Time-turner discussion

[TL]

Hii! As I'm rather new myself, I'm not sure if there's been a
discussion concerning this already (if there has, someone feel free
shush me), but I'll take a stab at it.

There is a problem concerning time travel--that is, one cannot (if one
follows logical reasoning), actually change time. Supposedly there is
a "Grandfather Paradox"--if one goes back in time to kill one's
grandfather while he is young, then what happens?

Well, since that would negate you existing, thus you couldn't go back
in time, thus your grandfather would still be alive...it's just not
possible. Something would prevent you from achieving your goal.

Or you could open an alternate universe...but that's a whoooole
'nother cat to let out of the bag.

Basically, if one goes back in time one perpetuates events that've
happened (Such as Cuaron sticking the rock-throwing in PoA...and when
Harry can cast a patronus large enough to throw of the dementors
because "I'd already done it")

I hope I've not sent you all to sleep, XD.

-TL, the rather boring sci-fi fan. (El Goonish Shive! I *love* El
Goonish Shive!)