  Macroscopic realism, as introduced by Leggett and Garg, is the world view in
which properties of macroscopic systems exist independent of and are not
influenced by measurement. Motivated by classical physical laws such as
Newtonian mechanics or Maxwell's electrodynamics, in this work we add the
restrictive postulate that the observables of macroscopic objects are evolved
continuously through space and time. Quantum theory violates both macroscopic
realism and the continuity assumption. While decoherence or collapse models
(e.g. due to a universal noise background or gravitational self energy) can
restore macroscopic realism, we show that a continuous spatiotemporal
description does not become possible in general. This shines new light on the
question how the classical world arises out of the quantum realm.
