A little while ago, I put out the welcome mat to ask me anything and be guaranteed an answer. And you responded. What’s more, your questions were so intense, so thought-provoking, that I decided that cramming all the answers into one forty-minute post would be a crime (or at least a misdemeanor).
With questions this good, each one deserves its own post in answer. So all this week, I’ll be answering questions.
Here’s the first, from my good friend Ben Trube:
Okay Brian, I know you’re the right person to ask this question:
“Are we living in a computer simulation?”
Some potential source material and my inspiration for the question: NPR article
This is a great question, and as the article points out, people have been asking it long before The Matrix came out – indeed, long before computers were even invented. The puzzle of whether reality is “real” has kept philosophers busy for about as long philosophy has existed.
And the answer is simple: it’s utterly impossible to know. We can’t even speak meaningfully about how likely it is that we’re in a computer simulation.
Here’s why.
There are certain properties we would expect a computer simulation to have: finite computing resources, logic errors, and so on. Conceivably, you might design experiments that could test for these properties. So why do I say it’s impossible to know?
Simple. Because all of our ideas about how computers work are based on computers in this reality, which – if we’re a simulation – might be nothing like how computers operate in the “real” reality.
Our parent reality might have totally different laws of physics. It might even have different laws of logic. Two and two might not equal four. Since our entire lives have passed inside this reality, we have to concede that we have absolutely no basis for even speculating about any other reality.
So if our experiments didn’t find evidence of a computer simulation, that could just mean that we have no idea what “real” computers are like. Conversely, if we did find evidence, it could just mean that our reality happens to have properties of what we think of as a computer simulation; it says nothing about whether our reality matches the properties of a “real” computer simulation, which is unimaginable to us.
The NPR article you referenced quotes philosopher Nick Bostrom as saying that we’re “almost certainly” living in a computer simulation. But he makes the same logical error I just described: all his reasoning presupposes a “real” reality with the same properties as our own. There’s just no basis for such an assumption.
Okay, so we have no idea whether we’re made of baryons or bytes. A follow-up question might be: does it matter? Occam’s Razor says that if a hypothesis makes no observable predictions (that is, if “real” reality and simulated reality are subjectively identical) then it’s not worth worrying about.
But that’s a pretty big if. It could be, as in The Matrix, that waking up from the simulation has profound implications. It’s a question worth asking.
And a question that’s impossible to answer – just as Neo can never know that Zion is the real world, and not just another Matrix.
What do you think? Am I right, or did I miss something? Let me know in the comments!
Tomorrow, I’ll answer Zeev’s question: “Where do you see the United States in 20 years?”
Brian D. Buckley 
I’ve seen this proposed as a thought experiment: Could Sherlock Holmes have deduced the existence of Arthur Conan Doyle? Probably not.
But, to take it further, if Holmes had been aware of the (possible) existence of Doyle, what could he have deduced about him? Probably that he was an Englishman, and possibly that he was a doctor. That would have been about it.
He would not have been able to deduce, for example, that Doyle was a devotee of the occult and seances and like that. Because, as you say, if we are in the matrix, there would be no way to figure out about the outer world without going there.
Reminds me of the Star Trek episode with Professor Moriarty leaving the holodeck, walking the decks of the Enterprise. Who knows what the world is like outside our personal holodecks? 🙂
My answer is much simpler than yours, and based on absolutely no philosophy whatsoever:
Of course not. If it was a computer simulation, I’d be able to skip the boring bits. And the plot would make sense.
Unless that’s just what the computer programmers WANT me to think…
If only computers really did skip the boring bits… 😉
I would add one additional thought to your reasoning, Brian.
As software engineers, we usually take the position that there is no perfect software (at least when part of a complex system). We might then try to extrapolate forward that because we can’t conceive of a perfect software architecture then if were in a simulation we would then expect to see flaws (as you mentioned). This logic is in itself flawed.
First, the supposition that we can’t create a perfect software (i.e. bug free) is simply wrong. It just very hard.
Second, the supposition that because the universe is boundless (debatable!) it would require infinite resources and energy to simulate is also flawed. While the bounds of the universe may be endless (I believe current theory is “ever expanding”), we’re fairly certain the Newton’s second law holds true, meaning there is a finite amount of mass an energy meaning a finite number of resources is needed to simulate it. We can also say that the simulation only need be accurate to what is observable from any and all vantage points (i.e. for each actor in the system – which for now, is only the Earth). While absurdly complex and certainly requiring more computational power than (likely) every computer on our planet combined, it is not outside the realm of possibility or even outside the conceivable ability of the human race.
If such a simulation is possible in our reality, then surly such a simulation is possible in other realities, regardless of the laws of physics (I like your point there by the way).
Sort answer, I completely agree with you, but I also think its possible we could do this to ourselves too.
“We can also say that the simulation only need be accurate to what is observable from any and all vantage points (i.e. for each actor in the system – which for now, is only the Earth).”
Agreed. Any such computer simulation doesn’t need to simulate the whole universe, if we can only observe a tiny piece of it. Good point.