Let's Kill Hitler!
Something that comes up somewhat often in time-travel works of speculative fiction is the whole "changing the past" thing. Recently, in Doctor Who, the whole predestination paradox (or as I like to call it, 'circular causality') thing has been cropping up quite a bit. Technically, it happens just about any time anyone goes back and tries to make sure history works out the way they remember it to be -- they're operating on memories of the corrected past, even though at the time, the non-corrected past is the subjectively 'proper' past.
Recently, in watching Rocky & Bullwinkle on Hulu, this even comes up in Mr. Peabody's Improbable History. In the first episode, Peabody and his boy go back in time and realize it's not very fun, since they can't change anything. So, they pop back to the present and re-adjust the Wayback Machine so instead of taking them to the past that was (and thus, immutable), it takes them to the past that could have been (which is a pretty cool way to introduce the Everett Many-Worlds Theory to folks).
Which, of course could lead to the fun of someone from a different time-line hopping to the 'proper' time-line and trying to make sure things work out the way they remember them to be.
Yes, it was this that prompted me making this Userpic
Recently, in watching Rocky & Bullwinkle on Hulu, this even comes up in Mr. Peabody's Improbable History. In the first episode, Peabody and his boy go back in time and realize it's not very fun, since they can't change anything. So, they pop back to the present and re-adjust the Wayback Machine so instead of taking them to the past that was (and thus, immutable), it takes them to the past that could have been (which is a pretty cool way to introduce the Everett Many-Worlds Theory to folks).
Which, of course could lead to the fun of someone from a different time-line hopping to the 'proper' time-line and trying to make sure things work out the way they remember them to be.
Yes, it was this that prompted me making this Userpic