 Implicit in this causal inference is the assumption that there was no “carefully calibrated” gravitational wave coming in from past infinity, converging on the location of the postulated black-hole event, and then re-diverging—thereby mimicking a wave produced by two colliding black holes. This alternative explanation of the simultaneously detected signals is ruled out as utterly implausible, because a source free gravitational field coming in from past infinity that mimicked the field associated with the black hole event would have required absurdly strongly correlated initial conditions in remote parts of spacetime. By positing an initial randomness assumption such seemingly miraculous correlations are effectively excluded.