1905-1930: The golden age of physics.- Mass, special relativity and the equivalence principle.- The strong force: From quarks to hadrons and nuclei.- The world of particles and the standard model.- The equivalence principle, special relativity and Newton's gravitational law.- The three and two rotating neutrino models: Particle confinement by gravity.- Energy and other properties of the rotational states.- Gravitational hadronization: How mass can be produced from gravity.- Model comparison with the main experimental features of the strong interaction force.- The Bohr-de Broglie approach in physics: The dual nature of matter.- Gravity at relativistic velocities and dark matter.- Force unification: Is the strong force simply gravity?.