This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor‐simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.
Interestingly, (3) is not “we are almost certainly living in an ancestor simulation, specifically”. I don’t know if that’s because Bostrom just chose not to write it that way or if he had a particular non-ancestor simulation in mind. Regardless, though, I think he was right not to say “ancestor simulation” in 3, because there’s another major type of simulation we could be in.
Imagine that you want to obtain a very efficient classical simulation of a quantum computer with many logical qbits. Imagine further that you have reserved a 1 hour timeslot on a cluster that can do 10^40 floating point operations per hour. You could just plug in the best known algorithms of today, but those scale poorly.
Maybe you can instead simulate a civilization which just happens to produce a lot of classical simulations of quantum phenomena. Or, maybe not just one. Maybe you run a beam search over a thousand simulated civilizations in parallel, prune the branches that try to do experiments that are too expensive for you to simulate, prune the branches that don’t seem to be making algorithmic advances, and fork the branches which produce the most promising advancements.
The people inside of your simulation would be correct to conclude that they’re probably living inside of a simulation, but incorrect if they assumed that that simulation was run by their descendants to determine how they would behave, or indeed that the simulation was in any meaningful sense “about” them at all.
[epistemic status: crackpottery]
The abstract of Bostrom’s Are You Living in a Computer Simulation reads
Interestingly, (3) is not “we are almost certainly living in an ancestor simulation, specifically”. I don’t know if that’s because Bostrom just chose not to write it that way or if he had a particular non-ancestor simulation in mind. Regardless, though, I think he was right not to say “ancestor simulation” in 3, because there’s another major type of simulation we could be in.
Imagine that you want to obtain a very efficient classical simulation of a quantum computer with many logical qbits. Imagine further that you have reserved a 1 hour timeslot on a cluster that can do 10^40 floating point operations per hour. You could just plug in the best known algorithms of today, but those scale poorly.
Maybe you can instead simulate a civilization which just happens to produce a lot of classical simulations of quantum phenomena. Or, maybe not just one. Maybe you run a beam search over a thousand simulated civilizations in parallel, prune the branches that try to do experiments that are too expensive for you to simulate, prune the branches that don’t seem to be making algorithmic advances, and fork the branches which produce the most promising advancements.
The people inside of your simulation would be correct to conclude that they’re probably living inside of a simulation, but incorrect if they assumed that that simulation was run by their descendants to determine how they would behave, or indeed that the simulation was in any meaningful sense “about” them at all.