 Another common claim is that the presence of singularities establish that GR is incomplete, since it fails to describe physics “at the  singularity”.[33]  This is difficult to spell out fully without a local analysis of singularities, which would give precise meaning to talk of “approaching” or being “near” the singularity. In any case, it is clear that the presence of a singularity in a cosmological model indicates that spacetime, as described by GR, comes to an end: there is no way of extending the spacetime through the singularity, without violating mathematical conditions needed to insure that the field equations are well-defined. Any description of physical conditions “before the big bang” must be based on a theory that supersedes GR, and allows for an extension through the singularity.