black swan event
n.— «On Black Monday, October 19, 1987, the Dow Jones index, for reasons still being debated, fell 508 points, almost a quarter of its total. (The current equivalent, for comparison’s sake, would be a 3,200-point loss on one day.) The drop turned out to be a “black swan event,” a weirdly poetic economist’s term meaning, basically, a fluke (though few people remember it, the Dow still eked out a positive finish for the year).» —“The Stench of ‘89″ by Michael Idov New York Magazine (New York City) Feb. 4, 2008. (source: Double-Tongued Dictionary)
Further reading
Astronauts returning from space say they experience what’s called the overview effect, a new understanding of the fragility of our planet and our need to reflect on what humans all share as a species. A book about the end of the universe...
In an interview about her magisterial history of the Great Migration, The Warmth of Other Suns (Bookshop|Amazon), Isabel Wilkerson noted that her own writing process poses the same challenge any writer has: “One word followed by another word...
I believe Nassim Taleb coined this term in his book “Fooled by Randomness: The Hidden Role of Chance in Life and the Markets”, and then explored it further in “The Black Swan: The Impact of the Highly Improbable”