By Melvin M. Vopson, University of Portsmouth
Physicists have long struggled to explain why the universe began with conditions suitable for life to evolve. Why do the physical laws and constants take on the very specific values that allow stars, planets and ultimately life to evolve? The expanding force of the universe, for example dark energy, is much weaker than theory suggests it should be – causing matter to clump together instead of being torn apart.
A common answer is that we live in an infinite multiverse of universes, so we shouldn’t be surprised if at least one universe turns out to be our own. But another is that our universe is a computer simulation, with someone (perhaps an advanced alien species) fine-tuning the conditions.
The latter option is supported by a branch of science called information physics, which suggests that space-time and matter are not fundamental phenomena. Instead, physical reality is fundamentally made up of bits of information from which our experience of space-time emerges. In comparison, temperature ‘arises’ from the collective motion of atoms. No atom fundamentally has temperature.
This leads to the extraordinary possibility that our entire universe is, in fact, a computer simulation. The idea is not that new. In 1989, legendary physicist John Archibald Wheeler suggested that the universe is fundamentally mathematical and could be thought of as arising from information. He invented the famous aphorism “it from bit”.
In 2003, philosopher Nick Bostrom of Oxford University in the United Kingdom formulated his simulation hypothesis. This states that it is very likely that we live in a simulation. That’s because an advanced civilization would have to reach a point where their technology is so advanced that simulations are indistinguishable from reality and the participants wouldn’t realize they were in a simulation.
Physicist Seth Lloyd of the Massachusetts Institute of Technology in the US took the simulation hypothesis to the next level by suggesting that the entire universe could be a giant quantum computer. And in 2016, Elon Musk concluded, “We are most likely in a simulation” (see video above).
There is some evidence that our physical reality could be a simulated virtual reality rather than an objective world that exists independently of the observer.
Any virtual reality world will be based on information processing. That means everything is eventually digitized or pixelated to a minimum size that can’t be further subdivided: bits. This seems to mimic our reality according to the theory of quantum mechanics, which rules the world of atoms and particles. It states that there is a smallest, discrete unit of energy, length, and time. Similarly, elementary particles, which make up all visible matter in the universe, are the smallest units of matter. Simply put, our world is pixelated.
The laws of physics that govern everything in the universe also resemble lines of computer code that a simulation would follow when executing the program. Moreover, mathematical equations, numbers and geometric patterns are everywhere – the world seems to be completely mathematical.
Another curiosity in physics that supports the simulation hypothesis is the maximum speed limit in our universe, the speed of light. In a virtual reality, this limit would correspond to the processor speed limit or processing power limit. We know that an overloaded processor slows down computer processing in a simulation. Similarly, Albert Einstein’s general theory of relativity shows that time slows down near a black hole.
Perhaps the most supportive evidence of the simulation hypothesis comes from quantum mechanics. This suggests that nature isn’t “real”: particles in certain states, such as specific locations, don’t seem to exist unless you actually observe or measure them. Instead, they are in a mix of different states at the same time. Similarly, virtual reality needs an observer or programmer to make things happen.
Quantum “entanglement” also makes it possible to eerily link two particles together, so that if you manipulate one, you automatically and instantly manipulate the other too, no matter how far apart they are – with the effect seemingly faster than the speed of light, which should be impossible.
However, this could also be explained by the fact that within a virtual reality code all “locations” (points) must be approximately the same distance from a central processor. So while we might think two particles are millions of light years apart, they wouldn’t be if they were created in a simulation.
Assuming that the universe is indeed a simulation, what kind of experiments could we deploy from the simulation to prove this?
It is reasonable to assume that a simulated universe would contain many bits of information all around us. These information bits represent the code itself. Therefore, detecting these bits of information will prove the simulation hypothesis. The recently proposed mass-energy information (M/E/I) equivalence principle – which suggests that mass can be expressed as energy or information, or vice versa – states that bits of information should have a small mass. This gives us something to look for.
I have postulated that information is in fact a fifth form of matter in the universe. I even calculated the expected information content per elementary particle. These studies led to the publication in 2022 of an experimental protocol to test these predictions. The experiment involves erasing the information in elementary particles by causing them and their antiparticles (all particles have “anti” versions of themselves that are identical but have opposite charges) to be destroyed in a flash of energy – with “photons” or light particles are emitted.
I predicted the exact range of expected frequencies of the resulting photons based on information physics. The experiment is very feasible with our existing tools and we have launched a crowdfunding site to achieve this.
There are also other approaches. The late physicist John Barrow has argued that a simulation would produce small computational errors that the programmer would have to solve to keep it running. He suggested that we might experience such a fixation as contradictory experimental results appearing suddenly, like the constants of nature changing. So monitoring the values of these constants is another option.
The nature of our reality is one of the greatest mysteries there is. The more seriously we take the simulation hypothesis, the more likely we are to prove or disprove it one day.
Melvin M. Vopson is an associate professor of physics at the University of Portsmouth. This article is republished from The Conversation under a Creative Commons license. Read the original article.