PART 1In the first chapter, the "conversion factors" are introduced, which are dimensionless coefficients used to evaluate the effect of accelerated expansion of spacetime on measurements. It is shown that these factors can be expressed through a common parameter, α, the fine-structure constant, which is linked to the ratio between the theoretical radius (13.6-13.8 Gly) and the measured radius (46.5-47 Gly) of the universe. In the second chapter, it is demonstrated that dark matter and dark energy do not exist, and the gravitational effects attributed to them are actually caused solely by ordinary matter. In the third and fourth chapters, Newton's theory of gravitation is first extended into the generalized gravitational theory and then into the generalized electrogravitational theory. The latter, among other things, predicts the existence of electrogravitational waves, suggesting that photon and graviton are the same particle and that the graviphoton is constituted by two elementary electric charges of opposite sign. In the fifth chapter, Planck's law is derived from first principles. This implies that Planck's constant is no longer a fundamental constant but derivable from other constants. In the sixth chapter, the electrogravitodynamic equations and the electrogravitational stress-energy tensor are developed. In the seventh chapter, the quantization of Einstein's field equation is carried out. PART 2In the eighth chapter, the possibility that elementary particles are in turn composed is examined and discussed: we have seen that the graviphoton corresponds to the elementary particle composed of two electric charges of opposite sign. In the ninth chapter, the mass ratio between proton and electron (approximately 1836) is calculated. In chapter ten, the concept of force is revised, as all particles can be exchanged, making them all carriers of force. In chapter eleven, the multiverse with repeated gravitational collapses (like a matryoshka) is introduced. In chapter twelve, the theory of information is integrated with the electrogravitational field: Information must be "contained" by something, whether it be a stone slab, a book, a CD, or any other means. This raises the question of whether there exists an ultimate level on which information can be encoded, the level of fundamental "0" and "1". This can only be spacetime itself (the electrogravitational field).