Time-Turner

[GulPlum]

No: HPFGUIDX 52351

My take on explaining the Time-Turner's effects (no, it doesn't involve 
Quantum Mechanics)... :-)

One way to avoid getting hung up on the paradoxes of time travel in PoA is 
to separate instrument from the effects of its use. Yes, the way the 
Time-Turner works, as the name implies, is time travel. However, the 
*effect* it has is bi-location (or tri-location in the case of Hermione's 
9am lessons). :-) If one separates these elements from each other, one 
doesn't need to waste time explaining Quantum Theory, etc.

There aren't alternate timelines, there is only one single timeline, in 
which Hermione was in two (or three) places at once during the school year 
to be in certain classes, and then at the end of the year, she and Harry 
are in two places at once. JKR deliberately has Hermione 
misdirect/misinform us when on that first day, when examining their 
timetables, she exclaims to Ron that "of course I won't be in three classes 
at once", because that's *exactly* what she's going to be doing!

Of course, during the climactic evening of the Shrieking Shack scene, 
Hermione doesn't *know* that she's going to be using the T-T. All year, she 
had dutifully applied McGonagall's instructions and used the T-T *only* to 
be in two classes at once, and the first time we (readers) run through the 
events of that evening, she didn't think that she might have used the T-T, 
although I must admit that I'm surprised that she didn't think of it. After 
all, she's a bright young lady, she's been using it all year, but she 
doesn't work out what might be going on? She's already broken school rules 
on several occasions, so she should have considered the possibility that 
she may have on this occasion.

This gives the admonition not to "change" anything when bilocated extra 
sense, and indeed, Harry and Hermione *don't* change anything. Everything 
their bilocated selves make happen, happened to their original selves, only 
it took them a while to realise it (they *assumed* Buckbeak had been 
executed - they didn't witness it beyond hearing the axe fall and the 
groans; Harry *assumed* he'd seen his dad cast a Patronus).

Earlier in the year, when Hermione misses a Charms lesson, she doesn't go 
back once she's realised her mistake, because that *would* be changing 
something which had happened - she had missed that lesson (and lunch).

The narrative (p. 217-218 UK PoA) tells us the schedule for that day was 
Care of Magical Creatures, then Charms, then lunch and then Divination (or 
at least that was the boys' schedule; it is implied that Hermione had 
Arithmancy while the boys were at Charms, and had forgotten to turn back 
for Charms). The boys find her after lunch, asleep in the common room on an 
Arithmancy book, and from dialogue, it's 20 minutes to Divination.

Assuming (not unreasonably) that standard lessons (and lunch) last no 
longer than an hour each with some kind of break between them, by the time 
the boys wake Hermione, at most 3 hours have passed. We know that the 
Time-Turner is capable of going back 3 hours ("three turns should do it"), 
so why didn't Hermione just go back to the beginning of Charms lesson, 
attend that and then go to lunch with the boys? Simple. Because by then, 
her absence at the Charms class and lunch had been noted.

When he sends them off on their mission (p. 288 UK PoA), Dumbledore is very 
emphatic, and the only time in the books to date, he repeats himself 
(despite being severely pressed for time): "You must not be seen. You know 
the law - you know what is at stake... You - must - not - be- seen." What 
he means is "you should not be seen somewhere when you're known to be 
elsewhere". (Bizarrely, though, this didn't seem to apply to Hermione for 
the whole year, as it would have taken simple deduction for two people who 
had been with Hermione in classes simultaneously to compare notes. )

His phrasing makes it seem that whilst it is not beyond the Time-Turner's 
ability to create an alternate timeline, it is certainly undesirable to do 
so, to the extent that it is a very important law. Hermione's return to a 
place (think of it as place rather than time) where she was known not to be 
is, if not impossible, then at least a VERY, VERY bad idea.

And thus, although some people have wondered since the Time-Turner was 
introduced in PoA why someone didn't go back and save the Potters that 
fateful Halloween, it would be either outside the possibility of a 
Time-Turner to create an alternate timeline in which they lived, or if not, 
then at least the consequences of creating such a timeline don't bear 
thinking about.

--
GulPlum AKA Richard, who was compelled to interrupt writing a post about 
life debts to put together the above, as the latest news from the PoA set 
made him think about the wonderful cinematic possibilities afforded by the 
bilocation plotline and glad that it won't be Columbus applying his limited 
imagination to filming those scenes...