By: David Dai
It fell to the floor, an exquisite thing, a small thing that could upset balances and knock down a line of small dominoes and then big dominoes and then gigantic dominoes, all down the years across Time. Eckels’ mind whirled. It couldn’t change things. Killing one butterfly couldn’t be that important! Could it?–Ray Bradbury, A Storm of Thunder (1952)
You’ve probably encountered the idea that small actions can lead to drastic, unimaginable changes. After all, you can never predict what happens in the future, right?
Of course, it captured certain figures’ attention as well, including French physicist Henri Poincaré, and American mathematician Norbert Wiener. But I’d like to focus on a man named Edward N. Lorenz (1917-2008), who not only addressed this very confusion, but also would’ve become closely linked to this blog’s topic–the butterfly effect.
How did this come about?
Lorenz, the meteorologist
After his studies at MIT in the 1940s, Lorenz engaged himself in the field of meteorology. He then became interested in NWP, which predicted future weather states using computer models. By the late 50s, Lorenz realized that linear models were ineffective at predicting weather–they were too unrealistic. Weather, as he knew, didn’t work like this.
A Day of Breakthrough
One day in 1961, using a simple computer model, Lorenz wanted to redo one of his weather predictions. Instead of repeating the whole process, however, he started the run from the middle as a shortcut, inputting the initial condition from the first run. Soon after, the weather patterns of the two runs diverged. How could this happen, since the simulation program used was the same! It turned out that significant figures were really significant! Instead of entering the full precision 0.506127, Lorenz only entered the rounded-off 0.506, from the printout. Since initial conditions could not be accurate completely, how could perfect weather prediction ever happen?
One meteorologist remarked that if the theory were correct, one flap of a sea gull’s wings would be enough to alter the course of the weather forever.Lorenz, Edward N. (1963). The Predictability of Hydrodynamic Flow
In order to connect to a larger group of audience, Lorenz began to use the more poetic “butterfly”.
From Seagull to Butterfly
On the day of December 29, 1972, Lorenz gave a presentation where the term “butterfly effect” grew from. What does the phrase imply? In a nutshell, the butterfly’s wings could create tiny changes, so that the final trajectory may be changed. Note this is not saying they would create a tornado directly! Rather, the wings have the potential to cause one; tiny changes can escalate into massive alterations of events. This effect, since then, serves the basis of chaos theory–a branch of mathematics that deals with unpredictable behavior in systems.
Why the Fuss?
Lorenz’s findings shattered the classical understanding of nature, namely, that of Newton and Laplace. They would prove to be revolutionary, exerting influences on diverse fields such as economics, business, geology, even biology. Thanks to James Gleick’s 1987 bestseller, which introduced to readers the world of chaos, the term “butterfly effect” has reached the general public successfully.
And of course, pop culture. Indeed, the media continuously misunderstood the effect, by embracing the idea that small changes at the beginning lead to dramatic outcomes. But, you may now argue that this is not true. Because, it is nearly impossible to forecast the future–after all, how can you predict if the outcome will be as significant as a tornado, or as trivial so as nothing really happens!