The scale of quantum mechanical effects in matter is set by Planck’s
constant, \hbarℏ.
This represents the quantisation scale for material objects. In this
article, we present a simple argument why the quantisation scale for
space, and hence for gravity, may not be equal to
\hbarℏ.
Indeed, assuming a single quantisation scale for both matter and
geometry leads to the `worst prediction in physics’, namely, the huge
difference between the observed and predicted vacuum energies.
Conversely, assuming a different quantum of action for geometry,
\beta \ll \hbarβ≪ℏ,
allows us to recover the observed density of the Universe. Thus, by
measuring its present-day expansion, we may in principle determine,
empirically, the scale at which the geometric degrees of freedom should
be quantised.