine the nature of interdependencies between actors and the ways in which these are related to outcomes of conflict and cooperation. Areas of study include cooperative behavior among participants in collective actions such as protests; promotion of peaceful behavior, social norms, and public goods within communities through networks of informal governance; the role of social networks in both intrastate conflict and interstate conflict; and social networking among politicians, constituents, and bureaucrats. In criminology and urban sociology, much attention has been paid to the social networks among criminal actors. For example, murders can be seen as a series of exchanges between gangs. Murders can be seen to diffuse outwards from a single source, because weaker gangs cannot afford to kill members of stronger gangs in retaliation, but must commit other violent acts to maintain their reputation for strength. Diffusion of ideas and innovations studies focus on the spread and use of ideas from one actor to another or one culture and another. This line of research seeks to explain why some become "early adopters" of ideas and innovations, and links social network structure with facilitating or impeding the spread of an innovation. A case in point is the social diffusion of linguistic innovation such as neologisms. Experiments and large-scale field trials (e.g., by Nicholas Christakis and collaborators) have shown that cascades of desirable behaviors can be induced in social groups, in settings as diverse as Honduras villages, Indian slums, or in the lab. Still other experiments have documented the experimental induction of social contagion of voting behavior, emotions, risk perception, and commercial products. In demography, the study of social networks has led to new sampling methods for estimating and reaching populations that are hard to enumerate (for example, homeless people or intravenous drug users.) For example, respondent driven sampling is a network-based sampling technique that relies on respondents to a survey recommending further respondents. The field of sociology focuses almost entirely on networks of outcomes of social interactions. More narrowly, economic sociology considers behavioral interactions of individuals and groups through social capital and social "markets". Sociologists, such as Mark Granovetter, have developed core principles about the interactions of social structure, information, ability to punish or reward, and trust that frequently recur in their analyses of political, economic and other institutions. Granovetter examines how social structures and social networks can affect economic outcomes like hiring, price, productivity and innovation and describes sociologists' contributions to analyzing the impact of social structure and networks on the economy. Analysis of social networks is increasingly incorporated into health care analytics, not only in epidemiological studies but also in models of patient communication and education, disease prevention, mental health diagnosis and treatment, and in the study of health care organizations and systems. Human ecology is an interdisciplinary and transdisciplinary study of the relationship between humans and their natural, social, and built environments. The scientific philosophy of human ecology has a diffuse history with connections to geography, sociology, psychology, anthropology, zoology, and natural ecology. In the study of literary systems, network analysis has been applied by Anheier, Gerhards and Romo, De Nooy, Senekal, and Lotker, to study various aspects of how literature functions. The basic premise is that polysystem theory, which has been around since the writings of Even-Zohar, can be integrated with network theory and the relationships between different actors in the literary network, e.g. writers, critics, publishers, literary histories, etc., can be mapped using visualization from SNA. Research studies of formal or informal organization relationships, organizational communication, economics, economic sociology, and other resource transfers. Social networks have also been used to examine how organizations interact with each other, characterizing the many informal connections that link executives together, as well as associations and connections between individual employees at different organizations. Many organizational social network studies focus on teams. Within team network studies, research assesses, for example, the predictors and outcomes of centrality and power, density and centralization of team instrumental and expressive ties, and the role of between-team networks. Intra-organizational networks have been found to affect organizational commitment, organizational identification, interpersonal citizenship behaviour. Social capital is a form of economic and cultural capital in which social networks are central, transactions are marked by reciprocity, trust, and cooperation, and market agents produce goods and services not mainly for themselves, but for a common good. Social capital is split into three dimensions: the structural, the relational and the cognitive dimension. The structural dimension describes how partners interact with each other and which specific partners meet in a social network. Also, the structural dimension of social capital indicates the level of ties among organizations. This dimension is highly connected to the relational dimension which refers to trustworthiness, norms, expectations and identifications of the bonds between partners. The relational dimension explains the nature of these ties which is mainly illustrated by the level of trust accorded to the network of organizations. The cognitive dimension analyses the extent to which organizations share common goals and objectives as a result of their ties and interactions. Social capital is a sociological concept about the value of social relations and the role of cooperation and confidence to achieve positive outcomes. The term refers to the value one can get from their social ties. For example, newly arrived immigrants can make use of their social ties to established migrants to acquire jobs they may otherwise have trouble getting (e.g., because of unfamiliarity with the local language). A positive relationship exists between social capital and the intensity of social network use. In a dynamic framework, higher activity in a network feeds into higher social capital which itself encourages more activity. This particular cluster focuses on brand-image and promotional strategy effectiveness, taking into account the impact of customer participation on sales and brand-image. This is gauged through techniques such as sentiment analysis which rely on mathematical areas of study such as data mining and analytics. This area of research produces vast numbers of commercial applications as the main goal of any study is to understand consumer behaviour and drive sales. In many organizations, members tend to focus their activities inside their own groups, which stifles creativity and restricts opportunities. A player whose network bridges structural holes has an advantage in detecting and developing rewarding opportunities. Such a player can mobilize social capital by acting as a "broker" of information between two clusters that otherwise would not have been in contact, thus providing access to new ideas, opinions and opportunities. British philosopher and political economist John Stuart Mill, writes, "it is hardly possible to overrate the value of placing human beings in contact with persons dissimilar to themselves.... Such communication [is] one of the primary sources of progress." Thus, a player with a network rich in structural holes can add value to an organization through new ideas and opportunities. This in turn, helps an individual's career development and advancement. A social capital broker also reaps control benefits of being the facilitator of information flow between contacts. Full communication with exploratory mindsets and information exchange generated by dynamically alternating positions in a social network promotes creative and deep thinking. In the case of consulting firm Eden McCallum, the founders were able to advance their careers by bridging their connections with former big three consulting firm consultants and mid-size industry firms. By bridging structural holes and mobilizing social capital, players can advance their careers by executing new opportunities between contacts. There has been research that both substantiates and refutes the benefits of information brokerage. A study of high tech Chinese firms by Zhixing Xiao found that the control benefits of structural holes are "dissonant to the dominant firm-wide spirit of cooperation and the information benefits cannot materialize due to the communal sharing values" of such organizations. However, this study only analyzed Chinese firms, which tend to have strong communal sharing values. Information and control benefits of structural holes are still valuable in firms that are not quite as inclusive and cooperative on the firm-wide level. In 2004, Ronald Burt studied 673 managers who ran the supply chain for one of America's largest electronics companies. He found that managers who often discussed issues with other groups were better paid, received more positive job evaluations and were more likely to be promoted. Thus, bridging structural holes can be beneficial to an organization, and in turn, to an individual's career. Computer networks combined with social networking software produce a new medium for social interaction. A relationship over a computerized social networking service can be characterized by context, direction, and strength. The content of a relation refers to the resource that is exchanged. In a computer-mediated communication context, social pairs exchange different kinds of information, including sending a data file or a computer program as well as providing emotional support or arranging a meeting. With the rise of electronic commerce, information exchanged may also correspond to exchanges of money, goods or services in the "real" world. Social network analysis methods have become essential to examining these types of computer mediated communication. In addition, the sheer size and the volatile nature of social media has given rise to new network metrics. A key concern with networks extracted from social media is the lack of robustness of network metrics given missing data. Based on the pattern of homophily, ties between people are most likely to occur between nodes that are most similar to each other, or within neighbourhood segregation, individuals are most likely to inhabit the same regional areas as other individuals who are like them. Therefore, social networks can be used as a tool to measure the degree of segregation or homophily within a social network. Social Networks can both be used to simulate the process of homophily but it can also serve as a measure of level of exposure of different groups to each other within a current social network of individuals in a certain area. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Bangkok] | [TOKENS: 14533] |
Contents Bangkok Bangkok,[a] officially known in Thai as Krung Thep Maha Nakhon[b] and colloquially as Krung Thep,[c] is the capital and most populous city of Thailand. The city occupies 1,568.7 square kilometres (605.7 sq mi) in the Chao Phraya River delta in central Thailand and has an estimated population of 11.4 million people as of 2024,[citation needed] 15.9% of the country's population. Over 17.4 million people (25% of Thailand's population) live within the surrounding Bangkok Metropolitan Region as of the 2021 estimate, making Bangkok a megacity and an extreme primate city, dwarfing Thailand's other urban centres in both size and importance to the national economy. Bangkok traces its roots to a small trading post during the Ayutthaya era in the 15th century, which eventually grew and became the site of two capital cities, Thonburi in 1767 and Rattanakosin in 1782. Bangkok was at the heart of the modernization of Siam during the late 19th century, as the country faced pressures from the West. The city was at the centre of the country's political struggles throughout the 20th century, as Siam—later renamed Thailand—abolished absolute monarchy, adopted constitutional rule, and underwent numerous coups and several uprisings. The city, incorporated as a special administrative area under the Bangkok Metropolitan Administration in 1972, grew rapidly during the 1960s through the 1980s and now exerts a significant impact on Thailand's politics, economy, education, media, and modern society. The Asian investment boom in the 1980s and 1990s led many multinational corporations to locate their regional headquarters in Bangkok. The city is now a regional force in finance, business, and pop culture. It is an international hub for transport and health care, and has emerged as a centre for the arts, fashion, and entertainment. The city is known for its street life and cultural landmarks, as well as its red-light districts. The Grand Palace and Buddhist temples, including Wat Arun and Wat Pho, stand in contrast with other tourist attractions such as the nightlife scenes of Khaosan Road and Patpong. Bangkok is among the world's top tourist destinations and has been named the world's most visited city in several international rankings. Bangkok's rapid growth, coupled with little urban planning, has resulted in a haphazard cityscape and inadequate infrastructure. Despite an extensive expressway network, an inadequate road network and substantial private car usage have led to chronic and crippling traffic congestion, which caused severe air pollution in the 1990s. The city has since turned to public transport to solve the problem, operating 10 urban rail lines and building other public transit; however, congestion remains a prevalent issue. History The history of Bangkok dates at least back to the early 15th century, to when it was a village on the west bank of the Chao Phraya River, under the rule of Ayutthaya. Because of its strategic location near the mouth of the river, the town gradually increased in importance. Bangkok initially served as a customs outpost with forts on both sides of the river, and was the site of a siege in 1688, in which the French were expelled from Siam. After the fall of Ayutthaya to the Burmese in 1767, the newly crowned King Taksin established his capital at the town, which became the base of the Thonburi Kingdom. In 1782, King Phutthayotfa Chulalok (Rama I) succeeded Taksin, moved the capital to the eastern bank's Rattanakosin Island, thus founding the Rattanakosin Kingdom. The City Pillar was erected on 21 April 1782, which is regarded as the date of the foundation of Bangkok as the capital. Bangkok's economy gradually expanded through international trade, first with China, then with Western merchants returning in the early to mid-19th century. As the capital, Bangkok was the centre of Siam's modernization as it faced pressure from Western powers in the late 19th century. The reigns of Kings Mongkut (Rama IV, r. 1851–68) and Chulalongkorn (Rama V, r. 1868–1910) saw the introduction of the steam engine, printing press, rail transport and utilities infrastructure in the city, as well as formal education and healthcare. Bangkok became the centre stage for power struggles between the military and political elite as the country abolished absolute monarchy in 1932. As Thailand allied with Japan in World War II, Bangkok was subjected to Allied bombing, but rapidly grew in the post-war period as a result of US aid and government-sponsored investment. Bangkok's role as a US military R&R destination boosted its tourism industry, as well as firmly establishing it as a sex tourism destination. Disproportionate urban development led to increasing income inequalities and migration from rural areas into Bangkok; its population surged from 1.8 million to 3 million in the 1960s. Following the US withdrawal from Vietnam in 1973, Japanese businesses took over as leaders in investment, and the expansion of export-oriented manufacturing led to the growth of the financial market in Bangkok. Rapid growth of the city continued through the 1980s and early 1990s, until it was stalled by the 1997 Asian financial crisis. By then, many public and social issues had emerged, among them the strain on infrastructure reflected in the city's notorious traffic jams. Bangkok's role as the nation's political stage continues to be seen in strings of popular protests, from the student uprisings in 1973 and 1976, anti-military demonstrations in 1992, and frequent street protests since 2006, including those by groups opposing and supporting former prime minister Thaksin Shinawatra from 2006 to 2013, and a renewed student-led movement in 2020. Administration of the city was first formalized by King Chulalongkorn in 1906, with the establishment of Monthon Krung Thep Phra Maha Nakhon (มณฑลกรุงเทพพระมหานคร) as a national subdivision. In 1915, the monthon was split into several provinces, the administrative boundaries of which have since further changed. The city in its current form was created in 1972 with the formation of the Bangkok Metropolitan Administration (BMA), following the merger of Phra Nakhon province on the eastern bank of the Chao Phraya and Thonburi province on the west during the previous year. Name The origin of the name Bangkok (บางกอก, pronounced in Thai as [bāːŋ kɔ̀ːk] ⓘ) is unclear. Bang บาง is a Thai word meaning 'a village on a stream', and the name might have been derived from Bang Ko (บางเกาะ), ko เกาะ meaning 'island', stemming from the city's watery landscape, this make the city well known as Venice of the East. Another theory suggests that it is shortened from Bang Makok (บางมะกอก), makok มะกอก being the name of Elaeocarpus hygrophilus, a plant bearing olive-like fruit.[d] This is supported by the former name of Wat Arun, a historic temple in the area, that used to be called Wat Makok. Officially, the town was known as Thonburi Si Mahasamut (ธนบุรีศรีมหาสมุทร, from Pali and Sanskrit, literally 'city of treasures gracing the ocean') or Thonburi, according to the Ayutthaya Chronicles. Bangkok was likely a colloquial name, albeit one widely adopted by foreign visitors, who continued to use it to refer to the city even after the new capital's establishment. When King Rama I established his new capital on the river's eastern bank, the city inherited Ayutthaya's ceremonial name, of which there were many variants, including Krung Thep Thawarawadi Si Ayutthaya (กรุงเทพทวารวดีศรีอยุธยา) and Krung Thep Maha Nakhon Si Ayutthaya (กรุงเทพมหานครศรีอยุธยา). Edmund Roberts, visiting the city as envoy of the United States in 1833, noted that the city, since becoming capital, was known as Sia-Yut'hia, and this is the name used in international treaties of the period. The city's ceremonial name came into use during the reign of King Mongkut.[e] The full name reads as follows:[f] Krungthepmahanakhon Amonrattanakosin Mahintharayutthaya Mahadilokphop Noppharatratchathaniburirom Udomratchaniwetmahasathan Amonphimanawatansathit Sakkathattiyawitsanukamprasitกรุงเทพมหานคร อมรรัตนโกสินทร์ มหินทรายุธยา มหาดิลกภพ นพรัตนราชธานีบูรีรมย์ อุดมราชนิเวศน์มหาสถาน อมรพิมานอวตารสถิต สักกะทัตติยวิษณุกรรมประสิทธิ์ The name, composed of Pali and Sanskrit root words, translates as: The city of angels, great city of immortals, magnificent city of the Nine Gems, seat of the King, city of royal palaces, home of gods incarnate, erected by Vishvakarman at Indra's behest. The name is listed in Guinness World Records as the world's longest place name at 168 letters.[g] Many Thais who recall the full name do so because of its use in the 1989 song "Krung Thep Maha Nakhon" by Thai rock band Asanee–Wasan, the lyrics of which consist entirely of the city's full name, repeated throughout the song. Today, the city is officially known in Thai by a shortened form of the full ceremonial name, Krung Thep Maha Nakhon (กรุงเทพมหานคร), which is colloquially further shortened to Krung Thep (กรุงเทพฯ) or the initialism Ko Tho Mo (กทม.). Krung กรุง is a Thai word of Khmer origin, meaning 'capital, king', while thep, เทพ is from Pali/Sanskrit deva, meaning 'deity' or 'god'. The name is more commonly translated as 'City of Angels', which is also used to draw comparisons with Los Angeles in the United States, a comparably sized city with similar traffic issues. Another nickname sometimes used to refer to the city is The Big Mango, a tongue-in-cheek comparison to The Big Apple for New York City. Government The city of Bangkok is locally governed by the Bangkok Metropolitan Administration (BMA). Although its boundaries are at the provincial (changwat) level, unlike the other 76 provinces, Bangkok is a special administrative area whose governor is directly elected to serve a four-year term. The governor, together with four appointed deputies, forms the executive body, who implement policies through the BMA civil service headed by the Permanent Secretary for the BMA. In separate elections, each district elects one or more city councillors, who form the Bangkok Metropolitan Council. The council is the BMA's legislative body and has power over municipal ordinances and the city's budget. The latest gubernatorial election took place on 22 May 2022 after an extended lapse following the 2014 Thai coup d'état, and was won by Chadchart Sittipunt. Bangkok is divided into fifty districts (khet, equivalent to amphoe in the other provinces), which are further subdivided into 180 sub-districts (khwaeng, equivalent to tambon). Each district is managed by a district director appointed by the governor. District councils, elected to four-year terms, serve as advisory bodies to their respective district directors. The BMA is divided into sixteen departments, each overseeing different aspects of the administration's responsibilities. Most of these responsibilities concern the city's infrastructure, and include city planning, building control, transportation, drainage, waste management, and city beautification, as well as education, medical, and rescue services. Many of these services are provided jointly with other agencies. The BMA has the authority to implement local ordinances, although civil law enforcement falls under the jurisdiction of the Metropolitan Police Bureau. As the capital of Thailand, Bangkok is the seat of all branches of the national government. The Government House, Parliament House, and Supreme, Administrative, and Constitutional Courts are all in the city. Bangkok is the site of the Grand Palace and Dusit Palace, respectively the official and de facto residence of the king. Most government ministries also have headquarters and offices in the capital. The city seal shows Hindu god Indra riding in the clouds on Airavata, a divine white elephant known in Thai as Erawan. In his hand Indra holds his weapon, the vajra. The seal is based on a painting done by Prince Naris, a brother of King Chulalongkorn. The tree symbol of Bangkok is Ficus benjamina. Giant barb (Catlocarpio siamensis) has been chosen as the aquatic animal of Bangkok. The official city slogan, adopted in 2012, reads: As built by deities, the administrative centre, dazzling palaces and temples, the capital of Thailand กรุงเทพฯ ดุจเทพสร้าง เมืองศูนย์กลางการปกครอง วัดวังงามเรืองรอง เมืองหลวงของประเทศไทย Geography Bangkok covers an area of 1,568.7 km2 (605.7 sq mi), ranking 69th among the other 76 provinces of Thailand. Of this, about 700 km2 (270 sq mi) forms the built-up urban area. It is ranked 73rd in the world in terms of land area. The city's urban sprawl reaches into parts of the six other provinces that it borders, namely, in clockwise order from northwest: Nonthaburi, Pathum Thani, Chachoengsao, Samut Prakan, Samut Sakhon, and Nakhon Pathom. Except for Chachoengsao, these provinces, together with Bangkok, form the greater Bangkok Metropolitan Region. Bangkok is situated in the Chao Phraya River delta in Thailand's central plain. The river meanders through the city in a southerly direction, emptying into the Gulf of Thailand approximately 25 km (16 mi) south of the city centre. The area is flat and low-lying, with an average elevation of 1.5 m (4 ft 11 in) above sea level.[h] Most of the area was originally swampland, which was gradually drained and irrigated for agriculture by the construction of canals (khlong) which took place from the 16th to 19th centuries. The course of the river as it flows through Bangkok has been modified by the construction of several shortcut canals. The city's waterway network served as the primary means of transport until the late 19th century, when modern roads began to be built. Up until then, most people lived near or on the water, leading the city to be known during the 19th century as the "Venice of the East". Many of these canals have since been filled in or paved over, but others still crisscross the city, serving as major drainage channels and transport routes. Most canals are now badly polluted, although the BMA has committed to the treatment and cleaning up of several canals. The geology of the Bangkok area is characterised by a top layer of soft marine clay, known as "Bangkok clay", averaging 15 m (49 ft) in thickness, which overlies an aquifer system consisting of eight known units. This feature has contributed to the effects of subsidence caused by extensive groundwater pumping. First discovered in the 1970s, subsidence soon became a critical issue, reaching a rate of 120 mm (4.7 in) per year in 1981. Ground water management and mitigation measures have since lessened the severity of the situation, and the rate of subsidence decreased to 10 to 30 mm (0.39 to 1.18 in) per year in the early 2000s, though parts of the city are now 1 m (3 ft 3 in) below sea level. Subsidence has resulted in increased flood risk, as Bangkok is already prone to flooding due to its low elevation and an inadequate drainage infrastructure, often compounded by blockage from rubbish pollution (especially plastic waste). The city now relies on flood barriers and augmenting drainage from canals by pumping and building drain tunnels, but parts of Bangkok and its suburbs are still regularly inundated. Heavy downpours resulting in urban runoff overwhelming drainage systems, and runoff discharge from upstream areas, are major triggering factors. Severe flooding affecting much of the city occurred in 1995 and 2011. In 2011, most of Bangkok's northern, eastern, and western districts were flooded, in some places for over two months. Bangkok's geology also makes its tall buildings vulnerable to powerful earthquakes from far away, despite not being in a seismically active area, as the clay layer has an amplifying effect on long-period ground motion, which tends to match the resonant frequency of high-rises. Occupants of skyscrapers in Bangkok have often felt effects from earthquakes centred hundreds of kilometres away in northern Thailand and Myanmar. Seismic considerations were only added to the building code in 2007, making older structures particularly at risk. Its coastal location makes Bangkok particularly vulnerable to rising sea levels due to global warming and climate change. A study by the OECD has estimated that 5.138 million people in Bangkok may be exposed to coastal flooding by 2070, the seventh highest figure among the world's port cities.: 8 There are fears that the city may be submerged by 2030. A study published in October 2019 in Nature Communications corrected earlier models of coastal elevations and concluded that up to 12 million Thais—mostly in the greater Bangkok metropolitan area—face the prospect of annual flooding events. This is compounded by coastal erosion, which is an issue in the gulf coastal area, a small length of which lies within Bangkok's Bang Khun Thian District. Tidal flat ecosystems existed on the coast; however, many have been reclaimed for agriculture, aquaculture, and salt works. The closest mountain range to Bangkok is the Khao Khiao Massif, about 40 km (25 mi) southeast of the city. Phu Khao Thong, the only hill in the metropolitan area, originated with a very large chedi that King Rama III (1787–1851) built at Wat Saket. The chedi collapsed during construction because the soft soil could not support its weight. Over the next few decades, the abandoned mud-and-brick structure acquired the shape of a natural hill and became overgrown with weeds. The locals called it phu khao (ภูเขา), as if it were a natural feature. In the 1940s, enclosing concrete walls were added to stop the hill from eroding. Like most of Thailand, Bangkok has a tropical savanna climate (Aw) under the Köppen climate classification and is under the influence of the Asian monsoon system. The city experiences three seasons: hot, rainy, and cool, although temperatures are fairly hot year-round, ranging from an average low of 23.2 °C (73.8 °F) in December to an average high of 35.7 °C (96.3 °F) in April. The annual average temperature is 28.9 °C (84.0 °F). The rainy season begins with the arrival of the southwest monsoon around mid-May. September is the wettest month, with an average rainfall of 335.9 millimetres (13.22 in). The rainy season lasts until October, when the dry and cool northeast monsoon takes over until February. The hot season is generally dry, but it also sees occasional summer storms. The surface magnitude of Bangkok's urban heat island has been measured at 2.5 °C (4.5 °F) during the day and 8.0 °C (14 °F) at night. The highest recorded temperature of Bangkok metropolis was 41.0 °C (105.8 °F) on 7 May 2023, and the lowest recorded temperature was 9.9 °C (49.8 °F) in January 1955. The Climate Impact Group at NASA's Goddard Institute for Space Studies projected severe weather impacts on Bangkok caused by climate change. It found that Bangkok in 1960 had 193 days at or above 32 °C. In 2018, Bangkok can expect 276 days at or above 32 °C. The group forecasts a rise by 2100 to, on average, 297 to 344 days at or above 32 °C. Bangkok's fifty districts serve as administrative subdivisions under the authority of the BMA. Thirty-five of these districts lie to the east of the Chao Phraya, while fifteen are on the western bank, known as the Thonburi side of the city. The fifty districts, arranged by district code, are: Bangkok's districts often do not accurately represent the functional divisions of its neighbourhoods or land usage. Although urban planning policies date back to the commission of the Litchfield Plan in 1960, which set out strategies for land use, transportation, and general infrastructure improvements, zoning regulations were not fully implemented until 1992. As a result, the city grew organically throughout its rapid expansion, both horizontally as ribbon developments extended along newly built roads, and vertically, with increasing numbers of high rises and skyscrapers being built in commercial areas. The city has grown from its original centre along the river into a sprawling metropolis surrounded by swaths of suburban residential development extending north and south into neighbouring provinces. The highly populated and growing cities of Nonthaburi, Pak Kret, Rangsit, and Samut Prakan are effectively now suburbs of Bangkok. Nevertheless, large agricultural areas remain within the city proper at its eastern and western fringes, and a small number of forest area is found within the city limits: 3,887 rai (6.2 km2; 2.4 sq mi), amounting to 0.4 per cent of the city area. Land use in the city consists of 23 percent residential use, 24 percent agriculture, and 30 percent used for commerce, industry, and government. The BMA's City Planning Department (CPD) is responsible for planning and shaping further development. It published master plan updates in 1999 and 2006, and a third revision is undergoing public hearings in 2012. Bangkok's historic centre remains the Rattanakosin Island in Phra Nakhon District. It is the site of the Grand Palace and the City Pillar Shrine, primary symbols of the city's founding, as well as important Buddhist temples. Phra Nakhon, along with the neighbouring Pom Prap Sattru Phai and Samphanthawong Districts, formed what was the city proper in the late 19th century. Many traditional neighbourhoods and markets are found here, including the Chinese settlement of Sampheng. The city was expanded toward Dusit District in the early 19th century, following King Chulalongkorn's relocation of the royal household to the new Dusit Palace. The buildings of the palace, including the neoclassical Ananta Samakhom Throne Hall, as well as the Royal Plaza and Ratchadamnoen Avenue, which leads to it from the Grand Palace, reflect the heavy influence of European architecture at the time. Major government offices line the avenue, as does the Democracy Monument. The area is the site of the country's seat of power as well as the city's most popular tourist landmarks. In contrast with the low-rise historic areas, the business district on Si Lom and Sathon Roads in Bang Rak and Sathon Districts teems with skyscrapers. It is the site of many of the country's major corporate headquarters, but also of some of the city's red-light districts. The Siam and Ratchaprasong areas in Pathum Wan are home to some of the largest shopping malls in Southeast Asia. Numerous retail outlets and hotels also stretch along Sukhumvit Road leading southeast through Watthana and Khlong Toei Districts. More office towers line the streets branching off Sukhumvit, especially Asok Montri, while upmarket housing is found in many of its sois ('alley' or 'lane'). Bangkok lacks a single distinct central business district. Instead, the areas of Siam and Ratchaprasong serve as a "central shopping district" containing many of the bigger malls and commercial areas in the city, as well as Siam Station, formerly the only transfer point between the city's then-two elevated train lines (the Sukhumvit and Silom BTS lines). The Victory Monument in Ratchathewi District is among its most important road junctions, serving over 100 bus lines as well as an elevated train station. From the monument, Phahonyothin and Ratchawithi / Din Daeng Roads respectively run north and east, linking to major residential areas. Most of the high-density development areas are within the 113-square-kilometre (44 sq mi) area encircled by the Ratchadaphisek inner ring road. Ratchadaphisek is lined with businesses and retail outlets, and office buildings also cluster around Ratchayothin Intersection in Chatuchak District to the north. Further from the city centre, most areas are primarily mid- or low-density residential. The Thonburi side of the city is less developed, with fewer high rises. Except for a few secondary urban centres, Thonburi, in the same manner as the outlying eastern districts, consists mostly of residential and rural areas. While most of Bangkok's streets are fronted by vernacular shophouses, the largely unrestricted building euphoria of the 1980s has transformed the city into an urban area of skyscrapers and high rises of contrasting and clashing styles. There are 581 skyscrapers over 90 metres (300 feet) tall in the city. Bangkok was ranked as the world's eighth-tallest city in 2016. As a result of persistent economic disparity, many slums have emerged in the city. In 2000, over one million people were living in about 800 informal settlements. Some settlements are squatted such as the large slums in Khlong Toei District. In total, there were 125 squatted areas. Bangkok has several parks, although these amount to a per capita total park area of only 1.82 square metres (19.6 sq ft) in the city proper. Total green space for the entire city is moderate, at 11.8 square metres (127 sq ft) per person. In the more densely built-up areas of the city, these numbers are as low as 1.73 and 0.72 square metres (18.6 and 7.8 sq ft) per person. More recent numbers claim that there is 3.3 square metres (36 ft2) of green space per person, compared to an average of 39 m2 (420 ft2) in other cities across Asia.[i] Bangkokians thus have 10 times less green space than is standard in the region's urban areas. Green belt areas include about 700 km2 (270 sq mi) of rice paddies and orchards on the eastern and western edges of the city, although their primary purpose is to serve as flood detention basins rather than to limit urban expansion. Bang Kachao, a 20 km2 (7.7 sq mi) conservation area on an oxbow of the Chao Phraya, lies just across the southern riverbank districts, in Samut Prakan province. A master development plan has been proposed to increase the total park area to 4 m2 (43 sq ft) per person. One of Bangkok's largest parks is the centrally located Lumphini Park near the Silom–Sathon business district with an area of 57.6 ha (142 acres). It is connected by a 1.3 km elevated pedestrian and bicycle walkway to the Benjakitti Park, which includes a recently completed expansion including wetlands, skywalks, and rare plants. Other parks include the 80-hectare (200-acre) Suanluang Rama IX in the east of the city, and the Chatuchak–Queen Sirikit–Wachirabenchathat park complex in northern Bangkok, which has a combined area of 92 hectares (230 acres). More parks are expected to be created through the Green Bangkok 2030 project, which aims to leave the city with 10 square metres (110 ft2) of green space per person, including 30% of the city having tree cover. Demography The city of Bangkok has a population of 8,305,218 according to the 2010 census, or 12.6 per cent of the national population, while 2020 estimates place the figure at 10.539 million (15.3 per cent). Roughly half are internal migrants from other Thai provinces; population registry statistics recorded 5,676,648 residents belonging to 2,959,524 households in 2018.[j] Much of Bangkok's daytime population commutes from surrounding provinces in the Bangkok Metropolitan Region, the total population of which is 14,626,225 (2010 census). Bangkok is a cosmopolitan city; the census showed that it is home to 567,120 expatriates from Asian countries (including 71,024 Chinese and 63,069 Japanese nationals), 88,177 from Europe, 32,241 from the Americas, 5,856 from Oceania, and 5,758 from Africa. Migrants from neighbouring countries include 216,528 Burmese, 72,934 Cambodians and 52,498 Lao. In 2018, numbers show that there are 370,000 international migrants registered with the Department of Employment, more than half of them migrants from Cambodia, Laos, and Myanmar. Following its establishment as the capital city in 1782, Bangkok grew only slightly throughout the 18th and early 19th centuries. British diplomat John Crawfurd, visiting in 1822, estimated its population at no more than 50,000. As a result of Western medicine brought by missionaries as well as increased immigration from both within Siam and overseas, Bangkok's population gradually increased as the city modernized in the late 19th century. This growth became even more pronounced in the 1930s, following the discovery of antibiotics. Although family planning and birth control were introduced in the 1960s, the lowered birth rate was more than offset by increased migration from the provinces as economic expansion accelerated. Only in the 1990s did Bangkok's population growth rates decrease, following the national rate; Thailand had long since become highly centralized around the capital. In 1980, Bangkok's population was fifty-one times that of Hat Yai and Songkhla, the second-largest urban centre at the time, making it the world's most prominent primate city. The majority of Bangkok's population identifies as Thai,[k] although details on the city's ethnic make-up are unavailable, as the national census does not document race.[l] Bangkok's cultural pluralism dates back to the early days of its founding: several ethnic communities were formed by immigrants and forced settlers including the Khmer, northern Thai, Lao, Vietnamese, Mon and Malay. Most prominent were the Chinese, who played major roles in the city's trade and became the majority of Bangkok's population—estimates include up to three-fourths in 1828 and almost half in the 1950s.[m] Chinese immigration was restricted from the 1930s and effectively ceased after the Chinese Communist Revolution in 1949.[citation needed] Their prominence subsequently declined as younger generations of Thai Chinese integrated and adopted a Thai identity. Bangkok is still, nevertheless, home to a large Chinese community, with the greatest concentration in Yaowarat, Bangkok's Chinatown. The majority (93 per cent) of the city's population is Buddhist, according to the 2010 census. Other religions include Islam (4.6 per cent), Christianity (1.9 per cent), Hinduism (0.3 per cent), Sikhism (0.1 per cent), and Confucianism (0.1 per cent). Apart from Yaowarat, Bangkok also has several other distinct ethnic neighbourhoods. The Indian community is centred in Phahurat, where the Gurdwara Siri Guru Singh Sabha, founded in 1933, is located. Ban Khrua on Saen Saep Canal is home to descendants of the Cham who settled in the late 18th century. Although the Portuguese who settled during the Thonburi period have ceased to exist as a distinct community, their past is reflected in Santa Cruz Church, on the west bank of the river. Likewise, Assumption Cathedral on Charoen Krung Road is among many European-style buildings in the Old Farang Quarter, where European diplomats and merchants lived in the late 19th to early 20th centuries. Nearby, the Haroon Mosque is the centre of a Muslim community. Newer expatriate communities exist along Sukhumvit Road, including the Japanese community near Soi Phrom Phong and Soi Thong Lo, and the Arab and North African neighbourhood along Soi Nana. Sukhumvit Plaza, a mall on Soi Sukhumvit 12, is popularly known as Koreatown. Economy Bangkok is the economic centre of Thailand, and the heart of the country's investment and development. In 2022, the city had an economic output of 5.747 trillion baht (US$164 billion). This amounted to a per-capita GDP value of 634,109 baht ($18,100), more than twice the national average. The Bangkok Metropolitan Region had a combined output of 8.096 trillion baht ($232 billion). Wholesale and retail trade is the largest sector in the city's economy, contributing 24 per cent of Bangkok's gross provincial product. It is followed by manufacturing (14.3 per cent); real estate, renting and business activities (12.4 per cent); transport and communications (11.6 per cent); and financial intermediation (11.1 per cent). Bangkok alone accounts for 48.4 per cent of Thailand's service sector, which in turn constitutes 49 per cent of GDP. When the Bangkok Metropolitan Region is considered, manufacturing is the most significant contributor at 28.2 per cent of the gross regional product, reflecting the density of industry in Bangkok's neighbouring provinces. The automotive industry, based around Greater Bangkok, is the largest production hub in Southeast Asia. Tourism is also a significant contributor to Bangkok's economy, generating 427.5 billion baht ($13.38 billion) in revenue in 2010. The Stock Exchange of Thailand (SET) is on Ratchadaphisek Road in inner Bangkok. The SET, together with the Market for Alternative Investment (MAI), has 648 listed companies as of the end of 2011, with a combined market capitalization of 8.485 trillion baht ($267.64 billion). Due to the large amount of foreign representation, Thailand has for several years been a mainstay of the Southeast Asian economy and a centre of Asian business. The Globalization and World Cities Research Network ranks Bangkok as an "Alpha -" world city, and it is ranked 59th in Z/Yen's Global Financial Centres Index 11. Bangkok is home to the headquarters of all of Thailand's major commercial banks and financial institutions, as well as the country's largest companies. Many multinational corporations base their regional headquarters in Bangkok due to the lower cost of labour and operations relative to other major Asian business centres. Seventeen Thai companies are listed on the Forbes 2000, all of which are based in the capital, including PTT, the only Fortune Global 500 company in Thailand. Income inequality is a major issue in Bangkok, especially between relatively unskilled lower-income immigrants from rural provinces and neighbouring countries, and middle-class professionals and business elites. Although absolute poverty rates are low—only 0.64 per cent of Bangkok's registered residents were living under the poverty line in 2010, compared to a national average of 7.75 per cent—economic disparity is still substantial. The city has a Gini coefficient of 0.48, indicating a high level of inequality. Tourism Bangkok is one of the world's top tourist destinations. Of 162 cities worldwide, MasterCard ranked Bangkok as the top destination city by international visitor arrivals in its Global Destination Cities Index 2018, ahead of London, with just over 20 million overnight visitors in 2017. This was a repeat of its 2017 ranking (for 2016). Euromonitor International ranked Bangkok fourth in its Top City Destinations Ranking for 2016. Bangkok was also named "World's Best City" by Travel + Leisure magazine's survey of its readers for four consecutive years, from 2010 to 2013. As the main gateway through which visitors arrive in Thailand, Bangkok is visited by the majority of international tourists to the country. Domestic tourism is also prominent. The Department of Tourism recorded 26,861,095 Thai and 11,361,808 foreign visitors to Bangkok in 2010. Lodgings were made by 15,031,244 guests, who occupied 49.9 per cent of the city's 86,687 hotel rooms. Bangkok also topped the list as the world's most popular tourist destination in 2017 rankings. In 2024, Euromonitor International ranks Bangkok the top tourism city in the world, welcoming a record 32.4 million visitors. Among Bangkok's well-known sights are the Grand Palace and major Buddhist temples, including Wat Phra Kaew, Wat Pho, and Wat Arun. The Giant Swing and Erawan Shrine demonstrate Hinduism's deep-rooted influence in Thai culture. Vimanmek Mansion in Dusit Palace is famous as the world's largest teak building, while the Jim Thompson House provides an example of traditional Thai architecture. Other major museums include the Bangkok National Museum and the Royal Barge National Museum. Cruises and boat trips on the Chao Phraya and the canals of Thonburi offer views of some of the city's traditional architecture and ways of life on the waterfront. Shopping venues, many of which are popular with both tourists and locals, range from the shopping centres and department stores concentrated in Siam and Ratchaprasong to the sprawling Chatuchak Weekend Market. Taling Chan Floating Market is among the few such markets in Bangkok. Yaowarat is known for its shops as well as street-side food stalls and restaurants, which are also found throughout the city. Khao San Road has long been famous as a destination for backpacker tourism, with its budget accommodation, shops, and bars attracting visitors from all over the world. Bangkok has a reputation overseas as a major destination in the sex industry. Although prostitution is technically illegal and is rarely openly discussed in Thailand, it commonly takes place among massage parlours, saunas, and hourly hotels, serving foreign tourists as well as locals. Bangkok has acquired the nickname "Sin City of Asia" for its level of sex tourism. Issues often encountered by foreign tourists include scams, overcharging, and dual pricing. In a survey of 616 tourists visiting Thailand, 7.79 per cent reported encountering a scam, the most common of which was the gem scam, in which tourists are tricked into buying overpriced jewellery. Culture The culture of Bangkok reflects its position as Thailand's centre of wealth and modernisation. The city has long been the portal of entry of Western concepts and material goods, which have been adopted and blended with Thai values to various degrees by its residents. This is most evident in the lifestyles of the expanding middle class. Conspicuous consumption serves as a display of economic and social status, and shopping centres are popular weekend hangouts. A distinct feature of Bangkok is the ubiquity of street vendors selling goods ranging from food items to clothing and accessories. It has been estimated that the city may have over 100,000 hawkers. While the BMA has authorised the practice in 287 sites, the majority of activity in another 407 sites takes place illegally. Although they take up pavement space and block pedestrian traffic, many of the city's residents depend on these vendors for their meals, and the BMA's efforts to curb their numbers have largely been unsuccessful. In 2015, however, the BMA, with support from the National Council for Peace and Order (Thailand's ruling military junta), began cracking down on street vendors in a bid to reclaim public space. Many famous market neighbourhoods were affected, including Khlong Thom, Saphan Lek, and the flower market at Pak Khlong Talat. Nearly 15,000 vendors were evicted from 39 public areas in 2016. While some applauded the efforts to focus on pedestrian rights, others have expressed concern that gentrification would lead to the loss of the city's character and adverse changes to people's way of life. The residents of Bangkok celebrate many of Thailand's annual festivals. During Songkran on 13–15 April, traditional rituals as well as water fights take place throughout the city. Loi Krathong, usually in November, is accompanied by the Golden Mount Fair. New Year celebrations take place at many venues, the most prominent being the plaza in front of CentralWorld. Observances related to the royal family are held primarily in Bangkok. Wreaths are laid at King Chulalongkorn's equestrian statue in the Royal Plaza on 23 October, which is King Chulalongkorn Memorial Day. The previous king's and queen's birthdays, respectively on 5 December and 12 August, are marked as Thailand's national Father's Day and national Mother's Day. These national holidays are celebrated by royal audiences on the day's eve, in which the king or queen gives a speech, and public gatherings on the day of the observance. The king's birthday is also marked by the Royal Guards' parade. Sanam Luang is the site of the Thai Kite, Sport and Music Festival, usually held in March, and the Royal Ploughing Ceremony, which takes place in May. The Red Cross Fair at the beginning of April is held at Suan Amporn and the Royal Plaza, and features numerous booths offering goods, games, and exhibits. The Chinese New Year (January–February) and Vegetarian Festival (September–October) are celebrated widely by the Chinese community, especially in Yaowarat. Bangkok was designated as the World Book Capital for the year 2013 by UNESCO. Bangkok's first Thai International Gay Pride Festival took place on October 31, 1999. Pride Parades have also been held in Bangkok, with the first official parade held in 2022 under the name "Bangkok Naruemit Pride Parade". Pride Parades were announced to be a part of Bangkok's "12 monthly festivals" in 2022. Bangkok also hosts major international exhibitions, including the annual Bangkok International Motor Show, one of the largest automotive events in Southeast Asia. Bangkok is the centre of Thailand's media industry. All national newspapers, broadcast media, and major publishers are based in the capital. Its 21 national newspapers had a combined daily circulation of about two million in 2002. These include the mass-oriented Thairath, Khao Sod and Daily News, the first of which currently prints a million copies per day, as well as the less sensational Matichon and Krungthep Thurakij. The Bangkok Post and The Nation are the two national English-language dailies. Foreign publications including The Asian Wall Street Journal, Financial Times, The Straits Times and the Yomiuri Shimbun also have operations in Bangkok. The large majority of Thailand's more than 200 magazines are published in the capital, and include news magazines as well as lifestyle, entertainment, gossip and fashion-related publications. Bangkok is also the hub of Thailand's broadcast television. Most free-to-air national terrestrial channels, including six original Channels 3, 5, and 7, MCOT, NBT and Thai PBS, have headquarters and main studios in the capital. GMM Grammy is Thailand's largest mass-media conglomerate is also headquartered in Bangkok. Except for local news segments broadcast by the NBT, all programming is done in Bangkok and repeated throughout the provinces. However, this centralised model is weakening with the rise of cable television, which has many local providers. There are numerous cable and satellite channels based in Bangkok. TrueVisions is the major subscription television provider in Bangkok and Thailand, and it also carries international programming. Bangkok was home to 40 of Thailand's 311 FM radio stations and 38 of its 212 AM stations in 2002. Broadcast media reform stipulated by the 1997 constitution has been progressing slowly, although many community radio stations have emerged in the city. Likewise, Bangkok has dominated the Thai film industry since its inception. Although film settings normally feature locations throughout the country, the city is home to all major film studios in Thailand, such as GDH 559 (GMM Grammy's film production subsidiary), Sahamongkol Film International, and Five Star Production. Bangkok has dozens of cinemas and multiplexes, and the city hosts two major film festivals annually, the Bangkok International Film Festival and the World Film Festival of Bangkok. Traditional Thai art, long developed within religious and royal contexts, continues to be sponsored by various government agencies in Bangkok, including the Department of Fine Arts' Office of Traditional Arts. The SUPPORT Foundation in Chitralada Palace sponsors traditional and folk handicrafts. Various communities throughout the city still practice their traditional crafts, including the production of khon masks, alms bowls, and classical musical instruments. The National Gallery hosts a permanent collection of traditional and modern art, with temporary contemporary exhibits. Bangkok's contemporary art scene has slowly grown from relative obscurity into the public sphere over the past two decades. Private galleries gradually emerged to provide exposure for new artists, including the Patravadi Theatre and H Gallery. The centrally located Bangkok Art and Culture Centre, opened in 2008 following a fifteen-year lobbying campaign, is now the largest public exhibition space in the city. There are also many other art galleries and museums, including the privately owned Museum of Contemporary Art and the newly opened Dib Bangkok. The city's performing arts scene features traditional theatre and dance as well as Western-style plays. Khon and other traditional dances are regularly performed at the National Theatre and Salachalermkrung Royal Theatre, while the Thailand Cultural Centre is a newer multi-purpose venue which also hosts musicals, orchestras, and other events. Numerous venues regularly feature a variety of performances throughout the city. Bangkok has been recognized as a "Design City" by UNESCO's Creative Cities Network since 2022. As is the national trend, association football and Muay Thai dominate Bangkok's spectator sport scene. Muangthong United, Bangkok United, BG Pathum United, Port and Police Tero are major Thai League clubs based in the Bangkok Metropolitan Region, while the Rajadamnern and Lumpini stadiums are the main kickboxing venues. While sepak takraw can be seen played in open spaces throughout the city, football and other modern sports are now the norm. Western sports introduced during the reign of King Chulalongkorn were originally only available to the privileged, and such status is still associated with certain sports. Golf is popular among the upwardly mobile, and there are several courses in Bangkok. Horse racing, highly popular at the mid-20th century, still takes place at the Royal Bangkok Sports Club. There are many public sporting facilities located throughout Bangkok. The two main centres are the National Stadium complex, which dates to 1938, and the newer Hua Mak Sports Complex, which was built for the 1998 Asian Games. Bangkok had also hosted the games in 1966, 1970 and 1978; the most of any city. The city was the host of the inaugural Southeast Asian Games in 1959, the 2007 Summer Universiade, and the 2012 FIFA Futsal World Cup. Transport Although Bangkok's canals historically served as a major mode of transport, they have long since been surpassed in importance by land traffic. Charoen Krung Road, the first to be built by Western techniques, was completed in 1864. Since then, the road network has vastly expanded to accommodate the sprawling city. A complex elevated expressway network and Don Mueang Tollway helps bring traffic into and out of the city centre, but Bangkok's rapid growth has put a large strain on infrastructure, and traffic jams have plagued the city since the 1990s. Although rail transport was introduced in 1893 and trams served the city from 1888 to 1968, it was only in 1999 that Bangkok's first rapid transit system began operation. Older public transport systems include an extensive bus network and boat services, which still operate on the Chao Phraya and two canals. Taxis appear in the form of cars, motorcycles, and "tuk-tuk" auto rickshaws. Bangkok is connected to the rest of the country through the national highway and rail networks, as well as by domestic flights to and from the city's two international airports (Suvarnabhumi and Don Mueang). Its centuries-old maritime transport of goods is still conducted through Khlong Toei Port. The BMA is largely responsible for overseeing the construction and maintenance of the road network and transport systems through its Public Works Department and Traffic and Transportation Department. However, many separate government agencies are also in charge of the individual systems, and much of transport-related policy planning and funding is contributed to by the national government. Bangkok is one of Asia's busiest air transport hubs. Two commercial airports serve Bangkok, the older Don Mueang International Airport and the newer Suvarnabhumi Airport. Suvarnabhumi, which replaced Don Mueang as Bangkok's main airport after its opening in 2006, served 52,808,013 passengers in 2015, making it the world's 20th busiest airport by passenger volume. This volume exceeded its designed capacity of 45 million passengers. Don Mueang reopened for domestic flights in 2007, and resumed international service focusing on low-cost carriers in October 2012. As of 2023, a new SAT-1 terminal has been opened at Suvarnabhumi to handle the increasing passenger count. Plans for further expansion are already being commenced. Meanwhile, Don Mueang is currently considering renovation. Krung Thep Aphiwat Central Terminal is the main terminus of the national rail network operated by the State Railway of Thailand (SRT). The older terminus, Bangkok (Hua Lamphong) railway station, was the main station for Bangkok for over a century and remains in use. The SRT operates long-distance intercity services from Krung Thep Aphiwat, while commuter trains running to and from the outskirts of the city during the rush hour continue to operate at Bangkok (Hua Lamphong). Bangkok is primarily served by three rapid transit systems: the BTS (Skytrain), the MRT (Metro), and the SRT (State Railway of Thailand). Although proposals for the development of rapid transit in Bangkok had been made since 1975, it was only in 1999 that the BTS finally began operation. The BTS consists of three lines: the Light Green (Sukhumvit) Line, the Dark Green (Silom) Line and the Gold Line. The MRT consists of two metro lines: the Blue Line and the Purple Line, and two monorail lines: the Yellow Line which opened in July 2023, and the Pink Line which opened in January 2024. The SRT Airport Rail Link Line opened in August 2010 and connects the city centre to Suvarnabhumi Airport to the east. The SRT Dark Red Line and SRT Light Red Line opened in 2021. Although initial passenger numbers were low and their service area was limited to the inner city until the 2016 opening of the Purple Line, these systems have become indispensable to many commuters. The BTS reported an average of 600,000 daily trips in 2012, while the MRT had 240,000 passenger trips per day. As of 2024[update], construction work is ongoing to extend the city-wide transit system's reach according to the Mass Rapid Transit Master Plan in Bangkok Metropolitan Region, which consists of eight main lines and four feeder lines totaling 508 kilometres (316 mi) to be completed by 2029. Road-based transport is the primary mode of travel in Bangkok. Due to the city's organic development, its streets do not follow an organized grid structure. Forty-eight major roads link the different areas of the city, branching into smaller streets and lanes (soi) which serve local neighbourhoods. Eleven bridges over the Chao Phraya link the two sides of the city, while several expressway and motorway routes bring traffic into and out of the city centre and link with nearby provinces. The first expressway in Bangkok is Chaloem Maha Nakhon Expressway, which opened in 1981. Bangkok's rapid growth in the 1980s resulted in sharp increases in vehicle ownership and traffic demand, which have since continued. In 2006, there were 3,943,211 in-use vehicles in Bangkok, of which 37.6 per cent were private cars and 32.9 per cent were motorcycles. These increases, in the face of limited carrying capacity, caused severe traffic congestion evident by the early 1990s. The extent of the problem is such that the Thai Traffic Police has a unit of officers trained in basic midwifery to assist deliveries that do not reach the hospital in time. While Bangkok's limited road surface area (8 per cent, compared to 20–30 per cent in most Western cities) is often cited as a major cause of its traffic jams, other factors, including high vehicle ownership rate relative to income level, inadequate public transport systems, and lack of transportation demand management, also play a role. Efforts to alleviate the problem have included the construction of intersection bypasses and an extensive system of elevated highways, as well as the creation of several new rapid transit systems. Plans to implement congestion pricing were announced in 2024. The city's overall traffic conditions, however, remain poor. Traffic has been the main source of air pollution in Bangkok, which reached serious levels in the 1990s. But efforts to improve air quality by improving fuel quality and enforcing emission standards, among others, had visibly ameliorated the problem by the 2000s. Atmospheric particulate matter levels dropped from 81 micrograms per cubic metre in 1997 to 43 in 2007. However, increasing vehicle numbers and a lack of continued pollution-control efforts threaten a reversal of the past success. In January–February 2018, weather conditions caused bouts of haze to cover the city, with particulate matter under 2.5 micrometres (PM2.5) rising to unhealthy levels for several days on end. Although the BMA has created thirty signed bicycle routes along several roads totalling 230 kilometres (140 mi), cycling is still largely impractical, especially in the city centre. Most of these bicycle lanes share the pavement with pedestrians. Poor surface maintenance, encroachment by hawkers and street vendors, and a hostile environment for cyclists and pedestrians make cycling and walking unpopular methods of getting around in Bangkok. In September 2025, there was a road collapse when the Dusit district experienced a major sinkhole on Samsen Road, located between the Samsen Police Station and Vajira Hospital. Bangkok has an extensive bus network providing local transit services within the Greater Bangkok area. The Bangkok Mass Transit Authority (BMTA) operates a monopoly on bus services, with substantial concessions granted to private operators. Buses, minibus vans, and song thaeo operate on a total of 470 routes throughout the region. A separate bus rapid transit system owned by the BMA has been in operation since 2010. Known simply as the BRT, the system currently consists of a single line running from the business district at Sathon to Ratchaphruek on the western side of the city. The Transport Co., Ltd. is the BMTA's long-distance counterpart, with services to all provinces operating out of Bangkok. Taxis are ubiquitous in Bangkok and are a popular form of transport. As of August 2012[update], there are 106,050 cars, 58,276 motorcycles and 8,996 tuk-tuk motorized tricycles cumulatively registered for use as taxis. Meters have been required for car taxis since 1992, while tuk-tuk fares are usually negotiated. Motorcycle taxis operate from regulated ranks, with either fixed or negotiable fares, and are usually employed for relatively short journeys. Despite their popularity, taxis have gained a bad reputation for often refusing passengers when the requested route is not to the driver. Motorcycle taxis were previously unregulated and subject to extortion by organized crime gangs. Since 2003, registration has been required for motorcycle taxi ranks, and drivers now wear distinctive numbered vests designating their district of registration and where they are allowed to accept passengers. Several ride hailing super-apps operate within the city, including Grab (offering car and motorbike options), and AirAsia in 2022. The Estonian company Bolt launched airport transfer and ride hailing services in 2020. Ride sharing startup MuvMi launched in 2018, and operates an electric tuk-tuk service in 9 areas across the city. Although much diminished from its past prominence, water-based transport still plays an important role in Bangkok and the immediate upstream and downstream provinces. Several water buses serve commuters daily. The Chao Phraya Express Boat serves thirty-four stops along the river, carrying an average of 19,834 passengers per day in 2023, while the smaller Khlong Saen Saep boat service serves twenty-seven stops on Saen Saep Canal with 28,801 daily passengers. Khlong Phasi Charoen boat service serves twenty stops on the Phasi Charoen Canal. Long-tail boats operate on fifteen regular routes on the Chao Phraya, and passenger ferries at thirty-two river crossings served an average of 136,927 daily passengers in 2010. Bangkok Port, popularly known by its location as Khlong Toei Port, was Thailand's main international port from its opening in 1947 until it was superseded by the deep-sea Laem Chabang Port in 1991. It is primarily a cargo port, though its inland location limits access to ships of 12,000 deadweight tons or less. The port handled 11,936,855 tonnes (13,158,130 tons) of cargo in the first eight months of the 2010 fiscal year, about 22 per cent of the total of the country's international ports. Health and education Bangkok has long been the centre of modern education in Thailand. The first schools in the country were established here in the late 19th century, and there are now 1,351 schools in the city. The city is home to the country's five oldest universities, Chulalongkorn, Thammasat, Kasetsart, Mahidol and Silpakorn, founded between 1917 and 1943. The city has since continued its dominance, especially in higher education; the majority of the country's universities, both public and private, are located in Bangkok or the Metropolitan Region. Chulalongkorn and Mahidol are the only Thai universities to appear in the top 500 of the QS World University Rankings. King Mongkut's University of Technology Thonburi, also located in Bangkok, is the only Thai university in the top 400 of the 2012–13 Times Higher Education World University Rankings. Over the past few decades, the general trend of pursuing a university degree has prompted the founding of new universities to meet the needs of Thai students. Bangkok became not only a place where immigrants and provincial Thais go for job opportunities, but also for a chance to receive a university degree. Ramkhamhaeng University emerged in 1971 as Thailand's first open university; it now has the highest enrollment in the country. The demand for higher education has led to the founding of many other universities and colleges, both public and private. While many universities have been established in major provinces, the Greater Bangkok region remains home to the greater majority of institutions, and the city's tertiary education scene remains overpopulated with non-Bangkokians. The situation is not limited to higher education, either. In the 1960s, 60 to 70 per cent of 10- to 19-year-olds who were in school had migrated to Bangkok for secondary education. This was due to both a lack of secondary schools in the provinces and perceived higher standards of education in the capital. Although this discrepancy has since largely abated, tens of thousands of students still compete for places in Bangkok's leading schools. Education has long been a prime factor in the centralization of Bangkok and will play a vital role in the government's efforts to decentralize the country. Much of Thailand's medical resources are disproportionately concentrated in the capital. In 2000, Bangkok had 39.6 per cent of the country's doctors and a physician-to-population ratio of 1:794, compared to a median of 1:5,667 among all provinces. The city is home to 42 public hospitals, five of which are university hospitals, as well as 98 private hospitals and 4,063 registered clinics.[dead link] The BMA operates nine public hospitals through its Medical Service Department, and its Health Department provides primary care through sixty-eight community health centres. Thailand's universal healthcare system is implemented through public hospitals and health centres as well as participating private providers. Research-oriented medical school affiliates such as Siriraj, King Chulalongkorn Memorial, and Ramathibodi Hospitals are among the largest in the country, and act as tertiary care centres, receiving referrals from distant parts of the country. Lately, especially in the private sector, there has been much growth in medical tourism, with hospitals such as Bumrungrad and Bangkok Hospital, among others, providing services specifically catering to foreigners. An estimated 200,000 medical tourists visited Thailand in 2011, making Bangkok the most popular global destination for medical tourism. Crime and safety Bangkok has a relatively moderate crime rate when compared to urban counterparts around the world. Traffic accidents are a major hazard while natural disasters are rare. Intermittent episodes of political unrest and occasional terrorist attacks have resulted in losses of life. Although the crime threat in Bangkok is relatively low, non-confrontational crimes of opportunity, such as pick-pocketing, purse-snatching, and credit card fraud, occur with frequency. Bangkok's growth since the 1960s has been followed by increasing crime rates partly driven by urbanisation, migration, unemployment and poverty. By the late 1980s, Bangkok's crime rates were about four times that of the rest of the country. The police have long been preoccupied with street crimes ranging from housebreaking to assault and murder. The 1990s saw the emergence of vehicle theft and organized crime, particularly by foreign gangs. Drug trafficking, especially that of ya ba methamphetamine pills, is also chronic. According to police statistics, the most common complaint received by the Metropolitan Police Bureau in 2010 was housebreaking, with 12,347 cases. This was followed by 5,504 cases of motorcycle thefts, 3,694 cases of assault, and 2,836 cases of embezzlement. Serious offences included 183 murders, 81 gang robberies, 265 robberies, 1 kidnapping, and 9 arson cases. Offences against the state were by far more common, and included 54,068 drug-related cases, 17,239 cases involving prostitution, and 8,634 related to gambling. The Thailand Crime Victim Survey conducted by the Office of Justice Affairs of the Ministry of Justice found that 2.7 per cent of surveyed households reported a member being victim of a crime in 2007. Of these, 96.1 per cent were crimes against property, 2.6 per cent were crimes against life and body, and 1.4 per cent were information-related crimes. Political demonstrations and protests are common in Bangkok. The historic uprisings of 1973, 1976, and 1992 are infamously known for the deaths from military suppression. Most events since then have been peaceful, but the series of major protests since 2006 has often turned violent. Demonstrations during March–May 2010 ended in a crackdown in which 92 were killed, including armed and unarmed protesters, security forces, civilians, and journalists. Terrorist incidents have also occurred in Bangkok, most notably the bombing in 2015 at the Erawan shrine, which killed 20, and also a series of bombings on the 2006–07 New Year's Eve. Traffic accidents are a major hazard in Bangkok. There were 37,985 accidents in the city in 2010, resulting in 16,602 injuries and 456 deaths, as well as 426.42 million baht in damages. However, the rate of fatal accidents is much lower than in the rest of Thailand. While accidents in Bangkok amounted to 50.9 per cent of the entire country, only 6.2 per cent of fatalities occurred in the city. Another serious public health hazard comes from Bangkok's stray dogs. Up to 300,000 strays are estimated to roam the city's streets, and dog bites are among the most common injuries treated in the emergency departments of the city's hospitals. Rabies is prevalent among the dog population, and treatment for bites poses a heavy public burden.[n] On July 27, 2025, a gunman shot and killed 5 security guards and wounded 2 others inside a Bangkok market before killing himself. Bangkok is faced with multiple problems, including congestion, and especially subsidence and flooding, which have raised the issue of moving the nation's capital elsewhere. The idea is not new: during World War II, Prime Minister Plaek Phibunsongkhram planned unsuccessfully to relocate the capital to Phetchabun. In the 2000s, the Thaksin Shinawatra administration assigned the Office of the National Economic and Social Development Council (NESDC) to formulate a plan to move the capital to Nakhon Nayok. The 2011 floods revived the idea of moving government functions from Bangkok. In 2017, the military government assigned NESDC to study the possibility of moving government offices from Bangkok to Chachoengsao in the east. International relations The city's formal international relations are managed by the International Affairs Division of the BMA. Its missions include partnering with other major cities through sister city or friendship agreements, participation and membership in international organizations, and pursuing cooperative activities with the many foreign diplomatic missions based in the city. Bangkok is a member of several international organizations and regional city government networks, including the Asian Network of Major Cities 21, the Japan-led Asian-Pacific City Summit, the C40 Cities Climate Leadership Group, the ESCAP-sponsored Regional Network of Local Authorities for Management of Human Settlements in Asia and Pacific (CITYNET), Japan's Council of Local Authorities for International Relations, the World Association of the Major Metropolises and Local Governments for Sustainability, among others. With its location at the heart of mainland Southeast Asia and as one of Asia's hubs of transportation, Bangkok is home to many international and regional organizations. Among others, Bangkok is the seat of the Secretariat of the UN Economic and Social Commission for Asia and the Pacific (ESCAP), as well as the Asia-Pacific regional offices of the Food and Agricultural Organization (FAO), the International Civil Aviation Organization (ICAO), the International Labour Organization (ILO), the International Organization for Migration (IOM), the International Telecommunication Union (ITU), the UN High Commission for Refugees (UNHCR), and the UN Children's Fund (UNICEF). Bangkok has made sister city or friendship agreements with: See also Explanatory notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Goliath:_Life_and_Loathing_in_Greater_Israel] | [TOKENS: 652] |
Contents Goliath: Life and Loathing in Greater Israel Goliath: Life and Loathing in Greater Israel is a 2013 book by Max Blumenthal. The book examines what Blumenthal characterizes as Israel's aggressive shift to the far-right, and its crackdown on local activism. In the preface, Blumenthal says that "Americans' tax dollars and political support are crucial in sustaining the present state of affairs" in Israel. Reception The book received a positive review by Nancy Murray in the academic journal Race & Class, calling it "a work of unsettling but scrupulous and courageous truth-telling". It was also positively reviewed in the Journal of Palestine Studies by Steven Salaita, who called it "one of the most important titles published on the Israel-Palestine conflict in the past few years". Eric Alterman, writing in The Nation, said "Goliath is a propaganda tract...this book could have been published by the Hamas Book-of-the-Month Club (if it existed)". Blumenthal responded in another issue of the magazine, saying that the Alterman review was a smear, loaded with inaccuracies that are refuted by several authors. He defended his comparison of Israeli actions with those of Nazi Germany. Alterman wrote a total of nine critical pieces on Goliath. The book was criticized by J.J. Goldberg in an opinion piece in The Forward, saying it was biased against Israel, and pointing to errors in spelling. Petra Marquardt-Bigman in The Jerusalem Post criticized how the book compares the Israeli state to Nazi Germany, calling it a form of "bigotry". Publishers Weekly wrote that the book is "a blunt look at a country where citizens are clearly divided into the "haves" and the "have nots"." Nina Burleigh, writing for The New York Observer, stated that the book is "a journalist's view of the country" that "balances" against the pro-Israel view promoted by the country's government that was "especially insightful" about left-wing, pro-Palestinian Israelis, although she felt the book was not being harsh enough on Islamist figures, calling the treatment "naive". James Fallows, the former chief speechwriter to U.S. president Jimmy Carter, wrote in The Atlantic that Goliath "is no more 'anti-Israel', let alone anti-Semitic, than The Shame of the Cities, The Jungle, and The Grapes of Wrath were anti-American for pointing out "extremes and abuses in American society." Glenn Greenwald described the book as "eye-opening and stunningly insightful", and Charles Glass wrote that "anyone who thinks he knows what is happening in Israel and its occupied territories will think again after reading this great work". Jim Miles, in his review in Foreign Policy, described it as "a powerful and distressing book for a view on what life in modern Israel is like." Kirkus Reviews described it as "A rich, roiling examination" of the country, while John Hudson in Foreign Policy described the book as an "indictment of Israel's treatment of Palestinians". Goliath was awarded the 2014 Lannan Cultural Freedom Award for An Especially Notable Book. References |
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[SOURCE: https://en.wikipedia.org/wiki/Theta1_Orionis_D] | [TOKENS: 166] |
Contents Theta1 Orionis D Theta1 Orionis D (θ1 Orionis D) is a member of the Trapezium open cluster that lies within the Orion Nebula. It is a B class blue main sequence star with several faint companions. θ1 Orionis consists of multiple components, primarily the four stars of the Trapezium cluster (A, B, C, and D) all within one arc-minute of each other. θ2 Orionis is a more distant grouping of three main stars plus several fainter companions, 1-2 arc-minutes from θ1. θ1 D itself has a faint optical companion 1.4" away and a spectroscopic companion in a 40-day orbit. Infrared Optical Telescope Array observations suggest another companion at 18.6 mas. References |
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[SOURCE: https://en.wikipedia.org/wiki/Federal_Trade_Commission] | [TOKENS: 5368] |
Contents Federal Trade Commission The Federal Trade Commission (FTC) is an independent agency of the United States government whose principal mission is the enforcement of civil (non-criminal) antitrust law and the promotion of consumer protection. It shares jurisdiction over federal civil antitrust law enforcement with the Antitrust Division of the U.S. Department of Justice. The FTC is headquartered in the Federal Trade Commission Building in Washington, D.C. The FTC was established in 1914 by the Federal Trade Commission Act, which the U.S. Congress passed in response to the 19th-century monopolistic trust crisis. Since its inception, the FTC has enforced the provisions of the Clayton Act, a key U.S. antitrust statute, as well as the provisions of the FTC Act, 15 U.S.C. § 41 et seq. Over time, the FTC has been delegated with the enforcement of additional business regulation statutes and has promulgated a number of regulations (codified in Title 16 of the Code of Federal Regulations). The broad statutory authority granted to the FTC provides it with more surveillance and monitoring abilities than it actually uses. The FTC is composed of five commissioners who were nominated by the president and subject to Senate confirmation. Commissioners serve seven-year terms, and by law can only be fired for "inefficiency, neglect of duty, or malfeasance in office." No more than three FTC members can be from the same party. One member of the body serves as FTC chair at the President's pleasure, with Commissioner Andrew N. Ferguson having served as chair since January 2025. History In the aftermath of the U.S. Supreme Court's landmark decision in Standard Oil Co. of New Jersey v. United States in 1911, the first version of a bill to establish a commission to regulate interstate trade was introduced on January 25, 1912, by Oklahoma congressman Dick Thompson Morgan. He would make the first speech on the House floor advocating its creation on February 21, 1912. Though the initial bill did not pass, the questions of trusts and antitrust dominated the 1912 election. Most political party platforms in 1912 endorsed the establishment of a federal trade commission with its regulatory powers placed in the hands of an administrative board, as an alternative to functions previously and necessarily exercised so slowly through the courts. With the 1912 presidential election decided in favor of the Democrats and Woodrow Wilson, Morgan reintroduced a slightly amended version of his bill during the April 1913 special session. The national debate culminated in Wilson's signing of the FTC Act on September 26, 1914, with additional tightening of regulations in the Clayton Antitrust Act three weeks later. The new FTC would absorb the staff and duties of Bureau of Corporations, previously established under the Department of Commerce and Labor in 1903. The FTC could additionally challenge "unfair methods of competition" and enforce the Clayton Act's more specific prohibitions against certain price discrimination, vertical arrangements, interlocking directorates, and stock acquisitions.[non-primary source needed] In 1984,[non-primary source needed] the FTC began to regulate the funeral home industry in order to protect consumers from deceptive practices. The FTC Funeral Rule requires funeral homes to provide all customers (and potential customers) with a General Price List (GPL), specifically outlining goods and services in the funeral industry, as defined by the FTC, and a listing of their prices.[non-primary source needed] By law, the GPL must be presented on request to all individuals, and no one is to be denied a written, retainable copy of the GPL.[non-primary source needed] In 1996, the FTC instituted the Funeral Rule Offenders Program (FROP), under which "funeral homes make a voluntary payment to the U.S. Treasury or appropriate state fund for an amount less than what would likely be sought if the Commission authorized filing a lawsuit for civil penalties. In addition, the funeral homes participate in the NFDA compliance program, which includes a review of the price lists, on-site training of the staff, and follow-up testing and certification on compliance with the Funeral Rule."[non-primary source needed] In the mid-1990s, the FTC launched the fraud sweeps concept where the agency and its federal, state, and local partners filed simultaneous legal actions against multiple telemarketing fraud targets. The first sweeps operation was Project Telesweep in July 1995 which cracked down on 100 business opportunity scams.[non-primary source needed] In the 2004 case In re Gateway Learning Corp., the FTC alleged that Gateway committed unfair and deceptive trade practices by making retroactive changes to its privacy policy without informing customers and by violating its own privacy policy by selling customer information when it had said it would not. Gateway settled the complaint by entering into a consent decree with the FTC that required it to surrender some profits and placed restrictions upon Gateway for the following 20 years. During the Obama Administration, Jon Leibowitz served as the Chair. In the 2009 case In the Matter of Sears Holdings Management Corp., the FTC alleged that a research software program provided by Sears was deceptive because it collected information about nearly all online behavior, a fact that was only disclosed in legalese, buried within the end user license agreement. The FTC secured a consent decree in the case. In September 2013, a federal court closed an elusive business opportunity scheme on the request of the FTC, namely "Money Now Funding"/"Cash4Businesses". The FTC alleged that the defendants misrepresented potential earnings, violated the National Do Not Call Register, and violated the FTC's Business Opportunity Rule in preventing a fair consumer evaluation of the business. This was one of the first definitive actions taken by any regulator against a company engaging in transaction laundering, where almost US$6 million were processed illicitly. In December 2018, two defendants, Nikolas Mihilli and Dynasty Merchants, LLC, settled with the FTC. They were banned from processing credit card transactions, though the initial monetary judgment of $5.8 million was suspended due to the defendant's inability to pay. In 2016, the FTC launched action against the academic journal publisher OMICS Publishing Group for producing predatory journals and organizing predatory conferences. This action, partly in response to ongoing pressure from the academic community, is the first action taken by the FTC against an academic journal publisher. The complaint alleges that the defendants have been "deceiving academics and researchers about the nature of its publications and hiding publication fees ranging from hundreds to thousands of dollars". It additionally notes that "OMICS regularly advertises conferences featuring academic experts who were never scheduled to appear in order to attract registrants" and that attendees "spend hundreds or thousands of dollars on registration fees and travel costs to attend these scientific conferences." Manuscripts are also sometimes held hostage, with OMICS refusing to allow submissions to be withdrawn and thereby preventing resubmission to another journal for consideration. Library scientist Jeffrey Beall has described OMICS as among the most egregious of predatory publishers. In November 2017, a federal court in the Court for the District of Nevada granted a preliminary injunction that: prohibits the defendants from making misrepresentations regarding their academic journals and conferences, including that specific persons are editors of their journals or have agreed to participate in their conferences. It also prohibits the defendants from falsely representing that their journals engage in peer review, that their journals are included in any academic journal indexing service or any measurement of the extent to which their journals are cited. It also requires that the defendants clearly and conspicuously disclose all costs associated with submitting or publishing articles in their journals. In April 2019, the court imposed a fine of US$50.1 million on OMICS companies for unfair and deceptive business practices. In addition to prospective analysis of the effects of mergers and acquisitions, the FTC has recently resorted to retrospective analysis and monitoring of consolidated hospitals. Thus, it also uses retroactive data to demonstrate that some hospital mergers and acquisitions are hurting consumers, particularly in terms of higher prices. Here are some recent examples of the FTC's success in blocking or unwinding of hospital consolidations or affiliations: In April 2011, the FTC successfully challenged in court the $195 million acquisition of Palmyra Medical Center by Phoebe Putney Memorial Hospital. The FTC alleged that the transaction would create a monopoly as it would "reduce competition significantly and allow the combined Phoebe/Palmyra to raise prices for general acute-care hospital services charged to commercial health plans, substantially harming patients and local employers and employees". The Supreme Court on February 19, 2013, ruled in favor of the FTC. Similarly, court attempts by ProMedica health system in Ohio to overturn an order by the FTC to the company to unwind its 2010 acquisition of St. Luke's hospital were unsuccessful. The FTC claimed that the acquisition would hurt consumers through higher premiums because insurance companies would be required to pay more. In December 2011, an administrative judge upheld the FTC's decision, noting that the behavior of ProMedica health system and St. Luke's was indeed anticompetitive. The court ordered ProMedica to divest St. Luke's to a buyer that would be approved by the FTC within 180 days of the date of the order. In November 2011, the FTC filed a lawsuit alleging that the proposed acquisition of Rockford by OSF would drive up prices for general acute-care inpatient services as OSF would face only one competitor (SwedishAmerican health system) in the Rockford area and would have a market share of 64%. Later in 2012, OSF announced that it had abandoned its plans to acquire Rockford Health System. In December 2020, the FTC sued Meta (formally known as Facebook) for anticompetitive conduct under Section 2 of the Sherman Act, which prohibits improper monopolization of a market. The FTC accused Meta of buying up its competitors to stifle competition which reduced the range of services available to consumers and by creating fewer social media platforms for advertisers to target. The FTC was chaired by Lina Khan during the Biden Administration. In the 2021 United States Supreme Court case, AMG Capital Management, LLC v. FTC, the Court found unanimously that the FTC did not have power under 15 U.S.C. § 53(b) of the FTC Act, amended in 1973, to seek equitable relief in courts; it had the power to seek only injunctive relief. Faced with this limitation, the FTC engaged in substantial unilateral activity under its independent rulemaking authority, particularly as to Section 5, which is the FTC's arsenal of powers related to market structure and stimulation of competition. Khan herself had written a law review article in 2023 foreshadowing this strategy and highlighting what she saw as the FTC's underutilized market regulatory powers. In November 2024, U.S. district judge Amit Mehta agreed with Assistant Attorney General Jonathan Kanter and FTC Chair Khan, ruling the company a monopoly, and ordering Google to sell its Chrome web browser. In September 2025, Mehta reversed course, ruling that Google would not be forced to sell Chrome. In lieu, Google must share data with search competitors and avoid exclusivity deals with hardware manufacturers. This FTC attempted to ban nearly every non-compete clause. This began with an FTC rule in April 2024. The agency estimates 30 million workers are bound by these clauses and only excludes senior executives from the ban on enforcing non-competes. The agency believes that this will allow workers to find better working conditions and pay, since switching companies, on average, provides the biggest pay raises. It also allows workers to leave abusive work environments and can prevent some doctors from having to leave medicine once they leave a practice. The ban was put on hold by U.S. district judge Ada Brown on July 3, 2024, but then upheld on appeal by U.S. district judge Kelley B. Hodge on July 23, 2024. On August 20, 2024, a federal court in Texas overturned the FTC's ban on non-compete agreements, which was originally scheduled to take effect on September 4, 2024. U.S. district judge Ada Brown said the FTC did not have the authority to issue the ban, which she said was "unreasonably overbroad without a reasonable explanation." Victoria Graham, an FTC spokeswoman responded to the ruling by stating "We are seriously considering a potential appeal..." The FTC blocked Nvidia from purchasing Arm Holdings in 2022. The FTC has pursued lawsuits against companies to lower drug prices, including for insulin and for inhalers. The FTC launched its investigation into pharmacy benefit managers (PBMs) in 2022. In July 2024, it released an interim report on its 2-year investigation into pharmacy benefit managers, the agency requested documents from the six largest PBMs as part of its investigation. The three largest – UnitedHealth Group's OptumRx, Cigna's Express Scripts and CVS Health's Caremark – manage about 80% of U.S. prescriptions. The top three PBMs share a parent company with a large medical insurance company. The FTC accused these companies of raising drug prices through conflicts of interest, vertical integration, concentration, and exclusivity provisions; the agency also alleged that the companies created a rebate system that prioritized high rebates from drug manufacturers, among other factors. The agency stated that several PBMs failed to provide documents in a timely manner and warned that it could take the companies to court to force them to comply, during the announcement in the preliminary findings. In September 2024, the FTC sued the three largest pharmacy benefit managers (PBMs) for allegedly engaging in anti-competitive practices that increased their profits while artificially inflating the list price of insulin. The agency is seeking to prohibit the PBMs from favoring medicines because certain pharmaceuticals make them more money. In August 2024, the FTC announced it would finalize rules to ban fake reviews and testimonials online. In February 2024, the FTC challenged the Kroger-Albertsons merger, arguing it would drive up grocery and pharmacy prices, worsen service, and lower wages and working conditions. On December 10, 2024, U.S. district judge Adrienne Nelson agreed with the FTC, that the merger would risk reducing competition at the expense of both consumers and workers. Judge Nelson halted Kroger’s $24.6 billion acquisition of Albertsons with a preliminary injunction. In March 2024, the FTC released a report that found higher profit margins as a driver of inflation for grocery prices. In August 2024, it announced it would be probing grocery prices to look for anti-competitive behavior and price gouging at chain supermarkets. In October 2023, the FTC proposed a new rule that would ensure that the cancellation process of subscription services is as easy as the process of signing up. On October 16, 2024, the FTC announced the new rule, dubbed "click to cancel", requiring companies to make subscription services "as easy for consumers to cancel their enrollment as it was to sign up." Khan said in an interview that the new rule is designed so that if consumers signed up online, they must also be able to cancel on the same website in the same number of steps. The rule’s final provisions will go into effect 180 days after it is published in the Federal Register. On May 9, 2025 the FTC voted to delay enforcing compliance on the "Click to cancel" provision until July 14, 2025. It also targeted airlines and credit card companies over junk fees and high prices. The rule for junk fees which covers, businesses selling live-event tickets and short-term lodging, requires disclosing total price upfront, and no misrepresentations about fees and charges, went into effect on May 12, 2025. In October 2023, the FTC authorized an administrative complaint against the merger between Microsoft and Activision Blizzard, Inc. The FTC alleged the deal would suppress competitors from accessing future content/games developed by Activision once the deal goes through. The FTC dropped its lawsuit on July 20, 2023. Microsoft had to restructure its deal to appease UK regulators. Microsoft reneged on promises it made in court filings by laying off 1900 employees in January 2024, signaling that it did not plan to let Activision Blizzard remain as independent as it had promised and leading the FTC to continue to appeal the decision. In July 2021, the FTC voted unanimously to enforce the right to repair as policy and to look to take action against companies that limit the type of repair work that can be done at independent repair shops. In October 2024, following a comment by the FTC to the US Copyright Office, an exemption to the Digital Millennium Copyright Act was granted allowing for repair of retail-level food preparation equipment, such as McDonald's ice cream machines. 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, the creator of ChatGPT, 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. In November 2023, the FTC passed an omnibus resolution to increase its ability to investigate companies adding AI into their products or making AI. The agency then reported concern with the Microsoft-Open AI partnership and the Amazon-Anthropic partnership. The circular spending in which, for example, Microsoft gives OpenAI credit to Microsoft Azure and the companies provide each other access to engineering talent was of particular concern for its potential negative impacts to the public. In August 2024, the FTC voted unanimously to ban marketers from using fake user reviews created by generative AI chatbots and influencers paying for bots to increase follower counts. On March 18, 2025, President Trump ordered the dismissal of Democratic commissioners Alvaro Bedoya and Rebecca Kelly Slaughter. Presidents do not have statutory authority to fire FTC commissioners for reasons other than inefficiency, neglect of duty, or malfeasance, none of which were cited in Trump's orders; these restrictions were upheld by the Supreme Court in Humphrey's Executor v. United States. Bedoya and Slaughter both stated the attempted firings were unlawful. Bedoya described it as "corruption plain and simple," while Slaughter stated it "violat[ed] the plain language of a statute and clear Supreme Court precedent." Republicans, including FTC chair Andrew N. Ferguson, have argued that Humphrey's Executor was wrongly decided. Legal analysts expect the firings of Bedoya and Slaughter, along with the attempted firing of Democratic NLRB member Gwynne Wilcox, to serve as a test case that will enable the Supreme Court to overrule Humphrey's Executor and grant the President unlimited authority to fire commissioners of independent agencies such as the FTC, NLRB, and the Federal Reserve. In July 2025, the FTC held a workshop on what it deemed "unfair or deceptive trade practices" in the provision of transgender health care, with a focus on trans healthcare for minors; done as part of the Trump administration's larger campaign to curtail trans rights. The event involved testimony from "anti-trans activists and clinicians", and detransitioners, during which such speakers stated that it constituted fraud for a doctor use someone's preferred pronouns. Another testimony stated, "No one is born with gender dysphoria." Organization The commission is headed by five commissioners, who each serve seven-year terms. Commissioners are nominated by the president and confirmed by the Senate. No more than three commissioners can be of the same political party. In practice, this means that two commissioners are of the opposition party. However, three members of the FTC throughout its history have been without party affiliation, with the most recent independent, Pamela Jones Harbour, serving from 2003 to 2009. (chair) University of Virginia School of Law (JD) University of Houston Law Center (JD) Notes The FTC has three main bureaus: the Bureau of Competition, the Bureau of Consumer Protection, and the Bureau of Economics. The Bureau of Competition is the division of the FTC charged with elimination and prevention of "anticompetitive" business practices. It accomplishes this through the enforcement of antitrust laws, review of proposed mergers, and investigation into other non-merger business practices that may impair competition. Such non-merger practices include horizontal restraints, involving agreements between direct competitors, and vertical restraints, involving agreements among businesses at different levels in the same industry (such as suppliers and commercial buyers). The FTC shares enforcement of antitrust laws with the Department of Justice. However, while the FTC is responsible for civil enforcement of antitrust laws, the Antitrust Division of the Department of Justice has the power to bring both civil and criminal action in antitrust matters. The Bureau of Consumer Protection's mandate is to protect consumers against unfair or deceptive acts or practices in commerce. With the written consent of the commission, Bureau attorneys enforce federal laws related to consumer affairs and rules promulgated by the FTC. Its functions include investigations, enforcement actions, and consumer and business education. Areas of principal concern for this bureau are: advertising and marketing, financial products and practices, telemarketing fraud, privacy and identity protection, etc. The bureau also is responsible for the United States National Do Not Call Registry. Under the FTC Act, the commission has the authority, in most cases, to bring its actions in federal court through its own attorneys. In some consumer protection matters, the FTC appears with, or supports, the U.S. Department of Justice. The Bureau of Economics was established to support the Bureau of Competition and Consumer Protection by providing expert knowledge related to the economic impacts of the FTC's legislation and operation. Activities The FTC investigates issues raised by reports from consumers and businesses, pre-merger notification filings, congressional inquiries, or reports in the media. These issues include, for instance, false advertising and other forms of fraud. FTC investigations may pertain to a single company or an entire industry. If the results of the investigation reveal unlawful conduct, the FTC may seek voluntary compliance by the offending business through a consent order, file an administrative complaint, or initiate federal litigation. During the course of regulatory activities, the FTC is authorized to collect records, but not on-site inspections. Traditionally an administrative complaint is heard in front of an independent administrative law judge (ALJ) with FTC staff acting as prosecutors. The case is reviewed de novo by the full FTC commission which then may be appealed to the U.S. Court of Appeals and finally to the Supreme Court.[citation needed] Under the FTC Act, the federal courts retain their traditional authority to issue equitable relief, including the appointment of receivers, monitors, the imposition of asset freezes to guard against the spoliation of funds, immediate access to business premises to preserve evidence, and other relief including financial disclosures and expedited discovery. In numerous cases, the FTC employs this authority to combat serious consumer deception or fraud. Additionally, the FTC has rulemaking power to address concerns regarding industry-wide practices. Rules promulgated under this authority are known as Trade Rules.[citation needed] One of the Federal Trade Commission's other major focuses is identity theft. The FTC serves as a federal repository for individual consumer complaints regarding identity theft. Even though the FTC does not resolve individual complaints, it does use the aggregated information to determine where federal action might be taken. The complaint form is available online or by phone (1-877-ID-THEFT).[citation needed] The FTC has been involved in the oversight of the online advertising industry and its practice of behavioral targeting for some time. In 2011 the FTC proposed a "Do Not Track" mechanism to allow Internet users to opt-out of behavioral targeting.[citation needed] The FTC, along with the Environmental Protection Agency and Department of Justice also empowers third-party enforcer-firms to engage in some regulatory oversight, e.g. the FTC requires other energy companies to audit offshore oil platform operators. In 2013, the FTC issued a comprehensive revision of its Green guides, which set forth standards for environmental marketing.[non-primary source needed] Section 5 of the Federal Trade Commission Act, 15 U.S.C. § 45 grants the FTC power to investigate and prevent deceptive trade practices. The statute declares that "unfair methods of competition in or affecting commerce, and unfair or deceptive acts or practices in or affecting commerce, are hereby declared unlawful." Unfairness and deception towards consumers represent two distinct areas of FTC enforcement and authority. The FTC also has authority over unfair methods of competition between businesses. Courts have identified three main factors that must be considered in consumer unfairness cases: (1) whether the practice injures consumers; (2) whether the practice violates established public policy; and (3) whether it is unethical or unscrupulous. In a letter to the chairman of the House Committee on Energy and Commerce, the FTC defined the elements of deception cases. First, "there must be a representation, omission or practice that is likely to mislead the consumer." In the case of omissions, the Commission considers the implied representations understood by the consumer. A misleading omission occurs when information is not disclosed to correct reasonable consumer expectations. Second, the commission examines the practice from the perspective of a reasonable consumer being targeted by the practice. Finally the representation or omission must be a material one – that is one that would have changed consumer behavior. In its Dot Com Disclosures guide, the FTC said that "disclosures that are required to prevent deception or to provide consumers material information about a transaction must be presented clearly and conspicuously." The FTC suggested a number of different factors that would help determine whether the information was "clear and conspicuous" including but not limited to: However, the "key is the overall net impression." See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Kip_Thorne] | [TOKENS: 2876] |
Contents Kip Thorne Kip Stephen Thorne (born June 1, 1940) is an American astrophysicist and author. He shared the 2017 Nobel Prize in Physics with Rainer Weiss and Barry C. Barish "for decisive contributions to the LIGO detector and the observation of gravitational waves". With John A. Wheeler and Charles Misner, he coauthored the general relativity textbook Gravitation. He has also written popular science, notably Black Holes and Time Warps. Thorne was the Richard P. Feynman Professor of Theoretical Physics at Caltech from 1991 until 2009. A longtime friend and colleague of Stephen Hawking and Carl Sagan, he advised Sagan on the physics of wormholes for his novel Contact. He was a scientific consultant for Christopher Nolan's films Interstellar and Tenet. He received the 2018 Lewis Thomas Prize for science writing. Life and career Thorne was born on June 1, 1940, in Logan, Utah. His father, D. Wynne Thorne (1908–1979), was a professor of soil chemistry at Utah State University, and his mother, Alison (née Comish; 1914–2004), was an economist and the first woman to receive a PhD in economics from Iowa State College. Raised in an academic environment, two of his four siblings also became professors. Thorne's parents were members of the Church of Jesus Christ of Latter-day Saints (LDS Church) and raised Thorne in the LDS faith, though he now identifies as an atheist. Shortly before his mother's death, she urged Kip and his siblings to leave the LDS Church because of its discrimination against women, which they all did. Regarding his views on science and religion, Thorne has stated: "There are large numbers of my finest colleagues who are quite devout and believe in God .... There is no fundamental incompatibility between science and religion. I happen to not believe in God." Thorne excelled at academics early in life, winning recognition in the Westinghouse Science Talent Search as a senior at Logan High School. He received his BS in physics degree from Caltech in 1962, and his master and PhD in physics from Princeton University in 1964 and 1965 under the supervision of John Archibald Wheeler with a doctoral dissertation on Geometrodynamics of Cylindrical Systems. He returned to Caltech as an associate professor in 1967 and became a professor of theoretical physics in 1970, becoming one of the youngest full professors in the history of Caltech at age 30. He became the William R. Kenan, Jr. Professor in 1981, and the Feynman Professor of Theoretical Physics in 1991. He was an adjunct professor at the University of Utah from 1971 to 1998 and Andrew D. White Professor at Large at Cornell University from 1986 to 1992. In June 2009, he resigned his Feynman Professorship (he is now the Feynman Professor of Theoretical Physics, Emeritus) to pursue a career of writing and movie making.[citation needed] Thorne and Linda Jean Peterson married in 1960. Their children are Kares Anne and Bret Carter, an architect. Thorne and Peterson divorced in 1977. Thorne was set up on a blind date with Lynda Obst, later a film producer, by physicist Carl Sagan. They dated in 1979–1980, and parted and remained friends, to the extent that they later collaborated on the movie Interstellar. Thorne and his second wife, Carolee Joyce Winstein, a professor of biokinesiology and physical therapy at USC, married in 1984. In 2015, he collaborated with Obst and Stephen Hawking on a movie script, for which they wrote several drafts. Throughout the years, Thorne has served as a mentor and thesis advisor to many leading theorists who now work on observational, experimental, or astrophysical aspects of general relativity. Approximately 50 physicists have received PhDs at Caltech under Thorne's personal mentorship. Thorne is known for his ability to convey the excitement and significance of discoveries in gravitation and astrophysics to both professional and lay audiences. His presentations on subjects such as black holes, gravitational radiation, relativity, time travel, and wormholes have been included in PBS shows in the U.S. and on the BBC in the United Kingdom.[citation needed] In 2017, Thorne gave the George Gamow Memorial Lecture at the Univerity of Colorado Boulder, on “Probing the Warped Side of the Universe with Gravitational Waves: From the Big Bang to Black Holes.” Research Thorne's research has principally focused on relativistic astrophysics and gravitation physics, with emphasis on relativistic stars, black holes and especially gravitational waves. He is perhaps best known to the public for his controversial theory that wormholes can conceivably be used for time travel. However, Thorne's scientific contributions, which center on the general nature of space, time, and gravity, span the full range of topics in general relativity. Thorne's work has dealt with the prediction of gravitational wave strengths and their temporal signatures as observed on Earth. These "signatures" are of great relevance to LIGO (Laser Interferometer Gravitational Wave Observatory), a multi-institution gravitational wave experiment for which Thorne has been a leading proponent – in 1984, he cofounded the LIGO Project (the largest project ever funded by the NSF) to discern and measure any fluctuations between two or more 'static' points; such fluctuations would be evidence of gravitational waves, as calculations describe. A significant aspect of his research is developing the mathematics necessary to analyze these objects. Thorne also carries out engineering design analyses for features of the LIGO that cannot be developed on the basis of experiment and he gives advice on data analysis algorithms by which the waves will be sought. He has provided theoretical support for LIGO, including identifying gravitational wave sources that LIGO should target, designing the baffles to control scattered light in the LIGO beam tubes, and – in collaboration with Vladimir Braginsky's (Moscow, Russia) research group – inventing quantum nondemolition designs for advanced gravity-wave detectors and ways to reduce the most serious kind of noise in advanced detectors: thermoelastic noise. With Carlton M. Caves, Thorne invented the back-action-evasion approach to quantum nondemolition measurements of the harmonic oscillators – a technique applicable both in gravitational wave detection and quantum optics. On February 11, 2016, a team of four physicists[a] representing the LIGO Scientific Collaboration, announced that in September 2015, LIGO recorded the signature of two black holes colliding 1.3 billion light-years away. This recorded detection was the first direct observation of the fleeting chirp of a gravitational wave and confirmed a prediction of the general theory of relativity. While studying for his PhD at Princeton University, his mentor John Wheeler assigned him a problem to think about: find out whether or not a cylindrical bundle of repulsive magnetic field lines will implode under its own attractive gravitational force. After several months wrestling with the problem, he proved that it was impossible for cylindrical magnetic field lines to implode.: 262–265 Why won't a cylindrical bundle of magnetic field lines implode, while spherical stars will implode under their own gravitational force? Thorne tried to explore the theoretical ridge between these two phenomena. He eventually determined that the gravitational force can overcome all interior pressure only when an object has been compressed in all directions. To express this realization, Thorne proposed his hoop conjecture, which describes an imploding star turning into a black hole when the critical circumference of the designed hoop can be placed around it and set into rotation. That is, any object of mass M around which a hoop of circumference 4 π G M c 2 {\displaystyle {\begin{matrix}{\frac {4\pi GM}{c^{2}}}\end{matrix}}} can be spun must be a black hole.: 266–267 : 189–190 As a tool to be used in both enterprises — astrophysics and theoretical physics — Thorne and his students have developed an unusual approach, called the "membrane paradigm", to the theory of black holes and used it to clarify the Blandford–Znajek mechanism by which black holes may power some quasars and active galactic nuclei.: 405–411 Thorne has investigated the quantum statistical mechanical origin of the entropy of a black hole. With his postdoc Wojciech Zurek, he showed that the entropy of a black hole is the logarithm of the number of ways that the hole could have been made.: 445–446 With Igor Novikov and Don Page, he developed the general relativistic theory of thin accretion disks around black holes, and using this theory he deduced that with a doubling of its mass by such accretion a black hole will be spun up to 0.998 of the maximum spin allowed by general relativity, but not any farther. This is probably the maximum black-hole spin allowed in nature. Thorne and his co-workers at Caltech conducted scientific research on whether the laws of physics permit space and time to be multiply connected (can there exist classical, traversable wormholes and "time machines"?). With Sung-Won Kim, Thorne identified a universal physical mechanism (the explosive growth of vacuum polarization of quantum fields), that may always prevent spacetime from developing closed timelike curves (i.e., prevent backward time travel). With Mike Morris and Ulvi Yurtsever, he showed that traversable wormholes can exist in the structure of spacetime only if they are threaded by quantum fields in quantum states that violate the averaged null energy condition (i.e. have negative renormalized energy spread over a sufficiently large region). This has triggered research to explore the ability of quantum fields to possess such extended negative energy. Recent calculations by Thorne indicate that simple masses passing through traversable wormholes could never engender paradoxes – there are no initial conditions that lead to paradox once time travel is introduced. If his results can be generalized, they would suggest that none of the supposed paradoxes formulated in time travel stories can actually be formulated at a precise physical level: that is, that any situation in a time travel story turns out to permit many consistent solutions.[citation needed] With Anna Żytkow, Thorne predicted the existence of red supergiant stars with neutron-star cores (Thorne–Żytkow objects). He laid the foundations for the theory of pulsations of relativistic stars and the gravitational radiation they emit. With James Hartle, Thorne derived from general relativity the laws of motion and precession of black holes and other relativistic bodies, including the influence of the coupling of their multipole moments to the spacetime curvature of nearby objects, as well as writing down the Hartle-Thorne metric, an approximate solution which describes the exterior of a slowly and rigidly rotating, stationary and axially symmetric body. Thorne has also theoretically predicted the existence of universally antigravitating "exotic matter" – the element needed to accelerate the expansion rate of the universe, keep traversable wormhole "Star Gates" open and keep timelike geodesic free float "warp drives" working. With Clifford Will and others of his students, he laid the foundations for the theoretical interpretation of experimental tests of relativistic theories of gravity – foundations on which Will and others then built. As of 2005[update], Thorne was interested in the origin of classical space and time from the quantum foam of quantum gravity theory.[citation needed] Publications In 1973, Thorne co-authored Gravitation with Charles Misner and John A. Wheeler; that according to John C. Baez and Chris Hillman, is one of the great scientific books of all time and has inspired two generations of students. In 1994, he published Black Holes and Time Warps, a popular science book that traces black holes from John Michell to Stephen Hawking and beyond. It has been published in fourteen languages: English, German(1994), Spanish(1995), French(1997), Japanese(1997), Greek(1999), Czech(2004), Polish(2005), Chinese(2005), Korean(2005), Thai(2008), and Italian(2013). In 2014, he published The Science of Interstellar, in which he explains the science behind Christopher Nolan's film; Nolan wrote the foreword. In September 2017, Thorne and Roger D. Blandford published Modern Classical Physics: Optics, Fluids, Plasmas, Elasticity, Relativity, and Statistical Physics, a graduate-level textbook covering the six major areas of physics listed in the title. With artist Lia Halloran, Thorne used poetry and illustrations to explore astrophysics in The Warped Side of Our Universe. Thorne's articles have appeared in publications such as: Thorne has published more than 150 articles in scholarly journals. Honors and awards Thorne has been elected to the: He has been recognized by numerous awards including the: He has been a Woodrow Wilson Fellow, Danforth Fellow, Guggenheim Fellow, and Fulbright Fellow. He has also received the honorary degree of doctor of humane letters from Claremont Graduate University and an honorary doctorate from the Physics Department of the Aristotle University of Thessaloniki. In 2024 he was awarded an honorary doctorate from University of Cambridge. He was elected to hold the Lorentz chair for the year 2009 Leiden University, the Netherlands. Thorne has served on the: Kip Thorne was selected by Time magazine in an annual list of the 100 most influential people in the American world in 2016. Adaptation in media Partial bibliography Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/List_of_contributors_to_general_relativity] | [TOKENS: 81] |
Contents List of contributors to general relativity This is a dynamic list of persons who have made major contributions to the (mainstream) development of general relativity, as acknowledged by standard texts on the subject. Some related lists are mentioned at the bottom of the page. A B C D E F G H I J K L M N O P R S T U V W X Y Z Notes See also |
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[SOURCE: https://en.wikipedia.org/wiki/Four_Holy_Cities] | [TOKENS: 694] |
Contents Four Holy Cities In Judaism, the "Four Holy Cities" are Jerusalem, Hebron, Tiberias, and Safed. The concept was created for the purpose of fundraising within the Jewish diaspora, originating in the 1640s when the Jewish communities of Jerusalem, Hebron and Safed formed an association for that purpose – Tiberias was to join approximately a century later. According to The Jewish Encyclopedia in 1906: "Since the sixteenth century the Holiness of Palestine, especially for burial, has been almost wholly transferred to four cities—Jerusalem, Hebron, Tiberias, and Safed." List of the cities and significance Jerusalem has had the highest significance for Jews since the 11th century BCE, when, according to the biblical narrative, David led the Israelites to conquer it from the Jebusites and established it as the capital city of the Kingdom of Israel and Judah. There, his son and successor Solomon constructed the Temple in Jerusalem, which held the Ark of the Covenant after the Holy of Holies of the Tabernacle. Though the First Temple and the Second Temple were both destroyed in antiquity, the Temple Mount, on which they stood, continues to serve as the basis of Jewish spirituality both inside and outside of the Land of Israel. Hebron, which is home to the Cave of the Patriarchs, is the burial place of the Hebrew patriarchs and their wives: Abraham and his wife Sarah; Abraham's son Isaac and his wife Rebecca; and Isaac's son Jacob and his wife Leah. As such, Hebron's significance for Jews is second only to Jerusalem, and it is also one of the four cities where Hebrew prophets (Abraham, in particular) purchased land: Abraham bought a field and a cave east of Hebron from the Hittites (Genesis 23:16–18); David bought a threshing floor at Jerusalem from Araunah the Jebusite (2 Samuel 24:24); Jacob bought land outside the walls of Shechem (Genesis 33:18–19); and Omri bought the site of Samaria. Further, Hebron was the first capital city of Israel and Judah during David's reign. Tiberias is significant in Jewish history for several reasons. It was the place where the Jerusalem Talmud was composed and served as the final meeting place of the Great Sanhedrin, which was disbanded in 425 CE. The tomb of famous rabbis and other Jewish scholars, such as Yohanan ben Zakkai, Akiva, and Maimonides, are also located in the city. It was the home of the Masoretes and the place where the Tiberian vocalization for the Hebrew Bible was devised. According to Jewish tradition, the redemption will begin in Tiberias and the Sanhedrin will be reconstituted there, and the Messiah will arise from Lake Tiberias, enter the city, and be enthroned on the summit of a lofty hill in Safed. Safed came to be regarded as a holy city at a significantly later time than the other three. The mass influx of Sephardic Jews following the Alhambra Decree, which was issued by the Catholic Monarchs of Spain during the Reconquista in 1492, enabled the transformation of Safed into a centre of Kabbalah and Jewish scholarship. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/SR_(programming_language)] | [TOKENS: 180] |
Contents SR (programming language) SR (short for Synchronizing Resources) is a programming language designed for concurrent programming. Resources encapsulate processes and the variables they share, and can be separately compiled. Operations provide the primary mechanism for process interaction. SR provides a novel integration of the mechanisms for invoking and servicing operations. Consequently, it supports local and remote procedure call, rendezvous, message passing, dynamic process creation, multicast, semaphores and shared memory. Version 2.2 has been ported to the Apollo, DECstation, Data General AViiON, HP 9000 Series 300, Multimax, NeXT, PA-RISC, RS/6000, Sequent Symmetry, SGI IRIS, Sun-3, Sun-4 and others. See also References External links This programming-language-related article is a stub. You can help Wikipedia by adding missing information. |
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[SOURCE: https://en.wikipedia.org/wiki/Mars#cite_note-:8-147] | [TOKENS: 11899] |
Contents Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", for its orange-red appearance. Mars is a desert-like rocky planet with a tenuous atmosphere that is primarily carbon dioxide (CO2). At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from −153 to 20 °C (−243 to 68 °F), and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, fog, frost, larger polar regions of permafrost and ice caps (with seasonal CO2 snow), but no bodies of liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. Its diameter, 6,779 km (4,212 mi), is about half the Earth's, or twice the Moon's, and its surface area is the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south divide, the Martian dichotomy, with the northern hemisphere mainly consisting of relatively flat, low lying plains, and the southern hemisphere of cratered highlands. Geologically, the planet is fairly active with marsquakes trembling underneath the ground, but also hosts many enormous volcanoes that are extinct (the tallest is Olympus Mons, 21.9 km or 13.6 mi tall), as well as one of the largest canyons in the Solar System (Valles Marineris, 4,000 km or 2,500 mi long). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos. With a significant axial tilt of 25 degrees, Mars experiences seasons, like Earth (which has an axial tilt of 23.5 degrees). A Martian solar year is equal to 1.88 Earth years (687 Earth days), a Martian solar day (sol) is equal to 24.6 hours. Mars formed along with the other planets approximately 4.5 billion years ago. During the martian Noachian period (4.5 to 3.5 billion years ago), its surface was marked by meteor impacts, valley formation, erosion, the possible presence of water oceans and the loss of its magnetosphere. The Hesperian period (beginning 3.5 billion years ago and ending 3.3–2.9 billion years ago) was dominated by widespread volcanic activity and flooding that carved immense outflow channels. The Amazonian period, which continues to the present, is the currently dominating and remaining influence on geological processes. Because of Mars's geological history, the possibility of past or present life on Mars remains an area of active scientific investigation, with some possible traces needing further examination. Being visible with the naked eye in Earth's sky as a red wandering star, Mars has been observed throughout history, acquiring diverse associations in different cultures. In 1963 the first flight to Mars took place with Mars 1, but communication was lost en route. The first successful flyby exploration of Mars was conducted in 1965 with Mariner 4. In 1971 Mariner 9 entered orbit around Mars, being the first spacecraft to orbit any body other than the Moon, Sun or Earth; following in the same year were the first uncontrolled impact (Mars 2) and first successful landing (Mars 3) on Mars. Probes have been active on Mars continuously since 1997. At times, more than ten probes have simultaneously operated in orbit or on the surface, more than at any other planet beyond Earth. Mars is an often proposed target for future crewed exploration missions, though no such mission is currently planned. Natural history Scientists have theorized that during the Solar System's formation, Mars was created as the result of a random process of run-away accretion of material from the protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points, such as chlorine, phosphorus, and sulfur, are much more common on Mars than on Earth; these elements were probably pushed outward by the young Sun's energetic solar wind. After the formation of the planets, the inner Solar System may have been subjected to the so-called Late Heavy Bombardment. About 60% of the surface of Mars shows a record of impacts from that era, whereas much of the remaining surface is probably underlain by immense impact basins caused by those events. However, more recent modeling has disputed the existence of the Late Heavy Bombardment. There is evidence of an enormous impact basin in the Northern Hemisphere of Mars, spanning 10,600 by 8,500 kilometres (6,600 by 5,300 mi), or roughly four times the size of the Moon's South Pole–Aitken basin, which would be the largest impact basin yet discovered if confirmed. It has been hypothesized that the basin was formed when Mars was struck by a Pluto-sized body about four billion years ago. The event, thought to be the cause of the Martian hemispheric dichotomy, created the smooth Borealis basin that covers 40% of the planet. A 2023 study shows evidence, based on the orbital inclination of Deimos (a small moon of Mars), that Mars may once have had a ring system 3.5 billion years to 4 billion years ago. This ring system may have been formed from a moon, 20 times more massive than Phobos, orbiting Mars billions of years ago; and Phobos would be a remnant of that ring. Epochs: The geological history of Mars can be split into many periods, but the following are the three primary periods: Geological activity is still taking place on Mars. The Athabasca Valles is home to sheet-like lava flows created about 200 million years ago. Water flows in the grabens called the Cerberus Fossae occurred less than 20 million years ago, indicating equally recent volcanic intrusions. The Mars Reconnaissance Orbiter has captured images of avalanches. Physical characteristics Mars is approximately half the diameter of Earth or twice that of the Moon, with a surface area only slightly less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity. Mars is the only presently known example of a desert planet, a rocky planet with a surface akin to that of Earth's deserts. The red-orange appearance of the Martian surface is caused by iron(III) oxide (nanophase Fe2O3) and the iron(III) oxide-hydroxide mineral goethite. It can look like butterscotch; other common surface colors include golden, brown, tan, and greenish, depending on the minerals present. Like Earth, Mars is differentiated into a dense metallic core overlaid by less dense rocky layers. The outermost layer is the crust, which is on average about 42–56 kilometres (26–35 mi) thick, with a minimum thickness of 6 kilometres (3.7 mi) in Isidis Planitia, and a maximum thickness of 117 kilometres (73 mi) in the southern Tharsis plateau. For comparison, Earth's crust averages 27.3 ± 4.8 km in thickness. The most abundant elements in the Martian crust are silicon, oxygen, iron, magnesium, aluminum, calcium, and potassium. Mars is confirmed to be seismically active; in 2019, it was reported that InSight had detected and recorded over 450 marsquakes and related events. Beneath the crust is a silicate mantle responsible for many of the tectonic and volcanic features on the planet's surface. The upper Martian mantle is a low-velocity zone, where the velocity of seismic waves is lower than surrounding depth intervals. The mantle appears to be rigid down to the depth of about 250 km, giving Mars a very thick lithosphere compared to Earth. Below this the mantle gradually becomes more ductile, and the seismic wave velocity starts to grow again. The Martian mantle does not appear to have a thermally insulating layer analogous to Earth's lower mantle; instead, below 1050 km in depth, it becomes mineralogically similar to Earth's transition zone. At the bottom of the mantle lies a basal liquid silicate layer approximately 150–180 km thick. The Martian mantle appears to be highly heterogenous, with dense fragments up to 4 km across, likely injected deep into the planet by colossal impacts ~4.5 billion years ago; high-frequency waves from eight marsquakes slowed as they passed these localized regions, and modeling indicates the heterogeneities are compositionally distinct debris preserved because Mars lacks plate tectonics and has a sluggishly convecting interior that prevents complete homogenization. Mars's iron and nickel core is at least partially molten, and may have a solid inner core. It is around half of Mars's radius, approximately 1650–1675 km, and is enriched in light elements such as sulfur, oxygen, carbon, and hydrogen. The temperature of the core is estimated to be 2000–2400 K, compared to 5400–6230 K for Earth's solid inner core. In 2025, based on data from the InSight lander, a group of researchers reported the detection of a solid inner core 613 kilometres (381 mi) ± 67 kilometres (42 mi) in radius. Mars is a terrestrial planet with a surface that consists of minerals containing silicon and oxygen, metals, and other elements that typically make up rock. The Martian surface is primarily composed of tholeiitic basalt, although parts are more silica-rich than typical basalt and may be similar to andesitic rocks on Earth, or silica glass. Regions of low albedo suggest concentrations of plagioclase feldspar, with northern low albedo regions displaying higher than normal concentrations of sheet silicates and high-silicon glass. Parts of the southern highlands include detectable amounts of high-calcium pyroxenes. Localized concentrations of hematite and olivine have been found. Much of the surface is deeply covered by finely grained iron(III) oxide dust. The Phoenix lander returned data showing Martian soil to be slightly alkaline and containing elements such as magnesium, sodium, potassium and chlorine. These nutrients are found in soils on Earth, and are necessary for plant growth. Experiments performed by the lander showed that the Martian soil has a basic pH of 7.7, and contains 0.6% perchlorate by weight, concentrations that are toxic to humans. Streaks are common across Mars and new ones appear frequently on steep slopes of craters, troughs, and valleys. The streaks are dark at first and get lighter with age. The streaks can start in a tiny area, then spread out for hundreds of metres. They have been seen to follow the edges of boulders and other obstacles in their path. The commonly accepted hypotheses include that they are dark underlying layers of soil revealed after avalanches of bright dust or dust devils. Several other explanations have been put forward, including those that involve water or even the growth of organisms. Environmental radiation levels on the surface are on average 0.64 millisieverts of radiation per day, and significantly less than the radiation of 1.84 millisieverts per day or 22 millirads per day during the flight to and from Mars. For comparison the radiation levels in low Earth orbit, where Earth's space stations orbit, are around 0.5 millisieverts of radiation per day. Hellas Planitia has the lowest surface radiation at about 0.342 millisieverts per day, featuring lava tubes southwest of Hadriacus Mons with potentially levels as low as 0.064 millisieverts per day, comparable to radiation levels during flights on Earth. Although Mars has no evidence of a structured global magnetic field, observations show that parts of the planet's crust have been magnetized, suggesting that alternating polarity reversals of its dipole field have occurred in the past. This paleomagnetism of magnetically susceptible minerals is similar to the alternating bands found on Earth's ocean floors. One hypothesis, published in 1999 and re-examined in October 2005 (with the help of the Mars Global Surveyor), is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded. Geography and features Although better remembered for mapping the Moon, Johann Heinrich von Mädler and Wilhelm Beer were the first areographers. They began by establishing that most of Mars's surface features were permanent and by more precisely determining the planet's rotation period. In 1840, Mädler combined ten years of observations and drew the first map of Mars. Features on Mars are named from a variety of sources. Albedo features are named for classical mythology. Craters larger than roughly 50 km are named for deceased scientists and writers and others who have contributed to the study of Mars. Smaller craters are named for towns and villages of the world with populations of less than 100,000. Large valleys are named for the word "Mars" or "star" in various languages; smaller valleys are named for rivers. Large albedo features retain many of the older names but are often updated to reflect new knowledge of the nature of the features. For example, Nix Olympica (the snows of Olympus) has become Olympus Mons (Mount Olympus). The surface of Mars as seen from Earth is divided into two kinds of areas, with differing albedo. The paler plains covered with dust and sand rich in reddish iron oxides were once thought of as Martian "continents" and given names like Arabia Terra (land of Arabia) or Amazonis Planitia (Amazonian plain). The dark features were thought to be seas, hence their names Mare Erythraeum, Mare Sirenum and Aurorae Sinus. The largest dark feature seen from Earth is Syrtis Major Planum. The permanent northern polar ice cap is named Planum Boreum. The southern cap is called Planum Australe. Mars's equator is defined by its rotation, but the location of its Prime Meridian was specified, as was Earth's (at Greenwich), by choice of an arbitrary point; Mädler and Beer selected a line for their first maps of Mars in 1830. After the spacecraft Mariner 9 provided extensive imagery of Mars in 1972, a small crater (later called Airy-0), located in the Sinus Meridiani ("Middle Bay" or "Meridian Bay"), was chosen by Merton E. Davies, Harold Masursky, and Gérard de Vaucouleurs for the definition of 0.0° longitude to coincide with the original selection. Because Mars has no oceans, and hence no "sea level", a zero-elevation surface had to be selected as a reference level; this is called the areoid of Mars, analogous to the terrestrial geoid. Zero altitude was defined by the height at which there is 610.5 Pa (6.105 mbar) of atmospheric pressure. This pressure corresponds to the triple point of water, and it is about 0.6% of the sea level surface pressure on Earth (0.006 atm). For mapping purposes, the United States Geological Survey divides the surface of Mars into thirty cartographic quadrangles, each named for a classical albedo feature it contains. In April 2023, The New York Times reported an updated global map of Mars based on images from the Hope spacecraft. A related, but much more detailed, global Mars map was released by NASA on 16 April 2023. The vast upland region Tharsis contains several massive volcanoes, which include the shield volcano Olympus Mons. The edifice is over 600 km (370 mi) wide. Because the mountain is so large, with complex structure at its edges, giving a definite height to it is difficult. Its local relief, from the foot of the cliffs which form its northwest margin to its peak, is over 21 km (13 mi), a little over twice the height of Mauna Kea as measured from its base on the ocean floor. The total elevation change from the plains of Amazonis Planitia, over 1,000 km (620 mi) to the northwest, to the summit approaches 26 km (16 mi), roughly three times the height of Mount Everest, which in comparison stands at just over 8.8 kilometres (5.5 mi). Consequently, Olympus Mons is either the tallest or second-tallest mountain in the Solar System; the only known mountain which might be taller is the Rheasilvia peak on the asteroid Vesta, at 20–25 km (12–16 mi). The dichotomy of Martian topography is striking: northern plains flattened by lava flows contrast with the southern highlands, pitted and cratered by ancient impacts. It is possible that, four billion years ago, the Northern Hemisphere of Mars was struck by an object one-tenth to two-thirds the size of Earth's Moon. If this is the case, the Northern Hemisphere of Mars would be the site of an impact crater 10,600 by 8,500 kilometres (6,600 by 5,300 mi) in size, or roughly the area of Europe, Asia, and Australia combined, surpassing Utopia Planitia and the Moon's South Pole–Aitken basin as the largest impact crater in the Solar System. Mars is scarred by 43,000 impact craters with a diameter of 5 kilometres (3.1 mi) or greater. The largest exposed crater is Hellas, which is 2,300 kilometres (1,400 mi) wide and 7,000 metres (23,000 ft) deep, and is a light albedo feature clearly visible from Earth. There are other notable impact features, such as Argyre, which is around 1,800 kilometres (1,100 mi) in diameter, and Isidis, which is around 1,500 kilometres (930 mi) in diameter. Due to the smaller mass and size of Mars, the probability of an object colliding with the planet is about half that of Earth. Mars is located closer to the asteroid belt, so it has an increased chance of being struck by materials from that source. Mars is more likely to be struck by short-period comets, i.e., those that lie within the orbit of Jupiter. Martian craters can[discuss] have a morphology that suggests the ground became wet after the meteor impact. The large canyon, Valles Marineris (Latin for 'Mariner Valleys, also known as Agathodaemon in the old canal maps), has a length of 4,000 kilometres (2,500 mi) and a depth of up to 7 kilometres (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one-fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 kilometres (277 mi) long and nearly 2 kilometres (1.2 mi) deep. Valles Marineris was formed due to the swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where 150 kilometres (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two-tectonic plate arrangement. Images from the Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter have revealed seven possible cave entrances on the flanks of the volcano Arsia Mons. The caves, named after loved ones of their discoverers, are collectively known as the "seven sisters". Cave entrances measure from 100 to 252 metres (328 to 827 ft) wide and they are estimated to be at least 73 to 96 metres (240 to 315 ft) deep. Because light does not reach the floor of most of the caves, they may extend much deeper than these lower estimates and widen below the surface. "Dena" is the only exception; its floor is visible and was measured to be 130 metres (430 ft) deep. The interiors of these caverns may be protected from micrometeoroids, UV radiation, solar flares and high energy particles that bombard the planet's surface. Martian geysers (or CO2 jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions. Similarly sized dust will settle from the thinner Martian atmosphere sooner than it would on Earth. For example, the dust suspended by the 2001 global dust storms on Mars only remained in the Martian atmosphere for 0.6 years, while the dust from Mount Pinatubo took about two years to settle. However, under current Martian conditions, the mass movements involved are generally much smaller than on Earth. Even the 2001 global dust storms on Mars moved only the equivalent of a very thin dust layer – about 3 μm thick if deposited with uniform thickness between 58° north and south of the equator. Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols. Atmosphere Mars lost its magnetosphere 4 billion years ago, possibly because of numerous asteroid strikes, so the solar wind interacts directly with the Martian ionosphere, lowering the atmospheric density by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected ionized atmospheric particles trailing off into space behind Mars, and this atmospheric loss is being studied by the MAVEN orbiter. Compared to Earth, the atmosphere of Mars is quite rarefied. Atmospheric pressure on the surface today ranges from a low of 30 Pa (0.0044 psi) on Olympus Mons to over 1,155 Pa (0.1675 psi) in Hellas Planitia, with a mean pressure at the surface level of 600 Pa (0.087 psi). The highest atmospheric density on Mars is equal to that found 35 kilometres (22 mi) above Earth's surface. The resulting mean surface pressure is only 0.6% of Earth's 101.3 kPa (14.69 psi). The scale height of the atmosphere is about 10.8 kilometres (6.7 mi), which is higher than Earth's 6 kilometres (3.7 mi), because the surface gravity of Mars is only about 38% of Earth's. The atmosphere of Mars consists of about 96% carbon dioxide, 1.93% argon and 1.89% nitrogen along with traces of oxygen and water. The atmosphere is quite dusty, containing particulates about 1.5 μm in diameter which give the Martian sky a tawny color when seen from the surface. It may take on a pink hue due to iron oxide particles suspended in it. Despite repeated detections of methane on Mars, there is no scientific consensus as to its origin. One suggestion is that methane exists on Mars and that its concentration fluctuates seasonally. The existence of methane could be produced by non-biological process such as serpentinization involving water, carbon dioxide, and the mineral olivine, which is known to be common on Mars, or by Martian life. Compared to Earth, its higher concentration of atmospheric CO2 and lower surface pressure may be why sound is attenuated more on Mars, where natural sources are rare apart from the wind. Using acoustic recordings collected by the Perseverance rover, researchers concluded that the speed of sound there is approximately 240 m/s for frequencies below 240 Hz, and 250 m/s for those above. Auroras have been detected on Mars. Because Mars lacks a global magnetic field, the types and distribution of auroras there differ from those on Earth; rather than being mostly restricted to polar regions as is the case on Earth, a Martian aurora can encompass the planet. In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25 times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month. Mars has seasons, alternating between its northern and southern hemispheres, similar to on Earth. Additionally the orbit of Mars has, compared to Earth's, a large eccentricity and approaches perihelion when it is summer in its southern hemisphere and winter in its northern, and aphelion when it is winter in its southern hemisphere and summer in its northern. As a result, the seasons in its southern hemisphere are more extreme and the seasons in its northern are milder than would otherwise be the case. The summer temperatures in the south can be warmer than the equivalent summer temperatures in the north by up to 30 °C (54 °F). Martian surface temperatures vary from lows of about −110 °C (−166 °F) to highs of up to 35 °C (95 °F) in equatorial summer. The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure (about 1% that of the atmosphere of Earth), and the low thermal inertia of Martian soil. The planet is 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight. Mars has the largest dust storms in the Solar System, reaching speeds of over 160 km/h (100 mph). These can vary from a storm over a small area, to gigantic storms that cover the entire planet. They tend to occur when Mars is closest to the Sun, and have been shown to increase global temperature. Seasons also produce dry ice covering polar ice caps. Hydrology While Mars contains water in larger amounts, most of it is dust covered water ice at the Martian polar ice caps. The volume of water ice in the south polar ice cap, if melted, would be enough to cover most of the surface of the planet with a depth of 11 metres (36 ft). Water in its liquid form cannot persist on the surface due to Mars's low atmospheric pressure, which is less than 1% that of Earth. Only at the lowest of elevations are the pressure and temperature high enough for liquid water to exist for short periods. Although little water is present in the atmosphere, there is enough to produce clouds of water ice and different cases of snow and frost, often mixed with snow of carbon dioxide dry ice. Landforms visible on Mars strongly suggest that liquid water has existed on the planet's surface. Huge linear swathes of scoured ground, known as outflow channels, cut across the surface in about 25 places. These are thought to be a record of erosion caused by the catastrophic release of water from subsurface aquifers, though some of these structures have been hypothesized to result from the action of glaciers or lava. One of the larger examples, Ma'adim Vallis, is 700 kilometres (430 mi) long, much greater than the Grand Canyon, with a width of 20 kilometres (12 mi) and a depth of 2 kilometres (1.2 mi) in places. It is thought to have been carved by flowing water early in Mars's history. The youngest of these channels is thought to have formed only a few million years ago. Elsewhere, particularly on the oldest areas of the Martian surface, finer-scale, dendritic networks of valleys are spread across significant proportions of the landscape. Features of these valleys and their distribution strongly imply that they were carved by runoff resulting from precipitation in early Mars history. Subsurface water flow and groundwater sapping may play important subsidiary roles in some networks, but precipitation was probably the root cause of the incision in almost all cases. Along craters and canyon walls, there are thousands of features that appear similar to terrestrial gullies. The gullies tend to be in the highlands of the Southern Hemisphere and face the Equator; all are poleward of 30° latitude. A number of authors have suggested that their formation process involves liquid water, probably from melting ice, although others have argued for formation mechanisms involving carbon dioxide frost or the movement of dry dust. No partially degraded gullies have formed by weathering and no superimposed impact craters have been observed, indicating that these are young features, possibly still active. Other geological features, such as deltas and alluvial fans preserved in craters, are further evidence for warmer, wetter conditions at an interval or intervals in earlier Mars history. Such conditions necessarily require the widespread presence of crater lakes across a large proportion of the surface, for which there is independent mineralogical, sedimentological and geomorphological evidence. Further evidence that liquid water once existed on the surface of Mars comes from the detection of specific minerals such as hematite and goethite, both of which sometimes form in the presence of water. The chemical signature of water vapor on Mars was first unequivocally demonstrated in 1963 by spectroscopy using an Earth-based telescope. In 2004, Opportunity detected the mineral jarosite. This forms only in the presence of acidic water, showing that water once existed on Mars. The Spirit rover found concentrated deposits of silica in 2007 that indicated wet conditions in the past, and in December 2011, the mineral gypsum, which also forms in the presence of water, was found on the surface by NASA's Mars rover Opportunity. It is estimated that the amount of water in the upper mantle of Mars, represented by hydroxyl ions contained within Martian minerals, is equal to or greater than that of Earth at 50–300 parts per million of water, which is enough to cover the entire planet to a depth of 200–1,000 metres (660–3,280 ft). On 18 March 2013, NASA reported evidence from instruments on the Curiosity rover of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock. Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of 60 centimetres (24 in), during the rover's traverse from the Bradbury Landing site to the Yellowknife Bay area in the Glenelg terrain. In September 2015, NASA announced that they had found strong evidence of hydrated brine flows in recurring slope lineae, based on spectrometer readings of the darkened areas of slopes. These streaks flow downhill in Martian summer, when the temperature is above −23 °C, and freeze at lower temperatures. These observations supported earlier hypotheses, based on timing of formation and their rate of growth, that these dark streaks resulted from water flowing just below the surface. However, later work suggested that the lineae may be dry, granular flows instead, with at most a limited role for water in initiating the process. A definitive conclusion about the presence, extent, and role of liquid water on the Martian surface remains elusive. Researchers suspect much of the low northern plains of the planet were covered with an ocean hundreds of meters deep, though this theory remains controversial. In March 2015, scientists stated that such an ocean might have been the size of Earth's Arctic Ocean. This finding was derived from the ratio of protium to deuterium in the modern Martian atmosphere compared to that ratio on Earth. The amount of Martian deuterium (D/H = 9.3 ± 1.7 10−4) is five to seven times the amount on Earth (D/H = 1.56 10−4), suggesting that ancient Mars had significantly higher levels of water. Results from the Curiosity rover had previously found a high ratio of deuterium in Gale Crater, though not significantly high enough to suggest the former presence of an ocean. Other scientists caution that these results have not been confirmed, and point out that Martian climate models have not yet shown that the planet was warm enough in the past to support bodies of liquid water. Near the northern polar cap is the 81.4 kilometres (50.6 mi) wide Korolev Crater, which the Mars Express orbiter found to be filled with approximately 2,200 cubic kilometres (530 cu mi) of water ice. In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior (which is 12,100 cubic kilometers). During observations from 2018 through 2021, the ExoMars Trace Gas Orbiter spotted indications of water, probably subsurface ice, in the Valles Marineris canyon system. Orbital motion Mars's average distance from the Sun is roughly 230 million km (143 million mi), and its orbital period is 687 (Earth) days. The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds. A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours. The gravitational potential difference and thus the delta-v needed to transfer between Mars and Earth is the second lowest for Earth. The axial tilt of Mars is 25.19° relative to its orbital plane, which is similar to the axial tilt of Earth. As a result, Mars has seasons like Earth, though on Mars they are nearly twice as long because its orbital period is that much longer. In the present day, the orientation of the north pole of Mars is close to the star Deneb. Mars has a relatively pronounced orbital eccentricity of about 0.09; of the seven other planets in the Solar System, only Mercury has a larger orbital eccentricity. It is known that in the past, Mars has had a much more circular orbit. At one point, 1.35 million Earth years ago, Mars had an eccentricity of roughly 0.002, much less than that of Earth today. Mars's cycle of eccentricity is 96,000 Earth years compared to Earth's cycle of 100,000 years. Mars has its closest approach to Earth (opposition) in a synodic period of 779.94 days. It should not be confused with Mars conjunction, where the Earth and Mars are at opposite sides of the Solar System and form a straight line crossing the Sun. The average time between the successive oppositions of Mars, its synodic period, is 780 days; but the number of days between successive oppositions can range from 764 to 812. The distance at close approach varies between about 54 and 103 million km (34 and 64 million mi) due to the planets' elliptical orbits, which causes comparable variation in angular size. At their furthest Mars and Earth can be as far as 401 million km (249 million mi) apart. Mars comes into opposition from Earth every 2.1 years. The planets come into opposition near Mars's perihelion in 2003, 2018 and 2035, with the 2020 and 2033 events being particularly close to perihelic opposition. The mean apparent magnitude of Mars is +0.71 with a standard deviation of 1.05. Because the orbit of Mars is eccentric, the magnitude at opposition from the Sun can range from about −3.0 to −1.4. The minimum brightness is magnitude +1.86 when the planet is near aphelion and in conjunction with the Sun. At its brightest, Mars (along with Jupiter) is second only to Venus in apparent brightness. Mars usually appears distinctly yellow, orange, or red. When farthest away from Earth, it is more than seven times farther away than when it is closest. Mars is usually close enough for particularly good viewing once or twice at 15-year or 17-year intervals. Optical ground-based telescopes are typically limited to resolving features about 300 kilometres (190 mi) across when Earth and Mars are closest because of Earth's atmosphere. As Mars approaches opposition, it begins a period of retrograde motion, which means it will appear to move backwards in a looping curve with respect to the background stars. This retrograde motion lasts for about 72 days, and Mars reaches its peak apparent brightness in the middle of this interval. Moons Mars has two relatively small (compared to Earth's) natural moons, Phobos (about 22 km (14 mi) in diameter) and Deimos (about 12 km (7.5 mi) in diameter), which orbit at 9,376 km (5,826 mi) and 23,460 km (14,580 mi) around the planet. The origin of both moons is unclear, although a popular theory states that they were asteroids captured into Martian orbit. Both satellites were discovered in 1877 by Asaph Hall and were named after the characters Phobos (the deity of panic and fear) and Deimos (the deity of terror and dread), twins from Greek mythology who accompanied their father Ares, god of war, into battle. Mars was the Roman equivalent to Ares. In modern Greek, the planet retains its ancient name Ares (Aris: Άρης). From the surface of Mars, the motions of Phobos and Deimos appear different from that of the Earth's satellite, the Moon. Phobos rises in the west, sets in the east, and rises again in just 11 hours. Deimos, being only just outside synchronous orbit – where the orbital period would match the planet's period of rotation – rises as expected in the east, but slowly. Because the orbit of Phobos is below a synchronous altitude, tidal forces from Mars are gradually lowering its orbit. In about 50 million years, it could either crash into Mars's surface or break up into a ring structure around the planet. The origin of the two satellites is not well understood. Their low albedo and carbonaceous chondrite composition have been regarded as similar to asteroids, supporting a capture theory. The unstable orbit of Phobos would seem to point toward a relatively recent capture. But both have circular orbits near the equator, which is unusual for captured objects, and the required capture dynamics are complex. Accretion early in the history of Mars is plausible, but would not account for a composition resembling asteroids rather than Mars itself, if that is confirmed. Mars may have yet-undiscovered moons, smaller than 50 to 100 metres (160 to 330 ft) in diameter, and a dust ring is predicted to exist between Phobos and Deimos. A third possibility for their origin as satellites of Mars is the involvement of a third body or a type of impact disruption. More-recent lines of evidence for Phobos having a highly porous interior, and suggesting a composition containing mainly phyllosilicates and other minerals known from Mars, point toward an origin of Phobos from material ejected by an impact on Mars that reaccreted in Martian orbit, similar to the prevailing theory for the origin of Earth's satellite. Although the visible and near-infrared (VNIR) spectra of the moons of Mars resemble those of outer-belt asteroids, the thermal infrared spectra of Phobos are reported to be inconsistent with chondrites of any class. It is also possible that Phobos and Deimos were fragments of an older moon, formed by debris from a large impact on Mars, and then destroyed by a more recent impact upon the satellite. More recently, a study conducted by a team of researchers from multiple countries suggests that a lost moon, at least fifteen times the size of Phobos, may have existed in the past. By analyzing rocks which point to tidal processes on the planet, it is possible that these tides may have been regulated by a past moon. Human observations and exploration The history of observations of Mars is marked by oppositions of Mars when the planet is closest to Earth and hence is most easily visible, which occur every couple of years. Even more notable are the perihelic oppositions of Mars, which are distinguished because Mars is close to perihelion, making it even closer to Earth. The ancient Sumerians named Mars Nergal, the god of war and plague. During Sumerian times, Nergal was a minor deity of little significance, but, during later times, his main cult center was the city of Nineveh. In Mesopotamian texts, Mars is referred to as the "star of judgement of the fate of the dead". The existence of Mars as a wandering object in the night sky was also recorded by the ancient Egyptian astronomers and, by 1534 BCE, they were familiar with the retrograde motion of the planet. By the period of the Neo-Babylonian Empire, the Babylonian astronomers were making regular records of the positions of the planets and systematic observations of their behavior. For Mars, they knew that the planet made 37 synodic periods, or 42 circuits of the zodiac, every 79 years. They invented arithmetic methods for making minor corrections to the predicted positions of the planets. In Ancient Greece, the planet was known as Πυρόεις. Commonly, the Greek name for the planet now referred to as Mars, was Ares. It was the Romans who named the planet Mars, for their god of war, often represented by the sword and shield of the planet's namesake. In the fourth century BCE, Aristotle noted that Mars disappeared behind the Moon during an occultation, indicating that the planet was farther away. Ptolemy, a Greek living in Alexandria, attempted to address the problem of the orbital motion of Mars. Ptolemy's model and his collective work on astronomy was presented in the multi-volume collection later called the Almagest (from the Arabic for "greatest"), which became the authoritative treatise on Western astronomy for the next fourteen centuries. Literature from ancient China confirms that Mars was known by Chinese astronomers by no later than the fourth century BCE. In the East Asian cultures, Mars is traditionally referred to as the "fire star" (火星) based on the Wuxing system. In 1609 Johannes Kepler published a 10 year study of Martian orbit, using the diurnal parallax of Mars, measured by Tycho Brahe, to make a preliminary calculation of the relative distance to the planet. From Brahe's observations of Mars, Kepler deduced that the planet orbited the Sun not in a circle, but in an ellipse. Moreover, Kepler showed that Mars sped up as it approached the Sun and slowed down as it moved farther away, in a manner that later physicists would explain as a consequence of the conservation of angular momentum.: 433–437 In 1610 the first use of a telescope for astronomical observation, including Mars, was performed by Italian astronomer Galileo Galilei. With the telescope the diurnal parallax of Mars was again measured in an effort to determine the Sun-Earth distance. This was first performed by Giovanni Domenico Cassini in 1672. The early parallax measurements were hampered by the quality of the instruments. The only occultation of Mars by Venus observed was that of 13 October 1590, seen by Michael Maestlin at Heidelberg. By the 19th century, the resolution of telescopes reached a level sufficient for surface features to be identified. On 5 September 1877, a perihelic opposition to Mars occurred. The Italian astronomer Giovanni Schiaparelli used a 22-centimetre (8.7 in) telescope in Milan to help produce the first detailed map of Mars. These maps notably contained features he called canali, which, with the possible exception of the natural canyon Valles Marineris, were later shown to be an optical illusion. These canali were supposedly long, straight lines on the surface of Mars, to which he gave names of famous rivers on Earth. His term, which means "channels" or "grooves", was popularly mistranslated in English as "canals". Influenced by the observations, the orientalist Percival Lowell founded an observatory which had 30- and 45-centimetre (12- and 18-in) telescopes. The observatory was used for the exploration of Mars during the last good opportunity in 1894, and the following less favorable oppositions. He published several books on Mars and life on the planet, which had a great influence on the public. The canali were independently observed by other astronomers, like Henri Joseph Perrotin and Louis Thollon in Nice, using one of the largest telescopes of that time. The seasonal changes (consisting of the diminishing of the polar caps and the dark areas formed during Martian summers) in combination with the canals led to speculation about life on Mars, and it was a long-held belief that Mars contained vast seas and vegetation. As bigger telescopes were used, fewer long, straight canali were observed. During observations in 1909 by Antoniadi with an 84-centimetre (33 in) telescope, irregular patterns were observed, but no canali were seen. The first spacecraft from Earth to visit Mars was Mars 1 of the Soviet Union, which flew by in 1963, but contact was lost en route. NASA's Mariner 4 followed and became the first spacecraft to successfully transmit from Mars; launched on 28 November 1964, it made its closest approach to the planet on 15 July 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth, and captured the first images of another planet from deep space. Once spacecraft visited the planet during the 1960s and 1970s, many previous concepts of Mars were radically broken. After the results of the Viking life-detection experiments, the hypothesis of a dead planet was generally accepted. The data from Mariner 9 and Viking allowed better maps of Mars to be made. Until 1997 and after Viking 1 shut down in 1982, Mars was only visited by three unsuccessful probes, two flying past without contact (Phobos 1, 1988; Mars Observer, 1993), and one (Phobos 2 1989) malfunctioning in orbit before reaching its destination Phobos. In 1997 Mars Pathfinder became the first successful rover mission beyond the Moon and started together with Mars Global Surveyor (operated until late 2006) an uninterrupted active robotic presence at Mars that has lasted until today. It produced complete, extremely detailed maps of the Martian topography, magnetic field and surface minerals. Starting with these missions a range of new improved crewless spacecraft, including orbiters, landers, and rovers, have been sent to Mars, with successful missions by the NASA (United States), Jaxa (Japan), ESA, United Kingdom, ISRO (India), Roscosmos (Russia), the United Arab Emirates, and CNSA (China) to study the planet's surface, climate, and geology, uncovering the different elements of the history and dynamic of the hydrosphere of Mars and possible traces of ancient life. As of 2023[update], Mars is host to ten functioning spacecraft. Eight are in orbit: 2001 Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, MAVEN, ExoMars Trace Gas Orbiter, the Hope orbiter, and the Tianwen-1 orbiter. Another two are on the surface: the Mars Science Laboratory Curiosity rover and the Perseverance rover. Collected maps are available online at websites including Google Mars. NASA provides two online tools: Mars Trek, which provides visualizations of the planet using data from 50 years of exploration, and Experience Curiosity, which simulates traveling on Mars in 3-D with Curiosity. Planned missions to Mars include: As of February 2024[update], debris from these types of missions has reached over seven tons. Most of it consists of crashed and inactive spacecraft as well as discarded components. In April 2024, NASA selected several companies to begin studies on providing commercial services to further enable robotic science on Mars. Key areas include establishing telecommunications, payload delivery and surface imaging. Habitability and habitation During the late 19th century, it was widely accepted in the astronomical community that Mars had life-supporting qualities, including the presence of oxygen and water. However, in 1894 W. W. Campbell at Lick Observatory observed the planet and found that "if water vapor or oxygen occur in the atmosphere of Mars it is in quantities too small to be detected by spectroscopes then available". That observation contradicted many of the measurements of the time and was not widely accepted. Campbell and V. M. Slipher repeated the study in 1909 using better instruments, but with the same results. It was not until the findings were confirmed by W. S. Adams in 1925 that the myth of the Earth-like habitability of Mars was finally broken. However, even in the 1960s, articles were published on Martian biology, putting aside explanations other than life for the seasonal changes on Mars. The current understanding of planetary habitability – the ability of a world to develop environmental conditions favorable to the emergence of life – favors planets that have liquid water on their surface. Most often this requires the orbit of a planet to lie within the habitable zone, which for the Sun is estimated to extend from within the orbit of Earth to about that of Mars. During perihelion, Mars dips inside this region, but Mars's thin (low-pressure) atmosphere prevents liquid water from existing over large regions for extended periods. The past flow of liquid water demonstrates the planet's potential for habitability. Recent evidence has suggested that any water on the Martian surface may have been too salty and acidic to support regular terrestrial life. The environmental conditions on Mars are a challenge to sustaining organic life: the planet has little heat transfer across its surface, it has poor insulation against bombardment by the solar wind due to the absence of a magnetosphere and has insufficient atmospheric pressure to retain water in a liquid form (water instead sublimes to a gaseous state). Mars is nearly, or perhaps totally, geologically dead; the end of volcanic activity has apparently stopped the recycling of chemicals and minerals between the surface and interior of the planet. Evidence suggests that the planet was once significantly more habitable than it is today, but whether living organisms ever existed there remains unknown. The Viking probes of the mid-1970s carried experiments designed to detect microorganisms in Martian soil at their respective landing sites and had positive results, including a temporary increase in CO2 production on exposure to water and nutrients. This sign of life was later disputed by scientists, resulting in a continuing debate, with NASA scientist Gilbert Levin asserting that Viking may have found life. A 2014 analysis of Martian meteorite EETA79001 found chlorate, perchlorate, and nitrate ions in sufficiently high concentrations to suggest that they are widespread on Mars. UV and X-ray radiation would turn chlorate and perchlorate ions into other, highly reactive oxychlorines, indicating that any organic molecules would have to be buried under the surface to survive. Small quantities of methane and formaldehyde detected by Mars orbiters are both claimed to be possible evidence for life, as these chemical compounds would quickly break down in the Martian atmosphere. Alternatively, these compounds may instead be replenished by volcanic or other geological means, such as serpentinite. Impact glass, formed by the impact of meteors, which on Earth can preserve signs of life, has also been found on the surface of the impact craters on Mars. Likewise, the glass in impact craters on Mars could have preserved signs of life, if life existed at the site. The Cheyava Falls rock discovered on Mars in June 2024 has been designated by NASA as a "potential biosignature" and was core sampled by the Perseverance rover for possible return to Earth and further examination. Although highly intriguing, no definitive final determination on a biological or abiotic origin of this rock can be made with the data currently available. Several plans for a human mission to Mars have been proposed, but none have come to fruition. The NASA Authorization Act of 2017 directed NASA to study the feasibility of a crewed Mars mission in the early 2030s; the resulting report concluded that this would be unfeasible. In addition, in 2021, China was planning to send a crewed Mars mission in 2033. Privately held companies such as SpaceX have also proposed plans to send humans to Mars, with the eventual goal to settle on the planet. As of 2024, SpaceX has proceeded with the development of the Starship launch vehicle with the goal of Mars colonization. In plans shared with the company in April 2024, Elon Musk envisions the beginning of a Mars colony within the next twenty years. This would be enabled by the planned mass manufacturing of Starship and initially sustained by resupply from Earth, and in situ resource utilization on Mars, until the Mars colony reaches full self sustainability. Any future human mission to Mars will likely take place within the optimal Mars launch window, which occurs every 26 months. The moon Phobos has been proposed as an anchor point for a space elevator. Besides national space agencies and space companies, groups such as the Mars Society and The Planetary Society advocate for human missions to Mars. In culture Mars is named after the Roman god of war (Greek Ares), but was also associated with the demi-god Heracles (Roman Hercules) by ancient Greek astronomers, as detailed by Aristotle. This association between Mars and war dates back at least to Babylonian astronomy, in which the planet was named for the god Nergal, deity of war and destruction. It persisted into modern times, as exemplified by Gustav Holst's orchestral suite The Planets, whose famous first movement labels Mars "The Bringer of War". The planet's symbol, a circle with a spear pointing out to the upper right, is also used as a symbol for the male gender. The symbol dates from at least the 11th century, though a possible predecessor has been found in the Greek Oxyrhynchus Papyri. The idea that Mars was populated by intelligent Martians became widespread in the late 19th century. Schiaparelli's "canali" observations combined with Percival Lowell's books on the subject put forward the standard notion of a planet that was a drying, cooling, dying world with ancient civilizations constructing irrigation works. Many other observations and proclamations by notable personalities added to what has been termed "Mars Fever". In the present day, high-resolution mapping of the surface of Mars has revealed no artifacts of habitation, but pseudoscientific speculation about intelligent life on Mars still continues. Reminiscent of the canali observations, these speculations are based on small scale features perceived in the spacecraft images, such as "pyramids" and the "Face on Mars". In his book Cosmos, planetary astronomer Carl Sagan wrote: "Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears." The depiction of Mars in fiction has been stimulated by its dramatic red color and by nineteenth-century scientific speculations that its surface conditions might support not just life but intelligent life. This gave way to many science fiction stories involving these concepts, such as H. G. Wells's The War of the Worlds, in which Martians seek to escape their dying planet by invading Earth; Ray Bradbury's The Martian Chronicles, in which human explorers accidentally destroy a Martian civilization; as well as Edgar Rice Burroughs's series Barsoom, C. S. Lewis's novel Out of the Silent Planet (1938), and a number of Robert A. Heinlein stories before the mid-sixties. Since then, depictions of Martians have also extended to animation. A comic figure of an intelligent Martian, Marvin the Martian, appeared in Haredevil Hare (1948) as a character in the Looney Tunes animated cartoons of Warner Brothers, and has continued as part of popular culture to the present. After the Mariner and Viking spacecraft had returned pictures of Mars as a lifeless and canal-less world, these ideas about Mars were abandoned; for many science-fiction authors, the new discoveries initially seemed like a constraint, but eventually the post-Viking knowledge of Mars became itself a source of inspiration for works like Kim Stanley Robinson's Mars trilogy. See also Notes References Further reading External links Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Local Volume → Virgo Supercluster → Laniakea Supercluster → Pisces–Cetus Supercluster Complex → Local Hole → Observable universe → UniverseEach arrow (→) may be read as "within" or "part of". |
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[SOURCE: https://en.wikipedia.org/wiki/Memory_Card] | [TOKENS: 1199] |
Contents Memory card A memory card is an electronic data storage device used for storing digital information, typically using flash memory. These are commonly used in digital portable electronic devices, such as digital cameras as well as in many early games consoles such as the Neo Geo. They allow adding memory to such devices using a card in a socket instead of protruding USB flash drives. Common types of flash memory card include SD cards (including microSD), Sony's Memory Stick and CompactFlash. As of 2024[update], SD cards are the most common type of memory cards. History The basis for memory card technology is flash memory. It was invented by Fujio Masuoka at Toshiba in 1980 and commercialized by Toshiba in 1987. The development of memory cards was driven in the 1980s by the need for an alternative to floppy disk drives that had lower power consumption, had less weight and occupied less volume in laptops. Some were also marketed as a lower cost alternative to ROM cartridges. Several competing and incompatible memory card formats were developed by several vendors, such as for example the Bee Card, Astron SoftCard, Sega Cards, NEC UltraLite memory cards, and the Mitsubishi Melcard which came in variants using 60 and 50 connector pins. The Sega Card was developed as a cheaper alternative to game cartridges. Some memory cards were used for memory expansion in laptops. JEIDA, the Japan Electronic Industry Development Association, began to work on a standard for memory cards in 1985, and developed the JEIDA memory card in 1986. The Personal Computer Memory Card International Association (PCMCIA) was an industry association created in 1989 to promote a standard for memory cards in PCs, and worked closely with JEIDA, adopting their 68 pin connector design. The specification for PCMCIA type I cards, later renamed PC Cards, was first released in 1990, and unified the JEIDA memory card standard with the PC Card standard. This format later included support for other devices besides memory cards. PC Card was among the first commercial memory card formats to come out, but is mainly used in industrial applications and to connect I/O devices such as modems. Some early memory cards used SRAM as a storage medium, which required a lithium battery to keep the contents in the SRAM. These cards were faster than their flash counterparts. Some of the first PCMCIA cards had capacities of 1 to 5 MB and cost US$100 per MB. Other early cards such as the Bee Card contained non-modifiable ROM, Write once read many EPROM or rewriteable EEPROM memory. In 1992, SanDisk introduced FlashDisk, a PCMCIA card and one of the first memory cards that did not require battery power to retain its contents, as it used flash memory. In 1994, memory card formats smaller than the PC Card arrived. The first one was CompactFlash and later SmartMedia and Miniature Card. The desire for smaller cards for cell-phones, PDAs, and compact digital cameras drove a trend that left the previous generation of "compact" cards looking big. In 2000 the SD card was announced. SD was envisioned as a single memory card format for several kinds of electronic devices, that could also function as an expansion slot for adding new capabilities for a device. In 2001, SmartMedia alone captured 50% of the digital camera market and CF had captured the professional digital camera market. However, by 2005, SD and similar MMC cards had nearly taken over SmartMedia's spot, though not to the same level and with stiff competition coming from Memory Stick variants, as well as CompactFlash. In industrial and embedded fields, even the venerable PC card (PCMCIA) memory cards still manage to maintain a niche, while in mobile phones and PDAs, the memory card has become smaller.[citation needed] Initially memory cards were expensive, costing US$3 per megabyte of capacity in 2001; this led to the development of miniaturized rotating disk memory devices such as the Microdrive, PocketZip and Dataplay. The Microdrive had higher capacities than memory cards at the time. All three concepts became obsolete once flash memory prices became lower and their capacities became higher by 2006. New products of Sony (previously only using Memory Stick) and Olympus (previously only using XD-Card) have been offered with an additional SD-Card slot beginning in 2010. Effectively, the format war has turned in SD-Card's favor. Data table of selected memory card formats Overview of all memory card types (full-duplex) Video game consoles Many older video game consoles used memory cards to hold saved game data. Cartridge-based systems primarily used battery-backed volatile RAM within each individual cartridge to hold saves for that game. Cartridges without this RAM may have used a password system, or would not save progress at all. The Neo Geo AES, released in 1990 by SNK, was the first video game console able to use a memory card. AES memory cards were also compatible with Neo Geo MVS arcade cabinets, allowing players to migrate saves between home and arcade systems and vice versa. Memory cards became commonplace when home consoles moved to read-only optical discs for storing the game program, beginning with systems such as the TurboGrafx-CD and Sega-CD. Until the sixth generation of video game consoles, memory cards were based on proprietary formats; Later systems used established industry formats for memory cards, such as FAT32. Home consoles commonly use hard disk drive storage for saved games and allow the use of USB flash drives or other card formats via a memory card reader to transport game saves and other game information. Though some consoles have implemented cloud storage saving, most portable gaming systems still rely on custom memory cartridges to store program data, due to their low power consumption, smaller physical size and reduced mechanical complexity. See also References |
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[SOURCE: https://en.wikipedia.org/wiki/S/SL_programming_language] | [TOKENS: 381] |
Contents S/SL programming language The Syntax/Semantic Language (S/SL) is an executable high level specification language for recursive descent parsers, semantic analyzers and code generators developed by James Cordy, Ric Holt and David Wortman at the University of Toronto in 1980. S/SL is a small programming language that supports cheap recursion and defines input, output, and error token names (& values), semantic mechanisms (class interfaces whose methods are really escapes to routines in a host programming language but allow good abstraction in the pseudocode) and a pseudocode program that defines the syntax of the input language by the token stream the program accepts. Alternation, control flow and one-symbol look-ahead constructs are part of the language. The S/SL processor compiles this pseudocode into a table (byte-codes) that is interpreted by the S/SL table-walker (interpreter). The pseudocode language processes the input language in LL(1) recursive descent style but extensions allow it to process any LR(k) language relatively easily. S/SL is designed to provide excellent syntax error recovery and repair. It is more powerful and transparent than Yacc but can be slower. S/SL's "semantic mechanisms" extend its capabilities to all phases of compiling, and it has been used to implement all phases of compilation, including scanners, parsers, semantic analyzers, code generators and virtual machine interpreters in multi-pass language processors. S/SL has been used to implement production commercial compilers for languages such as PL/I, Euclid, Turing, Ada, and COBOL, as well as interpreters, command processors, and domain specific languages of many kinds. It is the primary technology used in IBM's ILE/400 COBOL compiler, and the ZMailer mail transfer agent uses S/SL for defining both its mail router processing language and its RFC 822 email address validation. References |
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[SOURCE: https://en.wikipedia.org/wiki/Ministry_of_Education_(Israel)#bodyContent] | [TOKENS: 543] |
Contents Ministry of Education (Israel) The Ministry of Education (Hebrew: מִשְׂרָד הַחִנּוּךְ, translit. Misrad HaHinukh; Arabic: وزارة التربية والتعليم) is the branch of the Israeli government charged with overseeing public education institutions in Israel. The department is headed by the Minister of Education, who is a member of the cabinet. The ministry has previously included culture and sport, although this is now covered by the Ministry of Culture and Sport. History In the first decade of statehood, the education system was faced with the task of establishing a network of kindergartens and schools for a rapidly growing student population. In 1949, there were 80,000 elementary school students. By 1950, there were 120,000 - an increase of 50 percent within the span of one year. Israel also took over responsibility for the education of Arab schoolchildren. The first minister of education was Zalman Shazar, later president of the State of Israel. Since 2002, the Ministry of Education has awarded a National Education Award to five top localities in recognizing excellence in investing substantial resources in the educational system. In 2012, first place was awarded to the Shomron Regional Council and followed by Or Yehuda, Tiberias, Eilat and Beersheba. The prize has been awarded to a variety of educational institutions including kindergartens and elementary schools. In 2013–2014, the Ministry of Education promoted the regulation of the activities of external parties within the state schools, in a dialogue between the Ministry, the local government, parents' representatives, the business sector and philanthropic parties, as part of what was called "the intersectoral round table in the Ministry of Education". As part of the regulation, the Ministry compiled a database of external programs that have some kind of partnership with a representative from the Ministry of Education's headquarters. In 2019, a petition was filed by pluralist Jewish organizations against the Ministry of Education due to a procedure that reduces by tens of thousands of shekels the support for the activities of these organizations in schools. In April 2021, the High Court invalidated the procedure in question, and even emphasized the importance of implementing the principles of the Shanhar Committee report on the teaching of Judaism in state education. In November 2021 it was announced that the Ministry of Education is not implementing the High Court ruling and that the damage to those organizations continues. List of ministers References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Data_security] | [TOKENS: 2138] |
Contents Data security Data security or data protection is the process of securing digital information to protect it from online threats. Data security or protection means protecting digital data, such as those in a database, from destructive forces and from the unwanted actions of unauthorized users, such as a cyberattack or a data breach. Data security protects computer hardware, software, storage devices, and the data of user devices. Data security also protects the data of organizations, companies and administrative controls. Data security guarantees the protection of individual data, such as identity documents and bank data, and protects against unauthorized access, theft and loss of individual data. Data security also protects data breaches that occurs in companies and industries. Good security measures in industries reduce the probability of data breaches, and employees can rely on the company with their data and private information to be kept secured while companies can continue to maintain a stable reputation. The CIA Triad (Confidentiality, Integrity, and Availability) is what is used to practice what an information security is required to follow. Confidentiality, protects information from being accessed by unauthorized persons. Integrity, makes sure data is trustworthy; and Availability, meaning that data can be accessed by approved users when it is needed; are three goals for data security. Non-repudiation in data security definition, is a device/service that shows where the data originated from and the proof of integrity. Technologies Disk encryption refers to encryption technology that encrypts data on a hard disk drive. It takes data from a storage device and coverts it into an unreadable format. Disk encryption typically takes form in either software (see disk encryption software) or hardware (see disk encryption hardware) which can be used together. Disk encryption is often referred to as on-the-fly encryption (OTFE) or transparent encryption. Full disk encryption encrypts each individual sector of a disk volume. Files and user data are encrypted to hinder unauthorized users from accessing without a decryption key. A diversifier permits a plaintext of a specific disk sector to be encrypted into different ciphertexts, which does not require additional storage, such as an initialization vector (IV) or message authentication code (MAC). Software-based security solutions encrypt the data to protect it from theft. However, a malicious program or a hacker could corrupt the data to make it unrecoverable, making the system unusable. Hardware-based security solutions prevent read and write access to data, which provides very strong protection against tampering and unauthorized access. Hardware-based security or assisted computer security offers an alternative to software-only computer security. Security tokens such as those using PKCS#11 or a mobile phone may be more secure due to the physical access required in order to be compromised. Access is enabled only when the token is connected and the correct PIN is entered (see two-factor authentication). However, dongles can be used by anyone who can gain physical access to it. Newer technologies in hardware-based security solve this problem by offering full proof of security for data. Working off hardware-based security: A hardware device allows a user to log in, log out and set different levels through manual actions. Many devices use biometric technology to prevent malicious users from logging in, logging out, and changing privilege levels. The current state of a user of the device is read by controllers in peripheral devices such as hard disks. Illegal access by a malicious user or a malicious program is interrupted based on the current state of a user by hard disk and DVD controllers making illegal access to data impossible. Hardware-based access control is more secure than the protection provided by the operating systems as operating systems are vulnerable to malicious attacks by viruses and hackers. The data on hard disks can be corrupted after malicious access is obtained. With hardware-based protection, the software cannot manipulate the user privilege levels. A hacker or a malicious program cannot gain access to secure data protected by hardware or perform unauthorized privileged operations. This assumption is broken only if the hardware itself is malicious or contains a backdoor. The hardware protects the operating system image and file system privileges from being tampered with. Therefore, a completely secure system can be created using a combination of hardware-based security and secure system administration policies. Backup is the process of reproducing copies of essential data and storing in a separate, secured place. It is used to ensure data that is lost can be recovered from another source. Backups contains a minimum of one copy of the data that requires preservation. It is considered essential to keep a backup of any data in most industries and the process is recommended for any files of importance to a user. There are 3 types of backups; full backups, incremental backups, and differential backups. Full backups secure all data from a production system, such as a server, database, or other connected data source. It is impossible to lose all data in a full backup if a breach or corruption were to occur. Full backups require a significantly large amount of time to back up and may be time-consuming taking hours to days to complete. Incremental backups only secures changed data since last backup. While all backups are done in full backups, incremental backups only save data that is recently or frequently changed. Incremental backups require lower storage costs making it a prominent solution for growing datasets. Data privacy (or information privacy) is the right for individual's data to be secured to obstruct the use of unauthorized access. It gives individuals control over their data and how it can be shared to third parties. The U.S Privacy Protection Law (see Privacy laws of the United States) requires organizations to inform individuals of how their data is collected and when a data breach occurs. By implementing an encryption, it ensures that private data is unreadable to cybercriminals. Data masking of structured data is the process of obscuring (masking) specific data within a database table or cell to ensure that data security is maintained and sensitive information is not exposed to unauthorized personnel. This may include masking the data from users (for example so banking customer representatives can only see the last four digits of a customer's national identity number), developers (who need real production data to test new software releases but should not be able to see sensitive financial data), outsourcing vendors, etc. Data masking is a form of encryption, as it obscures data by modifying particular letters and numbers to keep data concealed and protected from potential hackers. The individual that has access to the code that decrypts the replaced characters are the only ones that can uncover the data. Data erasure (or data deletion, data destruction) is a method of software-based overwriting that permanently clears all electronic data residing on a hard drive or other digital media to ensure that no sensitive data is lost when an asset is retired or reused. Article 17: Right to be Forgotten states that users have the right to permanently remove all of their private information from their old devices/services to give people more control over their data. Users are able to switch between devices efficiently. Threats Malware (or malicious software) is designed to destroy, corrupt or gain unauthorized access to a computer for the purpose of stealing, or destroying data. Hackers who use malware typically utilize many types of malware, which includes computer virus, computer worms, ransomware, spyware and Trojan horse to create a vast system of disruption and cause easy data theft. One of the victims of the vast system of disruption includes healthcare workers, who are targeted by compromised systems by infections and then having their data attacked. Phishing is a type of scam that allows hackers to hoax people using psychological and social engineering (using human emotions such as their trust and fear) tactics into giving personal data through emails and messages, and install computer viruses if the individual were to click on a malicious link unknowingly. Attackers are able to create websites that are very similar to original websites, which makes it difficult to detect a fake website, causing individuals to fall for giving in information. Phishing attackers use human emotion to exploit them, such as making them feel fear, urgency, sympathy with the message being sent by the sender. Emails (Or Email spoofing) with impersonated companies and fake websites copying the original are ways to exploit people. Email spoofing show false names and emails of the original ones to copy several banks, companies and agencies, using warnings to manipulate people into feeling urgent about the email. International laws and standards In the UK, the Data Protection Act is used to ensure that personal data is accessible to those whom it concerns, and provides redress to individuals if there are inaccuracies. This is particularly important to ensure individuals are treated fairly, for example for credit checking purposes. The Data Protection Act states that only individuals and companies with legitimate and lawful reasons can process personal information and cannot be shared. Data Privacy Day is an international holiday started by the Council of Europe that occurs every January 28. Since the General Data Protection Regulation (GDPR) of the European Union (EU) became law on May 25, 2018, organizations may face significant penalties of up to €20 million or 4% of their annual revenue if they do not comply with the regulation. It is intended that GDPR will force organizations to understand their data privacy risks and take the appropriate measures to reduce the risk of unauthorized disclosure of consumers’ private information. The international standards ISO/IEC 27001:2013 and ISO/IEC 27002:2013 cover data security under the topic of information security, and one of its cardinal principles is that all stored information, i.e. data, should be owned so that it is clear whose responsibility it is to protect and control access to that data. The following are examples of organizations that help strengthen and standardize computing security: The Trusted Computing Group is an organization that helps standardize computing security technologies. The Payment Card Industry Data Security Standard (PCI DSS) is a proprietary international information security standard for organizations that handle cardholder information for the major debit, credit, prepaid, e-purse, automated teller machines, and point of sale cards. The General Data Protection Regulation (GDPR) proposed by the European Commission will strengthen and unify data protection for individuals within the EU, whilst addressing the export of personal data outside the EU. Safeguards The four types of technical safeguards are access controls, flow controls, inference controls, and data encryption. Access controls manage user entry and data manipulation, while flow controls regulate data dissemination. Inference controls prevent deduction of confidential information from statistical databases and data encryption prevents unauthorized access to confidential information. Health Insurance Portability and Accountability Act (HIPPA) is a law that requires entities such as healthcare providers to keep patient confidentiality for three required safeguards: administrative, physical, and technical. See also References External links |
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