[HPforGrownups] Problem with time travel in PoA

[Stacy Stroud]

No: HPFGUIDX 31393

At 04:02 PM 12/12/01 +0000, slurm3001 wrote:

>Harry1 could only have been saved by (time-travelling)
>Harry2's Patronus if Harry1 had survived the dementors in a different
>way in order to travel back in time and become Harry2. But in the
>book it is completely illogical:
>Harry1 survives because of Harry2 AND Harry2 only exists because
>Harry1 survived


Let me give a try at explaining this, since the PoA time-travel episode is 
a type of time travel situation I particularly like -- the self-reinforcing 
loop, as seen in the first Terminator movie.  This is a very different 
situation from the truly messed-up self-negating loop, like the classic 
grandfather paradox.  A self-negating loop is inherently contradictory, but 
a self-reinforcing loop is perfectly consistent, as long as you don't get 
caught up in issues of "before" and "after."

Let me ask you a question: Do you believe that Buckbeak was actually 
executed "before" Harry and Hermione used the Time-Turner to change 
things?  I don't.  I think that only one sequence of events actually 
happened the whole time -- we just didn't know about all of it until 
later.  When the kids heard that axe-blow, and Hermione1 started whimpering 
about how "they did it," they hadn't done it at all -- Harry2 and Hermione2 
had already gotten Buckbeak safely away, and the swish-thud was just 
Macnair letting off steam at not getting to kill something.

Similarly, things don't have to have been different "before" Harry traveled 
back to save himself.  Harry1 and Harry2 are at the lake at the same time, 
and it is perfectly possible for Harry2 to save Harry1.  Yes, Harry1 had to 
survive in order to become Harry2, but he DOES survive -- no contradiction 
there.  The causality is a little odd, but the sequence is *consistent*.

You're looking at things as "time goes along one way without the 
time-turner, and THEN Harry2 and Hermione2 go back and fix things."  But 
that's not it, as we see from the Buckbeak situation.  Going from past to 
future, there's only one sequence of events, and it includes three hours in 
which two versions of Harry and Hermione are running around 
simultaneously.  There is no need for Harry1 to have survived a different 
way without Harry2 -- indeed, if he had, Harry2 would have remembered 
*that* and would have had no need to save Harry1 himself.  Yes, IF 
something bad had happened to Harry1 or Hermione1, we would have a hard 
time explaining where Harry2 and Hermione2 come from -- but nothing like 
that happened.  The timeline is perfectly consistent.  It just *looks* odd 
to normal expectations because there are people jumping backwards, which 
doesn't normally happen.



Stacy Stroud (deadstop at gte.net)
Hex Entertainment, Inc. (http://www.hexgames.com)