From a GR perspective, how does the event horizon of a black hole know how to behave? Consider a simple scenario of a shell of material outside the event horizon of a black hole, in free fall. Once the material is consumed by the blackhole, the event horizon will be greater, but my understanding is that in advance of the material crossing the event horizon, the horizon will "grow" to meet the infalling material at the location of the new / expanded horizon. Is this because the material is in the future of the black hole so it (the black hole knows how to "pre-act")? If this is the case, are there other scenarios where such "pre-action" takes place? Regards, Noel.