[HPforGrownups] Time Turner Question

[Wildean]

No: HPFGUIDX 68931

From: "stardancerofas" <glcherry at bellsouth.net>
Subject: [HPforGrownups] Time Turner Question


> I think it was hermione, who said wizards had gone back in
> time and messed up, killing their selves? If time is time, they were
> alive when they went back, but if they kill their past selves how can
> they be alive to come back?

They can't have travelled back in time and killed themselves. This is
impossible, and is known to time travel theorists as the Grandfather
Paradox.

Basically, it states that if you travel back in time and (deliberately or
otherwise) kill your grandfather before he met your grandmother, then one of
your parents will not be born, and so neither will you. So you can't travel
back in time and (deliberately or otherwise) kill your grandfather before he
met your grandmother, because you don't exist. Are you still with me?
If this happens, no-one will travel back in time and (deliberately or
otherwise) kill your grandfather before he met your grandmother, so he's
free to meet your grandmother and your parent will be born. OK so far?
If this happens, you will exist and can in fact travel back in time and
(deliberately or otherwise) kill your grandfather before he met your
grandmother, then one of your parents will not be born, and neither will
you.
(the previous two paragraphs can be repeated endlessly)

What this all means (and I deliberately made it seem complicated because -
well... it is - sorry about that) is that it will give the poor writer a
headache if she tries to write it, and give the poor universe a much bigger
headache trying to sort it all out.

Wildean
(Everything I learned about time travel I learned from Doctor Who)