  We propose a mathematical structure, based on a noncommutative geometry,
which combines essential aspects of general relativity and quantum mechanics,
and leads to correct "limiting cases" of both these theories. We quantize a
groupoid constructed on space-time rather than space-time itself. Both space
and time emerge in the transition process to the commutative case. Our approach
clearly suggests that quantum gravitational observables should be looked for
among correlations of distant phenomena rather than among local effects. A toy
model is computed (based on a finite group) which predicts the value of
"cosmological constants" (in the quantum sector) which vanish when going to the
standard space-time physics.

General Relativity and Quantum Cosmology