  We show that a hypothesis that spacetime is quantum with coordinate algebra
$[x^i,t]=\lambda_P x^i$, and spherical symmetry under rotations of the $x^i$,
essentially requires in the classical limit that the spacetime metric is the
Bertotti-Robinson metric, i.e. a solution of Einstein's equations with
cosmological constant and a non-null electromagnetic field. Our arguments do
not give the value of the cosmological constant or the Maxwell field strength
but they cannot both be zero. We also describe the quantum geometry and the
full moduli space of metrics that can emerge as classical limits from this
algebra.

General Relativity and Quantum Cosmology;High Energy Physics - Theory;Quantum Algebra