title: History of artificial intelligence

text: The power of expert systems came from the expert knowledge they contained. They were part of a new direction in AI research that had been gaining ground throughout the 70s. "AI researchers were beginning to suspect—reluctantly, for it violated the scientific canon of parsimony—that intelligence might very well be based on the ability to use large amounts of diverse knowledge in different ways," writes Pamela McCorduck. "[T]he great lesson from the 1970s was that intelligent behavior depended very much on dealing with knowledge, sometimes quite detailed knowledge, of a domain where a given task lay". Knowledge based systems and knowledge engineering became a major focus of AI research in the 1980s.


title: History of artificial intelligence

text: The 1980s also saw the birth of Cyc, the first attempt to attack the commonsense knowledge problem directly, by creating a massive database that would contain all the mundane facts that the average person knows. Douglas Lenat, who started and led the project, argued that there is no shortcut ― the only way for machines to know the meaning of human concepts is to teach them, one concept at a time, by hand. The project was not expected to be completed for many decades.


title: History of artificial intelligence

text: Chess playing programs HiTech and Deep Thought defeated chess masters in 1989. Both were developed by Carnegie Mellon University; Deep Thought development paved the way for Deep Blue.


title: History of artificial intelligence

text: In 1981, the Japanese Ministry of International Trade and Industry set aside $850 million for the Fifth generation computer project. Their objectives were to write programs and build machines that could carry on conversations, translate languages, interpret pictures, and reason like human beings. Much to the chagrin of scruffies, they chose Prolog as the primary computer language for the project.


title: History of artificial intelligence

text: Other countries responded with new programs of their own. The UK began the £350 million Alvey project. A consortium of American companies formed the Microelectronics and Computer Technology Corporation (or "MCC") to fund large scale projects in AI and information technology. DARPA responded as well, founding the Strategic Computing Initiative and tripling its investment in AI between 1984 and 1988.


title: History of artificial intelligence

text: In 1982, physicist John Hopfield was able to prove that a form of neural network (now called a "Hopfield net") could learn and process information in a completely new way. Around the same time, Geoffrey Hinton and David Rumelhart popularized a method for training neural networks called "backpropagation", also known as the reverse mode of automatic differentiation published by Seppo Linnainmaa (1970) and applied to neural networks by Paul Werbos. These two discoveries helped to revive the field of connectionism.


title: History of artificial intelligence

text: The new field was unified and inspired by the appearance of "Parallel Distributed Processing" in 1986—a two volume collection of papers edited by Rumelhart and psychologist James McClelland. Neural networks would become commercially successful in the 1990s, when they began to be used as the engines driving programs like optical character recognition and speech recognition.


title: History of artificial intelligence

text: The development of metal–oxide–semiconductor (MOS) very-large-scale integration (VLSI), in the form of complementary MOS (CMOS) technology, enabled the development of practical artificial neural network (ANN) technology in the 1980s. A landmark publication in the field was the 1989 book "Analog VLSI Implementation of Neural Systems" by Carver A. Mead and Mohammed Ismail.


title: History of artificial intelligence

text: The business community's fascination with AI rose and fell in the 1980s in the classic pattern of an economic bubble. The collapse was due to the failure of commercial vendors to develop a wide variety of workable solutions. As dozens of companies failed, the perception was that the technology was not viable. However, the field continued to make advances despite the criticism. Numerous researchers, including robotics developers Rodney Brooks and Hans Moravec, argued for an entirely new approach to artificial intelligence.


title: History of artificial intelligence

text: The term "AI winter" was coined by researchers who had survived the funding cuts of 1974 when they became concerned that enthusiasm for expert systems had spiraled out of control and that disappointment would certainly follow. Their fears were well founded: in the late 1980s and early 1990s, AI suffered a series of financial setbacks.


title: History of artificial intelligence

text: The first indication of a change in weather was the sudden collapse of the market for specialized AI hardware in 1987. Desktop computers from Apple and IBM had been steadily gaining speed and power and in 1987 they became more powerful than the more expensive Lisp machines made by Symbolics and others. There was no longer a good reason to buy them. An entire industry worth half a billion dollars was demolished overnight.


title: History of artificial intelligence

text: Eventually the earliest successful expert systems, such as XCON, proved too expensive to maintain. They were difficult to update, they could not learn, they were "brittle" (i.e., they could make grotesque mistakes when given unusual inputs), and they fell prey to problems (such as the qualification problem) that had been identified years earlier. Expert systems proved useful, but only in a few special contexts.


title: History of artificial intelligence

text: In the late 1980s, the Strategic Computing Initiative cut funding to AI "deeply and brutally". New leadership at DARPA had decided that AI was not "the next wave" and directed funds towards projects that seemed more likely to produce immediate results.


title: History of artificial intelligence

text: By 1991, the impressive list of goals penned in 1981 for Japan's Fifth Generation Project had not been met. Indeed, some of them, like "carry on a casual conversation" had not been met by 2010. As with other AI projects, expectations had run much higher than what was actually possible.


title: History of artificial intelligence

text: Over 300 AI companies had shut down, gone bankrupt, or been acquired by the end of 1993, effectively ending the first commercial wave of AI. In 1994, HP Newquist stated in "The Brain Makers" that "The immediate future of artificial intelligence—in its commercial form—seems to rest in part on the continued success of neural networks."


title: History of artificial intelligence

text: In the late 1980s, several researchers advocated a completely new approach to artificial intelligence, based on robotics. They believed that, to show real intelligence, a machine needs to have a "body" — it needs to perceive, move, survive and deal with the world. They argued that these sensorimotor skills are essential to higher level skills like commonsense reasoning and that abstract reasoning was actually the "least" interesting or important human skill (see Moravec's paradox). They advocated building intelligence "from the bottom up."


title: History of artificial intelligence

text: The approach revived ideas from cybernetics and control theory that had been unpopular since the sixties. Another precursor was David Marr, who had come to MIT in the late 1970s from a successful background in theoretical neuroscience to lead the group studying vision. He rejected all symbolic approaches ("both" McCarthy's logic and Minsky's frames), arguing that AI needed to understand the physical machinery of vision from the bottom up before any symbolic processing took place. (Marr's work would be cut short by leukemia in 1980.)


title: History of artificial intelligence

text: In his 1990 paper "Elephants Don't Play Chess," robotics researcher Rodney Brooks took direct aim at the physical symbol system hypothesis, arguing that symbols are not always necessary since "the world is its own best model. It is always exactly up to date. It always has every detail there is to be known. The trick is to sense it appropriately and often enough." In the 1980s and 1990s, many cognitive scientists also rejected the symbol processing model of the mind and argued that the body was essential for reasoning, a theory called the embodied mind thesis.


title: History of artificial intelligence

text: The field of AI, now more than a half a century old, finally achieved some of its oldest goals. It began to be used successfully throughout the technology industry, although somewhat behind the scenes. Some of the success was due to increasing computer power and some was achieved by focusing on specific isolated problems and pursuing them with the highest standards of scientific accountability. Still, the reputation of AI, in the business world at least, was less than pristine. Inside the field there was little agreement on the reasons for AI's failure to fulfill the dream of human level intelligence that had captured the imagination of the world in the 1960s. Together, all these factors helped to fragment AI into competing subfields focused on particular problems or approaches, sometimes even under new names that disguised the tarnished pedigree of "artificial intelligence". AI was both more cautious and more successful than it had ever been.


title: History of artificial intelligence

text: On 11 May 1997, Deep Blue became the first computer chess-playing system to beat a reigning world chess champion, Garry Kasparov. The super computer was a specialized version of a framework produced by IBM, and was capable of processing twice as many moves per second as it had during the first match (which Deep Blue had lost), reportedly 200,000,000 moves per second. The event was broadcast live over the internet and received over 74 million hits.


title: History of artificial intelligence

text: In 2005, a Stanford robot won the DARPA Grand Challenge by driving autonomously for 131 miles along an unrehearsed desert trail. Two years later, a team from CMU won the DARPA Urban Challenge by autonomously navigating 55 miles in an Urban environment while adhering to traffic hazards and all traffic laws. In February 2011, in a Jeopardy! quiz show exhibition match, IBM's question answering system, Watson, defeated the two greatest Jeopardy! champions, Brad Rutter and Ken Jennings, by a significant margin.


title: History of artificial intelligence

text: These successes were not due to some revolutionary new paradigm, but mostly on the tedious application of engineering skill and on the tremendous increase in the speed and capacity of computer by the 90s. In fact, Deep Blue's computer was 10 million times faster than the Ferranti Mark 1 that Christopher Strachey taught to play chess in 1951. This dramatic increase is measured by Moore's law, which predicts that the speed and memory capacity of computers doubles every two years, as a result of metal–oxide–semiconductor (MOS) transistor counts doubling every two years. The fundamental problem of "raw computer power" was slowly being overcome.


title: History of artificial intelligence

text: A new paradigm called "intelligent agents" became widely accepted during the 1990s. Although earlier researchers had proposed modular "divide and conquer" approaches to AI, the intelligent agent did not reach its modern form until Judea Pearl, Allen Newell, Leslie P. Kaelbling, and others brought concepts from decision theory and economics into the study of AI. When the economist's definition of a rational agent was married to computer science's definition of an object or module, the intelligent agent paradigm was complete.


title: History of artificial intelligence

text: An intelligent agent is a system that perceives its environment and takes actions which maximize its chances of success. By this definition, simple programs that solve specific problems are "intelligent agents", as are human beings and organizations of human beings, such as firms. The intelligent agent paradigm defines AI research as "the study of intelligent agents". This is a generalization of some earlier definitions of AI: it goes beyond studying human intelligence; it studies all kinds of intelligence.


title: History of artificial intelligence

text: The paradigm gave researchers license to study isolated problems and find solutions that were both verifiable and useful. It provided a common language to describe problems and share their solutions with each other, and with other fields that also used concepts of abstract agents, like economics and control theory. It was hoped that a complete agent architecture (like Newell's SOAR) would one day allow researchers to build more versatile and intelligent systems out of interacting intelligent agents.


title: History of artificial intelligence

text: AI researchers began to develop and use sophisticated mathematical tools more than they ever had in the past. There was a widespread realization that many of the problems that AI needed to solve were already being worked on by researchers in fields like mathematics, electrical engineering, economics or operations research. The shared mathematical language allowed both a higher level of collaboration with more established and successful fields and the achievement of results which were measurable and provable; AI had become a more rigorous "scientific" discipline. describe this as nothing less than a "revolution". They had argued in their 2002 textbook that this increased rigor could be viewed plausibly as a "victory of the neats," but subsequently qualified that by saying, in their 2020 AI textbook, that "The present emphasis on deep learning may represent a resurgence of the scruffies."


title: History of artificial intelligence

text: Judea Pearl's influential 1988 book brought probability and decision theory into AI. Among the many new tools in use were Bayesian networks, hidden Markov models, information theory, stochastic modeling and classical optimization. Precise mathematical descriptions were also developed for "computational intelligence" paradigms like neural networks and evolutionary algorithms.


title: History of artificial intelligence

text: Algorithms originally developed by AI researchers began to appear as parts of larger systems. AI had solved a lot of very difficult problems


title: History of artificial intelligence

text: The field of AI received little or no credit for these successes in the 1990s and early 2000s. Many of AI's greatest innovations have been reduced to the status of just another item in the tool chest of computer science. Nick Bostrom explains "A lot of cutting edge AI has filtered into general applications, often without being called AI because once something becomes useful enough and common enough it's not labeled AI anymore."


title: History of artificial intelligence

text: Many researchers in AI in the 1990s deliberately called their work by other names, such as informatics, knowledge-based systems, cognitive systems or computational intelligence. In part, this may have been because they considered their field to be fundamentally different from AI, but also the new names help to procure funding. In the commercial world at least, the failed promises of the AI Winter continued to haunt AI research into the 2000s, as the "New York Times" reported in 2005: "Computer scientists and software engineers avoided the term artificial intelligence for fear of being viewed as wild-eyed dreamers."


title: History of artificial intelligence

text: In 1968, Arthur C. Clarke and Stanley Kubrick had imagined that, by the year , a machine would exist with an intelligence that matched or exceeded the capability of human beings. The character they created, HAL 9000, was based on a belief shared by many leading AI researchers that such a machine would exist by the year 2001.


title: History of artificial intelligence

text: In 2001, AI founder Marvin Minsky asked "So the question is why didn't we get HAL in 2001?" Minsky believed that the answer is that the central problems, like commonsense reasoning, were being neglected, while most researchers pursued things like commercial applications of neural nets or genetic algorithms. John McCarthy, on the other hand, still blamed the qualification problem. For Ray Kurzweil, the issue is computer power and, using Moore's Law, he predicted that machines with human-level intelligence will appear by 2029. Jeff Hawkins argued that neural net research ignores the essential properties of the human cortex, preferring simple models that have been successful at solving simple problems. There were many other explanations and for each there was a corresponding research program underway.


title: History of artificial intelligence

text: In the first decades of the 21st century, access to large amounts of data (known as "big data"), cheaper and faster computers and advanced machine learning techniques were successfully applied to many problems throughout the economy. In fact, McKinsey Global Institute estimated in their famous paper "Big data: The next frontier for innovation, competition, and productivity" that "by 2009, nearly all sectors in the US economy had at least an average of 200 terabytes of stored data".


title: History of artificial intelligence

text: By 2016, the market for AI-related products, hardware, and software reached more than 8 billion dollars, and the New York Times reported that interest in AI had reached a "frenzy". The applications of big data began to reach into other fields as well, such as training models in ecology and for various applications in economics. Advances in deep learning (particularly deep convolutional neural networks and recurrent neural networks) drove progress and research in image and video processing, text analysis, and even speech recognition.


title: History of artificial intelligence

text: Deep learning is a branch of machine learning that models high level abstractions in data by using a deep graph with many processing layers. According to the Universal approximation theorem, deep-ness isn't necessary for a neural network to be able to approximate arbitrary continuous functions. Even so, there are many problems that are common to shallow networks (such as overfitting) that deep networks help avoid. As such, deep neural networks are able to realistically generate much more complex models as compared to their shallow counterparts.


title: History of artificial intelligence

text: However, deep learning has problems of its own. A common problem for recurrent neural networks is the vanishing gradient problem, which is where gradients passed between layers gradually shrink and literally disappear as they are rounded off to zero. There have been many methods developed to approach this problem, such as Long short-term memory units.


title: History of artificial intelligence

text: State-of-the-art deep neural network architectures can sometimes even rival human accuracy in fields like computer vision, specifically on things like the MNIST database, and traffic sign recognition.


title: History of artificial intelligence

text: Language processing engines powered by smart search engines can easily beat humans at answering general trivia questions (such as IBM Watson), and recent developments in deep learning have produced astounding results in competing with humans, in things like Go, and "Doom" (which, being a first-person shooter game, has sparked some controversy).


title: History of artificial intelligence

text: Big data refers to a collection of data that cannot be captured, managed, and processed by conventional software tools within a certain time frame. It is a massive amount of decision-making, insight, and process optimization capabilities that require new processing models. In the Big Data Era written by Victor Meyer Schonberg and Kenneth Cooke, big data means that instead of random analysis (sample survey), all data is used for analysis. The 5V characteristics of big data (proposed by IBM): "Volume", "Velocity", "Variety", "Value", "Veracity".


title: History of artificial intelligence

text: The strategic significance of big data technology is not to master huge data information, but to specialize in these meaningful data. In other words, if big data is likened to an industry, the key to realizing profitability in this industry is to increase the "process capability" of the data and realize the "value added" of the data through "processing".


title: History of artificial intelligence

text: General intelligence is the ability to solve "any" problem, rather than finding a solution to a particular problem. Artificial general intelligence (or "AGI") is a program which can apply intelligence to a wide variety of problems, in much the same ways humans can.


title: History of artificial intelligence

text: Ben Goertzel and others argued in the early 2000s that AI research had largely given up on the field's original goal of creating artificial general intelligence. AGI research was founded as a separate sub-field and by 2010 there were academic conferences, laboratories and university courses dedicated to AGI research, as well as private consortiums and new companies.


title: History of artificial intelligence

text: Artificial general intelligence is also referred to as "strong AI", "full AI", or synthetic intelligence as opposed to "weak AI" or "narrow AI". (Academic sources reserve "strong AI" to refer to machines capable of experiencing consciousness.)


title: History of artificial intelligence

text: Foundation models, which are large artificial intelligence models trained on vast quantities of unlabeled data that can be adapted to a wide range of downstream tasks, began to be developed in 2018. Models such as GPT-3 released by OpenAI in 2020, and Gato released by DeepMind in 2022, have been described as important milestones on the path to artificial general intelligence.


title: Viverridae

text: Viverridae is a family of small to medium-sized, feliform mammals. The viverrids () comprise 33 species placed in 14 genera. This family was named and first described by John Edward Gray in 1821. Viverrids occur all over Africa, southern Europe, and South and Southeast Asia, across the Wallace Line. Their occurrence in Sulawesi and in some of the adjoining islands shows them to be ancient inhabitants of the Old World tropics.


title: Viverridae

text: Viverrids have four or five toes on each foot and half-retractile claws. They have six incisors in each jaw and molars with two tubercular grinders behind in the upper jaw, and one in the lower jaw. The tongue is rough with sharp prickles. A pouch or gland occurs beneath the anus, but there is no cecum.


title: Viverridae

text: Viverrids are the most primitive of all the families of feliform Carnivora and clearly less specialized than the Felidae. In external characteristics, they are distinguished from the Felidae by the longer muzzle and tuft of facial vibrissae between the lower jaw bones, and by the shorter limbs and the five-toed hind foot with the first digit present. The skull differs by the position of the postpalatine foramina on the maxilla, almost always well in advance of the maxillopalatine suture, and usually about the level of the second premolar; and by the distinct external division of the auditory bulla into its two elements either by a definite groove or, when rarely this is obliterated, by the depression of the tympanic bone in front of the swollen entotympanic. The typical dental formula is: , but the number may be reduced, although never to the same extent as in the Felidae.


title: Viverridae

text: Their flesh-shearing carnassial teeth are relatively undeveloped compared to those of other feliform carnivores. Most viverrid species have a penis bone (a baculum).


title: Viverridae

text: In 1821, Gray defined this family as consisting of the genera "Viverra", "Genetta", "Herpestes", and "Suricata". Reginald Innes Pocock later redefined the family as containing a great number of highly diversified genera, and being susceptible of division into several subfamilies, based mainly on the structure of the feet and of some highly specialized scent glands, derived from the skin, which are present in most of the species and are situated in the region of the external generative organs. He subordinated the subfamilies Hemigalinae, Paradoxurinae, Prionodontinae, and Viverrinae to the Viverridae.


title: Viverridae

text: In 1833, Edward Turner Bennett described the Malagasy fossa ("Cryptoprocta ferox") and subordinated the Cryptoprocta to the Viverridae. A molecular and morphological analysis based on DNA/DNA hybridization experiments suggests that "Cryptoprocta" does not belong within Viverridae, but is a member of the Eupleridae.


title: Viverridae

text: The African palm civet ("Nandinia binotata") resembles the civets of the Viverridae, but is genetically distinct and belongs in its own monotypic family, the Nandiniidae. There is little dispute that the "Poiana" species are viverrids.


title: Viverridae

text: DNA analysis based on 29 Carnivora species, comprising 13 Viverrinae species and three species representing "Paradoxurus", "Paguma" and Hemigalinae, confirmed Pocock's assumption that the African linsang "Poiana" represents the sister group of the genus "Genetta". The placement of "Prionodon" as the sister group of the family Felidae is strongly supported, and it was proposed that the Asiatic linsangs be placed in the monogeneric family Prionodontidae.


title: Cucurbitaceae

text: The Cucurbitaceae, also called cucurbits or the gourd family, are a plant family consisting of about 965 species in around 95 genera, of which the most important to humans are:


title: Cucurbitaceae

text: The plants in this family are grown around the tropics and in temperate areas, where those with edible fruits were among the earliest cultivated plants in both the Old and New Worlds. The family Cucurbitaceae ranks among the highest of plant families for number and percentage of species used as human food. The name "Cucurbitaceae" comes to international scientific vocabulary from New Latin, from "Cucurbita", the type genus, + "-aceae", a standardized suffix for plant family names in modern taxonomy. The genus name comes from the Classical Latin word "cucurbita", "gourd".


title: Cucurbitaceae

text: Most of the plants in this family are annual vines, but some are woody lianas, thorny shrubs, or trees ("Dendrosicyos"). Many species have large, yellow or white flowers. The stems are hairy and pentangular. Tendrils are present at 90° to the leaf petioles at nodes. Leaves are exstipulate, alternate, simple palmately lobed or palmately compound. The flowers are unisexual, with male and female flowers on different plants (dioecious) or on the same plant (monoecious). The female flowers have inferior ovaries. The fruit is often a kind of modified berry called a pepo.


title: Cucurbitaceae

text: One of the oldest fossil cucurbits so far is †"Cucurbitaciphyllum lobatum" from the Paleocene epoch, found at Shirley Canal, Montana. It was described for the first time in 1924 by the paleobotanist Frank Hall Knowlton. The fossil leaf is palmate, trilobed with rounded lobal sinuses and an entire or serrate margin. It has a leaf pattern similar to the members of the genera "Kedrostis", "Melothria" and "Zehneria".


title: Thoracic diaphragm

text: The thoracic diaphragm, or simply the diaphragm (), is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle.


title: Thoracic diaphragm

text: The term "diaphragm" in anatomy, created by Gerard of Cremona, can refer to other flat structures such as the urogenital diaphragm or pelvic diaphragm, but "the diaphragm" generally refers to the thoracic diaphragm. In humans, the diaphragm is slightly asymmetric—its right half is higher up (superior) to the left half, since the large liver rests beneath the right half of the diaphragm. There is also speculation that the diaphragm is lower on the other side due to heart's presence.


title: Thoracic diaphragm

text: Other mammals have diaphragms, and other vertebrates such as amphibians and reptiles have diaphragm-like structures, but important details of the anatomy may vary, such as the position of the lungs in the thoracic cavity.


title: Thoracic diaphragm

text: The diaphragm is an upward curved, c-shaped structure of muscle and fibrous tissue that separates the thoracic cavity from the abdomen. The superior surface of the dome forms the floor of the thoracic cavity, and the inferior surface the roof of the abdominal cavity.


title: Thoracic diaphragm

text: As a dome, the diaphragm has peripheral attachments to structures that make up the abdominal and chest walls. The muscle fibres from these attachments converge in a central tendon, which forms the crest of the dome. Its peripheral part consists of muscular fibers that take origin from the circumference of the inferior thoracic aperture and converge to be inserted into a central tendon.


title: Thoracic diaphragm

text: The muscle fibres of the diaphragm emerge from many surrounding structures and can be divided into vertebral, costal, sternal, and central tendon.


title: Thoracic diaphragm

text: The vertebral part of the diaphragram arises from the crura and arcuate ligaments. Right crus arises from L1-L3 vertebral bodies and their intervertebral discs. Smaller left crus arises from L1, L2 vertebral bodies and their intervertebral discs. Medial arcuate ligament arises from the fascia thickening from body of L2 vertebrae to transverse process of L1 vertebrae, crossing over the body of the psoas major muscle. The lateral arcuate ligament arises from the transverse process of L1 vertebrae and is attached laterally to the 12th rib. The lateral arcuate ligament also arises from fascia thickening that covers the quadratus lumborum muscle. The median arcuate ligament arises from the fibrous parts of right and left crura where descending thoracic aorta passes behind it. No diaphramatic muscle arises from the median arcuate ligament. Both adrenal glands lie the near diaphragmatic crus and arcuate ligament.


title: Thoracic diaphragm

text: The central tendon of the diaphragm is a thin but strong aponeurosis near the center of the vault formed by the muscle, closer to the front than to the back of the thorax. The central part of the tendon is attached above to pericardium. The both sides of the posterior fibres are attached to paracolic gutters (the curving of ribs before attaching to both sides of the vertebral bodies).


title: Thoracic diaphragm

text: There are a number of openings in the diaphragm through which structures pass between the thorax and abdomen. There are three large openings — one for the aorta, one for the esophagus, and one for the inferior vena cava (the caval opening), plus a series of smaller ones.


title: Thoracic diaphragm

text: The inferior vena cava passes through the caval opening, a quadrilateral opening at the junction of the right and middle leaflets of the central tendon, so that its margins are tendinous. Surrounded by tendons, the opening is stretched open every time inspiration occurs. However, there has been argument that the caval opening actually constricts during inspiration. Since thoracic pressure decreases upon inspiration and draws the caval blood upwards toward the right atrium, increasing the size of the opening allows more blood to return to the heart, maximizing the efficacy of lowered thoracic pressure returning blood to the heart. The aorta does not pierce the diaphragm but rather passes behind it in between the left and right crus.


title: Thoracic diaphragm

text: There are several structures that pierced through the diaphragm, including: left phrenic nerve pierce through the central tendon, greater, lesser, and least thoracic splanchnic nerves pierced through bilateral crura, and lymphatic vessels that pierced throughout the diaphragam, especially behind the diaphragm.


title: Thoracic diaphragm

text: The diaphragm is primarily innervated by the phrenic nerve which is formed from the cervical nerves C3, C4 and C5. While the central portion of the diaphragm sends sensory afferents via the phrenic nerve, the peripheral portions of the diaphragm send sensory afferents via the intercostal (T5–T11) and subcostal nerves (T12).


title: Thoracic diaphragm

text: From above, the diaphragm receives blood from branches of the internal thoracic arteries, namely the pericardiacophrenic artery and musculophrenic artery; from the superior phrenic arteries, which arise directly from the thoracic aorta; and from the lower internal intercostal arteries. From below, the inferior phrenic arteries supply the diaphragm.


title: Thoracic diaphragm

text: The diaphragm drains blood into the brachiocephalic veins, azygos veins, and veins that drain into the inferior vena cava and left suprarenal vein.


title: Thoracic diaphragm

text: The sternal portion of the muscle is sometimes wanting and more rarely defects occur in the lateral part of the central tendon or adjoining muscle fibers.


title: Thoracic diaphragm

text: The thoracic diaphragm develops during embryogenesis, beginning in the third week after fertilization with two processes known as transverse folding and longitudinal folding. The septum transversum, the primitive central tendon of the diaphragm, originates at the rostral pole of the embryo and is relocated during longitudinal folding to the ventral thoracic region. Transverse folding brings the body wall anteriorly to enclose the gut and body cavities. The pleuroperitoneal membrane and body wall myoblasts, from somatic lateral plate mesoderm, meet the septum transversum to close off the pericardio-peritoneal canals on either side of the presumptive esophagus, forming a barrier that separates the peritoneal and pleuropericardial cavities. Furthermore, dorsal mesenchyme surrounding the presumptive esophagus form the muscular crura of the diaphragm.


title: Thoracic diaphragm

text: Because the earliest element of the embryological diaphragm, the septum transversum, forms in the cervical region, the phrenic nerve that innervates the diaphragm originates from the cervical spinal cord (C3,4, and 5). As the septum transversum descends inferiorly, the phrenic nerve follows, accounting for its circuitous route from the upper cervical vertebrae, around the pericardium, finally to innervate the diaphragm.


title: Thoracic diaphragm

text: The diaphragm is the main muscle of respiration and functions in breathing. During inhalation, the diaphragm contracts and moves in the inferior direction, enlarging the volume of the thoracic cavity and reducing intra-thoracic pressure (the external intercostal muscles also participate in this enlargement), forcing the lungs to expand. In other words, the diaphragm's movement downwards creates a partial vacuum in the thoracic cavity, which forces the lungs to expand to fill the void, drawing air in the process.


title: Thoracic diaphragm

text: Cavity expansion happens in two extremes, along with intermediary forms. When the lower ribs are stabilized and the central tendon of the diaphragm is mobile, a contraction brings the insertion (central tendon) towards the origins and pushes the lower cavity towards the pelvis, allowing the thoracic cavity to expand downward. This is often called belly breathing. When the central tendon is stabilized and the lower ribs are mobile, a contraction lifts the origins (ribs) up towards the insertion (central tendon) which works in conjunction with other muscles to allow the ribs to slide and the thoracic cavity to expand laterally and upwards.


title: Thoracic diaphragm

text: When the diaphragm relaxes (moves in the superior direction), air is exhaled by elastic recoil process of the lung and the tissues lining the thoracic cavity. Assisting this function with muscular effort (called forced exhalation) involves the internal intercostal muscles used in conjunction with the abdominal muscles, which act as an antagonist paired with the diaphragm's contraction.


title: Thoracic diaphragm

text: The diaphragm is also involved in non-respiratory functions. It helps to expel vomit, feces, and urine from the body by increasing intra-abdominal pressure, aids in childbirth, and prevents acid reflux by exerting pressure on the esophagus as it passes through the esophageal hiatus.


title: Thoracic diaphragm

text: In some non-human animals, the diaphragm is not crucial for breathing; a cow, for instance, can survive fairly asymptomatically with diaphragmatic paralysis as long as no massive aerobic metabolic demands are made of it.


title: Thoracic diaphragm

text: If either the phrenic nerve, cervical spine or brainstem is damaged, this will sever the nervous supply to the diaphragm. The most common damage to the phrenic nerve is by bronchial cancer, which usually only affects one side of the diaphragm. Other causes include Guillain–Barré syndrome and systemic lupus erythematosus.


title: Thoracic diaphragm

text: A hiatus hernia is a hernia common in adults in which parts of the lower esophagus or stomach that are normally in the abdomen pass/bulge abnormally through the diaphragm and are present in the thorax. Hernias are described as "rolling", in which the hernia is beside the oesophagus, or "sliding", in which the hernia directly involves the esophagus. These hernias are implicated in the development of reflux, as the different pressures between the thorax and abdomen normally act to keep pressure on the esophageal hiatus. With herniation, this pressure is no longer present, and the angle between the cardia of the stomach and the oesophagus disappear. Not all hiatus hernias cause symptoms however, although almost all people with Barrett's oesophagus or oesophagitis have a hiatus hernia.


title: Thoracic diaphragm

text: Hernias may also occur as a result of congenital malformation, a congenital diaphragmatic hernia. When the pleuroperitoneal membranes fail to fuse, the diaphragm does not act as an effective barrier between the abdomen and thorax. Herniation is usually of the left, and commonly through the posterior lumbocostal triangle, although rarely through the anterior foramen of Morgagni. The contents of the abdomen, including the intestines, may be present in the thorax, which may impact development of the growing lungs and lead to hypoplasia. This condition is present in 0.8 - 5/10,000 births. A large herniation has high mortality rate, and requires immediate surgical repair.


title: Thoracic diaphragm

text: Due to its position separating the thorax and abdomen, fluid abnormally present in the thorax, or air abnormally present in the abdomen, may collect on one side of the diaphragm. An X-ray may reveal this. Pleural effusion, in which there is fluid abnormally present between the two pleurae of the lungs, is detected by an X-ray of the chest, showing fluid collecting in the angle between the ribs and diaphragm. An X-ray may also be used to reveal a pneumoperitoneum, in which there is gas in the abdomen.


title: Thoracic diaphragm

text: The adoption of a deeper breathing pattern typically occurs during physical exercise in order to facilitate greater oxygen absorption. During this process the diaphragm more consistently adopts a lower position within the body's core. In addition to its primary role in breathing, the diaphragm also plays a secondary role in strengthening the posture of the core. This is especially evident during deep breathing where its generally lower position increases intra-abdominal pressure, which serves to strengthen the lumbar spine.


title: Thoracic diaphragm

text: The key to real core stabilization is to maintain the increased IAP while going through normal breathing cycles. [...] The diaphragm then performs its breathing function at a lower position to facilitate a higher IAP.


title: Thoracic diaphragm

text: Therefore, if a person's diaphragm position is lower in general, through deep breathing, then this assists the strengthening of their core during that period. This can be an aid in strength training and other forms of athletic endeavour. For this reason, taking a deep breath or adopting a deeper breathing pattern is typically recommended when lifting heavy weights.


title: Thoracic diaphragm

text: The existence of a membrane separating the pharynx from the stomach can be traced widely among the chordates. Thus the model organism, the marine chordate lancelet, possesses an atriopore by which water exits the pharynx, which has been claimed (and disputed) to be homologous to structures in ascidians and hagfishes. The tunicate epicardium separates digestive organs from the pharynx and heart, but the anus returns to the upper compartment to discharge wastes through an outgoing siphon.


title: Thoracic diaphragm

text: Thus the diaphragm emerges in the context of a body plan that separated an upper feeding compartment from a lower digestive tract, but the point at which it originates is a matter of definition. Structures in fish, amphibians, reptiles, and birds have been called diaphragms, but it has been argued that these structures are not homologous. For instance, the alligator diaphragmaticus muscle does not insert on the esophagus and does not affect pressure of the lower esophageal sphincter. The lungs are located in the abdominal compartment of amphibians and reptiles, so that contraction of the diaphragm expels air from the lungs rather than drawing it into them. In birds and mammals, lungs are located above the diaphragm. The presence of an exceptionally well-preserved fossil of "Sinosauropteryx", with lungs located beneath the diaphragm as in crocodiles, has been used to argue that dinosaurs could not have sustained an active warm-blooded physiology, or that birds could not have evolved from dinosaurs. An explanation for this (put forward in 1905), is that lungs originated beneath the diaphragm, but as the demands for respiration increased in warm-blooded birds and mammals, natural selection came to favor the parallel evolution of the herniation of the lungs from the abdominal cavity in both lineages.


title: Thoracic diaphragm

text: However, birds do not have diaphragms. They do not breathe in the same way as mammals and do not rely on creating a negative pressure in the thoracic cavity, at least not to the same extent. They rely on a rocking motion of the keel of the sternum to create local areas of reduced pressure to supply thin, membranous airsacs cranially and caudally to the fixed-volume, non-expansive lungs. A complicated system of valves and air sacs cycles air constantly over the absorption surfaces of the lungs so allowing maximal efficiency of gaseous exchange. Thus, birds do not have the reciprocal tidal breathing flow of mammals. On careful dissection, around eight air sacs can be clearly seen. They extend quite far caudally into the abdomen.


title: Star Trek V: The Final Frontier

text: Star Trek V: The Final Frontier is a 1989 American science fiction film directed by William Shatner and based on the television series "" created by Gene Roddenberry. It is the fifth installment in the "Star Trek" film series, and takes place shortly after the events of "" (1986). Its plot follows the crew of the USS "Enterprise"-A as they confront renegade Vulcan Sybok, who is searching for God at the center of the galaxy.


title: Star Trek V: The Final Frontier

text: The film was directed by cast member William Shatner, following two films directed by his co-star Leonard Nimoy. Shatner developed the initial storyline, in which Sybok searches for God but instead finds a devil; his primary inspiration was the phenomenon of televangelism and the high potential for fraud among its practitioners. Many involved objected to the script and plot. Series creator Gene Roddenberry disliked the original script, while Nimoy and DeForest Kelley objected to the premise that their characters, Spock and Leonard McCoy, would betray Shatner's James T. Kirk. The script went through multiple revisions to please the cast and Paramount Pictures, including cuts in the effects-laden climax of the film. Despite a Writers Guild strike cutting into the film's pre-production, Paramount commenced filming in October 1988. Many "Star Trek" veterans assisted in the film's production; art director Nilo Rodis developed the designs for many of the film's locales, shots, and characters, while Herman Zimmerman served as its production designer. Production problems plagued the film on set and during location shooting in Yosemite National Park and the Mojave Desert. Because effects house Industrial Light & Magic's best crews were busy and would be too expensive, the production used Bran Ferren's company for the film's effects, which had to be revised several times in order to lower production costs. The film's ending was reworked because of poor test-audience reaction and the failure of some planned special effects. Jerry Goldsmith, composer for "", returned to score "The Final Frontier".


title: Star Trek V: The Final Frontier

text: "The Final Frontier" was released in North America on June 9, 1989. It had the highest opening gross of any "Star Trek" film at that point and was number one in its first week at the box office; however, its grosses quickly dropped in subsequent weeks. The film received generally mixed to negative reviews by critics on release, and, according to its producer, "nearly killed the franchise." The next entry in the series, "" (1991), received a much more positive reception.


title: Star Trek V: The Final Frontier

text: The crew of the newly commissioned are enjoying shore leave after the starship's shakedown cruise, with Kirk, Spock, and McCoy camping at Yosemite National Park. Their leave is interrupted when the "Enterprise" is ordered by Starfleet Command to rescue a human, a Klingon, and a Romulan, all diplomats who have been taken hostage on Nimbus III, a planet set aside as a neutral location to advance dialogue between the Federation, Klingon Empire, and Romulan Star Empire. Learning of the "Enterprise" mission, the ambitious Klingon Captain Klaa decides to pursue Kirk for personal glory.


title: Star Trek V: The Final Frontier

text: On Nimbus III, the "Enterprise" crew discovers that Sybok, a renegade Vulcan, is behind the hostage crisis, prompting Spock to admit that Sybok is his previously unmentioned half-brother. After the Enterprise crew saves the hostages, Sybok reveals that the hostage-taking was a ruse to lure a starship, which he plans to use to travel to the mythical planet Sha Ka Ree. Sybok believes that it lies behind the Great Barrier, a powerful energy field at the center of the galaxy, and that God is located there. To take control of the ship, Sybok uses his ability to reveal and heal the innermost pain of a person through the Vulcan mind meld, thus gaining the loyalty of most of the crew. McCoy's pain is that he had helped fulfill his terminally ill father's request to die only to later find that a cure could have saved his father's life, which has caused him years of guilt. Spock's pain is the knowledge that his father rejected him at birth for being "too human", though he is unmoved by the experience since he had since made peace with his father. Kirk refuses to let Sybok remove his pain, claiming that it is necessary to make him human. Sybok reluctantly declares a truce with Kirk, realizing that he needs his experience to navigate the ship to Sha Ka Ree.


title: Star Trek V: The Final Frontier

text: The "Enterprise" successfully breaches the Great Barrier, unaware that they are being followed by Captain Klaa's warship, a Klingon bird-of-prey. They discover a lone barren planet, and Sybok, Kirk, Spock, and McCoy take a shuttlecraft down to the surface. It seems uninhabited, but after Sybok calls out, a glowing field appears which quickly morphs through many forms representing various religions before settling into the image of a bearded human face, to which Sybok explains that they have come for "your wisdom". The entity asks how they breached the barrier, and upon being told about the "Enterprise", it declares that it will make use of the ship to carry its wisdom to every corner of the universe. A skeptical Kirk asks, "What does God need with a starship?", and when the entity asks who he is, Kirk expresses doubt that the actual supreme being would not already know. Irritated, the entity attacks him and then Spock as well, and they discover that it is a powerful and malicious being who had been entrapped to Sha Ka Ree in the distant past, with the Great Barrier put in place to keep it from escaping.


title: Star Trek V: The Final Frontier

text: Realizing his earlier naiveté, Sybok apologizes and attempts to distract the entity with a mind-meld, allowing the others the opportunity to escape. Kirk orders the "Enterprise" to fire a barrage of photon torpedos, but while Sybok is killed, the entity is only weakened. Spock and McCoy beam back to the ship right before the Klingon ship unexpectedly attacks and damages the "Enterprise", stranding Kirk on the planet with the weakened and enraged entity. Right as he is about to be killed, the Klingon Bird of Prey swoops down and destroys the entity with a volley of disruptor fire. Kirk is beamed aboard the Klingon ship where Spock is unexpectedly waiting. As Spock explains, he convinced the Klingon General Korrd (one of Sybok's hostages who had become a loyal follower) to order Captain Klaa to stand down and apologize for his actions, which Klaa grudgingly does. After returning to Earth, Kirk, Spock, and McCoy resume their camping trip at Yosemite.


title: Star Trek V: The Final Frontier

text: The other members of the USS "Enterprise"-A crew include chief engineer Montgomery Scott (James Doohan), helmsman Hikaru Sulu (George Takei), navigator Pavel Chekov (Walter Koenig), and communications officer Nyota Uhura (Nichelle Nichols). Takei said that despite studio pressure to complete the film on time, Shatner maintained a creative and enthusiastic atmosphere on set. "I have enormous admiration for his ability to block that kind of pressure from seeping on to the set." Takei said that he found the biggest challenge of the film was learning to ride horses. Moreover, Takei acknowledged, "despite our sometimes strained personal history, I found working with Bill [Shatner] as a director to be surprisingly pleasant."


title: Star Trek V: The Final Frontier

text: Casting director Bill Shepard was in charge of filling additional roles. He combed through initial auditions with promising actors, then presented his choices to Shatner. Both men called the actors back as many as two or three times before each role was cast. Additional players include Todd Bryant as Klingon Captain Klaa, with Spice Williams-Crosby as Vixis, Klaa's lieutenant. Bryant was playing ping pong at a beach party when a casting director offered him the role. Bryant performed his audition twice, as Shatner requested that he repeat his performance speaking in Klingon. Williams-Crosby thought Vixis was Kirk's girlfriend when she arrived for her audition, but recalled afterwards that it was "fun" to play a villain. David Warner, Charles Cooper, and Cynthia Gouw play the Federation, Klingon, and Romulan ambassadors to Nimbus III. Warner did not audition, but agreed to the role after Shatner swore that his character would survive the film. The director originally intended George Murdock to play the Klingon diplomat Korrd, but changed his mind on seeing Cooper's performance. Murdock was recast as the "God" entity. Bill Quinn played McCoy's father in one of his last roles. Producer Harve Bennett made a cameo as a Starfleet admiral.


title: Star Trek V: The Final Frontier

text: During the 1966–69 "" television series, Shatner and Nimoy's lawyers drafted what Shatner termed a "favored nations clause", with the result that whatever Shatner received—e.g., a pay raise or script control—Nimoy also got and vice versa. Nimoy had directed "" and "Star Trek IV: The Voyage Home". Shatner had previously directed plays and television episodes; when he signed on for "The Voyage Home" following a pay dispute, Shatner was promised he could direct the next film.


title: Star Trek V: The Final Frontier

text: Shatner conceived his idea for the film's story before he was officially given the director's job. His inspiration was televangelists; "They [the televangelists] were repulsive, strangely horrifying, and yet I became absolutely fascinated," he recalled. Shatner was intrigued that not only did these personalities convince others God was speaking directly to them, but they became wealthy by what Shatner considered false messages. The televangelists formed the basis for the character Zar, later Sybok. Shatner's first outline was titled "An Act of Love", and many of its elements—the Yosemite vacation, the abduction of Klingon, human and Romulan hostages on the failed paradise planet—survived to the final film. In Shatner's early draft, Kirk is overwhelmed by Zar's superior numbers of followers and Spock, McCoy and the rest of the "Enterprise" crew come to believe in Zar's divinity. Kirk feigns acceptance of Zar's beliefs to travel with him to the God planet, which to Shatner would be a desolate, fiery waste. When Kirk confronts "God", the image of the being transforms into that of Satan, and Kirk, Spock, and McCoy split up in their escape. Kirk eludes capture but goes back to save his friends from being carried away to Hell.


title: Star Trek V: The Final Frontier

text: Shatner had presented his idea to studio head Frank Mancuso while filming "The Voyage Home". Mancuso liked Shatner's idea and agreed to hire a writer to draft a film treatment. Shatner wanted novelist Eric Van Lustbader, but negotiations between Lustbader and Paramount failed over the author's requested $1 million salary. Shatner dictated the story himself and gave it to Paramount's production president Ned Tanen for input.


title: Star Trek V: The Final Frontier

text: Producer Harve Bennett was exhausted by his work on the previous three "Star Trek" films and wanted to move on, feeling that he was not part of the "Star Trek" "family" and that he had been mistreated by Nimoy. When Shatner tried to convince Bennett to reconsider, the producer insisted on a meeting at his home. After several hours of discussion Bennett agreed to return. Bennett disagreed with several elements of Shatner's story, feeling that because no one could assuredly answer the question of God's existence, the ending of the film would never be satisfying. Bennett also told Shatner that the film had the feeling of a tone poem rather than an adventure story. The studio agreed with Bennett, reasoning that the subject matter could be too weighty or offensive to theatergoers.


title: Star Trek V: The Final Frontier

text: Shatner and Bennett began reworking the story. Concerned that knowing the renegade Sybok's motivation from the beginning of the story was anticlimactic, the team moved the revelation to later in the story. Shatner said that Bennett also suggested turning the God entity into an "evil alien pretending to be God for his own gain". Having satisfied themselves and Paramount with the adjustments, Shatner and Bennett approached "" writer and director Nicholas Meyer to pen the script, but he was unavailable. Bennett found a script by David Loughery and showed his work to Shatner, who agreed that he would be a good fit for the task of scripting "Star Trek".


title: Star Trek V: The Final Frontier

text: Not everyone was happy with the story. "Star Trek" creator Roddenberry objected to the characters' search for God in general, and more particularly, the idea of a God as portrayed by Western religion. One of Roddenberry's employees suggested some of his employer's animosity towards the story stemmed back to "Star Trek: The Motion Picture". Roddenberry had wanted to approach that film with similar ideas that investigated the nature of God but was rejected by Paramount. Roddenberry, Nimoy and Kelley all disagreed that Spock and McCoy would betray Kirk, which Loughery explained was done to give a conflict in which "one man stands alone" from the rest.


title: Star Trek V: The Final Frontier

text: Loughery stopped work on the script when the Writers Guild of America went on strike, and the production was further delayed when Nimoy began working on another project. During this time, Shatner reconsidered elements of the "Star Trek V" story; he made Sybok's character softer and more sympathetic. When the writers' strike ended Loughery returned to work on the script while Shatner flew to the Himalayas for a job. When he returned, he felt betrayed by Loughery's revisions, which he felt transformed the search for God into the search for the mythical paradise Sha Ka Ree—a word play on "Sean Connery", whom they wanted for Sybok's role. Though Shatner convinced Bennett and Loughery to revise much of the script, Sha Ka Ree remained; it was changed to a place of ultimate knowledge of which Sybok had received visions. The script was also rewritten to address Nimoy and Kelley's concerns.


title: Star Trek V: The Final Frontier

text: While Roddenberry, Kelley and Nimoy gave their approval to the revised script, Paramount was concerned that the film would go over-budget as written and ordered cuts. Shatner's envisioned angels and demons at the film's climax were converted to rock monsters that the false god would animate from the earth. Shatner wanted six of the creatures, but was forced to accept just one. Concerned that the franchise's momentum following "The Voyage Home" had disappeared, Paramount rushed the film into production in late 1988 despite the writers' strike cutting into pre-production.


title: Star Trek V: The Final Frontier

text: Nilo Rodis, who had worked on two previous "Star Trek" features, was appointed the role of art director, and worked with Shatner to establish the film's visual design. Shatner sought a grittier and more realistic feel to the "Star Trek" universe, and so the two worked together to visualize the film from start to finish. After Shatner explained the entire story in a day-long session, Rodis went home and sketched out each scene from the script. Shatner was pleased with the results, especially with Rodis' designs for Shatner's most expansive or dramatic shots.


title: Star Trek V: The Final Frontier

text: Rodis' input in developing the early character and costume designs was significant. Shatner praised his costume designs as being futuristic but plausible and in keeping with the continuity established in previous "Star Trek" films. After being disappointed by the costume designers approached to realize Rodis' ideas, Shatner suggested that Rodis become the costume designer as well. Bennett hired Dodie Shepard as the costume supervisor; Shepard's role was to oversee the costume fabrication and keep track of the clothes during filming. To save on costs, Shepard clothed extras with existing items from Western Costume's warehouses. The constrained budget meant Shatner could not completely redesign the Starfleet uniforms, but Rodis created new brown field uniforms for the film's location scenes as well as the leisure clothes the crew wears during shore leave.


title: Star Trek V: The Final Frontier

text: Rodis and Shatner also drew up sketches of what the various aliens seen in the film would look like. Shatner picked Kenny Myers as the special-effects makeup artist. Myers discussed the sketches with Shatner and made casts of actors' faces using dental alginate. These casts were used for close-up, high-quality "A" makeups, as well as less complicated masks for far-away and background characters. Shatner hired Richard Snell as makeup supervisor, advising him to make each Klingon forehead distinct.


title: Star Trek V: The Final Frontier

text: Shatner hired Herman Zimmerman as production designer. His decision was based on Zimmerman's work on the sets for "", and he felt that the designer could convey Shatner's futuristic yet grounded aesthetic. Zimmerman was immediately put in charge of designing all-new sets for the bridges of "Enterprise" and the Klingon Bird-of-Prey, elevator and access shafts, and Nimbus III interiors. At one point, he was building five sets at once. Art department head Michael Okuda created LCARS backlit controls on the Klingon ship and "Enterprise". The corridors for the "Enterprise" were the same as those used in the "Next Generation" television series. The bridge set alone cost $250,000. The Nimbus III city of Paradise was one of the last locations to be designed and created, because its design relied on what exterior location and terrain was used. Zimmerman created a sketch of the town's layout over three days, drawing inspiration from a circular Moroccan fortress. Creation of the city cost $500,000 and took five weeks of construction in heat.


title: Star Trek V: The Final Frontier

text: Tim Downs scouted possible areas for location filming. He looked for a location that could stand in for three different venues without the production having to move or change hotels: the film's opening scene; the God planet's establishing shots; and the Nimbus III Paradise City. Downs was familiar with the Mojave desert and thought that locations near Ridgecrest, California, would serve the production's needs, so he took photos based on sketches Rodis had provided of what the locations might look like. Downs also shot photos with filters and tried to accomplish dust effects with his car to replicate ideas for how some sequences would be shot. When Downs returned with the photos, Shatner felt that the locations the scout found would be perfect for the film.


title: Star Trek V: The Final Frontier

text: Principal photography began in October 1988, in and around Los Angeles, California. Shortly before the beginning of location shooting, Hollywood union truck drivers or teamsters went on strike to protest pay cuts and overtime changes. With deadlines looming, the production searched for non-union drivers, aware that the Teamsters might retaliate by sabotaging equipment or flying airplanes above the filming to ruin audio recordings. After one of the production's camera trucks exploded in the studio parking lot, the non-union drivers headed to Yosemite National Park under cover of darkness with a police escort.


title: Star Trek V: The Final Frontier

text: The film's Yosemite scenes were all shot on location. Long shots of Kirk scaling the mountain were filmed with stunt doubles, while Shatner's closer shots had him on a fiberglass set positioned in front of the camera, with the real mountains visible in the background. Aided by two trainers, Shatner had spent weeks at the Paramount lot, learning to climb a wooden replica. Laszlo scouted out a tall peak on which the production created a rock face with safety net. The overhead shot gave the impression Kirk was climbing at a great height, while unnatural background features such as swimming pools were camouflaged. In the scene, Spock watches Kirk's ascent, levitates up behind him as a pest giving suggestions with the outcome that Kirk slips and Spock has to saves him using levitating boots. Most of the shots framed Nimoy from the waist up; in these scenes the actor was supported by a crane that gave the appropriate "float" to achieve the effect. Bluescreen footage of Shatner falling was shot later at Paramount and composited, while stuntman Ken Bates set a record for the highest American descender fall by plummeting off El Capitan—with a wire support rig—for long shots. In reviewing the dailies of the first two days of shooting, the production realized that a pine tree in the frame during Kirk and Spock's mountain dialogue ruined the illusion of height, while a shot of Shatner clinging to the face of El Capitan appeared muddy due to clouds obscuring the sun and ruining the depth of field. The scenes had to be reshot later.


title: Star Trek V: The Final Frontier

text: After the Yosemite shots, location shooting moved to desert locales. Nimbus III and its town, Paradise City, were recreated in the Mojave. The town was created as a haphazard collection of spaceship parts and futuristic scrap. Shatner "cracked" during the filming in heat, insulting the head electrician and ignoring Laszlo's request for additional setup time. When a driver failed to appear and stranded Shatner and a skeleton crew, a park ranger came to the rescue and the production managed to film scenes of Sybok's followers before they lost daylight. Shatner called the resulting half-jogging pace of the dehydrated extras "the Sybok shuffle". The production spent three more weeks filming the rest of the desert scenes, finishing the last night scene shortly before sunrise and the trip back to Los Angeles.


title: Star Trek V: The Final Frontier

text: At Paramount, the crew filmed all the scenes that would take place on soundstages, including the "Enterprise" and Bird-of-Prey sets, the Paradise City interiors, and the campfire location. Production was smoother on set, and the crew shot scenes ahead of schedule. The crew fabricated a stand-in set for the God planet location, where additional scenes were filmed to combine with the location footage. Spock's catching of Kirk as the captain falls off El Capitan was filmed against a set that replicated the forest floor and was rotated ninety degrees.


title: Star Trek V: The Final Frontier

text: Shatner scheduled the campfire scenes to be the last ones shot, after which the cast and crew had a small celebration before a traditional wrap party later. The cast celebrated the end of filming in the last week of December 1988, and gave a press conference on the set of the "Enterprise" bridge on December 28. Shatner returned to Paramount Studios a few days after principal photography had wrapped to organize the film's post-production schedule. This included showing a rough cut of the film—minus the special effects—to studio personnel. Shatner recalled that the film received praise and left the screening "reveling" in its reception; it turned out to be a "momentary victory" once he saw the special effects.


title: Star Trek V: The Final Frontier

text: During the writers' strike, producer Ralph Winter confronted what writer Paul Mandell termed an "unenviable" effects situation. Industrial Light & Magic had provided the effects for the three previous "Star Trek" films, and Winter wanted them to work on "The Final Frontier". However, all of the effects house's best technicians were busy working on "Indiana Jones and the Last Crusade" and "Ghostbusters II". With a stretched budget and short timeframe, Winter had to look elsewhere. To save time and money, he planned to create as many effects as he could either on stage, or through camera trickery. The producers solicited test footage from various effects houses to judge which was best able to create the film's main effects, including the planet Sha Ka Ree and the godlike being which resided there. Bran Ferren's effects company, Associates and Ferren, was chosen. Ferren had worked on films such as "Altered States" and "Little Shop of Horrors".


title: Star Trek V: The Final Frontier

text: Associates and Ferren had three months to complete the effects work—around half the usual industry timeframe. Shatner insisted on viewing much test footage before he proceeded with each shot, requesting time-consuming changes if he did not like an effect. Ferren promoted a "low-tech" approach to realizing complicated effects, but his cost estimates were too expensive and interfered with the scope of other live-action sequences. Winter recalled that the production had budgeted $4 million for the film's effects, slightly more than "The Voyage Home". "The first pass", he said, "with all the things [Shatner] wanted, was [$5 or $6] million". Combined with Ferren's figures, the film's budget climbed to $33 million. The studio called a meeting with executives and began cutting out effects shots.


title: Star Trek V: The Final Frontier

text: To reduce the optical effects workload, Ferren rejected bluescreen compositing, opting instead for rear projection. This cheaper process, he reasoned, would save time, and would make sense for elements such as the "Enterprise"s bridge viewer, where compositing would lack the softness of a real transmitted image. Designer Lynda Weinman used a Mac II to create the animatics cut into the film during production, which were eventually replaced by the film's finished effects.


title: Star Trek V: The Final Frontier

text: The rock monster climax of the film was ultimately dropped due to difficulties during filming. The monster, dubbed the Rockman, was a large latex rubber suit that breathed fire on command. Effects personnel smoked cigarettes and blew smoke into the suit's tubing, loading it with smoke that it would slowly emit, obscuring some obvious rubber parts. On the last day of location shooting, the Rockman began suffering mechanical problems; the suit stopped breathing fire, and the desert wind dissipated the smoke. The result, Shatner wrote, was that "our guy in the silly rubber suit ultimately just looked like ... well, a guy in a silly rubber suit." With no time to return to the location, Shatner was forced to get wide shots and hope that the setting could be reproduced in the studio, but admitted that it was likely not going to work for the film.


title: Star Trek V: The Final Frontier

text: Once back at the studio for non-location filming, Shatner and Ferren met to discuss how to replace the Rockman. The agreed-upon idea was an "amorphous blob of light and energy" that would rise up and chase after Kirk, shape-shifting while in pursuit. The visuals took weeks before they were ready to be shown after the completion of principal photography. When Shatner saw the effects, however, he was extremely disappointed with the low quality. Bennett and Shatner attempted to get money to reshoot the final scenes of the film, but Paramount turned them down.


title: Star Trek V: The Final Frontier

text: ILM delivered the main "Enterprise" model, which was built by Magicam in 1978 for "Star Trek: The Motion Picture", to Associates and Ferren. However, scenes which included the "Enterprise" in the Earth-orbiting Spacedock platform, as well as the Spacedock itself, were taken directly from ILM's previous work in "Star Trek IV: The Voyage Home". The "Enterprise" model had been damaged when it was loaned out for touring purposes, meaning the 30,000 panels on the model had to be repainted by hand. While production wrapped, Ferren continued work on the miniatures and other optical effects at his New Jersey studio. The opticals were completed in Manhattan before being sent west; for example, bluescreen footage of the motion controlled miniatures was filmed in Hoboken, New Jersey. In New York, the blue screen was replaced by a moving starfield—a single finished shot of a ship moving through space required as many as fifty pieces of film. The Great Barrier effects were created using chemicals, which were dropped into a large water tank to create swirls and other reactions. The "God column", in which the false god appeared, was created by a rapidly rotating cylinder through which light was shone; the result appeared on film as a column of light. Ferren used a beam splitter to project actor George Murdock's head into the cylinder, giving the appearance that the false god resided within the column.


title: Star Trek V: The Final Frontier

text: Days after filming was completed, Shatner returned to Paramount to supervise the film's edit, soundscape creation and score, and integration of optical effects. Editor Peter E. Berger had already assembled rough cuts of various sequences, and with only weeks before the film's scheduled completion, the production team set about the task of salvaging the film's ending through editing. The false god's screen time was reduced, and Ferren's "god blob" effect was replaced with a closeup of the actor's face, along with shots of lightning and smoke. At the time, Shatner felt that the edits "pulled a rabbit out of a hat", solving many of the film's problems.


title: Star Trek V: The Final Frontier

text: Shatner's cut ran slightly over two hours (not including end credits or the opticals), which Paramount thought was too long. Their target runtime was one hour forty-five minutes, which would guarantee twice-nightly theatrical screenings. Bennett was handed the task of shortening the film's running time, despite Shatner's view that nothing could possibly be removed. Shatner was horrified by Bennett's edit, and the two haggled over what parts to restore or cut.


title: Star Trek V: The Final Frontier

text: In early test screenings, the film received negative reviews. Of the first test audience, only a small portion considered the film "excellent", a rating that most other "Star Trek" films had enjoyed. Segments of the film were re-edited for the theatrical release. Five minutes of footage was excised to improve the film's pacing, and an additional scene was included on the Bird-of-Prey to make the circumstances of Kirk's rescue clearer. The second screening, with the final effects and sound in place, received much better reviews.


title: Star Trek V: The Final Frontier

text: Music critic Jeff Bond wrote that Shatner made "at least two wise decisions" in making "The Final Frontier"; beyond choosing Luckinbill as Sybok, he hired Jerry Goldsmith to compose the film's score. Goldsmith had written the Academy Award-nominated score for "Star Trek: The Motion Picture", and the new "Trek" film was an opportunity to craft music with a similar level of ambition while adding action and character—two elements largely missing from "The Motion Picture". Goldsmith did not want to accentuate the film's comedy with music, feeling it would "[take] drama to the point of silliness". He focused on the God planet as his most difficult task.


title: Star Trek V: The Final Frontier

text: Goldsmith's main theme begins with the traditional opening notes from Alexander Courage's original television series theme; an ascending string and electronic bridge leads to a rendition of the march from "The Motion Picture". According to Jeff Bond, Goldsmith's use of "The Motion Picture"s march led to some confusion among "" fans, as they were unfamiliar with the music's origins. Another theme from "The Motion Picture" to make a return appearance is the Klingon theme from the 1979 film's opening scene. Here, the theme is treated in what Bond termed a "Prokofiev-like style as opposed to the avant-garde counterpoint" as seen in "The Motion Picture". Goldsmith also added a crying ram's horn.


title: Star Trek V: The Final Frontier

text: The breadth of "The Final Frontier"s locations led Goldsmith to eschew the two-themed approach of "The Motion Picture" in favor of leitmotifs, recurring music used for locations and characters. Sybok is introduced with a synthesized motif in the opening scene of the film, while when Kirk and Spock discuss him en route to Nimbus III it is rendered in a more mysterious fashion. The motif also appears in the action cue as Kirk and company land on Nimbus III and try to free the hostages. When Sybok boards the "Enterprise", a new four-note motif played by low brass highlights the character's obsession. The Sybok theme from then on is used in either a benevolent sense or a more percussive, dark rendition. Arriving at Sha Ka Ree, the planet's five-note theme bears resemblance to Goldsmith's unicorn theme from "Legend"; "the two melodies represent very similar ideas: lost innocence and the tragic impossibility of recapturing paradise," writes Bond. The music features cellos conveying a pious quality, while the appearance of "God" begins with string glissandos but turns to a dark rendition of Sybok's theme as its true nature is exposed. As the creature attacks Kirk, Spock and McCoy, the more aggressive Sybok theme takes on an attacking rhythm. When Spock appeals to the Klingons for help, the theme takes on a sensitive character before returning to a powerful sequence as the ship destroys the god-creature.


title: Star Trek V: The Final Frontier

text: The original soundtrack for the film was originally released by Epic Records, and included nine score tracks (mostly out of film order) and the song "The Moon Is a Window to Heaven" by Hiroshima. On Tuesday November 30, 2010, La-La Land Records reissued the soundtrack in a two-CD edition featuring the film's complete score on the first disc and the original soundtrack album and some alternate cues on the second disc.


title: Star Trek V: The Final Frontier

text: Mark Mangini served as "The Final Frontier"s sound designer; he had previously worked on "The Voyage Home". Because Mangini was concerned about creating continuity within "Star Trek"s sounds, he decided to reuse some effects rather than create new and different-sounding ones—as such, the Bird-of-Prey's cloak effect, beaming sounds, and the "Enterprise" engines sound similar to that of past movies. Mangini collaborated with Shatner to work out how the completely new effects would sound. For Sybok's mind melds, Shatner wanted the sounds of beating hearts and breathing.


title: Star Trek V: The Final Frontier

text: Mangini was also responsible for the film's foley and dialogue replacement; foley editors created background audio in sync with actions on screen to enrich the soundscape. The sound of Klingons walking, for example, was conveyed with chains and leather for a "rough" sound.


title: Star Trek V: The Final Frontier

text: "The Final Frontier" appeared amidst several other films that grappled with quests for God and spiritual meaning; author Peter Hansenberg regarded the film as part of an "almost fashionable" trend of 1980s science fiction movies with religious motifs. Regent's Park College professor and Baptist minister Larry Kreitzer argues the film was "deliberately constructed" to raise the issues of God and the Biblical concept of paradise, Eden. Dixie State College professor Ace Pilkington went further, saying that after the "theological preoccupations" of the television series and previous films, "where else can the "Enterprise" go ... but in quest of God?" Pilkington notes that "The Final Frontier" has roots in many plots from the series including "The Way to Eden" (which also deals with a brilliant man hijacking the "Enterprise" to find the place of creation), "", and ""; a common thread between the paradises described is that they are always "too good to be true". John S. Schultes agrees, pointing out that the idea of paradise has been seen many times in the series, but almost always illusory or deadened.


title: Star Trek V: The Final Frontier

text: While many "Star Trek" episodes dealt with false deities, "The Final Frontier" is one of the few that, in the words of religious scholar Ross Shepard Kraemer, "intentionally confronted and explored theological questions, including the existence of God." Theologian Larry Kreitzer dubbed it the film most preoccupied with religious ideas. According to the film, centuries in the future, beliefs in Eden persist, even among other alien races such as the Klingons and Romulans. Moreover, the view of God is homogenized—no one disputes Sybok's references to God as a "he". Kreitzer finds that the film's theological interpretation is offered by Kirk's words: "Maybe He [God] is not out there, Bones. Maybe He's right here, in the human heart."


title: Star Trek V: The Final Frontier

text: "The Final Frontier" was expected to be one of the summer's biggest movies and a sure hit, despite its appearing in a market crowded with other sequels and blockbusters such as "Indiana Jones and the Last Crusade", "Ghostbusters II", and "Batman". Never before had so many sequels been released at the same time. Analysts expected "The Final Frontier" to make nearly $200 million.


title: Star Trek V: The Final Frontier

text: Marketing included an MS-DOS computer game "", part of an increasing trend of game tie-ins to movies. J. M. Dillard wrote the film's novelization, which was on "The New York Times" Best Seller list for four weeks. Paramount sold "Star Trek"-branded apparel through catalogues, and Kraft made a "Star Trek"-branded marshmallow dispenser. While "Star Trek" had a built-in fan market, marketing tie-ins were risky at the time and even high-grossing films could not guarantee success of related merchandise. Unlike other summer blockbusters, "Star Trek" had no mass-market appeal and no major food or beverage promotions, but sold pins and posters in theaters, bypassing retailers; other merchandise included pins and a pewter statue of "Enterprise", designed to appeal to "Star Trek"s relatively small but loyal group of collectors. Paramount released teaser posters for "Star Trek V" depicting a cinema seat in outer space with the tagline "Why are they putting seatbelts in theaters this summer?"


title: Star Trek V: The Final Frontier

text: In its first week, "The Final Frontier" was number one at the domestic box office. Its $17.4 million opening on 2,202 screens beat the $16.8 million total of "The Voyage Home" and made it the best "Star Trek" opening weekend to that point. "The Voyage Home", however, had played in only 1,349 theaters at a time with lower ticket prices. In its second week "The Final Frontier" tumbled 58% to make $7.1 million; in its third week it grossed only $3.7 million. It had a wide release of ten weeks, shorter than that of any "Star Trek" film before it.


title: Star Trek V: The Final Frontier

text: "The Final Frontier" grossed $49,566,330 in the domestic box office for a global total of $63 million. The season proved to be another record-breaker for the film industry, with domestic summer box-office revenues of $2.05 billion. "The Final Frontier" was the season's tenth-best-grossing film, although it failed to make expected returns. It and "Pink Cadillac" were the early summer's biggest box-office disappointments.


title: Star Trek V: The Final Frontier

text: On review aggregator Rotten Tomatoes, the film has an approval rating of 22% based on 49 reviews, with an average rating of 3.90/10. The site's critics' consensus reads: "Filled with dull action sequences and an underdeveloped storyline, this fifth Trek movie is probably the worst of the series." On Metacritic, it has a weighted average score of 43 out of 100 based on 16 reviews, indicating "mixed or average reviews". Audiences surveyed by CinemaScore gave the film a grade "A−" on scale of A to F.


title: Star Trek V: The Final Frontier

text: Rob Lowing of "The Sun Herald" called the film "likeable but average." The "Chicago Sun-Times" Roger Ebert and "The Washington Post"s Rita Kempley gave the film negative reviews, calling the film "a mess" and "a shambles," respectively. "The New York Times" Caryn James considered the film to be disappointing to fans and non-fans alike, while Chris Hicks of the "Deseret News" disagreed feeling that the film approached issues in the same vein as the television series and that fans would enjoy it. Ansen and Lowing considered Shatner's direction during action sequences weak with Lowing adding that the second half of the film felt directionless. Hicks wrote that the film's broad humor gave the film an inconsistent tone. In contrast, Chris Dafoe of the Toronto "The Globe and Mail" called it "the most intentionally funny" episode of the film series. "The Christian Science Monitor"s David Sterritt stated that at its best, "The Final Frontier" showed "flashes" of the humor that propelled "The Voyage Home", and Lowing deemed Shatner's direction at its best during comedic moments.


title: Star Trek V: The Final Frontier

text: Critics such as "Newsweek"s David Ansen judged the principal characters' performances satisfactory; "these veterans know each other's moves so well they've found a neat comic shorthand that gets more laughs out of the lines than they deserve," Ansen wrote. Stan James of "The Advertiser" wrote that Warner was wasted in his role and most characters lacked any "drive and motivation." In comparison, Luckinbill's Sybok received praise from critics such as "USA Today"s Mike Clark who wrote that "he has the voice and stature of the golden screen's most scintillating intellectual villains," although he felt that he never seemed threatening or suspenseful. James considered Sybok the most "distinctive, compelling villain" of the series since Khan Noonien Singh in "Star Trek II: The Wrath of Khan".


title: Star Trek V: The Final Frontier

text: The special effects were generally considered poor. Murphy wrote that the film fell apart after the arrival at Sha Ka Ree, where the "great special effects that graced parts I through IV are nowhere to be seen." Ebert's review agreed saying that the visuals managed to inspire awe ever so briefly before dissolving into "an anticlimactic special effects show with a touch of "The Wizard of Oz" thrown in for good measure." Kempley wrote the "Enterprise"s objective was "to pass through an impenetrable (Ha!) swirl of what appears to be cosmic Windex, beyond which is the planet Shockara, home of God, or perhaps California shot through a purple filter."


title: Star Trek V: The Final Frontier

text: Bennett blamed part of "The Final Frontier"s failure on the change from a traditional Thanksgiving-season "Star Trek" opening to the sequel-stuffed summer release period and the diffusion of "Star Trek" fan viewership following the premiere of "The Next Generation". Winter felt they should have recognized the film's plot was too reminiscent of V'ger from "Star Trek: The Motion Picture" and that the search for God was a mistake; while he felt many parts of the film were good, they "smoked [their] own press releases" and nearly killed the franchise. Initially, Shatner believed that the film would get a positive response. In the morning after the opening night, he woke Nimoy up to tell him that the "Los Angeles Times" had given "The Final Frontier" a positive review. Soon after a local television reporter also gave the film a good review and Shatner recalled that he incorrectly "began sensing a [positive] trend." He later agreed that the film nearly ended the film series and looking back on the film called it a "failed but glorious attempt" at a thought-provoking film that did not come together. "Star Trek" creator Roddenberry considered elements of this film to be "apocryphal at best," and particularly disliked the idea that Sarek had fathered a child (Sybok) with a Vulcan before Amanda. Nevertheless, the film is considered canon. Even George Takei expected the film to be a disappointment because "the script seemed rather a muddle...as if three separately interesting stories force-sealed together into one" which "made for a confusing and ultimately tiresome two hours."


title: Star Trek V: The Final Frontier

text: Considered a critical and commercial failure, the poor performance of "The Final Frontier" jeopardized the production of further "Star Trek" features. Bennett was given the go-ahead to begin work on his own prequel concept that would have cast new actors to play the main cast at Starfleet Academy. Loughery worked with Bennett on a story inspired by "Santa Fe Trail". When Paramount president Ned Tanen resigned, support for Bennett's prequel idea evaporated. Paramount instead wanted another film with the original cast and Bennett decided to leave the franchise. Winter remained with the production and "The Wrath of Khan" director Nicholas Meyer returned to direct "Star Trek VI: The Undiscovered Country", the last movie starring the entire original cast.


title: Star Trek V: The Final Frontier

text: At the 10th Golden Raspberry Awards, "The Final Frontier" was nominated for six Razzie Awards (Worst Picture, Worst Director, Worst Actor for Shatner, Worst Supporting Actor for Kelley, Worst Screenplay, and Worst Picture of the Decade), winning three (Picture, Director, and Actor).


title: Star Trek V: The Final Frontier

text: The film was released on VHS, pan-and-scan LaserDisc, and Betamax on December 21, 1989. The video was among the top-selling videocassettes for weeks after its release, and it enjoyed a resurgence in popularity in the months leading to the release of its sequel; it was Paramount's top-selling title in the third quarter of 1991. A LaserDisc version of the film was released by Pioneer LDCA; "The Final Frontier" was the 21st-best-selling title for the platform in 1990.


title: Star Trek V: The Final Frontier

text: The film was released on DVD-Video on April 20, 1999, as a bare-bones edition with no bonus extras. It was re-released on DVD as a 2-Disc Special Collector's Edition on October 14, 2003, with bonus extras added, including footage of the principal photography wrap press conference, an interview with Shatner the day before filming began, a retrospective documentary and a commentary track by Shatner and his daughter Liz.


title: Star Trek V: The Final Frontier

text: Paramount released "The Final Frontier" Blu-ray Disc in May 2009 to coincide with the release of J. J. Abrams' "Star Trek", along with the other five films featuring the original crew, packaged as "Star Trek: Original Motion Picture Collection". "The Final Frontier" was remastered in 1080p high definition from the 2000 high-definition master prepared for the DVD. All six films in the set have new 7.1 Dolby TrueHD audio. The disc features a new commentary track by renowned "Star Trek" authors and contributors Michael and Denise Okuda, Judith and Garfield Reeves-Stevens, and Daren Dochterman, as well as the previously recorded commentary track by Shatner and his daughter. Shatner wanted to produce a director's cut of the movie similar to that of "Star Trek: The Motion Picture" and "" with improved special effects and scenes omitted from the original release; however, he stated in an interview that Paramount would not support the venture.


title: Quantum suicide and immortality

text: Quantum suicide is a thought experiment in quantum mechanics and the philosophy of physics. Purportedly, it can falsify any interpretation of quantum mechanics other than the Everett many-worlds interpretation by means of a variation of the Schrödinger's cat thought experiment, from the cat's point of view. Quantum immortality refers to the subjective experience of surviving quantum suicide. This concept is sometimes conjectured to be applicable to real-world causes of death as well.


title: Quantum suicide and immortality

text: As a thought experiment, quantum suicide is an intellectual exercise in which an abstract setup is followed through to its logical consequences merely to prove a theoretical point. Virtually all physicists and philosophers of science who have described it, especially in popularized treatments, underscore that it relies on contrived, idealized circumstances that may be impossible or exceedingly difficult to realize in real life, and that its theoretical premises are controversial even among supporters of the many-worlds interpretation. Thus, as cosmologist Anthony Aguirre warns, "[...] it would be foolish (and selfish) in the extreme to let this possibility guide one's actions in any life-and-death question."


title: Quantum suicide and immortality

text: Hugh Everett did not mention quantum suicide or quantum immortality in writing; his work was intended as a solution to the paradoxes of quantum mechanics. Eugene Shikhovtsev's biography of Everett states that "Everett firmly believed that his many-worlds theory guaranteed him immortality: his consciousness, he argued, is bound at each branching to follow whatever path does not lead to death". Peter Byrne, author of a biography of Everett, reports that Everett also privately discussed quantum suicide (such as to play high-stakes Russian roulette and survive in the winning branch), but adds that "[i]t is unlikely, however, that Everett subscribed to this [quantum immortality] view, as the only sure thing it guarantees is that the majority of your copies will die, hardly a rational goal."


title: Quantum suicide and immortality

text: Among scientists, the thought experiment was introduced by Euan Squires in 1986. Afterwards, it was published independently by Hans Moravec in 1987 and Bruno Marchal in 1988; it was also described by Huw Price in 1997, who credited it to Dieter Zeh, and independently presented formally by Max Tegmark in 1998. It was later discussed by philosophers Peter J. Lewis in 2000 and David Lewis in 2001.


title: Quantum suicide and immortality

text: The quantum suicide thought experiment involves a similar apparatus to Schrödinger's cat – a box which kills the occupant in a given time frame with probability one-half due to quantum uncertainty. The only difference is to have the experimenter recording observations be the one inside the box. The significance of this is that someone whose life or death depends on a qubit could possibly distinguish between interpretations of quantum mechanics. By definition, fixed observers cannot.


title: Quantum suicide and immortality

text: At the start of the first iteration, under both interpretations, the probability of surviving the experiment is 50%, as given by the squared norm of the wave function. At the start of the second iteration, assuming a single-world interpretation of quantum mechanics (like the widely-held Copenhagen interpretation) is true, the wave function has already collapsed; thus, if the experimenter is already dead, there is a 0% chance of survival for any further iterations. However, if the many-worlds interpretation is true, a superposition of the live experimenter "necessarily" exists (as also does the one who dies). Now, barring the possibility of life after death, after every iteration only one of the two experimenter superpositions – the live one – is capable of having any sort of conscious experience. Putting aside the philosophical problems associated with individual identity and its persistence, under the many-worlds interpretation, the experimenter, or at least a version of them, continues to exist through all of their superpositions where the outcome of the experiment is that they live. In other words, a version of the experimenter survives all iterations of the experiment. Since the superpositions where a version of the experimenter lives occur by quantum necessity (under the many-worlds interpretation), it follows that their survival, after any realizable number of iterations, is physically necessary; hence, the notion of quantum "immortality".


title: Quantum suicide and immortality

text: A version of the experimenter surviving stands in stark contrast to the implications of the Copenhagen interpretation, according to which, although the survival outcome is possible in every iteration, its probability tends towards zero as the number of iterations increases. According to the many-worlds interpretation, the above scenario has the opposite property: the probability of a version of the experimenter living is necessarily one for any number of iterations.


title: Quantum suicide and immortality

text: In the book "Our Mathematical Universe", Max Tegmark lays out three criteria that, in abstract, a quantum suicide experiment must fulfill:


title: Quantum suicide and immortality

text: In response to questions about "subjective immortality" from normal causes of death, Tegmark suggested that the flaw in that reasoning is that dying is not a binary event as in the thought experiment; it is a progressive process, with a continuum of states of decreasing consciousness. He states that in most real causes of death, one experiences such a gradual loss of self-awareness. It is only within the confines of an abstract scenario that an observer finds they defy all odds. Referring to the above criteria, he elaborates as follows: "[m]ost accidents and common causes of death clearly don't satisfy all three criteria, suggesting you won't feel immortal after all. In particular, regarding criterion 2, under normal circumstances dying isn't a binary thing where you're either alive or dead [...] What makes the quantum suicide work is that it forces an abrupt transition."


title: Quantum suicide and immortality

text: The philosopher David Lewis explored the possibility of quantum immortality in a 2001 lecture titled "How Many Lives Has Schrödinger's Cat?", his first - and last, due to his death less than four months afterwards - academic foray into the field of the interpretation of quantum mechanics. In the lecture, published posthumously in 2004, Lewis rejected the many-worlds interpretation, allowing that it offers initial theoretical attractions, but also arguing that it suffers from irremediable flaws, mainly regarding probabilities, and came to tentatively endorse the Ghirardi–Rimini–Weber theory instead. Lewis concluded the lecture by stating that the quantum suicide thought experiment, if applied to real-world causes of death, would entail what he deemed a "terrifying corollary": as all causes of death are ultimately quantum-mechanical in nature, if the many-worlds interpretation were true, in Lewis' view an observer should subjectively "expect with certainty to go on forever surviving whatever dangers [he or she] may encounter", as there will always be possibilities of survival, no matter how unlikely; faced with branching events of survival and death, an observer should not "equally expect to experience life and death", as there is no such thing as experiencing death, and should thus divide his or her expectations only among branches where he or she survives. If survival is guaranteed, however, this is not the case for good health or integrity. This would lead to a cumulative deterioration that indefinitively stops just short of death.