‘Why can’t I change history? is such a common and complicated question it gets a packet for itself.
Firstly, just don’t try it. It’s not legal, you’ll get caught.
But residents of Haven often don’t accept ‘It’s illegal’, so just be aware it’s basically impossible for you to do that. You’ll break the law, and also accomplish nothing.
Why is very complicated
You can live your entire life in Haven without knowing any of this. Just don’t worry about it. But if you must know:
Fictional misunderstanding of Time Travel
Depending on what timeline you are from and when, you have probably seen fiction that talks about time travel and changing history. Time travel as a concept shows up in the 1700, and by 1887, Enrique Gaspar had his upon the idea of altering the past and causing paradox in the novel El Anacronópete.
The first thing you should understand is that ‘timelines’, as we use the term, are not the same as your idea of what they are.
No one is quite sure exactly when the concept of ‘a timeline’ entered science fiction. The origin appears to be a concept from the 1870s of a ‘time-line’, a piece of paper divided by intervals of time that you could draw on, a concept that still exists in scheduling today. No one is sure how fiction decided on the idea of altering history and getting multiple versions of that ‘timelines’ that split off from each other.
That’s not how timelines work.
Timelines
Timelines are not individual lines. They are not singular linear chains of events. They start out that way, but time travelers moving up and down them, even without deliberately changing things, create nearly identical versions of those lines with in the timeline, called ‘threads’. Any time travel (with some exceptions) causes a new thread, and their mere existence or a person cause air patterns to shift, small chaotic variations, so that thread is very slightly different.
These threads all stay next to each other, hundreds of them created from all the time travelers, and that forms a timeline. Whenever you arrive in the past, you split off a thread.
Within that timeline, the threads are almost identical, but not quite. And they constantly shift around, influenced by other threads, they becoming more and more similar. Individual threads eventually become so similar that they merge and become one thread.
If no one ever time traveled again, the timeline would eventually collapse down to a single thread.
Even deliberate changes get averaged like that. It just takes longer. You cannot change history just by changing the thread you happen to be in.
Mathematically, the ‘mode’ of the timeline, aka, the most common threads, appears to be an attractor that bends things towards it, but often in a chaotic and unpredictable manner. Sometimes the change towards it will be simple, other times infinitely complicated.
If this is all too complicated, another metaphor has recently been proposed: a room full of identical photo mosaics. Hundreds of them, all looking exactly the same twenty feet away. That’s the ‘timeline’, what all of them look like. But when you get very close, you can see almost all the photos in the mosaic are identical, but a few photos are slightly different…and sometimes there is a photo that are very very different, which would be a time traveler trying to do a change on purpose. And yet, somehow, the total image looks the same if you step back. And, to continue the metaphor awkwardly, the photos in the mosaic slowly shift to become more identical, and if any two mosaics are ever exactly identical, they merge.
New threads are not ‘branches’
When a new thread is created, it copies the entire existing thread it is from, past, present, and future, to a certain distance. Go far enough enough in the future, the changes have averaged out, and the same with the past.
It is as if time travel is creating temporary bulges that exist for a bit, of an extra thread. And this bulge slowly disappears, the changes slowly eroded way until it merges back in. How much bulging there is at any point technically called ‘density’.
But I did change something, that’s how I ended up here.
A few of you are very confused right now, because you got grabbed by one of the temporal enforcement authorities and told that you just changed history, and dumped in Haven. But you didn’t, really. They just didn’t want to explain what really happened. A better way to describe that that is you made a new thread and pulled it far enough out that it didn’t trivially average back in.
Most time travel doesn’t change anything, and the only thing that needs to average is slight air movement and footprints. That’s fine, no one cares about that. And even go past that. You can buy food, interact with people, whatever.
Fiction has the concept of the butterfly effect, where very small changes can ripple out and cause large changes. But the truth is the opposite, that things you do usually are damped down by the other threads, and don’t matter.
Unless you try. The larger the change, the more impact it has, the longer it takes to average out. This is because changes happen slowly, it might bounce off another thread, and lose, but the loss might be very small and it’s just barely changed.
Which means deliberately changing history will often create enough of a disruption that a TEA will show up to make sure that thread doesn’t do anything. They’re not trying to ‘fix things’ or ‘undo the changes’, they’re trying to make sure the thread you made doesn’t statistically slightly move the average. That’s likely all you could have possibly done.
They do this with a device called a ‘thread inducer’ that they place in a nearby thread, or sometimes more than one. It’s complicated, but that device just does a lot of time travel internally. This causes new threads to be created that are almost perfectly identical. This is called ‘increasing the density’.
This ‘cheats’ what the average is, and very quickly averages out what you did.
So it’s impossible to really change things?
It is not. It can even happen randomly.
Let’s say a time traveler goes back in time and takes a rock. They’re not trying to change anything, the rock doesn’t look important.
What normally happens all time is that the rock-less thread eventually averages into non-existence. It keeps bumping up against other threads, with rocks, that average existence-of-the-rock eventually win out, and the thread will alter itself enough that the rock is still there, or the entire thread will merge away, or something. It’s hard to define what truly happens, because anyone in the thread to observe it also be an additional change to get rid of. So no one is quite sure what actually happens, mechanically.
But regardless of how the interaction between threads work, your new thread can, hypothetically, win. Each interaction with another thread is a coin flip, and as long as it keeps winning the coin flip, it will slowly move all the timelines into not having the rock, instead. The odds of this happening are very small.
This basically doesn’t happen except for very trivial things.
The changer can cheat too
However, you can take a thread inducer and put it in your changed thread, instead. So it’s going to win most interactions.
This is why, incidentally, thread-inducers are illegal for non-TEA possession or sale in all timelines and on Haven.
But even if you had one, using is more complicated than it sounds.
For starters, if you’ve made a large change, and someone is trying to undo it, they can place multiple thread inducers in multiple nearby threads to reduce stress on any particular thread. But if you’re trying to illegal make your thread win, you only have a thread inducer in that one thread, you can’t distribute it to multiple ones to reduce stress.
Also, statistics are against you, because with trying to undo a change, it really doesn’t matter if the change wins a few times, eventually it will lose, just by sheer statistics.
Whereas if trying to make a change permanent, you have to make sure that you don’t, by sheer random chance, happened to lose near the start, and have your changes erased, and then you can’t even win.
So you have to crank the inducer way, way up.
And if the change is big, you may need to do that so high that it breaks the timeline.
Breaking the timeline?
If you try hard enough to make sure that new thread wins, if you increase the density past a certain point while making large changes, it can detach from the timeline, and create a parallel timeline right next to it.
This is almost certainly how we ended up with the three MTP timelines to start with. It is assumed that there was some sort of time travel event, or multi events, extremely far back, that created three nearly identical timelines.
Those timelines are ‘far apart’, when mapped, with empty space between them. They likely drifted apart, presumably because of a very long time without any time travel.
Which means the split likely happened centuries earlier, at least that’s the accepted theory. No one knows why or how or anything about this. It’s extremely unclear how anyone could have been time traveling centuries again.
But there have more recent splits, on a few documented instances. As the two timelines sit very close each other, if time travel continues in either timeline, eventually they will collapse back together, and the most dense will likely win.
Basically, what normally happens at a thread level happens at a timeline level, and just like with threads, the most dense version usually wins. We think.
There is an extremely well known example of this, the creation of the Collective timeline. The first directed time travel, ever, in that timeline, was over thirty years in the past and done in an extremely deliberate manner to create huge changes. That immediately split the timeline in half. And as their temporal agency was created in that new timeline, and started time travelling there, it increased the density there and doomed the original timeline even before they realized what would happen.
This Welcome Packet prepared by the Haven Provisional Government.