I think there's a subtler point in the parent comment, that is whenever we observe different parts of the universe we are collapsing its quantum wave function,

I think there's a subtler point in the parent comment, that is whenever we observe different parts of the universe we are collapsing its quantum wave function, which would have large consequences for any would-be simulation. https://physics.stackexchange.com/questions/43406/what-constitutes-an-observation-measurement-in-qm https://physics.stackexchange.com/questions/43406/what-const...