The Butterfly Effect

by Don Meyer, Ph.D. | Feb 20, 2010

"Today's forecast is bright and sunny with an 80 percent chance that I'm wrong."

Sooner or later weather predictions let us down. Several years ago I was planning on going to Africa to speak at a conference. Everything was in place. I had taken my shots. My flight was scheduled. The suitcase was packed. The material for my presentation was prepared. But the night before I was scheduled to leave we had a huge snowstorm and my whole trip was cancelled. As I recall, that snowstorm caught everyone by surprise, even the weatherman. 

Aristotle is considered the founder of meteorology. For 2000 years no one really added anything significant to his findings. Meteorology studies the changes in temperature, air pressure, moisture, and wind direction in the troposphere. Of course, it is the sun that starts it all. 

It was in the early '50s that the National Weather Service began using computers to create weather models. Today all kinds of sophisticated instruments are used to forecast the weather. From satellites which track weather patterns across entire continents to radar which shoots radio signals into the clouds and from barometers which measure air pressure and to anemometers which measure wind speed, we are equipped today to make much better predictions. But, we still get it wrong. 

Lewis Fry Richardson said, "Perhaps someday in the dim future it will be possible to advance the computations faster than the weather advances and at a cost less than saving mankind due to the information gained. But that is a dream." 

Dr. Chick Coles recently shared the story of Edward Norton Lorenz (1917-1987), who served as a weather forecaster in World War II with the US Army Air Corps. Following his military service he earned two degrees in meteorology from MIT where he later taught. According to the MITNews website, Lorenz"...tried to explain why it is so hard to make good weather forecasts and wound up unleashing a scientific revolution called chaos theory." 

In 1961, Lorenz was using a numerical computer model to rerun a weather prediction, when, as a shortcut on a number in sequence, he entered the decimal .506 instead of entering the full .506127 the computer would hold. The result was a total different weather scenario. 

At the core of his findings was the realization that small differences in the initial conditions of dynamic systems such as the atmosphere could trigger huge and unexpected results. In 1972 his work led to the formation of what became known as the butterfly effect, a term taken from a paper titled "Predictability: Does the Flap of a Butterfly's Wings in Brazil Set Off a Tornado in Texas?" 

Lorenz became the first to recognize what is called chaotic behavior in the mathematical modeling of weather systems. His work launched a field of study that affected every branch of science-biological, physical, and social. It is now known to be virtually impossible to predict the weather beyond two or three weeks with any degree of accuracy. 

Lorenz has documented what most of us know intuitively. Even our smallest initiatives can have huge effects...eventually. The butterfly effect can be applied to all of our lives. It can work for good or ill. Think of all that we set in motion when we went to our first day of school or we learned to drive or went on that first date with our sweetheart. Every major event in our lives started somewhere. 

Can we do anything about the weather? Probably not for as someone said, "Whether the weather will be fine; whether the weather will be not; whether the weather will be cold; whether the weather will be hot; we'll weather the weather; whatever the weather, whether we like it or not." 

But we can do something about our choices. And who knows, perhaps one tiny choice I make today can set in motion events that could change the whole world tomorrow. 

Think about it.

Dr. Don Meyer is President of 
Valley Forge Christian College, Phoenixville, PA 
Responses can be mailed to