Time Travel

There's a particular view of time travel that seems to be preferred by tv and movies. This view is that someone can travel back in time and change something which alters the future. Let's say the character lives till 2010 then travels back to 1980 and changes stuff then travels back to 2010. In the show his time line is continuous from 1980 to 2010 then jumps to 1980 then jumps to 2010. The "first" time he is in 2010 in the past there is only one of him in 1980, the time traveling him hasn't visited that time. The "second" time he's in 2010 in the new history of the world there were two of him in 1980, one the normal and one the time traveler.

Ok, before we go further we have to allow physics to be broken in order to time travel, and even bigger we have to allow causality to be broken. It is difficult to proceed with a logical argument once we're allowing causality to be broken, but logic minus causality is one more thing we'll have to allow for this post to proceed.

It's always seemed to me that if someone time travels from 2010 to 1980, then in 1980 there are two of him and all of the resulting consequences, no matter if it is the "first" time he gets to 2010 or the "second" time, since there aren't two 1980s. (Sometimes shows touch on the idea of switching to a different universe when the time traveling occurs - that would solve the problem, but then the person is both time and universe traveling, not just time traveling*). So that's not a new idea. But what finally occurred to me is why the two different 1980s view of time travel is so natural for TV - you are following the character who time travels and time is progressing based on his view of time so it is possible to see each moment in time more than once as soon as he starts time traveling. Even in a story with many characters, the story will take the view point of only the time traveler for that part of the story. (Heros may be an exception to that rule, but Heroes' time travel rules were really wacky, remember the crazy mesh of strings they called a timeline?)

If a TV show had to draw a time line (based on the reference of a third party - or a non-time traveling character) they would be hard pressed to make it work with this view of time travel. It would be equally difficult to make this work if they also showed events from the perspective of a non-time traveling character. Especially since the time traveler's friend's memory contains one set of events during the "first" 2010 and a different set of events during the "second" 2010.

So I blame the linearity of story telling and the tendency to perceive the story through the view point of a single character for this persistent view of time travel.

Although since we've dropped causality maybe I blame this persistent view of time travel for the linearity of story telling.

(*The universe hopping version of time travel is also somewhat less satisfying since if the character goes back in time to save someone they're not actually saving the person in the original universe, but rather just choosing to live in a universe in which the person survives - that seems to make the story much more shallow. Although I guess if they're not sure how time travel works they could still be well intentioned...)