Some people have argued that if this universe is a simulation, we might find out by examining its material properties. Only we can never know whether these properties, reflected in the laws of physics, are real or fake. Even when some property of our universe appears strange or consistent with simulation, it does not prove that this universe is a simulation. It can be a property of a real universe. And so, it seems unlikely that science can ever establish that we live inside a simulation.
Science aims to establish the properties of this universe reflected in the laws of reality, but science cannot establish whether or not these laws themselves are real. Hence, any argument for this universe being a simulation based on the properties of this universe is a dead end. In its simplest form, the argument goes like this: the universe is a simulation because the underlying properties are digital. At the lowest level, everything is just numbers that can exist in computer memory.
How does that work? A digital television screen consists of more than a million tiny coloured dots. Every single spot on the screen has a unique number. Also, every colour has a unique number. From a distance, you may see a person or a mountain. At the lowest level, the screen is just numbers. And you can store numbers in computer memory. You can represent an entire universe in this way.
Real universes could be digital too. We do not know. Being digital is a property, not a cause of existence. Similarly, in quantum physics, our reality is a sequence of states. Nothing exists or happens between them. Like the dots on a television screen, these states can be numbers. Again, this could mean that our universe exists inside a computer. Also, in this case, there is no way of knowing whether or not this applies to a universe that is not computer-generated.
Quantum entanglement implies that particles interact directly with each other. The distance between them does not matter. If one particle is at one end of the universe while the other is at the other end, they might still interact directly, as if there is no distance between them. This phenomenon mocks our idea of distance. It can raise questions about the age of this universe as estimates of its age are based on its size. But then again, we do not know whether this behaviour is also present in a real universe that is billions of years old.
Intelligent extraterrestrial civilisations are likely to exist, many believe. So far, there is no evidence of their presence. The famous physicist Fermi once asked, ‘Where is everybody?’ Perhaps humankind is the only advanced civilisation in the universe. If we live inside a simulation, there may be no point in using resources to simulate other beings on remote planets. But that is not the only possibility. Perhaps civilisations tend to die out before becoming advanced. Or maybe we overestimate the probability of advanced civilisations contacting us.
Then there is the observer effect. The argument goes that several types of small particles do not exist most of the time. They only come into being when someone observes them. If this universe is a simulation, it would be a waste of memory and processing power to represent them all the time. If this universe is real, these particles might, or even should, always exist even when no one is watching. The argument is the result of a misconception about these particles. They do not disappear when not being observed. They become waves instead. There is no way of knowing whether this kind of observer effect exists in real universes. And why are we able to notice this? In a simulation, it must be possible to conceal the non-existence of unobserved particles.
Latest revision: 2 April 2022
Featured image: Tunnel of the Large Hadron Collider (LHC) of the European Organization for Nuclear Research. Julian Herzog (2008). Wikimedia Commons.