Let's assume for a moment that we live within a simulation. Let's now assume that roughly 400k city (with inhabitants) and a couple of neighboring settlements gets removed from the simulation and then forked multiple times into smaller simulations. The original simulation gets thoroughly adjusted to remove most of the notions of existence of the city (maps, memory, books, contracts, etc.)
In one of the new simulations things continue to work as before - whatever is necessary for functioning of the city continues to do so and the people living inside to move outside of the city (let's not get into details why). What I am curious about is at the level of physics: would it possible for the simulation owner (or maintainer) to adjust the properties of physics in some small, but measurable ways (e.g. make speed of light different). In other words, would it be possible for a traveler from the original simulation to the forked one to make observations and see discrepancies from what he expects to see? Since there are far fewer observers of the simulation, is it possible to make some changes? The expectations of having certain properties (e.g. some constants) get adjusted within the new simulation, so the remaining scientist see these as normal.
To clarify: the folks in simulation A have memory of law of physics A, the folks in simulation B have the memory of law of physics B. When a person from simulation A travels to simulation B (with the exception of the people that were transplanted initially), they retain the knowledge from their original simulation.