Theory of Manifold Interfaces. A Cautious Interface Approach to Quantum Gravity

This text fixes a cautious transition from the physical layer of the Theory of Manifold Interfaces to its quantum-gravitational layer. The text does not claim that quantum gravity has already been solved. Its task is more modest: to introduce an interface framework in which the metric ceases to be a fixed background, geometry is treated as a quan- tum possibility, and the physical interface describes the transition from geometric uncertainty to an effective classical structure of spacetime.