An ancestor simulation is a simulation run by a Dreamtime or post-Dreamtime civilization of their ancestors or progenitors. Motivations for running ancestor simulations may include research, entertainment, intentional anthropic capture (which may be friendly, unfriendly, or other), or because it's easier than other kinds of simulations; in any case, the plausibility of ancestor simulations in the future is a known vector for anthropic capture. Ancestor sims of the behavioral/inferential variety are already possible with LLMs and have been run.
examples in fiction
The ancestor vir of the Gourd, where the hsien-kus of Sobornost make history. It is a giant puzzle, fragments of the past glued together with simulation. The hsien-kus observe and measure, search the memories of gogols bought from the soul merchants of Sirr, or stolen from the Oubliette β and run ensembles of simulations to find histories that match the observations. Averages over possible event sequences instantiated, culled and tweaked until they conform with what the hsien-kus think history should be.
The interface is overwhelming at first. I am a bodiless ghost in a four-dimensional world. A god-view and a new sense that allows me to step backwards and forwards in time. I hate the incorporeal aspect of it β I need to touch things β but there is no embodiment here, just the chill of watching processes unfold in gogol brains. The hsien-kus cheat as much as they can: in spite of my accusations, not everything is simulated down to the molecular or even cellular level to allow true physics-equivalence.
What do the gogols here think of their existence? Whole worlds spawned and wiped away and rewritten, just to fit a newly discovered fact of history. Only those who really existed have the right to live. The others are just sketches, erased when they are no longer needed. Poor bastards.
The Fractal Prince, Rajaniemi Hannu