I recently had a short (flash fiction) story published in Daily Science Fiction. This was my first professional publication (though I’ve self-published before). The story is available to read for free on their website. (Which you should do before continuing to read this.)

“The Simulation Test” is an experimental story, written in the form of a series of yes/no questions, and if you couldn’t tell by the title, it’s about the simulation theory—the idea that our entire universe could be a computer simulation.

First off, the simulation theory isn’t really a “theory” in the scientific sense of the word because theories (like gravity, evolution, and relativity) require evidence. There is no evidence for the simulation theory, so technically it’s just a hypothesis. (Though personally, I think “simulation theory” has a better ring to it, and most people don’t use the term “theory” in the true scientific sense.)

The idea that reality could be an illusion goes back a long time, at least thousands of years to the ancient Greeks. In Plato’s Republic (380 BC), he wrote about his famous “Allegory of the Cave,” where prisoners were locked inside a cave for their entire lives, forced to stare only at shadows on the wall while a fire burned behind them with people walking by. To them, those shadows were the full extent of reality. Then, when one prisoner was freed, he saw the shadows were not real—just an illusion caused by the fire. He left the cave and saw the real world outside in all its color and three-dimensionality. He and his fellow prisoners had no idea what they were missing all those years while locked in the cave. What they thought was the full extent of reality was merely a fabricated snippet of reality.

The story was just an allegory, but the lesson is that our reality could be like Plato’s cave. Things may not be as they seem. We could be in a simulation or a video game or a dream or a hologram or a Boltzmann brain or something else beyond our comprehension. The real world could be something far different than the world we currently perceive. And we would never know it—unless someone frees us from our “cave.”

The “reality is an illusion” idea gained new popularity after the invention of computers and video games, when, for the first time, people envisioned how such a simulation of reality could be constructed. Then in 1999, the computer simulation theory entered mainstream pop-culture with the release of the movie, The Matrix, and its sequels. I loved The Matrix (the original at least) but I never took the simulation theory seriously back then. It seemed like nothing more than pure science fiction—that humanity could unknowingly be trapped in a computer program created by (SPOILER ALERT) AI and machines in the future using human brains as batteries. The ultimate reveal seemed too far-fetched to believe.

It wasn’t until hearing the “Simulation Argument” proposed in 2003 by Oxford philosopher (and legitimate genius) Nick Bostrom, that I seriously considered the simulation theory as a real possibility. His argument was later popularized by Elon Musk, which is how I first encountered it. Basically, Bostrom’s hypothesis goes like this: If you look at our current technology, specifically video games and virtual reality, and how over time they get more and more realistic, and you project that technological trend into the future, eventually (be it decades, centuries, or millennia from now) humans (or AI) will be able to create virtual realities so realistic that they are completely indistinguishable from actual reality. They could conceivably simulate the entire universe, down to human consciousness itself.

The humans inside the simulation would not know they were in a simulation. They’d have no idea they were actually made of zeroes and ones—code in a computer program. They would think their universe was real (just like we do now). There may be no way for them to ever know, nor for us to ever know if we were in a computer simulation.

If a simulated universe like this is possible (which we’re not 100% sure it is, but there’s nothing yet proving it’s impossible), then there’s no limit to the number of simulations that could be created. There could be an infinite number of simulated universes, including “ancestor simulations,” or future humans recreating their ancestors from the past (us). Therefore, if you find yourself in a universe, the overwhelming odds are it will be one of the billions of simulations, rather than the one original universe.

Bostrom’s argument leaves three possibilities:

1. Future humans never get to such a point technologically that they are able to create ancestor simulations. (They go extinct from a natural disaster or destroy themselves before then.)
2. Future humans decide for whatever reason not to create ancestor simulations. (To me, this seems the least likely of the three.)
3. We are in an ancestor simulation created by future humans.

It’s a mind-blowing concept, and it sounds like science fiction, but if you really think about it, logically, the simulation argument makes complete sense. Technically there’s a fourth option: that ancestor simulations are possible, and we will be the first civilization to create them. But statistically speaking, the odds of that are so low (billions to one, at best) that it’s almost completely negligible. This doesn’t mean we are in a simulation—Bostrom gives roughly equal weight to all three possibilities—but it does mean that there’s about a 33% chance that we’re living in a simulation. (Frankly, I’d much prefer #3 to #1. It’s better to be in a simulated universe where humanity has thrived into the far future than be in a real universe where humanity is doomed to go extinct in the near future.)

Let’s say we are in a simulation. What are the implications?

Well… None, really.

Even if this is a simulation, you’d just go on living your life the same way as before. All the laws of physics remain the same. Everything we know about life and the universe still applies. We may or may not have free will, but at the very least we feel like we do and should continue to act as such. We’d have the same unanswered philosophical questions, such as does a God/creator exist, what is the purpose of the universe, and why is there something rather than nothing? Those questions would simply shift from the simulation to base reality.

Actually, those questions would be answered to a certain degree. In a simulated reality, “God” would be the computer programmers, and they would conceivably have an answer for why they decided to create a simulation of the past (AKA the purpose of the universe). However, those questions would remain unanswered in base reality. Who (if anyone) created the original universe and why?

In my story, I combined the simulation theory with the idea of the singularity, when humans can upload their minds to a computer, make a digital copy of their consciousness, and potentially live forever. If you believe Ray Kurzweil, this technology could be possible as soon as 2045 (within my expected lifetime). And if the technology is ever available to me, I would, without a doubt, upload.

A thought I then had was, if I upload my mind, perhaps all my memories could be extracted—everything I heard and saw throughout my life, even things my conscious brain forgot. Then, I could replay those memories—relive my entire life like a movie. Meaning this life I’m living right now could be a simulation of me (in the post-singularity future) replaying my life from the past (before I uploaded). In this sense, it wouldn’t be a simulation of the entire universe, but a simulation of my conscious experience of the universe. And of course, if this is possible, you could then share your memories with others and experience living simulations of their lives—and they, yours.

Therefore, the true nature of our reality might be that some random person millions of years in the future is doing a simulation of another random person from millions of years in the past: me (or you). Simulations like this could be their form of entertainment (like movies/reality TV/VR video games) or education (an incredibly detailed interactive history lesson). Again, it all sounds like science fiction (and it probably is), but in the future it could become science fact.

Are we actually in a simulation? I don’t know. No one knows, and we may never know. Scientists currently have no way of testing the simulation hypothesis, which is why it remains a hypothesis and not a theory. The simulation argument may remain nothing more than an interesting philosophical thought experiment and fodder for science fiction stories. (I’ve written several other pieces about this topic that I hope to publish in the future.) Bottom line, it doesn’t matter whether or not our universe is a simulation because if the simulation is completely indistinguishable from reality, then essentially it is reality.