Paradox of Time Travel in PoA

[smilingator4915]

No: HPFGUIDX 132073

Jonathan wrote:

Since we don't know all of the "rules" of how time travel works in
the 
HP universe, there is no right answer to this question, but based on 
different theories in our boring universe, you may be both right. Let
me explain:
> 
Theory 1 - Re-written history: Early time-travel theories generally
ran along the lines of "History happened a certain way, time traveler
comes along and changes things, world changes to follow suit, only
the 
time-traveler remembers the old history".

Theory 2 - Timeline jumping: Timeline jumping is a theory about time 
travel that states that there are two reference frames - personal
time 
and "world time". In this theory, world time is consistent and always 
flows the same. Time travelers have the ability to "leave" the world 
time and jump to different points in the world time line, in essence 
duplicating themselves (unless they have traveled to before their
birth, or after their death). Since the world time line is never
altered, there is always only one version of the events that occurred
within it.


smilingator (now):

I just want to say that PoA is my favorite book of the series so far
because of the time travelling element. After reading the recent
discourse on the boards (and getting a headache from it too... hehe),
I've decided to jump into the conversation.

First of all, I think that all parties (Dave, Steve, Heather,
Jonathan, etc.) have made good points and I understand what issues
everyone was trying to address and make the other parties understand.
But as Jonathan said, since JKR didn't lay down any clear guidelines
(other than that time travelers "must not be seen" because it is
against wizarding law), then it's impossible to know what type of time
traveling occurred. Jonathan laid out the two main types, which I
included above.

IMO, JKR is operating the Potterverse under Theory 2... in which there
is one time with possibly many perspectives. An important aspect of
this theory is that events can not be changed during time travel. If
someone attempted to change the past, they would fail. TTH! and TTHr!
could not have gone back and changed anything because this is
impossible. What happened the first time from 9-12 on that night is
exactly the same thing that happened the second time from 9-12. We
just saw the story from two different perspectives. (By the way, I
noticed that the kids left at 5 until midnight, yet when they
travelled back in time 3 hours, "golden sunlight was falling across
the paved floor". Is the sun still up at 9 p.m. in Britain?)

Anyway, a couple of comments that Hermione made in PoA (U.S. version)
makes me understand fully where Dave is coming from and why he
believes that the Potterverse is under Theory 1 (and he may be
entirely dead on).

"Nobody's supposed to change time!" (page 398, US) Hermione didn't say
that you CAN'T change time, just that you are not supposed to and it's
against wizarding law to do so. So, how would wizard officials know
that time was changed? According to Theory 1, only the time traveler
knows that events were changed. 

"Professor McGonagall told me what awful things have happened when
wizards have meddled with time... Loads of them ended up killing their
past or future selves by mistake!" (page 399, US). There have been
quite a few theories to explain how this could possibly happen. I
could always understand how a past self could kill a future self. But
I can not grasp how a future self could kill a past self unless a new
alternate universe was created at the moment of death; in one of the
universes, the future person would still be alive and continue on, but
in the newly created universe, the person would not exist.

I have a feeling that we have seen more time traveling in other HP
books, it just wasn't as obvious. In any event, I hope JKR explains
things a little further. And even if she doesn't, it's nice reading
intelligent conversation from you all!

Just my thoughts...