[HPforGrownups] Re: Who conjures the Prongs Patronus?

[GulPlum]

No: HPFGUIDX 53340

Norm wrote:

<snip>

>I follow the point about the dangerousness of seeing oneself again.
>I also follow that when they go back, they are re-living the earlier
>episode. What I'm still missing is this: doesn't Harry1 have to
>survive the dementor attack in order to *then* use the Time-Turner to
>alter that first version of events? Given that the principle of the
>Time-Turner is, after all, the ability to go back in time from a
>certain point in the future -- in this case, once they've made it
>back to Hogwarts -- don't they have to get to that point in order to
>then alter the way things happened before?

Errr... I think I've finally cottoned on to where you're going wrong. They 
don't *alter* anything. As I said in a lengthy post in a similar thread a 
couple of weeks ago (Msg # 52351), it helps if you try to think of it not 
so much as time travel (the mechanism) but as bi-location (the effect).

The fact is that everything that Harry2 and Hermione2 made happen, happened 
in the original timeline. Heck, I''m confusing myself now. There isn't an 
"original timeline". There is only *ONE* timeline, in which for three 
hours, there were two Harrys and two Hermiones.

Harry1 and Hermione1 didn't know that their duplicates were skulking around 
- like the principled people they are, they abided by the rules and aren't 
seen. However, Harry2 *was* seen (by Harry1), and it was when Harry2 
realised that what he'd seen earlier (as Harry1) was himself, and not his 
dad, that he knew that the timeline consisted of him showing himself to 
cast the Patronus. He therefore showed himself and cast the Patronus (as he 
explains to Hermione2 as soon as he's done it).

If you want to think about it in terms of temporal (meta)physics, yes, 
there's a causal loop in place: Harry2 has to save Harry1 in order for 
Harry1 to survive and become Harry2 who saves Harry1... (and so on, ad 
infinitum).

However, if you forget about the fact that time travel permitted all of 
this to happen and realise that there is only one, single timeline, in 
which one iteration of Harry saved another, you don't need to worry 
yourself with temporal (meta)physics.

>Put it another way: the dementors don't use the kiss, they use a
>good, old-fashioned, Muggle pistol. Bang bang, you're dead, Harry.
>How on earth (how in the Potter-verse?) can Harry, using the Time-
>Turner, alter this history if he is killed?

He can't. It's as simple as that. He can't alter history, and of course, if 
he's dead, he can't go back in time anyway.

>I hope I am missing something that's completely obvious, because
>otherwise I don't get this.

Well, it's obvious to *me*, but I'm not sure that I've explained it 
properly... If you take a look at the earlier message, I took a slightly 
different tack and that might be of assistance.

--
GulPlum AKA Richard, who's developing a headache :-)