Time-turning

[Zara]

No: HPFGUIDX 167497

> Magpie:
> Yes, but that's a different thing that I was talking about. There's 
> two different things here, there's how "time" is working within 
> canon, as if canon is real. Then there's the fact that canon is 
> actually words on a page.
<snip>
> She didn't in PoA. But leave aside for the moment that there's any 
> author of this universe. Imagine we can't argue it from that angle 
> and say "this is the way JKR writes it" or even "this is the way we 
> would have experienced it if it were true." 
> 
> Just think Sirius is a man confronted by a deadly curtain and his 
> cousin, about to fall through it. Just as Harry was a boy 
confronted 
> by a deadly Dementor about to kiss him. For either of them to 
travel 
> from their own future, they need to live into that future to do it. 
> Harry did, Sirius didn't. Sirius fell through the veil. 
> Harry...well, how did he live to become his future self that did 
not 
> yet exist at that moment? 

zgirnius:
I disagree that one can consider time travel in the Potterverse 
without considering how it was written. It is a universe endowed with 
certain laws by its creatrix, which govern, among other things, how 
time travel works. I guess we agree on what those laws are, something 
I had failed to understand from your earlier posts. 

The point you seem to want to discuss is how time travel *really* 
would work, logically, in our world, supposing it was actually 
possible, and someone invented it. Am I understanding your point 
correctly? 

If so, these laws are not known for our own world; they are a subject 
of disagreement among experts in the field of theoretical physics. I 
have sufficient familiarity with the esoterica of theoretical physics 
to have an opinion (I essentially completed a physics major, 
including a full-year course on quantum mechanics) before deciding to 
go to grad school in pure math), though not one I would assert with 
any authority. Until someone builds a time machine, I would say it is 
up in the air, my preference is based on the subjective criterion of 
what makes the most sense to me.  There are different interpretations 
of quantum mechanics acccepted by different experts in the field, and 
they yield mutually contradictory conclusions about the likely nature 
of real-life time travel.

The 'many worlds' interpretation would suggest that time travel would 
permit us to "change the past" with explanations about alternate 
timelines and universes existing. The 'consistent histories' 
interpretation (on which the Novikov Consistency Principle formulated 
and popularized by the Soviet physicist Igor Novikov and already 
mentioned in this thread is based) would suggest that we cannot 
change the past, as it seems is the case in the Potterverse.

FWIW, I side with Novikov and believe Rowling got it right, though I 
very much doubt it is due to her familiarity with theoretical 
physics. It is after all one of two choices she could have made. I 
think it was what made the most sense to her, as it does to a certain 
proportion of the posters who have weighed in, myself included. 
(Steve/bboyminn, once *is* bliss!).

--zgirnius, who has just now for the first time wondered whether 
Apparition constitutes a violation of Special Relativity.