  It has long been thought that observing distinctive traces of quantum gravity
in a laboratory setting is effectively impossible, since gravity is so much
weaker than all the other familiar forces in particle physics. But the quantum
gravity phenomenology community today seeks to do the (effectively) impossible,
using a challenging novel class of `tabletop' Gravitationally Induced
Entanglement (GIE) experiments, surveyed here. The hypothesized outcomes of the
GIE experiments are claimed by some (but disputed by others) to provide a
`witness' of the underlying quantum nature of gravity in the non-relativistic
limit, using superpositions of Planck-mass bodies. We inspect what sort of
achievement it would possibly be to perform GIE experiments, as proposed,
ultimately arguing that the positive claim of witness is equivocal. Despite
various sweeping arguments to the contrary in the vicinity of quantum
information theory or given low-energy quantum gravity, whether or not one can
claim to witness the quantum nature of the gravitational field in these
experiments decisively depends on which out of two legitimate modelling
paradigms one finds oneself in. However, by situating GIE experiments in a
tradition of existing experiments aimed at making gravity interestingly quantum
in the laboratory, we argue that, independently of witnessing or paradigms,
there are powerful reasons to perform the experiments, and that their
successful undertaking would indeed be a major advance in physics.
