The electric dipole moment of a particle-antiparticle pair of virtual particles (PVP) produced in the physical vacuum by a real particle is discussed. Accounting for the electric dipole moment of the PVP produced by an atomic electron permits one to explain some properties of the atom. For example, the force acting on the PVP in the electric field of the nucleus can balance the radiation reaction force acting on the electron; the moment acting on the PVP in the electric field of the nucleus explains the Coulomb spin-orbit interaction. The emergence of superconductivity/superfluidity in a medium can be attributed to formation of pairs of real particles, the bound particles, with zero total electric dipole moment of the PVP?s produced by the particles. In this case, the medium viscosity will decrease due to disappearance of the electric dipole interaction of pairs of bound particles. The possibility of annihilation of the PVP?s produced by real bound particles is examined, the emergence of the ?mass defect? of a bound particle being a consequence of the annihilation.
