butterfly effect

Coined by American author and historian of science James Gleick in 1987 in his book Chaos: Making a New Science, whose first chapter bears the title “The Butterfly Effect”, and in which he discusses “the paradox of the butterfly’s wings” potentially making the difference whether a hurricane will or will not arise somewhere else later. Meteorologist Edward Lorenz, the founder of modern chaos theory, had in 1972, at a scientific meeting, presented a paper entitled “Does the flap of a butterfly’s wings set off a tornado in Texas?” without using the specific term butterfly effect. Lorenz also notes that representations of the strange attractor now known as the “Lorenz attractor” resemble a butterfly, as well as that correspondents have drawn his attention to Ray Bradbury’s short science fiction story “A Sound of Thunder”, in which a time traveler’s crushing a butterfly in the Late Cretaceous changes the outcome of a present-day presidential election. But the metaphorical butterfly was actually introduced in the title of the 1972 presentation by meteorologist Philip Merilees, who was not familiar with Bradbury’s story.^[1]

butterfly effect (plural butterfly effects)

1. The technical notion of sensitive dependence on initial conditions in chaos theory.
2. (by extension, science fiction) The notion that small changes in the past via time travel can cause disproportionately large and unforeseeable consequences in the present.

   Example of butterfly effect: stepping on a bug 4,000 years ago causes a different person to win the presidential election today.

• domino effect
• ripple effect