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Simulated reality is the proposition that reality could be simulated—perhaps by computer simulation—to a degree indistinguishable …

Simulated reality is the proposition that reality could be simulated—perhaps by computer simulation—to a degree indistinguishable
from "true" reality. It could contain conscious minds which may or may not be fully aware that they are living inside a simulation.
This is quite different from the current, technologically achievable concept of virtual reality. Virtual reality is easily distinguished from the
experience of actuality; participants are never in doubt about the nature of what they experience. Simulated reality, by contrast, would be
hard or impossible to separate from "true" reality.
There has been much debate over this topic, ranging from philosophical discourse to practical applications in computing.

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  • 1. Log in / create account Article Discussion Read Edit Search Simulated reality From Wikipedia, the free encyclopedia This article has multiple issues. Please help improve it or discuss these issues on the talkMain page page.ContentsFeatured content It needs additional citations for verification. Tagged since April 2009.Current events It may contain original research. Tagged since April 2009.Random article Simulated reality is the proposition that reality could be simulated—perhaps by computer simulation—to a degree indistinguishableDonate to Wikipedia from "true" reality. It could contain conscious minds which may or may not be fully aware that they are living inside a simulation. Interaction This is quite different from the current, technologically achievable concept of virtual reality. Virtual reality is easily distinguished from the Help experience of actuality; participants are never in doubt about the nature of what they experience. Simulated reality, by contrast, would be About Wikipedia hard or impossible to separate from "true" reality. Community portal There has been much debate over this topic, ranging from philosophical discourse to practical applications in computing. Recent changes Contact Wikipedia Contents [hide] Toolbox 1 Types of simulation 1.1 Brain-computer interface Print/export 1.2 Virtual people Languages 1.3 Emigration Deutsch 1.4 Intermingled Español 2 Arguments Français 2.1 Nick Bostrom ‫עברית‬ 2.2 Relativity of reality Lietuvių 2.3 Computationalism & Platonic simulation theories 日本語 2.4 Dreaming Suomi 2.5 Computability of physics 中文 2.6 CantGoTu Environments िह दी 2.7 Computational load 2.7.1 Virtual people 2.8 Nested simulations 2.8.1 Validity of the arguments 3 Scientific and technological approaches 3.1 Software bugs 3.2 Hidden messages or "Easter eggs" 3.3 Processing power 3.4 Digital physics and cellular automata 4 Other issues 4.1 Non-player characters or "bots" 4.2 Subjective time 4.3 Recursive simulations 5 Simulated reality in fiction 6 See also 6.1 Major contributing thinkers 7 Bibliography 8 References 9 External links Types of simulation [edit] Brain-computer interface [edit] Main articles: brain-computer interface and brain in a vat In brain-computer interface simulations, each participant enters from outside, directly connecting their brain to the simulation computer. The computer transmits sensory data to the participant, reads and responds to their desires and actions in return; in this manner they interact with the simulated world and receive feedback from it. The participant may be induced by any number of possible means to forget, temporarily or otherwise, that they are inside a virtual realm (e.g. "passing through the veil", a term borrowed from Christian tradition, which describes the passage of a soul from an earthly body to an afterlife). While inside the simulation, the participants consciousness is represented by an avatar, which can look very different from the participants actual appearance. Virtual people [edit] Main article: Artificial consciousness In a virtual-people simulation, every inhabitant is a native of the simulated world. They do not have a "real" body in the external reality of the physical world. Instead, each is a fully simulated entity, possessing an appropriate level of consciousness that is implemented using the simulations own logic (i.e. using its own physics). As such, they could be downloaded from one simulation to another, or even converted by Web2PDFConvert.com
  • 2. archived and resurrected at a later time. It is also possible that a simulated entity could be moved out of the simulation entirely by meansof mind transfer into a synthetic body. Another way of moving an inhabitant of the virtual reality out of its simulation would be to "clone"the entity, by taking a sample of its virtual DNA and create a real-world counterpart from that model, assuming the real worlds physics iscompatible with the virtual worlds. The result would not bring the "mind" of the entity out of its simulation, but its body would be born inthe real world. In The Matrix Reloaded, a variant of this is played out. Former Agent Smith takes over the body of a "redpill" inside theMatrix, causing the persons avatar within to look like Smith. When that Smith uses one of the hard exits to return to the outside (real)world, the body of the "redpill" looks the same to the people around him, but he is in reality a version of Smith.This category subdivides into two further types: Virtual people-virtual world, in which an external reality is simulated separately to the artificial consciousnesses; Solipsistic simulation in which consciousness is simulated and the "world" participants perceive exists only within their minds.Emigration [edit]In an emigration simulation, the participant enters the simulation from the outer reality, as in the brain-computer interface simulation, butto a much greater degree. On entry, the participant could use a variety of hypothetical methods to participate in the simulated realityincluding mind transfer to temporarily relocate their mental processing into a virtual-person. After the simulation is over, the participantsmind is restored along with all new memories and experience gained within (as in the movie The Thirteenth Floor, or when one flatlines inNeuromancer).Further, there is the option (also from The Thirteenth Floor) of a completely virtual-person, born in the simulation, willing to escape thesimulation (after "waking up") and consequently somehow succeeding to be transferred into an outer-reality person. This would ultimatelymean exiting (emigrating) and getting transformed on exit into a "real" person. In this particular case, since the emigrating inhabitant ofthe simulation didnt have an associated outer-reality person (user with a "real body"), this virtual person would be transferred into either a"new-born" outer-reality person (assuming that possible), or an already existing/living one, whether being a "player" of the simulation ornot at all. And if being a player, he would be previously associated with some other inhabitant from the simulated world and thus with"taking over" (or merging with) this "special" previous-inhabitant that is emigrating, he could choose to destroy that other/old inhabitant, orabandon him (leaving him in the simulated world without a user/player temporarily or permanently). Or if neither destroying or abandoning,but willing to further "play" the simulation and choosing to play that same old inhabitant (that didnt emigrate), he would do that now as atransformed user ("enriched" with an emigrated virtual-person, or now even completely being that previously virtual person, if that waschosen and possible, and as such continuing to play the simulation using another virtual-person).Finally, there is the option of a simulated reality being dynamically constructed and modified using real-world matter and energy within anenclosing container or room, such as the "Holodeck" in Star Trek. Upon entering such a space, the real-world person would effectivelyfeel immersed in the simulated environment, with a variety of potential methods being used to convince the user of the presence ofmotion, gravity, environments, and so on, and with the user presumably able to interact (or not) with the simulated reality.Intermingled [edit]An intermingled simulation supports both types of consciousness: "players" from the outer reality who are visiting (as a brain-computerinterface simulation) or emigrating, and virtual-people who are natives of the simulation and hence lack any physical body in the outerreality.The Matrix movies feature an intermingled type of simulation: they contain not only human minds (with their physical bodies remainingoutside), but also sentient software programs that govern various aspects of the computed realm.Arguments [edit]Nick Bostrom [edit] Main article: Simulation argumentTen years after Hans Moravec first published the simulation argument (and three years after its update in Moravecs second full popscience book),[1] the philosopher Nick Bostrom investigated the possibility that we may be living in a simulation.[2] A simplified version ofhis argument proceeds as such: i. It is possible that an advanced civilization could create a computer simulation which contains individuals with artificial intelligence (AI). ii. Such a civilization would likely run many, billions for example, of these simulations (just for fun, for research or any other permutation of possible reasons). iii. A simulated individual inside the simulation wouldn’t necessarily know that it is inside a simulation — it is just going about its daily business in what it considers to be the "real world."Then the ultimate question is — if one accepts that the above premises are at least possible — which of the following is more likely? a. We are the one civilization which develops AI simulations and happens not to be in one itself? b. We are one of the many (billions) of simulations that has run? (Remember point iii.)In greater detail, his argument attempts to prove the trichotomy, either that: 1. intelligent races will never reach a level of technology where they can run simulations of reality so detailed they can be mistaken for reality (assuming that this is possible in principle); or 2. races who do reach such a sophisticated level do not tend to run such simulations; or 3. we are almost certainly living in such a simulation.Bostroms argument uses the premise that given sufficiently advanced technology, it is possible to simulate entire inhabited planets oreven larger habitats or even entire universes as quantum simulations in time/space pockets, including all the people on them, on acomputer, and that simulated people can be fully conscious, and are as fully sentient individuals as non-simulated people.A particular case provided in the original paper poses the scenario where we reason based on the trichotomy listed above. We deny thefirst hypothesis: We assume that the human race could reach such a technologically advanced level without destroying themselves in theprocess. We then deny the second hypothesis: We presume that once we reached such a level we would still be interested in history, converted by Web2PDFConvert.com
  • 3. the past, and our ancestors, and that there would be no legal or moral strictures on running such simulations. If these two assumptionsare made, then it is likely that we would run a very large number of so-called ancestor simulations to study our past; and that, by the same line of reasoning, many of these simulations would in turn run other sub-simulations, and so on; and that given the fact that right now it is impossible to tell whether we are living in one of the vast number of simulations or the original ancestor universe, the likelihood is that the former is true.Assumptions as to whether the human race (or another intelligent species) could reach such a technological level without destroyingthemselves depend greatly on the value of the Drake equation, which attempts to calculate the number of intelligent technological speciescommunicating via radio in a galaxy at any given point in time. The expanded equation looks to the number of posthuman civilizationsthat ever would exist in any given universe. If the average for all universes, real or simulated, is greater than or equal to one suchcivilization existing in each universes entire history, then the odds are rather overwhelmingly in favor of the proposition that the averagecivilization is in a simulation, assuming that such simulated universes are possible and such civilizations would want to run suchsimulations.Relativity of reality [edit]As to the question of whether we are living in a simulated reality or a real one, the answer may be indistinguishable, in principle. In acommemorative article dedicated to the The World Year of Physics 2005, physicist Bin-Guang Ma proposed the theory of Relativity ofreality [3] (though this notion has been suggested in other contexts like ancient philosophy (Zhuangzis Butterfly Dream) and psychologicanalytics [4]). By generalizing the relativity principle in physics, which is mainly about the relativity of motion, stating that the motion hasno absolute meaning (to say if something is in motion or rest, one must adopt some reference frame; without a reference frame, onecannot tell the state of being in rest or in uniform motion), a similar property has been suggested for reality, meaning that without areference world, one cannot tell the world one is living in is real or a simulated one. Therefore, there is no absolute meaning for reality.Similar to the situation in Einsteins relativity, there are two fundamental principles for the theory Relativity of reality. 1. All worlds are equally real. 2. Simulated events and simulating events coexist.The first principle (equally real) says that all worlds are equal in reality, even for partially simulated worlds (if there are living beings, theyfeel the same level of reality just as we feel). In this theory, the question "whether are we living in a simulated reality or a real one" ismeaningless, because they are indistinguishable in principle. The equally real principle doesnt mean that we cannot differentiate aconcrete computer simulation from our own world, since when we are talking about a computer simulation, we already have a referenceworld (the world we are in).Coupled with the second principle (coexistence), the space-time transformation between two across-reality objects (one is in real worldand the other is in virtual world) was supposed in this theory, which is an example of interreality (mixed reality) system. The firstinterreality physics experiment may be the one conducted by V. Gintautas and A. W. Hubler, where a mixed-reality correlation betweentwo pendula (one is real and the other is virtual) was indeed observed.[5]Computationalism & Platonic simulation theories [edit] Main article: ComputationalismComputationalism is a philosophy of mind theory stating that cognition is a form of computation. It is relevant to the SimulationHypothesis in that it illustrates how a simulation could contain conscious subjects, as required by a "virtual people" simulation. Forexample, it is well known that physical systems can be simulated to some degree of accuracy. If computationalism is correct, and ifthere is no problem in generating artificial consciousness from cognition, it would establish the theoretical possibility of a simulatedreality. However, the relationship between cognition and phenomenal consciousness is disputed. It is possible that consciousnessrequires a physical substrate not provided by a computational simulator, and simulated people, while behaving appropriately, would bephilosophical zombies. This would also seem to negate Nick Bostroms simulation argument; we cannot be inside a simulation, asconscious beings, if consciousness cannot be simulated. However, we could still be within a simulation, and yet be envatted brains. Thiswould allow us to exist as conscious beings within a simulated environment, even if a simulated environment could not simulateconsciousness.Some theorists[6][7] have argued that if the "consciousness-is-computation" version of computationalism and mathematical realism (alsoknown as mathematical Platonism) are both true our consciousnesses must be inside a simulation. This argument states that a "Platosheaven" or ultimate ensemble would contain every algorithm, including those which implement consciousness. Platonic simulationtheories are also subsets of the multiverse theories and theories of everything.Dreaming [edit] Further information: Dream argumentA dream could be considered a type of simulation capable of fooling someone who is asleep. As a result the "dream hypothesis" cannotbe ruled out, although it has been argued that common sense and considerations of simplicity rule against it.[8] One of the firstphilosophers to question the distinction between reality and dreams was Zhuangzi, a Chinese philosopher from the 4th century BC. Hephrased the problem as the well-known "Butterfly Dream," which went as follows: Once Zhuangzi dreamt he was a butterfly, a butterfly flitting and fluttering around, happy with himself and doing as he pleased. He didnt know he was Zhuangzi. Suddenly he woke up and there he was, solid and unmistakable Zhuangzi. But he didnt know if he was Zhuangzi who had dreamt he was a butterfly, or a butterfly dreaming he was Zhuangzi. Between Zhuangzi and a butterfly there must be some distinction! This is called the Transformation of Things. (2, tr. Burton Watson 1968:49)The philosophical underpinnings of this argument are also brought up by Descartes, who was one of the first Western philosophers to doso. In Meditations on First Philosophy, he states "... there are no certain indications by which we may clearly distinguish wakefulnessfrom sleep",[9] and goes on to conclude that "It is possible that I am dreaming right now and that all of my perceptions are false".[9]Chalmers (2003) discusses the dream hypothesis, and notes that this comes in two distinct forms: converted by Web2PDFConvert.com
  • 4. that he is currently dreaming, in which case many of his beliefs about the world are incorrect; that he has always been dreaming, in which case the objects he perceives actually exist, albeit in his imagination.[10]Both the dream argument and the Simulation hypothesis can be regarded as skeptical hypotheses; however in raising these doubts, justas Descartes noted that his own thinking led him to be convinced of his own existence, the existence of the argument itself is testamentto the possibility of its own truth.Another state of mind in which an individuals perceptions have no physical basis in the real world is called psychosis. Psychosis mayhave a physical basis in the real world, explanations vary.Computability of physics [edit] Further information: Computational universe theory and The Emperors New MindA decisive refutation of any claim that our reality is computer-simulated would be the discovery of some uncomputable physics, becauseif reality is doing something that no computer can do, it cannot be a computer simulation. (Computability generally means computabilityby a Turing machine. Hypercomputation (super-Turing computation) introduces other possibilities which will be dealt with separately). Infact, known physics is held to be (Turing) computable,[11] but the statement "physics is computable" needs to be qualified in variousways. Before symbolic computation, a number, thinking particularly of a real number, one with an infinite number of digits, was said to becomputable if a Turing machine will continue to spit out digits endlessly, never reaching a "final digit".[12] This runs counter, however, tothe idea of simulating physics in real time (or any plausible kind of time). Known physical laws (including those of quantum mechanics)are very much infused with real numbers and continua, and the universe seems to be able to decide their values on a moment-by-momentbasis. As Richard Feynman put it:[13] "It always bothers me that, according to the laws as we understand them today, it takes a computing machine an infinite number of logical operations to figure out what goes on in no matter how tiny a region of space, and no matter how tiny a region of time. How can all that be going on in that tiny space? Why should it take an infinite amount of logic to figure out what one tiny piece of space/time is going to do? So I have often made the hypotheses that ultimately physics will not require a mathematical statement, that in the end the machinery will be revealed, and the laws will turn out to be simple, like the chequer board with all its apparent complexities".The objection could be made that the simulation does not have to run in "real time".[14] It misses an important point, though: the shortfallis not linear; rather it is a matter of performing an infinite number of computational steps in a finite time.[15]Note that these objections all relate to the idea of reality being exactly simulated. Ordinary computer simulations as used by physicistsare always approximations.These objections do not apply if the hypothetical simulation is being run on a hypercomputer, a hypothetical machine more powerful thana Turing machine.[16] Unfortunately, there is no way of working out if computers running a simulation are capable of doing things thatcomputers in the simulation cannot do. No-one has shown that the laws of physics inside a simulation and those outside it have to be thesame, and simulations of different physical laws have been constructed.[17] The problem now is that there is no evidence that canconceivably be produced to show that the universe is not any kind of computer, making the simulation hypothesis unfalsifiable andtherefore scientifically unacceptable, at least by Popperian standards.[18]All conventional computers, however, are less than hypercomputational, and the simulated reality hypothesis is usually expressed interms of conventional computers, i.e. Turing machines. Inasmuch as they are, the hypothesis is falsifiable.Roger Penrose, an English mathematical physicist, presents the argument that human consciousness is non-algorithmic, and thus is notcapable of being modeled by a conventional Turing machine-type of digital computer. Penrose hypothesizes that quantum mechanicsplays an essential role in the understanding of human consciousness. The collapse of the quantum wavefunction is seen as playing animportant role in brain function.CantGoTu Environments [edit] Further information: The Fabric of Reality and Computational universalityIn his book The Fabric of Reality, David Deutsch discusses how the limits to computability imposed by Gödels Incompleteness Theoremaffects the Virtual Reality rendering process. In order to do this, Deutsch invents the notion of a CantGoTu environment (named afterCantor, Gödel, and Turing), using Cantors diagonal argument to construct an impossible Virtual Reality which a physical VR generatorwould not be able to generate. The way that this works is to imagine that all VR environments renderable by such a generator can beenumerated, and that we label them VR1, VR2, etc. Slicing time up into discrete chunks we can create an environment which is unlikeVR1 in the first timeslice, unlike VR2 in the second timeslice and so on. This environment is not in the list, and so it cannot be generatedby the VR generator. Deutsch then goes on to discuss a universal VR generator, which as a physical device would not be able to renderall possible environments, but would be able to render those environments which can be rendered by all other physical VR generators. Heargues that an environment which can be rendered corresponds to a set of mathematical questions whose answers can be calculated,and discusses various forms of the Turing Principle, which in its initial form refers to the fact that it is possible to build a universalcomputer which can be programmed to execute any computation that any other machine can do. Attempts to capture the process ofvirtual reality rendering provides us with a version which states: "It is possible to build a virtual-reality generator, whose repertoire includesevery physically possible environment". In other words, a single, buildable physical object can mimic all the behaviours and responses ofany other physically possible process or object. This, it is claimed, is what makes reality comprehensible.Later on in the book, Deutsch goes on to argue for a very strong version of the Turing principle, namely: "It is possible to build a virtualreality generator whose repertoire includes every physically possible environment." However, in order to include every physically possibleenvironment, the computer would have to be able to include a full simulation of the environment containing itself. Even so, a computerrunning a simulation need not have to run every possible physical moment to be plausible to its inhabitants.Computational load [edit]Virtual people [edit]The computational requirements for molecular dynamics are such that in 2002, "while the fastest proteins fold on the order of tens of converted by Web2PDFConvert.com
  • 5. microseconds", "current single computer processors" could "only simulate on the order of a nanosecond of real-time of folding in fullatomic detail per CPU day".[19][20] To simulate an entire galaxy would require more computing power than can presently be envisioned,assuming that no shortcuts are taken when simulating areas that nobody is observing.In answer to this objection, Bostrom calculated that simulating the brain functions of all humans who have ever lived would require roughly1033 to 1036 calculations.[2] He further calculated that a planet-sized computer built with computronium using known nanotechnologicalmethods would perform about 1042 calculations per second — and a planet-sized computer or an even larger stellar system-sizedcomputer is not inherently impossible to build, (although the speed of light could severely constrain the speed at which its subprocessorsshare data). In any case, a simulation need not compute every single molecular event that occurs inside it; it may only process eventsthat its participants can actively perceive. This is particularly the case if the simulation contained only a handful of people; far lessprocessing power would be needed to make them believe they were in a "world" much larger than was actually the case. A real worldexample of this could be the observer paradox or Heisenberg Uncertainty Principle - an unobserved region of space is indeterminate untilobserved - this could be because the simulating computer is not simulating it until it needs to.Nested simulations [edit]The existence of simulated reality is unprovable in any concrete sense: any "evidence" that is directly observed could be anothersimulation itself. In other words, there is an infinite regress problem with the argument. Even if we are a simulated reality, there is no wayto be sure the beings running the simulation are not themselves a simulation, and the operators of that simulation are not a simulation, adinfinitum. Given the premises of the simulation argument, any reality, even one running a simulation, has no better or worse a chance ofbeing a simulation than any other.Validity of the arguments [edit]It is perhaps erroneous to apply our current sense of feasibility to projects undertaken in an outer reality, where resources and physicallaws may be very different. It also assumes designers would need to simulate reality beyond our natural senses.Also, a simulated reality need not run in real time addressing computational constraints. The inhabitants of a simulated universe wouldhave no way of knowing if one day of subjective time actually required much longer to calculate in their host computer, or vice-versa, or ifthe simulation is run in pieces on different computers, or with a million generations of monks working weekends on abacuses — allwithout the simulation missing a beat in simulation time.Scientific and technological approaches [edit]Software bugs [edit]A computed simulation may have voids or other errors that manifest inside. As a simple example of this, when the "hall of mirrors" effectoccurs in the first person shooter Doom, the game attempts to display "nothing" and obviously fails in its attempt to do so. If a void canbe found and tested, and if the observers survive its discovery, then it may reveal the underlying computational substrate. However, lapsesin physical law could be attributed to other explanations, for instance inherent instability in the nature of reality.In fact, bugs could be very common. An interesting question is whether knowledge of bugs or loopholes in a sufficiently powerfulsimulation are instantly erased the minute they are observed since presumably all thoughts and experiences in a simulated world couldbe carefully monitored and altered. This would, however, require enormous processing capability in order to simultaneously monitorbillions of people at once. Of course, if this is the case we would never be able to act on discovery of bugs. In fact, any simulationsignificantly determined to protect its existence could erase any proof that it was a simulation whenever it arose, provided it had theenormous capacity necessary to do so.To take this argument to an even greater extreme, a sufficiently powerful simulation could make its inhabitants think that erasing proof ofits existence is difficult. This would mean that the computer actually has an easy time of erasing glitches, but we all think that changingreality requires great power. One could possibly take miracles and paranormal activity as software bugs especially those which seem tohave a negative effect on one; this notion has been explored in The Matrix, where déjà vu is considered a sign of crude alteration to thesystem; and Animatrix where software glitches are concentrated in a house which the neighbors call "haunted", subsequently correctedby the Agents. A possible exploit could regard demons and evil spirits as the hackers who attempt to take advantage of this system.Additionally, it can be argued that what are in fact errors in the software, we perceive as part of the "proper" reality. For example, it maybe the case that tornadoes were never meant to exist in this simulation, but due to an error in the programming came to be. It would thenbe only suspicious to remove them from this reality and doing so would raise more questions by its inhabitants. In such instance, it wouldmake more sense to leave the "error" in place.Hidden messages or "Easter eggs" [edit]The simulation may contain hidden/secret messages or exits placed there by the designer or by other inhabitants who have solved theriddle in the way that easter eggs in computer games and other media sometimes do. People have already spent considerable effortsearching for patterns or messages within the endless decimal places of the fundamental constants such as e and pi. In Carl Sagansscience fiction novel Contact, Sagan contemplates the possibility of finding a signature embedded in pi (in its base-11 expansion) by thecreators of our reality.However, such messages have not been made public if they have been found, and the argument relies on the messages being truthful. Asusual, other hypotheses could explain the same evidence. In any case, if such constants are in fact normal, then at some point anapparently meaningful message will appear in them (this is known as the infinite monkey theorem), not necessarily because it wasplaced there.The Easter Egg Theory also assumes that a simulation would want to inform its inhabitants of its real nature; it may not. Otherwise, if weconsider that the human race will eventually be capable of creating intelligent programs (i.e. machines) living inside a virtual subspace ofour "real" world, then an interesting question would be to define whether or not we will be capable of suppressing from our sentient robotstheir capability of knowing their artificial nature (see Philip K Dicks Do Androids Dream of Electric Sheep?).Processing power [edit]A computer simulation would be limited to the processing power of its host computer, and so there may be aspects of the simulation that converted by Web2PDFConvert.com
  • 6. A computer simulation would be limited to the processing power of its host computer, and so there may be aspects of the simulation thatare not computed at a fine-grained (e.g. subatomic) level. This might show up as a limitation on the accuracy of information that can beobtained in particle physics.However, this argument, like many others, assumes that accurate judgments about the simulating computer can be made from within thesimulation. If we are being simulated, we might be misled about the nature of computers.Taken one step further, the "fine grained" elements of our world could themselves be simulated since we never see the sub-atomicparticles due to our inherent physical limitations. In order to see such particles we rely on other instruments which appear to magnify ortranslate that information into a format our limited senses are able to view: computer print out, lens of a microscope, etc. Therefore, weessentially take on faith that theyre an accurate portrayal of the fine grained world which appears to exist in a realm beyond our naturalsenses. Assuming the sub-atomic could also be simulated then the processing power required to generate a realistic world would begreatly reduced.[citation needed]Digital physics and cellular automata [edit]In theoretical physics, digital physics holds the basic premise that the entire history of our universe is computable in some sense. Thehypothesis was pioneered in Konrad Zuses book Rechnender Raum (translated by MIT into English as Calculating Space, 1970), whichfocuses on cellular automata. Juergen Schmidhuber suggested that the universe could be a Turing machine, because there is a veryshort program that outputs all possible programmes in an asymptotically optimal way. Other proponents include Edward Fredkin,Stephen Wolfram, and Nobel laureate Gerard t Hooft. They hold that the apparently probabilistic nature of quantum physics is notincompatible with the notion of computability. A quantum version of digital physics has recently been proposed by Seth Lloyd. None ofthese suggestions has been developed into a workable physical theory.It can be argued that the use of continua in physics constitutes a possible argument against the simulation of a physical universe.Removing the real numbers and uncountable infinities from physics would counter some of the objections noted above, and at least makecomputer simulation a possibility. However, digital physics must overcome these objections. For instance, cellular automata wouldappear to be a poor model for the non-locality of quantum mechanics.Other issues [edit]Non-player characters or "bots" [edit]Some of the people in a simulated reality may be automatons, philosophical zombies, or bots added to the simulation to make it morerealistic or interesting or challenging. Indeed, it is conceivable that every person other than oneself is a bot. Bostrom called this a "me-simulation", in which oneself is the only sovereign lifeform, or at least the only inhabitant who entered the simulation from outside.Bostrom further elaborated on the idea of bots: In addition to ancestor-simulations, one may also consider the possibility of more selective simulations that include only a small group of humans or a single individual. The rest of humanity would then be zombies or "shadow-people" – humans simulated only at a level sufficient for the fully simulated people not to notice anything suspicious. It is not clear how much [computationally] cheaper shadow-people would be to simulate than real people. It is not even obvious that it is possible for an entity to behave indistinguishably from a real human and yet lack conscious experience.[2]The idea of "zombies" has a well known corollary in the video game industry where computer generated characters are known as Non-Player Characters ("NPCs"). The term bots is short for robots. The usage originated as the name given to the simple AI opponents ofmodern video games.Subjective time [edit]A brain-computer interface simulated reality may be required to progress at a rate that is near realtime; that is, time within it may berequired to pass at approximately the same rate as the outer reality which contains it. This might be the case because the players areinteracting with the simulation using brains which still reside in the outer reality. Therefore, if the simulation were to run faster or slower,those brains could notice because they were not contained within it.It is possible that time passes slower or quicker for brains in a dream state (i.e., in a brain-computer interface trance); however, the pointis that they still function at a finite, biological speed, and the simulation must track with them. Unless those interacting with thesimulation are augmented and capable of processing information at the same rate as the simulation itself.A virtual-people or emigration simulated reality, on the other hand, need not. This is because its inhabitants are using the simulationsown physics in order to experience, think, and react. If the simulation were slowed down or sped up, so also would the inhabitants ownsenses, brains, and muscles, as well as every other molecule inside. The inhabitants would perceive no change in the passage of time,simply because their method of measuring time is dependent on the cosmic clock that they are seeking to measure. (They could performthe measurement only if they had some access to data from the outer reality.)For that matter, they could not even detect whether the simulation had been completely halted: a pause in the simulation would pauseevery life and mind within it. When the simulation was later resumed, the inhabitants would continue exactly as they were before thepause, completely unaware that (for example) their cosmos had been paused and archived for a billion years before being resumed. Asimulation could also be created with its inhabitants already possessing memories as though they had already lived part of their livesbefore; said inhabitants would not be able to tell the difference unless informed of it by the simulation. (Compare with the five minutehypothesis and Last Thursdayism).One practical implication of this is that a virtual-people or a hybrid simulation does not require a computer powerful enough to model itsentire cosmos at full speed. Per the Turing completeness theorem, a simulation can progress at whatever speed its host computer canmanage; it would be constrained by available memory but not by computation rate.Recursive simulations [edit]Recursive simulation involves a simulation, or an entity in a simulation, creating another simulation within a simulated environment.[21]The parent simulator would be simulating all of the atoms of the computer, atoms which happen to be calculating a child simulation. Byway of illustration: in Fallout 3, Metal Gear Solid 2, and Xenosaga, the player character at one point must enter a virtual reality simulation converted by Web2PDFConvert.com
  • 7. in the game. Alternatively, imagine a Java Runtime Environment running a virtual computer on a "real-world" computer that itself is locatedwithin a simulation.This recursion could continue to infinitely many levels — a simulation containing a computer running a simulation containing a computerrunning a simulation and so on. The recursion is subject only to one constraint (assuming no level has infinite computational power): eachnested simulation must[citation needed] be: smaller than its parent reality, because its own memory must be a subset of the parents;...and must be at least one of the following: slower than its parent reality, because its own calculations must be a subset of the parents; or less complex than its parent reality, via simplifications of processes that are computationally intensive in the parent reality; or less complete than its parent reality, via approximations of objects that nobody is observing.The latter is the basis of the idea that quantum uncertainties are circumstantial evidence that our own reality is a simulation. However,this assumes that there is a finite limitation somewhere in the chain. Assuming an infinite number of simulations within simulations, thereneed not be any noticeable difference between any of the subsets.Simulated reality in fiction [edit] See Simulated reality in fictionSimulated reality is a theme that pre-dates science fiction. In Medieval and Renaissance religious theatre, the concept of the world astheater is frequent.Virtual reality, and to a lesser point simulated reality, are key facets in the Cyberpunk genre, regardless of format.See also [edit] This "see also" section may contain an excessive number of suggestions. Please ensure that only the most relevant suggestions are given and that they are not red links, and consider integrating suggestions into the article itself. (November 2010) Artificial life Margolus–Levitin theorem Artificial reality Metaverse Augmented reality Tiplers "Omega point" Artificial society Omnidirectional treadmill Boltzmann brain Philosophy of information Computational sociology Pseudorealism Consensus reality Reality in Buddhism Cyberpsychology Simulacra and Simulation Digital philosophy Simulacrum Digital physics Social simulation The Experience Machine Theory of knowledge Hyperreality Virtual worlds Infosphere Zenos paradoxes Interactive online charactersMajor contributing thinkers [edit] Jean Baudrillard Nick Bostrom René Descartes Philip K. Dick Stanislaw Lem Plato Zeno of EleaBibliography [edit] Copleston, Frederick (1993) [1946]. "XIX Theory of Knowledge". A History of Philosophy, Volume I: Greece and Rome. New York: Image Books (Doubleday). p. 160. ISBN 0-385-46843-1. Copleston, Frederick (1994) [1960]. "II Descartes (I)". A History of Philosophy, Volume IV: Modern Philosophy. New York: Image Books (Doubleday). p. 86. ISBN 0-385-47041-X. Deutsch, David (1997). The Fabric of Reality. London: Penguin Science (Allen Lane). ISBN 0-14-014690-3. Lloyd, Seth (2006). Programming the Universe: A Quantum Computer Scientist Takes On the Cosmos. Knopf. ISBN 978- 1400040926. Tipler, Frank (1994). The Physics of Immortality. Doubleday. ISBN 0-385-46799-0. Lem, Stanislaw (1964). Summa Technologiae. ISBN 3518371789.References [edit] This article may contain improper references to self-published sources. Please help improve it by removing references to unreliable sources, where they are used inappropriately. (April 2009) 1. ^ Moravec, Hans, Simulation, Consciousness, Existence converted by Web2PDFConvert.com
  • 8. 2. ^ a b c Are You Living in a Computer Simulation? by Nick Bostrom. July 2002. Accessed 21 December 2006 3. ^ About Mechanics of Virtual Reality, by Bin-Guang Ma, (2005) 4. ^ Warburg, B. (1942). The Relativity of Reality. Reflections on the Limitations of Thought and the Genesis of the Need of Causality: by René Laforgue. Translated byAnne Jouard. New York: Nervous and Mental Disease Monographs, 1940. 92 pp.. Psychoanal Q., 11:562. 5. ^ V. Gintautas and A. W. Hubler, Experimental evidence for mixed reality states in an interreality system Phys. Rev. E 75, 057201 (2007). 6. ^ Bruno Marchal 7. ^ Russel Standish 8. ^ "There is no logical impossibility in the supposition that the whole of life is a dream, in which we ourselves create all the objects that come before us. But although this is not logically impossible, there is no reason whatever to suppose that it is true; and it is, in fact, a less simple hypothesis, viewed as a means of accounting for the facts of our own life, than the common-sense hypothesis that there really are objects independent of us, whose action on us causes our sensations." Bertrand Russell, The Problems of Philosophy 9. ^ a b René Descartes, Meditations on the First Philosophy, from Descartes, The Philosophical Works of Descartes, trans. Elizabeth S. Haldane and G.R.T. Ross (Cambridge: Cambridge University Press, 1911 – reprinted with corrections 1931), Volume I, 145-46. 10. ^ Chalmers, J., The Matrix as Metaphysics , Department of Philosophy, University of Arizona 11. ^ PHYSICS, PHILOSOPHY AND QUANTUM TECHNOLOGY 12. ^ Alan Turing, On computable numbers, with an application to the Entscheidungsproblem, Proceedings of the London Mathematical Society, Series 2, 42 (1936), pp 230-265. (online version ). Computable numbers (and Turing machines) were introduced in this paper; the definition of computable numbers uses infinite decimal sequences. 13. ^ Feynman, R. The Character of Physical Law, page 57. 14. ^ Subjective time 15. ^ "But ordinary computing systems, such as Turing Machines (TM), can only take a finite number of states. Even if we combine the internal states of a TM with the content of the machine’s tape to increase the number of possible states, the total number of states that a TM can be in is only countably infinite. Moreover, TMs can only follow a countable number of state space trajectories. The same point applies to any ordinary computing system of the kinds used in scientific modelling. So ordinary computational descriptions do not have a cardinality of states and state space trajectories that is sufficient for them to map onto ordinary mathematical descriptions of natural systems. Thus, from the point of view of strict mathematical description, the thesis that everything is a computing system in this second sense cannot be supported"Computational Modelling vs. Computational Explanation: Is Everything a Turing Machine, and Does It Matter to the Philosophy of Mind? 16. ^ Hypercomputation, Toby Ord 17. ^ "The Cosmology Machine takes data from billions of observations about the behaviour of stars, gases and the mysterious dark matter throughout the universe and then calculates, at ultra high speeds, how galaxies and solar systems evolved. By testing different theories of cosmic evolution it can simulate virtual universes to test which ideas come closest to explaining the real universe."Cosmology Machine creates the Universe 18. ^ Popper, K. Science as Falsification 19. ^ Pande, Vijay S.; Baker, Ian; Chapman, Jarrod; Elmer, Sidney P.; Khaliq, Siraj; Larson, Stefan M.; Rhee, Young Min; Shirts, Michael R. et al. (January 2002). "Atomistic protein folding simulations on the submillisecond timescale using worldwide distributed computing" (PDF). Biopolymers 68 (1): 92. doi:10.1002/bip.10219 . PMID 12579582 . Retrieved November 29, 2009. archived at WebCite November 29, 2009 20. ^ IBM Blue Gene Team (2001). "Blue Gene: Avision for protein science using a petaflop supercomputer" . IBM Systems Journal 40 (2): 310-. doi:10.1147/sj.402.0310 . 21. ^ U.W. Pooch, F.J. Sullivan, Recursive simulation to aid models of decisionmakingExternal links [edit] This articles use of external links may not follow Wikipedias policies or guidelines. Please improve this article by removing excessive or inappropriate external links, and converting useful links where appropriate into footnote references (June 2010) Anthropic-principle.com Website maintained by Nick Bostrom with a collection of papers on SR and related topics. The Big Brother Universe Computer Universes and an Algorithmic Theory of Everything by Jürgen Schmidhuber The Computational Requirements for the Matrix discussion on Slashdot. Computationalism: The Very Idea , an overview of computationalism by David Davenport. The Cutting Edge of Haptics , an article in MITs Technology review on touch illusion technology by Duncan Graham-Rowe. God Is the Machine Wired article by Kevin Kelly. "That Mysterious Flow" . Davies, Paul, Sept. (2002) Scientific American 287 (3): 40–45. Philosophy & "The Matrix" Related to the Warner Brothers movie; including papers by David Chalmers and other philosophers. Simulated Universe Paper by Brent Silby provides objections to the Simulation Argument (also published in Philosophy Now: Issue 75, 2009). The Simulation Argument Website by Nick Bostrom, Director, Future of Humanity Institute, Oxford University. Includes his original paper. Simulation, Consciousness, Existence by Hans Moravec. Simulism , a wiki devoted to the possibility that our reality is a simulation. Superhumanism, an interview of Hans Moravec. by Charles Platt. What We Still Dont Know, Channel 4 documentary by British Astronomer Royal Sir Martin Rees. Zombies — Philosophical zombie article by Robert Kirk in the Stanford Encyclopedia of Philosophy. v · d· e· Brain–computer interface [show] v · d· e· Virtual reality · Augmented reality · Mixed reality [show] Rate this page View page ratings Whats this? Trustworthy Objective Complete Well-written converted by Web2PDFConvert.com
  • 9. I am highly knowledgeable about this topic (optional) Categories: Software architecture Concepts in epistemology Metaphysics Science fiction themes Philosophical arguments Thought experiments Internalism and externalism Philosophy of mind Hyperreality Mixed reality RealityThis page was last modified on 2 January 2012 at 20:51.Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. See Terms of use for details.Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.Contact usPrivacy policy About Wikipedia Disclaimers Mobile view converted by Web2PDFConvert.com