A terrible forest fire broke out one day, and all the animals fled their homes. But one hummingbird zipped over to a stream, got some water in its beak, and rushed back to the raging fire. The little hummingbird tried to douse the flames with a few drops of water, then back to the stream it flew to retrieve more water. The other animals watched in disbelief. They asked the hummingbird what it was doing—one tiny bird would not make a bit of difference. The hummingbird replied, “I’m doing the best I can.”
On a winter day 56 years ago, Edward Lorenz, a mild-mannered meteorology professor at MIT, entered some numbers into a computer program simulating weather patterns and then left his office to get a cup of coffee while the machine ran. When he returned, he noticed a result that would change the course of science.
The computer model was based on 12 variables, representing things like temperature and wind speed, whose values could be depicted on graphs as lines rising and falling over time. On this day, Lorenz was repeating a simulation he’d run earlier—but he had rounded off one variable from .506127 to .506. To his surprise, that tiny alteration drastically transformed the whole pattern his program produced, over two months of simulated weather.
The unexpected result led Lorenz to a powerful insight about the way nature works: small changes can have large consequences. The idea came to be known as the “butterfly effect” after Lorenz suggested that the flap of a butterfly’s wings might ultimately cause a tornado. And the butterfly effect, also known as “sensitive dependence on initial conditions,” has a profound corollary: forecasting the future can be nearly impossible.
It seemed to be going one way, and it turned out to go the opposite. The disaster is overwhelming, and you are powerless to change the tide. What do you do now? Be a hummingbird, be a butterfly. Do your best against impossible odds.
The hummingbird and the fire is a Japanese folktale, but you might like to hear it told by a masterful storyteller, political activist and Nobel laureate.
The story of Edward Lorenz is quoted from this article by Peter Dizikes in the MIT Technology Forum, Feb. 22, 2011.
And impossible things? They are happening every day.