if we avoid running ancestor simulations for the purpose of maximizing the probability that we are not in a simulation, is it valid to, based on this fact, increase our credence in not being in a simulation?
Unless you round sufficiently small increases down to zero, which is what people generally do. If somebody asked me that, and I estimated that the difference in probability was .00000000001, then I would answer “no”.
That is granted. However, I’m also fairly sure (p=.75) that the probability isn’t that small, because by deciding not to simulate a civilization yourself, you have greatly decreased the probability of being in an infinite descending chain. There remains singleton chance simulations and dynamic equilibria of nested simulations, but those are both intuitively less dense in clones of your universe—so you’ve ruled out a significant fraction of possible simulation-worlds by deciding not to simulate yourself yourself.
you have greatly decreased the probability of being in an infinite descending chain.
No matter what there aren’t going to be any infinitely descending chains unless our understanding of the laws of physics is drastically wrong. You can’t simulate n+1 bits with n qubits. So, even if you assume a quantum simulation for a purely classical setting, you still have strict limits.
There remains singleton chance simulations and dynamic equilibria of nested simulations, but those are both intuitively less dense in clones of your universe
Imagine that some Clarktech version of ourselves dedicates an entire galaxy to simulating the Milky Way. Would we have noticed by now?
Neither does the simulation need to be perfect: it only needs to be perfect wherever we actually look. This makes for a much more complex program, but might save on computing costs.
Anyway, yeah, you probably won’t get an infinite chain, but you’ll get a very long one, which leads to my second point:
A “singleton chance simulation” just means that someone randomly decided to simulate our universe in particular. This is rather unlikely.
A “dynamic equilibria of nested simulation” just means that Universe A simulates Universe B simulates Universe C which simulates Universe A, creating a descending chain that is not as dense as an immediate recursion, A->A->A.
Both these cases will contribute less possible universes than a (near-)infinite descending chain, so by eliminating the descending chain you’ve greatly decreased the probability of being in a simulation.
That’s not the question.
That’s the question, and the answer is “yes.”
Unless you round sufficiently small increases down to zero, which is what people generally do. If somebody asked me that, and I estimated that the difference in probability was .00000000001, then I would answer “no”.
That is granted. However, I’m also fairly sure (p=.75) that the probability isn’t that small, because by deciding not to simulate a civilization yourself, you have greatly decreased the probability of being in an infinite descending chain. There remains singleton chance simulations and dynamic equilibria of nested simulations, but those are both intuitively less dense in clones of your universe—so you’ve ruled out a significant fraction of possible simulation-worlds by deciding not to simulate yourself yourself.
No matter what there aren’t going to be any infinitely descending chains unless our understanding of the laws of physics is drastically wrong. You can’t simulate n+1 bits with n qubits. So, even if you assume a quantum simulation for a purely classical setting, you still have strict limits.
I’m not sure what you mean here. Can you expand?
Imagine that some Clarktech version of ourselves dedicates an entire galaxy to simulating the Milky Way. Would we have noticed by now?
Neither does the simulation need to be perfect: it only needs to be perfect wherever we actually look. This makes for a much more complex program, but might save on computing costs.
Anyway, yeah, you probably won’t get an infinite chain, but you’ll get a very long one, which leads to my second point:
A “singleton chance simulation” just means that someone randomly decided to simulate our universe in particular. This is rather unlikely.
A “dynamic equilibria of nested simulation” just means that Universe A simulates Universe B simulates Universe C which simulates Universe A, creating a descending chain that is not as dense as an immediate recursion, A->A->A.
Both these cases will contribute less possible universes than a (near-)infinite descending chain, so by eliminating the descending chain you’ve greatly decreased the probability of being in a simulation.