In The Big Bang (the concluding episode of the Pandorica arc), the Doctor is erased by the cracks in space-and-time. Yet Amy brings him back by remembering him, which is triggered by River Song dropping off her diary with Rory and then walking past the window. Since the Doctor never existed at that point, what made River Song go to Earth and drop off a blank diary with a random stranger?
I also wondered this. In fact, it kind of spoiled the conclusion of the story arc for me.– KalessinMay 27, 2011 at 23:41
Spoilers for S6E7, A Good Man Goes To War:
River, being part-Time Lord, probably is capable of remembering people after they're consumed by the crack. She didn't mention this detail in The Big Bang, as it would reveal too much about herself too soon. After the universe was restarted, she remembered the Doctor, and had her journal/diary although the writing in it had been wiped as it no longer happened. So she left it for Amy as a reminder of the Doctor, just like the ring had previously reminded her of Rory.
Given that Amy was capable of remembering the Doctor despite the fact that she's (probably) human, this behavior isn't necessarily exclusive to Time Lords - however, it probably doesn't hurt. Jun 7, 2011 at 18:48
She felt Rory was missing, but didn't really remember him during that season. But the Doctor fully remembered Rory the whole time. Compare their interactions with Auton Rory when they first see him. Amy treats him like a stranger, Doctor says 'sup Rory?'– user1027Jun 7, 2011 at 19:03
Right - it seems like the more exposure to the Time Vortex someone has, the less they're affected by people's "erasure" from the time stream (i.e. make them more like a Time Lord). Jun 7, 2011 at 19:31
Although, following from S6E7, in River's time line she will never exist. Or she would exist, but without the Doctor's intervention she wouldn't be part Time Lord.– KeithJun 8, 2011 at 20:45
2@Keith Although we have only a few examples to go from, it seems like she'd still exist, and be in prison. People don't actually have their existence altered as though the erased person never existed. Their memory of the removed person is wiped, but where they are isn't altered. When the clerics went into the crack, two clerics would have logically popped out of no where to replace the two empty slots on the squad.– user1027Jun 8, 2011 at 21:17
Likely the same way that the Doctor was able to hide Amy's memories of him in the wedding expression ("Something old, something new, something borrowed, something blue...") despite the fact that at at the time she starts to remember him, he would never had existed to create or hide those memories in any way.
That is to say, impossibly. Perhaps the Doctor managed to hide memories for her as well, albeit less important ones. All he had to do for River is make her remember to drop off a blue journal; Amy's hidden memories had to bring him directly into existence.
On some core level, considering it was possible for him to be remembered back into existence at all and the fact that the Universe corrected itself after his re-appearance (River's journal filling back up, etc.), it seems likely that he never entirely ceased to exist (the same way Amy had dormant memories of Rory after his "non-existence"). However, it seems the one thing that was not corrected was Rory's memories of being an Auton, as the real Rory was brought back and married Amy (but still remembers those years).
See http://tardis.wikia.com/wiki/The_Big_Bang and http://tardis.wikia.com/wiki/Rory_Williams for details.
1Also, remember, as of now, we still do not know why the Tardis exploded and are still waiting to see just what "Silence will fall" means. (Yes, we realize it's Silents instead of Silence, but we don't know what the fall is.) So it's very likely we'll still see more of an explanation about what happened during this arc (the one after the Pandorica with the Silents).– TangoMay 28, 2011 at 3:54
1@TangoOversway Actually the BBC website clarified that a lone one of them is a Silent, but the plural is Silence.– user1027May 28, 2011 at 6:02
@Keen: Thanks. Doctor Who is one of the few universes I like keeping up with, but it's hard to keep up with everything and all sources.– TangoMay 29, 2011 at 18:20
I assumed River would have been there because it's her parents' wedding and therefore was always there in any version of reality. In the rebooted reality though, she left her blank diary to subconsciously help Amy remember the Doctor.
duh......River was that black girl growing up with them so she knew they where getting married. That is why she is there.
That wouldn’t explain why she knew to leave the blue diary for Amy. And the person asking the question hasn’t necessarily seen season 6 yet. Dec 13, 2013 at 22:46