The strangest thing to ever happen to me took place in Tomsk, a Russian Siberian city. A week into my stay there, I bought a neon orange toothbrush to replace an old toothbrush. Some two weeks later I went to the bathroom to brush my teeth but the toothbrush was gone. It completely disappeared.

Looking for this neon orange toothbrush was the only time in my life that I felt insane. I scoured the bathroom on my hands and knees before extending the search to the entire apartment, even looking in trash cans, drawers, and cabinets. I figured that its disappearance was due to one of the following two reasons:

1. I sleptwalk and threw the toothbrush out the window. This is unlikely since I have no history of sleepwalking and sleep extremely light (so light that the sound of my own snoring wakes me up).

2. The landlord came during the early morning to dispose of the toothbrush, just to fuck with me. The problem with that scenario is that the front door was loud with a dungeon master lock. If I didn’t awaken to its opening, I would have when it was closed and locked again.

I stayed in the apartment for a week and the neon orange toothbrush never appeared again. At that time I didn’t consider a third explanation of its disappearance: there was a glitch—a bug—in the computer simulation we’re living in.

A paper by Oxford philosophy professor Nick Bostrom makes a case for the computer simulation argument. His paper, which I recommend reading, states that one of the following three scenarios must be true:

1. We will go extinct or somehow destroy ourselves before developing the technology or computational power to create simulations with conscious subjects (i.e. become “posthuman”).

2. A posthuman civilization that can create a simulation with consciousness will elect not to, perhaps for ethical reasons.

3. We are currently living in a computer simulation, one that has sufficient detail without major bugs that convince us our reality is not an artificial construct.

The first time I heard of simulation theory, I reviewed it just for curiosity’s sake, to see how convincing the argument was for us to be living in a sort of Matrix but without the physical pod component. While I’m not fully convinced, the logic presented is sound and I’m open to the small possibility that we’re part of a SimUniverse where the big bang was a start button pushed by an advanced species who wanted to learn more about their own creation, or perhaps who just wanted to be entertained. The fact that scientists today are eagerly hoping to simulate consciousness on computers suggest that the idea must be irresistible to advanced species.

My initial objection to believing a simulation is possible is the detail our reality provides. There’s no way I can be “fooled” of existence, but nearly every single night I’m fooled by a simulation called dreams, which not only lack rich detail, but are still believed by my mind in spite of having colossal bugs well known to lucid dreamers:

You can’t see your hands

Light switches don’t work

Clock faces never display

Is it possible that dreams are a simulation of a simulation, and that everything around us is digital data stored on quantum computers so powerful that it would take an entire planet to house them based on current technology?

If the environment is included in the simulation, this will require additional computing power – how much depends on the scope and granularity of the simulation. Simulating the entire universe down to the quantum level is obviously infeasible, unless radically new physics is discovered. But in order to get a realistic simulation of human experience, much less is needed – only whatever is required to ensure that the simulated humans, interacting in normal human ways with their simulated environment, don’t notice any irregularities.

There have been other theories that clash with the neatness of our current model of the world. One states that there are multiple universes operating concurrently, and another, my favorite, states that there has been a great many iterations of the universe, each with its own physical properties that determine its makeup and construction. Maybe we’re living in universe number 1,350,372—an advanced “species” of universe that evolved from previous ones like we evolved from previous animals—and when it inevitably collapses upon itself, another big bang will create a new universe with different conditions of physics, chemistry, and life.

How can we ever prove that we’re living in a simulation? The biggest indicator, based on probability formulas provided by Bostrom, is if we successfully create such a simulation ourselves. In that case, a posthuman scenario has most certainly occurred in the universe before, allowing there to be a far greater number of simulated organisms than real ones. If we create a posthuman simulation, Las Vegas odds would then heavily favor the fact that we are indeed living in one.

…we would have to suspect that the posthumans running our simulation are themselves simulated beings; and their creators, in turn, may also be simulated beings. Reality may thus contain many levels. Even if it is necessary for the hierarchy to bottom out at some stage – the metaphysical status of this claim is somewhat obscure – there may be room for a large number of levels of reality, and the number could be increasing over time. (One consideration that counts against the multi-level hypothesis is that the computational cost for the basement-level simulators would be very great. Simulating even a single posthuman civilization might be prohibitively expensive. If so, then we should expect our simulation to be terminated when we are about to become posthuman.)

One big part of our reality that can’t be explained is the double slit experiment, whereby the physics of our universe behaves differently just because we happen to be observing it. Watch the following clip if you are unfamiliar with this famous experiment, whose result has not changed after many replications:

This experiment is conclusive in proving that perception of objective reality can be dependent on the observer, meaning it changes simply because a set of eyes (mechanical sensors) are watching, without any other alteration to the environment. Can’t this mystery extend to life as a whole with people instead of electrons? Can things in our own reality change depending on if we’re looking or not? Are simulation programmers filling in information ad-hoc depending on how closely we are watching?

In my own life I noticed something consistently peculiar and frustrating—the attractiveness of women decline based on how carefully I’m looking for an attractive woman. If I decide on a day of dutiful work, I always see more attractive women than if I go out with the intent to meet women. Having a different mental goal changes what my eyes see and therefore what I get aroused by. While we can conclude that this difference in perception is due to my brain viewing reality differently based on the goal or intent it contains at the time, the double slit experiment offers up a potentially different explanation.

…a posthuman simulator would have enough computing power to keep track of the detailed belief-states in all human brains at all times. Therefore, when it saw that a human was about to make an observation of the microscopic world, it could fill in sufficient detail in the simulation in the appropriate domain on an as-needed basis. Should any error occur, the director could easily edit the states of any brains that have become aware of an anomaly before it spoils the simulation. Alternatively, the director could skip back a few seconds and rerun the simulation in a way that avoids the problem.

And so we may be coming full circle, from believing in a single creator, God, then killing him off in place of evolution and natural selection, a process that prefers ever increasing levels of complexity and intelligence even though robust gene replication can occur on a basic cellular level like in bacteria, and now back (for some) to believing in a creator, not of one God but a species whose intelligence we would be unable to grasp with our feeble minds.

While the simulation argument has no bearing on my day-to-day life and what I’m feeling in the present moment, it has made me wonder more about what we’re doing here. If there is no reason, as I suspect, then we’ll just have to find a reason ourselves by living in a purposeful way, but until then I would really like to know what happened to my neon orange toothbrush.

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