Edward Lorenz was staring at the new sets of output data that were streaming on his computer screen. They were totally different from what he had seen a few minutes before he went to get his coffee. The variance was now increasing with every new line of output.
As the assistant professor at MIT’s meteorology department in 1961, Lorenz was simulating weather patterns on a computer program he had designed. That day he stopped one simulation midway and keyed in a number that was generated in the first half and re-started. That one input was now changing everything.
He quickly realised what he had done. He had entered 0.506 instead of 0.506127. ‘The numbers that I had typed in were not the exact original numbers, but were the rounded-off values that had appeared in the original printout’
That one tiny alteration transformed his entire long term forecast. It lead him to publish a seminal research paper in 1963 that was the underlying principle for Chaos theory.
One of Lorenz’s colleagues helped him to explain this much better in another paper he presented in 1972. He gave this paper a title that made it one of the most powerful metaphors in modern physics and in popular culture.
“Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?’
The Butterfly effect was born. A metaphor that is now often used to show how very minor changes in circumstances can cause large unrelated changes in outcomes that we may never be able to explain.
‘Tiny variations … never repeat, and vastly affect the outcome. – Jeff Goldblum (“Ian Malcolm”), Jurassic Park’
A metaphor story.
Some of the awesome resources on the Butterfly Effect and Chaos theory:
Explainer, what is Chaos theory: From the The Conversation
Do check the wiki page on Butterfly effect and also Peter Dizikies famous article in The Boston Globe on Butterfly effect in Popular Culture