# Need clarification on the 'Butterfly Effect'... **URL:** \ **Category:** Factual Questions\ **Created:** [April 24, 2000, 2:20pm UTC](https://boards.straightdope.com/t/need-clarification-on-the-butterfly-effect/11104 "2000-04-24T14:20:00Z")\ **Posts on this page:** 2\ **Page:** 2
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [April 26, 2000, 1:18am UTC](https://boards.straightdope.com/t/need-clarification-on-the-butterfly-effect/11104/21 "2000-04-26T01:18:00Z")
> [@](#): > > Originally posted by SingleDad: > **Which small event “caused” the hurricane? Note that they _all_ didn’t cause it; if you remove all the small causes, the hurricane reappears! This experiment shows why small effects shouldn’t be considered a “cause” in the ordinary sense of the word.** Well, now we’re just arguing about what is the ordinary sense of the word. I maintain that there _is_ a sense of the word that allows the _butterfly effect_ to make sense. What was the cause of the the first world war? In many textbooks, it’s a small thing, really, and many historians have argued that it didn’t really “cause” the war–that there were larger issues without which the war wouldn’t have occurred. That’s the same sort of argument here. The butterfly effect illustrates mathematical chaos–and your examples bring up an interesting question: If you start two experiments, one with A and the other with A+x, and they result in f(A)=B and f(A+x)=C, can you find any other value y close to A so that f(y)=C also? In terms of your argument, you assert that the hurricane that was caused by the butterfly would have been caused by all sorts of other small things, too, and would have been prevented by many others. That’s easy to assert, hard to show. In fact, for some chaotic functions, you _cannot_, which makes the argument invalid, until you prove that this is not one of those functions. ---
**Author:** ![Doug\_Bowe](https://avatars.discourse-cdn.com/v4/letter/d/df788c/32.png) [@Doug\_Bowe](https://boards.straightdope.com/u/Doug_Bowe)\ **Post date:** [April 26, 2000, 5:01am UTC](https://boards.straightdope.com/t/need-clarification-on-the-butterfly-effect/11104/22 "2000-04-26T05:01:00Z")
Dex put in his two cents. May I put in mine? “Classic applied mathematics presumes an orderly periodicity that rarely occurs in nature…chaos theorists have set about constructing deterministic, nonlinear dynamic models to elucidate irregular, unpredictable behavior.” The above quote is from Columbia Encyclopedia…I ain’t that literate. Long story short: You don’t need a time machine to demonstrate chaos theory. All you need is _5 days of weather._ You see, it was chaos theory that first suggested that after 5 days weather information would contain too many dynamic variables to produce an accurate forcast. And that’s when a lot of weather people gave up trying to take their predictions out a week. So you are seeing chaos theory at work when you see the 5 day (not 6 or 7 day) forcast. Thanks. [Previous page](https://boards.straightdope.com/t/need-clarification-on-the-butterfly-effect/11104.md?page=1)