  Dynamical quantum jumps were initially conceived by Bohr as objective events
associated with the emission of a light quantum by an atom. Since the early
1990s they have come to be understood as being associated rather with the
detection of a photon by a measurement device, and that different detection
schemes result in different types of jumps (or diffusion). Here we propose
experimental tests to rigorously prove the detector-dependence of the
stochastic evolution of an individual atom. The tests involve no special
preparation of the atom or field, and the required efficiency can be as low as
\eta ~58%.
