Howling:Erasing events?

the off made it very clear that certain events in who-history have been erased to ake the inhabitants of earth unaware of aliens. but how can an event be swallowed by a crack without the people who took part being swallowed to. lets take journeys end for exaple. if that event was erased by the cracks, it would mean all 27 planets would have been erased along with their inhabitants as well as the doctor, the "children of time", the daleks and davros. i have a feeling that if that were the case, the post journeys end removal universe would look very different to what it does look like. so, if the cracks don't swallow everything in an event, how do they uncreate events? do the cracks just remove the cause, eg swallowing dalek caan so he can't go back and save davros and so that event never occured? i want to hear your theories. Imamadmad 09:07, August 8, 2011 (UTC)