Could we be living in a simulation?

Science has revolutionised the way that humans perceive the world in recent years. Not only have scientific and technological developments made daily life easier, more enjoyable and generally much safer, but they have also shaped the way humans think. Science has replaced the description of phenomena that may have been deemed “miracles” as a consequence of abstract scientific concepts including gravitational force, chemical interactions and evolution. Science in recent decades has seen incredible technological advancements, though many old questions have not yet been answered. Though much research has been done, these questions are even more complicated than once thought. Though many discoveries have been made, the fields of string theory, quantum mechanics, astronomy, genetics and many others, are significantly more complex than thought previously. Although many questions still go unanswered, progress, specifically in computer sciences and neuroscience, has shown that vast amounts of information can be stored in numbers or equations. Many physicists and neuroscientists nowadays believe that everything, yes, everything, can be described in such numbers or equations. This realm of science, termed physicalism, suggests that all one’s thoughts, emotions, memories, desires and even personality, are nothing more than a collection of enormous amounts of physical data (Brakel, 2021).

The idea of physicalism is that every object, even the universe as a whole, can be described in terms of the fundamental particles that constitute the object (Brakel, 2021). The particles that make up neutrons, protons and eventually atoms and molecules of an object can be described in terms of position and velocity, from which the evolution of the system could be calculated. Interestingly, the nature of these particles remains unknown. That is to say, scientists do not know what everything is made up of. If everything is indeed quantised, as scientists expect, it is likely that eventually computers will be developed that are so unbelievably powerful, that they can simulate planets, including plate tectonics, weather, an atmosphere, solar energy and everything on such celestial bodies, including humans (Bostrom, 2003). These computers would even be able to simulate each individual's thought processes and therefore have some capacity for free will. It would not be true free will in the human sense, however, rather it would be an illusion of free will. But if technology ever gets to such a point, where it replicates the human ability for free will, how can we be sure that we ourselves, are not living in a simulation right now? As many philosophers and physicists point out, we cannot (Bostrom, 2003; Chung, 2016; Irwin et al., 2020, Shoemaker, 2016).

Figure 1: Physicalism suggests that everything that makes a personality is based on molecules, atoms and smaller (Alcim, 2020).

So how likely is it that we are a simulation? It is hard to give precise statistics to answer this question, though this question of science has seriously developed over the past decade, ever since it was proposed in 2003 by Nick Bostrom, the now famous philosopher at Oxford University (Bostrom, 2003). In an interview with Neil deGrasse Tyson, an interesting argument comes up that results from the discussion put forward by Bostrom ([StarTalk], 2020). Bostrom suggests that if indeed, it is technologically possible to simulate a universe and intelligent lifeforms, then each of these simulated civilisations may in turn become so advanced that they create simulated lifeforms. As argued before, this requires the stream of physicalism to be true. These simulated civilisations can do the same, and so on and so on. In this case, there are innumerable simulated civilisations, and only one non-simulated, or real, universe. This would make it extraordinarily unlikely that our universe is the real one. Tyson notes, however, that we do not possess the power of making such a simulation as of now. That means that if we are a simulated universe, we do not yet have the power to simulate new universes ourselves, stopping this chain of simulations from multiplying. He therefore states that our universe is either the only real one, or the most newly simulated piece of software. Tyson concludes that instead of 1 in a gazillion, the odds, therefore, turn into 1 in 2. One thing that Tyson assumes in this argument, however, is that human beings are the only living things in our, potentially simulated, universe. Perhaps there are civilisations that co-inhabit this universe that are significantly more advanced than us. This thought experiment has been argued in two earlier articles by Arcadia, 'The Fermi Paradox' and 'The Kardashev Scale' (De Schrijver, 2022; De Schrijver, 2023). If there is indeed a civilisation much older and more advanced in this universe, perhaps that civilisation has already succeeded in creating simulated lifeforms, which would nullify Tyson’s argument.

The possibility of us living inside a simulation requires that everything around and inside of us is physical, and that this information can never be destroyed. The latter is a fundamental law of quantum mechanics: every object consists of particles with a unique combination of quantum numbers, or quantum information. The universe's total amount of quantum information must be conserved (Roncaglia, 2019). An example would be to burn a piece of paper, on which a note was written that is now inaccessible because the paper has turned to ash. If technology would allow us to describe the ash in terms of all quantum information, one would be able to reconstruct the piece of paper and read the note written on it. Interestingly, this indestructibility of information poses a problem that scientists have not yet been able to answer, termed the Information Paradox, as proposed by Stephen Hawking (Raju, 2022). Black holes are incredibly interesting in many ways. They are so large, that their gravitational pull is such that nothing can escape, not even light (Raju, 2022). Consequentially, they can never be directly observed, which explains the name; black, for their absence of light. When an object, say the same piece of paper, is sucked into a black hole, it will be irretrievably lost, as no one could ever go into the black hole and survive. This itself does not disobey the law mentioned earlier, especially given that it is known that black holes grow a small amount after something has entered into them. Problematically, Hawking has shown that black holes lose an unimaginably tiny proportion of their mass over vast lengths of time - this is known as Hawking radiation (Raju, 2022). Black holes, therefore, seem to “evaporate”, and no physicist currently knows where the information black holes store leaves to, or whether this information is destroyed. If information is not always conserved, as is currently believed, our complete understanding of the universe is faulty, and simulating a universe, therefore, may not be possible.

Figure 2 (Cartlidge, 2016).

There are more truly fascinating arguments promoting, or disagreeing with the idea that our universe is only a simulation, termed the Simulation Theory. This idea has become rather popular in recent years. As science advances, it seems like more and more can be explained in relation to numbers and mathematical concepts, allowing researchers to programme and simulate these very things. Although right now it is difficult to say how likely it is that we indeed are only a simulation, it seems like a possibility. At this point, however, it is only a theorem that remains unprovable for now. That does not mean that anyone’s life holds less value. Whatever one perceives is real to them, and therefore has meaning regardless of whether everything around us is real, or whether it is the result of an enormously complex computer.

Bibliographical References

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Bostrom, N. (2003). Are We Living in a Computer Simulation? The Philosophical Quarterly, 53(211), 243–255. https://doi.org/10.1111/1467-9213.00309

Brakel, L. A. W. (2021). Can Neuroscientists Test a New Physicalist Mind/Body View: DiCoToP (Diachronic Conjunctive Token Physicalism)? Frontiers in Human Neuroscience, 15. https://doi.org/10.3389/fnhum.2021.786133

Chung, D.-Y. (2016). We Are Living in a Computer Simulation. Journal of Modern Physics, 07(10), 1210–1227. https://doi.org/10.4236/jmp.2016.710110

De Schrijver, S. (2023). The Kardashev Scale: Exploring Other Forms of Life. https://www.byarcadia.org/post/the-kardashev-scale-exploring-other-forms-of-life

De Schrijver, S. (2022). Fermi Paradox: Are We Alone?. https://www.byarcadia.org/post/fermi-paradox-are-we-alone

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Irwin, K., Amaral, M., & Chester, D. (2020). The Self-Simulation Hypothesis Interpretation of Quantum Mechanics. Entropy, 22(2), 247. https://doi.org/10.3390/e22020247

Powell, C. (2018). Elon Musk says we may live in a simulation. Here’s how we might tell if he’s right. https://www.nbcnews.com/mach/science/what-simulation-hypothesis-why-some-think-life-simulated-reality-ncna913926

Raju, S. (2022). Lessons from the information paradox. Physics Reports, 943, 1–80. https://doi.org/10.1016/j.physrep.2021.10.001

Roncaglia, M. (2019). On the Conservation of Information in Quantum Physics. Foundations of Physics, 49(11), 1278–1286. https://doi.org/10.1007/s10701-019-00304-9

Shoemaker, N. (2016). Neil deGrasse Tyson and Brian Greene: Is Reality a Computer Simulation?. https://bigthink.com/surprising-science/question-the-nature-of-your-reality-with-neil-degrasse-tyson-brian-greene/

[StarTalk]. (2020, March 18). Neil deGrasse Tyson Explains the Simulation Hypothesis [Video]. Youtube. https://www.youtube.com/watch?v=pmcrG7ZZKUc

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