The concept of the “butterfly effect” holds that a seemingly insignificant action, such as the flapping of a butterfly’s wings, can have a dramatic effect on a system, such as the weather.
The butterfly effect is a term used in chaos theory to describe how small changes in a seemingly unrelated thing or condition (also known as an initial condition) can affect large, complex systems. The term comes from the suggestion that the flapping of a butterfly’s wings in South America can affect the weather in Texas, meaning that the slightest influence on one part of a system can have a huge effect on another part. More broadly, the butterfly effect is a way of describing how, unless all factors can be accounted for, large systems like weather remain impossible to predict with complete accuracy because there are too many unknown variables to track.
Origins in weather forecasting
The concept of the butterfly effect is attributed to Edward Norton Lorenz, a mathematician and meteorologist who was an early proponent of chaos theory. One day, Lorenz was running global climate models on his computer and, hoping to save some time, he ran a model from the middle instead of from the beginning. The two weather forecasts, one based on the entire process, including initial conditions, and the other based on a portion of the data, starting with the process already partially completed, diverged sharply. Lorenz, along with most scientists of his day, expected computer models to be identical no matter where they started. Instead, minor and unpredictable variations made the two models different.
Intrigued by the results, Lorenz set out to create a mathematical explanation that would show the sensible dependence of large, complex systems like the weather. Sensitive dependency means that the development of the system depends on a large number of factors. To simplify his findings, Lorenz coined the butterfly explanation that has since become widely known.
other systems
The butterfly effect applies to systems beyond climate; in fact, any complicated system can be vulnerable to seemingly small factors. For example, the journey of asteroids in the solar system can be difficult to predict. This is because asteroid paths can be affected by many different gravitational pulls throughout the solar system, including the gravity of the Sun, planets, moons, and even other asteroids.
In human behavior, small initial changes may make behavior unpredictable. For example, loved ones of someone who has committed suicide often wonder what could have caused the death. They may grieve over the myriad of little details they didn’t see, but which could have predicted the suicide. The butterfly effect may suggest that a wide variety of genetic, physical, and emotional experiences, dispositions, and factors were too many to account for in the person’s actions.
against the theories
Since its development, several contradictory theories have been described in opposition to chaos theory and the butterfly effect. They argue that the large systems in question, while immensely complex, still follow some kind of order and therefore do not deserve the description of “chaos”. Although the number of factors can be large, it is suggested that they be quantifiable and finite.
While the mathematical explanation that Lorenz developed could show the possible effects of a butterfly’s wings on weather patterns, there is no evidence that actually proves it. Observation has shown that the effects of a butterfly’s wings appear to be confined to a very small, localized area. Any large-scale effect appears to be dampened by the system as a whole.
Popular culture
The concept of small variations producing widespread effects actually predates chaos theory. Writers like Ray Bradbury were particularly interested in the repercussions it could have if a person traveled back in time and changed one small, insignificant detail. This concept has been the basis of numerous movies and stories.