Comment by d4nt

I suppose that really depends on what the subject of the simulation is. If it’s you personally, it only needs to simulate other scientists telling you about quarks, the solar system and the latest JWST images. If it’s humanity in general then other civilisations are not required. Of course it might be that this is a giant quark simulation and things like gravity, planets, life and humanity are an interesting quirk that’s arisen recently.