I think the info was sent to Bones rather than her finding it and going back, but your point may still stand. Perhaps “somebody sent something back to Amelia Bones” is vague enough to slip past the filter. There must be some nonzero cutoff, because otherwise the info would affect the whole future (from the point of receiving the info) light come of anyone who got time-traveled info, and the whole earth would be interdicted whenever somebody went back.
If I’m wrong about that, it’s possible that either Bones or Dumbledore wasn’t thinking, or Dumbledore realized that he was already blocked and that’s part of why he decided he wanted the info.
Amelia Bones learns something at time x is an event happening at time x and information of that event could be taken back to time x − 6. If the information that she gets is from time x + 4 then that information could only go back to time x-2.
But she got information from time x + 4: the fact that there was interesting information to get at that time.
Think of all of the logic puzzles where you have (just) enough information to deduce that somebody else had enough information to deduce that somebody else … etc.
I think the info was sent to Bones rather than her finding it and going back, but your point may still stand. Perhaps “somebody sent something back to Amelia Bones” is vague enough to slip past the filter. There must be some nonzero cutoff, because otherwise the info would affect the whole future (from the point of receiving the info) light come of anyone who got time-traveled info, and the whole earth would be interdicted whenever somebody went back.
If I’m wrong about that, it’s possible that either Bones or Dumbledore wasn’t thinking, or Dumbledore realized that he was already blocked and that’s part of why he decided he wanted the info.
Amelia Bones learns something at time x is an event happening at time x and information of that event could be taken back to time x − 6. If the information that she gets is from time x + 4 then that information could only go back to time x-2.
But she got information from time x + 4: the fact that there was interesting information to get at that time.
Think of all of the logic puzzles where you have (just) enough information to deduce that somebody else had enough information to deduce that somebody else … etc.