Of course, this whole discussion begs the question of what we mean when we distinguish a VR from a natural reality. If a simulation is perfect in every way, it is by definition indistinguishable from the thing it simulates. So there must be some difference between a natural reality and a virtual one, or else there’s nothing virtual about it. Maybe the VR is self-evidently low resolution. The ones we can build today certainly are! But that’s not the only possible difference.
The usual sort of difference that people are interested in is the existence of an entity that can look into the lives of players in the VR, a powerful player who is usually but not necessarily hidden. It’s similar to believing in a god. The rhetoric of VR thought experiments often plays up this angle. Some people imagine this creature as a pimply nerd in the sky who is running a cosmic copy of The Sims, who are us. Perhaps with that image in mind, one woman commented to me that she worried that this being might be able to see whether her underwear was clean on a given day.
A pimply video-game-playing kid is an especially unlikely “god” ruling over our reality.
Strangely enough, there are some recent empirical results that may influence whether we should believe in this underwear-obsessed dude. Before I describe them, though, I need to introduce the idea of a spectrum of possible gods, running from wimpy to omnipotent. All the supernatural beings of religion and science fiction fit somewhere on the spectrum.
The very wimpiest god can hypothetically see into our world but can’t do anything at all to interact with us in any way, in any world—including hypothetical afterlives. As far as we’re concerned, it’s meaningless to think of this god as one who exists. The second-wimpiest god might be able to perform just a trick or two that seem supernatural to us, but underwear spying is just one trick of many, and therefore unlikely.
Paradoxically, pseudostatistical reasoning suggests that the most omnipotent god won’t notice your underwear, either. Such a god can see and manipulate all possible versions of you and your world (including your wearing clean, filthy, or no underwear at all). If there is something special enough about your underwear to merit notice, there’s another version of you in another reality wearing even more special underwear. The Top God is infinitely less likely to focus on the particular pair of underwear you are wearing today than you are likely to focus on a particular grain of sand on a beach. He is just as moot as the weakest god.
So as far as underwear spying goes, it’s only those gods in the middle of the spectrum who should concern us. A god who spies would do so, presumably, only if he (or she for that matter) experiences surprise at the unveiling of the future and is able to see into only a narrow range of realities. The Greek gods were like this.
The empirical results that influence how we might think about God-as-video-game-player are the successful demonstrations of quantum cryptography, in which a sender and receiver can be assured that no natural observer has eavesdropped on a message. This system works because a component of the message is ruined by quantum effects as soon as it is read. For a god to eavesdrop on a quantum cryptography session and then cover his tracks, would, as it happens, require near omnipotence. When the first quantum cryptography experiments were done, I felt a little relieved and sad at the same time, because we then knew that one kind of potential exotic or supernatural form of life that might have been watching us either did not exist or wasn’t paying attention.
Continuing the pseudostatistical arguments, a god that can exist only within a narrow portion of the spectrum of possible gods is less likely than a god that can exist over a larger portion of the spectrum. The game-playing kid feels the squeeze from both ends. He has to be both weak enough to be able to focus on a particular pair of underwear and strong enough to be able to cover his tracks after eavesdropping on a quantum cryptography session—or else be willing not to peek at any messages we decide to keep secret.
That probably—no guarantees—places him within a razor-thin niche on a wide spectrum of possible gods. So I can’t swear that we’re not living in a simulation, but I can offer some assurance: A pimply virtual reality operator is an especially unlikely god.
