Are we living in a simulation? This experiment could tell us

Thomas Anderson, aka Neo, walks up the stairs and sees a black cat shake itself and walk past the doorway. Then the moment seems to repeat itself before his eyes. “Just a little déjà vu,” he thinks. But no, his comrades insist: he lives inside a computer program and has just witnessed a glitch.

This scene from Matrixmovie released in 1999, but we were fascinated and disturbed by the possibility that we could live in a simulated reality for centuries. This idea cuts so deeply in part because it is so hard to refute: if we are immersed in a false world, how can we know?

Some physicists take this concept seriously. “The entire universe could work like a giant computer,” says Melvin Whopson at the University of Portsmouth, UK, who has long been interested in modeling hypothesis. He believes there are already important clues that this is correct, and even suggested how we could find out the truth through experimentation.

The idea of ​​living in a false reality dates back at least to the ancient Greek philosopher Plato. In his allegory of the cave, Plato imagined people locked in a cave so that they could only see the shadows of objects passing outside. Plato thought that the prisoners would have no desire to escape – they could not imagine anything outside the cave and did not know that they were trapped.

In 2003, the philosopher Nick Bostrom published an article in which he claims that thisWe're more likely to live in a simulation than not.. Argument with the support of Elon Musk, among others. However, it is worth knowing who is making such statements. “Most of this comes from the world of technology – it's in their interest to say that we can build something as rich as reality,” says the astrophysicist. Franco Vazza from the University of Bologna, Italy, who published a paper earlier this year suggesting that it almost impossible, we live in a simulation.

However, there are reasons to think about the modeling hypothesis. Let's take quantum mechanics itself, which states that particles are in superposition – a cloud of ill-defined possibilities – before we measure them. We have been struggling with how to interpret this for a century. But if the universe really is a simulation, it would make sense. In a computer game, objects are not rendered until the player encounters them. Perhaps the same thing happens with unobservable particles?

However, this is circumstantial evidence at best. “It sounds a little far-fetched,” Vazza says. But can we develop the right test?

Vopson enters. He starts with the assumption that if the universe is a simulation, then it is essentially made of information. This has certain consequences. Take the equivalence between mass and energy enshrined in Albert Einstein's equation. E = M.C.². In 2019, Wopson went even further, postulating that this equivalence applies to information. Based on this principle, he then calculated the expected information content per elementary particle. This is exactly the amount of information required to encode one particle in our simulated Universe.

But how do you know how much information a particle contains? In 2022 Vopson proposed an experiment To do this, you need to take a particle-antiparticle pair, such as an electron and a positron, and let them mutually annihilate. This is a well-established process that produces energy in the form of photons. Vopson suspects that this process should also erase the information contained in the two original particles, and this missing information will leave a trace. If such collisions produced exactly the frequency range he predicted, he thinks it would be proof that the universe is indeed made of bits of information.

Testing the modeling hypothesis

Wapson tried to crowdfund this experimentbut he has not yet managed to raise money. But that doesn't matter, because he has since developed a different way of criticizing the modeling hypothesis. It is based on the second law of thermodynamics, an iron law of physics that states that disorder, or entropy, always increases in a closed system. This explains why ice cubes melt and cups of tea get cold.

If the universe is just information on some alien hard drive, similar principles should apply to the information itself, says Wopson. So in 2022 he proposed what he calls second law of infodynamics. This means that the average amount of information a system can contain must remain constant or decrease, balancing the increase in physical entropy. “Information can never record itself, but it can delete itself,” says Wopson. “Over time, files on a memory card will deteriorate and some files may disappear. But a document, book, or image will never appear on its own on an empty memory card.”

Wopson argues that his law holds true in nature, at least to some extent, based on his studies of how information in viral genomes changes over time. But his key discovery came when he applied his new law to the entire universe. Here the law breaks down, because over time, the influence of gravity turned matter into information-carrying structures – stars, planets, galaxies and the cosmic web.

What does it mean? Vopson says that gravity must be the mechanism that prevents the information entropy of space from getting out of control. This, he believes, would be exactly what anyone simulating the universe would want—a way to ensure that the size of the program did not become too large. “Gravity is not a force, but a compression mechanism that reduces the entropy of information by clumping together matter,” he says.

“I appreciate using information theory to look at physics differently,” Vazza says. But ultimately he doesn't think Wopson's work supports the modeling hypothesis. In fact, he calculated that this would require impossible amount of energy actually simulate our universe.

However, we may have other ways to detect glitches in the Matrix. In 2007, the late cosmologist John Barrow suggested that any modeling will create minor computational errors that the programmer will have to correct. Will we notice such interference? Barrow suggested that one subtle sign might be nature's constant changes. And, interestingly, one of the most heated debates in physics today is about the evidence that the rate of expansion of the universe has decreased over the past 3 billion years. Suspicious? Maybe. But the timing is too long to be the result of glitches, says computer scientist Roman Yampolsky of the University of Louisville, Kentucky. “It has to be sudden,” he says.

If we live in a simulation, this inevitably raises the question of whether we will ever be able to escape. Yampolsky weighed our options. document 2023. One possibility, he suggests, is to create your own simulation and then ask the AI ​​to break out. Perhaps then we could copy the AI's strategy. Alternatively, we could try to attract attention outside the program – perhaps by talking a lot about the simulation. “The best option is always to help us escape, when someone outside gives us information,” he says.

Then again, whoever is running the simulation might not want us to escape. We may not even be able to survive outside of our computerized cosmos. All this is enough to make us wonder: if we are living in a simulation, would we really want to know?

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