Also, if someone tried to do it within our universe, the distances between the two Earths and e.g. the nearest stars or galaxies would be different, so the gravitational force would introduce differences.
wave function collapse(s) would make them diverge almost instantly.
Just adding that this is true regardless of the interpretation of quantum mechanic.
In collapse models, each Earth’s wave function collapses separately, i.e. rolls different random numbers. In many-world models, we get a Cartesian product of “whatever happened to Earth1” and “whatever happened to Earth2″, and in most results, the states of the two Earths are different.
Also, if someone tried to do it within our universe, the distances between the two Earths and e.g. the nearest stars or galaxies would be different, so the gravitational force would introduce differences.
Just adding that this is true regardless of the interpretation of quantum mechanic.
In collapse models, each Earth’s wave function collapses separately, i.e. rolls different random numbers. In many-world models, we get a Cartesian product of “whatever happened to Earth1” and “whatever happened to Earth2″, and in most results, the states of the two Earths are different.