  In 1967 Zeldovich expressed the cosmological constant lambda in terms of G, m
and h, the gravitational constant, the mass of a fundamental particle and
Plancks constant. In 1972 Weinberg expressed m in terms of h, G, the speed of
light c and the Hubble parameter H. We proved that both expressions are
identical. We also found proportionality between c and H. The critical mass
balancing the outward quantum mechanical spreading of the wave function, and
its inward gravitational collapse, has been recently estimated. We identify
this mass with Zeldovich and Weinberg mass. A semi classical gravity model is
reinforced and provides an insight for the modelling of a quantum-gravitational
theory. The time evolution of the peak probability density for a free particle,
a wave function initially filling the whole Universe, explains the later
geometrical properties of the fundamental particles. We prove that they end up
acquiring a constant size given by their Compton wavelength. The size of the
fundamental particles, as well as their mass, is explained. The three findings
converge: Newton laws of motion and gravitation, while explaining Zeldovich and
Weinberg relations, also define the mass and size of the fundamental particles
when using the Schrodinger-Newton equation.
