The zero-point field and the emergence of the quantum

A new way of arriving at the quantum formalism is presented, based on the recognition of the reality of the random zero-point radiation field (ZPF). The quantization of both matter and radiation field is shown to emerge as a result of the permanent interaction of matter with the ZPF. Quantum mechanics (QM) is obtained both in its Schrödinger and its Heisenberg version, under certain well-defined conditions and approximations. The theory provides for an explanation of the origin of entanglement. Further, the same physical elements and hypotheses allow us to cross the doorway and go beyond QM, to the realm of (nonrelativistic) quantum electrodynamics (QED).