If you’re interested in virtual reality, you’ve probably thought at least once or twice about the simulation hypothesis – the idea that we might be living in a virtual reality world. Many people are familiar with the idea, especially thanks to movies like The matrix, and has been a topic among philosophers — in one way or another — perhaps for more than a millennium. But did you know that scientists thought it might be possible to verify experimentally if we live in a simulation?
The simulation hypothesis was reduced to a useful thought experiment by Oxford University philosopher Nick Bostrom in a 2003 paper entitled Do you live in a computer simulation?? which was published in the peer review Philosophical Quarterly magazine.
In the paper, Bostrom explores the idea that, given existing trends in computing power, a future “posthuman civilization” will likely exert immense computing power, enough to be able to run simulations of billions of universes like the ours. The question arises: if we believe that humanity will one day be able to simulate billions of universes … isn’t it likely that we already live in one of these billions of simulations instead of being real ourselves?
It’s an intriguing formulation of the simulation hypothesis that frankly is quite difficult to argue. Bostrom’s paper has provoked serious discussions on the subject; has been cited for more than 1,000 other academic papers since its publication.
Beyond philosophers, scientists have also taken the simulation hypothesis seriously, especially in the mysterious realm of quantum physics. Several articles have hypotheses about ways to test whether our reality is a simulation.
Pushing the limit
In the 2012 document Restrictions on the universe as a numerical simulation, published in peer review European Physical Journal A, physicists Silas R. Beane, Zohreh Davoudi and Martin J. Savage write that the latest developments in the simulation of quantum interactions point to a future where a full-fledged simulation of the universe is possible, suggesting that “ experimental searches for evidence in our universe are, in fact, a simulation that is both interesting and logical ”.
According to the authors, quantum computing seems like a reasonable basis for simulating an entire universe. But, like any program, a simulated universe will have some fundamental limitations of accuracy. If our reality is based on a quantum computer simulation, according to the authors, we should be able to predict some of these fundamental limitations and then look for them in nature.
Specifically, the authors say they study “the possibility that simulations […] employ an underlying cubic lattice structure “, which is fundamentally similar to the small-scale quantum computing-based simulations that humanity is capable of performing today. If we could observe limitations in our reality that are consistent with an underlying lattice structure for in space-time, rather than a continuous space-time, the authors say it could be evidence that our universe is really a simulation.
The authors leave us with a tempting conclusion: that it may be impossible for a simulation to be completely hidden from its subjects.
“[…] assuming that the universe is finite and therefore the resources of potential simulators are finite, then a volume containing a simulation will be finite and a lattice spacing must be nonzero and therefore in principle there is always the possibility for the simulator to discover the simulators “.
Observed Given up
In the 2017 document When testing the theory of simulation, published in peer review International Journal of Quantum Foundations, authors Tom Campbell, Houman Owhadi, Joe Sauvageau, and David Watkinson begin with a similar premise to the previous conclusion: that a simulated universe probably operates with finite resources. If this is the case, they argue, we should look for evidence that the behavior of our universe is consistent with a simulation optimized for computer performance.
The paper presents a concept that will be familiar to game developers: as a matter of optimizing to run a game with finite computing power, games only represent what the player can see at any given time. Anything else would be a waste that would drastically slow down the game.
The authors point out that physicists are already aware of a feature of the universe that seems suspiciously similar to representing a game only where the player is watching. This would be the so-called collapse of the wave function, in which the fundamental particles seem to act as wave functions to the point where they are observed, at which point their wave characteristics “collide. they slip ”and become predictable particle interactions.
The paper sets out a number of specific variations of the puzzling Double-Cutting Experiment, designed to isolate the precise role of the observer in determining the experimental outcome. The ultimate goal of the experiments is to look for a situation in which the universe would change its behavior to avoid creating a paradox. If this were observed, the authors argue, it would be “an indicator of a VR engine [simulated universe] reacting to the intention of the experiment “.
In addition, the authors suggest that finding a conflict between the possible requirements of this simulation (logical consistency and avoiding detection) could reveal observations consistent with a simulated universe.
“Two strategies can be followed to test the simulation theory: (1) Test the rendering moment; (2) Exploit the conflicting requirement of preserving logical coherence and avoid detection to force the VR rendering engine to create discontinuities in its rendering or produce a measurable signature event within our reality that indicates that our reality has of being simulated, ”the authors write.