The simulation hypothesis or simulation theory proposes that all of reality, including the Earth and the universe, is in fact an artificial simulation, most likely a computer simulation. Some versions rely on the development of a simulated reality, a proposed technology that would seem realistic enough to convince its inhabitants the simulation was real. The hypothesis has been a central plot device of many science fiction stories and films.
Nick Bostrom's premise:
Many works of science fiction as well as some forecasts by serious technologists and futurologists predict that enormous amounts of computing power will be available in the future. Let us suppose for a moment that these predictions are correct. One thing that later generations might do with their super-powerful computers is run detailed simulations of their forebears or of people like their forebears. Because their computers would be so powerful, they could run a great many such simulations. Suppose that these simulated people are conscious (as they would be if the simulations were sufficiently fine-grained and if a certain quite widely accepted position in the philosophy of mind is correct). Then it could be the case that the vast majority of minds like ours do not belong to the original race but rather to people simulated by the advanced descendants of an original race.
Nick Bostrom's conclusion:
It is then possible to argue that, if this were the case, we would be rational to think that we are likely among the simulated minds rather than among the original biological ones.
Therefore, if we don't think that we are currently living in a computer simulation, we are not entitled to believe that we will have descendants who will run lots of such simulations of their forebears.
In 2003, philosopher Nick Bostrom proposed a trilemma that he called "the simulation argument". Despite the name, Bostrom's "simulation argument" does not directly argue that we live in a simulation; instead, Bostrom's trilemma argues that one of three unlikely-seeming propositions is almost certainly true:
The trilemma points out that a technologically mature "posthuman" civilization would have enormous computing power; if even a tiny percentage of them were to run "ancestor simulations" (that is, "high-fidelity" simulations of ancestral life that would be indistinguishable from reality to the simulated ancestor), the total number of simulated ancestors, or "Sims", in the universe (or multiverse, if it exists) would greatly exceed the total number of actual ancestors.
Bostrom goes on to use a type of anthropic reasoning to claim that, if the third proposition is the one of those three that is true, and almost all people with our kind of experiences live in simulations, then we are almost certainly living in a simulation.
Bostrom claims his argument goes beyond the classical ancient "skeptical hypothesis", claiming that "...we have interesting empirical reasons to believe that a certain disjunctive claim about the world is true", the third of the three disjunctive propositions being that we are almost certainly living in a simulation. Thus, Bostrom, and writers in agreement with Bostrom such as David Chalmers, argue there might be empirical reasons for the "simulation hypothesis", and that therefore the simulation hypothesis is not a skeptical hypothesis but rather a "metaphysical hypothesis". Bostrom states he personally sees no strong argument for which of the three trilemma propositions is the true one: "If (1) is true, then we will almost certainly go extinct before reaching posthumanity. If (2) is true, then there must be a strong convergence among the courses of advanced civilizations so that virtually none contains any individuals who desire to run ancestor-simulations and are free to do so. If (3) is true, then we almost certainly live in a simulation. In the dark forest of our current ignorance, it seems sensible to apportion one's credence roughly evenly between (1), (2), and (3)... I note that people who hear about the simulation argument often react by saying, 'Yes, I accept the argument, and it is obvious that it is possibility #n that obtains.' But different people pick a different n. Some think it obvious that (1) is true, others that (2) is true, yet others that (3) is true."
As a corollary to the trilemma, Bostrom states that "Unless we are now living in a simulation, our descendants will almost certainly never run an ancestor-simulation."
Bostrom argues that if "the fraction of all people with our kind of experiences that are living in a simulation is very close to one", then it follows that we probably live in a simulation. Some philosophers disagree, proposing that perhaps "Sims" do not have conscious experiences the same way that unsimulated humans do, or that it can otherwise be self-evident to a human that they are a human rather than a Sim.Philosopher Barry Dainton modifies Bostrom's trilemma by substituting "neural ancestor simulations" (ranging from literal brains in a vat, to far-future humans with induced high-fidelity hallucinations that they are their own distant ancestors) for Bostrom's "ancestor simulations", on the grounds that every philosophical school of thought can agree that sufficiently high-tech neural ancestor simulation experiences would be indistinguishable from non-simulated experiences. Even if high-fidelity computer Sims are never conscious, Dainton's reasoning leads to the following conclusion: either the fraction of human-level civilizations that reach a posthuman stage and are able and willing to run large numbers of neural ancestor simulations is close to zero, or we are in some kind of (possibly neural) ancestor simulation.
Some scholars categorically reject or are uninterested in anthropic reasoning, dismissing it as "merely philosophical", unfalsifiable, or inherently unscientific.
Some critics reject the block universe view of time that Bostrom implicitly accepts and propose that we could be in the first generation, such that all the simulated people that will one day be created don't yet exist.
The cosmologist Sean M. Carroll argues that the simulation hypothesis leads to a contradiction: if a civilization is capable of performing simulations, then it will likely perform many simulations, which implies that we are most likely at the lowest level of simulation (from which point one's impression will be that it is impossible to perform a simulation), which contradicts the arguer's assumption that advanced civilizations can most likely perform simulations.
Some scholars accept the trilemma, and argue that the first or second of the propositions are true, and that the third proposition (the proposition that we live in a simulation) is false. Physicist Paul Davies deploys Bostrom's trilemma as part of one possible argument against a near-infinite multiverse. This argument runs as follows: if there were a near-infinite multiverse, there would be posthuman civilizations running ancestor simulations, and therefore we would come to the untenable and scientifically self-defeating conclusion that we live in a simulation; therefore, by reductio ad absurdum , existing multiverse theories are likely false. (Unlike Bostrom and Chalmers, Davies (among others) considers the simulation hypothesis to be self-defeating.)
Some point out that there is currently no proof of technology which would facilitate the existence of sufficiently high-fidelity ancestor simulation. Additionally, there is no proof that it is physically possible or feasible for a posthuman civilization to create such a simulation, and therefore for the present, the first proposition must be true.Additionally there are limits of computation .
Economist Robin Hanson argues a self-interested high-fidelity Sim should strive to be entertaining and praiseworthy in order to avoid being turned off or being shunted into a non-conscious low-fidelity part of the simulation. Hanson additionally speculates that someone who is aware that he might be a Sim might care less about others and live more for today: "your motivation to save for retirement, or to help the poor in Ethiopia, might be muted by realizing that in your simulation, you will never retire and there is no Ethiopia."
A long-shot method to test one type of simulation hypothesis was proposed in 2012 in a joint paper by physicists Silas R. Beane from the University of Bonn (now at the University of Washington, Seattle), and Zohreh Davoudi and Martin J. Savage from the University of Washington, Seattle.Under the assumption of finite computational resources, the simulation of the universe would be performed by dividing the continuum space-time into a discrete set of points. In analogy with the mini-simulations that lattice-gauge theorists run today to build up nuclei from the underlying theory of strong interactions (known as quantum chromodynamics), several observational consequences of a grid-like space-time have been studied in their work. Among proposed signatures is an anisotropy in the distribution of ultra-high-energy cosmic rays, that, if observed, would be consistent with the simulation hypothesis according to these physicists. In 2017, Campbell et al. proposed several experiments aimed at testing the simulation hypothesis in their paper "On Testing the Simulation Theory". In 2018 they started a Kickstarter campaign to fund the experiments, which reached $236,590, more than the required sum of $150,000.
In 2019, philosopher Preston Greene suggested that it may be best not to find out if we're living in a simulation since, if it were found to be true, such knowing may end the simulation.
Besides attempting to assess whether the simulation hypothesis is true or false, philosophers have also used it to illustrate other philosophical problems, especially in metaphysics and epistemology. David Chalmers has argued that simulated beings might wonder whether their mental lives are governed by the physics of their environment, when in fact these mental lives are simulated separately (and are thus, in fact, not governed by the simulated physics).They might eventually find that their thoughts fail to be physically caused. Chalmers argues that this means that Cartesian dualism is not necessarily as problematic of a philosophical view as is commonly supposed, though he does not endorse it.
Similarly, Vincent Conitzer has used the following computer simulation scenarios to illuminate further facts—facts that do not follow logically from the physical facts—about qualia (what it is like to have specific experiences), indexicality (what time it is now and who I am), and personal identity.Imagine a person in the real world who is observing a simulated world on a screen, from the perspective of one of the simulated agents in it. The person observing knows that besides the code responsible for the physics of the simulation, there must be additional code that determines in which colors the simulation is displayed on the screen, and which agent's perspective is displayed. (These questions are related to the inverted spectrum scenario and whether there are further facts about personal identity.) That is, the person can conclude that the facts about the physics of the simulation (which are completely captured by the code governing the physics) do not fully determine her experience by themselves. But then, Conitzer argues, imagine someone who has become so engrossed in the simulation that she has forgotten that it is a simulation she is watching. Could she not still reach the same conclusion? And if so, can we not conclude the same in our own daily lives?
Science fiction has highlighted themes such as virtual reality, artificial intelligence and computer gaming for more than fifty years. Simulacron-3 (1964) by Daniel F. Galouye (alternative title: Counterfeit World) tells the story of a virtual city developed as a computer simulation for market research purposes, in which the simulated inhabitants possess consciousness; all but one of the inhabitants are unaware of the true nature of their world. The book was made into a German made-for-TV film called World on a Wire (1973) directed by Rainer Werner Fassbinder. The movie The Thirteenth Floor (1999) was also loosely based on this book. "We Can Remember It for You Wholesale" is a short story by American writer Philip K. Dick, first published in The Magazine of Fantasy & Science Fiction in April 1966, and was the basis for Total Recall (1990 film) and Total Recall (2012 film). In Overdrawn at the Memory Bank , a 1983 television movie, the main character pays to have his mind connected to a simulation.
The Star Trek: The Next Generation episode "Ship in a Bottle" explores the idea of people being unaware they are living in simulation, with Picard postulating at the end that perhaps they are also in a simulation playing out in a box on a table. This is also a possible use of dramatic irony, with both the actors and audience aware the television programme is indeed a simulation of sorts.
More recently, the same theme was repeated in the 1999 film The Matrix , which depicted a world in which artificially intelligent robots enslaved humanity within a simulation set in the contemporary world. The 2012 play World of Wires was partially inspired by the Bostrom essay on the simulation hypothesis.In the episode "Extremis" (broadcast on 20 May 2017 on BBC One) of the science fiction series Doctor Who , aliens called "The Monks" plan an invasion of Earth by running and studying a holographic simulation of Earth with conscious inhabitants. When the virtual Doctor finds out about the simulation he sends an email about the simulation to his real self so that the real Doctor can save the world. In the first season of Rick and Morty , a science-fiction animated comedy, the episode "M. Night Shaym-Aliens!" aliens trap the lead role (Rick) in a simulated reality in order to trick him into revealing his formula for concentrated dark matter. In the game Xenoblade Chronicles , it is revealed that the whole world of the gods Bionis and Mechonis was a simulation run by Alvis, the administrative computer of a phase transition experiment facility (heavily implied to be "Ontos" in Xenoblade Chronicles 2) after Klaus destroyed the universe in a multi-verse experiment. The critically acclaimed book and movie: Ready Player One (2018), written by Ernest Cline and directed by Steven Spielberg, portrays the mass-adoption of a virtual simulated world in the near dystopian future. Simulation Theory is also the name of the eighth album by British alternative band Muse, released on 9 November 2018. "Answers In Simulation" by Iurii Vovchenko was released in 2019. This book addresses the subject of simulation from another angle. The author makes a statement "OK, we live in simulation" and then asks a question "What's next for us in that case?"
The anthropic principle is a philosophical consideration that observations of the universe must be compatible with the conscious and sapient life that observes it, and that there is hence a survivorship bias. Proponents of the anthropic principle reason that it explains why this universe has the age and the fundamental physical constants necessary to accommodate conscious life. As a result, they believe it is unremarkable that this universe has fundamental constants that happen to fall within the narrow range thought to be compatible with life. The strong anthropic principle (SAP), as explained by John D. Barrow and Frank Tipler, states that this is all the case because the universe is in some sense compelled to eventually have conscious and sapient life emerge within it. Some critics of the SAP argue in favor of a weak anthropic principle (WAP) similar to the one defined by Brandon Carter, which states that the universe's ostensible fine tuning is the result of selection bias : i.e., only in a universe capable of eventually supporting life will there be living beings capable of observing and reflecting on the matter. Most often such arguments draw upon some notion of the multiverse for there to be a statistical population of universes to select from and from which selection bias could occur.
Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only imaginary. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, reality is the totality of a system, known and unknown. Philosophical questions about the nature of reality or existence or being are considered under the rubric of ontology, which is a major branch of metaphysics in the Western philosophical tradition. Ontological questions also feature in diverse branches of philosophy, including the philosophy of science, philosophy of religion, philosophy of mathematics, and philosophical logic. These include questions about whether only physical objects are real, whether reality is fundamentally immaterial, whether hypothetical unobservable entities posited by scientific theories exist, whether God exists, whether numbers and other abstract objects exist, and whether possible worlds exist.
Whole brain emulation (WBE), mind upload or brain upload is the hypothetical futuristic process of scanning the mental state of a particular brain substrate and copying it to a computer. The computer could then run a simulation model of the brain's information processing, such that it would respond in essentially the same way as the original brain and experience having a conscious mind.
Simulated reality is the hypothesis that reality could be simulated—for example by quantum 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.
In philosophy, the brain in a vat is a scenario used in a variety of thought experiments intended to draw out certain features of human conceptions of knowledge, reality, truth, mind, consciousness, and meaning. It is an updated version of René Descartes's evil demon thought experiment originated by Gilbert Harman. Common to many science fiction stories, it outlines a scenario in which a mad scientist, machine, or other entity might remove a person's brain from the body, suspend it in a vat of life-sustaining liquid, and connect its neurons by wires to a supercomputer which would provide it with electrical impulses identical to those the brain normally receives. According to such stories, the computer would then be simulating reality and the "disembodied" brain would continue to have perfectly normal conscious experiences, such as those of a person with an embodied brain, without these being related to objects or events in the real world.
Permutation City is a 1994 science-fiction novel by Greg Egan that explores many concepts, including quantum ontology, through various philosophical aspects of artificial life and simulated reality. Sections of the story were adapted from Egan's 1992 short story "Dust", which dealt with many of the same philosophical themes. Permutation City won the John W. Campbell Award for the best science-fiction novel of the year in 1995 and was nominated for the Philip K. Dick Award the same year. The novel was also cited in a 2003 Scientific American article on multiverses by Max Tegmark.
Nick Bostrom is a Swedish philosopher at the University of Oxford known for his work on existential risk, the anthropic principle, human enhancement ethics, superintelligence risks, and the reversal test. In 2011, he founded the Oxford Martin Programme on the Impacts of Future Technology, and is the founding director of the Future of Humanity Institute at Oxford University. In 2009 and 2015, he was included in Foreign Policy's Top 100 Global Thinkers list.
The fine-tuned universe is the proposition that the conditions that allow life in the Universe can occur only when certain universal dimensionless physical constants lie within a very narrow range of values, so that if any of several fundamental constants were only slightly different, the Universe would be unlikely to be conducive to the establishment and development of matter, astronomical structures, elemental diversity, or life as it is understood.
In philosophy of mind, panpsychism is the view that mind or a mind-like aspect is a fundamental and ubiquitous feature of reality. It has taken on a wide variety of forms. Contemporary academic proponents hold that sentience or subjective experience is ubiquitous, while distancing these qualities from complex human mental attributes; they ascribe a primitive form of mentality to entities at the fundamental level of physics but do not ascribe it to most aggregates, such as rocks or buildings. On the other hand, some historical theorists ascribed attributes like life or spirits to all entities.
A superintelligence is a hypothetical agent that possesses intelligence far surpassing that of the brightest and most gifted human minds. "Superintelligence" may also refer to a property of problem-solving systems whether or not these high-level intellectual competencies are embodied in agents that act in the world. A superintelligence may or may not be created by an intelligence explosion and associated with a technological singularity.
Calculating Space is Konrad Zuse's 1969 book on digital physics. Zuse proposed that the universe is being computed by some sort of cellular automaton or other discrete computing machinery, challenging the long-held view that some physical laws are continuous by nature. He focused on cellular automata as a possible substrate of the computation, and pointed out that the classical notions of entropy and its growth do not make sense in deterministically computed universes.
The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis, in time, to expanding lasting life as measured by the Kardashev scale. The concept originates in Robin Hanson's argument that the failure to find any extraterrestrial civilizations in the observable universe implies the possibility something is wrong with one or more of the arguments from various scientific disciplines that the appearance of advanced intelligent life is probable; this observation is conceptualized in terms of a "Great Filter" which acts to reduce the great number of sites where intelligent life might arise to the tiny number of intelligent species with advanced civilizations actually observed. This probability threshold, which could lie behind us or in front of us, might work as a barrier to the evolution of intelligent life, or as a high probability of self-destruction. The main counter-intuitive conclusion of this observation is that the easier it was for life to evolve to our stage, the bleaker our future chances probably are.
Simulacron-3 (1964), by Daniel F. Galouye, is an American science fiction novel featuring an early literary description of a simulated reality.
The inverted spectrum is the hypothetical concept of two people sharing their color vocabulary and discriminations, although the colors one sees—one's qualia—are systematically different from the colors the other person sees.
In physics and cosmology, the mathematical universe hypothesis (MUH), also known as the ultimate ensemble theory, is a speculative "theory of everything" (TOE) proposed by cosmologist Max Tegmark.
In epistemology, the Münchhausen trilemma is a thought experiment used to demonstrate the impossibility of proving any truth, even in the fields of logic and mathematics. If it is asked how any given proposition is known to be true, proof may be provided. Yet that same question can be asked of the proof, and any subsequent proof. The Münchhausen trilemma is that there are only three options when providing further proof in response to further questioning:
Programming the Universe: A Quantum Computer Scientist Takes On the Cosmos is a 2006 popular science book by Seth Lloyd, professor of mechanical engineering at the Massachusetts Institute of Technology. The book proposes that the universe is a quantum computer, and advances in the understanding of physics may come from viewing entropy as a phenomenon of information, rather than simply thermodynamics. Lloyd also postulates that the universe can be fully simulated using a quantum computer; however, in the absence of a theory of quantum gravity, such a simulation is not yet possible.
Everything is all that exists; the opposite of nothing, or its complement. It is the totality of things relevant to some subject matter. Without expressed or implied limits, it may refer to anything. The Universe is everything that exists theoretically, though a multiverse may exist according to theoretical cosmology predictions. It may refer to an anthropocentric worldview, or the sum of human experience, history, and the human condition in general. Every object and entity is a part of everything, including all physical bodies and in some cases all abstract objects.
Simulated reality is a common theme in science fiction. It is predated by the concept "life is a dream". It should not be confused with the theme of virtual reality.
In philosophy, the phrase further facts refers to facts that do not follow logically from the physical facts of the world. Reductionists who argue that at bottom there is nothing more than the physical facts thus argue against the existence of further facts. The concept of further facts plays a key role in some of the major works in analytic philosophy of the late 20th century, including in Derek Parfit's Reasons and Persons, and David Chalmers's The Conscious Mind.
ABSTRACT Observable consequences of the hypothesis that the observed universe is a numerical simulation performed on a cubic space-time lattice or grid are explored. The simulation scenario is first motivated by extrapolating current trends in computational resource requirements for lattice QCD into the future. Using the historical development of lattice gauge theory technology as a guide, we assume that our universe is an early numerical simulation with unimproved Wilson fermion discretization and investigate potentially-observable consequences. Among the observables that are considered are the muon g-2 and the current differences between determinations of alpha, but the most stringent bound on the inverse lattice spacing of the universe, b−1 > ~ 10^11 GeV, is derived from the high-energy cut off of the cosmic ray spectrum. The numerical simulation scenario could reveal itself in the distributions of the highest energy cosmic rays exhibiting a degree of rotational symmetry breaking that reflects the structure of the underlying lattice.