  An experiment for checking the Dynamical Spacetime approach to wavefunction
collapse is proposed. The Dynamical Spacetime approach predicts deviations from
Born's rule, when a solid evolves into a three-state superposition, and when
the displacement between the superposed states is, at the reduction point in
time, significantly larger than the spatial variation of the solids nuclei,
being typically on the order of a tenth of an Angstroem. The solid is brought
into the three-state superposition by splitting a photon into three beams and
by detecting it in each beam by avalanche photodiodes, which displace the solid
at different distances with the help of a piezoactuator. The challenge of the
experiment is the precise prediction of the setup's reduction point in time to
ensure a sufficient separation between the states at this point in time. This
is addressed by avoiding interactions of the setup with the environment during
superposition, and by a precise calculation of the setup's reduction point in
time with the help of a formulary for the Diosi-Penrose criterion for solids in
quantum superpositions. Since the measurement of reduction probabilities is not
disturbed by state decoherence, the experiment can be performed at room
temperature. The quantitative analysis demonstrates that the predicted increase
of the reduction probability of one state by a factor of 1.5 with respect to
Born's rule can be measured by a few hundred statistically significant
measurements.
