New Delhi: Is the whole universe just a simulation? Zeb Rocklin, a professor of physics at Georgia Tech university has tackled this subject in The Converation, as part of a series aimed at Curious Kids. Here is my take on a subject that has captivated me since The Matrix, and is a great launchpad to explore some mind-blowing theories. This question forces us to consider the extent to which reality is a subjective experience, if some kind of divine mind sustains the material world, the extent to which external forces can fabricate our experiences, as well as the difference between things as they truly are and how we perceive them.
The advent of quantum mechanics showed us that the observer played a critical role in shaping reality, where measurement collapses wave functions, suggesting reality emerges from information processing. This was the crucial revelation of the Copenhagen Interpretation, championed by Neils Bohr and Werner Heisenberg. Building on insights derived from black hole thermodynamics by Gerard ‘t Hooft, Leonard Susskind suggested in the 1990s that the information of the universe is encoded in a lower-dimensional boundary, similar to a hologram, implying that our 3D experience could be a projection from a 2D computational substrate, and suggesting that information was the foundation of reality.
A posthuman civilisation running ancestral simulations
The modern simulation hypothesis was crystallised in the seminal paper by Nick Bostrom in 2003, titled Are you Living in a Computer Simulation? Bostrom argues that if advanced civilisations exist and run numerous ancestor simulations of their evolutionary history, then most conscious beings would be simulated rather than existing in reality. There are three scenarios in tension with one another, called a trilemma, civilisations go extinct before becoming posthuman, posthumans rarely run simulations, or we are all almost certainly simulated. With the metaverse, cloud computing, neural implants and AI gravitating towards some kind of convergence into a hivemind, humanity certainly seems to be headed in this direction. What would a hivemind do?
The idea draws from Hans P Moravec’s book, Robot: Mere Machine to Transcendent Mind that speculates on uploading minds and consciousness that is untethered to a substrate, assuming that mental states can run on non-biological hardware. One of the biggest challenges to the simulation hypothesis is the sheer amount of energy that would be required. Essentially the granularity and detail of the simulation would be more expensive than the real thing. It is just more economical to make a universe than simulate it. This has been demonstrated for even a low-resolution simulation of the Earth by the astrophysicist Franco Vazz.
Recent Advances
Scientists have argued that if we were in fact living in a simulation, then anomalies such as glitches or pixelation should be detectable. Researchers have also explored ‘business models‘ that would make such expensive simulations viable, and found that entertainment or research can fit the bill, but have determined that infinite nesting (simulations running inside simulations) as computationally infeasible. However, this last notion has been challenged by research that challenges the belief that deeper levels of simulations must be necessarily computationally weaker than the ones above them, allowing for infinite chains of simulated universes. Researchers have also warned that reckless research into creating simulations could actually end up terminating our reality!