Abstract <p>It is shown that the introduction of a non-zero volume of particles, as well as the concept of Casimir polarization of the electromagnetic field vacuum—EM vacuum in the vicinity of atoms, atomic nuclei, and elementary particles with the formation of corresponding EM polarons, allows us to understand the physical essence of quantum phenomena and processes determined by the “overlap” (interaction) of Casimir polarization regions in the vicinity of particles. The physical essence of the entanglement effect, the diversity of Bose–Einstein condensation processes of particles and the resulting condensates, the genesis of inertial forces arising in accordance with Newton’s 3rd law of mechanics at all levels of the spatio-temporal organization of the Universe, the key role of virtual photons in all of the above processes are discussed. It is shown that within the framework of the previously proposed model of the dynamics of the Universe as an integral open system, connections can be revealed that establish the nature of irreversibility of the dynamics of all processes, up to the processes of energy transfer to the electron subsystems of atoms and nuclear matter of atomic nuclei, which is necessary for stabilizing the functional activity of these systems. In particular, within the framework of the presented understanding of the physical essence of the phenomena of superconductivity and superfluidity, one of the key epistemological problems is solved—understanding the physical basis of the manifestations of the “non-dissipativity” of these phenomena.</p>