This study considers a variant of the realization of Dirac’s ideas regarding the limited number of Faraday force lines and allowance for the finite size of microparticles in physical theory. It is shown that within the framework of the classical approach, consideration of the limited number of Faraday force lines opens additional possibilities for describing and characterizing the physical field and associated phenomena. Specifically, it is shown that it becomes possible to obtain in a facile manner an expression for describing the discrete radiation of an atom, which agrees well with the empirical Balmer relation. An assumption is made about the possibility of the material existence of Faraday force lines as structural elements of the physical field. It is suggested that the natural fields of physical bodies can be considered as a set of materially existing lines of force, i.e., as a luminiferous ether.

The physical and mathematical aspects of the mutual spatial shielding of interacting elements in the framework of classical physics are considered. The mass-area equivalence is introduced for the formal unification of the Newtonian theory of gravity with the kinetic theories of Descartes-Fatio-Le Sage. A mathematical equation describing the dependence of the mutual shielding of objects on their size, number and relative location is proposed. Spatial mutual shielding is considered for mass-forming elements—nucleons in the atomic nucleus and atomic nuclei in ordinary substances. The close shielding is distinguished when the distance between the shielding elements is commensurate with their size, which is typical for nucleons in atomic nuclei and the far shielding, when the distance between the elements is much larger than their size, which is typical for atomic nuclei in ordinary substances. An analytical expression for the binding energy of nucleons in atomic nucleus is obtained. It allows us to estimate the distance between nucleons in the nucleus and consider stability of nuclei as a function of the distance between nucleons, which increases due to an increase in the Coulomb repulsion force with an increase in the number of protons. One of the three ideas of Dirac, presented by him for the further development of the physical theory, is implemented: taking into account the sizes of elementary particles—nucleons.

The possibility of gravitational shielding from more massive objects than the Moon-planet Earth and the giant planets of the Solar System is considered. Within the framework of the Lesage concept, the mutual spatial shielding of mass-forming elements-atomic nuclei in ordinary matter-was evaluated. It is concluded that the size of the Moon is insufficient for tangible gravitational shielding and partial mutual shielding is about 50% for planet Earth. It is determined that there is a critical thickness of ordinary matter at which complete mutual shielding of atomic nuclei is observed. The estimated critical thickness is about, which is typical for the sizes of giant planets. It is concluded that due to the presence of gravitational shielding, not the entire mass of massive celestial bodies participates in the act of gravitational interaction, which leads to the conclusion that there is a hidden mass of massive objects and to low values in the calculation of the density of the giant planets of the Solar System. It has been established that the true mass and true density of giant planets exceed their known values by 5 times. The presence of gravitational shielding from the planet Earth leads to a revision of the physical picture of nature and the consequences of tidal forces. The idea of P. Dirac concerning the accounting of the sizes of microparticles-nucleons, expressed for the further development of the physical theory, is realized. The gravitational size of the atomic nucleus is calculated on the order of 10 −18 m.

The result of mathematical and physical analysis of the daily change in gravity is presented. The subject of consideration was the manifestation of semidaily factors in diurnal variations of gravity. The assumption is investigated, according to which the cause of the half-day factors is the gravitational shielding of the planet Earth. Gravitational shielding is considered as a function of the size and thickness of celestial bodies and growing with distance from their poles. It is concluded that the planet Earth has the property of partial gravitational shielding, and the Moon does not have enough thickness to exhibit a tangible gravitational shielding. The obtained mathematical results correspond to the existing experimental data. It is suggested that gravitational shielding is the cause of the precession of the perihelion of Mercury and the peculiarities of the manifestation of tidal processes. It is assumed that gravitational shielding is one of the main reasons for the presence of hidden substances in the Universe. It is concluded that the physical picture with mutual shielding of interaction elements corresponds to the classical ideas of Fatio and Lesage. This approach is proposed as an alternative point of view to the existing theory on the description of tidal processes. It is shown that the existing basic approach to the description of tidal forces is unsatisfactory: the factors underlying the existing approaches have values 10 times less than those observed and cannot be considered as the reason for the manifestation of halfday manifestations in the daily change in gravity. The work is a continuation of the implementation by the author of P. Dirac's ideas about accounting for the size of microparticles in physical theory.