Butterfly Effect

[GreatScottMarty]

Is there a rule of thumb for the Butterfly Effect? By this I mean, is there a certain agreed upon amount of time for things to start changing worldwirde? Is this directly related to transportation technology? Or is it at the Author's discretion?

[robertp6165]

Is there a rule of thumb for the Butterfly Effect? By this I mean, is there a certain agreed upon amount of time for things to start changing worldwirde? Is this directly related to transportation technology? Or is it at the Author's discretion?

It's author's discretion.

[Boto von Ageduch]

The term "butterfly" in this forum is often abused. It is
a) sometimes used for more or less direct causality,
b) used as a vindication of random changes we want to have in our TLs.

(Not that I didn't like that procedure. But the term "butterfly effect" implies that something is not predictable. We do exactly this, predict - or rather determine what happens after PoDs. Imho, this does not qualify as butterflies.)

In other words, it's the author's discretion. ;)

[Cuāuhtemōc]

The term "butterfly" in this forum is often abused. It is
a) sometimes used for more or less direct causality,
b) used as a vindication of random changes we want to have in our TLs.

(Not that I didn't like that procedure. But the term "butterfly effect" implies that something is not predictable. We do exactly this, predict - or rather determine what happens after PoDs. Imho, this does not qualify as butterflies.)

In other words, it's the author's discretion. ;)
The most literal interpretation is that one minor change causes a rift which changes everything although it depends on what the change is and who does it affect. But for your question I say that after half a century since the POD, I would make up people.

[GreatScottMarty]

ok so with a post-POD date of 8 yrs is it considered plausible to move up something that happened 20 yrs later in OTL, especially because the root causes already exist. It sounds like I am good moving it up.

[Glen]

Wikipedia's article on the Butterfly Effect (http://en.wikipedia.org/wiki/Butterfly_effect) is a reasonable lay summary of the correct use of the term. Basically, if a system has large differences in outcomes for small changes in initial conditions, this is the butterfly effect, and it is one of the hallmarks of a chaotic system.

The term comes from this example - Imagine weather is a chaotic system. Theoretically, if a butterfly flutters its wings in one part of the world, it may eventually lead to the formation of a hurricane that wouldn't have formed if it had not.

Now then, there is also quantum indeterminacy to consider. Basically, even without a change in starting conditions, if you turn back time and rerun a quantum system, you can get a different outcome (since the outcome in a quantum system is probabilistic, not deterministic). Quantum effects are seen mostly on the subatomic scale, and only rarely scale up to the macroscopic level, as quantum effects tend to cancel out when you have enough of them (flipping three coins, then flipping them three times again, you're quite likely to get different outcomes in terms of % heads and % tails, but flipping three billion coins, and then flipping them again, the % heads and % tails is likely to look quite similar).

However, interesting things can happen if you have a chaotic system that shows the butterfly effect, and some of the initial conditions are quantum (i.e. probabilistic).

One of the things I've been wondering is how much do quantum effects have impact on fertilization of eggs by sperm, and how chaotic is the determination of which egg a woman releases each month. These are microscopic events that have a chance of producing some rather big effects on the macroscopic world.

Of course, since by its very definition, Alternate History involves changes to the initial conditions of history. If you change a single event, how far does it reach and how quickly? How much else changes from the fact that further changes to the initial conditions of events downstream from the initial POD are occurring, intentionally or not? And how scalable are quantum events, is the mere act of running a timeline again causing changes, small at first, but then propagating over time.

No one really knows the answers to these questions. Authors should choose how much change occurs and when as best fits the story they are telling, but in an internally consistent manner.

My current basic rule of thumb is that in about 60 years from the POD most of the major people actively impacting historic events should be different from those of OTL, except for the very long lived. It's usually safe to figure that within a generation, most people being born are not the same (though they may have the same parents and names as some from OTL). The trickiest part is determining the likelihood of the same people (or at least remarkably similar people with the same name from the same parents) being born is within 20 years of the POD. On the other end of the spectrum, you can probably figure safely that people being born up to 9-10 months after the POD are mostly identical genetically at least to those from OTL, 10-11 months nearly so, but those who are born a year or later may be more likely to be AH siblings with the same name rather than the genetic twin of the OTL version.

Now then, the above is clearly true for areas directly impacted by the POD and its easy to extrapolate knock-off effects. However, you have to decide about areas of the world only tenuously in contact with that area. If you think that the quantum effects on reproduction are strong, then it happens the same as the area impacted by the POD (though other events not as much, so history doesn't really start changing til that generation grows up, unlike in the POD impact zone). If, however, you think that reproduction is mostly deterministic, then you need to have some impact from the POD leak through before changes start, and they might be smaller changes at first. Now you also have to ask how chaotic of a system are human societies? Chaotic enough that even small amounts of change reaching them from the POD could lead to big changes in the history in those areas? In that case the changes can travel as fast as news. Are human societies more deterministic? Then it will take some significant changes leaking through from the POD before anything changes, news or no.

So those are a few talking points. My latest timeline, the Dominion of Southern America (http://www.alternatehistory.com/discussion/showthread.php?t=149643), is using what I call Retarded Butterflies. The POD is rather smallish (two men exchange jobs, essentially), but those lead to changes first in their provinces, then in their empire, and then in the world. The main impact really doesn't strike until a decade after the initial POD occurs. So I don't have many butterflies in that first decade, but by the end of the next they are really taking flight, and by the third decade things are changing in half the world (of course, changing the outcome of the American Revolutionary War can have some impact :)). I basically ignore the possibility of quantum indeterminacy scaling up, but once changes reach a certain critical mass in an area, the butterfly effect begins to impact. For North America and Britain, this is basically during the American Revolutionary War. For France it is starting to hit during the Reign of Terror. For the rest of Europe and the European colonies, it begins during the Napoleonic Wars. The butterflies will likely encompass the whole world before 1850, though given the places that are hit last won't really have impact on world history until even later than that, that will be hidden. For all practical purposes, major world history, and even day-to-day lives, are all changed (sometimes more, sometimes less, but changed nonetheless) by the 1820s (which, coincidentally enough, is close to that 60 year rule of thumb of mine).

[Glen]

ok so with a post-POD date of 8 yrs is it considered plausible to move up something that happened 20 yrs later in OTL, especially because the root causes already exist. It sounds like I am good moving it up.

Depends what the thing is, and whether it is demonstrable or at least plausible for it to occur earlier in this new history. But theoretically, yeah, you're good to go.

[GreatScottMarty]

Interesting. I can't say I have given the butterfly effect that much thought (which is why I started the thread :D). Your rule of thumb as you explain it are good rules of thumb.

I was thinking of taking my TL out to about 1900 or so. I can't say I am pre-planner and I am more interested in just seeing how it plays out. I was asking because I wanted to make the Barbary Wars happen earlier, to sort of spur along some developments in the US military that I thought would be necessary, for my larger goal.

Thanks