Nick Bostrom's self-sampling assumption treats us as a random sample from a set of observers, but this framework raises several paradoxes. Instead, why not treat the stuff we observe to be a random sample from the set of all stuff that exists? I elaborate on this proposal in a new essay subsection: "SSA on physics rather than observers?" At first glance, it seems to work better than any of the mainstream schools of anthropics. Comments are welcome.
Has this idea been suggested before? I noticed that Robin Hanson proffered something similar way back in 1998 (four years before Bostrom's Anthropic Bias). I'm surprised Hanson's proposal hasn't received more attention in the academic literature.
Yes, that's right. Note that SIA also favors sim hypotheses, but it does so less strongly because it doesn't care whether the sims are of Earth-like humans or of weirder creatures.
Here's a note I wrote to myself yesterday:
Like SIA, my PSA anthropics favors the sim arg in a stronger way than normal anthropics.
The sim arg works regardless of one's anthropic theory because it requires only a principle of indifference over indistinguishable experiences. But it's a trilemma, so it might be that humans go extinct or post-humans don't run early-seeming sims.
Given the existence of aliens and other universes, the ordinary sim arg pushes more strongly for us being a sim because even if humans go extinct or don't run sims, whichever civilization out there runs lots of sims should have lots of sims of minds like ours, so we should be in their sims.
PSA doesn't even need aliens. It directly penalizes hypotheses that predict fewer copies of us in a given region of spacetime. Say we're deciding between
and
H1 would have a billion-fold bigger probability penalty than H2. Even if H2 started out being millions of times less probable than H1, it would end up being hundreds of times more probable.
Also note that even if we're not in a sim, then PSA, like SIA, yields Katja's doomsday argument based on the Great Filter.
Either way it looks very unlikely there will be a far future, ignoring model uncertainty and unknown unknowns.
Upvoted for acknowledging a counterintuitive consequence, and "biting the bullet".
One of the most striking things about anthropics is that (seemingly) whatever approach is taken, there are very weird conclusions. For example: Doomsday arguments, Simulation arguments, Boltzmann brains, or a priori certainties that the universe is infinite. Sometimes all at once.