Can small, seemingly insignificant flutters create major impacts on the world? That’s a question that has long puzzled scientists and mathematicians. While the butterfly effect started out as a simple thought experiment from a meteorologist, it has grown into its own branch of mathematical Chaos Theory. It often seems like minor events can have a major influence on the future. So, what exactly is the butterfly effect?

With the flap of a butterfly’s wings

Butterfly landed on a flower
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“Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?” This was the question asked by meteorologist Edward Lorenz at a meeting of the American Association for the Advancement of Science in 1972. It sounds more like a tricky question someone might ask you during a job interview than a serious scientific inquiry.

Global weather patterns are so varied that Lorenz was curious if something extremely minor in the initial conditions, like the flapping of a butterfly’s wings, could have a large, unpredictable influence on how the system develops. What if, instead of a light drizzle continuing, a hurricane might develop? At the time, Lorenz was just curious about the development of weather systems, but the question had much larger implications to the scientific community. Because he used a butterfly in the original question, this idea became known as the butterfly effect.

The butterfly effect

Tornado forming above the street
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Although Lorenz’s question was specific to the weather, the scientific community took the idea and applied it to much, much more. Eventually, the butterfly effect was used to describe the idea that any small event can have a large, unpredictable influence on the future, not just regarding weather patterns.

Say, on a basic level: you stub your toe while getting dressed in the morning. This new injury will cause you walk slower. Because you walk slower, you get into work later. When you get to work late, your boss gets mad. When your boss gets mad, you get fired. Essentially, the minor act of stubbing your toe could cause you to lose your job. One insignificant event ends up having major repercussions in the future.

Chaos theory

Up close view of stock market tracker board showing numbers and data
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The butterfly effect was so profound that it spawned its own branch of mathematics called chaos theory. Unlike most math, which likes to follow a rigid set of rules, chaos theory involves calculating the incalculable, expecting the unexpected, and predicting the unpredictable. It’s the study of unpredictable or random behavior in systems that are governed by predetermined laws.

Because life is so unpredictable, chaos theory can be used in many ways like predicting the stock market, anticipating voting trends, or calculating the possible trajectories of molecules in a gas. The applications are endless!

Examples of the butterfly effect

A sandwich with salami and cheese on a wooden table
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It seems crazy that a butterfly flapping its wings in Asia could spawn a tornado in Texas, right? Well, it turns out that Lorenz might have actually been on to something. Here are just a few historical examples of the butterfly effect in action:

  • A dream leads to the assassination of Abraham Lincoln: Just over a week before he was assassinated, President Abraham Lincoln had a dream that he died and attended his own funeral. Naturally, he felt a little unnerved. He decided to take a trip to the theater to take his mind off it.
  • A sandwich starts World War I: There had been numerous attempts to assassinate the Austrian Archduke Franz Ferdinand, but none of them were successful. Supposedly, on one of the planned days of attack, the Archduke went to visit patients in the hospital, and his driver didn't get the message about changing their route of transport. The Archduke noticed and corrected him, and as his car was correcting course, the Archduke was gunned down by Gavrilo Princip, a hired assassin. Princip was reportedly in the area because he got hungry and decided to buy a sandwich at a nearby shop. If this was true, then the simple act of buying lunch essentially caused a world war.
  • An art school rejection starts World War II: In 1907 and 1908, an aspiring artist was twice rejected from the Academy of Fine Arts in Vienna. Instead of developing his talent in sketching and painting, he barely made a living and rented cheap rooms in the slums, where he reportedly developed intense anti-Semitic views. Since he didn’t have anywhere else to go, he joined the army, rose through the ranks, and eventually became the dictator of Germany. That failed art student was Adolf Hitler.