  The Kerr metric is considered in a synchronous frame of reference obtained by
using proper time and initial conditions for particles that freely move along a
certain set of trajectories as coordinates. Modifying these coordinates in a
certain way (keeping their interpretation as initial values at large
distances), we still have a synchronous frame and the direct analogue of the
Lemaitre metric, the singularities of which are exhausted by the physical Kerr
singularity (the singularity ring).
