  The inclusion of gravitation within the framework of quantum theory remains
one of the most prominent open problem in physics. To date, the absence of
empirical evidence hampers conclusions regarding the fundamental nature of
gravity -- whether it adheres to quantum principles or remains a classical
field manifests solely in the macroscopic domain. This article presents a
though experiment aimed at discerning the quantum signature of gravity through
the lens of macroscopic nonlocality. The experiment integrates a standard Bell
test with a classical Cavendish experiment. We illustrate that the measurement
apparatuses employed in a Bell experiment, despite lacking entanglement, defy
classical descriptions; their statistical behaviors resist explanations through
local hidden variable models. Extending this argument to encompass the massive
objects in the Cavendish experiment allows for further disputing classical
models of the gravitational field. Under favorable conditions and in light of
corroborating evidence from the recent loophole-free Bell experiments, the
quantum character of gravity is essentially substantiated.
