The Simulation Hypothesis: An MIT Computer Scientist Shows Why AI, Quantum Physics, and Eastern Mystics All Agree We Are in a Video Game

Before electronic computers had actually been built, Alan Turing mathematically proved a fundamental and profound property of them which has been exploited in innumerable ways as they developed and became central to many of our technologies and social interactions. A computer of sufficient complexity, which is, in fact, not very complex at all, can simulate any other computer or, in fact, any deterministic physical process whatsoever, as long as it is understood sufficiently to model in computer code and the system being modelled does not exceed the capacity of the computer—or the patience of the person running the simulation. Indeed, some of the first applications of computers were in modelling physical processes such as the flight of ballistic projectiles and the hydrodynamics of explosions. Today, computer modelling and simulation have become integral to the design process for everything from high-performance aircraft to toys, and many commonplace objects in the modern world could not have been designed without the aid of computer modelling. It certainly changed my life.Almost as soon as there were computers, programmers realised that their ability to simulate, well…anything made them formidable engines for playing games. Computer gaming was originally mostly a furtive and disreputable activity, perpetrated by gnome-like programmers on the graveyard shift while the computer was idle, having finished the “serious” work paid for by unimaginative customers (who actually rose before the crack of noon!). But as the microelectronics revolution slashed the size and price of computers to something individuals could afford for their own use (or, according to the computer Puritans of the previous generations, abuse), computer gaming came into its own. Some modern computer games have production and promotion budgets larger than Hollywood movies, and their characters and story lines have entered the popular culture. As computer power has grown exponentially, games have progressed from tic-tac-toe, through text-based adventures, simple icon character video games, to realistic three dimensional simulated worlds in which the players explore a huge world, interact with other human players and non-player characters (endowed with their own rudimentary artificial intelligence) within the game, and in some games and simulated worlds, have the ability to extend the simulation by building their own objects with which others can interact. If your last experience with computer games was the Colossal Cave Adventure or Pac-Man, try a modern game or virtual world—you may be amazed.Computer simulations on affordable hardware are already beginning to approach the limits of human visual resolution, perception of smooth motion, and audio bandwidth and localisation, and some procedurally-generated game worlds are larger than a human can explore in a million lifetimes. Computer power is forecast to continue to grow exponentially for the foreseeable future and, in the Roaring Twenties, permit solving a number of problems through “brute force”—simply throwing computing power and massive data storage capacity at them without any deeper fundamental understanding of the problem. Progress in the last decade in areas such as speech recognition, autonomous vehicles, and games such as Go are precursors to what will be possible in the next.This raises the question of how far it can go—can computer simulations actually approach the complexity of the real world, with characters within the simulation experiencing lives as rich and complex as our own and, perhaps, not even suspect they're living in a simulation? And then, we must inevitably speculate whether we are living in a simulation, created by beings at an outer level (perhaps themselves many levels deep in a tree of simulations which may not even have a top level). There are many reasons to suspect that we are living in a simulation; for many years I have said it's “more likely than not”, and others, ranging from Stephen Hawking to Elon Musk and Scott Adams, have shared my suspicion. The argument is very simple.First of all, will we eventually build computers sufficiently powerful to provide an authentic simulated world to conscious beings living within it? There is no reason to doubt that we will: no law of physics prevents us from increasing the power of our computers by at least a factor of a trillion from those of today, and the lesson of technological progress has been that technologies usually converge upon their physical limits and new markets emerge as they do, using their capabilities and funding further development. Continued growth in computing power at the rate of the last fifty years should begin to make such simulations possible some time between 2030 and the end of this century.So, when we have the computing power, will we use it to build these simulations? Of course we will! We have been building simulations to observe their behaviour and interact with them, for ludic and other purposes, ever since the first primitive computers were built. The market for games has only grown as they have become more complex and realistic. Imagine what if will be like when anybody can create a whole society—a whole universe—then let it run to see what happens, or enter it and experience it first-hand. History will become an experimental science. What would have happened if the Roman empire had discovered the electromagnetic telegraph? Let's see!—and while we're at it, run a thousand simulations with slightly different initial conditions and compare them.Finally, if we can create these simulations which are so realistic the characters within them perceive them as their real world, why should we dare such non-Copernican arrogance as to assume we're at the top level and not ourselves within a simulation? I believe we shouldn't, and to me the argument that clinches it is what I call the “branching factor”. Just as we will eventually, indeed, I'd say, inevitably, create simulations as rich as our own world, so will the beings within them create their own. Certainly, once we can, we'll create many, many simulations: as many or more as there are running copies of present-day video games, and the beings in those simulations will as well. But if each simulation creates its own simulations in a number (the branching factor) even a tiny bit larger than one, there will be exponentially more observers in these layers on layers of simulations than at the top level. And, consequently, as non-privileged observers according to the Copernican Principle, it is not just more likely than not, but overwhelmingly probable that we are living in a simulation.The author of this book, founder of Play Labs @ MIT, a start-up accelerator which works in conjunction with the MIT Game Lab, and producer of a number of video games, has come to the same conclusion, and presents the case for the simulation hypothesis from three perspectives: computer science, physics, and the unexplained (mysticism, esoteric traditions, and those enduring phenomena and little details which don't make any sense when viewed from the conventional perspective but may seem perfectly reasonable once we accept we're characters in somebody else's simulation).COMPUTER SCIENCE. The development of computer games is sketched from their origins to today's three-dimensional photorealistic multiplayer environments into the future, where virtual reality mediated by goggles, gloves, and crude haptic interfaces will give way to direct neural interfaces to the brain. This may seem icky and implausible, but so were pierced lips, eyebrows, and tongues when I was growing up, and now I see them everywhere, without the benefit of directly jacking in to a world larger, more flexible, and more interesting than the dingy one we inhabit. This is sketched in eleven steps, the last of which is the Simulation Point, where we achieve the ability to create simulations which “are virtually indistinguishable from a base physical reality.” He describes, “The Great Simulation is a video game that is so real because it is based upon incredibly sophisticated models and rendering techniques that are beamed directly into the mind of the players, and the actions of artificially generated consciousness are indistinguishable from real players.” He identifies nine technical hurdles which must be overcome in order to arrive at the Simulation Point. Some, such as simulating a sufficiently large world and number of players, are challenging but straightforward scaling up of things we're already doing, which will become possible as computer power increases. Others, such as rendering completely realistic objects and incorporating physical sensations, exist in crude form today but will require major improvements we don't yet know how to build, while technologies such as interacting directly with the human brain and mind and endowing non-player characters within the simulation with consciousness and human-level intelligence have yet to be invented.PHYSICS. There are a number of aspects of the physical universe, most revealed as we have observed at very small and very large scales, and at speeds and time intervals far removed from those with which we and our ancestors evolved, that appear counterintuitive if not bizarre to our expectations from everyday life. We can express them precisely in our equations of quantum mechanics, special and general relativity, electrodynamics, and the standard models of particle physics and cosmology, and make predictions which accurately describe our observations, but when we try to understand what is really going on or why it works that way, it often seems puzzling and sometimes downright weird.But as the author points out, when you view these aspects of the physical universe through the eyes of a computer game designer or builder of computer models of complex physical systems, they look oddly familiar. Here is how I expressed it thirteen years ago in my 2006 review of Leonard Susskind's  The Cosmic Landscape :“What would we expect to see if we inhabited a simulation? Well, there would probably be a discrete time step and granularity in position fixed by the time and position resolution of the simulation—check, and check: the Planck time and distance appear to behave this way in our universe. There would probably be an absolute speed limit to constrain the extent we could directly explore and impose a locality constraint on propagating updates throughout the simulation—check: speed of light. There would be a limit on the extent of the universe we could observe—check: the Hubble radius is an absolute horizon we cannot penetrate, and the last scattering surface of the cosmic background radiation limits electromagnetic observation to a still smaller radius. There would be a limit on the accuracy of physical measurements due to the finite precision of the computation in the simulation—check: Heisenberg uncertainty principle—and, as in games, randomness would be used as a fudge when precision limits were hit—check: quantum mechanics.”Indeed, these curious physical phenomena begin to look precisely like the kinds of optimisations game and simulation designers employ to cope with the limited computer power at their disposal. The author notes, “Quantum Indeterminacy, a fundamental principle of the material world, sounds remarkably similar to optimizations made in the world of computer graphics and video games, which are rendered on individual machines (computers or mobile phones) but which have conscious players controlling and observing the action.”One of the key tricks in complex video games is “conditional rendering”: you don't generate the images or worry about the physics of objects which the player can't see from their current location. This is remarkably like quantum mechanics, where the act of observation reduces the state vector to a discrete measurement and collapses its complex extent in space and time into a known value. In video games, you only need to evaluate when somebody's looking. Quantum mechanics is largely encapsulated in the tweet by Aatish Bhatia, “Don't look: waves. Look: particles.” It seems our universe works the same way. Curious, isn't it?Similarly, games and simulations exploit discreteness and locality to reduce the amount of computation they must perform. The world is approximated by a grid, and actions in one place can only affect neighbours and propagate at a limited speed. This is precisely what we see in field theories and relativity, where actions are local and no influence can propagate faster than the speed of light.THE UNEXPLAINED. Many esoteric and mystic traditions, especially those of the East such as Hinduism and Buddhism, describe the world as something like a dream, in which we act and our actions affect our permanent identity in subsequent lives. Western traditions, including the Abrahamic religions, see life in this world as a temporary thing, where our acts will be judged by a God who is outside the world. These beliefs come naturally to humans, and while there is little or no evidence for them in conventional science, it is safe to say that far more people believe and have believed these things and have structured their lives accordingly than those who have adopted the strictly rationalistic viewpoint one might deduce from deterministic, reductionist science.And yet, once again, in video games we see the emergence of a model which is entirely compatible with these ancient traditions. Characters live multiple lives, and their actions in the game cause changes in a state (“karma”) which is recorded outside the game and affects what they can do. They complete quests, which affect their karma and capabilities, and upon completing a quest, they may graduate (be reincarnated) into a new life (level), in which they retain their karma from previous lives. Just as players who exist outside the game can affect events and characters within it, various traditions describe actors outside the natural universe (hence “supernatural”) such as gods, angels, demons, and spirits of the departed, interacting with people within the universe and occasionally causing physical manifestations (miracles, apparitions, hauntings, UFOs, etc.). And perhaps the simulation hypothesis can even explain absence of evidence: the sky in a video game may contain a multitude of stars and galaxies, but that doesn't mean each is populated by its own video game universe filled with characters playing the same game. No, it's just scenery, there to be admired but with which you can't interact. Maybe that's why we've never detected signals from an alien civilisation: the stars are just procedurally generated scenery to make our telescopic views more interesting.The author concludes with a summary of the evidence we may be living in a simulation and the objection of sceptics (such that a computer as large and complicated as the universe would be required to simulate a universe). He suggests experiments which might detect the granularity of the simulation and provide concrete evidence the universe is not the continuum most of science has assumed it to be. A final chapter presents speculations as to who might be running the simulation, what their motives might be for doing so, and the nature of beings within the simulation. I'm cautious of delusions of grandeur in making such guesses. I'll bet we're a science fair project, and I'll further bet that within a century we'll be creating a multitude of simulated universes for our own science fair projects.

This book is great if you still need rationale that there is Reality besides the 3 spatial and 1 temporal dimension of our universe. It is gives a logical way to understand it, even for a non-religious or non-spiritual person. In fact, I came to a similar conclusion when reading the Bhagavad Gita. To me, it seemed like Krishna was describing the universe as a television program where the characters have free will. But, the author's description of a computer simulation is a better analogy. But, I only gave this book 4 stars because it the author tended to repeat points multiple times. They are good points, but they do not become more true by repetition.Having said that, I think the Computer Simulation Hypothesis is imperfect for a few reasons:First, I think the description is too simple. Describing the universe as a computer simulation may be about as good as we can do right now. But, as our understanding improves, I believe humans will look back on this metaphor as being as naive as we think today of the idea that "Hell is underground and Heaven is in the sky". This book is a step in the right direction, but it is not the end game.Second, we often assume that the "Out There" will have the similar laws of physics as the simulation (3 spatial dimensions and 1 time dimension), and sometime we will wake up as humans looking substantially the same as we did in the simulation. In fact, the metaphor of the simulation assumes that the "Out There" and the rendered universe have the same time dimension (the author talks about the clock speed of the simulation). But, there is no reason to think that when/if we exit the simulation that life will be substantially similar as here. There could be a different number of space and time dimensions. In fact, the idea of a Block Universe, implies that the "Out There" probably does not share the same time dimension as we experience. See for example "Hidden in Plain Sight 3: The Secret of Time," by Andrew Thomas.And, we need to be careful about how we describe consciousness. The author writes about consciousness being downloaded into our universe from the outside the simulation. The author cites Eastern philosophies a lot, but I think he has missed a key point. Both neuroscience and Eastern Philosophy are very clear that the superficial ego (the consciousness that we associate with our individual self and call by name: "George" or "Sue" etc.) is a product of our physical world. Just like our bodies, they part of the "rendered universe." They will not exist when the simulation ends. See for example "Beyond Self: Conversations Between Buddhism and Neuroscience" by Matthieu Ricard and Wolf Singer. As described in that Ricard and Singer's book: the part of the Self that can exist outside our universe is the deeper consciousness, that can be realized by meditation, prayer and similar techniques. It is called by different names by different traditions: Atman, Soul, True Self, but it is not your superficial self, which the Riz Virk seems to assume in this book. In fact, some traditions claim that "all life is one" suggesting that there are many characters in the simulation (universe) for every player outside the simulation. And, don't assume that humans are the only important characters.But, I think the biggest danger of the Simulation Hypothesis is this: we might assume that since our universe is just a rendering, that is is not real so it doesn't really matter what we do to it. I think this is scary. I don't think we should act in our lives like we sometimes act in a video game: reckless and destructive. If we do so, we will lose the game of life. All traditions are very clear on that point: Love your neighbor as yourself.

I must admit that, probably like many, I read this book after hearing the comments on Simulation Theory from Elon Musk. I already knew that the theory, which has been around for a while, was logically flawed, but I was hoping at least to find a thoughtful and well structured argument. This book did not provide it.It is clearly written by a computer game enthusiast rather than a serious scientist or philosopher. Much of the book is spent talking about computer games and the sections on mysticism and science are so shallow that they fail in any way to support the overarching thesis.Philosophically the Simulation Hypothesis is flawed for several reasons:Firstly, if reality is a simulation, and all of its contents (physical and mental) are within the simulation, and therefore unreal, then the very thought of the simulation hypothesis is also within the simulation and therefore also unreal.Secondly, all unreal simulations are based on real phenomena. Therefore if our physical and mental universe is a simulation, it must be based upon some alternative and real physical and mental universe (which in itself is an arbitrary division). However, for the beings of that reality, who have created an unreal simulation, there is now no reason to believe that their universe is real, so perhaps they are also in a simulation. This leads to an infinite regress of simulations. As any serious student of logic or philosophy will know, an infinite regress is a sign that something has gone wrong.Thirdly, the very premise that consciousness is a simulation is based on the materialistic view that consciousness arises from electro-chemical reactions and can therefore be programmed in a computer. It is important to know that despite this widely held belief, there is literally no evidence that consciousness is created in this manner. Putting that aside, the thesis of the Simulation Hypothesis is that consciousness has a real and material cause, and yet this real cause is used to explain why everything is in fact unreal, in the form of a simulation. This is an entirely unnecessary step - why bother imagining some real cause, only to use it to prove that something is unreal!In summary, Simulation Theory is nothing but a confused dualism between an unreal but unimagined simulation and a real but imagined external existence. Only for computer geeks.

i would like to say that i totally believe in simulation theory as i have a memory of coming here into it. i remember coming down a yellow tunnel of light into a dying four year old child. as a disembodied consiecness looking out through the childs eyes. i did not like what i saw. where the hell am i i thought said as i did not have a body then. the mother called out to the child. then i said oh well i know her name (mum) so i must meant to be here. next thing i know i wake up in hospital in the four year old child having just had menigitus. mum said id been asleep for two days. i tried telling my mum that i had just been born. well ive carried that memory with me all my life. and now the simulation theory actually explains to me what happened back then

Is the "real world" someone else's computer simulation? How could we tell, one way or the other?This is a well-researched and fascinating book covering both scientific arguments and religious teachings and beliefs, asserting that we are almost certainly living in a simulation. A strong analogy with computer-gaming simulated worlds is drawn, mainly to bring the discussion more easily into the realm of something many people can personally relate to.The question of whether we ourselves are also simulated beings (non-player characters in the gaming analogy terminology), or "real people" merely operating inside a simulated universe, is touched upon but not really investigated or discussed sufficiently, in my opinion.Several scientists' and religious leaders' opinions on whether the world is "real physics" or a computer-based simulation are presented, ranging from "it's extremely unlikely that we aren't" to "why make something so big and complicated when a universe has to exist already for it to be created in?".My preferred way of thinking about the question, though, is "what does it matter? This is life, whether it's 'real' or just a simulation someone else has created. Let's live it."

I was excited about this book, to begin with. As the book unfolds, it is seen as an attempt to synchronize the world of video games with the possibility that we are living in a gigantesque computer game ourselves.The author's premise is that as the world of gaming becomes ever more sophisticated, there must reach a point of 'singularity,' where we as humans are unable to distinguish reality from a computer simulated existence.He assumes that other civilizations, more technologically advanced than our own, must have reached that point.As rapidly as technology advances, I cannot believe that we, as humans, will reach that point within the hundred years that the author confidently predicts.He hasn't factored in climate change, warfare, pestilence or natural catastrophic events that may finish off humankind long before that questionable point may be reached.The book is interesting from the point of view of a gamer, but lacks in depth analysis of other possibilities.

In a large sense, it is almost irrelevant if this hypothesis is valid.The writing and logical arguments, and sequencing of narrative and layered argument is a tour de force of organised writing! it is captivating and catalytic, regardless of veracity. It also teaches quantum mechanics and how that relates to the real world in a crystal clear manner. And knits ideas together seamlessly.