Today I came across a curious throwaway reference buried in a news article about the Japanese attack on Pearl Harbor, stating that the incident was a black swan event.
Now I happen to absolutely adore a 1932 trashy romance named "The Black Swan" that was written by Rafael Sabatini (better known for "Captain Blood"). That particular "Black Swan" was about pirates, I dimly recall, and I was pretty sure that Pearl Harbor had nothing to do with pirates at all, so I looked up "black swan event."
Here’s a paraphrase and short form of the wikipedia article:
The term comes from the fact that in the 17th century, Europeans believed that all swans were white, because all historical records of swans reported that they had white feathers. So people referred to something impossible as a "black swan."
Then people discovered black swans in Australia, and the term came to mean something that was thought impossible that later turned out to exist.
Still later, author Nassim Nicholas Taleb used the term to explain "high-impact, hard-to-predict and rare events that are beyond the realm of normal expectations."
There. Now you can use the term Black Swan Event at swanky parties at Christmas, to amaze and amuse your family. Or just make them believe you’re a massive geek.