I Love Time Travel - Part 19 - Changing Back The Change

(This is as far as I go for now. Nineteenth time’s the charm. I hear Wolverine is time-traveling in an upcoming summer movie.  I’ll have to check that out.)

This is just a little beef I have.  Forgive me.

In a story, when a timeline is altered and time travel is used to fix the problem, there are some plot devices creators have to decide upon.  There are two types of stories that come to mind.  First, there is a problem in the present day, and the time travelers go back in time to change the future, or in one case, retrieve something from the past to fix the problem.  Or there is the other side of that, where an antagonist has gone back in time to change the present and the protagonist must travel back to stop him.

The latter issue presents the most problems.  In Men In Black 3, Agent J witnesses the world without Agent K after a villain goes back in time and kills him.  The world is overrun by an alien invasion and to stop it from happening, J goes back in time.  It is the thrust of the movie and a surprisingly fun one at that.  The most memorable scene happens when J jumps off the Chrysler building with the time travel device in his hand, and he can see the events slingshot all the way back to creation and back the to the 1960’s in one minute. 

But here is where we all notice story snags.  If someone goes back in time and alters the events of the future, what would that be like to an observer?  J experiences a ‘temporal fracture’, because he is the only one who remembers the previous timeline, and a life with K.  In any kind of time travel thinking, J would be just like everyone else.  The timeline would be altered and no one would be suspicious of anything, including our hero.  The simple act of going back in time somehow destroys an entire reality.  This is the basis of single string time travel.  It’s just as nutty as a loop, but for different reasons.  It’s a movie and there has to be someone who witnesses the change in reality. We need Will Smith to save the day, so his reality is given a pass so he can go back and stop the creepy alien guy played by Jemaine from Flight of the Conchords.

The same issue occurs in Star Trek: First Contact.  While being pursued by Picard and crew, the Borg have gone back in time through a vortex to the time where Earth first established contact with other worlds.  The Enterprise sees an Earth ruled by the Borg for centuries, then they follow them back in time to keep the whole thing from happening.  We need it to work out this way in the story, so we have a movie to watch.  But if the Borg went back in time and changed the future, there would be no Enterprise, Picard or anything else.  The reality should extend to all Earthlings and earth ships, not just the ones that happened to be on the planet that day. But the Enterprise is unscathed by the change, even though the entire Earth fell victim to the Borg, and they travel back in time to save the world.

 In other Star Trek lore, Star Trek IV: The Voyage Home is more of the other variety.  Earth is in danger of a weird floating cigar that is altering the oceans and atmosphere and is submitting whale noise.  Whales are extinct, so they go back to the 1980’s to snag a couple of whales to bring them back to talk some sense into the alien craft.  This is my favorite original crew Star Trek movie because it is such a kooky premise and it is pretty funny for a bunch of old stiffs wandering around San Francisco trying to fit in.  The time travel premise was a bit cleaner. Two whales taken from an aquarium and brought to the future would scantly change any timelines, and the Enterprise crew was not affected by the whale peaking alien craft in their own time.  They were not trying to rectify some alteration to a timeline, just averting a natural disaster.

This is where the time travel of story and the physics of a possible time travel event collide.  We can still accept artistic license because time travel is theoretical and art has no boundaries.  We need heroes to take us on a journey, but if the journey negated the hero from existing in the first place, where is the damn story?