We abandon as redundant the assumption that there exists something more in the physical world than action quanta, which constitute the atoms of the events of which the four-dimensional world consists. We derive metric, energy, matter, etc., from action and the structure formed by the quanta. In the microworld thequantization of space so introduced implies deviations from conventional metrics that make it possible in particular to explain nonlocality. The uncertainty relations, then, in conjunction with the action-based metric, appear to play (...) an essential role in making direct physical contact between emission and absorption events (i.e., retroactivity) possible, which concretely answers Bohr's conjecture that microprocesses constitute “wholes.” All of this appears to afford a realistic explanation of wave-particle “duality,” the EPR and other quantum paradoxes, the hidden variable problem, the “collapse” of wave packets, and the wave interference mechanism with the ¦ ϕ ¦2 rule. (shrink)