Time travel in PoA

[gkjpo <kristen@sanderson-web.com>]

No: HPFGUIDX 48983

--- In HPforGrownups at yahoogroups.com, "sharana.geo 
<sharana.geo at y...>" <sharana.geo at y...> wrote:

> The one thing I have realized is why it is so difficult for me to 
> accept it. I've known how to program software since I was 13 (or 
> something) and the process of it has always been easy for me. When 
> you are programming loops, you always need to establish a starting 
> point, set initial variables. To program loops is easy for me too. 
> This is why I understand easily Theory 3 (and time loops), but it 
is 
> the same reason why it is hard for me to believe how a loop can 
> exist without an initial state to set it off.
> 
Ok, I took some aspirin for my time loop headache :).  You've got me 
here, Sharana (beautiful name, by the way).  I am also a computer 
programmer.  However, by comparing the time loop in PoA to a simple 
programming loop is where I think you may be getting confused.  There 
is nothing in programming that could compare to this because no 
program can use the exact same resource in a single thread with one 
copy having foreknowledge of the other (ok, you could probably do 
something with a supercomputer, but we won't go there :).  

I would compare this more to a recursive function (one that can call 
itself, but not get lost in neverland).  In this case, the PoA story 
is a single computer program.  Harry and Hermione enter the timeloop 
function and go all the way through.  If they have satisfied certain 
circumstances (they leave Hagrid's, they enter the Whomping Willow, 
they exit with the group,they go to the hospital, etc...), then the 
recursion is invoked - the original H/H are pushed onto the stack and 
thn H/H(2) go through the loop again with different initial 
conditions that causes them to operate different logic in the loop.

It's not a perfect example - I won't go into the popping of the stack 
and the ordering, etc... but it is the best programming analogy I can 
think of.  In this case, the inital conditions you spoke of in your 
example for entering the loop were the things that happened leading 
up to Hagrid's.  However, the condtions that allowed them to go back 
through the loop were the conditions that occured during the first 
iteration of the loop.  If those weren't met, they would never have 
been able to re-invoke the loop through recursion.  Dumbledore would 
be a static global variable - able to interact and be cognizant of 
every iteration of the loop.

Obviously, this doesn't match up exactly with what happened - as I 
said no programming example could.  I am firmly in the "Time Moves 
Forward" camp. It is the simplest explanation and makes the most 
sense within the context of the story to me.

Kristen