Time Travel and Chuck Berry

[greatelderone]

No: HPFGUIDX 92997

--- In HPforGrownups at yahoogroups.com, "Robert Jones" 
<jones.r.h.j at w...> wrote:
> But this is like the Chuck Berry paradox from the movie "Back 
> to the Future" where the Michael J. Fox character learns Chuck 
> Berry's guitar licks off Chuck's records but then teaches Chuck 
> those same licks over the telephone — so Fox learns the licks from 
> Berry who learns them from Fox, and so on, and so on.  In effect 
the 
> earlier Chuck Berry learns his licks from the future Chuck Berry. 
> So there is no point in this loop for Chuck to actually create the 
> licks. 

But it's created. You are missing that fact that it exists. As to 
where it comes from who know? Probably the same place where space, 
time and everything else originated.

> And the same problem applies to Harry: Harry2 can make a 
> Patronus because Harry1 saw him already do it because Harry2 did it 
> because Harry1 saw . . .  At no point in the loop can Harry2 gain 
> the confidence to produce the Patronus.

Harry 2 gains it from seeing himself do it hours before suspecting 
that it was his dad. You are missing the fact that the loop keeps 
repeating infinitely. Harry I see Harry 2 accomplish it. He thinks 
it's his father then travel back in time then realizes that he was 
the one not his father which gives him the confidence to accomplish 
it. Then Harry I sees it and thinks it's James. The loop goes on and 
on with no beginning and no end.

 
> Bobby:  But my point is that JKR accepts that time-travelers can 
> change history and so if she uses it again she can do whatever she 
> wants to the plot (and that makes it a crumby plot device).

It's a simple mis-step. She figured out the concepts of the idea 
indepedently so she was bound to make a misstep. Classify this as a 
flint.