We may be bots in a reality-wide simulation, and perhaps the player(s) from above can violate our simulated physics when they want. In a more popular formulation of the same concept, called Religion, the player(s), called God(s), created our reality and can perform miracles.
The two formulations are equivalent for all practical purposes. Many religions assume that Gods are omnipotent and benevolent, but then we have the problem of evil: how can omnipotent and benevolent Gods permit evil and suffering?
If omnipotent and benevolent Gods permit evil and suffering, then they are either not omnipotent, or not benevolent, or neither, or perhaps they don’t exist at all. In fact, the problem of evil is one of the main reasons why former believers become atheists. It turns out that the problem of evil has a simple solution.
The picture to the right is a screenshot taken in the popular computer game Half Life 2 by Valve Software. The people in the picture are bots, or Non-Player Characters (NPCs). They have a limited “intelligence” and can respond to a limited range of situations that can arise in the game, for example if you go near the guards they will beat you.
The “intelligence” of bots in computer games is still light years behind real intelligence. However, I am persuaded that real, self-aware AI of human and higher-level will be achieved someday, perhaps by the computer gaming industry itself, and perhaps in the next couple of decades. Then, computer games will contain sentient, intelligent persons like you and I.
If computer game bots can be intelligent and sentient, perhaps we are sentient and intelligent computer game bots. Do we live in a computer simulation? This is a frequent discussion topic in transhumanist interest groups, and a matter of scientific investigation. Who is running the simulation? Perhaps unknowable aliens in another level of reality have invented our world and us. A frequent assumption (see The New God Argument) is that future humans run our reality as a historically accurate simulation of their past (our present).
In a 1992 essay entitled Pigs in Cyberspace, Hans Moravec formulated (in modern terms) the idea of our reality as a simulation. “The very moment we are now experiencing may actually be (almost certainly is) such a distributed mental event, and most likely is a complete fabrication that never happened physically,” he says, implying that observers living in simulated realities may vastly outnumber observers living in original physical realities.
Apparently, there is an important difference between Berkeley and Moravec: As a 18th century Christian and a representative of the Church, Berkeley believed in supernatural phenomena, in principle not understandable by science, while Moravec, as a modern engineer, believes reality is fully understandable and explainable by science. Future engineers within the framework of future science will develop Moravec’s simulated realities. If our reality is a simulation, everything in our universe can be understood in terms of the physical laws of the higher-level reality in which it is simulated.
But… this does not mean that it must always be understandable in terms of our own physical laws: Moravec’s simulation cosmology may contain supernatural phenomena, because the reality engineers up there may choose to violate the rules of the game. Yes, as Richard Dawkins says, they are creatures naturally evolved in their physical universe and they cannot violate their physics, but they can violate ours if they want.
Make this simple experiment: Run a Conways’s Game of Life program, choose an initial pattern, and let it evolve for a while. Now, stop the program, flip a cell, and resume the program. You have just performed a miracle: something that goes against the physical laws (the simple cellular automata evolution rules of Life) of the lower-level reality that you are simulating. Of course simple Life patterns are not complex enough to be sentient observers, but hypothetical observers within Life would observe an event that cannot be understood in terms of the physical laws of their universe. A miracle.
In the short movie CA Resurrection below, made with a Game of Life program, the protagonist pattern is doomed to certain death by interaction with a very unfriendly environment (sounds familiar?), but is copied before death and restored to life in a friendlier environment. This (scientifically plausible) computational resurrection is equivalent to the religious concept of resurrection in Heaven. I am a pattern doomed to certain death by interaction with a very unfriendly environment, and I hope to be copied and resurrected.
If we admit the possibility of a God who created our reality (or a post-human player who runs the simulation that is our reality, but the two concepts are really one and the same), able to perform miracles, we must face the Problem of Evil: a benevolent and omnipotent God would not permit evil, so since evil exists, God is either not benevolent, or not omnipotent, or neither.
The medieval philosophers, who were as smart as contemporary philosophers and thought a lot about these things, knew that “omnipotent” is a concept that needs to be defined and limited. Could an omnipotent being create a stone so heavy that even he could not lift it? If he could lift the rock, then it seems that the being could cease to be omnipotent, as the rock was not heavy enough; if he could not, it seems that the being was not omnipotent to begin with.
But a rock so heavy that it cannot be lifted by an omnipotent being cannot exist, because an omnipotent being is defined as a being who can lift all rocks. The rock is a contradiction in terms and a logical impossibility, like a triangle with four sides (a triangle is defined as a polygon with three sides).
No God can ever draw a triangle with four sides, because a triangle with four sides cannot exist by definition. I don’t believe in the supernatural, but I can believe in natural Gods, and I can believe that natural Gods created our reality. A natural God is only omnipotent in the sense that he is much more powerful than us, but still has necessary limitations.
If reality is a computation, it is probably an incompressible computation with no shortcuts: the only way to know what happens at time t, is to run the computation until time t. Besides some very simple initial configurations, the Game of Life is incompressible: if you want to know what happens at time step t, you must run the program through all intermediate time steps.
It makes sense to assume that reality is an incompressible computation, and the universe is the fastest computer that can compute itself. In other words, a 100% complete and accurate prediction of tomorrow’s weather cannot be done in less than 24 hours, and the only way to predict the future with complete accuracy is waiting for the future to happen.
This assumption makes sense because the existence of a faster-than-the-universe computer within the universe would lead to logical contradictions. Suppose you could compute the state of the universe tomorrow faster than the universe itself. The results of the computation will include the color of the shirt that you will wear tomorrow. Then you can invalidate the prediction by simply wearing, tomorrow, a shirt of another color.
The life of the prisoners brutalized by the guards in the Half Life 2 scene in the picture above is very ugly, and if they were sentient they would suffer a lot. Unfortunately, similar things have happened in our reality, for example in the 1930s, and millions of sentient persons have been brutalized by evil regimes, and suffered a lot. Surely a benevolent and omnipotent God would try to do something to avoid that.
But there are no computational shortcuts. The only way to predict with complete accuracy that certain events would lead to, say, Auschwitz, is to let the computation unfold until Auschwitz.
But wait a sec — you may be thinking — can’t God just use a faster computer to make the prediction? After all, we can predict the evolution of a Game of Life on our computer, by running it on a faster computer. If we see (on the faster computer) that something bad will happen to our favorite pattern, we can stop the game and try to flip some cells to ensure it doesn’t happen in our game.
Well, no, it wouldn’t work. Remember that these computations contain sentient beings. If God uses a faster reality simulator to predict Auschwitz before it happens in our reality simulator… Auschwitz will happen in the faster simulator, and people will suffer in the faster simulator.
This “solves” the Problem of Evil, because God is unable to predict the future with complete accuracy and can only work with incomplete resources and information, like us.
Image 1 and Image 4: A very ugly simulated reality in Half Life 2
Image 2: A Universal Turing Machine (UTM) implemented in Conway’s Game of Life, designed by Paul Rendell (http://rendell-attic.org/gol/utm/index.htm)