  The spin connections of the Dirac field have three ingredients that are
connected with the Ricci rotations, the Maxwell field, and an axial field which
minimally interacts with the axial current. I demonstrate that the axial field
provides an effective mechanism of auto-localization of the Dirac field into
compact objects. The condition that these objects are stable (the
energy-momentum is self-adjoint) leads to Einstein's field equations. The Dirac
field with its spin connection seem to be a natural material carrier of the
space-time continuum in which compact objects are moving along geodesic lines.
The long distance effect of the axial field is indistinguishable from Newton's
gravity, which reveals the microscopic nature of gravity and the origin of the
gravitational mass.
