Physicists have long struggled to explain why the universe began with conditions suitable for the development of life. Why do physical laws and constants take on very specific values that enable the development of stars, planets and ultimately life?
The expansive force of the universe, such as dark energy, is much weaker than theory predicts it should be—allowing matter to clump together rather than tear it apart.
A common answer is that we live in an infinite multiverse of universes, so we shouldn’t be surprised that at least one universe turns out to be ours. But another is that our universe is a computer simulation where someone (perhaps an advanced alien species) is fine-tuning the conditions.
The second possibility is supported by a field of science called information physics, which suggests that space-time and matter are not fundamental phenomena. Instead, physical reality is essentially made up of bits of information from which our experience of space-time arises.
By comparison, temperature “arises” from the collective motion of atoms. In principle, no atom has a temperature.
This leads to the extraordinary possibility that our entire universe may actually be a computer simulation.
The idea is not so new. In 1989, the legendary physicist John Archibald Wheeler proposed that the universe is fundamentally mathematical and can be thought of as emerging from information. He created the famous aphorism “it’s a piece of cake”.
In 2003, philosopher Nick Bostrom of the University of Oxford in Great Britain formulated his simulation hypothesis. This argues that it is indeed highly likely that we are living in a simulation.
This is because an advanced civilization should reach a point where their technology is so sophisticated that the simulations would be indistinguishable from reality and the participants would not be aware that they are in a simulation.
Physicist Seth Lloyd of the Massachusetts Institute of Technology in the US has taken the simulation hypothesis to the next level by suggesting that the entire universe could be a giant quantum computer.
There is some evidence to suggest that our physical reality might 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. This means that everything is eventually digitized or pixelated to a minimum size that cannot be further divided: bits.
It seems to mimic our reality according to the theory of quantum mechanics that governs the world of atoms and particles. It states that there is a the smallest independent unit energy, length and time.
Likewise, the elementary particles that make up all visible matter in the universe are the smallest units of matter. Simply put, our world is pixelated.
The physical laws that govern everything in the universe also resemble the lines of computer code that a simulation would follow when executing a program. In addition, mathematical equations, numbers and geometric patterns are present everywhere – the world seems to be completely mathematical.
Another curiosity in physics supporting the simulation hypothesis is the maximum speed limit in our universe, which is the speed of light. In virtual reality, this limit would correspond to the speed limit of the processor, or the limit of computing power.
We know that an overloaded CPU slows down computer processing in a simulation. Similarly, Albert Einstein’s theory of general relativity shows that time slows down near a black hole.
Perhaps the most supportive evidence for the simulation hypothesis comes from quantum mechanics. This suggests that nature is not “real”: particles in specified states, such as particular locations, do not seem to exist unless you actually observe or measure them. Instead, they are simultaneously in a mixture of different states. Similarly, virtual reality needs an observer or programmer to make things happen.
Quantum ‘entanglement’ also allows two particles to be eerily linked, so that if you manipulate one, you automatically and instantly manipulate the other, no matter how far apart they are – an effect seemingly faster than the speed of light, which would be impossible.
However, this could also be explained by the fact that, within the virtual reality code, all “places” (points) should be roughly the same distance from the 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 the universe is indeed a simulation, what kind of experiments could we deploy within the simulation to prove this?
It is reasonable to assume that a simulated universe would contain lots of bits of information all around us. These information bits represent the code itself. Thus, the detection of these information bits will confirm the simulation hypothesis.
The recently proposed mass-energy-information (M/E/I) equivalence principle—suggesting that mass can be expressed as energy or information or vice versa—states that bits of information must have little mass. That gives us something to look for.
I assumed that information was actually the 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 consists of erasing the information contained within elementary particles by causing them and their antiparticles (all particles have ‘anti’ versions of themselves that are identical but oppositely charged) to annihilate themselves in a flash of energy – emitting ‘photons’ or particles of light .
I predicted the exact range of expected frequencies of the resulting photons based on information physics. The experiment is highly achievable with our existing tools, and we’ve launched a crowdfunding page to make it happen.
There are other approaches. The late physicist John Barrow argued that the simulation would create tiny computational errors that the programmer would have to correct to maintain it.
He suggested that we might experience such fixation when contradictory experimental results suddenly appear, such as changes in the constants of nature. Another option is to monitor the values of these constants.
The nature of our reality is one of the greatest mysteries. The more we take the simulation hypothesis seriously, the greater the chance that we will one day prove or disprove it.
Melvin M. Vopson, Assistant Professor of Physics, University of Portsmouth.
This article is republished from The Conversation under a Creative Commons license. Read the original article.