- A Black Swan event is an unpredictable event of huge significance.
- The term "Black Swan" is based on an ancient saying that assumed that all swans are white.
- The concept of a Black Swan event is rooted in the the problem of induction which was formulated most famously by the Scottish philosopher David Hume, but it can be best understood through the Turkey Story from Bertrand Russel:
¶ Turkeys and the Problem of Induction
- Imagine you are a turkey living on a farm. Every morning without fail, the farmer brings food for you and your turkey friends. After this phenomenon repeats for days and months, you announce that you have discovered a new general law of nature - that every day at 11 am a farmer will come to bring you food. But at 11am on Thanksgiving Day, the farmer does not bring you food, instead he takes you and the rest of the Turkeys to be slaughtered. Bertrand Russel's turkey story shows that any knowledge we hold that we justify on the basis of something always acting in a certain way in the past could turn out to be false in the future. It is not necessarily the case that things will behave in the future as they did in the past.