Simulated reality
Encyclopedia
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.
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 participant's consciousness
is represented by an avatar
, which can look very different from the participant's actual appearance.
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 world's physics is compatible with the virtual world's. The result would not bring the "mind" of the entity out of its simulation, but its body would be born in the real world. In The Matrix Reloaded
, a variant of this is played out. Former Agent Smith takes over the body of a "redpill" inside the Matrix, causing the person's 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:
to temporarily relocate their mental processing into a virtual-person. After the simulation is over, the participant's mind is restored along with all new memories and experience gained within (as in the movie The Thirteenth Floor
, or when one flatline
s in Neuromancer
).
Further, there is the option (also from The Thirteenth Floor
) of a completely virtual-person, born in the simulation, willing to escape the simulation (after "waking up") and consequently somehow succeeding to be transferred into an outer-reality person. This would ultimately mean exiting (emigrating) and getting transformed on exit into a "real" person. In this particular case, since the emigrating inhabitant of the simulation didn't 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 or not 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, or abandon 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 didn't emigrate), he would do that now as a transformed user ("enriched" with an emigrated virtual-person, or now even completely being that previously virtual person, if that was chosen 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 an enclosing container or room, such as the "Holodeck
" in Star Trek
. Upon entering such a space, the real-world person would effectively feel immersed in the simulated environment, with a variety of potential methods being used to convince the user of the presence of motion, gravity, environments, and so on, and with the user presumably able to interact (or not) with the simulated reality.
The Matrix
movies feature an intermingled type of simulation: they contain not only human minds (with their physical bodies remaining outside), but also sentient software programs that govern various aspects of the computed realm.
first published the simulation argument (and three years after its update in Moravec's second full pop science book), the philosopher Nick Bostrom
investigated the possibility that we may be living in a simulation. A simplified version of his argument
proceeds as such:
Then the ultimate question is — if one accepts that the above premises are at least possible — which of the following is more likely?
In greater detail, his argument attempts to prove the trichotomy
, either that:
Bostrom's argument uses the premise that given sufficiently advanced technology, it is possible to simulate entire inhabited planets or even larger habitats or even entire universes as quantum simulations in time/space pockets, including all the people on them, on a computer, 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 the first hypothesis: We assume that the human race could reach such a technologically advanced level without destroying themselves in the process. We then deny the second hypothesis: We presume that once we reached such a level we would still be interested in history, the past, and our ancestors, and that there would be no legal or moral strictures on running such simulations. If these two assumptions are made, then
Assumptions as to whether the human race (or another intelligent species) could reach such a technological level without destroying themselves depend greatly on the value of the Drake equation
, which attempts to calculate the number of intelligent technological species communicating via radio in a galaxy at any given point in time. The expanded equation looks to the number of posthuman civilizations that ever would exist in any given universe. If the average for all universes, real or simulated, is greater than or equal to one such civilization existing in each universe's entire history, then the odds are rather overwhelmingly in favor of the proposition that the average civilization is in a simulation, assuming that such simulated universes are possible and such civilizations would want to run such simulations.
's 'Butterfly Dream') and psychologic analytics ). By generalizing the relativity principle in physics, which is mainly about the relativity of motion
, stating that the motion has no absolute meaning (to say if something is in motion or rest, one must adopt some reference frame
; without a reference frame, one cannot tell the state of being in rest or in uniform motion), a similar property has been suggested for reality, meaning that without a reference 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 Einstein's relativity, there are two fundamental principles for the theory 'Relativity of reality'.
The first principle ('equally real') says that all worlds are equal in reality, even for partially simulated worlds (if there are living beings, they feel 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" is meaningless, because they are indistinguishable in principle. The 'equally real principle' doesn't mean that we cannot differentiate a concrete computer simulation
from our own world, since when we are talking about a computer simulation, we already have a reference world (the world we are in).
Coupled with the second principle ('coexistence'), the space-time transformation between two across-reality objects (one is in real world and the other is in virtual world) was supposed in this theory, which is an example of interreality (mixed reality
) system. The first 'interreality physics' experiment may be the one conducted by V. Gintautas and A. W. Hubler, where a mixed-reality correlation between two pendula (one is real and the other is virtual) was indeed observed.
theory stating that cognition
is a form of computation
. It is relevant to the Simulation Hypothesis in that it illustrates how a simulation could contain conscious subjects, as required by a "virtual people" simulation. For example, it is well known that physical systems can be simulated to some degree of accuracy. If computationalism is correct, and if there is no problem
in generating artificial consciousness
from cognition, it would establish the theoretical possibility of a simulated reality. However, the relationship between cognition and phenomenal consciousness
is disputed
. It is possible that consciousness
requires a physical substrate not provided by a computational simulator, and simulated people, while behaving appropriately, would be philosophical zombies. This would also seem to negate Nick Bostrom
's simulation argument; we cannot be inside a simulation, as conscious beings, if consciousness cannot be simulated. However, we could still be within a simulation, and yet be envatted brain
s. This would allow us to exist as conscious beings within a simulated environment, even if a simulated environment could not simulate consciousness.
Some theorists have argued that if the "consciousness-is-computation" version of computationalism and mathematical realism (also known as mathematical Platonism
) are both true our consciousnesses must be inside a simulation. This argument states that a "Plato's heaven" or ultimate ensemble
would contain every algorithm, including those which implement consciousness. Platonic simulation theories are also subsets of the multiverse
theories and theories of everything
.
and considerations of simplicity
rule against it. One of the first philosophers to question the distinction between reality
and dream
s was Zhuangzi
, a Chinese
philosopher from the 4th century BC. He phrased the problem as the well-known "Butterfly Dream," which went as follows:
The philosophical underpinnings of this argument are also brought up by Descartes, who was one of the first Western
philosophers to do so. In Meditations on First Philosophy, he states "... there are no certain indications by which we may clearly distinguish wakefulness from sleep", and goes on to conclude that "It is possible that I am dreaming right now and that all of my perceptions are false".
Chalmers (2003) discusses the dream hypothesis, and notes that this comes in two distinct forms:
Both the dream argument
and the Simulation hypothesis can be regarded as skeptical hypotheses; however in raising these doubts, just as Descartes noted that his own thinking led him to be convinced of his own existence, the existence of the argument itself is testament to the possibility of its own truth.
Another state of mind in which an individual's perceptions have no physical basis in the real world is called psychosis
. Psychosis may have a physical basis in the real world, explanations vary.
. Hypercomputation
(super-Turing computation) introduces other possibilities which will be dealt with separately). In fact, known physics is held to be (Turing) computable, but the statement "physics is computable" needs to be qualified in various ways. Before symbolic computation
, a number, thinking particularly of a real number
, one with an infinite number of digits, was said to be computable
if a Turing machine will continue to spit out digits endlessly, never reaching a "final digit". This runs counter, however, to the 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-moment basis. As Richard Feynman
put it:
The objection could be made that the simulation does not have to run in "real time
". It misses an important point, though: the shortfall is not linear; rather it is a matter of performing an infinite number of computational steps in a finite time.
Note that these objections all relate to the idea of reality being exactly simulated. Ordinary computer simulations as used by physicists are always approximations.
These objections do not apply if the hypothetical simulation is being run on a hypercomputer, a hypothetical machine more powerful than a Turing machine. Unfortunately, there is no way of working out if computers running a simulation are capable of doing things that computers in the simulation cannot do. No-one has shown that the laws of physics inside a simulation and those outside it have to be the same, and simulations of different physical laws have been constructed.
The problem now is that there is no evidence that can conceivably be produced to show that the universe is not any kind of computer, making the simulation hypothesis unfalsifiable
and therefore scientifically unacceptable, at least by Popperian
standards.
All conventional computers, however, are less than hypercomputational, and the simulated reality hypothesis is usually expressed in terms 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 not capable of being modeled by a conventional Turing machine
-type of digital computer. Penrose hypothesizes that quantum mechanics plays an essential role in the understanding of human consciousness. The collapse of the quantum wavefunction is seen as playing an important role in brain function.
, David Deutsch discusses how the limits to computability imposed by Gödel's Incompleteness Theorem affects the Virtual Reality rendering process. In order to do this, Deutsch invents the notion of a CantGoTu environment (named after Cantor, Gödel, and Turing), using Cantor's diagonal argument
to construct an 'impossible' Virtual Reality which a physical VR generator would not be able to generate. The way that this works is to imagine that all VR environments renderable by such a generator can be enumerated, and that we label them VR1, VR2, etc. Slicing time up into discrete chunks we can create an environment which is unlike VR1 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 generated by the VR generator. Deutsch then goes on to discuss a universal VR generator, which as a physical device would not be able to render all possible environments, but would be able to render those environments which can be rendered by all other physical VR generators. He argues 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 universal computer which can be programmed to execute any computation that any other machine can do. Attempts to capture the process of virtual reality rendering provides us with a version which states: "It is possible to build a virtual-reality generator, whose repertoire includes every physically possible environment". In other words, a single, buildable physical object can mimic all the behaviours and responses of any 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 virtual reality generator whose repertoire includes every physically possible environment." However, in order to include every physically possible environment, the computer would have to be able to include a full simulation of the environment containing itself. Even so, a computer running a simulation need not have to run every possible physical moment to be plausible to its inhabitants.
are such that in 2002, "while the fastest proteins fold on the order of tens of microseconds", "current single computer processors" could "only simulate on the order of a nanosecond of real-time of folding in full atomic detail per CPU day".
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 roughly 1033 to 1036 calculations. He further calculated that a planet-sized computer built with computronium
using known nanotechnological methods would perform about 1042 calculations per second — and a planet-sized computer or an even larger stellar system-sized computer
is not inherently impossible to build, (although the speed of light could severely constrain the speed at which its subprocessors share data). In any case, a simulation need not compute every single molecular event that occurs inside it; it may only process events that its participants can actively perceive. This is particularly the case if the simulation contained only a handful of people; far less processing power would be needed to make them believe they were in a "world" much larger than was actually the case.
A real world example of this could be the observer paradox or Heisenberg Uncertainty Principle - an unobserved region of space is indeterminate until observed - this could be because the simulating computer is not simulating it until it needs to.
problem with the argument. Even if we are a simulated reality, there is no way to be sure the beings running the simulation are not themselves a simulation, and the operators of that simulation are not a simulation, ad infinitum
. Given the premises of the simulation argument, any reality, even one running a simulation, has no better or worse a chance of being a simulation than any other.
Also, a simulated reality need not run in real time addressing computational constraints. The inhabitants of a simulated universe would have no way of knowing if one day of subjective time actually required much longer to calculate in their host computer, or vice-versa, or if the simulation is run in pieces on different computers, or with a million generations of monks working weekends on abacus
es — all without the simulation missing a beat 'in simulation time'.
that manifest inside. As a simple example of this, when the "hall of mirrors" effect occurs in the first person shooter Doom, the game attempts to display "nothing" and obviously fails in its attempt to do so. If a void can be found and tested, and if the observers survive its discovery, then it may reveal the underlying computational substrate. However, lapses in 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 powerful simulation are instantly erased the minute they are observed since presumably all thoughts and experiences in a simulated world could be carefully monitored and altered. This would, however, require enormous processing capability in order to simultaneously monitor billions 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 simulation significantly determined to protect its existence could erase any proof that it was a simulation whenever it arose, provided it had the enormous 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 of its existence is difficult. This would mean that the computer actually has an easy time of erasing glitches, but we all think that changing reality requires great power. One could possibly take miracles and paranormal activity as software bugs especially those which seem to have a negative effect on one; this notion has been explored in The Matrix
, where déjà vu
is considered a sign of crude alteration to the system; and Animatrix where software glitches are concentrated in a house which the neighbors call "haunted", subsequently corrected by 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 may be 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 then be only suspicious to remove them from this reality and doing so would raise more questions by its inhabitants. In such instance, it would make more sense to leave the "error" in place.
sometimes do. People have already spent considerable effort searching for patterns or messages within the endless decimal places of the fundamental constants such as e
and pi
. In Carl Sagan
's science fiction
novel Contact
, Sagan contemplates the possibility of finding a signature embedded in pi (in its base-11
expansion) by the creators 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. As usual, other hypotheses could explain the same evidence. In any case, if such constants are in fact normal
, then at some point an apparently meaningful message will appear in them (this is known as the infinite monkey theorem
), not necessarily because it was placed 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 we consider that the human race will eventually be capable of creating intelligent programs (i.e. machines) living inside a virtual subspace of our "real" world, then an interesting question would be to define whether or not we will be capable of suppressing from our sentient robots their capability of knowing their artificial nature (see Philip K Dick's Do Androids Dream of Electric Sheep?
).
However, this argument, like many others, assumes that accurate judgments about the simulating computer can be made from within the simulation. 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-atomic particles due to our inherent physical limitations. In order to see such particles we rely on other instruments which appear to magnify or translate that information into a format our limited senses are able to view: computer print out, lens of a microscope, etc. Therefore, we essentially take on faith that they're an accurate portrayal of the fine grained world which appears to exist in a realm beyond our natural senses. Assuming the sub-atomic could also be simulated then the processing power required to generate a realistic world would be greatly reduced.
, digital physics
holds the basic premise that the entire history of our universe
is computable in some sense. The hypothesis was pioneered in Konrad Zuse
's book Rechnender Raum (translated by MIT into English as Calculating Space
, 1970), which focuses on cellular automata. Juergen Schmidhuber suggested that the universe could be a Turing machine
, because there is a very short 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 not incompatible with the notion of computability. A quantum version of digital physics has recently been proposed by Seth Lloyd
. None of these 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 number
s and uncountable infinities from physics would counter some of the objections noted above, and at least make computer simulation a possibility. However, digital physics must overcome these objections. For instance, cellular automata would appear to be a poor model for the non-locality of quantum mechanics
.
s, philosophical zombies, or 'bots
' added to the simulation to make it more realistic 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:
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 of modern video games.
simulated reality may be required to progress at a rate that is near realtime
; that is, time within it may be required to pass at approximately the same rate as the outer reality which contains it. This might be the case because the players are interacting 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 point is that they still function at a finite, biological speed, and the simulation must track with them. Unless those interacting with the simulation 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 simulation's own physics in order to experience, think, and react. If the simulation were slowed down or sped up, so also would the inhabitants' own senses, 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 perform the 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 pause every life and mind within it. When the simulation was later resumed, the inhabitants would continue exactly as they were before the pause, completely unaware that (for example) their cosmos had been paused and archived for a billion years before being resumed. A simulation could also be created with its inhabitants already possessing memories as though they had already lived part of their lives before; said inhabitants would not be able to tell the difference unless informed of it by the simulation. (Compare with the five minute hypothesis 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 its entire cosmos at full speed. Per the Turing completeness theorem
, a simulation can progress at whatever speed its host computer can manage; it would be constrained by available memory but not by computation rate.
The 'parent' simulator would be simulating all of the atoms of the computer, atoms which happen to be calculating a 'child' simulation. By way of illustration: in Fallout 3
, Metal Gear Solid 2, and Xenosaga
, the player character at one point must enter a virtual reality simulation in the game. Alternatively, imagine a Java Runtime Environment running a virtual computer
on a "real-world" computer that itself is located within a simulation.
This recursion could continue to infinitely many levels — a simulation containing a computer running a simulation containing a computer running a simulation and so on. The recursion is subject only to one constraint (assuming no level has infinite computational power): each 'nested' simulation must be:
...and must be at least one of the following:
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, there need not be any noticeable difference between any of the subsets.
Simulated reality is a theme that pre-dates science fiction
. In Medieval and Renaissance religious theatre, the concept of the world as theater is frequent.
Virtual reality, and to a lesser point simulated reality, are key facets in the Cyberpunk
genre, regardless of format.
Reality
In philosophy, reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible...
could be simulated—perhaps by computer simulation
Computer simulation
A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system...
—to a degree indistinguishable from "true" reality
Reality
In philosophy, reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible...
. 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
Virtual reality , also known as virtuality, is a term that applies to computer-simulated environments that can simulate physical presence in places in the real world, as well as in imaginary worlds...
. 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.
Brain-computer interface
In brain-computer interfaceBrain-computer interface
A brain–computer interface , sometimes called a direct neural interface or a brain–machine interface , is a direct communication pathway between the brain and an external device...
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 participant's consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
is represented by an avatar
Avatar (computing)
In computing, an avatar is the graphical representation of the user or the user's alter ego or character. It may take either a three-dimensional form, as in games or virtual worlds, or a two-dimensional form as an icon in Internet forums and other online communities. It can also refer to a text...
, which can look very different from the participant's actual appearance.
Virtual people
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 simulation's own logic (i.e. using its own physics). As such, they could be downloaded from one simulation to another, or even archived and resurrected at a later time. It is also possible that a simulated entity could be moved out of the simulation entirely by means of mind transferMind transfer
Whole brain emulation or mind uploading is the hypothetical process of transferring or copying a conscious mind from a brain to a non-biological substrate by scanning and mapping a biological brain in detail and copying its state into a computer system or another computational device...
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
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
and create a real-world counterpart from that model, assuming the real world's physics is compatible with the virtual world's. The result would not bring the "mind" of the entity out of its simulation, but its body would be born in the real world. In The Matrix Reloaded
The Matrix Reloaded
The Matrix Reloaded is a 2003 American science fiction film and the second installment in The Matrix trilogy, written and directed by the Wachowskis. It premiered on May 7, 2003, in Westwood, Los Angeles, California, and went on general release by Warner Bros. in North American theaters on May 15,...
, a variant of this is played out. Former Agent Smith takes over the body of a "redpill" inside the Matrix, causing the person's 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 consciousnessArtificial consciousnessArtificial consciousness , also known as machine consciousness or synthetic consciousness, is a field related to artificial intelligence and cognitive robotics whose aim is to define that which would have to be synthesized were consciousness to be found in an engineered artifact .Neuroscience...
es; - SolipsisticSolipsismSolipsism is the philosophical idea that only one's own mind is sure to exist. The term comes from Latin solus and ipse . Solipsism as an epistemological position holds that knowledge of anything outside one's own mind is unsure. The external world and other minds cannot be known, and might not...
simulation in which consciousness is simulated and the "world" participants perceive exists only within their minds.
Emigration
In an emigration simulation, the participant enters the simulation from the outer reality, as in the brain-computer interface simulation, but to a much greater degree. On entry, the participant could use a variety of hypothetical methods to participate in the simulated reality including mind transferMind transfer
Whole brain emulation or mind uploading is the hypothetical process of transferring or copying a conscious mind from a brain to a non-biological substrate by scanning and mapping a biological brain in detail and copying its state into a computer system or another computational device...
to temporarily relocate their mental processing into a virtual-person. After the simulation is over, the participant's mind is restored along with all new memories and experience gained within (as in the movie The Thirteenth Floor
The Thirteenth Floor
The Thirteenth Floor is a 1999 science fiction film directed by Josef Rusnak and loosely based upon Simulacron-3 , a novel by Daniel F. Galouye...
, or when one flatline
Flatline
A flatline is an electrical time sequence measurement that shows no activity and therefore when represented, shows a flat line instead of a moving one. It almost always refers to either a flatlined electrocardiogram, where the heart shows no electrical activity , or to a flat electroencephalogram,...
s in Neuromancer
Neuromancer
Neuromancer is a 1984 novel by William Gibson, a seminal work in the cyberpunk genre and the first winner of the science-fiction "triple crown" — the Nebula Award, the Philip K. Dick Award, and the Hugo Award. It was Gibson's debut novel and the beginning of the Sprawl trilogy...
).
Further, there is the option (also from The Thirteenth Floor
The Thirteenth Floor
The Thirteenth Floor is a 1999 science fiction film directed by Josef Rusnak and loosely based upon Simulacron-3 , a novel by Daniel F. Galouye...
) of a completely virtual-person, born in the simulation, willing to escape the simulation (after "waking up") and consequently somehow succeeding to be transferred into an outer-reality person. This would ultimately mean exiting (emigrating) and getting transformed on exit into a "real" person. In this particular case, since the emigrating inhabitant of the simulation didn't 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 or not 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, or abandon 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 didn't emigrate), he would do that now as a transformed user ("enriched" with an emigrated virtual-person, or now even completely being that previously virtual person, if that was chosen 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 an enclosing container or room, such as the "Holodeck
Holodeck
A holodeck, in the fictional Star Trek universe, is a simulated reality facility located on starships and starbases. The first use of a "holodeck" by that name in the Star Trek universe was in the pilot episode of Star Trek: The Next Generation, "Encounter at Farpoint", although a conceptually...
" in Star Trek
Star Trek
Star Trek is an American science fiction entertainment franchise created by Gene Roddenberry. The core of Star Trek is its six television series: The Original Series, The Animated Series, The Next Generation, Deep Space Nine, Voyager, and Enterprise...
. Upon entering such a space, the real-world person would effectively feel immersed in the simulated environment, with a variety of potential methods being used to convince the user of the presence of motion, gravity, environments, and so on, and with the user presumably able to interact (or not) with the simulated reality.
Intermingled
An intermingled simulation supports both types of consciousness: "players" from the outer reality who are visiting (as a brain-computer interface simulation) or emigrating, and virtual-people who are natives of the simulation and hence lack any physical body in the outer reality.The Matrix
The Matrix
The Matrix is a 1999 science fiction-action film written and directed by Larry and Andy Wachowski, starring Keanu Reeves, Laurence Fishburne, Carrie-Anne Moss, Joe Pantoliano, and Hugo Weaving...
movies feature an intermingled type of simulation: they contain not only human minds (with their physical bodies remaining outside), but also sentient software programs that govern various aspects of the computed realm.
Nick Bostrom
Ten years after Hans MoravecHans Moravec
Hans Moravec is an adjunct faculty member at the Robotics Institute of Carnegie Mellon University. He is known for his work on robotics, artificial intelligence, and writings on the impact of technology. Moravec also is a futurist with many of his publications and predictions focusing on...
first published the simulation argument (and three years after its update in Moravec's second full pop science book), the philosopher Nick Bostrom
Nick Bostrom
Nick Bostrom is a Swedish philosopher at the University of Oxford known for his work on existential risk and the anthropic principle. He holds a PhD from the London School of Economics...
investigated the possibility that we may be living in a simulation. A simplified version of his argument
Argument
In philosophy and logic, an argument is an attempt to persuade someone of something, or give evidence or reasons for accepting a particular conclusion.Argument may also refer to:-Mathematics and computer science:...
proceeds as such:
- i. It is possible that an advanced civilization could create a computer simulation which contains individuals with artificial intelligenceArtificial intelligenceArtificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
(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
Trichotomy
In mathematics, the Law of Trichotomy states that every real number is either positive, negative, or zero. More generally, trichotomy is the property of an order relation...
, either that:
- 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
- races who do reach such a sophisticated level do not tend to run such simulations; or
- we are almost certainly living in such a simulation.
Bostrom's argument uses the premise that given sufficiently advanced technology, it is possible to simulate entire inhabited planets or even larger habitats or even entire universes as quantum simulations in time/space pockets, including all the people on them, on a computer, 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 the first hypothesis: We assume that the human race could reach such a technologically advanced level without destroying themselves in the process. We then deny the second hypothesis: We presume that once we reached such a level we would still be interested in history, the past, and our ancestors, and that there would be no legal or moral strictures on running such simulations. If these two assumptions are 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 destroying themselves depend greatly on the value of the Drake equation
Drake equation
The Drake equation is an equation used to estimate the number of detectable extraterrestrial civilizations in the Milky Way galaxy. It is used in the fields of exobiology and the Search for ExtraTerrestrial Intelligence...
, which attempts to calculate the number of intelligent technological species communicating via radio in a galaxy at any given point in time. The expanded equation looks to the number of posthuman civilizations that ever would exist in any given universe. If the average for all universes, real or simulated, is greater than or equal to one such civilization existing in each universe's entire history, then the odds are rather overwhelmingly in favor of the proposition that the average civilization is in a simulation, assuming that such simulated universes are possible and such civilizations would want to run such simulations.
Relativity of reality
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 a commemorative article dedicated to the 'The World Year of Physics 2005', physicist Bin-Guang Ma proposed the theory of 'Relativity of reality' (though this notion has been suggested in other contexts like ancient philosophy (ZhuangziZhuangzi
Zhuangzi was an influential Chinese philosopher who lived around the 4th century BCE during the Warring States Period, a period corresponding to the philosophical summit of Chinese thought — the Hundred Schools of Thought, and is credited with writing—in part or in whole—a work known by his name,...
's 'Butterfly Dream') and psychologic analytics ). By generalizing the relativity principle in physics, which is mainly about the relativity of motion
Motion (physics)
In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is typically described in terms of velocity, acceleration, displacement and time . An object's velocity cannot change unless it is acted upon by a force, as...
, stating that the motion has no absolute meaning (to say if something is in motion or rest, one must adopt some reference frame
Frame of reference
A frame of reference in physics, may refer to a coordinate system or set of axes within which to measure the position, orientation, and other properties of objects in it, or it may refer to an observational reference frame tied to the state of motion of an observer.It may also refer to both an...
; without a reference frame, one cannot tell the state of being in rest or in uniform motion), a similar property has been suggested for reality, meaning that without a reference 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 Einstein's relativity, there are two fundamental principles for the theory 'Relativity of reality'.
- All worlds are equally real.
- 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, they feel 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" is meaningless, because they are indistinguishable in principle. The 'equally real principle' doesn't mean that we cannot differentiate a concrete computer simulation
Computer simulation
A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system...
from our own world, since when we are talking about a computer simulation, we already have a reference world (the world we are in).
Coupled with the second principle ('coexistence'), the space-time transformation between two across-reality objects (one is in real world and the other is in virtual world) was supposed in this theory, which is an example of interreality (mixed reality
Mixed reality
Mixed reality refers to the merging of real and virtual worlds to produce new environments and visualisations where physical and digital objects co-exist and interact in real time...
) system. The first 'interreality physics' experiment may be the one conducted by V. Gintautas and A. W. Hubler, where a mixed-reality correlation between two pendula (one is real and the other is virtual) was indeed observed.
Computationalism & Platonic simulation theories
Computationalism is a philosophy of mindPhilosophy of mind
Philosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
theory stating that cognition
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
is a form of computation
Computation
Computation is defined as any type of calculation. Also defined as use of computer technology in Information processing.Computation is a process following a well-defined model understood and expressed in an algorithm, protocol, network topology, etc...
. It is relevant to the Simulation Hypothesis in that it illustrates how a simulation could contain conscious subjects, as required by a "virtual people" simulation. For example, it is well known that physical systems can be simulated to some degree of accuracy. If computationalism is correct, and if there is no problem
Hard problem of consciousness
The hard problem of consciousness is the problem of explaining how and why we have qualitative phenomenal experiences. David Chalmers contrasts this with the "easy problems" of explaining the ability to discriminate, integrate information, report mental states, focus attention, etc...
in generating artificial consciousness
Artificial consciousness
Artificial consciousness , also known as machine consciousness or synthetic consciousness, is a field related to artificial intelligence and cognitive robotics whose aim is to define that which would have to be synthesized were consciousness to be found in an engineered artifact .Neuroscience...
from cognition, it would establish the theoretical possibility of a simulated reality. However, the relationship between cognition and phenomenal consciousness
Qualia
Qualia , singular "quale" , from a Latin word meaning for "what sort" or "what kind," is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'. Examples of qualia are the pain of a headache, the taste of wine, the experience of taking a recreational drug, or the...
is disputed
Chinese room
The Chinese room is a thought experiment by John Searle, which first appeared in his paper "Minds, Brains, and Programs", published in Behavioral and Brain Sciences in 1980...
. It is possible that consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
requires a physical substrate not provided by a computational simulator, and simulated people, while behaving appropriately, would be philosophical zombies. This would also seem to negate Nick Bostrom
Nick Bostrom
Nick Bostrom is a Swedish philosopher at the University of Oxford known for his work on existential risk and the anthropic principle. He holds a PhD from the London School of Economics...
's simulation argument; we cannot be inside a simulation, as conscious beings, if consciousness cannot be simulated. However, we could still be within a simulation, and yet be envatted brain
Brain in a vat
In philosophy, the brain in a vat is an element used in a variety of thought experiments intended to draw out certain features of our ideas of knowledge, reality, truth, mind, and meaning...
s. This would allow us to exist as conscious beings within a simulated environment, even if a simulated environment could not simulate consciousness.
Some theorists have argued that if the "consciousness-is-computation" version of computationalism and mathematical realism (also known as mathematical Platonism
Platonism
Platonism is the philosophy of Plato or the name of other philosophical systems considered closely derived from it. In a narrower sense the term might indicate the doctrine of Platonic realism...
) are both true our consciousnesses must be inside a simulation. This argument states that a "Plato's heaven" or ultimate ensemble
Ultimate ensemble
In physics and cosmology, the mathematical universe hypothesis , also known as the Ultimate Ensemble, is a speculative "theory of everything" proposed by the theoretical physicist, Max Tegmark.-Description:...
would contain every algorithm, including those which implement consciousness. Platonic simulation theories are also subsets of the multiverse
Multiverse
The multiverse is the hypothetical set of multiple possible universes that together comprise all of reality.Multiverse may also refer to:-In fiction:* Multiverse , the fictional multiverse used by DC Comics...
theories and theories of everything
Theory of everything
A theory of everything is a putative theory of theoretical physics that fully explains and links together all known physical phenomena, and predicts the outcome of any experiment that could be carried out in principle....
.
Dreaming
A dream could be considered a type of simulation capable of fooling someone who is asleep. As a result the "dream hypothesis" cannot be ruled out, although it has been argued that common senseCommon sense
Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...
and considerations of simplicity
Occam's razor
Occam's razor, also known as Ockham's razor, and sometimes expressed in Latin as lex parsimoniae , is a principle that generally recommends from among competing hypotheses selecting the one that makes the fewest new assumptions.-Overview:The principle is often summarized as "simpler explanations...
rule against it. One of the first philosophers to question the distinction between reality
Reality
In philosophy, reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible...
and dream
Dream
Dreams are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. The content and purpose of dreams are not definitively understood, though they have been a topic of scientific speculation, philosophical intrigue and religious...
s was Zhuangzi
Zhuangzi
Zhuangzi was an influential Chinese philosopher who lived around the 4th century BCE during the Warring States Period, a period corresponding to the philosophical summit of Chinese thought — the Hundred Schools of Thought, and is credited with writing—in part or in whole—a work known by his name,...
, a Chinese
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
philosopher from the 4th century BC. He phrased 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 didn't know he was Zhuangzi. Suddenly he woke up and there he was, solid and unmistakable Zhuangzi. But he didn't 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
Western world
The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...
philosophers to do so. In Meditations on First Philosophy, he states "... there are no certain indications by which we may clearly distinguish wakefulness from sleep", and goes on to conclude that "It is possible that I am dreaming right now and that all of my perceptions are false".
Chalmers (2003) discusses the dream hypothesis, and notes that this comes in two distinct forms:
- 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.
Both the dream argument
Dream argument
The dream argument is the postulation that the act of dreaming provides preliminary evidence that the senses we trust to distinguish reality from illusion should not be fully trusted, and therefore any state that is dependent on our senses should at the very least be carefully examined and...
and the Simulation hypothesis can be regarded as skeptical hypotheses; however in raising these doubts, just as Descartes noted that his own thinking led him to be convinced of his own existence, the existence of the argument itself is testament to the possibility of its own truth.
Another state of mind in which an individual's perceptions have no physical basis in the real world is called psychosis
Psychosis
Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...
. Psychosis may have a physical basis in the real world, explanations vary.
Computability of physics
A decisive refutation of any claim that our reality is computer-simulated would be the discovery of some uncomputable physics, because if reality is doing something that no computer can do, it cannot be a computer simulation. (Computability generally means computability by a Turing machineTuring machine
A Turing machine is a theoretical device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a...
. Hypercomputation
Hypercomputation
Hypercomputation or super-Turing computation refers to models of computation that are more powerful than, or are incomparable with, Turing computability. This includes various hypothetical methods for the computation of non-Turing-computable functions, following super-recursive algorithms...
(super-Turing computation) introduces other possibilities which will be dealt with separately). In fact, known physics is held to be (Turing) computable, but the statement "physics is computable" needs to be qualified in various ways. Before symbolic computation
Symbolic computation
Symbolic computation or algebraic computation, relates to the use of machines, such as computers, to manipulate mathematical equations and expressions in symbolic form, as opposed to manipulating the approximations of specific numerical quantities represented by those symbols...
, a number, thinking particularly of a real number
Real number
In mathematics, a real number is a value that represents a quantity along a continuum, such as -5 , 4/3 , 8.6 , √2 and π...
, one with an infinite number of digits, was said to be computable
Computable number
In mathematics, particularly theoretical computer science and mathematical logic, the computable numbers, also known as the recursive numbers or the computable reals, are the real numbers that can be computed to within any desired precision by a finite, terminating algorithm...
if a Turing machine will continue to spit out digits endlessly, never reaching a "final digit". This runs counter, however, to the idea of simulating physics in real time (or any plausible kind of time). Known physical laws (including
Continuous spectrum
The spectrum of a linear operator is commonly divided into three parts: point spectrum, continuous spectrum, and residual spectrum.If H is a topological vector space and A:H \to H is a linear map, the spectrum of A is the set of complex numbers \lambda such that A - \lambda I : H \to H is not...
those of quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
) are very much infused with real numbers and continua, and the universe seems to be able to decide their values on a moment-by-moment basis. As Richard Feynman
Richard Feynman
Richard Phillips Feynman was an American physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics...
put it:
"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
Real-time computing
In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...
". It misses an important point, though: the shortfall is not linear; rather it is a matter of performing an infinite number of computational steps in a finite time.
Note that these objections all relate to the idea of reality being exactly simulated. Ordinary computer simulations as used by physicists are always approximations.
These objections do not apply if the hypothetical simulation is being run on a hypercomputer, a hypothetical machine more powerful than a Turing machine. Unfortunately, there is no way of working out if computers running a simulation are capable of doing things that computers in the simulation cannot do. No-one has shown that the laws of physics inside a simulation and those outside it have to be the same, and simulations of different physical laws have been constructed.
The problem now is that there is no evidence that can conceivably be produced to show that the universe is not any kind of computer, making the simulation hypothesis unfalsifiable
Falsifiability
Falsifiability or refutability of an assertion, hypothesis or theory is the logical possibility that it can be contradicted by an observation or the outcome of a physical experiment...
and therefore scientifically unacceptable, at least by Popperian
Karl Popper
Sir Karl Raimund Popper, CH FRS FBA was an Austro-British philosopher and a professor at the London School of Economics...
standards.
All conventional computers, however, are less than hypercomputational, and the simulated reality hypothesis is usually expressed in terms of conventional computers, i.e. Turing machines. Inasmuch as they are, the hypothesis is falsifiable.
Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...
, an English mathematical physicist, presents the argument that human consciousness is non-algorithmic, and thus is not capable of being modeled by a conventional Turing machine
Turing machine
A Turing machine is a theoretical device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a...
-type of digital computer. Penrose hypothesizes that quantum mechanics plays an essential role in the understanding of human consciousness. The collapse of the quantum wavefunction is seen as playing an important role in brain function.
CantGoTu Environments
In his book The Fabric of RealityThe Fabric of Reality
The Fabric of Reality is a book by physicist David Deutsch written in 1997. It expands upon his views of quantum mechanics and its implications for understanding reality....
, David Deutsch discusses how the limits to computability imposed by Gödel's Incompleteness Theorem affects the Virtual Reality rendering process. In order to do this, Deutsch invents the notion of a CantGoTu environment (named after Cantor, Gödel, and Turing), using Cantor's diagonal argument
Cantor's diagonal argument
Cantor's diagonal argument, also called the diagonalisation argument, the diagonal slash argument or the diagonal method, was published in 1891 by Georg Cantor as a mathematical proof that there are infinite sets which cannot be put into one-to-one correspondence with the infinite set of natural...
to construct an 'impossible' Virtual Reality which a physical VR generator would not be able to generate. The way that this works is to imagine that all VR environments renderable by such a generator can be enumerated, and that we label them VR1, VR2, etc. Slicing time up into discrete chunks we can create an environment which is unlike VR1 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 generated by the VR generator. Deutsch then goes on to discuss a universal VR generator, which as a physical device would not be able to render all possible environments, but would be able to render those environments which can be rendered by all other physical VR generators. He argues 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 universal computer which can be programmed to execute any computation that any other machine can do. Attempts to capture the process of virtual reality rendering provides us with a version which states: "It is possible to build a virtual-reality generator, whose repertoire includes every physically possible environment". In other words, a single, buildable physical object can mimic all the behaviours and responses of any 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
Church–Turing–Deutsch principle
In computer science and quantum physics, the Church–Turing–Deutsch principle is a stronger, physical form of the Church–Turing thesis formulated by David Deutsch in 1985. The principle states that a universal computing device can simulate every physical process. The principle was originally...
, namely: "It is possible to build a virtual reality generator whose repertoire includes every physically possible environment." However, in order to include every physically possible environment, the computer would have to be able to include a full simulation of the environment containing itself. Even so, a computer running a simulation need not have to run every possible physical moment to be plausible to its inhabitants.
Virtual people
The computational requirements for molecular dynamicsMolecular dynamics
Molecular dynamics is a computer simulation of physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a period of time, giving a view of the motion of the atoms...
are such that in 2002, "while the fastest proteins fold on the order of tens of microseconds", "current single computer processors" could "only simulate on the order of a nanosecond of real-time of folding in full atomic detail per CPU day".
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 roughly 1033 to 1036 calculations. He further calculated that a planet-sized computer built with computronium
Computronium
Computronium is a material hypothesized by Norman Margolus and Tommaso Toffoli of the Massachusetts Institute of Technology to be used as "programmable matter," a substrate for computer modeling of virtually any real object....
using known nanotechnological methods would perform about 1042 calculations per second — and a planet-sized computer or an even larger stellar system-sized computer
Matrioshka brain
A matrioshka brain is a hypothetical megastructure proposed by Robert Bradbury, based on the Dyson sphere, of immense computational capacity. It is an example of a Class B stellar engine, employing the entire energy output of a star to drive computer systems...
is not inherently impossible to build, (although the speed of light could severely constrain the speed at which its subprocessors share data). In any case, a simulation need not compute every single molecular event that occurs inside it; it may only process events that its participants can actively perceive. This is particularly the case if the simulation contained only a handful of people; far less processing power would be needed to make them believe they were in a "world" much larger than was actually the case.
A real world example of this could be the observer paradox or Heisenberg Uncertainty Principle - an unobserved region of space is indeterminate until observed - this could be because the simulating computer is not simulating it until it needs to.
Nested simulations
The existence of simulated reality is unprovable in any concrete sense: any "evidence" that is directly observed could be another simulation itself. In other words, there is an infinite regressInfinite regress
An infinite regress in a series of propositions arises if the truth of proposition P1 requires the support of proposition P2, the truth of proposition P2 requires the support of proposition P3, .....
problem with the argument. Even if we are a simulated reality, there is no way to be sure the beings running the simulation are not themselves a simulation, and the operators of that simulation are not a simulation, ad infinitum
Ad infinitum
Ad infinitum is a Latin phrase meaning "to infinity."In context, it usually means "continue forever, without limit" and thus can be used to describe a non-terminating process, a non-terminating repeating process, or a set of instructions to be repeated "forever," among other uses...
. Given the premises of the simulation argument, any reality, even one running a simulation, has no better or worse a chance of being a simulation than any other.
Validity of the arguments
It is perhaps erroneous to apply our current sense of feasibility to projects undertaken in an outer reality, where resources and physical laws 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 would have no way of knowing if one day of subjective time actually required much longer to calculate in their host computer, or vice-versa, or if the simulation is run in pieces on different computers, or with a million generations of monks working weekends on abacus
Abacus
The abacus, also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes. Today, abaci are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of...
es — all without the simulation missing a beat 'in simulation time'.
Software bugs
A computed simulation may have voids or other errorsSoftware bug
A software bug is the common term used to describe an error, flaw, mistake, failure, or fault in a computer program or system that produces an incorrect or unexpected result, or causes it to behave in unintended ways. Most bugs arise from mistakes and errors made by people in either a program's...
that manifest inside. As a simple example of this, when the "hall of mirrors" effect occurs in the first person shooter Doom, the game attempts to display "nothing" and obviously fails in its attempt to do so. If a void can be found and tested, and if the observers survive its discovery, then it may reveal the underlying computational substrate. However, lapses in 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 powerful simulation are instantly erased the minute they are observed since presumably all thoughts and experiences in a simulated world could be carefully monitored and altered. This would, however, require enormous processing capability in order to simultaneously monitor billions 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 simulation significantly determined to protect its existence could erase any proof that it was a simulation whenever it arose, provided it had the enormous 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 of its existence is difficult. This would mean that the computer actually has an easy time of erasing glitches, but we all think that changing reality requires great power. One could possibly take miracles and paranormal activity as software bugs especially those which seem to have a negative effect on one; this notion has been explored in The Matrix
The Matrix
The Matrix is a 1999 science fiction-action film written and directed by Larry and Andy Wachowski, starring Keanu Reeves, Laurence Fishburne, Carrie-Anne Moss, Joe Pantoliano, and Hugo Weaving...
, where déjà vu
Déjà vu
Déjà vu is the experience of feeling sure that one has already witnessed or experienced a current situation, even though the exact circumstances of the prior encounter are uncertain and were perhaps imagined...
is considered a sign of crude alteration to the system; and Animatrix where software glitches are concentrated in a house which the neighbors call "haunted", subsequently corrected by 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 may be 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 then be only suspicious to remove them from this reality and doing so would raise more questions by its inhabitants. In such instance, it would make more sense to leave the "error" in place.
Hidden messages or "Easter eggs"
The simulation may contain hidden/secret messages or exits placed there by the designer or by other inhabitants who have solved the riddle in the way that easter eggs in computer games and other mediaEaster egg (media)
Image:Carl Oswald Rostosky - Zwei Kaninchen und ein Igel 1861.jpg|250px|thumb|right|Example of Easter egg hidden within imagerect 467 383 539 434 desc none...
sometimes do. People have already spent considerable effort searching for patterns or messages within the endless decimal places of the fundamental constants such as e
E (mathematical constant)
The mathematical constant ' is the unique real number such that the value of the derivative of the function at the point is equal to 1. The function so defined is called the exponential function, and its inverse is the natural logarithm, or logarithm to base...
and pi
Pi
' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...
. In Carl Sagan
Carl Sagan
Carl Edward Sagan was an American astronomer, astrophysicist, cosmologist, author, science popularizer and science communicator in astronomy and natural sciences. He published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books...
's science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
novel Contact
Contact (novel)
Contact is a science fiction novel written by Carl Sagan and published in 1985. It deals with the theme of contact between humanity and a more technologically advanced, extraterrestrial life form. It ranked No. 7 on the 1985 U.S. bestseller list....
, Sagan contemplates the possibility of finding a signature embedded in pi (in its base-11
Positional notation
Positional notation or place-value notation is a method of representing or encoding numbers. Positional notation is distinguished from other notations for its use of the same symbol for the different orders of magnitude...
expansion) by the creators 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. As usual, other hypotheses could explain the same evidence. In any case, if such constants are in fact normal
Normal number
In mathematics, a normal number is a real number whose infinite sequence of digits in every base b is distributed uniformly in the sense that each of the b digit values has the same natural density 1/b, also all possible b2 pairs of digits are equally likely with density b−2,...
, then at some point an apparently meaningful message will appear in them (this is known as the infinite monkey theorem
Infinite monkey theorem
The infinite monkey theorem states that a monkey hitting keys at random on a typewriter keyboard for an infinite amount of time will almost surely type a given text, such as the complete works of William Shakespeare....
), not necessarily because it was placed 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 we consider that the human race will eventually be capable of creating intelligent programs (i.e. machines) living inside a virtual subspace of our "real" world, then an interesting question would be to define whether or not we will be capable of suppressing from our sentient robots their capability of knowing their artificial nature (see Philip K Dick's Do Androids Dream of Electric Sheep?
Do Androids Dream of Electric Sheep?
Do Androids Dream of Electric Sheep? is a science fiction novel by American writer Philip K. Dick first published in 1968. The main plot follows Rick Deckard, a bounty hunter of androids, while the secondary plot follows John Isidore, a man of sub-normal intelligence who befriends some of the...
).
Processing power
A computer simulation would be limited to the processing power of its host computer, and so there may be aspects of the simulation that are not computed at a fine-grained (e.g. subatomic) level. This might show up as a limitation on the accuracy of information that can be obtained in particle physics.However, this argument, like many others, assumes that accurate judgments about the simulating computer can be made from within the simulation. 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-atomic particles due to our inherent physical limitations. In order to see such particles we rely on other instruments which appear to magnify or translate that information into a format our limited senses are able to view: computer print out, lens of a microscope, etc. Therefore, we essentially take on faith that they're an accurate portrayal of the fine grained world which appears to exist in a realm beyond our natural senses. Assuming the sub-atomic could also be simulated then the processing power required to generate a realistic world would be greatly reduced.
Digital physics and cellular automata
In theoretical physicsTheoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
, digital physics
Digital physics
In physics and cosmology, digital physics is a collection of theoretical perspectives based on the premise that the universe is, at heart, describable by information, and is therefore computable...
holds the basic premise that the entire history of our universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
is computable in some sense. The hypothesis was pioneered in Konrad Zuse
Konrad Zuse
Konrad Zuse was a German civil engineer and computer pioneer. His greatest achievement was the world's first functional program-controlled Turing-complete computer, the Z3, which became operational in May 1941....
's book Rechnender Raum (translated by MIT into English as Calculating Space
Calculating Space
Calculating Space is the title of MIT's English translation of Konrad Zuse's 1969 book Rechnender Raum , the first book on digital physics....
, 1970), which focuses on cellular automata. Juergen Schmidhuber suggested that the universe could be a Turing machine
Turing machine
A Turing machine is a theoretical device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a...
, because there is a very short program that outputs all possible programmes in an asymptotically optimal
Asymptotically optimal
In computer science, an algorithm is said to be asymptotically optimal if, roughly speaking, for large inputs it performs at worst a constant factor worse than the best possible algorithm...
way. Other proponents include Edward Fredkin
Edward Fredkin
Edward Fredkin is an early pioneer of digital physics. In recent work, he uses the term digital philosophy . His primary contributions include his work on reversible computing and cellular automata...
, Stephen Wolfram
Stephen Wolfram
Stephen Wolfram is a British scientist and the chief designer of the Mathematica software application and the Wolfram Alpha computational knowledge engine.- Biography :...
, and Nobel laureate Gerard 't Hooft. They hold that the apparently probabilistic nature of quantum physics is not incompatible with the notion of computability. A quantum version of digital physics has recently been proposed by Seth Lloyd
Seth Lloyd
Seth Lloyd is a professor of mechanical engineering at the Massachusetts Institute of Technology. He refers to himself as a "quantum mechanic"....
. None of these suggestions has been developed into a workable physical theory.
It can be argued that the use of continua in physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
constitutes a possible argument against the simulation of a physical universe. Removing the real number
Real number
In mathematics, a real number is a value that represents a quantity along a continuum, such as -5 , 4/3 , 8.6 , √2 and π...
s and uncountable infinities from physics would counter some of the objections noted above, and at least make computer simulation a possibility. However, digital physics must overcome these objections. For instance, cellular automata would appear to be a poor model for the non-locality of quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
.
Non-player characters or "bots"
Some of the people in a simulated reality may be automatonAutomaton
An automaton is a self-operating machine. The word is sometimes used to describe a robot, more specifically an autonomous robot. An alternative spelling, now obsolete, is automation.-Etymology:...
s, philosophical zombies, or 'bots
Computer game bot
A bot, most prominently in the first-person shooter types , is a type of weak AI expert system software which for each instance of the program controls a player in deathmatch, team deathmatch and/or cooperative human player. Computer bots may play against other bots and/or human players in unison,...
' added to the simulation to make it more realistic or interesting or challenging. Indeed, it is conceivable that every person other than oneself is a bot
Solipsism
Solipsism is the philosophical idea that only one's own mind is sure to exist. The term comes from Latin solus and ipse . Solipsism as an epistemological position holds that knowledge of anything outside one's own mind is unsure. The external world and other minds cannot be known, and might not...
. 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.
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
Ai
AI, A.I., Ai, or ai may refer to:- Computers :* Artificial intelligence, a branch of computer science* Ad impression, in online advertising* .ai, the ISO Internet 2-letter country code for Anguilla...
opponents of modern video games.
Subjective time
A brain-computer interfaceBrain-computer interface
A brain–computer interface , sometimes called a direct neural interface or a brain–machine interface , is a direct communication pathway between the brain and an external device...
simulated reality may be required to progress at a rate that is near realtime
Real-time computing
In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...
; that is, time within it may be required to pass at approximately the same rate as the outer reality which contains it. This might be the case because the players are interacting 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 point is that they still function at a finite, biological speed, and the simulation must track with them. Unless those interacting with the simulation are augmented and capable of processing information
Information theory
Information theory is a branch of applied mathematics and electrical engineering involving the quantification of information. Information theory was developed by Claude E. Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and...
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 simulation's own physics in order to experience, think, and react. If the simulation were slowed down or sped up, so also would the inhabitants' own senses, 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 perform the 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 pause every life and mind within it. When the simulation was later resumed, the inhabitants would continue exactly as they were before the pause, completely unaware that (for example) their cosmos had been paused and archived for a billion years before being resumed. A simulation could also be created with its inhabitants already possessing memories as though they had already lived part of their lives before; said inhabitants would not be able to tell the difference unless informed of it by the simulation. (Compare with the five minute hypothesis 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 its entire cosmos at full speed. Per the Turing completeness theorem
Turing completeness
In computability theory, a system of data-manipulation rules is said to be Turing complete or computationally universal if and only if it can be used to simulate any single-taped Turing machine and thus in principle any computer. A classic example is the lambda calculus...
, a simulation can progress at whatever speed its host computer can manage; it would be constrained by available memory but not by computation rate.
Recursive simulations
Recursive simulation involves a simulation, or an entity in a simulation, creating another simulation within a simulated environment.The 'parent' simulator would be simulating all of the atoms of the computer, atoms which happen to be calculating a 'child' simulation. By way of illustration: in Fallout 3
Fallout 3
Fallout 3 is an action role-playing game released by Bethesda Game Studios, and the third major installment in the Fallout series. The game was released in North America, Europe and Australia in October 2008, and in Japan in December 2008 for Microsoft Windows, PlayStation 3 and Xbox 360...
, Metal Gear Solid 2, and Xenosaga
Xenosaga
is a series of science fiction video games developed by Monolith Soft and published by Namco Bandai. Xenosaga's main story is in the form of a trilogy of PlayStation 2 video games. There have been three spin-off games and an anime adaptation. The Xenosaga series serves as a spiritual successor to...
, the player character at one point must enter a virtual reality simulation in the game. Alternatively, imagine a Java Runtime Environment running a virtual computer
Virtual Computer
Virtual Computer is a venture-backed software company in the Boston area that produces desktop virtualization products, which combine centralized management with local execution on a hypervisor running on PCs. Virtual Computer has developed a type-1 hypervisor that runs directly on end-user PCs,...
on a "real-world" computer that itself is located within a simulation.
This recursion could continue to infinitely many levels — a simulation containing a computer running a simulation containing a computer running a simulation and so on. The recursion is subject only to one constraint (assuming no level has infinite computational power): each 'nested' simulation must be:
- smaller than its parent reality, because its own memory must be a subset of the parent's;
...and must be at least one of the following:
- slower than its parent reality, because its own calculations must be a subset of the parent's; 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, there need not be any noticeable difference between any of the subsets.
Simulated reality in fiction
- See Simulated reality in fictionSimulated reality in fictionSimulated reality is a theme that pre-dates science fiction. In Medieval and Renaissance religious theatre, the concept of the world as theater is frequent...
Simulated reality is a theme that pre-dates science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
. In Medieval and Renaissance religious theatre, the concept of the world as theater is frequent.
Virtual reality, and to a lesser point simulated reality, are key facets in the Cyberpunk
Cyberpunk
Cyberpunk is a postmodern and science fiction genre noted for its focus on "high tech and low life." The name is a portmanteau of cybernetics and punk, and was originally coined by Bruce Bethke as the title of his short story "Cyberpunk," published in 1983...
genre, regardless of format.
See also
- Artificial lifeArtificial lifeArtificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...
- Artificial realityArtificial realityArtificial reality was the term Myron W. Krueger used to describe his interactive immersive environments, based on video recognition techniques, that put a user in full, unencumbered contact with the digital world. He started this work in the late 1960s and is considered to be a key figure in the...
- Augmented realityAugmented realityAugmented reality is a live, direct or indirect, view of a physical, real-world environment whose elements are augmented by computer-generated sensory input such as sound, video, graphics or GPS data. It is related to a more general concept called mediated reality, in which a view of reality is...
- Artificial societyArtificial societyArtificial Society is the specific agent based computational model for computer simulation in social analysis. It is mostly connected to the theme in complex system, emergence, Monte Carlo Method, computational sociology, multi-agent system, and evolutionary programming. The concept itself is...
- Boltzmann brainBoltzmann brainA Boltzmann brain is a hypothesized self-aware entity which arises due to random fluctuations out of a state of chaos. The idea is named for the physicist Ludwig Boltzmann , who advanced an idea that the known universe arose as a random fluctuation, similar to a process through which Boltzmann...
- Computational sociologyComputational sociologyComputational sociology is a branch of sociology that uses computationally intensive methods to analyze and model social phenomena. Using computer simulations, artificial intelligence, complex statistical methods, and new analytic approaches like social network analysis, computational sociology...
- Consensus realityConsensus realityConsensus reality is an approach to answering the philosophical question "What is real?" It gives a practical answer: reality is either what exists, or what we can agree seems to exist....
- CyberpsychologyCyberpsychologyThe developing field of cyberpsychology encompasses all psychological phenomena that are associated with or affected by emerging technology. Cyber comes from the word cybernetics, the study of the operation of control and communication; psychology is the study of the mind and behavior...
- Digital philosophyDigital philosophyDigital philosophy is a direction in philosophy and cosmology advocated by certain mathematicians and theoretical physicists, e.g., Gregory Chaitin, Edward Fredkin, Stephen Wolfram, and Konrad Zuse ....
- Digital physicsDigital physicsIn physics and cosmology, digital physics is a collection of theoretical perspectives based on the premise that the universe is, at heart, describable by information, and is therefore computable...
- The Experience MachineThe Experience MachineThe experience machine is a thought experiment put forward by philosopher Robert Nozick in his Anarchy, State, and Utopia. It is one of the best known attempts to refute ethical hedonism, and does so by imagining a choice between everyday reality and an apparently preferable simulated reality.If...
- HyperrealityHyperrealityHyperreality is used in semiotics and postmodern philosophy to describe a hypothetical inability of consciousness to distinguish reality from fantasy, especially in technologically advanced postmodern societies...
- InfosphereInfosphereInfosphere is a neologism composed of information and sphere.The first documented use of the word "InfoSphere" was a 1971 Time Magazine book review by R.Z...
- Interactive online charactersInteractive online charactersAn automated online assistant is a program that uses artificial intelligence to provide customer service or other assistance on a website. Such an assistant may basically consist of a dialog system, an avatar, as well an expert system to provide specific expertise to the user.Automated online...
- Margolus–Levitin theorem
- MetaverseMetaverseThe Metaverse is our collective online shared space, created by the convergence of virtually enhanced physical reality and physically persistent virtual space, including the sum of all virtual worlds, augmented reality, and the internet...
- Tipler's "Omega point"
- Omnidirectional treadmillOmnidirectional treadmillAn omnidirectional treadmill, or ODT, is a device that allows a person to perform locomotive motion in any direction. The ability to move in any direction is how these treadmills differ from their basic counterparts...
- Philosophy of informationPhilosophy of informationThe philosophy of information is the area of research that studies conceptual issues arising at the intersection of computer science, information technology, and philosophy.It includes:...
- PseudorealismPseudorealismPseudorealism, also spelled pseudo-realism, is a term used in a variety of discourses connoting any artistic and dramatic technique, or work of art, film and literature perceived as superficial, not-real or non-realistic...
- Reality in BuddhismReality in BuddhismBuddhism evolved a variety of doctrinal/philosophical traditions, each with its distinct ideas of reality. The following are still regularly studied in some branches of the Buddhist tradition: Theravada, Vaibhashika, Sautrantika, Jojitsu, Madhyamika, Yogacara, tiantai, Huayan...
- Simulacra and SimulationSimulacra and SimulationSimulacra and Simulation is a philosophical treatise by Jean Baudrillard seeking to interrogate the relationship among reality, symbols, and society.-Overview:...
- SimulacrumSimulacrumSimulacrum , from the Latin simulacrum which means "likeness, similarity", was first recorded in the English language in the late 16th century, used to describe a representation, such as a statue or a painting, especially of a god...
- Social simulationSocial simulationSocial simulation is a research field that applies computational methods to study issues in the social sciences. The issues explored include problems in sociology, political science, economics, anthropology, geography, archaeology and linguistics ....
- Theory of knowledge
- Virtual worldVirtual worldA virtual world is an online community that takes the form of a computer-based simulated environment through which users can interact with one another and use and create objects. The term has become largely synonymous with interactive 3D virtual environments, where the users take the form of...
s - Zeno's paradoxesZeno's paradoxesZeno's paradoxes are a set of problems generally thought to have been devised by Greek philosopher Zeno of Elea to support Parmenides's doctrine that "all is one" and that, contrary to the evidence of our senses, the belief in plurality and change is mistaken, and in particular that motion is...
Major contributing thinkers
- Jean BaudrillardJean BaudrillardJean Baudrillard was a French sociologist, philosopher, cultural theorist, political commentator, and photographer. His work is frequently associated with postmodernism and post-structuralism.-Life:...
- Nick BostromNick BostromNick Bostrom is a Swedish philosopher at the University of Oxford known for his work on existential risk and the anthropic principle. He holds a PhD from the London School of Economics...
- René DescartesRené DescartesRené Descartes ; was a French philosopher and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day...
- Philip K. DickPhilip K. DickPhilip Kindred Dick was an American novelist, short story writer and essayist whose published work is almost entirely in the science fiction genre. Dick explored sociological, political and metaphysical themes in novels dominated by monopolistic corporations, authoritarian governments and altered...
- Stanislaw LemStanislaw LemStanisław Lem was a Polish writer of science fiction, philosophy and satire. He was named a Knight of the Order of the White Eagle. His books have been translated into 41 languages and have sold over 27 million copies. He is perhaps best known as the author of the 1961 novel Solaris, which has...
- PlatoPlatoPlato , was a Classical Greek philosopher, mathematician, student of Socrates, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the Western world. Along with his mentor, Socrates, and his student, Aristotle, Plato helped to lay the...
- Zeno of EleaZeno of EleaZeno of Elea was a pre-Socratic Greek philosopher of southern Italy and a member of the Eleatic School founded by Parmenides. Aristotle called him the inventor of the dialectic. He is best known for his paradoxes, which Bertrand Russell has described as "immeasurably subtle and profound".- Life...
External links
- Anthropic-principle.com'' Website maintained by Nick BostromNick BostromNick Bostrom is a Swedish philosopher at the University of Oxford known for his work on existential risk and the anthropic principle. He holds a PhD from the London School of Economics...
with a collection of papers on SR and related topics.
- Computer Universes and an Algorithmic Theory of Everything by Jürgen SchmidhuberJürgen SchmidhuberJürgen Schmidhuber is a computer scientist and artist known for his work on machine learning, universal Artificial Intelligence , artificial neural networks, digital physics, and low-complexity art. His contributions also include generalizations of Kolmogorov complexity and the Speed Prior...
- The Computational Requirements for the Matrix discussion on SlashdotSlashdotSlashdot is a technology-related news website owned by Geeknet, Inc. The site, which bills itself as "News for Nerds. Stuff that Matters", features user-submitted and ‑evaluated current affairs news stories about science- and technology-related topics. Each story has a comments section...
.
- Computationalism: The Very Idea, an overview of computationalism by David Davenport.
- The Cutting Edge of Haptics, an article in MIT's Technology review on touch illusion technology by Duncan Graham-Rowe.
- God Is the Machine WiredWired (magazine)Wired is a full-color monthly American magazine and on-line periodical, published since January 1993, that reports on how new and developing technology affects culture, the economy, and politics...
article by Kevin Kelly.
- Philosophy & "The Matrix" Related to the Warner Brothers movie; including papers by David ChalmersDavid ChalmersDavid John Chalmers is an Australian philosopher specializing in the area of philosophy of mind and philosophy of language, whose recent work concerns verbal disputes. He is Professor of Philosophy and Director of the Centre for Consciousness at the Australian National University...
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 BostromNick BostromNick Bostrom is a Swedish philosopher at the University of Oxford known for his work on existential risk and the anthropic principle. He holds a PhD from the London School of Economics...
, Director, Future of Humanity Institute, Oxford University. Includes his original paper.
- Simulation, Consciousness, Existence by Hans MoravecHans MoravecHans Moravec is an adjunct faculty member at the Robotics Institute of Carnegie Mellon University. He is known for his work on robotics, artificial intelligence, and writings on the impact of technology. Moravec also is a futurist with many of his publications and predictions focusing on...
.
- Simulism, a wiki devoted to the possibility that our reality is a simulation.
- Superhumanism, an interview of Hans Moravec. by Charles PlattCharles Platt (science-fiction author)Charles Platt is an author, journalist and computer programmer. He relocated from England to the United States in 1970, is a naturalized U.S. citizen and has one daughter, Rose Fox...
.
- http://www.channel4.com/science/microsites/W/what_we_still_dont_know/textonly/to_arewereal.htmlWhat We Still Don't Know, Channel 4Channel 4Channel 4 is a British public-service television broadcaster which began working on 2 November 1982. Although largely commercially self-funded, it is ultimately publicly owned; originally a subsidiary of the Independent Broadcasting Authority , the station is now owned and operated by the Channel...
documentary by British Astronomer RoyalAstronomer RoyalAstronomer Royal is a senior post in the Royal Household of the Sovereign of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the second is the Astronomer Royal for Scotland dating from 1834....
Sir Martin Rees.]
- Zombies — Philosophical zombiePhilosophical zombieA philosophical zombie or p-zombie in the philosophy of mind and perception is a hypothetical being that is indistinguishable from a normal human being except in that it lacks conscious experience, qualia, or sentience...
article by Robert Kirk in the Stanford Encyclopedia of PhilosophyStanford Encyclopedia of PhilosophyThe Stanford Encyclopedia of Philosophy is a freely-accessible online encyclopedia of philosophy maintained by Stanford University. Each entry is written and maintained by an expert in the field, including professors from over 65 academic institutions worldwide...
.