  The hypothesis is suggested that the equation for the Dirac free wave field
is, in fact, a group-theoretical relation describing propagation of specific
microscopic deviations of space geometry from the euclidean one (closed
topological manifolds). The Dirac equation for a hydrogen atom can also be
interpreted as a relation that accounts for the symmetry properties of a piece
of curved space. Within the framework of this concept, atoms have no any
pointlike particles (electrons) inside, and the gauge invariance of
electromagnetic field proves to be the natural consequence of the basic
principles of the proposed geometrical approach.
