Yet Another Time Turner Q

[judyserenity]

No: HPFGUIDX 33196

--- In HPforGrownups at y..., "tex23236" <jbryson at r...> wrote:
> Science Fiction has many ways of dealing with time travel.  The one
> JKR seems to have selected is the idea that the time traveler can't
> change history. In fact, in this solution, the time traveler often 
> causes the events that happen.  For example, if Neville breaks 
> something, he can't go back in time and prevent the accident.  In 
> many time travel stories of this sort, the time traveler causes the 
> thing he was trying to prevent. Harry saw himself, then went back 
> and conjured the big patronus.  His time travel caused the final 
> state of the reality.  I suspect Dumbledore's admonition that they 
> not be seen had more to do with witnesses seeing them when they 
> were supposed to be elsewhere, but that's just me.

I agree completely -- in the Potterverse, it seems that time travelers 
don't change the past; any effects of time travelers are right there 
in history, all along. 

In fact, this view of time travel has often been proposed in serious 
scientific discussion of the topic. The idea is that anything that 
happened in the past has, by definition, already happened.  So, 
suppose a person wants to go back in time and save Abraham Lincoln 
from assassination.  We *know* that they will fail.  How do we know 
that?  Well, because if they had suceeded, Lincoln would not have been 
assassinated, and our current history books wouldn't say that he was 
assasinated.  After all, whatever happened to Lincoln, happened over  
a century ago.  From the point of view of the time traveler, it might 
*seem* like it hasn't happened yet ("Tomorrow, I'll get in my time 
machine and go back to 1865"), but this is an illusion.

(There is another serious view of time travel, that time travelers in 
fact arrive in a parallel universe that just seems like our own 
universe.  But, JKR doesn't seem to have any interest in parallel 
universes.) 

Is there anything in canon that suggests time travelers can change 
history?  Well, Hermione talks about the problem of killing one's 
"past self."  This implies a change in history; if the time traveler 
had died in the past, he'd be in a grave, not getting into a time 
machine. But, maybe Hermione was misinformed; she heard about this 
second-hand from McGonagall. 

What about Dumbledore's statement "You must not be seen?"  Well, this 
could be interpreted as a warning to stay out of trouble with the 
Ministry of Magic.  But, there's another interpretation.  It could 
tell Harry and Hermione what they will be *capable* of doing, thus 
giving them guidance about what they should try to do.  The idea here 
is, if history doesn't tell us what happened, then maybe time 
travelers were involved, and we just don't know about. There's no 
point trying to save Lincoln, because we know he was assasinated. But, 
what about saving Amelia Earhart?  Well, no one knows what happened to 
her.  So, if we have a time machine, we might as well go back in time 
and try to rescue her.  Who knows, maybe we succeeded and just don't 
know it yet. 

No one saw two Harrys or two Hermiones wandering around.  So, 
Dumbledore knows they weren't seen, and is telling them they shouldn't 
try anything that requires being seen; he knows it will fail.  By the 
way, this rule (no point going back and trying to do something if we 
already know we didn't succeed) explains why Hermione doesn't try 
going back to the Charms class that she missed. Harry and Ron told her 
she was absent, so she knows that her absence has already happened and 
can't be changed. 

When Dumbledore says "You know the law", he could in fact be referring 
to *natural* law, the laws of physics.  Hermione doesn't seem to take 
it this way, but then, a 13 year old would find time travel confusing, 
even if she were very bright. 

Of course, maybe it's JKR who hasn't thought time travel through.  
But, I'd like to find a way to make the story consistent.