[Kim Dae-sik Column] Is Reality an Infinitely Replicated Simulation?

③ Ultimately, the identity of 'Na' is the most important

The movie "The Matrix," first released in 1999, is a classic in the film industry that has maintained its popularity for nearly 25 years. The core appeal of The Matrix likely lies in its - at least at the time - shocking premise: the hypothesis that the world we live in is not real, but a simulation created by a superintelligent AI. The world we see, childhood memories, the voice of a loved one?none of it is real but merely an illusion generated by a computer! If my entire life is a simulation and all my choices are already predetermined by computer code, then what exactly is the existence called "me"?

Of course, the premise of The Matrix is just a simple imagination. However, there is a growing number of people, especially centered in Silicon Valley, who argue that we might already be living in a computer simulation. Elon Musk, in particular, has said that the probability of us living in the real reality is only one in billions. On what basis does he make such a claim? Professor Nick Bostrom of Oxford University argued in 2003 in his paper "Are You Living in a Computer Simulation?" that "There is always only one original, but copies and simulations can be infinite."

"Copies and simulations can be infinite"

Now, let's imagine this: early in the morning, you randomly find Leonardo da Vinci's "Mona Lisa" right in front of your house. The probability that this painting you found by chance, without any effort, is the one and only original Mona Lisa in the world is almost zero. The original is probably still hanging in the Louvre Museum in Paris, and the painting you found this morning is overwhelmingly likely to be a copy.

A similar logic can be applied to the reality we experience. We were born into this world without any effort. We did not choose the world, reality, parents, or environment we live in. We were simply born and opened our eyes to the reality we are experiencing now. Therefore, the probability that this reality, obtained by chance without any effort, is the one and only true reality in the universe is close to zero. Conversely, the probability that the reality we are experiencing now is one of infinitely many copies or simulations is overwhelmingly high.

So, whose simulation are we experiencing now? Humanity is already creating many simulations. In 100, 1,000, or 10,000 years, humanity will be able to create simulations so sophisticated that we cannot even imagine. They will be able to create simulations not only of physics, weather, and economics but also historical simulations of past humanity.

How did the Roman Empire dominate the world? The history of the Mongol Empire and the Crusades, and the development of semiconductor and AI technology in the 20th century. Especially the history of 21st-century ChatGPT and generative AI is likely a simulation created by future superintelligent AI machines originating not from our descendants but from 21st-century generative AI. It might be that these machines are simulating the 21st century, the core of machine history, to learn more about their origins.

The simulation hypothesis: impossible to prove or disprove

So, are we really living in a simulation? In fact, Professor Bostrom's hypothesis is a philosophical claim rather than a scientific theory. Scientific hypotheses must always be provable or disprovable through experiments and experience. However, the simulation hypothesis is neither provable nor disprovable. Any experiment or proof we conduct would itself be a simulation result attempting to prove the simulation.

German writer Bertolt Brecht once said that rather than the existence of God, how our lives change depending on God's existence is more important. Similarly, whether or not we live in a simulation is less important than how our attitude toward life and existence changes if reality is a simulation.

And in such a simulation, the identity of the "self" is most important. Am I ultimately an NPC (Non-Player Character) in the simulated world, just an artificial character within the simulation? Or am I the protagonist and player running this simulation? And if I am the player, am I a human from tens of thousands of years in the future? Or am I a superintelligent AI simulating the life of a human from tens of thousands of years ago?

Professor Daesik Kim, Department of Electrical Engineering, KAIST