Time travel is dangerous! (part 1)

[nkafkafi]

No: HPFGUIDX 88788

> Neri wrote:
> It is even possible that DD himself sent Ron, the 
> young version of himself, to the past in order to become DD and 
carry 
> out this special mission.
> 
> vmonte responds:
> 
> I like the idea of Ron having a special mission but I'm not sure I 
> understand the theory that you are allowed to go back in time as 
long 
> as you do not change anything?  Why go back in the first place 
unless 
> you want to change something? 
> 

Neri answers:
Well <tries to recall where this argument was left. Ah, yes>  because 
in the frame of the "What's Done Is Done" (WDID) theory, you are 
allowed to "help the past along its way", even though you are not 
allowed to change it. So if you detected a suspicious hole in a plot 
that went in the right direction for you, you might want to go back 
and plug it.

For example, DD had witnessed that Buckbeak had disappeared before 
the execution, and he probably had a shrewd guess who was responsible 
for that, so he sent Harry and Hermione to the past to carry it out.

A more accurate (but more confusing) way to look at it is that the 
hole must plug itself, because it *was* plugged. If for example HRH 
were saved from the dementors by Harry from the future, then you know 
that he is destined to go back and do it. It would work (because it 
did work) even if he does not know about it. But if he does know, he 
may consider it a special mission, and with a bit of careful planning 
he may carry it out with less damage to his future self. After all, 
even if Harry knows his future self will be there just in time to 
save his past self, he does not know what will happen to his future 
self a second *after* that. The future Harry might still be attacked 
from behind by another gang of dementors and be finished off before 
he has the time to call the patronous back. So it is always a good 
idea to plan ahead (or in whatever direction...).

If this is still confusing, try my extensive explanation in the 
original post (#88636).

Neri