Paradox of Time Travel in PoA - Before & After

[jlv230]

No: HPFGUIDX 137409

> Davenclaw:
> Something at 10pm can't affect something at 6pm until 10pm takes 
> place, but 6pm has to take place before 10pm, right?  So there you 
> have it, plain and simple.  6-10pm happens before 10pm changes 
what 
> happened at 6pm.  If 6pm never happens without the influence of 
10pm 
> then all of time has already occurred and is just being witnessed.

JLV:
6pm takes place before 10pm *to the clock*, but to TT!Harry 10pm-to-
the-clock on Hogwart's wall takes place twice, once earlier-to-Harry 
and once later-to-Harry. You also assume that "6-10pm happens before 
10pm changes what happened at 6pm" which is begging the question. 
You also miss, throughout your response, the crucial distinction 
between `affect' and `change'. These words do not mean the same 
thing. In the context of this discussion, `affect' means `be a cause 
of' and `change' means `to stop being one way and start being 
another'. I steer clear of using the word change because it is a 
temporal term – stop being one way as it was in the past and start 
being another way as it will be in the future. Of course we use the 
word `change' a lot in everyday language, but in a precise 
discussion such as this one we must keep this distinction clear.

> JLV:
> > Your point seems to be that a `future' event may affect a `past' 
> > event on the single-timeline theory. Gasp! You say this is 
> > impossible, and I say that this is the whole point of time-
travel!
> 
> Davenclaw:
> No, my point is that before a future event can affect a past event 
> the past events have to occur without the future events having 
taken 
> place.  There has to be a time when Harry exists at 7pm without a 
> time traveling Harry in the scene because he hasn't time traveled 
> yet.

JLV:
Actually, at 9.15pm-to-the-clock he *has* time travelled in a sense, 
because there are two Harrys around. It must have happened, because 
the effect is there.




> Davenclaw:
> And, um, in case you missed it, most single-timeline theorists 
> insist that time traveling can't change past events, which you 
have 
> just contradicted.

JLV:
I did no such thing. I said `affect'. You read `change'. Please bear 
the distinction I have made in mind because there is a lot of 
potential ambiguity here.

> > JLV:
> > Myself and other posters have pointed out that the dual-timeline 
> > theory you propose is *logically* inconsistent, which I regard 
to 
> > be the worst sort of inconsistency (as anything follows from a 
> > contradiction). 

> Davenclaw:
> I don't see the logical inconsistency with a dual-timeline theory.

JLV:
Okay, but that doesn't mean it isn't there.

> Davenclaw:
> but I also don't see how you can fail to see the huge problem with 
> the single timeline theory.  9pm can't come before 6pm, so 6-9pm 
> must take place before time traveling occurs, meaning that there 
is 
> a timeline without a time traveler before there is a timeline with 
a 
> time traveler.

JLV:
That simply isn't true. Remember 6pm takes place before 10pm *to the 
clock*, but to TT!Harry 10pm-to-the-clock on Hogwart's wall takes 
place twice, once earlier-to-Harry and once later-to-Harry.

> > JLV:
> > So we prefer the single-timeline theory. But not just 
> > from this logical perspective – it is also from a canon one.
> 
> 
> Davenclaw:
> Um, you mean all the canon that says that past events can be 
> changed?  Oh wait, no, you ignore that canon and make up fake 
canon 
> about how McGonagal is a hysterical liar. Or maybe that was 
someone 
> else.

JLV:
Ouch. Is fake canon an oxymoron? Anyway, I didn't say 
that "McGonagal is a hysterical liar". Those are your words. Please 
don't put words in my mouth.

> > JLV:
> > I say that, from the perspective of reasoning alone, I don't 
even 
> > think that the word `change' really can apply to the past - how 
> can 
> > the past *have been* one way *in the past* but *now be* 
something 
> > different? I don't think that even makes sense. In what past was 
> the 
> > past different exactly?
> Davenclaw:
> I'll answer your question with your own words: "I say that this is 
> the whole point of time-travel!"

JLV:
I'm not sure what you mean. I think you've missed my point. Remember 
the `change'/'affect' distinction.

> > JLV:
> > If you remove the book context, the timelines 
> > fall apart *but* (I can hear you shouting) that doesn't mean 
that 
> JKR 
> > couldn't write her book this way! Of course it doesn't – after 
all 
> > there are loads of books that do. 
> > All I am saying is that she 
> > *didn't* write it this way. In your own way, you actually said 
so 
> too.
> 
> Davenclaw:
> The timelines don't fall apart by removing the book context.  
There 
> is just a timeline that must have been there if time travel works 
> the way it is described in her book, which she never realized and 
> never wrote.  The single timeline theory is nonsensical because it 
> requires the future to take place before the past, ALWAYS, even 
> before time traveling takes place, and canon explicitly states 
that 
> traveling in time can change events, which I think necessitates 
> multiple timelines.

JLV:
An event at 10pm-to-the-clock in Hogwarts can affect one at 9pm-to-
the-clock. This what I call `backwards causation'. It can happen 
because Harry was affected by something at 10pm-to-the-clock, say he 
heard the first-time-to-him the clock struck ten. Two-hours-later-to-
Harry he may have heard the clock strike nine, but he had a memory 
of the clock striking ten. The clock striking ten was the cause of 
this memory. This future-to-the-clock event is a past-to-Harry 
event. There is no inconsistency here. There is just a necessity for 
relating past and future to the individuals involved to remove the 
ambiguity.

Alternatively, you could propose a `multiple timelines' theory, in 
which events happen and then are rewritten, and memories are 
modified to `change' them to what they should be as if the new 
events did indeed happen that way the `first time round'.

> Davenclaw:
> It's just that after the time traveling takes place all 
> knowledge of pre-time-traveling events is lost.

Almost as if those events really did happen that way all along. I 
really think this reduces to the single-timeline theory. Why imagine 
events happened that JKR "never wrote"?

> > JLV:
> > All I can say is that I really do think that JKR is writing from 
> the 
> > single-timeline perspective. I support this by again saying that 
> > there is *only one* timeline given in the books.
> 
> Davenclaw:
> Your "support" is simply JKR's mistake or ommission. She makes it 
> clear that traveling in time can change past events but she 
> apparently didn't consider what the events were before Harry went 
> and saved himself.

JLV:
So you are allowed to think JKR made a mistake, but anyone who says 
she might possibly have made a mistake when she wrote Hermione's 
speech is really saying that "McGonagal is a hysterical liar" and 
creating fake canon?
 
> > JLV:
> > It is explicitly stated 
> > that magic cannot bring people back to life. The dual-timeline 
> theory 
> > allows this to happen!
>
> Davenclaw:
> Harry and Hermione's time travel saved Sirius and Buckbeak, so 
> apparently this is an exception.

JLV:
In the single-timeline view, Buckbeak never died. It is your view 
that makes the exception.