You might have heard the news: Our world could be a clever computer simulation that creates the impression of living in a real world.
Elon Musk brought up this topic a few weeks ago. Truth be told — he is probably right. However, there is a very important point missing in this whole “real vs. fake” discussion: It actually makes no difference.
But first...why might our world be a simulation? Musk is nowhere near the first one to suggest our world might be fake. The idea reaches back to the ancient Greeks, though what we call a computer simulation, the ancient Greeks called a dream. The first thing to realize is this: Our perception of reality is already separate from reality itself.
To paraphrase Morpheus from the movie The Matrix, reality is simply an electrical impulse being interpreted by your brain. We experience the world indirectly and imperfectly. If we could see the world as it is, there would be no optical illusions, no color blindness and no mind tricks.
Further, we only experience a simplified version of all this mediated sensory information. The reason? Seeing the world as it is requires too much processing power — so our brain breaks it into heuristics (or simplified but still useful representations). Our mind is constantly looking for patterns in our world and will match them with our perception.
From this we can conclude the following: Our perception of reality is already different from reality itself. What we call reality is our brains’ attempt to process the incoming flood of sensory data.
If our perception of reality is dependent on a simplified flow of information, it doesn't matter what the source of this information is — whether it’s the physical world or a computer simulation feeding us the same information. But is it really possible to create such a powerful simulation? Let’s see by taking a look at the universe from a physical point of view.
From a physical point of view, four basic forces underlie everything: the strong force, electromagnetic force, weak force and gravitational force. These forces govern every interaction of every particle in the known universe. Their combination and equilibrium make up all there is.
Calculating these forces and simulating simple interactions is fairly easy, and we are already doing it — at least to some extent. It gets complicated once you add more and more particles interacting with each other — this, however, is just a question of computational power and not feasibility.
Right now, we lack the computational power to simulate the whole universe. Physicists would even argue that simulating the universe in a computer is impossible — not because of the complexity, but because a computer that simulates the universe would be bigger than the universe itself. Why? You would need to simulate every particle and would thus need multiple bits and bytes to store the position, spin and type of each particle and then do the calculations with those.
READ: Parallel Universes: Theories & Evidence
You don’t need a physics PhD to recognize the impossibility of this endeavor. However, there is a flaw in this type of thinking that results from the mathematical mindset most physicists employ. There is a big difference between simulating the whole universe and creating the virtual feeling of living in a whole universe.
Welcome the heuristics — again. Many computational scenarios would be impossible to solve if our human mind could not easily be tricked. From real-time computing to moving pictures and video streams (which include quite heavy audio/video delays) to ping delays and many other things. They make us feel as if everything is continuous and normal when there is quite a lot of trickery involved.
The basic pattern is always the same: Reduce the details to a level with the best compromise between quality and complexity where our mind won’t notice the difference.
There are many tricks we can use to reduce the computational power needed to simulate a universe to a degree we can handle. The most obvious being: Don’t render anything no-one is looking at. If you feel a slight tingling sensation in your body, this might be because you are familiar with Heisenberg's uncertainty principle and the observer effect. Modern physics tells us reality is such that the state of the smallest particles is dependent on whether they are being observed.
Next trick you could use: Make the universe seem vast and limitless even though it isn’t. This one is actually used quite a lot in video games. By reducing the details on far away objects you can save huge amounts of computational power and generate objects only when they are discovered. If this sounds hard to grasp, please take a look at the game No Man’s Sky — a video game in which a whole virtual universe is being procedurally generated while you discover it.
Last but not least: Add basic physical principles that make it amazingly hard or impossible to reach any other planet and keep the simulated beings stranded in their own world (speed of light and exponentially expanding universe — cough, cough).
If you combine these “cheats” with some mathematical trickery like reusable patterns and basic fractal geometry, you end up with a fairly good heuristic-based simulation of our universe — a universe that seems almost endless and infinite but is little more than a reality hack. This, however, still does not explain why Musk (and others) say there’s a high probability we are part of a virtual universe. Let’s have a look.
The simulation argument is a logical deduction proposed by Oxford University philosopher Nick Bostrom. It is based on some prerequisites that, depending on your view of each, can lead to the conclusion that our universe is most likely simulated. This is straightforward:
1. It is possible to simulate a universe (we covered this point above).
2. Every civilization either goes extinct (the pessimistic view) before it is technologically able to simulate a universe; loses interest in the development of simulation technology; or continues to advance and eventually reaches the technological level that is capable of simulating a universe and will do it. It’s just a matter of time. (Would we do it? Of course we would…)
3. Once achieved, this society will create many different simulations resulting in uncountable numbers of simulations. (Everyone wants to have a universe of their own.)
4. Once a simulation reaches a certain level, it too will create simulations of its own (and so forth).
If you do the math, you will soon get to the point where you have to recognize the probability of living in a real world is very slim because it is simply dwarfed by the number of existing simulations.
From this point of view, it is more likely that our world is 20 levels deep in a vicious simulation cycle than it being the original world. However, here is the good thing: It doesn’t matter.
We already covered how our perception of reality is very different from reality itself. Let’s assume for a minute, that our universe is a computer simulation. This assumption calls for another logical deduction chain:
1. If the universe is simulated it is basically a combination of bits and bytes (or qBits or Snags or whatever…) — essentially information.
2. If the universe is information or data, then so are you. Every one of us is.
3. If we are all information, then our bodies are simply a representation of this information — like an avatar.The best thing about information is: It is not bound to a certain object. You can copy, transform and change it any way you like (all you need are the proper coding techniques).
4. Any society that is capable of simulating a virtual world is also capable of giving your “personal” information a new avatar (because this requires less knowledge than simulating a universe).
Altogether, this means you are basically information, and the information that defines you is not bound to a certain object like your body. Philosophy and theology have long debated the concept of duality between our body and soul (mind, uniqueness — whatever you name it). So, the concept should sound familiar to you — this is just a more rational explanation for the phenomenon.
Let’s conclude. Reality is information, and so are we. A simulation is part of the reality that simulates it — and everything we further simulate is reality from the perspective of those being simulated.
Reality is, therefore, what we experience: From a physical point of view, there is no objectivity in the quantum space — only a very subjective perspective on things. There are even some widely accepted theories claiming that every object we see could be the projection of information at the other side of the universe — or any other universe.
So, in essence: Everything is “real” if you experience it. And a simulated universe is as real as the universe that simulates it because reality is defined by the information it represents — no matter where it’s physically stored.