A simulation is a representation of something else, just as a model of the Empire State building represents it, and an information simulation is a representation based on information. For example, simulating the weather with a computer lets us predict it, and flight simulators let pilots experience a plane without actually flying it. A simulation then represents what is real, but isn’t itself it.
The simulation hypothesis is that our world is a simulation created by computers in another physical reality, as portrayed in the film The Matrix, where Morpheus says:
“What is real? How do you define ‘real’? If you’re talking about what you can feel, what you can smell, what you can taste and see, then ‘real’ is simply electrical signals interpreted by your brain.”
The hero Neo then discovers that his reality is actually a simulation of New York in 1999, fed into his brain as electrical signals by future machines in the real world, who are using humans as energy sources. Physical machines are then simulating physical events, but is that possible?
The classical processing needed to simulate a system increases exponentially with the number of particles in it because they interact, so classical computers can only calculate the behavior of a few entities (Eck, 2017), and to simulate even a couple hundred electrons would take more atoms than exist in the universe (Kendra, 2017), let alone simulating New York city or the universe. Other research finds that these calculations aren’t just implausible but logically impossible (Faizal et al., 2025), so physicists conclude that we can’t be living in a computer simulation.
Undeterred, simulation theory supporters suggest that our simulation has holes in it, so that doesn’t matter. For example, why simulate the 14 billion years of history before humans arrived, or galaxies and stars we can’t travel to, or quantum events we can’t observe? Instead of simulating a far-off galaxy, just show a dot of light so it appears real, just as movie do. Simulation theory then proposes that our world has flaws in it because it is fake.
The big computer of simulation theory (Campbell, 2003) can’t calculate quantum events, so it expects to find flaws in quantum theory (Campbell, Owhadi, Sauvageau, & Watkinson, 2017), but quantum theory critics have been trying to falsify it for over a century, so it is unlikely to succeed. And even if it did, finding a fault in quantum theory would just result in its revision, as scientific theories succeed by predicting their own results not by falsifying others.
If simulation theory is impossible then machines, aliens, or our future-selves can’t be creating our physical world from another, but this isn’t the only version of virtualism. Annex 1 summarizes how a physical world could be a virtual reality generated by something else, and concludes that what generates physical events can’t have a physical base. This excludes not only physical virtualism (the Matrix option), but also information virtualism that is based on hardware, and even the mind virtualism suggested by Kastrup (Kastrup, 2019).
The remaining option is quantum virtualism, that quantum events generate physical events, as proposed here. A simulation must simulate something, but what creates our world isn’t like it at all, and that is why it works. Unlike classical processing, quantum processing increases exponentially as it grows, so as space expands it scales to match the demand. This allows a quantum network the size of our universe to generate it.
Processing costs aren’t now an issue because the network is always active anyway, so every moment of the past fourteen billion years happened, every far-away galaxy seen in our telescopes exists, and quantum events actually happen. Hence however hard we look, in the past, far away, or microscopically, there are no cracks or rifts in the world we see.
Our universe is on a scale we can barely imagine, so we don’t really know what it is doing, any more than the billions of animals that lived and died in biological history knew that they were taking part in an evolution. Our universe is then not just a virtual reality but one that is evolving, so what is evolution?