The 2004 film The Butterfly Effect was bad, but its badness wasn’t just a product of Ashton Kutcher’s horrible performance, Amy Smart’s scenery chewing, or director Eric Bress’s bruised pallet. The movie failed for a scientific reason: It’s eponymous premise, a theory first espoused by Edward Lorenz in 1972, was being applied nonsensically. The notion that small events inevitably affect outcomes, much less the lives of specific people, is ridiculous. The future is more predictable than Hollywood would have us believe.

It feels right that the best example of how Lorenz’s butterfly effect has co-opted and done damage to the time travel genre is a movie that bears the name of the theory (thought experiment might be a better word). The film is built around the idea that its main character can travel back in time and inhabit his younger self with his older, wiser brain that’s full of bad memories so that he can right some wrongs and figure out a way to manipulate time into giving himself and those closest to him a happy ending instead of the dark and tragic future they’ve been dealt. But, because everything is connected he inevitably changes stuff for the worse. Nothing works out.

Time does present very real paradoxes and it makes causality hard to understand, much less explain. As such, it’s a popular tool for story tellers — so much so that many workshops use it as an example of a cliched premise. Still, whatever one thinks of the narrative possibilities, the whole thing crumbles if every action taken in the past has the potential to influence everything about the future. It gets too easy to get lost in the details. Fake scientific thinking replaces both propulsive plot and real scientific conjecture.

Edward Lorenz came up with the idea of the butterfly effect while studying chaos theory and trying to come up with a way to predict weather over long periods of time. What he discovered was that weather is produced by a system so sensitive to slight changes in conditions and variables that it is impossible to predict in the long term. Sudden cold fronts, changes in wind patterns, fluctuations in barometric pressure, and human behavior can affect the weather in unpredictable ways. When one thing changes, it affects weather conditions in many other places. It is essentially the domino effect, but nonlinear. Where the domino effect describes one thing leading to another in a chain reaction, the butterfly effect, like other chaos theory concepts, describes something unpredictable with lots of variables.

It’s easy to see how this idea can be applied to time travel. The stakes get high if you assume that a 30-second delay caused by, let’s say, lost keys, can have a profound effect on a human life. That’s a compelling idea, but it’s also nonsense because human lives don’t work like the weather. One thing can lead to another with humans, but it can also not. Sometimes we just walk faster to make up for delayed time. Sometimes our decisions don’t affect anything at all.

When our decisions do affect change — let’s say in some sort of time loop — it’s hard to imagine that the change will be super easy to track. Maybe we can, as Lorenz would suggest, cause it to rain by accident. That could change a lot about the world, but it would do so in such a convoluted way that we’d never be able to understand or draw any conclusions about how we changed the past. And if we changed specific personal decisions, it’s very possible nothing would happen. It’s very easy to overestimate individual agency.

And this is where the butterfly effect fails the writers and directors who wish to employ it as a narrative device. The Butterfly Effect didn’t really even engage with the significance of the butterfly effect. Ashton Kutcher’s changes were easy to track and limited in scope and had very specific consequences. Chaos theory implies unpredictability. Chaos. But that wasn’t the point of the movie. Instead it was about making very specific changes that had easily understood consequences, which is ridiculous and implies a completist understanding of moments in time that seems implausible.

Here’s the deal: If you go back in time and change history, stuff might change profoundly and it also might not. The chances that you’d be able to observe a potential change are minimal.

Time travel narratives really only make sense when they involved big events. If you’re going to go back, you’ve got to kill Hitler or the scene when you return to your natural time will be a confounding dud. Assuming extrapolation is as ridiculous as trying to beat back a hurricane with the wings of butterfly. That’s just not how it works.

Photos via Flickr/Kerry Randolph

Megan is a freelance writer whose work has appeared on WIRED, Slate, Travel + Leisure and GigaOm. When she’s not writing, she’s hiking, brewing beer, and extolling the virtues of The Cranberries.