Blind Oracles

Humankind has always wanted to predict the future. It seems we are genetically inclined to want to find out what is coming up around the next corner. This is especially true of scientists, many of whom believe that prediction is the real aim, and the best test, of any scientific theory. Just ask the writers of those leaked emails from the University of East Anglia’s Climatic Research Unit.

But the histories of science and prediction have long been closely intertwined. The most successful forecasting operation of all time was the oracle at Delphi, in ancient Greece. It lasted for almost a thousand years, beginning in the 8th century BC. The predictions were made by a woman, known as the Pythia, who was chosen from the local population as a channel for the god Apollo. Her predictions were often vague or even two sided, which perhaps explains how she lasted so long—rather like Alan Greenspan.

Our western tradition of numerical prediction can be said to have...