Are We Living in a Computer Simulation?

The Simulation Argument was first coined by Nick Bostrom in a 2003 paper titled “Are You Living in a Computer Simulation?“. Also see the key points from Bostrom’s book “Superintelligence: Paths, Dangers, Strategies” (2014).

Bostrom’s Simulation Argument purports to show that one of three propositions is true, one of which is the Simulation Hypothesis:

1. All civilizations go extinct before reaching technological maturity.
   • This could be due to nuclear war, asteroid impact, gamma ray, a pandemic, etc.
     
2. There is a strong convergence among all technologically mature civilizations, such that they all loose interest in creating ancestor simulations.
   • This could be due ethical reasons, that they see certain negative consequences of doing so, etc.
     
3. Posthuman civilizations have the technological maturity to run ancestor simulations, and choose to do so (the Simulation Hypothesis).
   • If that is the case, given their abundance of computing power, it would be likely that they would run a large number of simulations (e.g. for fun, research purposes, as a form of art like movies or the opera, themed holidays to some bygone age, or some combination of these), making it highly unlikely that we are now living in base reality and not in one of these simulations. In other words, we are most likely living in a simulation.
     
   • It may also be possible that a simulated civilization becomes technological mature, and starts to run their own simulations. In such a case, you would have nested simulations. This would also theoretically mean that there could a very high number of simulations at each nested layer of simulations, which also makes it very unlikely that we are living in base reality.

The full Simulation Argument (in Bostrom’s paper: “Are You Living in a Computer Simulation?“) is built on some probability theory and formalism, however, the gist of it can be understood intuitively. Suppose that proposition (1) is false. Then, a significant fraction of all civilizations at our level of development eventually becomes technologically mature. Suppose, further, that proposition (2) is false as well. Then, some significant fraction of the civilizations that have become technologically mature will use some portion of their abundance of computational power to run computer simulations of minds like ours. The number of simulated minds that any such technologically mature civilization could run is astronomically huge. Thus, if both (1) and (2) are false, there will be an astronomically huge number of simulated minds like ours. This in turn, from a probability standpoint, makes it very unlikely that we are now living in base reality, rather in one of the myriad of simulations.

Thus, it follows that if we do not think that we are currently living in a computer simulation, we are not entitled (as it would not be logically sound) to believe that we will have descendants who will run lots of such simulations of their ancestors.

Further Explanations of Relevant Terms

• Ancestor simulations means very detailed computer simulations of people like their historical forbearers. Detailed enough that simulated people in the simulations would be conscious.
  
  
• Technological maturity in this case means the ability to run ancestor simulations (e.g. having the required computing power). Consider that in 1972, the first computer game, Pong, was invented, which was just two bars and dot. Merely a few decades later, we have advanced virtual reality games, haptic suits, etc. that makes the gaming experience seem very life-like. Imagine how things will looks like 20 years from, 100 years from now, 1 000 years from now. Given any rate of progress in this field, it seems inevitable that we will eventually develop the computing power and capabilities to make virtual worlds indistinguishable from reality. Unless, proposition (1) from the Simulation Argument holds true.
  
  One should also consider it would not be required to simulate the entire universe with all its sub-atomic particles etc. only the parts that are being observed at any given point in time. This concept is also use in the gaming industry today, in which the z-buffer only renders what is visible to us, and not say the pixels not visible behind a crate or behind a wall in a computer game. This saves a lot of computing power, and in a large simulation, it would save enormous amounts computing power. It would be reasonable to assume that all such efficiency approaches would be put to use by post-human civilization (that by definition would be much more advanced and more intelligent than us).
  
  Currently it is possible for us to estimate, at a very rough level, how much computing power it would take to implement a human mind along with a virtual reality that would seem completely realistic for it to interact with. Furthermore, we can roughly estimate the lower bounds on how powerful the computers of an advanced civilization could be. Technological futurists have already proposed designs for physically possible computers that could be built using advanced molecular manufacturing technology. The result of such an analysis is that a technologically mature civilization that has developed at least those technologies that we already know are physically possible, would be able to build computers powerful enough to run an astronomical number of human-like minds, even if only a tiny fraction of their resources was used for that purpose.
  
  

• Building further on the Simulation Hypothesis, substrate independence is the idea that in principle conscious minds could be implemented not only on carbon-based biological neurons (e.g. those inside your head), but also on some other computational substrate such as silicon-based processors. The computers we have today are not powerful enough to run the computational processes that take place in your brain, and even if they were, we would not know how to program them to do it. What allows you to have conscious experiences is not that your brain is made of wetware/biological matter, but rather that it implements a certain computational architecture. This assumption is quite widely (but not universally) accepted among cognitive scientists and philosophers of the mind.
  
  Given substrate independence, it would in principle possible to implement a human mind on a sufficiently fast computer. However, it would require very powerful hardware that is not yet available. It would also require advanced programming abilities, or sophisticated ways of making a very detailed scan of a human brain that could then be uploaded to the computer. Although we will not be able to do this in the near future, the challenges appears to be merely of technical nature. There is no known physical law or material constraint that would prevent a sufficiently technologically advanced civilization from implementing human minds in computers.
  
  

If Living in a Simulation, Would You be Able to Tell?

If you are such a simulated mind, there might be no direct observational way for you to tell. The simulation you would be living in, would look and feel real. Thus, you could never be completely sure that you are not living in a simulation, whether you are indeed in a simulation or in base reality.

Building any kind of simulation containing conscious simulated brains would be extremely challenging. Any being capable of such a feat, would almost certainly also be able to prevent any glitches in their simulation from being noticed by the people living in it. Even if someone noticed an anomaly in the simulation, it is reasonable to assume that the creator of the simulation could backtrack the simulation a few seconds and re-run it in a way that avoided the anomaly entirely, or simply editing out the memory of the anomaly from whoever had noticed something out of the ordinary.

There are a number of different ways to interpret the Simulation Hypothesis. Some people believe that it is a literal possibility, while others believe that it is a metaphor for the way that we interact with reality. Ultimately, the Simulation Hypothesis is a philosophical question that at this point only have a probabilistic answer. However, if we were to become technologically mature enough to create a such a simulation, then it would be even more likely that we ourselves are already living in one right now.

Example

One very good example of the Simulation Hypothesis is the “Matrix” film trilogy (especially the first film from 1999). In the Matrix, humans are unknowingly living in a simulated reality that is created by machines. The machines have created the Matrix in order to harvest the energy of humans, who are kept in pods and hooked up to a life support system.

The Matrix is a fictional story, but it is based on an almost identical idea as the Simulation Hypothesis. The film explores the idea that our reality might not be what it seems, and that we might be living in a computer simulation. The Matrix is a thought-provoking film that raises important questions about the nature of reality and our place in the universe.

The Link to Plato’s Cave Allegory

The ancient Greek philosopher Plato‘s Cave Allegory is a philosophical concept of how our reality is perceived. In the allegory, Plato describes a group of people who have lived chained in a cave all of their lives, facing a blank wall. The people watch shadows projected on the wall from objects passing in front of a fire behind them. These prisoners begin to ascribe forms to these shadows. According to Plato’s theory of Forms, the shadows are as close as the prisoners get to viewing reality. He then explains how the philosopher is like a prisoner who is freed from the cave and comes to understand that the shadows on the wall do not make up reality at all, as he can perceive the true form of reality rather than the mere shadows seen by the prisoners.

The Simulation Hypothesis is a similar concept, in that it suggests that our reality might be a simulation. Just as the prisoners in Plato’s Cave Allegory believe that the shadows on the wall are reality, we might believe that our reality is real, when it is actually a simulation.

There are a number of similarities between the Simulation Hypothesis and Plato’s Cave Allegory. Both concepts suggest that our reality might not be what it seems, and raise questions about the nature of reality and our place in the universe. Both concepts also suggest that there is more to reality than we can see or understand, that there is a reality that exists beyond our own, and that we might not be as in control of our reality as we think we are. Furthermore, both concepts suggest that we might be able to access this reality, beyond our own, if we are able to break free from our current limitations.

The Simulation Hypothesis is a fascinating idea that has the potential to change the way we think about reality. Plato’s Cave Allegory is a classic philosophical concept that has been interpreted in many different ways. The connection between the two concepts is a reminder that the nature of reality is a complex and illusive question.

Resources to Learn More

Recommend watching the crisp, clear and well visualized Kurzgesagt video below “Is Reality Real? The Simulation Argument” (8:46 min).

Also see the video “Are we living in a simulation?” (4:23 min) on the TED-Ed channel.

Recommend watching the below interview with Nick Bostrom at the Future of Humanity Institute Oxford University, for which the video is called “Nick Bostrom – The Simulation Argument” (23:27 min).

We would also encourage reading the article “The Simulation Argument: Why the Probability that You Are Living in a Matrix is Quite High” (2003) and the article “Why Make a Matrix? And Why You Might Be In One” by Nick Bostrom.

Watch the high-level and somewhat whimsical overview video of various clips and photos called “Why Elon Musk says we’re living in a simulation” (3:39 min), on the Vox channel.

Watch the YouTube video of Lex Fridman in conversation with Nick Bostrom (1:56:37 hours), on the Lex Fridman podcast episode #83 from March 25^th 2020, in which they, among other things, discuss the Simulation Argument.

Great TED Talk from 2015 by cognitive scientist Donald Hoffman on “Do we see reality as it is?” (21:51 min), or have our perceptions evolved to teach us tricks and hacks to increase our chance of survival, rather than rendering reality as accurately as it is. Watch this mind-bending talk below.