All of statistics and much of science depends on probability—an astonishing achievement, considering no one’s really sure what it is.

By David Spiegelhalter & Nature magazine

Life is uncertain. None of us know what is going to happen. We know little of what has happened in the past, or is happening now outside our immediate experience. Uncertainty has been called the ‘conscious awareness of ignorance’ — be it of the weather tomorrow, the next Premier League champions, the climate in 2100 or the identity of our ancient ancestors.