The Standard Model of Particles gathers almost the whole present knowledge in theoretical physics, in a consistent system. It describes the universe as constituted fundamentally of particles, both for matter and for interactions. It is incomplete since it does not include gravitation with the three other interactions, and leans upon elementary particles such as electrons or quarks, which are considered as point-like with no known internal structure. The Einstein’s program offers means to circumvent these difficulties. It is founded upon a scalar field e (r0,t0) propagating at speed of light c, as a consistent system for universe description. Standing waves correspond to matter, which kinematical and dynamical properties are formally identical. Their space-like amplitude function u0(k0r0), supplements usual fundamental time-like equations of classical and quantum mechanics. In geometrical optics approximation conditions, when frequencies are infinitely high, and then hidden, u0(k0r0) yields Dirac’s distribution δ(r0), describing a particle as a singularity. The scalar field e(r0,t0) brings theoretical economy by yielding also the energy-momentum conservation laws, and the least action law, with determination of the Lagrangian.The frequency variations of the field e (r0,t0) are linked to electromagnetic interaction, constituted by progressive waves. Quantum domain corresponds to wave optics approximation conditions, with wave-particle duality. Adiabatic variations of frequencies, give rise to introduction of an adiabatic constant, formally identical with Planck's constant, with unification of first quantification for interactions and second quantification for matter. Local variations of speed of light yield gravitation interaction and General Relativity framework.