Once, my little son asked me why people fear the dark. I told him that our brains constantly dream, even when we’re awake. When awake, this dream is in sync with the outside world we perceive (what we see, hear, etc.). When it’s dark, visual stimuli disappear, and our brains start filling the void.
And why does it fill it with scary things? Perhaps there’s an evolutionary reason for this. If we assume there are frightening things in the dark, we become more cautious. Better safe than sorry.
When I explained this to my son, I didn’t know that it was an existing theory with a name: the Free Energy Principle.
According to the Free Energy Principle, our brain is fundamentally a prediction machine. Its most important function is to anticipate the future. The evolutionary reason for this is quite obvious: if you can predict a predator’s attack, you can escape in time; if you can’t, you die.
Artem Kirsanov made an excellent video about the Free Energy Principle. For anyone interested in delving deeper into the topic, it’s highly recommended to watch it:
According to the theory, every human brain contains an abstract model of reality (a world model) that it uses to make predictions. The brain continuously fine-tunes these predictions based on incoming stimuli from the environment, and this is how our perception of reality is constructed.
Artem illustrates this with an example involving a tiger in his video. If we see yellow and black stripes in the distance, our brain can generate several predictions. It could be a person wearing a tiger-striped shirt, a toy tiger lost by a child, or even a real tiger. The brain, therefore, has multiple theories about how to interpret the sensory input. This “uncertainty” is referred to in the theory as free energy, and the brain’s goal is to minimize this free energy—essentially reducing the chance of being surprised as much as possible.
As more information comes in from the environment, the number of possible theories decreases. For example, if we see the tiger pattern moving, the toy tiger theory can be ruled out, leaving us with either a person or a real tiger. If we’re in a park, it’s most likely a person walking through the bushes. If we’re on a safari, however, it’s far more likely to be a real tiger.
According to the Free Energy Principle, perceiving reality is not a passive process. The reality we experience is something we project rather than merely perceive. The perceived reality largely originates from within, while sensory input from the environment serves to fine-tune this internal concept.
There’s an idea that has been on my mind for a long time: what would happen if we removed sensory input from the process and connected brains directly to each other?
Imagine four people lying in isolation tanks, completely shutting out all external stimuli. Their brains are connected via advanced BCI (Brain-Computer Interface) systems. It’s far from certain that this could ever be achieved, and it’s obviously not trivial from a technological standpoint, but let’s entertain the thought experiment.
At the moment of connection, without any external stimuli, the state would likely be quite chaotic (with a very high level of free energy). However, since each brain would be working to reduce this free energy, an equilibrium state would eventually be reached, and the four brains would synchronize. What would it feel like to experience this equilibrium state?
We have experienced what it’s like when our brain generates “reality” without sensory input based on its world model. This happens when we dream. But what would it be like if four people were to dream the same dream simultaneously?
Since four brains would be working simultaneously to minimize surprises (reduce free energy), this shared dream would likely feel much more real than traditional dreams—perhaps so real that it would be entirely indistinguishable from external reality.
When we think about fully immersive virtual reality, we often assume it will require immense computational power, as simulating the physical world is an incredibly complex task. However, it’s quite possible that simply connecting people’s brains directly could be enough—the brain might handle the rest on its own.
To create the true metaverse, we don’t need supercomputers capable of perfectly simulating the physical world—what we need are wires connecting brains.
How human brains could be “wired together” is, of course, a very difficult question to answer. The most likely candidate for this would be some form of BCI (Brain-Computer Interface), such as Neuralink, where electrodes detect neural activity and stimulate neurons. Other possibilities include magnetic field-activated nanoparticles or light (I wrote an entire article on this topic a few years ago), but something entirely unconventional could also emerge—for instance, direct biological connections using specialized fungi.
Imagine if people spent the majority of their lives in fully immersive VR—it could drastically reduce humanity’s consumption and environmental impact. In a world where resource usage is minimized and existing resources are optimally distributed, there would be no scarcity, no inequality, wars would lose their purpose, and there would be no need to exploit nature.
For those interested in exploring this topic further, you can read a full article about it here:
The question arises: if the fake reality created by connecting brains is completely indistinguishable from “real reality”, isn’t it possible that we’re already living in such a fake reality? Yes, yes—this brings us to the good old Simulation Hypothesis.
Several studies have explored how we might prove if we are indeed living in a simulation. Without exception, these theories focus on identifying the limits of the computer running the simulation. They propose experiments designed to push the simulating computer into calculations it cannot perform.
But what if there is no computer? What if the simulation runs directly on our brains? In such a case, it would be impossible to prove we are living in a simulation because no matter what experiment we conduct, we would always receive results that align with our expectations and confirm that our world is not a simulation.
But if we are indeed living in a simulation, who created it? This is another common question related to the Simulation Hypothesis. However, there’s a very simple answer to this: perhaps we have always existed in this interconnected state, as a single mind, and the real illusion is that we are separate individuals.
This idea is the focus of my recent article on the Thinking Universe. For those interested in exploring the topic further, I delve into this concept in detail there.
The Free Energy Principle is a fascinating theory from the perspectives of neuroscience and artificial intelligence. However, the most exciting aspect is that it allows us to understand our brain’s functioning deeply enough to potentially “hack” it. Such a technology would surpass all others, as it wouldn’t just solve problems—it would enable us to create entirely new realities for ourselves where those problems don’t even exist!
