Hello! If we have a 1m stick (as measured in its stationary reference frame, call it S) and we (S') move with a high enough velocity, we can make the length of the stick in our frame as small as we want. So for high enough velocities, the stick will appear so small in our frame, S', that it will reach a quantum domain i.e. we need a wavefunction to describe it. Does this mean that the same object can be described in one frame using classical physics but in the other we need quantum mechanics? Will the 2 descriptions still coincide, as we have a deterministic description vs a probabilistic ones? I am just a bit confused about the actual transition from classical to quantum.