  This Oberwolfach report describes published work with Carlos Vega introducing
the null distance on a spacetime, and announces unpublished applications of
this work jointly with Carlos Vega and with Anna Sakovich applying the null
distance to define a spacetime intrinsic flat convergence (SF convergence). The
announced work with Vega concerns convergence of sequences of big bang
spacetimes and the announced work with Anna Sakovich concerns convergence of
future maximal developments of initial data sets. Both were originally
announced at the 2018 JMM. This report lists some open questions that will be
discussed at the Oberwolfach meeting this coming August.
