Spirit known as MER-A or MER-2, is a robotic rover on Mars, active from 2004 to 2010. It was one of two rovers of NASA's Mars Exploration Rover Mission, it landed on Mars at 04:35 Ground UTC on January 4, 2004, three weeks before its twin, which landed on the other side of the planet. Its name was chosen through a NASA-sponsored student essay competition; the rover became stuck in a "sand trap" in late 2009 at an angle that hampered recharging of its batteries. The rover completed its planned 90-sol mission. Aided by cleaning events that resulted in more energy from its solar panels, Spirit went on to function over twenty times longer than NASA planners expected. Spirit logged 7.73 km of driving instead of the planned 600 m, allowing more extensive geological analysis of Martian rocks and planetary surface features. Initial scientific results from the first phase of the mission were published in a special issue of the journal Science. On May 1, 2009, Spirit became stuck in soft soil; this was not the first of the mission's "embedding events" and for the following eight months NASA analyzed the situation, running Earth-based theoretical and practical simulations, programming the rover to make extrication drives in an attempt to free itself.
These efforts continued until January 26, 2010 when NASA officials announced that the rover was irrecoverably obstructed by its location in soft soil, though it continued to perform scientific research from its current location. The rover continued in a stationary science platform role until communication with Spirit stopped on March 22, 2010. JPL continued to attempt to regain contact until May 24, 2011, when NASA announced that efforts to communicate with the unresponsive rover had ended, calling the mission complete. A formal farewell took place at NASA headquarters shortly thereafter; the Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Office of Space Science, Washington. The primary surface mission for Spirit was planned to last at least 90 sols; the mission lasted about 2,208 sols. On August 11, 2007, Spirit obtained the second longest operational duration on the surface of Mars for a lander or rover at 1282 Sols, one sol longer than the Viking 2 lander.
Viking 2 was powered by a nuclear cell. Until Opportunity overtook it on May 19, 2010, the Mars probe with longest operational period was Viking 1 that lasted for 2245 Sols on the surface of Mars. On March 22, 2010, Spirit sent its last communication, thus falling just over a month short of surpassing Viking 1's operational record. An archive of weekly updates on the rover's status can be found at the Spirit Update Archive. Spirit's total odometry as of March 22, 2010 is 7,730.50 meters. The scientific objectives of the Mars Exploration Rover mission were to: Search for and characterize a variety of rocks and soils that hold clues to past water activity. In particular, samples sought will include those that have minerals deposited by water-related processes such as precipitation, sedimentary cementation or hydrothermal activity. Determine the distribution and composition of minerals and soils surrounding the landing sites. Determine what geologic processes have shaped the local terrain and influenced the chemistry.
Such processes could include water or wind erosion, hydrothermal mechanisms and cratering. Perform calibration and validation of surface observations made by Mars Reconnaissance Orbiter instruments; this will help determine the accuracy and effectiveness of various instruments that survey Martian geology from orbit. Search for iron-containing minerals and quantify relative amounts of specific mineral types that contain water or were formed in water, such as iron-bearing carbonates. Characterize the mineralogy and textures of rocks and soils and determine the processes that created them. Search for geological clues to the environmental conditions that existed when liquid water was present. Assess whether those environments were conducive to life. NASA sought evidence of life on Mars, beginning with the question of whether the Martian environment was suitable for life. Life forms known to science require water, so the history of water on Mars is a critical piece of knowledge. Although the Mars Exploration Rovers did not have the ability to detect life directly, they offered important information on the habitability of the environment during the planet's history.
Spirit are six-wheeled, solar-powered robots standing 1.5 meters high, 2.3 meters wide and 1.6 meters long and weighing 180 kilograms. Six wheels on a rocker-bogie system enable mobility over rough terrain; each wheel has its own motor. The vehicle is steered at front and rear and is designed to operate safely at tilts of up to 30 degrees. Maximum speed is 5 centimeters per second. Both Spirit and Opportunity have pieces of the fallen World Trade Center's metal on them that were "turned into shields to protect cables on the drilling mechanisms". Solar arrays generate about 140 watts for up to four hours per Martian day while rechargeable lithium ion batteries store energy for use at night. Spirit's onboard computer uses a 20 MHz RAD6000 CPU with 128 MB of DRAM, 3 MB o
Three Laws of Robotics
The Three Laws of Robotics are a set of rules devised by the science fiction author Isaac Asimov. The rules were introduced in his 1942 short story "Runaround", although they had been foreshadowed in a few earlier stories; the Three Laws, quoted as being from the "Handbook of Robotics, 56th Edition, 2058 A. D.", are: These form an organizing principle and unifying theme for Asimov's robotic-based fiction, appearing in his Robot series, the stories linked to it, his Lucky Starr series of young-adult fiction. The Laws are incorporated into all of the positronic robots appearing in his fiction, cannot be bypassed, being intended as a safety feature. Many of Asimov's robot-focused stories involve robots behaving in unusual and counter-intuitive ways as an unintended consequence of how the robot applies the Three Laws to the situation in which it finds itself. Other authors working in Asimov's fictional universe have adopted them and references parodic, appear throughout science fiction as well as in other genres.
The original laws have been elaborated on by Asimov and other authors. Asimov himself made slight modifications to the first three in various books and short stories to further develop how robots would interact with humans and each other. In fiction where robots had taken responsibility for government of whole planets and human civilizations, Asimov added a fourth, or zeroth law, to precede the others: A robot may not harm humanity, or, by inaction, allow humanity to come to harm; the Three Laws, the zeroth, have pervaded science fiction and are referred to in many books and other media. They have impacted thought on ethics of artificial intelligence as well. In The Rest of the Robots, published in 1964, Asimov noted that when he began writing in 1940 he felt that "one of the stock plots of science fiction was... robots were created and destroyed their creator. Knowledge has its dangers, but is the response to be a retreat from knowledge? Or is knowledge to be used as itself a barrier to the dangers it brings?"
He decided that in his stories a robot would not "turn stupidly on his creator for no purpose but to demonstrate, for one more weary time, the crime and punishment of Faust."On May 3, 1939, Asimov attended a meeting of the Queens Science Fiction Society where he met Earl and Otto Binder who had published a short story "I, Robot" featuring a sympathetic robot named Adam Link, misunderstood and motivated by love and honor. Asimov admired the story. Three days Asimov began writing "my own story of a sympathetic and noble robot", his 14th story. Thirteen days he took "Robbie" to John W. Campbell the editor of Astounding Science-Fiction. Campbell rejected it, claiming that it bore too strong a resemblance to Lester del Rey's "Helen O'Loy", published in December 1938—the story of a robot, so much like a person that she falls in love with her creator and becomes his ideal wife. Frederik Pohl published the story under the title “Strange Playfellow” in Super Science Stories September 1940. Asimov attributes the Three Laws to John W. Campbell, from a conversation that took place on 23 December 1940.
Campbell claimed that Asimov had the Three Laws in his mind and that they needed to be stated explicitly. Several years Asimov's friend Randall Garrett attributed the Laws to a symbiotic partnership between the two men – a suggestion that Asimov adopted enthusiastically. According to his autobiographical writings, Asimov included the First Law's "inaction" clause because of Arthur Hugh Clough's poem "The Latest Decalogue", which includes the satirical lines "Thou shalt not kill, but needst not strive / officiously to keep alive". Although Asimov pins the creation of the Three Laws on one particular date, their appearance in his literature happened over a period, he wrote two robot stories with no explicit mention of the Laws, "Robbie" and "Reason". He assumed, that robots would have certain inherent safeguards. "Liar!", his third robot story, makes the first mention of the First Law but not the other two. All three laws appeared together in "Runaround"; when these stories and several others were compiled in the anthology I, Robot, "Reason" and "Robbie" were updated to acknowledge all the Three Laws, though the material Asimov added to "Reason" is not consistent with the Three Laws as he described them elsewhere.
In particular the idea of a robot protecting human lives when it does not believe those humans exist is at odds with Elijah Baley's reasoning, as described below. During the 1950s Asimov wrote a series of science fiction novels expressly intended for young-adult audiences, his publisher expected that the novels could be adapted into a long-running television series, something like The Lone Ranger had been for radio. Fearing that his stories would be adapted into the "uniformly awful" programming he saw flooding the television channels Asimov decided to publish the Lucky Starr books under the pseudonym "Paul French"; when plans for the television series fell through, Asimov decided to abandon the pretence. In his short story "Evidence" Asimov lets his recurring character Dr. Susan Calvin expound a moral basis behind the Three Laws. Calvin points out that human beings are expected to refrain from harming other human beings (except in times of extreme d
Proprioception, is the sense of self-movement and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by mechanically-sensitive proprioceptor neurons distributed throughout an animal's body. Most vertebrates possess three basic types of proprioceptors: muscle spindles, which are embedded in skeletal muscle fibers, Golgi tendon organs, which lie at the interface of muscles and tendons, joint receptors, which are low-threshold mechanoreceptors embedded in joint capsules. Many invertebrates, such as insects possess three basic proprioceptor types with analogous functional properties: chordotonal neurons, campaniform sensilla, hair plates; the central nervous system integrates information from proprioception and other sensory systems, such as vision and the vestibular system, to create an overall representation of body position and acceleration. The sense of proprioception is ubiquitous across mobile animals, is essential for the motor coordination of the body.
More proprioception has been described in flowering land plants. Proprioception is from Latin proprius, meaning "one's own", "individual", capio, capere, to take or grasp, thus to grasp one's own position in space, including the position of the limbs in relation to each other and the body as a whole. The word kinesthesia or kinæsthesia refers to movement sense, but has been used inconsistently to refer either to proprioception alone or to the brain's integration of proprioceptive and vestibular inputs. Kinesthesia is a modern medical term composed of elements from Greek; the position-movement sensation was described in 1557 by Julius Caesar Scaliger as a "sense of locomotion". Much in 1826, Charles Bell expounded the idea of a "muscle sense", credited as one of the first descriptions of physiologic feedback mechanisms. Bell's idea was that commands are carried from the brain to the muscles, that reports on the muscle's condition would be sent in the reverse direction. In 1847 the London neurologist Robert Todd highlighted important differences in the anterolateral and posterior columns of the spinal cord, suggested that the latter were involved in the coordination of movement and balance.
At around the same time, Moritz Heinrich Romberg, a Berlin neurologist, was describing unsteadiness made worse by eye closure or darkness, now known as the eponymous Romberg's sign, once synonymous with tabes dorsalis, that became recognised as common to all proprioceptive disorders of the legs. In 1880, Henry Charlton Bastian suggested "kinaesthesia" instead of "muscle sense" on the basis that some of the afferent information comes from other structures, including tendons and skin. In 1889, Alfred Goldscheider suggested a classification of kinaesthesia into three types: muscle and articular sensitivity. In 1906, Charles Scott Sherrington published a landmark work that introduced the terms "proprioception", "interoception", "exteroception"; the "exteroceptors" are the organs that provide information originating outside the body, such as the eyes, ears and skin. The interoceptors provide information about the internal organs, the "proprioceptors" provide information about movement derived from muscular and articular sources.
Using Sherrington's system and anatomists search for specialised nerve endings that transmit mechanical data on joint capsule and muscle tension, which play a large role in proprioception. Primary endings of muscle spindles "respond to the size of a muscle length change and its speed" and "contribute both to the sense of limb position and movement". Secondary endings of muscle spindles detect changes in muscle length, thus supply information regarding only the sense of position. Muscle spindles are stretch receptors, it has been accepted that cutaneous receptors contribute directly to proprioception by providing "accurate perceptual information about joint position and movement", this knowledge is combined with information from the muscle spindles. A major component of proprioception is joint position sense, determined by measuring the accuracy of joint–angle replication. Clinical aspects of joint position sense are measured in joint position matching tests that measure a subject's ability to detect an externally imposed passive movement, or the ability to reposition a joint to a predetermined position.
These involve an individual's ability to perceive the position of a joint without the aid of vision. It is assumed that the ability of one of these aspects will be related to another; this suggests that while these components may well be related in a cognitive manner, they may in fact be physiologically separate. More recent work into the mechanism of ankle sprains suggests that the role of reflexes may be more limited due to their long latencies, as ankle sprain events occur in 100 ms or less. In accordance, a model has been proposed to include a'feedforward' component of proprioception, whereby the subject will have central information about the body's position before attaining it. Kinesthesia is a key component in muscle memory and hand-eye coordination, training can improve this sense; the ability to swing a golf club or to catch a ball requires a finely tuned sense of the position o
Virginia the Commonwealth of Virginia, is a state in the Southeastern and Mid-Atlantic regions of the United States located between the Atlantic Coast and the Appalachian Mountains. Virginia is nicknamed the "Old Dominion" due to its status as the first English colonial possession established in mainland North America and "Mother of Presidents" because eight U. S. presidents were born there, more than any other state. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna; the capital of the Commonwealth is Richmond. The Commonwealth's estimated population as of 2018 is over 8.5 million. The area's history begins with several indigenous groups, including the Powhatan. In 1607 the London Company established the Colony of Virginia as the first permanent New World English colony. Slave labor and the land acquired from displaced Native American tribes each played a significant role in the colony's early politics and plantation economy.
Virginia was one of the 13 Colonies in the American Revolution. In the American Civil War, Virginia's Secession Convention resolved to join the Confederacy, Virginia's First Wheeling Convention resolved to remain in the Union. Although the Commonwealth was under one-party rule for nearly a century following Reconstruction, both major national parties are competitive in modern Virginia; the Virginia General Assembly is the oldest continuous law-making body in the New World. The state government was ranked most effective by the Pew Center on the States in both 2005 and 2008, it is unique in how it treats cities and counties manages local roads, prohibits its governors from serving consecutive terms. Virginia's economy has many sectors: agriculture in the Shenandoah Valley. S. Department of Defense and Central Intelligence Agency. Virginia has a total area of 42,774.2 square miles, including 3,180.13 square miles of water, making it the 35th-largest state by area. Virginia is bordered by Maryland and Washington, D.
C. to the north and east. Virginia's boundary with Maryland and Washington, D. C. extends to the low-water mark of the south shore of the Potomac River. The southern border is defined as the 36° 30′ parallel north, though surveyor error led to deviations of as much as three arcminutes; the border with Tennessee was not settled until 1893, when their dispute was brought to the U. S. Supreme Court; the Chesapeake Bay separates the contiguous portion of the Commonwealth from the two-county peninsula of Virginia's Eastern Shore. The bay was formed from the drowned river valleys of the James River. Many of Virginia's rivers flow into the Chesapeake Bay, including the Potomac, Rappahannock and James, which create three peninsulas in the bay; the Tidewater is a coastal plain between the fall line. It includes major estuaries of Chesapeake Bay; the Piedmont is a series of sedimentary and igneous rock-based foothills east of the mountains which were formed in the Mesozoic era. The region, known for its heavy clay soil, includes the Southwest Mountains around Charlottesville.
The Blue Ridge Mountains are a physiographic province of the Appalachian Mountains with the highest points in the state, the tallest being Mount Rogers at 5,729 feet. The Ridge and Valley region includes the Great Appalachian Valley; the region includes Massanutten Mountain. The Cumberland Plateau and the Cumberland Mountains are in the southwest corner of Virginia, south of the Allegheny Plateau. In this region, rivers flow northwest, into the Ohio River basin; the Virginia Seismic Zone has not had a history of regular earthquake activity. Earthquakes are above 4.5 in magnitude, because Virginia is located away from the edges of the North American Plate. The largest earthquake, at an estimated 5.9 magnitude, was in 1897 near Blacksburg. A 5.8 magnitude earthquake struck central Virginia on August 2011, near Mineral. The earthquake was felt as far away as Toronto and Florida. 35 million years ago, a bolide impacted. The resulting Chesapeake Bay impact crater may explain what earthquakes and subsidence the region does experience.
Coal mining takes place in the three mountainous regions at 45 distinct coal beds near Mesozoic basins. Over 64 million tons of other non-fuel resources, such as slate, sand, or gravel, were mined in Virginia in 2018; the state's carbonate rock is filled with more than 4,000 caves, ten of which are open for tourism, including the popular Luray Caverns and Skyline Caverns. The climate of Virginia is humid subtropical and becomes warmer and more humid farther south and east. Seasonal extremes vary from average lows of 26 °F in January to average highs of 86 °F in July; the Atlantic Ocean has a strong effect on southeastern coastal areas of the state. Influenced by the Gulf Stream, coastal weather is subject to hurricanes, most pronouncedly near the mouth of Chesapeake Bay. In spite of its position adjacent to the Atlantic Ocean the coastal areas have a significant continental influence with quite large temperature differences between summ
Information engineering (field)
Information engineering is the engineering discipline that deals with the generation, distribution and use of information and knowledge in systems. The field first became identifiable in the early 21st century; the components of information engineering include more theoretical fields such as machine learning, artificial intelligence, control theory, signal processing, information theory, more applied fields such as computer vision, natural language processing, medical image computing, autonomous robotics, mobile robotics, telecommunications. Many of these originate from computer science, as well as other branches of engineering such as computer engineering, electrical engineering, bioengineering; the field of information engineering is based on mathematics probability, calculus, linear algebra, differential equations, variational calculus, complex analysis. Information engineers hold a degree in information engineering or a related area, are part of a professional body such as the Institution of Engineering and Technology or Institute of Measurement and Control.
They are employed in all industries due to the widespread use of information engineering. The term information engineering used to refer to a software engineering methodology, now more known as information technology engineering or information engineering methodology, it began to gain its current meaning early on in the 21st century. Machine learning is the field that involves the use of statistical and probabilistic methods to let computers "learn" from data without being explicitly programmed. Data science involves the application of machine learning to extract knowledge from data. Subfields of machine learning include deep learning, supervised learning, unsupervised learning, reinforcement learning, semi-supervised learning, active learning. Causal inference is another related component of information engineering. Control theory refers to the control of dynamical systems, with the aim being to avoid delays, overshoots, or instability. Information engineers tend to focus more on control theory rather than the physical design of control systems and circuits.
Subfields of control theory include classical control, optimal control, nonlinear control. Signal processing refers to the generation and use of signals, which could take many forms such as image, electrical, or biological. Information theory studies the analysis and storage of information. Major subfields of information theory include data compression. Computer vision is the field that deals with getting computers to understand image and video data at a high level. Natural language processing deals with getting computers to understand human languages at a high level; this means text, but often includes speech processing and recognition. Bioinformatics is the field that deals with the analysis and use of biological data; this means topics such as genomics and proteomics, sometimes includes medical image computing. Cheminformatics is the field that deals with the analysis and use of chemical data. Robotics in information engineering focuses on the algorithms and computer programs used to control robots.
As such, information engineering tends to focus more on mobile, or probabilistic robots. Major subfields studied by information engineers include control, perception, SLAM, motion planning. In the past some areas in information engineering such as signal processing used analog electronics, but nowadays most information engineering is done with digital computers. Many tasks in information engineering can be parallelized, so nowadays information engineering is carried out using CPUs, GPUs, AI accelerators. There has been interest in using quantum computers for some subfields of information engineering such as machine learning and robotics. Aerospace engineering Chemical engineering Civil engineering Internet of things List of engineering branches Mechanical engineering Statistics
DARPA Grand Challenge
The DARPA Grand Challenge is a prize competition for American autonomous vehicles, funded by the Defense Advanced Research Projects Agency, the most prominent research organization of the United States Department of Defense. Congress has authorized DARPA to award cash prizes to further DARPA's mission to sponsor revolutionary, high-payoff research that bridges the gap between fundamental discoveries and military use; the initial DARPA Grand Challenge was created to spur the development of technologies needed to create the first autonomous ground vehicles capable of completing a substantial off-road course within a limited time. The third event, the DARPA Urban Challenge extended the initial Challenge to autonomous operation in a mock urban environment; the most recent Challenge, the 2012 DARPA Robotics Challenge, focused on autonomous emergency-maintenance robots. Autonomous vehicles have been an international pursuit for many years, from endeavors in Japan, Italy, the European Union, the United States of America, other countries.
DARPA funded the development of the first autonomous robot beginning in 1966 with the Shakey the robot project at Stanford Research Institute, now SRI International. The first autonomous ground vehicle capable of driving on and off roads was developed by DARPA as part of the Strategic Computing Initiative beginning in 1984 leading to demonstrations of autonomous navigation by the Autonomous Land Vehicle and the Navlab; the Grand Challenge was the first long distance competition for driverless cars in the world. The U. S. Congress authorized DARPA to offer prize money for the first Grand Challenge to facilitate robotic development, with the ultimate goal of making one-third of ground military forces autonomous by 2015. Following the 2004 event, Dr. Tony Tether, the director of DARPA, announced that the prize money had been increased to $2 million for the next event, claimed on October 9, 2005; the first and third places in the 2007 Urban Challenge received $2 million, $1 million, $500,000, respectively.
The competition was open to teams and organizations from around the world, as long as there were at least one U. S. citizen on the roster. Teams have participated from high schools, universities and other organizations. More than 100 teams registered in the first year, bringing a wide variety of technological skills to the race. In the second year, 195 teams from 36 U. S. states and 4 foreign countries entered the race. The first competition of the DARPA Grand Challenge was held on March 13, 2004 in the Mojave Desert region of the United States, along a 150-mile route that follows along the path of Interstate 15 from just before Barstow, California to just past the California–Nevada border in Primm. None of the robot vehicles finished the route. Carnegie Mellon University's Red Team and car Sandstorm traveled the farthest distance, completing 11.78 km of the course before getting hung up on a rock after making a switchback turn. No winner was declared, the cash prize was not given. Therefore, a second DARPA Grand Challenge event was scheduled for 2005.
The second competition of the DARPA Grand Challenge began at 6:40am on October 8, 2005. All but one of the 23 finalists in the 2005 race surpassed the 11.78 km distance completed by the best vehicle in the 2004 race. Five vehicles completed the 212 km course: Vehicles in the 2005 race passed through three narrow tunnels and negotiated more than 100 sharp left and right turns; the race concluded through Beer Bottle Pass, a winding mountain pass with a sheer drop-off on one side and a rock face on the other. Although the 2004 course required more elevation gain and some sharp switchbacks were required near the beginning of the route, the course had far fewer curves and wider roads than the 2005 course; the natural rivalry between the teams from Stanford and Carnegie Mellon was played out during the race. Mechanical problems plagued H1ghlander. Gray Team's entry was a miracle in itself, as the team from the suburbs of New Orleans was caught in Hurricane Katrina a few short weeks before the race.
The fifth finisher, Terramax, a 30,000 pound entry from Oshkosh Truck, finished on the second day. The huge truck spent the night idling on the course, but was nimble in picking its way down the narrow roads of Beer Bottle Pass; the third competition of the DARPA Grand Challenge, known as the "Urban Challenge", took place on November 3, 2007 at the site of the now-closed George Air Force Base, in Victorville, California. The course involved a 96 km urban area course. Rules included obeying all traffic regulations while negotiating with other traffic and obstacles and merging into traffic. Unlike previous challenges, the 2007 Urban Challenge organizers divided competitors into two "tracks," A and B. All Track A and Track B teams were part of the same competition circuit, but the teams chosen for the Track A program received US $1 million in funding; these 11 teams represented major universities and large corporate interests such as CMU teaming with GM as Tartan Racing, Stanford teaming with Volkswagen, Virginia Tech teaming with TORC Technologies as VictorTango, Oshkosh Truck, Raytheon, Autono
In computer science, artificial intelligence, sometimes called machine intelligence, is intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and animals. Computer science defines AI research as the study of "intelligent agents": any device that perceives its environment and takes actions that maximize its chance of achieving its goals. Colloquially, the term "artificial intelligence" is used to describe machines that mimic "cognitive" functions that humans associate with other human minds, such as "learning" and "problem solving"; as machines become capable, tasks considered to require "intelligence" are removed from the definition of AI, a phenomenon known as the AI effect. A quip in Tesler's Theorem says "AI is whatever hasn't been done yet." For instance, optical character recognition is excluded from things considered to be AI, having become a routine technology. Modern machine capabilities classified as AI include understanding human speech, competing at the highest level in strategic game systems, autonomously operating cars, intelligent routing in content delivery networks and military simulations.
Artificial intelligence can be classified into three different types of systems: analytical, human-inspired, humanized artificial intelligence. Analytical AI has only characteristics consistent with cognitive intelligence. Human-inspired AI has elements from emotional intelligence. Humanized AI shows characteristics of all types of competencies, is able to be self-conscious and is self-aware in interactions with others. Artificial intelligence was founded as an academic discipline in 1956, in the years since has experienced several waves of optimism, followed by disappointment and the loss of funding, followed by new approaches and renewed funding. For most of its history, AI research has been divided into subfields that fail to communicate with each other; these sub-fields are based on technical considerations, such as particular goals, the use of particular tools, or deep philosophical differences. Subfields have been based on social factors; the traditional problems of AI research include reasoning, knowledge representation, learning, natural language processing and the ability to move and manipulate objects.
General intelligence is among the field's long-term goals. Approaches include statistical methods, computational intelligence, traditional symbolic AI. Many tools are used in AI, including versions of search and mathematical optimization, artificial neural networks, methods based on statistics and economics; the AI field draws upon computer science, information engineering, psychology, linguistics and many other fields. The field was founded on the claim that human intelligence "can be so described that a machine can be made to simulate it"; this raises philosophical arguments about the nature of the mind and the ethics of creating artificial beings endowed with human-like intelligence which are issues that have been explored by myth and philosophy since antiquity. Some people consider AI to be a danger to humanity if it progresses unabated. Others believe that AI, unlike previous technological revolutions, will create a risk of mass unemployment. In the twenty-first century, AI techniques have experienced a resurgence following concurrent advances in computer power, large amounts of data, theoretical understanding.
Thought-capable artificial beings appeared as storytelling devices in antiquity, have been common in fiction, as in Mary Shelley's Frankenstein or Karel Čapek's R. U. R.. These characters and their fates raised many of the same issues now discussed in the ethics of artificial intelligence; the study of mechanical or "formal" reasoning began with philosophers and mathematicians in antiquity. The study of mathematical logic led directly to Alan Turing's theory of computation, which suggested that a machine, by shuffling symbols as simple as "0" and "1", could simulate any conceivable act of mathematical deduction; this insight, that digital computers can simulate any process of formal reasoning, is known as the Church–Turing thesis. Along with concurrent discoveries in neurobiology, information theory and cybernetics, this led researchers to consider the possibility of building an electronic brain. Turing proposed that "if a human could not distinguish between responses from a machine and a human, the machine could be considered "intelligent".
The first work, now recognized as AI was McCullouch and Pitts' 1943 formal design for Turing-complete "artificial neurons". The field of AI research was born at a workshop at Dartmouth College in 1956. Attendees Allen Newell, Herbert Simon, John McCarthy, Marvin Minsky and Arthur Samuel became the founders and leaders of AI research, they and their students produced programs that the press described as "astonishing": computers were learning checkers strategies (and by 1959 were playing better than the average human