After reading a recent post from Yumeka, I wanted to write about my own theory of time travel, in a sense rewrite the comment I made. Let me preface this by saying that basically everything here is pure speculation. I simply look for an explanation that has the fewest inconsistencies…it could be totally wrong for all I know. Time travel is a topic that is often rife with paradoxical scenarios, so I just try to address as many of these as possible. Also, this is a purely theoretical interpretation of the concept with no considerations to the practical implications of actually creating a device that can achieve it (I don’t really care about black holes and whatnot for this).
In general, there are two broad interpretations of time travel. First, there’s the idea that time is immutable, so any trip back in time would have already happened. In this scenario (let’s call it the “constant theory” of time), it’s impossible to change history because whatever you do should already have happened. The second case (let’s call it the “variable theory” of time) is simply the opposite, where going back in time creates a new timeline with an altered future. Each case has a subset of cases with minor differences, but for the most part, all theories of time travel will fall into one of these categories.
My idea is a subset of the variable theory of time, so let’s look at the constant theory first. This is a hypothetical scenario that a friend of mine proposed in a random Skype conversation. Say you’ve been offered this choice: you could gain Jedi powers (he’s a huge Star Wars fan, can’t you tell?) or gain access to a Delorean like the one in Back to the Future. My friend asks “why can’t you just pick the Delorean, then travel back to the past to tell yourself to pick the Jedi powers?” Well, according to the constant theory of time, a second “you” would appear as you’re making this brilliant plan to tell you to go for the Jedi powers.
In order for the constant theory to hold, you must somehow be stopped from choosing Jedi powers because doing so will change history. But in this scenario, the choice is a result of your will, so there really isn’t anything stopping you from just changing it. It’s almost as if some personification of time itself has to stop you. Granted, the whole scenario is a bit much, but even in popular media, it seems like there is some unknown force that makes the protagonist repeat the actions from his past (almost like everything is too convenient).
For example, when Kyon goes back in time in Haruhi and when Harry Potter uses the Time Turner, they are both instructed not to do anything that could cause a temporal paradox because of the horrible consequences or whatever. But what exactly is it stopping them from just doing whatever they want? What’s to stop Kyon from taking the younger Haruhi to a police box rather than help her sneak into the school? What’s to stop Harry from just pushing his past self off a cliff? I don’t know about you, but I have trouble accepting something like “time will find a way to maintain everything.”
Now that I’ve successfully rambled for a bit, let’s get on to my own theory (let’s arbitrarily call it “Y theory”). The basis comes mostly from Steins;Gate: the concept of an infinite set of timelines (I say they’re parallel in Y theory whereas Steins;Gate has branching of lines to account for alternate futures). In Y theory, it’s almost like a time traveler is moving across dimensions rather than moving forward or backwards in time. So let’s say you wish to travel back to the year 1934 at some specific date and time. Rather than moving yourself backwards in time, the idea is that you somehow move yourself to a nearby parallel line with a universe that is identical to your origin, but has only reached the year 1934…theoretically possible in an infinite number of lines.
That’s the core of the idea. Notice a few things:
- Obviously, this idea stems from the many-worlds interpretation by Hugh Everett from quantum physic. Basically, it’s a theory that for every universe, there exists an infinite number of universes for all possible scenarios within that universe, and it’s a theory I’ve always liked.
- In Y theory, you can change the future, but only in the destination timeline. It doesn’t change the events that have occurred in your point of origin (the idea being that you can change, but you can’t undo).
- You’re going to a timeline where the events up to 1934 have occurred, but that doesn’t mean that the events after 1934 will occur. This idea assumes that there is no encompassing force governing time, so there is no “hard drive” holding “history data” for events after 1934. This may make little sense going backwards, but it makes a lot more sense going forwards. If you travel to a timeline in a future year, then returning to your timeline doesn’t ensure the events that you have seen because you’ve only seen one of the possibilities.
- If you wish to believe the idea from Steins;Gate of determinism of certain events, that’s perfectly fine in Y theory (I think they call it an Attractor Field). The thought is that if you travel to a line within a certain divergence factor of your origin, events such as a person’s death will always gravitate to a certain point in time despite a difference in events leading up to the death. Although, Steins;Gate attributes this to a converging point in the world lines, it’s fine to think of the same idea happening in parallel lines.
To finish up, I want to specify something that differs from what Steins;Gate proposes in order to cover some inconsistencies. When Rintarou travels to the past in some parts of the show, he basically overwrites the Rintarou of that past time period and takes his place. While this idea makes for a very entertaining show and it follows the logic of the show (sending messages back), I feel like it runs into some issues. For example, what happens if you travel to a point in the past further back than your birth? There would be no “you” to inhabit.
Would you inhabit someone else to make up for it? If so, what are the parameters for who it must be? There would likely be plenty of ancestors available. What if the only two ancestors available are both comatose and will awaken later and fall in love? In my theory, a time traveler is moving to another dimension, and is thus “an outsider,” an extra person in that dimension. So if Rintarou traveled in the way I have outlined, he would go back and be a second instance of himself (which he does later in the show).
And that’s basically it. Marth’s theory of time travel. If you were able to follow all of that, then great! Let me know what you think. If something isn’t explained well enough, let me know in the comments below and I’ll see what I can do to help clear things up. I have a lot of fun thinking about these sorts of things. Sure hope it was entertaining…