The P2P Simulation Hypothesis and Meta-Problem of Everything Marcus Arvan University of Tampa marvan@ut.edu Abstract: In a new paper, David. J. Chalmers examines eleven possible solutions to the metaproblem of consciousness, 'the problem of explaining why we think that there is a problem of consciousness.' The present paper argues that Chalmers overlooks an explanation that he has otherwise taken seriously, and which a number of philosophers, physicists, and computer scientists have taken seriously as well: the hypothesis that we are living in a computer simulation. This paper argues that a particular version of the simulation hypothesis is at least as good of a solution to the meta-problem of consciousness as many explanations Chalmers considers, and may even be a better one-as it may be the best solution to a much broader meta-philosophical problem: the meta-problem of everything, the problem of explaining why our world has the quantum-mechanical, relativistic, and philosophical features it does. In a new paper, David. J. Chalmers examines the meta-problem of consciousness, 'the problem of explaining why we think that there is a problem of consciousness.'1 According to Chalmers, this is an empirical problem-one concerning the mechanisms that lead people to believe and report that there is a hard problem of consciousness.2 Chalmers then examines eleven possible explanations of the meta-problem, that is, eleven empirical hypotheses about why people believe and say that there is a hard problem of consciousness. The present paper argues that Chalmers overlooks a solution to the meta-problem which he has otherwise taken seriously3, and which a number of philosophers4, physicists5, computer scientists6, and programmers7 have taken seriously as well: the theory that we live in a computer simulation. It is not altogether surprising that Chalmers ignores this hypothesis in discussing the metaproblem of consciousness-as the simulation hypothesis has been argued by some to lack 1 Chamers (2018a): 6. 2 Ibid: 10. 3 Chalmers (2015, 2017, 2018b). 4 Bostrom (2003), Arvan (2013, 2014, 2015), Johnson (2011), Mizrahi (2017). 5 Beane et al (2012) and Campbell et al. (2017). 6 Moravec (1998), and Whitworth (unpublished manuscript). 7 Grange (2016). 2 any evidential support.8 However, this paper argues to the contrary that a particular version of the simulation hypothesis has at least as much evidential support as many of the hypotheses Chalmers considers, while also possessing far greater explanatory power-as the simulation hypothesis in question may be best solution to a much broader metaphilosophical problem: the 'meta-problem of everything.' §1. The Case for the P2P Simulation Hypothesis Our world has a wide variety of deeply perplexing physical and philosophical features. Consider physics. At present, our two best theories of fundamental physics are the General Theory of Relativity, which explains gravitation, and Quantum Mechanics, which explains all other known forces. Both theories have been systematically confirmed by experiment-yet both theories tell us our world's physics is incredibly strange. General Relativity tells us that: i. Space and time are relative to observers: simultaneous events in one reference frame are non-simultaneous from another, time moves at different rates depending on the observer's frame of reference, and the physical properties of objects in spacetime (e.g. their length) depends on the observer's reference-frame. ii. The physical world has a 'speed-limit': no information can travel faster than light. Quantum mechanics, in turn, tells us that all of the following are true of our world: iii. Quantum superposition: every particle simultaneously exists in many different eigenstates (i.e. a superposition of different space-time locations and properties). iv. Quantum indeterminacy: the eigenvalue a particle will be observed to have upon measurement is indeterminate, in that the value can in principle only be predicted probabilistically. 8 Huemer (2016). 3 v. Wave-particle duality: every individual particle simultaneously has properties of particle (existing at a particular point) and a wave (spread out over space and time). vi. Wave-function collapse: observation of a particle (or measurement of quantum system it is a part of) leads the wave-like features of a particle (viz. the particle's superposition) to 'collapse' to a single observed value (i.e. the observed properties of the particle). vii. Quantum entanglement: particles arbitrary distances apart can become entangled, such that changing the physical properties of one particle will instantaneously change the other particle's properties without any observable exchange of information. viii. Minimum space-time distance: there is a minimum space-time distance below which space and time themselves have no physical meaning (the Planck Length).9 ix. Quantum retrocausality: measurements of a quantum system can have observable effects on the system earlier in time, causing wave-function collapse before the measurement is taken.10 These features of our world are incredibly bizarre-yet they are implied by the equations of quantum mechanics, and quantum mechanics been systematically confirmed by experiment. Finally, our world has a number of puzzling metaphysical features-among them (to simplify a great deal): x. The mind-body problem (hard problem of consciousness): it appears impossible to reduce or identify phenomenal consciousness to anything physical.11 9 Padmanabhan (1985). 10 Leifer & Pusey (2017). 11 See e.g. Chalmers (2016). 4 xi. The problem of causation: events in our world are 'constantly connected' (viz. causal regularities), yet empirical observation appears insufficient to explain why events are constantly connected, or whether there is a primitive metaphysical 'causal force' that connects them.12 xii. The problem of time and time's passage: although some arguments in physics and philosophy suggest that all times (past, present, and future) exist eternally, time seems to pass.13 xiii. The problem of personal identity: although we experience ourselves as though we persist as identical persons across time, it appears impossible to explain personal identity in physical or psychological terms.14 xiv. The problem of free will: philosophical considerations and the laws of physics suggest that our choices must be determined-which some philosophers think entails we have no free will. Yet it seems, for all that, like we have free will.15 All of these puzzling features of our world-the puzzling features of physics, and the philosophical problems just presented-are typically grappled with independently: with the physicists doing physics, and philosophers doing the philosophy. Both groups, however, have run up against apparently insuperable obstacles. On the one hand, physicists have been unable to explain why our world has relativistic and quantum-mechanical features. Physics merely studies how the world actually behaves, basing its equations and explanations on observation. However, that is all physics can do: explain what we observe and how what we 12 See Schaffer (2016) for an overview. 13 Markosian (2016), Le Poidevin (2015). 14 Ninan (2009). 15 O'Connor & Franklin (2018). 5 observe 'works' (viz. the equations of relativity and quantum theory). What physics cannot do is explain why our world has the observable features in the first place. Why, of all of the metaphysically possible universes that could have existed, do we exist in world with relativistic and quantum mechanical physics? This does not appear to be a question of physics, but rather of metaphysics. Alas, metaphysics arguably faces insuperable problems of its own. Metaphysical debates on most major issues-ranging from mind-body problem to problems of time, personal identity, free will, and so on-typically result in interminable stalemates: with different groups of philosophers defending different, fundamentally opposed metaphysical theories, with no clear way to resolve which theory is true.16 For example, in the mind-body problem literature alone, there are serious proponents of eliminative materialism, mind-brain identity-theory, non-reductive physicalism, functionalism, panpsychism, property dualism, and substance dualism.17 Similar stalemates exist across metaphysics, and in philosophy in general-leading some to wonder whether philosophy makes real progress.18 Another way of putting this is that physics and philosophy together face what we might call the meta-problem of everything: the question of explaining why our world spears to us to have the many puzzling physical and metaphysical features it does, including the meta-problem of consciousness. Might there be a single, unified solution to this broader meta-problem that in turn solves the meta-problem of consciousness? Indeed, there may be. 16 See Willard (2013). 17 Bogardus (2013). 18 Dietrich (2011), Slezak (2018). 6 Consider the hypothesis that we are living in a computer simulation. Do we have any evidence for the simulation hypothesis beyond Bostrom's probabilistic speculation19? In a recent article, Arvan notes that although each of the following theories is controversial, philosophers and physicists have argued there is some evidence for each of them20: A. Eternalism: past, present, and future objects and properties all exist "timelessly." B. The Multiverse Hypothesis: the observable universe is a small part of a vast 'multiverse.' C. The Holographic Principle: to unify quantum mechanics and general relativity, the universe must be understood as digital information written on the cosmological horizon. D. Mind-body Dualism: the mind is in some sense non-physical. E. Subjectivity About the Flow of Time: time's passage is not in the objective physical world but rather within us (i.e. within consciousness). F. The Further Fact Theory of Personal Identity: personal identity is a brute, simple fact that cannot be reduced to any physical or psychological phenomena. G. Single Commonly-Experienced (or"Actualized") Timeline: only one physical universe-our Universe-is experienced by conscious observers. Arvan argues that if all of these theories are jointly true, then our 'physical world' is a hologram generated by each individual's consciousness 'reading' digital information on the cosmological horizon, projecting that digital information as a four-dimension 'world' of 19 Bostrom (2003). 20 Arvan (2013): Section I. 7 objects in space-time, such that the joint projections of each person's consciousness constitute an intersubjective reality that we all experience together.21 In the same article and in several follow-up pieces, Arvan argues that this metaphysical model of reality is functionally identical to a certain kind of computer simulation: a peer-to-peer networked (P2P) simulation.22 First, Arvan notes that online videogames just are physical mechanisms (computer processor) reading digital information (e.g. on a DVD), projecting that information as a four-dimensional world for different 'users' to navigate-which is what hypotheses (A)-(G) jointly entail our world is. Second, Arvan argues that a particular kind of simulation-peer-to-peer networked (P2P) simulations-actually replicate our world's relativistic and quantum-mechanical physical features due to the computational structure of peer-to-peer networking itself.23 For consider what a P2P simulation is. In contrast to dedicated server simulations-where there is a central computer representing the spatio-temporal locations of all objects in the simulation-a P2P simulation has no central computer at all: instead, a P2P simulation is simply a network of independent simulations interacting with each other (see Figure 1). In a P2P simulation, each 'user' only ever experiences their simulation, and 'the physical world' that all users experience in common is just a superposition of all of the simulations interacting on the network. 21 Ibid: Section II. 22 Ibid: footnotes 60-61; Arvan (2014, 2015). 23 Arvan (2014, 2015). 8 Figure 1. Two Types of Simulations Dedicated Server Simulation Peer-to-Peer (P2P) Simulation Next, Arvan shows24 that because there is no central server representing where objects 'really are' in a P2P simulation, P2P simulations computationally replicate every basic feature of quantum mechanics: 24 Arvan (2014, 2015). Computer A Computer B Computer C Computer D Computer E Computer F Computer G Computer H DEDICATED SERVER (Simulated Environment) Computer A Computer B Computer C Computer D Computer E Computer F Computer G Computer H "The" Simulated Environment 9  Replicating quantum superposition: A P2P simulation just is a superposition of multiple simulated environments interacting in parallel.  Replicating quantum indeterminacy: 'The' location of any object or property in a P2P simulation is therefore indeterminate, given that each computer on the network has its own representation of where 'the' object or property is, with no dedicated server on the network to represent where the object or property 'really' is.  Replicating wave-particle duality: Because different simulations in a P2P network represent the same objects in slightly different positions at any given instant, a dynamical description of where a given object/property probably is in 'the environment' will have features of a wave (viz. an amplitude equivalent to the number of computers representing the object at a given point, and wavelength equivalent to dynamical change of how many computers represent the object at a given point at the next instant). At the same time, because each individual simulation always has its own representation of where objects are in the environment, any measurement taken by any simulation in the network will always represent fundamental objects as existing at a particular point (qua particle).  Replicating wave-function collapse: Because a P2P simulation is superposition of parallel interacting simulations, but any measurement by a user in any one simulation will represent that object at a determinate location within their individual simulation, any measurement taken in a P2P simulation will appear to any observer to 'collapse' the superposition/wave-like properties of any object to a point. 10  Replicating quantum entanglement: If a P2P simulation does not have perfect error-correction, then multiple computers on a network can represent one particle as existing in two places, representing them as one entangled particle.  Replicating minimum space-time distance: Because a simulated reality is comprised by digital rather than continuous information, that reality must be 'pixelated' at a fundamental level-that is, its smallest objects and properties must be separated by some minimum distance ('between the digital information') that has no informational content in the simulation.  Replicating quantum retrocausality: in P2P simulations, spatiotemporal conflicts between different simulations on the network may be resolved by error-correction algorithms that 'alter the past.'25 The P2P simulation not only replicates quantum features-it replicates relativistic ones:  Replicating spatio-temporal relativity: P2P simulations have no 'master clock' or objective representation where things are in their simulated space-time: all observations are relative to individual users on each individual simulation. Further, Grange argues that processing limitations in a P2P system should have relativistic effects on observed time and space.26  Replicating maximum speed-limit: Grange argues that in a P2P simulation, bandwidth limitations constraining communication-speed between different 25 Here is one actual example: in the videogame Halo 3, if I kill your character slightly before you kill me on my simulation, but the opposite occurs on your simulation (i.e. you kill me slightly before I kill you), the network retroactively resolves the temporal conflict by killing both characters 'simultaneously' (something which notoriously frustrated many gamers). 26 Grange (2016). 11 simulations on the network entail a maximum speed limit of information travel within each simulation.27 Finally, Arvan shows that P2P simulations replicate a variety of metaphysical problems:  Replicating the mind-body problem: Because each individual's 'subjective point of view' is constituted by a processor that underlies and generates their 'physical' reality as a projection, each individual in a P2P simulation would have the sense that their 'mind' cannot be reduced to anything physical-functional in their world...and they would be right (the processor they are is not in the simulation at all: it grounds the simulation as the projecting mechanism that represents 'their world' as a hologram).  Replicating the problem of causation: because each individual in a P2P system would experience their reality as a connected series of events, each individual would have the sense that there must be something to causation beyond the series events itself-some 'force' that explains why those events are connected...and they would be right (their processor connects the events).  Replicating the problem of time, time's passage, and subjectivity of time's flow: Because a P2P simulation consists of digital information 'being read' by a processing mechanism, individuals living in a P2P simulation would believe there is a sense in which past, present, and future exist 'timelessly', while also believing time passes subjectively...and they would be right (as time's passage would consist in their processor processing 'timeless' digital information, projecting a 'moving present').  Replicating problems of personal identity and free will: Individuals living in a P2P simulation would be inclined to believe that there is something more to their personal 27 Ibid. 12 identity and free will beyond their 'physical world'...and they would be right (their identity over time would be comprised by the processor that grounds their projected point-of-view, and their 'choices' in the simulation would actually be made in a higherreference frame (the level of the 'user' or processor'), giving rise to apparent causalclosure in the simulation (and hence, the worry that they are not free).28 The P2P Simulation Hypothesis is, to my knowledge, the only unified explanation currently on offer of all of the above physical and meta-physical features of our world: that is, it is the only unified explanation we have of the meta-problem of everything-of which the metaproblem of consciousness is a special case. 2. Comparison to Alterative Solutions to the Meta-Problem of Consciousness Chalmers considers the following eleven explanations of the hard problem of consciousness (each of which thus constitutes a 'solution' to the meta-problem of consciousness): 1. Introspective models: by modeling its own internal states, the brain represents its own states in a way that gives rise to the hard-problem of consciousness.29 2. Phenomenal concepts: the hard-problem results from special concepts presenting our conscious states to us as otherwise than physical.30 3. Independent roles: the hard-problem results from phenomenal and physical concepts lacking strong inferential connections to one another.31 28 As a simple example, consider the videogame PacMan. From within PacMan's simulated world, just about everything appears 'deterministic'. Even PacMan's behavior-the character you control as a user-can be predicted probabilistically, given your tendencies as a player. However, PacMan's behavior (unbenknownst to anyone 'living in' that reality) is actually controlled by you as the outside user. PacMan's behavior in the simulation, then, is not actually determined by the 'physical laws' of the simulation (including whatever probabilistic equations explain how he behaves). His behavior just appears to be determined because no one in the simulation has any observational access to the inputs to the system you are making as its outside 'user.' 29 Chalmers (2018a): 12-3. 30 Ibid: 13-4. 31 Ibid: 14. 13 4. Introspective opacity: the hard-problem results from brain-processes representing other brain-processes as though they are not brain processes.32 5. Direct access: the hard-problem results from introspective states being direct and non-inferential, representing things like 'greenness' as primitive properties.33 6. Primitive quality attribution: the hard-problem results from our perceptual capacities attributing primitive qualities (e.g. colors) to things.34 7. Primitive relation attribution: the hard-problem results from introspective models introducing primitive relations of seeing, hearing, etc., to simplify highly complex relations (such as color-wavelengths) in a cognitively efficient way.35 8. Introjection and the phenomenological fallacy: the hard-problem results from fallaciously inferring from phenomenal experiences (e.g. consciousness experience of redness) that the object of the experience (phenomenal redness) exists.36 9. The user illusion: the hard-problem is the result of consciousness itself being an illusion generated by the brain, much like folders on computer desktop are illusions regarding the computational reality that underlies them.37 10. The use-mention fallacy: the hard-problem results from the way we think about consciousness being different than the way we think about brain states.38 32 Ibid: 14-5. 33 Ibid: 15-6. 34 Ibid: 16-8. 35 Ibid: 18-20. 36 Ibid: 20-1. 37 Ibid: 21. 38 Ibid: 21-2 14 11. Historical explanations: the hard-problem can be explained away in either evolutionary terms39, re-entrant feedback loops in a higher-dimensional space40, conflicts in judgments about consciousness from dual-process cognitive systems41, the necessity of cognitive system to avoid a regress in positing subject-object distinctions42, and so on.43 How should we evaluate each of these explanations against each other, and against the P2P Simulation Hypothesis? Although there are complex issues in the philosophy of science here, two criteria immediately present themselves: empirical adequacy (support from empirical evidence) and explanatory power. For example, whereas Ptolemaic astronomy falsely predicted planetary orbits, and could not explain observations of retrograde motion, Copernican astronomy explained and predicted retrograde motion. Finally, empirical adequacy can be broken down into roughly two issues: how much positive empirical support a hypothesis has (viz. confirmation), and the extent to which the hypothesis conflicts with observations (viz. disconfirmation). Let us consider then, first, how much positive empirical support Chalmers' eleven hypotheses have. To the best of my knowledge, all eleven hypotheses are based primarily on philosophical conjecture: I do not know of a single empirical study that suggests the existence of phenomenal concepts, introspective opacity, and so on. Because the P2P Hypothesis is largely based on conjecture as well (viz. seven philosophical and physical hypotheses philosophers and physicists have argued there is some evidence for), the P2P Hypothesis 39 Humphrey (2014), 40 Ibid. 41 Fiala et al (2011). 42 Molyneux (2012). 43 Chalmers (forthcoming): 22-3. 15 appears to have roughly the same level of positive empirical support as many of the eleven hypotheses Chalmers considers. Now consider disconfirmation: the question how much different hypotheses conflict with our observed evidence. The most obvious concern to have here about the P2P Hypothesis is that, insofar as it explains the problem of consciousness in functionalist terms (viz. simulated reality), it cannot explain phenomenal properties themselves (i.e. 'what it is like' to phenomenally experience the color red). However, as Chalmers argues, this appears to be a problem with many of the hypotheses he considers.44 Thus, the P2P Hypothesis fares no worse than many of the hypotheses that Chalmers considers as serious explanations of the meta-problem of consciousness. Finally, what about explanatory power? Here, the P2P Hypothesis is a clear winner. For whereas the eleven hypotheses Chalmers considers would at best explain why we think there is a problem of consciousness, the P2P Hypotheses may provide the first unified explanation of a much wider variety of physical and philosophical problems-not just the meta-problem of consciousness, but also the meta-problem of everything. 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